M_PS_5_-_94_scan.pdf

ASTM PS5=I4-O-759530 0554220 T&t-i-Designation:PS 5-94 AMERICAN SOCIETY FOR TESTING AND MATERIALS 1916 Race St Philadelphia,Pa 19103 Reprinted from the Annual Book of ASTM Standards Copyright ASTM II not Itsted in the current combined index.will appear in the next edition Provisional Standard Test Method for Static and Dynamic Spinal Implants Assembly in a Corpectomy Model This provisional slandard is issued by ASTM in accordance wilh a special procedure lo meet the demand/or rapid issuance ofspecijic documenu.2 1.Scope 1.1 This provisional test method covers the materials and methods for the static and dynamic testing of spinal implant assemblies in a corpectomy model.The test materials for most combinations of spinal implant components can be specific depending on the intended spinal location and intended method of application to the spine.1.2 This provisional test method is intended to provide a basis for the mechanical comparison among past,present and future spinal implant assemblies.This provisional test method allows comparison of spinal implant constructs with different intended spinal locations and methods of applica-tion to the spine.This provisional test method is not intended to define levels of performance,since sufficient knowledge is not available to predict the consequences of the use of a particular device.1.3 This provisional test method sets out guidelines for load types and methods of applying loads.Methods for four static load types and one dynamic test are defined for the comparative evaluation of spinal implant assemblies.1.4 This provisional test method establishes guidelines for measuring displacements,determining the yield load,evalu-ating the stiffness and strength of the spinal implant as-sembly.1.5 Some spinal constructs may not be testable in all test configurations.1.6 The values stated in SI units are to be regarded as standard.1.7 This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents 2.1 ASTM Standards:E 4 Practices for Force Verification of Testing Machines2 E 6 Terminology Relating to Methods of Mechanical Testing2 E 122 Practice for Choice of Sample Size to Estimate a Measure of Quality for a Lot or Process3 E 468 Practices for the Presentation of Constant Ampli-tude Fatigue Test Results for Metallic Materials 1 This provisional test method is under the jurisdiction of ASTM Committee F-4 on Medical and Suraical Materials and Devices and is the direct responsibility of Subcommittee on F04.35 on Constructs.Current edition approved July 20 1994.Published October 1994.2 See Section 13 of the Regulations Governing ASTM Technical Commiuees.3 Annual Book oJASTM Stondard.y,Vol 03.01.E 739 Practice for Statistical Analysis of Linear or Linear-ized Stress-Life(S-N)and Strain-Life(c-N)Fatigue Data2 E 1150 Definitions of Terms Relating to Fatigue2 F 648 Specification for Ultra-high-molecular-weight Poly-ethylene Powder and Fabricated Form for Surgical Implants4 3.Terminology 3.1 Definitions:3.1.1 For definitions of terms relating to this provisional test method,see Terminology E 6 and Definitions E 1150.3.2 Descriptions of Terms Specific to This Standard:3.2.1 active length of the longitudinal element-the straight line distance between the center of attachment of the superior anchor and the center of attachment of the inferior anchor.3.2.2 angular displacement at 2%offset yield-The an-gular displacement(degrees)when an assembly has a perma-nent angular displacement in the x-y plane equal to 0.020 times the torsional aspect ratio.(See Point A in Fig.1.)3.2.3 anchor-components that are directly attached to bony elements of the spine(sacrum,lamina,pedicle,verte-bral body,spinous process,transverse process,the pelvis,or ribs).3.2.3.1 band-a flexible anchor component with a non-circular cross section that connects the bony elements of the spine,pelvis,or ribs to each other or to other implant components using knot or similar tying mechanism,forming a locked,closed loop.3.2.3.2 bolt-an anchor component that connects to the bony elements of the spine,pelvis or ribs by means of threads with the lead threads accommodating a nut thus sandwiching the bony elements or implant component between the nut or washer and bolt head or other fixed stop.3.2.3.3 hook-an anchor component that fastens to the spine by means of a curved blade passed under or over lamina,transverse or spinous processes or into an anatomic or surgically created notch or opening.(1)hook blade-that portion of a spinal hook that is placed under,over or into a bony structure to provide attachment.(2)hook body-that portion of a spinal hook that con-nects the hook blade to the longitudinal element.3.2.3.4 post-a non-threaded anchor component that connects to the bony elements of the spine,