_STP_1431-2003.pdf

STP 1431 Spinal Implants:Are We Evaluating Them Appropriately?M.N.Melkerson,M.S.;S.L.Griffith,Ph.D.;and J.S.Kirkpatrick,M.D.,editors ASTM Stock Number:STP 1431 ml ASTM International 100 Barr Harbor Drive PO Box C700 West Conshohocken,PA 19428-2959 Printed in the U.S.A.Foreword The Symposium on Spinal Implants:Are We Evaluating Them Appropriately?was held in Dallas,Texas on 6-7 November 2001.ASTM International Committee F04 on Medical and Surgical Materials and Devices was its sponsor.Symposium chairmen and co-editors of this publication were Mark N.Melkerson,M.S.;John S.Kirkpatrick,M.D.;and Steven L.Griffith,Ph.D.iii Library of Congress Cataloging-in-Publication Data Symposium on Spinal Implants,Are We Evaluating Them Appropriately?(2001:Dallas,Tex.)Spinal implants:are we evaluating them appropriately?/M.N.Melkerson,S.L.Griffith,and J.S.Kirkpatrick,editors.p.;cm.-(STP;1431)Symposium on Spinal Implants,Are We Evaluating Them Appropriately?was held in Dallas,Texas on 6-7 November 2001.Includes bibliographical references and index.ISBN 0-8031-3463-0 Spinal Implants:Are We Evaluating Them Appropriately?ASTM Stock Number:.STP1431.1.Spinal implants-Testing-Congresses.I.Melkerson,M.N.(Mark N.)1961-II.Griffith,Steven L.,1960-111.Kirkpatrick,J.S.(John S.)1958-1V.Title.V.ASTM special technical publication;1431.DNLM:1.Spine-surgeryongresses.2.Device Approvalngresses.3.Implants.Experimental-Congresses.4.Prosthesis Design-Congresses.WE 725 S9869s 2003 RD768.$847 2003 617.56059-dc21 2003049605 Copyright?9 2003 ASTM Intemational,West Conshohocken,PA.All rights reserved.This material may not be reproduced or copied,in whole or in part,in any printed,mechanical,electronic,film,or other distribution and storage media,without the written consent of the publisher.Photocopy Rights Authorization to photocopy items for internal,personal,or educational classroom use,or the internal,personal,or educational classroom use of specific clients,is granted by ASTM International(ASTM)provided that the appropriate fee is paid to the Copyright Clearance Center,222 Rosewood Drive,Danvers,MA 01923;Tel:978-750-8400;online:http:/ Review Policy Each paper published in this volume was evaluated by two peer reviewers and at least one editor.The authors addressed all of the reviewers comments to the satisfaction of both the technical editor(s)and the ASTM International Committee on Publications.To make technical information available as quickly as possible,the peer-reviewed papers in this publication were prepared camera-ready as submitted by the authors.The quality of the papers in this publication reflects not only the obvious efforts of the authors and the technical editor(s),but also the work of the peer reviewers.In keeping with long-standing publication practices,ASTM International maintains the anonymity of the peer reviewers.The ASTM International Committee on Publications acknowledges with appreciation their dedication and contribution of time and effort on behalf of ASTM International.Printed in Bridgeport,NJ 2003 Contents FOREWORD OWRVmW SESSION I:SPINAL CONSTRUCTS History of Isola-VSP FatigueTesting Results with Correlation to Clinical Implant Failures-w.L.CARSON,M.ASHER,O.BOACHIE-ADJEI,B.AKBARNIA,R.DZIOBA,AND N.LEBWOHL Gauge Length and Mobility of Test Blocks Strongly Affect the Strength and Stiffness of Posterior Occipito-Cervico-Thoracic Corpectomy Constructs-M.SLIVKA,H.SERHAN,D.SELVITELLI,AND K.TORRES Relative 3 Dimensional Motions Between End Vertebrae in a Bi-level Construct,The Effect of Fixture Constraints on Test Results-w.L.CARSON Spinal Implant Transverse Rod Connectors:A Delicate Balance Between Stability and Fatigue Performance-H.SERHAN AND M.A.SLIVKA Corrosion on Spinal Implant Constructs:Should Standards be Revised?-J.s.KIRKPATRICK,R.VENUGOLOPALAN,M.BIBBS,J.E.LEMONS,AND P.BECK iii vii 17 24 34 40 SESSION II:SPINAL DEVICE COMPONENTS,SUBASSEMBLIES,AND INTERCONNECTIONS Effect of Transverse Connector Design on Development of Late Operative Site Pain:Preliminary Clinical Findings-s.M.COOK,M.ASHER,W.L.CARSON,AND S.M.LAI lnterconnectiou Strength Testing and its Value in Evaluating Clinical Performance L.M.JENSEN,S.SPRINGER,S.CAMPBELL,AND E.GRAY Protection of the Longitudinal Member Interconnection by ASTM F1798-97 lnterconnection Mechanism and Subassemblies Standard Guide-w.L.CARSON Clinical Relevance of Pull-out Strength Testing of Pedicle Screws-J.M.DAWSON,P.BOSCHERT,M.MACENSKI,AND N.RAND 47 55 63 68 V vi CONTENTS SESSION IlI:CAGES AND INTERBODY FUSION DEVICES Extrusion of Interbody Fusion Devices-Clinical Examples-s.M.THEISS IS Push-out Testing of Cage Devices Worthwhile in Evaluating Clinical Perfornlance.9s.SPRINGER,S.CAMPBELL,R.HOUFBURG,A.SHINBROT,AND J.PAVLOVIC A Comparison of Two Strength-Testing Methodologies for Interbody Structural Allografts for Spinal Fusion-j.M.DAWSON,AND S.L.GRIFFITH 81 86 92 SESSION IV FUNCTIONAL SPINAL DEVICES AND/OR ARTIFICIAL DISKS The Influence ofln Vitro Testing Method on Measured Interverte