Decompression for ASD with and without fusion achieves same reduction in pain

SAN FRANCISCO — Decompression with fusion was found to be associated with fewer subsequent surgeries in patients with adjacent segment disease compared with decompression treatment alone.

“We also found that extension of fusion is associated with a significantly lower reoperation rate than decompression alone. We believe this may be due to the inherently destabilizing nature of the decompression procedure being performed at an already unstable adjacent segment,” Haydn A. Hoffman, a medical student at University of California-Los Angeles, said in a presentation at the American Association of Neurological Surgeons Annual Meeting, here.

“Decompression and extension with fusion is associated with fewer reoperations than decompression alone in the treatment of adjacent segment disease. The two treatments are equally effective in reducing pain and disability.”

Two procedures, two results

Hoffman and colleagues analyzed the results in 169 patients who underwent decompression surgery at a level adjacent to a previous fusion performed in the past 10 years; 54 patients underwent decompression alone and 115 patients underwent decompression with extension of fusion.

Hoffman said the study was designed to determine the efficacy of both treatments in regard to adjacent segment disease (ASD). The average follow-up was 61 months and the most commonly affected segments were L3-4 in the lumbar spine and C6-7 in the cervical spine, which he said is consistent with the relative distribution of the levels at which fusions are performed.

“Both groups improved significantly after the surgery for ASD, but there was no difference in the amount of improvement or the mean VAS score in each group at the last follow-up. The same pattern was observed in the ODI [Oswestry Disability Index]. Both groups improved significantly after surgery, however there was no difference in the amount of improvement or the mean ODI in each group at the last the last follow-up. We did a lumbar and cervical subgroup analysis and the same pattern was observed,” Hoffman said. “For those who had preoperative motor weakness, a greater percentage of patients in the fusion group improved as compared to the decompression group.”

Need for reoperation differed

The biggest difference in the two groups was the need for reoperation, according to Hoffman. He noted the reoperation rate was significantly higher in the decompression group when compared to the fusion group. For the patients with decompression only who required additional surgery, Hoffman said they most commonly needed a fusion at a previously decompressed level. In the fusion group, the most common reoperation procedure performed was needed for the development of new ASD adjacent to the extended fusion.

“As the volume of spinal fusions increases annually, adjacent segment pathology will continue to be a major concern. Both decompression with fusion and decompression alone are associated with significant long-term improvement with pain and disability,” Hoffman said. “Other studies have shown a similar effect in regards to fusion as a treatment for ASD, but none have looked at decompression alone and none have compared the two treatments.” – by Robert Linnehan

Reference:

Hoffman HA. Paper #623. Presented at: American Association of Neurological Surgeons Annual Meeting; April 5-9, 2014; San Francisco.

For more information:

Haydn A. Hoffman can be reached at the David Geffen School of Medicine at UCLA, 10833 Le Conte Ave., Los Angeles, CA 90095; email: hhoffman@mednet.ucla.edu.
Disclosure: Hoffman has no relevant financial disclosures.