Surgical Results Overly Optimistic

What percentage of success would you want from your potential surgery on your lower back before you decided to proceed with a major surgical intervention such as a back fusion or artificial disc? Most of my patients feel that they would like a greater than 75% chance of significantly decreasing their pain, and many want more than 90% chance of being pain-free.  Surgery is often presented to patients in this light—offering a high chance of definitive positive results. What are the real numbers?

Dr Carragee at Stanford performed a very well designed study comparing lumbar fusions for discogenic pain to fusions performed for a structural instability.

In the discogenic group, he only would perform a fusion if there was one disc at L4-5 or L5-S1 that was painful on carefully done discography. The patient’s stress profile was also carefully looked at and only those who had few psychosocial risk factors for chronic pain were included.

The structural group was a group that had an isthmic spondylolithesis AND over 4 mm of translational motion. In the spine world, that is considered quite unstable.  That means that in the study, there was a very clean distinction between a structural and non-structural problem.

The discogenic group had a success rate of 27% compared to a 70% success rate in the structural group.

This study was surprising to me for a couple of reasons. I was first of all surprised that the success rate for the unstable spondylolithesis was only 70%. It reinforced my idea that even in the face of a probable source of low back pain, the treatment of the surrounding soft tissues should first be maximized. There is a chance that enough of the pain will be diminished so that surgery can be completely avoided.

In spite of my strong rehab bias, the surgeon part of me thinks that if I can really localize the pain to just one disc with this level of quality discography, the results should be pretty good. It was surprising to me that the success rate in this carefully controlled set of circumstances was so low.

Proponents of fusions will argue that the study only had about 30 patients in each group. It is too small a sampling of patients. My argument is that it is not completely a numbers game. The ability to control the variables as carefully as they did is the most important factor.  In any case, I think most proponents of fusions believe, deep down, that the surgery isn’t as effective as they tell their patients, because research shows many of them wouldn’t even undergo the procedure themselves.

Dr Franklin in 1993 showed that the return-to-work rate was 16% one year and 32% two-years from the lumbar fusion. Surgery actually decreased the patient’s ability to return to work compared to those patients who did not have surgery.

The most quoted paper about this, published in 2001 by Dr. Fritzell, showed that although back pain was decreased significantly six months after surgery, two years after, the pain and function had improved by only 20-30%. Depression had improved by about 20%.

My guess is that many of you are not being made completely aware of these numbers. Many surgeons will feel there results are better than that. Ask them to produce their data. Their results are not better. There is still not a study definitively showing that doing surgery on a normal spine for ill-defined anatomy is a great idea.

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