Dynamic ultrasound assessment of hip instability and anterior and posterior hip impingement

Objective: In this technical report, we describe our protocol for the dynamic sonographic evaluation of the hip and assess reliability of the ultrasound assessment of hip microinstability.

Materials and methods: Our clinical experience with a standardized dynamic ultrasound of the hip performed in a series of 27 patients with imaging performed by an experienced musculoskeletal radiologist during physical examination by an orthopedic surgeon specializing in hip preservation is illustrated with clinical photographs and ultrasound images from volunteers and selected patients. Interrater reliability for the diagnosis of microinstability was calculated.

Results: Dynamic ultrasound technique and findings of hip instability, femoroacetabular impingement, and ischiofemoral impingement with corresponding clinical photos showing the necessary physical examination maneuvers are described. Interrater agreement for the diagnosis of microinstability was substantial (κ 0.606 [0.221-0.991]).

Conclusion: At our institution, dynamic ultrasound of the hip during physical examination complements information gathered from static imaging by providing real-time correlation of symptoms with what is occurring anatomically.