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There are many conditions which can destabilize the spine: arthritis, removal of intervertebral disc, or osteoporosis. Nevertheless, if the spine becomes too unstable, conditions and pain may worsen. The aim of this type of surgery is to stabilize the vertebrae.
If you are considering surgery, there’s no better time to get in good physical shape. The stronger your back and abdominal muscles are before surgery, the easier rehab will be.
You may be under the impression that fusions are undesirable and restrict mobility. And it’s true that fusion will restrict some mobility when compared to somebody with no spine issues. However, this procedure can be a saving grace, particularly when your joints have totally deteriorated and bone spurs obstruct nerve passages.
Fusion is in actual fact what the body does naturally in reply to trauma. Surgery furthers the process and also benefits patients by releasing trapped nerves. Some people may find their mobility is actually improved after fusion as they are no longer in pain. The painful segment which prevented them from moving at all is now immobile, allowing the rest of the spine to bend and twist.
Traditional fusion can generate pressure on the surrounding vertebrae, which can result in disc problems elsewhere in the spine. This is known as adjacent segment disease. It is one reason surgeons are unwilling to do multilevel fusions. The longer a fused segment, the more pressure it provides to neighbouring levels and with time there may be a need for further surgery.
In fusion, the aim is to immobilize the painful segment and bridge the two vertebrae with bone. First, surgeons stabilize the spine using titanium or stainless steel rods and screws. This acts as an internal brace. A bone graft next inserted to grow between the two vertebrae. Bone graft material is obtained from the bony decompression, the patient’s own hip (although this is not usually done these days), a donor, or a genetically engineered source. It usually requires around six months for the spinal bones to completely fuse together.
Sometimes decompression may make the spine unstable but not to the point that a fusion is required. Dynamic stabilization strengthens the spine to produce a more natural motion than a fusion. This is still an investigational procedure but it can lower the risk of adjacent segment disease.
One benefit of dynamic stabilization is that it delivers support without fusion, so little motion is lost. The aim is to lessen the chance of the next vertebral segment from the spine wearing out as fast because you can distribute forces. The disadvantages are that this procedure is not considered a standard of care, so the majority of insurance companies do not cover it. Only some surgeons in the United States perform dynamic stabilization. There is some concern that the hardware may loosen over time as there is motion there. Once a fusion has healed, there is no movement, so hardware does not become loose. Furthermore, dynamic stabilization allows motion at the treated level, which may produce pain. In some cases, a fusion reduces the painful motion and may be a better choice.
If a disc has to be completely removed, something needs to replace it otherwise the vertebrae will sit on top of one another. In cases of serious disc degeneration, the disc has practically disappeared anyway. Any movement of the spine will produce bone-on-bone friction. So the patient’s options are either fusion or disc replacement.
Developing an artificial disc has been attempted for decades. Producing a device which works for a diverse population and can replicate the natural movements allowed by real discs is difficult, but progress has been made. In 2004, the CHARITÈ Artificial Disc was the first artificial disc to be accepted by the U.S. Food and Drug Administration as a surgical treatment for patients suffering with single-level degenerative disc disease in the lower back.
However, artificial discs, especially in the lumbar region, perform no better than fusion in long-term studies. Actually, they have been linked with more complications, because they permit movement and are subject to mechanical failure. Due to this, few insurance companies in the United States cover this procedure.
Whilst not suitable for everyone or every condition, artificial discs do help simulate the movement of a real intervertebral disc. Two metal plates with a plastic centre supplant the natural disc and permit movement of the spine.
Vertebra can fracture due to trauma or tumours. For patients who have weak bones from osteoporosis or from steroids, the trauma causing the fracture can be as minor as coughing or sneezing. As these fractures are painful and the structural integrity of the bone is at risk, surgery is usually considered. Vertebroplasty and kyphoplasty are two procedures which can help heal such fractures.
Vertebroplasty is a minimally invasive outpatient procedure; only a small nick is made. A needle containing injectable cement is directed using X-ray and inserted into the fractured vertebra. The cement fills in the microfractures within the vertebral body and therefore stabilizes the bone. It requires roughly 10 minutes for the cement to set.
This is a newer procedure and is similar to vertebroplasty, but with an important advancement: it restores some bone height. Don’t forget that if a vertebra is fractured, it very often collapses. This can produces a domino effect and result in other vertebrae to become misaligned. With kyphoplasty, a temporary balloon is blown up inside the vertebrae to produce space and restore some height. The balloon is retracted and the space is filled with cement, and the natural size of the vertebra is restored.