Do femoral version abnormalities play a role in hip function of patients with hip pain?

Abstract

BackgroundA high prevalence of femoral version abnormalities has been observed in hip pain patients, with impact on hip range of motion and muscle strength that should be elucidated. MethodsCross-sectional study. Thirty-one patients with hip pain (16 men and 15 female) were subjected to Biplanar X-Rays to quantify femoral version using three-dimensional measurements. The 62 hips were divided into normal version (10–20°, n = 18), anteverted (>20°, n = 19), and retroverted (<10°, n = 25). Joint range of motion for flexion, internal rotation, and external rotation was assessed through digital goniometry. Maximal isometric hip strength (flexion, extension, internal rotation, external rotation at 0° and 30°, abduction, adduction) was evaluated through hand-held dynamometry. Hip rotation index was calculated as external rotation minus internal rotation. FindingsAnteverted hips had greater internal rotation, while retroverted hips had greater external rotation (p = 0.001). Anteverted hips were weaker than retroverted hips for external rotation at 30° (p < 0.001), abduction (p = 0.006) and adduction (p < 0.001), and weaker than normal version hips for extension (p = 0.018). All three groups had different rotation index: retroverted>normal>anteverted (p < 0.001). The ordinal logistic regression found higher values of rotation index with higher probability of being retroverted (common odds ratio = 1.20). There was a strong correlation between femoral version group and rotation index (rS = 0.76, p < 0.001). There was probability >70% of a hip being anteverted if the rotation index was <11°, and being retroverted if the index was >40°. InterpretationRange of motion and muscle strength differed in hips with different femoral versions. The hip rotation index was a strong femoral version predictor.