Spinal fusion surgery is one of the most common types of surgery performed to relieve chronic lower back pain. It is an invasive procedure that should be reserved only for cases of back pain that have been unresolved by every conceivable form of conservative treatment.
Spinal fusion entails the fusion of two or more vertebrae in the spine to eliminate painful motion caused by spinal instability. Instability is often caused by degenerated spinal discs that no longer absorb shock and prevent contact between vertebrae. Spondylolisthesis, or the forward movement of one vertebra over another, can also cause instability. This condition often results from a vertebral fracture.
Vertebrae are usually fused by the use of hardware and bone grafts that cause the bones to grow together. Along with the risks associated with any surgery such as infection, scar tissue formation and damage to nerves and/or blood vessels, spinal fusion carries a unique risk: adjacent segmental degeneration. This occurs when joints or discs surrounding the site of fusion wear at an accelerated rate due to the increased stress they are subjected to, since joints and discs in the fused area are no longer absorbing shock.
The rigidity of spinal fusion affects overall spinal mechanics and may cause further back problems down the road. Two alternative surgeries are available that may limit this concern, both with their share of advantages and disadvantages.
Artificial Disc Replacement
Artificial disc replacement is a procedure that has been performed in the U.S. since 2000 and is in some cases an alternative to spinal fusion surgery. The operation entails the removal of a degenerated disc and its replacement by a synthetic one designed to perform the same tasks as a natural disc, including mobility facilitation and shock absorption. This eliminates the concern of adjacent segmental degeneration.
Disc replacement can be performed on both lumbar and cervical spinal sections. It is less invasive than fusion, requiring a smaller incision and less hospital time. The cost of artificial disc replacement, according to Spine-Health.com, ranges from $35,000 to $45,000. Spinal fusion, considering hospital stay required, can max out over $100,000. However, many insurance companies do not offer full reimbursement for disc replacement due to its newness, meaning this must be factored into your cost comparison.
The criteria for receiving disc replacement are more limiting than those for receiving fusion. Artificial disc replacement is not recommended for those with joint problems like arthritis, multilevel degeneration, bone weakness associated with osteoporosis or, finally, spinal misalignment. This means that spinal instability caused by spondylolisthesis cannot be treated by artificial disc replacement.
Lumbar Dynamic Stabilization
This form of spinal surgery is also less invasive than fusion. It entails two small incisions and only takes about 15 minutes to perform. The only stabilization system approved for use in the U.S. by the FDA to date is the Dynesys system, which uses pedicle screws, spacers and cords to stabilize spinal segments while still allowing some motion. The spacers set the vertebrae at their natural distance from one another, alleviating pressure off discs and joints.
The availability of this procedure is limited and the exact cost is unknown. One Mexican clinic, Hospital Angeles, offers it starting at $12,500. As with artificial disc replacement, dynamic stabilization is fairly new and long-term studies to assess its effectiveness and the risks associated with it are lacking. This means insurance coverage will not likely be available.
Theoretically, lumbar dynamic stabilization minimizes the risk of adjacent segmental degeneration by allowing mobility of the stabilized spinal segments. Long-term studies are needed to confirm this, however. One study showed that dynamic stabilization may not actually reduce the risk of adjacent wear; this can be found at www.ncbi.nlm.nih.gov.
Unlike artificial disc replacement, dynamic stabilization can be performed to treat spondylolisthesis and multilevel degeneration. It cannot, however, be performed in the cervical spine. Because it is minimally invasive and maintains range of motion, dynamic stabilization may be a preferred alternative to lumbar fusion surgery.
Any type of surgery comes with risks and should not be considered until all conceivable conservative treatments have been tried. Keeping informed about all of your options and comparing benefits and risks will help you make informed decisions about you health.