Dynamic sonography of snapping hip due to gluteus maximus subluxation over greater trochanter

Abstract

We report on the dynamic sonographic findings of a 10-year-old avid female dancer who presented with symptoms of abrupt left hip motion and associated painful snapping sensation while performing lateral motions of the pelvis suggesting external snapping hip syndrome. Dynamic sonographic evaluation of both hips demonstrated that symptoms were due to gluteus maximus subluxation over the greater trochanter. This etiology of external snapping hip syndrome is rare with limited imaging descriptions in the literature. We present case history, physical examination, and dynamic ultrasound examination, including multiple still images and cine clips, comprehensively characterizing this uncommon source of external snapping hip syndrome.

Greater trochanteric pain syndrome: Evaluation and management of a wide spectrum of pathology

“…Dynamic evaluation with sonography may also be useful in the workup of lateral hip pain, including confirming the diagnosis of external coxa saltans. 41 Sonographic evaluation offers several advantages, including low cost and the ability to accurately localize and administer CSIs. 35 , 38 …”

US-guided Musculoskeletal Interventions in the Hip with MRI and US Correlation

“…External snapping hip syndrome is best assessed dynamically at US, with the transducer placed in the transverse plane over the greater trochanter. With the patient in a supine or upright position, hip flexion or external rotation is performed to assess for sudden motion of the ITB, which is often accompanied by reproduction of the patient's pain or an audible or palpable snap (36).…”

Current Concepts in Extra-articular Impingement of the Hip: Clinical Diagnosis, Imaging, and Treatment

“…[74][75][76] Dynamic ultrasound is considered the best test when the clinical diagnosis of external snapping hip is uncertain or when the condition is painful and unresponsive to conservative treatment. 59,77 MRI or CT can provide additional information in a minority of cases. 78 Ultrasound examination for suspected external snapping hip should follow a standard hip assessment protocol.…”

“…In addition, the patient should be examined while standing and reproducing the motion that causes the snap. 59,77 The snapping of the ITB or the gluteus maximus over the greater trochanter is visualized as a rapid movement of the structures over the posterior aspect of the trochanter with the transducer in the transverse position and corresponds to the snap experienced by the patient. The snap has been described to occur when the adducted extended hip is flexed or when the adducted internally rotated hip is flexed and externally rotated with the knee flexed.…”