Heterotopic Ossification


How to Say It: Het-toro-toe-pik Oss-if-a-kay-shun


Heterotopic ossification (HO) is the growth of bone in places where it is not supposed to be. It can happen anywhere in the body. The hip, knees, shoulders, and elbows are the most common places. Growths can be small or large.


The cause is not known. It may be due to genes or trauma.

Risk Factors

Things that may raise the risk of this problem are:

  • Traumatic brain injury or stroke
  • Recent spinal cord injury
  • Hip surgery or other joint surgery
  • Burns
  • Long period of inactivity
  • Joint infection
  • Fractures
  • Some tendon injuries


The problems a person has depends on how serious HO is. It also depends on where there is bone growth. Problems may be:

  • Poor range of motion
  • Joint swelling or redness
  • Pain
  • Fever


You will be asked about your symptoms and health history. A physical exam will be done. You may be sent to a specialist.

These tests may also be done:

  • Blood and urine tests
  • Tests on fluids from the skin or cysts
  • Imaging tests:

X-ray of Pelvic Repair

repiared pelvis x-ray
HO may happen after joint surgery.
Copyright © Nucleus Medical Media, Inc.


The level of care needed depends on how serious HO is. Choices are:

  • Physical therapy to increase strength, flexibility, and range of motion, depending on the location of the problem
  • Medicines, such as:
    • Nonsteroidal anti-inflammatory drugs (NSAIDs) to ease swelling and pain
    • Bisphosphonates to prevent the bone loss
  • Radiation therapy to prevent abnormal bone growth
  • Surgery to remove abnormal bone


There are no known guidelines to prevent this health problem.


Ortho Info—American Academy of Orthopaedic Surgeons
United Spinal Association


Canadian Orthopaedic Association
When it Hurts to Move—Canadian Orthopaedic Foundation


Heterotopic ossification. Craig Hospital website. Available at: https://craighospital.org/resources/heterotopic-ossification. Accessed October 22, 2020.
Spinal cord injury—InfoSheet #12. Spinal Cord Injury Information Network website. Available at:
...(Click grey area to select URL)
Accessed October 22, 2020.
Last reviewed September 2020 by EBSCO Medical Review Board Daniel A. Ostrovsky, MD
Last Updated: 5/19/2021

EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

To send comments or feedback to our Editorial Team regarding the content please email us at healthlibrarysupport@ebsco.com. Our Health Library Support team will respond to your email request within 2 business days.