1、Designation: F755 99 (Reapproved 2011)Standard Specification forSelection of Porous Polyethylene for Use in SurgicalImplants1This standard is issued under the fixed designation F755; the number immediately following the designation indicates the year of originaladoption or, in the case of revision,
2、the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the properties and test meth-ods for porous high density and ultra high molecula
3、r weightpolyethylenes intended for use in surgical implants. The porouspolyethylene may be used as a free standing product or as acoating on a substrate in nonloaded applications.1.2 Evaluation of tissue response to a porous polyethylenemust be completed. Guidance in establishing biocompatibilitymay
4、 be found in the list of references.1.3 Clinical experience and animal studies have shown thattissue will grow into the open pores of porous polyethylene.The tissue ingrowth into the pores may allow for the establish-ment of implant fixation.1.4 The values stated in SI units are to be regarded assta
5、ndard. No other units of measurement are included in thisstandard.1.5 This section does not purport to address all of the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applic
6、ability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D638 Test Method for Tensile Properties of PlasticsD732 Test Method for Shear Strength of Plastics by PunchToolD790 Test Methods for Flexural Properties of Unreinforcedand Reinforced Plastics and Electrical Insu
7、lating MaterialsD883 Terminology Relating to PlasticsD1238 Test Method for Melt Flow Rates of Thermoplasticsby Extrusion PlastometerD1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD1621 Test Method for Compressive Properties of RigidCellular PlasticsD1623 Test Method for T
8、ensile and Tensile Adhesion Prop-erties of Rigid Cellular PlasticsD1898 Practice for Sampling of Plastics3D2238 Test Methods for Absorbance of Polyethylene Dueto Methyl Groups at 1378 cm1D2873 Test Method for Interior Porosity of Poly(VinylChloride) (PVC) Resins by Mercury Intrusion Porosim-etry3E56
9、2 Test Method for Determining Volume Fraction bySystematic Manual Point CountF316 Test Methods for Pore Size Characteristics of Mem-brane Filters by Bubble Point and Mean Flow Pore TestF648 Specification for Ultra-High-Molecular-Weight Poly-ethylene Powder and Fabricated Form for Surgical Im-plantsF
10、748 Practice for Selecting Generic Biological Test Meth-ods for Materials and DevicesF763 Practice for Short-Term Screening of Implant Materi-alsF981 Practice for Assessment of Compatibility of Biomate-rials for Surgical Implants with Respect to Effect ofMaterials on Muscle and Bone2.2 Other Documen
11、ts:Code of Federal Regulations Title 21, Paragraph 177.15204U.S. Pharmacopeia, Vol 23, 199553. Significance and Use3.1 Porous polyethylene is a matrix of substantially opencells, interconnected to form multidirectional paths. Perfor-mance of these structures, including tissue ingrowth, dependsupon t
12、he biocompatibility of the polymer, average pore andinterstitial opening diameters (ordinarily referred to as averagepore size) in conjunction with void volume (referred to as porevolume or percent porosity).1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical M
13、aterials and Devices and is the direct responsibility ofSubcommittee F04.11 on Polymeric Materials.Current edition approved Dec. 1, 2011. Published January 2012. Originallyapproved in 1982. Last previous edition approved in 2005 as F755 99 (2005).DOI: 10.1520/F0755-99R11.2For referenced ASTM standar
14、ds, 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.3Withdrawn. The last approved version of this historical standard is referencedon www.ast
15、m.org.4Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.5Available from U.S. Pharmacopeia (USP), 12601 Twinbrook Pkwy., Rockville,MD 20852-1790, http:/www.usp.org.1Copyright ASTM Internat
16、ional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 This specification is applicable to all device standards inwhich a porous polyethylene is used. A complete list of enduses has not been established. In those cases where the use ofa porous polyethylene has
17、 not been established, the mechanicaland physical characteristics required shall be determined byproper testing. The pore size, pore volume, and the mechanicalproperties will be specified in the particular device standard.4. Raw Material Requirements4.1 The polyethylene plastic shall consist of basi
18、c polymersmade with ethylene as essentially the sole monomer as definedin Terminology D883.4.2 High-density polyethylene shall exhibit a density of notless than 0.941 g/cm3when tested in accordance with TestMethod D1505.4.3 Ultra-high-molecular-weight polyethylene shall con-form to those sections of
19、 Specification F648 that apply to baseresin.4.4 Particular raw materials shall contain no dirt or otherforeign matter which will cause the end product to fail to meetthe product requirement specified in 5.2.4.5 The polyethylene resin shall conform to all parts ofParagraph 177.1520 of Title 21 which
20、apply to polyethylene.4.6 The polymer shall be characterized by determining theinfrared absorption spectrum. An acceptable procedure may befound in Test Methods D2238.4.7 The polymer shall be characterized by one or more ofthe following test methods:4.7.1 The polymer shall be characterized by determ
21、iningthe melt point range and rate of melt by thermal analysis.4.7.2 The compositional characteristics of the polymer shallbe analyzed by thermogravimetric analysis.4.7.3 The flow rate of high density polyethylene shall bedetermined in accordance with Test Method D1238.5. Product Requirements Produc
22、t Requirements5.1 Until a porous polymer biocompatibility standard isavailable, porous polyethylene shall be screened by biocom-patibility and toxicology tests applicable to its end use.Biological test procedures appropriate to determine biologicalsafety and tissue reactions are described in Practic
23、es F748 andF981 and the United States Pharmacopeia which recommendsgeneric biological test methods according to end use applica-tions. Short term screening for implant materials are describedin Practice F763.5.2 The surface of the porous polyethylene shall not containparticles of residue or loose pa
24、rticles of plastic of a diametergreater than 300 m. The concentration of particles visible at83 magnification shall not be greater than 10 particles/400cm2.5.3 The level of extractables found in the porous productwhen tested in accordance with 4.5 shall not increase from thatfound in the raw materia
25、l.5.4 The porous product shall be inspected under 83magnification to assure that the surface porosity is open.5.5 The average pore size shall be specified by vendor-useragreement and shall be held to within 20 % of the nominalvalue unless the end-use application requires less deviation.5.6 Porous pr
26、oduct quality and uniformity shall be assuredby the appropriate test methods as specified by vendor-useragreement and listed in Section 6.6. Test MethodsNOTE 1The shape and end use of the porous product dictates whichtests are appropriate. For example, it is impossible to perform a bubblepoint analy
27、sis on a total ossicular replacement, while mercury intrusionporosimetry is quite acceptable. A flexural test may be an acceptablenondestructive test where tensile strength tests are destructive.6.1 All mechanical and physical tests shall be sampled asrequired in Practice D1898.6.2 Average pore size
28、 shall be established by appropriatetest methods such as is found in Test Method F316 or bymercury intrusion porosimetry. Test Method D2873 is anacceptable method.6.3 Average pore volume shall be established using one ofthe following methods:6.3.1 Pore volume can be measured by mercury intrusionporo
29、simetry. Test Method D2873 is an acceptable method.6.3.2 Pore volume can be approximated by measurement ofweight of a nonsolvent saturant of known gravity and relatingits volume to the matrix volume.6.3.3 Pore volume can be estimated by optical microscopyas described in Practice E562.6.4 The tensile
30、 properties shall be determined in accor-dance with Test Method D638. Test Method D1623 may beused as an alternative method.6.5 The compressive properties shall be determined inaccordance with Test Method D1621.6.6 The flexural properties shall be determined in accor-dance with Test Methods D790.6.7
31、 The shear properties shall be determined in accordancewith Test Method D732.7. Certification7.1 Vendor of Porous Materials:7.1.1 Vendor shall certify that the raw material conforms toSection 4 of this specification.7.1.2 Vendor shall certify that the porous polyethyleneconforms to Section 5 of this
32、 specification and is made of thesame raw material as has been characterized by Section 4.7.1.3 Vendor shall certify that the mechanical properties asdetermined by 6.4-6.7 conform to the vendor-user agreement.7.1.4 Porosity requirements as determined by 6.2 and 6.3shall be certified by the vendor to
33、 conform to the vendor-useragreement.7.1.5 Vendor shall specify in the certification report all testmethods used.NOTE 2Certification is employed since verification would alter ordestroy functionality.8. Keywords8.1 plastic surgical devices/applications; polyethylene (PE)plastics/surgical implant app
34、lications; polymers-surgical appli-cantF755 99 (2011)2APPENDIXES(Nonmandatory Information)X1. RATIONALEX1.1 The use of some solid polyethylenes in vivo has beenwell established. Because of their mechanical and physicalproperties, some porous polyethylenes have also shown con-siderable promise for ma
35、ny in vivo applications. The list ofapplications currently being investigated is quite lengthy but,even so, does not exhaust the possibilities. It is to be expectedthat as applications are developed the properties of the porouspolyethylene which are acceptable for a given application willbe uniquely
36、 specified. This will necessitate the writing of astandard for each end-use product.X1.2 It is not the purpose of this generic standard toeliminate a priori any candidate porous polyethylene. For thisreason, it is seen that in some respects the requirements for thisare rather broad. The pore size an
37、d pore volumes are notspecified since they will be a function of the end use and thetype of tissue ingrowth desired. The same is true of themechanical properties. The function of this specification is tospecify those characteristics and tests to which a material isexpected to conform to be used as a
38、 surgical implant and to becalled porous polyethylene. To this end, the following fiveareas are addressed: (1) raw material requirements; (2) limits ofimpurities and extractables; (3) end product property testmethods; (4) tissue response test methods; and (5) responsi-bilities of vendor certificatio
39、n.X1.3 Porous polyethylenes which conform to this specifi-cation will be safe for selected applications and of a uniformhigh quality. Those properties which are critical to its beingefficacious are the responsibility of an end-use product stan-dard.X2. BIOCOMPATIBILITYX2.1 The material covered by th
40、is specification has beenemployed successfully in human implant applications in con-tact with soft tissue and bone for over a decade. Due to the wellcharacterized level of biological response exhibited by thismaterial, the ultra high molecular weight form (Practice F648)has been used as a control ma
41、terial in Practice F981.X2.2 No known surgical implant material has ever beenshown to be completely free of adverse reactions in the humanbody. However, long-term clinical experience of use of thismaterial referred to in this specification has shown that anacceptable level of biological response can
42、 be expected, if thematerial is used in appropriate applications.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any su
43、ch patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invit
44、ed either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a
45、 fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this
46、 standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F755 99 (2011)3
