Surgical outcomes of non-periprosthetic distal femur fragility fractures treated with a locking plate.

Background: Management of distal femur fractures can be challenging, particularly in the aged female population. This retrospective study aims to analyze the surgical outcomes of aged female patients with non-periprosthetic distal femur fractures treated with a locking plate.

Methods: This is an IRB approved retrospective review conducted at a level 1 trauma center. Fifty-five female patients (mean age of 71 years) with non-periprosthetic distal femur fractures underwent open reduction internal fixation using a locking plate from 2005 to 2019. The average follow-up time was 67 weeks from the date of injury. Criteria used for diagnosis of nonunion included one or more of the following: (I) three consecutive months without progression of healing on postoperative radiographs, (II) a total of nine months postoperative without complete healing, or (III) the physician diagnosed nonunion using clinical judgement. Outcome data was analyzed and compared amongst patients with and without obesity or diabetes. Statistical analysis was performed utilizing Microsoft Excel 2022 Data Analysis ToolPak with a standard statistically significant P value of <0.05.

Results: Thirty-two patients (58%) with distal femur fractures achieved union after initial treatment while 23 patients (42%) were diagnosed with nonunion. Fourteen patients (61%) underwent revision with 9 of these patients (64%) achieving union while 5 patients (36%) had persistent nonunion. Average healing time from initial treatment to union was 29 weeks, while average time from definitive treatment to union was 22 weeks. Obese patients [body mass index (BMI) >30 kg/m] had a nonunion rate of 65%, while non-obese patients had a nonunion rate of 28%. Patients with diabetes had a nonunion rate of 65%, while patients without diabetes had a nonunion rate of 28%.

Conclusions: Union can be successfully achieved in aged female patients with distal femur fractures treated with locking plates; however, the risks for nonunion and revision remain high. Patients with obesity and diabetes appear to be at an increased risk of nonunion (P=0.008 and 0.008, respectively). However, further research should be conducted with a prospective study or multivariate analysis and increased number of patients to reaffirm this data.