Comparative outcomes between a new robotically assisted and a manual technique for total knee arthroplasty in patients with osteoarthritis: a prospective matched comparative cohort study

Purpose: Studies comparing clinical outcomes between manual (mTKA) and robotic-assisted TKA (raTKA) are limited. This prospective comparative cohort study aimed to compare early postoperative outcomes, satisfaction, and patient-reported outcome measures (PROMS) between patients undergoing mTKA and ROSA raTKA (Zimmer Biomet, Warsaw, IN) performed by one surgeon.

Methods: Thirty ROSA raTKAs and 30 mTKAs performed by one surgeon during 2020-2021 were prospectively evaluated. Groups were matched for age, sex, and body mass index. All procedures were primary unilateral TKAs using the same posterior-stabilized prosthesis (Nexgen Legacy, Zimmer Biomet, Warsaw, IN). Length of hospital stay (LOS) and blood transfusion rate were recorded. Complications, visual analogue scale score (VAS), and Oxford Knee Score (OKS) were assessed preoperatively and for six postoperative months. The Forgotten Joint Score (FJS) and patient satisfaction were evaluated 6 months postoperatively.

Results: No complications and similar blood transfusion rate were recorded between groups (p = 0.228). The LOS was non-significantly shorter in raTKA than in the mTKA group (p = 0.120). Mean preoperative and third-month OKS and VAS scores were comparable between groups. However, the mean 6-month OKS (p = 0.006) and VAS score (p = 0.025) were significantly better for the raTKA group. The 6-month FJS was significantly greater for raTKA than the mTKA group (p < 0.001). One patient was unhappy in raTKA, and three in the mTKA group (p = 0.301). Significantly more raTKA patients answered that they would undergo surgery again (p = 0.038).

Conclusion: raTKA was associated with the same complication risk, less pain level, better patient satisfaction, and PROMs on 6-month follow-up than the mTKA group.