Spinal Fusion Has Not Lowered Risk of Repeat Back Surgery

Despite increased rates of spinal fusion surgery, the percentage of patients requiring further low back surgery after spinal fusion has actually increased since the early 1990s, according to a new study.

Researchers of the Center for Cost and Outcomes Research at the University of Washington (Seattle, USA) analyzed rates of spinal fusion and repeated low back surgery during two periods: 1990-93 and 1997-2000. The analysis included about 2,500 patients undergoing some type of surgery on the lumbar spine during each period. During the 1990s, the percentage of patients undergoing spinal fusion more than doubled, from about 9% during 1990-93 to 19% during 1997-2000.

However, the researchers found, as the rate of spinal fusion surgery increased, so did the proportion of patients who later required another lower-back operation. Of patients undergoing spinal fusion during 1990-93, about 12% had another lumbar spine operation within four years. For patients undergoing spinal fusion during 1997-2000, this figure increased to 14%. After adjustment for other factors, the risk of repeated low-back surgery after spinal fusion increased by about 16% from the beginning to the end of the decade. Among patients undergoing spinal fusion in 1997-2000, the risk of repeated lower back surgery within the first year was about 40% higher than for patients initially operated on in the early 1990s. After the first year, repeat operation rates were similar between the two periods. The study was published in the September 1, 2007, issue of Spine.

"Repeat lumbar spine operations are generally undesirable, implying persistent symptoms, progression of degenerative changes, or treatment complications,” concluded lead author Brook I. Martin, M.P.H., and colleagues. "A higher proportion of fusion procedures and the introduction of new spinal implants between 1993 and 1997 did not reduce reoperation rates.”

The researchers also highlighted the need for efforts to better identify patients most likely to benefit from spinal fusion surgery, as well as to demonstrate the safety and effectiveness of new surgical devices and techniques.


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