Three Rare Cases of Cervical Spondylolysis

Sometimes surgeons encounter patients with a condition so rare, it's worth writing about. In this article, three cases of cervical spondylolysis are presented. Only 100 cases of this type have ever been reported in the entire world. What is cervical spondylolysis?

Cervical refers to the neck and in these three cases, only one segment was affected: the sixth cervical vertebra (C6). Spondylolysis tells us there is a defect or deformity of some kind. In the lumbar spine, 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. In all three patients, this defect was present on both sides resulting in a forward migration or movement of the vertebra on top.

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.

Most people with a cervical spondylolysis defect don't even know they have it until trauma occurs and they develop symptoms. In two of these cases, the patients were involved in a car accident resulting in a trauma-induced injury. Sometimes it is seen when X-rays are taken for some other reason and the lesion is observed at that time. They call this unexpected discovery an incidental finding.

Pain with neck motion often accompanied by weakness in the arms is an indication that the spinal cord is being pinched or pulled. The spondylolytic defect is clearly visible on X-rays. MRIs may or may not show changes in signal intensity indicating a force is being exerted against the spinal cord. Even though MRIs don't show cord compression, the symptoms can be severe enough to schedule surgery to stabilize and fuse the spine.

The three patients in this report had a good result from the surgery. Painful symptoms were alleviated, they could return to their daily activities (including work), and their quality of life was restored. The authors point out that not everyone with this condition must have surgery. whenever possible, conservative care should be considered. Nonoperative care is most likely when the neck is stable and symptoms are mild. The neck is then immobilized in a brace to allow for healing of the bone.

Surgeons involved with patients like this wonder what causes cervical spondylolysis? There is some evidence by the way the structures look that they might be born with this problem. In some cases, the pedicle (supporting column of bone) is missing, so it's clear that there's a genetic defect. In other people with this problem, repetitive microtrauma might be the reason stress fractures occurred causing the bones to separate and form a cleft. There is some speculation that the reason C6 is so often involved has to do with the way this particular bone is shaped.

The authors conclude that this rare condition deserves careful evaluation and treatment planning. Early diagnosis is important though not always possible. Anyone with this type of congenital deformity (present at birth) is at risk for serious neurologic impairment with even minor neck trauma. The surgeon should not hesitate to stabilize the involved segments when there is any sign of instability to reduce the risk of serious neurologic damage.



References: Poong Gee Ahn, MD, et al. Cervical Spondylolysis. In Spine. February 1, 2010. Vol. 35. No. 3. Pp. E80-E83.