Correlation Between Functional Scores and Objective Gait Parameters Following Rotating Hinge Knee Megaprosthesis...

Although the Musculoskeletal Tumor Society (MSTS) score, Toronto Extremity Salvage Score (TESS), and Knee Society Score (KSS) are widely used for postoperative functional evaluation in patients undergoing rotating hinge knee (RHK) megaprosthesis reconstruction, their accuracy in reflecting objective gait performance remains uncertain. The study aimed to analyze the correlations between these scoring systems and gait parameters.

This retrospective study included 21 patients who underwent RHK between April 2023 and April 2025. At one-year follow-up, functional outcomes were assessed using MSTS, TESS, and KSS. Gait parameters were collected using the Intelligent Device for Energy Expenditure and Activity (IDEEA v3.1, MiniSun LLC). All functional assessments were completed on the same day as the gait analysis. Linear regression analyzed correlations between each scoring system and gait parameters. Friedman and Wilcoxon signed-rank tests compared median coefficients of determination across scoring systems. Stepwise multiple linear regression was used to examine the relationships between the scoring system subitems and gait parameters.

Significant correlations were observed between all three scoring systems and multiple gait parameters after RHK (p < 0.05). The TESS had a significantly greater median R ² than did the MSTS score and KSS (p < 0.05), especially for walking velocity (R ² = 0.76), step length (R ² = 0.75), initial contact phase (R ² = 0.65), and stride length (R ² = 0.58). Multiple linear regression analysis revealed that the MSTS "walking" and KSS "function" subitems independently or jointly predicted key gait parameters, including walking velocity, step length, and cadence (R ² > 0.48).

All three scoring systems showed correlations with multiple key gait parameters in patients who underwent RHK. However, TESS demonstrated stronger and more consistent correlations and therefore appeared to be a more representative score of gait recovery.