Relaxed Hip Precautions Do Not Increase Early Dislocation Rate Following Total Hip Arthroplasty

Historically, hip precautions have been prescribed after total hip arthroplasty (THA) to limit certain motions felt to place the arthroplasty construct in a position at increased risk for dislocation. This study aimed to determine whether relaxed hip precautions after primary THA done via a posterolateral approach resulted in a higher early dislocation rate compared with standard hip precautions.

The hip precaution protocol was changed from standard to relaxed at our institution for all patients with THA in December 2016. One cohort had THA in the 18 months before the protocol change and had standard hip precautions, and the second cohort had THA in the 18 months after the protocol change and had relaxed precautions. We determined the early dislocation rate (within 3 months postoperatively) for both cohorts and controlled for selected demographic and surgical details.

The standard precaution group included 597 primary THAs and the relaxed precaution group included 692 hips. No notable differences were found between the groups in terms of age at surgery, body mass index, sex, laterality, or diagnosis. Early dislocation occurred in seven hips (1.2%) in the standard precaution cohort and in nine hips (1.4%) in the relaxed precaution cohort. This difference was not statistically significant (P = 0.77).

The results of our study suggest that well-trained, high-volume surgeons may potentially relax hip precautions prescribed to the patients after primary THA done via a posterolateral approach without subjecting patients to a markedly higher incidence of dislocation. However, unlike previous studies, this study controlled for femoral head size, which is a well-known confounder for dislocation risk.