Leave it to my mother-in-law to have some condition that is rare and potentially life-threatening. Among other things, now she tells us she has something called spondylolysis of the neck. She says the doctor told her there have only been 100 cases of this on the whole earth. Does this ring true? It sounds so made up. And what is the problem, anyway?

To answer your first question, it is true that only 100 cases of cervical spondylolysis have ever been reported in the entire world since it was first diagnosed by X-rays back in 1946.

To answer your second question, what is cervical spondylolysis? Cervical refers to the neck or upper portion of the spine. Spondylolysis tells us there is a defect or deformity of some kind. In the lumbar spine (low back), spondylolysis means there is a fracture in the pedicle, a supporting column of bone. In the cervical spine, spondylolysis describes a cleft or place where the bone doesn’t meet in the middle.

Cervical spondylolysis occurs where the upper or superior facet (spinal) joint meets the lower or inferior facet joint. This defect occurs most often at the C6 segment and is usually present on both sides (bilateral). The disruption in the bone bilaterally results in a forward migration or movement of the affected vertebra over the intact vertebral bone below.

Any time a vertebral body shifts forward, it pulls on the spinal cord and spinal nerve roots causing neck and/or arm pain and neurologic symptoms such as numbness and tingling or even paralysis. When the bone is disconnected in this way, instability of the spine is a major concern. Because of the risk of permanent paralysis, treatment to stabilize the spine is important.