Heterotopic Bone Formation 20 Years After Gunshot Wound to the Cervical Spine: A Rare Cause of Progressive Cervical Myelopathy in a Previously Asymptomatic Patient.

Background: Gunshot wounds are the most common etiology of penetrating spine injuries and have been increasing in incidence in civilian populations. Although these injuries typically result in severe neurologic deficits, operative intervention remains is controversial and is usually reserved for patients with neurologic deterioration, a persistent externalized cerebrospinal fluid fistula, mechanical instability, metallic toxicity, or a bullet location at high risk of migration.

Case Description: A previously asymptomatic patient who had sustained a gunshot wound to the cervical spine 20 years previously presented with new-onset progressive myelopathy and radiculopathy secondary to heterotopic ossification (HO) surrounding the retained bullet fragments near the left lateral masses of C5-T1. Computed tomography myelography demonstrated no cranial migration of contrast material past this region of the spine, suggesting severe spinal canal stenosis. Intraoperatively, bullet shrapnel and heterotopic bone fragments were found within the central canal causing compression of the spinal cord. Following decompression and stabilization, the patient had complete resolution of his symptoms and returned to his neurologic baseline. Although HO has been reported as a complication following through and through gunshot wounds, there is a paucity of literature discussing HO formation around retained bullet fragments in the spine.

Conclusions: HO surrounding retained bullet fragments in the spine is a rare cause of progressive neurologic deterioration following gunshot wounds. Surgical excision of the shrapnel and heterotopic bone can lead to symptomatic relief, and therefore surgery should be considered as a treatment option in carefully selected patients.