The U.S. Food and Drug Administration (FDA) has granted Premarket Approval (PMA) to Empirical Spine Inc.’s LimiFlex Dynamic Sagittal Tether, a motion-preserving system for patients receiving surgical decompression for grade 1 lumbar degenerative spondylolisthesis with spinal stenosis.

Developed from foundational research at Stanford University, LimiFlex represents more than 20 years of refinement and clinical validation, according to the company.

“Degenerative spondylolisthesis with stenosis causes patients severe pain and disability,” noted Empirical Spine Co-Founder Dr. Todd Alamin, a professor of Orthopaedic Spine Surgery at Stanford University School of Medicine. “We can now relieve their symptoms with a minimally invasive procedure without the added physiologic and mechanical burden of fusion.”

Degenerative spondylolisthesis affects a large, growing patient population and results in more than 250,000 surgical procedures annually in the United States, accounting for approximately half of all lumbar fusion procedures. For decades, surgeons have faced a structural treatment dilemma when treating degenerative spondylolisthesis. While decompression relieves neural compression, it does not address the underlying instability; similarly, fusion stabilizes the spine but permanently eliminates motion and increases physiologic stress on adjacent segments. Consequently, many patients with this condition undergo fusion primarily to prevent instability and recurrence rather than to treat deformity.

The LimiFlex Dynamic Sagittal Tether stabilizes the spine following decompression without rigid fixation. By providing dynamic restraint to pathologic motion while preserving controlled movement, the procedure offers an alternative surgical strategy. Motion-preserving stabilization for these patients creates a new treatment category positioned between decompression alone and fusion. The device stabilizes pathologic motion while preserving native anatomy, maintaining a surgical magnitude similar to decompression rather than reconstruction.

“Lumbar fusion for degenerative spondylolisthesis has been a bedrock of spine surgery for decades. I have been involved in many IDE trials, and LimiFlex promises to be one of the most thoughtful advances in spine care,” said Dr. Hyun Bae of The Spine Institute and Cedars Sinai Medical Center. “Patients always prefer motion-preserving and outpatient options, and I am excited to be able to offer this option to the community.”

In an FDA pivotal trial, LimiFlex demonstrated non-inferior two-year clinical outcomes compared with instrumented fusion. Procedures were substantially shorter than fusion surgery and supported outpatient treatment in appropriately selected patients.

“We have great outcomes with LimiFlex at our Center,” stated Dr. Rick Sasso of Indiana Spine Group, a principal IDE study investigator. “Nearly all of our patients were treated in our ambulatory surgery center, and all would have otherwise had a fusion.”

Empirical Spine will soon begin an initial U.S. limited launch of the LimiFlex Dynamic Sagittal Tether at certain medical centers that participated in the IDE trial. A broader product introduction will take place later this year.

Based in San Carlos, Calif., Empirical Spine develops surgical solutions that align treatment magnitude with disease magnitude. The company’s technologies address structural spine conditions using motion-preserving approaches intended to reduce the physiologic burden of traditional surgical constructs.