Abstract
Six patients with nonunion of long bones, one with delayed bone formation during distraction osteogenesis, and one with nonunion of the neck of the femur were enrolled in a clinical trial. Duration of nonunion was from 8 to 94 months (mean 29,4 months). Recombinant human OP‐1 (BMP‐7) was purchased from the manufacturer. One unit (3,5 mg of active substance mixed with 1 gram of type I bovine bone‐derived collagen) was used in each patient. In four patients OP‐1 implant was delivered by standard open operative procedure, in 3 percutaneously. In one patient with femoral neck nonunion OP‐1 implant was placed intramedullary. No patient had serious adverse reactions related to the implant. At 5 to 8 weeks following the operative procedure five out of 6 patients with nonunion of long bones and one patient with delayed bone formation in distraction osteogenesis were judged by clinical and radiological criteria to have been treated successfully. In one patient with femoral neck nonunion bone union was achieved after 22 weeks. To determine whether the local stimulation with OP‐1 might induce prolonged changes in systemic levels of growth and angiogenic factors, the serum levels of the angiogenin (ANG), interleukin‐8 (IL‐8), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and insulin‐like growth factor‐1 (IGF‐1) were assessed prior, and 1, 2, 6 and 12 weeks after operative treatment with OP‐1 device. There is no evidence for a potentially harmful systemic rise in growth and angiogenesis factors after local administration of the amount of BMP‐7 used in our study.