title: Serum ion levels after ceramic-on-ceramic and metal-on-metal total hip arthroplasty: 8-year minimum follow-up.
abstract: 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.
authors.affiliation: Laboratory for Pathophysiology of Orthopaedic Implants, Istituti Ortopedici Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy. lucia.savarino@ior.it
authors.forename: Lucia
authors.initials: L
authors.lastname: Savarino
authors.forename: Giovanni
authors.initials: G
authors.lastname: Padovani
authors.forename: Massimo
authors.initials: M
authors.lastname: Ferretti
authors.forename: Michelina
authors.initials: M
authors.lastname: Greco
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Cenni
authors.forename: Giorgio
authors.initials: G
authors.lastname: Perrone
authors.forename: Francesco
authors.initials: F
authors.lastname: Greco
authors.forename: Nicola
authors.initials: N
authors.lastname: Baldini
authors.forename: Armando
authors.initials: A
authors.lastname: Giunti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D016022:Case-Control Studies; D002516:Ceramics; D002857:Chromium / Q000097:blood*; D003035:Cobalt / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D012016:Reference Values; D055815:Young Adult
chemical_list: D008670:Metals; D002857:Chromium; D003035:Cobalt