2008 Post-traumatic Heterotopic Ossification

Description: Physical Medicine. In 1918, Dejerine and Ceillier first described heterotopic ossification (HO) in paraplegic patients injured in World War I, referring to the process as paraosteoarthropathy. HO has been defined as the formation of mature lamellar bone in soft tissues. The process involves true osteoblastic activity and bone formation. HO has been reported in cases of brain injury, spinal cord injury, stroke, poliomyelitis, myelodysplasia, tabes dorsalis, carbon monoxide poisoning, spinal cord tumors, syringomyelia, tetanus, and multiple sclerosis. This condition also has been reported after burns and total hip replacement/joint arthroplasty. Several terms have been used to describe the condition, including heterotopic ossification, ectopic ossification, and myositis ossificans. HO usually involves the large joints of the body (eg, hips, elbows, shoulders, knees). Excessive bone formation may result in significant disability by severely limiting the range of motion (ROM) of these joints .
The following 3 categories of HO have been described: Myositis ossificans progressiva is a rare metabolic bone disease in children with progressive metamorphosis of skeletal muscle to bone and is characterized by an autosomal dominant pattern of genetic transmission.
Myositis ossificans circumscripta without trauma is a localized soft tissue ossification after neurologic injury or burns. This process also is referred to as neurogenic HO.
Traumatic myositis ossificans occurs from direct injury to the muscles. Fibrous, cartilaginous, and osseous tissues near bone are affected. The muscle may not be involved.