Introduction

Advances in hip arthroscopy have increased the understanding of both intra-articular and extra-articular hip pathology. The anatomic and surgical techniques involved in hip arthroscopy have been described. Increasing enthusiasm for hip arthroscopy and minimally invasive surgery in addition to advances in magnetic resonance imaging of the hip have broadened arthroscopic application. Intra-articular pathologies—including loose bodies, labral tears, ligamentum teres tears, chondral lesions, synovial chondromatosis and femoroacetabular impingement—have now been arthroscopically treated.

Hip arthroscopy has recently been expanded to allow for the visualization and treatment of extra-articular pathology, specifically in the peritrochanteric compartment. Disorders in this compartment include external coxa saltans or snapping hip, trochanteric bursitis, and gluteus medius and gluteus minimus tears (Tables 17-1, 17-2, and 17-3). These pathologies, which were underappreciated before hip arthroscopy, have now been identified as significant causes of lateral hip pain. The previous treatment of these disorders with conservative modalities or open surgery has had varied efficacy, and it has been associated with significant postoperative morbidity. Conservative treatment is often the preferred treatment modality and includes corticosteroid and anesthetic injections in combination with a structured physical therapy regimen. Patients for whom conservative treatment is ineffective have previously required open surgery.

Table 17–1 External Coxa Saltans

Table 17–2 Trochanteric Bursitis

Table 17–3 Gluteus Medius and Minimus Tears

Indications

• External coxa saltans

Generally asymptomatic or can be treated conservatively with rest, activity modification, stretching, corticosteroid injections, and physical therapy

Recalcitrant cases as defined by unabated symptoms may be addressed with either open or arthroscopic treatment

• Trochanteric bursitis

Conservative treatment with local corticosteroid and anesthetic preparation injections in combination with physical therapy as the mainstay of diagnosis and treatment

Refractory cases treated with open and arthroscopic trochanteric bursectomy

• Gluteus medius and minimus tears

Present as refractory trochanteric bursitis or iliotibial band syndrome with lateral hip pain and an ambulatory limp likely related to hip abductor weakness

Treatment described in an open and arthroscopic fashion when conservative treatment has failed

Brief history and physical examination

An in-depth patient history is one of the most effective tools for evaluating a complaint of hip pain. A historic description of hip pain can differentiate intra-articular versus extra-articular pathology. Extra-articular complaints can then be localized to lateral hip pain in the peritrochanteric compartment. When a description of extra-articular lateral hip pain is achieved, the diagnostic differential can be narrowed with descriptive characteristics specific to each peritrochanteric space disorder. External coxa saltans, or “snapping hip,” is characterized by a palpable or audible snapping as the hip moves from flexion to extension; this is often seen during athletic activity. Trochanteric bursitis and greater trochanteric pain syndrome are characterized by chronic intermittent aching pain over the lateral aspect of the hip; these conditions are prevalent among older females. Gluteus medius and gluteus minimus tears often produce symptoms that are similar to those of trochanteric bursitis but on a shorter time line.

Lateral hip pain can arise from direct pain from the peritrochanteric space or from referred pain from intra-articular pathology. Palpation of the lateral hip aids in the differential diagnosis, because referred pain may be reproduced with passive and active joint motion but should not produce tenderness with direct palpation. In this vein, palpation should begin with the origin of the gluteus maximus at the inferoposterior aspect of the ileum and sacrum. The insertion can then be examined in two locations: the lateral base of the linea aspera on the proximal femur and the tensor fascia latae. Next, the gluteus medius should be palpated from its origin on the anterior and middle aspect of the ileum to its two insertions on the middle and superoposterior facets of the greater trochanter. The gluteus minimus can be examined from its origin deep to the gluteus medius to its insertion at the greater trochanter anterior facet. The greater trochanteric bursa should also be appreciated overlying the greater trochanter at the mid-posterior proximal aspect of the femur. The physical examination of muscle strength can be used to evaluate abductor strength in the presence or absence of pain. This examination should be conducted with the hip in flexion to assess the tensor fascia latae, in neutral to evaluate the gluteus medius, and in extension for the gluteus maximus. This examination should be performed with the knee both flexed and extended to allow for the tension and relaxation of the iliotibial band, respectively. External coxa saltans can be replicated with audible or palpable snapping during physical examination. Gluteus medius and gluteus minimus tears often present with pain along the lateral aspect of the greater trochanter and may mimic trochanteric bursitis.

Imaging and diagnostic studies

All patients who present with hip pain are evaluated with an anteroposterior radiograph of the pelvis as well as a Dunn lateral radiograph (90 degrees of hip flexion, 20 degrees of abduction, and the beam centered on and perpendicular to the hip) to assess for avulsions of the greater trochanter, cam and pincer lesions, loss of joint space, crossover sign, acetabular dysplasia, and sacroiliac joint pathology. Magnetic resonance imaging provides the most information about the soft tissues that surround the hip (Figure 17-1). Every magnetic resonance imaging study of the hip should include a screening examination of the whole pelvis that is acquired with use of coronal inversion recovery and axial proton-density sequences. Detailed hip imaging is obtained with use of a surface coil over the hip joint, with high-resolution, cartilage-sensitive images acquired in three planes (sagittal, coronal, and oblique axial) with use of a fast-spin-echo pulse sequence and an intermediate echo time. Other alternatives include the use of magnetic resonance arthrography of the hip for the evaluation of hip pathology. Ultrasound is used most commonly to confirm the placement of injections into the trochanteric space for diagnostic and therapeutic purposes. Dynamic ultrasound has also been described to evaluate external coxa saltans; it provides real-time images of the sudden abnormal displacement of the iliotibial band or the gluteus maximus muscle overlying the greater trochanter as a painful snap during hip motion. In addition, sonography can identify gluteus medius and gluteus minimus tendinopathy and provide information about the severity of the disease.

Figure 17–1 Magnetic resonance image of the left hip that reveals increased signal at the greater trochanter; this is consistent with a tear of the gluteus medius tendon.

Surgical technique

The importance of proper portal placement is critical during hip arthroscopy. For arthroscopy of the peritrochanteric space, a technique has been described that involves the use of both traditional and unique portals (Figure 17-2). The technique begins with the accurate identification of the trochanter and the marking of the arthroscopic portals. The procedure begins with routine central compartment hip arthroscopy to rule out associated intra-articular pathologies. Although intra-articular pathologies typically result in primary anterior or groin symptoms, it is also possible for these pathologies to result in primary lateral-sided hip pain. Central compartment arthroscopy is performed in all cases of peritrochanteric space endoscopy to document and treat any associated labral or chondral pathology that may coexist with the lateral-based pathology. The anterolateral portal is first established with the use of the standard Seldinger technique of a cannulated trochar over a guidewire, which is performed with the aid of fluoroscopy. To minimize trauma to the lateral femoral cutaneous nerve, a mid-anterior portal is then established. This portal is made slightly more lateral and distal than the traditional anterior portal. The portal is critical to get into the peritrochanteric space, because it is the initial primary viewing portal. Thus, fluoroscopy is used to assist with the optimal placement of the mid-anterior portal over the lateral prominence of the greater trochanter. Before entry into the peritrochanteric space and after the completion of the central compartment evaluation, the peripheral compartment should be entered if there is any concern about peripheral compartment pathology.

Figure 17–2 Intraoperative photograph of the right hip anterolateral (AL), mid-anterior (MA), distal anterolateral accessory (DALA), posterolateral (PL), and proximal anterolateral accessory (PALA) portals for entry into the peritrochanteric space. The anterosuperior iliac spine is denoted by the arrow.