TOPS System
From Wikipedia, the free encyclopedia
The TOPS System (Total Posterior Spine System) is a spinal implant designed to stabilize the lower spine and maintain range of motion following lumbar decompression surgery for spinal stenosis and related conditions. Unlike spinal fusion, which eliminates motion at the treated level, TOPS aims to preserve mobility while providing stability. The device is manufactured by Premia Spine and has received approval for clinical use in the United States by the Food and Drug Administration (FDA) and in the European Union under the CE (Conformité Européenne) marking.[1]
Design and mechanism
The device consists of two titanium plates connected by a mechanical articulating core. The plates are fixed to the vertebrae using pedicle screws, while the core allows controlled motion in flexion, extension, lateral bending, and axial rotation. This design provides stability against shear forces while permitting physiological movement of the operated segment.[2]
Surgical procedure
TOPS is implanted following a lumbar decompression, in which bone and ligament tissue compressing the spinal nerves are removed. After decompression, the facet joints are excised and replaced with the TOPS implant. The goal is to preserve mobility at the treated level while preventing instability that would otherwise be addressed with spinal fusion.
Clinical indications
TOPS is generally indicated for patients with lumbar spinal stenosis, with or without grade I spondylolisthesis. Higher-grade instability is usually treated with spinal fusion rather than motion-preserving devices.[3][4]
Regulatory history
The device was evaluated under an investigational device exemption in the United States, where it was compared against transforaminal lumbar interbody fusion. It was later granted FDA Breakthrough Device designation in 2021,[5][6] followed by full FDA approval in 2023 after demonstrating superiority over fusion in composite clinical success.[7] The TOPS System also holds CE marking, signifying that it meets health, safety, and environmental requirements for sale in the European Economic Area.
Clinical evidence
Randomized controlled trials have compared TOPS to lumbar fusion in patients with lumbar spinal stenosis and grade I degenerative spondylolisthesis. In a large multicenter trial, TOPS demonstrated significantly higher rates of clinical success compared with fusion at two years.[8] An earlier multicenter study reported similar findings, with improved patient-reported outcomes relative to fusion.[9] These improvements included greater reductions in disability as measured by the Oswestry Disability Index (ODI), a standard scale used to assess limitations in daily activities due to back pain.[10] Long-term follow-up has shown that TOPS preserves near-normal motion and may reduce the risk of adjacent segment degeneration.[11]
Health economics
Economic analyses suggest that TOPS may be cost-effective compared with fusion. These findings are based on improvements in quality of life, faster recovery, and reduced need for reoperation over time.[12]
Limitations and safety
Clinical trials comparing lumbar facet arthroplasty with the TOPS system to lumbar fusion have reported overall complication and reoperation rates that are broadly similar between procedures.[13][14]
Reported adverse events include infection, dural tear, pedicle screw loosening or implant-related complications, and the need for revision surgery.[14]
In randomized studies with two-year follow-up, symptomatic adjacent segment degeneration has been reported more frequently after fusion than after facet arthroplasty.[14]
Appropriate patient selection remains important, as the device is not indicated for individuals with high-grade spondylolisthesis, severe osteoporosis, or significant spinal deformity.[13]