THE EFFECT OF METHYLPREDNISOLONE ON PORCINE BONE MORPHOGENETIC PROTEIN IN FRACTURE-HEALING - AN EXPERIMENTAL ALLOGRAFT MODEL IN RABBITS

Four different experiments were performed to study the effect of methylprednisolone on porcine bone morphogenetic protein (pBMP) in an allograft in adult rabbits. In each animal, a 2-cm segment of radius was excised and replaced with frozen allograft. Fifteen milligrams pBMP was applied over the graft-host junction in Groups I and III, and 30 mg pBMP was applied in Groups II and IV. In Groups III and IV, methylprednisolone was given intramuscularly for three weeks. Incorporation was assessed by roentgenography, analysis of the area of callus formation, and histologic and biomechanical analysis at four and eight weeks. Methylprednisolone inhibited pBMP-induced bone formation and incorporation of frozen cortical bone allograft.