1、Designation: F 981 04Standard Practice forAssessment of Compatibility of Biomaterials for SurgicalImplants with Respect to Effect of Materials on Muscle andBone1This standard is issued under the fixed designation F 981; the number immediately following the designation indicates the year oforiginal a
2、doption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice provides a series of experimental protocolsfor biologi
3、cal assays of tissue reaction to nonabsorbablebiomaterials for surgical implants. It assesses the effects of thematerial on animal tissue in which it is implanted. Theexperimental protocol is not designed to provide a comprehen-sive assessment of the systemic toxicity, immune response,carcinogenicit
4、y, teratogenicity, or mutagenicity of the materialsince other standards deal with these issues. It applies only tomaterials with projected applications in humans where thematerials will reside in bone or soft tissue in excess of 30 daysand will remain unabsorbed. It is recommended that short-termass
5、ays, according to Practice F 763, first be performed. Appli-cations in other organ systems or tissues may be inappropriateand are therefore excluded. Control materials will consist ofany one of the metal alloys in Specifications F 67, F 75, F 90,F 136, F 138, or F 562, high purity dense aluminum oxi
6、de asdescribed in Specification F 603, ultra high molecular weightpolyethylene as stated in Specification F 648 or USP polyeth-ylene negative control.1.2 This practice is a combination of Practice F 361 80and Practice F 469 78. The purpose, basic procedure, andmethod of evaluation of each type of ma
7、terial are similar;therefore, they have been combined.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 standard to establish appro-priate safety and health practices and determine the applica-bility
8、of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F67 Specification for Unalloyed Titanium for SurgicalImplant Applications (UNS R50250, UNS R50400, UNSR50550, UNS R50700)F75 Specification for Cobalt-28Chromium-6MolybdenumAlloy Castings and Casting Alloy for Surgical
9、Implants(UNS R30075)F86 Practice for Surface Preparation and Marking of Me-tallic Surgical ImplantsF90 Specification for Wrought Cobalt20-Chromium15-Tungsten10-Nickel Alloy for Surgical Implant Applica-tions (UNS R30605)F 136 Specification for Wrought Titanium-6Aluminum-4Vanadium ELI (Extra Low Inte
10、rstitial) Alloy for SurgicalImplant Applications (UNS R56401)F 138 Specification for Wrought-18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for SurgicalImplants (UNS S31673)F 361 Practice for Assessment of Compatibility of MetallicMaterials for Surgical Implants with Respect to Effec
11、t ofMaterials on Tissue3F 469 Practice for Assessment of Compatibility of Nonpo-rous Polymeric Materials for Surgical Implants with Re-gard to Effect of Materials on Tissue3F 562 Specification for Wrought Cobalt-35Nickel-20Chromium-10Molybdenum Alloy for Surgical ImplantApplications (UNS R30035)F 60
12、3 Specification for High-Purity Dense Aluminum Ox-ide for Surgical Implant ApplicationF 648 Specification for Ultra-High-Molecular-Weight Poly-ethylene Powder and Fabricated Form for Surgical Im-plantsF 763 Practice for Short-Term Screening of Implant Mate-rials3. Summary of Practice3.1 This practic
13、e describes the preparation of implants, thenumber of implants and test hosts, test sites, exposure sched-ule, implant sterilization techniques, and methods of implantretrieval and tissue examination of each test site. Histologicalcriteria for evaluating tissue reaction are provided.1This practice i
14、s under the jurisdiction ofASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.16 on Biocompatibility Test Methods.Current edition approved May 1, 2004. Published June 2004. Originallyapproved in 1986. Last previous edition approved in
15、2003 as F 981 99 (2003).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.3Withdrawn.1Copyright ASTM Internatio
16、nal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 This practice covers a test protocol for comparing thelocal tissue response evoked by biomaterials, from whichmedical implantable devices might ultimately be fabricated,with the local
17、tissue response elicited by control materialscurrently accepted for the fabrication of surgical devices. Thematerials may include metals (and metal alloys), dense alumi-num oxide, and polyethylene that are standardized on the basisof acceptable long-term well-characterized long-term response.The con
18、trols consistently produce cellular reaction and woundhealing to a degree that has been found to be acceptable to thehost.5. Test Hosts and Sites5.1 Rats (acceptable strains such as Fischer 344), NewZealand White rabbits, and other small laboratory animals maybe used as test hosts for soft tissue im
19、plant response. It issuggested that the rats be age and sex matched. Rabbits orlarger animals may be used as test hosts for bone implants.When larger animals such as dogs, goats, or sheep are used, thedecision should be based upon special considerations of theparticular implant material or study.5.2
20、 The sacro-spinalis, paralumbar, gluteal muscles, and thefemur or tibia can serve as the test site for implants. However,the same site must be used for test and material implants in allthe animal species.5.3 There shall be a minimum of four animals at eachsacrifice interval for a total of twelve ani
21、mals per study. Iflarger animals are used, in which a greater number of implantscan be placed, there shall be at least two animals sacrificed ateach time period.6. Implant Specimens6.1 FabricationEach implant shall be made in a cylindri-cal shape with hemispherical ends (see 6.3 and 6.4 for sizes).I
22、f the ends are not hemispherical, this shall be reported. Eachimplant shall be fabricated, finished, and its surface cleaned ina manner appropriate for its projected application in humansubjects in accordance with Practice F86. If the specimens areporous, the method of preparation of the porous spec
23、imensshall be representative of the contemplated human implantapplication and shall yield a specimen with characteristic poresize, pore volume, and pore interconnection diameter. Thechoice between using solid core specimens with porous coat-ings and specimens that are porous throughout shall be adec
24、ision of the investigator and shall be reported.6.2 Reference metallic specimens shall be fabricated inaccordance with 6.1 from materials such as the metal alloys inSpecifications F 67, F 75, F 90, F 138, or F 562, ceramic inSpecification F 603, or polymers such as in Specification F 648polyethylene
25、 or USP Negative Control Plastic. If the testmaterials are porous, consideration should be given to usingporous specimens for reference specimens. Alternatively, non-porous reference specimens may be used.6.3 Suggested Sizes and Shapes of Implants for Insertion inMuscle:6.3.1 The implants shall be c
26、ylindrical in shape and mayrange from 1 mm to 6 mm in diameter and from 10 mm to 20mm in length depending upon the relative size of the speciesunder study.6.3.2 The dimensions used shall be reported in accordancewith 8.1.6.3.3 Depending upon the particular device application,other sample shapes may
27、be used. For instance, an investigatormight wish to test the biocompatibility of a new material forscrews in the form of a screw. If an alternative specimen shapeis used, this should be reported in accordance with 8.1.6.4 Sizes and Shapes of Implants for Insertion in Bone:6.4.1 Implant diameters for
28、 use in bone shall be approxi-mately equal to the cortex thickness. Implant lengths shallallow them to reside in one cortex and the medulla withoutexcessive protrusion beyond the periosteum.6.4.2 The dimensions used shall be reported in accordancewith 8.1.6.5 Number of Test and Control Implants:6.5.
29、1 In each rat, due to size, there may be two implants; oneeach test and control material implant.6.5.2 In each rabbit, due to size, there may be six implants;four test materials and two control material implants.6.5.3 In larger animals, there may be twelve implants; eighttest materials and four cont
30、rol material implants.6.5.4 In rabbits or larger animals, there shall be tested atleast sixteen test material implants and eight control materialimplants at each time period.6.6 Conditioning:6.6.1 Remove all surface contaminants with appropriatesolvents and rinse all test and control implants in dis
31、tilled waterprior to sterilization. It is recommended that the implantmaterials be processed and cleaned in the same way the finalproduct will be.6.6.2 Clean, package, and sterilize all implants in the sameway as used for human implantation.6.6.3 After final preparation and sterilization, handle the
32、 testand control implants with great care to ensure that they are notscratched, damaged, or contaminated in any way prior toinsertion.6.6.4 Report all details of conditioning in accordance with8.1.6.7 Implantation PeriodInsert all implants into each ani-mal at the same surgical session for implantat
33、ion periods of 12,26, and 52 weeks.7. Procedure7.1 Implantation (Muscle):7.1.1 Place material implants in the paravertebral muscles insuch a manner that they are directly in contact with muscletissue.7.1.2 Introduce material implants in larger animals by thetechnique of making an implantation site i
34、n the muscle byusing a hemostat to separate the muscle fibers. Then insert theimplant using plastic-tipped forceps or any tool that is non-abrasive to avoid damage to the implant.F9810427.1.3 Introduce material implants using sterile technique.Sterile disposable needles or hypodermic tubing and troc
35、harmay be used to implant the material implants into the paraver-tebral muscles along the spine. In rats, insert a negative controlimplant on one side of the spine and a test material implant onthe other side. In rabbits, implant one negative control materialon each side of the spine and implant two
36、 test materials on eachside of the spine. If larger diameter specimens are used, analternative implantation technique is that described in 7.1.2.7.2 Implantation (Femur)Expose the lateral cortex ofeach rabbit femur and drill undersized pilot holes through thelateral cortex using the technique and in
37、strument appropriatefor the procedure. Final reaming of the holes should beperformed by hand to yield holes which are smaller than theimplant specimens by 0.1 mm or less. Into each one of theseholes, insert one of the implants by finger pressure. Then closethe wound.NOTE 1Caution should be taken to
38、minimize the motion of theimplant in the tissue to prevent the effects of motion on the desired result.7.3 Postoperative Care:7.3.1 All animal studies must be done in a facility approvedby a nationally recognized organization and in accordance withall appropriate regulations.7.3.2 Carefully observe
39、each animal during the period ofassay and report any abnormal findings.7.3.3 Infection or injury of the test implant site mayinvalidate the results. The decision to replace the animal so thatthe total number of retrieved implants will be as represented inthe schedule shall be dependent upon the desi
40、gn of the study.7.3.4 If an animal dies prior to the expected date of sacrifice,perform a necropsy in accordance with the procedure in 7.4 todetermine the cause of death. Replacement of the animal to thestudy shall be dependent upon the design of the study. Includethe animal in the assay of data if
41、the cause of death is relatedto the procedure or test material.7.4 Sacrifice and Implant Retrieval:7.4.1 Euthanize animals by a humane method at the inter-vals specified in 6.7.NOTE 2The necropsy periods start at 12 weeks because it is assumedthat acceptable implant data has been received for earlie
42、r periods fromshort term implant testing according to Practice F 763. If the 90-daysacrifice period has been utilized under Practice F 763, that group need notbe repeated under this protocol, and thus, the 12-week group may beeliminated.7.4.2 At necropsy, record any gross abnormalities of coloror co
43、nsistency observed in the tissue surrounding the implant.Remove each implant with an intact envelope of surroundingtissue. Include in the tissue sample a minimum of a 4-mm thicklayer of tissue surrounding the implant. If less than a 4-mmthick layer of tissue is removed, report in accordance with 8.1
44、.7.5 Postmortem ObservationsIn accordance with stan-dard laboratory practice, perform a necropsy on all animals thatare sacrificed for the purposes of the assay or die during theassay period. Establish the status of the health of the experi-mental animal during the period of the assay. Report asdesc
45、ribed in Section 8.7.6 Histological Procedure:7.6.1 Tissue Sample PreparationPrepare appropriateblocks from each implantation site and indicate the orientationof the axis of the femur relative to the axis of the implant (forbone implants). Also indicate the orientation of the implantrelative to the
46、axis of rotation of the femoral condyles.7.6.1.1 Process the excised tissue block containing either atest implant or control implant for histopathological examina-tion and such other studies as are appropriate. Cut the samplemidway from end to end into appropriate size and in theappropriate orientat
47、ion for each study. Transfer, or record, orboth, the orientational details noted in 7.6.1 to each part of thesample. Record the gross appearance of the implant and thetissue. If the sample is porous, it is imperative that sectioningprocedures be used that maintain the implant within its tissueenvelo
48、pe to allow the evaluation of tissue within the pores.Such procedures may include ground section preparation.7.6.1.2 If special stains are deemed necessary, prepareadditional sections and make appropriate observations.7.7 Histopathological ObservationsCompare the amountof tissue reaction adjacent to
49、 the test implant to that adjacent toa similar location and orientation on the control implant withrespect to thickness of scar, presence of inflammatory or othercell types, presence of particles, and such other indications ofinteraction of tissue and material as might occur with the actualmaterial under test. A suggested method for the evaluation oftissue response after implantation is Turner, et al. (1)4.Ifaporous sample is being tested, the evaluation of the tissuereaction must include areas within the pores of the test andcontrol samples at similar locations.7.7.1 Sugge
