Neurosurgeon

The spine The spinal column consists of 33 vertebrae (figure 1A): 7 cervical (neck)(figure 1B) 12 thoracic (each connects to 1 pair of ribs) 5 lumbar (low back) 5 sacral (in an adult they are joined together as one bone called the sacrum and do not contain discs) 4 coccygeal (joined to form the single coccyx)

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Lumbar disc degeneration, tear and prolapse

Anatomy

The lumbar spine has five pieces (vertebrae) whose bodies are stacked like building blocks and which sit on top of the sacrum (tailbone). The disc acts like a cushion or shock absorber between the bodies of the vertebrae. The disc is like an onion with layers on the outside (annulus) which if torn can be painful. In the centre of the annulus is the nucleus, which is like crab meat. The disc dries out with degeneration (meaning wear and tear that occurs with getting older and which may be accelerated by injury).

Pathology

Disc degeneration is best seen on magnetic resonance imaging (MRI) but usually doesn't cause any symptoms. However, sometimes disc degeneration can cause pain which might be due to annulus tear, mechanical failure or toxic ("poisonous") chemicals caused by breakdown of the disc. Disc degeneration may occur with or without reduction of disc height. Rupture of the annulus with outpouching of the nucleus is referred to as a "ruptured disc", "herniated disc", "disc prolapse" or "slipped disc". The fresh prolapse is initially well hydrated (like a grape) but with time it usually shrinks due to dehydration (like a sultana). This is why most disc prolapses improve without surgery. As we get older the spine often forms bony spurs (called osteophytes). This condition is called osteoarthritis, osteoarthrosis or spondylosis and is the commonest form of arthritis in our community. Surprisingly, these bony spurs do not usually cause any back pain but they can grow and press on a nerve in the spine to cause nerve pain (sciatica).

Symptoms

The nucleus can burst through the annulus to press on a nerve to cause pain, tingling and/or numbness down the leg, which is called sciatica. Disc disease can cause low back pain directly or may cause "referred" pain, meaning pain from the lumbar spine which is felt elsewhere - into the bony pelvis, hips and/or thighs. Sciatica is also a type of referred pain due to pressure producing a painful nerve. A torn disc (or irritated facet joint) can trigger low back muscle spasm. The muscles try to protect the joint from moving but sometimes the pain from this can be worse than from the underlying problem.

Treatment

The best treatment is prevention - i.e. taking good care of your back. The spine is strongest when the vertebrae are vertical rather than when tilted or twisted. Therefore, the spine is best used to carry a load if it is vertical, which is why you should bend your knees with your back vertical when lifting something from the floor. Similarly, you should not twist from side to side when lifting something. Sit-ups are a bad exercise for your back.

Pressure in the disc is least when you lay flat, higher when you stand and, surprisingly, highest when you sit, and obviously higher if you carry a weight. Thus, standing is usually better than sitting if you have a painful disc. If there is low back pain from a damaged disc, the pain is usually least if you lay flat. However, you should try to keep mobile by walking and swimming (freestyle or breaststroke) in particular, or at least mobilising in a warm pool. However, laying flat is good treatment if there is very severe and acute (recent onset) sciatica (not just low back pain). With acute severe sciatica you may be advised to have strict rest in bed for up to two weeks with bathroom (toilet and shower) privileges only. Otherwise, as for low back pain, you will be encouraged to be active. Walking twice a day requires comfortable flat shoes (not high heels), walking about a kilometre at a time. Walking is an excellent low impact activity. Jogging is unwise as there are repetitive high impact loads on your spine.

Swimming is an ideal exercise because your back is horizontal with the least load on the discs and it helps strengthens the back and abdominal ("core") muscles to help support your spine. If you are unable to swim, you can get into a pool with a kickboard and use your legs to kick in the water. Out of the water, a simple exercise can be done any time of the day and as often as you like - pull your lower tummy in gently by pulling your belly button in towards your spine, but don't hold your breath. This activity also makes your low back muscles tighten and therefore strengthens them, helping support your lower spine. This exercise needs to be practised long-term in order to get real benefit. A brace can sometimes be of benefit if there is a lot of back pain which is worsened by movements, but generally you are advised not to have a brace because your core muscles can become lazier and weaker. A brace can be useful to protect your back if you need to do some heavy work. A comfortable firm bed is helpful if you have a lumbar spine problem. Most beds are satisfactory but you are advised not to have a water bed or any bed which sags a lot with your body weight. These are all things that you can do for yourself but supervision and treatment by a physiotherapist is valuable and recommended, particularly to strengthen the core muscles.

Because most cases of sciatica will settle with time, the aim of treatment is to manage the pain while waiting for this natural improvement. Most times sciatica noticeably improves over about 3-6 weeks. Sciatica is less likely to settle if the pain has come on gradually rather than rapidly, if the sciatica has been present for several weeks, or if there is a large disc prolapse on X-rays.

You can often predict the time course of improvement by charting a graph of pain versus time:

Occasionally, benefit can be obtained with a nerve root sleeve cortisone injection. Surgery is generally a last resort option.

The three reasons why you might need surgery are:

1) the pain is too severe to cope with in the short term - e.g. you need hospitalisation

2) the pain is persisting for too long, interfering with your quality of life

3) if you have significant muscle weakness from pressure on a nerve

Generally, if your problem is #1 or #2, it is basically your decision as to whether surgery is needed. You should not be pushed into an operation if your problem is purely pain. However, if you have problem #3 your surgeon may advise surgery because the nerve pressure is too great and the nerve may not recover if the pressure is not taken away from it.

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Nerve Root Sleeve Injection (NRSI)

NRSI means an injection around a nerve root in the spine. Usually the injection consists of local anaesthetic to give immediate but short-lasting pain relief from half to several hours, mixed with a steroid. The steroid is an anti-inflammatory drug which reduces swelling and which may take several days to have its full effect.

The effect of a NRSI usually lasts days to a few weeks, but may be very brief or need help for months. NRSI can be ordered by your General Practitioner or specialist. NRSI is usually done using a CT scan, in which case a radiologist doctor (radiologist) gives the injection. Otherwise it is given by a pain specialist, in which case it is done in an operating theatre under x-ray control, often with the patient sedated.

NRSI is used for two main reasons: Therapy - to help severe arm pain (brachalgia) or leg pain (sciatica) from a compressed nerve in the spine, usually from a disc prolapse or bony compression. Most times these pains will settle over a number of weeks. NRSI is one way to help relieve the pain while the condition naturally improves. NRSI can be very helpful for the severe pain that might otherwise require surgery. For this reason it is helpful in elderly or frail patients on whom we would wish to avoid surgery. Diagnosis - it may not be clear which nerve is causing the pain. For example, arm pain going into the fingers may be due to C6, C7 or C8 nerve compression. X-rays may not be clear as to which nerve is compressed. In these cases it can be helpful to perform a NRSI to see if the pain is helped by the injection. For example, the doctor may suspect that C7 nerve is the problem. If a C7 NRSI helps the pain, even for a few minutes, then this indicates that C7 is the problem. This is helpful if the surgeon is considering which nerve to operate upon.

Complications from NRSI
Complications are very rare. However, sticking a needle into any part of the body must have a risk, particularly infection. Rarely a nerve may be injured if it is injected into, instead of next to. Very rarely a cervical (neck) NRSI may travel into the blood supply of the spinal cord and cause spinal cord injury. I have never seen this happen.

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Lumbar disc surgery

Broadly speaking, there are three types of surgery for lumbar disc disease:

removal of the offending disc fragment (prolapse, hernia) that is compressing a nerve to cause sciatica. This can be performed under a microscope or with an endoscope, both through a small (keyhole) incision called a microdiscectomy

• removal of the entire disc (total discectomy), which then needs to be replaced with bone (fusion) or an artificial disc (A.D.)

• interspinous buttress - this is fixed between two spinous processes (the sharp, backward pointing part of each vertebra which can be felt through the skin) to stabilise the disc space... e.g. Diam, Wallis and X-Stop devices

The DIAM System implant is a dynamic stabilization product that can be used to treat low back pain. The term dynamic stabilization refers to technology that preserves, maintains or restores a natural range of motion and stability. The core of the DIAM System is made of silicone. The outer mesh and tether are made of polyethylene terephthalate (polyester). The first DIAM System surgery was performed in 1996. Since then, thousands of cases have been performed.

One can perform combinations of these three operations at different levels... e.g. a microdiscectomy is commonly combined with an interspinous buttress in order to try to stabilise the damaged disc and reduce the future risk of low back pain and recurrent disc prolapse.

Complete discectomy can be performed from anterior (in front, through the abdomen) or posterior (behind, through the back). If a disc is removed the space needs to be filled with something. Otherwise the space will collapse, causing back pain. This filler can be bone (called a fusion, which has been the standard operation for many years) or, more recently, an artificial disc (A.D.).

Following lumbar discectomy:

• You are encouraged to walk on the day after the surgery, and not uncommonly on the day of the surgery.

• It is generally advisable that you sit as little as possible for the first six weeks. This is to try to minimise the risk of a recurrent disc prolapse. If you sit, try to sit higher rather than lower - e.g. in a car, sit on a cushion. There are no sitting restrictions if an interspinous stabilisation device has been used.

• Walking is an excellent exercise. You should try to build up to at least one kilometre two times a day.

• Avoid impact-type activities - e.g. jogging, land aerobics.

• To minimize scarring of the nerves at the site of the disc surgery, you are advised to straight leg raise each leg separately, holding it as high as pain permits two times a day, one minute at a time.

• There are usually no stitches to be removed - your stitches are buried and will dissolve with time. You can shower with a dressing on for the first two days after surgery. Generally I advise removal of the large dressing 48 hours after surgery, leaving the paper strip [Steri-Strip] on for another 24 hours. After 72 hours postoperatively, the wound should be left totally exposed - i.e. you can shower with the wound exposed. If there is some persistent oozing, a dressing will be required for longer. The wound should not be soaked (as in swimming or sitting in a bath) for one week postoperatively.

• After surgery it is not uncommon to have various aches and pains in and around the wound, and in the bony pelvis, hips and thighs. These should improve with time. For the first two weeks postoperatively, your sciatica may return because of nerve swelling. If this occurs, be less active. This recurrent pain ususally resolves within two weeks. If the pain is severe, please contact me so I may consider prescribing dexamethasone (a strong anti-inflammatory steroid drug).

• It is very helpful to have seen a physiotherapist before your surgery and even more important to see one postoperatively. You can receive heat, ultrasound and massage, information on exercises and how to move and how to build up your core (back and abdominal) muscles long-term in order to help best maintain the strength of your back.

• Your back will never be back to normal so it is important to take good care of it.

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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). 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. 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 (Figure 3) at the back (which connects the adjacent laminae), thickening of the facet joint capsules at the two sides, and bulging of the discs 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.

In the cervical spine the most common reason to perform a laminectomy is when the spinal cord is being compressed by bony narrowing and/or thickening of spinal canal ligaments and/or bulging discs. This condition is called cervical spondylotic myelopathy. Patients experience difficulty using their hands, which may feel as though they are wearing gloves, and may also have difficulty with lower limb weakness. 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 has been removed. The yellow structures are the ligamentum flavum (yellow ligament) which connects adjacent laminae.

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Dynamic Lumbar Spine Stabilisation

Dynamic stabilisation is a new change in thinking about the lumbar spine, similar to artificial disc replacement but less invasive. The term basically means strengthening a spinal segment without making it rigid - i.e. without performing a fusion. Artificial disc replacement does not really strengthen the spine. The two current procedures which strengthen the spine segment and at the same time allow maintenance of movement are: Interspinous stabilisation. This operation involves inserting a firm buttress between the spinous processes, performed from behind. Dynamic pedicle screw fixation. This procedure involves placement of a pair of screws above and below the operated disc segment (i.e. a total of four screws per disc), as would be done in a posterior fusion. However, instead of using metal rods to cross the disc segment, as would be done in a fusion, a pair of firm plastic rods are used which allow a small amount of movement at this level. It is thought that this minor amount of movement at the disc level will protect the adjacent segments from the added stress which would otherwise occur with a fusion. Both interspinous stabilisation and dynamic pedicle screw fixation are performed by a posterior approach (from behind).

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Lumbar Spondylolisthesis

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).

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

• 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) 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.

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Anterior Lumbar Interbody Fusion (ALIF)

Anterior fusion requires an incision through the lower abdomen. This is usually a horizontal incision. A total discectomy is performed, then the disc space is filled with bone taken from the iliac crest (bony pelvis, above the hip joint). Usually a plastic cage is filled with bone chips and then placed into the disc space so that the disc space doesn't collapse.

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 lumbar spine are a pair of nerves 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 the left 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 ejaculate to be expelled from the penis. By dissecting over the disc space the nerves can stop working and without this coordinating innervation to the valve the ejaculate 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.

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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. if at all possible, but most patients are not suitable.

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.

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).

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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, which can identify facet joint problems when the other tests appear less obviously abnormal.

Treatment consists of:

• pain killers as necessary

• 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. 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 the spinal cord or nerves. In the lumbar spine interspinous spacers or stabilizers 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.

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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.

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