The Food and Drug Administration (FDA) has approved a unique device for pediatric patients with idiopathic scoliosis who have not responded to conservative treatment options.

The Tether Vertebral Body Tethering System (Zimmer Biomet) is indicated for skeletally immature patients who require surgical treatment to obtain and maintain correction of progressive idiopathic scoliosis, with a major Cobb angle of 30 to 65 degrees whose osseous structure is dimensionally adequate to accommodate screw fixation, as determined by radiographic imaging. 

The system is comprised of anchors and vertebral body screws that are placed using an endoscopic minimally invasive approach on the side of the spinal curvature through a few small openings between the ribs. Tension is then applied to a flexible cord that is connected to the screws during surgery which compresses one side of the spine and partially corrects the curve; the cord continues to straighten the spine while the patient continues to grow. 

A close up of the vertebral body screws and Tether installation (image courtesy of Zimmer Biomet)

The approval was based on data from 57 patients who received the device. Results showed that after 2 years, 43 patients had sufficient improvement of the curvature of their spines and did not need spinal fusion. With regard to safety, pain, respiratory problems, nerve injuries, and bleeding were general complications, while more serious adverse events included overcorrection of the curvature, tether breakage, and pneumothorax. 

“For children and adolescent patients with idiopathic scoliosis that does not respond favorably to bracing, treatment options have been limited to fusion surgeries,” said Capt. Raquel Peat, PhD, director of the Office of Orthopedic Devices in the FDA’s Center for Devices and Radiological Health. “Today’s approval provides access to a new treatment option that could improve quality of life for patients with idiopathic scoliosis.”

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