Review Question - QID 215522

Internal snapping hip, or coxa saltans, is caused by abnormal motion of the iliopsoas muscle belly and tendon. The origin and insertion of the iliopsoas is the anterior surface and lower borders of transverse processes of L1 - L5 and the iliac fossa and the lesser trochanter (Answer 2).

Coxa saltans, or snapping hip, is a condition characterized by a snapping sensation about the hip joint. It is a common cause of pain and discomfort in athletes and dancers in their early twenties. There are three main subtypes of coxa saltans: external, internal, and intra-articular. External snapping hip, the most common form, is caused by the iliotibial band sliding over the greater trochanter. Internal snapping hip is caused by the iliopsoas impinging on either the femoral head, a prominent iliopectineal ridge, the lesser trochanter and/or the iliopsoas bursa. Intra-articular snapping hip can be caused by loose bodies in the hip or labral tears. Initial treatment is nonoperative, with surgery reserved for those whose symptoms are recalcitrant to conservative measures.

Yen et al. provide a review of the epidemiology and treatment of snapping hip. They explain that moving a patient's hip from a position of flexion, abduction and external rotation to a position of extension, adduction and internal rotation will often provoke an anterior snapping in those patients with coxa saltans internal.

Frank et al. in their 2013 JAAOS article review a variety of causes of hip pain and disability frequently experienced by adolescent athletes. They explain that moving a hip from a flexed and internally rotated position to an extended and externally rotated position can elicit an audible or palpable snap in patients with coxa saltans internal. They go on to state that dynamic ultrasonography can be used to visualize the abnormal iliopsoas motion.

Allen and Cope outline the causes, diagnosis and treatment of coxa saltans, or snapping hip. They note that while the external subtype is most common, both the internal and intra-articular subtypes must be considered when evaluating a young patient with hip pain.

Illustration A demonstrates the origin and insertion of the iliopsoas.

Incorrect Answers:
Answer 1: This describes the origin and insertion of the acetabular labrum which, when torn, can cause the intra-articular type of coxa saltans. The labrum, when torn, typically causes pain in hip flexion, adduction and internal rotation (FADIR).
Answer 3: The iliopsoas inserts at the lesser trochanter, not the greater trochanter.
Answer 4: This describes the course of the iliotibial tract, which is implicated in external snapping hip. External coxa saltans is diagnosed through direct palpation of the greater trochanter when moving the hip into flexion.
Answer 5: The insertion of the iliotibial tract is the lateral condyle of the tibia, at Gerdy's tubercle.