FDA approves first spinal tether implant for correcting childhood scoliosis

The FDA approved the first spinal tether medical device to correct the most common form of scoliosis in children and adolescents—a ropelike implant that pulls the vertebrae into shape as the child grows, following the failure of treatments like external braces.

Zimmer Biomet’s new tethering system for idiopathic scoliosis is intended for children whose sideways curvature of the spine has become so severe that surgery such as a bone fusion procedure may be necessary.

Idiopathic scoliosis is the most common spinal deformity in children. Though the cause is unknown, most are diagnosed between the ages 10 and 18, with the FDA estimating that about 6,800 patients in the U.S. each year will not respond to conservative, nonsurgical treatments like bracing. And while spinal fusion implants and surgeries may be successful, they can lead to long-term complications and future deformities.

Zimmer’s tether alternative aims to correct the curvature of the developing spine while allowing a fuller range of motion. It starts with anchors and vertebral body screws placed along the vertebrae through an minimally invasive incision on the side of the chest.

A flexible cord is then connected to the screws, with tension applied to compress one side of the spine. As the child grows taller, the spine is pulled into alignment. It is not intended to be removed unless certain complications develop, such as overcorrections.

“This decision takes an innovative surgical approach, vertebral body tethering, and finally recognizes it as a mainstream option for scoliosis treatment,” said Baron Lonner, chief of minimally invasive scoliosis surgery at The Mount Sinai Health System and a consultant for Zimmer Biomet’s spine division.

Previously, surgeons performing the tethering surgery off-label in the U.S. have had to repurpose an implant designed for adult lumbar procedures, Lonner described. “This FDA approval sets the stage for better patient outcomes for thousands of children who undergo surgery for scoliosis around the country every year,” he said.

Through the humanitarian device exemption process, the FDA reviewed clinical data from 57 patients who received Zimmer’s device and saw that 43 had sufficient improvements in spinal curvature after two years and no longer needed a spinal fusion procedure. The company said this marks the first approval for a humanitarian use device in spinal pediatrics in 15 years.

Zimmer’s spine division is also partnering with the Harms Study Group, an international cohort of surgeons focused on children and adolescents with spinal deformities, to develop a patient data registry to track the device’s long-term performance.

“The FDA continues to collaborate with stakeholders to encourage the development of registries, including the one being developed for this device, as an additional tool to gather and track real world evidence,” FDA Principal Deputy Commissioner Amy Abernethy said in an agency statement.

“This type of post-market data generation can provide ongoing device safety surveillance and additional evidence for effectiveness,” Abernethy said. “More broadly, real world evidence can help support innovative developments while ensuring that patient health and safety remains the top priority.”