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At least 883 records · Page 49Linked to original sources
PubMed1986

Conventional versus resurfacing total hip arthroplasty. A long-term prospective study of concomitant bilateral implantation of prostheses.

Fifty patients requiring bilateral total hip arthroplasty underwent a concomitant conventional hip arthroplasty on one side and an articular resurfacing procedure on the other, done by the senior one of us (M. A. R.). The average age of the patients was sixty-two years (range, twenty-one to eighty-seven years), and forty-seven of them were followed with serial radiographs and clinical evaluation for one year or more. The length of follow-up was five years for thirty-four patients with both prostheses intact. The average pain score for all hips at three years postoperatively was 5.5 points. Although the majority of patients at each follow-up interval did not prefer one procedure to the other, the conventional arthroplasty was significantly superior for those who had a preference, and radiographic evaluation revealed a statistically significant increased incidence of acetabular lucency at the bone-cement interface of the resurfacing arthroplasty at one, two, three, five, and seven years postoperatively (p less than 0.002). Two of the conventional prostheses were revised during this time-period (one because of infection and one, a broken stem) whereas thirteen (26 per cent) of the resurfacing prostheses were revised (eight hips had femoral loosening, five with concomitant acetabular loosening; three had acetabular loosening; and one had a femoral neck fracture) at an average of fifty-two months postoperatively (p less than 0.001).

Acetabulum↗
PubMed1985

Indium-111 chloride imaging in the detection of infected prostheses.

Thirty-three patients with painful joint prostheses and a suspicion of infection were imaged with [111In]chloride. A final diagnosis was established by culture in 19. Of these, 12 were categorized as true positives and three as true negatives. There were two false-positive studies, occurring in patients with knee prostheses. In both, the culture was obtained by aspiration. Two false negatives were in patients with hip prostheses, one of whom had been on long-term antibiotic suppressive therapy. The sensitivity was 86%, specificity 60%, and accuracy 79%. Seventeen of the proven cases had bone imaging prior to [111In]chloride imaging. All 17 static images were positive and were not helpful in differentiating loosening from infection. Using increased uptake on the blood-pool image as a criteria for infection, the sensitivity was 89%, but the specificity was 0. Adding flow studies made little difference in interpreting the blood-pool images. This study shows that [111In]chloride accurate in evaluating infection in prosthesis than bone imaging.

Adult↗
PubMed1985

[Trochanteric fractures in the elderly: Ender nails, prostheses or direct osteosyntheses. Apropos of a continuous series of 265 cases].

The results of 265 trochanteric fractures in the elderly treated between 1980 and 1983 have been analysed. Among them, 136 were treated by Ender's nailing, 110 by prostheses and 19 by internal fixation. In an earlier study, Ender's nailing had been used in 75 p. 100 of cases. The conclusions were that the increasing use of a prosthesis has brought about an improvement in the results-80 p. 100 satisfactory in the present series compared with 54 p. 100 in the preceding one. The mortality rate was comparable after Ender's nailing and prostheses. Ender's nailing is indicated in stable fractures and, in unstable fractures, internal fixation is indicated in very active persons, Ender's nailing in non-ambulatory patients and prostheses in elderly patients with sufficient walking ability.

Aged↗
PubMedDate not supplied

[Long-term results of 2 continuous series of total hip prostheses of the McKee-Farrar metallo-metal type and the Charnley metallo-plastic type].

Two continuous series of McKee-Farrar type metal-metal and Charnley type metal-plastic prostheses have been examined. Results are analysed and complications examined ten years after the operation. The McKee-Farrar prostheses showed inferior results in all parameters and a markedly higher incidence of late complications compared to the Charnley prostheses.

Adult↗
PubMed1978

Evaluation of polytetrafluoroethylene-graphite-coated total hip prostheses in goats.

This study was designed to determine if a porous polytetrafluoroethylene-graphite coating could furnish long-term stabilization of total hip prostheses. Prostheses were surgically implanted in 12 mature goats, which were observed postoperatively for as long as 1 year. Effective stabilization occurred in only 4 animals. Poor results in the other animals were attributed to lack of stabilization of the prostheses following initial implantation, which allowed movement at the interface between bone and polytetrafluoroethylene-graphite.

Animals↗
PubMed1983

[Recurrent ejection of aortic valve prostheses. Apropos of 22 case reports].

Twenty two cases of recurrent perivalvular leaks in aortic valve prostheses were reviewed in a multicentre cooperative study. From 1963 to 1978, 22 patients, mean age 39 years, underwent aortic valve replacement; 18 patients had aortic regurgitation, 6 due to infective endocarditis, and 4 patients had calcific aortic stenosis. Eight Starr-Edwards, 6 Smeloff-Cutter, 2 Braunwald-Cutter, 3 Björk, 1 Lillehei-Kaster and 2 bioprostheses were inserted. All 22 patients had to be reoperated for perivalvular leaks due to active or previous infective endocarditis in 7 cases. The prostheses implanted (3 reinsertions, 19 valve replacements) were 10 Starr-Edwards, 4 Smeloff-Cutter, 5 Björk, 1 Lillehei-Kaster, 1 Magovern and 1 bioprosthesis. All 22 patients had further perivalvular leaks, 6 caused by infective endocarditis, and 15 patients underwent a third operation. The prostheses implanted this time (2 reinsertions, 13 valve replacements) were 4 Starr-Edwards, 3 Smeloff-Cutter, 7 Björk and 1 bioprosthesis. Four patients had a third perivalvular leak, and 2 patients a fourth perivalvular leak. The first and second episodes of perivalvular leak were detected early in over half the cases. They were associated with cardiac failure, angina and hemolysis in 20 to 45% of cases. The average period between the first and second operations, and the 2nd and 3rd operations were 15 months and 9 months respectively. Overall, 11 patients died (50%), 4 due to cardiac failure and 3 of sudden death; 3 patients have been lost to follow-up (14%), and there are 8 survivors (36%) with a mean follow-up period of 5 years. However, the mortality rate when the cause of perivalvular leak was infective, was 82%, and only 18% when the cause was mechanical. The factors which favour recurrent perivalvular leaks are infection (30% of cases) and technical difficulties related to the poor quality of the aortic ring (calcification, dystrophy or dilatation). The prevention of this complication depends on careful peroperative technique, the use of certain surgical bypass techniques, a constant battle against infection, and regular examination of operated patients.

Adult↗
PubMedDate not supplied

Pseudo-endothelial cell growth on auto-alloplastic vascular prostheses. Experimental studies on rats.

Pseudo-endothelial cell growth on Sparks' auto-alloplastic vascular prostheses which had been grafted in the arterial circulatory system are examined by light- and electron microscopy at different intervals after application. The obtained data clarify that in future we should speak of prosthetic endothelium or lining cells when referring to those cells which line the inner surface of prostheses; the present study reveals that these cells lack some important criteria, e.g. complete basement membrane and intercellular bridges, by which real endothelial cells are distinguished. The rapid and complete growth of lining cells, expected to accompany use of Sparks' prostheses, could not be confirmed by the present experiments. Using a new microsurgical experimental model in the rat, we were able to show that even in a small animal species prosthetic arterial replacement is possible. Hereby, an important contribution has been made to microsurgical work in the field of experimental vascular surgery with a technique hitherto unknown in the literature.

Animals↗
PubMed1984

The problem of cardiac valve prostheses, anticoagulants, and pregnancy.

To assess the maternal and fetal risks in patients with cardiac valve prostheses, a series of 223 pregnancies in 156 women was studied. In 68 pregnancies (group I) treatment with antiplatelet agents was substituted for that with coumarinics from the first trimester on. Group II (128 pregnancies) received coumarinics through the thirty-eighth week of gestation. Three patients in group I died as a result of thrombosis of their caged-ball valves. The incidence of cerebral embolism was 25.0% in group I and 2.3% in group II patients, while that of spontaneous abortion was 10.3% and 28.1%, respectively. Coumarin embryopathy was found in 7.9% of group II infants. Fetal death did not occur in the 12 cases in which subcutaneous heparin was substituted for the coumarin derivative in the first trimester and the last 2 weeks of pregnancy (group III), but maternal cerebral embolism developed in 8.3% of the patients. Finally, uneventful pregnancies and deliveries were observed in 12 of 15 mothers (group IV) with biological prostheses who received no anticoagulants. It is concluded that (1) women with cardiac valve prostheses should be counseled against becoming pregnant, (2) antiplatelet agents do not provide protection against thromboembolism in these patients, (3) because of the high incidence of fetal death and birth defects use of coumarinics is contraindicated in the first trimester and the last weeks of pregnancy, (4) the substitution of heparin at these times may decrease the incidence of these complications, and (5) bioprostheses are indicated in women who wish to bear children.

Acenocoumarol↗
PubMed1984

Implications of late morphology of Braunwald-Cutter mitral heart valve prostheses.

Interrelationships among silicone poppet wear, cloth wear, and tissue ingrowth were investigated in 14 retrieved Braunwald-Cutter heart valve prostheses following implantation of 37 to 118 (mean 83) months. Six aortic valves (mean 81 months) had severe cloth and poppet wear. In three the poppet had escaped. The lesser wear of the strut covering on the eight mitral valves (mean 84, range 37 to 108 months) was generally functionally insignificant. Mean decrease in mitral poppet diameter was 0.4% (range 0% to 1.5%), in contrast to a mean of 5.8% for aortic poppets. Histologic examination of the cloth/tissue complex demonstrated well-collagenized tissue ingrowth in areas of intact fabric with focal endothelial lining. Functionally trivial calcific deposits were often noted deep in the tissue coating, adjacent to cloth fibers or the strut metal. These results suggest that the mitral Braunwald-Cutter prosthesis need not be electively replaced without specific indication. A model is presented which explains the favorable clinical course demonstrated for mitral recipients and provides a rationale for the disparate clinicopathological behavior of mitral and aortic Braunwald-Cutter prostheses. Although inconsequential in this setting, the focal microcalcification noted in all mitral prostheses implanted for more than 72 months may have implications for the development of clinical cardiac assist devices for long-term application.

Aortic Valve↗
PubMed1981

[Long-term results of tricuspid prostheses].

The results of a series of 38 patients with a tricuspid valve prostheses (:76% Starr-Edwards ball valves) associated with correction of one or two left heart valvular lesions are presented. 24 patients underwent clinical and haemodynamic assessment on average 4,2 years after surgery. The conclusions were that signs of systemic venous hypertension were mainly related to residual right ventricular failure despite normal valve function and secondarily to the poor hemodynamic profile of these prostheses and their paradoxical motion. Using these results: 18% early mortality; 24% late mortality; 24% late thrombosis amongst survivors and 52% residual right ventricular failure; and 47,5% of excellent results. The clinical and haemodynamic profiles of the patients were analysed to determine the surgical indications. Apart from the correction of associated left heart valve lesions, it seems that the prognosis in tricuspid valve repair depends on the duration of tricuspid regurgitation and the severity of right ventricular myocardial disease. In elderly patients with chronic tricuspid regurgitation and severe right ventricular failure, long-term analysis showed 87,5% poor results, whilst in younger patients with a shorter history of tricuspid regurgitation and less severe right ventricular failure, there was 77,7% excellent long-term results. Semi circular annuloplasty is widely indicated in mild or severe functional tricuspid regurgitation. Tricuspid valve replacement, a much more serious operation, remains essential in chronic organic lesions and in some cases of massive functional tricuspid regurgitation. A regards the choice of prosthesis, the authors suggest the Hancock bioprosthesis as a logical choice in cases of severe right ventricular failure as they are less prone to thrombosis than mechanical prostheses and have good haemodynamic profiles. The evolution of the right ventricular failure even after correction of tricuspid regurgitation underlines the importance of preventative therapy by early correction of left heart lesions.

Adolescent↗
PubMed1983

Comparative study of Björk-Shiley and Starr-Edwards prostheses for aortic valve replacement.

Thirty-nine patients received aortic valve replacement prostheses. The 19 patients who received Starr-Edwards (SE) caged-ball valve prostheses and the 20 patients who received Björk-Shiley (BS) tilting-disc valve prostheses were followed up for a mean period of 20 and 19 mo, respectively. The cumulative mortality rate was 5.3% in the SE group and 15% in the BS group. The clinical improvement was more remarkable in the BS than in the SE series. Major thromboembolic complications developed in three patients in each group, and two patients in each group developed infectious endocarditis. Tests for intravascular hemolysis indicated a higher rate in the SE than in the BS group. The serum haptoglobin levels were 39 +/- 22 and 102 +/- 63 g/dl (mean +/- SD), respectively (P less than 0.001). The hemoglobin level was 12.4 +/- 1.8 g/dl in the SE group and 13.4 +/- 0.6 g/dl in the BS group (P less than 0.03). The BS tilting-disc valve caused less hemolysis and the smaller size led to greater clinical improvement.

Adult↗
PubMed1980

Effect of controlled oral hygiene procedures in patients with fixed prostheses.

The purpose of this study was to determine the effect of frequent recall appointments for a professional oral prophylaxis, specificaly for patients with fixed prostheses. By a dental hygienist the prophylaxis was repeated every month for a test group and twice a year for a control group (24 subjects). All patients were reexamined at 6- and 12-month intervals to reevaluate the oral health. This study demonstrated that careful professional cleaning of the teeth of patiens with fixed prostheses once every month is sufficient to maintain satisfactory oral hygiene. For the private practitioner it hardly seems realistic to organize a recall program once every month. However, professional clearning twice a year cannot guarantee oral health in all patients with fixed prostheses. Therefore further examinations over a longer period of time are necessary to determine reasonable recall intervals for the successful establishment and maintenance of oral health.

Adult↗
PubMed1980

Histochemical and histophysical detection of wear products resulting from prostheses.

The authors determined the wear products in tissues following hip prostheses implantations in 40 cases. The interval between prostheses implantation and histochemical examinations varied from 3 weeks to 15 years. The authors found that on the inner layer of the neighbouring joint capsule immediate to the implant a metal-protein layer developed and cobalt, chrom, nickel particles were demonstrated later in the connective and scar tissues as well. In the connective and fat tissues around the hip prostheses (from 4 cm) cobalt and chrom, in the regional lymph nodes cobalt, chrom nickel and in some cases manganese particles were found. Bone cement and plastic materials were found in the joint capsule, in the bone marrow of the distal part of the femur, but they were not present in the lymph nodes.

Aged↗
PubMed1980

Clinical investigations of tolerance to materials and acrylic cement in patients with hip prostheses.

In forty-two patients with prostheses of the hip followed up after an interval, the authors carried out skin allergy tests against the metals of which the prostheses were composed, and against methacrylate. They found that the tests gave positive results in about 25 per cent of cases. They also investigated whether this finding showed any relationship with loosening or movement of the prostheses. There was no statistically significant relationship, either with loosening or with the passage of time since the operation.

Acrylates↗
PubMed1980

[Flow through various cardiac valves prostheses (author's transl)].

We have studied the flow through various cardiac valves prostheses, with the assistance of an artificial left ventricular pump. We took photographs during the whole of the cardiac cycle but we present here only the view of the middle systolic period. As regards the mechanics prostheses (Bjork-Shiley, Lillehei-Kaster, Saint-Jude-Medical, Starr-Edwards) the flow changes with the shape and opening of the valve. Biologic prostheses (Carpentier-Edwards, Hancock, Ionescu-Shiley) present an impertubated flow.

Biophysical Phenomena↗
PubMed1993

[Intraprostatic prostheses].

Intraprostatic stents appeared as an alternative to surgery in high surgical risk obstructed patients. A critical review of the different types of endoprostatic prostheses is made. Finally we tried to establish the true cost/effectiveness ratio in our country, comparing the temporary prostheses with the indwelling catheter and the permanent prostheses with prostatic surgery.

Humans↗
PubMed1995

Cultures from genitourinary prostheses at reoperation: questioning the role of Staphylococcus epidermidis in periprosthetic infection.

PURPOSE: We determine the colony counts of organisms present on culture of clinically uninfected genitourinary prostheses at reoperation for reasons other than infection. These results served as control data for comparison with cultures from infected devices to determine the relative incidence of organisms involved. MATERIALS AND METHODS: Cultures were prospectively obtained from 65 penile prostheses and 22 artificial urinary sphincters. Patients were followed for a minimum of 12 months after reoperation or until development of infection (mean 27 months) at which time cultures were again obtained. RESULTS: Low colony counts of Staphylococcus epidermidis were isolated from 40% of uninfected penile prostheses and 36% of artificial urinary sphincters. Only 3 of these devices later became infected (9%) and in all cases a higher colony count of another organism was found at explanation. CONCLUSIONS: While Staph. epidermidis can cause prosthesis infection, low colony counts of the organism may not be associated with clinical infection. Therefore, the high incidence of infection attributed to this organism may be overestimated.

Case-Control Studies↗
PubMed1995

The tradeoffs associated with modular hip prostheses.

In an effort to gain greater insight into the tradeoffs associated with modular hip prostheses, 2 approaches were taken. A questionnaire was sent to each of the orthopaedic implant manufacturing companies asking specific questions regarding modular components, and a series of retrieved prostheses, both modular and nonmodular, were examined to determine the potential sources of problems associated with modular connections. The respondents to the questionnaire generally agreed that it was more expensive to produce modular prostheses due to the required tolerances at the modular connections, and that the increased flexibility provided by the modularity was important to surgical outcome. There was less consensus on whether inventories were reduced and little data to support any improvement in surgical outcome caused by modularity. The most frequent problems associated with modular connections were fretting and corrosion. Easily observable significant fretting occurred in 4% of 701 head/neck tapers. Corrosion was observed in > 30% of the mixed-alloy head/stem combinations, in < 10% of all-titanium-alloy modular components, and in < 6% of all-cobalt-alloy devices. In 1 series of retrieved modular femoral components (15 titanium alloy and 15 cobalt alloy) with both sets having approximately the same duration of implantation, 7% of the all-cobalt-alloy components had corrosion, whereas 33% of the mixed-alloy components had corrosion.

Alloys↗