The invasiveness of robot-assisted total hip replacement is similar to that of conventional surgery

Robot-assisted total hip arthroplasty (R-THA) is increasingly being performed throughout the world. The invasiveness of this operation is unknown. We retrospectively reviewed the cohort of consecutive osteonecrosis of the femoral head (ONFH) patients who received primary R-THA or manual THA (M-THA) from January 2020 to January 2022 in our institution. One experienced surgeon performed all procedures. We calculated the propensity score to match similar patients in different groups by multivariate logistic regression analysis for each patient. We included confounders consisting of age, sex, body mass index (BMI), and operation time. Preoperative serum markers and Harris hip scores (HHS), postoperative serum markers at first day and third day, complications rate, postoperative HHS and Forgotten Joint Score (FJS) at 6 months after surgery of different cohorts were compared. We analyzed 218 ONFH patients treated with THA (98 R-THA patients, and 120 M-THA patients). After propensity score matching, we generated cohorts of 95 patients in R-THA and M-THA groups. We found no significant difference in preoperative serum markers and HHS. In the R-THA cohort, the PLT count was significantly lower on the postoperative day 1 (192.36 +/- 41.72 x 10(9)/L Vs 210.47 +/- 72.85 x 10(9)/L, p < 0.05). The Hb level was significantly lower on the postoperative third day in the R-THA cohort (98.52 +/- 12.99 g/L Vs 104.74 +/- 13.15 g/L, p < 0.05). There was no significant difference in the other serum markers between the cohorts on postoperative day 1 and 3 (p > 0.05). 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). The R-THA is not associated with a serious invasiveness compared to M-THA. Patients who underwent R-THA had a better early function compared to those who underwent M-THA.