A Rare Case of Non-ossifying Fibroma Causing Pathological Subtrochanteric Femur Fracture in a Child: A Common Lesion at an Uncommon Location

Non-ossifying fibroma (NOF) is a benign expansive lytic lesion more frequently found in children and adolescents at the metaphysis of long bones in and around the knee joint, typically resolving spontaneously or by ossification. This report presents a rare case of an 11-year-old child with a pathological subtrochanteric femur fracture attributed to an underlying NOF. We describe the diagnosis and surgical management of curettage and internal fixation using a proximal humerus locking plate, resulting in complete resorption of the lytic zone and an excellent clinical outcome. This report emphasizes recognizing benign lesions such as NOF at rare locations such as the proximal femur as potential contributors to pathological fractures in the pediatric population.