Acute fractures and dislocations of the cervical spine. An analysis of three hundred hospitalized patients and review of the literature.

(SBQ06SN.5) A 61-year-old man with ankylosing spondylitis falls and hits his forehead while getting out of the shower. On arrival to the emergency room he complained of neck pain, but his neurologic exam is normal. A CT scan shows a nondisplaced extension-type fracture of the lower cervical spine and no evidence of epidural hematoma. He is treated with a cervical orthosis and admitted for pain management. Seven hours later he reports increasing paresthesias in his upper and lower extremities. Examination now shows weakness in his upper and lower extremities, including 3+/5 ankle dorsal and ankle plantar flexion. An MRI scan is performed emergently and is shown in Figure A . What is the most appropriate next step in management.