Heterotopic Ossification (HO)

What is Heterotopic Ossification (HO)?

Heterotopic Ossification (HO) is an abnormal process which leads to excessive bone formation outside the normal areas of the skeleton. It is a medical condition characterized by the growth of bonelike tissue from soft tissue, and is most commonly seen in patients with spinal cord trauma, muscular injuries, and burn victims. HO can lead to stiffness, mobility limitations, and pain in the affected areas.

Causes of HO

HO is most commonly seen in patients with spinal cord trauma, muscular injuries, and burn victims, but it can occur in anybody at any age. It is believed to occur as a result of excessive soft-tissue inflammation caused by the initial injury. It can also occur as a result of genetic or acquired mutations that are linked to increased bone formation.


  • Stiffness and pain in the affected areas
  • Decreased range of motion
  • Muscle contractures
  • Muscle atrophy
  • Bone deformities


HO can be diagnosed through imaging techniques such as x-rays or MRI scans, which can detect excess bone formation outside of the areas of the skeleton. A clinical examination can also be performed to assess the extent of the HO and to evaluate the level of pain and range of motion.


Treatment for HO depends on the severity and location of the condition. In mild cases, exercise and physical therapy may be sufficient to improve range of motion and reduce pain. For more severe cases, surgery may be necessary to remove the extra bone formation.

In some cases, medications such as nonsteroidal anti-inflammatory drugs, bisphosphonates, and calcitonin may be used to reduce pain and inflammation. In addition, a combination of physical therapy, massage, and other therapies can be used to improve joint function and reduce pain.