Orthopedic devices

Urethane gels and ultrasoft elastomers are a more recent development.18 They are made primarily by reacting high-molecular-weight polyether polyols with a stoichiometric deficiency of isocyanate. The low NCO-to-OH ratio allows for a wide latitude in hardness adjustment. These low-hardness elastomers are used for seating applications (such as gel bicycle seats), shoe inserts, and soft padding for orthopedic devices. 

S. epidermidis is implicated in many medical implant infections. Mechanical heart valves, shunts, catheters and orthopedic devices are examples of implanted devices... 

The success of hip replacements has been greatly advanced by major development in the biomaterials for orthopedic devices. What aspects of chemistry must be considered in designing an effective artificial hip ... 

Biomedical devices, 3 707, 709 cardiovascular devices, 3 709-721 orthopedic devices, 3 721-735 tantalum, 24 327 Biomedical research, 9 43 radiotracers in, 21 279-280 transgenic and gene-targeted mice for, 12 466-167... 

Cobalt alloys, 7 219-226. See also Cobalt high temperature alloys for orthopedic devices, 3 728 selenium and metallurgy of, 22 98 Cobalt alloy T-800, 7 223 properties, 7 223t CobaltCII) aluminate, uses, 7 241t Cobalt aluminate blue spinel, formula and DCMA number, 7 348t Cobalt Aluminate Blue, pigment for plastics, 7 370t... 

Orthopedic devices, 3 721-735 joint replacement, 3 727-735 Orthopedic marrow needles, 3 743-744 Orthophosphate (PO4), in soil, 11 112 Orthophosphates, 18 830-841 20 637 magnesium, 18 839 manufacture of, 18 853-855 Orthophosphate salts, 18 836 Orthophosphoric acid, 18 815, 817-826 condensation of, 18 826 properties of, 18 817-819 solubility of boron halides in, 4 140t orf/zo-phthalic resins, 20 101, 113 formulation of, 20 102 Orthorhombic crystal system, 8 114t Orthorhombic phosphorus pentoxide, 19 49 Orthorhombic structure, of ferroelectric crystals, 11 95, 96 Orthorhombic symmetry, 8 114t Orthosilicate monomers, in silicate glasses, 22 453... 

Orthopedic devices -trans-l,4-polyisoprene m [ELASTOMERS SYNTHETIC - POLYISOPRENE] (Vol 9)... 

III Cardiac pacemakers, intrauterine devices, intraocular tens, heart valves, orthopedic devices PMA... 

Middleton, J. C. Tipton, A. J., Synthetic biodegradable polymers as orthopedic devices. Biomaterials 2000, 21, 2335-2346... 

Electrochemical corrosion is important to the stability and longevity of implants. Evidence suggests that uniform attack and crevice and pitting corrosion are the most important degradation modes with multipart orthopedic devices (17). Corrosion of devices with blood contact is more complex, due to the oxygenated flowing electrolyte. The cost of this corrosion has not been estimated, but it could be substantially greater than the battery market because the latter is a small fraction of the total cost of the device and associated medical operations. 

Being used in several forms of orthopedic devices Making inroads in a number of new vascular applications... 

Ultra high molecular weight polyethylene Linear thermoplastics with very high molecular weight (>2 X 10 g/mol) used for orthopedic devices such as acetabular cup for hip joint replacement. Umbilical cord vein grafts Vascular graft made from umbdical cord veins. 

MAJOR APPLICATIONS Used mainly in high-quality golf ball covers and orthopedic devices and splints in transmission belts, cable coverings, and adhesives and in prosthetics, braces, casts, and attachments for artificial limbs. ... 

Campoccia, D., Montanaro, L. Arciola C. R. (2006). The significance of infection related to orthopedic devices and issues of antibiotic resistance. Biomaterials, 27, 2331-2339. 

Table 12.1 summarizes some of the tests discussed in the FDA guidance document Data Requirements for Ultra-High Molecular Weight Polyethylene (UHMWPE) used in Orthopedic Devices (FDA 1995). If the new polyetirylene has almost identical properties to a polyethylene already on the market after stage 1 testing, no further testing may be required. If it does differ in properties from an existing... 

The American Standards for Testing and Materials (ASTM) has compiled a list of the recommended properties that polyethylene components must meet or exceed if they are to be used in orthopedic devices. This list is summarized in ASTM F648 and D4020-01a. The FDA usually refers to these standards when considering a new UHMWPE for orthopedic implants. A summary of all possible tests, including their ASTM standard numbers, where applicable, is summarized in Table 12.2, and indicates where the individual tests are appropriate for UHMWPE powder, consolidated stock, or irradiated stock. 

Mechanical properties are critical for UHMWPE that is to be used in an orthopedic device. The tests indicated next are commonly used by researchers in preparing an FDA application. 

Creep, or room-temperature flow upon application of a stress such as body weight, is an issue in orthopedic devices containing a UHMWPE (Kang and Nho 2001). These components are usually machined to tight tolerances, and long-term stability of the implant depends on maintaining these tolerance dimensions in the body. If an acetabular liner or tibial tray undergoes excessive creep, the leg can shorten or dislocations can occur. Minimization of creep is thus desired. 

Federal Dmg Administration. 1995. Data requirements for ultra-high molecular weight polyethylene (UHMWPE) used in orthopedic devices. Document FOD180. Rockville, MD FDA. 

Orthopedic Devices Branch Division of General and Restorative Devices Center for Devices and Radiological Health U.S. Food and Drug Administration... 

The purpose of this document is to list the data needed for orthopedic devices containing UHMWPE. These data should be included in premarket notifications (510k), Investigational Device Exemptions (IDE) applications. Premarket Approval (PMA) applications, reclassification petitions, and master files to aid FDA in determining the substantial equivalence and/or safety and effectiveness of UHMWPE in implantable orthopedic devices. In this document UHMWPE is referred to as polyethylene (PE). 

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