What is a lumbar laminectomy and rhizolysis?
A lumbar laminectomy and rhizolysis is an operation on the spine in the lower back. Its purpose is to relieve pressure on the nerve roots that leave the spine and run down to form the nerves in your legs.
The back of the spine has a bony ‘shingle’ on either side of the midline. These angled segments of bone are known as the laminae, and their purpose is to permit muscles to attach to the spine and also to protect the nerve roots. Removal of portions of these laminae is known as a ‘laminectomy’, ‘hemilaminectomy’, or ‘partial hemilaminectomy’.
By simply removing portions of the laminae, the underlying nerve roots may remain somewhat compressed. To adequately decompress the nerve root, it is often necessary to remove part of the facet joint (‘medial facetectomy’), as well as any thickened ligament. Decompression of a nerve root is known in surgical terms as a ‘rhizolysis’.
What is an interspinous distractor?
In some cases an interspinous distractor is inserted between the pointy portions of bone at the back of the spine (the ‘spinous processes’). These ‘shock absorbers’ may reduce the pressure on the disc, as well as increasing the amount of room for the nerves in the spinal canal, lateral recesses, and intervertebral foraminae.
Why might I need a lumbar laminectomy and rhizolysis?
Decompressive lumbar spine surgery may be needed for a variety of problems. Generally, surgery may be performed for degenerative disorders or disc prolapses.
A lumbar laminectomy (more commonly a partial hemilaminectomy) and rhizolysis is usually performed to treat pressure on one or more spinal nerves in the lower back. Such pressure may be caused by lumbar spondylosis (with lumbar canal, lateral recess or subarticular stenosis), an intervertebral disc prolapse, and/or foraminal stenosis.
Surgery is usually recommended when all reasonable conservative measures (pain medications, nerve sheath injections, physical therapy, hydrotherapy, etc.) have failed. In cases of significant instability or neurological problems, surgery may be the appropriate first option.
Why might I need an interspinous distractor?
Interspinous distractors are often placed in conjunction with either a partial hemilaminectomy and rhizolysis, or a lumbar microdiscectomy. The goal is to offer some protection to an already injured or diseased intervertebral disc, create more room for the nerves in the locations where a simple decompression is not usually satisfactory (in the intervertebral foramen), and hopefully reduce the risk of post-operative back pain or recurrent leg pain.
In some cases, for example neurogenic claudication in the elderly or unwell, an interspinous distractor may be inserted without decompression, thereby providing a quick, safe, and often very effective alternative to a longer and slightly more risky decompressive procedure.
What exactly is wrong with my back?
The spinal canal and intervertebral foraminae are bony tunnels in the spine through which run the spinal cord and spinal nerves (nerve roots) respectively. When the size of these tunnels is reduced, there is less room for the spinal nerves and/or spinal cord, the consequence of which may be pressure on these structures. Disorders that can cause nerve root compression include spinal stenosis, degenerative disc disease, a bulging or prolapsed intervertebral disc, bony spurs (osteophytes), or spondylosis (osteoarthritis of the spine). Commonly, two or more of these conditions are seen together.
Symptoms of nerve root compression include pain, aching, stiffness, numbness, tingling sensations, and weakness. As spinal nerves branch out to form the peripheral nerves, these symptoms may radiate into other parts of the body. For example, lumbar nerve root compression (pinched nerves in the lower back) can cause symptoms in the buttocks, thighs, calves and feet.
What is intervertebral disc degeneration?
Intervertebral discs sit between each bone (vertebrae) in the spine. They act as shock absorbers as well as allowing normal movement between the bones in your lower back. Each disc has a strong outer ring of fibres (annulus fibrosis), and a soft jelly-like central portion (nucleus pulposus). The annulus is the toughest part of the disc, and connects each vertebral bone. The soft and juicy nucleus of the disc serves as the main shock absorber.
In degenerative disc disease the discs or cushion pads between your vertebrae shrink, causing wearing of the disc, which may lead to herniation. You may also have osteoarthritic areas in your spine. This degeneration and osteoarthritis can cause back pain. Pain, numbness, tingling and weakness in the legs may result from pressure on the spinal nerves.
An annular tear is where the annulus fibrosis is torn, often the first event in the process of disc prolapse. An annular tear can cause back pain with or without leg pain.
A lumbar disc prolapse (or herniation) occurs when the nucleus pulposus escapes from its usual position and bulges into the spinal canal, sometimes placing pressure on the nerves or spinal cord.
What are osteophytes?
Osteophytes are abnormal bony spurs which form as part of the degenerative process, osteoarthritis or following a longstanding disc prolapse. This extra bone formation can cause lumbar canal stenosis as well as intervertebral foraminal stenosis, resulting in compression of the spinal nerves.
What is subarticular or lateral recess stenosis?
Within the spinal canal in the lumbar (lower back) region, the nerves run across the intervertebral disc and just under the facet joints (subarticular region). They may therefore be compressed by a bulging disc, or anything that reduces the amount of space in the subarticular (or lateral recess) compartment. For example, in spinal osteoarthritis, the facet joints may enlarge (‘facet joint hypertrophy’) and the ligament may thicken (‘ligamentum flavum hypertrophy’), with the end result being subarticular and lateral recess stenosis. As part of the degenerative or osteoarthritic process, additional bone may form at the margins of the disc, and these bony spurs are known as ‘osteophytes’. Osteophytes commonly contribute to compression of the nerves in the spine.
What are the surgical options?
In a decompressive lumbar laminectomy, your neurosurgeon removes the lamina— the bone which forms a roof over the spinal canal. This is done via a midline incision over the lower back.
Laminotomy is a less extensive type of spinal surgery, and comprises a partial laminectomy (or partial hemilaminectomy- removal of a portion of one half of the lamina), and removal of part of the facet joint. This is a more targeted approach, and may be utilized when nerve compression is more localised. It can be done to relieve pressure on the nerves or to allow access to a herniated disk or bone spur. Laminotomy has similar surgical goals and risks as a full laminectomy, but is performed through a smaller incision and has a faster recovery time.
Spinal fusion permanently joins two or more vertebral bones, and may be especially helpful in cases when one or more vertebrae slip out of their correct position. It can be done alone or at the same time as a laminectomy or laminotomy. To fuse the spine, a carbon or PEEK cage filled with tricalcium phosphate and bone chips is placed in the disc space after the disc has been removed. Screws are inserted into the pedicles of the bones and they are connected with rods. In some cases a fusion is performed without screws or cages (non-instrumented fusion). Fusion will be discussed further in a separate section.
An alternative approach is the use of dynamic stabilization devices, such as the X-Stop interspinous distractor. These devices may be used alone (without a decompression) to relieve or reduce the symptoms of neurogenic claudication in lumbar canal stenosis. They may also be used as an adjunct to a laminotomy.
The results with surgery to correct spinal stenosis are usually good. Generally, 80% to 90% of patients have relief from their pain after surgery.
What are the alternatives to decompressive lumbar surgery?
A number of alternatives to a lumbar decompression may exist, depending upon your individual circumstances. These include:
What are the goals (potential benefits) of surgery?
The goals of decompressive lumbar spine surgery include the relief of pain, numbness, tingling and weakness.
The rationale, aims, and potential benefits of surgery may therefore include:
Generally, the symptom that improves the most reliably after surgery is buttock and leg pain. Back pain may or may not improve (occasionally it can be worse). The next symptom to improve is usually weakness. Your strength may not return completely back to normal, however. Improvement in strength generally occurs over weeks and months. Numbness or pins and needles may or may not improve with surgery, due to the fact that the nerve fibres transmitting sensation are thinner and more vulnerable to pressure (they are more easily permanently damaged than the other nerve fibres). Numbness can take up to 12 months to improve.
The chance of obtaining a significant benefit from surgery depends upon a wide variety of factors.
How does Revision Surgery differ?
Revision surgery (ie. surgery after a previous spinal surgical procedure) often requires the removal of scar tissue.
The risk of complications from lumbar spine revision surgery is significantly higher than in first-time procedures. This is due to a number of factors, particularly scar tissue formation around the nerve roots. It is also more difficult to relieve pain and restore function in revision surgery. It is important be aware that the possibility of experiencing long-term back pain is increased with revision surgery.
What are the possible outcomes if treatment is not undertaken?
If your condition is not treated appropriately (and sometimes even if it is), the possible outcomes may include:
What are the specific risks of lumbar spine surgery?
Generally, surgery is fairly safe and major complications are uncommon. The chance of a minor complication is around 3 or 4%, and the risk of a major complication is 1 or 2%. Over 90% of patients should come through their surgery without complications.
The specific risks of decompressive lumbar spine surgery and interspinous distractor insertion include (but are not limited to):
What are the risks of anaesthesia and the general risks of surgery?
Having a general anesthetic is generally fairly safe, and the risk of a major catastrophe is extremely low. All types of surgery carry certain risks, many of which are included in the list below:
What are the implications of surgery?
Most patients are admitted on the same day as their surgery; however some patients are admitted the day before. Patients admitted the day before surgery include those who: reside in country regions, interstate, or overseas; have complex medical conditions or who take warfarin; require further investigations before their surgery; are first on the operating list for the day. You will be given instructions about when to stop eating and drinking before your admission.
You will be in hospital for between 1 and 3 days after your surgery. You will be given instructions about any physical restrictions that will apply following surgery, and these are summarised later in this section.
Several X-rays of your back will be taken during surgery to make sure that the correct spinal level is being fused, and also to optimise the positioning of the interspinous distractor (if this is being done). It is critical that you inform us if you are pregnant or think you could possibly be pregnant, as X-rays may be harmful to the unborn child.
There is significant variability between patients in terms of the outcome from surgery, as well as the time taken to recover. You will be given instructions about physical restrictions, as well as your return to work and resumption of recreational activities. You should not drive a motor vehicle or operate heavy machinery until instructed to do so by your neurosurgeon.
You should not sign or witness legal documents until reviewed by your GP post-operatively, as the anaesthetic can sometimes temporarily muddle your thinking.
What do you need to tell the doctor before surgery?
It is important that you tell your surgeon if you:
What do I need to do before surgery?
Before you surgery it is imperative that you stop smoking.
If you are fairly overweight, it is advisable that you engage in a sensible weight loss program before you surgery.
In order to prevent unwanted bleeding during or after surgery, it is critical that you stop taking aspirin, and any other antiplatelet (blood-thinning) medications or substances including herbal remedies at least 2 weeks before your surgery.
If you normally take warfarin, you will usually be admitted to hospital 3 or 4 days before your surgery. Your warfarin will be ceased at that time (it takes a few days to wear off) and you may be commenced on shorter-acting anti-clotting agents for a few days. These can then be stopped a day or so before surgery.
Ideally, you should take a Zinc tablet a day, commencing one month before surgery, and continuing for 3 months after. This should help wound healing.
Will I need further investigations?
Most patients will have had X-rays of their back, as well as a CT scan and MRI. Sometimes ‘dynamic’ X-rays of the lumbar spine are performed, with X-rays taken bending forwards and backwards; this is to determine the presence and site of any instability.
In some patients there is uncertainty either about the diagnosis or exactly which disc or discs in the back are responsible for their symptoms: in those patients, nerve conduction studies and/or a nerve block may shed light on the diagnostic issues.
If you have not had an MRI for over 12 months before your surgery, or if your symptoms have changed significantly since your most recent MRI, then this investigation will need to be repeated to make sure that there are no surprises at the time of surgery!
Who will perform surgery? Who else will be involved?
Surgery will be carried out by Dr Wong. A surgical assistant will be present and an experienced consultant anaesthetist will be responsible for your general anaesthetic.
How is a lumbar decompression performed?
A general anaesthetic will be administered to put you to sleep. A breathing tube (‘endotracheal tube’) will be inserted and intravenous antibiotics and steroids injected (to prevent infection and post-operative nausea). Calf compression devices will be used throughout surgery to minimise the risk of developing blood clots in your legs. You will be placed face-down on the operating table on a special spinal frame.
Your skin will be cleaned with antiseptic solution and some local anaesthetic will be injected.
The skin incision is usually about 2-4cm in the middle of you lower back. It is vertical.
The bony structures of your spine are carefully defined, and using microsurgical techniques, a fine high-speed drill is used to shave some bone away over the top of the nerves. The ligament is then detached and removed and the underlying nerve root is identified. The nerve root is decompressed (this is known as a ‘rhizolysis’) and the disc is visualised. If there is a significant disc prolapse, a microdiscectomy is performed; otherwise the disc is left alone.
If the disc is to be removed (microdiscectomy), this is done by first cutting the outer annulus fibrosis (fibrous ring around the disc) and removing the nucleus pulposus (the soft inner core of the disc). Disc removal is performed using a combination of special instruments.
During the procedure at least one X-ray is performed to check that the operation is being carried out at the correct disc level. At the end of the decompression, a small piece of fat is taken from beneath the skin and placed over the nerve root to minimise scarring. The surgical field is checked for excessive bleeding or any other problems, and a final check is made to ensure that the nerves are no longer under pressure.
If an interspinous distractor is being inserted, this is the final step of the operation. It is placed between the midline ‘spinous processes’ at the back of the spine.
The wound is closed with dissolving sutures or staples. A wound drain is rarely required.
What happens immediately after surgery?
It is usual to feel some pain after surgery, especially at the incision site. Pain medications are usually given to help control the pain. While tingling sensations or numbness is common, and should lessen over time.
Most patients are up and moving around within a few hours of surgery. In fact, this is encouraged in order to keep circulation normal and avoid blood clot formation in the legs.
You will be able to drink after 4 hours, and should be able to eat a small amount later in the day.
You can be discharged home when you are comfortable. Some patients benefit from a short period of time (usually around a week) in an inpatient rehabilitation facility.
What happens after discharge?
You should be ready for discharge from hospital 1-3 days after surgery. Your GP should check your wounds 4 days after discharge. Your sutures may be dissolving, in which case they will not require removal.
You will need to take it easy for 6 weeks, but should walk for at least an hour every day. You should avoid sitting for more than 15-20 minutes continuously during this time.
During the first 2 weeks after surgery, you should not drive. At 4-6 weeks it is likely that you will be able to return to work on “light duties”. This, and the step-wise progression in your physical activities, will be determined on an individual basis.
Bear in mind that the amount of time it takes to return to normal activities is different for every patient. Discomfort should decrease a little each day. Increases in energy and activity are signs that your post-operative recovery is progressing well. Maintaining a positive attitude, a healthy and well-balanced diet, and ensuring plenty of rest are excellent ways to speed up your recovery.
Signs of infection such as swelling, redness or discharge from the incision, and fever should be brought to the surgeon’s attention immediately.
You will be reviewed after 6-8 weeks by your neurosurgeon. Until then, you should not lift objects weighing more than 2kg, and should not engage in bending or twisting movements.
The results of spinal surgery are not as good in patients who smoke or are very overweight. It is therefore important that you give up smoking permanently before your surgery and try to lose as much weight as possible.
You should continue wearing your TED stockings for a couple of weeks after surgery.
Detailed discharge instructions are as follows:
Maintain normal healthy diet, high in fibre to avoid constipation
You may be prescribed analgesia, muscle relaxants, and stool softeners. Be aware that analgesics tend to cause constipation. Please take only the analgesia that has been prescribed for you.
Restrictions (aimed at protecting your back and allowing healing to occur)
Smoking impairs wound healing and damages the discs in your back. Stopping smoking may improve outcomes.
What do I need to tell my surgeon about after the operation?
You should notify your neurosurgeon and should also see your GP if you experience any of the following after discharge from hospital:
What are there results of surgery?
Overall, 80-90% of patients will obtain a significant benefit from surgery, and this is usually maintained in the long term.
Generally, the symptom that improves the most reliably after surgery is leg pain. Back pain may or may not improve (very occasionally they can be worse). The next symptom to improve is usually weakness. Your strength may not return completely back to normal, however. Improvement in strength generally occurs over weeks and months. Numbness or pins and needles may or may not improve with surgery, due to the fact that the nerve fibres transmitting sensation are thinner and more vulnerable to pressure (they are more easily permanently damaged than the other nerve fibres). Numbness can take up to 12 months to improve.
What are the costs of surgery?
Private patients undergoing surgery will generally have some out-of-pocket expenses.
A quotation for surgery will be issued, however this is an estimate only. The final amount charged may vary with the eventual procedure undertaken, operative findings, technical issues etc. Separate accounts will be rendered by the anaesthetist and sometimes the assistant, and hospital bed excess charges may apply.
You should fully understand the costs involved with surgery before going ahead, and should discuss any queries with your surgeon.
What is the consent process?
You will be asked to sign a consent form before surgery. This form confirms that you understand all of the treatment options, as well as the risks and potential benefits of surgery. If you are unsure, you should ask for further information and only sign the form when you are completely satisfied.