Patients with degenerative lumbar spondylolisthesis (DLS) with up to 25% listhesis can have similar improvements in disability and pain as patients without DLS after undergoing minimally invasive decompression without fusion, according to a review of 157 cases.

There was about an 11.5% reoperation rate in patients with and without DLS.

“The message is that perhaps we do not need to fuse patients who have a stable, low-grade spondylolisthesis and are undergoing decompression surgery for lumbar stenosis,” said Langston Holly, MD, director of the UCLA Spine Center and vice chairman of the University of California, Los Angeles’ Department of Neurosurgery, who was not involved in the study. “The belief that fusion is necessary, due to concerns about worsening of the listhesis by the decompression, may not be valid in many patients, particularly if the decompression is performed with minimally invasive techniques. There’s less disruption of the musculature, ligamentous and even bony supporting structures, with MIS [minimally invasive surgery] than with an open approach.”

Significant cost savings can also accrue from MIS compared with traditional open combined laminectomy/decompression and fusion, he added.

Lead investigator Raja Rampersaud, MD, medical director of the Back and Neck Specialty Program at Altum Health, University Health Network, in Toronto, Canada, and his colleagues published a paper in 2010 that showed MIS decompression can be successful for correcting lumbar spinal stenosis even in patients with spondylolisthesis (Spine 2010;25:E981-E987). The impetus for trying MIS decompression alone was the significant potential for improved outcomes and lowered cost. The 2010 paper included 75 patients, 46% of whom had grade 1 spondylolisthesis. There was an overall revision rate of 10%, with three-fourths of the revisions being in patients with degenerative scoliosis and preoperative lateral (rotatory) listhesis.

The team now has reviewed the consecutive cases Dr. Rampersaud performed from January 2007 to June 2011 and that have at least two years of follow-up. Sixty-two of the 157 MIS-decompression patients had DLS and the other 95 did not. The criteria for MIS decompression alone were leg-dominant symptoms (claudicant or radicular); no or tolerable mechanical back pain; up to 25% listhesis; stable listhesis as indicated by more than 5 mm of motion both standing compared with supine, and in flexion-extension radiographs; and anatomy favorable to MIS decompression. Patients with more than 10 degrees of scoliosis or any lateral/rotatory listhesis were excluded.

There were similar reductions in Oswestry Disability Index scores at two-year follow-up in patients with and without DLS, from an average of approximately 40 to 25. Furthermore, the leg pain levels, as measured by a numeric pain scale of 0 to 10, fell from a mean of approximately 6.5 to a mean of approximately 3, and the back pain levels from a mean of 6 to 3.3.

There was a mean follow-up of 3.06 years among the DLS patients and 4.49 years among the non-DLS patients. During that time, seven of the 62 (11.3%) DLS patients underwent reoperation, as did 11 of the 95 (11.6%) non-DLS patients. The times to reoperation ranged from 418 to 1,247 days in the DLS patients and from 466 to 1,457 days in the non-DLS patients.

Reoperations in five of the seven DLS patients and eight of the 11 non-DLS patients were at the same level. Additionally, three of the five (60%) reoperations in the DLS patients were MIS decompression, as were four of 11 (36%) non-DLS patient reoperations. The rest of the reoperations were MIS decompression plus fusion.

“This validates the previous economic evaluation,” concluded Dr. Rampersaud, referring to a study he co-authored, showing decompression without fusion is more cost-effective than instrumented fusion in patients with leg-dominant pain with stable grade 1 spondylolisthesis (Spine J 2012;12:44-54). “MIS decompression now represents up to 50% of my DLS surgery, resulting in significant cost savings.”

The study was presented at the Canadian Spine Society’s 2015 annual meeting.

— Rosemary Frei, MSc

Dr. Holly receives grant support from the National Institutes of Health and is a consultant for Medtronic. Dr. Rampersaud is a consultant for Medtronic.

Source - http://www.painmedicinenews.com