Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Joint 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 379 records · Page 21Linked to original sources
PubMed2004

Temperature prediction in a finite element model for sliding contact analysis of total hip prosthesis.

A finite-element model for sliding contact in total hip joint prosthesis is presented in this paper. The hip prosthesis studied consists of an ultra-high molecular weight polyethylene (UHMWPE) acetabular cup articulating against cobalt-chrome and alumina-ceramic femoral heads. Various aspects of prosthesis operation were analysed using the finite-element model. For example, bulk material and surface stresses were analysed under varying conditions of elastic modulus, friction coefficient, sliding speed, and radial clearance. The resulting variations of temperature were also recorded. The results obtained from the model are useful in understanding the operating conditions and the causes of wear in the hip prosthesis.

Computer Simulation↗
PubMed2006

Management of infections of osteoarticular prosthesis.

Prosthetic joint infections are an uncommon complication of joint replacement surgery, but are associated with significant morbidity and costs when they do occur. Gram-positive cocci, in particular Staphylococcus aureus and Staphylococcus epidermidis, are the most commonly recovered microorganisms (>or=50% of all isolates). About 60% of prosthetic joint infections probably occur by direct contamination during the operative procedure. Certain systemic conditions in the patients, as well as foreign material, have been identified as risk factors for prosthetic joint infection. The clinical diagnosis is only certain when there are sinus tracts that reach the prosthesis or purulent secretion is obtained from joint aspiration or during open surgery. The treatment of an infected joint prosthesis must be individualised, but it generally involves both systemic antibiotics and surgical intervention. Exchange arthroplasty in one or two stages continues to be the standard approach to management. Prosthesis retention, in conjunction with debridement and prolonged (for at least 3 months) oral antibiotic therapy, can be an alternative for early postoperative or late acute haematogenous infections, when the duration of symptoms is less than 1 month, the implant is stable, and the pathogen is relatively avirulent and sensitive to an orally well absorbed antibiotic. Good results have been achieved under these conditions in staphylococcal infections with rifampin associated with quinolones and other antibiotics, e.g., cotrimoxazole, fusidic acid, and linezolid.

Acetamides↗
PubMed2003

Medical devices; reclassification of the knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis and the knee joint femorotibial (unicompartmental) metal/polymer porous-coated uncemented prosthesis. Final rule.

The Food and Drug Administration (FDA) is announcing that it has reclassified two fixed-bearing knee joint prostheses, the knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis, which is intended to be implanted to replace a knee joint, and the knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis, which is intended to be implanted to replace part of a knee joint. FDA has reclassified the devices from class III (premarket approval) into class II (special controls). The special control that will apply is a guidance document entitled "Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA." The agency is reclassifying these devices into class II because special controls, in addition to general controls, will provide reasonable assurance of the safety and effectiveness of the devices, and there is sufficient information to establish special controls. The agency is also announcing that it has issued an order in the form of a letter to the Orthopedic Surgical Manufacturers Association (OSMA) reclassifying the devices.

Device Approval↗
PubMed1980

The Guildford elbow joint.

The Guildford Elbow Joint prosthesis uses a non-rigid hinge articulation combined with intra-medullary stems to replace the humero-ulnar joint. The metal-on-plastic articulating surfaces are designed to allow some subluxation and accessory movements while remaining self-centering and stable under load. The intra-medullary stems are shaped to provide a good fit in the curves shafts of the ulna and humerus and should provide good fixation without the removal of large amounts of bone. The prosthesis is fixed with acrylic cement. The design follows, where possible, the normal anatomy and function of the elbow. A correct operative technique is important, but the procedure shows no particular difficulties.

Elbow Joint↗
PubMed2004

Wear properties of alumina/zirconia composite ceramics for joint prostheses measured with an end-face apparatus.

While only alumina is applied to all-ceramic joint prostheses at present, a stronger ceramic is required to prevent fracture and chipping due to impingement and stress concentration. Zirconia could be a potential substitute for alumina because it has high strength and fracture toughness. However, the wear of zirconia/zirconia combination is too high for clinical use. Although some investigations on composite ceramics revealed that mixing of different ceramics was able to improve the mechanical properties of ceramics, there are few reports about wear properties of composite ceramics for joint prosthesis. Since acetabular cup and femoral head of artificial hip joint are finished precisely, they indicate high geometric conformity. Therefore, wear test under flat contact was carried out with an end-face wear testing apparatus for four kinds of ceramics: alumina monolith, zirconia monolith, alumina-based composite ceramic, and zirconia based composite ceramic. Mean contact pressure was 10 MPa and sliding velocity was 40 mm/s. The wear test continued for 72 hours and total sliding distance was 10 km. After the test, the wear factor was calculated. Worn surfaces were observed with a scanning electron micrograph (SEM). The results of this wear test show that the wear factors of the both composite ceramics are similarly low and their mechanical properties are much better than those of the alumina monolith and the zirconia monolith. According to these results, it is predicted that joint prostheses of the composite ceramics are safer against break down and have longer lifetime compared with alumina/alumina joint prostheses.

Aluminum Oxide↗
PubMed1984

Scintigraphic evaluation of the painful prosthetic joint: a comparison of gallium-67 citrate and indium-111 labelled leucocyte imaging.

The radiopharmaceuticals gallium-67 and indium-111 labelled leucocytes have been compared in 15 patients with a painful joint prosthesis in an attempt to identify those patients with periprosthetic infection. Gallium-67 images were abnormal in five out of six patients with periprosthetic infection and normal in seven out of nine without evidence of infection. Indium-111 leucocyte images were abnormal in three out of six patients with infection and normal in all nine patients without infection. Indium-111 labelled leucocyte imaging is technically more difficult to perform than gallium-67 imaging. This, combined with the higher sensitivity of gallium-67 imaging for infection around a prosthetic joint, leads us to conclude that gallium-67 imaging is superior to indium-111 leucocyte imaging in identifying infection as a cause of a painful prosthetic joint.

Adult↗
PubMed2005

Design rationale and dimensional considerations for a femoral neck prosthesis.

Despite the high level of survivorship of cemented and uncemented stemmed components, there is a need for a joint prosthesis that does not invade the femoral canal. This type of prosthesis would be useful in treating younger and more active patients, in whom the use of such a design would usefully prolong the time before a conventional total joint replacement design was necessary. We present the rationale for a femoral neck prosthesis and show its feasibility as an off-the-shelf system based on a morphologic analysis of the proximal femur. The new design concept consists of a barrel with longitudinal flutes that enters the neck of the femur, loads on the calcar, and contacts the lateral cortex below the greater trochanter. Areas of porous ingrowth are placed so that the load transfer between the implant and the bone resembles that of the two main trabecular patterns in the proximal femur. A new method, cluster analysis, was used for defining a set of 12 sizes that could fit a population of femurs with acceptable dimensional discrepancies. We conclude that this type of device could be implanted reproducibly so that it was a close fit against the target areas of bone in the proximal neck area and against the lateral cortex.

Arthroplasty, Replacement, Hip↗
PubMed1988

A rat model of resorption of bone at the cement-bone interface in the presence of polyethylene wear particles.

Resorption of bone and the formation of a membrane at the interface between acrylic cement and bone were induced by particles of high-density polyethylene that were similar in size to those that are present in the tissues surrounding a human joint prosthesis. A non-weight-bearing plug of methylmethacrylate was inserted through the knee joint into the distal part of the femur of the rat. The plug rapidly became surrounded by a shell of bone. After repeated injections of particles of high-density polyethylene into the knee joint, resorption of bone occurred at this stable interface. No resorption of bone occurred after the opposite knee was injected with a control preparation that did not contain particles. The resorption of bone that occurred around the plug after the injection of particles of polyethylene took place in the absence of mechanical causes for loosening and in the absence of infection.

Animals↗
PubMed1992

Functional evaluation of patients fitted with total knee prostheses.

Degenerative or inflammatory diseases of the knee joint account for a large proportion of diseases affecting the elderly. Treatment aims to eliminate pain, correct the deformity and maintain complete joint mobility. In cases of total joint degeneration, fitting of a joint prosthesis is the technique currently favoured since elimination of pain and correction of the deformity, accompanied by recovery of joint mobility (the fundamental requirements for normal everyday life) can only be obtained if the knee joint is completely replaced. With the discovery of new materials and increasingly sophisticated knowledge about articular mechanics, the knee prosthesis, although more recent than the hip prosthesis, has become ever more widespread to the point that it now represents an irreplaceable aid in the treatment of this common disease. The clinical results obtained are already stable and particularly encouraging and prosthesis design is sophisticated and accurate. There is, however, still the suspicion that current prostheses can be considered "rudimentary" in comparison with the physiological and biomechanical behaviour of the human joint. We therefore wanted to begin an evaluation using a gait analysis system to assess patients fitted with knee prostheses. The first impressions gained in this study are the subject of this article.

Activities of Daily Living↗
PubMed2002

[Application of prosthesis replacement in limb salvage treatment of mild-malignant tumors at the articular ends of femurs].

OBJECTIVE: To investigate the clinical outcome of application of joint prosthesis in limb salvage treatment of mild-malignant tumor at the articular ends of femurs, with severe osteolysis. METHODS: The treatment of 15 cases of mild-malignant tumor at the articular ends of femurs with severe bone destruction, from 1978 to 1999, was reviewed. There were 10 cases of giant-cell bone tumor and 5 cases of chondrosarcoma, among which there were 5 cases at the stage of I A, 9 cases at I B, and 1 case at II A, with 4 cases at the proximal end and 11 cases at the distal end. The tumor was totally removed, with a massive bone defect left at the foci, and then the prosthesis replacement was performed to reconstruct the articular joint. All of the 15 patients were followed up for 9 months to 20 years, 4 years and 3 months on average, before clinical evaluation. RESULTS: All of the wound healed well, with primary healing. Local relapse occurred in one case and the patient died of lung metastasis; the amputation of the replaced knee joint was performed in one case due to severe infection after trauma; radiograph showed there was slight sunk of the prosthesis in 2 cases after replacement. The other 11 cases recovered well with satisfactory function. CONCLUSION: The limb salvage treatment of mild-malignant tumor at the articular ends of femurs would be available, especially for those with massive bone destruction, when the tumor is removed by whole and rationally marginal resection, followed by properly utilization of prosthesis and general post-operative exercise.

Adolescent↗
PubMed1993

The response to particulate debris.

The most common cause of failure of total hip and other arthroplasties is aseptic loosening of the prosthesis. Substantial evidence suggests that the adverse tissue response to prosthesis wear particles is an important contributor to bone loss around implants. The results may be an increased risk of loosening and severe bone loss, which makes revision surgery more difficult. Studies in humans have demonstrated that the appearances of the periprosthetic tissues are related to the type, number, and size of wear particles. The appearance and tissue response around any given prosthesis is related to the balance among the rate of production of wear particles, the ability of the tissues to deal with the particles, and the rate of clearance of the particles from the joint. Prosthesis wear particles may be produced by wear at the articulating surface, particularly if there is three-body wear, by abrasion due to movement at the prosthesis-bone interface of uncemented prostheses, by abrasion at the prosthesis-cement and cement-bone interfaces of cemented prostheses, or at any articulation of the components of modular prostheses. Future in vivo and in vitro studies of the effects of wear particles should focus on quantitative measurement of the effects of particles and on the use of particles of comparable size and in concentrations similar to those found in the tissues surrounding failed prostheses.

Animals↗
PubMed2004

Early results with a total patellofemoral joint replacement arthroplasty prosthesis.

This report concerns a new prosthesis for total patellofemoral joint replacement. Patients severely disabled due to isolated patellofemoral arthritis in whom all other treatment options had been tried and failed, or were not indicated, became candidates for this surgery. Fifteen patients met these criteria and were followed an average of 3.75 years (range: 2.25-5.5 years). Using the Activities of Daily Living Scale, 14 of 15 patients (93%) had excellent (85%-100%) or good (75%-84%) results, and 1 was fair (65%-74%).

Activities of Daily Living↗
PubMed2001

The influence of inserting a Fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics.

OBJECTIVE: To investigate the influence of inserting a Fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics. DESIGN: A finite element analysis was used to investigate the alteration of contact characteristics of the tibiofemoral joint due to inserting a pressure sensitive film between the contacting surfaces. BACKGROUND: The discrepancy between actual contact behaviors of tibiofemoral joint of knee prosthesis and the measurement using Fuji pressure sensitive film was not discussed extensively. The change of direct contact circumstance of the tibiofemoral joint due to inserting a pressure sensitive film was not well reported. METHOD: A two-dimensional finite element model of the tibiofemoral joint of knee prosthesis in the sagittal plane was constructed. Four different radii of the femoral component were used to investigate the conformity effect. Two-layers of plane strain element were used to model the pressure sensitive film. The influence of inserting a pressure sensitive film on the actual contact characteristics was analyzed by comparing the results of the change in contact radius. RESULTS: Inserting a pressure sensitive film between contacting surfaces would disturb the original contact behaviors, especially in the lowest conformity design. The maximum difference of contact radius between the model simulating actual contact circumstance and the model with inserting a pressure sensitive film between contacting surface was 77% in the lowest conformity condition at the smallest load. CONCLUSIONS: This study proposes a quantitative analysis of contact characteristics in the tibiofemoral joint of knee prosthesis between the models with and without inserting a pressure sensitive film into the contact surface. The measurement of contact area in artificial tibiofemoral joints by using Fuji pressure sensitive film is always overestimated its true contact area by 14-77%. RELEVANCE: This study revealed the measurement of contact characteristics of artificial tibiofemoral joints by using Fuji pressure sensitive film which depends on not only the applied load, but also the conformity and material properties of the contact surface. Therefore, the information of the conformity and material properties of the contact surface should be provided as well as the applied load wherever a measurement of contact characteristics using Fuji pressure sensitive film is analyzed and interpreted.

Biomechanical Phenomena↗