by Karen Schroeder, MS, RD
Anatomy and Physiology
The spine consists of a series of interconnected bones, called vertebra, extending from the base of the skull to the tailbone. The lumbar, or lower back, region is where most of the problems of the spine develop.
In between each bony vertebra lies a shock-absorbing intervertebral disc. The spinal cord is protected within the vertebrae, and many ligaments and muscles hold the structure together.
The spinal cord and nerves are bathed in cerebrospinal fluid and surrounded by a protective membrane called the dura. The spinal nerves emanate from the spinal cord at regular intervals.
Each spinal nerve passes through a narrow opening between the vertebral bones and behind the intervertebral discs. Spinal nerves in the lumbar region come together to form the larger nerves that pass into the legs.
Reasons for Procedure
The intervertebral discs consist of two parts: a tough outer layer called the annulus fibrosis and a spongy inner material called the nucleus pulposus.
Over time, or on account of injury, the annulus fibrosis may weaken or degenerate. When this occurs the disc may bulge, resulting in inflammation and pain.
If the annulus completely breaks down, the nucleus may ooze through, causing a disc herniation or rupture. The resulting inflammation and swelling can compress and irritate the nearby spinal nerve, leading to pain, weakness, and numbness along the path of the nerve.
Other conditions can cause pain by compressing the spinal nerves. Degenerative discs, for example, are often accompanied by osteoarthritis, the most common kind of arthritis. Osteoarthritis affects a number of different joints in the body, including those of the spine, and can produce bony spurs that may place pressure on the nearby spinal nerves. Rarely, a tumor or an infection may also compress a spinal nerve.
Depending on which part of the spine is affected, spinal nerve compression can lead to symptoms in the neck, back, arms, or legs. Leg pain due to spinal nerve irritation in the lower back, or lumbar region, is called sciatica.
Doctors use a number of tests to help determine the cause of a suspected spinal nerve compression. Sometimes the physical examination of the affected arm or leg provides clues to the cause and location of the problem. Often an MRI scan of the spine is used to make the diagnosis.
Laminectomies and discectomies are surgical procedures designed to relieve pressure on a spinal nerve by removing a portion of the bone and intervertebral disc, respectively, adjacent to the nerve.
Low back pain is the most common cause of missed workdays. Most cases resolve on their own in 2-6 weeks. Conservative treatment begins with 1-2 days of rest followed by gradually increasing activity and exercises to stretch the ligaments and strengthen the muscles of the lower back. If pain persists, doctors may prescribe oral medications and physical therapy.
When conservative treatments do not relieve the pain, doctors may inject medications into the space surrounding the spinal cord near the inflamed region. Steroid injections, the most commonly prescribed of these medications, produce a temporary anti-inflammatory effect at the site of the inflammation, and are commonly used to treat spinal arthritis and intervertebral disc problems.
When conservative treatments fail to resolve the pain, surgery may become necessary to relieve the pressure on a spinal nerve. Surgery may also be indicated if a herniated disc, or other source of nerve compression, is clearly producing persistent or worsening neurologic symptoms, such as weakness and/or numbness. In a laminectomy, part of the bone and ligament next to the spinal nerve, called the lamina, is removed. This technique allows the surgeon to see and, if necessary, remove the source of the compression.
In a discectomy, the protruding part of the herniated disc is removed if it is found to be compressing the nerve. If there are only small, focal areas of nerve compression, related procedures called microlaminectomy and microdiscectomy may produce the same result with the help of a microscope.
The incision is smaller and recovery is usually quicker.
In the days leading up to your procedure: Arrange for a ride to and from the hospital and for help at home as you recover. The night before, eat a light meal and do not eat or drink anything after midnight. Your doctor may ask you to temporarily discontinue certain medications, herbs, or dietary supplements that you regularly take, especially those that thin the blood, Coumadin®, aspirin, or similar drugs. Do not start taking any new medications, herbs, or dietary supplements before consulting your doctor. You may be given antibiotics to take before coming to the hospital, especially if you have a heart valve disorder. You may also be given laxatives and/or an enema to clean out your intestines.
Before the procedure, an intravenous line will be started. A catheter may be placed in your bladder to drain your urine. Most laminectomies are done under general anesthesia, which puts you to sleep for the duration of the operation. If this is the case, a breathing tube will be inserted through your mouth and into your windpipe to help you breathe during the procedure.
A laminectomy generally takes 1-3 hours. You will be positioned on your stomach while asleep. An x-ray may be taken to confirm the surgery site. Your surgeon will make a small incision over your spine and pull aside the fat and muscles with retractors to expose the lamina.
Using a special bone drill and other instruments, your surgeon will cut away all or part of the lamina, exposing the ligamentum flavum. This is a ligament that overlies the dura and connects one vertebra to the next. Your surgeon will remove a portion of this ligament in order to see into the spinal canal and find the source of the nerve compression.
Any bone spurs your surgeon finds will be removed. If a herniated disc is causing the compression, your surgeon may perform a discectomy by removing the protruding part of the disc. Often, the nerve itself needs to be gently manipulated in order to remove the disc material.
To complete the procedure, your surgeon will close the deep tissue and skin incisions in your back with stitches, staples, or simple adhesive strips.
Risks and Benefits
Possible complications of laminectomy or discectomy in the lumbar region include: infection, heart attack, stroke, recurring disk herniations, ongoing leg pain and numbness, poor wound healing, damage to the spinal cord and/or spinal nerves, blood clot in a leg that can travel to the lungs, paralysis to the lower half of the body, loss of bowel and bladder function, adverse reaction to general anesthesia.
Potential benefits of a lumbar laminectomy or discectomy include: relief of pressure on a spinal nerve, decreased pain or numbness in the affected leg, increased strength in the affected leg.
In a laminectomy or discectomy, or any other procedure, you and your doctor must carefully weigh the risks and benefits to determine whether it's the most appropriate treatment choice for you.
After the Procedure
After surgery, you will be taken to the recovery room. The nursing staff will monitor your vital signs and leg strength on the side where you had surgery to be sure the nerves are intact. You will be encouraged to walk and eat as soon as you feel able. If a catheter was placed in your bladder, it will be removed before you go home. Most patients are released 1-2 days after surgery.
Once you are home, be sure to contact your doctor if you experience: increasing pain in your legs or back, increasing numbness or weakness in your legs, signs of infection, such as fever and chills, redness, swelling, increasing pain, excessive bleeding, or discharge at the site of your surgery, cough, shortness of breath, or chest pain, abdominal pain, blood in the urine or stool, pain, burning, urgency, or frequency of urination, inability to control your bowel or bladder, persistent nausea or vomiting.
During your recovery: avoid heavy lifting, twisting, and prolonged sitting. Walking is helpful to your recovery, so walk as much as you comfortably can. Do not plan on driving or resuming your normal work schedule for several weeks; your doctor will let know when you can safely return to these activities. Do not drive or operate machinery while still taking postoperative pain medications.
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