What is heterotopic ossification in traumatic brain injury (TBI)?

Updated: Mar 02, 2020
  • Author: Percival H Pangilinan, Jr, MD; Chief Editor: Stephen Kishner, MD, MHA  more...
  • Print


Heterotopic ossification is described as ectopic bone formation in the soft tissue surrounding the joints. In TBI, the incidence of heterotopic ossification is 11-76%, with a 10-20% incidence of clinically significant heterotopic ossification. [7] Heterotopic ossification generally causes joint pain and decreases range of motion (ROM). It is often associated low-grade fever, peri-articular swelling, peri-articular warmth, and peri-articular erythema.

In decreasing order of frequency, heterotopic ossification occurs in the hips, knees, elbows, shoulders, hands, and spine. Risk factors associated with the development of heterotopic ossification after TBI are a posttraumatic coma lasting longer than 2 weeks, limb spasticity, and decreased mobility. The risk of heterotopic ossification is greatest during the first 3-4 months after injury. [32]

The pathophysiology of heterotopic ossification remains unclear. However, inappropriate differentiation of mesenchymal cells into osteoblasts is believed to be the basic defect. Autonomic dysregulation (due to increased vascularity and venous hemostasis), humoral factors, and local inflammatory mediators contribute to the development of heterotopic ossification.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!