Incidence and Associated Risk Factors for Falls in Older Adults After Elective Total Knee Replacement Surgery: A Prospective Cohort Study

OBJECTIVE: The aim of the study was to determine the incidence and associated risk factors for falls in older adults in the 12 mos after elective, primary total knee replacement surgery. DESIGN: A prospective observational cohort of older adults undergoing total knee replacement were followed. Baseline measurements included risk factors of history of falls, using a gait aid and number of medications. Falls data were recorded after discharge for 12 mos alongside patient reported outcomes (Oxford Knee Score). Analyses used logistic and negative binomial regression modeling. RESULTS: There were 267 participants (mean age = 70 [6.7] yrs) enrolled. Participants who fell (n = 102 [40.6%]) reported 200 falls in the 12 mos after surgery. The incidence of falls was 2.4 falls per 1000 patient days in the 12 mos after surgery, with the highest incidence (2.6 falls per 1000 patient days) in month 1. Risk factors for falling were a history of falls (adjusted odds ratio = 2.41, 95% confidence interval = 1.35-4.31) and number of central nervous system acting medications taken before surgery (adjusted odds ratio = 1.66, 95% confidence interval = 1.25-2.21). Using a walking aid at baseline was associated with falls after discharge (adjusted incident rate ratio = 2.38, 95% confidence interval = 1.57-3.60). CONCLUSIONS: Older adults experience a high incidence of falls after elective total knee replacement. Further research that investigates falls prevention after total knee replacement is required.