Preoperative Predictors of Instrumental Activities of Daily Living Disability in Older Adults 6 Months After Knee Arthroplasty

Abstract

ObjectiveTo investigate preoperative predictors of instrumental activities of daily living (IADL) disability in older adults 6 months after knee arthroplasty (KA). DesignProspective cohort study. SettingGeneral hospital with an orthopedic surgery department. ParticipantsTwo hundred twenty (N=220) patients 65 years or older with total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA). InterventionsNot applicable. Main Outcome MeasuresIADL status was evaluated for 6 activities. Participants chose “able,” “need help,” or “unable” according to their capacity of executing these IADL. If they chose “need help” or “unable” for 1 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 1 month before and 6 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. ResultsIn total, 166 patients completed the follow-up assessment, and 83 (50.0%) reported IADL disability 6 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% CI, 1.38-7.56; P=.007) was determined as a significant independent variable. ConclusionsThe present study demonstrated the importance of evaluating preoperative gait speed to predict the presence of IADL disability in older adults 6 months after KA. Patients with poorer preoperative mobility should be provided careful postoperative care and treatment.