One-Stage Lengthening of Femoral Nonunion Augmented With Human Bone Morphogenetic Protein

Abstract

Fifteen patients with posttraumatic shortened atrophic femoral nonunions were treated with one-stage lengthening. The alloimplant was composed of allogeneic antigen extracted autolyzed human bone perfused with partially purified human cortical bone morphogenetic protein associated with noncollagenous protein and used as graft. The composite was lyophilized and sterilized with ethylene oxide. All 15 nonunions were atrophic diaphyseal and were lengthened through intercalary segmental defects bridged with the human bone morphogenetic protein composite alloimplants stabilized to the medial femoral cortex through plate osteosynthesis and lag screw fixation. One lengthened proximal femur had fatigue failure of the plate and was treated successfully by exchange plating. The average increase in length was 2.8 cm (range, 1.5-5 cm) and an average percentage increase in length of 8% (range, 4%-132%) of the residual shortened femur. The human bone morphogenetic protein composite produced an immediate reactive bone formation in the host bone and progressive remodeling of the donor recipient interfaces. There were no infections, allergic reactions, clinical rejection of the human bone morphogenetic protein composite alloimplants, or evidence of malignant disease. One-stage femoral lengthening augmented with human bone morphogenetic protein composite graft bridged the intercalary defect, remodeled the atrophic host bone and restored bone continuity within 1 to 2 years. Human bone morphogenetic protein composite alloimplants are a substitute of autogeneic bone graft and offer an alternative to iliac crest bone without the associated morbidity.