Hip Strength Deficits in Patients With Symptomatic Femoroacetabular Impingement and Labral Tears

Purpose: To determine the prevalence of hip strength deficits in a consecutive cohort of patients with unilateral femoroacetabular impingement (FAI) compared with the asymptomatic contralateral hip. Methods: Fifty consecutive patients undergoing hip arthroscopy for symptomatic FAI underwent preoperative hip strength dynamometer measurements and were included in the study. Manual isometric hip strength measurements were performed with a handheld dynamometer and included measurements of various hip strengths (flexion, extension, adduction, abduction, internal rotation, and external rotation). Weakness greater than or equal to 10% for any given measurement was defined as a strength deficit in this study. Clinical data including age, gender, size of labral tear, and preoperative outcome scores were recorded. Outcome scores included the modified Harris Hip Score and Short Form 12 Physical Component. Results: The mean age of patients in the study was 32.0 years (range, 18.1 to 49.8 years). There were 32 male and 18 female patients. Hip abduction strength deficits were seen in 46% of patients and flexion strength deficits in 42% of patients. An 8% decrease in strength of the involved hip was seen in flexion, and an 8.7% decrease was seen in abduction. Patients with hip flexion strength deficits had a loss of function (mean modified Harris Hip Score, 57.8 v 66.1; P = .021) and larger labral tears (mean, 39 mm v 28 mm; P = .003). Hip flexion strength deficits correlated with loss of hip flexion (r = 0.373, P = .008). Conclusions: Hip strength deficits were common in patients presenting with unilateral symptomatic FAI and occurred most commonly in hip abduction and flexion. Strength deficits in hip flexion were associated with decreased function, loss of motion, and larger labral tears in patients with FAI and labral tears.