Mr Ben Okafor FRCS (Orth.)

Consultant Orthopaedic and Spinal Surgeon

What is Wallis dynamic stabilization?

There are two problems that cause back pain with moderate wear and tear in the lower back.  First, abnormal loads through the disc and facet joints can be painful.  The affected segment also becomes a little loose and soft, causing abnormal movements to occur.

The disc is often compared with a car tyre. Like a good, well inflated tyre, the normal disc is firm but compliant, able to absorb stresses and allow some degree of movement.  Degeneration causes the disc to become soft, rather like a deflated tyre.  Bumps and stresses are not well absorbed - they cause jarring in the back, and the disc becomes 'wobbly' or unstable.  This instability is often described as the back 'going', often with quite trivial movements, and can cause further damage to the disc, with tears in the outer wall of the disc developing, a bit like splits in the wall of a flat tyre.

The Wallis implant reduces the abnormal loads through the disc and facet joints.  It also brings the movement of the affected segment back into the normal range, reducing the instability.

Who is Wallis stabilization suitable for?

The Wallis technique is suitable for some causes of back pain for disc degeneration, especially where the disc and facet joints are still  preserved.  However, it's less likely to reduce back pain if the discs are very badly damaged.

The support provided by the Wallis system may be useful in some cases of disc protrusion or disc prolapse causing sciatica.  The most obvious situation is sciatic pain developing in someone who has previously had problems of back pain.  The Wallis technique is also a good idea if the disc prolapse is very large or where there has been a recurrent prolapse. In these cases, the disc itself is vulnerable, more likely to cause problems in the future and in need of some protection.

The Wallis technique helps to open out the space in the spinal canal and where the nerves leave the spine, so it can be very useful in operations to decompress nerve roots.

What happens during the operation?

The minimally invasive nature of the procedure means that it is not a lengthy operation.  Wallis stabilization is often performed as an addition to other procedures, such as decompression of the nerves in the spinal canal or removal of a disc protrusion.

During the operation, you will be placed face down and a small incision (normally about 4-5cm long) is made over the affected level.

After making the incision, the muscles are moved to the side a little, together with the strong ligament which runs over the spinous processes.  Any additional procedures required, such as decompression, are undertaken before Wallis stabilization. 

After carefully clearing a space for the Wallis implant, the bands from the implant are passed around the spinous processes and fixed back to the implant using special clips.  The implant is positioned and the bands carefully tightened.  Crimps are placed on the bands close to the implant and the excess band cut off.

What can I expect after the operation?

After the operation, you will be aware of some soreness and stiffness in the lower back but you should find that you will quickly and easily get moving after the operation.  The nursing staff will work with you to try and ensure that any post-op discomfort is kept to a minimum.  Initially this may well be through the use of pain killing medication through a line which you control through the simple press of a button (Patient Controlled Analgesia, or PCA), but quite quickly you will be able to switch to simple tablets.

We will usually aim to get you up, standing and taking a few steps later the same day or the day after the operation.  Your mobility will quickly improve and as it does so the physiotherapist will work with you on a programme of muscle strengthening exercises, which will continue after you go home.  Your therapist will show you ways to protect your back while doing everyday things such as getting in or out of bed, dressing, getting up out of a chair or getting into a car.

To minimise the risk of a deep vein thrombosis (DVT), you will be provided with special elasticated stockings.  When resting in bed, you will be fitted with A-V impulse boots and we will ask you not to cross your legs and to do special foot exercises. 

All these measures help to reduce the chance of a thrombosis forming, as will walking which is another reason we encourage you to get up and start mobilising quite early.

The position of the implant will be checked on x-ray, usually the day after your operation.

Once you are comfortable and happy with your ability to get up and around you'll be able to go home (most people are ready 2-4 days after their operation).  By this stage you will be safe to sit, walk and travel in a car for moderate periods.

What will my convalescence be like after leaving hospital?

The surgical wound - the clips are removed once the wound has healed, usually 9 days after your operation.  This is not uncomfortable and is very simple.  You can either come into the hospital or we can arrange for your district nurse to remove the clips for you at home.

Activity and movement - you'll need to continue with your programme of home exercises and supervised physiotherapy after your discharge from hospital.  This will usually involve attending physiotherapy sessions about twice a week.  Initially, your physio may use treatments to help settle soreness, muscle spasm and bruising from the operation.  Regular walks are also helpful.  You will be taught what to do to protect your back and how to position yourself when you sit or lie down.  Quite soon you will move onto more active treatments to build up your strength and improve your flexibility.  It can be quite daunting when you first start gentle bending.  Working steadily on both strengthening and movement exercises will help you gain confidence and flexibility. 

Endurance exercises such as treadmill walking and static cycling further help muscle strengthening. 

Over the next few weeks you will find that you should be able to return to most normal day to day activities.  This should be a gradual and progressive process, guided by how you feel and by the progress you make with your physiotherapist.  Take care and don't try and be too ambitious.  It's important to achieve good muscle control before you try and push your range of movements too far.  As you gain confidence in your movements you can incorporate these in everyday tasks and activities, including bending.

Driving and travel - you can return to driving as soon as you feel reasonably confident about getting in and out of your car and happy that you will be able to sit comfortably for the necessary time.  You shouldn't drive if your concentration is impaired, for example if you are uncomfortable, or if you are taking medication which might make you drowsy.
There are no specific concerns about airline travel after Wallis stabilization, but if you do plan to travel take an aisle seat so you can get up for a stretch and do a little walking periodically.  You may want to take an anti-inflammatory to help reduce stiffness and discomfort.

Sports and fitness training - you will probably be able to return to light aerobic fitness training at your health club during the first six weeks after your surgery.  You can discuss appropriate exercise with your physiotherapist.  It's best to wait until about three months before returning to golf and competitive sports.

Return to work - you'll be able to consider returning to light, semi-sedentary work in three to six weeks but if your work is more physically demanding, you may benefit from a longer period of recovery.  In the weeks after an operation you will tend to tire more easily and it might be better to return on a part time basis initially.

Will I still have symptoms after surgery?

One of the big advantages of Wallis stabilization is that it is much less invasive than other similar procedures.  The muscles will feel somewhat bruised and sore and the wound tender and sensitive to start off with, but this should settle over the days and weeks following your operation. The implant itself is quite deeply seated and you won't feel this through the skin.

You will require physiotherapy, and will be monitored in clinic as part of routine review including x-rays.

What are the risks and complications of Wallis stabilization?

Like all procedures, this carries with it the general risks associated with having an anaesthetic.  These will depend to some degree upon your age, your general state of health and any other specific medical problems that affect you.

The Wallis stabilization procedure is  minimally invasive, so the risks of the surgery are very minimal.  There is a very small risk of a blood clot forming under the skin but if this does occur, it will usually resolve itself straight away.  As with all operations there is a small chance of a wound infection occurring. The risk of nerve damage is also minimal.

Problems with the implant or bands are almost unknown, but if they were to occur this would be safe and easy to deal with.  An important feature of the Wallis Stabilization system is that it preserves all options for the future.  This includes exchanging the implant very easily if necessary.

Return to treatments and operations






Painful lumbar disc degeneration

The Wallis device

The Wallis device in place

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