Wear of
There are many methods for analysing wear volume in failed
Nanometre-sized particles of ultra-high molecular weight
Our aim was to analyse the influence of the size, shape and number of particles on the pathogenesis of osteolysis. We obtained peri-implant tissues from 18 patients having revision surgery for aseptically loosened Freeman total knee replacements (10), Charnley total hip replacements (3) and Imperial College/London Hospital double-cup surface hip replacements (5). The size and shape of the
We have reviewed 70 patients with bilateral simultaneous total hip arthroplasties to determine the rate of failure and to compare
In ten male rats we inserted ceramic ‘drawing-pin’ implants in weight-bearing positions within the right proximal tibia. Two animals were killed 6 weeks after surgery and two more 14 weeks after surgery. The remaining six received intra-articular injections of either high-density
We used a rat model in vivo to study the effects of the concentration of
In this prospective, randomised study, we have compared the wear rate of cemented, acetabular
We have investigated whether the presence of
Although the response of macrophages to
Wear particles commonly used for experiments may carry adherent endotoxin on their surfaces, which may be responsible for the observed effects. In this study, we attached titanium plates to the tibiae of 20 rats. After osseointegration, endotoxin-contaminated or uncontaminated high-density-polyethylene (HDPE) particles were applied. Contaminated specimens showed a dramatic resorption of bone after seven days but new bone filled the site again at 21 days. Uncontaminated specimens showed no resorption. In 18 rats we implanted intramuscularly discs of ultra-high-molecular-weight
We implanted bone harvest chambers (BHCs) bilaterally in ten mature male New Zealand white rabbits.
Sterilisation by gamma irradiation in the presence of air causes free radicals generated in
We report the findings from independent prospective clinical and laboratory-based joint-simulator studies of the performance of ceramic femoral heads of 22.225 mm diameter in cross-linked
We used radiostereometric analysis to compare wear rates between uncemented porous sockets and cemented all-polyethylene sockets in a series of 102 hips randomised for either a Harris-Galante or a Charnley cup. Wear was evaluated in 95 hips at a mean of five years (2 to 7). All hips had a cemented, 22 mm head mono-bloc Charnley stem. The mean annual wear rate was 0.09 mm in the Charnley sockets and 0.10 mm in the Harris-Galante sockets, with no statistically significant differences in wear, migration or rotation. We conclude that, up to five years, the wear characteristics of the modular and porous Harris-Galante socket resemble that of the Charnley socket.
We analysed revised Mathys isoelastic polyacetal femoral stems with stainless-steel heads and
Ultra-high-molecular-weight
We retrieved 159 femoral heads at revision surgery to determine changes in surface configuration. Macroscopic wear of the head was observed in three bipolar hip prostheses as a result of three-body wear. There was a considerable change in surface roughness in the internal articulation of bipolar hip prostheses. Roughness in alumina heads was almost the same as that in new cobalt-chromium heads. The annual linear wear rate of