Revision Surgery Using Retrograde Nail versus Replating in Nonunion Distal Femur Fracture Treated with Plate

Abstract

Articular distal femur fractures represent 4% to 6% of femur fractures. Locking compression plates (LCPs) are the main treatment option. Nevertheless, a reoperation rate of 12.9% has been reported; nonunion is reported at 4.8%, delayed union at 1.6%, and malunion at 0.6%. Treatment of nonunions can be challenging as no unanimous consensus regarding the best surgical technique has been reached. The aim of this study was to evaluate and compare two types of revision surgery as treatment of LCP-treated articular distal femoral fracture nonunion: retrograde nail or replating. A retrospective cohort study of patients admitted from January 2015 to February 2017 for nonunion of AO/OTA 33C2 fractures previously treated with a lateral LCP was conducted. Patients were treated either with intramedullary nailing (Group A) or with replating (Group B). One independent observer performed clinically and radiographically followed up at 1, 3, 6, 9, 12, 24, and 36 months after surgery. The nonunion scoring system (NUSS) was used. Nine patients were included in our study. The mean follow-up was 2 years. Five patients were treated with intramedullary nailing and four with replating. The NUSS score was 24.2 ± 6.8 in the nailing group and 37.3 ± 3 in the replating group ( $P=0.03$ ). In the nailing group, radiographic consolidation was obtained in all cases. In the replating group, nonunion was found in 3 patients and failure of osteosynthesis in one patient. Therefore, four patients (Group B) underwent implant removal and retrograde femoral nailing, obtaining radiological healing. The union time was 7.6 months in the nailing group. Retrograde intramedullary nailing can be used as an effective treatment of aseptic AO-33C distal femoral nonunion following primary locking plating.