Stenosis

Spinal Stenosis

Definition

Stenosis refers to narrowing of the space for the spinal cord or nerve branches in the spine. This may lead to pressure on the spinal cord. Bone spurs that stick into the spinal canal take up space, making the spinal canal smaller. They can press against the spinal cord or nerve roots.

Causes

Aging causes spinal discs to lose some of their moisture and shock-absorbing ability. Tears in the outer disc ring, called the annulus, usually occur first and without symptoms. These tears heal by forming scar tissue, which is weaker than normal tissue. Repeated injuries and tears cause more wear and tear, making the disc progressively less "spongy" until it is unable to act as a shock absorber. The disc eventually begins to collapse, reducing the space between vertebrae and affecting how the facet joints in the back of the spine "line up." As with all other body joints, changes in the way spine bones fit together affect pressure on the articular cartilage that covers the joints. Articular cartilage is a smooth, shiny material covering the end of the bones in most joints. Over time this abnormal pressure causes wear and tear arthritis, or osteoarthritis, to the facet joints.

Bone spurs sometimes form around vertebrae and facet joints. They can press against the spinal cord, leading to symptoms of myelopathy, or put pressure on the nerves at the points where they exit the spinal canal.

Symptoms

The symptoms of spinal stenosis depend on whether pressure is affecting the spinal nerve roots or the spinal cord. A "pinched" nerve in the neck (radiculopathy) usually only causes symptoms in the neck and arms. Pressure on the spinal cord (myelopathy) can affect the arms and legs. It's a greater concern, because it can lead to permanent spinal cord damage. Symptoms of myelopathy vary. Feelings of numbness or weakness can affect both arms and both legs. A loss of muscle control in the legs, called spasticity, may cause difficulty walking. "Position sense" may be lost in the arms or legs. This affects the ability to know where your arms or legs are when your eyes are closed. When this occurs it becomes difficult to use arms and hands, and to know where you are placing your feet as you walk. Myelopathy may disturb the normal function of the bowels and bladder.

Diagnosis

Finding the cause of your problem begins with a complete history and physical exam. These should give your doctor a good idea of the cause of your pain and symptoms. To make sure of the exact cause of your pain, several diagnostic tests can be used. X-rays taken in the doctor's office are usually a first step in looking into any problem, and will give your doctor an idea of whether spinal stenosis exists. These X-rays may include an oblique (angled) view, along with X-rays taken as you bend forward (flexion) and backward (extension). Your doctor will also determine whether other tests, such as an MRI, are needed.

Non-surgical treatments

Surgical treatments

Your surgeon may recommend an operation called a laminectomy, in which the backside of the vertebrae is opened, allowing more room for the spinal cord. Discectomy, which is the removal of one or more discs, may be suggested if stenosis originates from problems of disc herniation. Or your surgeon may suggest a corpectomy and strut graft. This operation involves removing discs and vertebral bodies, as well as any bone spurs that push into the spinal cord, in the locations where problems are occurring.  The vertebrae are then replaced with a solid piece of bone graft, known as a strut graft. The strut graft heals over time, creating a solid fusion of the spine where the vertebral bodies have been removed.

Recovery

Here's what you can expect at home after your laminectomy:

  • Some significant pain is likely to occur, requiring strong medicine such as narcotics or opiates. Don't drive while taking opiate pain medicines. Most people are able to cease taking opiates or narcotics and return to driving in between one and two weeks. Your surgeon will tell you when it's safe to resume driving.
  • Limitation of activities that include bending, stooping, or lifting, for a period of several weeks following laminectomy.
  • Keep the incision site clean and dry. Your doctor can provide instructions for showering and bathing.
  • After about two weeks your doctor will remove stitches or staples. 
  • Avoid prolonged sitting, as usually happens on long plane flights or car rides. This can lead to blood clots in the legs. If you must travel during this time, stand and walk at least once per hour.

Recovery time depends on the extent of your surgery and other personal factors. Here are some general time periods to keep in mind:

  • Following minor (decompressive) laminectomy, light activity (desk work and light housekeeping) can usually resume within a few days to a few weeks.
  • If laminectomy is accompanied by spinal fusion, the recovery time is longer. Resumption of light activity may not take place until between two and four months.
  • A return to full activities involving lifting and bending may not be possible for between two and three months.
  • Begin light walking for exercise and for physical therapy exercises as soon as your doctor says it's OK to do so, as this will speed your recovery.

Following discectomy, here's what to expect:

  • Healing and recovery will not happen overnight.
  • Soreness will continue for 2 to 3 days.
  • Pain will gradually reduce over the following 1 to 2 weeks, as healing begins.
  • Deep healing will require 4 to 6 weeks.
  • If before surgery you experienced numbness and/or tingling in your legs and/or your feet, these symptoms may still be present following surgery. These symptoms are usually the last to improve.

How can I manage my pain?

Pain in your back after the surgery is normal, as is leg pain. Pain is caused by the incision and swelling around the nerve. It will decrease as your back heals. You may also experience muscle spasms across your back and down your legs. This does not mean that the surgery was unsuccessful or that your recovery will be slow.

Remember these points:

  • Everyone experiences pain differently.
  • Most pain or spasms can be controlled or reduced.
  • In general, the more active you are, the less pain you will have. Muscles that are not used will become stiff and sore.
  • You may be given a prescription for pain medications before you leave the hospital. Take your pain medication as directed. Do not allow your pain to become too severe.
  • You may also use ice on your low back to relieve pain during the first week after surgery. Use crushed ice in a plastic bag, a bag of frozen peas, or a frozen gel pack for 15 to 20 minutes at a time. From the second week on, you may use heat to relieve pain as the swelling in your back goes down. Moist heat such as a warm shower or gel pack is best. Leave heat on for 30 minutes at a time.

After corpectomy with strut graft

  • Most patients will wear a rigid neck brace, or a halo vest, for at least three months following surgery. Such restrictive measures may not be necessary if metal hardware was attached to the spine during the surgery.
  • Patients usually remain hospitalized following surgery for up to one week. During this period a physical therapist will schedule daily sessions in order to help patients learn safe techniques for moving, dressing, and performing normal activities without adding unnecessary strain to the neck.
  • Patients may return home when their medical condition has stabilized. However, they are usually required to keep activities to a minimum to give the graft time to heal. Outpatient physical therapy usually begins five weeks after the date of surgery.

Rehabilitation

What should I expect during my recovery?

  • Rehabilitation following corpectomy surgery can be a slow process. Patients will probably need therapy sessions for two to three months, and should expect up to one year required for a full recovery.
  • Many surgeons prescribe physical therapy on an outpatient basis beginning a minimum of five weeks following surgery. At first, treatments help control pain and inflammation. Ice and electrical stimulation treatments are commonly added to help with these goals. Your therapist may in addition use massage and other hands-on treatments, in order to ease muscle spasm and pain.
  • Active treatments are slowly added, including exercises designed to improve heart and lung function. Cardiovascular exercises such as walking, stationary cycling, and arm cycling are ideal. Therapists also may teach specific exercises in order to help tone and control the muscles used to stabilize the neck and upper back.