Validity and reliability of functional performance tests in meniscectomized patients with or without knee osteoarthritis

Abstract

Reduced functional performance and muscular dysfunction after knee injury and in knee osteoarthritis (OA) is suggested to be a factor in OA development. Validated functional performance tests applicable in the clinic and large-scale studies are lacking. The aim was to study the reliability and validity of 10 functional performance tests. Two hundred and eighty-five subjects, 15-22 years post-meniscectomy, performed 10 functional performance tests. The mean age was 54 years (SD+/-11.2) and 79% were men; 52% had radiographic OA, and 48% were categorized as symptomatic. The tests were evaluated for test-retest reliability, discriminative ability (younger vs older age, men vs women, symptom-free vs symptomatic) and floor and ceiling effects. Two of the 10 tests, maximum number of knee bendings in 30 s and one-leg hop for distance, had good test-retest reliability (ICC 0.92, 95% CI 0.86-0.96 and 0.93, 95% CI 0.87-0.97) and were able to discriminate with regard to age, gender and symptoms, and had acceptable floor effects (9% and 3%, respectively). This study suggests the use of two functional performance tests: knee bendings/30 s and one-leg hop for distance, easy to use for evaluation of interventions due to knee injury and knee OA and when attaining long-term data of natural disease history.