Osteogenic protein-1 in treatment of tibial nonunions: current status

Between 5% to 10% of tibial fractures progress to nonunion, causing substantial disability. Bone autografts, along with internal fixation, are the usual treatment for these failures, but the morbidity associated with autogenous tissues remains problematic. Bone morphogenetic proteins are currently available for clinical use and preclinical models, as well as an increasing number of patients treated with these molecules demonstrate their safety and efficacy. Osteogenic Protein-1, OP-1, has been evaluated in a randomized, prospective, multi-institution study of tibial nonunions. Sixty-one patients with 63 nonunions received OP-1 and intramedullary rod fixation, and were compared with 61 patients with 61 nonunions treated with fresh autogenous bone graft and the same fixation. Clinical outcomes (success in 81% of OP-1 and 85% of autograft-treated patients) and radiographic evaluation (healing in 75% of OP-1 and 84% of autograft-treated patients) were statistically indistinguishable at 9 months following treatment. No OP-1 or graft-related adverse events occurred. More than 20% of the autograft group had significant donor-site pain 6 months following surgery. OP-1 is a safe and effective alternative to autogenous bone in treatment of tibial nonunions.