Complex Femoral Reconstruction Following Pathologic Subtrochanteric Femur Fracture Secondary to Paget's Disease of the Bone: A Case Report with Long-Term Follow-up.

Introduction Paget's disease (PD) is the most common metabolic bone disorder after osteoporosis. Clinically, it can result in pain, bony deformity, pathologic fractures, and, in the late stage, progression to malignancy. At a pathophysiological level, PD manifests as an imbalance between the homeostasis of bone destruction and formation. Bones most often involved with this disease process include the pelvis, femur, tibia, vertebra, and skull. The goals of orthopedic intervention in PD are two-fold: Prevention of pathologic fracture with internal stabilization and reconstruction following fracture, which is often complicated by poor bone quality and advanced deformity. In this case report, authors detail a patient with PD who presented with a pathologic left subtrochanteric femur fracture requiring a novel complex femoral reconstruction with a 29-year follow-up period. To the best of our knowledge, no such report exists, particularly with this degree of long-term follow-up. Case report A 70-year-old Caucasian man with PD presented with an atypical subtrochanteric femur fracture after a ground level fall. Due to his significant femoral deformity and osteopenia, proximal femoral resection followed by composite femoral allograft reconstruction with total hip arthroplasty was performed. Long-term durability of this novel reconstruction method as well as longitudinal clinical and radiographic outcomes is described. Conclusion Complex pathologic fractures in patients with PD can be effectively treated with composite femoral allograft reconstruction and total hip arthroplasty with good long-term radiographic and clinical outcomes. Broadly, it is important to note the unique healing pattern seen in PD bone and to consider the implications it may have when planning surgical intervention.