1、Designation: F1672 95 (Reapproved 2011)Standard Specification forResurfacing Patellar Prosthesis1This standard is issued under the fixed designation F1672; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers patellar resurfacing devicesused to provide a functioning articulation between the patellaand the femur.1.2
3、 This specification is intended to provide basic descrip-tions of material and device geometry. Additionally, thosecharacteristics determined to be important to in-vivo perfor-mance of the device are defined.1.3 This specification does not cover the details for qualityassurance, design control, and
4、production control contained in21 CFR 820 and ISO 9001.NOTE 1Devices for custom applications are not covered by thisspecification.2. Referenced Documents2.1 ASTM Standards:2F75 Specification for Cobalt-28 Chromium-6 MolybdenumAlloy Castings and Casting Alloy for Surgical Implants(UNS R30075)F86 Prac
5、tice for Surface Preparation and Marking of Me-tallic Surgical ImplantsF90 Specification for Wrought Cobalt-20Chromium-15Tungsten-10Nickel Alloy for Surgical Implant Applica-tions (UNS R30605)F136 Specification for Wrought Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial) Alloy for SurgicalI
6、mplant Applications (UNS R56401)F138 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for SurgicalImplants (UNS S31673)F451 Specification for Acrylic Bone CementF562 Specification for Wrought 35Cobalt-35Nickel-20Chromium-10Molybdenum Alloy for Surgical Implant
7、Applications (UNS R30035)F563 Specification for Wrought Cobalt-20Nickel-20Chromium-3.5Molybdenum-3.5Tungsten-5Iron Alloyfor Surgical Implant Applications (UNS R30563)3F603 Specification for High-Purity Dense Aluminum Oxidefor Medical Application3F648 Specification for Ultra-High-Molecular-Weight Pol
8、y-ethylene Powder and Fabricated Form for Surgical Im-plantsF732 Test Method for Wear Testing of Polymeric MaterialsUsed in Total Joint ProsthesesF745 Specification for 18Chromium-12.5Nickel-2.5Molybdenum Stainless Steel for Cast and Solution-Annealed Surgical Implant ApplicationsF746 Test Method fo
9、r Pitting or Crevice Corrosion ofMetallic Surgical Implant MaterialsF748 Practice for Selecting Generic Biological Test Meth-ods for Materials and DevicesF799 Specification for Cobalt-28Chromium-6MolybdenumAlloy Forgings for Surgical Implants (UNS R31537,R31538, R31539)F981 Practice for Assessment o
10、f Compatibility of Biomate-rials for Surgical Implants with Respect to Effect ofMaterials on Muscle and BoneF983 Practice for Permanent Marking of Orthopaedic Im-plant ComponentsF1044 Test Method for Shear Testing of Calcium PhosphateCoatings and Metallic CoatingsF1108 Specification for Titanium-6Al
11、uminum-4VanadiumAlloy Castings for Surgical Implants (UNS R56406)F1147 Test Method for Tension Testing of Calcium Phos-phate and Metallic Coatings2.2 Government Document:21 CFR 820 Good Manufacturing Practice for MedicalDevices42.3 ISO Standard:ISO 9001 Quality Systems Model for Quality Assurance in
12、Design/Development, Production, Installation, and Ser-vicing51This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is under the direct responsibility ofSubcommittee F04.22 on Arthroplasty.Current edition approved March 1, 2011. Published
13、 April 2011. Originallyapproved in 1995. Last previous edition approved in 2005 as F1672 95 (2005).DOI: 10.1520/F1672-95R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, r
14、efer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Available from Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402.5Available from American National Standards
15、Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Terminology3.1 DefinitionsDimensions defined as follows are mea-sured in whole or in part in the sagittal, transverse,
16、and coronal(or frontal) planes as appropriate. See Fig. 1 and Fig. 2.3.1.1 T1 total overall prosthetic thickness, for example,from the apex of the dome to the free end of pegs or otherfixation geometry.3.1.2 T2 thickness of the patellar prosthesis from theplane of the bone-prosthesis interface (excl
17、uding pegs, keels,and so forth) to the apex of the articulating surface.3.1.3 T3 minimum polymer thickness of the patellarprosthesis in direct contact with the femoral component that is“at risk” for wear; this is measured perpendicular to the tangentof the wear surface at the point of contact with t
18、he femoralcomponent.3.1.4 DiscussionThe dimension T3is shown in Fig. 1 andFig. 2 to be the distance from a surface contact point to aninternal peg or an edge of the metal back. The exact location ofthe minimum thickness at risk may be at a different site andwill depend on the design of the patella p
19、rosthesis and themating femoral component. For devices manufactured from asingle material, T3should be measured from the wear surfaceto the back of the fixation surface.3.1.5 W1maximum medial-lateral width of the articulat-ing surface in the frontal plane.3.1.6 W2maximum medial-lateral width of the
20、metal backin the frontal plane.3.1.7 H1articulating surface superior-inferior height in thefrontal plane.3.1.8 H2metal back superior-inferior height in the frontalplane.3.1.9 Rcradius of curvature for single radius axisymmet-ric domes only.3.2 Definitions of Terms Specific to This Standard:3.2.1 dom
21、ea style of axisymmetrical prosthesis that has asingle uniform radius of curvature (that is, button).3.2.2 fixation elementany peg, keel, or other protrusionfrom the nonarticulating side of the patellar component in-tended to increase the surface contact or mechanical interlockbetween the component,
22、 the bonding agent (bone cement) orthe natural patella, or both.3.2.3 marker wirea nonstructural, generally thin metallicwire, designed to be apparent on X-rays taken after placementof implants that otherwise would not be apparent on suchX-rays.3.2.4 metal backa metal structure supporting the articu
23、-lating surface material. This may be fixed rigidly to thearticulating surface or it may be fixed such that it allows thearticulating surface to rotate or translate.3.2.5 radii of curvaturethe geometry of the articularsurface may be described by a list of appropriate radii ofcurvature.3.2.6 sombrero
24、a style of axisymmetric prosthesis that hasmultiple radii of curvature. (SeeFig. 1c.)4. Classification4.1 Patellar replacement devices may be classified accord-ing to geometry:4.1.1 Axisymmetric The articulating surface is symmetricon an axis perpendicular to the prepared bonding surface (forexample
25、, Dome patellas and sombrero-type patellas). See Fig.1.4.1.2 Nonsymmetric The articulating surface is not axi-symmetric but may be symmetric on a plane. Examples of thistype are anatomical or oblong prosthesis. See Fig. 2.4.2 It is important to define the type of fixation geometry sothat the user ca
26、n understand the degree of bone invasion:4.2.1 PegNumber, size (for example: length, width, di-ameter, and so forth), and location and4.2.2 KeelWidth, length, thickness, geometry, and loca-tion.5. Materials and Manufacture5.1 The choice of materials is understood to be a necessarybut not sufficient
27、assurance of function of the device madefrom them.All devices conforming to this specification shall befabricated from materials with adequate mechanical strengthand durability, corrosion resistance and biocompatibility.5.1.1 Mechanical StrengthComponents of various pros-theses have been successfull
28、y fabricated from materials in thefollowing Specifications: F75, F90, F136, F138, F562, F563,F603, F648, F745, F799, and F1108. The articulating surfaceshould be fabricated from a material such as UHMWPE inaccordance with Specification F648.5.1.2 Corrosion ResistanceMaterials with limited or nohisto
29、ry of successful use for orthopedic implant applicationshall exhibit corrosion resistance equal to or better than one ofthe materials listed in 5.1.1 when tested in accordance withTest Method F746.(a) (b) (c)NOTE 1Figure 1(a) and (b) show a dome style and Fig. 1(c) shows asombrero style.FIG. 1 Two V
30、ersions of Axisymmetric Patella Prostheses(a) Transverse Cross Section WithLateral to the Right(b) Sagittal Cross SectionFIG. 2 Example of a Nonsymmetric Patella ProsthesisF1672 95 (2011)25.1.3 Biocompatibility Materials with limited or no his-tory of successful use for orthopedic implant applicatio
31、n shallexhibit an acceptable biological response equal to or better thanone of the materials listed in 5.1.1 when tested in accordancewith Practices F748 and F981.6. Performance Requirements6.1 The implant shall be capable of withstanding sustainedstatic and dynamic physiologic loads without comprom
32、ise ofits function for the intended use and environment. At this timethere are no device-specific test methods and there are noacceptable performance levels. Device testing shall be done inkeeping with the implants intended function.6.2 There are relevant failure modes listed as follows which,at a m
33、inimum, shall be considered in the evaluation of thesafety and efficacy of a patella prosthesis. Literature references(18)6have been included in the rationale statement in supportof these failure modes.6.2.1 Dislocation or Lateral SubluxationSubluxationover the lateral portion of the femoral articul
34、ar surface hasoccurred in the past and is design- and patient-specific.6.2.2 Component DisassociationDevices made from mul-tiple layers or components have disassociated under clinicaluse (for example, the articulating surface from the metal back,porous coating from the metal back, and so forth). Thi
35、sdisassociation may be evaluated through shear loading orcompression loading, or a combination of the two.6.2.3 Fixation Failure Devices have loosened at theinterface with bone.Attachment mechanisms such as pegs havesheared or failed. Components have become loose within thebone cement.6.2.4 Device F
36、racture Partial or complete fracture ofeither the articular surface or the metal back has occurred.6.2.5 Articular Surface WearPatella prostheses havefailed due to excessive wear of the articulating surface result-ing in polymer debris and in some cases “wear through” of thearticular surface with su
37、bsequent metal-on-metal wear debris.Thin UHMWPE may accelerate this wear but it is design-dependent.6.3 The failure modes may be addressed through relevanttesting (for example, shear testing of device component inter-faces) and analysis (for example, analysis of internal stress dueto loading). The t
38、esting may encompass some combination ofstatic and dynamic loading environments.6.4 Polymeric components as manufactured shall be madefrom materials demonstrating wear rates substantially equiva-lent to or less than UHMWPE as determined by Practice F732.NOTE 2In situations where the pin-on-flat test
39、 may not be consideredappropriate, other test methods may be considered.6.5 Porous metal coatings shall be tested according to TestMethod F1044 (shear strength) and Test Method F1147 (tensilestrength).7. Dimensions, Mass, and Permissible Variations7.1 Dimensions of patellar resurfacing devices shall
40、 be asdesignated, but not limited to those described, in Fig. 1 and Fig.2. The tolerance and methods of dimensional measurementshall conform with industry practice and, whenever possible,on an international basis.8. Finish and Product Marking8.1 Items conforming to this specification shall be finish
41、edin accordance with Practice F86, where applicable.8.2 Polymeric Bearing Surface FinishThe polymericbearing surface finish shall conform to the manufacturersdocumented standards concerning concentricity, sphericity, andsurface roughness, where applicable.8.3 The manufacturer, lot number, and materi
42、al type shall bemarked (space permitting) on the device in accordance withPractices F86 and F983 in the order of priority listed.8.4 Optional marking shall specify the orientation for non-symmetric devices.8.5 If one of the components is not radiographically opaque,it may be appropriately marked for
43、 radiographic evaluation.The marker wire is a noncritical element and may not benecessary. If a marker wire is used it should be placed in anoncritical area to avoid degrading the structural and functionalproperties of the device.9. Packaging and Package Marking9.1 Adequate dimensioning to describe
44、overall size andshape (see Fig. 1 and Fig. 2 for examples) shall be included inthe product labeling.9.2 The material(s) used for the implant shall be specifiedon the package labels and inserts.10. Keywords10.1 arthroplasty; patella; prosthesis6The boldface numbers given in parentheses refer to a lis
45、t of references at theend of the text.F1672 95 (2011)3APPENDIX(Nonmandatory Information)X1. RATIONALE STATEMENTX1.1 The objectives of this specification are to establishguidelines for the manufacture and function of components forpatellar replacement. Current prostheses include single mate-rial desi
46、gns and multiple material/component designs all pre-assembled at the manufacturing site. Some multi-componentdesigns allow a certain degree of mobility of the bearingsurface over the fixation surface. Patellar replacement parts areintended for use in a patient who is skeletally mature. They willbe s
47、ubjected to considerable dynamic loads in a corrosiveenvironment and virtually continuous motion at the bearingsurfaces.X1.2 This specification is designed to provide a standard-ization of device terminology, classification, dimensions, andlabeling; alert designers to potential failure mechanisms su
48、chas disassociation, excessive wear, dislocation, and so forth(Refs (1-8); and provide guidance regarding suitable materialsfor fabrication based on current technology and clinical use.X1.3 Laboratory tests to accurately simulate physiologicalloads, aggressive electrolytes, and complex constituents
49、ofbody fluids cannot to date entirely simulate long-term in-vivoperformance. It is recognized that failure of the arthroplastycan occur without failure of the device itself. Long-termprojections of satisfactory performance can be suggested butnot accurately predicted using available testing procedures.This specification identifies those factors felt to be important toensure a satisfactory useful prosthetic life.X1.4 Under applicable documents and materials, the listsreflect the current state of the art. It is recognized that shouldmaterials not
