Risk Factors for Postoperative Falls in Foot and Ankle Surgery

Abstract

Category: Other Introduction/Purpose: Falls following orthopaedic surgery are a known entity in the healthcare field possessing significant patient morbidity and driving increased healthcare cost. The vast majority of studies have focused on the incidence and risk factors for postoperative falls in the inpatient setting, however, this is in direct contrast to shifts seen toward same-day outpatient orthopaedic surgery over the past decade. It is crucial to better understand the incidence and risk factors for falls in a mixed inpatient and outpatient model. Additionally, no study to date has examined the risk factors for falls after foot and ankle surgery. Methods: A total of 168 patients were administered a questionnaire and interviewed to investigate the incidence of postoperative falls. Patients completed surveys pertaining to fall history pre- and post-operatively, fall risks, current medical status, and use of an ambulatory assist device. Medical records were reviewed. Questionnaires and interviews were completed at 2 week and 6-week post-operative follow up visits. Factors found to be associated with postoperative falls in univariate analysis (p<.05) were included in a binary logistic regression model. Results: Full six-week follow-up was present in 138 patients. A total of 87 (63.0%) females and 51 (37.0%) males with a median age of 52 (21 IQR) and BMI of 32.4 (11 IQR) were included. The total fall incidence in the first six postoperative weeks was 29.7% (41 patients). In multivariate analysis, antidepressant use and VAS score at two weeks postoperatively were independently associated with falls OR 3.6 (95% CI 1.3 - 10.1) and OR 1.3 (95% CI 1.1 -1.5), respectively. The results of other variables included in the model were as follows: The Johns Hopkins Fall Risk Score OR 1.0 (95% CI.87-1.2), total number of medications excluding as needed OR.85 (95% CI.65-1.1), anticonvulsant use OR 1.8 (95% CI.67 - 5.0), and history of falls in the past six months preoperatively 1.6 (.95% CI.44 - 5.7). Conclusion: The high outpatient fall rate in foot and ankle surgery warrants awareness of risk factors. Antidepressant use has been associated with falls, but has not been established as a risk factor for postoperative falls. Surgeons should be aware of the risk of postoperative falls in this patient population. The postoperative VAS score at two weeks was also shown to be independently associated with falls. Adequate postoperative pain control is vital to minimize such falls. This study has identified antidepressant use and postoperative VAS score at two weeks as two independent risk factors for postoperative falls in foot and ankle surgery.