1、Designation: F1541 02 (Reapproved 2015)Standard Specification and Test Methods forExternal Skeletal Fixation Devices1This standard is issued under the fixed designation F1541; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. 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 provides a characterization of thedesign and mechanical function of external skeletal fixation
3、devices (ESFDs), test methods for characterization of ESFDmechanical properties, and identifies needs for further devel-opment of test methods and performance criteria. The ultimategoal is to develop a specification, which defines performancecriteria and methods for measurement of performance-relate
4、dmechanical characteristics of ESFDs and their fixation to bone.It is not the intention of this specification to define levels ofperformance or case-specific clinical performance of thedevices, as insufficient knowledge is available to predict theconsequences of the use of any of these devices in in
5、dividualpatients for specific activities of daily living. Furthermore, it isnot the intention of this specification to describe or specifyspecific designs for ESFDs.1.2 This specification describes ESFDs for surgical fixationof the skeletal system. It provides basic ESFD geometricaldefinitions, dime
6、nsions, classification, and terminology; mate-rial specifications; performance definitions; test methods; andcharacteristics determined to be important to the in-vivoperformance of the device.1.3 This specification includes a terminology and classifi-cation annex and five standard test method annexe
7、s as follows:1.3.1 Classification of External FixatorsAnnex A1.1.3.2 Test Method for External Skeletal FixatorConnectorsAnnex A2.1.3.3 Test Method for Determining In-Plane CompressiveProperties of Circular Ring or Ring Segment BridgeElementsAnnex A3.1.3.4 Test Method for External Skeletal Fixator Jo
8、intsAnnex A4.1.3.5 Test Method for External Skeletal Fixator Pin Anchor-age ElementsAnnex A5.1.3.6 Test Method for External Skeletal FixatorSubassembliesAnnex A6.1.3.7 Test Method for External Skeletal Fixator/ConstructsSubassembliesAnnex A7.1.4 A rationale is given in Appendix X1.1.5 The values sta
9、ted in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 The following safety hazards caveat pertains only to thetest method portions (Annex A2 Annex A6):1.7 This standard does not purport to address all of thesafety concerns, if any, associated w
10、ith its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A938 Test Method for Torsion Testing of WireD790 Test Methods for
11、 Flexural Properties of Unreinforcedand Reinforced Plastics and Electrical Insulating Materi-alsE4 Practices for Force Verification of Testing MachinesF67 Specification for Unalloyed Titanium, for Surgical Im-plant Applications (UNS R50250, UNS R50400, UNSR50550, UNS R50700)F90 Specification for Wro
12、ught Cobalt-20Chromium-15Tungsten-10Nickel Alloy for Surgical Implant Applica-tions (UNS R30605)F136 Specification for Wrought Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial)Alloy for SurgicalImplant Applications (UNS R56401)F138 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum
13、Stainless Steel Bar and Wire for SurgicalImplants (UNS S31673)F366 Specification for Fixation Pins and WiresF543 Specification and Test Methods for Metallic MedicalBone ScrewsF544 Reference Chart for Pictorial Cortical Bone Screw1This specification is under the jurisdiction of ASTM Committee F04 onM
14、edical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee F04.21 on Osteosynthesis.Current edition approved Sept. 1, 2015. Published October 2015. Originallypublished as F1541 94. Last previous edition approved in 2011 as F1541 02(2011)1. DOI: 10.1520/F1541-02R15.2For
15、 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 International, 100 Barr Harbor Drive, PO Box C700,
16、 West Conshohocken, PA 19428-2959. United States1Classification (Withdrawn 1998)3F1058 Specification for Wrought 40Cobalt-20Chromium-16Iron-15Nickel-7Molybdenum Alloy Wire and Strip forSurgical Implant Applications (UNS R30003 and UNSR30008)F1264 Specification and Test Methods for IntramedullaryFixa
17、tion DevicesF1472 Specification for Wrought Titanium-6Aluminum-4VanadiumAlloy for Surgical ImplantApplications (UNSR56400)F1713 Specification for Wrought Titanium-13Niobium-13Zirconium Alloy for Surgical Implant Applications(UNS R58130)3. Terminology3.1 DefinitionsThe definitions of terms relating t
18、o externalfixators are described in Annex A1.4. Classification4.1 External skeletal fixators are modular devices assembledfrom component elements.4.2 Test methods can address individual elements (forexample, anchorage elements, bridge elements); subassembliesof elements (for example, connectors, joi
19、nts, ring elements); orthe entire fixator.4.3 Tests of an entire assembled fixator may include thefixator alone, or alternatively, the fixator as anchored to arepresentation of the bone(s) upon which it typically would bemounted in clinical usage.5. Materials5.1 All ESFDs made of materials that have
20、 an ASTMstandard shall meet those requirements given in ASTM Stan-dards listed in 2.1.6. Performance Considerations and Test Methods6.1 Individual ComponentsThe anchorage pins by whichan ESFD is attached to a skeletal member or members typicallyexperience high flexural, or torsional loads, or both.
21、Often, themajority of the overall compliance of an ESFD is in itsanchorage elements.Atest method for evaluating the mechani-cal performance of an ESFD anchorage element in either ofthese loading modes is described in Annex A5.6.2 Subassemblies of Elements:6.2.1 The sites of junction between ESFD anc
22、horage ele-ments (for example, pins) and bridge elements (for example,rods) normally require specialized clamping or grippingmembers, known as connecting elements. Often, connectingelements are subjected to high loads, especially moments, soadequacy of their intrinsic mechanical stiffness, or streng
23、th, orboth, is critical to overall fixator performance. A test methodfor evaluating the mechanical performance of ESFD connectorelements is described in Annex A2.6.2.2 ESFDs involving ring-type bridge elements are usedwidely both for fracture treatment and for distraction osteo-genesis. The anchorag
24、e elements in such fixators usually arewires or thin pins, which pass transverse to the bone long axisand which are tensioned deliberately to control the longitudinalstiffness of the fixator. Tensioning these wires or pins causesappreciable compressive load in the plane of the ring element.A test me
25、thod for evaluating the mechanical performance ofESFD ring elements in this loading mode is described in AnnexA3.6.2.3 The high loads often developed at ESFD junction sitesare of concern both because of potentially excessive elasticdeformation and because of potential irrecoverable deforma-tion. In
26、addition to the connecting element itself (Annex A2),overall performance of the junction also depends on theinterface between the connecting element and the anchorage,or bridge elements, or both, which it grips. A test method forevaluating the overall strength, or stiffness, or both, at anexternal f
27、ixator joint, as defined in AnnexA1 as the connectingelement itself plus its interface with the anchorage, or bridge,or both, elements, which it grips, is described in Annex A4.6.2.4 The modular nature of many ESFD systems affordsthe surgeon particularly great latitude as to configuration of thefram
28、e subassembly, as defined in Annex A1 as the bridgeelements plus the connecting elements used to join bridgeelements, but specifically excluding the anchorage elements.Since the configuration of the frame subassembly is a majordeterminant of overall ESFD mechanical behavior, it is impor-tant to have
29、 procedures for unambiguously characterizingframe subassemblies, both geometrically and mechanically.Test methodology suitable for that purpose is described inAnnex A6.6.3 Entire Assembled FixatorNo test methods are yetapproved for entire assembled fixators.7. Keywords7.1 anchorage element; bending;
30、 bridge element; connector;external skeletal fixation device; fracture fixation; joints;modularity; orthopedic medical device; osteosynthesis; ringelement; subassembly (frame); terminology; torsion3The last approved version of this historical standard is referenced onwww.astm.org.F1541 02 (2015)2ANN
31、EXES(Mandatory Information)A1. CLASSIFICATION OF EXTERNAL SKELETAL FIXATORSA1.1. ScopeA1.1.1 This classification covers the definitions of basicterms and considerations for external skeletal fixation devices(ESFDs) and the mechanical analyses thereof.A1.1.2 It is not the intent of this classificatio
32、n to definelevels of acceptable performance or to make recommendationsconcerning the appropriate or preferred clinical usage of thesedevices.A1.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standa
33、rd to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.A1.2. Referenced DocumentsA1.2.1 ASTM Standards:2F366 Specification for Fixation Pins and WiresF543 Specification and Test Methods for Metallic MedicalBone ScrewsF544 Refe
34、rence Chart for Pictorial Cortical Bone ScrewClassification (Withdrawn 1998)3A1.3 BackgroundA1.3.1 ESFDs are in widespread use in orthopedic surgery,primarily for applications involving fracture fixation or limblengthening, or both. The mechanical demands placed on thesedevices often are severe. Cli
35、nical success usually depends onsuitable mechanical integration of the ESFD with the host boneor limb.A1.3.2 It is important, therefore, to have broadly acceptedterminology and testing standards by which these devices canbe described and their mechanical behaviors measured.A1.3.3 Useful terminology
36、and testing standards must takeinto account that the modular nature of most ESFDs deliber-ately affords a great deal of clinical latitude in configuring theassembled fixator.A1.4. Significance and UseA1.4.1 The purpose of this classification is to establish aconsistent terminology system by means of
37、 which these ESFDconfigurations can be classified. It is anticipated that a com-panion testing standard using this classification system willsubsequently be developed.A1.5 Basis of ClassificationA1.5.1 An assembled ESFD and the bone(s) or bone ana-log(s) to which it is affixed constitute a fixator-b
38、one construct.A1.5.1.1 The assembled ESFD itself, apart from the hostbone, is termed the fixator assembly.A1.5.1.2 The individual parts (or modules of individualparts) from which the end user assembles the fixator are termedits elements.A1.5.2 An ESFD normally is configured to span a mechani-cal dis
39、continuity in the host bone that otherwise would beunable to transmit one or more components of the appliedfunctional load successfully. This bony discontinuity is termedthe mechanical defect.A1.5.3 Examples of mechanical defects are fracturesurfaces, interfragmentary callus, segmental bone gaps, ar
40、ticu-lar surfaces, neoplasms, and osteotomies.A1.5.4 Coordinate System(s)The relative positions of thebones or bone segments bordering the mechanical defectshould be described in terms of an orthogonal axis coordinatesystem (Fig. A1.1).A1.5.4.1 Where possible, coordinate axis directions shouldbe ali
41、gned perpendicular to standard anatomical planes (forexample, transverse (horizontal or axial), coronal (frontal), andsagittal (median).A1.5.4.2 Where possible, translation directions should beconsistent with standard clinical conventions (for example,ventral (anterior), dorsal (posterior), cranial
42、(cephalad orsuperior), caudal (inferior), lateral, or medial).A1.5.4.3 Rotation measurement conventions must followthe right-hand rule and, where possible, should be consistentwith standard clinical terminology (for example, right or leftlateral bending, flexion, extension, and torsion).A1.5.5 A bas
43、e coordinate system (X, Y, Z) should be affixedto one of the bones or major bone segments bordering themechanical defect. This bone or bone segment is termed thebase segment, Sb, and serves as a datum with respect to whichpertinent motion(s) of bone segments or fixator elements, orboth, can be refer
44、enced. Depending on context, Sbmay bedefined as being on either the proximal or the distal side of amechanical defect.A1.5.6 The other bone(s) or bone segment(s) bordering themechanical defect, whose potential motion(s) with respect toSbis of interest, is termed the mobile segment(s), Sm.Ifnecessary
45、, a local right-handed orthogonal coordinate system(x, y, z) may be embedded within the Sm(s).A1.5.7 Degrees of Freedom: Describing the position, orchange in position, of Smrelative to Sbrequires specifying oneor more independent variables. These variables shall be termedpositional degrees of freedo
46、m (P-DOF).A1.5.7.1 Depending on context, this may involve as manyas six variables (three translation and three orientation).A1.5.7.2 Also depending on context, P-DOFs may be usedto describe motions of interest in various magnitude ranges.For example, P-DOFs may be used to describe one or morecompone
47、nts of visually imperceptible motion (for example,F1541 02 (2015)3elastic flexure of a thick rod) or one or more components ofgrossly evident motion (such as interfragmentary motion at anunstable fracture site).A1.5.8 Application or adjustment of an ESFD normallyincludes an attempt to achieve or mai
48、ntain a specific position ofSmrelative to Sb. The adjustability afforded by the ESFDdesign for this purpose, most commonly, fracture fragmentreduction, will be characterized in terms of adjustment degreesof freedom (A-DOF).A1.5.9 Some ESFDs are designed optionally to transmitselected components of l
49、oading or displacement across thedefect, usually by disengaging a locking mechanism. Thecomponent of motion of Smpermitted by such unlocking, oftengiven the clinical name “dynamization,” will be termed un-locked degrees of freedom (U-DOF).A1.5.9.1 Depending on the specifics of design, the motionpermitted in an unlocked degree of freedom may be opposedsubstantially and deliberately by a specific mechanism such asa spring or a cushion. Such an unlocked degree of freedom istermed a resisted unlocked degree of freedom.A1.5.9.2 Unlocked degrees of freedom in which moti
