Differences in ion release after ceramic-on-ceramic and metal-on-metal total hip replacement. Medium-term follow-up.
Modern metal-on-metal bearings produce less wear debris and osteolysis, but have the potential adverse effect of release of ions. Improved ceramic-on-ceramic bearings have the lowest wear of all, but the corrosion process has not been analysed. Our aim was to measure the serum ion release (ng/ml) in 23 patients having stable hip prostheses with a ceramic-on-ceramic coupling (group A) and to compare it with the release in 42 patients with a metal-on-metal bearing (group B) in the medium term. Reference values were obtained from a population of 47 healthy subjects (group C). The concentrations of chromium, cobalt, aluminium and titanium were measured. There was a significant increase of cobalt, chromium and aluminium levels (p < 0.05) in group B compared with groups A and C. Group A did not differ significantly from the control group. Despite the apparent advantage of a metal-on-metal coupling, especially in younger patients with a long life expectancy, a major concern arises regarding the extent and duration of ion exposure. For this reason, the low corrosion level in a ceramic-on-ceramic coupling could be advantageous.
The Rizzoli Orthopaedic Institute, Bologna, Italy. lucia.savarino@ior.it
L
L
Savarino
M
M
Greco
E
E
Cenni
L
L
Cavasinni
R
R
Rotini
N
N
Baldini
A
A
Giunti
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000535:Aluminum / Q000097:blood; 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 / Q000097:blood*; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery; D011474:Prosthesis Design; D014025:Titanium / Q000097:blood
D008670:Metals; D002857:Chromium; D003035:Cobalt; D000535:Aluminum; D014025:Titanium