This is a type of back surgery that places bone either in the front (disc space) and/or along the back of the spine so that the bone grows together and fuses the spine. Fusing the spine is designed to decrease back pain by limiting the motion at a painful motion segment. The fusion will set up over a 3 to 6 month period of time following the spinal surgery.
When is lumbar fusion recommended?
- if you've failed to get better after 'conservative' treatment such as physiotherapy, osteopathy, medications, and sometimes lumbar injection therapies
- if you've had back pain for at least six months, which has limited your ability to do ‘every day activities’
- are suffering form back pain and limited function due to degenerative disc disease, instability (spondylolisthesis), post discectomy back pain or recurrent disc prolapse
Investigations to determine the need for surgery
To confirm a diagnosis, you would have had x-rays and an MRI scan of the lumbar spine. These tests will show the extent of the structural damage to your spine, and will help the surgeon plan your surgery with respect to which segments of the spine to operate on and how many nerves need to be released.
Prior to the surgery
- you'll need to attend a pre-assessment clinic where you will be assessed, and additional preoperative test carries out Including blood test, blood group and typing, urine analysis and ECG heart tracing (if you're elderly or have had previous heart problems). If you have a respiratory condition, you'll need a chest X-ray
- patients on warfarin will be asked to stop taking it approximately 3-4 days prior to the surgery
- if you are on the oral contraceptive pill, you should stop taking it 6 weeks prior to the surgery
- smoking has an adverse effect on the ability of the body to recover from surgery, and also slows down the ability of the body to form new bone that is important for successful spine fusion. It is therefore important to try to stop smoking prior to surgery
The day of the surgery
- you'll be seen by your surgeon, which will also allow you the opportunity to ask any further questions
- you should have signed a consent form allowing the operation to take place
- you'll be fitted with anti-thrombotic stocking which will be worn continuously until you are mobilising freely (up to 6 weeks after the operation)
- you will be seen by your anaesthetist
How is the surgery done?
- under general anaesthesic and with antibiotics
- the procedure lasts approx for 2.5 hours
- usually, the operation is performed by making an incision along your back (sometimes it can be done through a front/abdomen incision, and your surgeon will have informed you of this beforehand)
- the nerves are exposed and protected. The disc is removed, and a spacer or cage filled with bone graft is inserted where the disc was i.e. between the 2 vertebrae. Pedicle screws, made of titanium, are used to hold the bones together
- a combination of artificial bone graft and your own natural bone is used; sometimes, a bone graft is taken from your pelvis
- an X-ray is taken to provide a record of your surgery, and checks the placement of implants/metalwork in your spine
- once the operation is completed, the wound is closed
- you may have a urinary catheter
- you will have strong painkillers administered into your vein
- a drain will be inserted into the back, and is removed after 24 – 48 hours
Immediately after a lumbar fusion
- you'll be encouraged to mobilize after 24 hours or when you are feeling better, and will be given a back support (brace or corset)
- you'll be required to wear leg stockings to prevent leg clots (deep vein thrombosis). You will also be fitted with a pneumatic leg compression device (FLOWTRON), also to minimise leg clot formation
- you will be given appropriate advice and information from the physiotherapist about exercises
- you maybe required to wear a brace/corset to support the spine for up to 6 weeks following surgery
- pain control usually takes the form of patient controlled analgesia (PCA) that allows you to administer strong painkillers initially after surgery. From then on, you will be given a combination of intramuscular and oral painkillers. It is quite common to experience pain in the back and leg, and a tingling sensation - this will settle down.
What is the expected outcome?
- in most patients, the likelihood of good/excellent relief of back/leg pain is approximately 80%, but this may vary depending on duration of your symptoms and associated medical conditions.
- numbness is slow to recover and may persist, particularly if you've had symptoms for a long period prior to the surgery
- weakness also may take time to recover although this can at times be incomplete particularly if the weakness was severe and prolong before surgery
- pins and needles usually start to improve immediately
- you may experience difficulty with sitting for the first few weeks due to back pain and muscle spasm
- often, there is some degree of back pain following surgery; this tends to improve with the passage of time, with the majority of symptoms settling by 3 months. However the recovery process can take up-to one year. You may require pain control medication from time to time
- you can drive after 6 weeks and should be able to return to light work after 6 -12 weeks
- you will encouraged to walk ½ to 1 miles a day
- you will be referred to physiotherapy for back exercises usually after 6 weeks post-surgery in-order to improve flexibility and strength of the spine
- you will have a follow up appointment in outpatients to check on your progress
What are the potential risks and side effects?
Generally, the majority of patients are happy with the outcome of their lumbar fusion operation with at least 80% expected good result. However, no surgery is totally risk-free, and the specific risks of this surgery, in the order of 1-5%, include:
- infection (less than 1% risk)
- deep vein thrombosis (less than 1% risk)
- neural injury/dural tear (1-5% risk) – usually transient bruising of nerves which settle. It's very rare for permanent weakness to occur
- 'Cauda equina syndrome' (less than 1% risk) – this is extremely uncommon, and can be due to development of a clot. This causes weakness and bladder symptoms and will require return to theatre for removal of the clot
- increased back pain – this tends to be transient, and settles down
- burning pain- this often reflects damage to the nerve at the microscopic level from the chronic severe compression
- residual back pain and stiffness
- implant/metalwork failure
Lumbar fusion is a good operation for back pain, where conservative treatments have not worked. An important part of its success is the motivation of the patient and the will to recover. Remember - good back care is the rule for life!
Return to treatments and operations.