YY/T 1720-2020 English PDFUS$259.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. YY/T 1720-2020: Standard test method for determining the forces for disassembly of modular acetabular devices Status: Valid
Basic dataStandard ID: YY/T 1720-2020 (YY/T1720-2020)Description (Translated English): Standard test method for determining the forces for disassembly of modular acetabular devices Sector / Industry: Medical Device & Pharmaceutical Industry Standard (Recommended) Classification of Chinese Standard: C35 Word Count Estimation: 14,154 Date of Issue: 2020 Date of Implementation: 2021-03-01 Issuing agency(ies): State Drug Administration Summary: This standard specifies a standard method for measuring the strength of the connection between the acetabular cup and the acetabular lining. Although this method cannot faithfully reproduce physiological loading conditions, it has become a method for comparing the integrity of various locking mechanisms. This standard applies to combined acetabular components in hip prostheses. YY/T 1720-2020: Standard test method for determining the forces for disassembly of modular acetabular devices---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. Standard test method for determining the forces for disassembly of modular acetabular devices People's Republic of China Pharmaceutical Industry Standards 2020-02-26 released Implementation of 2021-03-01 Issued by the National Medical Products Administration 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Overview of test methods 1 5 Significance and use 2 6 Instruments and equipment 3 7 Select sample 3 8 Test procedure 3 9 Report 6 Appendix A (informative appendix) Basic principles 7 Reference 8 ForewordThis standard was drafted in accordance with the rules given in GB/T 1.1-2009. Please note that some of the contents of this document may involve patents. The issuing agency of this document is not responsible for identifying these patents. This standard was proposed by the State Drug Administration. This standard is prepared by the Orthopedic Implants Sub-Technical Committee of the National Standardization Technical Committee for Surgical Implants and Orthopedic Devices (SAC/TC110/ SC1) Centralized. Drafting organizations of this standard. Tianjin Medical Device Quality Supervision and Inspection Center, Beijing Aikang Yicheng Medical Equipment Co., Ltd., Shandong Weigao Orthopedic Materials Co., Ltd., School of Mechanical and Electrical Engineering and Automation, Shanghai University. The main drafters of this standard. Zhang Shu, Li Wenjiao, Wang Caimei, Li Xinyu, Gu Yingsong, Huang Wenxiang, Hua Zikai, Cai Peng. Test method for separating force of combined acetabular components1 ScopeThis standard specifies a standard method for measuring the strength of the connection between the acetabular cup and the acetabular lining. Although this method cannot truly reproduce the physiology Load conditions, but it has become a way to compare the integrity of various locking mechanisms. This standard applies to combined acetabular components in hip prostheses.2 Normative referencesThe following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document. GB/T 16825.1 Inspection of static uniaxial testing machine Part 1 Inspection and test of force measuring system of tensile and (or) compression testing machine calibration3 Terms and definitionsThe following terms and definitions apply to this document. 3.1 A part of the combined acetabulum, including the hemispherical socket of the femoral ball head forming the articular surface. The external geometry of the acetabulum lining and the outside of the acetabulum The cup is matched, the locking mechanism is made integral by the design of the inner lining and the outer cup, or other parts (for example, metal ring, Screws, etc.). 3.2 The external, hollow structure (usually a metal material) of the acetabular component provides additional support or reinforcement for the acetabular lining, and its external features are straight Mate with the acetabular fossa bone of the pelvis (for example, through bone cement, tight press fit, bone ingrowth into porous structure, integral thread, anchor screw, Nails, etc.). The acetabular cup can be solid, or contain holes for fixation, or holes for tools, or both.4 Overview of test methods4.1 Installation Apply a force of 2kN to insert the acetabular liner into the acetabular cup for testing. This value is the same as that required to install the ball head in the ASTMF 2345 test method The force is similar. 4.2 Axial separation 4.2.1 The test method for axial separation of acetabular components provides a way to measure the axial locking strength of the acetabular lining in the combined acetabular product. method. 4.2.2 After the acetabular liner is correctly assembled in the acetabular cup, install the component on the fixture with the cup mouth facing down. Support the acetabular cup, the same Apply axial force to the acetabular lining until it disengages. Record the force required to detach the acetabular liner from the acetabular cup. 4.3 Pull out eccentrically or pry out to separate 4.3.1 The eccentric pull-out or pry-out method is designed to evaluate the resistance of the locking mechanism when the neck of the hip prosthesis hits the edge of the acetabular lining. The impact force may cause the edge of the acetabular liner opposite the impact contact area to push out of the acetabular cup. The acetabular lining is pulled from the acetabular cup The resistance produced by the edge of the lining when loosened is measured as the resistance of the acetabular lining against impact. 4.3.2 After the acetabular liner is correctly assembled in the acetabular cup, install the component on the fixture with the cup mouth facing upwards. Round the top of the acetabular cup At least 4 positions evenly spaced around the circumference are compressed to restrain its movement. For eccentric pull-out, force is applied to the contact point of the liner near the top surface. The line of action of the required force is parallel to the direction of the polar axis of the inner liner. Record the force required to detach the acetabular liner from the acetabular cup. 4.3.3 For the pry-out test, the force is applied to the contact point of the lining near the top surface through the lever mechanism, and the fulcrum is outside the lining and in the contact point. Opposite the contacts. The center line of the lever should intersect the polar axis of the lining. Record the force required to detach the acetabular liner from the acetabular cup. Record leverage power Length of arm (L2) and resistance arm (L1). These values are used to calculate the prying force. 4.4 Torsion separation 4.4.1 The torsional separation method is designed to evaluate the effect of the locking mechanism when strong friction forces try to cause the acetabular lining to rotate in the acetabular cup. resistance. 4.4.2 After the acetabular liner is correctly assembled in the acetabular cup, install the component on the fixation device. The opening must not be obstructed so that the acetabular liner is It is not affected when the acetabular cup is pushed out. Squeeze at least 4 positions evenly spaced around the top of the acetabular cup. Suitable for ball heads with lining diameter At least 4 equally spaced locations are matched or bonded to the lining. Torque is applied to the ball head along the polar axis of the liner. Record the acetabular lining from the acetabulum The torque required for the cup to break away or the adhesion between the articular surface of the acetabular liner and the ball head is broken.5 Significance and use5.1 This test method aims to evaluate the locking strength of the acetabular lining in the acetabular cup under three different force conditions. Basic test method See Appendix A for the principle. 5.2 This test method may not be suitable for all implants. Users of this standard should consider the impact of this method on the tested materials and design The applicability of and its potential applications. 5.3 Although this test method can be used to measure the separation force of modular acetabular components, it should be considered when comparing the data of different design components The size of the implant evaluated and the type of locking mechanism. The size and design of the acetabular product may determine the locking mechanism corresponding to the applied load The location of the system. In addition, the locking mechanism itself may vary with size, especially when the design is circular in nature (for example, large straight Small diameter implants have a larger area of acetabular cup/acetabular liner mating surface than small diameter implants. 5.4 When axially separated or eccentrically pulled out/pryed out, the material may have failed before the locking mechanism fails. This may be because it is fully measured Before the strength of the locking mechanism, the test has exceeded the shear strength of the material. If this happens, the results should be included in the report and taken Take measures to minimize this impact. In order to reduce the shear force, the smallest size parts can be used, using flat-end rods instead of round-end rods, or in A small metal plate is placed between the acetabular liner and the acetabular cup (during the push-out test). For well-designed polyethylene parts, it will not break Under circumstances, it may not be possible to push out the lining or eccentrically pull out/levers out. In some cases, the maximum force value is recorded in the report and the true The separation force may be higher.6 Equipment6.1 A device capable of supporting only the acetabular cup while allowing the acetabular liner to be freely separated from the outer cup is required. 6.2 The testing machine should meet the requirements of GB/T 16825.1.The load to determine the connection strength should be in the test machine range specified in GB/T 16825. 内内。 In the enclosure. 6.3 The testing machine should be able to apply pressure or tension at a constant rate of displacement. The testing machine should have a load monitoring and recording system.7 Select samples7.1 All acetabular linings should be able to represent the quality of the implant product. This includes all sterilization or Heat treatment process. 7.2 Only the internal material, surface state, locking mechanism and geometry of the semi-finished acetabular cup or permanent fixation block are the same as those of the actual acetabular cup. At the same time, it can be used to replace the finished acetabular cup. 7.3 For each test (axial separation, eccentric pull or prying and torsion separation), at least 5 sets of acetabular cup and inner liner components should be tested to determine Separation force value. The acetabular outer cup and inner liner should be paired randomly, otherwise it should be recorded in the report. For the test using polyethylene lining, if the If there is no damage to the acetabular cup in a trial, you can continue to use the same 5 acetabular cups for 3 trials.8 Test procedure8.1 Assembly procedure The acetabular liner is installed in the acetabular cup, and the peak installation force is within the range of 2kN±50N. If the load is applied by displacement control, load The speed is 0.04mm/s. If force control is used, the loading speed is 1kN/s or lower. The line of action of the force should be collinear with the polar axis of the lining. Correct For specific products, a surgical tool (or a ball with the same diameter as the liner articular surface) can be used to apply the load. 8.2 Axial separation 8.2.1 After assembly, place the cup lining structure in a solid metal device that can support the acetabular cup, as shown in Figure 1.Support the solid of the acetabular cup The fixed device shall have no visible signs of deformation during and after the test. The round rod passes through the hole of the cup (along the polar axis of the acetabular cup) at a rate of 5.1 cm/min The speed at which applies an axial force to the inner liner (collinear with the polar axis of the inner liner and the cup). The direction of force application and the longitudinal axis of the rod should be in line with the poles of the inner liner and the acetabular cup. The axes are collinear, and the included angle should be less than 2°; and the distance between the center of the rod in contact with the liner and the polar axis of the liner should be less than 2mm. To apply to the lining Axial force, if necessary, a hole can be made at the top of the acetabular cup. Small diameter drill blanks or rods can be used as a force application tool. The rod diameter must not be less than 5mm. If the rod diameter is too small, holes may be punched on the inner lining during the test. The drill blank or rod should have enough rigidity to make it under test It will not bend under the test force, and there should be enough clearance between the hole of the acetabular cup and the drill blank or rod, so that there is no connection between the hole and the drill blank or rod. touch. Measure and record the maximum force required to detach the acetabular liner from the acetabular cup. 8.2.2 Record the maximum separation force. 8.2.3 The test should be terminated when any of the following situations occurs. a) The separation force is so small that it can be ignored; b) Before separation, the inner lining was excessively damaged (ie, the inner lining was partially broken or severely deformed). This situation should be considered Invalid test. 8.2.4 For the thin polyethylene liner test, the rod applying force may actually pierce the liner. If this happens, it is recommended to increase the rod The cross-sectional area. If penetration still occurs, and if the liner is thin and the liner locking mechanism is strong, the penetrating liner may be The mat serves as an effective test. 8.3 Pull out eccentrically or pry out to separate 8.3.1 Before assembly, the rectangular slot cut or hole drilled on one side of the inner surface of the liner is used as the force point for the test. Slot is at least long 8mm, 4mm wide. The long axis of the slot should be substantially perpendicular to the load axis. The diameter of the hole should be 4mm ~ 6mm. The slot or hole should be approximately perpendicular to mechanism. 8.3.2 In addition, the metal gasket can be bonded to the inner surface of the liner as the point of application of the test. The position of the hole in the gasket should conform to 8.3.1 Requirements for the position of the middle hole. For ceramic liners, it may be necessary to bond the metal tip to the inner liner for... ...... |
