A longitudinal comparative study of falls in persons with knee arthroplasty and persons with or at high risk for knee osteoarthritis.

OBJECTIVES: we determined the yearly prevalence of single and multiple falls in persons with or at risk of knee osteoarthritis (OA) and persons undergoing knee arthroplasty over an 8-year period. We also compared annual fall rates among persons with and without knee arthroplasty to determine if fall rates are associated with knee arthroplasty. METHODS: we studied 4,200 persons from the Osteoarthritis Imitative (OAI), a National Institutes of Health funded prospective study of persons 45-79 years and conducted from 2004 to 2012. All either had knee OA or were at risk of developing knee OA but did not have knee arthroplasty. The surgical group comprised 413 persons who underwent knee arthroplasty. Key fall risk factors were assessed at yearly study visits. Graphical depictions illustrated single and multiple fall trajectories. Multinomial regression adjusted for potential confounders compared fall rates for those with and without knee arthroplasty. RESULTS: fall rate trajectories for the two samples were generally flat and fall rates were similar. For the arthroplasty sample, fall rates did not increase in the immediate perioperative period relative to earlier and later periods. No differences in fall rates were found among the arthroplasty and non-arthroplasty samples after adjustment for potential confounding (P > 0.05). CONCLUSIONS: fall rates were generally stable and similar over an 8-year period among persons with and without knee arthroplasty. Clinicians should not assume that persons undergoing knee arthroplasty are at greater risk for falls either before or after surgery as compared to persons with or at risk for knee OA.