Lumbar Laminectomy

A laminectomy can be performed on all regions (lumbar, thoracic, cervical) of the spinal column to relieve pressure on the spinal cord or the nerve roots. There is no spinal cord in the lumbar spine, thus the compression is only of nerves. The lamina is the bony roof of the spinal canal. Laminectomy is the term used to refer to the process of removing the lamina (usually both sides). Removing the lamina increases the size of the spinal canal, giving more room for the spinal nerve roots.

This procedure is also called a spinal decompression. As mentioned in the section on Lumbar Disc Disease, this compression can be the result of bony overgrowth, disc Herniation, or a combination of both.

Pathology

With advancing age, several changes occur in the bone, disk, joints and ligaments of the lumbar spine.

1. Bones. The bones tend to loose water and become less dense (spondylosis). Because of degenerative changes near the disk margins, an overgrowth of bone may occur producing bony spurs (osteophytes) that may encroach on the exiting foramina with compression of the enclosed nerve roots
2. Disk. The disks also loose water and thus narrowing the disk space. The spacing between the vertebrae likewise narrows resulting in further narrowing of the foramina
3. Joints. Along with the other degenerative changes, there develops a degenerative arthritis of the facet joints that causes the joints to enlarge. Sometimes the lining of the joint (synovium) enlarges or becomes cystic. This combination of events results in narrowing of the spinal canal and increasing stiffness of the spine. If the joints degenerate such that the fibrous capsule loosens, then one vertebrae may slip over the one below causing further narrowing of the canal and instability
4. Ligaments. With advancing age the ligaments tend to stretch and thicken. This further encroaches on the spinal canal and foramina

The above combination of changes results in nerve roots being compressed within the spinal canal or as the nerve roots exit from the spinal canal through the foramina

Surgical Procedure:

Decompressive lumbar laminectomy is the procedure most commonly carried out for LSS. The procedure is carried out in the following manner:

• The number of vertebra that are involved is determined and an incision is made extending from one vertebrae above to one vertebrae below the vertebra to be operated upon
• The muscles are elevated off of the spinous processes and lamina of the vertebra and held apart with an instrument called a retractor
• The spinous processes and lamina of the involved vertebra are then carefully removed under magnification (magnification loupes or operating microscope).
• These structures are removed using a special drill and small bone biting instruments called rongeurs (Figure 8)
• Using the same instruments, the overgrowth of the facet joints and the bone pushing in on the foramina are removed as necessary
• The overgrown and stretched ligaments are also removed
• All bleeding is stopped and the incision is sutured.

Post-operatively, patients are in the hospital for one to three days, and the individual patient’s mobilization (return to normal activity) is largely dependent on his/her pre-operative condition and age. Directly following the procedure, patients are encouraged to walk. However, it is recommended that patients avoid excessive bending, lifting or twisting for six weeks in order to avoid pulling on the suture line before it heals.

The success rate of laminectomy surgery is favorable. After healing, approximately 70 - 80% of patients will have significant improvement in their function (ability to perform normal daily activities) and markedly reduced level of pain and discomfort. The surgical results are much better for relief of leg pain caused by spinal stenosis, and not nearly as reliable for relief of lower back pain.

Risks and Possible Complications

While decompressive laminectomy is a relatively safe procedure, and despite even the greatest care, complications do occur;

• Hemorrhage. Hemorrhage may cause compression of the nerve roots with resulting weakness or paralysis in the legs, loss of feeling and loss of bowel or bladder control
• Tearing of the dura over the nerve roots. This problem occurs because the ligaments may be stuck to the dura, and can lead to injury to the nerve roots, pain, and leakage of cerebrospinal fluid (the fluid that surrounds the nerve roots). If leakage occurs, this must be corrected to prevent later infection.
• Infection of the wound
• Direct injury to the nerve roots causing weakness or paralysis in the legs, loss of feeling and loss of bowel or bladder control. Tears in the dura and injury to the nerve roots are minimized by the use of magnification at the time of surgery
• Deep venous thrombosis with pulmonary embolism. This is a very serious problem. In some patients, blood clots will form in the veins of the legs or pelvis. These clots may come loose from the vein wall and travel to the lungs causing severe difficulty with respiration and even death
• Since this surgery is most often performed on an older population, the patient may also be subject to complications related to heart or lung disease, diabetes, or hypertension.

Also, please read the paper entitled, "Risks and Possible Complications"

After Surgery

The leg or buttock pain that you experienced prior to surgery should begin to diminish shortly after surgery. However, it is not unusual for some degree of this pain to linger for quite some time, especially if you had the pain for a long time prior to the surgery.

Some patients experience nerve swelling 2-4 days after their surgery. This can cause recurrence of the leg pain that was experienced prior to surgery. Once the swelling diminishes, the pain will begin to go away. By 4-6 weeks, the incision pain is mostly gone. Back and abdominal strengthening program are started in physical therapy at 3 - 4 weeks. Return to work will be determined on an individual basis.

Numbness and Weakness

If you experienced numbness and/or weakness in your foot or leg prior to surgery, it may not change much immediately after surgery. This will depend greatly on the extent of nerve damage that resulted from the nerve compression. For some patients, recovery of the nerve can take up to several months. For others, the nerve may have been so severely damaged that recovery is not possible. Nerve recovery is very unpredictable and is dependent on many factors, all of which are individual to each patient.

Activity Level

We expect you to get out of bed as soon as possible, no later than the morning after surgery. We ask that you alternate walking and lying down several times throughout the day, minimizing sitting, as this will aggravate back spasms. Immediately after surgery, walking is the best exercise. This should involve slow progressions in distance and frequency. Always rest between the walks. Some patients are also able to begin walking programs in a swimming pool. This, however, is not advisable until 2 weeks after surgery.

Do not lift anything over 10 lbs. until we have decided otherwise.

You may carefully engage in sexual activity 3 weeks after surgery

Driving

Do not drive until we’ve discussed it in a follow-up visit, or you are 3 weeks out from surgery. Before driving can safely be resumed, a practice session in a parking lot is needed to be certain that the patient can get from the accelerator pedal to the brake quickly enough for safe driving.

Please walk as much as is comfortable. Short distances are better than long. Do not spend the day in bed. Even when you are lying down, you should exercise your legs frequently. For more detailed instruction, see the web page entitled "Going Home After Lumbar Laminectomy"

Generally, lumbar spine surgery is safe and very effective in properly selected patients. However, both the doctor and the patient must participate fully to get the best possible result.