Results of Spine Surgery Differ Across the U.S.
Patients who have spine surgery (laminectomy and/or fusion) have different results depending on where the surgery was done. Those are the findings of a recent review of data collected from 13 spine centers in 11 different cities across the United States. Naturally, the reasons for these differences in outcomes are of interest but will have to wait for another study.

For now, this study shows that patients with stenosis (narrowing of the spinal canal) or degenerative spondylolisthesis (age-related fracture and slippage of the vertebra) who have the same surgery may not get the same results. And that is a significant finding. Let's take a closer look at the details of this study.

The background information about these patients may be helpful. All had severe low back, buttock, and/or leg pain and were unable to walk very far. Conservative (nonoperative) care was unable to change their symptoms. The purpose of the surgery was to remove the bone putting pressure on the nerve tissue (laminectomy) and to stabilize the spine (fusion).

Most of the time this type of surgery is successful with good postoperative outcomes. But there are cases where there is no change in painful, limiting symptoms, and the patient ends up having another surgery.

There are many different reasons why some patients don't fare well after these procedures. Sometimes the patient was misdiagnosed or the surgical technique failed. In other cases, the spine was unstable and this problem wasn't addressed during the surgery. Many studies have shown that over time, adjacent segment disease (breakdown of the spinal segment next to the fusion site) is a problem.

Most of the studies reporting results of surgery for lumbar stenosis and degenerative spondylolisthesis are done at one single center. Often, there is only one surgeon performing all of the procedures being studied. This review is different because it reports on both short- and long-term outcomes across multiple centers with many surgeons.

In each of the nearly 800 similar cases, surgery performed varied slightly and the number of levels operated on was anywhere from one to three or more. Events associated with the procedures (e.g., length of time in the operating room, amount of blood lost, number of dural tears) varied from center to center. And there were significantly different reports on how long patients stayed in the hospital and the number of wound infections.

Long-term results (measured at one, two, three, and four years after surgery) were also significantly different across the spinal centers involved. For example, the number of patients who required another surgery ranged from five to 21 per cent. The level of pain and physical function reported by patients was also different.

The data was collected and analyzed in such a way as to make sure that these differences were directly linked with the effect of the center rather than being due to patient factors such as age, size, smoking history, socioeconomic status, or level of preoperative exercise. Factors that may be important (but as yet unproven) include: surgeon preference for certain techniques, patient genetics, neurobiological responses to the underlying condition, and differences in patient response to pain.

In summary, this study cannot answer the "why" of differences in response to surgery for these two conditions. But it does bring to our attention the fact that there are broad ranges of patient outcomes across centers for the same conditions using similar surgical approaches. This new information should be a springboard for the next study: to answer the "why" question. What characteristics of patient, surgeon, or center make for better patient results following surgery for spinal stenosis and degenerative spondylolisthesis?
Atman Desai, MD, et al. Variation in Outcomes Across Centers After Surgery for Lumbar Stenosis and Degenerative Spondylolisthesis in the Spine Patient Outcomes Research Trial. In Spine. April 15, 2013. Vol. 38. No. 8. Pp. 678-691.