Robotic-assisted total hip arthroplasty in the United States: a nationwide propensity-matched analysis of adoption, outcomes, and complications

TL;DR

This study analyzes the adoption and outcomes of robotic-assisted hip replacement surgery in the U.S., finding it is linked to shorter hospital stays and fewer complications, though at higher costs.

Contribution

This is the first nationwide analysis of robotic-assisted total hip arthroplasty (RA-THA) using real-world data and propensity matching.

Findings

Robotic-assisted THA was associated with shorter hospital stays and lower complication rates compared to conventional THA.

RA-THA adoption increased from 1.2% in 2016 to 6.7% in 2022.

Hospital charges were higher for RA-THA despite its clinical benefits.

Abstract

Robotic assisted total hip arthroplasty (RA-THA) has been introduced to improve the precision of implant positioning and potentially enhance outcomes in THA. However, large scale national data on its real-world impact are lacking. This study presents the first nationwide analysis of RA-THA using the National Inpatient Sample (NIS), evaluating trends in adoption and comparing perioperative outcomes between RA-THA and conventional THA.

We performed a retrospective cohort study using the NIS (2016–2022). Adult patients undergoing primary elective THA were identified, and those with robotic assistance were classified using ICD-10 procedural codes for robot-assisted surgery. Propensity score matching (1:1) was employed to create comparable cohorts of RA-THA vs. conventional THA, controlling for patient demographics, hospital characteristics, and comorbidities. Temporal trends in RA-THA utilization were assessed. Outcomes included length of stay (LOS), hospital charges, and in-hospital complications. Matched outcomes were compared with appropriate statistical tests, and relative risks (RR) of specific complications were analyzed.

A total 1.9 million THA cases were identified nationwide, of which 2.9% involved robotic assistance. RA-THA utilization increased significantly over the study period (from 1.2% in 2016 to 6.7% in 2022, P < 0.01). In unmatched comparisons, patients undergoing RA-THA were slightly younger on average and more frequently treated at urban teaching hospitals than those with conventional THA. After propensity matching RA-THA was associated with a shorter mean LOS (by 0.7 days) and higher mean hospital charges (by 10,000$~, P < 0.01). The matched RA-THA cohort had a significantly lower overall complication rate compared to matched conventional. In particular, non-robotic THA patients had higher risks of transfusion, in-hospital prosthetic complications, and venous thromboembolism. A forest plot of matched outcomes demonstrated that conventional THA carried elevated RRs for multiple postoperative complications relative to RA-THA (RR > 1 favoring RA-THA for most complication endpoints).

In this first nationwide analysis of RA-THA, we found that robotic assistance, while still used in a minority of THA cases, grew steadily in adoption through 2022. RA-THA was associated with shorter hospital stays and a reduced risk of in-hospital complications compared to conventional THA, with higher hospitalization costs. These findings suggest that RA-THA can confer perioperative benefits in routine practice, though its economic impact and long-term clinical advantages remain areas for further investigation.

Levels of Evidence: LEVEL III.

The online version contains supplementary material available at 10.1007/s00423-025-03963-7.

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