Semi-active robot-assisted total hip arthroplasty versus conventional surgery: A meta-analysis of randomized controlled studies

Objective Conventional total hip arthroplasty (cTHA) may be technically challenging in some scenarios. Robotic-assisted THA (rTHA) was introduced in the 1980s with an active ROBODOC system. Considering the miscellaneous drawbacks of this early system, more recent semi-active systems were subsequently introduced. The present meta-analysis aimed to compare the operative and clinical outcomes of rTHA assisted by semi-active systems with those of cTHA in randomized controlled trials (RCTs). Methods The present study was conducted in line with the recommendations of the Preferred Reporting Items for Systematic Review and Meta-Analyses 2020 expanded statement. Three databases were searched for relevant studies (July 2025) in English, including PubMed, Web of Science Core Collection and Scopus. The outcome data included the operative time, amount of intraoperative and total blood loss, duration of hospital stay, number of patients in the Lewinnek or Callanan safe zones, postoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, postoperative Harris hip score and leg length discrepancy (LLD). The risk of bias in the included studies was assessed via the risk of bias assessment tool. Results Eleven RCTs with 834 patients were included in this study. No significant differences were found between rTHA and cTHA regarding blood loss, hospital stay, WOMAC score or Harris hip score. While cTHA had a significantly shorter operative duration (MD: 22.12; 95% CI: 9.75, 34.48), rTHA was associated with a significantly greater frequency of patients in the Lewinnek (OR: 4.11; 95% CI: 2.04, 8.31) and Callanan (OR: 3.93; 95%: 1.15, 13.57) safe zones and a significantly lower LLD (SMD: -0.45; 95% CI: -0.60, -0.30). Conclusion Compared with cTHA, rTHA is a more accurate surgical technique with comparable blood loss, hospital stay and clinical scores.