Spinal Stabilisation 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.