Hintermann Ankle Replacement Problems Draw New FDA Warning Over ‘Higher-Than-Expected’ Failure Rates

Warning follows post-approval data showing 16.1% of Hintermann H3 ankle replacement patients required revision surgery or implant removal, far above failure rates seen in premarket testing.

Federal health officials are strengthening warnings about problems with the Hintermann Series H3 Total Ankle Replacement (TAR) system, advising surgeons and patients to consider other treatment options when possible.

The U.S. Food and Drug Administration (FDA) issued the updated safety communication on June 3, warning that long-term data continues to show elevated rates of device failure among recipients of the Hintermann Series H3 TAR system. Risks include the possibility that the implant’s polyethylene component may fracture, potentially requiring additional surgery.

Hintermann Ankle Replacement System Concerns

The Hintermann H3 Total Ankle Replacement system received FDA approval in 2019 as a three-component implant consisting of metal tibial and talar components separated by a mobile polyethylene insert. The device is intended to relieve pain and preserve ankle motion in patients suffering from degenerative conditions such as osteoarthritis, rheumatoid arthritis and post-traumatic arthritis.

Federal regulators first raised concerns about the system in February 2024, when post-approval study data revealed that 16.1% of Hintermann H3 ankle replacement recipients underwent revision procedures or removal of implant components. This was substantially higher than the 9.9% failure rate reported during the device’s premarket clinical testing.

In October 2025, an FDA safety update indicated that earlier projections significantly underestimated the long-term failure risk because they did not fully account for surgeries involving replacement of the implant’s polyethylene insert. After incorporating those procedures, regulators reported that nearly one-third of patients may require additional surgery within 10 years of implantation.

Hintermann Ankle Implant Warning Expanded

Following a review of additional postmarket data, scientific literature, adverse event reports and registry information, the FDA expanded its warning and now recommends that patients and physicians carefully consider alternative treatment options before selecting the Hintermann H3 system.

The agency is recommending that patients considering ankle replacement surgery discuss all available treatment options, including ankle fusion and alternative replacement devices, and specifically ask why the Hintermann implant would be the preferred choice over other options.

For patients who already have a Hintermann ankle implant, the FDA is not recommending preventive removal if the device is functioning properly and there are no new symptoms. However, regulators advise patients to seek medical evaluation if they experience worsening pain, swelling, weakness, inability to bear weight or unusual grinding noises in the ankle. Physicians may use X-rays or CT scans to evaluate whether implant components have loosened or fractured.

The expanded warning also highlights growing concerns that Hintermann H3 recipients may face a higher-than-expected risk of revision surgery, including procedures to replace or remove implant components. The FDA has identified polyethylene fractures, implant loosening, infection, instability, persistent pain and bone loss around the implant as factors that may lead to additional surgery.

According to the FDA, registry data from Australian health authorities showed polyethylene fractures occurred at substantially higher rates among Hintermann H3 recipients than among patients who received other total ankle replacement systems, raising concerns that the device may be more prone to certain failure mechanisms.

The Hintermann H3 is one of only two mobile-bearing total ankle replacement devices approved for use in the United States, alongside the Scandinavian Total Ankle Replacement (STAR) system, which received FDA approval in 2009. Federal regulators previously issued a separate 2021 safety communication for the STAR device, warning that fractures involving its polyethylene bearing component could increase the risk of ankle replacement failure and revision surgery.

The FDA has said it will continue reviewing required post-approval studies and other real-world data to better understand the long-term performance of the Hintermann Series H3 system and determine whether additional regulatory actions are necessary.

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