Heterotopic ossification is a true ossification that occurs para-articularly in soft tissue and only involves neurologically affected joints. The extensive heterotopic ossification is a cause of limitation of active or passive joint motion and ultimately bony ankylosis which interferes independency in activities of daily living and ability of maximum rehabilitation

The purpose of this study is to define the various clinical, laboratory and radiologic findings of heterotopic ossification and to help early diagnosis, understanding of clinical progression and early treatment of heterotopic ossification. This study reports the 7 cases in 6 men with heterotopic ossification who were admitted to the Institute of Rehabilitation Medicine of the Presbyterian Medical Center from April, 1982 through September, 1986 with the review of literatures.