How do dislocation rates differ between different approaches to total hip arthroplasty? A systematic review and meta-analysis

Background: Different surgical approaches for total hip arthroplasty (THA) exist, without predisposition when it comes to dislocation risk. The direct anterior approach (DAA) is thought to have reduced risk since soft tissue trauma is minimalized. Therefore, we assessed the dislocation risk for different surgical approaches, and the relative dislocation risk of DAA compared to other approaches. Methods: Six electronic databases were systematically searched for prospective studies reporting dislocation following THA. Proportion meta-analyses were performed to assess the dislocation rate for subgroups of the surgical approach. Meta-analysis for binary outcomes was performed to determine the relative risk of dislocation for the DAA compared to other approaches. Results: Eleven studies with 2025 patients were included (mean age 64.6 years, 44% male, mean follow-up 10.5 months), of which four studies were also used in the risk ratio meta-analysis. Overall dislocation rate was 0.79% (95% CI 0.37–1.69). Subgroup analyses showed that most dislocations occurred in the posterior approaches group (1.38%), however non-significant. Furthermore, the DAA emerged with a non-significant lower risk of dislocation (RR 0.37, 95% CI 0.05–2.46) compared to other surgical approaches. Conclusion: Current literature shows non-significant predisposition for a surgical approach to THA regarding dislocation risk. To what extent patient characteristics influence the risk of dislocation could not be determined. Future research should focus on this, as well as on the influence of a surgeon's experience with a specific approach.