GAP-TENSION MATRIX-DRIVEN SOFT-TISSUE BALANCING AND BONE RESECTION YIELDS SUPERIOR CLINICAL OUTCOMES IN ROBOTIC TOTAL KNEE ARTHROPLASTY: A PROPENSITY SCORE-MATCHED STUDY

Aims Integrating intraoperative measurement of joint gap width and soft-tissue tension into robotic-assisted total knee arthroplasty (rTKA) may optimize surgical planning, thereby facilitating superior soft-tissue balancing and more precise bone resection. The aim of this study was to evaluate the clinical superiority of a gap-tension matrix-driven (GTM) balancing and bone resection strategy in rTKA. Methods We conducted a retrospective analysis of prospectively collected data for patients who underwent rTKA between May 2021 and December 2023. GTM strategy was based on intraop measurement using a novel tensor (Balance Solver). Graded tensions (30 N to 90 N) were programmed and applied to medial and lateral gap at full extension, early extension and 90° of knee flexion. Intra-op surgical planning and subsequent bone resection were driven by a multi-dimensional gap-tension matrix, which mapped soft-tissue elastokinematics into executable robotic targets. GTI strategy was compared to standard rTKA workflow with manually applied tension after 1:1 propensity score matching based on age, sex, body mass index, Charlson Comorbidity Index, and preoperative alignment. A restricted functional alignment (rFA) was targeted in all cases. Outcomes were assessed using overall patient satisfaction, the Forgotten Joint Score (FJS), and the Knee injury and Osteoarthritis Outcome Score (KOOS). Results 280 patients (140 in GTM group and 140 in standard rTKA group) with a minimum two-year follow-up (mean 32.7 months) were included in the analysis. The GTM group demonstrated a significantly higher mean FJS (72.10 ± 22.81 vs. 63.72 ± 13.99; p < 0.001) and improved KOOS symptom subscale scores (87.17 ± 11.13 vs. 82.12 ± 13.75; p < 0.001). No significant differences were observed across the remaining KOOS subscales (p > 0.05). Overall patient satisfaction was comparable between the matrix-driven and standard TKA groups (93.6% vs. 90.7%, respectively; p =0.374). postop alignment Conclusion This matrix driven soft tissue balancing and bone resection strategy in rTKA yields superior joint awareness (FJS) and improved symptom scores at short-term follow-up. Matrix-driven balancing and bone resection based on graded elasto-kinematic profiling demonstrates clear clinical advantages over conventional manual tension in rTKA.