Animal models of heterotopic ossification.

Heterotopic ossification is often a severe clinical complication of joint arthroplasty, neurologic trauma, and muscle injury. In rare genetic disorders, such as fibrodysplasia ossificans progressiva, heterotopic ossification can be crippling and often leads to premature death. Reliable animal models of heterotopic ossifications that mimic pathologies seen in man would be invaluable for the development of new treatments to combat heterotopic ossification. Various methods used to induce heterotopic ossification in animals including the use of bone morphogenetic proteins, urinary tract epithelia, and transformed cell lines are described. Genetic animal models of heterotopic ossification and various miscellaneous examples of heterotopic ossification in animals are described. Finally, the use of transgenic mice to manipulate bone morphogenetic protein expression is discussed as a possible future animal model of heterotopic ossification.