Cervical (related to the spine in the neck) spinal stenosis [narrowing of a canal or vessel] causes constriction and compression (pressure) on the spinal cord. The spinal cord carries all of the information from the brain to the body, and from the body back to the brain, so when there is pressure on the cord, this can result in a reduced flow of information back and forth.
While more detailed information about each condition is located at the bottom of this page, we summarize it as follows:
Common causes of cervical spinal stenosis include conditions one was born with (congenital spinal stenosis) , where the patient was born with a smaller than average canal (just like some people have large feet or ears). Another factor is the presence of consequences of arthritis and the normal aging process (degenerative spinal stenosis), which can result in ridging of the spinal canal at the disk spaces, and gaps in between. Another cause of cervical spinal stenosis include trauma, which can affect and speed the normal degenerative process, or cause a piece of the normal tissue to be displaced into the normal spinal canal, through a herniation of the disk material, fracture of the bones of the canal, or of the contents of the facet joints (synovial cyst). Trauma can also cause blood to collect in a layer where it doesn’t belong, putting pressure on the spinal cord. Tumors can cause spinal stenosis, growing from within the spinal cord, from one of the nerve roots that arise from the spinal cord, from the covering of the spinal cord, or in some cases having spread to one of those structures from another place in the body (spinal metastases). Infections in and around the spine can cause spinal stenosis, often with rapidly progressing and devastating effects. Often more than one condition is present, so the addition of another condition such as someone with a congenitally small canal either develops mild to moderate arthritis or a disk herniation that otherwise might not be large enough to be symptomatic, when the two conditions are combined the result is worse than either alone.
Some of the symptoms of cervical spinal stenosis include weakness in the hands, arms, legs, and trunk muscles. There can be impairment of bladder or bowel function with either incontinence (unable to stop going, such as having accidents‘ or retention where it is hard to get rid of the contents, making one either constipated or like they cannot go adequately). Other signs include difficulty with control of the arms, legs, or body, such as uncontrollable spasms, lack of coordination of walking or loss of the fine control of the hands. Another potential sign or symptom of cervical spinal stenosis is pain in the body, such as a sharp, burning, or electrical pain, which can go up or down the neck, back, arms or legs. If you suffer from any of these conditions, you should discuss them with your physician as soon as possible.
The treatment of cervical stenosis is usually dependent upon the severity of the stenosis, whether there is associated spinal deformity, and what is the cause of the stenosis, but can include anterior procedures in the neck (such as diskectomies or corpectomies), and posterior procedures in the neck (such as laminectomy, with or without fusion, laminoplasty, or minimally invasive treatments, when appropriate). Sometimes surgeons will combine an anterior procedure with a posterior procedure, either to treat two overlapping conditions at the same time, or because they feel that in that particular patient both treatments need to be performed to ensure a good outcome.
Anterior Cervical procedures
An anterior cervical diskectomy is one of the oldest procedures performed by spinal surgeons, and when combined (see below) with another treatment, is a part of the current standard of care for disk herniations. Many of the other treatments below are more commonly used today for a number of reasons, but occasionally there is a reason for performing the simple diskectomy without any other treatment. Some of the reasons it has fallen out of favor is that there are several potential consequences of this procedure:
- Patients typically have more chronic neck pain
- The disk, once removed, collapses and the neck becomes more kyphotic, which can put more strain on adjacent levels in the spine
- When the disk is removed, the space between the bodies becomes smaller resulting in greater likelihood of pinching of nerves where they leave the spine
Although almost all spine surgeons do still perform this procedure, most have abandoned JUST doing this procedure, in favor of performing a discectomy AND either a fusion or artificial disk replacement (where appropriate, see below).
Diskectomy with fusion
In the 1950’s, Cloward and Smith and Robinson popularized different techniques of placing a bone graft where the disk used to be, to prevent the consequences listed above: In theory, by keeping the alignment in the neutral lordosis, there should be less degeneration in adjacent levels over time. By keeping the two vertebral bodies apart, there should be less pinching of nerves over time. By encouraging the bones to fuse together, there is typically less neck pain as the two vervical vertebral bones no longer rubbed against each other without the benefit of a disk in between. And the distraction of the two bodies kept the ligaments in the spinal canal from bulging into the canal and spinal cord, preventing delayed spinal stenosis. At this time most surgeons who perform a diskectomy with a fusion will do so using a plate on the front of the spine to help the fusion along. This is called instrumentation.
Diskectomy with total disk replacement (TDR)
Instead of replacing the disk material with a bone graft, some surgeons may choose instead to replace the disk (in a limited number of patients who are deemed candidates for the procedure) with an artificial disk implant that normally allows for some movement at the level operated on, instead of fusing and eliminating movement at that level. The theoretical advantage is that it preserves some motion at that level, even if it is not completely normal motion. It has the same other advantages fusion has over simple diskectomy, in that it prevents collapse and kyphosis and most of the consequences listed above.
The FDA approved indications for cervical TDR are for single level disease without significant facet disease, and are primarily indicated for disk herniations with nerve root compression. Any use other than above is considered “off-label”, including more than one level of disk implantation. Some patients do go on to fuse around the artificial disk. Outcomes after both an artificial disk replacement and after diskectomy and fusion are generally good, with return to function. One exception is that professional athletes such as NFL players, and combat pilots in the military, are not usually cleared to return to active duty or play after an artificial disk replacement. There is generally a much larger and longer experience for follow-up after a fusion than there is after a disk replacement, and newer generations of disk replacement will likely come along; and additional information about the long-term results in such high-performance athletes may change these reccomendations.
Anterior keyhole foramenotomy
For those patients whose spinal stenosis is caused by a single off-centered disk herniation or bone spur from the disk space (anterior osteophyte), a small procedure with a similar approach as the diskectomy can remove the compression without complete removal of the disk, and without a fusion. This procedure involves less disruption of the rest of the disk space, and so the majority of the native disk material is left untouched, and the patient is able to maintain their pre-operative range of motion. The restrictions are slightly less after an anterior foramenotomy for diskectomy or decompression, and so consequently the procedure is slightly easier to recover from.
However, this procedure does have a significant recurrence rate (precisely because it does not involve removal of the entire disk material, which typically requires a fusion or total disk replacement), and does result in some damage to the disk. Although most surgeons who perform this procedure will not completely immobilize the patient after surgery in a collar, strenuous activity is typically curtailed initially.
Sometimes, such as when the compression is more than just disk material or bone spurs at the disk level, or a major deformity is involved, or removal of the entire vertebral body is necessary because of tumor of other disease involving the bone, then a more complete removal of the vertebral body is required. This is called a vertebrectomy or a corpectomy. Whenever a corpectomy is performed, either a fusion or an instrumentation is usually performed. This is to maintain a more ideal position. The corpectomy is more destructive than a diskectomy and fusion, and may have a higher nonunion rate, and multilevel procedures are more likely to require a second procedure to provide supplemental instrumentation from the posterior approach to ensure a solid fusion.
Posterior Cervical Procedures
Laminectomy has been performed for more than 80 years to take the back of the spinal canal off, like openinig a convertible roof or a can of sardines. By removing the back of the canal (an “-ectomy” or removal of the lamina or back of the spine), the contents of the spinal canal (the spinal sac, with its column of spinal fluid and the spinal cord and nerve roots) can expand backwards and be less compressed. This usually alleviates or improves the neurological symptoms caused by the compression and gives the best environment to recover in.
However, there are many circumstances where the removal of the bone in the back results in delayed kyphosis or forward tipping. This forward tipping essentially bends and stretches the spinal cord over the disk spaces and bone spurs, and over time this can result in more neurological symptoms. For this reason, most spine surgeons will perform an instrumentation and fusion with a laminectomy when done for spinal canal stenosis, especially if there is already a forward or kyphotic tipping of the spine, or if there is significant weakness to suggest that the muscles of the neck will be too weak to hold the neck in position over time.
Laminectomy with fusion
Fusion, when performed as part of a laminectomy procedure, will eliminate movement in the levels so fused. This is usually achieved with some form of instrumentation to hold the bones rigidly until the bone heals, and adds stability to the neck (assuming the fusion heals properly). Most skilled practitioners believe that getting the spinal alignment to fuse in as close to the normal neutral lordosis will keep the remaining levels from degenerating as quickly. There are various competing forces and issues (difficulty in getting the alignment of the spine corrected, risks of being more aggressive, among others). Generally, we try, where possible, to restore or maintain a 20 degree or more curve within the entire cervical spine (normal is generally considered 20 to 40 degrees).
The consequences of the procedures include reduced neck range of motion (and the amount of reduced range of motion depends on the levels so fused), slightly increased risks associated with the more extensive nature of placing screws, cables, or other forms of instrumentation into the spine, the need to observe the patient over the year or so after the operation to make sure the fusion takes and doesn’t develop into a pseudoarthrosis [failed fusion, see the section on re-operations].
Laminotomy or foramenotomy
When the area of stenosis is less extensive or off to one side, a smaller procedure can be performed. Some disk herniations can also be treated by a small procedure from the back of the neck, which doesn’t require a fusion to achieve the goal of decompression of the nerves or spinal cord. The indications for a “keyhole” foramenotomy [because the surgery is small like an old-fashioned key hole] may be different than that of a discectomy or a laminectomy, and in some cases either procedure may be appropriate.
Laminoplasty is used to repair or treat (“-plasty” or repair) the lamina when there is significant spinal stenosis. This procedure has the advantage of maintaining most of the range of motion they had pre-operatively (as opposed to a fusion) but still significantly increasing the canal area (almost doubles the space available for the cord). The procedure allows for the retention of the majority of the normal anatomy of the spine, which keeps the spine from tipping forward over time. While there are several techniques for performing a laminoplasty of the cervical spine, the one Dr. Jenkins usually employs is known as the “open door” technique.
Essentially, the back of the spine (lamina) is hinged open on one side after cutting it free and elevating it from the other side, held in place usually by a custom titanium miniplate designed for just this procedure. It’s like raising the roof on one side of the house, but because the roof is curved or with a reverse “V” shape, once elevated takes on a shape like the top of an octagon.
This procedure should not be applied to patients whose spines are already severely tipped forward (Kyphotic) or in those for whom instability is present. This procedure can be performed either as a laminoplasty at all levels (Case 1), or when part of the region to be operated on is already somewhat unstable and requires instrumentation and fusion, a hybrid procedure can be performed in the part that is not unstable (Case 2)
Case 1: Laminoplasty for acute spinal cord injury
14 year old boy who was checked to ground playing basketball, started with hand and leg weakness and progressed to near quadriplegia (almost no function in arms or legs).
Case 2:Hybrid laminectomy with fusion, AND laminoplasty
51 year old musician with progressive hand weakness and incoordination. Was noted to have severe degenerative changes from C5 to T1, but also to have superimposed congenital stenosis which made the condition worse.
Instead of fusing 5 levels, we only fused 3 levels and left the other two levels decompressed via the laminoplasty procedure. The patient was very satisfied with the range of motion he has post-op.