1、Designation: F1672 95 (Reapproved 2011)F1672 14Standard 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 re
2、vision. 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 devices used to provide a functioning articulation between the patella and the
3、femur.1.2 This specification is intended to provide basic descriptions of material and device geometry. Additionally, thosecharacteristics determined to be important to in-vivo performance of the device are defined.1.3 This specification does not cover the details for quality assurance, design contr
4、ol, and production control contained in 21CFR 820 and ISO 9001.NOTE 1Devices for custom applications are not covered by this specification.2. Referenced Documents2.1 ASTM Standards:2F75 Specification for Cobalt-28 Chromium-6 Molybdenum Alloy Castings and Casting Alloy for Surgical Implants (UNSR3007
5、5)F86 Practice for Surface Preparation and Marking of Metallic Surgical ImplantsF90 Specification for Wrought Cobalt-20Chromium-15Tungsten-10Nickel Alloy for Surgical Implant Applications (UNSR30605)F136 Specification for Wrought Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial) Alloy for Su
6、rgical ImplantApplications (UNS R56401)F138 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for Surgical Implants(UNS S31673)F451 Specification for Acrylic Bone CementF562 Specification for Wrought 35Cobalt-35Nickel-20Chromium-10Molybdenum Alloy for Surgical
7、Implant Applications(UNS R30035)F563 Specification for Wrought Cobalt-20Nickel-20Chromium-3.5Molybdenum-3.5Tungsten-5Iron Alloy for Surgical ImplantApplications (UNS R30563) (Withdrawn 2005)3F603 Specification for High-Purity Dense Aluminum Oxide for Medical ApplicationF648 Specification for Ultra-H
8、igh-Molecular-Weight Polyethylene Powder and Fabricated Form for Surgical ImplantsF732 Test Method for Wear Testing of Polymeric Materials Used in Total Joint ProsthesesF745 Specification for 18Chromium-12.5Nickel-2.5Molybdenum Stainless Steel for Cast and Solution-Annealed SurgicalImplant Applicati
9、ons (Withdrawn 2012)3F746 Test Method for Pitting or Crevice Corrosion of Metallic Surgical Implant MaterialsF748 Practice for Selecting Generic Biological Test Methods for Materials and DevicesF799 Specification for Cobalt-28Chromium-6Molybdenum Alloy Forgings for Surgical Implants (UNS R31537, R31
10、538,R31539)F981 Practice for Assessment of Compatibility of Biomaterials for Surgical Implants with Respect to Effect of Materials onMuscle and Bone1 This specification is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is under the direct responsibilit
11、y ofSubcommittee F04.22 on Arthroplasty.Current edition approved March 1, 2011April 1, 2014. Published April 2011April 2014. Originally approved in 1995. Last previous edition approved in 20052011 asF1672 95 (2005).(2011). DOI: 10.1520/F1672-95R11.10.1520/F1672-14.2 For referencedASTM standards, vis
12、it theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This docum
13、ent is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as a
14、ppropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1F983 Practice for Permanent Marking of Orthopaedic Implant
15、 ComponentsF1044 Test Method for Shear Testing of Calcium Phosphate Coatings and Metallic CoatingsF1108 Specification for Titanium-6Aluminum-4Vanadium Alloy Castings for Surgical Implants (UNS R56406)F1147 Test Method for Tension Testing of Calcium Phosphate and Metallic CoatingsF1160 Test Method fo
16、r Shear and Bending Fatigue Testing of Calcium Phosphate and Metallic Medical and Composite CalciumPhosphate/Metallic Coatings2.2 Government Document:21 CFR 820 Good Manufacturing Practice for Medical Devices42.3 ISO Standard:ISO 9001 Quality Systems Model for Quality Assurance in Design/Development
17、, Production, Installation, and Servicing53. Terminology3.1 DefinitionsDimensions defined as follows are measured in whole or in part in the sagittal, transverse, and coronal (orfrontal) planes as appropriate. See Fig. 1 and Fig. 2.3.1.1 T1total overall prosthetic thickness, for example, from the ap
18、ex of the dome to the free end of pegs or other fixationgeometry.3.1.2 T2thickness of the patellar prosthesis from the plane of the bone-prosthesis interface (excluding pegs, keels, and soforth) to the apex of the articulating surface.3.1.3 T3minimum polymer thickness of the patellar prosthesis in d
19、irect contact with the femoral component that is “at risk”for wear; this is measured perpendicular to the tangent of the wear surface at the point of contact with the femoral component.3.1.4 DiscussionThe dimension T3 is shown in Fig. 1 and Fig. 2 to be the distance from a surface contact point to a
20、n internalpeg or an edge of the metal back. The exact location of the minimum thickness at risk may be at a different site and will dependon the design of the patella prosthesis and the mating femoral component. For devices manufactured from a single material, T3should be measured from the wear surf
21、ace to the back of the fixation surface.3.1.5 W1maximum medial-lateral width of the articulating surface in the frontal plane.3.1.6 W2maximum medial-lateral width of the metal back in the frontal plane.3.1.7 H1articulating surface superior-inferior height in the frontal plane.4 Available from Superi
22、ntendent of Documents, U.S. Government Printing Office, Washington, DC 20402.5 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.(a) (b) (c)NOTE 1Figure 1(a) and (b) show a dome style and Fig. 1(c) shows a sombrero style.FIG. 1 Two Versions of
23、 Axisymmetric Patella Prostheses(a) Transverse Cross Section WithLateral to the Right(b) Sagittal Cross SectionFIG. 2 Example of a Nonsymmetric Patella ProsthesisF1672 1423.1.8 H2metal back superior-inferior height in the frontal plane.3.1.9 Rcradius of curvature for single radius axisymmetric domes
24、 only.3.2 Definitions of Terms Specific to This Standard:3.2.1 domea style of axisymmetrical prosthesis that has a single uniform radius of curvature (that is, button).3.2.2 fixation elementany peg, keel, or other protrusion from the nonarticulating side of the patellar component intended toincrease
25、 the surface contact or mechanical interlock between the component, the bonding agent (bone cement) or the naturalpatella, or both.3.2.3 marker wirea nonstructural, generally thin metallic wire, designed to be apparent on X-rays taken after placement ofimplants that otherwise would not be apparent o
26、n such X-rays.3.2.4 metal backa metal structure supporting the articulating surface material. This may be fixed rigidly to the articulatingsurface or it may be fixed such that it allows the articulating surface to rotate or translate.3.2.5 radii of curvaturethe geometry of the articular surface may
27、be described by a list of appropriate radii of curvature.3.2.6 sombreroa style of axisymmetric prosthesis that has multiple radii of curvature. (See Fig. 1c.)4. Classification4.1 Patellar replacement devices may be classified according to geometry:4.1.1 AxisymmetricThe articulating surface is symmet
28、ric on an axis perpendicular to the prepared bonding surface (forexample, Dome patellas and sombrero-type patellas). See Fig. 1.4.1.2 NonsymmetricThe articulating surface is not axisymmetric but may be symmetric on a plane. Examples of this type areanatomical or oblong prosthesis. See Fig. 2.4.2 It
29、is important to define the type of fixation geometry so that the user can understand the degree of bone invasion:4.2.1 PegNumber, size (for example: length, width, diameter, and so forth), and location, and4.2.2 KeelWidth, length, thickness, geometry, and location.5. Materials and Manufacture5.1 The
30、 choice of materials is understood to be a necessary but not sufficient assurance of function of the device made fromthem. All devices conforming to this specification shall be fabricated from materials with adequate mechanical strength anddurability, corrosion resistance and biocompatibility.5.1.1
31、Mechanical StrengthComponents of various prostheses have been successfully fabricated from materials in thefollowing Specifications: F75, F90, F136, F138, F562, F563, F603, F648, F745, F799, and F1108. The articulating surface shouldbe fabricated from a material such as UHMWPE in accordance with Spe
32、cification F648.5.1.2 Corrosion ResistanceMaterials with limited or no history of successful use for orthopedic implant application shallexhibit corrosion resistance equal to or better than one of the materials listed in 5.1.1 when tested in accordance with Test MethodF746.5.1.3 BiocompatibilityMate
33、rials with limited or no history of successful use for orthopedic implant application shall exhibitan acceptable biological response equal to or better than one of the materials listed in 5.1.1 when tested in accordance withPractices F748 and F981.6. Performance Requirements6.1 The implant shall be
34、capable of withstanding sustained static and dynamic physiologic loads without compromise of itsfunction for the intended use and environment. At this time there are no device-specific test methods and there are no acceptableperformance levels. Device testing shall be done in keeping with the implan
35、ts intended function.6.2 There are relevant failure modes listed as follows which, at a minimum, shall be considered in the evaluation of the safetyand efficacy of a patella prosthesis. Literature references (18) (1-8)6 have been included in the rationale statement in support ofthese failure modes.6
36、.2.1 Dislocation or Lateral SubluxationSubluxation (Over the Lateral Portion of the Femoral Articular Surface)Subluxation over the lateral portion of the femoral articular surface This has occurred in the past and is design-design andpatient-specific. patient specific.6.2.2 Component DisassociationD
37、evices made from multiple layers or components have disassociated under clinical use (forexample, the articulating surface from the metal back, the porous coating from the metal back, and so forth). This disassociationmay be evaluated through shear loading or compression loading, or a combination of
38、 the two.6.2.3 Fixation FailureDevices have loosened at the interface with bone. Attachment mechanisms such as pegs have shearedor failed. Components have become loose within the bone cement.6 The boldface numbers given in parentheses refer to a list of references at the end of the text.F1672 1436.2
39、.4 Device FracturePartial or complete fracture of either the articular surface or the metal back has occurred.back.6.2.5 Articular Surface WearPatellaPatellar prostheses have failed due to excessive wear of the articulating surface resultingin polymer debris and in some cases “wear through” of the a
40、rticular surface with subsequent metal-on-metal wear debris. ThinUHMWPE may accelerate this wear but it is design-dependent.6.3 The failure modes may be addressed through relevant testing (for example, shear testing of device component interfaces)and analysis (for example, analysis of internal stres
41、s due to loading). stress analysis due to loading in accordance with 6.3.1). Thetesting may encompass some combination of static and dynamic loading environments.6.3.1 Contact area and contact pressure distributions may be determined at various flexion angles using one of several publishedmethods (9
42、-14) to provide a representation of stresses applied to the bearing surfaces and to the components. Fig. 3 shows apossible test set-up configuration. The position of the patella component in relation to the femoral component should be definedas a result of biomechanical analysis. Flexion angles of 1
43、5, 45, and 90 with corresponding loads of 377, 961, and 2195 N,respecitvely, are recommended (15-19). If the prosthesis is designed to function at higher flexion angles, then these measurementsshould also be made at the maximum flexion angle and the corresponding loading conditions justified. If the
44、se tests are performed,it is important to maintain consistent test parameters and to evaluate other prostheses under the same conditions.6.4 Polymeric components as manufactured shall be made from materials demonstrating wear rates substantially equivalent toor less than UHMWPE as determined by Prac
45、tice F732.NOTE 2In situations where the pin-on-flat test may not be considered appropriate, other test methods may be considered.6.5 Porous metal coatings shall be tested according to Test Method F1044 (shear strength) and Test Method F1147 (tensilestrength).strength) and the coating strength for ea
46、ch test should exceed 20 MPa. The fatigue properties may be evaluated inaccordance with Test Method F1160.7. Dimensions, Mass, and Permissible Variations7.1 Dimensions of patellar resurfacing devices shall be as designated, but not limited to those described, in Fig. 1 and Fig. 2.The tolerance and m
47、ethods of dimensional measurement shall conform with industry practice and, whenever possible, on aninternational basis.8. Finish and Product Marking8.1 Items conforming to this specification shall be finished in accordance with Practice F86, where applicable.8.2 Polymeric Bearing Surface FinishThe
48、polymeric bearing surface finish shall conform to the manufacturers documentedstandards concerning concentricity, sphericity, and surface roughness, where applicable.8.3 The manufacturer, lot number, and material type shall be marked (space permitting) on the device in accordance withPractices F86 a
49、nd 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 radiographic evaluation. Themarker wire is a noncritical element and may not be necessary. If a marker wire is used it should be placed in a noncritical areato avoid degrading the structural and functional properties of the device.FIG. 3 Test Configuration for Contact Area and Contact Stress MeasurementsF1672 1449. Packaging and Pa
