Metal-on-metal bearing in hip prosthesis generates 100-fold less wear debris than metal-on-polyethylene.
Aseptic loosening due to osteolysis in total hip replacement has been related to wear debris released from prosthetic components. Retrospective longterm observations of patients with the metal-on-metal prosthesis has shown long-term survivorship and good mechanical performance. Thus, the new and modified metal-on-metal prosthesis has been introduced on the market. Historical clinical data from the 1st generation metal-on-metal hip prosthesis may not be relevant for the 2nd generation of metal-on-metal hip prosthesis. Therefore, preclinical testing of the prosthesis must be conducted before clinical evaluation. We assessed the tribological performance of the metal-on-metal prosthesis versus the metal-on-polyethylene prosthesis introduced on the market as Metasul and Protasul, respectively. In a 12-channel joint simulator, 6 metal-on-metal bearing and 3 metal on polyethylene prostheses were tested, with the same number of corresponding soak controls. The wear was assessed gravimetrically. The "steady-state" wear-rates from the metal-on-metal prosthesis were almost 100 times less than that from the metal-on-polyethylene prosthesis. The tribological wear performance of the metal-on-metal hip prosthetic system is promising.
Anissian
H L
HL
Department of Orthopaedic Surgery, Karolinska Hospital, Stockholm, Sweden. Anissian@ort.ks.se
Stark
A
A
Gustafson
A
A
Good
V
V
Clarke
I C
IC
D006622:Hip Prosthesis; D008422:Materials Testing; D008670:Metals; D020959:Polyethylene; D011475:Prosthesis Failure; D013314:Stress, Mechanical
D008670:Metals; D020959:Polyethylene