The patient had a full set of spinal x-rays. The lateral views demonstrated fusion of the bodies and posterior elements of C3 and C4, suspected to be a developmental abnormality, and severe degenerative changes of the lower vertebrae, leading to a provisional diagnosis of cervical spondylosis causing cord compression.
This diagnosis was supported by the CT images, which showed fused posterior elements of C2–C5, narrowing of C5/C6 foramina, osteoarthritis of the odontoid peg and generalised spondylotic changes. However, in light of the clinical picture and upgoing plantars, an MRI was requested.
Apart from the spondylitic features, the MRI also showed an irregular, eroded odontoid peg (). There was evidence of a low-density, soft tissue pannus making contact with the anterior cord as it emerged from the skull base, leading to significant canal narrowing at the C1 level with effacement and signal change in the intrinsic cord.
MRI demonstrating soft tissue pannus around C2 causing deformity.
The patient was referred to a specialist neurosurgical unit for urgent intervention. He underwent a partial odontoidectomy with removal of the posterior pannus. The histology report of the resected tissue showed focal necrosis with infiltration with a basophilic granular material. This comprised of birefringent crystals with rectangular and rhomboidal shapes, consistent with calcium pyrophosphate, which causes pseudogout.