Heterotopic ossification in non-traumatic myelopathies.

Heterotopic ossification (HO) is an important complication of spinal cord and brain injuries but is rarely reported among patients with non-traumatic myelopathies. In a prospective study on medical problems seven (6.04%) among the 114 subjects with non-traumatic myelopathies had heterotopic ossification. All of them had involvement of hip joints. The co-morbid conditions were: urinary tract infection, seven; spasticity, three; pressure sores, five; and deep venous thrombosis, one. The initial diagnosis was often other than heterotopic ossification. Erythrocyte sedimentation rate and serum alkaline phosphatase levels were elevated in all subjects. Following rest and non-steroidal anti-inflammatory drugs, the range of motion improved in two patients. Heterotopic ossification can occur in patients with non-traumatic myelopathies and has risk factors and clinical features similar to patients with traumatic spinal cord injury. A high index of suspicion about this complication is necessary for early diagnosis and prompt intervention.