Relationship between femoral anteversion and findings in hips with femoroacetabular impingement.

The purpose of this study was to investigate the relationship between femoral neck version and pre- and intraoperative findings in hips with femoroacetabular impingement (FAI). The authors retrospectively reviewed prospectively collected data on 188 patients (204 hips) who underwent hip arthroscopy for FAI and labral pathology. Femoral version was measured on magnetic resonance imaging by a fellowship-trained musculoskeletal radiologist. The study group comprised 100 men and 88 women with a mean age of 35 years (range, 18 to 62 years). Mean femoral version was 9° (range, -10° to 27°). No relationship was found between femoral version and patient demographics (ie, age, sex, weight, height, and body mass index). A significant correlation was found between version and degrees of external rotation (r=-0.208; P=.027) and internal rotation (r=0.231; P=.002) on physical examination. Patients with femoral version less than 5° had significantly increased external rotation (P=.027). Intraoperative findings demonstrated that femoral version greater than 15° was related to larger labral tears that averaged approximately 38 mm in size, whereas patients with anteversion less than 5° had tear sizes measuring 30 mm and patients with angles between 5° and 15° had tear sizes averaging 34 mm (P=.008). Hips with femoral version greater than 15° were 2.2 times more likely (95% confidence interval, 1.2 to 4.1) to have labral tears that extended beyond the 3 o'clock position, denoting more anterior tears. Hips in which a psoas release was performed had higher version angles (8° vs 11°; P=.023).