Heterotopic ossification of the extensor tendons in the hand associated with traumatic spinal cord injury

Heterotopic ossification (HO) occurs in spinal cord injury (SCI), most frequently in the large joints such as hips, shoulders, knees, and elbows. It always occurs below the level of neurologic lesion. In the upper extremities, HO associated with SCI usually involves the flexor side of the involved joint. HO has only been reported once to involve the hands and rarely develops parallel to the long bones. We present a 44-year-old male with C5 traumatic SCI who developed HO involving the extensor tendons of one hand. The HO was discovered four months after the SCI and involved the extensor sheaths of the second, third, and fourth digits, from the metacarpal-phalangeal joint to the proximal inter-phalangeal joint. The patient had been improving neurologically with poor to fair extension of the right wrist allowing for tenodesis finger flexion, but with the onset of HO he lost some functional grasp. Diagnosis, possible etiology, and treatment (including options of radiation therapy and surgery) are discussed.