1、Designation: F543 13Standard Specification and Test Methods forMetallic Medical Bone Screws1This standard is issued under the fixed designation F543; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber
2、 in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification provides requirements for materials,finish
3、and marking, care and handling, and the acceptabledimensions and tolerances for metallic bone screws that areimplanted into bone. The dimensions and tolerances in thisspecification are applicable only to metallic bone screwsdescribed in this specification.1.2 This specification provides performance
4、considerationsand standard test methods for measuring mechanical propertiesin torsion of metallic bone screws that are implanted into bone.These test methods may also be applicable to other screwsbesides those whose dimensions and tolerances are specifiedhere. The following annexes are included:1.2.
5、1 Annex A1Test Method for Determining the Tor-sional Properties of Metallic Bone Screws.1.2.2 AnnexA2Test Method for Driving Torque of Medi-cal Bone Screws.1.2.3 Annex A3Test Method for Determining the AxialPullout Strength of Medical Bone Screws.1.2.4 Annex A4Test Method for Determining the Self-Ta
6、pping Performance of Self-Tapping Medical Bone Screws.1.2.5 Annex A5Specifications for Type HA and Type HBMetallic Bone Screws.1.2.6 Annex A6Specifications for Type HC and Type HDMetallic Bone Screws.1.2.7 Annex A7Specifications for Metallic Bone ScrewDrive Connections.1.3 This specification is base
7、d, in part, upon ISO 5835, ISO6475, and ISO 9268.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 Multiple test methods are included in this standard.However, it must be noted that the user is not obligated to testusing a
8、ll of the described methods. Instead, the user shouldonly select test methods that are appropriate for a particulardevice design. In most instances, only a subset of the hereindescribed test methods will be required.1.6 This standard may involve the use of hazardousmaterials, operations, and equipme
9、nt. This standard does notpurport to address all of the safety concerns, if any, associatedwith its use. It is the responsibility of the user of this standardto establish appropriate safety and health practices anddetermine the applicability of regulatory limitations prior touse.2. Referenced Docume
10、nts2.1 ASTM Standards:2E4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE8 Test Methods for Tension Testing of Metallic MaterialsE122 Practice for Calculating Sample Size to Estimate, WithSpecified Precision, the Average for a Characteris
11、tic of aLot or ProcessF67 Specification for Unalloyed Titanium, for Surgical Im-plant Applications (UNS R50250, UNS R50400, UNSR50550, UNS R50700)F86 Practice for Surface Preparation and Marking of Metal-lic Surgical ImplantsF116 Specification for Medical Screwdriver BitsF136 Specification for Wroug
12、ht Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial)Alloy for SurgicalImplant Applications (UNS R56401)F138 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for SurgicalImplants (UNS S31673)F565 Practice for Care and Handling of Orthopedic Implantsand
13、InstrumentsF620 Specification for Titanium Alloy Forgings for SurgicalImplants in the Alpha Plus Beta ConditionF799 Specification for Cobalt-28Chromium-6MolybdenumAlloy Forgings for Surgical Implants (UNS R31537,R31538, R31539)1This specification is under the jurisdiction of ASTM Committee F04 onMed
14、ical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee Osteosynthesis.Current edition approved May 1, 2013. Published June 2013. Originallyapproved in 1977. Last previous edition approved in 2009 as F543 071. DOI:10.1520/F0543-13.2For referenced ASTM standards, visit
15、 the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959
16、. United States1F983 Practice for Permanent Marking of Orthopaedic Im-plant ComponentsF1295 Specification for Wrought Titanium-6Aluminum-7Niobium Alloy for Surgical Implant Applications (UNSR56700)F1314 Specification for Wrought Nitrogen Strengthened 22Chromium13 Nickel5 Manganese2.5 MolybdenumStain
17、less Steel Alloy Bar and Wire for Surgical Implants(UNS S20910)F1472 Specification for Wrought Titanium-6Aluminum-4VanadiumAlloy for Surgical ImplantApplications (UNSR56400)F1537 Specification for Wrought Cobalt-28Chromium-6Molybdenum Alloys for Surgical Implants (UNSR31537, UNS R31538, and UNS R315
18、39)F1586 Specification for Wrought Nitrogen Strengthened21Chromium10Nickel3Manganese2.5Molybdenum Stainless Steel Alloy Bar for SurgicalImplants (UNS S31675)F1713 Specification for Wrought Titanium-13Niobium-13Zirconium Alloy for Surgical Implant Applications(UNS R58130) (Withdrawn 0)3F1813 Specific
19、ation for Wrought Titanium-12Molybdenum-6Zirconium-2Iron Alloy for Surgical Implant (UNSR58120)F1839 Specification for Rigid Polyurethane Foam for Use asa Standard Material for Testing Orthopaedic Devices andInstrumentsF2066 Specification for Wrought Titanium-15 MolybdenumAlloy for Surgical Implant
20、Applications (UNS R58150)2.2 ISO Standards:5835 Implants for SurgeryMetal Bone Screws with Hex-agonal Driver Connection, Spherical Under Surface ofHead, Asymmetrical ThreadDimensions46475 Implants for SurgeryMetal Bone Screws withAsym-metrical Thread and Spherical Under-SurfaceMechanical Requirement
21、s and Test Methods48319-1 Orthopaedic InstrumentsDrive connectionsPart1: Keys for use with hexagon socket heads48319-2 Orthopaedic InstrumentsDrive connectionsPart2: Screwdrivers for single slot head screws, screws withcruciate and cross-ecessed head screws49268 Implants for SurgeryMetal Bone Screws
22、 with Coni-cal Under-Surface of HeadDimensions410664 Hexalobular Internal Driving Feature for Bolts andScrews43. Terminology3.1 DefinitionsSome of the terms defined in this sectionare shown in Fig. 1.3.1.1 axial pullout strengththe tensile force required tofail or remove a bone screw from a material
23、 into which thescrew has been inserted.3.1.2 breaking angleangle of rotation when the screw failsin torsion as demonstrated by a rapid decrease in the indicatedtorque.3.1.3 buttress threadan asymmetrical thread profile char-acterized by a pressure flank which is nearly perpendicular tothe screw axis
24、.3.1.4 cancellous screwa screw designed primarily to gainpurchase into cancellous bone. Cancellous screws typicallyhave an HB (see 4.1.2) thread and may or may not be fullythreaded.3.1.5 cortical screwa screw designed primarily to gainbiocortical purchase into cortical bone. Cortical screws typi-cal
25、ly have a HA (see 4.1.1) thread and are fully threaded.3.1.6 core diameterthe smallest diameter of the threadedportion of the screw measured at the thread root. This is alsoknown as the minor diameter or root diameter.3.1.7 gage lengththe distance between the holding device(for example, a split coll
26、et) and the underside of the screwhead.3.1.8 grip lengththe length of threads held fast in the splitcollet or other holding mechanism.3.1.9 insertion depththe threaded length as inserted intothe test block.3.1.10 insertion torquethe amount of torque required toovercome the frictional force between t
27、he screw and thematerial used for testing while driving the screw into thematerial.3.1.11 maximum torque (N-m)the largest value of torquerecorded during the period of rotation before screw failure intorsional shear when tested in accordance with Annex A1.3.1.12 nontapping screwa screw that has a tip
28、 that doesnot contain a flute. Nontapping screws usually require a tap tobe inserted into the pilot hole before the insertion of the screw,when used in moderate or hard bone.3.1.13 partially threaded screwa screw whose threadedportion does not extend fully from the screw point to the screwhead but i
29、nstead has a smooth shaft running between the headand threads.3.1.14 pilot holethe hole drilled into the bone into whichthe screw tip is inserted. The pilot hole is normally slightlylarger than the screws core diameter. However, if the screw is3The last approved version of this historical standard i
30、s referenced onwww.astm.org.4Available from American National Standards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10036.FIG. 1 Schematic of Screw TermsF543 132to be used to provide compression across a fracture, a portionof the pilot hole may be larger to allow for a clearance fit.3.1.15 pit
31、chthe length between the thread crests.3.1.16 removal torquethe amount of torque required toovercome the frictional force between the screw and thematerial used for testing while removing the screw from thematerial (for example, counterclockwise rotation for right-handthread).3.1.17 screw headthe en
32、d of the screw which is oppositeof the tip and from which the means of inserting the screw iscoupled.3.1.18 screw lengththe overall length of the screw mea-sured from the screw head to the screw tip.3.1.19 screw threada helical groove on a cylindrical orconical surface. The projecting helical ridge
33、thus formed iscalled a screw thread, consisting of peaks (crests) and valleys(roots).3.1.20 self-tapping force (N)the amount of axial forcerequired to engage the self-tapping features of self-tappingstyle screws when tested in accordance with Annex A4.3.1.21 self-tapping screwa screw that has any nu
34、mber offlutes at its tip which are intended to cut the screws threadform into the bone upon insertion.3.1.22 sizean identification of a screw based on its nomi-nal thread diameter, as defined in Section 6.3.1.23 solid corea screw that does not contain a cannula-tion along its longitudinal axis.3.1.2
35、4 thread diameterthe largest diameter of the threadedportion of the screw measured over the thread crests. This isalso known as the major diameter.3.1.25 thread lengththe length of the threaded portion ofthe screw, measured from the thread runout to the screw tip.3.1.26 thread runoutthe intersection
36、 of the screw threadwith either the screw shaft or screw head.3.1.27 torsional yield strength (N-m)the point at whichthe screw reaches its proportional limit when tested in accor-dance with Annex A1. This will be determined by the offsetmethod. A 2 offset value shall be used.4. Classification4.1 The
37、re are a large variety of medical bone screwscurrently in use. They may be classified by the definitionsprovided in Section 3. This specification currently includesinformation that defines the following types of screws:4.1.1 Type HASpherical undersurface of head, shallow,asymmetrical buttress thread
38、, and deep screw head.4.1.2 Type HBSpherical undersurface of head, deep,asymmetrical buttress thread, and shallow screw head.4.1.3 Type HCConical undersurface of head, symmetricalthread.4.1.4 Type HDConical undersurface of head, asymmetri-cal thread.5. Material5.1 Screws shall be fabricated from a m
39、etallic materialintended for surgical implant applications, and having ASTMmedical material. In addition, the materials shall be biocom-patible for the intended application.6. Dimensions and Tolerances6.1 There are many types of metallic bone screw designsavailable, so a complete list of dimensions
40、and tolerances forall screws covered by this specification is unfeasible. However,this specification does provide required dimensions and toler-ances for four types of screws as classified in 4.1. Screwsconforming to this specification, and designated HA, HB, HC,or HD screws, shall be fabricated in
41、accordance with thedimensions and tolerances described in Annex A5 and AnnexA6, respectively.7. Finish and Marking7.1 The screw shall be free from nicks, dents, burrs, andscratches when examined in accordance with Practice F86.7.2 When size permits, the following information should belegibly marked
42、on the head of the screw (in order of prefer-ence):7.2.1 Manufacturers name or logo,7.2.2 Screw SizeIf a screw is manufactured in accordancewith ASTM or ISO specifications, the ASTM or ISO designa-tion should be provided,7.2.3 Material,7.2.4 Catalog number, and7.2.5 Manufacturing lot number.7.3 Scre
43、ws shall be marked in accordance with PracticeF983, unless otherwise specified in 7.2, in a manner such thatthe mechanical integrity of the screw is not compromised.8. Care and Handling8.1 Screws should be cared for and handled in accordancewith Practice F565, as appropriate.9. Driving Instruments9.
44、1 A variety of screwdrivers exist for the insertion andremoval of bone screws. The classification and dimensions forvarious screw-drive recesses currently used in the medicalindustry are documented in Annex A7. Specification F116provides related dimensional information for several types ofmedical sc
45、rewdrivers.9.2 Screws conforming to this specification, and designatedHA, HB, HC, or HD screws, shall be manufactured with driverecesses that conform to the requirements specified in AnnexA5 and Annex A6, respectively.10. Performance Considerations and Test Methods10.1 The following properties may b
46、e important whendetermining the suitability of a screw for a particular applica-tion. However, the test methods referenced as follows may notbe appropriate for all types of implant applications. The user iscautioned to consider the appropriateness of the test methods inview of the devices being test
47、ed and their potential application.F543 13310.1.1 Torsional StrengthThis test method is an importantparameter to prevent screw breakage during insertion orremoval. The torsional strength shall be determined using thetest methods described in Annex A1.10.1.2 Breaking AngleThis test method provides a
48、mea-sure of the ductility of the screw when undergoing a torsionalmoment.Ascrew with a greater breaking angle may provide anearlier tactile warning to the surgeon that the screw is reachingits maximum torsional strength. The breaking angle shall bedetermined using the test methods described in Annex
49、 A1.10.1.3 Axial Pullout StrengthThis test method may be animportant parameter if the screw is subjected to axial tensileforces, or if the screw is fixed into poor quality or osteoporoticbone. The pullout strength may be determined using the testmethods described in Annex A3.10.1.4 Insertion TorqueThis test method may be an im-portant parameter to avoid failure of the screw during insertionand to ensure that the screw may be easily inserted by thesurgeon. The insertion torque should be much less thantorsional yield s
