Robotic Versus Conventional Primary Total Knee Arthroplasty: Achievement of Minimal Clinically Important Difference at One-Year Follow-Up.

BACKGROUND: Total knee arthroplasty (TKA) is an effective treatment for end-stage knee osteoarthritis. However, conventional jig-based TKA (C-TKA) techniques often lack reproducibility in achieving balanced flexion-extension gaps and consistent mediolateral ligament tension. Robotic-assisted TKA (R-TKA) has emerged as a potential solution to improve accuracy in prosthesis positioning, gap balancing, and soft tissue management. This study compared R-TKA and C-TKA using validated patient-reported outcome measures (PROMs), including KOOS JR (Knee Injury and Osteoarthritis Outcome Score for Joint Replacement), PROMIS (Patient-Reported Outcomes Measurement Information System) Physical Health (PH), and PROMIS Mental Health (MH), to evaluate achievement of the minimal clinically important difference (MCID).

METHODS: A retrospective cohort study was conducted on patients who underwent primary TKA. Preoperative and one-year postoperative scores for KOOS JR, PROMIS PH, and PROMIS MH were analyzed. MCID achievement was defined using the distribution-based method.

RESULTS: Both R-TKA and C-TKA groups demonstrated significant postoperative improvements across all PROMs. At the one-year follow-up, 100% of patients in both cohorts achieved the MCID for the KOOS JR score. Similarly, high rates of MCID achievement were observed for PROMIS PH and PROMIS MH in both groups. While the R-TKA group showed a higher percentage improvement in KOOS JR scores compared to the C-TKA group, the differences between the two techniques were not statistically significant.

CONCLUSION: Both R-TKA and C-TKA result in excellent clinical outcomes and high rates of MCID achievement at one year. While R-TKA showed a trend toward greater functional improvement in joint-specific measures, it did not demonstrate statistical superiority over conventional methods in this cohort.