Hip Circumferential Labral Reconstruction Provides Similar Distractive Stability to Labral Repair After Cam Over-Resection in a Biomechanical Model

Abstract

To evaluate the change in hip distractive stability after a cam over-resection, labral tear, repair, labrectomy, or circumferential 6- or 10-mm labral reconstruction in a biomechanical model. Ten fresh-frozen matched-pair human cadaveric hips were analyzed using a materials testing system to measure the force and distance required to disrupt the suction seal of the hip (1) with an intact capsule and labrum; (2) after a capsulectomy and labral repair; (3) after a capsulectomy, 5-mm cam over-resection and labral repair; (4) after a capsulectomy, 5-mm cam over-resection and labral tear; (5) after a capsulectomy, 5-mm cam over-resection and labrectomy; and (6) after a capsulectomy, 5-mm cam over-resection and a 6- or 10-mm circumferential labral reconstruction with iliotibial band (5 hips each). Each specimen was retested at 0° flexion, 45° flexion, and 45° flexion and at 15° internal rotation and analyzed using nonparametric statistical methods. The Friedman test of differences was significant among structural conditions and hip positions (P= .001). In all positions, the resistive force that opposed the disruption of the suction seal in an intact hip was significantly greater compared with all other conditions. The resistive force for the capsulectomy, 5-mm cam over-resection and labrectomy condition was significantly less compared with almost all other conditions and hip positions. A qualitative suction seal was achieved in 20% of hip specimens with a 6-mm labral reconstruction, whereas a seal was in achieved 60% of specimens with a 10-mm labral reconstruction. After a cam over-resection, a circumferential labral reconstruction improves the distractive stability of a labral deficient hip, comparable to a labral repair or tear in a biomechanical model. Circumferential labral reconstruction may be a viable treatment option for patients with ongoing symptoms after hip arthroscopy with evidence of a cam over-resection and a deficient labrum.