The U.S. Food and Drug Administration (FDA) has announced the approval of a new 3D printed implant, the Patient Specific Talus Spacer from Additive Orthopaedics. The device is described by the FDA as “the first in the world and first-of-its-kind implant to replace the talus.”
The talus is the bone in the ankle that joins the leg and the foot. In particular, this world first could be used to treat avascular necrosis (AVN) of the ankle joint, in which bone tissue is destroyed by a lack of blood supply to the area. AVN is typically the result of an acute injury, such as a broken bone, or prolonged tissue damage. In joints, the cartilage that prevents bones from grinding against one another can degrade over time, resulting in arthritis and pain. In the case of the ankle, the talus may collapse and require the fusing of joints, which can reduce pain but makes movement of the joint impossible, or even amputation of the leg below the knee.
Now that there is a 3D printable implant to treat this problem, it may be used to replace other surgical interventions and spare the joint of people suffering from late-stage AVN. As the name suggests, the Patient Specific Talus Spacer is tailored to each patient based off of their computed tomography data. The damaged talus can then be replaced with a 3D printed, cobalt chromium replacement that perfectly fits the patient’s anatomy.
“Avascular necrosis of the ankle, while a rare condition, is a serious and potentially debilitating one that causes pain and can lead to inhibited motion of the ankle joint, and in some cases, removal of part of the leg,” said Capt. Raquel Peat, Ph.D., M.P.H., USPHS, director of the FDA’s Center for Devices and Radiological Health’s Office of Orthopedic Devices. “Today’s action provides patients with a treatment option that could potentially reduce pain, retain range of motion of their joint and improve quality of life.”
The Patient Specific Talus Spacer device has been used 31 patients and 32 talus replacement surgeries, including an individual who had both ankle bones replaced. Three years after operation, patients said that pain been reduced from “moderate to severe” before surgery to “mild” after, with improved range of motion as well. Only three individuals required further surgery, mostly to address pain and scarring at the surgery site.
Greg Kowalczyk, President of Additive Orthopaedics, stated, “Avascular necrosis of the talus is extremely painful and debilitating for these patients. Surgical treatment options are below-the-knee amputation or joint fusion, which results in loss of motion of the ankle and can have poor outcomes. The Patient Specific Talus Spacer is another example of how 3D printed devices can improve the standard of care. This is a tremendous regulatory win which took significant effort from our team and I want to thank everyone, including the U.S. Food and Drug Administration, who assisted in making this technology commercially available in the domestic market for patients suffering from AVN.”
The data from these procedures was reviewed by the FDA under the humanitarian device exemption (HDE) process for Humanitarian Use Device (HUD), meant to aid patients affected by a condition that impacts fewer than 8,000 people in the U.S. annually.
Now that 3D printed hip implants are manufactured with repeatability and proper quality control, the next frontier for medical 3D printing to tackle seems to be the ankle. The first total talus replacement surgery using 3D printing occurred in 2018. 3D Systems is now pioneering the use of 3D printed, patient-specific surgical guides for ankles. Additive Orthopaedics is clearly aware on top of this trend, though it’s worth noting that the company has long been focused on nearly every area of the foot. It sounds as though the startup, which is an Asimov Ventures portfolio company, has tackled an impairment that has been particularly difficult to treat until now.