Dislocation Rates Between Manual and Robotic-Assisted Total Hip Arthroplasty Using the Posterolateral Approach

Introduction: Dislocation is a known risk after total hip arthroplasty (THA), occurring in approximately 2% of cases. Although the posterolateral approach is the most commonly used approach to the hip, the disruption of posterior soft tissue is a concern for implant stability. The introduction of robotic assistance in arthroplasty has demonstrated improved implant positioning, although the effect on outcomes is still being assessed. The purpose of our study was to assess the 90-day dislocation rate between robotic-assisted and manual primary THA through the PL approach. Methods: Data were collected from two board-certified adult reconstruction surgeons who performed THA through a PL approach from 2014 to 2023. These two surgeons had high-volume arthroplasty practices and transitioned from manual to robotic-assisted surgery within this period. Variables including patient demographic information, use of robotic assistance, total 90-day complications, and Hip Disability and Osteoarthritis Outcome Score were collected and analyzed. Statistical analysis for numerical values was conducted using Student t -test and categorical variables with chi-square analysis, with alpha set at 0.05. Results: Two thousand five hundred forty-eight patients underwent a THA through the PL approach at our institution from 2014 to 2023. One thousand seven hundred twenty-seven patients had a manual THA, and 821 patients had a robotic-assisted THA. No significant difference was noted in total complication rates (n = 59, 3.4% vs. n = 18, 2.2%, P = 0.092) or dislocation rates (n = 7, 0.4% vs. n = 3, 0.4%, P = 0.88) between the manual and robotic-assisted groups, respectively. No statistical difference was found in the Hip Disability and Osteoarthritis Outcome Score at any of the postoperative time points. Total surgical time was markedly longer for the robotic-assisted group (88 minutes) compared with the manual group (74 minutes). Conclusion: This study demonstrated no notable difference in 90-day dislocation rates for high-volume arthroplasty-trained surgeons when comparing manual versus robotic-assisted THA when using the PL approach.