Methylprednisolone has a preventive effect on heterotopic bone formation and on knee thickening and stiffening following manipulation of immobilized rabbit legs.

The effect of methylprednisolone administered following manipulation of the immobilized knee of 35 adult rabbits was investigated. In the legs of 15 control rabbits which received no methylprednisolone, heterotopic cartilage and bone in the periarticular tissues and in the vastus intermedius muscle, and extensive knee stiffening and thickening regularly developed. In the other rabbits, methylprednisolone showed a marked preventive effect on the development of all these pathological signs.