Nonhereditary heterotopic ossification: Implications for injury, arthropathy, and aging

Nonhereditary heterotopic ossification (NHHO) usually arises in the setting of trauma, certain arthropathies, or following injury, often in the setting of common age-related conditions. In this article, we discuss the pathophysiology, diagnosis, and clinical findings in periarticular NHHO and the relevance to age-related pathology, as well as the prevention and treatment of NHHO. Except for the precipitating events or clinical conditions in which NHHO occurs, primary etiological mechanisms remain unknown. Many forms of NHHO develop in the context of injury and inflammation, suggesting that the formation of extraskeletal bone may share similar initiating events with ectopic ossification in fibrodysplasia ossificans progressiva.