Assessing Minimal Detectable Changes and Test-Retest Reliability ofthe Timed Up and Go Test and the 2-Minute Walk Test in Patientswith Unicondylar Knee Replacement

Abstract

Background: The two-minute walk test (2MWT) and Timed Up and Go (TUG) test are inexpensive, fast, and reliable tests for the evaluation of mobility in patients. These tests have proven reliable and valid in many patient groups. This study aimed to measure the minimal detectable change (MDC) scores and test-retest reliability of the TUG and 2MWT in patients who underwent unicondylar knee arthroplasty (UKA). Methods: Sixty-eight patients (53 men and 15 women) who underwent UKA at the same center were evaluated. Range of motion (ROM) and Hospital for Special Surgery (HSS) scores were also measured. The TUG test and 2MWT were performed twice on the same day with a one-hour interval. Results: The interclass correlation coefficient values were 0.96 and 0.98 for the TUG test and 2MWT, respectively, which showed perfect test-retest reliability in patients who underwent UKA. The MDC values were 1.28 seconds and 5.55 meters, respectively, while the standard error measures (SEMs) were ±0.46 and ±2.00, respectively. Conclusion: The TUG test and 2MWT are cheap, reliable, easy, and simple performance-oriented tests with excellent test-retest reliability for patients with a history of UKA. For the TUG test, 1.28 seconds and more caused a real difference, while 5.55 meters was the limit for real difference for the 2MWT. These values should be considered when evaluating patients with a history of UKA.