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 modular neck stems in two case studies: (I) when and stem are both made same Ti6Al4V alloy, (II) from different alloys, CoCrMo alloy. Our study integrates orthopedic patients who have undergone primary uncemented THA for usual indications centers (Community Health Centre University Medical Centre). Both part national public health care system. surgeries were performed by skilled surgeons with more than 10 years experience THA. The survivorship cast alloy was 24 months. 84 Multivariate analyses to assess differences fretting, corrosion, fatigue prematurely failed stems: stereo light microscopy (SLM), scanning electron (SEM), X-ray energy-dispersive spectroscopy (EDS), backscatter diffraction (EBSD). Patient demographic information, including sex, age, body mass index, implants, reason revision, collected medical records. We found that fretting occurred on neck-stem retrievals due additional galvanic but CoCrMo/Ti6Al4V system suffered corrosion fractured earlier Ti6Al4V/Ti6Al4V metal metallic systems used application known be highly corrosion-resistant, bio-tribo-corrosion processes need understood detail characterized so appropriate improvements design materials can made.