A New Method for Defining Balance

TLDR

Technological advances now allow quantification of pressure across the bearing surface during total knee arthroplasty. The study aims to define knee balance and assess whether balanced knees improve short‑term clinical outcomes. Using intraoperative sensors across multiple centers, the study compared outcome scores between balanced and unbalanced knees. Balanced knees achieved significantly higher KSS and WOMAC scores at 6 months, were the strongest predictor of improved outcomes, and were 2.5, 1.3, and 1.8 times more likely to reach meaningful improvement in KSS, WOMAC, and activity level.

Abstract

Recently, technological advances have made it possible to quantify pounds of pressure across the bearing surface during TKA. This multicenter evaluation, using intraoperative sensors, was performed for two reasons: 1) to define "balance" 2) to determine if patients with balanced knees exhibit improved short-term clinical outcomes. Outcomes scores were compared between "balanced" and "unbalanced" patients. At 6-months, the balanced cohort scored 172.4 and 14.5 in KSS and WOMAC, respectively; the unbalanced cohort scored 145.3 and 23.8 in KSS and WOMAC (P < 0.001). Out of all confounding variables, balanced joints were the most significant contributing factor to improved postoperative outcomes (P < 0.001). Odds ratios demonstrate that balanced joints are 2.5, 1.3, and 1.8 times more likely to achieve meaningful improvement in KSS, WOMAC, and activity level, respectively.