Minimal invasive posterior total hip arthroplasty: are 6 weeks of hip precautions really necessary?

Introduction: Postoperative hip dislocations have been reported in 0.5 to 10.6 % of patients after primary posterolateral total hip arthroplasty (THA). Hip precautions are currently recommended for 6 weeks postoperatively to reduce early dislocation and facilitate healing of the posterior soft tissue repair.
Materials and Methods: To determine the impact of a modified 4-week precaution protocol on the dislocation rate, 698 consecutive patients (797 hips) operated by a single surgeon between September 2008 and December 2012 were retrospectively evaluated. All patients had a standard THA using a minimal invasive posterior approach with posterior soft tissue repair and 28-36-mm head size. 98.7 % of the patients were available for follow-up.
Results: There were eight (1 %) dislocations in 797 hips in the first 12 months after surgery with 4 weeks of hip precautions. The average time to dislocation was 7.5 weeks after surgery (range 1.0-16.9 weeks); two dislocations (25 %) took place in the first 4 weeks.
Conclusions: Shortening the time of posterolateral hip precautions from 6 to 4 weeks after surgery does not increase the risk of postoperative dislocation.