Cervical spine disease is a fairly common problem seen in adults. When that disease involves the compression of spinal nerves in the neck, people may seek advice from their doctor. Symptoms can range from mild neck pain to severe numbness in the hand and electric-like pain shooting down the shoulder, arm, and hand. Some patients can even experience significant weakness in the arm or hand. Fortunately, most people can be treated successfully without surgery or aggressive treatment. In a few patients, however, these symptoms can persist despite conservative treatment or become so severe that surgery is recommended for relief. Anterior cervical discectomy and fusion (ACDF) is a well known procedure to address such a problem. It involves going through the front of the neck and removing disc material from a spinal level and then stabilizing that level by placing bone graft material and metallic hardware. When the spine is fused, there is no longer motion at that level. Posterior cervical foraminotomy is an alternative surgical procedure to relieve symptoms of a pinched spinal nerve. This procedure is performed through the back of the neck and it creates more space for the spinal nerve to pass through. In properly selected patients, posterior cervical foraminotomy is as effective as ACDF surgery without requiring a fusion procedure.
The spine is composed of three basic elements: bones, named vertebrae; intervertebral discs, which act as shock absorbers between the vertebrae; and nerve tissue, the spinal cord and nerve roots. The vertebrae are hollow bones which look like rings. They are stacked one on top of another to form a column with a central canal. The discs separate one vertebra from another and they serve to cushion the spinal column. The spinal cord is fairly delicate, and it is protected as it runs from the brain down through the canal of the bony vertebral column. The nerve roots are nerve branches that exit from both sides of the spinal cord, and they travel out of the spinal column through boney passages called foramen. The spinal cord resembles a tree trunk while the individual nerve roots look like branches of the tree. Once out of the spine, the nerve roots travel to various parts of the body to relay information. In the neck, there are seven vertebrae, and eight pair of cervical nerve roots.
In cases of cervical spine disease, discs can weaken and bulge or even rupture to cause pinching or compression of either the spinal cord or more commonly, particular nerve roots. The bone itself can wear out and then develop spurs which also compress the spinal cord or nerve roots as they pass through their foramen. Spinal cord compression is a serious problem and it usually requires surgical intervention. Nerve root compression if significant can also be problematic, and it may also require treatment by a spinal surgeon. You may experience neck pain; neck stiffness; numbness in the hands; weakness in the arms or hands; or pins and needles sensation in the arms and hands, called radiculopathy. The severity of these complaints can vary and in some cases can worsen with time. You may be referred to a spinal surgeon as the symptoms progress. A spinal surgeon can assess the extent of the cervical disease process by listening to your description of the symptoms, by conducting a thorough physical examination, and by studying the results of radiographic studies, such as MRIs or CT/myelograms. The decision to operate is made with great care and with your permission if non-operative care is unsuccessful.
Posterior cervical foraminotomy relieves spinal nerve root compression by creating more room for the nerve root to pass through the foramen. When disc material compresses the nerve root on one side (unilateral compression), the cervical foraminotomy can be used to remove the portion of the offending disk. When a bone spur narrows the foramen and compresses the nerve root, a posterior cervical foraminotomy can be used to chisel away the spur to widen the passageway. Some refer to this procedure as minimally invasive, in that the incision is relatively small and no fusion of the spine is required.
The procedure is performed in the back of the neck, which means that you will be lying face down on the operating table. You will be under general anesthesia so that you will feel nothing during the procedure. The spinal surgeon will make a small 1 to 2 inch skin incision and with the help of magnification, he/she will dissect away soft tissue on the side of the compression. Precision instruments are used to carefully remove a small amount of bone which serves as the outer wall of the foramen. Once the foramen is opened, the nerve root can be seen. In cases of compression due to disc material, the nerve root is gently lifted and the disc material is removed. The wound is then closed, and the surgeon may provide you with a soft collar. A variation of this technique is a truly minimally invasive procedure where the surgeon may use an even smaller skin incision and use a tubular retractor to access your spine. Regardless of which approach, standard skin incision or with minimally invasive tubes, posterior cervical foraminotomy provides relief of nerve root compression with minimal bone removal. Symptomatic relief is seen in 85- 90% of cases. Some patients may require a short course of post-operative physical therapy. Risks of this procedure are uncommon but they include: bleeding, infection, neck stiffness, repeat disc herniation, incomplete relief of symptoms, damage to nerve root or spinal cord, or problems with anesthesia.
One option for removing compression from multiple levels in the neck is called a cervical laminoplasty. A laminoplasty is performed via an incision in the back of the neck which is called a posterior approach. During surgery, the patient will be lying face down on the operating table. Frequently, specialized monitoring devices are used to check the spinal cord during the surgery to ensure that there is no damage to the spinal cord during the surgery. Instead of removing the bone and other compressive structures, the bone overlying the spinal cord (the “lamina”) is partially cut on both the right and left sides. This creates a hinge on one side of the lamina and a small opening on the other side. The lamina is then moved into the “open” position by elevating the lamina on the open side [Figure 2]. This vastly increases the space available for the spinal cord and takes the pressure off of it. The spinal cord can move away from whatever was compressing it including disc herniations or bone spurs (as seen in Figure 1), and the spinal fluid can then flow around the spinal cord more normally (the white substance seen Figure 1). A spacer made out of bone, metal, or plastic, is usually inserted to hold the spinal canal open [Figure 2]. The final position resembles an open door being help open with a door stop, and many surgeons refer to this technique as an “open-door” laminoplasty. Another type of laminoplasty called a “French-door” laminoplasty is performed by creating hinges on both side of the lamina and an opening in the center of the lamina. The lamina is then opened by elevating both sides and ultimately resembles a French-style patio door.
Anterior Cervical Fusion
Cervical Stenosis, Myelopathy and Radiculopathy
Radiographic Assessment of Spinal Disorders