Unrestricted weightbearing and ability to achieve postoperative ambulation after distal femur fracture fixation in elderly patients is not associated with decreased mortality

PurposeThe purpose of this study is to evaluate the association between 1) early postoperative mobilization on 30-day and 1-year mortality in patients >= 65 years who underwent fixation of distal femur fractures and 2) postoperative weightbearing instructions and early postoperative mobilization in this patient population.MethodsA multicentre, retrospective review of all patients >= 65 years of age who underwent operative fixation of a distal femur fracture between August 2012 and June 2023 at two academic level 1 trauma centres and one academic level 2 trauma centre was conducted. Univariate comparisons and binary logistic regression analyses were performed to identify factors associated with postoperative weightbearing instruction, postoperative mobilization, and mortality.ResultsThree hundred and forty-seven patients were included in final analyses, with 347 patients included in the all-comer group and 274 patients included in the isolated distal femur fracture group. After adjusting for demographics and modified 5-factor frailty index (mFI-5) score, unrestricted postoperative weightbearing was associated with achievement of early postoperative mobilization in both the all-comer (p = 0.005, OR = 3.159 [95% CI 1.412-7.067]) and isolated fracture groups (p = 0.001, OR = 4.735 [95% CI 1.869-11.992]). Thirty-day mortality occurred in only 10 patients, therefore, analyses were not independently performed for this time point. After adjusting for demographics, mFI-5 score, and postoperative weightbearing instruction, postoperative mobilization was not associated with survival at one year in neither the all-comer (p = 0.281, OR = 0.589 [95% CI 0.225-1.542] nor isolated fracture groups (p = 0.432, OR = 0.664 [95% CI 0.240-1.841).ConclusionPatients with unrestricted postoperative weightbearing instructions were more likely to achieve early postoperative mobilization; however, early mobilization after fixation of distal femur fractures in patients >= 65 years does not appear to correlate with 1-year mortality.