The trial compares outcomes of patients who receive either LimiFlex or transforaminal lumbar interbody fusion (TLIF) after decompression surgery. The trial reached its target of 135 LimiFlex patients enrolled into the investigational arm of the trial in December 2019 and the control arm has achieved its target of 160 patients. To date, a total of 168 study subjects have reached 12 months follow up. The results of the LimiFlex trial will form the basis for a PMA application to the U.S. Food and Drug Administration (FDA), anticipated by the end of 2021.
Watch a video detailing the surgical technique for LimiFlex here.
"As we reach this major milestone, our thanks go out to the fantastic partners who have joined us in the LimiFlex trial," said Richard Treadwell, CEO of Empirical Spine. "We recognize and appreciate the hard work and dedication of the surgeon investigators and research coordinators, as well as the enthusiasm of the patients in participating in this investigation of a non-fusion alternative for degenerative spondylolisthesis. We would also like to thank our review team at FDA for the collaborative process that has allowed us to complete study enrollment with minimal impacts to the PMA submission timing from COVID-19 disruptions."
Co-primary investigator Rick Sasso, M.D., of the Indiana Spine Group, commented, "My experience with LimiFlex has been very positive. The device may offer a minimally invasive way to stabilize the spine yet preserve motion. Many patients are extremely interested in less invasive stabilization options that avoid the complications of fusion, so they are attracted to LimiFlex."
William Welch, M.D., of the University of Pennsylvania and co-principal investigator of the LimiFlex IDE study, added "I am encouraged by the clinical outcomes and results we have seen so far in the study. LimiFlex is an exciting new possibility for patients currently undergoing fusion for degenerative spondylolisthesis and would offer much faster recovery for patients, significant savings for payors and more surgical offerings for spine surgeons."
Traditional means of stabilizing the spine after decompression surgery involve lengthy, invasive procedures that use bone graft material, combined with instrumentation such as pedicle screws and rods, to fuse two or more vertebrae together. The resulting constructs reduce spinal flexibility and magnify the forces experienced by adjacent levels, often leading to accelerated degeneration of the adjacent spinal segments. While the acute clinical outcomes may be excellent, this accelerated degeneration can lead to longer term issues, sometimes requiring additional surgery.
Occasionally, patients with this instability diagnosis forego stabilization in favor of standalone decompression surgery, which carries a high risk of recurrence and reoperation due to progressive instability.
The LimiFlex was developed as a way of bridging this therapy gap by offering a minimally invasive way to stabilize the spine yet preserve motion. The device aims to restore the spine's natural biomechanics, along parameters such as stiffness, lordosis, and facet engagement.
The LimiFlex IDE trial is a prospective, multi-center, controlled clinical trial studying the safety and efficacy of the LimiFlex Paraspinous Tension Band compared to TLIF in patients suffering from degenerative spondylolisthesis and lumbar spinal stenosis. The study endpoint is the rate of overall clinical success at 24 months. The goal is to show that patients can achieve fusion-equivalent results without the fusion.
The device received the CE mark in 2009 and has been implanted with excellent results in over 2,000 European patients.
The LimiFlex Paraspinous Tension Band is a new, investigational device designed as an alternative to spinal fusion for patients receiving surgical decompression for grade 1 lumbar degenerative spondylolisthesis with spinal stenosis. LimiFlex does not involve any screws or bone grafts, which eliminate the natural motion between spine segments. Instead, LimiFlex is designed to stabilize the spine without fusing it, thereby preserving motion. The device works by supporting and enhancing the spine's natural biomechanics with stabilizing yet flexible elements. The LimiFlex device is placed following a standard decompression surgery, typically in less than 20 minutes.