This is an operation, performed from behind, designed to remove the disc, free the nerves and pack bone into the disc. The bone is packed inside hollow rectangular ‘cages’, which are then inserted into the disc from behind.
Screws and rods / plates are then used to stabilize the vertebrae. The figure below shows the problem, which the operation is designed to solve.
Why is the operation needed – indications?
If you have back pain and or leg pain from a degenerate and painful disc, and all the non-surgical treatments have failed, then a spinal fusion could be considered if your symptoms interfere with your quality of life and your activities of daily living. The operation is also performed if one vertebra has slipped forward on the other (spondylo-listhesis) and for pain which develops after a discectomy operation( for Post Discectomy Syndrome).
What is causing my back pain and leg pain?
The most likely cause of pain is a degenerate disc that has become inflamed and is painful on loading.
Normally 80% of your body weight in transmitted through the disc. The disc bulging may also have cause some pressure on the nerves to cause you leg pain. You may also have pain in your legs referred from nerve pathways in the disc itself.
Do I have arthritis?
This is a common concern. The term arthritis is loosely applied to mean any problem with a joint. The best way to understand this is to think of it as age related wear – like that of a rubber car tyre. As the tyre ages it starts thinning and tearing, and is unable to absorb normal loads – very similar to the disc.
Is it an inherited problem?
Not really. Back pain is very common 30-50% of the population have it in any given year – though not as severe or prolonged as you have.
What is the principle of the operation?
The operation is designed to do the following:
- 1. Restore the normal height of the disc
- 2. Free any trapped nerves
- 3. Remove the pain source – the degenerate and inflamed disc
- 4. Correct any deformity – like a forward or sideways slip of a vertebra
- 5. Fuse the disc- by packing bone into the disc
- 6. Restore normal load transmission across the disc
It therefore deals with all the possible pain generators at that level – the disc, the nerves and the facet
What are the alternatives to surgery?
It is important to understand that surgery is not essential in most cases. It is a quality of life decision. You will only be offered surgery once you have failed all the non-surgical treatments available-like physiotherapy and an exercise program.
If you do not have surgery you will not ‘end up in a wheelchair’ or be ‘much worse as you get older’. You will have ups and downs with your symptoms. Injections in your back are another option, and provide short term relief- usually 3 months. The decision to undergo surgery is based on how your quality of life is affected now.
What are the chances I will be better after surgery?
This varies depending on your individual circumstances. In general we advise patients that if this is their first operation there is a good chance of being much better following surgery. Some patients also have no pain after surgery. Remember there is a small chance that surgery may not help you and that even if you are much better – you may still have some minor residual symptoms.
Why are the results not as predictable as say, hip replacement surgery?
There are a lot of gaps in our understanding of low back pain. We do not know why some degenerative discs are painful, and others are not. Psychological issues also play an important role in back pain, but not in hip pain.
What are the risks of surgery – and the chances I may end up being worse off?
I have a lot of experience with this operation now, having done more than 2500 cases over the last 15 years – and it has been recommended in your case because your I think it has a good chance of success.
Nevertheless there are definite risks you need to know about. It also important to know how common these risks are. Some, like dying from surgery or being paralyzed are very rare – like dying in a car or airplane crash. Having said that , I have never had a death or a patient paralysed from surgery since I started my practice in 1996 . Lets go into some detail now:
Infection: The risk of this is around 1-2% – but has become uncommon with new advances in theatre design (using clean filtered air in theatre) and the use of antibiotics. If it does occur you may need some antibiotics or uncommonly a second operation to wash the wound out.
Leakage of spinal fluid (CSF leak): This occurs uncommonly in about 2-4% of patients and is caused by a tear in the spinal membrane called the dura. The risk is higher if this is your second operation and we have to go through scar tissue. This is usually repaired during surgery. Rarely this may present after surgery and you may need repeat surgery to repair this tear.
Nerve root injury : The screws while being inserted may injure a nerve. Handling may also injure a nerve during surgery. The risk of this is also around 2% – slightly higher if this is your second operation. Nerve pain usually settles with pain relief support only, but occasionally requires further injections or surgery.
Nerve swelling: Occasionally the nerves swell after surgery and they do not have enough room- and you get increasing leg pain. Repeat surgery or an injection usually sorts this problem out. The risk of this is about 2-3%.
Bladder dysfunction : Occurs in less than 1% of patients – usually if there is some underlying risk factor already present.
Thrombosis (blood clots in the blood vessels): Fortunately this is quite uncommon in this type of surgery and the best way to avoid them is to get up and about as soon as possible after surgery. If you are a high risk (having had a clot in your lungs before) then we will use special blood thinning drugs to reduce this risk further. Please let me know if you have had a previous blood clot in the legs or lungs.
Pseudarthrosis: This means that the bone does not fuse in your disc space and you have persisting symptoms. This is quite uncommon with this technique. Long term risks : In a small proportion of patients, the discs next to the one fused may become painful several years later. This is usually treated as a separate problem.
Rarer risks: Death, paralysis, injury to big blood vessels in your tummy, stroke etc are very rare and cannot be quantified.
Having more pain: If you have a problem, and it cannot be sorted after repeat surgery – you may end up with more back and / or leg pain than you have now.
Repeat surgery: You may require repeat surgery to sort out the problems outlined above.
Anesthetic risks: These are best discussed with your anesthetist who will meet you prior to surgery.
What happens before surgery?
You will have some blood tests, x-rays and maybe an ECG. You will meet the anesthetist prior to surgery. You will also be counseled regarding surgery by one of the nurse practitioners who work in the unit.
What do you actually do during the operation?
The surgery is done under general anesthetic. You are given antibiotics prior to starting. The anesthetist will lower your blood pressure during the operation to reduce the bleeding.
You are placed face downwards on a special frame. A cut (incision) is made in your back and the muscles stripped from the spine. Special screws made of titanium are inserted through narrow pillars of bone (pedicles) into the vertebral body. 2 screws are placed in each vertebra, one on either side.
A window is made in the spine by removing your facet joints. The nerves are freed and moved to one side to reveal the disc. Most of the disc is removed and the height of the disc is restored to normal by using special instruments.
The local bone that is removed is chopped into fine pieces, mixed with some blood and packed into the front of the disc. The bone is also packed into hollow rectangular ‘cages’, and these cages are inserted into the disc, one on either side.
The ‘cages’ are used to keep the 2 vertebrae apart while the bone inside the cages fuses the 2 vertebra together. Plates are applied across the screws and the cages are compressed down, by pulling the screws towards each other on the plate. The operation for a 1-level problems usually takes 2 hours and for 2-levels, about an hour longer.
It usually takes an hour from the time you enter the anesthetic room, to starting surgery – because of all the preparation involved. Following surgery you will be in the recovery room for a while before going to the ward. Every effort is made to minimize bleeding during surgery, but some patients end up needing a blood transfusion.
How much pain will I have after surgery?
The first 24 hrs are difficult, but after that most patients recover quickly. You will have a combination of a patient controlled morphine pump and an epidural catheter (this is a way of injecting pain-relieving drugs directly around the nerves). You will also be given a variety of oral tablets . The nurse will ask you to mark your pain from 0 (no pain) to 5 (severe pain).
We try and keep the pain around 0-2. You need to tell the nurse if your pain relief is inadequate. Please do not hesitate to speak up! Some drugs cause nausea (make you sick) – there are other drugs we can give to minimize this.
What happens after surgery?
You will go the ward. You will feel quite drowsy, but will probably not sleep the first night. You will feel stiff and achy. The next morning you will be reviewed and taken out of bed and take a few steps. You will feel dizzy when you first get up, but this soon settles. A blood sample is taken and you will also have an x-ray. Once you get up you will feel better. By the second day you will feel much better and may even be well enough to go home that evening.
How long will I stay in hospital?
This does vary from 1-3 days on average after surgery – but it depends on the extent of your surgery, and is very individual. You are ready for discharge once you are walking on your own, your pain is well controlled by tablets, and your bowel and bladder are working normally.
What happens when I go home?
You are advised ‘no restrictions’ when you go home. Its good to have someone at home when you get back.
You will be able to manage on your own as well – otherwise we will not send you home. You can start driving when you feel safe – probably between 1-2 weeks. Take a test drive first and make sure you feel safe. Try walking a bit more each day.
You should continue taking the pain killers as long as you need them – but can start tapering them off gradually if you don’t. Try and stop the tramadol and voltarol first, and lastly the paracetamol. You may have different pain-killers depending on your circumstances. You will return to the hospital for wound checks and be reviewed by your consultant at 2 weeks.
If you experience any problems – please ring the consultant or the ward first. You will start some gentle physiotherapy a few weeks after surgery.
Will the metal work and the cages stay in?
Yes, they will. We do not remove implants unless there is a problem.
Will the implants buzz, at security, in airports?
No one has reported this so far.
Will I be able to return to active sport or manual work?
There is a good chance that you will, depending on how you do – but will need to work hard at building your muscle strength, endurance and aerobic capacity.
You will need to start training gently and gradually build this up. It depends on your motivation. Patients have gone skiing at 3 months, played cricket at 6 weeks, done competitive cycling at 3 months and dancing as entertainers at 6 months, among others. Some have completed the Great North Run.
When can I return to work?
This varies depending on your job, your motivation to return to work and how well you do following the surgery. Patients return to work usually between 4 and 12 weeks after surgery.
What about rehabilitation?
Remember that your spinal muscles have wasted away because of your inactivity and pain. These need to be strengthened up for you to make a full recovery.
This is where your determination is important. This needs to be done gradually.
Rehabilitation will focus on: strengthening the muscles, stretching for maximum flexibility, and aerobic exercise. A physical therapist will help you develop a program suited for your condition and needs.
For a complete recovery, it is important to stick with your program. You should join a gym when your pain settles and also go swimming. You need strong muscles to protect the rest of your spine from further stresses.
How should I prepare for surgery?
Stop smoking: as soon as you are advised surgery. Avoid all smoke inhalation for up to 12 months after surgery. In smokers the spinal fusion fails twice as often as in non-smokers, because the blood supply to the disc is affected. Your surgeon may recommend you avoid surgery if you cannot stop smoking.
Losing weight: while a good idea in general if you are over-weight, is not critical to the success of the surgery.
Oral contraceptive pills: You should stop taking them 2-3 weeks prior to surgery as they can increase the risk of a blood clot in your legs.
Anti-inflamatory tablets: Please stop taking them atleast a week before surgery – because they can cause excessive bleeding during surgery.
Allergies: Let the surgeon , the anesthetist and the nursing staff know if you are allergic to any medicines.
Gather knowledge: about your operation. Ask questions. Speak to patients from the spinal support group – so you are completely relaxed about what is going to happen. The more relaxed you are the better your experience in hospital. Ask your medical team any questions you may have.
Keeping fit: Stay as active as possible prior to surgery.
Medical problems: You need to inform your medical team of ALL your current medical problems and medication. If you are on blood thinning drugs (like warfarin) please let us know.
If you have any infections or coughs or colds at the time you come for surgery- please let the team know. If you have high blood pressure or diabetes make sure it is well controlled , leading up to your surgery.
Have a positive attitude: Patients who have a positive attitude and are determined to be better, do better after surgery.
MRI scan of A 38 year old person with a 23 year history of back pain.
Has a degenerate and narrowed disc at L4/5.
X-rays 2 years post-surgery has a good fusion (bone growth) across the L4/5 disc. The screws and plates are also seen. This patient had a complete relief of the pre-operative pain – and went back to work for the first time in many years.