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PubMedDate not supplied

Evaluation of carcinogenic risk in friction product workers.

Mortality rates of two cohorts of asbestos friction product (FP) workers were studied in comparison with the population of the adjoining towns over periods of 20 and 40 years respectively. The second cohort was subdivided into 3 subcohorts exposed to chrysotile asbestos (CA), vulcanization and/or polymerization vapours and gases (VPGV) and asbestos bakelite (AB) or asbestos rubber (AR) dusts. In the first cohort no deaths from lung cancer were recorded, even though the total tumour mortality was higher than in the general population. In the second cohort an excess tumour mortality was observed in the first subcohort for stomach cancer only. In the other two subcohorts the expected rates were higher for all the tumour sites. Following intraperitoneal injection of CA, AB and AR dusts, malignant tumours developed in 31.5% of the rats which received CA, and in about 10% of the rats which were injected with AB and AR dusts. Also, the mean longevity of CA-treated animals was significantly lower than in the other two groups. Thus, the carcinogenic risk was real in the group of FP production workers with significant CA exposure only.

Adult↗
PubMed1993

Psoas tenotomy and heterotopic ossification after Charnley low-friction arthroplasty.

One hundred twelve cases of Charnley low-friction arthroplasty (LFA), with elevation of the psoas tendon from the lesser trochanter, were reviewed. Twenty-six (23.3%) had heterotopic ossification in that area. No heterotopic ossification was present in 124 cases without psoas tenotomy. Periosteal elevation at the time of tenotomy is a likely cause of psoas heterotopic ossification.

Adult↗
PubMed1993

Charnley low-friction arthroplasty of the hip. Long-term results.

Charnley low-friction arthroplasty (LFA) has become the method of choice for patients with destroyed arthritic hip joints; the authors' 18-26-year observation suggests that LFA could be considered the gold standard for total hip arthroplasty (THA). The continuity of concept, design, and the surgical technique extends beyond 29 years and offers predictability of outcome. Fatal postoperative pulmonary embolism, initially at 0.7% within one year of surgery, shows significant seasonal variation and as yet unexplained declining incidence. Incidence of dislocation is 0.63%, with a 0.11% chance of revision. The incidence of deep infection is 0.3%-1.5% in primary surgery and varies with the underlying hip pathology. Introduction of the intramedullary bone block has reduced the revision rate for stem loosening to less than 1% at 14 years and completely eliminated stem fracture. There has not been a fracture of a recently manufactured stem (Ortron). Revision for socket loosening has been reduced to 3% by the introduction of the ogee-flanged socket. The outcome of the socket survivorship is determined by the depth of socket penetration, the relationship between the two being exponential. Because the socket demarcation and migration are usually asymptomatic, the timing of revision would be determined by the surgeon's awareness of the problem. Repeated revisions produce conditions almost comparable to a locally malignant condition: dwindling bone stock, increasing implant size, local recurrence of the problem. Accumulation of the experience with the Charnley LFA has been shown to benefit both old and young patients.

Adult↗
PubMedDate not supplied

Socket wear of Charnley low friction arthroplasty: fifteen year follow-up.

Ninety seven hips of primary Charnley low friction arthroplasty in 78 patients were followed up for fifteen to twenty one years. Survival rates calculated by clinical loosening as an end point were 89.8%, and by radiological loosening as an end point were 81.9% for fifteen years. The average rate of socket wear in ninety one of ninety seven hips was 0.11 +/- 0.09 mm per year with an ascending curve. Survival rates at fifteen year follow-up evaluation were 90.4% in the group with a socket wear rate less than 0.20 mm per year and 66.0% in the group with the rate equal to 0.20 mm or more per year. Severe socket wear correlated with radiological loosening of the socket (p<0.001), the presence of a radiolucent line or osteolysis (p<0.0001), and the younger age of the patients less than sixty years old (p<0.05).

Adult↗
PubMedDate not supplied

[A concept of need and construction of a hip joint prosthesis with isolation of the friction point from the tissue].

The paper presents data available in the literature and the author's own data on the causes of bone tissue resolution around endoprostheses and on the occurrence of their aseptic instability. The author's own clinical data on 546 operations and follow-ups up to 16 years are strong evidence and his experimental findings are unique in the number of animals operated on and follow-up periods. The material was examined roentgenologically, morphologically, spectroscopically and the mineral content of bone tissue microstructures were determined. With the methods applied, the author clearly shows the role of tissue metallosis in the occurrence of aseptic instability of prosthesis. The author presents two up-to-day constructions of the total-type endoprostheses with the friction point isolated from tissue. The prostheses are accessible for manufacture at the modern enterprises and require no materials in short supply.

Animals↗
PubMed1997

Charnley low friction arthroplasty in young patients with osteoarthritis. A 12- to 24-year clinical and radiographic followup study of 84 cases.

The long term outcome of 84 Charnley low friction arthroplasties performed between January 1973 and December 1984 on 69 patients (84 hips) with osteoarthritis was assessed. The patients were 55 years old or younger (mean, 46 years) at the time of surgery. The probability of survival was 89.8% (range, 85.9%-93.7%) after 10 years with 69 hips at risk and 73.3% (range, 65.5%-81.1%) after 18 years with 33.5 hips at risk. Of the 84 hips in the study, 24 (28.6%) failed. Of the hips that survived, clinical results were good and excellent with Charnley scores of four or more for pain and function in all hips. Of the hips that survived, 93.3% achieved good or excellent results for movement.

Adult↗
PubMed1997

Survival of the Charnley low-friction arthroplasty. A 12-24-year follow-up of 276 cases.

The long-term results (12-24 years) of Charnley low-friction arthroplasty performed in 113 hips in 93 patients with a mean age of 45 years, were compared to those achieved in 163 hips in 144 patients with a mean age of 66 years treated with the same procedure. Survivorship analysis showed a 73% prosthesis survival after 17 years in the younger age group and an 86% in the older age group.

Adult↗
PubMed1997

Long-term results of Charnley low-friction arthroplasty for coxarthrosis with congenital hip dysplasia. 15 year follow-up study.

We studied more than fifteen-years' follow-up results of cases treated with low-friction arthroplasty (LFA) for coxarthrosis with congenital hip dysplasia. Thirty-four LFAs in 32 patients (2 males and 30 females) were followed up for an average of 18.8 years (range: 15 to 23.3 years). The mean age at surgery was 53 years (range: 36 to 67 years). In three patients, 4 hips needed revision surgery due to loosening of the prostheses. At the final follow up, using Hodgkinson's criteria, type 0 demarcation of the socket appeared in 9 cases, type 1 in 5 cases, type 2 in 4 cases, type 3 in 4 cases, and type 4 in 12 cases. According to Harris' criteria, there was no sign of loosening of the stem in 16 cases, however there was a possibility of loosening in 8 cases, probability in 2 cases, and definite loosening in 8 cases. The survival rate with socket loosening as the end point was 76.5% at the 10 year follow-up, 67.6% at 15-years' follow-up, and 50.9% at 20-years' follow-up. The survival rate with stem loosening as the end point was 82.4% at 10-years' follow-up, 79.4% at 15-years' follow-up, and 63.8% at 20-years' follow-up. The survival rate with prostheses loosening either socket or stem as the end point was 64.7% at 10-years' follow-up, 55.9% at 15-years' follow-up, and 34.6% at 20-years' follow-up. The survival rate with revision surgery as the end point was 100% at 10-years' follow-up, 94% at 15-years' follow-up, and 85.1% at 20-years' follow-up.

Adult↗
PubMedDate not supplied

Dislocation and instability complicating low friction arthroplasty of the hip joint.

Among the complications in a series of 1,400 consecutive Charnley low friction arthroplasty procedures, there were 8 dislocations, and 3 highly unstable hips. Three dislocations followed severe trauma, in 2 of the 3 there was only fibrous union of the greater trochanter. In all but 2 of the hips, more than one previous operation had been performed. More than one technical fault was evident in most dislocations. Six of the 8 dislocations required reoperation. Meticulous attention to the Charnley procedure, including soft tissue elements of the hip joint is necessary to avoid instability and dislocation following total hip arthroplasty.

Adult↗
PubMed2004

Kinetic friction.

Explore the source record for details and available documents.

Friction↗
PubMed2006

Influence of frictional heating on temperature gradients in ultra-high-pressure liquid chromatography on 2.1mm I.D. columns.

The effects of viscous heat dissipation on some important HPLC parameters, such as efficiency (N) and retention factors (k), using 2.1mm columns at pressures up to 1000 bar have been investigated from both a theoretical and experimental point of view. Two distinct experimental set-ups and their respective influences on non-homogenous temperature gradients within the column are described and discussed. In the first instance, a still-air column heater was used. This set-up leads to approximate 'adiabatic' conditions, and a longitudinal temperature gradient is predicted across the length of the column. The magnitude of this gradient is calculated, and its occurrence confirmed with experimental measurements also indicating that no appreciable loss in efficiency occurs. Secondly, when a water bath is used to thermostat the column, a radial temperature gradient is prevalent. The extent of this gradient is estimated, and the loss in efficiency associated with this gradient is predicted and demonstrated experimentally. It is also observed that approximate adiabatic conditions can lead to floating retention factors. The implications of temperature gradients for routine HPLC analysis at ultra-high pressure are discussed.

Chromatography, High Pressure Liquid↗