A spinal fusion is an operation to stabilise an area of the spine. It can be done by a variety of techniques depending upon the condition of the spine that is being treated, and the underlying pathology. The commonest 2 types of spinal fusion are called a Transforaminal Lumbar Interbody Fusion (TLIF) or a Posterior Lumbar Interbody Fusion (PLIF). Other options include an anterior operation (ALIF) or surgery with a surgical approach from the side (XLIF).

The aim of a spinal fusion is to ‘weld’ two vertebrae together to prevent painful movement. Spinal fusion is achieved by the use of bone graft between two bony surfaces of the spine. The idea is to make the body behave as if there has been a fracture, so that the two bony surfaces are joined together with new bone. This fusion is enhanced by the use of instrumentation.

There are 3 main indications for fusion surgery:

1. To treat a spondylolisthesis. In this condition the arch of one of the vertebrae weakens or fractures. This allows a deformity to occur in which the nerves become increasingly compressed.
2. When symptoms persist after previous surgical decompression or discectomy.
3. To treat chronic mechanical spinal pain arising from one or more of the lower three spinal segments.

Although the success of surgery with regards to achieving fusion is excellent, this operation remains uncertain with regard to clinical outcome. The clinical outcome varies according to the underlying pathology.

Before you come into Hospital

Smoking has been shown to have an adverse affect on the outcome of fusion surgery. We, therefore, strongly advise you to stop smoking before you have your operation. If you are overweight, then please try to reduce it as this will lower your anaesthetic risk and optimise your recovery.

If you are on any medication that has the potential to thin your blood such as aspirin, clopidogrel, warfarin or any other blood thinning medication then we do need to know about this prior to the date of your injection as this will usually need to be stopped prior to your operation.

If you take anti-inflammatory tablets then you must stop taking them 7 days before your surgery.

How do we do a TLIF/PLIF?

The surgery is done under a general anaesthetic. You will meet the anaesthetist on the ward prior to your surgery who will explain the anaesthetic to you. The operation takes about 3 hours. Once asleep the patient is placed on their front on the operating table. X-ray is used to identify the correct area of the lower back. Either one or two incisions will be made, depending on the underlying pathology. A TLIF / PLIF involves the following steps:

• The spinal nerves are decompressed
• The disc is removed. The disc space is filled with a spacer, called a ‘cage’. Bone graft is packed in front of the cage. The bone graft used is bone that is removed as a part of the surgical approach.
• The adjacent vertebral bodies are rigidly fixed with rods and screws.

When appropriate minimally invasive techniques will be used for your surgery. These techniques cause less muscle damage, result in less post-operative pain, and lead to a quicker recovery.

At the end of the operation the wound(s) will be closed with dissolvable stitches and covered with a dressing.

What are the Risks?

Infection

The risk of infection is less than 1%. All patients receive a dose of intravenous antibiotics when they are going off to sleep. If you develop an infection it is most likely to be a superficial wound infection that will resolve with a short course of oral antibiotics. Occasionally patients develop a deep infection. This is much more serious and may require a prolonged course of intravenous antibiotics or additional surgery.

Bleeding

You will lose some blood during the operation. We would normally expect your body to be able to deal with this blood loss without needing a blood transfusion. There are large blood vessels in front of the disc and there are reported cases of these blood vessels being damaged during surgery resulting in a very serious and potentially life-threatening blood loss. This type of bleeding is extremely rare and is reported to occur in approximately 1 in 25 000 cases.

DVT

Developing blood clots in the legs (deep vein thrombosis – DVT) is a risk of any surgery. We worry about DVTs as bits can break off a travel around your body. This is called an embolus. An embolus can affect your breathing, cause you to have a stroke, and could potentially be fatal. DVTs occur in approximately 1 in 200 patients having back surgery. An embolus is a much less common occurrence. We minimize the risk of DVT by asking patients to wear hospital stockings following their surgery (TEDS), and mechanical pumps during and immediately after surgery. These pumps squeeze your lower legs, helping the blood to circulate. They are put on when you go to sleep and stay on until you start to mobilize. We encourage early mobilization as this also helps to prevent DVTs. If a patient is considered to be high risk for a DVT then we will prescribe blood thinning medication for a couple of weeks after your surgery.

Nerve Injury

The spinal instrumentation is inserted very close to the emerging spinal nerves. In doing this there is a risk of physical damage to the nerve. This can lead to loss of nerve function with persisting pain, weakness, and numbness in the territory of that nerve. This complication can occur in up to 5% of patients. Although further surgery may be undertaken to remove or adjust an implant, the loss of function and pain from a damaged nerve may be permanent.

With any lower back surgery there is a risk of nerve injury which could cause leg pain and weakness. It is possible that a nerve injury could also affect your bladder and bowel function, as well as erectile function in men.

Dural Tear

Occasionally the lining to the nerve (the dura) can be damaged causing the leakage of the fluid that surrounds the nerves (the cerebro-spinal fluid). Some tears are managed conservatively, whilst others require surgical repair. Patients who have had a dural tear may be asked to stay in bed for a short period of time following their operation on flat bed rest. This would normally be for between 24 hours and 5-days. Occasionally a persistent leakage of spinal fluid occurs which may require further surgery.

Scar Tissue

Scar tissue can form around the nerve and can cause persisting neurological symptoms. This is not common. We will usually try and treat this with injections rather than further surgery.

Back Pain

Even is a successful fusion is achieved, it does not guarantee the relief of back pain. 5-10% of patients will report increased back pain following this type of surgery.

Failure of Fusion

A small number of patients do not develop a satisfactory fusion. In these cases there can be on-going pain, usually back pain. In this situation your fusion may need to be redone.

Risks Associated with having an Operation on your Front

When getting you ready for surgery, care is taken to ensure that everything is protected. The does however remain a small risk of pressure damage. This can cause some temporary skin damage to the tip of your nose and your chin. This would normally completely recover over 2-3 weeks. There is a very small risk of some damage to your vision. Visual damage is reported as occurring in 1 in 10 000 cases.

Medical Complications

Following any operation there is a small risk of post-operative medical complications, such as chest infections or urine infections.

What Can I Expect Following my Fusion?

When you wake up following your operation you will feel bruised in your lower back. We try and minimize this by injecting local anaesthetic around the wound. You will also be given a patient controlled morphine pump (PCA) to help with your pain relief for the first 24-hours after your operation. Some patients require a urinary catheter.

Day 1 post-op – You will be seen by a physiotherapist with the aim of getting you up on to your feet. You should continue to practice getting up.

Days 2-5 post-op – Gradually increase your mobility about the ward with the aid of the physiotherapists and nursing staff. When resting, it is good to alternate between sitting and lying down. If you place a pillow between your knees then you can lie on your side. You will be discharged home when you are moving around comfortably and safely. Before you go home the nurses will explain how you need to look after your wound(s).

What Next?

The post-operative discomfort will take a few weeks to settle down. The wound will be closed with a dissolvable suture, so there will be no stitches that need to be taken out. Your wound will require minimal attention after discharge.

Following your operation you should not take any anti-inflammatories. This is because they reduce the potential for fusion, and therefore reduce the likelihood of a successful outcome.

For the first 6-weeks you will need to take things relatively easy. During this time you should gradually increase your walking distance. You should aim to walk twice a day. During the first 6-weeks you should limit activity to gentle walking and stretches. You must avoid any lifting.

You should continue to wear your hospital stockings for the first 6-weeks.

After 6-weeks you can increase your activity level and start to do some gentle non-impact exercise as comfort allows (gentle swimming, light cycling, cross-trainer). You can start to do some light lifting, but should not lift more than 10kg until 3-months following your operation. Do not return to impact or increased torsion exercise (eg. jogging, golf) for 6-months.

Returning to Work

People with non-manual jobs will normally be able to return to work after 4-weeks, pending a satisfactory review. It will be 3-months before you can return to manual work.

Driving

There is no restriction with the DVLA, though there will be with your insurance company. You will need to be able to undertake an emergency stop, and be in complete control of your car at all times without being distracted by pain. If this is not the case then your insurance will NOT be valid. Most patients are back to driving within 4 weeks of their surgery.

Flying

You should not fly for 6-weeks following your surgery. You should not undertake any long haul flights for 3-months. If traveling on a long haul flight within 6-months of your operation then you should wear your hospital stockings when flying.

Follow-Up

You will be seen back in the clinic a few weeks after your operation. An appointment will be made for you before you are discharged.