A comparative surface analysis of explanted hip joint prostheses made of different biomedical alloys /Analisis comparativo de superficies de protesis de caderas explantadas de diferentes aleaciones biomedicas

• Published in: Revista Facultad de Ingeniería 2021-07 (100), p.35
• Main Authors: Bermudez-Castaneda, Angela, Arce, Johanna Esguerra, Esguerra-Arce, Adriana, Vargas-Pabon, Sofia Valentina, O, Blanco-Estupinan, David Leonardo, Castano, Juan Guillermo, Mischler, Stefano
• Format: Article
• Language: Spanish
• Subjects: Chromium alloys; Cobalt; Comparative analysis; Corrosion and anti-corrosives; Implants, Artificial; Prosthesis
• ISSN: 0120-6230
• DOI: 10.17533/udea.redin.20210320

The introduction of modular design in total hip arthroplasty has enabled the use of different materials in one single configuration and the adjustment of the prosthesis to the patient's body, and facilitated medical revisions. However, modularity leads to the presence of new interfaces created between pieces in contact, raising the issue of degradation. Tribocorrosion phenomena have been identified as the main degradation mechanism due to the mechanical, chemical, and electrochemical conditions acting on the materials. In addition, conditions inside the human body are unclear, regarding electrochemical settings and the interaction between the electrochemical and mechanical action. This work is focused on the degradation of monopolar hip joint implants made from biomedical alloys such as stainless steel, Ti, and CoCr alloys. Three cases are presented and analyzed in terms of the degradation level along the trunnion length. Surface analysis done on a titanium trunnion showed a significant ploughing on the distal part, compared to what was found for stainless steel and cobalt-chromium alloys, which can produce a stuck in this area. Meanwhile, in the proximal part, wear debris is found, which suggests more movement in the internal part. Although few debris particles were identified in CoCr trunnion, a large amount of material inside the contact was observed. This could be related to the ploughing generated in the distal thread pattern, which allowed the material to come inside and outside the contact. KEYWORDS: Retrieval explants; tribocorrosion; modular hip joint implants; wear; corrosion EL uso de implantes modulares de cadera ha permitido el uso de diferentes materiales en un solo dispositivo, un mejor ajuste a La anatomia del paciente y, ha facilitado los procedimientos de revision. Sin embargo, dicha modularidad crea nuevas interfaces que pueden sufrir degradacion por mecanismos triboquimicos como fretting--corrosion, por las condiciones mecanicas, quimicas y electroquimicas propias del cuerpo. Actualmente, dichas condiciones no son completamente claras, ni la interaccion ellas. Este trabajo se centra en el analisis de la degradacion de implantes mono-polares de cadera elaborados en aleaciones biomedicas: acero inoxidable (SS), aleaciones de Ti y CoCr, en los que se analiza el nivel de degradacion a lo largo de la longitud del cono femoral. El cono femoral de titanio mostro una deformacion mas significativa de la zona distal que causa un bloqueo entre las