1、BRITISH STANDARD BS7254-4: 1990 Orthopaedic implants Part4: Recommendations for retrieval and examination of implants and associated tissues UDC 615.461:616.71-74:616.091.5-089.843:613.003.93BS7254-4:1990 This BritishStandard, having been prepared under the directionof the Health Care Standards Poli
2、cy Committee, waspublished under the authorityof the Board of BSI andcomes into effect on 31August1990 BSI 01-2000 The following BSI references relate to the work on this standard: Committee referenceHCC/22 Draft announced BSI News, October1989 ISBN 0 580 18324 6 Committees responsible for this Brit
3、ishStandard The preparation of this BritishStandard was entrusted by the Health Care Standards Policy Committee (HCC/-) to Technical Committee HCC/22, Upon which the following bodies were represented: British Institute of Surgical Technologists British Investment Casting Trade Association British Me
4、dical Association British Orthopaedic Association British Steel Industry British Surgical Trades Association Department of Health Institute of Sterile Services Management Medical Sterile Products Association Ministry of Defence National Association of Theatre Nurses Royal College of Surgeons of Engl
5、and Royal Veterinary College Scottish Office Coopted members Amendments issued since publication Amd. No. Date CommentsBS7254-4:1990 BSI 01-2000 i Contents Page Committees responsible Inside front cover Foreword ii 0 Introduction 1 1 Scope 1 2 Retrieval and sampling 1 3 Handling and sterilization of
6、 removed implant and associated samples 2 4 Packaging, labelling and transport of removedimplantandassociatedsamples 3 5 Documentation 3 6 Examination of removed implant and associated samples 4 Appendix A Checklist for retrieval of orthopaedic implants 5 Appendix B Extract from1986 issue of Post Of
7、fice Guide 6 Appendix C Examples of the information to be compiledandrecordedwhenanimplant is removed 7 Appendix D Examples of the information tobecompiledonmetallurgicalexamination of removed implant and/or component 9 Figure 1 Checklist for retrieval of orthopaedic implants 5 Publications referred
8、 to Inside back coverBS7254-4:1990 ii BSI 01-2000 Foreword This Part of BS7254 has been prepared under the direction of the Health Care Standards Policy Committee and supersedes BS3531-22:1988 which is withdrawn. It takes cognizance of the work in progress within Technical Committee150 Implants for
9、surgery, of the International Organization for Standardization (ISO). Requirements for orthopaedic implants (then termed “surgical implants”) were first published in1962 as BS3531. In1968 a part revision of BS3531:1962 was issued as BS3531-1, which dealt with surgical implants made of all materials.
10、 In1980 the first four Parts of a multi-part version of BS3531 were published. A further19 Parts of BS3531 were subsequently published, Part22:1988 giving recommendations for retrieval and examination of orthopaedic implants. In view of the increase in the number of Parts, and with a view to facilit
11、ating the implementation of published or forthcoming ISO implant standards, the BritishStandard relating to implants has been restructured. Accordingly, the number BS3531 is reserved for standards for implants for osteosynthesis, BS7251 covers joint prostheses, BS7252 covers metallic materials for s
12、urgical implants, BS7253 covers non-metallic materials for surgical implants and BS7254 covers orthopaedic implants, i.e.aspects common to both osteosynthesis and joint replacement. This edition of BS7254-4 introduces editorial changes to reflect this restructuring, and up-dates cross-references but
13、 otherwise makes no changes to the recommendations for retrieval and examination of implants first published as BS3531-22:1988. It does not reflect a full review or revision of the standard, which will be undertaken in due course. Once implantation has been completed, an implant should never be reus
14、ed after removal. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This d
15、ocument comprises a front cover, an inside front cover, pagesi andii, pages1 to10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS7254-4:199
16、0 BSI 01-2000 1 0 Introduction Orthopaedic implants may be removed and retrieved from the body for a variety of reasons, including routine removal, upon completion of the treatment, removal at the time of a revision operation and removal because of failure, either of the treatment or of the implant
17、itself. Implants may also be removed post-mortem. Care should be taken to ascertain the legal ownership of an implant before any destructive tests are carried out. No destructive test should be performed until permission has been obtained from all parties who have, or may have, an interest in the ou
18、tcome. It is important that this is borne in mind where there is any likelihood of regulation or litigation. This Part of BS7254 gives general guidance on procedures for the retrieval, handling and examination of implants and is intended to facilitate accurate comparison of results from different ce
19、ntres. Procedures and methods are not described in detail since they are many and varied, and will differ depending on the circumstances pertaining to each case and depending on the nature of the information required. A summary of the stages involved in the handling and examination of retrieved impl
20、ants and associated tissue is given for information in Appendix A. The examination of retrieved orthopaedic implants permits analysis of the performance of implants and/or the materials from which they are made, including the reactions of the body tissues to the implant. The performance of any indiv
21、idual implant depends on various interacting factors and consideration needs to be given to design, materials, surgical technique and patient factors. Patient factors have often been ignored, even though it is known that the patients level of activity, mass and physiological reactions may affect the
22、 acceptance and functional life of an implant. For performance analyses to be effective, the maximum possible data are required. A detailed analysis based on only one parameter may lead to inaccurate conclusions and such analyses should be avoided. In drawing conclusions, a distinction should be mad
23、e between the mechanism of failure and the cause of failure. This distinction is essential when determining whether the failure is related to clinical factors or to implant factors. Although the mechanism of failure of an implant is often very easy to determine, e.g.fatigue breakage, the actual caus
24、e of failure is multi-factorial and may be related to the quality of materials, the techniques of implantation, inappropriate patient activity, bone pathology, etc. Failure, e.g.breakage, of the implant does not necessarily mean that the problem is related to the device. A programme of examining ret
25、rieved implants may readily lead to identification of the mechanism of failure but the causes of failure may be much more difficult to determine without all available data, including clinical information, being available. It should be noted that a much more detailed testing and reporting protocol th
26、an that given in this Part of BS7254 will be required for clinical trials. 1 Scope This part of BS7254 recommends procedures for the retrieval, handling and examination of orthopaedic surgical implants and associated tissue samples which have been removed from the body, either living or post-mortem.
27、 NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Retrieval and sampling 2.1 Planning Before starting to remove the implant, the availability of up-to-date radiographs should be checked, and if necessary, new radiographs taken. Radiographic recor
28、ds should be made, even if the implant is to be removed post-mortem. It should be noted that little or no useful information can be obtained, or should be expected, from an implant removed from a cadaver that has undergone cremation. It is important to decide what samples are required for laboratory
29、 testing and when they should be taken, because subsequent procedures such as washing and disinfection can invalidate results. An obvious example is samples for microbiological testing, which should be taken as soon as the implant is exposed, but histological properties of body tissue can also be af
30、fected.BS7254-4:1990 2 BSI 01-2000 2.2 Procedure In order to allow the maximum information to be obtained, the implant should be removed in a way which causes it minimal damage but is consistent with the requirements of surgical procedures. It is particularly important to protect bearing surfaces of
31、, for instance, a total joint prosthesis and the fracture surfaces of a broken implant. However, certain techniques of removal unavoidably cause damage, e.g.drilling into the articular surface of a plastics acetabular component During removal, note should be taken of the orientation of the implant a
32、nd all component parts. For example, screws should be removed in such a way that their positions in a bone plate may be identified subsequently, and they should be placed in separate, shatter-proof containers, numbered sequentially from proximal to distal, immediately upon removal. The orientation o
33、f bone plates may be identified by inserting a suture through the most proximal hole or slot. Pieces of bone cement that have become detached from the implant or bone should be retrieved and handled in the same manner as the implant itself. All observations regarding the condition of the implant and
34、 surrounding tissues before, during and after implant, removal should be recorded. A photographic record of the implant in situ, of the surgical site and of the removed implant is recommended. It may also be desirable to make a preliminary examination of the implant immediately upon removal (see6.2)
35、. However, handling of the implant should be minimized and it should be placed in shatter-proof protective or storage containers when not being examined. 2.3 Microbiological sampling The advice of a microbiologist should be sought when planning retrieval of an implant. Samples for microbiological ex
36、amination should be taken in collaboration with the microbiologist, and should be taken as soon as the implant, tissue, tissue fluid etc. is exposed. All samples should be placed immediately in the appropriate culture medium. Incorrect handling of the samples can invalidate results. 2.4 Tissue sampl
37、ing Samples of tissue adjacent to the implant and from other relevant sites (for example lymph nodes or any tissue with abnormal appearance) should be taken wherever possible and subjected to histological examination, since the interfacial reactions are of importance in determining long-term human t
38、issue acceptability. A record of the location of the site of tissue excision and an indication of the tissue orientation relative to the implant should be made. If possible, the proximal end of the sample should be marked and the sample should be maintained at its original length, e.g.with plastics
39、muscle biopsy clamps or other means. Any collection of fluid within the tissues or in a joint should be aspirated and saved for examination. 3 Handling and sterilization of removed implant and associated samples 3.1 Handling All operative, biopsy and autopsy procedures should be carried out using pr
40、ocedures, and under conditions, appropriate to the safety of the patient and the surgical staff. Where rubber gloves are worn, gloves complying with BS1884 or BS4005 are recommended. Unless and until disinfection or sterilization procedures have been completed, all retrieved implants and associated
41、samples should be treated as though they are infected. When there is contamination with blood there is always the risk of transmission of hepatitis or other virus mediated disease. Guidance on handling procedures and precautions may be found in Health Notice HN(87)1 “Decontamination of equipment, li
42、nen or other surfaces contaminated with Hepatitis B or Human Immunodeficiency Virus” 1) , Health Notice HN(87)22 “Decontamination of health care equipment prior to inspection, service or repair” 1) , the DHSS “Code of practice for the prevention of infection in clinical laboratories and post-mortem
43、rooms” 2) , and in the chapter dealing with precautions for invasive procedures including specimen taking, in “LAV-HTLV3 Causative agent of AIDS and related conditions revised guidelines, 1986” 1) . 1) Available from the Department of Health, 14Russell Square, London WC1B5EP. 2) Prepared by the Depa
44、rtment of Health and Social Security and available from Her Majestys Stationery Office.BS7254-4:1990 BSI 01-2000 3 After all observations (see6.2) have been made on the implant in its immediate post-operative condition and any samples which are required have been taken, it should be decided whether
45、further examination or tests are necessary in order to determine if disinfection or sterilization of the implant is indicated. 3.2 Cleansing and sterilization The implant should initially be rinsed while immersed in water but not cleaned or scrubbed in any way. Unless contra-indicated by the prerequ
46、isites of subsequent methods of examination, implants should be sterilized. Experience has shown that immersion for6h in2% (V/V) aqueous glutaraldehyde solution 3)buffered to a pH value of between7.5 and8.5 is not harmful to metals and generally not harmful to plastics. This treatment, however, is i
47、nappropriate if absorption of tissue constituents by plastics materials is to be studied. 4 Packaging, labelling and transport of removed implant and associated samples 4.1 General principles Subject to the requirements of the carrier as indicated in4.2 and4.3, the following principles should be ado
48、pted. Care should be taken to package the implant in a manner that will protect bearing surfaces, fracture surfaces, corners and edges from damage, and that will prevent sharp corners and edges from penetrating the package. Components of an implant should be packaged in separate inner containers, or
49、 in a manner that will prevent contact between components. All packages should be labelled to identify the contents and to indicate the total number of packages in each consignment. They should be marked with the name and address of the sender. The inner containers should be shatter-proof and sufficiently robust to resist the loads that may be exerted by the contents during handling and transit. Glass containers are unlikely to be suitable for other than non-metallic implants or small and light metallic implants. Documentation (see clause5) should be enclosed in, or secure
