1、Designation: F2077 14F2077 17Test Methods ForIntervertebral Body Fusion Devices1This standard is issued under the fixed designation F2077; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in paren
2、theses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the materials and methods for the static and dynamic testing of intervertebral body fusion deviceassemblies, spinal implants d
3、esigned to promote arthrodesis at a given spinal motion segment.1.2 This test method is intended to provide a basis for the mechanical comparison among past, present, and future nonbiologicintervertebral body fusion device assemblies. This test method allows comparison of intervertebral body fusion
4、device assemblieswith different intended spinal locations and methods of application to the intradiscal spaces. This test method is intended to enablethe user to compare intervertebral body fusion device assemblies mechanically and does not purport to provide performancestandards for intervertebral
5、body fusion device assemblies.1.3 The test method describes static and dynamic tests by specifying force types and specific methods of applying these forces.These tests are designed to allow for the comparative evaluation of intervertebral body fusion device assemblies.1.4 These tests are designed t
6、o characterize the structural integrity of the device and are not intended to test the bone-implantinterface.1.5 This test method does not address expulsion testing of intervertebral body fusion device assemblies (see 1.4).1.6 Guidelines are established for measuring displacements, determining the y
7、ield force or moment, evaluating the stiffness, andstrength of the intervertebral body fusion device assemblies.1.7 Some intervertebral body fusion device assemblies may not be testable in all test configurations.1.8 The values stated in SI units are to be regarded as standard. No other units of mea
8、surement are included in this standard,with the exception of angular measurements, which may be reported in terms of either degrees or radians.1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standa
9、rd to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.10 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Deci
10、sion on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to
11、 Methods of Mechanical TestingE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE1823 Terminology Relating to Fatigue and Fracture TestingE2309 Practices for Verification of Displ
12、acement Measuring Systems and Devices Used in Material Testing MachinesF1582 Terminology Relating to Spinal Implants1 This test method is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.25 .Current edition
13、 approved Oct. 1, 2014Oct. 1, 2017. Published December 2014October 2017. Originally published in 2000. Last previous edition approved in 20112014as F2077 11F2077 14 DOI: 10.1520/F2077-14.10.1520/F2077-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Ser
14、vice at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previo
15、us version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM Inte
16、rnational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 For definition of terms refer to Terminology E6, E1823, and F1582.3.2 Definitions of Terms Specific to This Standard:3.2.1 coordinate system/axes, nThree orthogonal axes are defined by Te
17、rminology F1582. The center of the coordinate systemis located at the geometric center of the intervertebral body fusion device assembly. The XY plane is to bisect the sagittal planeangle between superior and inferior lines (surfaces) that are intended to simulate the adjacent vertebral end plates.
18、The positiveZ axis is to be directed superiorly. Force components parallel to the XY plane are shear components of loading. The compressiveaxial force is defined to be the component in the negative Z direction. Torsional force is defined to be the component of momentparallel to the Z axis.3.2.2 crac
19、k, nan externally visible physical discontinuity in the form of a narrow opening that arises from mechanical forces.3.2.3 fatigue life, nthe number of cycles, N, that the intervertebral body fusion device assembly can sustain at a particularforce or moment before mechanical or functional failure occ
20、urs.3.2.4 functional failure, npermanent deformation that renders the intervertebral body fusion device assembly ineffective orunable to resist force and/or maintain attachment adequately.3.2.5 ideal insertion location, nthe implant location with respect to the simulated inferior and superior verteb
21、ral bodies(polyacetal or metal blocks) dictated by the type, design, and manufacturers surgical installation instructions.3.2.6 intended method of application, nintervertebral body fusion device assemblies may contain different types of stabilizinganchors such as threads, spikes, and knurled surface
22、s. Each type of anchor has an intended method of application or attachmentto the spine.3.2.7 intended spinal location, nthe anatomic region of the spine intended for the intervertebral body fusion device assembly.Intervertebral body fusion device assemblies may be designed and developed for specific
23、 regions of the spine such as the lumbar,thoracic, and cervical spine. Also, there exists different anatomical potential surgical approaches, which will result in differentimplant orientation at different levels of the spine.3.2.8 intervertebral body fusion device, na structure (biologic or syntheti
24、c) that is placed in the disc space between twoadjacent vertebral bodies to provide support for eventual arthrodesis of the two adjacent vertebral bodies.3.2.9 intradiscal height, nthe straight-line distance along the Z axis between the unaltered simulated vertebral bodiesminimum height of 4 mm and
25、a maximum height of 18 mm. See Fig. 1.3.2.10 force point, nthe point through which the resultant force on the intervertebral device passes (that is, the geometriccenter of the superior fixtures sphere) (Figs. 2-5).3.2.11 maximum run out force or moment, nthe maximum force or moment for a given test
26、that can be applied to anintervertebral body fusion device assembly in which all of the tested constructs have withstood 5 000 000 cycles without functionalor mechanical failure.3.2.12 mechanical failure, nthat associated with the onset of a new defect in the material (that is, initiation of fatigue
27、 crack).3.2.13 offset angular displacement, n(Distance OBFig. 6)offset on the angular displacement axis equal to 10 % of theintradiscal height, H, divided by the outside diameter or height of the implant (maximum dimension of implant in XZ plane if notcylindrical) (for example, for a 10-mm intradisc
28、al height and 16-mm intervertebral body fusion device assembly, distance OB =10 mm/16 mm (0.10)(180)/pi = 3.6).3.2.14 offset displacement, n(Distance OBFig. 6)offset on the displacement axis equal to 2 % of the intradiscal height(that is, 0.2 mm for a 10-mm intradiscal height).FIG. 1 Intradiscal Hei
29、ght DiagramF2077 1723.2.15 permanent deformation, nthe remaining displacement (mm or degrees or radians) relative to the initial unloadedcondition of the intervertebral body fusion device assembly after the applied force has been removed.3.2.16 stiffness (N/mm or N*mm/Degree (Radian) (The Slope of L
30、ine OGFig. 6),nthe slope of the initial linear portion ofthe force-displacement curve or the slope of the initial linear portion of the momentangular displacement curve.FIG. 2 Compression Testing ConfigurationFIG. 3 Compression-Shear Testing ConfigurationF2077 1733.2.17 test block, nthe component of
31、 the test apparatus for mounting the intervertebral body fusion device assembly for theintended test configuration.3.2.18 ultimate displacement (mm or degrees or radians) (Displacement OFFig. 6),nthe displacement associated with theultimate force or ultimate moment.3.2.19 ultimate force or moment (N
32、 or N*mm) (Point EFig. 6),nthe maximum applied force, F, transmitted by the pushrod(assumed equal to force component parallel to and indicated by load cell), or the applied moment about the Z axis that can beapplied to an intervertebral body fusion device assembly.FIG. 4 Torsion Testing Configuratio
33、n With Pin-Slot GimbalFIG. 5 Spherical Gimbal (Cross Section) for Torsion Testing ApparatusF2077 1743.2.20 yield displacement (Distance OAFig. 6),nthe displacement (mm) or angular displacement (deg) when an interbodyfusion device asembly has a permanent deformation equal to the offset displacement o
34、r the offset angular displacement.3.2.21 yield force or moment (Point DFig. 6),nthe applied force, F, transmitted by the pushrod (assumed equal to forcecomponent parallel to and indicated by load cell), or the applied moment about the Z axis required to produce a permanentdeformation equal to the of
35、fset displacement or the offset angular displacement.4. Summary of Test Method4.1 These test methods are proposed for the mechanical testing of intervertebral body fusion device assemblies specific to thelumbar, thoracic, and cervical spine.4.2 Fatigue testing of the intervertebral body fusion devic
36、e assemblies will simulate a motion segment via a gap between twopolyacetal test blocks. The polyacetal will eliminate the effects of the variability of bone properties and morphology for the fatiguetests. The minimum ultimate tensile strength of the polyacetal blocks shall be no less than 61 MPa.4.
37、3 Static testing of the intervertebral body fusion device assemblies will simulate a motion segment via a gap between twostainless steel blocks. The minimum ultimate tensile strength of the blocks shall be no less than 1310 MPa.4.4 The pushrod shall also be manufactured from stainless steel, which s
38、hall also have a minimum ultimate tensile strength noless than 1310 MPa.4.5 Static and dynamic tests will evaluate the intervertebral body fusion device assembly. The user of this test method mustdecide which series of tests are applicable to the intervertebral body fusion device assembly in questio
39、n. The user of this testmethod may choose to use all or a selection of the tests described in this test method for testing a particular intervertebral bodyfusion device assembly.5. Significance and Use5.1 Intervertebral body fusion device assemblies are generally simple geometric-shaped devices whic
40、h are often porous orhollow in nature. Their function is to support the anterior column of the spine to facilitate arthrodesis of the motion segment. ThisFIG. 6 Typical Force Displacement CurveF2077 175test method outlines materials and methods for the characterization and evaluation of the mechanic
41、al performance of differentintervertebral body fusion device assemblies so that comparisons can be made between different designs.5.2 This test method is designed to quantify the static and dynamic characteristics of different designs of intervertebral bodyfusion device assemblies. These tests are c
42、onducted in vitro to allow for analysis and comparison of the mechanical performanceof intervertebral body fusion device assemblies to specific force modalities.5.3 The forces applied to the intervertebral body fusion assemblies may differ from the complex loading seen in vivo, andtherefore, the res
43、ults from these tests may not directly predict in vivo performance. The results, however, can be used to comparemechanical performance of different intervertebral body fusion device assemblies.5.4 Since the environment may affect the dynamic performance of intervertebral body fusion device assemblie
44、s, dynamic testingin a saline environment may be considered. Fatigue tests should first be conducted in air (at ambient temperature) for comparisonpurposes since the environmental effects could be significant. If a simulated in vivo environment is desired, the investigator shouldconsider testing in
45、a saline environmental bath at 37C (for example, 0.9-g NaCl per 100-mL water) at a rate of 1 Hz or less. Asimulated body fluid, a saline drip or mist, distilled water, or other type of lubrication at 37C could also be used with adequatejustification.5.5 If the devices are known to be temperature and
46、 environment dependent, testing should be conducted in physiologic solutionas described in 5.4. Devices that require physiologic solution for testing should be tested in the same type solution for comparisonpurposes.5.6 The location within the simulated vertebral bodies and position of the intervert
47、ebral body fusion device assembly withrespect to the loading axis will be dependent upon the design, the manufacturers recommendation, or the surgeons preferredmethod for implant placement.5.7 It is well known that the failure of materials is dependent upon stress, test frequency, surface treatments
48、, and environmentalfactors. Therefore, when determining the effect of changing one of these parameters (for example, frequency, material, orenvironment), all others must be kept constant to facilitate interpretation of the results.6. Apparatus6.1 Test machines will conform to the requirements of Pra
49、ctices E4.6.2 The intradiscal height, H, shall be determined from vertebral body and disc morphometric data at the intended level ofapplication. Suggested heights are as follows: 10 mm for the lumbar spine, 6 mm for the thoracic spine, and 4 mm for the cervicalspine. The intradiscal height should not reach zero before the onset of functional or mechanical failure. If this occurs, the test isconsidered a failure. The user of the test method should select the intradiscal height that is appropriate for the device being tested.6.3 Axial
