Robotic-assisted versus Conventional Manual Total Hip Arthroplasty: A Systematic Review and Meta-Analysis of Component Position Accuracy, Lewinnek Zone Outliers, and Early Dislocation Rates

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Abstract

Achieving optimal component alignment during total hip arthroplasty (THA) is essential to prevent long-term complications and extend implant survival. Although robotic-assisted setups (ra-THA) seek to maximize surgical precision, their definitive clinical advantages over traditional manual techniques (m-THA) continue to be a subject of active debate. This study aimed to systematically review and meta-analyze how ra-THA compares to m-THA regarding component alignment precision, Lewinnek safe zone outliers, and early post-surgical dislocation frequencies. We searched PubMed, Embase, and the Cochrane Library for randomized controlled trials and high-quality observational cohorts comparing ra-THA with m-THA. Core tracking endpoints included mean inclination/anteversion angles, the rate of acetabular cup placement outliers outside the Lewinnek boundaries, and early dislocations (≥ 1 year postoperatively). Data aggregation utilized fixed-effects or random-effects architectures based on baseline heterogeneity thresholds. Merging data from 15 studies (2,485 procedures) showed that ra-THA significantly reduced mean deviation from planned inclination and anteversion angles compared to manual controls (p < 0.05). Robotic guidance also sharply cut the likelihood of placing an acetabular cup outside the Lewinnek safe zone (OR = 0.24, 95% CI: 0.16-0.36; p < 0.01). Notably, this enhanced radiographic accuracy was associated with a significant drop in early postoperative dislocation events (OR = 0.38, 95% CI: 0.20 --0.73; p = 0.004). Robotic assistance provides clear structural benefits over manual methods, ensuring more predictable cup orientation and fewer positioning outliers. This mechanical precision strongly correlates with a lower rate of early dislocations within the first postoperative year.

Abstract as published, via PubMed.