Hip Disorders in the Female Athlete

Femoroacetabular Impingement and Associated Labral Tears

Femoroacetabular impingement syndrome (FAIS) refers to pathologic abutment between the femoral head-neck junction and the acetabular rim. This generally occurs due to a combination of structural, soft tissue, and activity-related factors. Two main forms of FAIS include cam morphology and pincer morphology, and many people have both. Cam morphology refers to an abnormally shaped femoral head and neck junction that causes either a convexity at this location or a flattening at this location on the bone ( Fig. 11.1 ). This effectively causes a mismatch between the shape of the acetabulum and the femoral head, and the cam lesion impinges on the acetabular rim and labrum, and as it moves farther into the joint with flexion, it impinges on the cartilage as well. Pincer morphology refers to an abnormality of the acetabulum in which the socket is deep and covering too far over the femoral head ( Fig. 11.2 ). This causes the edge of the acetabulum and labrum to impinge upon the femoral neck with hip flexion. Many people have a combination of both these abnormalities. FAIS can cause labral tears from the chronic impingement of the labrum between the bones. , Additionally, impingement between a prominent anterior inferior iliac spine (AIIS) and the femoral head-neck junction, also called subspine impingement, can occur. Although all three types of FAIS are noted in female athletes, pincer morphology is more common in females, while males generally have larger cam lesions. FAIS is most often seen in active adolescents and adults and in athletes, as the demand on the hip is higher than that in sedentary people. All types of female athletes can develop FAIS; however, it is commonly seen in soccer, lacrosse, dance, and gymnastics.

Fig. 11.1, Cam morphology of the femoral head and neck junction. Note the lack of offset between the superior aspect of the femoral head and the femoral neck.

Fig. 11.2, Pincer morphology of the acetabulum. Note the deep acetabular coverage over the femoral head.

Clinical Symptoms, Examination, Radiology, and Diagnosis

Most commonly, FAIS is described as a slow progression of pain over time rather than an acute injury. Classically, pain is in the groin or anterior hip and is described in a C-shaped location over the anterior and lateral groin crease, which is termed a “c-sign”. However, female patients may have pain patterns that are more laterally or even posteriorly based. Generally, pain is described as activity related, particularly with running or squatting, but it can also be associated with sitting for prolonged periods. Mechanical symptoms due to labral tears or cartilage injury in the hip may be present; however, most often a complaint of popping will be due to an associated internal or external snapping hip. Pain in certain muscle groups such as hip flexors, glutes, and short external rotators is commonly associated and should be considered as a source of pain, in addition to FAIS. ,

Physical examination related to possible FAIS should include a gait assessment, palpation of periarticular muscles, range-of-motion testing, and strength testing to determine if an intra- or extra-articular source of pain is present. , Classically, FAIS will cause pain with flexion, adduction, and internal rotation (FADIR) ( Fig. 11.3 ). This places the most contact between the femur and acetabulum and places the most pressure on the labrum. However, the combination of flexion, abduction, and external rotation (FABER) can cause pain if a labral tear or the position of impingement is more posteriorly based in some cases ( Fig. 11.4 ). Pain with flexion past 90 degrees may be associated with AIIS impingement.

Fig. 11.3, The flexion, adduction, and internal rotation (FADIR) test. With the patient supine, the examiner brings affected leg into hip flexion, adduction, and internal rotation. Intra-articular pathology such as labral tears or chondral injury usually results in anterior groin pain.

Fig. 11.4, The flexion, abduction, and external rotation (FABER) test. The patient supine and hip is placed into the flexed, abducted, and externally rotated position to elicit pain. The examiner should note if anterior, lateral, or posterior pain is reported.

Radiographs including an anteroposterior (AP) pelvis view, lateral hip view, and often a false profile view are taken for assessment of femoroacetabular impingement (FAI) morphology including cam lesion, pincer lesion, and prominent AIIS. The lateral center edge angle (LCEA) and the Tonnis angle are measured on an AP pelvis radiograph to evaluate the amount of coverage of the acetabulum and the slope of the acetabular roof, respectively ( Fig. 11.5A and B ). An LCEA between 25 and 40 degrees and a Tonnis angle between 0 and 10 degrees are considered normal. , The alpha angle is measured on a lateral view of the femur and measurements above 50–55 degrees indicate cam morphology. ( Fig. 11.5C ) The AIIS should have approximately 1 cm of space between its base and the edge of the acetabulum. , A thorough assessment of any concomitant acetabular dysplasia should be performed, as this is more common in females than males. Magnetic resonance imaging (MRI) is useful to determine the presence and extent of labral pathology, cartilage injury, and possible associated psoas or rectus tendonitis ( Fig. 11.6 ). Computed tomographic (CT) scan is helpful to understand the three-dimensional anatomy of the cam or pincer lesion and evaluate the femoral torsion for any femoral retroversion that could be exacerbating the FAIS.

Fig. 11.5, (A) Measurement of lateral center edge angle, (B) measurement of the Tonnis angle, and (C) measurement of alpha angle.

Fig. 11.6, Magnetic resonance image of the hip showing labral tearing due to femoroacetabular impingement.


Initial treatment for FAIS includes conservative care including activity modification, physical therapy, and antiinflammatory medications. Therapy should focus on core strength, stability, and balancing of muscle groups including anterior and posterior chains. Selective injections may be helpful in confirming a diagnosis of FAIS when a possible extra-articular source of pain is in question, such as psoas or rectus tendonitis. Female athletes have a higher incidence of psoas snapping and tendonitis than males, and this may be difficult to differentiate from FAIS. , Intra-articular injections may also be used as part of conservative treatment. A single injection may be an effective aide in pain relief and may facilitate a course of physical therapy or allow further athletic participation. There is evidence, however, that 2–3 months should pass between the injection of corticosteroid and surgical intervention to prevent an increase in perioperative infection rate.

If nonoperative treatment fails to improve pain and mechanical symptoms, surgical intervention most commonly includes hip arthroscopy to perform labral repair (or reconstruction with a graft), femoroplasty and/or acetabuloplasty, and possible AIIS decompression. If a concomitant diagnosis of acetabular dysplasia is present, the surgeon should consider whether a periacetabular osteotomy for correction of dysplasia is necessary. Patients should be counseled that an associated snapping psoas or iliotibial band (ITB) may not be immediately corrected with hip arthroscopy. Rather, their soft tissues will benefit from a course of postoperative physical therapy after the underlying anatomic abnormalities have been addressed.


Outcomes of hip arthroscopy for FAIS show good improvement in functional scores and return to athletic participation in 50%–95% of female patients. Some studies show that overall improvement is lower in females than males. Older females, especially, tend to show less improvement in functional scores and worse outcomes than their younger female counterparts. , There is evidence that arthroscopy in patients with combined borderline acetabular dysplasia and FAI can be successful, but arthroscopy for isolated dysplasia with a labral tear is not indicated.

Hip Dysplasia and Associated Labral Tears

Acetabular dysplasia refers to an increasingly wide spectrum of pathologies that affect the acetabular and proximal femoral morphology. , The dysplastic acetabulum is typically shallow and low in volume, creating an abnormal articulation between it and the femoral head ( Fig. 11.7 ). This mismatch can create intra-articular damage due to excessive stress on the labrum and cartilage and extra-articular stress on muscles and tendons, which are overloaded due to the abnormal hip joint. Dysplasia is now recognized as a cause of primary osteoarthritis (OA) of the hip. Various patterns of dysplasia can occur, and some can be subtle on radiographic examination. The undercoverage of the femoral head can be global, or it can be focal in the anterior, lateral, or even posterior acetabulum in cases of acetabular retroversion. , Each of these may cause a different location of labral or chondral injury, as well as a different pattern of symptoms. The concept of microinstability in the setting of dysplasia refers to the mismatch and undercoverage of the femoral head causing some laxity of the joint, which is sensed by the body. The periarticular muscles such as gluteal muscles or hip flexors are then overloaded and can become a source of discomfort. It is common to see a combination of ligamentous laxity and dysplasia in females. This combination can exacerbate the microinstability due to the increased range of motion these athletes will have, in addition to increased capsular volume or incompetence. ,

Fig. 11.7, Anteroposterior pelvis radiograph showing undercoverage of the femoral head by the acetabulum on the right hip consistent with acetabular dysplasia.

Clinical Symptoms, Examination, Radiology, and Diagnosis

Many female athletes presenting with symptoms from acetabular dysplasia will note an insidious onset of pain that is often activity related. If groin pain or a c-sign is a main complaint, intra-articular pathology or hip flexor tendonitis should be considered. If the pain is mainly laterally based, often a large component of pain is due to gluteal overload. If posterior pain is present, posterior undercoverage should be considered. , Anterior pain may be exacerbated with activities involving hip flexion and significant external rotation, as they place stress on the labrum and anterior capsule, respectively. Additionally, symptoms of psoas snapping may be a sign of anterior instability, as the psoas acts as a secondary stabilizer. Long periods of weight-bearing activity such as walking or running also place stress on the gluteal musculature and may exacerbate lateral pain.

Physical examination of a patient with possible acetabular dysplasia should include evaluation of gait, palpation of periarticular muscles, range of motion, and strength to determine locations of pain and intra- versus extra-articular sources of pain. Examination maneuvers related to dysplasia include an anterior apprehension test in which the patient is placed in the position in Fig. 11.4 and the femur is forced into external rotation ( Fig. 11.8 ). Pain or apprehension anteriorly, which is improved with posteriorly directed force on the joint (similar to a shoulder apprehension test), can be a sign of anterior instability. FADIR or FABER test results may be positive for pain if there is a labral tear. Evaluation of abductor fatigue with the Trendelenburg sign or trochanteric region pain with abductor strength testing indicates lateral overload. Internal and external rotation in flexion gives an idea of femoral torsion. Increased internal rotation indicates femoral anteversion, and increased external rotation indicates femoral retroversion. Both are seen in the setting of dysplasia and have treatment implications. Ligamentous laxity should be evaluated, as this also has treatment implications. The Beighton criteria is the most common way to qualify the level of general ligamentous laxity. Laxity, specifically of the hip capsule, can be tested with a log roll test and a dial test, both of which evaluate the amount of rotation and the spring back the capsule has in a neutral position of extension.

Fig. 11.8, Apprehension test. The examiner places the hip into flexion and external rotation and places a posteriorly directed force on the hip. Anterior pain or apprehension with a sense of instability is a positive test result.

Initial radiographic evaluation is similar to evaluation for FAIS with AP Pelvis, lateral, and false profile radiographs. An LCEA below 25 degrees indicates dysplasia. Evaluation for increased alpha angle and combined dysplasia and FAI is important for treatment. MRI may show a labral tear, and it is important to evaluate the quality of the labral tissue, as it can often appear degenerative. , CT scan with evaluation of femoral torsion also aides in the evaluation of the three-dimensional nature of the acetabular dysplasia and any contribution of femoral anteversion to an instability picture.


In most cases, treatment for dysplasia begins with conservative management. Activity modification, antiinflammatory medications, and physical therapy are first-line treatment options. Physical therapy will focus on core strength, abductor strength, and balancing of anterior and posterior chain muscle groups. If the athlete is a dancer or other flexibility sport athlete, a thorough evaluation of compensatory movements during sport should be performed.

If nonsurgical management fails, treatment of dysplasia often requires periacetabular osteotomy for correction of the acetabular anatomy. , The goal of this surgery is to reorient the acetabulum such that the weight-bearing dome of the acetabulum is centered over the femoral head. Often this is combined with a hip arthroscopy if a labral tear or cam lesion is also present.

Iliopsoas Tendonitis and Internal Snapping Hip Syndrome

The iliopsoas muscle has been seen to be a source of a spectrum of hip symptoms, from debilitating mechanical hip pain to asymptomatic snapping of the hip. Internal snapping hip, also known as coxa saltans interna, is defined as the iliopsoas musculotendinous junction snapping over the anterior pelvic structures deep to it, including the iliopectineal ridge, the iliopsoas bursa, the iliofemoral ligament, the superior pubic ramus, the anterior capsule, the femoral head, or the lesser trochanter of the femur, with the femoral head being the most common location. ,

The psoas muscle originates from the lumbar spine (T12-L4), joins with the iliacus muscle at the levels of L5-S2, and inserts on the lesser trochanter as the iliopsoas tendon acting as one of the body's strongest hip flexors. , Additional movements of the iliopsoas muscle include abduction and external rotation of the femur, in addition to flexion. Philippon et al. report in their anatomic study of cadaveric iliopsoas tendons that the majority of hips examined had iliopsoas tendons composed of more than two tendons and that the largest tendon usually was the psoas major, which tends to lie more medially and may not be the first tendon encountered endoscopically.

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