What is a laminectomy?
The lamina is the flat part of the vertebra that covers the back of the spinal cord and nerves. Laminectomy simply means removal of the lamina. The picture below shows the normal situation with the nerves in red.
The next picture shows spinal stenosis, where the spinal canal is narrowed (stenotic) due to enlargement of the facet joints and bulging of the disc.
In the following picture the lamina has been removed but the nerves are still squashed on the sides by the thickened facet joints.
After undercutting the facet joints the laminectomy is complete and the nerves are no longer compressed.
What is a foraminotomy?
Very often, the outlet of the nerve (foramen) is also stenotic and needs to be widened (foraminotomy). The picture below shows the normal foramen with the nerve in red and the next picture shows a stenotic foramen due to narrowing of the disc space. This is made worse by arthritis in the facet joint and bulging of the disc.
How is the operation done?
The operation is done with you lying face down in a kneeling position on the operating table as this reduces the pressure on the chest and abdomen. An x-ray is taken to confirm the correct level. An incision is then made over the affected part of the spine and after the flat part of the spine (lamina) is cleared of muscle, it is drilled away using a high speed burr. Care is taken to preserve the small facet joints on either side of the spine so that spinal stability is not affected. Drilling the bone away widens the central part of the spinal canal and allows access to undercut the overgrown facet joints. This clears the sides of the spinal canal and the holes through which the nerves exit (foraminae). The muscles are then closed over the laminectomy defect and a dissolving stitch is used under the skin so that no stitches need to be removed later.
What to expect post-operatively
Postoperatively you will be able to lie in any position that you find comfortable and the physiotherapist will get you up out of bed the following morning. You will be encouraged to walk or lie down but not to sit for prolonged periods as this is likely to make your back muscles sore. You will have some aching and tenderness in the back but this will improve fairly quickly. Most people are able to go home after four or five days. You will need some help at home for the first couple of weeks as it will be difficult to do things like cooking and cleaning for yourself. In most cases it is best to avoid any bending or lifting for six weeks and then to gradually increase activities over the following six weeks. The physiotherapist will give you a booklet explaining what exercises to do. You should notice a significant improvement in your walking tolerance as you get over the discomfort from the surgery. If you have numbness in your legs preoperatively this may not go away completely. Your back pain is likely to still be a problem but can be helped with antiinflammatories and exercise. You will be given an appointment to see me in my rooms in 4 to 6 weeks.
Are there risks involved?
There are risks involved with anything in life and surgery is no different. Some of these risks are common to most or all operations and some are specific to the particular procedure.
The following are the most common or most serious complications. Other problems may occur rarely and it is impossible to list every one of them. Just try to list all of the possible things that could happen on your drive to work-a car crash is obvious; an aeroplane crashing onto the road in front of you is also possible but extremely unlikely and would not normally be considered common enough to affect your decision to drive. If there is anything in particular that you are concerned about, please ask me.
General risks of any operation
Anaesthetic complications such as heart attack, drug allergy or even death are possible but very rare.
Blood clots in the leg (DVT) or lung (pulmonary embolus) may occur unexpectedly but are very uncommon in otherwise healthy people.
Infections such as pneumonia, wound infection or urinary tract infection may occur after any operation.
Bleeding may occur especially in people taking aspirin. It is therefore recommended to cease aspirin (also called Cartia or Disprin) two weeks before elective surgery.
The aim of the operation is to relieve leg pain due to pressure on a nerve. Back pain is usually due to the fact that the disc and facet joints are affected by arthritis and this will not be helped by surgery. If most of your pain is back pain rather than leg pain surgery would not normally be recommended.
The spinal cord finishes at L1 in most cases and lumbar spinal stenosis occurs below this level. In this area are the nerves going to the legs, bladder and bowels. These nerves are more resistant to damage than the spinal cord but can still be injured and at the very worst this can result in paraplegia. This would be an extremely rare complication of laminectomy.
A single nerve can be injured by surgical manipulation or by subsequent scarring. This can result in numbness or weakness in the distribution of that nerve as well as pain and pins-and-needles. When this occurs as a complication of surgery, which is unusual, it would usually improve over two to three months. Permanent nerve damage however can occur rarely.
Infection is uncommon and you will be given an antibiotic during the operation.
Bleeding is unusual except in patients taking Aspirin or other anti-clotting medications. Spinal fluid leaks are uncommon and usually respond to extra sutures in the wound or insertion of a small tube to drain the fluid and reduce the pressure for a few days.
Although care is taken to preserve the integrity of the facet joints, sometimes these can become unstable and lead to slight slippage of one vertebra on another, occasionally requiring a spinal fusion. The actual incidence of this is extremely low.
Coming into hospital for surgery
These days, most operations are done on the same day as admission. You will need to come to the hospital admissions area at the advised time. If you have not already sent in the hospital admission forms, bring them with you.
You will need to fast for 6 hours which means nothing to eat or drink after the time notified.
You will usually be able to take your normal tablets but medications that affect your bleeding will usually be stopped preoperatively. Aspirin, (also called Disprin or Cartia),and Plavix (also called clopidogrel) should be stopped for two weeks if possible before an elective operation. Fish oil should be stopped for a week. Anti-inflammatories should be stopped for 48 hours. Warfarin will need to be discussed with me and your GP.
Make sure you bring your Xrays as these will be essential for most operations. If you cannot find them please let me know early so that they can be repeated if necessary.
If you would like to have a private room that should be indicated on the hospital admission forms. There are only a finite number of single rooms and sometimes it will not be possible to go straight into one, but if you indicate your preference every effort will be made to move you into a private room as soon as possible. (I do not have any say in this except in cases of medical need eg infections).
I will see you in hospital before you go to the operating room and the anaesthetist will also see you preoperatively and will want to know about your general health and any medications you are on. Please bring your usual tablets with you.