Reconstruction of segmental bone defects. Relevance of autologous cancellous bone grafts

The relevance of autologous cancellous bone grafts (ACBG)for the treatment of segmental bone defects is not clearly defined. In the literature, 5-6 cm is considered the maximum defect length that can be bridged. Longer defects carry an increased risk of graft necrosis and resorption. The major concerns of ACBG for segmental bone defects are the limited resources and the significant comorbidities of cancellous bone harvesting. The recently developed reamer-aspirator-irrigator system has opened the opportunity to gain more cancellous bone with fewer comorbidities. In combination with the technique of induced membranes developed by Masquelet, where a well-vascularised membrane develops within 12 weeks around a polymethylmethacrylate spacer which is inserted into a segmental defect, being filled with cancellous bone, both restrictions of cancellous bone transplantation might be overcome. Systematic evaluations are necessary to more precisely define the indications for the different procedures at hand to treat segmental bone defects. It can be expected that ACBG will take an important place in the treatment of segmental bone defects beyond the currently accepted indication for defects of 5-6 cm.