Comparison of postoperative balance and function between primary and revision total knee arthroplasty

Abstract

Objective: This study aimed to compare postural balance, functional performance, and patient-reported outcomes between primary total knee arthroplasty (pTKA) and revision total knee arthroplasty (rTKA) patients. Methods: A cross-sectional analysis was conducted on 37 patients (57 knees: 30 pTKA, 27 rTKA) who were at least one-year post-surgery. Balance was evaluated using the Biodex Biosway system (postural stability, limits of stability, sensory interaction), while functional mobility was assessed with the 2-Minute Walk Test (2MWT), Timed Up and Go Test (TUGT), and 30-Second Chair Stand Test (30CST). Patient-reported outcomes included the Hospital for Special Surgery knee scale, Lower Extremity Functional Scale, Activities-specific Balance Confidence Scale, and SF-12 health survey. The Benjamini-Hochberg correction was applied for multiple comparisons. Results: The rTKA group was significantly older compared to the pTKA group (p < 0.01). The rTKA group demonstrated significantly worse postural stability with higher scores on the Anteroposterior Stability Index (p = 0.01) and Overall Stability Index (p = 0.007). In functional performance, the pTKA group significantly outperformed the rTKA group on the 2MWT (p = 0.003), TUGT (p = 0.03), and 30CST (p = 0.03). However, there were no significant differences in most patient-reported outcomes, except for a higher SF-12 Mental Component score in the rTKA group (p = 0.036). Conclusions: rTKA patients exhibit significantly worse objective postural balance and functional performance compared to pTKA patients, despite achieving similar pain and functional scale scores. These findings, while influenced by the rTKA group's older age, highlight the need for tailored rehabilitation protocols that specifically address balance deficits and proprioception in this patient population.