Falls after total knee arthroplasty : frequency, circumstances, and associated factors—a prospective cohort study

Abstract

Background. Individuals with total knee arthroplasty (TKA) often experience pain and reduced balance control, which may predispose them to greater fall risk. Objective. The objective of this study was to determine the frequency and circumstance of falls and fall-related risk factors within a 6-month follow-up period in individuals after TKA. Design. This study was a prospective cohort study. Methods. Knee proprioception, the Balance Systems Evaluation Test, knee pain, knee extension and flexion muscle strength, knee range of motion, and balance confidence were evaluated in 134 individuals (39 men, 95 women; mean age = 66.3 years [SD = 6.6 years]) 4 weeks after TKA. Monthly follow-up sessions, via face-to-face or telephone interviews, were implemented to obtain data on fall incidence over 6 months. Results. Twenty-three individuals after TKA (17.2%) sustained at least 1 fall during the 6-month follow-up period. The median time of the first fall episode was 15 weeks after TKA. Of the 31 fall episodes, most occurred during walking (67.7%). Slipping (35.5%) and tripping (35.5%) were identified as the most frequent causes of falling. Most falls occurred at home (45.2%) or another indoor environment (29.0%). Multivariate binary logistic regression revealed that younger age (odds ratio: 0.91), reduced proprioception of the knee that had undergone surgery ("operated knee") (odds ratio: 1.62), reduced sensory orientation (odds ratio: 0.92), and greater operated knee pain (odds ratio: 1.68) were significantly associated with more falls during the follow-up period. Limitations. The results of this study may be generalizable up to 6 months after TKA. Conclusions. Intervention efforts should target deficits in knee proprioception and sensory orientation and operated knee pain to prevent future falls in individuals with TKA.