Robotic hip replacement shows similar implant survival, fewer malposition-related revisions

A target trial emulation published in The BMJ compared early outcomes of robotic and conventional total hip replacement for arthritis using National Joint Registry data. The observational study included 666,283 procedures performed in public and private hospitals between 2018 and 2024: 656,080 conventional and 10,203 robotic replacements. Propensity score matching was used to create comparable groups. Outcomes included implant survival, revision risks, intraoperative complications, and patient survival; mean follow-up was 2.5 years.

Estimated five-year implant survival was 98.8% in both matched groups. Overall revision risk did not differ significantly (hazard ratio 0.96, 95% confidence interval 0.75 to 1.22). Robotic surgery was associated with a lower risk of revision related to implant malposition, encompassing dislocation, leg length discrepancy, and malalignment (hazard ratio 0.53, 95% confidence interval 0.30 to 0.93). Other cause-specific revision risks and intraoperative complication risks did not differ. Five-year patient survival was 96.3% with conventional surgery and 96.2% with robotic surgery, without a significant mortality difference.

These findings suggest a potential reduction in malposition-related revisions without demonstrated improvement in overall implant or patient survival. The observational design leaves possible unmeasured and residual confounding, and mean follow-up was shorter than the five-year outcome horizon. The authors emphasise careful evaluation of robotic technology given its substantially higher capital and procedural costs.