Metal debris release is commonly seen from explanted total ankle replacements.

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Wear Analysis

Background:

• Total ankle replacement (TAR) failure can be linked to wear debris.
• Understanding damage mechanisms in explanted TARs is crucial for improving implant design and longevity.

Purpose of the Study:

• To characterize the damage mechanisms on metal components of contemporary total ankle replacements.
• To investigate the prevalence and types of wear and debris in explanted TARs.

Main Methods:

• Analysis of 27 explanted total ankle replacements (8 designs).
• Utilized microscopy, non-contact profilometry, and scanning electron microscopy with energy-dispersive X-ray spectroscopy.
• Examined both articulating and non-articulating surfaces, as well as polyethylene inserts.

Main Results:

• Pitting and scratching were the most frequent wear features.
• Metallic pitting observed on 52% of tibial and 95% of talar components, more prevalent on cobalt-chromium than titanium alloys.
• Significant surface roughness changes due to pitting; scratching indicated third-body particle presence on 78% of talar components.
• Coating degradation on 80% of metal components; embedded metallic debris found in 19% of polyethylene inserts.

Conclusions:

• Explanted total ankle replacements frequently release metal debris from articulating surfaces and coatings.
• Metal particulate debris release may be more common than previously thought.
• Metal debris should be considered a factor in the etiology of total ankle arthroplasty failure.