Mark M. Mikhael, M.D.
Advanced arthritic changes in the cervical spine can lead to narrowing of the spinal canal at multiple levels throughout the neck. When the narrowing becomes severe, it can lead to compression of the spinal cord, referred to as “myelopathy.” Symptoms of myelopathy can include difficulty with walking and balance, trouble with handwriting and other fine motor skills, or shooting pains with numbness in tingling in the arms or hands. The most severe consequences of myelopathy include progressive weakness or even paralysis. To treat this condition and prevent any further decline, several types of surgical procedures have been utilized with good results.
Regardless of the surgical procedure performed, the goal of the operation is to take pressure off the spinal cord and create more space in the spinal canal. When the disease is only present at only one or two levels, a procedure commonly performed is called, “Anterior Cervical Decompression and Fusion (ACDF).” The surgeon removes the disc and bone spurs compressing the spinal cord from the front of the neck and then fuses the two levels together. Several studies have shown this to be a very effective and reliable treatment for patients with one or two levels of compression.
A “fusion” procedure relies on bone formation between two spinal levels until they are united. This process can take up to 6 months to be completely solid or “healed.” When a fusion fails to heal after 8-12 months, this is then considered a “non-union.” When attempting to perform an ACDF procedure at three or more levels in the front of the neck, studies have shown that patients can be at slightly increased risk for non-union compared to those patients who have the same procedure for only one or two levels. In order to avoid this problem, some surgeons prefer to take pressure off of the spinal cord from the back of the neck when three or more levels of compression are involved.
To take pressure off of the spinal cord from the back of the neck, the surgeon must remove portions of the bones, called “laminectomy,” which creates more space for the spinal cord. Because the removal of these bones disrupts the attaching ligaments and structures in the neck, this can cause gradual neck deformity or instability. To help prevent this from occurring, laminectomy is combined with a fusion procedure using screws and rods to hold the vertebral segments together until bone grows and fuses them to one another. This treatment has also been shown to be very effective and reliable for the treatment of patients with spinal cord compression at multiple levels.
Arthritis in any joint, including the spine, can cause significant pain with motion. Because spinal cord compression and myelopathy typically occur in the setting of advanced arthritis, the elimination of motion with a fusion procedure also may help decreased pain associated with arthritis in the spine. However, there are some patients who have evidence of spinal cord compression at multiple levels with myelopathy, but do not complain of any neck pain. These patients may be good candidates for cervical laminaplasty.
Cervical laminaplasty, a procedure first described in Asia, involves creating more space for the spinal cord while avoiding fusion and maintaining spinal motion. Several different types of procedures have been described, but they all involve the same basic concepts. This procedure is performed from the back of the neck and involves creating an “opening door hinge” with the bones to create more space for the spinal canal instead of removing portions of the bones as done with laminectomy, thus avoiding disruption of some of the supporting structures. Small plates and screws have been designed to hold open the door-hinge and maintain the increased space for the spinal canal. The spinal segments are not fused together and post-operative motion is encouraged to avoid any residual stiffness following the procedure.
While cervical laminaplasty is a novel and effective treatment for multilevel spinal cord compression while avoiding fusion and sparing motion, it is not for everybody. Appropriate patients need to be carefully selected in order to ensure the best possible outcome following this procedure. In particular, patients should have little or no neck pain prior to the procedure. Because this procedure avoids fusion and post-operative motion is expected, those patients who are suffering from neck pain related to spine arthritis will continue to have those complaints with maintained motion. This procedure also relies on what is termed “indirect decompression” to take pressure off of the spinal cord. Any procedure that relies on indirect decompression requires that the patient have near normal curvature to their cervical spine, specifically no excessive kyphosis, instability, or scoliosis. The surgeon can evaluate for this with x-rays taken before the operation.
In appropriately selected patients, cervical laminaplasty has been shown to be an effective treatment of multilevel spinal cord compression and myelopathy. The procedure can be a reasonable option for the relatively active patient who wants to maintain motion and avoid a fusion procedure. It is important for the surgeon and patient to carefully discuss the goals and expected outcomes of the procedure to ensure the best possible recovery. In patients with either one or two level compression or significant neck pain from arthritis, traditional front or back decompression and fusion procedures may be the more appropriate choice. Correct patient selection by the surgeon is the key to successful cervical laminaplasty. As with any surgical procedure, patient safety and satisfactory outcome should be the primary goal.