The choice of the right bearing couple in hip arthroplasty is crucial for the longevity and functionality of a hip prosthesis. While ceramic-on-ceramic bearings (CoC) were considered advanced for a long time, CoXPE (ceramic on highly cross-linked polyethylene) is increasingly establishing itself as the gold standard. The reason: CoXPE combines low wear rates with high stability and flexibility, while CoC struggles with some specific disadvantages that limit its acceptance.

Ceramic on ultra-high cross-linked polyethylene: Minimal abrasion and highest reliability

CoXPE sliding pairs offer an outstanding combination of wear resistance and protection of the surrounding tissues. The highly cross-linked polyethylene plastic reduces abrasion to a minimum, which significantly reduces the risk of osteolysis (bone degradation through particles). This is a decisive advantage over older sliding pairs such as metal on metal or metal on soft polyethylene, which have become notorious for their high particle formation.

The problems of ceramic on ceramic

Although CoC stands out for its extremely hard and durable surface, it has disadvantages that limit its use:

Ceramic fracture

Despite modern manufacturing methods, the risk of fracture under heavy stress or malalignment remains. This aspect is particularly problematic for younger and physically active patients.

Squeaking phenomenon

The occurrence of unpleasant squeaking noises (squeaking) in CoC bearing pairs can significantly impair quality of life. Although this is rare, it is perceived as disturbing by patients.

Cost and complexity

CoC prostheses are more expensive and require a more precise implantation technique to achieve optimal results.

Why CoXPE is displacing CoC

The outstanding properties of ceramic on highly cross-linked polyethylene – particularly high resilience and flexibility – make this bearing couple the preferred choice in modern hip arthroplasty. While CoC remains an option in specific cases, it is increasingly being displaced by CoXPE, as the risk of undesirable complications is minimized here.

Vitamin E makes highly cross-linked polyethylene even more resistant

The addition of vitamin E to highly cross-linked polyethylene (XPE) in hip arthroplasty is an important measure to improve the long-term durability and stability of the material. Vitamin E is added due to its antioxidant properties to protect the polyethylene from oxidation.

Reasons for adding vitamin E to polyethylene:

Prevention of Oxidation

Increased abrasion resistance: By preventing oxidation, the polyethylene remains more robust and less susceptible to material fatigue. This means that the bearing pair made of ceramic and XPE, which is often used in modern hip prostheses, generates less abrasion and thus offers a longer service life​

Improvement of long-term performance: Studies have shown that XPE with Vitamin E has a significantly higher long-term stability, making it a preferred choice for patients who require a durable and resistant hip prosthesis. Vitamin E not only protects against oxidation but also helps to make the material more resistant to wear, especially in young and active patients.

Vitamin E is therefore an important component of modern highly cross-linked polyethylene materials in hip arthroplasty, as it improves the chemical stability of the material and thus contributes to better long-term results.

Conclusion: The future belongs to the ceramic-on-highly cross-linked polyethylene bearing pair

Modern articulating pairs like CoXPE are exemplary of advancements in endoprosthetics. By combining longevity, safety, and comfort, they set new standards, while other articulating pairs like CoC are increasingly pushed into the background. The addition of Vitamin E to polyethylene significantly improves its properties.