BMC Musculoskeletal Disorders, cilt.27, sa.1, 2026 (SCI-Expanded, Scopus)
Background: Total knee arthroplasty (TKA) has become increasingly common in younger and more active patients. However, conventional patient-reported outcome measures frequently demonstrate ceiling effects and fail to capture the high functional demands of this population. The High-Activity Arthroplasty Score (HAAS) was designed to assess advanced functions such as running, stair climbing, and demanding daily activities. This study aims to translate, culturally adapt, and validate the Turkish version of HAAS (T-HAAS) for patients undergoing total knee arthroplasty (TKA). Methods: Following Beaton’s guidelines, the HAAS was translated, back-translated, and pilot tested. Reliability was assessed using Cronbach’s alpha, the intraclass correlation coefficient (ICC₂,₁) based on a 7-day test–retest interval, the standard error of measurement (SEM), and the minimal detectable change (MDC). Content validity was ensured through expert committee review and pilot testing. Construct validity was examined via convergent validity, using correlations between the T-HAAS and the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Forgotten Joint Score–12 (FJS-12), the Numerical Pain Rating Scale (NPRS), and the Short Form Health Survey–36 (SF-36). Agreement was analyzed with Bland–Altman plots, and floor and ceiling effects were determined. Results: Fifty-one patients with TKA (mean age 59.3 ± 5.4 years; 94.1% female) were included. The T-HAAS demonstrated excellent internal consistency (Cronbach’s α = 0.83) and excellent test–retest reliability (ICC₂,₁ = 0.96; 95% CI: 0.93–0.98). Measurement error indices were low (SEM = 0.55; MDC = 1.52), indicating high measurement precision and score stability. Exploratory factor analysis supported a single-factor structure of the T-HAAS, indicating sufficient one-dimensionality. Construct validity was supported in accordance with predefined hypotheses, with strong correlations observed for KOOS Pain (r = 0.65) and KOOS Sport (r = 0.61), and moderate correlations for the Forgotten Joint Score–12 (r = 0.52), KOOS Function (r = 0.50), and the NPRS (r = − 0.47) (all p < 0.001). Bland–Altman analysis demonstrated excellent agreement between repeated measurements, and no floor or ceiling effects were identified. Conclusions: T-HAAS showed high reliability, strong construct validity, and no floor or ceiling effects in TKA patients. Trial registration: ClinicalTrials.gov ID NCT05217264. Date of registration 18th January, 2022.