Neurogenic heterotopic ossification of the hip. Presentation of two cases

Abstract Objective To describe two cases of neurogenic heterotopic ossification (NHO) of the hip and to review the literature on this condition. Material and methods Two patients of 28 and 32 years old who spent some time in a coma due to a traumatic head injury and stroke respectively. Both developed NHO that required surgery. Results In the first case flexion improved 65 degrees and abduction 20 degrees. In the second, flexion improved 75 degrees, external rotation 15 degrees and abduction 30 degrees. Both patients could walk without pain and could tolerate a prolonged sitting position. Discussion The pathogenesis of these ossifications remains unknown. With CT we can see the exact location, the relationship of ossification to the femoral vascular bundle, the bone density and the hip joint condition. The removal of these lesions should be done when the ossification is mature enough, but before a significant lack of mobility of the hip is established.