Treatment of symptomatic intercostal heterotopic ossification after surgical stabilization of rib fractures: report of two cases and review of the literature.

Abstract

Heterotopic ossification (HO) is the abnormal growth of bone in soft tissue outside of the usual skeletal anatomical locations. This condition should not be confused with metastatic or dystrophic calcification, both of which result from calcium deposition in soft tissues rather than from the transformation of primitive mesenchymal cells into osteogenic cells, resulting in the growth of true mature lamellar bone, as is seen in HO (1-3). HO can cause swelling, limitations in range of motion secondary to ankylosis, and pain secondary to peripheral nerve entrapment, all of which contribute to significant long term disability. Although the pathophysiology of HO is complicated and poorly understood, identifiable precipitants include traumatic musculoskeletal injuries (e.g., fractures, dislocations, orthopedic surgeries, etc.), central nervous system (CNS) injuries, and, rarely, genetic diseases (4). Orthopedic surgeries, including joint arthroplasty and surgical fixation of upper and lower extremity fractures, are some of the most widely reported operations linked to HO; however, to our knowledge, HO following fixation of traumatic rib fractures has not previously been reported in the literature.