Hazard alert: Hintermann Series H3 Total Ankle Replacement System

Allegra Innovations Pty Ltd is alerting patients, caregivers, and health care providers about a higher-than-expected risk of device failure with the Hintermann Series H3 Total Ankle Replacement (TAR) system, manufactured by DT MedTech LLC.

What is the problem?

The U.S. Food and Drug Administration (FDA) is evaluating interim post-approval study (PAS) results - external site for the Hintermann Series H3 TAR system and other real-world data. Interim results suggest a higher rate of failure associated with the implanted device.

• Removals or revisions of metal components - at least 16.1%, compared with the rate in the premarket clinical studies - 9.9%.
• When all types of revisions are included, such as revisions of the plastic component as well as the metal component, the rate of additional surgery is at least 28.5%.

No defects were identified with the device and the root cause of the problem is to be determined.

What are the risks?

If you have an implanted Hintermann Series H3 TAR system, you may be at higher risk of requiring additional surgery. Symptoms of device failure may include:

• any new or worsening pain or swelling 
• inability to use your ankle or bear weight 
• grinding or other noise
• weakness around your implanted device.

Surgical removal is not recommended if the implant is functioning well and you have no new or worsening pain or symptoms.

What should patients do?

You may or may not feel pain or changes in ambulation.

Contact your surgeon or health care provider if you have a Hintermann Series H3 TAR system implanted, and you experience any of the symptoms mentioned in the ‘What are the risks’ section above in your implanted device.

What should health professionals do?

When making treatment recommendations, consider that there is a higher risk of device failure with the Hintermann Series H3 TAR system compared with the rate in the premarket clinical studies.

Monitor patients with the Hintermann Series H3 TAR system for device problems such as loosening and fractures of the implant components of the device. 

For suspected device problems, such as a fractured plastic (polyethylene) component, consider performing X-rays to further evaluate the device integrity.

• Be aware that changes on X-rays can be subtle. If X-rays are negative and polyethylene fracture is still suspected, a CT scan may be needed to determine whether a plastic component fracture has occurred.
• Be aware that the clinical presentation and the signs or symptoms of fracture in plastic materials such as polyethylene can be subtle even in a CT scan. 

If patients experience worsening symptoms, based on clinical exam and on a case-by-case basis, discuss the benefits and risks of all relevant treatment options with them.

Reporting problems

Consumers and health professionals are encouraged to report problems with medical devices. Your report will contribute to our monitoring of these products. For more information see the TGA Incident Reporting and Investigation Scheme (IRIS).

We cannot give advice about an individual's medical condition. You are strongly encouraged to talk with a health professional if you are concerned about a possible adverse event associated with a medical device.