Correlation of Isokinetic Strength Deficits and Subjective Complaints in Patients with Knee Osteoarthritis Scheduled for Total Knee Arthroplasty.

Abstract

This study investigated isokinetic muscle strength deficits in patients with advanced knee osteoarthritis (KOA) scheduled for total knee arthroplasty (TKA) to explore the relationship between objective strength measures and subjective symptoms such as pain and functional limitations. By analyzing muscle function using isokinetic dynamometry, the study aimed to provide insights into how strength deficits relate to patient-reported outcomes and whether these assessments could inform surgical decision-making. A total of 52 patients (mean age: 66.96 years, 53.85% female) with advanced KOA awaiting TKA were included. Isokinetic muscle strength of the knee, measured in peak torque (Newton-meters), work (Joules), and power (Watts), was assessed bilaterally before surgery using a Biodex dynamometer at angular velocities of 180 degrees/s and 60 degrees/s. Subjective symptoms were evaluated using standardized assessments, including the Numeric Rating Scale (NRS), Knee Injury and Osteoarthritis Outcome Score (KOOS), Short Form-12 (SF-12), Hospital Anxiety and Depression Scale (HADS-D), and EuroQol 5-Dimension 3-Level questionnaire. Findings revealed a significant strength deficit on the affected side scheduled for surgery (p < 0.050). However, correlations between isokinetic knee parameters and symptom scores were weak (|r| ≤0.5), suggesting that subjective complaints do not necessarily align with objective strength measurements. Notably, isokinetic parameters were significantly intercorrelated (p < 0.050). These results indicate that isokinetic dynamometry effectively quantifies muscle strength differences in KOA patients, yet its findings should be considered alongside clinical assessments and patient-reported symptoms to form a comprehensive evaluation of disease severity and surgical necessity.