Spinal Normalisation

These devices continue to be evaluated in clinical trials. Early results suggest a possible role in the management of degenerative disorders of the lumbar spine (Christie, Song et al. 2005).

Spinal Normalisation/Stabilisation with the DIAM System (Device for Intervertebral Assisted Motion)

The DIAM Spinal Stabilisation System can be used with minimally invasive surgical techniques, and provides flexible support of the lumbar spine while treating spinal degeneration.

The "Device for Intervertebral Assisted Motion" (DIAM) is a new technology from Medtronic that treats back problems without the need for spinal fusion.

The DIAM Spinal stabilisation system was designed to aid in the treatment of degenerative disc disease. The DIAM acts as a spacer which when placed between two spinous process restores the natural height of the disc, taking the pressure off the intervertebral disc and associated structures, and allows the nerve to exit freely from the spinal cord while maintaining normal movement of the spine.

The device is made of a hardened silicone covered with a polyethylene sock and has two ligatures, which allow it to be secured in place between the two spinous processes.

What are the advantages of the DIAM system?

Following standard surgery where a part of the intervertebral disc is removed (discectomy), the rest of the disc can degenerate further potentially requiring fusion surgery at a later date. In fusion surgery the surgeon uses a bone graft to join, or fuse, two or more vertebrae together. Once the bone and spinal bone grow together, the two vertebrae function as one unit, stabilizing that part of the spine. With the disc space restored to its original height, pressure on nerves is usually relieved. The DIAM spinal stabilization system negates the need for fusion in some patients and can act as an alternative for fusion in some patients. The device is designed to assist in allowing normal motion in the spine. In addition, the device may help to protect the spine from mechanical stress that can cause further degeneration of discs near the level of surgery.

Who can benefit from surgery?

You may benefit from the DIAM spinal stabilization system if:

The surgeon has confirmed by your history and x-ray studies that you have degenerative disc disease in your lower back;

You have narrowing of a vertebral opening due to loss of disc height; or

You have back and/or leg pain that has not responded to non-surgical treatment.

In series of 43 patients suffering from lower limb pain, almost constantly associated with chronic or acute backpain, treated by microsurgical nerve root decompression and by implantation of a soft intervertebral prothesis (DIAM). Satisfying results were obtained in 97% of cases, inducing to consider the device a reliable tool for curing low-back pain and ciatica (Mariottini, Pieri et al. 2005).

How is the surgery performed?

The DIAM spinal stabilisation system surgery takes only a short time added onto the standard procedure of discectomy. The surgeon will access your spine through an opening in your back, remove portions of the degenerated disc, measure the required height and then position the DIAM to maintain function of your spine. There are alternative treatments to this surgery, both surgical and non-surgical. You should discuss these options with the surgeon before making your decision.

What is the recovery process?

Immediately after surgery, you will be moved to the recovery room where you will remain for a few hours while your recovery from the anaesthesia is monitored. After you awaken fully, you will be taken to your hospital room. You may have a drainage tube in your wound and the surgeon may prescribe medicines to control pain and nausea. Ask the surgeon about your hospital stay and your specific recovery plan following surgery. It is important to follow your doctor's instructions carefully to recover from surgery as quickly as possible and increase your chances of a successful outcome. After surgery the surgeon may refer you to a physical therapist that will teach you exercises to improve your strength and mobility. The goal of physical therapy is to help you become active as soon as possible, using safe body movements that protect your back. You and your surgeon will continue to work together during your recovery. Before you leave the hospital, the surgeon may schedule follow up visits with you so he can evaluate your progress.

What are the possible complications?

As with any surgery, spinal surgery is not without risk. Complications, such as infection, blood loss, bowel or bladder problems, are some of the potential adverse risks. Please consult the surgeon for a complete list of indications, warnings, precautions, adverse events, clinical results and other important medical information, if necessary.

Spinal Normalisation with the Wallis Implant

In the management of degenerative disc disease, flexible stabilisation of the lumbar spine is potentially a very attractive alternative to spinal fusion, especially for younger patients. Disc replacement is certainly another option but it requires major surgery. In certain cases, the Wallis implant is considered to be the best treatment for disc degeneration.

This implant is most commonly used in the treatment of intervertebral disc herniation and for tears in the outer layer of the disc. The initial flexible vertebral fixation concept began in 1984 in order to restore the normal kinematics of the diseased level. This design acts to normalise the movement of the diseased disc which helps to reduce pain and promote disc healing by reducing load and stress. After 15 years experience the second generation implant has been developed called the “Wallis Implant.” Contrary to spinal screws, the Wallis implant will preserve the mobility of the spine segment. It will also eliminate any bone disruption, is totally reversible, and will keep all other options of treatment open. The Wallis implant was introduced into Australia in 2002 and has received Therapeutic Goods Administration approval.

The Wallis is an interspinous implant dedicated to lumbar degenerative instabilities such as:

Herniated disc

Modic 1 degenerative lesions

Degenerative disc disease at a level adjacent to a previous fusion

Narrowing of the spinal canal treated without laminectomy

The Wallis non-fusion interspinous implant:

Restores and preserves disc height

Allows shock absorption and load sharing

Preserves anatomy with minimal bone and ligament removal

The implant acts to treat the back pain while preserving the mobility and anatomy of the treated segment. The Wallis is completely reversible as compared to an instrumented spinal fusion which demands significant bone removal and is completely non reversible. Current figures indicate 1 in 4 spinal fusions require reoperation.

The interspinous placement of the implant allows restoration of disc height and reduction of the load on the disc and the facets. During movements of forward and backward bending the disc loading conditions are reduced, which leads to pain relief with preserved mobility.

Without doubt the Wallis is an effective, simple and reversible alternative to a spinal fusion. For the right candidate, the Wallis implant is an ideal way to treat pain and return the spine to normal mechanical activity, without the costs and complications of Spinal Fusion. There have been over 300 Wallis procedures carried out in Australia since its introduction with no documented negative results, and the popularity of this excellent implant is growing as more positive outcomes are established.

Bibliography

Christie, S. D., J. K. Song, et al. (2005). "Dynamic interspinous process technology." Spine 30(16 Suppl): S73-8.

Mariottini, A., S. Pieri, et al. (2005). "Preliminary results of a soft novel lumbar intervertebral prothesis (DIAM) in the degenerative spinal pathology." Acta Neurochir Suppl 92: 129-31.