1、BRITISH STANDARD BS3531-5.6: 1991 ISO6475:1989 Implants for osteosynthesis Part5: Bone screws and auxiliary equipment Section5.6 Specification for the mechanical requirements and test methods for screws having asymmetrical thread and spherical undersurfaceBS3531-5.6:1991 This British Standard, havin
2、g been prepared under the directionof the Health Care Standards Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 30 August1991 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference HCC/22 Draft for comment86/
3、55442DC ISBN 0 580 19966 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Health Care Standards Policy Committee to Technical Committee HCC/22, upon which the following bodies were represented: British Institute of Surgical Technologist
4、s British Investment Casting Trade Association British Medical Association British Orthopaedic Association British Steel Industry British Surgical Trades Association Department of Health Institute of Sterile Services Management Medical Sterile Products Association National Association of Theatre Nur
5、ses Royal College of Surgeons of England Royal Veterinary College Scottish Office The following body was also represented in the drafting of the standard, through subcommittees and panels: Department of Trade and Industry (National Engineering Laboratory) Amendments issued since publication Amd. No.
6、 Date CommentsBS3531-5.6:1991 BSI 09-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Normative references 1 3 Test method 1 4 Test report 1 Annex A (normative) Mechanical requirements for stainless steel bone screws 2 Annex B (informativ
7、e) Interrelationship of International Standards dealing with bone screws, bone plates and relevant tools 3 Annex C (informative) Bibliography: International Standards referred to in table of Annex B 4 Table A.1 Minimum breaking torque and minimum angle of rotation at failure 2 Publication(s) referre
8、d to Inside back coverBS3531-5.6:1991 ii BSI 09-1999 National foreword This Section of BS3531 has been prepared under the direction of the Health Care Standards Policy Committee. It is identical with ISO6475 “Implants for surgery Metal bone screws with asymmetrical thread and spherical under-surface
9、 Mechanical requirements and test methods”, published by the International Organization for Standardization (ISO). BS3531-5 was first published in 1982 and gave requirements for particular types of bone screw, for taps, drills and screwdrivers, and for holes and slots in bone plates. The revision of
10、 BS3531-5 offered the opportunity to facilitate the implementation of published and forthcoming International Standards, and to separate, in different Parts of BS3531, requirements for screws and auxiliary equipment from those for bone plates. Requirements for bone screws and their auxiliary equipme
11、nt are retained in BS3531-5, which is now published in a number of Sections, whilst requirements for bone plates are specified in BS3531-23, also published in Sections. BS3531-5:1982 is withdrawn. This standard is for use with screws specified in BS3531-5.3. It is strongly recommended that the produ
12、cts specified in this Section of BS3531 should be manufactured according to the recommendations given in the “Quality Systems for Orthopaedic Implants 1990 Good Manufacturing Practice” 1) . Product certification. Users of this British Standard are advised to consider thedesirability of third party c
13、ertification of product conformity with this BritishStandard based on testing and continued surveillance, which may be coupled with assessment of a suppliers quality systems against the appropriate Part of BS5750. Enquiries as to the availability of third party certification will be forwarded by BSI
14、 to the Association of Certification Bodies. If a third party certification scheme does not already exist, users should consider approaching an appropriate body from the list of Association members. A British Standard does not purport to include all the necessary provisions of a contract. Users of B
15、ritish 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 document comprises a front cover, and inside front cover, pagesi andii, pages1 to4, an inside back cover and a back cove
16、r. 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. Cross-references International Standard Corresponding British Standard ISO5832-1:1987 BS7252 Metallic materials for surgical impla
17、nts Part 1:1990 Specification for wrought stainless steel (Identical) ISO5835:1991 BS3531 Implants for osteosynthesis Section5.3:1991 Specification for dimensions of screws having hexagonal drive connection spherical under-surfaces and asymmetrical thread (Identical) 1) Compiled by the Department of
18、 Health; published and available from Her Majestys Stationery Office,49High Holborn, London WC16HB for personal callers or by post from HMSO, POBox276, London SW85DT.BS3531-5.6:1991 BSI 09-1999 1 Introduction This International Standard does not purport to address all of the safety problems associat
19、ed with its use. It is the responsibility of whoever uses it to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. The results obtained in this method bear no direct correlation to the use of the subject bone screw. T
20、his test method is used only for purposes of maintaining the uniformity of the product tested. 1 Scope This International Standard specifies the test methods for determining breaking torque and angle of rotation at failure for metal bone screws for surgery. Mechanical requirements for bone screws ar
21、e specified in Annex A. NOTE 1At present data are only available for bone screws with dimensions according to ISO5835 and made from stainless steel according to ISO5832-1. If data become available for bone screws made from other materials and/or with other standardized dimensions, they will be added
22、 in further annexes. NOTE 2The interrelationship of International Standards dealing with bone plates, bone screws and relevant tools is shown for information in Annex B. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of
23、this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indica
24、ted below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO5832-1:1987, Implants for surgery Metallic materials Part1: Wrought stainless steel. ISO5835:, Implants for surgery Metal bone screws with hexagonal drive connection Spherical under-surface of head, a
25、symmetrical thread Dimensions 2) . 3 Test method 3.1 Apparatus A test machine having the following characteristics shall be used: a) a maximum sensitivity on the lowest measuring range of not less than0,01Nm or equivalent, and on other scales of not less than1% of full scale reading; b) a selection
26、of measuring ranges (see3.2.4); c) the capability of recording the maximum torque attained during the test; d) a device to prevent the screw becoming disengaged from the component by means of which the torque is applied. NOTEIn some countries the test machine must comply with the requirements laid d
27、own by the national test or verification authority. 3.2 Procedure 3.2.1 Insert the screw under test into the test block and clamp it so that the following conditions are met: a) if possible, five full threads from the thread run-out shall be exposed; b) movement of the clamped portion shall be preve
28、nted; c) the axes of the screw and the component by means of which the torque is applied shall be coincident. 3.2.2 Apply torque so that the screw head rotates at a uniform angular velocity within the range from1r/min to5r/min 3)with continuous augmentation until fracture occurs. 3.2.3 Record the ma
29、ximum breaking torque and the angle of rotation at failure. 3.2.4 If the maximum torque recorded is less than20% of the full scale reading of the test machine, disregard this result and repeat the test using a lower range. 4 Test report The test report shall include the following particulars: a) a r
30、eference to this International Standard; b) the maximum breaking torque, expressed to the nearest0,1Nm; c) the angle of rotation at failure, expressed to the nearest10 ; d) a statement of the precise test conditions if lessthan five full threads are exposed. 2) Will cancel and replace ISO5835-1 at n
31、ext revision stage. (ISO5835-1 cancelled and replaced ISO5835-1:1978 and ISO5835-2:1978.) 3) 1r/min=0,104rad/sBS3531-5.6:1991 2 BSI 09-1999 Annex A (normative) Mechanical requirements for stainless steel bone screws A.1 Scope This annex specifies the mechanical requirements for unused non-self-tappi
32、ng bone screws for surgery, complying with ISO5835 and made from stainless steel according to ISO5832-1. A.2 Test specimens Each screw in the test sample shall be examined to check that they all comply with the dimensional requirements specified in ISO5835-1; only those screws with dimensions that d
33、o so comply shall be tested. A.3 Surface finish When examined by normal or corrected vision, the surface of metal bone screws shall be free from imperfections, such as nicks, scratches and other defects that would impair the serviceability of the screw. When examined by normal or corrected vision, t
34、he surface finish shall be uniform and free from marks which have been caused by previous operations, such as grinding, polishing, burnishing, tumbling, etc. A.4 Breaking torque and angle of rotation at failure Each screw in the test sample shall be tested in accordance with clause3 to determine the
35、 minimum breaking torque and minimum angle of rotation to failure. The minimum breaking torque and minimum angle of rotation to failure of each screw shall be as specified in Table A.1. Table A.1 Minimum breaking torque and minimum angle of rotation at failure A.5 Compliance and re-tests Should any
36、of the screws in the test sample not comply with any of the requirements, a further sample, comprising at least twice the number of screws of the original test sample, shall be taken from the lot in question and all tests described in this International Standard shall be carried out on the new test
37、sample. Any failure amongst the second sample of screws shall constitute failure of the particular lot of screws to comply with this International Standard. Screw in accordance with ISO5835-1 (Code and nominal thread diameter) Minimum breaking torque Nm Minimum angle of rotation at failure (if five
38、threads are exposed) HA1,5 HA2,0 HA2,7 HA3,5 HA4 HA4,5 HA5 HB4 HB6,5 0,2 0,35 1 2,3 4 4,4 5,5 1,3 6,2 150 150 180 180 180 180 180 90 90BS3531-5.6:1991 BSI 09-1999 3 Annex B (informative) Interrelationship of International Standards dealing with bone screws, bone plates and relevant tools It has been
39、 decided that the set of International Standards dealing with bone screws, bone plates and relevant tools should be divided into two parallel series. The basis of the division into two series is the essentially different designs of the screw threads of the bone screws (HA and HB type screws as oppos
40、ed to HC and HD type screws). A simplified schematic guide illustrating the interrelationship between screws, plates and tools covered by the two parallel series of International Standards is given below. ISO5835 ISO9268 Screws Thread Head under-surface Drive connection Mechanical requirements ISO64
41、75 Breaking torque/angle of rotation In preparation Holes and slots ISO5836 ISO9269 Plates Mechanical requirements ISO9585 ISO9585 ISO8319-1 ISO8319-2 Driving tools Keys and screwdrivers Drill bits, taps, countersink cutters ISO9714-1 In preparationBS3531-5.6:1991 4 BSI 09-1999 Annex C (informative)
42、 Bibliography: International Standards referred to in table of Annex B ISO5835:, Implants for surgery Metal bone screws with hexagonal drive connection Spherical under-surface of head, asymmetrical thread Dimensions 4) . ISO5836:1989, Implants for surgery Metal bone plates Holes corresponding to scr
43、ews with asymmetrical thread and spherical under-surface. ISO6475:1989, Implants for surgery Metal bone screws with asymmetrical thread and spherical under-surface Mechanical requirements and test methods. ISO8319-1:1986, Orthopaedic instruments Drive connections Part1: Keys for use with screws with
44、 hexagon socket heads. ISO8319-2:1986, Orthopaedic instruments Drive connections Part2: Screwdrivers for single slot head screws, screws with cruciate slot and cross-recessed head screws. ISO9268:, Implants for surgery Metal bone screws with conical under-surface of head Dimensions 5) . ISO9269:1988
45、, Implants for surgery Metal bone plates Holes and slots corresponding to screws with conical under-surface. ISO9585:, Implants for surgery Method for testing bending strength and stiffness of bone plates 5) . ISO9714-1:, Orthopaedic instruments Drilling instruments Part1: Drills bits, taps and coun
46、tersink cutters 5) . 4) Will cancel and replace ISO5835-1 at next revision stage. (ISO5835-1 cancelled and replaced ISO5835-1:1978 and ISO5835-2:1978.) 5) To be published.BS3531-5.6:1991 BSI 09-1999 Publication(s) referred to See national foreword.BS3531-5.6: 1991 ISO6475:1989 BSI 389 Chiswick High
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