Skip to main content
Optum Perks

Heterotopic Ossification

Heterotopic Ossification

Myositis ossificans happens when bone grows in a place that it would not normally grow. Doctors do not know why bone cells appear where they should not be. This illness goes by a few names. Sometimes, it is called MO. Other times you may hear it referred to as heterotopic ossification or HO. There are different kinds of this disease. Traumatic myositis ossificans − Damage can happen to muscle when it is bruised. Normally, new muscle cells grow while it heals. In myositis ossificans, bone cells grow in the muscle instead of new muscle. These areas of bone growth are sometimes called calcifications. They most often start 2 to 4 weeks after the muscle is hurt. They may keep growing for up to 6 months. Neurogenic heterotopic ossification − This may happen after an injury to the nervous system. This may be a spinal cord injury, stroke, or brain injury. Myositis ossificans progressiva or fibrodysplasia ossificans progressiva − A rare genetic problem. Bone grows in the muscle.