Evidence backs a ‘generational shift’ in artificial hips... Fourth-generation ceramic lowers dislocation and revision risks [Health Check]

[Financial News] Using fourth-generation ceramic bearing surfaces in hip replacement surgery was associated with lower risks of both postoperative dislocation and long-term revision than using third-generation ceramic. The finding comes from an analysis of about 75,000 hip replacement surgeries performed in South Korea and confirms the benefits of the new material using real-world clinical data.
A team led by Professors Lee Young-kyun and Park Jeong-wi of the Department of Orthopedic Surgery at Seoul National University Bundang Hospital said it analyzed 75,475 hip replacement surgeries performed from 2003 to 2019 using data from the National Health Insurance Service, together with a team led by Professors Jo Ju-hee and Danbee Kang of Samsung Medical Center (SMC). Of these, 31,923 surgeries (42.3%) used third-generation ceramic and 43,552 (57.7%) used fourth-generation ceramic. The findings were published in the international journal Scientific Reports.
The research team adjusted for differences in factors including age, sex, hospital type, reason for surgery and comorbidities before comparing the two generations. The outcomes compared were postoperative dislocation, infection and fracture around the artificial joint, revision of components on the pelvic and femoral sides, and the overall risk of revision surgery.

The first difference to emerge was in dislocation. The risk of dislocation within 30 days of surgery was 1.43 times as high with third-generation ceramic as with fourth-generation ceramic, and the gap persisted through the first year after surgery.

The difference was also evident in long-term outcomes. Compared with fourth-generation ceramic, third-generation ceramic was associated with a pelvic-side component revision risk 1.43 times as high and an overall revision-surgery risk 1.36 times as high. The 10-year survival rate without revision surgery was 96.5% for fourth-generation ceramic, higher than the 94.9% for third-generation ceramic. By contrast, there was no significant difference between the two generations in the risks of infection or fracture around the artificial joint.
Hip replacement surgery replaces a damaged hip joint with an artificial joint, often because of conditions such as osteonecrosis of the femoral head or degenerative hip arthritis. Choosing a durable material is as important as the surgical technique. As the joint moves, wear of the bearing surfaces that meet can produce tiny particles that damage surrounding bone and loosen the artificial joint, potentially leading to revision surgery.
Ceramic has advanced through successive generations as materials and manufacturing technology have improved since its introduction in the 1970s. Third-generation ceramic performed well in long-term follow-up studies, but rare ceramic fractures remained a challenge. Fourth-generation ceramic was developed to address this and further reduce the risk of fracture. However, better material performance does not necessarily mean better surgical outcomes. Because the material must work well with the artificial joint’s design and the surgical method to produce better results in practice, the need for large-scale direct comparisons had been noted.

Unlike earlier studies, which examined the safety of fourth-generation ceramic mainly in patients of specific ages or with particular conditions, this study directly compared the clinical outcomes of third- and fourth-generation ceramic using large-scale, nationwide data. This is what makes the study significant.
Professor Park Jeong-wi said, “As the use of fourth-generation ceramic in hip replacement surgery continues to increase, it is meaningful that the fourth generation showed lower risks of dislocation and revision surgery than the third generation. However, fourth-generation ceramic, introduced in 2003, has a shorter follow-up period for individual patients than third-generation ceramic, which has been used since 1994, so we will continue to monitor long-term clinical outcomes.”
Professor Lee Young-kyun said, “Because an artificial hip is used over the long term, it is important to choose a bearing surface while considering both the risk of revision surgery and long-term outcomes. We will continue our research to establish criteria for choosing bearing surfaces that patients can use safely for longer.”
The hip team in the Department of Orthopedic Surgery at Seoul National University Bundang Hospital has published more than 420 papers in domestic and international journals on hip conditions such as osteonecrosis of the femoral head and degenerative arthritis, hip replacement surgery, and hip fracture surgery. The team has also performed more than 5,000 related operations.
 
[email protected] Jung Myung-jin, Medical Correspondent Reporter