Superiority in any given surgery for any given device is one of the rarest, most elusive FDA designations available to medical device companies. In the world of treating single-level lumbar spinal stenosis and grade-I degenerative spondylolisthesis, only one manufacturer has ever achieved a superiority claim—that company is Premia Spine, and the implant is the Total Posterior Spine System (TOPS).
In the June 19, 2024, edition of The Journal of Bone and Joint Surgery, researchers published updated data from the FDA study which not only reaffirms TOPS superiority over fusion but added more depth and understanding as to why that is the case.
This latest study was an FDA Investigational Device Exemption trial. The researchers assigned 321 patients with single-level lumbar spinal stenosis and grade-I degenerative spondylolisthesis to undergo either decompression plus lumbar facet arthroplasty or decompression plus fusion.
“The novelty of the TOPS System is that, like cervical disc replacement, it preserves motion and yields outstanding clinical outcomes,” said Steven DeLuca, D.O., Orthopedic Institute of Pennsylvania in Harrisburg, a co-author on two TOPS studies. “For patients with lumbar spinal stenosis, degenerative spondylolisthesis, and a relatively normal lumbar disc, we can avoid a fusion. We remove the posterior elements, i.e., the facet joints, lamina, and spinous process, and instead of screws, rods and fusion, we implant this mobile device.”
The TOPS study was a multicenter research effort, and the outcomes of that study have been published on several occasions. The latest data offers evidence that for patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis, a lumbar facet arthroplasty (TOPS) provided patients with a higher rate of clinical success than fusion at 24 months.
Why is TOPS superior? “Fusion locks up the motion and opens patients up to pseudoarthrosis and stress at the levels above and below the treated segment. With TOPS, my patients have no risk of non-fusion and significantly less stress at the adjacent levels,” explained Dr. DeLuca.
The researchers found that 73.5% of patients in the TOPS arthroplasty group achieved composite clinical success at 24 months postoperatively compared to only 25.5% in the fusion group. The arthroplasty group outperformed the fusion group in patient-reported outcome measures, including the Oswestry Disability Index, Visual Analog Scale for back pain, and Zurich Claudication Questionnaire scores, all at time points including the pivotal 24-month postoperative follow-up visit.
Patients in the fusion group exhibited a higher rate of symptomatic adjacent segment degeneration and had a higher revision rate. The researchers found that surgical variables and overall complications were similar between the groups.
Dr. DeLuca told OTW, “TOPS doesn’t require that patients wear a brace, and unlike with fusion patients, they can use anti-inflammatories for pain. The procedures have the same amount of blood loss, the same duration and complications—but the TOPS patients do so much better and improve so much faster than the fusion patients.”
While designed for use at a single level between L3 through L5, some surgeons have elected to combine the TOPS device with an adjacent fusion procedure for multilevel pathologies.
Speaking of the above images, Dr. DeLuca told OTW: “Here you can see where I used the TOPS device above a fusion level. This patient had an L5-S1 microdiscectomy in 2015. In 2017, she had MIS TLIF at L5-S1 using Premia Spine’s ProMIS fixation system. She presented in 2023 with a grade 1 degenerative spondylolisthesis at L4-5, the level above her fusion, with a well-maintained disc. In February 2024, she underwent TOPS at L4-5 which was connected to the L5-S1 fusion using Premia’s VersaLink connecting rods. This was the first case of a TOPS device connected to a fusion performed in the U.S. following the TOPS IDE Study.”
