Combat-Related Heterotopic Ossification

Heterotopic ossification (HO) within traumatized tissue has been a scourge of war surgeons with documentation leading back to the US Civil War. Owing to improvements in body armor, point of injury tourniquet use, and streamlined casualty evacuation, many severely wounded service members survive despite devastating extremity trauma. The concussive blast caused by Improvised Explosive Devices (IEDs) adds to the component of central nervous system injury to the injured - a well-known risk factor for HO. While prophylaxis against HO found in civilian trauma and arthroplasty is well established, these treatments are either contraindicated in patients with severe systemic polytrauma and/or logistically not feasible in combat. Treatment of these wounds may also contribute to HO development. Conservative and surgical options are available for treatment of combat-related HO, each with advantages and disadvantages. Recent research has focused on genes, inflammatory mediators, and osteogenic progenitor cells responsible for the complex interplay of systemic and local factors inducing HO in order to develop novel targeted therapies. The goal is to develop an adaptable regimen to give to wounded combat soldiers at risk. This chapter discusses HO as it relates to combat, its clinical features, prophylaxis and treatment, and recent and future directions of research efforts.