It occurs in many spinal cord injured individuals and may develop within days following the injury or several months later.
Heterotopic ossification occurs below the level of injury.
The cause of HO is unknown. Most cases of heterotopic ossification cause no significant additional physical limitations, but in a minority of patients, HO may result in a major limitation of joint motion. The first symptom you may notice is difficulty or limitation in your ability to perform activities of daily living, especially activities that require you to bend at the hips. However, sometimes the onset of HO is more rapid, and symptoms at that time may be swelling of one hip and warmth and redness overlying the swelling. If you suspect you have HO, contact your physician.