Savarino Lucia, Padovani Giovanni, Ferretti Massimo, Greco Michelina, Cenni Elisabetta, Perrone Giorgio, Greco Francesco, Baldini Nicola, Giunti Armando
Laboratory for Pathophysiology of Orthopaedic Implants, Istituti Ortopedici Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy.
J Orthop Res. 2008 Dec;26(12):1569-76. doi: 10.1002/jor.20701.
Alternative bearing surfaces for total hip arthroplasty, such as metal-on-metal and ceramic-on-ceramic, offer the potential to reduce mechanical wear and osteolysis. In the short and medium term, the second generation of metal-on-metal bearings demonstrated high systemic metal ion levels, whereas ceramic-on-ceramic bearings showed the lowest ones. We aimed to verify whether the long-term ion release in metal-on-metal subjects was still relevant at a median 10-year follow-up, and whether a fretting process at the modular junctions occurred in ceramic-on-ceramic patients and induced an ion dissemination. Serum levels were measured in 32 patients with alumina-on-alumina implants (group A), in 16 subjects with metal-on-metal implants (group B), and in 47 healthy subjects (group C). Group B results were compared with medium-term findings. Cobalt and chromium levels were significantly higher in metal-on-metal implants than in ceramic-on-ceramic ones and controls. Nevertheless, ion levels showed a tendency to decrease in comparison with medium-term content. In ceramic-on-ceramic implants, ion values were not significantly different from controls. Both in groups A and B, aluminum and titanium release were not significantly different from controls. In conclusion, negligible serum metal ion content was revealed in ceramic-on-ceramic patients. On the contrary, due to the higher ion release, metal-on-metal coupling must be prudently considered, especially in young patients, in order to obtain definitive conclusions.
全髋关节置换术的替代承重表面，如金属对金属和陶瓷对陶瓷，具有减少机械磨损和骨溶解的潜力。在短期和中期，第二代金属对金属承重表面显示出较高的全身金属离子水平，而陶瓷对陶瓷承重表面的金属离子水平最低。我们旨在验证在中位10年随访时，金属对金属置换患者的长期离子释放是否仍然显著，以及陶瓷对陶瓷置换患者的模块化连接处是否发生微动过程并导致离子扩散。对32例使用氧化铝对氧化铝植入物的患者（A组）、16例使用金属对金属植入物的患者（B组）和47例健康受试者（C组）进行了血清水平检测。将B组结果与中期研究结果进行比较。金属对金属植入物中的钴和铬水平显著高于陶瓷对陶瓷植入物和对照组。然而，与中期含量相比，离子水平呈下降趋势。在陶瓷对陶瓷植入物中，离子值与对照组无显著差异。在A组和B组中，铝和钛的释放与对照组均无显著差异。总之，陶瓷对陶瓷置换患者的血清金属离子含量可忽略不计。相反，由于金属对金属置换的离子释放较高，尤其是对于年轻患者，必须谨慎考虑金属对金属的组合方式，以便得出明确结论。
