Rockwood & Green’s Fractures in Adults
6th Edition

Chapter 55
Fractures of the Calcaneus
Roy W. Sanders
Michael P. Clare
Fractures of the calcaneus are among the most challenging for the orthopaedic surgeon. Calcaneal fractures account for approximately 2% of all fractures, with displaced intra-articular fractures comprising 60% to 75% of these injuries. Of patients with calcaneal fractures, 10% have associated spine fractures and 26% are associated with other extremity injuries (1,2). Of calcaneal fractures, 90% occur in males between 21 and 45 years of age, with the majority being in industrial workers; thus the economic implications of this injury are substantial (1,3,4,5,6,7). Several authors have reported that patients may be totally incapacitated for up to 3 years and partially impaired for up to 5 years post injury (1,3–6). Although modern surgical techniques have improved the outcome in many patients, controversy still exists regarding classification, treatment, operative technique, and post-operative management.
HISTORICAL PERSPECTIVES
Although first classically described in 1843 by Malgaigne (8,9), calcaneal fractures were not routinely diagnosed until the development of x-rays in the late 1890s (10,11,12). Since then, the distinction between the tongue type and joint-depression type of fracture has been known and treatment has often been type specific.
In 1908, Cotton (11) suggested that an open reduction of a calcaneal fracture was contraindicated and favored closed manipulation using a hammer to reduce the lateral wall and “reimpact” the fracture (Fig. 55-1). Despite his initial enthusiasm for this technique, by the 1920s he had given up the treatment of acute fractures altogether and turned instead to the treatment of healed malunions (13).
The first documented treatment of a series of calcaneal frac-
P.2294

tures with internal fixation was by Leriche (14) in 1922. Lenormant and other French surgeons popularized this technique, alternating between screws and bone graft for stabilization of the reduction (6,12). Böhler (10) began to advocate open reduction of calcaneal fractures in 1931 based on his experience with the French methods. Despite this, forcible closed reduction with tongs and hammers, or traction followed by manual manipulation and casting, were the standard treatments of his time, because of technical problems associated with surgery. Böhler (15) himself popularized traction in multiple planes, and improved on reduction, developing devices such as his unique clamp (Fig. 55-2).
FIGURE 55-1 Closed reduction using a hammer. (From Cotton F. Dislocations and Joint-Fractures. Philadelphia: WB Saunders, 1910.)
In 1935 Conn (16) concluded that calcaneus fractures were best treated using a delayed triple arthrodesis. Gallie (17) did not believe that the midfoot should be fused, however, and in 1943 proposed subtalar arthrodesis as the definitive treatment. Given his stature, the technique immediately became the standard for care.
FIGURE 55-2 Böhler’s clamp for lateral compression of the calcaneus. (From Key and Conwell. Fractures, Dislocations, and Sprains. Mosby, 1934.)
Fixation techniques for tongue-type fractures using a percutaneous “nail” were first advocated by Westhues (18). The technique was modified by Gissane (19), who developed a specific tool, the Gissane spike for this procedure. It was Essex-Lopresti (6), however, who described the technique in detail and popularized the maneuver, but specifically for tongue-type fractures.
Palmer (20) was dissatisfied with both nonoperative management and delayed reconstruction of these fractures and published his results of operative treatment for acute displaced intra-articular calcaneal fractures in 1948. Based on his understanding of the works of Lenormant and others, and through a lateral approach, he stabilized the lateral articular fragment with bone graft. He reported good results and stated that many of his patients were able to return to work. Similar results were reported by Essex-Lopresti (6) in 1952, who clearly stated that joint-depression fractures required formal open reduction with internal fixation.
During the 1950s, these varied techniques were employed, but because subtalar fusion was the easiest to perform, it became the most commonly practiced treatment. In Canada, many of these patients were subsequently evaluated in long-term follow-up by Lindsay and Dewar (1). Despite the fact that more than 50% of their patients were lost to follow-up, their results indicated that primary subtalar fusions were being unnecessarily performed, that operative intervention had many complications, and that the best results occurred in patients treated nonoperatively. As a result, operative treatment of acute calcaneal fractures once again fell into disfavor, both in the United States and elsewhere, and during the 1960s and 1970s most authors continued to advocate nonoperative treatment (2,5,21,22,23,24). Over the last 25 years, however, marked advances in anesthesia, prophylactic antibiotics, computed tomography (CT) scanning, and fluoroscopy have allowed surgeons improve outcomes when operating on fractures (25), and these techniques have been applied to calcaneal fractures as well (26,27,28,29,30,31,32,33,34,35,36,37,38). Overall, operative treatment of acute fractures has become the standard of care with many surgeons who have critically evaluated their results and concluded that good outcomes are possible (26,27,28,29,30,31,32,33,34,35,36,37,38). Despite these improvements, it is recognized that operative treatment is still beset with difficulties.
SIGNS AND SYMPTOMS
Associated Injuries
Up to 50% of patients with calcaneus fractures may have associated injuries, including lumbar spine fractures or other fractures of the lower extremities; intuitively, these injuries are more common in higher-energy injuries (2,6,22). Thordarson estimated that 10% of patients with calcaneus fractures also have lumbar
P.2295

spine fractures, and noted that 26% have associated lower extremity injuries (35). Thus, a high index of suspicion must be maintained for these associated injuries and an appropriate diagnostic evaluation should be completed where necessary.
Injury to the Soft Tissue Envelope
The severity of fracture displacement and the extent of soft tissue disruption are proportional to the amount of force and energy involved in producing the injury. Lower-energy injuries with minimal force produce only mild swelling and ecchymosis, whereas higher-energy injuries result in severe soft tissue disruption and may result in an open fracture. Patients typically experience severe pain overlying the fracture, which is related to the extent of bleeding into the tightly enveloping soft tissue surrounding the heel. Several hours after the injury, soft tissue swelling in the hindfoot is typically so severe that a distinct lack of skin creases in the area is noted.
Skin Blisters
Fracture blisters may appear anywhere about the foot secondary to swelling (40,41,42,43). The blister results from a cleavage at the dermal-epidermal junction, and the fluid within the blister represents a sterile transudate. The fluid remains clear if the dermis retains some epidermal cells. The fluid becomes bloody if the dermis is completely devoid of epidermal cells (41). Giordano et al (42) prospectively evaluated various treatment methods for blister management, including aspiration of the blister, unroofing the blister with subsequent application of Silvadene cream or coverage with a nonadherent dressing, or leaving the blister intact and covered by loose gauze or exposed to air. Although there was no significant difference in the outcome of the various soft tissue management techniques, wound healing complications developed in two patients who had incisions through blood-filled blisters. Thus, surgical incisions should be modified to avoid areas of blistered skin. Additionally, Varela et al (40) retrospectively reviewed 53 cases and identified 2 cases with major wound infections secondary to incisions passing through the blister. They noted colonization with normal skin flora in 11 ruptured vesicles soon after rupture, which persisted until reepithelialization of the area.
Compartment Syndrome
There are four compartments within the foot: the medial, lateral, central, and interosseous. The central compartment is divided into two separate compartments by a transverse septum in the hindfoot: the superficial compartment containing the flexor digitorum brevis muscle and the deep or calcaneal compartment containing the quadratus plantae and the lateral plantar nerve (44). The calcaneal compartment communicates directly with the deep posterior compartment of the lower leg (45). The long-term sequelae of an unrecognized compartment syndrome in the foot can include clawtoe deformities with permanent loss of function, contracture, weakness, and sensory disturbances.
A compartment syndrome develops when increased pressure within a closed fascial space affects pulse pressure such that arterial flow is decreased. This classically produces pain out of proportion to the injury, not unlike that typically associated with a calcaneal fracture. Thus, care must be taken to ensure that the severe pain associated with the fracture is not due to a compartment syndrome of the foot, particularly in the calcaneal compartment. A self-contained needle manometer system (Quikstik, Stryker, Kalamazoo, MO) is most commonly used to measure compartment pressures. Most authors recommend fasciotomy when the compartment pressure rises to within 10 to 30 mm Hg of the patient’s diastolic blood pressure (44,46,47).
Open Fractures
Open fractures of the calcaneus are distinct injuries relative to closed fractures, and thus require different treatment (48) (Fig. 55-3). Between 7.7% and 17% of fractures to the calcaneus are open (49,50,51). They are generally associated with a higher complication rate than their closed counterparts, including deep infection, osteomyelitis, and need for amputation (26,52,53,54,55). Coughlin (7), in a review of calcaneal fractures in industrial workers, also found that open fractures were associated with increased total cost of treatment and time off work.
Folk et al (56) reported wound complications in 13 of 18 open calcaneal fractures that were operatively treated (72%) and calculated that patients with an open fracture were 2.8 times more likely to develop a wound complication than those with a closed fracture. The incidence of these major complications also seems to increase with increasing severity of the soft tissue injury. Siebert et al (57) reviewed the results of 36 open intra-articular fractures treated with internal fixation with an average follow-up of 44 months. Of this group, 9 of 15 (60%) Type III open fractures developed osteomyelitis, resulting in five amputations. Aggressive surgical treatment of the soft tissue envelope and nonoperative management of the open fracture was recommended.
FIGURE 55-3 Medial wound—Gustilo Type IIIA open calcaneal fracture.
P.2296

Heier et al (49), reported on the results of 43 open fractures in 42 patients managed according to a standard treatment protocol of immediate intravenous antibiotics, aggressive surgical debridement of the wound, and provisional limb stabilization. There were many injuries that defied classification because of the irregular shape and size of the wound. Definitive soft tissue coverage was completed at an average of 10.6 days; final fracture stabilization was delayed until the wound was clean and soft tissue swelling had dissipated. All Gustilo Type I open fractures, and Gustilo Type II open fractures with a medial wound, were treated with open reduction with internal fixation and a lateral incision after debridement and when tissue edema had resolved. Gustilo Type II fractures with lateral, posterior, or plantar wounds and Gustilo Type IIIA fractures had limited or no internal fixation. All Gustilo Type IIIB open fractures required vascularized free tissue transfer as soon as possible. The overall infection rate was 37%, and osteomyelitis developed in 19%, including 7 of 26 (27%) Type III open fractures. All six amputations occurred in patients with open Type IIIB fractures. The authors concluded that the degree of soft tissue injury was the most important variable in predicting outcome; thus, all open Type I and those open Type II fractures with a medial wound could be treated by delayed open reduction with internal fixation once the soft tissues were suitable for surgery. They recommended either external fixation or limited percutaneous fixation for those open Type II injuries with nonmedial wounds and all open Type IIIA wounds, and delayed or late reconstruction for all open Type IIIB wounds and for fractures resulting from penetrating trauma.
Aldridge et al (58) reviewed the results of 19 open calcaneal fractures treated by a similar standard protocol at an average follow-up of 26.2 months. Definitive fracture stabilization was completed through a lateral approach, regardless of wound location, at an average of 7 days after injury, at which point soft tissue swelling had adequately dissipated. Of 19 patients, 2 (10.5%) developed a deep infection and subsequent osteomyelitis, one open Type II fracture and one open Type IIIC fracture, the latter being the only one that went on to amputation. Their results confirmed that open Type I fractures had a predictably good outcome with respect to soft tissue infection or osteomyelitis, whereas the open Type II and Type III fractures were associated with a less predictable outcome, although the overall complication rate was considerably lower than most reported series to date.
Berry et al (51) reviewed the results of 30 open fractures in 29 patients managed with a standard open fracture protocol and various methods of fracture treatment. There were 2 Sanders Type II, 6 Type III, and 6 Type IV fractures. There were 5 Gustilo grade I fractures, 12 grade II fractures, and 13 grade III fractures (9 IIIA, 2 IIIB, and 2 IIIC injuries). Most of the open wounds occurred along the medial foot (25), with 2 posterior injuries and 3 plantar wounds. There were no lateral open wounds. Two patients with Gustilo grade IIIC injuries underwent below-knee amputation within the first 24 hours postinjury as a result of massive crush injuries and dysvascular feet. Only five fractures underwent acute open reduction with internal fixation. Functional outcome was evaluated using validated assessment tools. Although the authors reported only one superficial infection and no cases of deep infection or osteomyelitis, most patients had only fair to poor functional results, and those with plantar wounds had significantly worse functional outcomes relative to those with medial wounds. They concluded that aggressive debridement of open wounds with provisional stabilization of the limb was critical in limb salvage, and, based on their five cases, that delayed open reduction with internal fixation was a safe treatment option. In Lawrence and Grau’s series of 48 open fractures treated over a 7-year period (59), more than 80% of the wounds were medial injuries, with 23% of these associated with a significant neurovascular deficit. Five patients required a free-tissue transfer, and two patients underwent below-knee amputations as primary treatment. The authors stressed the need for soft tissue management and delay of definitive internal fixation.
In contrast, Benirschke and Kramer (50) reviewed the results of 39 open calcaneal fractures in 38 patients treated by open reduction and rigid internal fixation through an extensile lateral approach as part of a large series of calcaneal fractures. Their series included 19 open Type IIIA and 3 open Type IIIB fractures. Although wound location data were not included, they reported only a 7.7% “serious” wound complication rate and none required amputation. They concluded that patient noncompliance was the single biggest issue precluding wound healing.
Open fractures of the calcaneus may present with a puncture wound medially from a spike of bone protruding from the medial wall of the calcaneus, or they may present with a more substantial wound with significant soft tissue disruption, typically laterally. When a calcaneal fracture is associated with an injury to the soft tissue envelope, it is important to categorize the wound, noting its size and location, as well as its Gustilo type (60,61). The fracture is then classified, and together these factors can give the surgeon an estimation of the severity of the injury and its eventual outcome, because all of these factors play a role in prognosis (49,50,51,58,59).
Treatment should include irrigation with 9 liters of normal saline and debridement of the wound with stabilization of the fracture to protect the soft tissues. When in doubt regarding the degree of soft tissue trauma, closed reduction and percutaneous stabilization may be performed to realign the extremity. This may be with Kirshner wires (K-wires), an external fixator, or both. Standard antibiotic prophylaxis is begun, and subsequent treatment must be tailored to the injury, but early and aggressive internal fixation should be avoided because the additional operative trauma will compromise the limb, and amputation may result (62). Three or more months may be required to allow the soft tissues to heal sufficiently before surgical salvage can be contemplated, and these procedures are invariably designed at treatment of a severe calcaneal malunion.
RADIOGRAPHIC DIAGNOSIS
Anatomy
The calcaneus is an odd-shaped bone. The superior surface consists of three articular facets (the anterior, middle, and posterior)
P.2297

that articulate with the talus. The posterior facet is the major weight-bearing surface and the largest facet. The middle facet is anterior and medial and is located on the sustentaculum; it is often contiguous with the anterior facet. The sustentaculum sits under the talar neck and is medial to the calcaneal body. It is attached to the talus by the interosseous talocalcaneal ligament and by the deltoid ligament medially. The flexor hallucis longus tendon runs below the sustentaculum. Laterally the peroneal tendons run obliquely along the lateral wall of the calcaneus and sit in two shallow grooves, with a bony prominence between them known as the peroneal tubercle. The entire calcaneal surface behind the posterior facet is known as the posterior tuberosity. On its plantar surface, it has two processes, the lateral and medial. The lateral process is the origin of the abductor digiti quinti (minimi) muscle. The medial process is the origin of the abductor hallucis muscle and the major weight-bearing structure in the hindfoot. Finally, the Achilles tendon inserts on the posterior surface of the tuberosity.
FIGURE 55-4 Neutral triangle.
Plain Radiography
The initial radiographic evaluation of the patient with a suspected calcaneal fracture should include a lateral x-ray of the hindfoot, an anteroposterior x-ray of the foot, a Harris axial heel view (63), and an ankle series. In this way all fractures, subluxations, or dislocations can be diagnosed. Because of the association with lumbar spine fractures in patients with calcaneal fractures and a fall from a height, routine lumbar spine x-rays should also be obtained (64). If the x-rays reveal an intra-articular component to the calcaneal fracture, obtaining a CT scan is indicated. Multiple radiographic projections have been described; however, most of these views are hard to read and even more difficult to consistently reproduce (63,65,66,67). In contrast, CT evaluation, when interpreted correctly, provides a wealth of data for both diagnosis and treatment.
Lateral Radiographs
Traction trabeculae extending from the inferior cortex of the calcaneus combine with compression trabeculae supporting the posterior and anterior articular facets. The area between these trabeculae creates a space seen on the lateral x-ray known as the neutral triangle (68) (Fig. 55-4). The lateral x-ray of the hindfoot also demonstrates two important angles, the tuber angle of Böhler, and the crucial angle of Gissane (Fig. 55-5A,B). The tuber angle of Böhler is indicated by a line drawn from the highest point of the anterior process of the calcaneus to the highest point of the posterior facet and a line drawn tangential to the superior edge of the tuberosity (10). The angle is normally between 20 and 40 degrees; a decrease in this angle indicates that the weight-bearing posterior facet of the calcaneus has collapsed, thereby shifting body weight anteriorly. McLaughlin (24) determined that reduction or reversal of this angle indicates only the degree of proximal displacement of the tuberosity and thus can be decreased in both intra-articular and extra-articular fractures, thus limiting its usefulness. The crucial angle of Gissane is formed by two strong cortical struts extending laterally, one along the lateral margin of the posterior facet and the other extending anterior to the beak of the calcaneus. These cortical struts form an obtuse angle usually between 95 and 105 degrees (6) and are visualized directly beneath the lateral process of the talus (69).
FIGURE 55-5 Anatomic angles for evaluation of surgical reduction. A. Gissane’s angle. B. Böhler’s angle.
The lateral x-ray should confirm the diagnosis of a calcaneal fracture. X-rays of intra-articular fractures usually show a loss
P.2298

in the height of the posterior facet, with a decrease in the angle of Böhler and an increase in that of Gissane, but only if the entire facet is separated from the sustentaculum and depressed. If only the lateral half of the posterior facet is fractured and displaced, a split in the articular surface will be seen as a double density (70), and Böhler’s and Gissane’s angles may appear to be normal (Fig. 55-6). The articular surface can be found within the body of the calcaneus, usually rotated plantarly up to 90 degrees in relation to the remainder of the subtalar joint. The lateral x-ray also indicates whether the fracture is of the joint-depression or tongue type according to the classification of Essex-Lopresti (6).
FIGURE 55-6 The so-called double density; a joint depression fracture in which the lateral portion of the joint is impacted but both Böhler’s and Gissane’s angle are normal.
Other Radiographic Views
The anteroposterior x-ray of the foot may show extension of the fracture line into the calcaneocuboid joint (Fig. 55-7). This x-ray provides very little information and usually may be omitted. The Harris axial x-ray of the heel allows visualization of the joint surface as well as loss of height, increase in width, and angulation of the tuberosity fragment (Fig. 55-8). Unfortunately, this x-ray is very difficult to obtain in the acute setting because of pain. Tomograms are rarely indicated, because they provide no additional information when computed tomography is available and they expose the patient to increased doses of radiation (71). Deutsch et al (72) pointed out that tomograms may fail to show the extent of articular incongruity.
FIGURE 55-7 Anteroposterior view of the foot showing the calcaneocuboid joint.
FIGURE 55-8 Harris axial view of the heel.
Broden’s view, however, is a reproducible means of demonstrating the articular surface of the posterior facet on plain x-rays (73). This view, known as Broden projection I, is obtained with the patient lying supine and the x-ray cassette under the leg and the ankle. The foot is in neutral flexion, and the leg is internally rotated 30 to 40 degrees. The x-ray beam then is centered over the lateral malleolus, and four x-rays are made with the tube angled 40, 30, 20, and 10 degrees toward the head of the patient. These x-rays show the posterior facet as it moves from posterior to anterior; the 10-degree view shows the posterior portion of the facet, and the 40-degree view shows the anterior portion. Although this view is difficult to explain to, and obtain from, a technician, a mortise view of the ankle will recreate this view perfectly (Fig. 55-9). Therefore, an ankle series should be requested. Furthermore, this view should be obtained intraoperatively using the fluoroscope and is indispensable to verify reduction of the articular surface (74).
Computed Tomography Scanning
Computed tomography scanning has vastly improved our understanding of calcaneal fractures and has subsequently allowed for consistent analysis of treatment results (71,75,76,77,78,79,80). CT images are obtained in the axial, 30-degree semi-coronal, and sagit-
P.2299

tal planes. The coronal views provide information about the articular surface of the posterior facet, the sustentaculum, the overall shape of the heel, and the position of the peroneal and flexor hallucis longus tendons. The axial views reveal information about the calcaneocuboid joint, the anteroinferior aspect of the posterior facet, and the sustentaculum. Sagittal reconstruction views provide additional information as to the posterior facet, the calcaneal tuberosity, and the anterior process (Figs. 55-10 and 55-11).
FIGURE 55-9 Broden’s view of the subtalar joint. This is best shown by taking a mortise view of the ankle. Note intra-articular fracture of the calcaneus (arrows).
The use of three-dimensional computed tomographic scanning for intra-articular calcaneal fractures was recently evaluated in several studies (81,82). Although this is an interesting modality, the definition of the articular surface was not sufficient to assist in preoperative planning or to justify the costs. Vannier et al (82), concluded that the diagnostic value of three-dimensional computed tomography was equivalent to that of conventional two dimensional computed tomography.
FIGURE 55-10 Axial (coronal) CT scan views of the calcaneus. Note that the lateral fragment gets smaller and rotates, as the sections move from posterior (A) to anterior (D). S, sustentaculum.
Principles of Management
General Considerations
Nonoperative Management
Specific indications for nonoperative treatment include (a) nondisplaced or minimally displaced extra-articular fractures, (b) nondisplaced intra-articular fractures, (c) anterior process fractures with less than 25% involvement of the calcaneocuboid articulation, (d) fractures in patients with severe peripheral vascular disease or type 1 diabetes, (e) fractures in patients with other medical comorbidities prohibiting surgery, and (f) elderly patients who are household ambulators. It must be noted that chronological age is not a contraindication to surgery, because many older patients are healthy and active well into their 70s. Nonoperative treatment may also be necessary when fractures are associated with blistering and massive prolonged edema; large, open wounds; or life-threatening injuries.
Nonoperative treatment consists of a supportive splint to allow dissipation of the initial fracture hematoma, followed by conversion to a prefabricated fracture boot, with the ankle locked in neutral flexion to prevent an equinus contracture and an elastic compression stocking to minimize dependent edema. Early subtalar and ankle joint range-of-motion exercises are initiated, and non–weight-bearing restrictions are maintained for approximately 10 to 12 weeks, until radiographic union is confirmed.
Operative Treatment
Operative treatment is primarily indicated for (a) displaced intra-articular fractures involving the posterior facet, (b) anterior process of the calcaneus fractures with more than 25% involvement of the calcaneocuboid articulation, (c) displaced fractures of the calcaneal tuberosity, (d) fracture-dislocations of the calcaneus, and (e) selected open fractures of the calcaneus. Basic fracture patterns can be delineated with plain x-rays. A decision can then be made regarding ancillary tests, most commonly CT scans. Surgery should be performed within the initial 3 weeks of injury, before early consolidation of the fracture. Surgery should not be attempted, however, until swelling in the foot and ankle has adequately dissipated, as indicated by a positive wrinkle test (25). The test is performed by direct palpation and visual assessment of the lateral calcaneal skin with dorsiflexion and eversion of the involved foot. The test is positive if skin wrinkling is seen and no pitting edema is evident, indicating that operative intervention may be safely undertaken (Fig. 55-12).
A variety of methods may be used to reduce swelling of the affected extremity. If the patient is seen initially in the emergency room, immediate elevation in combination with a Jones-
P.2300

type compression dressing with a posterior splint may be used, with or without a compressive pneumatic foot pump (83). In the event of an isolated injury, the patient may be discharged from the hospital and converted to an elastic compression stocking and fracture boot locked in neutral flexion several days later. Computed tomographic scans and plain x-rays may be reviewed with the patient and a management plan outlined at that time. Full resolution of soft tissue edema may require up to 21 days. We prefer to proceed with surgical intervention within 2 weeks of injury, although surgery may be safely performed up to 3 weeks from injury. Beyond this interval, early consolidation of the fracture occurs, the fragments become increasingly difficult to separate and reduce, and the articular cartilage may delaminate away from the underlying subchondral bone.
FIGURE 55-11 Transverse CT scan sections showing lateral fragment (white arrow) rotated such that joint surface is parallel to calcaneocuboid joint (black arrow). symbol, anterolateral wall fragment.
Figure. No caption available.
FIGURE 55-12 Wrinkle sign. Note the wrinkling of the skin throughout, as well as the visualization of the subluxated peroneal tendons (black arrows).
Extra-articular Fractures
Anterior Process Fractures
These fractures will present with pain, swelling, and ecchymosis overlying the anterolateral hindfoot region, along with tenderness to palpation directly over the anterior process fragment. They are typically misdiagnosed as ankle sprains, hence the designation “sprain-fractures” (84,85,86,87,88). They often result from a forced inversion and plantarflexion injury, which increases tension on the bifurcate ligament and produces an avulsion fracture (89). The fracture line exits into the calcaneocuboid
P.2301

articulation and typically includes minimal amounts of the articular surface, although variable proportions of the joint surface may be involved. The extensor digitorum brevis muscle may also contribute to the injury pattern. Alternatively, injury to the anterior process region may result from forced abduction of the foot, producing an impaction fracture of the calcaneocuboid articular surface (90). In this instance, the fragment is typically larger, with more involvement of the articular surface, and may displace posteriorly and superiorly.
Tuberosity (Avulsion) Fractures
Fractures of the calcaneal tuberosity can result in either an open beak–type fracture or an avulsion fracture (91,92). The distinction lies in that the avulsion fracture pulls the entire Achilles tendon from its insertion. Protheroe (93) has questioned this as he described cases of open-beak fractures with the entire Achilles tendon avulsed. These two fractures probably represent a spectrum of injury resulting most commonly from a violent pull of the gastrocnemius-soleus complex, such as occurs with forced dorsiflexion following a low-energy stumble and fall, producing an avulsed fragment of variable size.
Patients with fractures of the calcaneal tuberosity will present with pain and swelling in the posterior hindfoot, and may also have weakness with resisted plantarflexion, as a result of the shortened gastrocnemius-soleus complex. Because of the limited soft tissue envelope overlying the tuberosity, displacement of the fragment may endanger the surrounding skin. Thus, care must be taken to assess the overlying skin, because expedient care of the fracture may be necessary to avoid skin slough. Surgical repair of calcaneal tuberosity avulsion fractures is indicated when (a) the posterior skin is at risk because of pressure from the displaced tuberosity, (b) the posterior portion of the bone is extremely prominent and will affect shoe wear, (c) the gastrocnemius-soleus complex is incompetent, or, rarely, (d) the avulsion involves the articular surface of the joint.
FIGURE 55-13 A. Anterior process fracture (arrow 1) with associated talar neck fracture (arrow 2), and ankle instability (arrow 3). B. Postoperative reduction and fixation with screws, miniplate, and bone anchors. C. Healed fractures at 13 months.
FIGURE 55-14 Extra-articular avulsion fracture A. Lateral and axial x-rays. B. Initial CT scan sections showing nonarticular fracture. C. Further CT scan sections showing nondisplaced fracture into joint. D. Lateral and axial x-rays 1 year after simple cerclage band fixation. E. Displaced avulsion fracture. F. Five years after tension band with lag screw fixation.
Body Fractures
True extra-articular fractures of the calcaneus, not involving the subtalar joint, probably account for 20% of all calcaneal fractures (2,67). The mechanism of injury is identical to that of an intra-articular fracture, with the difference being that the lines of force do not cross the posterior facet. Standard x-rays will typically show the fracture involving the body of the calcaneus, but a CT scan is required to determine whether an intra-articular fracture exists and the amount of displacement (Fig. 55-16). Surgery is based on both these factors. Minimally displaced fractures (<1 cm) are treated nonoperatively with early motion and non–weight-bearing for 10 to 12 weeks (2,95,96). Those with significant displacement resulting in varus/valgus deformity, lateral impingement, loss of heel height, or translation of the posterior tuberosity require either closed manipulation of the fracture or open reduction with internal fixation (95,96,97).
FIGURE 55-15 Cerclage of tuberosity avulsion fractures according to B.G. Weber.
P.2303

Medial or Lateral Process Fractures
Isolated medial or lateral process fractures of the posterior tuberosity are rare and usually nondisplaced. The mechanism of injury is typically a fall directly on the tuberosity of the heel either with the foot inverted, causing a shear fracture of the lateral process, or with the foot in eversion, causing a fracture of the medial process (Fig. 55-17). Usually the heel pad is exquisitely tender, with the area ecchymotic and swollen. The fracture is best seen on the axial radiographic view or on the coronal CT scans. Treatment is based on the amount of displacement. Nondisplaced fractures can be treated with a short-leg weight-bearing cast until they heal at 8 to 10 weeks (10,24,98). When fractures are displaced, closed manipulation may be considered (95).
P.2304

FIGURE 55-16 Body fracture. CT scan showing no intra-articular involvement.
FIGURE 55-17 Medial process fracture.
Intra-articular Fractures
Displaced intra-articular fractures of the calcaneus are typically the result of high energy trauma, such as a fall from a height or a motor vehicle accident. The pattern of fracture lines and extent of comminution are determined by the position of the foot, the amount of force, and the porosity of the bone at the time of impact. Although controversy remains as to the exact mechanism of injury, there is a general consensus among most authors (6,20,37,99,100).
Essex-Lopresti (6) believed the primary fracture line was initially produced laterally by the lateral process of the talus and the lateral edge of the talus, and then extended medially. He believed that at the moment of impact the subtalar joint was forced into eversion, thus dividing the lateral wall and body of the calcaneus at the crucial angle of Gissane. The remaining force then dissipated into the sustentaculum medially. With continuation of the force, the fracture line could exit through the anterior process or calcaneocuboid joint, resulting in an anterolateral fragment. A secondary fracture line was created with increased force. If the force was directed posteriorly, the fracture would continue both posterior to and into the posterior facet, thereby producing a joint-depression type fracture. If the force was directed inferiorly, a tongue-type fracture was produced (Fig. 55-18).
Carr et al (99) reported on experimentally created, intra-articular calcaneal fractures in a cadaveric model. Two primary fracture lines were identified: one fracture line divided the calcaneus into medial and lateral portions, with the fracture either extending into the calcaneocuboid joint or exiting in the anterior
P.2305

facet. The second primary fracture line divided the calcaneus into anterior and posterior portions, beginning laterally at the angle of Gissane and extending medially (Fig. 55-19). This second fracture line often continued medially to divide the middle facet; laterally the fracture line extended inferiorly, either toward the plantar surface or anteriorly. These two primary fracture lines produced a combination of fracture patterns, including both tongue-type and joint-depression fractures, as well as the commonly observed anterolateral and superomedial fragments, thus confirming the work of Essex-Lopresti and others (6,66,101).
FIGURE 55-18 Mechanism of injury according to Essex-Lopresti. A–C. Joint depression. DF. Tongue.
FIGURE 55-19 Mechanism of injury according to Carr.
Fracture Classifications
In the past, the inability to accurately classify calcaneal fractures has contributed to the difficulty in treating these injuries. Classification systems are designed to facilitate communication among surgeons, plan operative procedures, and assist in determining outcomes. Historically, calcaneal fracture classification systems based on plain x-rays existed, but were of limited use (2,3,6,20,67). With the advent of CT scanning, standardization of imaging techniques has allowed for the development of modern classification systems, which have greatly enhanced the management of intra-articular calcaneal fractures.
Classifications Based on Plain Radiography
Although described as early as 1851 by Malgaigne (9), Essex-Lopresti (6) in 1952, popularized the concept of two distinct intra-articular fracture patterns: a tongue-type fracture, in which the articular fragment remained attached to a tuberosity fragment, and a joint-depression type fracture, in which the articular fragment was separate from the adjacent tuberosity. The advantage of this distinction was that the surgeon could accurately choose the correct treatment method. Unfortunately, this classification provided little prognostic information. Several other authors described fracture patterns and classifications; however, these systems were in essence variations of the Essex-Lopresti classification (3,67,102,103).
P.2306

In 1975, Soeur and Remy (66) reported on a new classification system, which was uniquely based on the number of articular fragments as determined on anteroposterior, lateral, and Harris axial heel views. First-degree fractures were nondisplaced shear-type fractures with widening of the joint surface. Second-degree fractures included secondary fracture lines, resulting in a minimum of three fragments, two of which included the articular surface. Third-degree fractures were highly comminuted such that they could not be classified, and therefore the authors could not specify if the comminution referred to the body or the articular surface of the posterior facet. Although they proposed that displaced intra-articular fractures should be managed surgically with internal fixation, their results could not be correlated to their classification.
Classifications Based on Computed Tomography Scanning
The use of computed tomography scanning in the diagnosis and treatment of calcaneal fractures was first described by Segal et al (29) and was also used by Stephenson (104). Zwipp et al (101), however, were the first to apply information provided on CT evaluation into a rational understanding of the injury. In Zwipp’s classification, the entire calcaneus was considered, with a total of five possible fragments, similar to the systems of Essex-Lopresti, and Souer and Remy, but based on CT scan data (6,66) (Fig. 55-20). Although surgical outcomes were evaluated, no prognosis based on fracture classification was made.
Crosby and Fitzgibbons (33) were the first authors to correlate clinical outcome (albeit as a result of nonoperative treatment) with a fracture classification system based on CT evaluation. They divided their fractures into three types based on the articular surface displacement: Type I, nondisplaced; Type II, displaced; and Type III, comminuted. Subsequently, Sanders (26,105) developed a CT scan classification system based on the number and location of articular fracture fragments alone. This was the natural progression of fracture patterns identified by Soeur and Remy (66). The classification was found to be useful in determining both treatment methods and prognosis after surgical fixation (26). Many additional authors have since used this classification and found it to be prognostic with respect to outcome as well (106,107,108,109,110,111,112). During the analysis of the results of operative treatment, it became clear to Sanders et al (26), that the body of the calcaneus could be restored surgically to virtual anatomic shape by using a lateral approach, irrespective of the degree of comminution. Because the prognostic factor for outcome was the quality of the articular reduction and the degree of cartilage damage, the classification was purposely limited to articular displacement.
FIGURE 55-20 Zwipp CT scan classification of calcaneal fractures.
The articular fracture classification system of Sanders et al (26) is based on images in the coronal plane (Fig. 55-21). Although all coronal sections were analyzed, the original classification arbitrarily used the one CT scan view with the widest undersurface of the posterior facet of the talus (in reality, the entire CT scan should be evaluated to watch fracture lines move in and out of plane and to determine what is artifact and which are real). The talus was divided into three equal columns by
P.2307

P.2308

two lines which were then extended across the calcaneal posterior facet; with the addition of a third line, just medial to the medial edge of the posterior facet, the posterior facet of the calcaneus could be arbitrarily divided the into three potential fragments: medial, central, and lateral. These fragments plus the sustentaculum resulted in a total of four potential articular pieces. All nondisplaced articular fractures (less than 2 mm), irrespective of the number of fracture lines, were considered Type I fractures. Type II fractures were two-part fractures of the posterior facet. Three Types: IIA, IIB, and IIC existed, based on the location of the primary fracture line. Type III fractures were three-part fractures that usually featured a centrally depressed fragment. Types included IIIAB, IIIAC, and IIIBC, again based on the location of the primary fracture line. Type IV fractures, or four-part articular fractures, were highly comminuted and often had more than four articular fragments. Although the subclassification of articular fracture lines by medial to lateral location is important prognostically, most surgeons simply identify the number of articular fragments (113) (Fig. 55-22).
FIGURE 55-21 Sanders’ CT scan classification of calcaneal fractures. (From Sanders R. Current concepts review—displaced intra-articular fractures of the calcaneus. J Bone Joint Surg Am 2000;82:233.)
Originally, this classification system was described for joint-depression fractures exclusively. With the addition of the initial lateral x-ray, however, the surgeon can determine whether the fracture is a joint-depression, or a tongue-type fracture. Once this is established, tongue-type fractures can be classified using this system as well. The true extra-articular tongue is typically a Type IIC, in which the entire facet is displaced, but intact (114). If the tongue fracture extends intra-articularly, the fracture is typically a IIB. In addition, tongue-type fractures with joint-depression components (mixed fractures) can clearly be evaluated using this CT scan classification. Tornetta (114) has used and verified this concept in his treatment of displaced tongue fractures (Figs. 55-23 and 55-24).
Preoperative planning requires evaluation of the body of the calcaneus on CT scans. Miric and Patterson (107) described the patterns of comminution of the anterior process (Fig. 55-25). These typically mirror the lines that divide the articular surface and are best seen on the transverse CT scan. Importantly, they reaffirmed the need to obtain an anatomic reduction of the body of the calcaneus as well as the joint. Finally, on the transverse CT scan, a medial to lateral extra-articular fracture at the level of the anterior edge of the posterior facet often can be seen, as originally described by Carr et al (99). This fracture line is important to find, because its presence indicates that the medial component of the joint can be rotated plantarly and must be brought out from under the anterior process, in order to obtain an anatomic joint reduction. It is our belief that the main limitation of this classification, as well as all CT scanning at the present time (even with the advent of reformatting techniques), is that it cannot define whether the sagittally split fragment is additionally fractured in the coronal plane. Because neither reformatting or three-dimensional CT scans can identify this fracture, it is often not seen until the fracture is surgically treated and occasionally not until the fragment falls apart while being repositioned.
FIGURE 55-22 CT scans of various fracture patterns according to Sanders.
Current Treatment Options
Before the development of computed tomography, studies evaluating the treatment of calcaneal fractures were difficult to interpret because of inherent flaws in study design. Treatment methods, classification, and outcome measurements were all non-standardized, making comparison and critical analysis difficult (1,2,6,23,115,116,117,118,119). As a result, these studies cannot be used to reach any conclusion regarding treatment or outcome, because one would be comparing “apples to oranges” (120). Thus, studies published before the advent of CT should be considered only from a historical perspective. Many subsequent series
P.2309

P.2310

have been published using modern treatment and standardized methods of outcomes analysis. These studies can be categorized into nonoperative treatment, studies comparing operative to nonoperative treatment, and operative treatment.
FIGURE 55-23 The different types of tongue fractures. (Courtesy P. Tornetta, MD.)
FIGURE 55-24 True intra-articular tongue fracture (Type IIB). Plain radiographs are unable to indicate whether the fracture involves the posterior facet. Semi-coronal and transverse CT scans verify intra-articular displacement. Note black arrows indicating intra-articular fracture, and white arrows indicating the intact lateral wall component typical of tongue fractures.
FIGURE 55-25 Miric and Patterson’s schematic representation of the periarticular fracture extension lines into the anterior process (A) and around the posterior facet (B).
Nonoperative Treatment
Crosby and Fitzgibbons (33) reviewed their results of casting without reduction of calcaneal fractures using a CT classification based on the fracture pattern involving the posterior facet. Small or nondisplaced fractures were classified as Type I fractures; displaced fractures as Type II fractures; and comminuted fractures as Type III fractures. In their series, there were 13 Type I, 10 Type II, and 7 Type III fractures. They reported good results with closed treatment in all Type I fractures, but poor results in most Type II and Type III fractures, and suggested operative treatment was indicated for these fractures.
Kitaoka et al (116) reviewed the gait analysis outcomes of 16 of 27 patients treated without reduction and casting. Most patients in their series exhibited an altered gait pattern, especially on uneven ground, thus confirming that nonoperative management of displaced calcaneus fractures led to at least some persistent functional impairment.
Operative Versus Nonoperative Treatment
In recent years, several studies have been published comparing operative to nonoperative treatment (30,121,122,123,124,125,126,127). Jarvholm et al (123) evaluated 20 patients treated operatively over a 12-year period and compared the results to a historical control group treated nonoperatively over the same time period by other surgeons. They concluded that the problems associated with internal fixation did not justify operative treatment; however, several limitations in their study design were apparent: (a) only a few operative procedures were performed each year, (b) the surgeons did not consistently use lag screws and never stabilized the calcaneal body with a plate or staple, (c) intraoperative fluoroscopy was not available, and (d) the authors conceded they were never able to obtain a perfect reduction. This study illustrates many of the inherent flaws seen in the published literature on calcaneal fractures that prevent the reader from reaching meaningful conclusions.
Parmar et al (126) compared 31 displaced fractures treated nonoperatively to 25 treated operatively. They used their own classification and fixed fractures with K-wires through a lateral Kocher approach. No attempt was made to reduce the calcaneal tuberosity, and they encountered difficulty in evaluating the postoperative CT scans. Using their own scoring system, they found no difference in clinical outcome between the two groups. The limitations of this study include poor operative fixation techniques and lack of assessment of the postoperative reduction by CT scans.
O’Farrell et al (125) treated 12 patients operatively and 12 patients nonoperatively. Computed tomography was used; however, the fractures were not classified. In those treated operatively, a Kocher incision was used with lag screw and plate fixation. Postoperative CT evaluation was completed. Clinical outcome was based on walking distance, subtalar motion, return to work, and shoe size. They concluded that operative treatment was superior, but their limited patient population precluded statistical significance.
Leung et al (124) compared 44 patients treated operatively with 19 treated nonoperatively in a nonrandomized, retrospective study with an average follow-up of 3 years. Fractures were classified according to the Crosby and Fitzgibbons classification. They used an extensile lateral approach, and the reduction was held with lag screws and plate fixation. At an average of 3 years follow-up, the authors found significantly better results in the surgically treated group with respect to pain, activity, range of motion, return to work, and swelling of the hindfoot.
P.2311

Crosby and Fitzgibbons (33) first reported on the results of nonoperative treatment of intra-articular calcaneal fractures in 1990. Because of the poor outcomes with the displaced and comminuted fractures, the authors began treating displaced (Type II) fractures operatively (34). Results of their operative cases were then compared to their nonoperative cases using the same outcomes assessment instrument. They found better results in those fractures that were treated operatively; the difference was highly statistically significant. As a result, they recommended operative intervention for displaced fractures.
Thordarson and Krieger (35) performed a randomized, prospective trial comparing operative to nonoperative treatment in 30 patients. Fractures were classified by computed tomography, and only Sanders Type II and III (displaced) fractures were included in their study. Nonoperative treatment consisted of non–weight-bearing and early range-of-motion exercises. Operative treatment was performed by a single surgeon and consisted of an extensile lateral approach with lag screw and plate fixation. Clinical outcome using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score (128) was completed in all 15 operatively treated fractures and in 11 of 15 nonoperatively treated fractures. The functional results and overall outcome in the operatively treated group were superior to those in the nonoperative group; the differences were statistically significant. Despite small numbers and a relatively short period of follow-up, this study represented the first randomized, prospective trial in which many variables were held constant, and this study was the first to confirm that operative intervention could lead to improved outcomes.
Buckley and Meek (30) first reported their matched cohort series of 34 calcaneal fractures in 1992. Seventeen fractures were treated operatively, and 17 were treated nonoperatively. The patients were matched with respect to age, sex, work type, and time to follow-up. They concluded that their best results were in patients with an anatomic reduction of the posterior facet, and that if an anatomic reduction was not possible, there appeared to be no difference between operative and nonoperative treatment. Unfortunately, the fractures were not consistently classified. More importantly, 12 different surgeons participated in surgical treatment of the 17 patients, and all used different techniques.
The same group of surgeons then evaluated the literature on this topic. Randle et al (129) performed a meta-analysis of articles between 1980 and 1996 dealing with calcaneal fractures. Of the 1845 articles, 6 compared operative versus nonoperative treatment for displaced calcaneal fractures using the minimum criteria for inclusion in the meta-analysis. A statistical summary of information across the 6 articles revealed a trend for surgically treated patients to be more likely to return to the same type of work as compared with nonoperatively treated individuals. There also was a trend for nonoperatively treated patients to have a higher risk of experiencing severe foot pain than did operatively treated patients. Unfortunately, none of the other outcomes could be summarized formally across studies using statistical techniques because of the variability in reporting across studies. Although the tendency was always for operatively treated patients to have better outcomes (reaching statistical significance in some of the articles), the strength of evidence to recommend operative treatment for displaced intra-articular calcaneal fractures remained weak.
Because of their concerns, the Canadian Orthoapedic Trauma Society performed a prospective, randomized, multicenter trial and compared operative with nonoperative treatment of displaced intra-articular calcaneal fractures in 424 patients with 471 fractures (121). Two-hundred eighteen patients with 262 fractures were treated nonoperatively; 206 patients with 249 fractures underwent operative treatment through an extensile lateral approach, with screw, plate, or wire fixation. Seventy-three percent of patients were followed for a minimum of 2 years, with an average of 3 years. Fractures were classified according to Sanders et al, and outcomes were evaluated using two separate previously validated assessment tools. Analysis revealed significantly better results in certain fracture groups undergoing operative treatment, including women, younger patients, patients with a lighter workload, patients not receiving Worker’s Compensation, patients with a higher initial Böhler angle (less severe initial injury), and those with an anatomic reduction on postoperative CT evaluation. There was no difference in overall outcome between the operative and nonoperative groups; however, those having nonoperative treatment of their fracture were 5.5 times more likely to require a subtalar arthrodesis for post-traumatic arthritis than those undergoing operative treatment.
Operative Treatment
Closed Reduction and Percutaneous Fixation
Fixation techniques for tongue-type fractures using a percutaneous “nail” were first advocated by Westhues (18). The technique was modified by Gissane (19), who developed the Gissane spike for this procedure. It was Essex-Lopresti (6), however, who described the technique in detail and popularized the maneuver specifically for tongue-type fractures. Over time, this technique was used for all types of calcaneal fractures, with poor results, and thus fell into disfavor. Recently Tornetta (130), revived the original technique, reporting on the results of 26 patients with Sanders Type IIC (tongue-type) fractures using the Essex-Lopresti maneuver with a modification of fixation (Fig. 55-26). Steinmann pins were initially used for definitive fixation, but these were later changed to 6.5-mm cannulated screws later in the series. Three patients were considered intraoperative failures, in that the technique was abandoned in these patients in favor of traditional open reduction with internal fixation. The reduction maneuver was successful in 88%. There were 86% good or excellent results based on the Maryland foot score at an average follow-up of 2.9 years.
Rammelt et al (131) noted that percutaneous reduction methods play an important role in the management of calcaneal fractures with severe soft tissue compromise, particularly open fractures. Percutaneous reduction by pin leverage (Westhues or
P.2312

Essex-Lopresti maneuver) followed by minimally invasive screw fixation was a treatment option that yielded good to excellent results in tongue-type fractures with posterior facet displacement as a whole (Sanders-type IIC). The authors noted that the method could also be applied to selected Sanders Type IIA or IIB fractures if the joint reduction was controlled arthroscopically.
FIGURE 55-26 Essex-Lopresti technique as modified by Tornetta. Once guide pins are correctly positioned, they are exchanged for 6.5- to 8.0-mm cannulated cancellous lag screws.
Sangeorzan and Ringler (132) reviewed the results of 36 tongue-type calcaneal fractures managed with a minimally invasive reduction technique and small fragment fixation with an average follow-up of 25.5 months. The operative technique involved small (<1 cm) incisions, which were used for the introduction of Shantz pins and small elevators for the reduction. The fracture fragments were aligned using the Essex-Lopresti reduction technique. All reductions were performed under fluoroscopic guidance and were stabilized with small–fragment screw fixation. Two screws were introduced in an axial direction, and any subsequent screws were introduced from the lateral surface to secure the sustentaculum. Postoperatively, patients were placed in a removable splint and range of motion was begun postoperatively within 1 to 2 days. Weight-bearing was initiated after 2 to 3 months. There were no infections and no cases of lost fracture reduction, and only one patient went on to require a subtalar arthrodesis. They concluded that their technique lowered the incidence of postoperative risks and reduced the length of hospital stay compared to that in historical controls.
P.2313

Some authors have expanded the use of percutaneous reduction by traction, leverage, and compression with subsequent K-wire or screw fixation for all types of calcaneal fractures (131,133). Inadequate joint reduction and redislocation of the fragments in highly unstable fractures may occur however in a significant number of cases. Prolonged transfixation of the subtalar and calcaneocuboid joints may be needed to maintain reduction, but should be avoided because significant subtalar stiffness may result (6).
Ziran and Bosch (133) described their results in 28 comminuted, Sanders Type III/IV calcaneus fractures treated with closed reduction and percutaneous pinning. With the help of a traction bow and a transverse Steinmann pin, reduction of the body was performed. There was no attempt made to reduce the subtalar joint. After fixation, patients were splinted and then braced with a posterior relief ankle-foot-orthosis (AFO) that allowed ankle motion. Pin care was performed 3 times a day. Patients remained non–weight-bearing for 12 weeks, at which point the pins were taken out in the office and weight-bearing was initiated. Twenty-five fractures in 21 patients were available for review, with an average follow-up of 1 year. Subtalar motion was less than 10 degrees in all cases. Twelve patients reported minimal to no pain with full activity. These patients used normal shoes and had no limp. Seven patients had moderate discomfort with full activity; two had peroneal tendonitis from compression by the lateral wall of the calcaneus. Two patients had severe pain with activity and had difficulties with shoe wear. They both had a shortened hindfoot with 15 degrees of varus of their calcaneus. The authors concluded that in all their cases an anatomic, open reduction would have been the better technique.
Open Reduction and Internal Fixation
Surgical Approaches
Medial Approach
The medial approach was popularized by McReynolds (134); it consists of a 2- to 3-inch incision centered in the midportion of the medial side of the heel, between the plantar surface and the medial malleolus, and in line with the longitudinal axis of the os calcis (Fig. 55-27). Because the incision should be over the site of medial displacement, it may shift either anteriorly or posteriorly, based on the fracture. The fascia is incised in line with the skin incision, with care being taken to locate and then avoid the neurovascular bundle. After the bundle is identified and retracted with the use of a Penrose-type drain, the muscle of the quadratus plantae and the abductor hallucis longus are separated down to the medial wall of the calcaneus and a fracture reduction is then performed (97,135). This approach was modified by Johnson (136), who developed a vertical incision, posterior to the neurovascular bundle. The incision was directed halfway between the medial malleolus and the Achilles tendon, and once the bundle was exposed, it could be retracted forward to expose the fracture. The medial plantar nerve had to be protected to avoid damage to it in the plantar aspect of the wound. Zwipp and Tscherne (137) published another modification that essentially combined these two approaches (Fig. 55-28). This approach paralleled the neurovascular bundle in a large J-type incision, much like an extended tarsal tunnel exposure. Once the nerve and its plantar branches were identified, exposure of the fracture could be accomplished with ease.
FIGURE 55-27 Medial approach after McReynolds. (From McReynolds IS. Trauma to the os calcis and heel cord. In: Jahss M, ed. Disorders of the Foot and Ankle. Philadelphia: WB Saunders; 1984:1497–1538.)
FIGURE 55-28 Medial approach according to Zwipp.
Lateral Approach
The original lateral approach was a standard Kocher approach (6,12,20,138,139). This approach limited access to the body of the calcaneus, scarred down the peroneal tendons, and frequently damaged the sural nerve. In 1984, Fernandez (140) first described the extensile posterolateral approach (Fig. 55-29A). In this approach, an incision halfway between the fibula and Achilles tendon and starting three fingerbreaths above the tip of the lateral malleolus was made. This
P.2314

was extended around the malleolus, following the course of the sural nerve and small saphenous vein toward the fifth metatarsal base. The sural nerve was identified and protected, and then full-thickness flaps were developed to bone. After the peroneal tendons were dislocated over the tip of the malleolus, the calcaneofibular ligament was detached from the calcaneus and then retracted anteriorly such that the subtalar joint and sinus tarsi was exposed.
FIGURE 55-29. A. Lateral approach, modified Kocher, according to Fernandez. B. Lateral approach according to Seligson. (A adapted from D. Fernandez. B adapted from N. Gould.)
Seligson described a very similar incision in a report by Gould (141) that same year (Fig. 55-29B). The goal of the incision was to expose the entire lateral face of the calcaneus to the level of the calcaneocuboid joint. This approach combined the posterior approach for the ankle, described by Picot in 1924 (142), with a unique plantar limb that undulated so that the final closure could be tension free. The incision was made just lateral to the Achilles tendon and carried vertically to the superior pole of the calcaneus. The incision was then curved gently, following a line where the thinner skin of the lateral side of the hindfoot met the skin of the heel pad. The incision was carried to the base of the fifth metatarsal. Seligson stressed that in the gently curved portion of the incision, the knife should be taken straight to bone, with the skin, subcutaneous layer, and periosteum kept as a single layer. The lateral flap was then developed as a single, thick flap. The peroneal tendons were elevated off the peroneal tubercle and reflected dorsally, while the calcaneofibular ligament was detached from the calcaneus. After subtalar capsulotomy, the entire lateral calcaneus, calcaneocuboid joint and subtalar joint were exposed.
Many surgeons reported problems with the sural nerve and with wound healing using a form of the lateral approach (25,28,143). Recently Borelli and Lashgari (144) described the arterial blood supply of the subcutaneous tissues of the lateral
P.2315

hindfoot and defined the relationships between these arteries and the lateral extensile incision used for open reduction with internal fixation of calcaneal fractures (Fig. 55-30). Three arteries, the lateral calcaneal, the lateral malleolar, and the lateral tarsal artery, were consistently found along the lateral aspect of the hindfoot. The lateral calcaneal artery appeared to be responsible for the majority of the blood supply to the corner of the flap, and, because of its proximity to the vertical portion of the typical incision, it appeared most likely to be injured from inaccurate placement of the incision. As a result of this work and to protect the sural nerve, the authors recommended that the vertical limb of the incision be started just anterior to the lateral edge of the Achilles tendon and at the crease of the heel pad and lateral foot. This study supports the original description and incision of Seligson (141).
Results of Open Reduction and Internal Fixation
Medial Approach
Historically, many authors emphasized the correction of Böhler’s angle and restoration of the overall morphology of the calcaneus more so than reduction of the articular surface (3,6,20,100,145,146,147,148). As a result, McReynolds, Burdeaux, and others popularized the medial approach in reconstructing the extra-articular body of the calcaneus (134,149,150,151). This approach, however, resulted in an indirect and often incomplete reduction of the articular surface, thus leading Stephenson (152) to use a medial approach for reduction of the calcaneal body and a lateral approach for reduction of the articular surface (27,104).
Burdeaux (149) reported on his 21-year experience with articular surface reduction from the medial side in 1997. Sixty-one fractures classified according to the Essex-Lopresti method were managed according to a standard protocol with an average follow-up of 4.4 years. A limited medial approach was used to reduce the calcaneal tuberosity to the sustentaculum with a threaded Steinmann pin. The superolateral fragment of the posterior facet was manipulated through the medially exposed primary fracture line, and the lateral wall was decompressed with closed, manual compression. The articular reduction was assessed with intraoperative fluoroscopy. Fourteen fractures (23%), however, required an additional lateral incision to obtain a better joint reduction. Patients were allowed to bear weight fully in a shoe at 8 weeks, and the average time to return to work was 4.9 months. Few wound complications were reported, and the average AOFAS ankle and hindfoot score (128) was 94.7. Because CT scanning was not used, the data cannot be used for comparison purposes. The author acknowledged the limitations of the medial approach.
FIGURE 55-30 Lateral vascular anatomy after Borelli.
Lateral Approach
The majority of recent published series on operative treatment of calcaneal fractures have employed a lateral approach through which reduction of the calcaneal body and restoration of calcaneal height, length, and width was consistently reproducible, irrespective of the extent of comminution (26,28,30,35,38,52,101,105,124,143,153,154,155,156,157,158,159,160,161,162). Additionally, the articular reduction, when technically possible, was attainable through this lateral approach, such that a supplemental medial approach was rarely needed (163). Six separate large series of displaced intra-articular
P.2316

calcaneus fractures (representing 979 fractures), treated surgically through a lateral approach alone, confirmed that good to excellent results are possible with operative treatment (26,28,38,52,121,164).
Sanders et al (26) reported on 132 displaced intra-articular calcaneal fractures (Types II to IV) using their CT classification system. One hundred and twenty cases returned for follow-up at an average of 29 months. All fractures were managed through an extensile lateral approach with lag screw fixation of the posterior facet, plate fixation of the calcaneal body, and no bone grafting. All patients underwent CT evaluation preoperatively, postoperatively, and at 1-year follow-up. Clinical outcome was based on the Maryland Foot Score (26); those cases requiring subsequent subtalar arthrodesis for post-traumatic arthritis were immediately considered failures. Calcaneal height, length, and width were restored to 98%, 100%, and 110% of normal, respectively, regardless of fracture type. Böhler’s and Gissane’s angle were reduced to within 5 degrees of normal in all but three fractures.
In Type II fractures, 68 of 79 (86%) had an anatomic reduction of the articular surface as verified by follow-up evaluation; 10 had near-anatomic (within 2 to 3 mm) reductions; and 1 had an approximate (within 4 to 5 mm) reduction. Clinically, 58 fractures (73%) had good or excellent results. Eight fractures (10%) had a fair result and 13 were considered failures, with 10 of these 21 requiring a subtalar arthrodesis. In all 10 of these cases, arthrography, CT, and visual inspection of the joint at time of subtalar arthrodesis verified an anatomically reduced articular surface with damaged cartilage.
In Type III fractures, 18 of 30 (60%) had an anatomic reduction of the posterior facet; 8 had near-anatomic reductions; and 4 had approximate reductions. Twenty-one fractures had good or excellent results, 3 had fair results, and 6 were failures. Of the 7 fractures that ultimately required a subtalar arthrodesis, 4 had been anatomically reduced. In Type IV fractures, there were no anatomic, 3 near-anatomic, and 2 approximate reductions, with 6 complete failures (>5-mm step-off). Clinically, there was 1 good result, 2 fair results, and 8 complete failures; the 1 good and 2 fair results were in the 3 patients with near anatomic reductions. The authors concluded that although an anatomic articular reduction was needed to obtain a good or an excellent result, it could not guarantee it, likely because of articular cartilage injury at the moment of impact. Furthermore, clinical prognostication was possible, because good or excellent results decreased as the number of articular fracture fragments increased. Finally, worse results occurred at the start of the series while the number of good to excellent outcomes improved each successive year. It became apparent that Type II fractures were easier to fix than Type III fractures; however, with time even Type III results improved. The results of operative intervention in Type IV fractures were not improved even after 4 years of experience.
Other recently published reports are similar in their use of CT scans, extensile lateral approaches, plate and screw fixation, and clinical assessment using standardized tools (34,35,36,124,157,165,166,167,168). These studies all used either the Crosby and Fitzgibbons or the Sanders classifications and either the Maryland Foot Score or the Creighton-Nebraska Assessment tool (33), thus allowing comparison between studies. As a result, the studies of Crosby and Fitzgibbons (34) Song et al (167), Thordarson and Krieger (35), Laughlin et al (166), and Tornetta (169) suggest that operative intervention, when properly executed, can achieve good results. Additionally, these authors noted that calcaneal fracture classifications based on computed tomography appear to be prognostic: the more comminuted the articular surface, the worse the prognosis, thus confirming the findings of Sanders et al (26).
The Use of Bone Graft and Graft Substitutes. Bone grafting was originally advocated by Palmer (20) who, dissatisfied with contemporary internal fixation techniques alone, used bone graft to support the reduction of the articular surface, rather than screws or staples. In contrast, LeTournel (38,158) suggested that bone graft was not needed if lag screws were used, because they were able to maintain the articular surface reduction alone. Stephenson (104) used no bone graft and only had one late collapse, while Leung et al (159) used bone graft in all cases and felt it was needed (170). O’Farrell et al (125) did not use bone graft and found no cases of posterior facet collapse. Sanders et al (26) did not use bone graft in 120 cases and found no cases of subsequent loss of articular reduction. Longino and Buckley (32), in a prospective historical cohort study, compared patients who received bone graft supplementation with those who had not and found no functional or radiographic benefit to the use of bone graft in these fractures.
Although conventional bone grafting techniques do not appear to accelerate healing or weight-bearing, several authors have reported on the use of an injectable, osteoconductive calcium phosphate cement to assist in earlier weight-bearing in the treatment of both metaphyseal and calcaneal fractures (125,171,172,173,174,175). These cements harden without producing much heat, develop compressive strength, and are remodeled slowly in vivo. The main purpose of the cement is to fill voids in metaphyseal bone and offer structural support, thereby reducing the need for bone graft (176,177,178).
Schildhauer et al (179) used Norian SRS (Synthes, USA, Paoli, PA) in conjunction with standard open reduction with internal fixation for joint-depression calcaneal fractures to determine whether early postoperative full weight-bearing was possible. Cement injection averaged 10 cm3 and could easily be performed under fluoroscopic control. Progressively earlier full weight-bearing was achieved without loss of reduction. There was no statistical difference in clinical outcome scores in patients with full-weight bearing before or after 6 weeks post-operatively. Biopsies taken from clinically satisfactory cases showed nearly complete bone apposition, areas of vascular penetration, and reversal lines illustrating progressive cycles of resorption and new bone formation. The authors concluded that calcium phosphate cement augmentation in joint-depression calcaneal fractures allowed full weight-bearing as early as 3 weeks postoperatively.
Open Reduction with Internal Fixation with Primary Subtalar Arthrodesis
Van Stockum (180) was the first to perform a subtalar fusion for a fracture of the os calcis. Wilson (181), Gallie (17),
P.2317

Harris (182), and Dick (183) all suggested that this method be used as the primary treatment for acute calcaneal fractures. Lindsay and Dewar (1) however, questioned the efficacy of this method for all fractures, noting that nonoperative treatment appeared to be better than a fusion in most cases. In 1960 Hall and Pennal (184) recommended open reduction with internal fixation for simpler fractures, and primary subtalar arthrodesis only for the treatment of highly comminuted fractures. Sanders et al (26), reported on a modification of this method in 1993, which included open reduction with internal fixation of the fracture, followed by immediate primary subtalar fusion. Using this method for highly comminuted Sanders Type III and IV fractures, the author was able to achieve better results than with internal fixation alone. The authors stressed that essential to achieving a good outcome, and based on the principles of Pennal, an anatomic reduction of the calcaneal body must first be obtained (185). By reestablishing the overall calcaneal morphology and talocalcaneal relationship, both ankle and transverse tarsal joint range of motion could be restored.
Using this method, Buch et al (186) reviewed the results of 16 patients with severely comminuted calcaneus fractures treated by open reduction and internal fixation and primary subtalar arthrodesis via an extensile lateral approach. They used a femoral distractor intraoperatively to assist with restoration of calcaneal height and alignment and routinely used iliac crest autograft. Fixation included one or more lateral plates, and either a single fully threaded cannulated screw or a noncompressed, partially threaded cannulated screw, thereby relying on the broad bleeding cancellous bone surfaces to achieve arthrodesis. All fractures and arthrodeses healed, and 11 of 12 patients who were employed at the time of injury were able to return to their original occupation at an average of 8.8 months after injury.
Infante et al (187) reported the results of open reduction with internal fixation and primary subtalar arthrodesis in 33 patients with Sanders Type IV calcaneal fractures performed through an extensile lateral approach. Ten patients had open fractures, and 16 had significant other musculoskeletal injuries. Iliac crest autograft was used in 21 fractures. A 93.3% union rate was reported. The average scores for the Creighton Nebraska, AOFAS, and Maryland foot were 61 points (33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80), 78 points (55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94), and 81 points (66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95), respectively, at 38 months average follow-up. By performing the open reduction with internal fixation and subtalar fusion in one procedure, the authors noted that the surgeon could limit the morbidity associated with this fracture, with patients returning to work sooner.
Huefner et al (188) treated six closed, severely comminuted calcaneal fractures with open reduction with internal fixation and primary subtalar fusion. Iliac crest autograft was used in four fractures. All fractures and arthrodeses healed. Detailed radiographic analysis revealed near complete restoration of calcaneal length, Böhler’s and Gissane’s angles, as well as talocalcaneal angle. Ankle range of motion was restored to within 10 degrees of normal in all patients. Clinical outcomes included five excellent and one fair result, and the average AOFAS score was 88 at 4.9 years average follow-up. The authors concluded that reconstruction of the calcaneus with primary fusion of the subtalar joint led to good results.
Bilateral Fractures
Few studies specifically analyzing the treatment of bilateral calcaneal fractures exist in the literature. Several studies have commented on small subgroups of patients with bilateral injuries, and the general consensus has been that patients with bilateral fractures have a worse prognosis than those with unilateral fractures (121,189,190).
Zmurko and Karges (191) retrospectively reviewed 13 patients with bilateral calcaneal fractures, who underwent surgical treatment of their injuries using an extensile lateral approach and lag screw and plate fixation. Fractures were classified according to the Sanders classification, and CT evaluation was repeated at follow-up. They assessed functional outcome with the Musculoskeletal Functional Assessment score and the AOFAS ankle and hindfoot score, and compared their results with a historical control group of patients with unilateral injuries treated surgically. Nine of 13 patients were contacted, and follow-up clinical and radiographic examination was completed in 6 patients at an average follow-up of 56 months. Five of the 9 patients required secondary surgical procedures, including 2 patients who underwent a late subtalar arthrodesis. They found that surgical treatment of patients with bilateral injuries resulted in lower functional outcomes compared to those patients with unilateral injuries.
Dooley et al (192) in a randomized, prospective trial compared operative and nonoperative treatment of bilateral calcaneal fractures in 47 patients. Subjective and objective measurement tools were utilized at a minimum follow-up of 2 years, and these data were compared to those from patients with unilateral injuries. They found that the Böhler’s angle was significantly less, but subtalar joint range of motion was significantly better, in the unilateral group compared with the bilateral group. They also found no difference in subjective outcome between the operative and nonoperative groups with bilateral fractures; however, those patients with bilateral fractures treated surgically were significantly less likely to require a late subtalar arthrodesis than patients treated nonsurgically.
P.2327

Transcalcaneal Talonavicular Dislocation
A subgroup of high-energy, open intra-articular calcaneal fractures was recently described (62). In this injury pattern, a severely plantarflexed foot is driven axially toward the ankle (for example, a plantarflexed foot on the brake pedal with the floorboard driving through the foot). As a result, the talonavicular joint may dislocate, with the talar head being driven through the anterior portion of the calcaneus and even through the plantar skin in the most severe of cases. This injury may or may not be associated with ligamentous disruptions of the ankle. Ricci et al (62) have described this injury as a transcalcaneal talonavicular dislocation (Fig. 55-42).
FIGURE 55-42 Transcalcaneal talonavicular dislocation.
Because of the high rate of amputation with early attempts at open reduction with internal fixation, the authors recommend reduction and K-wire stabilization of the talonavicular joint and the application of an external fixator to stabilize both the foot and the ankle. Treatment should be delayed to allow the soft tissue envelope to heal. Surgery should include a late reconstruction for a calcaneal malunion. In addition, ankle ligament instability should be repaired, as well as peroneal tendon dislocation, if present. If the talonavicular or calcaneocuboid joints are arthritic as a result of the original injury, a triple arthrodesis should be considered.
Fracture-Dislocations of the Calcaneus
Fractures of the calcaneus generally occur with impaction of the lateral articular fragment into the body of the calcaneus creating either a tongue-type or joint-depression type fracture (6). Occasionally the superolateral fragment remains part of the lateral wall, such that the entire lateral fragment and the posterior tuberosity dislocate laterally (Fig. 55-43). There have been 26 reports of this injury in the literature over the last 28 years (194,195,196,197,198,199,200). In this injury, the laterally shifted posterior tuberosity drives into the lateral malleolus, either fracturing or crushing it. The peroneal tendons are usually dislocated. Rupture of the lateral collateral ligament causes inversion of the hindfoot, usually seen as talar tilt.
The injury was first described in 1977 by Biga and Thomine (195). They observed four cases in which the fracture line was in the sagittal plane with only two fragments. An anterior and medial fragment maintained its normal relationship with the talus, but the posterior and lateral fragment became dislocated laterally underneath the fibular malleolus. They called this a fracture-dislocation of the calcaneus and suggested that treatment always be surgical by open reduction and screw fixation. They noted that two of the four cases that were not operated upon had poor results.
Court-Brown et al (196) described two patients with calcaneal fracture-dislocation in which the calcaneus split into a small anteromedial fragment and a larger posterolateral fragment. The authors believed that closed reduction was impossible and open reduction essential. Ebraheim et al (197) described another two cases. In addition to the findings already mentioned, they also noted that the peroneal tendons were dislocated. CT scans also showed obvious talar tilt, indicating ankle instability. Again, these authors believed that conservative treatment by casting or early range of motion was contraindicated and that a lateral approach with open reduction and internal fixation should be performed.
FIGURE 55-43 Fracture dislocation of the calcaneus. A. Lateral radiographic clearing demonstrating dislocation of lateral calcaneus (black arrows). B. Mortise view of ankle demonstrating fibula abutment (white arrow) with rupture of lateral ligaments and subluxation of ankle (black arrow). C. Coronal CT scan demonstrating same findings as shown in B.
P.2328

Eastwood et al (194) reported four cases in which radiographic features of a fracture of the lateral malleolus and talar tilt of varying severity were associated with a displaced fracture of the calcaneus. In two cases, the initial diagnosis was of a primary ankle injury, which led to inappropriate initial management. Gross fracture subluxation of the posterior subtalar joint had occurred in all four cases, but could only be fully appreciated on CT scan. Open reduction and internal fixation of the calcaneus led to spontaneous reduction of the talar displacement. The authors noted that a swollen hindfoot, talar tilt, and a flake fracture of the lateral malleolus must alert clinicians to the possibility of a calcaneal fracture-dislocation. Ebraheim et al (198), in a subsequent report, evaluated another 11 calcaneal fracture-dislocations. These injuries all had an intra-articular calcaneal fracture, lateral subluxation or dislocation of the posterior facet, peroneal tendon subluxation, subluxation of the talus in the ankle mortise, and complete disruption of the anterior talofibular and calcaneal fibular ligaments or fracture of the lateral malleolus.
Turner and Haidukewych (199) reported on two calcaneal fractures associated with a locked dislocation of the posterior facet. Both were treated with minimally invasive open reduction and percutaneous screw fixation of the fragment using cannulated screws, with an uncomplicated course. Finally, Randall and Ferretti (200) recently presented a case report of a lateral subtalar joint dislocation with an associated calcaneal fracture that was not evident on plain x-rays but clearly seen on subsequent CT scans.
When evaluating a calcaneal fracture, the first suggestion that a fracture-dislocation exists is a dislocation of the peroneal tendons, which can be palpated anterior to the fibular malleolus. Plain x-rays may show the calcaneal pathology, but careful inspection will reveal a small degree of varus talar tilt. CT scans clearly show the fracture-dislocation, generally associated with severe hindfoot varus, peroneal tendon dislocation, and lateral ligamentous disruption of the ankle. All pathology must be addressed surgically through a lateral approach.
The calcaneal fracture component to these injuries is usually a simple two-part split fracture. Because the articular surfaces are still part of their respective tuberosity fragments, if the dislocation can be reduced, the fracture usually will recoil into an anatomic position. To accomplish this, however, reduction must occur sooner rather than later. Therefore, when a fracture dislocation is suspected, CT scans should be obtained immediately in order to verify the diagnosis and surgery should be performed soon thereafter. If there is a significant time delay, the fracture-dislocation will be exceedingly difficult to reduce without a formal open reduction.
FIGURE 55-44 Peroneal tendon dislocation. A. Reduced. B. Tendons dislocated over fibula.
Complications
Peroneal Tendon Problems
Peroneal Tendonitis and Stenosis
Peroneal tendonitis and stenosis is generally seen following nonoperative treatment and is due to lateral impingement, in which the displaced, expanded lateral wall subluxes the peroneals against the distal tip of the fibula or dislocates the tendons. Entrapment may also occur after operative treatment (201) and is more common with a standard Kocher approach, because the tendons are released from their sheath to allow access to the subtalar joint. The extensile lateral approach has largely circumvented this problem (135,141); however, care must be taken when operating near the fibula to sublux, but not dislocate, the peroneal tendons when exposing the fracture.
Patients may also develop adhesions and scarring of the tendons, either from the surgical approach or from prominent adjacent hardware. Differential local anesthetic injections can be used to document that the source of the pain is the peroneal tendons, but Mizel et al (202) proposed that this may not be completely accurate and suggested that a simultaneous injection of contrast material be performed with the anesthetic to alert the clinician to any lack of specificity of the anesthetic test. If the pain is diagnosed as peroneal scarring or impingement, either tenolysis or removal of the symptomatic hardware may be needed if nonoperative modalities, such as massage and stretching, fail to provide relief.
Peroneal Tendon Dislocation
The surgeon will occasionally diagnose dislocation of the peroneal tendons preoperatively, usually by palpation along the lateral malleolus (Fig. 55-44). Although the tendons are often reducible after the lateral wall abutment is removed, occasionally the tendons will continue to dislocate as the surgeon manipulates the subtalar joint after completing the reduction and fixation of the calcaneus. In these cases, the surgeon should attempt to reconstruct the superior peroneal retinaculum and surrounding soft tissue envelope to stabilize the tendons (203,204,205,206). This is most easily done by tacking the periosteal sleeve back down to the posterior edge of the fibula with a staple or suture anchor. This will prevent the tendons from redislocating into the soft tissue defect created by the injury (Fig. 55-45).
FIGURE 55-45 Peroneal tendon dislocation. A. Normal anatomy. B. Tendon sheath avulsion with tendon dislocation. C. Repair of sheath using small staples (anchors may be used instead).
P.2330

Heel Pad Pain and Exostoses
Heel Pad Pain
Chronic heel pad pain may result from damage to the unique septated architecture of the heel pad. Sallick and Blum (207) recommended sensory denervation for this problem, but their ability to distinguish various causes of pain was limited and they performed this procedure indiscriminately. Both Barnard and Odegard (208) and Lance et al (23) recognized that plantar pain from a damaged heel pad was not improved by operative treatment. Currently, there still remains no effective treatment for this problem, beyond providing a cushioned heel insert or custom orthotics.
Heel Exostoses
Patients may develop painful plantar bony prominences following a calcaneal fracture. If nonoperative methods such as heel pads are unsuccessful, these painful exostoses can be removed surgically, as originally described by Cotton in 1921 (13). A plantar incision should be avoided, because this is associated with painful scarring.
Ankle Pain
In the event of subtalar joint stiffness, inversion and eversion are borne by the ankle joint, because of the coupled nature of the ankle and subtalar joint complex (69). The ankle joint, however, is not intended to bear these stresses, and the patient experiences lateral ankle pain, most commonly in the form of a chronic ankle sprain. These sequelae are typically managed nonoperatively, using nonsteroidal anti-inflammatory medication, temporary casting, or the use of a lace-up ankle brace. Patients with recalcitrant pain may require a magnetic resonance scan to rule out other ankle pathology. If the pain can be localized to the anterolateral gutter, it is our experience that arthroscopy to remove plicae that have developed during the immobilization period of fracture healing will often be beneficial.
Neurologic Complications
Cutaneous Nerve Injury
The most common neurologic complication associated with operative management of calcaneal fractures is iatrogenic injury to a sensory cutaneous nerve. The sural nerve is the most common nerve involved, because of the frequency of use of the lateral approach, and may occur in up to 15% of cases (209). In this approach, the nerve may be injured either at the proximal or distal portions of the incision, and the injury may vary from a stretch neuropraxia, which may be transient or permanent, to a laceration of the nerve. Nerve injury may also occur with the medial approach, with the calcaneal branch of the posterior tibial nerve most commonly involved, occurring in up to 25% of cases (55). Clinically the patient may develop a partial or complete loss of sensation in the affected area, or a painful neuroma. Nonoperative treatment is generally advised and may include pharmacologic management, such as gabapentin or amitriptyline, physical therapy modalities, and soft accommodative shoe inserts or modifications. In the event of a painful neuroma that does not respond to nonoperative treatment, neurolysis with resection of the neuroma and stump burial into deep tissue may be considered.
Nerve Entrapment
Nerve entrapment is most common following nonoperative management of a calcaneal fracture and typically involves entrapment or compression of the posterior tibial nerve secondary to soft tissue scarring, a malunited fracture fragment, or bony exostosis causing impingement against the nerve (116,209,210). Patients experience medial-sided heel pain with associated paresthesias in the distribution of the posterior tibial nerve, and the pain is commonly worse at night or with activities such as standing or walking. Clinically there may be a positive Tinel’s sign along the course of the involved nerve. The diagnosis can be confirmed by injection of a local anesthetic in the tarsal tunnel or by electrodiagnostic studies. When clinical and diagnostic tests indicate nerve entrapment, surgical neurolysis and decompression of the posterior tibial nerve and its branches may be indicated.
Complex Regional Pain Syndrome
Reflex sympathetic dystrophy, now known as complex regional pain syndrome Type I, may occur following operative or nonoperative management. Once present, it may result in long-term and potentially permanent functional impairment of the patient. The diagnosis is made clinically, and examination initially reveals burning or aching pain out of proportion to the injury that is refractory to narcotic pain medication, extreme intolerance to cold, and pain with passive range of motion and light touch. Patients note irritation from any contact with the skin, including socks and bedsheets. Later, the patient may exhibit cold clammy skin, cyanotic discoloration, and scant hair growth. X-rays obtained at this point may reveal patchy, disuse osteopenia, and three-phase bone scan frequently shows altered uptake in the affected limb. Lastly, as the limb becomes atrophic, the skin often assumes a pale, shiny, cyanotic appearance with absence of skin folds, and significant restrictions in joint range of motion. X-rays at this stage will typically reveal severe osteopenia.
Those patients diagnosed in the acute stage of this disease may be managed with aggressive physical therapy, including manual desensitization and massage, and pharmacologic agents such as gabapentin or amitriptyline. Protracted cases may require lumbar sympathetic nerve blockade, epidural or intrathecal pain pumps, alpha-adrenergic blockers, or other medications. Prompt referral to a pain management specialist may be beneficial. In the absence of a specific stimulus as a cause of the underlying pain (for example, a prominent screw or a neuroma), further surgical treatment should be avoided (209).
Wound Complications and Calcaneal Osteomyelitis
The most common complication following operative treatment of a calcaneal fracture is wound dehiscence, which may occur in up to 25% of cases (26,50,53,56,122,143,164,209). The incision typically will approximate relatively easily; however, the wound later separates, up to 4 weeks after surgery, most com-
P.2331

monly at the apex of the incision. Risk factors for wound dehiscence and wound complications in general include smoking, diabetes, open fractures, high body mass index, and a single-layer closure (56,211). The majority of the wounds will eventually heal; deep infection and osteomyelitis develop in approximately 1% to 4% of closed fractures (50,122,164,209) and in up to 19% of open fractures (49,50,51,58).
In the event of a wound dehiscence, all range-of-motion exercises should be stopped so as to prevent further dehiscence. The limb may be placed in a cast with a window over the wound, and damp-to-dry dressing changes or other granulation-promoting wound agents are started on a daily basis. Alternatively, the patient may be placed in a fracture boot and the wound managed with daily whirlpool treatments. In either case, a course of oral antibiotics is begun. This regimen is usually successful, as long as the wound is limited to a partial-thickness necrosis of the skin. Once the wound is healed, range-of-motion exercises are reinstituted. It has been our experience that recalcitrant wounds of this type (Fig. 55-46) benefit significantly from the use of a negative-pressure device, such as the wound-vac (Vacuum-Assisted Closure, KCI, Inc., San Antonio, TX). If all treatment methods have failed, a low-profile fasciocutaneous flap such as a lateral arm flap may be needed to achieve wound coverage (53).
If gross purulence is present, hospitalization with serial surgical debridements and administration of culture-specific antibiotics must be started. These problems are usually seen in the first 6 weeks of the postoperative period, and thus most patients have not developed diffuse osteomyelitis, but rather superficial osteomyelitis due to direct extension from the wound (212). If the infection is superficial, the plate and screws should be retained, at least until the fracture has healed (typically a minimum of 6 months). After the wound bed is determined to be clean, a delayed closure, or the use of a vacuum-assisted device, is attempted if at all possible. If the wound is too large to treat with the latter methods, a free-tissue transfer is performed. Culture-specific intravenous antibiotics are administered for a minimum of 6 weeks. In the event of diffuse osteomyelitis, all implants must be removed, along with all necrotic and infected bone. In this case, an antibiotic-impregnated spacer should be placed in the wound. After repeated debridements and 6 weeks of culture-specific antibiotics, the patient is readmitted to the hospital, serial debridements are performed, wound cultures are obtained, and, if the defect is clean, a subtalar fusion using a large structural iliac crest autograft can be performed, based on the amount of remaining calcaneal bone stock. In rare instances this will not be possible and an amputation will be required, but this is the exceptional situation.
FIGURE 55-46 Wound dehiscence.
Subtalar Arthritis
One of the goals of internal fixation is an anatomic reconstruction of the joint surface of the posterior facet. Patients will develop rapid deterioration of the joint if the reduction is inadequate, if screws protrude into the joint, or if the articular cartilage has been extensively damaged at the time of injury. Severe pain and disability will certainly result (26,55,213). Even in cases with a truly anatomic reduction, however, subtalar arthritis may develop as a result of cartilage damage at the time of injury (25). This has been shown to be true in an experimental model by Borelli and Torzilli (214), in which the authors proved that profound and possibly irreversible articular cartilage damage occurs after a single high-energy impact load.
If post-traumatic arthritis is present clinically and radiographically, it should be verified as the cause of the pain (55). This can be accomplished by injecting a local anesthetic into the subtalar joint. If the pain is relieved, nonoperative measures such as shoe modifications, a University of California Berkeley Laboratory (UCBL) orthosis, ambulatory aids, and nonsteroidal anti-inflammatory agents can be tried before operative treatment is contemplated. If these fail, removal of any implants and an in situ subtalar fusion using a bone graft and 6.5- to 8.0-mm large cannulated lag screws should be performed (215).
Calcaneocuboid Arthritis
Calcaneocuboid joint arthritis can be a sequelae of operative intervention, most commonly if the anterolateral fragment is not perfectly repositioned, as well as nonoperative treatment. If the joint appears to be the area of pain, an injection of local anesthetic can be performed to differentiate between arthritis and peroneal tendonitis. In cases in which it is the site of pain, nonoperative treatment is offered, followed by a fusion if all other methods fail (216).
Calcaneal Malunions
Many surgeons still elect to treat calcaneal fractures nonoperatively, because of either a lack of familiarity with operative techniques or fear of potential operative complications (1,117). Nonoperative management of a displaced intra-articular calcaneal fracture can result in equally problematic compli-
P.2332

cations including: (a) post-traumatic subtalar or calcaneocuboid arthritis from residual joint surface incongruity; (b) subfibular impingement resulting from residual expansion of the lateral calcaneal wall and subsequent heel widening; (c) peroneal tendon impingement, subluxation or dislocation, due in part to the subfibular bony impingement, and resulting in pain and instability; (d) loss of calcaneal height, resulting in relative dorsiflexion of the talus in the ankle mortise, leading to anterior ankle impingement and loss of ankle dorsiflexion; (e) residual hindfoot malalignment, resulting in altered gait patterns and shoe wear; and (f) posterior tibial or sural neuritis (13,17,26,201,213,217,218,219,220,221,222,223). These problems affect function of the ankle, subtalar, and calcaneocuboid joints, and result in pain and disability in a surprisingly large number of patients. In an effort to improve the outcome, treatment must focus on correction of the specific sequelae of calcaneal malunions (Fig. 55-47).
As early as 1921, Cotton (13) identified residual problems following calcaneal fractures, accurately describing the residual lateral wall expansion that limited subtalar joint motion and caused painful subfibular and peroneal tendon impingement. He performed an aggressive exostectomy of the lateral calcaneal wall, along with an extra-articular osteotomy for heel malalignment, resection of symptomatic plantar heel spurs, and forceful manipulation of the subtalar joint as described by Gleich in 1893 (224). The results of his technique were indeed impressive and were duplicated by Magnuson, who used a large bone wrench to pry open the subtalar joint (223). Kalamchi and Evans (222) combined the technique of Conn (16) with the Gallie fusion (17), using the lateral exostosis as autograft. They noted that the trapezoidal slot for the graft allowed for correction of heel valgus, thus realigning and stabilizing the heel in neutral position, and reported good results in six patients. Braly et al (221) performed a lateral wall exostectomy combined with a peroneal tenolysis as an alternative to subtalar arthrodesis in patients with calcaneal malunions with lateral pain. They reported good results in 9 of 11 patients.
Carr et al (219), published their preliminary results with a subtalar distraction bone block arthrodesis, which was a modification of the Gallie fusion technique (17). They used a femoral distractor medially and a differentially wedged tricortical iliac crest bone graft to restore the talocalcaneal angle, thus correcting the horizontal talus and the talonavicular subluxation. Fixation was achieved with 6.5-mm fully threaded cancellous screws placed in a non-lag fashion to prevent compression of the autograft. Although good results were reported in 6 of 8 patients, complications included one nonunion and two varus malunions. Other authors have reported similar problems using this technique. Buch et al (186) reported good results in only 7 of 14 patients, and 2 patients had varus malunions requiring reoperation. Sanders et al (215) reported four varus malunions in a series of 15 patients, 2 of which required reoperation. Bednarz et al (225) reported on 29 feet treated with a subtalar distraction bone block arthrodesis with a mean follow-up of 33 months. Four patients developed a symptomatic nonunion, all of whom were smokers, and 2 went on to varus malunion. In contrast, Trnka et al (226) reported on 41 feet managed with subtalar distraction bone block arthrodesis, 29 of which were calcaneal malunions, at a mean follow-up of 70 months. Although 5 patients went on to nonunion, there were no varus malunions in their series.
FIGURE 55-47 Calcaneal malunion. Note widened calcaneal body, with fibular abutment, dislocation of peroneal tendons, and severe subtalar (A) and calcaneocuboid (B) arthritis.
Romash (217) described a complex calcaneal osteotomy through the primary fracture line for management of calcaneal malunions. The tuberosity fragment was translated beneath the
P.2333

sustentacular fragment medially, thereby restoring calcaneal height and eliminating residual varus angulation. He reported satisfactory results in 9 of 10 feet at an average follow-up of 14 months.
FIGURE 55-48 Calcaneal malunions according to Stephens and Sanders. Type I: lateral wall exostosis. Type II: lateral wall exostosis and subtalar arthritis. Type III: lateral wall exostosis, subtalar arthritis, and angular deformity.
Stephens and Sanders (227) developed a treatment algorithm based on a CT scan classification of calcaneal malunions (Fig. 55-48). Type I malunions included a large lateral exostosis, with or without extremely lateral subtalar arthrosis. Type II malunions included a lateral wall exostosis combined with subtalar arthrosis across the width of the joint. Type III malunions included a lateral exostosis, severe subtalar arthrosis and a calcaneal body malunited in hindfoot varus or valgus angulation. An extensile lateral approach was used in all patients, and treatment was specific to malunion type: Type I malunions underwent a lateral wall exostectomy and a peroneal tenolysis, as described by Cotton and Henderson (218) and Magnuson (223); Type II malunions underwent a lateral wall exostectomy, a peroneal tenolysis, and an in situ subtalar arthrodesis, using the local bone as graft as described by Kalamchi and Evans (222); Type III malunions underwent a lateral wall exostectomy, a peroneal tenolysis, a subtalar fusion, and a calcaneal osteotomy to correct hindfoot malalignment or shortening, as described by Dwyer (228). Their preliminary results included 26 malunions at an average follow-up of 32 months. There were no nonunions, no varus malunions, and no deep infections and the classification and protocol proved to be prognostic of outcome. Recently Clare et al (229) reported the intermediate- to long-term results of this protocol. Forty-five malunions in 40 patients were available for follow-up evaluation at a minimum of 24 months, with an average of 5.3 years (range 24 to 151 months). Thirty-seven of 40 arthrodeses (92.5%) achieved initial union, with 42 of 45 malunions (93.3%) aligned in neutral to neutral-slight valgus hindfoot alignment. All 45 feet were plantigrade. Statistical analysis revealed no significant difference in Maryland foot, AOFAS Ankle and Hindfoot scores, SF-36 Health Survey subscales, lateral talocalcaneal, talar declination, or calcaneal pitch angles among the three malunion groups. Smoking was a significant risk factor for fusion nonunion and wound complications in the series.
REFERENCES
1. Lindsay WRN, Dewar FP. Fractures of the os calcis. Am J Surg 1958;95:555–576.
2. Rowe CR, Sakellarides H, Freeman P, et al. Fractures of os calcis: a long-term follow-up study of one hundred forty-six patients. JAMA 1963;184:920.
3. Widen A. Fractures of the calcaneus: a clinical study with special reference to the technique and results of open reduction. Acta Chir Scanda 1954;188:1–119.
4. Aaron AD. Ankle fusion: a retrospective review. Orthopedics 1990;13:1249–1254.
5. Parkes II JC. The nonreductive treatment for fractures of the os calcis. Orthop Clin North Am 1973;4:193–195.
6. Essex Lopresti P. The mechanism, reduction technique, and results in fractures of the os calcis. Br J Surg 1952;39:395–419.
7. Coughlin MJ. Calcaneal fractures in the industrial patient. Foot Ankle Int 2000;21:896–905.
8. Goff CW. Fresh fracture of the os calcis. Arch Surg 1938;36:744–765.
9. Malgaigne J-F. Operative surgery, based on normal and pathological anatomy. Philadelphia: Blanchard and Lea; 1851. Frederick Brittan, translator.
10. Bohler L. Diagnosis, pathology and treatment of fractures of the os calcis. J Bone Joint Surg 1931;13:75–89.
11. Cotton FJ. Fractures of the os calcis. Boston Med Surg J 1908;18:559–565.
12. Lenormant C, Wilmoth P. Les Fractures sous thalamiques du Calcaneum. J Chirugie 1928;54:1353–1355.
13. Cotton FJ. Old os calcis fractures. Ann Surg 1921;74:294–303.
14. Leriche R. Osteosynthese pour fracture par ecrasement du calcaneum a sept fragments. Lyon Chir 1922;19:559.
15. Bohler L. Treatment of Fractures. 4th ed. Vienna: 1935.
16. Conn HR. The treatment of fractures of the os calcis. J Bone Joint Surg 1935;17:392–405.
17. Gallie WE. Subastragalar arthrodesis in fractures of the os calcis. J Bone Joint Surg 1943;XXV:731–736.
18. Westhues H. Eine neue Behandlungsmethode der Calcaneusfrakturen. Arch Orthop Unfallchir 1934;35:211.
19. Gissane W. Proceedings of the British Orthopaedic Association. J Bone Joint Surg 1947;29:254–255.
20. Palmer I. The mechanism and treatment of fractures of the calcaneus. J Bone Joint Surg Am 1948;30:2–8.
21. Aitken AP. Fractures of the os calcis. Clin Orthop 1963;30:67–75.
22. Cave EF. Fractures of the os calcis. Clin Orthop 1963;30:64–66.
23. Lance EM, Carey Jr EJ, Wade PA. Fractures of the os calcis: treatment by early immobilization. Clin Orthop 1963;30:76–90.
24. McLaughlin HL. Treatment of late complications after os calcis fractures. Clin Orthop 1963;30:111–115.
25. Sanders R. Intra-articular fractures of the calcaneus: present state of the art. J Orthop Trauma 1992;6:252–265.
26. Sanders R, Fortin P, DiPasquale T, et al. Operative treatment in 120 displaced intraarticular calcaneal fractures: results using a prognostic computed tomography scan classification. Clin Orthop 1993;290:87–95.
27. Stephenson JR. Displaced fractures of the os calcis involving the subtalar joint: the key role of the superomedial fragment. Foot Ankle 1983;4:91–101.
28. Zwipp H, Tscherne H, Thermann H, et al. Osteosynthesis of displaced intraarticular fractures of the calcaneus: results in 123 cases. Clin Orthop 1993;290:76–86.
29. Segal D, Marsh JL, Leiter B. Clinical application of computerized axial tomography (CAT) scanning in calcaneus fractures. Clin Orthop Relat Res 1985;199:114–123.
30. Buckley RE, Meek RN. Comparison of open versus closed reduction of intraarticular calcaneal fractures: a matched cohort in workmen. J Orthop Trauma 1992;6:216–222.
31. Hildebrand KA, Buckley RE, Mohtadi NG, et al. Functional outcome measures after displaced intra-articular calcaneal fractures. J Bone Joint Surg Br 1996;78:119–123.
32. Longino D, Buckley RE. Bone graft in the operative treatment of displaced intraarticular calcaneal fractures: is it helpful? J Orthop Trauma 2001;15:280–286.
33. Crosby LA, Fitzgibbons T. Computerized tomography scanning of acute intra-articular fractures of the calcaneus. J Bone Joint Surg 1990;72:852–859.
34. Crosby LA, Fitzgibbons TC. Open reduction and internal fixation of Type II intra-articular calcaneus fractures. Foot Ankle Int 1996;17:253–258.
35. Thordarson DB, Krieger LE. Operative vs. nonoperative treatment of intra-articular fractures of the calcaneus: a prospective randomized trial. Foot Ankle Int 1996;17:2–9.
36. Monsey RD, Levine BP, Trevino SG, et al. Operative treatment of acute displaced intra-articular calcaneus fractures. Foot Ankle Int 1995;16:57–63.
37. Burdeaux BD. Reduction of calcaneal fractures by the McReynolds medial approach technique and its experimental basis. Clin Orthop 1983;177:87–103.
38. LeTournel E. Open treatment of acute calcaneal fractures. Clin Orthop 1993;290:60–67.
39. Mizel MS, Miller RA, Scioli MW, American Academy of Orthopaedic Surgeons, American Orthopaedic Foot and Ankle Society. OKU: Orthopaedic Knowledge Update. 2nd ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 1998.
40. Varela CD, Vaughan TK, Carr JB, et al. Fracture blisters: clinical and pathological aspects [published erratum appears in J Orthop Trauma 1994;8:79]. J Orthop Trauma 1993;7:417–427.
41. Giordano CP, Koval KJ, Zuckerman JD, et al. Fracture blisters. Clin Orthop 1994;307:214–221.
42. Giordano CP, Koval KJ. Treatment of fracture blisters: a prospective study of 53 cases. J Orthop Trauma 1995;9:171–176.
43. Giordano CP, Scott D, Koval KJ, et al. Fracture blister formation: a laboratory study. J Trauma 1995;38:907–909.
44. Fakhouri AJ, Manoli A. Acute foot compartment syndromes. J Orthop Trauma 1992;6:223–228.
45. Manoli A, Fakhouri AJ, Weber TG. Concurrent compartment syndromes of the foot and leg. Foot Ankle 1993;14:339.
46. Myerson M. Acute compartment syndromes of the foot. Bull Hosp Joint Dis 1987;47:251–261.
47. Myerson MS. Experimental decompression of the fascial compartments of the foot: the basis for fasciotomy in acute compartment syndromes. Foot Ankle 1988;8:308–314.
48. Cotton FJ. Dislocations and Joint-Fractures. Philadelphia: WB Saunders; 1910.
49. Heier KA, Infante AF, Walling AK, et al. Open fractures of the calcaneus: soft-tissue injury determines outcome. J Bone Joint Surg Am 2003;85:2276–2282.
50. Benirschke SK, Kramer PA. Wound healing complications in closed and open calcaneal fractures. J Orthop Trauma 2004;18:1–6.
51. Berry GK, Stevens DG, Kreder HJ, et al. Open fractures of the calcaneus: a review of treatment and outcome. J Orthop Trauma 2004;18:202–206.
52. Bezes H, Massart P, Delvaux D, et al. The operative treatment of intraarticular calcaneal fractures: indications, technique, and results in 257 cases. Clin Orthop 1993;290:55–59.
53. Levin LS, Nunley JA. The management of soft-tissue problems associated with calcaneal fractures. Clin Orthop 1993;290:151–156.
54. Myerson M, Manoli A. Compartment syndromes of the foot after calcaneal fractures. Clin Orthop 1993;290:142–150.
55. Paley D, Hall H. Intra-articular fractures of the calcaneus: a critical analysis of results and prognostic factors. J Bone Joint Surg Am 1993;75:342–354.
56. Folk JW, Starr AJ, Early JS. Early wound complications of operative treatment of calcaneus fractures: analysis of 190 fractures. J Orthop Trauma 1999;13:369–372.
57. Siebert CH, Hansen M, Wolter D. Follow-up evaluation of open intra-articular fractures of the calcaneus. Arch Orthop Trauma Surg 1998;117:442–447.
58. Aldridge JM, III, Easley M, Nunley JA. Open calcaneal fractures: results of operative treatment. J Orthop Trauma 2004;18:7–11.
59. Lawrence SJ. Open calcaneal fractures. Orthopedics 2004;27:737–741.
60. Gustilo RB, Anderson JT. Prevention of infection in the treatment of one thousand and twenty-five open fractures of long bones: a retrospective and prospective analysis. J Bone Joint Surg Am 1976;58:453–458.
61. Gustilo RB, Mendoza RM, Williams DN. Problems in the management of Type III (severe) open fractures: a new classification of Type III open fractures. J Trauma 1984;24:742–746.
62. Ricci WM, Bellabarba C, Sanders R. Transcalcaneal talonavicular dislocation. J Bone Joint Surg Am 2002;84:557–561.
63. Isherwood I. A radiographic approach to the subtalar joint. J Bone Joint Surg Br 1961;43:566–574.
64. Hermann OJ. Conservative therapy for fractures of the os calcis. J Bone and Joint Surg 1937;XIX:709–718.
65. Anthonsen W. An oblique projection for roentgen examination of the talo-calcaneal joint, particularly regarding intra-articular fractures of the calcaneus. Acta Radiol 1943;24:306–310.
66. Soeur R, Remy R. Fractures of the calcaneus with displacement of the thalamic portion. J Bone Joint Surg Br 1975;57:413–421.
67. Warrick CK, Bremner AE. Fractures of the calcaneum. J Bone Joint Surg Br 1953;35:33–45.
68. Harty M. Anatomic considerations in injuries of the calcaneus. Orthop Clin North Am 1973;4:179–183.
69. Sarrafian SK. Anatomy of the Foot and Ankle. Philadelphia: JB Lippincott Co; 1983.
70. Sanders R. Displaced intra-articular fractures of the calcaneus. J Bone Joint Surg Am 2000;82:225–250.
71. Guyer BH, Levinsohn EM, Fredrickson BE, et al. Computed tomography of calcaneal fractures: anatomy, pathology, dosimetry, and clinical relevance. AJR AM J Roentgenol 1985;145:911–919.
72. Deutsch AL, Resnick D, Campbell G. Computed tomography and bone scintigraphy in the evaluation of tarsal coalition. Radio 1982;144:137–140.
P.2335

73. Broden B. Roentgen examination of the subtaloid joint in fractures of the calcaneus. Acta Radiol 1949;31:85–91.
74. Koval KJ, Sanders R. The radiologic evaluation of calcaneal fractures. Clin Orthop 1993;290:41–46.
75. Gilmer PW, Herzenberg J, Frank JL, et al. Computerized tomographic analysis of acute calcaneal fractures. Foot Ankle 1986;6:184–193.
76. Heger L, Wulff K, Seddiqi MSA. Computed tomography of calcaneal fractures. AJR Am J Roentgenol 1985;145:131–137.
77. Rosenberg ZS, Feldman F, Singson RD, et al. Peroneal tendon injury associated with calcaneal fractures: CT findings. AJR Am J Roentgenol 1987;149:125–129.
78. Smith RW, Staple TW. Computerized tomography (CT) scanning technique for the hindfoot. Clin Orthop 1983;177:34–38.
79. Solomon MA, Gilula LA, Oloff LM, et al. CT scanning of the foot and ankle:1. Normal anatomy. AJR Am J Roentgenol 1986;146:1192–1203.
80. Solomon MA, Gilula LA, Oloff LM, et al. CT scanning of the foot and ankle: 2. Clinical applications and review of the literature. AJR Am J Roentgenol 1986;146:1204–1214.
81. Adler SJ, Vannier MW, Gilula LA, Three-dimensional computed tomography of the foot: optimizing the image. Comput Med Imaging Graph 1988;12:59–66.
82. Vannier MW, Hildebolt CF, Gilula LA, et al. Calcaneal and pelvic fractures: diagnostic evaluation by three-dimensional computed tomography scans. J Digit Imaging 1991;4:143–152.
83. Thordarson DB, Greene N, Shepherd L, et al. Facilitating edema resolution with a foot pump after calcaneus fracture. J Orthop Trauma 1999;13:43–46.
84. Bradford CH, Larsen I. Sprain: fractures of the anterior lip of the os calcis. N Engl J Med 1951;244:970–972.
85. Dachtler HW. Fractures of the anterior superior portion of the os calcis due to indirect violence. J Bone J Surg 1930;25:629–631.
86. Degan TJ, Morrey BF, Braun DP. Surgical excision for anterior process fractures of the calcaneus. J Bone Joint Surg 1982;64:519–524.
87. Gellman M. Fractures of the anterior process of the calcaneus. J Bone Joint Surg 1951;33:382–386.
88. Green W. Fractures of the anterior-superior beak of the os calcis. N Y State J Med 1956;56:3515–3517.
89. Jahss MH, Kay B. An anatomic study of the anterior superior process of the os calcis and its clinical application. Foot Ankle Int 1983;3:268–281.
90. Hunt D. Compression fracture of the anterior articular surface of the calcaneus. J Bone Joint Surg Am 1970;52:1637–1642.
91. Dieterle JO. A case of so-called “open-beak” fracture of the os calcis. J Bone Joint Surg 1940;XXII:740.
92. Rothberg AS. Avulsion fractures of the os calcis. J Bone Joint Surg 1939;XXI:218–220. 1939.
93. Protheroe K. Avulsion fractures of the calcaneus. J Bone Joint Surg Br 1969;51:118–122.
94. Brunner CF, Weber BG. Special Techniques in Internal Fixation. Berlin: Springer-Verlag; 1982.
95. Dodson CF. fractures of the os calcis. J Ark Med Soc 1977;73:319–322.
96. Geckeler EO. Comminuted fractures of the os calcis. Arch Surg 1950;61:469–476.
97. McReynolds IS. Trauma to the os calcis and heel cord. In: Jahss M, ed. Disorders of the Foot and Ankle. Philadelphia: WB Saunders; 1984:1497–1538.
98. Schottstaedt ER. Symposium: treatment of fractures of the calcaneus. J Bone J Surg 1963;45:863–864.
99. Carr JB, Hamilton JJ, Bear LS. Experimental intra-articular calcaneal fractures: anatomic basis for a new classification. Foot Ankle 1989;10:81–87.
100. Thoren O. Os calcis fractures. Acta Orthop Scand Suppl 1964;70:1–116.
101. Zwipp H, Tscherne H, Wulker N. Osteosynthese Dislozierter Intraartikularer Calcaneusfrakturen. Unfallchirurg 1988;91:507–515.
102. Arnesen A. Fractures of the os calcis and its treatment. II. A contribution to the discussion on the treatment of calcaneus fracture based on an analysis of a ten-year material treated by closed reduction and traction, from Sentralsykehuset i Trondheim. Acta Chir Scanda Suppl 1958;15:1–51.
103. Gaul JS, Greenberg BG. Calcaneus fractures involving the subtalar joint. South Med J 1966;59:605–613.
104. Stephenson JR. Treatment of displaced intra-articular fractures of the calcaneus using medial and lateral approaches, internal fixation, and early motion. J Bone and Joint Surg Am 1987;69:115–130.
105. Sanders R. Intra-articular fractures of the calcaneus: present state of the art. J Orthop Trauma 1992;6:252–265.
106. Csizy M, Buckley R, Tough S, et al. Displaced intra-articular calcaneal fractures: variables predicting late subtalar fusion. J Orthop Trauma 2003;17:106–112.
107. Miric A, Patterson BM. Pathoanatomy of intra-articular fractures of the calcaneus. J Bone Joint Surg Am 1998;80:207–212.
108. Thermann H, Hufner T, Schratt HE, et al. [Treatment of intraarticular calcaneal fractures in adults: a treatment algorithm]. Unfallchirurg 1999;102:152–166.
109. Heffernan G, Khan F, Awan N, et al. A comparison of outcome scores in os calcis fractures. Ir J Med Sci 2000;169:127–128.
110. Tennent TD, Calder PR, Salisbury RD, et al. The operative management of displaced intra-articular fractures of the calcaneum: a two-centre study using a defined protocol. Injury 2001;32:491–496.
111. Andermahr J, Jesch AB, Helling HJ, et al. [CT morphometry for calcaneal fractures and comparison of the Zwipp and Sanders classifications]. Z Orthop Ihre Grenzgeb 2002;140:339–346.
112. Furey A, Stone C, Squire D, et al. Os calcis fractures: analysis of interobserver variability in using Sanders classification. J Foot Ankle Surg 2003;42:21–23.
113. Rammelt S, Gavlik JM, Zwipp H. Historical and current treatment of calcaneal fractures. J Bone Joint Surg Am 2001;83:1438–1440.
114. Tornetta P, III. The Essex-Lopresti reduction for calcaneal fractures revisited. J Orthop Trauma 1998;12:469–473.
115. Hammesfahr RFLL. Calcaneal fractures: a good prognosis. Foot Ankle 1981;2:161–171.
116. Kitaoka HB, Schaap EJ, Chao EY, et al. Displaced intra-articular fractures of the calcaneus treated non-operatively: clinical results and analysis of motion and ground-reaction and temporal forces. J Bone Joint Surg Am 1994;76:1531–1540.
117. Pozo JL, Kirwan OE, Jackson AM. The long term results of conservative management of severely displaced fractures of the calcaneus. J Bone and Joint Surg Br 1984;66:386–390.
118. Salama R, Benamara A, Weissman SL. Functional treatment of intra-articular fractures of the calcaneus. Clin Orthop 1976;115:236–240.
119. Simpson LA, Shulak DA, Spiegel PG. Intraarticular fractures of the calcaneus: a review. Contemp Orthop 1983;6:19–28.
120. Sanders R. The problem with apples and oranges. J Orthop Trauma 1997;11:465–466.
121. Buckley RE, Tough S, McCormack R, et al. Operative compared with nonoperative treatment of displaced intra-articular calcaneal fractures: a prospective, randomized, controlled multicenter trial. J Bone Joint Surg Am 2002;84:1733–1744.
122. Howard JL, Buckley R, McCormack R, et al. Complications following management of displaced intra-articular calcaneal fractures: a prospective randomized trial comparing open reduction internal fixation with nonoperative management. J Orthop Trauma 2003;17:241–249.
123. Jarvholm U, Korner L, Thoren O, et al. Fractures of the calcaneus. Acta Orthop Scand 1984;55:652–656.
124. Leung KS, Yuen KM, Chan WS. Operative treatment of displaced intra-articular fractures of the calcaneum: medium-term results. J Bone Joint Surg Br 1993;75:196–201.
125. O’Farrell DA, O’Byrne JM, McCabe JP, et al. Fractures of the os calcis: improved results with internal fixation. Injury 1993;24:263–265.
126. Parmar HV, Triffitt PD, Gregg PJ. Intra-articular fractures of the calcaneum treated operatively or conservatively: a prospective study [see comments]. J Bone Joint Surg Br 1993;75:932–937.
127. Thordarson DB, Triffon MJ, Terk MR. Magnetic resonance imaging to detect avascular necrosis after open reduction and internal fixation of talar neck fractures. Foot Ankle Int 1996;17:742–747.
128. Kitaoka HB, Alexander IJ, Adelaar RS, et al. Clinical rating systems for the ankle-hindfoot, midfoot, hallux, and lesser toes. Foot Ankle Int 1994;15:349–353.
129. Randle JA, Kreder HJ, Stephen D, et al. Should calcaneal fractures be treated surgically? A meta-analysis. Clin Orthop 2000;377:217–227.
130. Tornetta P, III. The Essex-Lopresti reduction for calcaneal fractures revisited. J Orthop Trauma 1998;12:469–473.
131. Rammelt S, Amlang M, Barthel S, et al. Minimally-invasive treatment of calcaneal fractures. Injury 2004;35(Suppl 2):SB55–SB63.
132. Sangeorzan BJ, Ringler JR. Minimally invasive reduction and small fragment fixation of tongue-type calcaneus fractures, OTA 17th Annual Meeting, poster # 46. Orthopaedic Trauma Association 200117, poster #46,275.
133. Ziran B, Bosch P. Closed reduction and percutaneous pinning for comminuted intra-articular fractures of the calcaneus: preliminary results, OTA 15th Annual Meeting, Paper #50. Orthopaedic Trauma Association; 1999.
134. McReynolds IS. The case for operative treatment of fractures of the os calcis. In: Leach RE, Hoaglund FT, Riseborough EJ, eds. Controversies in Orthopedic Surgery. Philadelphia: WB Saunders; 1982:232–254.
135. Tscherne H, Zwipp H. Calcaneal fractures. In: Tscherne H, Schatzker J, eds. Major Fractures of the Pilon, the Talus, and the Calcaneus. Berlin: Springer-Verlag; 1993:153–174.
136. Johnson EE. Intraarticular fractures of the calcaneus: diagnosis and surgical management. Orthopedics 1990;13:1091–1100.
137. Zwipp H, Tscherne H. Calcaneusfracturen: Offene Reposition und mediale Stabilisierung. Unfallchirurg 1989;91:507.
138. Judet R, Judet J, Lagrange J. Tritement des fractures du calcaneum comportant une disjonction astragalo-calcaneene. Mem Acad Chir 1954;80:158–160.
139. Leriche R. Traitement chirurgical des fractures du calcaneum. Bull Mem Soc Nat Chir 1929;55:8–9.
140. Fernandez DL. Transarticular fracture of the calcaneus. Arch Orth Traum Surg 1984;103:195–200.
141. Gould N. Lateral approach to the os calcis. Foot Ankle 1984;4:218–220.
142. Picot G. L’intervention sanglante dans les fratures malleolaires. J Chir 1923;21:529.
143. Benirschke SK, Sangeorzan BJ. Extensive intraarticular fractures of the foot: surgical management of calcaneal fractures. Clin Orthop 1993;292:128–134.
144. Borrelli Jr J, Lashgari C. Vascularity of the lateral calcaneal flap: a cadaveric injection study. J Orthop Trauma 1999;13:73–77.
145. Mann RA. Major surgical procedures for disorders of the ankle, tarsus and midtarsus. In: Mann RA, ed. Surgery of the Foot. 5th ed. St. Louis: Mosby; 1986:284–308.
146. Martinez S, Herzenberg JE, Apple JS. Computed tomography of the hindfoot. Orthop Clin North Am 1985;16:481–496.
147. Tanke GMH. Fractures of the calcaneus. Acta Chir Scand Suppl 1982;505.
148. Maxfield JE, McDermott FJ. Experiences with the palmar open reduction of fractures of the calcaneus. J Bone and Joint Surg Am 1955;37:99–106.
149. Burdeaux BJ. Fractures of the calcaneus: open reduction and internal fixation from the medial side: a 21 year prospective study. Foot Ankle Int 1997;18:685–692.
150. Burdeaux BJ. The medical approach for calcaneal fractures. Clin Orthop 1993;290:96–107.
151. Burdeaux BJ. Fractures of the calcaneus. In: Chapman M, Madison M, eds. Operative Orthopedics 1989:1723–1736.
152. Stephenson JR. Surgical treatment of displaced intraarticular fractures of the calcaneus: a combined lateral and medial approach. Clin Orthop 1993;290:68–75.
153. Bezes H, Massart P, Fourquet JP. Die Osteosynthese der Calcaneus: Impressionsfraktur. Unfallheilkunde 1984;87:363–368.
P.2336

154. Eastwood DM, Gregg PJ, Atkins RM. Intra-articular fractures of the calcaneum. I. Pathological anatomy and classification [see comments]. J Bone Joint Surg Br 1993;75:183–188.
155. Eastwood DM, Langkamer VG, Atkins RM. Intra-articular fractures of the calcaneum. II. Open reduction and internal fixation by the extended lateral transcalcaneal approach [see comments]. J Bone Joint Surg Br 1993;75:189–195.
156. Fernandez DL, Koella C. Combined percutaneous and “minimal” internal fixation for displaced articular fractures of the calcaneus. Clin Orthop 1993;290:108–116.
157. Hutchinson F, Huebner MK. Treatment of os calcis fractures by open reduction and internal fixation. Foot Ankle Int 1994;15:225–232.
158. LeTournel E. Open reduction and internal fixation of calcaneal fractures. In: Spiegel P, ed. Topics in Orthopedic Surgery. Baltimore, MD: Aspen Publishers; 1984:173–192.
159. Leung KS, Chan WS, Shen WY, et al. Operative treatment of intraarticular fractures of the os calcis: the role of rigid internal fixation and primary bone grafting—preliminary results. J Orthop Trauma 1989;3:232–240.
160. Melcher G, Bereiter H, Leutenegger A, et al. Results of operative treatment for intra-articular fractures of the calcaneus. J Trauma 1991;31:234–238.
161. Melcher G, Degonda F, Leutenegger A, et al. Ten-year follow-up after operative treatment for intra-articular fractures of the calcaneus. J Trauma 1995;38:713–716.
162. Zwipp H, Tscherne H, Wulker N, et al. Der intraartikulare Fersenbeinbruch. Unfallchirurg 1989;92:117–129.
163. Johnson EE, Gebhardt JS. Surgical management of calcaneal fractures using bilateral incisions and minimal internal fixation. Clin Orthop 1993;290:117–124.
164. Harvey EJ, Grujic L, Early JS, et al. Morbidity associated with ORIF of intra-articular calcaneus fractures using a lateral approach. Foot Ankle Int 2001;22:868–873.
165. Darder PA, Silvestre MA, Segura LF, et al. Surgery for fracture of the calcaneus. 5 (2–8) year follow-up of 20 cases. Acta Orthop Scand 1993;64:161–164.
166. Laughlin RT, Carson JG, Calhoun JH. Displaced intra-articular calcaneus fractures treated with the Galveston plate. Foot Ankle Int 1996;17:71–78.
167. Song KS, Kang CH, Min BW, et al. Preoperative and postoperative evaluation of intra-articular fractures of the calcaneus based on computed tomography scanning. J Orthop Trauma 1997;11:435–440.
168. Tornetta P. Open reduction and internal fixation of the calcaneus using minifragment plates. J Orthop Trauma 1996;10:63–67.
169. Tornetta P, III. Open reduction and internal fixation of the calcaneus using minifragment plates. J Orthop Trauma 1996;10:63–67.
170. Leung K, Chan W, Shen W, et al. Operative treatment of intraarticular fractures of the os calcis. J Orthop Trauma 1989;3:232–240.
171. Mermelstein LE, Chow LC, Friedman C, et al. The reinforcement of cancellous bone screws with calcium phosphate cement. J Orthop Trauma 1996;10:15–20.
172. Xu HH, Simon CG, Jr. Self-hardening calcium phosphate composite scaffold for bone tissue engineering. J Orthop Res 2004;22:535–543.
173. Welch RD, Zhang H, Bronson DG. Experimental tibial plateau fractures augmented with calcium phosphate cement or autologous bone graft. J Bone Joint Surg Am 2003;85:222–231.
174. Horstmann WG, Verheyen CC, Leemans R. An injectable calcium phosphate cement as a bone-graft substitute in the treatment of displaced lateral tibial plateau fractures. Injury 2003;34:141–144.
175. Larsson S, Bauer TW. Use of injectable calcium phosphate cement for fracture fixation: a review. Clin Orthop 2002;395:23–32.
176. Morgan EF, Yetkinler DN, Constantz BR, et al. Mechanical properties of carbonated apatite bone mineral substitute: strength, fracture and fatigue behaviour. J Mater Sci Mater Med 1997;8:559–570.
177. Constantz BR, Barr BM, Ison IC, et al. Histological, chemical, and crystallographic analysis of four calcium phosphate cements in different rabbit osseous sites. J Biomed Mater Res 1998;43:451–461.
178. Constantz BR, Ison IC, Fulmer MT, et al. Skeletal repair by in situ formation of the mineral phase of bone. Science 1995;2675:1796–1799.
179. Schildhauer TA, Bauer TW, Josten C, et al. Open reduction and augmentation of internal fixation with an injectable skeletal cement for the treatment of complex calcaneal fractures. J Orthop Trauma 2000;14:309–317.
180. van Stockum. Operative behandlung de calcaneus und talus fractur. Zentralbl Chir 1912;39:1438.
181. Wilson PD. Treatment of fractures of the os calcis by arthrodesis of the subastragalar joint. JAMA 1927;89:1676–1683.
182. Harris RI. Fractures of the os calcis. Ann Surg 1946;124:1082–1100.
183. Primary fusion of the posterior subtalar joint in the treatment of fractures of the calcaneum. J Bone Joint Surg Br 1953;35:375–380.
184. Hall MC, Pennal GF. Primary subtalar arthrodesis in the treatment of severe fractures of the calcaneum. J Bone Joint Surg Br 1960;42:336–343.
185. Flemister Jr AS, Infante AF, Sanders RW, et al. Subtalar arthrodesis for complications of intra-articular calcaneal fractures. Foot Ankle Int 2000;21:392–399.
186. Buch BD, Myerson MS, Miller SD. Primary subtalar arthrodesis for the treatment of comminuted calcaneal fractures. Foot Ankle Int 1996;17:61–70.
187. Infante AF, Lewis B, Heier KA, et al. Open reduction internal fixation and immediate subtalar fusion for comminuted intra-articular calcaneal fractures: a review of 33 cases, OTA 15th Annual Meeting, paper #49. Orthopaedic Trauma Association, 1999.
188. Huefner T, Thermann H, Geerling J, et al. Primary subtalar arthrodesis of calcaneal fractures. Foot Ankle Int 2001;22:9–14.
189. Loucks C, Buckley R. Bohler’s angle: correlation with outcome in displaced intra-articular calcaneal fractures. J Orthop Trauma 1999;13:554–558.
190. Tufescu TV, Buckley R. Age, gender, work capability, and worker’s compensation in patients with displaced intraarticular calcaneal fractures. J Orthop Trauma 2001;15:275–279.
191. Zmurko MG, Karges DE. Functional outcome of patients following open reduction internal fixation for bilateral calcaneus fractures. Foot Ankle Int 2002;23:917–921.
192. Dooley P, Buckley R, Tough S, et al. Bilateral calcaneal fractures: operative versus nonoperative treatment. Foot Ankle Int 2004;25:47–52.
193. Tornetta P III. Percutaneous treatment of calcaneal fractures. Clin Orthop 2000;375:91–96.
194. Eastwood DM, Maxwell AC, Atkins RM. Fracture of the lateral malleolus with talar tilt: primarily a calcaneal fracture not an ankle injury. Injury 1993;24:109–112.
195. Biga N, Thomine JM. [Fracture-dislocation of the calcaneus: apropos of 4 cases]. Rev Chir Orthop Reparatrice Appar Mot 1977;63:191–202.
196. Court-Brown CM, Boot DA, Kellam JF. Fracture dislocation of the calcaneus: a report of two cases. Clin Orthop 1986;213:201–206.
197. Ebraheim NA, Savolaine ER, Paley K, et al. Comminuted fracture of the calcaneus associated with subluxation of the talus [see comments]. Foot Ankle 1993;14:380–384.
198. Ebraheim NA, Elgafy H, Sabry FF, et al. Calcaneus fractures with subluxation of the posterior facet: a surgical indication. Clin Orthop 2000;377:210–216.
199. Turner NS, Haidukewych GJ. Locked fracture dislocation of the calcaneus treated with minimal open reduction and percutaneous fixation: a report of two cases and review of the literature. Foot Ankle Int 2003;24:796–800.
200. Randall DB, Ferretti AJ. Lateral subtalar joint dislocation: a case with calcaneal fracture. J Am Podiatr Med Assoc 2004;94:65–69.
201. Isbister JF. Calcaneo-fibular abutment following crush fracture of the calcaneus. J Bone Joint Surg Br 1974;56:274–278.
202. Mizel MS, Michelson JD, Newberg A. Peroneal tendon bupivacaine injection: utility of concomitant injection of contrast material. Foot Ankle Int 1996;17:566–568.
203. Mason RB, Henderson JP. Traumatic peroneal tendon instability. Am J Sports Med 1996;24:652–658.
204. Sobel M, Geppert MJ, Warren RF. Chronic ankle instability as a cause of peroneal tendon injury. Clin Orthop 1993;296:187–191.
205. Steinbock G, Pinsger M. Treatment of peroneal tendon dislocation by transposition under the calcaneofibular ligament. Foot Ankle Int 1994;15:107–111.
206. Slatis P, Santavirta S, Sandelin J. Surgical treatment of chronic dislocation of the peroneal tendons. Br J Sports Med 1988;22:16–18.
207. Sallick MA, Blum L. Sensory denervation of the heel for persistent pain following fractures of the calcaneus. J Bone Joint Surg Am 1948;30:209–212.
208. Barnard L, Odegard JK. Conservative approach in the treatment of fractures of the calcaneus. J Bone Joint Surg Am 1955;37:1231–1236.
209. Lim EV, Leung JP. Complications of intraarticular calcaneal fractures. Clin Orthop 2001;391:7–16.
210. Myerson MS, Berger BI. Nonunion of a fracture of the sustentaculum tali causing a tarsal tunnel syndrome: a case report. Foot Ankle Int 1995;16:740–742.
211. Abidi NA, Dhawan S, Gruen GS, et al. Wound-healing risk factors after open reduction and internal fixation of calcaneal fractures. Foot Ankle Int 1998;19:856–861.
212. Cierny G. Classification and treatment of chronic osteomyelitis. In: Evarts CM, ed. Surgery of the Musculoskeletal System. 2nd ed. New York: Churchill Livingstone; 1989:10–35.
213. Myerson M, Quill-GE J. Late complications of fractures of the calcaneus. J Bone Joint Surg Am 1993;75:331–341.
214. Borelli Jr J, Torzilli PAGRHD. Effect of impact load on articular cartilage: development of an intra-articular fracture model. J Orthop Trauma 1997;11:319–326.
215. Sanders R, Fortin P, Walling A. Subtalar arthrodesis following calcaneal fracture. Orthop Trans 1991;15:656.
216. Sanders R, Gregory P. Operative treatment of intra-articular fractures of the calcaneus. Orthop Clin North Am 1995;26:203–214.
217. Romash MM. Reconstructive osteotomy of the calcaneus with subtalar arthrodesis for malunited calcaneal fractures. Clin Orthop 1993;290:157–167.
218. Cotton FJ, Henderson FF. Results of fractures of the os calcis. Am J Orthop Surg 1916;14:290.
219. Carr JB, Hansen ST, Benirske SK. Subtalar distraction bone block fusion for late complications of os calcis fractures. Foot Ankle 1988;9:81–86.
220. Miller WE. Pain and impairment considerations following treatment of disruptive os calcis fractures. Clin Orthop 1983;177:82–86.
221. Braly WG, Bishop JO, Tullos HS. Lateral decompression for malunited os calcis fractures. Foot Ankle 1985;6:90–96.
222. Kalamchi A, Evans J. Posterior subtalar fusion. J Bone Joint Surg Br 1977;59:287–289.
223. Magnuson PB. An operation for relief of disability in old fractures of the os calcis. JAMA 1923;80:1511.
224. Gleich A. Beitrag zur operativen Plattfussbehandlung. Arch Klin Chir 1893;46:358.
225. Bednarz PA, Beals TC, Manoli A. Subtalar distraction bone block fusion: an assessment of outcome. Foot Ankle Int 1997;18:785–791.
226. Trnka HJ, Easley ME, Lam PW, et al. Subtalar distraction bone block arthrodesis. J Bone Joint Surg Br 2001;83:849–854.
227. Stephens HM, Sanders R. Calcaneal malunions: results of a prognostic computed tomography classification system. Foot Ankle Int 1996;17:395–401.
228. Dwyer FC. Osteotomy of the calcaneum for pes cavus. J Bone Joint Surg Br 1959;41:80–86.
229. Clare MP, Lee WE, Sanders RW. Intermediate to long-term results of a treatment protocol for calcaneal fracture malunions. J Bone Joint Surg Am 2005;87:963–973.