According to a review done by doctors at the Boston University School of Medicine, lumbar fusion doubled from the 1980s to the 1990s. It continues to increase as a popular treatment method. Why?
Some researchers think the trend reflects the success of the treatment. Positive clinical reports continue to be published. There's also the fact that companies making surgical supplies related to fusion are marketing heavily in this area.
There's been some thought that reimbursement to doctors is higher with spinal fusion than more conservative treatment. We don't like to think the pocketbook rules decisions, but there may be some truth to the idea.
The fact that the overall fusion rate or rate of success hasn't changed in 20 years has been brought out. Further study of your question about the best treatment is needed before a final answer can be given.