Robot-assisted total hip arthroplasty is not associated with serious invasiveness

Abstract Background: Robot-assisted total hip arthroplasty (R-THA) is increasingly being performed throughout the world. The invasiveness of this operation is unknown. Methods: Data from patients who received primary R-THA or manual THA (M-THA) for osteonecrosis of the femoral head between January 2020 and January 2022 were retrospectively reviewed. Preoperatively and on postoperative days 1 and 3, we compared the platelet (PLT), white blood cell (WBC), neutrophil rate, lymphocyte rate, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6), delta hemoglobin drop (delta Hb),creatine kinase (CK), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) levels between the groups. Age, gender, the pre- and post-operative Harris Hip Score (HHS), operating time, transfusion rate, the post-operative Forgotten Joint Score (FJS), and 12-week postoperative complications rate were all recorded. Results: The PLT count was significantly lower, and the lymphocyte rate was significantly higher on the postoperative day 1, in the R-THA than M-THA group (both p < 0.05). There was no significant difference in the other serum markers between the groups on postoperative day 1 and 3 (p > 0.05). The operating time was significantly longer in the R-THA than M-THA group (p < 0.01). The FJS was significantly higher in the R-THA than M-THA group (p = 0.01). There was no significant difference in the postoperative HHS or complication rate between the groups (p > 0.05). Conclusion: The R-THA is not associated with a serious invasiveness compared to M-THA, despite with longer operating time. Patients who underwent R-THA had a better early function compared to those who underwent M-THA.