Reliability prediction methods for early design stages suffer from the lack of empirical failure data. However, expert knowledge and data from similar in-service components are information sources ready available. In this work, an expert elicitation procedure for failure rate prediction is presented. In contrast to direct elicitation procedures such as FMEA, relations to in-service components a...

Severe metallosis following medial unicompartmental knee arthroplasty (UKA) is relatively rare. It is usually due to long-standing wear of the polyethylene component, resulting in frictional wear between the femoral and tibial metallic components. Biomechanical and cadaveric studies have shown the effects of anterior cruciate ligament (ACL) transection following medial UKA. We describe a case o...

There is a direct relationship between the efficiency of mechanized excavation in hard rocks and that of disc cutters. Disc cutter wear is an important effective factor involved in the functionality of tunnel boring machines. Replacement of disc cutters is a time-consuming and costly activity that can significantly reduce the TBM utilization and advance rate, and has a major effect on the total...

background and objective: failure to thrive (ftt) is a sign that describes a particular problem rather than a diagnosis and explain growth failure or more advanced failure to gain weight appropriately. the aim of this study was to determine the prevalence and type of chromosomal abnormalities in patients presented with ftt. materials and method: one hundred ftt cases with clinical impression o...

In this study the effect of Al–5Ti–1B grain refiner on the structural characteristics and wear properties of Al–12Zn–3Mg–2.5Cu alloy was investigated. The optimum amount for Ti containing grain refiners was selected as 2 wt.%. T6 heat treatment, (i.e. heating at 460 °C for 1 h before water quenching to room temperature and then aging at 120 °C for 24 h) was applied for all specimens before wear...

Osteolysis is due to particulate wear debris and is responsible for the long-term failure of total hip replacements. It has stimulated the development of alternative joint surfaces such as metal-on-metal or ceramic-on-ceramic implants. Since 1988 the second-generation metal-on-metal implant Metasul has been used in over 60 000 hips. Analysis of 118 retrieved specimens of the head or cup showed ...

Wear of high-density polyethylene on bone and cartilage has resulted in a large volume of plastic particles being shed into the two knees and two hips studied. The giant-cell foreign-body reaction of the synovium may not be sufficient to cope with the amount of debris presented and the destruction of the endosteal bone in one hip, caused by the wear particles and movement of the prosthesis, has...

In 1960s, toxic heart failure due to cobalt poisoning was firstly reported from Canadian industrial worker. Following development of bearing materials in hip arthroplasties, using cobalt-chrome alloy in bearing surface, there were rarely reported of systemic affect toxic cobaltism include toxic heart failure due to articulation wear in Western countries. It could be happened more easily by thir...

PURPOSE To identify the modes of failure after total knee arthroplasty (TKA) in patients >55 years of age and to compare with those >55 years of age in patients who underwent revision TKA. MATERIALS AND METHODS We retrospectively reviewed 256 revision TKAs among patients who underwent TKA for knee osteoarthritis between January 1992 and December 2012. The causes of TKA failure were analyzed a...

Two Durasul highly crosslinked polyethylene liners were exchanged during revision surgery four and five years after implantation, respectively. The retrieved liners were evaluated macroscopically and surface analysis was performed using optical and electron microscopy. A sample of each liner was used to determine the oxidation of the material by Fourier transform infrared spectroscopy. Samples ...