NEW YORK (Reuters Health) – The prevalence of heterotopic ossification in victims of war injuries is roughly 65%, much higher than the rates typically reported with civilian trauma, according to a report in The Journal of Bone and Joint Surgery for May.

The results also suggest that it is not local wound conditions that most strongly impact the risk of heterotopic ossification, but rather systemic causes.

The findings stem from a study of 243 war-wounded patients who were treated at the National Naval Medical Center, Bethesda, Maryland, from March 2003 to December 2006. Eligibility criteria included undergoing at least one orthopedic procedure and having 2 or more months or radiologic follow-up.

“The purposes of this study were to report our experiences with high-energy wartime extremity wounds, to define the prevalence of heterotopic ossification in these patients, and to determine the factors that might lead to development of the condition,” lead author Dr. Jonathan Agner Forsberg, from said in a statement.

Heterotopic ossification was seen in 157 of the patients (64.6%), the report indicates.

The presence (p = 0.006) and severity (p = 0.003) of traumatic brain injury were both directly linked to heterotopic ossification, the authors note.

Likewise, multiple extremity injuries (OR = 3.9), age of less than 30 years (OR = 3.0), an amputation (OR = 2.9), and an Injury Severity Score of at least 16 (OR = 2.2) were all significant predictors of heterotopic ossification.

Injury to the brain and spinal cord can cause a systemic inflammatory response, which is likely a principal contributor to the development of heterotopic ossification, Dr. Forsberg noted. Because such injuries are more common in victims of war rather than civilian trauma, this may explain why heterotopic ossification is also more common in this patient population.

Reference:
J Bone Joint Surg Am 2009;91:1084-1091.