20.500.12556/DiRROS-18131 Mechanisms of premature fracture in modular neck stems made of CoCrMo/Ti6Al4V and Ti6Al4V/Ti6Al4V alloy In this paper, we present the mechanisms of premature fracture of modular neck stems in two case studies: (I) when the neck and stem are both made of the same Ti6Al4V alloy, and (II) when the neck and stem are made from two different alloys, CoCrMo and Ti6Al4V alloy. Our study integrates two orthopedic patients who have undergone primary uncemented THA for usual indications in two orthopedic centers (Community Health Centre and University Medical Centre). Both centers are part of the national public health care system. Both surgeries were performed by two skilled orthopedic surgeons with more than 10 years of experience in THA. The survivorship of the modular neck of cast CoCrMo alloy was 24 months. The survivorship of the modular neck from Ti6Al4V alloy was 84 months. Multivariate analyses were performed to assess the differences in the fretting, corrosion, and fatigue of the two prematurely failed modular neck stems: stereo light microscopy (SLM), scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), and electron backscatter diffraction (EBSD). Patient demographic information, including sex, age, body mass index, survivorship of implants, and reason for the revision, was collected from medical records. We found that fretting and fatigue occurred on both neck-stem retrievals due to additional galvanic corrosion, but the CoCrMo/Ti6Al4V alloy system suffered more corrosion due to additional galvanic corrosion and fractured earlier than the Ti6Al4V/Ti6Al4V metal alloy system. Both metallic alloy systems used in this application are known to be highly corrosion-resistant, but the bio-tribo-corrosion processes need to be understood in detail and characterized so that appropriate improvements in design and materials can be made. total hip arthroplasty modular neck Ti6Al4V alloy CoCrMo alloy corrosion aluminijevo-grafitne prevleke totalna artroplastika kolka Ti6Al4V zlitina CoCrMo zlitina korozija true false true MDPI Švica Angleški jezik Slovenski jezik © 2023 by the authors Neznano 2024-02-07 12:15:31 2024-02-07 12:15:32 2024-04-15 07:59:19 0000-00-00 00:00:00 2023 0 0 Nasl. z nasl. zaslona; Opis vira z dne 2. 8. 2023; str. 1-12 iss. 7, [article no.]1255 Vol. 13 Jul. 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2023-07-16 617.3 2079-6412 10.3390/coatings13071255 160450819 https://www.mdpi.com/2079-6412/13/7/1255 1 d3de8db8-c5a1-11ee-8001-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=24634 RAZ_Dolinar_Drago_2023.pdf RAZ_Dolinar_Drago_2023.pdf 1 6B58C322620B8F2005730EE746159AB1 cfae6acf5d2e8192179d6dfb760c22f6c566c520fcdecac6ca9dd13435e32a0f d9b6f5e3-c5a3-11ee-8001-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=24635 Inštitut za kovinske materiale in tehnologije 0 0 0