BMP-2 CAN INHIBIT BONE HEALING - BONE-CHAMBER STUDY IN RABBITS

We came across a bone growing situation in which BMP-2 inhibits bone f ormation. Collagen sponges with BMP-2 were inserted in titanium bone c hambers in rabbits. In this model, bone formation occurs spontaneously . With 2.4 and 0.12 mu g BMP-2 per mm(3) of the chamber volume, bone i ngrowth was reduced to 16% and 42% of collagen controls, respectively. Sponges with 2.4 mu g BMP-2 per mm(3) that were placed in a similar t itanium chamber in an intramuscular subfascial site induced bone forma tion in 4 cases of 5. The BMP-2 concentrations used are considered opt imal for extraskeletal bone induction, and intramuscular sponges in ra ts all induced bone. The inhibitory effect is most likely model-relate d, but indicates unknown effects of BMP-2.