RESUMEN
BACKGROUND: Knee osteoarthritis (OA) is a debilitating condition that leads to functional limitations. Self-reported questionnaires and performance-based tests are tools commonly used for measuring physical function. OBJECTIVES: (1) To evaluate the impact of end-stage knee OA on functional outcomes and examine the association between self-reported and performance-based measures of function in patients with end-stage knee osteoarthritis awaiting total knee arthroplasty (2) To explore the interrelationships among pain, strength, and overall physical function in this patient population. METHODS: In this cross-sectional analysis, 33 patients with end-stage knee OA were recruited and completed the knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS) and executed performance-based tests including the Timed Up and Go, the 30-second chair stand test, and the Stair Climbing Test. Knee pain, and isometric hip and knee strength were evaluated. RESULTS: Patients perceived deficits in their physical functionwith a score of 35/100 on the KOS-ADLS and demonstrated functional limitations in all performed tasks. KOS-ADLs was weakly associated with TUG and 30s-CST (r=-0.301, p= 0.047, and r= 0.39, p= 0.014. respectively). Knee pain was linked with the KOS-ADL score and GRS score (r=-0.406, p= 0.010; r=-0.343, p= 0.027; respectively), while the strength of the affected side was correlated with the performed (p=< 0.001) and reported function outcomes (p= 0.007). CONCLUSION: Participants exhibit declines in both perceived and executed functional abilities. Self-reported and performance-based functional measures are weakly correlated within our study group, highlighting the importance of incorporating both measures in clinical practice for a comprehensive evaluation of physical function. Pain was linked to subjective aspect of physical function, while strength was connected to perceived and performed functional capacity. Implementing a tailored rehabilitation program targeting muscle weakness and pain holds the potential to mitigate functional decline in individuals awaiting total knee arthroplasty (TKA).
