Heterotopic Ossification
(HO)
Pronounced: Het-toro-toe-pik Oss-if-a-kay-shun
Definition
Heterotopic ossification (HO) is the growth of bone in abnormal places like soft tissue. It can occur anywhere in the body. The hip, knees, shoulders and elbows are the most common locations. This condition can vary from minor to heavy growth.
The sooner this condition is treated, the better the outcome. If you suspect you have HO, contact your doctor promptly.
Causes
The exact cause of HO is unknown. There may be a genetic link to the development of this condition.
Risk Factors
Although the exact cause is unknown, there are well known factors that increase your chance of getting HO. Tell your doctor if you have any of these risk factors:
Symptoms
Symptoms vary based on the severity and site of the bone growth. If you have any of these, do not assume it is due to HO. These symptoms may be caused by other conditions. Tell your doctor if you have any of these:
- Decreased range of motion
- Swelling or redness to joint(s)
- Pain
- Fever
Diagnosis
Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may be referred to a specialist. An orthopedic doctor focuses solely on problems of the bones and joints.
Tests may include the following:
- Bone scan —a test that determines mineralization of the bones and detects abnormal bone in tissue
- Serum alkaline phosphatase level—increased levels of this substance in the blood is linked to heterotopic ossification
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Several tests have been studied for HO. These are used less often and include:
- Serum osteocalcin
- C-reactive protein
- Erythrocyte sedimentation rate
- Creatine kinase
- Urine hydroxyproline, deoxypyridinoline, and prostaglandin
- X-ray —may only be able to detect abnormal bone in later phases of the disease
X-ray of Pelvic Repair
Treatment
Talk with your doctor about the best plan for you. Options vary based on the scope of the disease, and include the following:
Physical Therapy
Therapy is an important part of treatment. Range of motion exercises will help to maintain mobility. It can also keep the disease from getting worse. Therapy may also include some stretching and strength training.
Medications
Your doctor may prescribe:
- Bisphosphonate drug (eg, etidronate (Didronel))—to block calcium from depositing in new boney growths
- Nonsteroidal antiinflammatory drugs (NSAIDs)—to help prevent more bone growth in soft tissue
Radiation Therapy
Radiation is used to prevent abnormal bone growth, mainly after hip surgery.
Surgery
Surgery may be used to remove the abnormal bone and increase range of motion. Radiation and medications are often given after surgery, since the disease can recur.
RESOURCES:
American Academy of Orthopaedic Surgeons
http://www.aaos.org/
Spinal Cord Injury Information Network
http://www.spinalcord.uab.edu
CANADIAN RESOURCES:
Canadian Orthopaedic Association
http://www.coa-aco.org/en.html
Canadian Orthopaedic Foundation
http://www.canorth.org/
References:
Black DL, Smith JD, Dalziel RE, Young DA, Shimmin A. Incidence of heterotopic ossification after hip resurfacing. Australian and New Zealand Journal of Surg . 2007;77:642-647.
Fact Sheet 1: Heterotopic ossification in spinal cord injury. Arkansa Spinal Cord Commission website. Available at: http://www.spinalcord.ar.gov/Publications/FactSheets/sheets1-5/fact1.html . Accessed October 28, 2008.
Heterotopic ossification—SCI inforsheet. Spinal Cord Injury Information Network website. Available at: http://images.main.uab.edu/spinalcord/pdffiles/info-12.pdf . Accessed October 28, 2008.
Pape HC, Marsh S, Morley JR, Krettek C, Giannoudis PV. Current concepts in the development of heterotopic ossification. Journal of Bone and Joint Surgery . 2004;86(6):783-7.
Frontera: Essentials of Physical Medicine and Rehabilitation .1st ed. Philadelphia; Hanley and Belfus; 2002.
Last reviewed November 2008 by John C. Keel, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.