Session II - Post-Traumatic Reconstruction

*The Treatment of Complex, Recalcitrant Long-Bone Nonunion with a Human Recombinant Bone Morphogenic Protein: Results of a Prospective Pilot Study

Michael D. McKee, MD, FRCS(C); Emil H. Schemitsch, MD, FRCS(C); Lisa Wild, BScN; James P. Waddell, MD, FRCS(C); St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada (a-Stryker Biotech, Inc.)

Purpose: We sought to determine the safety and efficacy of a human recombinant osteogenic protein (rhBMP-7) in the treatment of recalcitrant human long-bone nonunion.

Methods: In a prospective pilot study, we identified 15 patients with complex, recalcitrant long-bone nonunion whose previous treatment was unsuccessful. There were nine men and six women with a mean age of 52.8 years (range, 38 to 76). The involved bones included five tibiae, four clavicles, four humerii, and two femora. All patients had radiographic nonunion, and had had a mean of 2.8 prior unsuccessful operative procedures (range, 0 to 6). Eleven patients had received prior autogenous bone grafting in an attempt to promote union. All patients underwent removal of any previously implanted hardware, debridement of the nonunion, correction of deformity, stable internal fixation, and addition of the rhBMP-7 compound to the nonunion defect.

Results: The mean follow-up was 22 months (range, 6 to 52), and no patient was lost to follow-up. The nonunion of 13 patients healed at a mean of 11 weeks postoperatively, and all demonstrated abundant bone formation. The tibia of one patient developed a recurrence of deep infection and required below-knee amputation. One patient with a segmental clavicular defect had delayed radiographic union at the 6-month follow-up but had progressive bone formation, was clinically stable, and declined further intervention. Technically, the rhBMP-7 bone substitute was easy to handle and simple to apply, and there were no adverse clinical events related to its use. Patient satisfaction was high.

Conclusions: The bone substitute was technically feasible to use, was not associated with any adverse events, and promoted union in 13 of 15 (87%) patients with refractory long-bone nonunion that had not responded to conventional bone grafting. As part of a standard protocol, this bone graft substitute appears to be safe and effective in providing sufficient biological stimulation for bony union to occur in this difficult-to-treat patient population. Its use eliminates the requirement for autogenous grafting.