On 14th May the Swiss company Mathys Orthopaedics filed an opposition to the recent granting of an European patent for the medical use of Zirconia Toughened Alumina (ZTA) ceramics comprising:
• 70 to 90% Vol. of aluminum oxide with chromium doping (Al2O3:Cr)
• 12 to 22% Vol. zirconium oxide with Y stabilization (ZrO2:Y) and
• 1 to 5% Vol. strontium aluminate having the formula SrAl12-xCrxO19 with variable Cr doping
According to Mathys the material claimed was already known in the medical field and was in fact marketed in the orthopaedics sector (femoral heads and cups) by CeramTec under the trademark Biolox Delta. Mathys’ arguments are mainly based on four documents disclosed before the priority date of CeramTec’s:
• “Severe Simulation Test for run-in wear of all-alumina compared to alumina composite THR”, I.C.Ciarke et al. in Bioceramies and Alternative Bearings in Joint Arthroplasty: 1Oth BIOLOX Symposium. Washington D.C., June 10-11, 2005. Proceedings (Ceramics in Orthopaedics)
• “Alumina Matrix Composites in Arthroplasty”, C. Picconi et al., in Bioceramics, Volume 17: Proceedings of the 17th International Symposium on Ceramies in Medicine; the Annual Meeting of the International Society for Ceramies in Medicine, New Orleans, Louisiana, USA, 8-12 December 2004
• “Biolox Delta- Eine neue Keramik für die Orthopädie”, CeramTec GmbH, Stand 10/2004
• “Wear Study in the Alumina-Zirconia System”, C. Kaddick et al., in Bioceramies in Hip Joint Replacement, 2000.
Mathys requests the European Patent Office (EPO) to fully revoke the patent due to the lack of novelty of the claimed invention.
Source: European Patent Office