Composite implant of native bovine bone morphogenetic protein (BMP), collagen carrier and biocoral in the treatment of resistant ulnar nonunions: report of five preliminary cases

Introduction Bone morphogenetic protein (BMP) has been shown to induce bone formation and union in long bone defects and nonunions. There are, however, no previous reports of BMP being used for ulnar nonunions. We report on five cases of resistant ulnar nonunions treated with a composite implant consisting of a biocoral frame, collagen carrier, and bovine BMP.Materials and methods Four diaphyseal and one olecranon ulnar nonunions were treated using BMP/coral implant combined with internal fixation. Additional autografting was used in three cases. All of the cases were challenging in their own ways: Three of the patients had been operated on earlier for their nonunion without success, one had a 40 mm bone loss, and one had a 9-month-old untreated olecranon fracture. After excision of the sclerotic surfaces of the nonunion, the gap was filled with autograft and a composite implant containing BMP. Fixation was done with a compression plate in the diaphyseal nonunions and with a tension band in the olecranon nonunion.Results Solid union was achieved in all five cases. No infections or other adverse effects were encountered.Conclusion These preliminary results suggest that BMP-containing implants might be a feasible alternative or superior to autografting in the treatment of resistant ulnar nonunions.