1、Designation: F543 131Standard 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.Anumbe
2、r 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 U.S. Department of Defense.1NOTEAnnex A6 was corrected editorially and portions of the standard
3、 were reformatted in December 2013.1. Scope1.1 This specification provides requirements for materials,finish 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 applic
4、able only to metallic bone screwsdescribed in this specification.1.2 This specification provides performance 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 s
5、crewsbesides those whose dimensions and tolerances are specifiedhere. The following annexes are included:1.2.1 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 Deter
6、mining the AxialPullout Strength of Medical Bone Screws.1.2.4 Annex A4Test Method for Determining the Self-Tapping 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 Bon
7、e Screws.1.2.7 Annex A7Specifications for Metallic Bone ScrewDrive Connections.1.3 This specification is based, 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
8、methods are included in this standard.However, it must be noted that the user is not obligated to testusing all 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
9、methods will be required.1.6 This standard may involve the use of hazardousmaterials, operations, and equipment. 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 a
10、nd health practices anddetermine the applicability of regulatory limitations prior touse.2. Referenced Documents2.1 ASTM Standards:2E4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE8 Test Methods for Tension Testing of Metallic Materials
11、E122 Practice for Calculating Sample Size to Estimate, WithSpecified Precision, the Average for a Characteristic 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 Mark
12、ing of Metal-lic Surgical ImplantsF116 Specification for Medical Screwdriver BitsF136 Specification for Wrought Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial)Alloy for SurgicalImplant Applications (UNS R56401)F138 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel
13、 Bar and Wire for SurgicalImplants (UNS S31673)F565 Practice for Care and Handling of Orthopedic Implantsand Instruments1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee F04.21 on Osteosynt
14、hesis.Current edition approved May 1, 2013. Published June 2013. Originallyapproved in 1977. Last previous edition approved in 2009 as F543 071. DOI:10.1520/F0543-13E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annua
15、l 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. United States1F620 Specification for Titanium Alloy Forgings for SurgicalImplants in the Alp
16、ha Plus Beta ConditionF799 Specification for Cobalt-28Chromium-6MolybdenumAlloy Forgings for Surgical Implants (UNS R31537,R31538, R31539)F983 Practice for Permanent Marking of Orthopaedic Im-plant ComponentsF1295 Specification for Wrought Titanium-6Aluminum-7Niobium Alloy for Surgical Implant Appli
17、cations (UNSR56700)F1314 Specification for Wrought Nitrogen Strengthened 22Chromium13 Nickel5 Manganese2.5 MolybdenumStainless Steel Alloy Bar and Wire for Surgical Implants(UNS S20910)F1472 Specification for Wrought Titanium-6Aluminum-4VanadiumAlloy for Surgical ImplantApplications (UNSR56400)F1537
18、 Specification for Wrought Cobalt-28Chromium-6Molybdenum Alloys for Surgical Implants (UNSR31537, UNS R31538, and UNS R31539)F1586 Specification for Wrought Nitrogen Strengthened21Chromium10Nickel3Manganese2.5Molybdenum Stainless Steel Alloy Bar for SurgicalImplants (UNS S31675)F1713 Specification f
19、or Wrought Titanium-13Niobium-13Zirconium Alloy for Surgical Implant Applications(UNS R58130)F1813 Specification for Wrought Titanium-12Molybdenum-6Zirconium-2Iron Alloy for Surgical Implant (UNSR58120)F1839 Specification for Rigid Polyurethane Foam for Use asa Standard Material for Testing Orthopae
20、dic Devices andInstrumentsF2066 Specification for Wrought Titanium-15 MolybdenumAlloy for Surgical Implant Applications (UNS R58150)2.2 ISO Standards:35835 Implants for SurgeryMetal Bone Screws with Hex-agonal Driver Connection, Spherical Under Surface ofHead, Asymmetrical ThreadDimensions6475 Impla
21、nts for SurgeryMetal Bone Screws withAsym-metrical Thread and Spherical Under-SurfaceMechanical Requirements and Test Methods8319-1 Orthopaedic InstrumentsDrive connectionsPart1: Keys for use with hexagon socket heads8319-2 Orthopaedic InstrumentsDrive connectionsPart2: Screwdrivers for single slot
22、head screws, screws withcruciate and cross-ecessed head screws9268 Implants for SurgeryMetal Bone Screws with Coni-cal Under-Surface of HeadDimensions10664 Hexalobular Internal Driving Feature for Bolts andScrews3. Terminology3.1 DefinitionsSome of the terms defined in this sectionare shown in Fig.
23、1.3.1.1 axial pullout strengththe tensile force required tofail or remove a bone screw from a material 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 asymmet
24、rical thread profile char-acterized by a pressure flank which is nearly perpendicular tothe screw axis.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 sc
25、rewa screw designed primarily to gainbiocortical purchase into cortical bone. Cortical screws typi-cally 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 diamet
26、er or root diameter.3.1.7 gage lengththe distance between the holding device(for example, a split collet) 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 tes
27、t block.3.1.10 insertion torquethe amount of torque required toovercome the frictional force between the 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 i
28、ntorsional shear when tested in accordance with Annex A1.3.1.12 nontapping screwa screw that has a tip 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 threade
29、d screwa screw whose threadedportion does not extend fully from the screw point to the screwhead but instead has a smooth shaft running between the headand threads.3Available from American National Standards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10036.FIG. 1 Schematic of Screw TermsF543
30、13123.1.14 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 isto be used to provide compression across a fracture, a portionof the pilot hole may be larger to allow for a clear
31、ance fit.3.1.15 pitchthe 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.
32、17 screw headthe end 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 projec
33、ting helical ridge 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 sc
34、rew that has any number 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 long
35、itudinal axis.3.1.24 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 run
36、outthe intersection 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. Cl
37、assification4.1 There 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,asymmetri
38、cal buttress thread, 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
39、fabricated from a metallic 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
40、list of dimensions 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, shal
41、l be fabricated in 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 shoul
42、d belegibly marked 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
43、lot number.7.3 Screws 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. Dr
44、iving Instruments9.1 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
45、 types ofmedical screwdrivers.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 followi
46、ng properties may be 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
47、 devices being tested and their potential application.F543 131310.1.1 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 tes
48、t method provides a 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 method
49、s described in Annex 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 l
