ASTM_F_2790_-_10_2014.pdf

Designation:F279010(Reapproved 2014)Standard Practice forStatic and Dynamic Characterization of Motion PreservingLumbar Total Facet Prostheses1This standard is issued under the fixed designation F2790;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 parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice provides guidance for the static anddynamic testing of Lumbar Total Facet Prostheses(FP).Theseimplants are intended to allow motion and lend support to oneor more functional spinal unit(s)through replacement of thenatural facets.1.2 These test methods are intended to provide a basis forthe mechanical comparison among past,present,and futurenon-biologic FP.These test methods allow comparison ofdevices with different methods of application to the lumbarspine.These test methods are intended to enable the user tomechanically compare devices and do not purport to provideperformance standards for them.1.3 These test methods describe static and dynamic tests byspecifying load types and specific methods of applying theseloads.1.4 These test methods do not purport to address all clini-cally relevant failure modes for FP,some of which will bedevice specific.For example,these test methods do not addressimplant wear resistance under expected in vivo loads andmotions.In addition,the biologic response to wear debris is notaddressed in these test methods.1.5 Requirements are established for measuring displace-ments and evaluating the stiffness of FP.1.6 Some devices may not be testable in all test configura-tions.1.7 The values stated in SI units are to be regarded as thestandard with the exception of angular measurements,whichmay be reported in terms of either degrees or radians.1.8 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.2.Referenced Documents2.1 ASTM Standards:2D638 Test Method for Tensile Properties of PlasticsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE468 Practice for Presentation of Constant Amplitude Fa-tigue Test Results for Metallic MaterialsE739 Practice for StatisticalAnalysis of Linear or LinearizedStress-Life(S-N)and Strain-Life(-N)Fatigue DataF1582 Terminology Relating to Spinal Implants3.Terminology3.1 All functional and kinematic testing terminology isconsistent with the referenced standards(including Teminol-ogy E6 and Terminology F1582),unless otherwise stated.3.2 Definitions:3.2.1 coordinate systems/axesGlobal XYZ orthogonal axesare defined following a right-handed Cartesian coordinatesystem in which the XY plane is parallel to and co-planar withthe superior endplate of the inferior vertebral body.Alternativecoordinate systems may be used with justification.The globalaxes are fixed relative to the inferior vertebral body.Lowercase letters,xyz,denote a local moving orthogonal coordinatesystem attached to the superior vertebral body with directionsinitially coincident with those of the global XYZ axes,respec-tively.The 3D motion of the superior relative to inferiorvertebra is specified and is to be measured in terms ofsequential Eulerian angular rotations about the xyz axes,respectively(z axial rotation,x lateral bend,and y flexion-extension).3.2.1.1 origincenter of the global coordinate system thatis located at the posterior medial position on the superiorendplate of the inferior vertebral body.3.2.1.2 X-axispositive X-axis is to be directed anteriorlyrelative to the specimens initial unloaded position.3.2.1.3 Y-axispositive Y-axis is directed laterally(towardthe left)relative to the specimens initial unloaded position.1This practice is under the jurisdiction ofASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.25 on Spinal Devices.Current edition approved Nov.1,2014.Published November 2014.Originallyapproved in 2010.Last previous edition approved in 2010 as F2790-2010.DOI:10.1520/F279010R14.2For 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 International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.1.4 Z-axispositive Z-axis is to be directed superiorlyrelative to the specimens initial unloaded position.3.2.2 failurefunctional failure or substantial mechanicalfailure.3.2.2.1 functional failurepermanent deformation resultingfrom fracture,plastic deformation,or loosening beyond theultimate displacement or loosening that renders the spinalimplant assembly ineffective