The impact of femoral head surface roughness on wear of gamma-irradiation sterilized (3 MRad in nitrogen crosslinked) and nonsterilized (not crosslinked) UHNWPE acetabular cups has been evaluated. Gravimetric wear testing was performed in a hip joint simulator for 2x106 cycles. CoCrMo heads were used with different surface roughness (Ra=15 nm and Ra=400 nm). The surface roughness after wear test was unchanged for the roughened heads, whereas the initially smooth heads showed a few scratches. The roughened heads increased the wear of the acetabular cups 2-fold. The gamma-irradiated cups tested against rough heads underwent the highest wear. The absorption of water was highest for the gamma-irradiated cups (0,0204% compared to 0,0031% after 85 days). Raman spectroscopy showed small but significant crystallinity changes in the wear zone, where the gamma-irradiated cups with the most extensive abrasion increased in crystallinity, whereas the nonsterilized cups underwent a crystallinity decrease.
Effect of head surface roughness and sterilization on wear of UHMWPE acetabular cups / A. Jedenmalm; S. Affatato; P. Taddei; W. Leardini; U.W. Geddel; C. Fagnano; M. Viceconti. - In: JOURNAL OF BIOMEDICAL MATERIALS RESEARCH. PART A. - ISSN 1549-3296. - STAMPA. - 90A:4(2009), pp. 1032-1042. [10.1002/jbm.a.32161]
Effect of head surface roughness and sterilization on wear of UHMWPE acetabular cups
TADDEI, PAOLA;FAGNANO, CONCEZIO;M. Viceconti
2009
Abstract
The impact of femoral head surface roughness on wear of gamma-irradiation sterilized (3 MRad in nitrogen crosslinked) and nonsterilized (not crosslinked) UHNWPE acetabular cups has been evaluated. Gravimetric wear testing was performed in a hip joint simulator for 2x106 cycles. CoCrMo heads were used with different surface roughness (Ra=15 nm and Ra=400 nm). The surface roughness after wear test was unchanged for the roughened heads, whereas the initially smooth heads showed a few scratches. The roughened heads increased the wear of the acetabular cups 2-fold. The gamma-irradiated cups tested against rough heads underwent the highest wear. The absorption of water was highest for the gamma-irradiated cups (0,0204% compared to 0,0031% after 85 days). Raman spectroscopy showed small but significant crystallinity changes in the wear zone, where the gamma-irradiated cups with the most extensive abrasion increased in crystallinity, whereas the nonsterilized cups underwent a crystallinity decrease.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.