Lumbar disc arthroplasty is a rapidly exploding area of surgical practice as prior to the last 10 to 15 years the only option for individuals with significant discogenic spinal pain was a fusion operation. However, Circle Health's expert spinal surgeons are now able to offer this new, innovative treatment which replaces damaged spinal discs with an artificial disc.
Over many years it has been found that fusion surgery for persistent and disabling spinal pain, due to the nature of immobilizing the painful spinal level may cause rapid wear and tear at the adjacent spinal levels (sometimes termed transition syndrome). This potential problem has been particularly prevalent in younger, more active individuals.
With increasing amounts of spinal pain seen in younger patients a lumbar disc arthroplasty is now a safe and effective operation to reduce the spinal pain while maintaining a more normal structure and biomechanical properties at the affected level.
Patients who may benefit from a lumbar disc replacement operation include those suffering with persistent and disabling levels of lower spinal pain in spite of appropriate physiotherapy and injection therapies available.
Associated symptoms may include sciatic pains as a result of the nerve compression that is sometimes associated with significant disc damage.
MRI scans will deem whether the spinal pain and any associated symptoms are arising from one particular spinal segment and if this is the case then that individual may benefit from a disc replacement at that level.
Often significantly degenerative or damaged discs have undergone previous decompressive operations and there is a long history of spinal pain and it is very likely that disc was never morphologically normal. Any previous surgery may have de-stabilized the relevant spinal segment even further making a disc replacement necessary further down the line.
Although there are several types of lumbar disc replacements on the market, In general, a disc replacement uses two metal endplates that are able to fit on to each adjacent vertebral bodies with a sliding/ rolling core. This enables the metal endplates to move in a characteristically normal way for the replaced spinal motion segment. The aims of a lumbar disc replacement are as follows:
- Restore normal disc height (this is extremely important for not only the spinal pain itself but for allowing normal space for the spinal nerve roots - thus reducing any associated sciatic leg pain).
- Restoring normal spinal level motion flexibility
- Reduce adjacent spinal segment degenerative change
A lumbar disc arthroplasty 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.
The operation is normally performed with the patient on their back after they are anaesthetised. This enables the surgeon to make an incision and access the relevant levels of the lumbar spine from the front or obliquely from the side (anterolateral approach).
To achieve the arthroplasty, the surgeon will firstly use x-rays to identify the disc to be removed. The skin will then be marked and the incisions made. Carefully, a muscle called the psoas and the abdominal organs will be pushed aside manually by the surgeon to avoid any damage to these tissues.
A tube known as a dilator will then be inserted above the disc to be removed and a retractor tool will be used to split the muscles and allow the surgeon to more easily visualise and work on the spine. The entire disc will then be removed with specialised tools and replaced with a combination of a bone graft the replacement disc.
There are also some specific risks associated with a lumbar disc arthroplasty operation. These will be discussed in detail with you by your surgeon prior to your operation and can include:
- Migration of the metal endplates attached the bone (vertebrae).
- Fracture of the vertebrae upon inserting the implant
- Failure of the implant itself either early on or later on, although failure rates appear low on current data.
- Due to the anterior (front) approach to this operation there can be a complication in males termed "retrograde ejaculation" which means men are able to feel a normal orgasm but do not ejaculate.
Some general complications of lumbar spine surgery which affect a very small percentage of patients can include:
- Infection can occur although our theatres have ultra-clean air operating conditions keeping infection rates to the minimum.
- 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 lumbar spine which may result in sensory loss and weakness in the 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 lumbar disc replacement 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 to 12 weeks should weigh no more than a kettle.
All patients will be recalled and clinically reviewed by their spinal surgeon at 6 weeks after the operation. As well as a clinical review with your surgeon you will have a check x-ray which provides two important functions.
Firstly, the check x-ray ensures that the disc replacement has remained in the right place and has not become unstable itself. Secondly, the xray provides further evidence that there is no sign of infection around the operation site.
In general, 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 replaced.
In spite of the activity restrictions noted above, most patients who have undergone a disc replacement operation are back to full activities of daily life at their six week review.
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 your disc replacement
- Reduce spinal stiffness following your disc replacement
Once your activity restrictions are lifted, to enable the best possible results following lumbar disc arthroplasty 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, Circle Health'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.