Preoperative predictors of instrumental activities of daily living disability in older adults six months after knee arthroplasty

Objective To investigate preoperative predictors of instrumental activities of daily living (IADL) disability in older adults six months after knee arthroplasty (KA). Design Prospective cohort study Setting General hospital with an orthopedic surgery department Participants Two hundred twenty (N = 220) patients 2: 65 years old with total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) Interventions: Not applicable Main Outcome Measure IADL status was evaluated for six activities. Participants chose “able,” “need help,” or “unable” according to their capacity of executing these IADL activities. If they chose “need help” or “unable” for one or more items, they were defined as “disabled.” Their usual gait speed (UGS), range of motion for the knee, isometric knee extension strength (IKES), pain status, depressive symptoms, pain catastrophizing, and self-efficacy were evaluated as predictors. Baseline and follow-up assessments were conducted one month before and six months after KA, respectively. Logistic regression analyses with IADL status as the dependent variable were performed at follow-up. All models were adjusted using age, sex, severity of the knee deformity, operation type (TKA or UKA), and preoperative IADL status as covariates. Results In total, 166 patients completed the follow-up assessment, and 83 (50.0%) reported IADL disability six months after KA. Preoperative UGS, IKES on the non-operated side, and self-efficacy were statistically significantly different between those with a disability at follow-up and those who did not and were therefore included in logistic regression models as independent variables. UGS (odds ratio = 3.22, 95% confidence interval = 1.38–7.56, p = 0.007) was determined as a significant independent variable. Conclusion The present study demonstrated the importance of evaluating preoperative gait speed to predict the presence of IADL disability in older adults six months after KA. Patients with poorer preoperative mobility should be provided careful postoperative care and treatment.