Nonunion with Extensive Bone Loss: Reconstruction with Ilizarov Techniques and Orthobiologics

Numerous procedures for the treatment of chronic bone loss have been devised to reconstitute bone stock, obtain union, and provide a stable functional limb. These procedures include bone transport as well as new orthobiologic adjuvant methodologies. Bone transport is a reliable technique; however, it is very time consuming, requires extreme patient compliance, and requires diligence on part of the surgeon to avoid potential complications. With advancements in external fixator technology, newer frame configurations have simplified the mechanics of frame mounting and transport. New frames permit constant adjustment of the proposed docking site without the misalignment potential that can occur with traditional circular frame constructs. Development of hydroxy–appetite-coated pins and other substrate biomaterials, as well as advancements in intramedullary designs, have decreased the time period requiring external transport devices. The emergence of orthobiologics holds great promise for large skeletal defects. The ability to augment large regenerate segments with percutaneously applied growth factor adjuvants to reduce prolonged consolidation times in patients is an attractive alternative a patient spending 1.5 to 2 years in an external transport device. New composite grafting techniques have been devised to be applied in a staged fashion after the development of a well-vascularized psuedomembrane in the defect tract. These techniques include composite grafting using reamer irrigator aspirator techniques, demineralized bone matrix and cellular marrow concentrates, bone morphogenetic protein with allograft composites, and the implantation of titanium cages directly into the defect sites augmented with all the aforementioned adjuvants. This article reviews the current state of defect management.

Keywords: bone defect, bone transport, composite bone graft, titanium cages, vascularized pseudomembrane