3D-Printed Implant Is Approved to Replace Ankle Joint Bone | Medical Devices and Equipment | JAMA | JAMA Network
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News From the Food and Drug Administration
April 6, 2021

3D-Printed Implant Is Approved to Replace Ankle Joint Bone

JAMA. 2021;325(13):1246. doi:10.1001/jama.2021.4029

The FDA has approved a 3-dimensional (3D)–printed implant designed to treat people with avascular necrosis (AVN) of the ankle joint.

According to the agency, the Patient Specific Talus Spacer is a first-of-its-kind device created to replace the talus—the bone in the ankle joint that connects the foot with the leg and enables the ankle to move up and down and from side to side. The implant, made from cobalt chromium alloy, is modeled from computed tomographic imaging to fit each patient’s anatomy.

Although rare, AVN of the ankle joint is a painful, debilitating condition that “can lead to inhibited motion of the ankle joint, and in some cases, removal of part of the leg,” Raquel Peat, PhD, MPH, director of the FDA’s Office of Orthopedic Devices, said in a statement.

AVN occurs when the bone tissue’s blood supply is cut off, causing the tissue to die. A sudden injury such as a broken bone or dislocated joint or tissue damage sustained over time can result in AVN. In late-stage AVN of the ankle joint, the talus may partially or fully collapse. Current treatments include fusing together the foot and ankle joints or below-the-knee amputation.

FDA officials said data supporting the implant’s safety and probable benefit included results from 32 talus replacement surgeries involving 31 patients, including 1 who had the surgery on both ankles. Using standard subjective scoring systems, patients’ average self-reported pain levels at the 3-year follow-up had decreased from moderate or severe to mild and range of motion in the ankle joint had improved. The most common adverse events were pain and scar tissue at the surgery site.

The implant received approval through the FDA’s humanitarian device exemption process, a pathway for devices intended to benefit patients with a disease or condition that doesn’t affect more than 8000 people annually in the US.