Progressive quadriparesis caused by anterior odontoid screw upward migration in rheumatoid arthritis

A 70-year-old male known for seropositive rheumatoid arthritis underwent placement of an anterior odontoid screw in 2005 at an outside hospital for a posttraumatic type 2 odontoid fracture (Fig. 1). At the time of the accident, he did not have documented rheumatoid changes in the cervical spine. A postoperative lateral radiograph showed the screw going beyond the distal cortex of the dens (Fig. 2). The patient initially did well and was subsequently lost to follow-up. The patient now presented with neck pain and progressive weakness in all four limbs. He was able to walk with assistance (Ranawat Class IIIa). Neurologic examination revealed spastic quadriparesis. A computed tomography scan showed upward migration of the odontoid screw with bone resorption around the screw, indicating non-union of the