Choosing the right sliding pairing in hip arthroplasty is crucial for the longevity and functionality of a hip prosthesis. While ceramic-on-ceramic pairings (CoC) were long considered advanced, today CoXPE (ceramic on ultra-highly cross-linked polyethylene) is increasingly establishing itself as the gold standard. The reason: CoXPE combines low abrasion values ​​with high stability and flexibility, while CoC has to struggle with some specific disadvantages that limit its acceptance.

Ceramic on ultra-highly cross-linked polyethylene: minimal abrasion and maximum reliability

CoXPE bearing pairs offer an outstanding combination of wear resistance and protection of the surrounding tissue. The highly cross-linked polyethylene plastic reduces abrasion to a minimum, which significantly reduces the risk of osteolysis (bone breakdown caused by particles). This is a decisive advantage over older sliding pairings such as metal on metal or metal on soft polyethylene, which have fallen into disrepute due to their high particle formation.

The problems of ceramic on ceramic

Although CoC shines with an extremely hard and durable surface, it has disadvantages that limit its use:

Ceramic fragments

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

Squeaking phenomenon

The occurrence of unpleasant squeaking noises in CoC bearing pairs can significantly impair the quality of life. Although this is rare, patients find it annoying.

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 - in particular the high resilience and flexibility - make this sliding pairing the preferred choice in modern hip arthroplasty. While CoC remains an option in specific cases, it is increasingly being replaced by CoXPE as it minimizes the risk of unwanted complications.

Vitamin E makes the highly cross-linked polyethylene even more resistant

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

Reasons for Adding Vitamin E to Polyethylene:

Preventing Oxidation : Polyethylene can oxidize over time, which can weaken the material structure and lead to increased abrasion. This abrasion is a major cause of hip prosthesis failure because it promotes the formation of wear particles that can attack the bone and cause aseptic loosening. Vitamin E helps to slow down this oxidation process and thereby extend the lifespan of the implant

Increasing abrasion resistance : By preventing oxidation, the polyethylene remains more robust and less susceptible to material fatigue. This means that the ceramic and XPE sliding pairing often used in modern hip prostheses produces less abrasion and therefore offers longer service life

Improving Long-Term Performance : Studies have shown that XPE with Vitamin E has significantly greater long-term stability, making it a preferred choice for patients requiring a durable and resilient hip prosthesis​. Vitamin E not only protects against oxidation, but also helps the material remain 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 prosthetics, as it improves the chemical stability of the material and thus contributes to better long-term results.

Conclusion: The future belongs to ceramic sliding contacts on highly cross-linked polyethylene

Modern bearing pairs such as CoXPE are examples of progress in endoprosthetics. By combining durability, safety and comfort, they set new standards, while other sliding pairs such as CoC are increasingly taking a back seat. Adding vitamin E to polyethylene significantly improves its properties.