Human Bone Morphogenetic Protein Allografting for Reconstruction of Femoral Nonunion

Abstract

A composite inductive allograft consisting of an allogeneic, autolysed, antigen-free cortical bone carrier lyophilized with partially purified human bone morphogenetic protein was implanted in 30 consecutive femoral reconstructions that resulted from failure of fracture healing. There were 24 atrophic shortened femoral nonunions, four equal length femoral nonunions, and two femoral malunions. There were 10 men and 20 women with an average age of 47 years (range, 28-75 years). Allogeneic, autolysed antigen-free cortical bone was used as a structural alloimplant and as a delivery system for partially purified human bone morphogenetic protein. The composite implant of human bone morphogenetic protein/allogeneic, autolysed antigen-free cortical bone was used in conjunction with one-stage lengthening of the extremity, restoration of mechanical axis and rotational alignment. In 26 of 30 femurs, the human bone morphogenetic protein/allogeneic autolysed antigen-free cortical bone consisted of an allogeneic cortical bone implant incorporated into a one-stage lengthening of atrophic femoral nonunion. In four patients with equal length femoral nonunions, the human bone morphogenetic protein/allogeneic, autolysed antigen-free implant was placed as an medical femoral shaft onlay graft. Internal remodeling of the implant occurred within 8 to 12 weeks after implantation. Lengthening defects greater than 2 cm were supplemented with intercalary autogeneic bone graft. Twenty-four femurs healed at an average of 6 months at an average followup of 55 months. Four of six plate fatigue failures were salvaged with repeat plating. Two patients were lost to followup. The human bone morphogenetic protein/allogeneic, autolysed antigen-free bone allograft is an excellent structural and delivery system that induces host bone formation and implant remodeling allowing salvage of difficult femoral nonunions.