Aseptic loosening due to wear and dislocation of the implant represents the main complication after total hip arthroplasty. To gain more insight into the influence of the implant position on wear, commercial alumina couplings have been tested in a hip joint simulator under three different angles of cup inclination (23°, 45°, 63°) with respect to a horizontal plane. The planned length of the test was ten million cycles. However, the test was stopped at 5.5 million cycles due to the fracture of one of the femoral heads, tested with at angle of 63°. The residual stress state in the worn acetabular cups and in the fractured femoral head were evaluated by the frequency shift and broadening of the R1 and R2 fluorescence bands due to the Cr3+ ions naturally present in alumina ceramics as trace impurities. The gravimetric measurements did not show significant differences among the three different inclinations tested, in agreement with previous simulator studies, but in disagreement with in vivo findings. The fluorescence measurements allowed to affirm that an angle of 63° represents a worsened mechanical condition for the prosthetic component, with a consequently higher probability of fracture and/or damage potentially conducive to massive wear. In the light of the fluorescence results, it did not appear surprising that the femoral head that fractured was the one being tested at 63°.

The influence of the acetabular cup inclination on the wear of alumina-on-alumina couplings tested in a hip joint simulator: SEM and fluorescence study / P. Taddei; S. Affatato; C. Fagnano; A. Toni. - STAMPA. - (2005), pp. 633-633. (Intervento presentato al convegno 19th European Conference on Biomaterials tenutosi a Sorrento (NA) nel 11-16 settembre 2005).

The influence of the acetabular cup inclination on the wear of alumina-on-alumina couplings tested in a hip joint simulator: SEM and fluorescence study.

TADDEI, PAOLA;FAGNANO, CONCEZIO;TONI, ALDO
2005

Abstract

Aseptic loosening due to wear and dislocation of the implant represents the main complication after total hip arthroplasty. To gain more insight into the influence of the implant position on wear, commercial alumina couplings have been tested in a hip joint simulator under three different angles of cup inclination (23°, 45°, 63°) with respect to a horizontal plane. The planned length of the test was ten million cycles. However, the test was stopped at 5.5 million cycles due to the fracture of one of the femoral heads, tested with at angle of 63°. The residual stress state in the worn acetabular cups and in the fractured femoral head were evaluated by the frequency shift and broadening of the R1 and R2 fluorescence bands due to the Cr3+ ions naturally present in alumina ceramics as trace impurities. The gravimetric measurements did not show significant differences among the three different inclinations tested, in agreement with previous simulator studies, but in disagreement with in vivo findings. The fluorescence measurements allowed to affirm that an angle of 63° represents a worsened mechanical condition for the prosthetic component, with a consequently higher probability of fracture and/or damage potentially conducive to massive wear. In the light of the fluorescence results, it did not appear surprising that the femoral head that fractured was the one being tested at 63°.
2005
19th European Conference on Biomaterials
633
633
The influence of the acetabular cup inclination on the wear of alumina-on-alumina couplings tested in a hip joint simulator: SEM and fluorescence study / P. Taddei; S. Affatato; C. Fagnano; A. Toni. - STAMPA. - (2005), pp. 633-633. (Intervento presentato al convegno 19th European Conference on Biomaterials tenutosi a Sorrento (NA) nel 11-16 settembre 2005).
P. Taddei; S. Affatato; C. Fagnano; A. Toni
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/15180
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