Composite implant of native bovine bone morphogenetic protein (BMP) and biocoral in the treatment of scaphoid nonunions--a preliminary study.

Background And Aims: Bone morphogenetic protein (BMP) has been shown to induce bone formation and union in long bone defects and nonunions. We report a preliminary study of a composite implant consisting of a biocoral frame, carrier collagen and bovine BMP in the treatment of scaphoid nonunions.

Material And Methods: Two proximal and eight waist area scaphoid nonunions were treated using BMP/coral implant combined with either the Matti-Russe procedure (2 cases) or an interpositional bone graft fixed with screws or compression fixation pins (8 cases). In two cases only a one piece BMP/coral implant was used as an interpositional graft and in other cases interpositional autograft was used with granular BMP/coral implant placed between the fragments and the graft.

Results And Conclusions: Only two wrists resulted in complete union. These preliminary results suggest that composite implant of BMP, as used in the present study, may not solve the problems encountered in the treatment of scaphoid nonunions. Poor vascular conditions in scaphoid may not provide enough mandatory osteogenic cells for BMP to function properly. In avascular conditions coral does not resorb edequately and implants may also work as a sequester between the bone graft and the scaphoid bone and therefore actually inhibit the healing process.