SNAPPING HIP (COXA SALTANS)
Patients present complaining of a painful snap or popping sensation that is exacerbated by very specific hip positions. The snapping may be either internal (iliopsoas) or external (iliotibial band). Patients with external snapping hip will often describe their hip as “dislocating.” Onset is variable and most commonly associated with a change in activity or training regimen. External snapping pain will be mainly trochanteric based, whereas internal snapping causes deeper groin pain that is nonpalpable.
Differential diagnosis includes trochanteric bursitis, labral tear, or hip loose body.
A general hip examination is performed as discussed previously, with focus on hip range of motion and hip abduction strength (Trendelenburg test), as well as a gait examination. Palpation of the lateral hip should help guide the cause of pain. Palpation must take place over the greater trochanter, gluteus medius tendon, and piriformis, because they all may contribute to this syndrome. The Ober test is also performed to determine if the iliotibial band is contracted. External snapping is often visible and audible from the other side of the examination room. Internal snapping may often be reproduced by the patient by specific movements and will be audible. On examination, this is often reproduced by taking the hip from a flexion/abduction and external rotation to extension/adduction and internal rotation or neutral.
Similar to other hip complaints, standard anteroposterior pelvis, true anteroposterior, and lateral views of the affected hip are warranted. Advanced imaging (MRI) is warranted when treatment has failed to determine an intra-articular pathologic process, as well as to examine the iliopsoas bursa. Ultrasound may also be used to diagnose the iliopsoas tendon as the snapping agent on dynamic examination.
Initial treatment for coxa saltans is physical therapy and oral anti-inflammatory pain medication. For the external variety, rehabilitation is focused on core and abductor strengthening and iliotibial band stretching. Internal coxa saltans is treated with hip extension stretching and a gradual hip flexion strengthening program.
If the symptoms persist for 3 months after the initiation of therapy, injection with a corticosteroid is employed. Patients with iliotibial band snapping receive a trochanteric-based injection. Iliopsoas snapping is treated with an ultrasound-guided injection into the iliopsoas bursa. Physical therapy is then continued for another 3 months.
At this point, if symptoms still persist, surgical intervention may be considered. Hip arthroscopy is performed for each of the two types. For internal coxa saltans, a central (hip joint) examination and treatment of any labral pathologic process is undertaken. The iliopsoas tendon then can be released either from the central, peripheral compartment or directly off the lesser trochanter.
For external snapping, endoscopy or open excision of the trochanteric bursa can be performed. The area of snapping (most commonly posterior) can be identified by direct visualization and movement of the leg. The offending area of iliotibial band snapping is then excised until the snapping is no longer seen with leg movement.