Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PROSTHESIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

Studies on a novel anterior cruciate ligament polyethylene fiber prosthesis: the histomorphological pattern of organization and bony anchorage of a polyethylene fiber prosthesis in the stifle of the goat.

The anterior cruciate ligament of goats was substituted by a high-tensile polyethylene fiber prosthesis. The animals were sacrificed after 6-12 months. Histologically, the implants were separated from a newly formed bony shell by a thick fibrous interface membrane, which was anchored to the bone by Sharpey-like fibers. Within the joint cavity, the implants were enclosed in thick fibrous sheaths, which were continuous with the intra-osseous interface membranes. While the inner granulomatous layer of the interface membrane extended in between the polyethylene fibrils for a short distance, the bulk of the prosthesis was poorly organized. A thick central fibrous band accompanied the intra-osseous and intra-articular portions of the implants throughout their entire lengths. Oblique fibrous tracks linked the interface membranes with the central fibrous bands. The intra-osseous tunnels were considerably expanded when compared to the initially drilled tunnels.

Animals↗

[Long-term influence of the spongiosa metal surface prosthesis on the periprosthetic bone. A radiological and osteodensitometric analysis of implantation of the S& G (ESKA) hip prosthesis].

INTRODUCTION: The anatomically shaped, cementless total hip replacement (THR) (S and G, ESKA Lübeck) has a fully porous coating for secondary osseointegration. The aim of the present study was to analyse the long-term effect of the prosthesis on periprosthetic bone remodelling. METHODS: 137 THR in 117 patients were analysed clinically and radiographically 12.8 years (10-14.9 years) postoperatively. The average age at the last follow-up was 71.8 years (range: 34-87 years). Osteodensitometric DEXA measurements of the periprosthetic bone in comparison to the contralateral non-operated femora were performed. RESULTS: Cumulative survival rates of all implanted THR (n = 231) at 14.9 years were 86.2 % (+/-5.3 %) for the fully porous coated stem and 90.1 % (+/- 8 %) for the cup. Five stem fractures (3.6 %) at the middle part were recorded. The Harris hip score of the non-revised THR at the last follow-up averaged 88.3 (34-100) points. Bony atrophy in the proximal periprosthetic femora in Gruen zones I (16.8 %) and VII (34.6 %) confirmed a proximal stress-shielding. Osteodensitometric analyses demonstrated in comparison to the contralateral femora (BMD 1.3 g/cm (2)) a significantly reduced bone density at the calcar femoris (BMD 0.9 g/cm (2)) (p < 0.001). CONCLUSION: The original goal of a physiological load transfer has not been realised with this fully porous, cementless THR. The anatomic S & G stem will mainly be osseointegrated by distal load transfer.

Absorptiometry, Photon↗

Hybrid small-caliber vascular prosthesis for coronary artery bypass grafting: a preliminary study of plasmin-treated fibrin-coated vascular prosthesis.

The potential use of plasmin-treated fibrin-coated vascular prosthesis (PF-V) for coronary artery bypass grafting (CABG) in animal models was investigated. PF-V grafts, 3 mm in internal diameter, were studied on 5 sheep in off-pump CABG model and on 18 rabbits in abdominal aortic bypass grafting (AABG) model. Patency, blood flow, angiography, Indium-111 platelet scintigraphy, and histology of the graft were evaluated. In the sheep CABG model, the PF-V grafts were patent for a range of 12 to 22 days without postoperative antiplatelet therapy. Graft flows ranged 58 to 90 ml/min until the day before graft occlusion by thrombus. In rabbit AABG model, the fibrin coating of the PF-V grafts was completely absorbed and replaced with neofibrin net between 7 and 14 days after implantation. Platelet depositions on the graft between 7 and 14 days after implantation were significantly higher than those at other periods (p < 0.05). The small-caliber PF-V graft in sheep CABG model had a good blood flow with high antithrombogenicity in acute phase, but occluded over 2 to 3 weeks without antiplatelet agents after implantation. The current problem of the PF-V graft was a thrombus formation at the time of the degradation of fibrin coating. Further improvements are needed.

Animals↗

[Experience with the cementless hip prosthesis, with special reference to the implantation of prosthesis stems].

Authors report on their experiences gained during 7 years with 102 PM (Aesculap) and 76 Etropal cementless hip endoprosthesis and with the implantation without sticking of 264 standard prosthesis stems. They explain their results with bone rebuilding that can be certified also by Roentgenograms. The lack of success in a few per cent of the cases can be explained mainly by technical insufficience.

Cementation↗

[Platelet kinetics during arterial diseases. Macro-angiopathy, cardiac valve prosthesis and prosthesis of the aortic bifurcation: 73 cases (author's transl)].

From 73 platelet kinetic studies in vascular diseases, some conclusions can be drawn: excessive platelet consumption is not as usual as previously published; abnormal platelet recovery is an usual feature in patients with vascular or valvular prosthesis; correlation between platelet kinetic abnormalities and thrombo-embolic complications needs reevaluation; constant abnormal platelet kinetics in the cases of aorto-femoral graft made these cases a valuable model for the clinical and biological evaluation of the drugs committed to a change of the platelet functions.

Adult↗

Left ventricular outflow tract obstruction related to a valve prosthesis: case caused by a low-profile mitral prosthesis.

Mechanical and bioprosthetic mitral prostheses may have many potential complications. In patients with isolated mitral stenosis and a small left ventricular cavity, low-profile prostheses are recommended to avoid myocardial impingement that can result from a high-profile valve and lead to possible left ventricular inflow or outflow obstruction or ventricular arrhythmias. This case report illustrates that left ventricular outflow obstruction may also result from a low-profile mitral valve prosthesis. This obstruction was not diagnosed before cardiac catheterization. Assessment of patients with suspected prosthetic valve dysfunction is difficult and may necessitate cardiac catheterization or even direct surgical inspection for conclusive information.

Adult↗

[Maxillary prosthesis for better QOL--early setting and faster construction of maxillary prosthesis].

The maxillofacial prosthesis (MFP) is well accepted as one of the modalities to ameliolate the postsurgical crippling in the patients with maxillary malignancy. In this report, we analyzed 55 primary cases of MFP out of 100, from July, 1981 to July, 1987 in terms of the time of start after operation, and the duration and procedure of the MFP-making. MFP-making set about within 4 weeks in 35% of patients, 8 weeks in 25%, 12 weeks in 22%, and more than 12 weeks in 18%. The completion of MFP-making averaged 10 days. As a result of simplifying of MFP-making, we shortened a period requiring MFP-making within 3 days in recent 10 cases. There were no adverse effects of early wear of MFP after operation. We believe that early wear of MFP after operation improve the quality of life of patients with maxillary malignancy and considered that wear of MFP is not the completion of treatment, but is one of the procedures of treatment for the patients undergone maxillectomy.

Adolescent↗

Late results of aortic valve replacement with Bjork Shiley prostheses: a comparison of standard aortic valve prosthesis with reversed mitral valve prosthesis implanted in aortic position.

Between 1976 and 1983, 435 patients underwent aortic valve replacement (AVR) with Bjork Shiley prostheses. Standard aortic Bjork Shiley prostheses (ABP) were used in 150 patients (Group I) and a reversed mitral Bjork Shiley prostheses in 285 (MBP in 250 and MBC in 35) patients (Group II). There was no significant difference in the number of the patients with valve calcification or the size of aortic root in the 2 groups. There was no significant difference in the early mortality in these two groups. The total follow up period in Group I was 912 years and 2130 years in Group II. The incidence of major aseptic prosthetic dehiscence and valve occlusion with tissue ingrowth were higher in Group I than in Group II. Reversed Bjork Shiley mitral valve prosthesis was successfully used in aortic position with reduced incidence of valve related complications.

Aortic Valve↗

[Reconstructive surgery using a massive prosthesis in loosening of a hip prosthesis].

Thirteen cases with loosening of THR treated by a massive prosthesis are reviewed. In previous years, with more conservative surgery, the loss of bone stock was most important. The results after a long follow-up were satisfactory. This was a desperate procedure during a period without a bone-bank. Despite the major problems with failure of this procedure, the author still recommends it in elderly patients who need early mobilization or when the use of a bank-bone is not possible.

Adult↗

Dipyridamole-aspirin as thromboembolic prophylaxis in patients with aortic valve prosthesis. Prospective study with the Model 2320 Starr-Edwards prosthesis.

In a prospective study, the efficacy of a dipyridamole-aspirin regimen in prevention of thromboembolism was evaluated in 50 patients having isolated aortic valve replacement with the Model 2320 Starr-Edwards prosthesis. These operations were performed between February, 1972, and October, 1974. In 1,380 patient-months of follow-up, there was a 20% incidence of thromboembolism with a rate of 8.7/100 patient-years and a 19% probability of an embolic episode occurring by 3 years. Seven patients had transient episodes, two had permanent neurologic residua, and one patient died. Comparison is made to a similar group of patients having solitary aortic valve replacement but receiving no medication, studied by Starr and associates. There was no statistical difference in the incidence of thromboembolism between the two groups. In November, 1975, all patients were converted to a regimen of warfarin therapy. Since conversion to anticoagulation, there have been two thromboembolic episodes in 2,132 patient-months of follow-up for a rate of 1.1/100 patient-years. We conclude that the use of antiplatelet therapy in the form of dipyridamole-aspirin is inadequate for routine thromboembolic prophylaxis following SE 2320 aortic valve replacement.

Adult↗

[Surface arthroplasty of the knee by marmor prosthesis. Study of 35 unicompartimental prosthesis seen with a follow-up of 1 to 5 years (author's transl)].

The Marmor prosthesis may be used for a surface arthroplasty of the knee by means of a system of unicompartmental modules including 4 sizes of condylar ramps and 6 thicknesses of tibial plateaux in two widths. It is thus possible to treat one or both compartments and correct any axial deviation. The operative technique must be careful and accurate with regard to the positioning of the prostheses and the choice of thickness of the plateau to be inserted. Preoperative radiological assessment must be very precise, and include in particular films with monopodal weight bearing and in forced position in order to study the joint surfaces and predict the correction which must be applied. Fifty operations have been performed (in 37 cases for osteoarthrosis), but the essential aim of the present study is to report the results of 35 unicompartmental prostheses with a follow-up of 1 to 5 years (mean : 2 years and 2 months). Thirty results were assessed as good or very good. The most spectacular features were freedom from pain and the rapidity with which the results were obtained. They would seem to be clinically stable. Nevertheless, the development of 3 deteriorations of the tibial plateau after Marmor would appear to contraindicate the use of 6 mm thickness plateaux. In contrast to widespread opinion, the remaining compartment does not degenerate, so long as it was normal preoperatively and there has not been any hypercorrection of the deviation after unicompartimental arthroplasty. Nevertheless, the latter has its limits and whilst it may play a role in the treatment of certain cases of osteoarthrosis of the knee, it cannot replace either tibial osteotomy for correction of the axis or bicompartimental prostheses or total prostheses anchored in the diaphysis, which also have their indications.

Follow-Up Studies↗

Aortic valve replacement with a small mechanical valve prosthesis--a clinical and echocardiographic study of a St Jude Medical valve prosthesis.

The use of small aortic valve prostheses raises concerns about harmful effects of residual obstruction to left ventricular outflow. The present study was undertaken to examine long-term clinical and echocardiographic results in 193 patients who underwent isolated aortic valve replacement (AVR) with a St Jude Medical (SJM) valve of 25 mm or smaller. The study subjects comprised 128 male and 65 female patients with a mean age of 54.1 years. The patients were divided into 2 groups according to the size of the valve prosthesis used for AVR. Small valves (19 or 21 mm) were implanted in 49 patients (group S) and large valves (23 or 25 mm) were used in 144 patients (group L). The group S patients were mainly female, older, and had smaller body surface areas. There were no significant differences in early and late mortality in group S as compared with group L. Furthermore, there was no difference in the incidence of valve-related or cardiac, non-valve-related death, including the incidence of sudden death, between the 2 groups, and they enjoy a similar level of daily routine activity regardless of the valve size used. Left ventricular (LV) function (ejection fraction, fractional shortening, LV mass index, LV end-systolic volume index, and LV end-diastolic volume index) measured by echocardiography improved significantly and returned to normal values after AVR in both groups. Moreover, no significant differences were observed in the postoperative variables of the LV function. These results suggest that 19-mm and 21-mm SJM valves can be safely used for AVR in the majority of Japanese patients.

Aged↗

Diastolic rumbles with porcine heterograft prosthesis in the atrioventricular position. Normal or abnormal prosthesis?

Three patients with porcine atrioventricular valves (two mitral, one tricuspid) with diastolic rumbles and presystolic murmurs are presented. Full hemodynamic and angiographic studies demonstrated moderate to severe prosthetic stenosis, even in the one patient who was minimally symptomatic. Diastolic murmurs across atrioventricular porcine heterografts indicate prosthetic stenosis until proved otherwise by full hemodynamic and angiographic studies. If the studies indicate normal function of the device and calculated prosthetic valve area that is small for the patient, then it must be recognized that the device is hemodynamically "stenotic" for that particular patient (valve prosthesis--patient mismatch).

Adult↗

Pannus resection through the tilting disc prosthesis: successful treatment preserving the prosthesis.

A 59-year-old woman was admitted to our hospital because of heart failure. In 1988, she underwent aortic valve replacement with an Omnicarbon valve and mitral valve replacement with a bioprosthetic valve. She was doing well until July in 1996 when she developed heart failure. Echocardiography revealed massive mitral valve regurgitation, and cinefluoroscopy showed implanted Omnicarbon valve dysfunction with a leaflet opening angle of 35 degrees. At reoperation, it was revealed that pannus formation prevented the valve from functioning well. The pannus was resected through the major orifice, and the leaflet was rotated toward the right anterolateral orientation. The worn bioprosthetic valve was replaced with a mechanical one. Postoperative cinefluoroscopy of the rotated Ominicarbon valve showed the opening angle to be 61 degrees.

Aortic Valve↗