Infection Precedes Heterotopic Ossification in Combat Wounded

Heterotopic ossification is the formation of ossified bone in soft tissue, particularly after soft tissue trauma. Heterotopic ossification is known cause of pain, prosthetic/orthotic malfit, and reoperation following combat extremity injury. The purpose of this research was to examine injury and treatment characteristics that are associated with heterotopic ossification in a broader population of deployment-injured subjects. The Department of Defense Trauma Registry and Military Orthopaedic Trauma Registry was queried for a sample of deployment-injured subjects and the complication of heterotopic ossification. Heterotopic ossification was identified in 15% of subjects following 5% of all injuries. Symptoms attributed to the heterotopic bone were present in 40% of subjects with diagnosed with heterotopic ossification. Heterotopic ossification was not associated with injury severity or aggressiveness of open wound treatment. However, infection was the only positive predictor of heterotopic ossification resulting in two-times greater odds of heterotopic bone formation. This finding is consistent with prior research suggesting that heterotopic ossification requires persistent inflammation to be present in at-risk soft tissue. Among all wounds sustained during deployment injury, heterotopic may not be abundantly common; however, the risk may be further minimized by focused infection control.