The Effect of Capsulectomy on Hip Joint Biomechanics.

Abstract

Background:Capsulectomy is performed during hip arthroscopic surgery in young adult patients with hip pain to improve intraoperative visualization. The stability of the hip joint after anterior capsulectomy is relatively unknown.Purpose:To evaluate anterior hip stability in capsular sectioned states with a labral injury to test whether the load required for anterior translation would decrease with greater capsular injuries.Study Design:Controlled laboratory study.Methods:Sixteen hips from 8 of 10 human cadaveric pelvises (mean age, 54.25 years) were prepared/mounted onto a custom-built fixture and tested in 5 states: intact capsule, intact labrum (all intact); sutured capsule, intact labrum (sutured intact); sutured capsule, 1-cm partial labrectomy (sutured labrectomy); partial capsulectomy, 1-cm partial labrectomy (partial capsulectomy); and total capsulectomy, 1-cm partial labrectomy (total capsulectomy). Each hip was tested in a neutral position with a 20-N compressive force. The load at 12 mm of anterior translation was recorded for each state after 2 preconditioning trials.Results:A repeated-measures analysis of variance with Bonferroni adjustment showed no difference between the all-intact versus sutured-intact states and demonstrated no significant difference between the sutured-intact and sutured-labrectomy states. There were significant differences between the sutured-labrectomy and partial capsulectomy (P = .01), sutured-labrectomy and total capsulectomy (P < .001), and partial capsulectomy and total capsulectomy (P = .04) states.Conclusion:The findings demonstrate that the capsule/labrum plays an important role in anterior hip stability and that the iliofemoral ligament is crucial for preventing anterior translation in labral-injured states. In addition, the ischiofemoral and pubofemoral ligaments provide resistance to anterior translation in iliofemoral- and labral-deficient states. Intraoperative capsulectomy should be avoided in patients with large, irreparable labral tears to prevent postoperative anterior hip instability.Clinical Relevance:This study quantifies the roles of the capsulolabral structures in anterior hip stability and demonstrates the importance of maintaining/repairing them during hip arthroscopic surgery.