Practical Orthopaedic Sports Medicine & Arthroscopy
1st Edition

The snapping occurs as the iliotibial band flips back and forth across the greater trochanter (Fig 30-1). This is often attributed to a thickening of the posterior part of the iliotibial tract or anterior border of the gluteus maximus (1,2). Coxa vara and reduced bi-iliac width have been proposed as predisposing anatomic factors (3,4). Tightness of the iliotibial band may also be an exacerbating feature. This condition has classically been described in the downside leg of runners training on a sloped surface, such as a roadside (5). Some patients can demonstrate this phenomenon as an incidental asymptomatic maneuver. Symptomatic cases are most commonly associated with repetitive activities, but the snapping may occur following trauma. It has also been reported as a postsurgical iatrogenic process (6,7).

The snapping or subluxation sensation described by the patient is a dynamic process that they can usually demonstrate better than it can be produced by passive examination. The symptoms and findings are located laterally and the patient can usually produce this best while standing. The snap can be palpated over the greater trochanter and applying pressure to this point may block the snap from occurring. The Ober test evaluates for associated tightness of the iliotibial band.

The diagnosis is usually clinically evident. Radiographs and further investigative studies are rarely of benefit except to assess for other associated disorders. Ultrasonography may help to substantiate the diagnosis, but is rarely necessary. Magnetic resonance imaging (MRI) may demonstrate evidence of trochanteric bursitis or inflammation within the abductor mechanism.

Once the diagnosis is established, most will respond to conservative measures. These include modification of activities to avoid offending factors, oral anti-inflammatory medication, therapeutic modalities, and a gentle stretching and conditioning program directed specifically at the iliotibial band. Corticosteroid injection in the trochanteric bursa does not resolve the snapping, but may alleviate the symptoms so other measures can be effective.

The published results of surgical intervention for recalcitrant snapping of the iliotibial band range from poor to excellent. Various techniques have been described, but it is generally accepted that the common goal, regardless of the method, is to eliminate the snapping by some type of relaxing procedure of the iliotibial band. The success of the operation may be less dependent on the exact technique as much as careful patient selection. In fact, the published results of the same operation among two different military populations ranged from “less than optimal” to “excellent and predictable” (8,9).

It is important to remember that snapping of the iliotibial band is usually a dynamic process, better demonstrated by the patient than observed by passive examination, and there may be a deliberate or voluntary component to this snapping phenomenon. Thus, the surgeon must carefully evaluate that patient’s motivation and emotional stability. The patient is causing no harm by living with the condition but, if they have exhausted all efforts at conservative treatment, then surgical intervention is an appropriate final step for select recalcitrant cases. The patient must be aware that, while the results of surgery may be successful at eliminating the snapping, there is a risk that they may still experience similar or different pain or dysfunction. For correctly diagnosed cases that do not respond to surgical intervention, it is unlikely that there is a reliable subsequent salvage procedure.

Most recent published literature has been based on the Z-plasty technique popularized by Brignall and Stainsby in 1991 (10) (Fig 30-2). They reported eight hips in six patients, mean age 19 years, all with resolution of the snapping and excellent pain relief. Three hips in two patients experienced occasional aching, and one patient underwent a second, more extensive Z-plasty in order to achieve a successful outcome. Faraj et al. (11) in 2001, reported on 11 hips in 10 patients, mean age 17.3 years. All experienced resolution of pain and snapping, although three patients developed painful scars requiring desensitization treatment for 2 to 6 months. In 2002, Kim et al. (8) reported on three active duty soldiers with a successful result in only one case. Conversely, a report by Proventure et al. (9) in 2004 included eight hips in seven active duty military personnel with six of the seven returning to full military duties. One underwent subsequent surgical intervention and was eventually medically discharged from the service. Of note, this study excluded an unknown number of patients who had other concomitant diagnoses, prior fracture, childhood hip pathology, or had undergone previous surgical procedures.

In 1986, Zoltan et al. (12) described seven athletic individuals treated with excision of an ellipsoid-shaped segment of the iliotibial band over the greater trochanter (Fig 30-3). All experienced resolution of the snapping, were able to return to sports activities, and considered themselves significantly
improved, although only three were asymptomatic. One patient underwent a subsequent revision procedure with further excision of the iliotibial band in order to achieve a successful outcome.

The largest single series was published by Larsen and Johansen (4) in 1986 with 31 hips in 24 patients who underwent resection of the posterior half of the iliotibial tract at its insertion with the gluteus maximus. The details of this study were brief, but they reported that 22 (71%) were pain-free, six (19%) had persistent snapping without pain, three (10%) had persistent snapping with pain, and there were no major complications. Two of the three with pain underwent revision surgery with good results.

In 1979, Brooker (13) described a cruciate incision of the iliotibial band over the greater trochanter as a successful method of management for severe trochanteric bursitis. William Allen from Missouri (personal communication, 1995) has proposed a modification of the cruciate incision in the management of the snapping iliotibial band. This is a method that these authors have employed which includes an 8 to 10 cm longitudinal incision just posterior to the midpoint of the greater trochanter in the thickest portion of the iliotibial band along with two pairs of 1 to 1.5cm transverse incisions (6) (Fig 30-4). Limited experience in five cases has resulted in complete resolution of the snapping, excellent patient satisfaction, and no complications. The advantage of this technique is that it is simple, it accomplishes the desired effect, it minimizes violation of the iliotibial band, and there are no repair lines that must be counted upon to heal. This also facilitates a liberal, although structured, postoperative rehabilitation program. Crutches are used only for comfort as the gait pattern is normalized, typically in 10 to 14 days. Gentle stretching and flexibility is emphasized, although aggressive stretching is not necessary.

Recent experience has begun to emerge on the role of trochanteric bursoscopy (14,15). A natural progression of this may be toward endoscopic release of the iliotibial band. The concern is either inadequate or excessive resection. Currently, the open method still seems to be better suited for quantitating the extent of tendinous release.

Certain activities, such as ballet, have a predilection for developing this process as an insidious overuse phenomenon (3). Snapping may occur as a consequence of injury, but the structural change that precipitates the snapping is elusive. It is well accepted that the snapping phenomenon occurs as the iliopsoas tendon subluxes from lateral to medial while the hip is brought from a flexed, abducted, externally rotated position into extension with internal rotation (Fig 30-5). It is less clear which structure is responsible for impeding the translation of the iliopsoas, thus creating the snapping phenomenon (18,19). This issue has some importance as authors have proposed various surgical techniques based on which structure seems to be most responsible for the snapping (20,21). The most popular theories are that the tendon snaps back and forth across the anterior aspect of the femoral head and capsule, or that it lodges across the pectineal eminence at the anterior brim of the pelvis (20,22). A less commonly proposed concept is that it can snap across an exostosis of the lesser trochanter.

Characteristically, the patient will describe a painful clicking sensation emanating from deep within the anterior groin. Usually, this is audible, but sometimes it may occur more as
a sensation experienced by the patient rather than what the examiner can objectively observe. The most specific examination maneuver is performed with the patient lying supine, bringing the hip from a flexed, abducted, externally rotated position down into extension with internal rotation, producing the associated pop (1). Applying pressure over the anterior joint may block the tendon from snapping and assist in confirming the diagnosis. Some patients may also describe an element of aching rising from the flank, buttock, or sacroiliac region attributed to irritation of the iliacus and psoas muscle origins.

Radiographs are an integral part of the assessment, but there are no findings specific for involvement of the iliopsoas tendon. Similarly, MRI findings are rarely specific for involvement of the iliopsoas, but may reveal indirect evidence if there is inflammation within the surrounding iliopsoas bursa (Fig 30-6). Iliopsoas bursography can be quite specific for snapping of the iliopsoas tendon when the tendon is visualized under fluoroscopy flipping back and forth in concert with the patient’s snapping sensation (24,25) (Fig 30-7). Problems with this technique include that it requires that the patient be able to produce the snapping while lying supine on the fluoroscopy table, and the fluoroscopy imaging unit may block the patient’s ability to produce the snap in a position where it can be visualized. Concomitant injection of bupivicaine may have some diagnostic value and injecting corticosteroid may potentially have some therapeutic benefit. Ultrasonography may also be quite good at visualizing the dynamic motion of the iliopsoas tendon (26). The advantages are that it is noninvasive and can easily allow comparison with the uninvolved hip. It does require a high resolution ultrasound unit and an experienced ultrasonographer.

Once the diagnosis has been established, the treatment for most people is little more than assurance that this is a normal variant and that the snapping is not indicative of future problems. For symptomatic cases, standard conservative methods include identifying and modifying offending activities and a gentle stretching and flexibility program to reduce tension in the iliopsoas, while incorporating a core stabilization program. Oral anti-inflammatory medications are routinely employed and a corticosteroid injection in the iliopsoas bursa may be tried, although this is rarely curative. When a patient fails conservative measures, careful attention should be given to assess for influencing motivational and emotional factors.

Surgery consists of relaxation of the iliopsoas to eliminate the snapping. This is accomplished by partial or complete release of its tendinous portion. Various open techniques have been described, mostly influenced by the authors’ interpretation of the principal location of the snapping.

Surgery to address snapping of the iliopsoas tendon has been most influenced by Allen et al. (1,22,23). They felt the tendon most commonly snapped across the anterior femoral head and capsule and described an anterior approach to address the tendon at this level. They initially used a vertical incision but then switched to a much more cosmetic transverse incision (Fig 30-8). They release the posteromedial tendinous portion of the iliopsoas, leaving the anterior muscular portion intact, effectively producing a lengthening of the musculotendinous unit. Their cohort consisted of 20 hips in 18 patients (22). Seventy percent had complete resolution of snapping, 25% had partial resolution and, overall, 85% were subjectively improved. Complications included 50% with reduced skin sensation, 15% with subjective weakness, and 10% underwent re-operation.

Gruen et al. (20) hypothesized that the tendon was most taut over the pelvic brim and proposed fractional lengthening of the iliopsoas tendon at this location. They described an ilioinguinal approach used in 11 patients (Fig 30-9). They reported 100% resolution of snapping with overall 83% patient satisfaction. Complications included 45% subjective weakness and one patient who underwent multiple re-operations.

Dobbs et al. (21) hypothesized that fractional lengthening of the tendon over the iliopectineal eminence might lead to less postoperative loss of hip flexion strength. They described a modified iliofemoral approach used in 11 hips of 9 adolescent children (Fig 30-10). All were satisfied with the results of the procedure, and none had detectable loss of flexion strength; however, one patient developed recurrent snapping and two experienced an area of decreased skin sensation. They acknowledged that, although the approach was extensive, it did provide excellent visualization, which is important because they emphasized the extreme caution necessary to correctly identify the tendon from the femoral nerve, which lies in close proximity at this level.

Taylor and Clark (27) advocated a medial approach, citing cosmesis and avoidance of sensory deficits associated with the anterior approach as its principal advantages (Fig 30-11). They reported on 16 hips in 14 patients where the tendinous portion of the iliopsoas was released from the lesser trochanter, leaving its muscular portion in tact. All patients were subjectively improved with 57% experiencing complete resolution of the snapping and 36% partial resolution. Fourteen percent experienced persistent weakness of hip flexion above 90 degrees.

Recently, these authors have gained experience with an endoscopic method of releasing the tendinous portion of the iliopsoas at the lesser trochanter (16,28). Among the open techniques, this most closely simulates the method described by Taylor and Clark (27).

The hypothesis is that the solution to snapping of the iliopsoas tendon centers on relaxation of the musculotendinous structure. Successful results have been reported with relaxation at various levels. Thus, the principal feature is to develop a technique that reliably allows relaxation of the iliopsoas with the least amount of morbidity. In this regard, these authors have found the endoscopic method to satisfy this criterion. Also, it has been recognized that snapping of the iliopsoas tendon can occur in association with intra-articular pathology. Thus, the endoscopic method accommodates simultaneous arthroscopic assessment of the joint.

Endoscopic release of the iliopsoas tendon is a continuation of routine hip arthroscopy as previously described using a standard supine technique on a fracture table (29,30). After completing arthroscopy of the hip, the instruments are removed and the traction released. The hip is flexed 15 to 20 degrees, which slightly relaxes the iliopsoas tendon, and the hip is externally rotated. This brings the lesser trochanter more anterior for access to the endoscopic portals.

A portal is established distal to the standard anterolateral hip portal at the level of the lesser trochanter using fluoroscopic guidance. An ancillary portal is then established for
instrumentation (Fig 30-12A). The iliopsoas bursa is the largest bursa in the body. Adhesions within the bursa can be cleared, providing excellent visualization of the iliopsoas tendon.

The tendinous portion of the iliopsoas is then transected directly adjacent to its insertion on the lesser trochanter, using either an arthroscopic bovie or other thermal device (Fig 30-12B). As the tendon is released, it will retract 1 to 2 cm, exposing its muscular remnants which are preserved.

Postoperatively, the patient is maintained on crutches for approximately 2 weeks until their gait pattern is normalized. Aggressive hip flexion strengthening is avoided for the first 6 weeks but otherwise the patient follows a normal post-arthroscopy protocol.

Preliminary experience in nine cases with at least 1 year follow up has been quite good (16). There was 100% resolution of the snapping and patient satisfaction, with no complications. No patient has experienced subjective weakness; however these authors have been cautious to select only patients with severe recalcitrant symptoms and it is likely that their improved function due to pain relief may have overshadowed any residual strength deficit. Also five of these nine cases (56%) had associated intra-articular pathology addressed at the time of releasing the iliopsoas tendon. This is similar to the experience of Ilizaliturri, et al. who found associated intra-articular pathology in four of seven cases (57%) who underwent successful endoscopic release of the iliopsoas tendon (17). It is postulated that failure to address this intra-articular pathology in conjunction with open procedures could be a factor in poorer outcomes.

For recalcitrant cases, endoscopic release of the iliopsoas tendon seems to represent an excellent alternative to traditional open techniques. It is an outpatient procedure that allows concomitant assessment for hip joint pathology and excellent cosmesis. The results are at least comparable to those reported for open methods, with minimal morbidity. However, few patients require surgery for snapping of the iliopsoas tendon, regardless of whether it is performed open or endoscopic. When the surgeon is certain of the diagnosis, the patient must still demonstrate convincing evidence that he or she is an appropriate candidate for the procedure. They must acknowledge that they would not be deterred by the chance of residual weakness. This is especially important for athletes where weakness could be an inhibiting factor to resuming their competitive career.

Snapping hip, or coxa saltans, most clearly encompasses two distinct entities, the external type due to the iliotibial band and the internal type due to the iliopsoas tendon (1). With an understanding of the anatomy, etiology, and pathomechanics, the characteristic history and examination findings will usually lead the clinician to the correct diagnosis. Further investigative studies may occasionally assist in substantiating this.

An intra-articular type of coxa saltans has also been proposed (1). This term is less clear as it encompasses numerous intra-articular lesions that can cause symptoms. It may be a challenge to distinguish whether the source of the patient’s symptoms is entirely extra-articular, or whether there may be an intra-articular component. It is not uncommon that patients may present with an element of both. The treatment strategy for hip joint pain may vary sharply from the symptomatic management employed for the extra-articular disorders.

The prevalence of asymptomatic snapping hips in the normal population is unknown. Similarly, the incidence of
symptomatic cases is not well-defined. However, it is clear that when treatment is necessary, most will respond to a properly constructed conservative strategy. It is rare that surgical intervention is necessary. Various techniques have been described with moderate success. The ultimate goal is the least invasive procedure with the lowest potential complications that accomplishes the desired effect of correcting the painful snapping. Certainly it is important to select an operation that adequately addresses the structural problem but, perhaps more important to this success is selecting the appropriate patient. This is only partly determined by the anatomic lesion and perhaps more so by the patient’s motivation and expectations of what the procedure may accomplish.