Fractures which occur near the base of the dens have a low propensity to unite spontaneously. One of the major complications of nonunion is displacement of the fracture resulting in neuraxis compression and the development of myelopathy. Hypertrophic nonunion of the dens may cause spinal cord compression even if displacement does not occur. This situation has not to our knowledge previously been reported. A literature review and appraisal of the issues raised are discussed. Appropriate therapeutic options are outlined, including posterior surgery and the use of transoral decompression.