1、Designation: F 543 07Standard Specification and Test Methods forMetallic Medical Bone Screws1This standard is issued under the fixed designation F 543; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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,
3、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 applicable only to metallic bone screwsdescribed in this specification.1.2 This specification provides perfo
4、rmance 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 includ
5、ed: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 Determining the AxialPullout Strength of Medical Bone Screws.1.2.4 Annex A4Test Method for Determining the
6、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 Bone Screws.1.2.7 Annex A7Specifications for Metallic Bone ScrewDrive Connections.1.3 This specification
7、is based, in part, upon ISO 5835, ISO6475, and ISO 9268.1.4 Unless otherwise indicated, the values stated in SI unitsare to be regarded as standard. The values in parentheses aregiven for information only.1.5 This standard may involve the use of hazardous mate-rials, operations, and equipment. This
8、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 Documents2.1 AS
9、TM Standards:2E4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical Test-ingE8 Test Methods for Tension Testing of Metallic MaterialsE 122 Practice for Calculating Sample Size to Estimate,With a Specified Tolerable Error, the Average for aCharacteris
10、tic of a Lot or ProcessF67 Specification for Unalloyed Titanium, for SurgicalImplant Applications (UNS R50250, UNS R50400, UNSR50550, UNS R50700)F86 Practice for Surface Preparation and Marking of Me-tallic Surgical ImplantsF116 Specification for Medical Screwdriver BitsF 136 Specification for Wroug
11、ht Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial) Alloy for SurgicalImplant Applications (UNS R56401)F 138 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for SurgicalImplants (UNS S31673)F 565 Practice for Care and Handling of Orthopedic Im-plants
12、 and InstrumentsF 620 Specification for Alpha Plus Beta Titanium AlloyForgings for Surgical ImplantsF 799 Specification for Cobalt-28Chromium-6MolybdenumAlloy Forgings for Surgical Implants (UNS R31537,R31538, R31539)F 983 Practice for Permanent Marking of Orthopaedic Im-plant ComponentsF 1295 Speci
13、fication for Wrought Titanium-6Aluminum-7Niobium Alloy for Surgical Implant Applications (UNSR56700)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
14、 June 1, 2007. Published June 2007. Originallyapproved in 1977. Last previous edition approved in 2002 as F 543 02e1.2For 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
15、 the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.F 1314 Specification for Wrought Nitrogen Strengthened 22Chromium 13 Nickel 5 Manganese 2.5 MolybdenumStainless Steel Alloy Bar a
16、nd Wire for Surgical Implants(UNS S20910)F 1472 Specification for Wrought Titanium-6Aluminum-4Vanadium Alloy for Surgical Implant Applications (UNSR56400)F 1537 Specification for Wrought Cobalt-28 Chromium-6Molybdenum Alloy for Surgical ImplantsF 1586 Specification for Wrought Nitrogen Strengthened
17、21Chromium10 Nickel3 Manganese2.5 MolybdenumStainless Steel Alloy Bar for Surgical Implants (UNSS31675)F 1713 Specification for Wrought Titanium-13Niobium-13Zirconium Alloy for Surgical Implant Applications(UNS R58130)F 1813 Specification for Wrought Titanium12 Molybde-num6 Zirconium2 IronAlloy for
18、Surgical Implant (UNSR58120)F 1839 Specification for Rigid Polyurethane Foam for Useas a Standard Material for Testing Orthopaedic Devicesand Instruments2.2 ISO Standards:5835 Implants for SurgeryMetal Bone Screws with Hex-agonal Driver Connection, Spherical Under Surface ofHead, Asymmetrical Thread
19、Dimensions36475 Implants for SurgeryMetal Bone Screws withAsymmetrical Thread and Spherical Under-SurfaceMechanical Requirements and Test Methods39268 Implants for SurgeryMetal Bone Screws with Coni-cal Under-Surface of HeadDimensions33. Terminology3.1 DefinitionsSome of the terms defined in this se
20、ctionare 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 inserted.3.1.2 breaking angleangle of rotation when the screwfails in torsion as demonstrated by a rapid decrease in theindicated torque.3.1.3 bu
21、ttress threadan asymmetrical 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 a HB thread and may or may not be fully threaded.3.1.5
22、cortical screwa screw designed primarily to gainbiocortical purchase into cortical bone. Cortical screws typi-cally have a HA thread and are fully threaded.3.1.6 core diameterthe smallest diameter of the threadedportion of the screw measured at the thread root. This is alsoknown as the minor diamete
23、r 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 lengththe length of threads held fast in the splitcollet or other holding mechanism.3.1.9 insertion depththe threaded length as inserted intothe tes
24、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
25、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
26、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.3.1.14 pilot holethe hole drilled into the bone into whichthe screw tip is inserted. The pilot hole is normally slightlylarger than the
27、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 clearance fit.3.1.15 pitchthe length between the thread crests.3.1.16 removal torquethe amount of torque required toovercome the frictional force
28、 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 end of the screw which is oppositeof the tip and from which the means of inserting the screw iscoupled.3.1.18 screw lengtht
29、he 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 thus formed iscalled a screw thread, consisting of peaks (crests) and valleys(roots).3Available from American National St
30、andards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10036.FIG. 1 Schematic of Screw TermsF5430723.1.20 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 scre
31、w 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 longit
32、udinal axis.3.1.24 thread diameterthe largest diameter of thethreaded portion of the screw measured over the thread crests.This is also 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 runou
33、tthe 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 will be used.4. Class
34、ification4.1 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,asymmetrical
35、 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 fab
36、ricated from one of the followingmaterials:5.1.1 Stainless steel alloy (Specification F 138).5.1.2 Nitrogen-strengthened stainless steel alloy (Specifica-tions F 1314 and F 1586).5.1.3 Unalloyed titanium (Specification F67).5.1.4 Titanium-aluminum-vanadium alloy (SpecificationsF 136, F 620, and F 14
37、72).5.1.5 Titanium-aluminum-niobium alloy (SpecificationF 1295).5.1.6 Titanium-niobium-zirconium alloy (SpecificationF 1713).5.1.7 Cobalt-chromium-molybdenum alloy (SpecificationsF 799 and F 1537).5.1.8 Titanium-molybdenum-zirconium-iron alloy (Specifi-cation F 1813).6. Dimensions and Tolerances6.1
38、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. However,this specification does provide required dimensions and toler-ances for four types of screws as classified in 4.1. Screwsco
39、nforming 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 AnnexA6, respectively.7. Finish and Marking7.1 The screw shall be free from nicks, dents, burrs, andscratches when examined in accorda
40、nce with Practice F 86.7.2 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 or logo,7.2.2 Screw SizeIf a screw is manufactured in accordancewith ASTM or ISO specifications, the ASTM or ISO designa-tion sh
41、ould 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 PracticeF 983, 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
42、be cared for and handled in accordancewith Practice F 565, as appropriate.9. Driving 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 A
43、nnex A7. Specification F116provides related dimensional information for several 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 A
44、6, respectively.10. Performance Considerations and Test Methods10.1 The following 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 use
45、r iscautioned to consider the appropriateness of the test methods inview of the devices being tested and their potential application.10.1.1 Torsional StrengthThis test method is an importantparameter to prevent screw breakage during insertion orremoval. The torsional strength shall be determined usi
46、ng 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.Ascrew with a greater breaking angle may provide anearlier tactile warning to the surgeon that the screw is reachingits maximum torsional
47、 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 parameter if the screw is subjected to axial tensileF543073forces, or if the screw is fixed into poor quality or osteoporoticbone. The pullou
48、t 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 th
49、antorsional 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 than tor-sional yield strength of the screw and of the appropriatescrewdriver bit. The removal torque may be determined usingthe test methods d
