1、Designation: F543 072Standard 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 Department of Defense.1NOTEUnits information was editorially corrected in August 2009.2NOTEEdit
3、orial changes were made throughout in March 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 thisspecificat
4、ion are applicable 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 applica
5、ble to other screwsbesides 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 Me
6、thod for Determining 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
7、HDMetallic Bone 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
8、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 and health practices anddeterm
9、ine 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 MaterialsE122 Practice for Calculating
10、 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 Marking of Metal-lic Surgical Imp
11、lantsF116 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 Bar and Wire for SurgicalImp
12、lants (UNS S31673)F565 Practice for Care and Handling of Orthopedic Implantsand 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,
13、R31539)1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee Osteosynthesis.Current edition approved June 1, 2007. Published June 2007. Originallyapproved in 1977. Last previous edition approve
14、d in 2002 as F543 021. DOI:10.1520/F0543-07E02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM
15、 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. 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
16、 for Wrought Nitrogen Strengthened 22Chromium 13 Nickel 5 Manganese 2.5 MolybdenumStainless 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-2
17、8Chromium-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 for Wrought Titanium-13Niobium-13Zir
18、conium Alloy for Surgical Implant Applications(UNS R58130)F1813 Specification for Wrought Titanium12 Molybde-num6 Zirconium2 Iron Alloy for Surgical Implant(UNS R58120)F1839 Specification for Rigid Polyurethane Foam for Use asa Standard Material for Testing Orthopaedic Devices andInstruments2.2 ISO
19、Standards:5835 Implants for SurgeryMetal Bone Screws with Hex-agonal Driver Connection, Spherical Under Surface ofHead, Asymmetrical ThreadDimensions36475 Implants for SurgeryMetal Bone Screws withAsym-metrical Thread and Spherical Under-SurfaceMechanical Requirements and Test Methods39268 Implants
20、for SurgeryMetal Bone Screws with Coni-cal Under-Surface of HeadDimensions33. 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 into which thescrew has been inser
21、ted.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.3.1.4 cancellous screwa screw desi
22、gned primarily to gainpurchase into cancellous bone. Cancellous screws typicallyhave a HB thread and may or may not be fully threaded.3.1.5 cortical screwa screw designed primarily to gainbiocortical purchase into cortical bone. Cortical screws typi-cally have a HA thread and are fully threaded.3.1.
23、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 collet, and the underside of the screw head.3.1.8 grip lengthth
24、e 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 the screw and thematerial used for testing while driving th
25、e 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 that doesnot contain a flute. Nontapping screws usually r
26、equire 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 instead has a smooth shaft running between the headand thre
27、ads.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 isto be used to provide compression across a fracture, a portionof the pilot hole may be larger to allow for a clear
28、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.
29、17 screw headthe end of the screw which is oppositeof the tip and from which the means of inserting the screw iscoupled.3Available from American National Standards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10036.FIG. 1 Schematic of Screw TermsF543 07223.1.18 screw lengththe overall length of
30、 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 thus formed iscalled a screw thread, consisting of peaks (crests) and valleys(roots).3.1.20 self-tapping force (N)the amount of axial forcere
31、quired 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 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
32、 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.3.1.24 thread diameterthe largest diameter of the threadedportion of the screw measured over the thread crests. This isalso known as the major dia
33、meter.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 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 pr
34、oportional limit when tested in accor-dance with Annex A1. This will be determined by the offsetmethod. A2 offset value will be used.4. Classification4.1 There are a large variety of medical bone screwscurrently in use. They may be classified by the definitionsprovided in Section 3. This specificati
35、on currently includesinformation that defines the following types of screws:4.1.1 Type HASpherical undersurface of head, shallow,asymmetrical 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 HCConic
36、al undersurface of head, symmetricalthread.4.1.4 Type HDConical undersurface of head, asymmetri-cal thread.5. Material5.1 Screws shall be fabricated from one of the followingmaterials:5.1.1 Stainless steel alloy (Specification F138).5.1.2 Nitrogen-strengthened stainless steel alloy (Specifica-tions
37、F1314 and F1586).5.1.3 Unalloyed titanium (Specification F67).5.1.4 Titanium-aluminum-vanadium alloy (SpecificationsF136, F620, and F1472).5.1.5 Titanium-aluminum-niobium alloy (SpecificationF1295).5.1.6 Titanium-niobium-zirconium alloy (SpecificationF1713).5.1.7 Cobalt-chromium-molybdenum alloy (Sp
38、ecificationsF799 and F1537).5.1.8 Titanium-molybdenum-zirconium-iron alloy (Specifi-cation F1813).6. Dimensions and Tolerances6.1 There are many types of metallic bone screw designsavailable, so a complete list of dimensions and tolerances forall screws covered by this specification is unfeasible. H
39、owever,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 accordance with thedimensions and tolerances described in Annex A5 and Anne
40、xA6, 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 on the head of the screw (in order of prefer-ence):7.2.1 Manufacturers name
41、 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 Screws shall be marked in accordance with PracticeF983, unless otherwise specif
42、ied 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 Instruments9.1 A variety of screwdrivers exist for the insertion andremoval of bone scre
43、ws. 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 screwdrivers.9.2 Screws conforming to this specification, and designatedHA, H
44、B, 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 be important whendetermining the suitability of a screw for a particular app
45、lica-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 tested and their potential application.F543 072310.1.1 Torsional StrengthThis t
46、est 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 mea-sure of the ductility of the screw when undergoing a torsionalmoment.A
47、screw 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 A1.10.1.3 Axial Pullout StrengthThis test method may be animportant param
48、eter 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 scr
49、ew during insertionand to ensure that the screw may be easily inserted by thesurgeon. The insertion torque should be much less thantorsional yield strength of the screw and of the appropriatescrewdriver bit. The insertion torque may be determined usingthe test methods described in Annex A2.10.1.5 Removal TorqueThis test method may be an im-portant parameter to avoid failure of the screw during removaland to ensure that the screw may be easily removed by thesurgeon. The removal torque should be much less tha
