[Oxidation of ultra high molecular weight polyethylene as a result of sterilization].
OBJECTIVE
To improve (UHMWPE) Ultra High Molecular Weight Polyethylene quality for use in arthroplastic components, sterilization related oxidative changes were investigated in raw and manufactured material.


METHODS
To evaluate sterilization related effects, 15 x 15 mm samples of UHMWPE were taken from a defined area of raw manufactured UHMWPE plates. The raw manufactured plates were produced using the compression molding method. For sterilization, gamma irradiation with and without air, ETO-sterilization and autoclave sterilization were performed.


METHODS
Infrared spectroscopy was used to detect oxidation damage of the implant in superficial and deep layers of the material.


RESULTS
Gamma sterilization on air showed 40% more oxidation compared with air-free sterilization. The superficial oxidation on air was 0.33 and showed the lowest value without air on argon with 0.155. Using ethylenoxide sterilization, no great changes in superficial oxidation (0.229) were observed; the smallest change (0.07) was observed at a depth of 2.79 mm. Autoclave sterilization caused the greatest superficial oxidation with 0.622 but low oxidation at 0.094 mm depth. In all samples, further oxidation and ongoing crystallinity was seen with increasing storage time.


CONCLUSIONS
Ethylenoxide sterilization should be recommended for UHMWPE since oxidative changes is lowest. Gamma sterilization can only be recommended without air and at low doses.
Fuchs
S
S
Département de Chirurgie Orthopédique, Westfälische Wilhelms University Münster, Albert-Schweitzer-Str. 33, 48129 Münster, Allemagne.
Linnenbecker
S
S
Langenbrinck
A
A
Chylarecki
C
C
D007595:Joint Prosthesis; D008970:Molecular Weight; D010084:Oxidation-Reduction; D011095:Polyethylenes; D013242:Sterilization
D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene