Vitamin E-infused highly cross-linked polyethylene (E1) has recently been introduced in total knee arthroplasty (TKA). An in vitro wear simulator study showed that E1 reduced polyethylene wear. However there is no published information regarding in vivo wear. Previous reports suggest that newly introduced materials which reduce in vitro polyethylene wear do not necessarily reduce in vivo polyethylene wear. To assist in the evaluation of the newly introduced material before widespread use, we established an in vivo polyethylene wear particle analysis for TKA. The aim of this study was to compare in vivo polyethylene wear particle generation between E1 and conventional polyethylene (ArCom) in TKA. A total of 34 knees undergoing TKA (17 each with ArCom or E1) were investigated. Except for the polyethylene insert material, the prostheses used for both groups were identical. Synovial fluid was obtained at a mean of 3.4 years (SD 1.3) postoperatively. The in vivo polyethylene wear particles were isolated from the synovial fluid using a previously validated method and examined by scanning electron microscopy.Aims
Methods
The use of vitamin E-infused highly crosslinked polyethylene (HXLPE) in total knee prostheses is controversial. In this paper we have compared the clinical and radiological results between conventional polyethylene and vitamin E-infused HXLPE inserts in total knee arthroplasty (TKA). The study included 200 knees (175 patients) that underwent TKA using the same total knee prostheses. In all, 100 knees (77 patients) had a vitamin E-infused HXLPE insert (study group) and 100 knees (98 patients) had a conventional polyethylene insert (control group). There were no significant differences in age, sex, diagnosis, preoperative knee range of movement (ROM), and preoperative Knee Society Score (KSS) between the two groups. Clinical and radiological results were evaluated at two years postoperatively.Aims
Patients and Methods
1. A three-year survey of avascular necrosis of bone has been carried out in a community of some 400 professional divers for shell-fish who had used no modern technique of decompression. 2. Of 301 divers radiographed, 152 (50ยท5 per cent) had bone lesions. 3. The incidence of bone necrosis increased in proportion to the length of diving experience, being highest in men with over ten years, experience. 4. The incidence was also higher in men who usually dived deeper than thirty metres. 5. There was a high incidence in men with a history of the bends but no significant relationship between the sites of the bends and those of the lesions. 6. Bone lesions were more frequently multiple than solitary. 7. The upper end of the humerus was significantly more affected than the upper end of the femur or tibia, but not significantly more than the lower end of the femur. 8. At the upper ends of the humerus and femur the lesions were more frequently unilateral than bilateral.
