The degenerated cervical intervertebral disc is one of the most common causes for neck pain. Several symptoms may indicate the presence of degenerative conditions in the cervical spine. These symptoms include: neck pain, pain around shoulder blades, arm pain, numbness or weakness. The disc may be injured by sudden movements, herniate, or it may gradually wear out. With a herniated disc, the nucleus bulges through the annulus, or the annulus tears and can eventually impinge on the nerves exiting the spine resulting in numbness, tingling, or burning sensation in patient’s arms. This condition also is known as cervical radiculopathy.
In addition, abnormal bone spurs can form on the vertebrae, foramen, and spinal canal causing stenosis. The narrowing of the spinal canal places pressure on the spinal cord and results in neck pain, weakness or numbness in the shoulders, arms, and legs; loss of coordination, gait and balance disturbances, or even bladder and bowel control problems. The condition that presents with some or all of these symptoms is called myelopathy. One of the first symptoms usually are increased knee and ankle reflexes, followed by changes in gait (clumsiness, loss of balance) and loss of sensitivity in hands, which makes it difficult to button a shirt or open a jar.
At Boulder Neurosurgical & Spine Associates (BNA), we typically start with a course of conservative treatment before surgery is considered unless the pathological process requires immediate surgical intervention. Nonsurgical treatment options usually include analgesic agents, immobilization, cervical traction, physical therapy, and epidural steroid injections.
There are several surgical treatment options.
Anterior Cervical Discectomy and Fusion (ACDF) is the most frequently performed procedure to treat neck pain, cervical radiculopathy, and myelopathy. The main purpose of this operation is to relieve pressure on the neural elements of the spinal cord and nerve roots. It is called anterior because the cervical spine is typically reached through a small incision in the front of the neck (anterior means front).
Please watch an animation, which describes anterior cervical discectomy and fusion (ACDF)
During the surgery, the soft tissues of the neck are separated using minimally invasive techniques. The surgeon then performs complete or partial discectomy (removal of the disc between two vertebrae) and places bone graft between the adjacent vertebrae using an anterior approach. Normal disc space height is restored by implanting of bone graft. An allograft bone (donor bone from a cadaver) eliminates the need to harvest the patient’s own bone and acts as calcium scaffolding in which the patient’s own bone grows. There are no living cells in the bone graft, so there is a little chance of graft rejection. A small metal plate (Figure 1) is fixed in front of the vertebrae to stabilize the spine and improve the chance of fusion.
Figure. Anterior cervical plate (intraoperative image) and lateral x-rays.
The patient usually can go home a few hours after surgery. With a continued effort to improve patient care and minimize morbidity, the physicians at Boulder Neurosurgical & Spine Associates published a landmark study (PDF) (Villavicencio AT, Pushchak E, Burneikiene S. The Safety of Instrumented Outpatient Anterior Cervical Discectomy and Fusion, Spine Journal, 2007) on the safety of performing this procedure on an outpatient basis. All intraoperative and perioperative complications for 103 patients that underwent ACDF surgery were analyzed. The overall complication rate was only 3.8%. Based on these results we have concluded that it is in the patients’ best interest to let patients recover in the privacy of their own homes.
Neurosurgeons at BNA not only make sure that patients have the best surgical experience possible, but also make it possible to receive such care at the most reasonable cost. Patients usually pay less co-insurance for the surgeries performed on an outpatient basis. The final decision to perform surgery on an outpatient basis is always based on a mutual agreement between the patient, surgeon, and anesthesiologist.
Excellent/good clinical outcomes of up to 95% have been reported in medical literature after ACDF. Dr. Villavicencio was one of the surgeons that participated in the nationwide ACDF Clinical Outcome Registry. Patients that were operated on by Dr. Villavicencio (a total of 100 patients included) had higher satisfaction with results (PDF) and SF-36 (health related quality of life) scores than the average scores in the country.
Physicians at Boulder Neurosurgical & Spine Associates prospectively evaluated clinical outcomes after ACDF. The main purpose of the study was to establish if alterations in cervical sagittal alignment correlated with a higher degree of improvement in clinical outcomes. The results of this study determined that patients who had the segmental sagittal alignment maintained or improved towards lordosis, had higher improvement in their clinical outcomes scores. Follow the link (PDF) to read the results of this study published by BNA physicians.
Other procedures in the cervical spine are performed less often than ACDF. Cervical laminectomy is a procedure to treat cervical stenosis. A section of the lamina bone is removed to relieve the pressure on the spinal cord. This procedure is performed to preclude progression of the spinal cord damage (myelopathy) and improve some of the symptoms that occurred due the disease progression. Sometimes a more technically difficult procedure is required, which is called laminoplasty. Its goal is to relieve pressure on the spinal cord and nerve roots while maintaining your normal motion of your neck. It is called posterior because the cervical spine is typically reached through an incision in the back of the neck (posterior means back). During the surgery, the soft tissues and muscles of the neck are separated often using less-invasive techniques. The bone (called the lamina) overlying the spinal cord and canal is opened (similar to opening a door on a hinge) taking pressure off the spinal cord and/or nerve roots (thereby completing the ‘decompression’) but maintaining as much of the normal spinal anatomy as possible. After completing the spinal decompression, the bone (lamina) are repositioned in a similar anatomic alignment as before the surgery but small spacers made from donor bone or PEEK (a body-friendly polymer) is fastened into place with a set of small metal plates where needed. Over time, the bone overlying the spinal canal grow back together in a manner that allows a greater amount of room for the spinal cord and nerve roots while maintaining normal or near-normal motion.
Cervical foraminotomy is a minimally invasive procedure that widens the space where a spinal nerve root exits the spinal canal and therefore relieves radiculopathy symptoms that are caused by nerve compression.
Posterior Cervical Fusion
Posterior Cervical Fusion with instrumentation is often performed in addition to foraminotomy, laminectomy or laminoplasty. Besides stenosis and myelopathy, such conditions like neck fractures, cervical instability, and tumors are treated. The goal is to relieve pressure on the spinal cord and nerve roots, or to help stabilize abnormal motion or instability in the cervical spine (neck). It is sometime used in conjunction with other surgery, such an anterior cervical discectomy and fusion to allow additional support and to promote fusion of the bones in the neck. It is called posterior because the cervical spine is typically reached through an incision in the back of the neck.
Figures: Anterior Cervical Discectomy and Fusion (ACDF) and Posterior Cervical Fusion (PCF), anteroposterior and lateral radiographs
Please watch an animation, which describes posterior cervical fusion
During the surgery, the soft tissues and muscles of the neck are separated often using less-invasive techniques. The bone (called the lamina) overlying the spinal cord and canal is sometimes removed taking pressure of the spinal cord and/or nerve roots (thereby completing the ‘decompression’). After removing any necessary bone (lamina) and performing microsurgery to decompress the spinal cord and/or nerves, small titanium screws are placed in the bones that surround the spinal cord, and are attached together with a titanium rod. We then place chips of your own bone (taken from the decompression), or other bone-promoting material along the exposed bones and around the titanium screws to help the vertebrae grow together and fuse. We often use bone morphogenic protein (BMP, a synthetic analog of our own body’s ‘bone-growth promoting protein’). BMP was originally discovered and approved for use in the lumbar spine (low back) to help promote fusion and rapid/solid bone growth. Although not approved for use in the neck, many surgeons use BMP to help promote bone growth because it has been so successfully throughout the spine. Occasionally, we need to extend fusion (including the screws and rods) up to the back of the skull, or down to the upper part of the thoracic spine (mid-back) depending on your specific condition. It usually takes a few months for the vertebrae to fuse and complete fusion may take up to a year or two.
Cervical Artificial Disc
Cervical disc replacement is a newer surgical procedure to treat damaged cervical discs where motion preservation is desired. It allows for effective decompression while preserving normal physiological capacity and without sacrificing segmental motion. The procedure begins as anterior discectomy during which the degenerated disc is removed and replaced with a prosthesis. There are currently three types of FDA-approved cervical artificial discs in the United States: Bryan (Medtronic), Prestige (Medtronic), and ProDisc-C (Synthes). Boulder Neurosurgical & Spine Associates surgeons are trained to implant all of these devices. We are also involved in the Advent cervical artificial disc (Blackstone Medical) FDA-controlled clinical trial.
Figure. Cervical artificial disc (ProDisc-C), lateral extension and flexion radiographs.
Figure. Cervical Artificial Disc (Prestige), lateral flexion and extension radiographs.
Click the links to read papers published by BNA physicians that describe the main cervical artificial disc design features Part I (PDF)
, indications for cervical arthroplasty, surgical technique, preliminary clinical outcomes Part II (PDF)
and current status of clinical evidence (PDF)
Spinal Cord and Nerve Monitoring
For most patients with degenerative or traumatic conditions, tumors, infections, or vascular malformations of the spinal cord, Boulder Neurosurgical & Spine Associates (BNA) uses the services of intraoperative neuromonitoring (IOM) specialists. BNA surgeons were instrumental in bringing such technology to the region and actually founded the company that has since then gone on to impact the care of thousands of patients. The sensory and motor nerves, or muscle groups are monitored to ensure that neural tissues at risk are not damaged during the surgery.
Different neurophysiological tests are performed in real-time during surgery allowing the surgeon to carefully monitor the selected region(s) of the spine. Neurophysiological modalities are selected depending on the region of the spine and condition. Sensory and motor pathways are monitored if there is a risk of spinal cord injury.
Triggered Electromyography is performed to test pedicle screw placement where nerve roots are at risk. This adds safety to spinal surgeries and allows BNA surgeons to have as much information as possible during surgery. The surgeon identifies patients that may benefit from this specialized procedure and always provides the safest possible surgical management.
It is important to remember that this added information does not guarantee the procedure’s success or that it will be without complications, but in conjunction to the other techniques, such as intraoperative image guidance and advanced minimally invasive technology, it significantly increases the margin of safety.