Lumbosacral
Procedures

Lumbar Disc Replacement San Francisco

Over recent decades, a great deal of research has been dedicated to devising joint replacement for the lumbar spine discs. This has been in part stimulated by the successful development of hip replacements and knee replacements, replacing fusions of these joints, which were quite problem and seem archaic compared to our current state of the art. The first device placed in the intervertebral disc was a ball bearing referred to as the Fernstrom ball. Further development led to the first complex artificial disc, developed in German, the Charité disc replacement. This device originally looked like two bottlecaps with a plastic saucer in the middle. It was actually quite successful in some patients and was improved several times. This was the first disc that was released for use in the United States by the FDA. The usefulness was compared to fusion for people with painful lumbar spinal joints from deteriorated discs. In the clinical FDA-directed multi-center trials, which were randomized, the artificial disc looked at least as effective as a complex fusion. This particular device, however, had occasional problems with the middle piece displacing, requiring revision. San Francisco Spine Surgeons of San Francisco stay up-to-date on these advancements.

The next device to go through FDA clinical trials was the Maverick device, which was an all-metal lumbar spinal joint, and the ProDisc, developed by Dr. Marnet in France. Both of these devices were shown to be effective in clinical trials and did not have the disarticulation problem. The Maverick device had to be pulled by its manufacturer due to patent litigation issues. The ProDisc device proved to be reliable, with thousands of cases being done and good results, which have held up in seven-year follow-up.

There are many other devices that have not reached so far into market penetration. One device developed in England, the Rainier disc replacement, made out of a viscoelastic polymer, looks most similar to a human disc. The early results in Europe with this device were favorable. It is not available in the United States and has not started trials here. Currently, the ProDisc-L by Johnson & Johnson is by far the most commonly used lumbar disc replacement in the United States. In our early experience with over 400 cases of single- and double-level operations using the ProDisc-L, complications were unusual, and the need for revision or repeat surgery was less than 1 in 100 with close to ten-year follow-up now. Unfortunately, in the United States, in general, insurance carriers have been loath to approve lumbar disc replacements and most recently resisted approving any surgical treatment for painful degenerative disc disease despite multiple clinical trials that show both disc replacement and fusion treatment are usually effective in appropriately selected patients.

The procedures are performed in San Francisco through an incision over the abdomen, and the spine is approached behind the sac that holds the organs and intestinal contents. Here, the entire disc is readily accessible and can largely be removed and replaced with the device. Hospitalization is usually two to four days, and most patients notice less symptomatology than they had before the surgery by six weeks from the time of the surgery. Of course, patients who have had many years of chronic pain can take much longer to achieve the benefits of the surgery.

The lumbar spine serves the function of forward bending of the low back area. Fortunately, this is flexion is redundant, with five lumbar discs and hip joints overlapping in this function. However, if several of the joints are immobilized with fusion, more demand is placed on the remaining joints, and this can accelerate deterioration of the remaining joints. A simplistic way to look at this is if you were driving your car with three flat tires and remove them because they are worn out and drive on the remaining tire, which is taking all the stresses that the others were and were worn out by, how long will your remaining tire last? Because the disc replacements allow continued motion and apparent normal spinal function of the worn-out joints they are applied to, they likely diminish the rate of wear and tear on the remaining joints. In general, about 20% of patients develop degeneration requiring surgery of the non-operated joints within ten years. Disc replacements should diminish this problem as long as they function over many years and do not wear out themselves. So far, this appears to be the case.

It should also be noted that fusion techniques have also improved greatly over the time in which the disc replacements were studies and the FDA trials, so that if new trials were done comparing the disc replacements with the new fusion techniques highly utilized, it is not clear which of the devices would have the most favorable results.