My brother had spine surgery to fuse two bones together. They used a new bone growth protein called BMP. He swelled up so bad, he had to go back to the hospital. Why would they use this BMP stuff if it’s going to have such a bad result?

Recombinant bone morphogenetic protein-2 (rh-BMP-2) or BMP for short is a protein that helps bone (and cartilage) grow. It sets up an inflammatory reaction that stimulates bone growth, but can also cause soft-tissue swelling from the inflammation.

Cases of extreme reactions with soft tissue swelling such as you describe are very rare. The use of BMP is usually very safe and very effective. The fusion site heals faster, allowing the patient to resume normal motion and activity sooner.

It does not appear to be a problem with antibody formation and rejection. The protein is cleared from the circulation quickly. There probably isn’t enough time to set up an antibody response.

Studies of this problem show that the dose or amount used of the BMP may be the key to preventing severe reactions. By using a smaller dose or releasing it more slowly, a controlled amount of BMP can be delivered.