Complications of patellofemoral arthroplasty often occur soon after implantation and, as well as other factors, can be due to the design of the implant or its surgical positioning. A number of studies have previously considered the wear of ultra-high-molecular-weight polyethylene patellae following suboptimal implantation; however, studies have primarily been carried out under a limited number ...

The physical properties of a polyethylene resin are mainly though not exclusively dependent on basic molecular properties such as short chain branching, average molecular weight and molecular weight distribution. These basic properties in turn are controlled by the size, structure and uniformity of the polyethylene molecules. Ethylene is a gaseous hydrocarbon composed of two carbon atoms and fo...

Polyethylene glycol dinitrates (PEGN) with molecular weights between 400 and 20 000 g·mol-1 were prepared from polyethylene glycols by esterification with nitric acid/sulfuric acid in dichloromethane. The products were characterized by gel permeation chromatography. The yield of PEGN increases with increasing reaction temperature (0-40 °C) however large liberation of nitrogen oxides was observe...

BACKGROUND Radiostereometric analysis provides highly precise measurements of component micromotion relative to the bone that is otherwise undetectable by routine radiographs. This study compared, at a minimum of five years following surgery, the micromotion of tantalum and titanium acetabular cups and femoral head penetration in highly cross-linked polyethylene liners and conventional (ultra-h...