Treatment Strategies for Nonunion After Intramedullary Nailing for Femoral Fracture: Experiences of Fifty Nonunion Patients

Abstract Background: Femoral nonunion is mainly caused by factors such as instability of the fracture end, insufficient blood supply, or infection. However, these factors are mainly related to the different fracture types and inappropriate treatment plans. It is important to analyze the etiology of femoral nonunion and use a simple and effective treatment method to resolve it. The purpose of this study was to divide femoral nonunion into different types and give corresponding treatment strategies.Methods: We retrospectively evaluated 50 patients with femoral nonunion. Patients were divided into six groups and each group was treated with a different strategy. All patients were followed up clinically and radiologically every month until fracture healing.Results: All 50 patients were followed up with an average follow-up time of 17.44 ± 5.48 months. Based on the type of primary femoral fracture and the factors causing nonunion, we divided the femoral nonunion into six types. These included Type I: nonunion caused by instability of simple fracture (AO classification 32-A); Type II: nonunion caused by stress shielding at fracture ends of a simple fracture (AO/OTA classification 32-A); Type III: nonunion in femoral fracture with third fragment (AO/OTA classification 32-B); Type IV: nonunion in femoral fracture with segmental femoral fracture (AO/OTA classification 32-C2); Type V: nonunion in comminuted femoral fracture (AO/OTA classification 32-C3); and Type VI: nonunion caused by infection. Based on these classifications, the following methods are used to treat femoral nonunion. Type I femoral nonunion will achieve fracture healing by blocking screws, exchanging intramedullary nails, or adding plates. Type II femoral nonunion can be addressed through dynamitization or bone graft (possibly in combination with plate fixation) to achieve fracture healing. Type III femoral nonunion requires a treatment plan of bone graft or bone graft combined with plate fixation. The treatment plan for Type IV femoral nonunion is to add a plate, and autogenous bone graft if necessary. Type V femoral nonunion treatment is bone graft combined with plate fixation, or external fixation with subsequent bone segment transport or lengthening. Type VI requires placement of antibiotic bone cement or external fixation added to fix the fracture end.Conclusions: There are several factors associated with failure of femoral fracture treatments by intramedullary nailing. We need to carefully analyze the causes of fracture treatment failure. Our six classifications and corresponding treatment strategies resulted in satisfactory clinical outcomes.