摘要:

AbstractExamination of a great number of tissue samples taken from the newly formed capsules surrounding artificial joints reveals small particles of prosthetic material. Abraded from the joint by wear and tear, these particles of plastic, metal, and acrylic cement initiate a foreign‐body reaction and result in the formation of granulation tissue, including macrophages and foreign‐body giant cells. Typical features of tissue reactions exist for each of the materials from which prostheses are made. The consequent formation of scar tissue produces a thickening of the capsule, which, in turn, may cause a reduction in the mobility of the joint.In small amounts, the foreign‐body particles are eliminated via the perivascular lymph spaces. Where this transport system is insufficient to handle the volume, however, the foreign‐body response may extend to the whole environment surrounding the joint. In such cases, there may be loosening of the cemented prosthetic parts because of deterioration of contiguous bone anchors by the tissue membrane lining the bone

ISSN:0021-9304    

DOI:10.1002/jbm.820110202

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractReplamineform porous implants (4 mm × 4 mm diameter) were placed into full‐thickness cartilage and bone defects of the weight‐bearing surface of the lateral femoral condyles of adult male white rabbits. These were analyzed at 1 day, 1 week, 6 weeks, 3 months, and 6 months for (1) ingrowth of tissue within the implants and (2) restoration of the articular surface overlying them. Appropriate unfilled, but similar, control defects were also studied.Mineralized bone was seen within the substance of both the TiO2and hydroxyapatite implants at 1 week; this extremely rapid response was present in every specimen studied and was not seen with αAl2O3or control animals. With the passage of time, maturation of this bone ingrowth occurred so that by 3 months, they were all incorportated into the surrounding bone.Only the hydroxyapatite implants showed consistent regenerative healing of hyaline articular cartilage from the margins of the defects with the passage of time; this occurred whenever the subchondral bone adjacent to the defect proliferated in a “creeping” fashion over the articular aspect of the implant, and the undamaged cartilage then followed it. Fibrocartilage, and not hyaline cartilage, formed the articular surface over the TiO2and αAl2O3implants and in th

ISSN:0021-9304    

DOI:10.1002/jbm.820110203

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractAn evaluation of a porous biodegradable ceramic, tricalcium phosphate, has been carried out. When implanted in cancellous bone, it is rapidly infiltrated with bone and slowly resorbed. When held rigidly against raw, bleeding, cortical bone, again rapid bone ingrowth occurs.The material does not give rise to any untoward tissue reaction, nor does it cause any systemic reaction. It can therefore be concluded that the material is safe for use in clinical practice, and can be used in specific instances either to replace or to supplement bone grafting.

ISSN:0021-9304    

DOI:10.1002/jbm.820110204

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractA single application of fluoride to the epiphysis of the femur induced accelerated bone formation. The additional bone gave rise to a stability effect on the implant inserted in the femur as expressed by an increased dislodgement force required.

ISSN:0021-9304    

DOI:10.1002/jbm.820110205

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractThirty different test patches of various thin film materials were chronically implanted in the subdural space of cats to determine their suitability as components for proposed neuroprosthetic devices. In particular, materials employed by the microelectronics industry were screened, and reactions were found to be quite dependent on specific formulations or surface preparations of otherwise similar materials. A nonspecific but severe complication of pressure necrosis under thin films that spontaneously roll and curlin vivowas noted.

ISSN:0021-9304    

DOI:10.1002/jbm.820110206

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractThe fate of methyl methacrylate in fresh human blood was investigatedin vitroby using gas chromatography. It was found that methyl methacrylate is present in cells in concentrations twice as large as in plasma, but it disappears exponentially with time at a rate that is at least 10 times faster than that in cells. The rate constant in cells is very small or even zero. The half‐life of methyl methacrylate in whole blood is 3 hr at 20°C. Gas chromatography is a convenient method for the rapid determination of methyl methacrylate levels in blo

ISSN:0021-9304    

DOI:10.1002/jbm.820110207

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractThe preparation and some properties of microspheres composed of oxidized polysaccharides and some vinyl polymers are described. The microspheres contain immobilized enzyme and can be slowly solubilized in water solutions, thereby releasing active a enzyme into the surrounding medium. The kinetic characteristics of the immobilized enzyme bound with a fragment of matrix after complete solubilization are unchanged, but the enzyme exhibits high thermostability. These preparations could have a wide range of medical applications, e.g., to form a drug “depot” directly in an affected or

ISSN:0021-9304    

DOI:10.1002/jbm.820110208

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractSurfaces of a segmented polyurethane were varied by casting on poly(ethylene terephthalate) (PET) and glass substrates, and were characterized through infrared‐attenuated total‐reflection spectroscopy (ATR). Surfaces cast on glass substrates showed a higher content of polyether segments, whereas those cast on PET contained a higher relative concentration of aromatic segments. Adsorption, and possible conformational changes of fibrinogen, were found to be more substantial on polymer surfaces having a higher content of polyether segments. It is concluded that the relatively good blood compatibility of segmented polyurethanes is partly due to the presence of peptide‐like bonds on aromatic seg

ISSN:0021-9304    

DOI:10.1002/jbm.820110209

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractA new antithrombogenic polymer was synthesized by photoinduced graft copolymerization of both a hydrophilic polymer and a cationic polymer to hydrophobic poly (vinyl chloride) copolymer, and by quarternizing and heparinizing the obtained graft copolymer.For polymers of various compositions obtained by the method described above, chemical composition, water absorption, membrane potential, and quantity of adsorbed heparin were determined and antithrombogenicity evaluatedin vivo. Thus, it has been found that the polymer of excellent antithrombogenicity has a negative membrane potential, a moderate elution rate of heparin, adsorbs heparin in a quantity of approximately 15 wt‐%, and has a degree of water adsorption of about 30 wt‐%. Also, measurement of membrane potential was very useful for the estimation of the quantity of the adsorbed heparin and its change with t

ISSN:0021-9304    

DOI:10.1002/jbm.820110210

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractThe analysis of the bonding interface between hip prostheses and bone after functional use in animals was carried out. Scanning electron microscopy (SEM) with energy dispersive analysis (EDX), and Auger electron spectroscopy were used to evaluate the bonding interface. Various methods of postsacrifice sample preparation were used to evaluate the effect of such different methods on the analysis of the bonding interface. Comparison of the results with several rat tibia implant experiments is also presented.

ISSN:0021-9304    

DOI:10.1002/jbm.820110211

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY