the data on the effect of ethylene concentration on polymerization rate for several modifications of modern highly active titanium–magnesium catalysts ticl4/mgcl2 are presented. these catalysts differ in titanium content and conditions of support preparation, activities, and the shape of kinetic curves. it is found that the observed order of polymerization rate with respect to ethylene in the r...

Substantially reducing the rate of generation of wear particles at the surfaces of ultra-high-molecular-weight polyethylene (UHMWPE) orthopedic implant bearing components, in vivo, is widely regarded as one of the most formidable challenges in modern arthroplasty. In the light of this, much research attention has been paid to the myriad of endogenous and exogenous factors that have been postula...

A triethylaluminium(TEAl)-modified Phillips ethylene polymerisation Cr/Ti/SiO2 catalyst has been developed with two distinct active regions positioned respectively in the inner core and outer shell of the catalyst particle. DRIFTS, EPR, UV-Vis-NIR DRS, STXM, SEM-EDX and GPC-IR studies revealed that the catalyst produces simultaneously two different polymers, i.e., low molecular weight linear-ch...

Calcium sulfate bone void fillers are increasingly being used for dead space management in infected arthroplasty revision surgery. The presence of these materials as loose beads close to the bearing surfaces of joint replacements gives the potential for them to enter the joint becoming trapped between the articulating surfaces; the resulting damage to cobalt chrome counterfaces and the subseque...

There is considerable interest in characterization of wear debris from polyethylene (UHMWPE) bearing components used in total joint replacement. To isolate UHMWPE wear debris, tissue samples must be excised from regions adjacent to revised UHMWPE implant components, followed by exposure to one of many available tissue digestion methods. Numerous studies demonstrate successful digestion, but the...

A 74-year-old man underwent total knee arthroplasty in 1996 and subsequent revision total knee arthroplasty for aseptic loosening in 2005. During revision, an all-polyethylene, 7-mm, second-generation, highly cross-linked ultra-high-molecular-weight polyethylene patellar component (Durasul; Zimmer, Warsaw, Indiana) was used. The patient recovered well, but he presented with severe acute pain af...