Cam Osteochondroplasty for Femoroacetabular Impingement Increases Microinstability in Deep Flexion: A Cadaveric Study

Purpose The purpose of this in vitro cadaveric study was to examine the contributions each surgical stage during cam femoroacetabular impingement (FAI) surgery (i.e., intact-cam hip, T-capsulotomy, resection, and capsular repair) toward hip range motion, translation, microinstability. Methods Twelve hips were denuded capsule mounted onto a robotic tester. positioned several flexion positions—full extension, neutral (0°), 30° flexion, 90° flexion—and performed internal-external rotations 5 Nm torque position. underwent series stages (T-capsulotomy, retested after stage. Changes microinstability (overall translation normalized by femoral head radius) measured Results Regarding resection increased internal rotation at (change = +6°, P .001) but did not affect external rotation. Capsular repair restrained compared with –8° –4°, ? .04). In terms translated medial-lateral plane +1.9 mm, .04) relative intact capsulotomy stages. microinstability, [?M] +0.05, .003), further increase resection. At (?M +0.03, .2) substantially +0.08, .03), accounting for 31% change respect Conclusions Cam deep hip. This finding suggests that iatrogenic may be due separation labral seal resected contour head. Clinical Relevance Our showed that, time zero prior postoperative recovery, excessive motion could disrupt seal. Complete should cautiously avoid disruption