Tubular Remodeling of Massive Cancellous Bone Graft in the Treatment of Long Bone Defects

Abstract Background: This case report describes the clinical and radiological result at the 4.5-year follow-up after an extensive reconstruction of the femoral diaphysis using autologous cancellous bone graft. The radiological study including axial tomography demonstrates secondary remodelling to form tubular diaphyseal bone. Methods: A patient with an existing hip fusion, who sustained a fracture of the proximal femur 12 years later, was treated by open internal fixation using a plate and screws. Infection followed which became chronic, causing bone resorption and necrosis and producing a septic non-union. Reconstruction in two stages was performed: open radical debridement which ended with a 14.5 cm diaphyseal defect of the femur, temporary alloplastic spacer interposition and secondary de-arthrodesis of the hip with massive autologous cancellous grafts into the induced foreign body membrane left by the spacer. Fixation was provided by a plate and screws. Results: The femur was free of infectious recurrence at 4.5 years. The patient walks without crutches with a shortened lower limb using a leg length compensation shoe and a painfree sine-sine hip arthroplasty. The former bone defect is fully remodelled into new cortical bone. X-ray and CT-scan demonstrate the tubular form of the reconstructed bone. Conclusion: This clinical case demonstrates the restoration of a medullar cavity after massive cancellous bone grafting of a diaphyseal defect of the femur. The question remains open as to whether the foreign body membrane has only a simple passive protective function against extraosseous bone resorbing factors or whether it functions actively by producing growth factors or other beneficial bone inducing factors.