A 25-year-old man came with chronic neck pain and restricted neck movements since two years. On examination the patient had a short neck with a limited range of motion. The facet joints are fused. The laminae and the dysplastic spinous processes of the involved vertebrae are close to each other.
The lateral radiograph of the cervical spine shows fusion of the C3 and C4 vertebral bodies with a rudimentary "button hole" intervertebral disc space between them. There is "waisting" of the vertebral bodies at the level of the disc space. The vertebre are taller than broad. The fused vertebral segment appears as a single bony unit with smooth, continuous cortical margins.