Utilisation trends and early outcomes of robotic arm-assisted total hip arthroplasty in a tertiary joint replacement centre in Hong Kong.

INTRODUCTION This study evaluated utilisation trends and early outcomes of robotic arm-assisted primary total hip arthroplasty (rTHA) compared with conventional THA (cTHA) in Hong Kong.

METHODS This retrospective cohort study included all patients who underwent primary THA in public hospitals under the Hong Kong West Cluster (HKWC) from 2019 to 2024. Data were retrieved from the Hospital Authority's electronic databases. The primary outcome was the percentage utilisation of rTHA relative to cTHA. Secondary outcomes included operating time (skin-to-skin), length of stay (LOS), 30- and 90-day reoperation rates, and 30- and 90-day emergency department attendance. Differences in these outcomes between rTHA and cTHA were examined.

RESULTS In total, there were 311 and 242 cases of rTHA and cTHA, respectively. Robotic utilisation increased from 32.0% in 2019 to 62.2% in 2024. Regarding patient outcomes, rTHA increased operating time by 14.59 minutes (142.02 ± 53.88 vs 127.43 ± 53.34; P=0.002). There was no significant difference in median LOS between the two groups. Robotic surgery was also associated with a lower 30-day reoperation rate (0.32% vs 2.07%; P=0.049). One reoperation due to dislocation was performed in the rTHA group. In the cTHA group, one dislocation, two periprosthetic fractures, and two infections required revision surgery.

CONCLUSION Given the increasing use of rTHA in the HKWC, the present findings suggest that rTHA is associated with a lower 30-day reoperation rate. As the first local study on early outcomes of rTHA, these results may serve as reference data for other centres.