Hand Surgery
1st Edition

Intraarticular Injuries of the Distal and Proximal Interphalangeal Joints
Joseph J. Dias
This chapter covers the presentation, decision making, and management of difficult intraarticular injuries of the proximal and distal interphalangeal joints of the hand and outlines the principal complications and their prevention, identification, and management. Injuries of the interphalangeal joints of the digital skeleton are common and account for approximately 19% of phalangeal fractures (1). A large number of injuries of the interphalangeal joint can be treated conservatively. An undisplaced stable fracture or a simple dislocation of the joint that is stable after reduction very rarely, if ever, needs early intervention, and the outcome of these injuries is expected to be good. This chapter concentrates on injuries that challenge hand surgeons.
The proximal interphalangeal joint is a hinge joint allowing movement in essentially a single plane so that the pulp of the volar surface of the digit can contact an object either to recognize or manipulate it or so that the digit is brought into a position that together with other digits forms a gesture for communication. The range of movement at this joint is 100 degrees, with stability required throughout the range to manipulate objects of different sizes in different directions.
The convex surface is formed by the distal part of the proximal phalanx. The concave surface is the proximal surface of the middle phalanx. The surface of the proximal part of the middle phalanx subtends an angle of 110 degrees on the condyles of the proximal phalanx compared with 180 degrees’ cover of the olecranon on the trochlea at the elbow or 105 degrees’ cover of the glenoid on the humeral head at the shoulder. The proximal interphalangeal joint is therefore essentially nonconstrained. To allow 100 degrees of flexion, 210 degrees of the condyles must be covered by articular cartilage. As stability is required throughout the arc of motion, the radius of curvature in the sagittal plane is similar for all parts of each condyle in this plane. There is therefore, unlike the knee joint, no cam effect in any one sector of the range. This also means that the center of rotation remains almost static throughout the range of movement.
Like the knee joint, the proximal interphalangeal joint has two condyles separated by a shallow intercondylar sulcus extending from the dorsal margin of the articular surface to its volar margin. The reciprocal surface of the middle phalanx has a sagittal ridge corresponding to the intercondylar sulcus. The radius of curvature of the condyles in the coronal and sagittal planes is less than the corresponding radii of curvature of the proximal articular surface of the middle phalanx. This slight difference causes the joint surfaces to be incongruent and confers on the proximal interphalangeal joint the limited ability to rotate such that the pulp of the digit can accommodate to the shape of the object being manipulated.
Bony Anatomy
As in the knee joint, in the transverse plane, the dorsal width of the proximal phalangeal condyle is almost half the palmar width, and there is a similar but less apparent difference between the dorsal and palmar widths of the base of the middle phalanx. The anteroposterior length of each condyle of the proximal phalanx is different, with the condyle away from the ring finger being longer. In the ring finger, the radial condyle is just longer than the ulnar one. Thus, in the transverse plane, the condyles are trapezoid in shape with a tilt toward the ring finger. For the little finger, the ulnar condyle is longer than the radial condyle, whereas for the index, middle, and ring fingers, the radial condyle is longer than the ulnar condyle. In the coronal plane, the articular surfaces lie in a curved line tilting away from the second web space. Finally, the radius of curvature of the two condyles is different such that the longer condyle has a

greater radius of curvature. These three factors in the anatomy of the condyles allow the pulp of each digit to be rotated toward the middle finger as the joint is flexed. The index finger pronates 9 degrees toward the middle finger in flexion (2). These differences allow the bending finger to converge toward, but not precisely to, the scaphoid tubercle. Although the predominant motion at the proximal interphalangeal joints is in flexion and extension, the anatomic factors described previously allow some lateral and rotational movement similar to but much less than the human knee joint. The proximal interphalangeal joint is therefore best described as a “sloppy” hinge joint.
Static Soft Tissue Constraints
Three structures provide the primary constraints to the movement of the proximal interphalangeal joint: the two collateral ligaments and the volar plate.
Collateral Ligament
The collateral ligaments arise from the tiny notch just distal and volar to the epicondyle of the proximal phalanx. The collagen fibers fan out from this point and are arranged radially along the length of the ligament. The collateral ligament is inserted into the base of the middle phalanx in the anterior 40% of its lateral margin up to the lateral tubercle of the base of the middle phalanx. It has a dorsal and volar part, the former being taut in extension and the latter being taut in flexion. Extending from the front of the collateral ligament is the accessory collateral ligament. Structurally, it is similar to the true collateral ligament, but it differs from it: Dorsally, it is attached to bone adjacent to the attachment of the true collateral ligament, but its distal volar edge is continuous with each lateral free edge of the volar plate. The hiatus between the proximal free edge of the accessory ligament and the lateral bands of the volar plate provides an avenue for branches of the digital artery and nerves to pass underneath the volar plate to the front of the proximal phalangeal neck. As the finger flexes, the accessory collateral ligament becomes slack, but the true collateral ligament becomes further tensioned by the wider volar width of the condyles. This mechanism permits stability of the flexed proximal interphalangeal joint. Division or injury to one part of the true collateral ligament results in little clinical increase in the laxity of this joint, but division of both bands of the true collateral ligament can cause appreciable instability (2).
The ligaments contain tightly packed bundles of collagen with virtually no elasticity. Histopathology demonstrates that at their insertion the collagen bundles are tethered deeply into the bone. The zones change from fibrous tissue to cartilage, which is then calcified before merging into bone. This provides a gradual transition of stiffness from fibrous tissue to bone. The two collateral ligaments constrain sideways angulation and forward translation of the middle phalanx on the proximal phalanx but allow some rotation. The accessory collateral ligaments stabilize the edges of the volar plate as the joint flexes and prevent the volar plate from crumpling. The two accessory ligaments impart tension to the volar plate from side to side keeping it stretched. This permits the volar plate to slide smoothly proximally as the digit flexes and thereby prevents a crumpled volar plate from forming a soft tissue block to flexion. The accessory collateral ligament has very little direct influence on the stability of the proximal interphalangeal joint. However, any adhesion or injury or surgical tethering of this alters the gliding of the volar plate and thereby restricts flexion and extension by tethering the volar plate. Tethering of the true lateral ligament due to surgery or a misplaced pin or screw effectively shortens it and increases the restriction of joint movement by compressing the joint surfaces at the end of the range of the new shortened length of ligament.
Volar Plate
The volar plate is a unique structure of digital joints. In a way, its action is similar to the cruciate ligaments of the knee in preventing sagittal displacement rather than coronal displacement, although an intact collateral ligament resists coronal displacement to an extent, especially when the joint is extended. Proximally, the lateral edges of the volar plate are prolonged, and these prolongations are tethered to bone adjacent to and just within the distal mouth of the second annular pulley in common with the proximal attachment of the oblique ligament of Landsmeer and the attachment of the first cruciate pulley. The whole structure resembles a sail of a boat, with the proximal edge free from bone. The lateral margin of the volar plate forms a continuous arch, also free from any attachments with the proximal edge of the accessory collateral ligaments. The lateral margin of the volar plate is thick and attached distally on the lateral volar tubercles at the base of the middle phalanx. The fibrocartilaginous sheet is stretched across the front of the joint between the two lateral tethers and is thinner, with a larger proportion of the collagen fibers running transversely. The distal attachment of the middle portion of the volar plate is weaker than the lateral attachments; it is attached just distal to the volar articular edge and is not continuous with the articular surface. It appears to be continuous with the periosteum of the middle phalanx. The deep surface is lined with synovium, and there is a meniscuslike fold at its margin adjacent to the articular surface. In full flexion, this edge is pulled away from the volar articular edge, allowing the last few degrees of flexion as the volar edge abuts the front of the proximal phalanx. Its superficial surface forms the floor of the fibrous flexor sheath under the first cruciate and the third annular pulley. It provides attachment to the lateral edges of the third annular pulley. The two flattened slips of the flexor digitorum

superficialis tendon cover its volar surface almost completely. It is the principal constraint to dorsal displacement of the middle phalanx in extension.
Blood vessels run from the digital vessels under the distal lateral edge of the volar plate and form an anastomosis proximal to the condyles of the proximal phalanx, from which arise the vincular vessels to the tendons and branches to the joint and bone. Articular nerve branches run with the vessels to provide primary innervation of the proximal interphalangeal joint.
Apart from the three main static soft tissue constraints to the movement of the proximal interphalangeal joint, the fascia (Greyson’s and Cleland’s fascia) and the firm attachment of the volar skin through suspensory ligaments provide a measure of restriction of movement, particularly in the injured digit and in the presence of soft tissue edema.
Dynamic Stabilizers of the Proximal Interphalangeal Joint
The proximal interphalangeal joint has important dynamic stabilizers. Dorsally, the central slip is attached to bone just distal to the articular end. It has a wide attachment. The central slip is the dynamic stabilizer of the joint, which restricts dorsal displacement of the middle phalanx. It functions as a stabilizer to increase joint compression force. On the volar surface, the flexor tendons stabilize the joint. The superficialis slips lie flat in front of the volar plates and are inserted into the shaft of the middle phalanx at the junction of its proximal and middle thirds. The superficialis and profundus tendons are held close to the volar plate by the third annular pulley. The thickness of the volar plate in front of the joint is between 1.5 mm and 2 mm; this increases the moment arm of the flexor tendons by approximately 25%. The lateral extensor bands and the transverse and oblique retinacular ligaments wrap over the lateral aspect of the proximal interphalangeal joint.
Distal Interphalangeal Joint
The distal interphalangeal joint is similar to the proximal interphalangeal joint. However, the condyles and the base of the distal phalanx are less well defined. The joint has a range of 70 degrees, and the extensor tendon is inserted into the base of the distal phalanx along most of the extensor surface width. The flare of the base of the distal phalanx is much more pronounced compared with its shaft size than the proximal phalanx. The remainder of the anatomic features are similar but less well defined in comparison with the same structure in the proximal interphalangeal joint.
Joint Forces
Joint forces have been measured by Weightman and Amis (3). The factor for the distal interphalangeal joint is 4.7, and that for the proximal interphalangeal joint is 8.3. If pinch strength is 1 kg (approximately 10 newtons), the joint compressive force is 4.7 kg at the distal interphalangeal joint and 8.3 kg at the proximal interphalangeal joint.
In summary, the proximal interphalangeal joints of the digits are sloppy hinge joints with essentially uniplanar movement constrained by the shape of the articular surfaces, the collateral ligaments and the volar plates providing static restraint and the flexor and extensor mechanisms providing dynamic joint compression.
Fractures of the proximal interphalangeal joint can affect the condyles or the base of the middle phalanx. Fractures of the condyles are uncommon and usually occur in the young adult. Patients are usually in their early 20s, and males predominate. Between half and four-fifths of these injuries are due to sport, usually a ball sport (4,5). Weiss and Hastings suggested that the outstretched digits are suddenly forced apart, such as when a ball strikes the hand, causing an oblique fracture of one condyle. Coronal shear fractures occur in hyperflexion or extension. The sudden impact with rapid loading of the digit may predispose to a fracture rather than a ligamentous injury (4).
London (6) described three patterns of fracture in his diagrams, indicating that the fracture was essentially in the sagittal plane. The patterns were of a square box fracture, an oblique fracture, and a bicondylar fracture. Weiss and Hastings (4) described in addition the shearing coronal fracture in hyperflexion when the fragment comes off the dorsal part of the condyle and in hyperextension when the fragment comes off the volar part of the condyle. These complete the more common patterns of this injury. The fracture usually occurs when an axial load is combined with a sudden sideways angulation in a young athlete. The box fracture (London type I) has a transverse metaphyseal fracture line and is intrinsically stable if it isn—t displaced. This pattern accounted for a third of the fractures reported by London, whereas Weiss and Hastings did not find a single example of such a fracture. Oblique fractures of the condyle (London type II) accounted for between 50% and 79% of condylar fractures. His description suggests two patterns with an equal distribution: a short oblique fracture where the fracture line extended into the intercondylar sulcus and a long oblique fracture where the fracture line extended onto the convex surface of the opposite condyle. Weiss and Hastings, too, described a short oblique fracture that accounted for 58% of their fractures; additionally, they observed that the fracture plane is not purely sagittal but faces palmarward so that the dorsal fracture line is toward the lateral border of the digit, an observation that has implications when one considers percutaneous

fixation of this fracture. They also described a long oblique fracture with the fracture line extending into the intercondylar fracture accounting for 21% of their fractures. They believed that this pattern was caused by a pure anteroposterior load or a pure lateral stress without any flexion of the finger at the moment of impact. The oblique fracture is potentially unstable even when undisplaced, and depression of this fragment leads to sideways angulation of the digit distal to the fracture. The stability of the bicondylar fracture (London type III) depends on its displacement and the presence of an oblique metaphyseal fracture plane. The unstable configurations of condylar fractures can displace during conservative treatment in approximately 71% of cases (4) and leads to an angular deformity of the digit. As there is a variable component of crushing in the mechanism of the fracture, the injury may be predisposed to secondary degeneration of the articular cartilage. A malunion can lead to a step within the articulation usually in the line of movement, and if the fracture line passes across the convexity of a condyle, such a step could result in damage to the articular lining with use. In addition, Amend et al. (7) recommend noting whether the injury is closed, open, or complicated by injury to one or more tendons. A hybrid of the classification systems described is presented in Figure 1.
The distribution of the digit involved is similar in the series reported by London (6) and Weiss and Hastings (4). The little finger is most commonly (46%) involved; the middle finger is least commonly (6%) involved, with the ring, index, and thumb contributing equally (18%, 15%, and 15%, respectively). Although there is no difference in whether the ulnar or radial condyle is fractured, it is interesting to note that the condyle toward the second web space, which relates to the coronal inclination of the joint, is involved twice as frequently as that involving the condyle away from the second web space.
Clinical Presentation
The patient usually presents after an injury to the digit with swelling and pain in the region of the proximal interphalangeal joint. Movement of the joint is restricted both by pain and swelling. Bruising may be seen. At times, a hemarthrosis in the joint can occur. Any sideways angulation of the digit should suggest a condylar fracture. Palpating the finger on its dorsal surface identifies spot tenderness over one or the other condyle. Plain radiographs of the involved proximal interphalangeal joint should be obtained in the true posteroanterior and a true lateral plane (Fig. 2). The latter should be acquired because the two condyles, if not fractured, should overlap. The orientation of the base of the middle phalanx assists in determining whether the proximal phalanx is in a true lateral projection. The clinical examination and plain radiographs are usually sufficient to establish the diagnosis. The radiographs should be viewed to determine whether the fracture is split by more than 1 mm or whether it is depressed by any extent. In addition, the inclination of the middle phalanx to the axis of the proximal phalanx should be noted in the posteroanterior projection. Clinically, a note should also be made of any compound or complicated injury. The presence of the injury, its displacement, and any associated injury help decide management and prognosis.
FIGURE 1. Classification of condylar fractures. Condylar fractures can be described in terms of fracture line and displacement. Type 1 is a potentially stable injury and if undisplaced or minimally displaced is treated conservatively. The metaphyseal fracture line is transverse. Type 2 is an oblique fracture, which can be short (A) or long (B). The fracture line faces volarward. It is an unstable fracture that requires close monitoring or early fixation. Type 3 is a bicondylar fracture, which requires fixation if displaced. Type 4 represents coronal fractures, which can be either dorsal (A) or volar (B). In addition to the type of fracture, displacement requires documentation. For digital fractures, (0) represents no displacement; displacement may (1) not cause visible deformity, (2) cause visible deformity, or (3) alter the range or direction of movement. It may be associated with (a) crushing of tissue, (b) a clean open wound, (c) a dirty open wound, (d) flexor or extensor tendon injury, or (e) a nerve injury. These associated injuries may occur in combinations. Finally, whether it is the (i) sole injury or with (ii) associated injury to the same limb or with (iii) other injuries to other parts should be documented. These three main attributes together with the type of the fracture accurately define the fracture, assist in decision making, and help provide a prognosis. (From London PS. Sprains and fractures involving the interphalangeal joints. Hand 1971;3:155–158; and Weiss APC, Hastings H. Distal unicondylar fractures of the proximal phalanx. J Hand Surg [Am] 1993;18:594–599, with permission.)
Conservative Management
Conservative treatment of undisplaced or minimally shifted but not depressed fractures of the condyle has two main

aims: preventing fracture displacement and promoting recovery of movement. These aims have to be delivered against two principal patient factors of pain appreciation and compliance. The latter varies between complete recklessness and such great apprehension that adequate movement is not actually performed for fear of displacing the fracture. A prerequisite of adequate conservative management is careful and skilled monitoring with a keen appreciation of the surgical window. Avoidable delay in deciding to intervene could expose the patient to more stiffness, could make the intervention more difficult, and in the unusual event that the patient is a child, could involve taking down a healing fracture within weeks of the injury.
FIGURE 2. Radiographs of an oblique condylar fracture (type 2B). On the posteroanterior view (A), there is a sideways inclination as the fracture fragment is depressed. On the lateral view (B), the fragment is volar, and the fracture line appears to face volarward. The proximal phalanx has a clear lateral projection, but the middle and distal phalanges appear in oblique projection, suggesting rotation of the finger as the fragment has moved volarward.
Against this background, a transverse fracture of the condyle that has not shifted more than 1 mm can be managed with buddy strapping. Ideally, the fracture should be away from the adjoining surfaces of the two digits being strapped. It must be appreciated that the very act of strapping one digit to the next restricts movement for two reasons. The proximal interphalangeal joints are at different levels. This is marked for the little finger, where the distal interphalangeal joint is almost in line with the ring finger proximal interphalangeal joint. The offset between joints can impose a rotational movement of the injured digit and promote rather than restrict fracture displacement. In addition, there is the proximal to distal slip of one digit against the other that is least between the index and middle fingers but increases toward the ulnar border of the hand. The little finger slips the most. In full digital flexion, the fingertips are level but in full extension; the little fingertip is at the level of the ring-finger distal interphalangeal joint. If there is concern about patient recklessness or relative instability of the fracture—e.g., the condylar fracture is oblique but essentially undisplaced (split less than 1 mm, no depression or rotation)—the injured finger and its neighbor may be immobilized in an intrinsic plus position with the metacarpophalangeal joints flexed as much as they will comfortably and the interphalangeal joints extended as much as they will comfortably. This position can then be maintained on a volar aluminum strip or on a volar plaster of Paris slab. Two weeks’ immobilization followed by a double digital sleeve and physiotherapy assists recovery of digital flexion. If the fracture is stable on movement at first assessment and the patient is cooperating, the injured digit may be splinted with a double digital sleeve and immediately mobilized. The aim of physiotherapy is to decrease swelling and assist in the recovery of movement. For the more apprehensive patient, the Belfast regimen for early mobilization after flexor tendon injury repair provides a more rigid schedule for mobilization. This is widely known by therapy units and can be easily described to the patient in clinic.
Fractures that are oblique, in particular, require frequent and adequate monitoring, as three-fourths may slip. Digital angulation assessed visually by comparing the long axis of the middle phalanx with the long axis of the proximal phalanx and adequate radiographs in two planes perpendicular to each other assist in ensuring that the fracture has not moved. At 2 weeks, although the risk of displacement decreases, it is still possible for the potentially unstable injury to displace. The patient and the surgeon need to be aware of this possibility and the injury monitored. It is usual to recover a large part of the joint movement in approximately 3 to 6 weeks. The injured digit remains slightly swollen for several months, with activity-related aching and occasionally a sharp stabbing pain if knocked awkwardly. Some residual swelling and discomfort, which is not intrusive in domestic, occupational, and leisure activities, may persist thereafter. The patient needs to be informed and reassured about these symptoms.
If the displaced fracture can be reduced adequately with less than a 1-mm gap and no step-off or rotation, conservative treatment may be attempted, understanding that conservative treatment carries a high risk of fracture displacement. A fracture that retains its position without digital traction may be immobilized on a volar splint, as described previously. When the fracture reduction can be maintained only with digital traction, it may be immobilized by strapping the digit under traction onto the volar splint. The risk of losing position is very high, especially as the efficiency of traction using this technique diminishes with time. Conservative management of the unstable

condylar fracture requires attention to detail and a very low threshold to convert to an invasive alternative. It is probably best undertaken in hand surgery units with the skill to recognize and remedy any displacement. A malunited unicondylar fracture imposes very considerable disability and is challenging to manage surgically. This must be avoided. The major benefit of conservative management is that the patient has not taken any additional surgical risk, and the outcome, if the fracture unites without angulation of the digit, is very satisfactory.
Surgery for Displaced Condylar Fractures
A displaced fracture with a gap of more than 1 mm and any step or rotation should be reduced. Reduction of the fracture, even when the proximal interphalangeal joint is swollen, is usually achieved by traction on the extended proximal interphalangeal joint. Stability of the fracture may be improved using conservative techniques described previously or by surgical techniques. These include percutaneous transverse Kirschner wire or open reduction and internal fixation. External fixation has been described for these injuries but is not commonly used.
Percutaneous Kirschner Wire Fixation
Percutaneous Kirschner wire fixation of unicondylar fractures can be difficult when the joint is swollen. It is usually conducted under image intensification using spot films to reduce the radiation exposure. Continuous screening is only rarely required. The digit is put into a finger-traction stall, usually of a wire mesh or nylon mesh design. This can be used to maintain traction from outside the fluoroscopy area. It is important to avoid repeated attempts at siting the wire so as not to traumatize the injured joint further, risk infecting the injury, or cause damage to the tiny condylar fragment. Careful appreciation of the fracture anatomy assists in deciding on the point of entry of the Kirschner wire and its direction. The entry position can be confirmed on the image intensifier and marked on the skin. For unicondylar fractures, 0.6- or 0.9-mm Kirschner wires with a trocar tip are preferred. The entry position is just distal or just proximal to the proximal attachment of the true collateral ligament. In the swollen proximal interphalangeal joint, this can be identified on the skin as the point just behind the midlateral line on a line joining the apex of the flexed joint with proximal volar crease of the proximal interphalangeal joint. The Kirschner wire is stabbed into the skin and pushed straight down to bone to lie on its surface and the position checked on image intensifier. The wire is then engaged into the condylar fragment, with attention being paid to its direction so that it lies in the coronal plane and is perpendicular to the shaft of the proximal phalanx. Digital traction and the Kirschner wire, used as a joystick, reduce the fracture. Once a satisfactory position has been achieved, the proximal interphalangeal joint is squeezed side to side with a tissue forceps or reduction clamp, and the wire is driven into the intact opposite condyle until the tip of the wire just engages the opposite cortex. The anatomy of the fracture and the diameter of the wire used may permit a second wire to be introduced in a similar fashion. Wires are bent to lie just flush with the skin, without indenting or tethering it. The Kirschner wire is then cut. The digit is flexed and extended to ensure that there is adequate movement of the joint and to ensure that the fracture has been stabilized satisfactorily.
FIGURE 3. Radiographs of a short oblique condylar fracture (type 2A) that has been fixed with a single screw, restoring the proximal interphalangeal joint anatomy.
A limited approach using only a short part of the midlateral incision may be used as an adjunct to the percutaneous technique to fix a reduced condyle with a fine screw (Fig. 3), with care being taken to sink the screw head below the collateral attachment (8).
The correct tools must be available to conduct a satisfactory procedure. Using oversized wires and large power drills greatly increases the working distance from the digit and risks damaging the tiny condylar fragment. The wire-release mechanism should be simple and quick so that the procedure can be performed efficiently. Wrapping the other digits in a bandage or taping them to the palm with a sterile adhesive dressing assists in the manipulation and imaging of the injured finger. It is the attention to small detail that ensures a smooth, efficient, and satisfying execution of this surgical procedure.
If the fracture plane is markedly palmar-tilted, the entry position is more anterior or from the normal condyle (the side opposite to the condyle fractured) and directed more palmarward.
Thereafter, the patient is cared for as described under Conservative Management. The percutaneous Kirschner wires are removed at 3 weeks or so. Meticulous attention to pin site placement and pin site care is essential. There are

three principal risks of this technique. The collateral ligaments and the short oblique retinacular ligament may be tethered to the wire, severely restricting movement. The volar-directed wire may injure the neurovascular structures, especially if the wire is being introduced from the opposite condyle. The pin sites may become infected. The patient should be carefully instructed about these risks, taught how to look after the wire, and given instruction to return to the treating unit should any worrying signs arise.
Open Reduction and Internal Fixation of Condylar Fractures of the Proximal Phalanx
An angled or curved dorsal incision with its apex over the proximal interphalangeal joint is made. The flap is raised with the fascia over the extensor apparatus, preserving as many dorsal veins as possible. If it is a unicondylar fracture, Pratt’s approach between the central slip and the lateral band on the side of the fractured condyle is made (9). Flexing the digit allows the lateral band to move palmarward. A slender retractor under the central slip improves exposure of the proximal interphalangeal joint. A longitudinal capsulotomy is then made and the joint inspected and washed out with saline in a syringe. This syringe can also be used as a suction tool. Using a 21-gauge needle with or without the needle broken off provides a jet to clear away any clot and cartilage debris. Alternatively, the fracture may be approached through a midlateral incision, dividing the short oblique retinacular ligament and displacing the lateral band dorsally before the arthrotomy.
The superior edge of the collateral ligament is identified, and a 0.9-mm Kirschner wire is introduced into the condylar fragment. A dental pick is used to manipulate the fracture and disimpact it if required. The fracture is reduced using the dental pick or a Watson-Cheyne elevator and transfixed with the Kirschner wire. Alternately, a fine reduction clamp may be gently applied to hold the reduction. A 1- or 1.5-mm screw is then introduced as a lag screw if the size of the fragment and bone quality permit. Care should be taken to ensure that the head of the screw does not skewer or snag the collateral ligament. The single screw may need further reinforcement with either another Kirschner wire or a further screw depending on the size of the fragment and the anatomy of the fracture. Once again, a careful and thoughtful approach avoids a disaster. The length of the screw should just engage the opposite cortex but not snag the opposite collateral ligament. Once the fracture is fixed, stability should be checked on joint movement and the position and adequacy of reduction recorded on the image intensifier. The capsule is then closed with fine 5-0 dissolving sutures, as is the interval between the lateral band and the central slip. The author’s preference is to use interrupted fine nylon sutures for skin closure, as they permit early mobilization. A bulky dressing is used to splint the digit and hand for the first day or two. Thereafter, the dressing is reduced and gentle movement commenced. The sutures are removed at 1 week, and treatment thereafter is as for stable fractures and has been discussed previously.
Internal Fixation of a Bicondylar Fracture
A displaced T-shaped bicondylar fracture may be approached dorsally as described previously. The exposure of the fracture may be improved in two ways. Both sides of the proximal phalanx may be visualized by entry on either side of the central slip but by keeping its attachment intact (8). Alternately, a Chamay distally based V flap of the extensor mechanism may be raised by cutting a V through the medial edges of the lateral bands and the vertex of the V being sited at the junction of the proximal and middle thirds of the proximal phalanx (10). The V flap of the extensor mechanism is displaced distally, providing full access to the proximal interphalangeal joint and the distal part of the proximal phalanx. This allows full exposure of the fracture for reduction and fixation. The use of as little metalware as one can get away with to convert an unstable fracture into a fracture that is stable enough to allow gentle early mobilization is recommended. It is uncommon to require plate fixation other than for reconstruction when the lowest profile plate is chosen.
The first steps in surgery are to reconstruct the intercondylar fracture. Any small defects between condyles can be ignored, but the very uncommon larger defect may need primary grafting. The initial reconstruction is done with 0.6-mm Kirschner wires. Attention is then turned to the metaphyseal fracture, and a decision is made on the stability of the fracture by moving the proximal interphalangeal joint. A single 0.9-mm Kirschner wire from the larger condylar fragment directed into the shaft may be all that is required to stabilize the metaphyseal fracture. A dorsal Y-plate, a lateral mini condylar plate, or a low-profile L-plate present alternatives but at the risk of interfering with the extensor mechanism and making its repair more difficult. Once a decision has been made on the metaphyseal fixation technique, the temporary intercondylar fixation can be completed either with Kirschner wire or intercondylar screws carefully positioned to avoid altering the movement of the collateral ligaments. At the end of the procedure, all wires are cut short and punched into bone so that no wire is protruding from the bone on any side. The position is confirmed and documented on image intensifier.
The V flap or the incisions between the central slips and the lateral bands are approximated with fine sutures and the joint moved several times to ensure the sutures do not pull out. Skin is closed, and the postsurgical care is as for the surgically managed unicondylar fracture. The Norwich therapy regimen (11) may be instituted early.
Coronal Fractures of the Condyles
Coronal fractures are relatively uncommon, although Weiss and Hastings (4) reported 21% of their group of 38 condylar fractures as involving this pattern equally distributed

between the dorsal and volar patterns. These fractures, when they are displaced, pose a difficult management problem with a high incidence of displacement even when fixed. The dorsal fracture is approached dorsally. After the joint is washed and the fracture anatomically reduced, an assessment is made of depression. If the fragment can be easily depressed, a small amount of cancellous bone graft may assist in buttressing it up. The fracture can then be stabilized with 0.6-mm Kirschner wires just across the fracture site that are then cut short and punched down into the subchondral plate in the manner of Smillie pin fixation of other osteochondral fractures. Alternately, a headless compression screw of slender diameter and short length can be considered, the screw being advanced into the subchondral plate. Weiss and Hastings (4) noted that the volar coronal fracture was particularly liable to lose position after fixation, and hence, postsurgical mobilization needs to be correspondingly gentle and probably supervised by a therapist. Fixation is often tenuous, especially if the fracture plane is oblique.
Primary author Year Number London I London II London III Coronal Fixation Complications Range of motion Follow-up (yrs) Late results
London (6) 1971 30 10 15 5   Kirschner wires NA NA NA NA
Weiss (4) 1993 38   30   8 36 Fixed 4 Displaced 13–85 3 Satisfactory
14 Screws 4 Stiff
21 Wires
1 Loop
Ramos (5) 1997 5         Screws None 8–95 1 Good
O’Rouke (12) 1989 9 3 3 3   8 Cons       2 of 9 OA
1 Wire Infection Good 11 6 Good/excellent
3 Fair
NA, not applicable; OA, osteoarthritis.
Surgical Outcome for Condylar Fractures
There are very few articles describing the outcome of condylar fractures of the proximal phalanx. The overall impression is that outcomes of properly managed condylar fractures of the proximal phalanx are satisfactory. It is usual to lose some extension and flexion after surgical treatment of this injury. Stiffness appears to be more common after bicondylar fractures. Table 1 shows the outcome documented in four studies. Weiss and Hastings (4) are the only authors to document their complications in some detail and reported four of 38 (10.5%) displacements after fixation and four of 38 (10.5%) with such great stiffness after surgery as to require an arthrotenolysis of the proximal interphalangeal joint. They followed up their patients for a mean of 3 (range of 1 to 8) years and reported a mean range of 13 to 85 degrees. Ramos (5) reported on five cases at 1 year and found a range of 8 degrees to 95 degrees without any complications. The only late (11-year) review of condylar fractures is by O’Rouke et al. (12), who reported the outcome on nine condylar fractures, although three involved the condyles of the middle phalanx. They demonstrated improvement between the early and late results; three of their nine patients continued to have a fair outcome at 11 years. Only one patient had deteriorated slightly in the 11-year interval due to the onset of mild degenerative change. In their experience, osteoarthritis developed in two of nine (22%) of their patients, but this was not disabling. There is no information in the literature on malunion or nonunion.
Malunited Condylar Fracture
The principal management conundrum is the malunited unicondylar fracture, which leads to angulation of the digit and interferes with the hand function sufficiently to make the surgeon consider intervention. The intraarticular malunion alters the mechanics and loadings of the joint. If the step is marked at the articular surface and especially if it does not end in the intercondylar sulcus, the surgeon is forced to consider the technically very difficult procedure of an intraarticular corrective osteotomy. On the other hand, if the step is small and angulation minimal, the surgeon may consider an extraarticular correction to change the alignment of the digit rather than take the potentially higher risks of performing an intraarticular corrective osteotomy. Experience of such interventions is sparse and, by its very uncommon nature, anecdotal.
The osteotomy is best performed through a lateral or dorsal approach between the central slip and the lateral band. This exposes the shaft of the proximal phalanx. The osteotomy is marked on the bone with a marking pen and cut in one of two techniques. It can be cut by using an oscillating saw with the risk, due to the speed of the oscillations, of causing bone necrosis. Alternatively, multiple 0.6-mm Kirschner drill holes can be made in line with the osteotomy and the osteotomy then completed using a fine osteotome. The osteotomy can be

secured with Kirschner wires, two screws, or a small low-profile plate. The extensor mechanism is then repaired, and the skin is closed. The digit is bandaged in a bulky bandage for a day or two before commencing mobilization.
Performing an intraarticular osteotomy is much more difficult and is best performed through a Pratt’s approach in the extensor mechanism (9). This allows the entire articular surface of the proximal phalanx to be visualized. The line of the fracture can be identified. This is particularly difficult because of the slight palmar tilt of the fracture plane. The fracture can be opened up using fine osteotomes and then reduced by mobilizing it distally and secured with 0.6-mm Kirschner wires in the subchondral plate. Once the intraoperative image intensifier confirms adequate position and the digit is corrected and moves well, it can be secured with one or two flat head compression screws of adequate diameter, taking care that the head of the screw does not impede collateral ligament excursion. Postoperative mobilization is as noted previously. The main risk of intervention is stiffness. This is in addition to the other surgical risks of infection, extensor mechanism adhesion, and displacement of the osteotomy during healing to recreate the deformity. Failure of union is possible but unlikely. The patient needs to be advised of these risks, which need to be balanced against the risk of degenerative change occurring in the joint if it is left in a malunited position.
Open and Crushing Injuries
When the condylar fracture of the proximal phalanx is associated with open or crushing injuries, the balance shifts to internal fixation, as increased scarring between the injured planes compromises mobilization. The same is true when multiple digits are injured. The therapy, mobilization, monitoring, and intervention must be suited to the individual to ensure the best possible functional outcome in the shortest time and at the lowest risk of complications. Adequate stability of the fracture is essential so that attention can be directed principally to recovery of extensor and flexor tendon function. In this regard, the approach to the index and middle fingers is in the favor of stability, whereas that for the little and ring digits is to favor mobility. Salvage options for destroyed and arthritic proximal interphalangeal joints, which include arthrodesis or joint replacement, are discussed in Chapter 71, Osteoarthritis of the Hand and Digits: Distal and Proximal Interphalangeal Joints.
Fracture dislocation of the proximal interphalangeal joint is a common injury of the proximal interphalangeal joint, and stability is the principal concern in management. Two structures are involved.
The volar plate is avulsed with or without a fragment of the volar rim of the base of the middle phalanx. The size of the volar fragment provides a clue on the stability, with an anteroposterior size of the volar fragment of more than 40% of the anteroposterior width indicating that the entire distal attachment of the lateral collateral ligament lies with the volar fragment. There is therefore no constraint on the dorsal part of the middle phalanx.
The second factors that determine stability are the degree and extent of impaction of the remaining dorsal part of the articular surface. It is uncommon but possible to have in addition a disruption of one or both collateral ligaments or the central slip of the extensor tendon to produce a severe instability. The direction of dislocation, size, and location of the avulsed fragment determine both the classification (Fig. 4) of these injuries and their management.
Clinical Presentation
The patient is usually a young adult, and the majority of these injuries are acquired during sporting activity. The flexed digit is extended violently backward, with the degree of axial load and flexion determining the fracture pattern and impaction of the articular surface. The middle and ring fingers are usually involved. The patient or colleagues or attendants at the site of the injury often manipulate the digit, and the appearance of the digit can be surprisingly normal when seen by the clinician. The degree of swelling of the digit and bruising depends on the severity of the injury and the time elapsed before seeing the hand surgeon. Neither the finger nor the movement indicates a fracture, and often, apart from the general discomfort, point tenderness is difficult to elicit. Absence of point tenderness on the condyles rules out a significant injury to the condyles. When palpated from the back, there is minor tenderness, if at all, over the dorsum of the middle phalanx. Palpation between the two volar digital creases causes tenderness, and tenderness in the midlateral line in line with the distal volar proximal interphalangeal joint crease indicates the probable presence of a fracture. Active range may be only restricted by swelling or be severely reduced if the joint is in a dislocated position. If there is comminution of the dorsal part of the articular surface in particular, it would remain in a dislocated position. When the joint is dorsally dislocated, the digit can assume a dinner fork deformity, and the proximal interphalangeal joint is held in flexion. Diffuse swelling can sometimes mask the displaced position of the digit. In a volar dislocation, the digit may be in a fixed swan-neck position. The digit can also assume a similar position when there is a locked dorsal dislocation. Only active range is assessed at this time, and no attempt is made to assess stability.
The next stage in management is to obtain good-quality biplanar images on x-ray. Every effort should be made to avoid an overlap of digits. This can be achieved easily by taping other digits into the palm and putting a loop of 1-cm adhesive tape around the base of the proximal phalanx and securing the two ends to the dorsal skin. Careful positioning of the digit provides

posterior anterior and true lateral radiographs (Fig. 5). The radiographs should then be viewed to document the position of the joint. Although an overt misplacement will not be missed, a subtle subluxation of the middle phalanx can easily be overlooked (Fig. 6). In a reduced joint, the dorsal articular surface should be congruent with the dorsal surface of the condyles on a true lateral view. Any loss of congruence creates a divergence of the two articular surfaces, commonly called the dorsal V sign, and indicates that the joint is subluxed. The second clue is in the alignment of the shaft of the middle phalanx to that of the proximal phalanx. In all flexed positions of the digit, the axis of the shaft should go through the center of the head of the proximal phalanx, and in the extended digit, the axis of the middle phalanx should line up with the axis of the proximal phalanx. If the axis of the middle phalanx does not do this, the joint is subluxed. The next factors to document are the size and separation of the volar fragment. The size is expressed as a percentage of the sagittal width of the articular surface and gives an indication of the true collateral ligament that is still attached to the dorsal part of the fracture. If it is more than 40%, it is likely that all or most of the collateral ligament is attached to the volar fragment and that the injury is potentially unstable. The degree of separation of the fragments indicates the axial rent in the collateral ligament. The surgeon cannot assume that this is minor if no separation exists, as joint relocation masks the magnitude of any separation. If the dorsal part is subluxed, it is likely that the axial rent in the collateral ligament is complete.
FIGURE 4. Classification of dislocations and fracture dislocations of the interphalangeal joints. Dislocations and injuries of the joint may be dorsal (A), volar (B), or lateral (C). Each may be further categorized as follows: Type 0 represents a sprain without malalignment of the joint. Type 1 is a dislocated joint with or without an avulsion flake fracture and no depressed fragment that is stable throughout active range of movement after reduction. Type 2 injury is unstable at less than 30 degrees of extension (for dorsal fracture dislocations) after relocation; any articular fragment involves less than 40% of the anteroposterior articular width; and any depressed articular fragment of the major part is small enough not to compromise joint stability (usually less than 20% of the width). Such an injury is an unstable injury that dislocates after reduction at a more than 30-degree angle. The articular avulsion fragment is more than 40% anteroposterior width, and the collateral ligament is attached entirely to it. Up to a half of the remaining articular surface of the dorsal part may be impacted. This injury may be treated conservatively with very close and skilled monitoring, or alternative techniques described in the text may be considered. Type 3 injury carries a bone injury similar to type 2 but with greater disruption of the stabilizing collateral ligaments, leading to potentially greater instability. Type 4 is an injury for which intervention must be considered and includes a locked dislocation; the articular fragment is rotated or blocking reduction; and reduction is lost as soon as distraction is released and when most of the remaining articular surface is impacted. For a volar dislocation, a central slip detachment may require repair.
Finally, attention should be given to the alignment of the articular surface of both fragments. The articular surface should be roughly perpendicular with a very slight volar incline to the long axis of the bone. It should be congruent with the articular surface of the condyles on the lateral view, adjusting for the displaced position. Any loss of this position indicates an impaction depression of the articular surface. The greater the impaction injury, the more likely that the injury is unstable and that the injury is a combination of avulsion of the volar plate and an axial pilon-type injury to the base of the middle phalanx. Agee (13) found that nine of his 16 patients (56%) had impaction of fragments.
The final step in assessment of the injury is to determine its stability. This is an active and passive assessment and is best carried out under local anesthetic block of the finger. Long-acting anesthetic is preferred without vasoconstrictive agents such as adrenaline. It is prudent to document the circulatory and sensory status before the block. Rather than give a ring block, a single injection into the digital flexor sheath with a short bevel needle just engaged into the flexor tendon at the proximal mouth of the first annular pulley achieves a numb digit with the introduction of 2 to 3 mL of the anesthetic agent. This occurs by the spread of the anesthetic agent along the neurovascular branches and into the neurovascular sheaths. The assessment can be conducted clinically alone but is best done with an image intensifier. Digital traction and flexion of the proximal interphalangeal joint usually easily obtain reduction. With the lateral image


of the joint on the screen, the patient is first instructed to flex the digit fully, and attention is paid as to whether the gap between the volar and dorsal fragment is abolished. Persistent gapping indicates interposition of fragments of bone or cartilage, blood clot if the injury has been left in the displaced position for a while, or impaction of the articular surfaces of the volar fragment. The patient is then asked to extend the digit fully, and the flexion degree at which the digit dislocates (if it does) is noted. This assesses unstressed instability (14). The joint subluxes as the flexor digitorum superficialis is attached to the middle of the shaft of the middle phalanx, and its action causes the dorsal fragment to tilt backward. If the dislocation angle is more than 60 degrees or so, consideration should be given to alternative techniques discussed below. If the dislocation angle is less than 30 degrees and the dorsal part of the joint remains congruent with the condyles at this angle, the injury can be treated conservatively. Between these two extremes lies the gray zone in decision making.
FIGURE 5. Radiographs showing a simple dorsal dislocation (A). Reduction should result in a stable joint that can be mobilized early. B: A lateral dislocation. Reduction may result in relocation with unprovoked or provoked instability. The collateral ligament is torn and probably the volar plate as well. C: A volar dislocation. After reduction, any lag should suggest central slip avulsion.
FIGURE 6. Subtle signs of subluxation. A: The lateral radiographs of the proximal interphalangeal joint looks satisfactory at first inspection. Closer scrutiny reveals (a) loss of congruity of the joint, (b) the V sign showing divergence of the dorsal articular surfaces of the proximal phalanx and the base of the middle phalanx, and (c) the axis of the middle phalanx not passing through the center of the head of the proximal phalanx. These signs should alert the doctor that the joint is still just subluxed. B: Unsatisfactory position on extension-block splintage should have been anticipated given the configuration of the fracture and the extent of articular involvement. C: Percutaneous pinning of a fracture dislocation. Note the impaction of the articular surface of the volar fragment. The wire has been introduced antegrade and has to skewer the extensor mechanism to the condyle of the proximal phalanx. The middle phalanx is just subluxed with a slight V sign. A retrograde pin entering the bare area of the middle phalanx and advanced into the proximal phalanx would have been preferable.
Coronal instability is assessed both unstressed and provoked. Instability in extension suggests disruption of the collateral ligament and the volar plate. Instability in more than 70 degrees of flexion indicates collateral ligament disruption. Between 10 degrees and 70 degrees of flexion, any instability is difficult to attribute and must be compared with the contralateral digit (14).
Conservative Treatment
Conservative treatment must be matched with meticulous, frequent, and skillful assessment to ensure that the joint does not sublux during treatment. A depression of the articular surface or a large fragment favors intervention.
In the past, the reduced joint was transfixed with a Kirschner wire for 3 weeks, followed by removal of the wire and mobilization of the joint. McElfresh et al. (15) revolutionized conservative treatment by introducing extension-block splinting, thereby permitting early recovery of flexion. This, in its various forms, is the basis of modern conservative treatment of this injury. The main risk is subluxation of the joint dorsally during treatment. Once the angle of dislocation has been determined, the joint is held flexed approximately 5 degrees to 10 degrees further, and an extension-block device is fashioned (Fig. 7).
In the initial 2 weeks when the digit is swollen, it is preferable not to secure the device to block extension to the digit itself, as this requires circumferential taping of the digit and may promote further swelling and stiffness. A length of aluminum splint is bent at the predetermined angle and secured to the back of the hand with adhesive tape or incorporated into a short arm plaster cast. Satisfactory reduction is confirmed radiologically and the patient encouraged to flex the finger as much as swelling allows. The risk of displacement should be explained clearly and documented in the records. The patient and digit should be examined clinically and radiologically at frequent intervals no more than a week apart in the initial 2 weeks. If the patient is apprehensive, formal sessions with the therapist to encourage movement may be required. Most, however, are content to exercise themselves. If compliance is in doubt, a more robust plaster of Paris dorsal extension-block splint may be fashioned to attempt to prevent subluxation.
FIGURE 7. Versions of the extension-block splint may be incorporated in a plaster cast, strapped to the hand (A), or secured only to the injured finger (B). (From Strong ML. A new method of extension block splinting for the proximal interphalangeal joint: a preliminary report. J Hand Surg [Am] 1980;5:606–607, with permission.)
Percutaneous Wire
Consideration may need to be given to introducing an extension-blocking percutaneous Kirschner wire into the intercondylar sulcus of the proximal phalanx (16) in spite of the additional risk of joint infection. Such a wire should be introduced into a longitudinal split in the central slip to allow mobilization of the digit. Using a no. 11 pointed knife to create the stab wound to the joint and with the blade facing proximally, the digit is flexed to create the split. The Kirschner wire can then be introduced at the appropriate angle and bent and cut short. The wire tip should just engage the volar cortex of the proximal phalanx but not tether the flexor tendons. This wire should be removed at 2

weeks and extension-blocking splintage applied. The degree of extension blocking is then reduced serially at weekly or fortnightly intervals to recover full extension usually in 6 to 8 weeks. The digit can then be protected in a buddy sleeve (Bedford splint) to allow the individual to return to full activity. This type of splintage, if used, need be continued only for a further 6 weeks to permit fracture callus maturation. At each visit, the reduced position should be confirmed on x-rays. It is usual at 2 weeks to convert the splint into a digital one, as described by Strong (17) and shown in Figure 7B. The large proportion of these injuries can be managed in this way.
Treatment Primary author Year Number Treatment Range of motion (degrees) Complications Pain Follow-up (yr) Other
Extension block McElfresh (15) 1972 17 Splint 2–90 1 Redislocation Not recorded 0.45  
Hamer (18) 1992 27 Splint 20–110 3 (11%) Subluxations Not recorded 1.70 3 (11%) Associated injury
4 (15%) Ulnar deviation     77% Excellent
5 (19%) Poor
Force couple Agee (13) 1987 11 Wires and rubber band 10–105 1 Subluxation 1 1.40 5 (45%) Associated injury
No pin track infection     9 of 16 (56%) Depressed fracture
External fixator Bostock (34) 1993 8 “S” Quattro 85-degree range Not recorded 2 1.20  
Bain (35) 1998 6 ORIF and Compass hinge 14–84 2 pin track infection Not recorded 0.60  
ORIF Takami (36) 1997 3 ORIF 0–95 None None 2.20  
Deitch (24) 1999 7 ORIF 20–80 23% Complication rate of 56 patients 1 Arthrodesis 3.8 10 Cases required 13 additional operations
3 Dislocations
2 Deep infections
VPA Eaton (21) 1980 7 (acute) VPA 95-degree range 1 Dislocation 3.0
1 extensor adhesion      
ORIF, open reduction and internal fixation; VPA, volar plate arthroplasty.
Outcome of Conservative Treatment
Hamer and Quinton (18) reported on 27 consecutive patients with dorsal fracture dislocation of the proximal interphalangeal joint treated conservatively, of which three (11%) displaced during treatment. Patients regained 87 degrees (20 to 110) of joint range, and five (19%) had poor results, with osteoarthritis developing between 12 and 42 months after injury. These patients had comminution of the articular surface (Table 2). O’Rouke et al. (12) reported on proximal interphalangeal joint injury outcomes after conservative treatment. Nine of 11 had good or excellent early results, and all 11 had good or excellent results at 11 years after injury. All six patients with large fragments had fair or poor results early. These had improved to four fair and two good at 11 years. None had deteriorated. Even the patients with comminuted fractures (4) improved over 11 years.
When the stability angle is more than 60 degrees, due consideration should be given to intervention. Agee (13) and Suzuki et al. (19) described elegant techniques of setting percutaneous wire–based devices with or without traction that can be used for the unstable dislocation. Neither on its own addresses the impacted and depressed plateau fracture, and this may need to be additionally treated.
Wire-Based Devices
Agee Force Couple
Agee (13) described an elegant percutaneous wiring technique that reduces the dislocated fragment and allows mobilization (Fig. 8A). Pin 1 is introduced in the coronal plane across the condyles of the proximal phalanx just distal to the attachment of the collateral ligament. Pin 2 is introduced at the base of the middle phalanx just dorsal to the fracture line. Pin 2 is then bent at right angles to lie in the coronal plane, and then the part of the wire that lies proximal and volar to pin 1 is bent backward in the sagittal plane after reduction of the fracture. The dorsal end of the wire is trimmed back so that the pin protrudes approximately 2 cm

from the skin, and the tip is fashioned into a hook facing proximally. Pin 1 is bent around the limbs of the pin 2 wire and cut short. Pin 3 is introduced in the sagittal plane dorsally in the bare area of the middle phalanx and trimmed to protrude approximately 2 cm from the skin, a hook being formed facing distally. The wire should engage both cortices of the middle phalanx for secure fixation. The two hooks of pin 2 are then engaged to pin 3 using a rubber band. The digit is mobilized under image intensification, and the reduced position and congruence of the joint throughout movement are confirmed. This external fixation device can be maintained for 6 weeks, and meticulous care of the pin sites should be taught, carried out, and monitored. At 4 to 6 weeks, the wires are removed, and at that stage, the digit may need to be splinted in an extension-block splint to allow controlled recovery of extension. Of nine acute cases (13) with such a dislocation treated by the force couple system, three patients (33%) developed early osteoarthritis, and one had an infection. The mean range of movement was 95 degrees (25 to 116).
FIGURE 8. A: The Agee force couple showing pin 1, a trans-condylar pin, and pin 2, a reduction pin through the base of the middle phalanx bent proximally under pin 1 and then bent dorsally; hooks are fashioned at the tips of the pin on both sides of the finger. A sagittal pin is introduced into the shaft of the middle phalanx. The second and third pins are connected with a rubber band (see text for details). B: The Suzuki et al. traction device is set up using three pins. The long axial pin is introduced across the condyles of the proximal phalanx and bent distally so that each limb lies next to the digit and is longer than the finger by approximately a centimeter and distally facing hooks are fashioned. A short axial pin is introduced across the condyles of the middle phalanx and proximally facing hooks fashioned; this is the distraction pin that is pulled from the long axial pin with two rubber bands. A reduction wire placed through the base of the middle phalanx and lying volar to the first pin prevents dorsal displacement. The first wire may be bent to prevent tilting of the device dorsally. C: The push traction device provides static traction to the proximal interphalangeal joint yet allows free range of motion.
Suzuki Traction Device
Suzuki and others in 1994 described another elegant technique to give traction to the middle phalanx using percutaneous wires (Fig. 8B) (19). The first wire is introduced in a similar fashion to the Agee technique across the condyles of the proximal phalanx and bent in the coronal plane distally. The distal ends must be at least 3 cm distal to the fingertip. At that point, it is bent to form a hook facing distally. The second pin is put into the condyles of the middle phalanx, again in the coronal plane. It is bent distally in the coronal plane, and immediately at the bend, hooks are fashioned to face proximally. Rubber bands are used to distract the middle phalanx on the first pin, which is called by the authors the axial traction pin. The system has been further modified to reduce the dislocated base of the middle phalanx by putting in a third transverse pin at the base of the middle phalanx dorsal to the fracture to lie volar to the axial traction pin and bending the ends backward. The third pin is called the reduction pin. Suzuki and his coauthors also made the point that the long axial pin may displace dorsally, and to correct this, it may sometimes need to be bent volarward. The pins are removed at 4 to 6 weeks.
Suzuki and his coauthors reported a reasonable recovery range between 5 months and 20 months after injury and initial treatment. The poorest result had a 0- to 40-degree flexion range at the proximal interphalangeal joint; the best result had a full range of movement. Most patients, however, lost the last few degrees of flexion and extension. Only one of their seven reported cases had occasional pain. They admitted that with this technique, the range of movement is not full with the traction device in place but suggested that even some movement is better than none.
Stockport Serpentine Spring System
Fahmy (1993) from the United Kingdom described a serpentine spring system called “S” Quattro. This is a flexible mini external fixator (Fig. 9). It consists of modified Kirschner wires with notches on them and two serpentine springs. The unthreaded notched Kirschner wires are introduced percutaneously into the normal phalangeal bone into both sides of the injured joint. In the middle phalanx, they are put into the bare area distal to the central slip attachment, and both cortices are engaged in the sagittal plane. Proximally, they are put into the neck or shaft of the proximal phalanx, and once again both cortices are engaged. Before introducing the proximal pin, a cut is made in the central slip, as described for the pin stabilization dorsal block previously. Two springs are involved, one being stiffer than the other. The stiff pin is compressed and then slotted into the notches; this causes both the pins to diverge. The second spring is then applied more distally and is put in tension by stretching it before engaging it on the pins. Both springs are secured with adhesive.

The wires are cut short. The appropriate amount of tension is the one that allows the pins to be just divergent if traction is desired. Early controlled mobilization is started. The device is then left in place for between 2 and 6 weeks. Fahmy (20) reported 81% movement in the fractured joints that he treated at 6 months and stated that the majority of the patients were pain-free; all but one out of 20 cases were satisfied with the results.
FIGURE 9. The “S” Quattro for a pilon fracture. A: Radiograph demonstrating the pilon fracture with displacement of fragments. B: The “S” Quattro applied in traction mode showing that the fracture’s position is improved. C: Final appearance at 1 year. (Reproduced from Mr. N. Fahmy, Stockport, United Kingdom, with permission.)
All these techniques require intensive physiotherapy after the device is removed. The main risk is one of pin track infection, which can potentially cause joint infection. Additionally, the pins can work loose.
Open Surgical Techniques
The fracture dislocation can be reduced either by the dorsal or the volar approach. The dorsal approach is as for the fixation of condylar fractures of the proximal phalanx and has been described previously. The Chamay flap is not used. The middle phalanx can be subluxed out of the wound to improve access to the fracture and elevate any impacted joint surface that may need cancellous bone grafting. The debris within the joint is washed out, and two tension band sutures approximate and hold the corners of the volar articular fragment. It is sometimes necessary to use a 0.6-mm Kirschner wire to stabilize each corner in addition to the tension band stitch to prevent the tilt of the fragment. These wires are cut short and impacted with the Kirschner wire impactor so that they lie flush within bone. Alternately, a fine, flat-headed screw may be used to replace the Kirschner wire (8). The advantage of this technique is that no pulleys need sacrifice, although transverse incisions need to be made into the flexor sheath to retrieve the needle on the volar lateral surface. Attention needs to be paid to avoid suturing the flexor digitorum superficialis slip to the repair. Fine drill holes are made in each corner of the metaphysis, and needle and stitch delivered through this to secure the tension band. Firm bite is taken into the volar plate and anterior edge of the collateral ligament at its attachment to the volar lateral tubercle at the base of the middle phalanx. The stitches are held tightened, and the joint is moved to check that the volar fragment does not tilt. If it does and the fragment is large enough, a 0.6-mm Kirschner wire is introduced into the fragment. The fracture is reduced and the Kirschner wire advanced for a short distance. It is cut short and then punched back into bone. If it has been advanced too far, one would need to withdraw it by a millimeter or so to allow impaction. This is to be avoided, as the interference fit of the smooth Kirschner wire is compromised. Alternatively, the wire may be replaced with a fine screw. The stability of the joint is then confirmed under fluoroscopy and the joint treated with extension-block splinting as described previously.
The volar approach to the fragment has been well described by Eaton and Malerich (21). It is a more destructive approach and should be reserved for severely comminuted volar margin fractures with marked instability of the

joint or when volar plate arthroplasty is being considered appropriate as a delayed procedure.
Under anesthesia and tourniquet control, the volar aspect of the proximal interphalangeal joint is approached through a Bruner zigzag incision. The neurovascular bundles are identified on both sides of the joint. The third annular pulley and the first and second cruciate pulleys are then resected to expose the flexor tendons. The flexor tendons are retracted to one side, and extension of the proximal interphalangeal joint exposes the proximal edge of the volar plate. The volar plate is retracted proximally, and the joint is washed out. If the collateral ligaments are attached to the volar fragment, it may now be possible, although difficult, to deliver the dorsal part of the joint for inspection. If impaction fragments need elevating and this cannot be done without true ligament sacrifice, Eaton has recommended sacrifice of one or both ligaments to permit full dislocation of the base of the middle phalanx to face distally by bending the digit back (21). Any large depression can then be elevated and grafted with cancellous bone. The volar plate is secured with a pullout wire suture, and a 0.9-mm Kirschner wire is used to create holes in the middle phalanx going from the fracture site to present dorsally in the bare area of the middle phalanx between the lateral bands and distal to the insertion of the central slip. Eaton described a pullout suture secured over a button, but a 1-cm longitudinal middorsal incision over the middle of the middle phalanx permits the sutures or wire (22) to be knotted deep to the extensor apparatus. Alternatively, small anchors may be used. If the volar fragment is extensively crushed, Eaton and Malerich have recommended a primary volar plate advancement by excision of all the crushed volar lip, freshening of the dorsal articular surface, and advancement of the volar plate to come flush with this. They have recommended that the joint should not be bent by more than 30 degrees or so to achieve this approximation.
The joint is then additionally immobilized with the transarticular Kirschner wire for 3 weeks, followed by physiotherapy to regain flexion and then gradually to stretch the joint to recover extension.
In 1980, Eaton and Malerich (21) reported a 10 years’ experience of volar plate arthroplasty of the distal interphalangeal joint in 24 patients. It was used acutely in seven patients and as a late reconstructive procedure in 17 patients at an average of 7 months after injury. They recommended lengthening the check-rein ligaments if the volar plate cannot be advanced appropriately. They found that in the seven acute cases, the proximal interphalangeal joint range was 95 degrees on average at a follow-up of 3 years. Of their seven patients, there were two complications. One joint subluxed after surgery and required reoperation; the second had distal extensor mechanism adhesion.
Seno et al. (23) reported 12 of 43 (28%) cases with fair or poor results after surgery at 94 months after treatment; Deitch et al. (24) reported an 18% serious complication rate after surgery (Table 2).
Persistent Subluxation of the Proximal Interphalangeal Joint
The principal adverse outcome of a fracture with dislocation injury is the persistent dorsal subluxation of the middle phalanx. The paradox is that, although an impacted depressed joint makes the whole joint more unstable, as the articular surface is splayed, it heals in a relatively congruent fashion and permits a useful and usually a pain-free range of digital movement with permanent restriction at the end of both flexion and extension. Such an injury runs the risk of degenerative change in the damaged articular lining; however, this is uncommon, and it is rare to come across such a case late requiring reconstruction. If the articular surface of the dorsal part of the middle phalanx is not impacted and it is subluxed, any flexion leads to point loading, with the middle phalanx pivoting on the anterior edge of the dorsal articular surface. This expectedly results in further damaging the condylar cartilage and predisposes to early onset of traumatic arthritis in the joint.
The patient presents with pain on flexion of the joint, and the dorsal rim of the middle phalanx becomes easier to palpate. The range of motion is considerably restricted, especially in flexion, and may be accompanied by crepitus if degenerative change has set in. The assessment of the hand is similar to that for the acute injury, although often, the joint cannot be relocated or immediately bounces back out.
In such a case, a volar plate arthroplasty is probably the best option, although in this event, both the true collateral ligaments always have to be excised to get full access to the middle phalanx and obtain full correction. Eaton and Malerich (21) reported that in their 17 delayed cases, there were one case of slight lateral instability and three cases of angular deformity of approximately 15 degrees to 30 degrees. The distal interphalangeal joint lost approximately 10 degrees of range. Three patients complained of some discomfort too, when the joint was stressed. The remainder had no discomfort. In the delayed cases, patients recovered 78 degrees of motion at 3 years.
The next uncommon outcome specific to this injury is hyperextension of the proximal interphalangeal joint with subsequent flexion of the distal interphalangeal joint to assume the swan-neck position. Patients can usually flex the digit normally. The digit rarely locks in extension, as it tends to do in patients with severe joint laxity. The treatment is directed to keeping the digit in slight flexion using a tenodesis or a volar plate reattachment, as described previously.
Other Dislocations
The most common injury to the proximal interphalangeal joint is a dorsal dislocation with or without a fracture. If the dislocation can be reduced and is stable, it is treated conservatively, with a good outcome expected. It is uncommon to have a volar dislocation, but this is a serious injury, as the

joint can only dislocate volarward with disruption of the collateral ligaments and very frequently an avulsion of the central slip from the base of the middle phalanx. The patient usually presents with a traumatic swan-neck injury, with the finger extended and the patient being unable to flex the finger. If the joint is dislocated, this should be relocated, but it is mandatory to check that active extension at the proximal interphalangeal joint is present. If there is an extensor lag, the dorsal part of the joint should be explored and the central slip reattached to the base of the middle phalanx. This can be done with small anchor sutures. The joint is thereafter immobilized in extension but allowing the distal interphalangeal joint to flex. The splint is used to immobilize the proximal interphalangeal joint. Flexion of the distal interphalangeal joint allows some translation of the extensor mechanism and guards against extensor mechanism adhesion. This splintage is continued for 4 to 6 weeks. Thereafter, the patient is treated in a Capner splint for a further 4 weeks followed by physiotherapy to recover flexion.
The third type of a dislocation is a lateral dislocation. A joint that is unstable laterally indicates rupture of the collateral ligament on the convex side and the volar plate. A dislocated joint that cannot be reduced or one that moves abnormally after reduction may need exploration, reduction, and stabilization through a midlateral approach. A block to relocation such as an interposed collateral ligament is very rare. A relative indication for surgery is such an injury to the radial collateral ligament of the index interphalangeal joints. Chronic instability is rare (25).
Pilon fractures of the base of the middle phalanx are uncommon. These accounted for only three of 110 (2.7%) intraarticular fractures of the base of the middle phalanx (26), and a further five (4.5%) had a volar lateral split depressed injury of the base of the middle phalanx. Direct axial loading of the digit due to an impact at the tip of the finger can cause impaction of the base of the middle phalanx on the condyles of the proximal phalanx. The rim avulsion and split depressed fracture configurations have been discussed previously as different grades of a dorsal or volar dislocation injury of the proximal interphalangeal joint. In this section, the management of the severe pilon fracture of the base of the middle phalanx with depression of the articular fragments is discussed.
Clinical Presentation
The presentation is similar to that for condylar fractures of the proximal interphalangeal joint, only differing in the absence of tenderness over the distal part of the proximal phalanx and the presence of tenderness all around the joint and dorsally over the base of the middle phalanx. Like most interphalangeal joint fractures, it occurs mostly in men (4:1) and usually after a sports injury. The little (60%) and ring (25%) fingers account for five out of six such injuries (27).
Posterior, anterior, and lateral radiographs are obtained, and four factors are assessed:
  • The fracture lines into the joint and whether and by how much these are split and/or depressed are noted.
  • The fracture line around the metaphysis and an assessment of the circumference of the metaphysis involved in the fracture and the magnitude of displacement of the main fragments are noted.
  • The state of the proximal interphalangeal joint is documented as being normally aligned, subluxed, or dislocated.
  • Any additional injuries, particularly at the distal interphalangeal joint of a similar nature, are also assessed.
The alternatives for management are conservative treatment, external fixators, or surgical reconstruction of the cone of the middle phalanx (Table 3).
Conservative Treatment
When there is splaying of the cone of the proximal part of the middle phalanx, the digit requires traction to attempt to reduce the fracture and to prevent further displacement, although the latter is unlikely. Traction can be applied in various ways. The simplest and least intrusive is to apply a volar plaster of Paris or aluminum splint with the metacarpal joints flexed comfortably, usually approximately 70 degrees to 80 degrees, and the interphalangeal joints extended comfortably, usually 15 degrees to 20 degrees. The injured digit has a longitudinal loop of tape applied to its volar and dorsal surface, and the digit is pulled. The digit and the tape are then secured to the tip of the plaster or splint, and the digit is strapped transversely to the splint as shown in Figure 10. The digit is immobilized for 2 to 4 weeks but monitored at more frequent intervals to adjust the traction, which tends to lose its tension. At 3 to 4 weeks, the digit is assessed under image intensifier, and if there is no displacement between fragments without traction—and this is the usual finding—the digit is mobilized formally, sometimes with physiotherapy monitoring. It is splinted in between exercises and at night. Free active mobilization is commenced at 6 weeks or so. It is usual in such an injury to lose moderate movement in both flexion and extension because of the nature of the injury and the immobilization during treatment. Stern et al. (27) achieved a 20- to 85-degree range with splintage in four cases with a pilon fracture, but two cases had persistent pain requiring arthrodesis.
External Fixation for Pilon Fractures
The alternative technique is to use a transverse pin in the condyles of the middle phalanx to set up skeletal traction

on a plaster or plastic splint. Bohler described traction for digital fractures in 1939, which was used by Bunnel, reporting on this in 1945, and Moberg, reporting on it in 1949 (38). No complications were documented.
Treatment Primary author Year Number Treatment Range of motion Complications Pain Follow-up (yr) Late results
Splint Stern (27) 1991 4 Splint 20–90 None reported 4 1.75 2 Arthrodeses
Traction     7 Static traction 10–90 None reported 3 2.00  
Schenck (29) 1986 10 Traction and passive movement 5–92 None reported None reported 1.30  
Morgan (37) 1995 5 Traction and movement 5–90 43% Pin track infection 1 2.75  
36% Pin loosening      
Low-profile push traction Gaul (30) 1998 2 Push traction 5–95 None reported None 2.50  
Hynes (31) 2001 9 Push traction 12–88 2 Pin track infection’healed 3 1.00  
ORIF Stern (27) 1991 9 ORIF 10–80 1 Pyoarthrosis None reported 2.50  
1 Arthrodesis
1 Ligament injury
ORIF, open reduction and internal fixation.
Traction Devices
One version of such a setup is the banjo splint also described by Toussaint and Rickaert in Europe (28) and modified by Schenck (29) to allow passive movement. A single percutaneous pin is introduced in the coronal plane through the condyles of the middle phalanx, and a loop is fashioned with its vertex distal to the pulp of the injured finger. Elastic band traction is applied onto a ring, which is incorporated in a short arm splint or plaster cast. The traction is put on a hook on the ring. This allows early mobilization of the digit by manually moving the hook along the ring. Stern et al. (27) used static skeletal traction in six patients and reported a 10- to 90-degree proximal interphalangeal joint range; at review, 50% of these cases had some pain, but none required further treatment. Schenck in 1986 presented 10 cases of pilon fractures with 20% to 100% involvement of the articular surface. The duration of traction was from 6 to 8 weeks. An extensive program of hand therapy was required to recover 87 degrees of motion on average at the proximal interphalangeal joint from 5 degrees to 92 degrees of flexion. This splint is demanding to set up and requires a skilled therapist but when done correctly provides both traction and movement to assist in the recovery of movement.
FIGURE 10. Traction of the digit on a Zimmer splint. The splint is fastened to the palm of the hand with adhesive strapping. A traction tape is put on to the injured digit and traction given. The distracted finger is secured to the Zimmer splint with adhesive tape.
An alternative low-profile fixed traction system may be constructed by introducing a coronal wire across the proximal phalanx condyles and bending both ends distally. A second wire is introduced in the same plane across the distal part of the middle phalanx. The ends of the first wire are fashioned into hooks facing distally approximately half a centimeter distal to the second wire. The digit is distracted to hook the distal wire into the hooks of the proximal wire, thereby distracting the base of the middle phalanx. All excess wires are trimmed and secured. Early mobilization is commenced. Recovery of movement is good (30,31), but the pin tracks can become infected.
Both the Agee force couple and the Suzuki device provide traction with a rubber band and can be used to distract

and reduce a pilon fracture as can external fixator devices such as the “S” Quattro, the Joshi fixator, or the Compass hinge fixator.
FIGURE 11. A,B: External fixator for pilon fracture.
“S” Quattro Fixator
The “S” Quattro (Fig. 9) is easy to apply and is, like the Agee force couple, very simple to apply. It is applied in the sagittal plane rather than the coronal plane and is therefore less intrusive to the movement of the neighboring digit. It can also be applied in the coronal plane for the border digits. The Joshi fixator (Fig. 11) is simple to construct and versatile in its application and is particularly useful for the management of complex tissue injuries and in salvage situations such as infected injuries or severe joint contracture management.
Compass Hinge Fixator
The Compass hinge fixator (Fig. 12) has a benefit of allowing early movement and has been shown to be an efficient technique in the management of complex comminuted fractures of the phalanges. However, there is a very high complication rate. All the traction techniques, whether they are conservative or using some form of external fixation, depend on the concept that the ligament, tendon, and capsular attachments to the disrupted part of the middle phalanx become tense on distraction and allow the fragments to move into a better and more acceptable alignment. They do not reduce a depressed articular fragment and do not account for any fragment jammed between major fragments, thus preventing their reduction. A large disrupted fracture fragment may be manipulated percutaneously from the dorsum by introducing a stout 1.1-mm Kirschner wire, then using the blunt end of the same device or a smaller diameter wire to push down the depressed fragment. A small Kirschner wire 0.6-mm in diameter can then be introduced transversely to maintain the depressed fragment down. The traction techniques described previously can therefore be supplemented with minimal open or percutaneous intervention to correct and reduce at least the major fragments.
FIGURE 12. A,B: Compass hinge fixator.
Open Reduction and Internal Fixation of Pilon Fractures
The next alternative is to consider open reduction and internal fixation of the pilon fracture. This is very difficult and is surgically challenging. It is usually performed through a dorsal approach, as described by Pratt (9). Once the joint capsule is opened, the joint is washed out, and distraction may allow inspection of the fracture fragments. Additionally, the use of 1.1-mm arthroscope can assist in the assessment of the fracture

fragments. A dental pick or a 1.1-mm Kirschner wire or a rounded edge of a Watson-Cheyne dissector may be used to assist in the assessment and reduction both on the articular surface and through one of the linear fractures or the metaphysis split. Once a satisfactory reduction has been achieved, the main fragments can be transfixed with transverse 0.6-mm Kirschner wires, and a cerclage stitch using a fine wire or other suitable material can be used, secured just distal to the flare of the base of the middle phalanx lying under the central slip and through the distal parts of the collateral ligaments and volar plate. Such a cerclage stitch squeezes together the cone and maintains reduction. The joint is washed out, and the split between the lateral band and the central slip is approximated with fine sutures. The digit is then splinted; depending on the security of fixation, some traction may need to be applied. Once the wounds have healed and sutures removed, the joints are gently mobilized to recover movement.
FIGURE 13. A–C: Internal fixation of a pilon fracture.
The alternative approach to the pilon fracture at the base of the middle phalanx is provided by sacrifice of both collateral ligaments and dislocation of the proximal interphalangeal joint dorsally to present the surface of the articulation for precise reduction and cerclage fixation (Fig. 13). The true collateral ligament is not repaired. Weiss described his experience with 38 joints, but the outcomes are by no means good (39). Stern et al. (27) reported on the outcome of surgery, and at 25 months found the range of movement similar to patients treated with traction, although those operated on had a significantly higher complication rate. O’Rouke et al. (12), on the other hand, have shown very satisfactory outcomes for similar injuries both at the distal interphalangeal joint and proximal interphalangeal joint in the long term. Review of the literature does not permit the advocacy of aggressive internal fixation of such fractures unless it is done in dedicated hand units. The complication rates and risks of stiffness are considerable, and the potential to improve the outcome beyond one described using conservative techniques is very small indeed. Decision making in such injuries is difficult, and the surgery, if one is to avoid damaging additional structures, is challenging. The clinician should be encouraged to refer these cases to specialist units rather than “having a go” with various homemade and unproven modifications of treatment.
Injuries of the distal interphalangeal joint match those of the proximal interphalangeal joint, and the treatment too parallels the treatment of the proximal interphalangeal joint. Avulsion of the extensor tendon insertion to the base of the distal interphalangeal joint is a particularly common injury and can be associated with a fracture. If the fracture is large, the joint may sublux volarly and require stabilization with a percutaneous pin for 3 weeks, followed by external splintage using stack splint for a further 3 weeks or so.
When more than one digit or more than one phalanx in the same digit is fractured with the fractures displaced, decision making swings in favor of stabilizing the injury surgically to permit early mobilization. The injuring force is of a much greater magnitude and has associated crushing or injury to neighboring structures, promoting stiffness. The same is true for open injuries. The outcomes in such situations are inferior to outcomes of fractures in a single digit and a single

phalanx. Nakago et al. (32) described three patterns of simultaneous injury to the interphalangeal joints of the digit. Sixty-nine percent of their 16 cases had a swan-neck injury avulsing the dorsal rim of the distal phalanx and the volar rim of the middle phalanx. Twenty-nine percent had a hyperextension injury with dorsal dislocation of both joints. Only one case had a pilon injury. Seventy-five percent of their cases involved the ring and middle fingers. Stiffness was particularly common at the distal joint.
The final special case is when there are fractures on both side of the joint. This is indeed a major injury. If the fractures are not displaced, it is possible to splint them and to try and recover movement at approximately 2 to 3 weeks. If the fragments are large, one could consider doing surgical stabilization. This needs to be meticulously carried out to reconstruct the joint to a sufficient degree to permit early joint movement to recover useful movement. Every attempt should be made in the proximal interphalangeal joint of the little and ring fingers to recover range. Early joint replacement may be indicated, although the range recovered is poor (33). In the distal interphalangeal joint, if it is fractured to an extent to which surgical reconstruction is not considered possible, primary joint fusion may be considered to shorten the disability period.
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