You are here

Heterotopic Ossification M61.9 728.10

 

synonyms: HO, heterotopic ossification

HO ICD-10

HO ICD-9

  • 728.10 (muscular calcification and ossification, unspecified)

HO Etiology / Epidemiology / Natural History

  • Definition: bone formation that occurs in soft tissues.
  • Etiology: unknown. Presumed to be caused by pluipontential mesenchymal cell differentiation into osteoblasts.
  • Males > females.
  • Typically matures 6 months following the inciting event.
  • Occurs in 64.6% of high-energy wartime extremity injuries. Risk factors = brain injury, age <30, an amputation, multiple extremity injuries, ISS >16 (Forsberg JA, JBJS 2009;91A:1084)

HO Risk Factores

  • Males c ankylosing spondylitis (occurs is 23% of pts with ankylosing spondylitis undergoing THA)
  • DISH
  • Past hx of heterotopic bone
  • Hypertrophic osteoarthritis
  • Paget's disease
  • Post-traumatic arthritis
  • Osteonecrosis
  • Rheumatoid arthritis
  • Wartime Risk factors = brain injury, age <30, an amputation, multiple extremity injuries, ISS >16 (Forsberg JA, JBJS 2009;91A:1084)

HO Clinical Evaluation

  • May present with pain, swelling, warmth, and/or loss of motion.

HO Xray

  • HO is generally diagnosed with xrays of involved area. Initialy HO is seen as a fluffy opacity which matures to that of bone in 3-5 months. First appears on plain films at 4-6 weeks.

HO Prophylaxis

  • Indomethacin 75mg QD or Indomethacin 25 mg TID for 3-6 weeks
  • single fraction dose about 700-800 rads given within 72 hours postop had 2% incidence of H.O.(Lewallen DG: Heterotopic Ossification following total hip arthroplasty. Instr Course Lect 1995;44:287-292).

HO Classification / Treatment

  • Brooker Classification (Brooker AF, JBJS 1973;55A:1629)
    -Grade 1: Islands of bone within the soft tissues about the hip. Typically asymptomatic.
    -Grade 2: Bone spurs in the pelvis or the proximal end of the femur with at least 1c, between the opposing bone surfaces. Typically asymptomatic.
    -Grade 3: Bone spurs from the pelvis of proximal end of the femur with <1cm between opposing bone structures.
    -Grade 4: ankylosis.
  • Once ossification has begun there are no effective treatments to halt or decrease amount of HO.
  • HO generally matures by 3-5 months after which time surgical resection may be considered.
  • Kjaersgaard-Andersen classification: (Kjaersgaard-Andersen P, J Arthroplasty 1989;4:99)

HO Review References

Disclaimer

The information on this website is intended for orthopaedic surgeons.  It is not intended for the general public. The information on this website may not be complete or accurate.  The eORIF website is not an authoritative reference for orthopaedic surgery or medicine and does not represent the "standard of care".  While the information on this site is about health care issues and sports medicine, it is not medical advice. People seeking specific medical advice or assistance should contact a board certified physician.  See Site Terms / Full Disclaimer