In Vitro Analyses of the Contributions of the Hip Capsule to Joint Biomechanics
Abstract
Optimal management of the hip capsule during arthroscopic surgery has not been established. The impact of incisions made to the capsule during minimally invasive procedures on joint biomechanics, and whether repair provides any benefit, continue to be debated. The effectiveness of capsular repair to restore native kinematics may be insufficient. Therefore, a better understanding of joint behavior during various capsule conditions is needed. A new robotic system was used to analyze the effect of progressive capsulotomy incision and repairs on the behavior of a normal hip within range of motion (ROM) limits with respect to the intact joint. Complete repairs increased the torque at end ROM across all tested joint positions compared to their unrepaired counterparts, though equivalent restraint to the intact joint was not always restored. Although repairs did not restore native joint kinematics, total displacement was increased with an interportal or T-capsulotomy, with and without repair.