Spinal fusion surgery refers to operations that are performed on the bones, discs and soft tissues of the spine. Almost all fusion surgery is performed on the lumbar spine (lower back) as this area of the spine takes far greater load during daily activities than the rest of the spine and, therefore, is more prone to pain and disability.
There are several reasons why a spinal fusion may be needed. The first is that one or more of the joints in the spine may be suffering with instability. In general instability of the lumbar spine can be caused by a developmental fracture which occurs to parts of the vertebrae and is often referred to as a pars defect.
The second cause is age related changes to the stabilizing structures of the joint/s including the vertebrae themselves, discs and ligaments.
Thirdly, the relevant spinal joint may have previously undergone surgery to remove part of the disc or soft tissue to decompress neurological tissue. This can subsequently, destabilize the joint and lead to instability. This is by far the most common cause for needing to consider a spinal fusion operation.
For this reason, if a significant decompression of the neurological tissue within the lumbar spine is conducted a surgeon may make the decision to perform a fusion at the same time to stop the chance of needing further surgery in the future. The diagnosis prior to surgery may be referred to as spinal stenosis which is a term used to describe the narrowing of the spinal canal and subsequent compression of the nerve roots within that canal.
Lower spine pain is commonly treated with appropriate analgesia, physiotherapy and injections. However, in cases of persistent levels of disabling lower spinal pain, this may also be an indication to consider a spinal fusion operation.
The vast majority of spinal fusion operations are considered in the over 60s due to many of the common causes (as above) being in some way age related. This is a rapid and expanding area of spinal surgical practice and with new techniques surgeons are able to significantly reduce some patient’s levels of pain.
Spinal fusion surgery is carried out in hospital under general anaesthetic. You will be admitted the evening before the operation. This allows you time to settle in and be prepared. You will not be able to eat for eight hours prior to surgery although you will be able to drink small amounts of water up to four hours before.
To achieve the fusion, a surgeon will very carefully expose the targeted joint within the spine and normally remove the entire disc with specialised tools. The disc will normally then be replaced with a combination of a bone graft and a metal fusion cage. Sometimes, instrumentation known as pedicle screws will also be inserted depending on the underlying cause for the instability and pain.
There are several different methods to achieve a spinal fusion. Depending on the underlying problem as well as general health status of the patient each spinal surgeon will plan the most safe and effective approach to take.
Two main surgical techniques include a trans-foraminal lumbar interbody fusion known as a TLIF and a Lateral lumbar interbody fusion known as an XLIF.
A trans-foraminal lumbar interbody fusion is performed with the patient positioned on their front enabling the surgeon to make an incision and access the relevant levels of the lumbar spine from the back. This is useful as most of the instrumentation is inserted posteriorly (from behind).
A lateral lumbar interbody fusion is performed by turning the patient on their side after they are anaesthetised. This enables the surgeon to make an incision and access the relevant levels of the lumbar spine from the side.
More rarely an anterior lumbar interbody fusion (ALIF) is considered which involves positioning the patient on their back and approaching the spine from the front. This procedure is done with the additional help of a vascular surgeon to help access the spine adequately.
There are also some specific risks associated with a spinal fusion operation. These will be discussed in detail with you by your surgeon prior to your operation and can include:
- Infection is one of the biggest concerns following fusion surgery. Although, infection is a risk our theatres have ultra-clean air operating conditions keeping infection rates to the minimum.
- Failure to fuse at the operated level
- Persistent pain at the site of the bone graft (normally the iliac bone at the pelvis)
- Progression of spinal disease especially at the adjacent spinal joints which may have increased loads and movement placed on them due to the fusion
Some general complications of spinal surgery which affect a very small percentage of patients can include:
- Blood clots are possible after any operation and are more common in patients with some pre-existing medical conditions. However, again they affect a very small percentage of patients and have well established treatments including aspirin.
- In rare circumstances patients, may suffer a stroke as a result of a blood clot developing.
- Damage to the nerves in the cervical spine or lumbar spine which may result in sensory loss and weakness in the arms and/ or legs and in extreme circumstances loss of bladder/bowel/sexual function.
- The intended benefits of reduced pain and increased function may not be felt.
In general, for the first 6 to 12 weeks after a spinal fusion operation you will be able to return to a sensible, independent standard of living at home ensuring that you do not push your activities too much too early.
Walking around the house and up to two miles per day outside are sensible activities. You may also be instructed to ensure not to stay in one position for too long i.e. prolonged sitting or standing may increase pain levels during the initial period of time following your spinal fusion. Any weight lifted during the initial 6-12 weeks should weigh no more than a kettle.
In spite of these activity restrictions most patients can expect to feel a significant reduction in their pre-operative pain levels very early on as the painful spinal segment or the spinal segment responsible for the nerve compression has now been fused.
Following your operation, nurses, doctors and physiotherapists on the ward will monitor your function and help you to get back to independence as quickly as possible. Following your discharge our expert spinal physiotherapy team will continue to monitor your progress in an outpatient clinic and where necessary advise you regarding appropriate strategies to:
- Reduce pain following lumbar fusion surgery
- Reduce spinal stiffness following lumbar fusion surgery
To enable the best possible results following spinal fusion surgery your surgeon and expert spinal physiotherapist may advise you to limit higher level activities for 6-12 weeks after your operation. Furthermore, your activity should be very gradually increased. Once at a point where your surgeon is happy for you to increase your function to normal levels, CircleHealth’s expert spinal physiotherapists will work closely with you to:
- Increase strength in your spine
- Increase balance and co-ordination
- Where necessary prepare you for a return to sports and other higher-level activities.