BACKGROUND AND PURPOSE In the reconstruction of unicondylar femoral bone defects with morselized bone grafts in revision total knee arthroplasty, a stem extension appears to be critical to obtain adequate mechanical stability. Whether stability is still assured by this reconstruction technique in bicondylar defects has not been assessed. The disadvantage of relatively stiff stem extensions is t...

The ability of an interlocking screw fixation technique to minimize bone loss related to stress shielding in the tibia was investigated and compared to the abilities of cement and press-fit fixation. Full bony ingrowth has been associated with greater stress shielding than partial ingrowth; therefore, the effect of intimate bonding of the stem to bone on subsequent bone loss was also studied. A...

Plastic increases in stem elongation in dense vegetation are generally believed to be induced by canopy shading, but because plants protect each other from wind, shielding (reduced mechanical stress) could also play a role. To address this issue, tobacco Nicotiana tabacum plants were subjected to two levels of mechanical stress, 0 (control) or 40 (flexed) daily flexures, and grown solitarily, i...

In this thesis we evaluated two different hip arthroplasty concepts trough in vitro studies and numerical analyses. The cortical strains in the femoral neck area were increased by 10 to 15 % after insertion of a resurfacing femoral component compared to values of the intact femur, shown in an in vitro study on human cadaver femurs. There is an increased risk of femoral neck fracture after hip r...

Hip resurfacing is a popular treatment for osteoarthritis in young, active patients. Previous studies have shown that occasional failures--femoral neck fracture and implant loosening, possibly associated with bone adaptation--are affected by prosthesis sizing and positioning, in addition to patient and surgical factors. With the aim of improving tolerance to surgical variation, finite element m...

progressive loss of bone mineral density around the femora! component of total hip replacement continues to pose a threat to long term prosthetic survival. a linear study was undertaken to measure bone mineral density on a monthly basis following total hip arthroplasty in 11 male patients. the opposite femur was used as the control measurement. bone mineral density was unchanged at two months f...

Progress of the shielding calculation of the Super-FRS is reported here. At least as important as the shielding of the target area is the determination of the shielding in the region of the first dipoles as the part of the primary beam that will not interact in the target will be stopped here. The Monte-Carlo-method with FLUKA [1] used for the shielding assessment here has already been describe...

Using solid state multiple pulse techniques the magnetic shielding tensors a of the F nuclei in a single crystal of KZnF 3 have been measured. The F~-site symmetry in KZnF3 , D 4 h , allows axial anisotropy of a and determines fully the principal shielding directions. Using CaF 2 as the reference compound, the average shielding is + 85 ppm and the shielding anisotropy is + 18.4 ppm. These resul...

This article presents some new experimental data for study the shielding effect of electromagnetic wave. The frequencies of electromagnetic wave are mainly focused on emission of daily electrical equipments, which are normally called “low frequency electromagnetic waves”. In this work, a water pump with maximum magnetic field intensity of ca. 2300 mG was applied as emission source of the electr...