Biomechanical Comparison of Capsular Repair, Capsular Shift, and Capsular Plication for Hip Capsular Closure: Is a Single Repair Technique Best for All?

Abstract

Background: In hip arthroscopy, the best capsular closure technique to prevent microinstability in some patients while preventing overconstraints in other patients has yet to be determined. Purpose: To evaluate the biomechanical effects of capsular repair, capsular shift, and combination capsular shift and capsular plication for closure of the hip capsule. Study Design: Controlled laboratory study. Methods: Eight cadaveric hips (4 male and 4 female hips; mean age, 55.7 years) were evaluated in 7 conditions: intact, vented, capsulotomy, side-to-side repair, side-to-side repair with capsular plication (interval closure between iliofemoral and ischiofemoral ligaments), capsular shift repair, and capsular shift repair with plication. Measurements, via a 360° goniometer, included internal and external rotation with 1.5 N·m of torque at 5° of extension and 0°, 30°, 60°, and 90° of flexion. In addition, the degree of maximum extension with 5 N·m of torque and the amount of femoral distraction with 40 N and 80 N of force were obtained. Repeated-measures analysis of variance and Tukey post hoc analyses were used to analyze differences between capsular conditions. Results: At lower hip positions (5° of extension, 0° and 30° of flexion), there was a significant increase in external rotation and total rotation after capsulotomy versus the intact state (P .05). Among repair constructs, there were significant differences in range of motion between side-to-side repair and combined capsular shift with plication (P