The reliability and validity of the Lie‑To‑Sit‑To‑Stand‑To‑Walk transfer test in total knee arthroplasty.

Background: Total knee arthroplasty (TKA) is the standard procedure for treating end-stage knee osteoarthritis. Nevertheless, some residual issues can persist, leading to various problems, including pain, compromised strength, impaired proprioception, postural instability, dynamic balance issues, and gait deficiencies. The Lie-to-Sit-to-Stand-to-Walk Transfer Test (LSSWT) implements a multi-faceted methodology to evaluate basic transfer abilities. The purpose of this study is to investigate the validity, reliability, and minimal clinically important difference of the LSSWT in TKA patients.

Methods: Twenty-two patients with TKA were enrolled in this study. The patients were administered the LSSWT, the Timed Up and Go Test (TUG), and the Hospital for Special Surgery (HSS) knee score. Patients rested between the tests for an hour to prevent fatigue.

Results: The mean age was 68.1 ± 2.59 years and the mean HSS Knee Score was 85.43 ± 3.47 of the patients. The relative (ICC coefficient) and absolute (SEM and SRD95) reliability values were 0.88, 1.21, and 3.33 respectively. The Spearman correlation coefficient of the LSSWT with the TUG was 0.63.

Conclusions: The LSSWT displays excellent reliability and high validity in assessing fall risk, complex dynamic balance, and mobility required for daily activities in patients post-TKA. The low MCID value (3.33) indicates its sensitivity and ability to identify minor changes in a patient's status over time or in response to rehabilitation applications. Therefore, it is recommended to use the LSSWT when evaluating fall risk, dynamic balance, and mobility for community living, discharge planning, or facility admission.