Spinal fusion is a form of surgery in which two or more vertebrae within the spine are fused together. When the discs or joints of the spine begin to wear or suffer injury, this can result in painful instability and nerve impingement. Pain may also be caused by spinal stenosis, a condition in which a disc, swollen ligament or bone spur protrudes into the spinal canal, narrowing this space. Spinal fusion is the most common type of back pain surgery performed in these instances.
Spinal fusion is associated with risks, like any surgery. One unique and particularly troubling risk associated with this procedure is called adjacent segment degeneration, characterized by rapid disc degeneration surrounding the fusion site. This occurs because fusion changes spinal mechanics; with a now-stable segment, surrounding discs are subjected to greater forces.
Most back pain patients don’t require surgery. Those who do aren’t always aware that, depending on the situation, there may be more than one surgical option available.
Wallis Ligament Stabilization
For patients with a degenerated disc or spinal stenosis, the Wallis ligament implant may serve as a substitute for spinal fusion. This implant acts as a spacer between vertebrae with bands that attach it to the spinous processes of the vertebrae above and below the spacer. It allows for appropriate space between the vertebrae while maintaining mobility, as opposed to fusion. The Wallis implant can be used in patients receiving a discectomy – removal of bulging or herniated disc material – or laminectomy – widening of the spinal canal. It generally entails a shorter recovery time than fusion as you don’t need to wait for bones to fuse.
One small study comparing the impacts of fusion and the Wallis implant on patients checked their progress at one and two years post-surgery; twenty-four patients received the Wallis implant, while 21 received fusion. The researchers noted a number of significant differences. The Wallis ligament reduced the amount of vertebral slippage, or olisthesis, post-surgery better than fusion. Patients in the Wallis group had better physical function scores than fusion recipients at two years. Disability scores were lower for Wallis patients than fusion patients. Perhaps most notable is the fact that only 4.1% of Wallis patients (1 patient) exhibited signs of adjacent segment degeneration after surgery, whereas 28.6% of fusion recipients (6 patients) exhibited degeneration.
For more on this study, see http://www.ncbi.nlm.nih.gov.
The Wallis procedure may not be suitable for people with notable vertebral slippage (spondylolisthesis) or severe disc degeneration that requires total disc removal (in which case artificial disc replacement may be preferable).
If you’re a candidate for spinal fusion surgery, talk with your surgeon about all your available options. You may be a candidate for a less risky and extensive procedure. Learn more about the Wallis implant at www.stockport.nhs.uk.