Retrograde Intramedullary Nailing vs. Lateral Locking Plate Fixation for Distal Femur Fractures: Which Technique is Superior?

Abstract

Objective: Distal femur fractures are challenging to treat, especially in elderly osteoporotic patients. Retrograde intramedullary nailing (RIMN) and lateral locking plate (LP) fixation are commonly used surgical methods for these fractures. This study aimed to compare the clinical and radiological outcomes of these two techniques.

Methods: In this retrospective study, a total of 72 patients with distal femur fractures classified according to the AO/OTA system and treated surgically were included. Patients were divided into two groups: RIMN (n=36) and LP (n=36). Demographic data, fracture classification, surgical method, operative time, intraoperative blood loss, early weight-bearing status, knee range of motion, union time, and complication rates were evaluated. Additionally, union rate, infection, implant failure, and reoperation requirement were compared. A power analysis was conducted assuming 70% power to detect a clinically significant difference. Statistical analyses included T-test, Mann-Whitney U test, Chi-square test, and Fisher's exact test. Kaplan-Meier analysis was used to assess union time. A p-value <0.05 was considered statistically significant.

Results: The union rate was 86.1% in the RIMN group and 75.0% in the LP group. The average union time was 15.4 weeks for RIMN and 17.2 weeks for LP. Knee range of motion was significantly better in the RIMN group (115.2° vs. 110.4°, p=0.03). Early weight-bearing was achieved in 61.1% of RIMN patients and 44.4% of LP patients (p=0.11). The overall complication rate was 16.7% in the RIMN group and 25.0% in the LP group. Infection rates were 5.6% and 8.3%, respectively. Implant failure was observed in 5.6% of patients in both groups. Reoperation was required in 8.3% of RIMN and 13.9% of LP patients.

Conclusion: Our findings suggest that RIMN may offer advantages over LP in terms of higher union rates, shorter union time, and better functional outcomes, particularly in osteoporotic patients. However, both techniques demonstrated acceptable complication rates, and treatment choice should be tailored to the fracture pattern and patient characteristics. Further prospective, randomized studies are needed to support these findings.