Less Postoperative Restrictions Following Total Hip Arthroplasty With Use of a Posterolateral Approach: A Prospective, Randomized, Noninferiority Trial

Patient restrictions are prescribed after total hip arthroplasty (THA) to ensure proper healing and prevent early dislocation. It has been suggested that less or nonrestrictive protocols following THA do not lead to higher dislocation rates. Nonetheless, restrictions are still widely used. The aim of this study is to evaluate the rate of early dislocations when patients were restricted to supine sleeping or unrestricted sleeping in the first 8 weeks after THA using a posterolateral approach.

The study design was a single-center, parallel-group, stratified, randomized, noninferiority trial in which primary THA patients were allocated to either a restricted group or a nonrestricted group. The primary outcome was early (<8 weeks) dislocation rate. Secondary outcomes include pain (visual analog scale [VAS]), function in activities of daily living (Hip Disability and Osteoarthritis Outcome Score [HOOS]), and quality of life (EuroQoL 5 Dimension [EQ-5D]).

A total of 408 patients were randomized into 2 groups: those who were restricted in their sleeping position ( n = 203) and those who received no restrictions in sleeping position ( n = 205). Three patients (1.48%) from the restricted group and 3 patients (1.46%) from the unrestricted group had a dislocation. The noninferiority of the restricted group compared to the nonrestricted group was established for early dislocation. In addition, no statistically significant differences were found for VAS, HOOS, and QoL-5D between both groups. Both groups showed a significant improvement in VAS, HOOS, and QoL-5D.

Early dislocation rates in patients who were advised to comply to an unrestricted sleeping position following THA were not inferior to the dislocation rates in patients who were advised to sleep in a supine position following THA. The results of the present study strengthen the discussion regarding the relevance of providing patients with restrictions following THA.