Facet joint disease
Each vertebra in the spine joins its neighbour via three joints - the large disc in the front and two small facet joints behind, forming a triangle of joints surrounding the spinal canal. The facet joints are also sometimes called zygapophyseal joints.
The facet joints are most commonly affected by osteoarthritis (wear and tear arthritis). Facet joint pain can be felt over the affected joint but can also be referred - to the shoulder girdle, shoulder blade or arm in the case of the neck, or into the bony pelvis, hip or thigh in the case of the low back. It tends to be worse with extension of the spine (bending backwards).
|
|
Plain x-rays, CT or MRI scans can identify facet joint disease but sometimes the most sensitive test is a nuclear bone scan (see figure), which can identify facet joint problems when the other tests appear less obviously abnormal.
Treatment consists of:
- glucosamine may be useful as for other joints affected by osteoarthritis.
- physical therapy using local treatments (heat, ultrasound and massage) but particularly to learn to strengthen the supporting spinal muscles of the neck or low back - this builds up the body's own brace for the spine.
- acupuncture can be useful.
- facet joint injections can be very helpful. This can be done by a radiologist who injects cortisone and local anaesthetic directly into the joint or by a pain specialist who either injects the joint or else can block the sensory (feeling) nerves supplying the joint.
- radiofrequency (RF) rhizotomy - if a facet joint injection is helpful, a much longer period of pain relief can be obtained by heating the nerves supplying the affected facet joint, which is also called a medial branch block. This is performed by a pain specialist.
- surgery is rarely used for pure facet joint disease and pain. Usually, surgery is reserved for when facet joints develop osteophytes (bony spurs) which press on a spinal nerve. In the lumbar spine, interspinous spacers or stabilisers can occasionally be used to reduce the movement and distract the painful facet joint. This has only been used in the last several years and requires further long-term study before it is accepted as a standard treatment, but it certainly seems to have a benefit. Facet joint disease is a contraindication to artificial disc replacement, which only replaces the disc, not the facet joints.
Top
Lumbar laminectomy
|
Laminectomy means removal of part or all of a lamina, at one or more levels in the spine (pictured to the left, where a C4 laminectomy has been performed). "ectomy" means removal - e.g. appendicectomy means removal of appendix.
The lamina is the back (or posterior) part of the spinal canal. The spinal cord ends at just below the junction of the thoracic and lumbar vertebral level. Between each pair of laminae is a flat ligament called the ligamentum flavum which acts like a small elastic band. Therefore, the spinal canal contains the spinal cord in the cervical and thoracic spine, and nerve roots in the lumbar and sacral spine.
Pictured to the left is a left view of the cervical spine. The spinal cord is the vertical yellow structure.
|
|
The most common reason to do a laminectomy is to decompress the squashed nerves in the lumbar spine, in a condition called lumbar canal stenosis. This is most common at L4/5 but is often at multiple levels.
The narrowing of the spinal canal is due to a combination of thickened ligamentum flavum (see diagram directly below) at the back (which connects the adjacent laminae), thickening of the facet joint capsules at the two sides, and bulging of the disc at the front.
Patients typically complain of pain and/or weakness and/or numbness/tingling in one or both legs whenever they stand or walk for too long, but are fine with sitting and laying.
|
| View of the spine, spinal cord and nerves from the left side. The orange structure is the spinal cord, ending at about the L1/2 junction. |
|
|
Apart from decompression of nerves and the spinal cord, laminectomy is also performed to gain access to the spinal canal, e.g. for removal of tumours.
The picture to the left is looking at the spine from behind. The lower half of a lamina, plus the adjacent ligamentum flavum, have been removed. The yellow structures are the ligamentum flavum (yellow ligament) which connects adjacent laminae.
|
Postoperative
You are usually up with the physiotherapist on the day after surgery. A urinary catheter is normally in place until the second day after surgery, at which time you may need a suppository to help open your bowels.
Discharge home is usually about five to seven days after the surgery, by which time you should have already noticed an improvement in your legs. Plenty of walking is encouraged and I suggest you start regular walking as far as you feel comfortable - e.g. 200-500m, twice a day.
You are also encouraged to perform straight leg raising one minute at a time for each leg, twice a day, every day, for six weeks. Your Mount Hospital physiotherapist will show you how to do this.
The wound dressing is usually removed on the second day postoperatively and the wound left totally exposed, unless there is oozing.
Top
Lumbar Spondylolisthesis
Spondylolisthesis simply means the abnormal slip of one vertebra with respect to the vertebra immediately below. This is usually a slip forwards (anteriorly) of the upper vertebra, also known as anterolisthesis. Less common is a backwards (posterior) slip, also known as retrolisthesis. Much less common is a sideways (lateral) slip, called a laterolisthesis.
There are four grades of severity of slip, determined by the amount that the upper vertebra has slipped in relation to the lower one. A slip of less than 25% is grade 1, 25-50% is grade 2, 50-75% is grade 3 and 75-100% is grade 4. Most slips are grade 1.
There are two major types of lumbar spondylolisthesis:
|
Degenerative (pictured right)
Degenerative spondylolisthesis usually occurs in older women, most often at L4/5. This causes either low back pain and/or pain / weakness / numbness / tingling down one or both legs due to compression of the lumbar nerve roots.
This type of slip is due to degeneration of the pair of facet joints between the two affected vertebrae. It is virtually never worse than grade 1.
|
|
|
Lytic or spondylolytic (pictured left)
Lytic spondylolisthesis usually occurs at L5/S1 and normally presents in the teenage years or 20s. The classical example is the so-called fast (cricket) bowler's "stress fracture". It occurs due to repetitive stresses in the lumbar spine but it often appears with no obvious history of repetitive trauma.
It is a little difficult to understand the anatomy of this condition. There is an acquired fracture through the portion of the vertebra between the two articular processes. This part of the vertebra is called the pars or pars interarticularis, meaning the part of the vertebra between the adjacent two facet joints. The mainstay of treatment is lifestyle modification and physiotherapy. Surgical treatment for this condition is virtually confined to posterior fusion (see section on Posterior Lumbar Interbody Fusion).
|
Top
Discography
|
Discography is a test to see if one or more discs are causing pain. MRI can often identify an abnormal disc but it can be difficult to identify exactly which disc(s) is (are) producing pain. It involves a radiologist (x-ray doctor) or a pain specialist injecting one or more discs while you are awake. This is done under x-ray or CT. You need to be awake so that you can report what, if any, type of pain the injection produces. Surprisingly, injection of a normal disc causes very little discomfort. Injection of a painful disc will reproduce your pain and can stir up the pain for some days. Discography would only be performed if there is a serious consideration of surgery to remove one or more painful discs.
|
|
Fusion
Fusion simply means joining two bones together to form one.
Fusion can be performed from in front or behind. There are two types of posterior fusion:
posterior lumbar interbody fusion (PLIF - see below) intertransverse fusion, where bone is placed between the transverse processes (T.P.). The T.P.s are the side-pointing parts of a vertebra, one on each side.
Either type of fusion should be supplemented with instrumentation which keeps the bone graft material stable until the bone has knitted (fusion). This usually means the insertion of screws - two into the vertebra above, two into the vertebra below, and then connecting the screws with a pair of vertical rods, much like a scaffold which stays in permanently.
Patient information for Posterior Lumbar Interbody Fusion (PLIF)
These are only guidelines - each patient will have different abilities and needs. Your hospital physiotherapist will give you additional information.
Principles
|
Your fusion is like fixing a broken bone, aiming to join one vertebra (spinal bone) to another. It takes six months to two years for the bones to knit [fuse]. In the meantime, your screws and rods keep the fusion site solid. Your recovery will need supervision with a physiotherapist, plus some common sense, to balance between trying to mobilise the lumbar (low back) joints that aren't fused, and trying not to put too much stress on the fusion site until it is fused.
|
Expectations
Be realistic and don't expect too much. Your back will never be as good as new. It is unusual to be totally cured of pain and to not be left with some lumbar pain and/or pain in the buttocks, hips or thighs. The aim of surgery is to get significant improvement in your symptoms.
Posture
Low back advice after surgery applies to you as to everybody in the community. The best posture is keeping your low back as vertical as possible, like a column of bricks - e.g. bend your knees to get low to the ground rather than bending your low back. Try to minimise bending (forwards, backwards or sideways) and twisting, especially if you are carrying something. However, (and this sounds contradictory) postoperatively you will be encouraged to try to mobilise your low back so that it does not become stiff at the unoperated levels. Postoperatively you can sit as soon and long as you like, until it becomes uncomfortable. You can drive as soon as you wish but this may be painful and it would be preferable if you were driven by someone else early on.
Brace
A light lumbar support may be used postoperatively for additional pain relief. You are encouraged to do away with the brace as soon as possible (0-3 weeks), or only use it intermittently, because you will be encouraged to strengthen and mobilise your trunk (back and abdominal) or core muscles.
Smoking
There is absolutely no doubt that smoking reduces the success rate of fusion. Smoking interferes with the development of new blood vessels that are essential for developing new bone.
Top
Physical therapy
Your hospital physiotherapist will supervise you postoperatively and will make sure that your care continues after discharge with a physiotherapist convenient to you.
Walking
You will be up walking with the physiotherapist the day after surgery. Walking is a great exercise. Once out of hospital, try to walk as much as possible - e.g. at least one kilometre twice a day.
Straight leg raises
On the day after surgery you will begin straight leg raises (each leg separately for one minute, up as far as tolerable) twice a day for at least six weeks, or until you get your leg up to 90 degrees to your body. Someone should assist you initially. These leg exercises are to diminish postoperative scarring at the site where the sciatic nerve roots in your back have been operated upon.
Trunk muscle strengthening
A simple exercise can be done anytime and anywhere, before and after surgery. Start four times a day by tightening your abdominal muscles for at least 10 seconds, like straining on the toilet, breathing at the same time. The more you do this the better. Swimming (particularly freestyle) is an excellent exercise, puts little stress on your low back and can start once I am happy that your wound has healed (about 1-2 weeks).
Lumbar spine mobilisation (movement)
This is to prevent your entire low back from getting stiff. Your fusion is immediately solid due to the metal work. Back mobilisation will be difficult initially because of wound pain and muscle spasm but you will be encouraged to move within the limits of discomfort, commencing as soon as possible after surgery. Twice a day try bending forwards, backwards, right and left sideways, and right and left rotation (twisting), going as far as is comfortable, holding each position for 10 seconds. On the other hand, with everyday activities, you should maintain the principles of low back care, keeping your back vertical and not doing unnecessary lifting, twisting, bending, etc. Initially it will also help if you mobilise in a warm pool (hydrotherapy).
Manipulation
It is arguable if your low back should be manipulated after a fusion, but certainly not until the bone has fully knitted.
Long term outcome
You should gradually get back to all your activities of daily living (dressing, showering, driving, etc). Because a portion of your spine has been operated on and stiffened, patients often describe a fullness at the operation site. You should not expect to return to all of your former activities although this is possible, depending on your demands - e.g. a labourer is unwise to return to former heavy work but a casual golfer could gradually return to golf once the bone has fully knitted. In general, low impact activities are encouraged - e.g. walking as opposed to jogging. The aim of surgery is to get you as comfortable as possible and return your quality of life.
|
Top
Anterior Lumbar Interbody Fusion (ALIF)
|
Anterior fusion requires a cut through the lower abdomen. This is usually a horizontal incision. A total discectomy is performed, then the disc space is filled with granules of calcium which act as bone substitute. Usually a plastic cage is filled with these granules and then placed into the disc space so that the disc space doesn't collapse.
The great advantage of anterior lumbar spine surgery is that there is less pain compared to posterior surgery. When operating through the abdomen it is a surprising fact that no muscles are actually cut. The muscles are simply separated. In contrast, posterior surgery requires muscle to be peeled off the bone. After anterior surgery patients generally remain in hospital about four nights, whereas after PLIF they tend to remain about eight nights. The cost of instrumentation for an A.D. is about half that for a PLIF.
|
While there is a quicker recovery with an ALIF compared to a PLIF, ALIF certainly has potential complications unique to this approach:
1. Injury to major blood vessels
There are major arteries and veins in front of the lumbar spine - the aorta, which divides into two major arteries, one to each leg - and the inferior vena cava, which also divides into two major veins. Although uncommon, a major artery or vein can be injured because they have to be dissected off the lumbar spine and displaced to the right. Arterial injury can result in lack of blood flow to a leg. Venous (vein) injury can result in poor return of blood from a leg, resulting in swelling of that leg. Injury to major blood vessels may result in massive blood loss on the operation table or, less likely, early postoperatively.
2. Sympathectomy
On the front and side of the spine are a pair of nerves running the length of the spine called the sympathetic trunks. These do not supply any movement or feeling to the legs but do supply the skin of the legs, making the skin sweat and the blood vessels constrict. Blood vessel constriction of the skin makes the skin cool and pale. Therefore, cutting a sympathetic trunk (called a sympathectomy) results in a warm and dry leg. This occurs in a few percent of anterior lumbar spine operations and occurs usually on the left side because the dissection over the lumbar spine is from left to right in order to displace the major vessels to the right. Injury to a sympathetic trunk can sometimes result in abnormally excessive sweating in a leg.
|
3. Retrograde ejaculation
For males, another risk unique to this approach is that approaching the L5-S1 disc space from the front has a small risk of creating a condition known as retrograde ejaculation. There are very small nerves directly in front of this disc that control a valve that causes the sperm to be expelled from the penis. By dissecting over the disc space the nerves can stop working and without this coordinating nerve supply to the valve the sperm takes the path of least resistance, which is up into the bladder. The sensation of ejaculating is largely the same but it makes conception very difficult. If this is a potential concern, the male is advised to make a sperm bank donation for future storage. Otherwise, there are special sperm harvesting techniques if sperm has not been stored. Fortunately, retrograde ejaculation happens in less than a few percent of cases and tends to resolve over time (a few months to a year). This complication does not result in impotence as these nerves do not control erection.
Top
Lumbar Artificial Disc Replacement (A.D.)
|
A.D. is also placed through the abdomen. The A.D. is a mechanical device that allows movement within the device. There are various products - Maverick, ProDisc-L and Charite. It is believed that preservation of motion at a disc space places the adjacent vertebral joints under less stress compared with fusion. This will only be known after several more years of patient follow-up. My general approach is to perform A.D., in preference to fusion if at all possible, but most patients are not suitable.
|
Not all patients are suitable for A.D. The following are prerequisites:
bone must be of normal density... i.e. no osteoporosis, otherwise the A.D. device may sink into the bone. facet joints must be healthy - anterior surgery does not touch the posterior two facet joints. There is no point removing a damaged disc and leaving painful facet joints behind. absence of sciatica - the presence of sciatica indicates that a nerve is being compressed by a disc fragment. This disc fragment may be difficult but not impossible to remove from in front. a collapsed and/or severely degenerate disc, particularly one with a lot of bony spurs (osteophytes). This is usually the situation among older patients (over 50).
|
|
Post-operative care, advice and physiotherapy are essentially the same as following Posterior Lumbar Interbody Fusion (see PLIF).
Top
Risks of spine surgery
Infection
This may simply be an infection of the wound which requires some dressings, removal of a stitch and/or antibiotics. Deeper infection may require a return to theatre to drain the collection of pus. Infection may also affect the CSF (cerebrospinal fluid) around the nerve roots and spinal cord, which is called meningitis and requires hospitalisation and intravenous antibiotics, but is virtually always curable. Infection of an operated disc space or of bone often requires initial hospitalisation and intravenous antibiotics, and then several weeks or months of oral antibiotics, often supervised by an infectious diseases doctor.
Paralysis
Prior to surgery, there may already be some nerve or spinal cord damage causing muscle weakness. A nerve or the spinal cord may be already squashed and at increased risk of being injured because of the manipulation needed to try to free the nerve or spinal cord. Nerve or spinal cord damage may also affect control of the bladder and bowel.
Cerebrospinal Fluid (CSF) leak
The brain and spinal cord are surrounding by CSF, which looks like water and is salty. CSF leak occurs if the outermost layer of the meninges (= the three outer coats of the brain and spinal cord), called the dura, is not completely closed watertight. CSF can leak through the dura and then through the skin and this will need to be fixed, otherwise there is a risk of meningitis. Just like a leak in the roof, there only needs to be a small hole to let water through and this can sometimes be troublesome to repair, but is virtually always correctable. Repair may require a simple skin stitch, a spinal drain tube inserted in the low back to drain the CSF via another route, or a trip back to theatre.
Deep Vein Thrombosis (DVT)
DVT means a blood clot developing in the leg. The patient may notice a painful swelling of the calf but a DVT may not be noticed. This clot may dislodge and travel to the lungs and heart to block the circulation, which is known as a pulmonary embolus (PE). A PE can be fatal and usually occurs about 1-2 weeks after surgery, or 1-2 weeks after a patient has commenced being confined to bed. Increased risks for DVT and PE are bed rest, prolonged surgery, obesity, cancer, past DVT, paralysed leg/s and heart failure. To prevent DVT, the patient is encouraged to get out of bed as soon as possible, usually the day after surgery. Before this, the patient can wiggle the toes and move the legs around in bed as soon as wakening from the anaesthetic. Prior to surgery, the patient will have elastic stockings put on. While in surgery, the patient has leg pumps to improve the circulation. In most cases prior to surgery, blood thinning injections are commenced - I like to use Clexane injections into the stomach each morning until discharge from hospital.
Wrong spinal level
This sounds unbelievable but it can be easily done. Spine surgery can be like trying to find where your car has been parked in a multilevel car park - all the levels and areas look similar. There are 33 bones in the spine and they mostly look similar. They don't have labels on them telling the surgeon which level is which. All patients vary and different anatomy can be confusing to the surgeon. This is particularly the case when a patient has an L5 vertebra joined to the sacrum. In this case some doctors will call the lowest disc L4/5 while others call it L5/S1 or, even more confusingly, L5/6. Don't worry if you don't understand this - this is for the surgeon to work out. Perhaps a simpler example is that some people have 11 or 13 instead of 12 ribs. It then becomes confusing as to what you call the next lumbar vertebra - T12 or L1.
Death
Death on the operating table is very rare. Death can occur with any surgery and usually occurs after the operation. The most common reasons are myocardial infarct (heart attack) due to the stress of the surgery, a rare reaction to a drug (anaphylaxis) or pulmonary embolus. I mention the risk of death or paralysis (stroke) to any patient having an operation, no matter how minor the procedure.
Top
|
