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 91 records · Page 5Linked to original sources

Determination of cantilever length-anterior-posterior spread ratio assuming failure criteria to be the compromise of the prosthesis retaining screw-prosthesis joint.

The maximum cantilever length-anterior-posterior spread (CL-AP) ratio is often used as an indication of the ability to cantilever in completely implant-supported prostheses. The CL-AP ratios were determined assuming that failure occurs when the prosthesis retaining screw-prosthesis joint was compromised by either compressive (exceeding the pretorque value) or tensile (opening of the joint via plastic deformation) vertical forces using the Skalak model. Geometric arrangements of three, four, five, and six implants were analyzed. Force variables were 143, 200, and 400 N for the applied force, the pretorque value, and the joint tensile yield strength, respectively. The pretorque value was always exceeded before the yield strength. Allowable CL-AP ratios were (1) lower than those previously reported and (2) found to be 0.5 to 1.8, 0.7 to 1.6, 1.1 to 1.7, and 1.8 for three, four, five, and six implants, respectively. Although implant distributions with the highest AP often provide adequate occlusion, the results of this study indicate that the use of a single CL-AP ratio alone is not necessarily a good indicator of the ability to cantilever.

Algorithms↗

Rearthroplasty after conventional total hip prosthesis and double-cup prosthesis. A comparative study.

Revision of 19 Müller total hip prostheses and 9 ICLH double-cup prostheses is compared. In the Müller group the mean operation time was 186 min, the amount of blood transfused 3526 ml, and the hospital stay 34.9 days. The corresponding figures for the ICLH group were 94 min, 1389 ml, and 25.7 days. Revision of the conventional hip prostheses involved technical difficulties and complications such as femoral fractures and postoperative dislocations, which were not seen in the ICLH group, in which the revision was as easy to perform as the primary operation. The clinical result 6 months after revision was significantly better in the ICLH group. Thus, the double-cup prosthesis provides another possibility for revision. However, a relatively high incidence of early loosening indicates that it should not be used in older patients in whom one would expect a follow-up shorter than the lifetime of a conventional hip prosthesis.

Aged↗

Mucosal topography around implants in edentulous upper jaws. Photogrammetric three-dimensional measurements of the effect of replacement of a removable prosthesis with a fixed prosthesis.

A photogrammetric technique was tested to measure the topography of the mucosa around implants, placed in edentulous upper jaws. Photographs were taken of casts from 6 patients, who all had used a removable overdenture for one year. Another series of photographs was taken on new casts after the use of a fixed prosthesis for a second year. The 6 pairs of photographs were measured and compared in an analytical stereo plotter for surface contour and implant positions. The results from the measurements indicated a trend of general recession of the mucosa after one year with fixed prosthesis, both on the buccal as well as on the palatal side. The mean volume of recession was 222.4 mm3, corresponding to an average of 0.4 mm3/mm2 of mucosa. More recession was generally observed on the palatal side, but obvious variations between the patients were present. In conclusion, the photogrammetric technique was considered to be well suited for analysing tissue contours in various dental situations.

Aged↗

The below-elbow myo-electric prosthesis. A comparison of the Otto Bock myo-electric prosthesis with the hook and functional hand.

The place of the myo-electric prosthesis in below-elbow amputees has been reviewed. Forty-three patients were seen and all possessed both a myo-electric prosthesis and a standard artificial limb. Nearly half the patients used the newer device almost all the time at work and many of these wore it for the majority of their waking hours. Its use at work was mainly related to the patient's type of job and here in turn there was concern about damaging the device. It is suggested that acceptance would be further increased if greater attention were paid to the durability of the arm and its glove. Criteria for prescription and future developments are discussed.

Adult↗

[Maxillary prosthesis for better QOL--analysis of maxillary prosthesis stability].

We report here an analysis of 100 cases of maxillary prosthesis, experienced from July, 1981 through June, 1989, with special reference to stability. Sixty-four percent of prostheses were partial denture type and complete denture type comprised thirty-two percent. Eighty-six percent of cases were estimated to have defects exceeding 2/6 and 3/6 of the surface width of the palate. Ninety percent of prostheses weighed less than 15 gm. The stability of these prostheses was estimated to be good in 85% of cases, the stability of the denture type being good in 95% of partial denture type cases, and 62% of complete denture type cases. According to type distinctions among maxillary defects as a whole, in the smaller 1/6 and 2/6 defect cases, good stability can be expected, and in 3/6 and 4/6 defect cases, 80% achieve good stability. According to prosthesis weight, 80% of those weighing less than 15 gm were considered to have shown good stability. Thus, these maxillary prostheses can remain in place and functional ameliorating disability and contributing to the patient's quality of life.

Adult↗

Mitral valve replacement with the Smeloff-Cutter prosthesis. Experience with 154 patients and comparison with results of replacement with a Starr-Edwards prosthesis.

Mitral valve replacement with the Smeloff-Cutter (S-C) prothesis was performed in 154 patients between September, 1965, and January, 1970. In 84, only the mitral valve was replaced; in the remainder, other valves were reconstructed or replaced. The hospital and late mortality rates for isolated replacement were 6 and 25 per cent, respectively. Comparable figures for the Starr-Edwards (S-E) (Models 6000 and 6120) prosthesis during this period were 11 and 23 per cent. Similar rates of thromboembolism were associated with the use of either prosthesis in surviving patients (27 per cent for the S-C valve and 30 per cent for the S-E valve). In spite of the acceptable hospital mortality rate for the S-C valve, it is not now considered suitable for clinical use because of the high late mortality rate and the high risk of thromboembolism that accompany its use.

Adolescent↗

[The results of cosmetic prosthesis in patients in relation to the method of formation of a moveable base for the prosthesis following removal of the eyeball].

The paper analyses remote results of cosmetic prosthesis (more than 4 months) in 107 patients with anophthalmos. For formation of the stump after enucleation different methods were used: simple enucleation; enucleation with suturing of rectus muscles to the conjunctiva of the eye ball; enucleation followed by introducing a lavsane implant into the cavity of the Tenon's capsule; evisceration followed by introducing a lavsane implant into the cavity of the scleral disc. The best results were achieved in groups of patients when enucleation was followed by plastic formation of a mobile volume stump using a vascular wicker, crimped lavsane prosthesis.

Adolescent↗

Surgery for gastro-oesophageal reflux: the Angelchik prosthesis compared to the floppy Nissen fundoplication. Two-year follow-up study and a five-year evaluation of the Angelchik prosthesis.

Twenty-two patients were followed for 5 years after insertion of an Angelchik prosthesis for gastro-oesophageal reflux (GOR) and the 2-year results compared with a subsequent group of 28 patients treated by floppy Nissen fundoplication. The overall clinical results of the two procedures were equivalent at 2 years (Angelchik Visick 1 and 2, 80%; Nissen Visick 1 and 2, 78%) but the reasons for failure were different. In the Angelchik group failures were due to mechanical problems associated with the device, whereas the Nissen failures were mainly due to recurrent GOR. There were no patients in the Angelchik group with recurrent reflux at 5 years, but between 4 and 5 years postoperatively four patients developed mild dysphagia. The Angelchik prosthesis appears to be as effective as the floppy Nissen fundoplication, but further long-term studies are required before its widespread use can be recommended.

Adolescent↗

[Replacement of loose cemented total prosthesis of the hip by cementless prosthesis of the madreporic type (author's transl)].

The authors have inserted 77 cementless prosthesis of the madreporic type in cases of loosening of previously-inserted cemented prosthesis. 66 p. 100 of satisfactory results have been obtained with a follow up of one to six years. The analysis have shown that those with good results achieved stability in the course of time. The technique is fully described. In some cases bone grafting was necessary. In five cases a fracture of the femur was done during the operation. The possibility of a flare-up of infection is discussed. The authors consider that the absence of cement diminishes the liability to septic complications.

Acetabulum↗

[Comparative evaluation of various methods of treatment of mitral valve diseases. Apropos of 4 series of 100 patients operated on using the Starr prosthesis, Bjork prosthesis, bioprosthesis and valve reconstruction].

The results of 4 groups of 100 patients undergoing mitral valvuloplasty (group I), isolated mitral valve replacement by a bioprosthesis (group II), a Starr-Edwards prosthesis (group III) and a Björk prosthesis (group IV) between 1974 and 1977 were compared. The selection of patients for each group was identical and made according to strict criteria. The average age was between 47.1 +/- 12.5 years and 51.8 +/- 10.5 years according to the particular group; the average functional classification was 2.4 +/- 0.4 to 2.5 +/- 0.6; the average cardiothoracic ratio was 0.58 +/- 0.07. Most patients were in atrial fibrillation. Ninety-seven per cent of patients were followed-up by questionnaires. The results were expressed with respect to simple clinical events used in all previously reported series. The long-term mortality was identical in the 3 groups undergoing valve replacement (40 p. 100 at 7 years) but was much less in the group undergoing valvuloplasty (18 p. 100 at 7 years). The mortality rate due to valvular problems was significantly less in the valvuloplasty group (2 p. 100 at 7 years) than in the groups with mechanical prostheses (20 p. 100 at 7 years). Intermediate results were observed in the bioprosthetic group (9 p. 100 at 7 years). Thrombo-embolism was significantly less common in the groups undergoing valvuloplasty and bioprosthetic valve replacement (2 p. 100 and 6 p. 100 at 7 years) than in the group with Starr-Edwards and Björk prostheses (30 p. 100 and 32 p. 100 at 7 years).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[The implantation of a heterologous prosthesis in reparative abdominal-thoracic surgery. Experience with the use of clindamycin in preventing prosthesis-related infection].

The authors point out how infection of heterologous prosthesis, widely used in surgery, can be a dramatic event. On the other hand, antibiotic prophylaxis is difficult because of the difference between "in vitro" and "in vivo" activity of many antibiotics, due to the production, by many bacteria, of the so-called glycocalyx. This would allow bacteria to clump and adhere to many surfaces, forming micro-colonies, causing delay in phagocytosis, and reducing the efficacy of antibiotics. On the basis of their, although limited, experience, the authors suggest, for the prophylaxis of prosthesis infection, the use of antibiotics such as clindamycin, able to reduce glycocalyx production.

Abdominal Muscles↗

[Comparison of long-term clinical results of the three models of the Björk-Shiley valve prosthesis and the Omnicarbon valve prosthesis].

A multi-institutional cooperative study, that was a comparison of long-term results of the replacement of the four models of the oblique disc valve prosthesis which had been implanted on aortic and mitral position alone or double from December 1976 to September 1992 in the eight national hospitals in Japan was performed. Seven hundred and thirty-four patients and 765 prostheses that consisted of 582 patients and 610 prostheses of the Björk-Shiley (BS) valve, including 326 patients of the Spherical disc (SP) valve (49 aortic, 259 mitral, and 18 double aortic-mitral), 103 patients of the Convexoconcave disc (CC) valve (45, 51, 7) and 153 patients of the Monostrut (MS) valve (101, 49, 3), and of 152 patients (71, 78, 3) and 155 prostheses of the Omnicarbon (OC) valve were compared with their mortality and morbidity in every valve position respectively according to the approval by STS-guideline. The MS valve and the OC valve showed 0% to 11.3% of operative mortality, 0.3%/py to 1.8%/py of valve related mortality, 85.5% +/- 5.6% to 98.4% +/- 1.6% of actuarial survival rate at 10 years, and 58.5% +/- 6.4% to 82.7% +/- 5.7% of actuarial free rate of all mortality and morbidity at 10 years in every valve position. Structural deteriorations occurred in two patients of the CC valve in the mitral position only, and its rate of all valve positions showed 0.04%/py. Significant differences were seen in actuarial survival rate at 10 years after aortic valve replacement, and in operative mortality rate, improved degree of NYHA class, structural deterioration rate and actuarial free rate of all mortality and morbidity after mitral valve replacement between the group of the MS and OC valve and the group of the SP and CC valve. Therefore the MS valve or the OC valve should be selected to implant rather than the SP valve or the CC valve, and the patient who had been implanted with the CC valve should be treated considering valve position, valve position, valve size, age and activity of the patient and the manufactured date of the prosthesis.

Bioprosthesis↗

[Titanium modular revision prosthesis stem in revision hip prosthesis].

In revision arthroplasty of the hip, femoral defects and fractures must be bridged by a long stem. The implant has to be adapted exactly to the diameter of the cortical tube and has to be placed distally beyond the pathologic area. The titanium modular revision prosthesis (MRP) stem consists of the titanium alloy Ti6Al7Nb and is offered in various diameters, lengths, and special devices, which allows individual and load-stable reconstruction. The aim of the current study is to scrutinize first clinical and radiological results of the titanium MRP revision stem in revision arthroplasty of the hip. We report the midterm results of 130 non-cemented revision arthroplasties of the hip using the titanium MRP revision stem with a mean follow-up of 2.9 years (minimum: 1 year, maximum: 8 years), including 56 men and 74 women. The indication for revision arthroplasty was aseptic loosening of the cup and stem in 94 cases, loosening of the stem in 17 cases, reimplantation in a Girdlestone situation in 11, and periprosthetic fractures in 8 cases. The Harris hip score improved from 50.9+/-24.6 preoperatively to 88.5+/-11.5 postoperatively. The score according to Merle d'Aubigné improved from 9.8+/-4.0 preoperatively to 15.2+/-2.8 postoperatively. We found three recurrent dislocations, two lesions of the sciatic nerve, three cases of persisting deep infection, two periprosthetic fractures, and one case of subsidence of the stem of 2 cm required revision of the MRP stem. Atrophy of the proximal femur was visible in all cases with a stem diameter >17 mm (39/130). Stable primary fixation was achieved in 129 of 130 cases. The titanium MRP revision has proved to be a very reliable implant in cementless revision arthroplasty of the hip.

Aged↗

Transforming an existing fixed provisional prosthesis into an implant-supported fixed provisional prosthesis with the use of healing abutments.

Maintaining a fixed provisional prosthesis through all phases of complex implant prosthodontic therapy for a soon-to-be completely edentulous arch is a difficult task. This article focuses on the treatment phase in which teeth and/or transitional implants supporting a provisional fixed partial denture are removed. The described technique makes use of healing abutments to support a modified provisional fixed partial denture. This protocol ensures patient comfort and allows proper soft tissue healing before definitive implant abutment selection. It also eliminates the placement of interim implant abutments.

Clinical Protocols↗

[Operative aspects of prosthesis change in the hip joint after fracture of the prosthesis shaft].

Between 1983 and 1988 revision arthroplasty was performed in 45 patients with broken femoral stems, an average of 11 years after primary total hip replacement. There were 25 men and 20 women, with an average age of 70 years at revision. The primary endoprostheses were all cemented and of the following types: Buchholz A1 (41) Charnley-Müller (2), Weber-Huggler (1), Charnley (1). In 8 cases the femoral stem only was changed, while in 37 both components had to be replaced. The posterior approach with the patient in the lateral position gave excellent exposure of both the acetabulum and the femur. This approach gave ready access to a dorsal window, through which the broken femoral stem could be removed with a punch. To achieve stability of the femur permitting immediate full weight-bearing, the femoral defect was always made good by a revision stem with at least twice the femoral diameter. In order to stabilize large acetabular defects a combination of homologous bone graft and an acetabular support ring was used. The implanted prostheses were of the revision type, cemented and individually selected in each case. It was possible to implant an adequate revision prosthesis in all cases. The following complications were noted during surgery: fracture of the femur (1) defects of the femur (5), and haemorrhages that were difficult to manage (2). It was necessary to reoperate in 2 patients, in 1 because of a stitched-up drain and in 1 because of postoperative haematoma. Postoperatively, 21 patients had cardiopulmonary complications, which were successfully treated in the intensive care unit in all cases but 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[A hip prosthesis with a non-rigid femoral implant. The Butel iso-elastic prosthesis].

A new type of femoral prosthesis is described by the authors. This non-rigid implant respects the natural elasticity of bone and, because of this, avoids excessive stress protection of the bone. In addition, bone atrophy caused by rigid components and osteolysis provoked by cement are eliminated. Experimental studies and the clinical and radiological results five years after insertion seem to confirm the value of this concept.

Adolescent↗

A second-generation cementless hip prosthesis: improved results over the first-generation prosthesis.

Forty-two patients who had a Porous Coated Anatomic (PCA) "E" series, second-generation, cementless hip arthroplasty (Howmedica, Rutherford, NJ) were compared with 42 patients who had a first-generation PCA prosthesis. Patients were directly matched for age, sex, diagnosis, weight, Charnley functional status, and duration of follow-up. All of the operations were done by the same two surgeons, who used the same operative approach and the same postoperative rehabilitation plan. All of the patients were followed up for at least 5 years (range, 60 to 76 months). In the "E" series group, there were 41 of 42 (98%) good and excellent clinical results with a mean Harris hip score of 94 points (range, 46 to 100 points); the first-generation group had 34 of 42 (81%) good and excellent clinical results and a mean Harris score of 81 points (range, 42 to 100 points) (P = 0.001). There was one acetabular component revision in the "E" series group (2%), which can be compared with eight revisions (19%) in the first-generation group (P = 0.012). The incidence of femoral radiolucencies was 19% (eight hips) for the "E" series group compared with 50% (21 hips) in the first-generation group (P = 0.009). The radiolucencies in the "E" series group were small, nonprogressive, and confined typically to zone I. We believe that the improvements in design of the "E" series component may account for these differences.

Adult↗