Comorbidities in Patients With End-Stage Knee OA: Prevalence and Effect on Physical Function

Abstract

ObjectiveTo investigate the prevalence of comorbidities and their effect on physical function, quality of life (QOL), and pain, in patients with end-stage knee osteoarthritis (OA). DesignA cross-sectional study. SettingA rehabilitation facility at university hospital. ParticipantsPatients (N=577; 503 women and 74 men) diagnosed with end-stage knee OA between October 2013 and June 2018. InterventionNot applicable. Main Outcome MeasuresComorbidities were as follows: osteoporosis, presarcopenia, degenerative spine disease, diabetes, and hypertension. All patients completed the following performance-based physical function tests: stair-climbing test (SCT), 6-minute walk test (6MWT), timed Up and Go (TUG) test, and gait analysis. Self-reported physical function and pain were measured using Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and a visual analog scale (VAS), respectively, and self-reported QOL was measured using EuroQoL 5 dimensions (EQ-5D) questionnaire. ResultsUnivariate analyses revealed that patients with osteoporosis had significantly higher scores in SCT ascent, SCT descent, TUG, WOMAC pain tests, and lower scores in 6MWT, gait speed, and cadence tests than those without osteoporosis. Patients with presarcopenia recorded higher scores in SCT ascent, TUG, EQ-5D, and lower scores in 6MWT and gait speed tests than those without presarcopenia. Patients with degenerative spine disease showed higher scores in WOMAC pain and lower scores in gait speeds than those without degenerative spine disease. Patients with diabetes showed higher scores in SCT ascent than those without diabetes, and patients with hypertension showed lower scores in 6MWT than those without hypertension. After adjusting age, sex, and body mass index, SCT descent retained significant association with osteoporosis, SCT ascent showed independent association with presarcopenia and diabetes, and WOMAC pain revealed significant association with degenerative spine disease. ConclusionThe results confirm associations between comorbidities, performance-based and self-reported physical functions, and QOL in patients with end-stage knee OA.