New approaches in the treatment of critical-size segmental defects in long bones

The treatment of large segmental diaphyseal bone deficiencies presents a formidable challenge. The standard treatment modalities such as cancellous bone grafting, cortical allografts, vascularized bone transfer, or distraction osteogenesis exhibit extremely high complication rates, and can culminate in limb amputation or major functional deficits. Recent efforts to develop new treatment modalities for segmental bone loss have resulted in designing new biodegradable polymeric and metallic mesh implants that can incorporate novel osteogenic, osteoinductive, and/or osteoconductive bone healing augmentation materials. These biologic implant composites are capable of further enhancing the efficacy of the treatment applied. This paper briefly reviews the limitations of the currently applied standard treatment modalities for segmental critical size bone defects, provides insight into the specific treatment challenges, and presents the animal and initial clinical results of new alterative treatment approaches that involve the application of cylindrical mesh implants consisting of biodegradable polylactide membranes or titanium cages as a means of potentiating the efficacy of bone graft.