HINTERMANN ANKLE REPLACEMENT RECEIVES RARE FDA APPROVAL (Orthopedics This Week)

After almost three years of FDA review, DT MedTech, LLC has won FDA premarket approval (PMA) for its Hintermann Series H3 total ankle replacement system.

PMAs are a big deal. No 510(k)-clearance tinkering at the edges to get a device to market in the cheapest, quickest way possible. The company submitted its application in August 2016. The FDA granted approval on June 4, 2019.

The System

According to a June 5, 2019 announcement by the company, the ankle replacement system is a three-piece, mobile-bearing implant “…consisting of a tibial implant component, a talar implant component, and an ultra-high molecular weight polyethylene mobile bearing insert (PE inlay). The tibial and talar implants,” according to the company, “can also be custom-manufactured in an alternative material for patients who are sensitive to Cobalt-Chrome (CoCr) alloys.”

“The tibial implant is comprised of a flat-loading plate and an anterior shield. The anatomically shaped flat surface allows for optimal contact with the subchondral bone of the entire resected tibia, including the cortical rim of the metaphysis to maximize the load transfer area without creating stress shielding. The tibial implant is available in seven sizes 0-6.”

“The talar implant is conically shaped to mimic the anatomic shape of the talus. Rims are provided on each side of this implant to provide mediolateral stability to the PE inlay bearing and to serve as a guide for anteroposterior translation. Polished overhangs on the medial and lateral side serve as anatomical articular surfaces. The talar implant is available in seven sizes 0-6.”

Indication

The FDA Approval Order Statement states the device is indicated “for use as a non-cemented implant to replace a painful arthritic ankle joint due to primary osteoarthritis, post-traumatic osteoarthritis or arthritis secondary to inflammatory disease (e.g. rheumatoid arthritis, hemochromatosis, etc.). The device system is for prescription use.”

The device, “replaces the damaged articulating surfaces of the shin (tibia) and ankle (talus) bones…after the damaged parts of the ankle joint are removed.”

In the clinical data provided, patients receiving the implant, “had fewer serious device-related adverse events (other than a revision or removal) 2 years after surgery than another similar total ankle replacement system.”

In fact, the Summary of Safety and Effectiveness Data cited by the company stated, “the clinical data used to support the PMA showed that 95.9% of H3 patients were moderately satisfied to very satisfied with the procedure at five years post-implantation, and survivorship of 88% at 7 years.”

Professor Hintermann

The implant was developed by Prof. Dr. Beat Hintermann, M.D., a foot and ankle surgeon based in Liestal, Switzerland. The company says “The H3 has been implanted in more than 20,000 patients outside of the U.S. since its first release in May 2000.” The company received CE Marking in 2016.

Professor Hintermann’s website says the H3 is the “best documented 3 component prosthesis on [the] market. Beside over 130 peer-reviewed articles in Orthopaedic surgery, in particular relating to ankle arthroscopy, ankle instability, ankle osteoarthritis, total ankle replacement and foot and ankle trauma, he was the author of 3 medical textbooks related to reconstructive surgery of the ankle and hindfoot complex.”

DT Medtech acquired the Hintermann lower extremities assets, including the H3 total ankle replacement and revision system and the Kalix II implant designed to treat flat-foot deformities, in March 2016.

The company has offices in Baltimore, Maryland; Dublin, Ireland; Saint-Louis, France; and Liestal, Switzerland