1、Designation:F269407(Reapproved 2013)Standard Practice forFunctional and Wear Evaluation of Motion-PreservingLumbar Total Facet Prostheses1This standard is issued under the fixed designation F2694;the number immediately following the designation indicates the year oforiginal adoption or,in the case o
2、f 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 functional,kinematic and wear testing of motion-preserving t
3、otal facetprostheses for the lumbar spine.These implants are intended toallow motion and lend support to the functional spinal unit(s)through replacement of the natural facets.1.2 This test method is not intended to address the boneimplant interface or the static characteristics of the prosthesiscom
4、ponents.Fatigue characteristics are included,but only as aby-product of cyclic wear testing under facet load and thus arenot addressed in the typical process of generating an S-Ncharacterization.1.3 Biocompatibility of the materials used in a total facetprosthesis are not addressed in this practice.
5、1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4.1 The values stated in SI units are to be regarded as thestandard with the exception of angular measurements,whichmay be reported in either degrees or radians.1.5 This stand
6、ard does not purport to address all of thesafety concerns,if any,associated with 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 S
7、tandards:2F561 Practice for Retrieval and Analysis of MedicalDevices,and Associated Tissues and FluidsF732 Test Method for Wear Testing of Polymeric MaterialsUsed in Total Joint ProsthesesF1714 Guide for Gravimetric WearAssessment of ProstheticHip Designs in Simulator DevicesF1877 Practice for Chara
8、cterization of ParticlesF2346 Test Methods for Static and Dynamic Characteriza-tion of Spinal Artificial Discs3.Terminology3.1 All functional and kinematic testing terminology isconsistent with the referenced standards,unless otherwisestated.3.2 Definitions:3.2.1 coordinate systems/axes,nglobal XYZ
9、orthogonalaxes are 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.The globalaxes are fixed relative to the inferior vertebral body,which inthis practice is also considered to be s
10、tationary with respect tothe test machines frame.Lower case letters,xyz,denote a localmoving orthogonal coordinate system attached to the superiorvertebral body with directions initially coincident with those ofthe global XYZ axes,respectively.The 3D motion of thesuperior relative to inferior verteb
11、ra is specified and is to bemeasured in terms of sequential Eulerian angular rotationsabout the xyz axes,respectively(z axial rotation,x lateral bend,and y flexion-extension).3.2.1.1 origin,ncenter of the global coordinate systemthat is located at the posterior medial position on the superiorendplat
12、e of the inferior vertebral body.3.2.1.2 X-axis,npositive X-axis is to be directed anteriorlyrelative to the specimens initial unloaded position.3.2.1.3 Y-axis,npositive Y-axis is directed laterally(to-ward the left)relative to the specimens initial unloadedposition.3.2.1.4 Z-axis,npositive Z-axis i
13、s to be directed superi-orly relative to the specimens initial unloaded position.3.2.2 fluid absorption,nfluid absorbed by the devicematerial during testing or while implanted in vivo.3.2.3 functional failure,npermanent deformation or wearthat renders the total facet prosthesis assembly ineffective
14、orunable to perform its intended function.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 March 1,2013.Published March 2013.Originallyapproved
15、in 2007.Last previous edition approved in 2007 as F269407.DOI:10.1520/F2694-07R13.2For 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 ont
16、he ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.4 interval net volumetric wear rate VRiduring cycleinterval i(mm3/million cycles),nVRi=WRi/;where =mass density(for example,units of g/mm3)of the wearmaterial.3.2.5 interval net wear rate WRiduring cycle interval i(g/million cycles),nWRi=(NWi NWi-1)/(number of cyclesin interval i)106;for i=1,NWi-1=0.3.2.6 total facet prosthesis,nnonbiologic structure in-tended to rest
