The effect of conjoint tendon release on gait after direct anterior total hip arthroplasty

Introduction: There has been considerable interest in the direct anterior (DA) approach to total hip arthroplasty (THA) recently. To facilitate exposure of the proximal femur it is sometimes necessary to release the conjoint tendon. Aim: To prospectively investigate whether release of the conjoint tendon has an impact on gait in the early postoperative period. Methods: We measured gait velocity, stride length, single-limb support and single-limb support symmetry preoperatively, at discharge from the hospital, and 2, 6 and 12 weeks and postoperatively. Participants also completed the Timed Up and Go and a series of questionnaires (WOMAC, SF-12, Harris Hip Score, and pain VAS) at each visit. Results: 36 participants undergoing a DA THA with a single surgeon were enrolled in this study. 22 participants had a release of the conjoint tendon during their surgery. We found no differences between the groups for any gait, patient-reported or surgical outcomes (p < 0.05). There was a total of 3 complications reported in the release group, and 1 complication in the group that did not have a release. Conclusion: Although the conjoint tendon has an important role in the biomechanics of the hip, we found release of the conjoint tendon during the DA approach for THA to have no impact on gait or patient reported outcomes within 12 weeks post-surgery. Therefore, if the exposure of the proximal femur is limited, a low threshold for release of the conjoint tendon is recommended to improve visualisation.