Addressing Extra-Articular Impingement in the Athlete

Abstract

Extra-articular impingement (EAI) is an atypical, infrequent source of hip pain. Unlike femoroacetabular impingement (FAI) and acetabular dysplasia (AD), EAI results from abnormal contact of the proximal femur and trochanteric region, and the ischium or subspine areas. Hip pain and potential instability are reported. Causes of EAI include a narrowed ischiofemoral space, coxa valga, femoral torsion abnormalities, avulsion malunions, and more complex deformities resulting from pediatric hip diseases. Unique history and examination findings not commonly seen with standard FAI are noted, including pain with standing and hip extension and imbalanced hip motion with excessive internal rotation and limited external rotation (or vice versa). Surgical indications are yet to be definitively defined, but surgical treatment options include lesser trochanter resection, femoral osteotomy, and surgical hip dislocation. Proper workup and surgical planning have demonstrated good outcomes for treatment of EAI with these techniques, but information to optimally define which patients benefit most from which surgeries is pending.