-i-
`
`Smith & Nephew Ex. 1033
`IPR Petition - USP 7,534,263
`
`

`
`CLINICAL ORTHOPAEDICS
`
`AND RELATED RESEARCH
`
`Number Three Hundred Fifty-Four
`
`Sponsored by
`
`THE ASSOCIATION OF BONE AND JOINT SURGEONS
`
`The Official Publication of the Academic Orthopaedic Society
`The Official Publication of The Hip Society (USA)
`The Official Publication of the Musculoskeletal Tumor Society
`A Publication of the Knee Society (USA)
`
`Board of Trustees
`
`Franklin T. Hoaglund, MD, Chair
`Mark C. Gebhardt, MD
`Clifford W. Colwell, Jr., MD, Senior Member-at-Large (I 994—I998)
`Stuart A. Green, MD, Active Member-at-Large (1996-2000)
`John F. Connolly, MD, Editor’s Representative
`Dempsey S. Springfield, MD
`David J . Schurman, MD
`Guy T. Vise, Jr., MD
`David G. Lewallen, MD
`Carl T. Brighton, MD, PhD, Editor
`
`
`
`-ii-
`
`

`
`CLINICAL ORTHOPAEDICS AND RELATED RESEARCH
`Guidelines for Authors
`
`Clinical Orthopaedics and Related Research publishes original articles offering significant contributions to
`advancement of orthopaedic knowledge. Articles are accepted only for inclusive publication in Clinical Orthopaedics
`and Related Research. Published articles and their illustrations become the property of Clinical Orthopaedics and
`Related Research.
`
`- A one-time submission fee to cover postage and over-
`head must be included with your manuscript. Authors
`should send a check payable to ABJS for $50.00 (US),
`$75.00 (other countries) with each unsolicited manuscript
`to Carl T. Brighton, MD, PhD, Clinical Orthopaedics and
`Related Research, University City Science Center, 3550
`Market Street, Suite 220, Philadelphia, PA 19104.
`- Submissions must include a covering letter signed by
`the responsible author stating that all coauthors have seen
`and agree with the contents of the manuscript and indicat-
`ing that the work has not been submitted or published
`elsewhere. This requirement is absolute. Authors are en-
`couraged to provide names of potential reviewers and may
`also request that a specific individual not review the work.
`- Submit an original and three high quality copies of
`the manuscript. All sections of the manuscript must be
`typed double spaced and with ample margins. Pages
`should be numbered consecutively in the following order:
`Title page, Abstract, Introduction, Materials and Methods,
`Results, Discussion, Acknowledgments, References, Ta-
`bles and Legends. The first author's name and page
`number should be typed in the upper right corner of each
`page. Use only letter quality print in a readable typeface.
`'- The accuracy of the information presented in the
`manuscript and references is the sole responsibility of
`the author(s).
`- The title page should include the title of the manu-
`script in no more than 80 spaces (letters and blanks)
`and a running title of no more than 40 spaces (letters
`and blanks). List author(s)’s full name, highest acade-
`mic degree, institutional affiliation, and address. The
`author who will receive communications and reprint re-
`quests should be listed with complete mailing address,
`telephone, and FAX numbers.
`- The abstract should consist of a one paragraph
`statement less than 200 words (15-18 lines) in length,
`stating the main conclusions and clinical relevance of
`the article.
`
`° References must be typed double spaced and in al-
`phabetical order. References should not be a listing of
`a computerized literature search, but should have been
`read by the authors and have pertinence to the manu-
`script. Do not use boldface, underlining, or complete
`uppercase in the references. Manuscripts in prepara-
`tion, unpublished data, including articles submitted but
`not in press, and personal communications may not be
`included in the reference listing. They may be listed in
`the text, in parentheses, only if absolutely necessary to
`the content and meaning of the article. When citing
`journal articles, arrange as follows: (1) author(s), list
`
`up to five; if there are more, cite first three, then et al;
`(2) title; (3) journal name, using Index Medicus abbre-
`viation; (4) volume; (5) inclusive page numbers; (6)
`year. Example: Kaplan FS, August CS, Dalinka MK:
`Bone densitometry observations of osteopetrosis in re-
`sponse to bone marrow transplantation. Clin Orthop
`294279--84, 1993. For chapters: (1) author(s); (2) chap-
`ter title; (3) editor(s); (4) book title; (5) edition number,
`if it is not the first; (6) city of publication; (7) publisher;
`(8) specific pages; (9) year. Example: Young W: Neuro-
`physiology of Spinal Cord Injury. In Errico TJ, Bauer
`RD, Waugh T (eds). Spinal Trauma. Philadelphia, JB
`Lippincott Company 377414, 1991. For a book: Hop-
`penfeld S, Zeide MS: Orthopaedic Dictionary. Philadel-
`phia, JB Lippincott Company 39-41, 1994.
`- Type tables double spaced on pages separate from
`the text. Tables should be numbered in order of citation
`in the text. They mustlbe titled and all columns must
`have a heading. Abbreviations used within tables
`should be spelled out fully in a footnote at the bottom of
`each table. Tables are limited to six columns. Do not
`use photocopy reduction.
`*'
`- Send four sets of unmounted, high quality, black
`and white glossy prints. Remove all markings, such as
`patient
`identification, from radiographs before pho-
`tographing. Arrows or lettering should be applied with
`a professional product such as Letraset or Paratype.
`These should be large enough to be seen when the
`photograph is reduced in size. Photographs of recog-
`nizable persons must be accompanied by signed con-
`sent
`from the patient or
`legal guardian. Written
`permission from the author or copyright holder must be
`submitted with previously published figures or tables.
`A self-stick label should be attached to the back of each
`
`figure indicating “top,” figure number, and the the firsf
`author's name. All line or original drawings must be
`done by a professional medical illustrator. Magnifica-
`tion, internal scale markers, and stains must be included
`when appropriate. Legends for the illustrations should be
`typed double spaced on a separate page from the text.
`- Transfer of copyright to Clinical Orthopaedics and
`Related Research is needed before publication. The corre-
`sponding author will receive a copy of this form from the
`Editorial Office along with the formal letter of accep-
`tance.
`
`- The publisher will provide the reprint author 50
`free reprints of his or her article. If additional reprints
`are desired, they may be ordered on the form supplied
`with the page proofs.
`
`Copyright © 1998, BY LIPPINCOTT WILLIAMS & WILKINS
`Library of Congress Catalog Card Number 53-7647
`CLINICAL ORTHOPAEDICS AND RELATED RESEARCH (ISSN 0009-921X) is published monthly by Lippincott Williams and Wilkins. 12107 Insurance Way,
`Hagerstown MD, 21740. Business offices are located at 227 East Washington Square, Philadelphia, PA 19106. © Copyright 1998 by Lippincott Williams &
`Wilkins. Printed in the USA. All rights reserved. Periodicals postage paid at Hagerstown. Maryland and at additional mailing offices.
`Address for subscription information, orders, or changes of address: 12107 Insurance Way. Hagerstown. MD 21740. or call 1-800-638-3030. In Japan, contact
`lgaku-Shoin. Ltd. 1-28-36 Hongo, Bunkyo-ku. Tokyo 113, Japan.
`Annual subscription rates: US: $299.00 individual, $587.00 institution, special resident/student rates available upon request. Canada and Mexico: $485.00 individ-
`ual. $683.00 institution. $85.00 special resident rate. The Canadian GST tax of 7% will be added to the subscription price of all orders shipped to Canada. Lippincott
`Williams & Wilkins’ GST identification number is 130876246. Canada Post International Publications Mail Product Sales Agreement number is 0863912. All other
`countries (except Japan): $485.00 individual. $683.00 institution. International subscriptions must be prepaid. Single copies $58.00. (All rates are subject to
`change.) In Japan contact Igaku-Shoin. Ltd., 1-28-36 Hongo, Bunkyo-ku. Tokyo 113, Japan. Copies will be replaced without charge if the publisher receives a re-
`quest within 90 days of the mailing date, both in the US and worldwide.
`Indexing: Articles are indexed in Biological Abstracts, Chemical Abstracts, Excerpta Medica, Index Medicus, Science Citation Index, Current Contents,
`Hospital Literature Index, Social Science: Citation Index. and BRS.
`'
`POSTMASTER: Send address changes to CLINICAL ORTHOPAEDICS AND RELATED RESEARCH. PO Box 1550. Hagerstown MD 21741.
`
`Text printed on acid-free paper.
`
`-1..-
`
`{£1
`
`-iii-
`
`

`
`ons to
`aedics
`es and
`
`:n et al;
`5 abbre-
`ers; (6)
`<a MK:
`is in re-
`
`Orthop
`Z) chap-
`number,
`.blisher;
`Neuro-
`', Bauer
`nhia, JB
`k: Hop-
`hi1adel-
`
`.te from
`citation
`as must
`tables
`yttom of
`Do not
`
`7, black
`such as
`
`nce Way,
`illiams &
`
`n, COIIIZICI
`
`0 individ-
`.ippincott
`All other
`;ubject to
`:ives a re~
`
`Contents,
`
`
`
`
`
`-I.‘.,,..v;._.u_'..v:;..--.-...z.;t~:.4,.
`
`Contents
`
`
`
`
`SECTION I SYMPOSIUM
`
`Computer Assisted Orthopaedic Surgery: Medical Robotics
`and Image Guided Surgery
`
`Anthony M. DiGi0ia, III, MD
`Guest Editor
`
`Editorial Comment
`
`Anthony M. DiGioia, III, MD
`
`The Classic
`
`Computer-Integrated Surgery: Technology and Clinical Applications
`Edited by Russell H. Taylor, Stéphane Lavallée, Grigore C. Burdea,
`and Ralph Mosges
`
`Computer Assisted Orthopaedic Surgery: Image Guided and Robotic
`Assistive Technologies
`Anthony M. DiGioia, III, MD; Branislav Jaramaz, PhD;
`and Bruce D. Colgan, MS
`.
`
`Medical Imaging and Registration in Computer Assisted Surgery
`David A. Simon, PhD; and Stéphane Lavallée, PhD
`
`Computer Assisted Orthopaedic Surgery With Image Based Individual
`Templates
`Klaus Radermacher, Dipl-Ing; Frank Portheine, Dipl-Ing;
`Marc Anton, Dipl-Ing; Andreas Zimolong, Dipl-Ing; Giinther Kaspers, MD;
`Giinter Rau, PhD; and Hans—Walter Staudte, MD
`
`Pedicle Screw Placement Using Image Guided Techniques
`R Merloz, MD; J. Tonetti, MD; L. Pittet, MD; M. Coulomb, MD;
`S. Lavallee’, PhD; and P. Sautot, PhD
`
`Computer Assisted Knee Replacement
`Scott L. Delp, PhD; S. David Stulberg, MD; Brian Davies, PhD;
`Frederic Picard, MD; and Francois Leitner; PhD
`
`Computer Assisted Reconstruction of the Anterior Cruciate Ligament
`Rémi Julliard, MD; Stéphane Lavallée, PhD; and Vincent Dessenne, PhD
`
`Computer Assistance in Arthroscopic Anterior Cruciate Ligament
`Reconstruction
`I
`
`Tiburtius VS. Klos, MD; Raymond J.E. Habets, MS; Anne Z. Banks, MS;
`Scott A. Banks, PhD; Roger J.J. Devilee, MD; and Frank F.’ Cook, MD
`
`.17
`
`28
`
`39
`
`49
`
`57
`
`65
`
`_iV_
`
`-iv-
`
`

`
`Vi
`
`Computer Assisted Measurement of Cup Placement in Total Hip
`Replacement
`,
`Branislav Jaramaz, PhD; Anthony M. DiGioia III, MD;
`Mike Blackwell, MS; and Constantinos Nikou, BS
`
`Clinical Orthopaedics
`and Related Research
`
`70
`
`Primary and Revision Total Hip Replacement Using the Robodoc® System
`William L. Bargar, ~MD,' Andre’ Bauer; MD; and Martin Bo'rner, MD
`
`Computer Assistancefor Pelvic Osteotomies
`Frank Langlotz, PhD; Richard Béichler; MSc; Ulrich Berlemann, MD;
`Lutz-Peter Nolte, PhD; and Reinhold Ganz, MD
`
`Percutaneous Iliosacral Screw Placement Using Image Guided Techniques
`Jerome Tonetti, MD; Lionel Carrat, PhD; Stephane Lavallee’, PhD;
`Laurence Pittet, MD; Philippe Merloz, MD; and Jean-Paul _Chirossel, MD
`
`Augmented Reality and Its Future in Orthopaedics
`Mike Blackwell, MS; Fritz Morgan, MS; and Anthony M. DiGioia III, MD
`
`SECTION II
`
`ORIGINAL ARTICLES
`
`Shoulder
`
`Electromyographic Analysis of Shoulder Joint Function of the Biceps
`Brachii Muscle During Isometric Contraction
`Goro Sakurai, MD; Jiro Ozaki, MD; Yasuharu Tomita, MD;
`Katsuo Nishimoto, PhD; and Susumu Tamai, MD
`
`Shoulder Joint Kinetics During the Push Phase of Wheelchair Propulsion
`Kornelia Kulig, PhD; Sreesha S. Rao, MS; Sara J. Mulroy, PhD;
`Craig J. Newsam, MPT; JoAnne K. Gronley, DPT;
`Ernest L. Bontrager, MS; and Jacquelin Perry, MD
`
`Upper Extremity
`
`The Triceps Preserving Approach to Total Elbow Arthroplasty
`Troy D. Pierce MD, MS; and James H. Herndon MD, MBA
`
`Right Versus Left Symmetry of Ulnar Variance: A Radiographic
`Assessment
`
`Douglas M. Freedman, MD; George S. Edwards, Jr, MD;
`Matthew J. Willems, BS; and Roy A. Meals, MD
`
`Hip
`
`Radiographic Predictors of Outcome of Core Decompression for Hips
`With Osteonecrosis Stage III
`A
`Michael A. Mont, MD; Lynne C. Jones, PhD; Ivan Pacheco, MD;
`and David S. Hungerford, MD
`
`-v-
`
`

`
`aedics
`-earch
`
`Number 354
`September, 1998
`
`70
`
`82
`
`92
`
`103
`
`111
`
`123
`
`132
`
`144
`
`153
`
`159
`
`Knee
`Patella Height After High Tibial Osteotomy With lntemal Fixation
`and Early Motion
`Geofirey H. Westrich, MD; Lance E. Peters, MD; Steven B. Haas, MD;
`Robert L. Buly, MD; and Russell E. Windsor MD
`
`Pseudoaneurysm After High Tibial Osteotomy and Limb Lengthening
`James E Grzflith, MBBCh; Jack C.l/. Cheng, MBBS; TK. Lung MBBS;
`and Michael Chan, MBBS
`
`Relationship Between Gait and Clinical Results After High Tibial
`Osteotomy
`Makoto Wada, MD; Shinichi Imura, MD; Kenji Nagatani, MD;
`Hisatoshi Baba, MD; Seiichiro Shimada, RPT; and Shinichi Sasaki, RPT
`
`Pediatrics
`
`Postlaminectomy and Postirradiation Kyphosis in Children and Adolescents
`Norman Y. Otsuka, MD; Lloyd Hey, MD; and John E. Hall, MD
`
`Fracture
`
`The Evolution of Femoral Shaft Plating Technique
`S. Robert Rozbruch, MD; Urs Miiller; MD; Emanuel Gautier MD;
`and Reinhold Ganz, MD
`
`Research
`
`Effect of Methotrexate on Distraction Osteogenesis
`Dale E. Jarka, MD; Richard W Nicholas, MD; and James Aronson, MD
`
`Periosteal Augmentation of the Acetabulum
`Merv Letts, MD; Elizabeth Pang, BSc; Jianping Yang, MD;
`and Blair Carpenter; MD
`
`Cartilage Changes Caused by a Coronal Surface Stepoff in a Rabbit Model
`Gyorgy Lovcisz, MD; Adolfo Llina’s, MD; Paul D. Benya, PhD;
`Sang-Hyun Park, PhD; Augusto Sarmiento, MD; and James V Luck Jr., MD
`
`Role of Medial Capsule and Transverse Metatarsal Ligament
`in Hallux Valgus Deformity
`Hideji Kura, MD; Zong-Ping Lao, PhD; Harold B. Kitaoka, MD;
`and Kai-Nan An, PhD
`
`3 SECTION III
`
`REGULAR AND SPECIAL FEATURES
`
`Kappa Delta Award
`
`Low Back Pain and Whole Body Vibration
`Malcolm H. Pope, DMSc, PhD; Marianne Magnusson, P7} DMSc;
`and David G. Wilder, PhD
`
`vii
`
`169
`
`175
`
`180
`
`189
`
`195
`
`209
`
`216
`
`224
`
`235
`
`241
`
`_Vi_
`
`-vi-
`
`

`
`Clinical Orthopaedics
`V'“ and Related Research
`
`
`
`Orthopaedic {Radiology - Pathology Conference
`Unusual Soft Tissue Mass in a 43-Year-Old Man
`H. Thomas Temple, MD; Julie Fanburg-Smith, MD; '
`and Mark D. Mmphey, MD
`
`Letters to the Editor
`
`Dietrich Klueber; DM
`
`249
`
`253
`
`Reply to Klueber
`Barry J. Waldman, MD; Michael A. Mom‘, MD; and David S. Hungerford, MD
`
`PERMISSION TO PHOTOCOPY ARTICLES
`
`This publication is protected by copyright. Permission to photocopy must be secured in writing from:
`Permissions Department, Lippincott Williams & Wilkins, 227 East Washington Square, Philadelphia,
`PA 19106-3780; fax 215-238-4419 or Copyright Clearance Center (CCC), 222 Rosewood Drive,
`Danvers, MA 01923; fax 508-750-4470 or UMI, Box 49, 300 North Zeeb Road, Ann Arbor, MI 48106-
`1346; fax 313-761-1203.
`
`
`
`-vii-
`
`

`
`CLINICAL ORTHOPAEDICS AND RELATED RESEARCH
`Number 354, pp 28-38
`0 1998 Lippincott Williams & Wilkins
`
`Computer Assisted Orthopaedic
`Surgery With Image Based
`Individual Templates
`Klaus Radermacher, Dipl-Ing"; Frank Portheine, Dipl-Ing*;
`Marc Anton, Dipl-Ing**; Andreas Zimolong, Dipl-Ing*;
`Giinther Kaspers, MD**; Giinter Rau, PhD*;
`and Hans- Walter Staudte, MD**
`
`Recent developments in computer assisted
`surgery offer promising solutions for the trans-
`lation of the high accuracy of the preoperative
`imaging and planning into precise intraopera-
`tive surgery. Broad clinical application is hin-
`dered by high costs, additional time during in-
`tervention, problems of intraoperative man and
`machine interaction, and the spatially con-
`strained arrangement of additional equipment
`within the operating theater. An alternative
`technique for computerized tomographic image
`based preoperative three-dimensional planning
`and precise surgery on bone structures using in-
`dividual templates has been developed. For the
`preoperative customization of these mechanical
`tool guides, a desktop computer controlled
`milling device is used as a three-dimensional
`printer to mold the shape of small reference ar-
`eas of the bone surface automatically into the
`body of the template. Thus, the planned position
`and orientation of the tool guide in spatial rela-
`tion to bone is stored in a structural way and can
`be reproduced intraoperatively by adjusting the
`
`From the *Helmholtz Institute for Biomedical Engi-
`neering, kdchen University of Technology, Aachen,
`Germany; and **Department for Orthopedic Surgery,
`District Hospital Marienhohe, Wurselen, Germany.
`Supported in part by the European Commission in the
`framework of the Telematics Applications Program
`(TAP) project
`IGOS
`(Image Guided Orthopedic
`Surgery) project number HC1026HC.
`Reprints requests to Klaus Radermacher, Dipl-Ing,
`Helmholtz Institut for Biomedical Engineering, Aachen
`University of Technology, Pauwelsstrasse 20, D-52074
`Aachen, Germany.
`
`position of the customized contact faces of the
`template until the location of exact fit to the
`bone is found. No additional computerized
`equipment or time is needed during surgery.
`The feasibility of this approach has been shown
`in spine, hip, and knee surgery, and it has been
`applied clinically for pelvic repositioning 0s-
`teotomies in acetabular dysplasia therapy.
`
`Recent research activities in the area of com-
`puter assisted surgery have concentrated on
`the introduction of additional sensor and robot
`based guiding systems into the operating the-
`ater to enable adequate computer assisted
`transferral of the high accuracy of preopera-
`tive imaging and planning to precise surgery.
`Different promising solutions have been de-
`veloped concerning the related problems of
`multimodal information processing and regis-
`tration, safety and sensor concepts, and ade-
`quate control strategies.5J9.22 Nevertheless,
`problems still remain such as the time needed
`intraoperatively for the interaction with addi-
`tional technical system components, for the
`additional intraoperative registration of bone
`structures, the spatial arrangement of dis-
`plays, sensors and robot systems within the
`operating room, the overall costs of the sensor
`or robot based systems, and mismatches re-
`garding ergonomic design aspects of cogni-
`tion and manual contr01.l~ An exact medical,
`technical, and ergonomic analysis is neces-
`
`28
`
`-28-
`
`

`
`Number 354
`September, 1998
`
`Surgery With Image Based Individual Templates
`
`29
`
`sary to identify during which phases and se-
`quences of intraoperative work additional
`guiding systems or even robotic assistance
`contributing a specific complementary func-
`tion would be required.
`In this context, the task sequences of dif-
`ferent conventional orthopaedic interven-
`tions were investigated,12J6 such as total hip
`and total knee replacement surgery being
`typical applications for computer assisted
`surgery ~ystems.9~19 One result of these in-
`vestigations was that observable activities of
`direct orientation6 only took approximately
`2% to 4% of the overall operating time. If all
`activities are taken into account that have
`some connection with exact three-dimen-
`sional positioning, their share of total inter-
`vention time is approximately 10% to
`15%.12J6 Hence, the potential to shorten op-
`erating time and the related time slot for the
`introduction of computer assisted guiding
`systems seems to be limited. Prolongation of
`the operating time by additional intraopera-
`tive tasks and interactions with additional in-
`traoperative equipment can be tolerated only
`to a limited degree because of medical, orga-
`nizational, and economic reasons. In every
`case, it would have to be justified by signifi-
`cant enhancement of the therapeutic out-
`come. Moreover, the costs of additional
`equipment must be balanced against the re-
`quirement to deliver higher quality treatment
`to a larger number of patients.
`The goal of the work described here was
`to develop a relatively simple, low cost solu-
`tion that facilitates exact, safe, and fast im-
`plementation of planned surgery on bone
`structures, eliminates the need for continual
`radiographic monitoring, and avoids over-
`burdening surgery with complex equipment
`and time consuming procedures.
`PRINCIPLE OF INDIVIDUAL
`TEMPLATES
`
`In orthopaedic surgery standard template sys-
`tems are familiar technical means to guide
`drills and saws in total knee replacement.
`
`However, the design of these tool guides is
`based on averaged anatomic geometries. The
`positioning of the template on the bone bears
`no precise relationship to the position defined
`by individual preoperative planning.
`Essentially, the missing information is the
`precise spatial correspondence between the
`individual bone structure in situ and the in-
`tended position of the tool guides.
`The authors investigated a means of
`adding this missing information to the clas-
`sic templates by providing shape based phys-
`ical matching between the reference surface
`of the individual bone and the reference sur-
`face of the computer based model. This in-
`formation is incorporated into an individual
`template. 12-16
`Individual templates are customized on the
`basis of three-dimensional reconstructions of
`the bone structures extracted from computer-
`ized tomographic (CT) image data in accor-
`dance with individual preoperative surgical
`planning. For preoperative customization, a
`low cost desktop milling machine is used as a
`three-dimensional printer to mold the shape of
`a small reference area on the individual bone
`automatically into the template. By this means
`the planned position and orientation of the tool
`guide in spatial relation to the bone is stored in
`a structural way and can be reproduced in situ
`adjusting the position of the contact faces of
`the template until they fit exactly on the bone
`(Fig 1). Neither iterative time consuming work
`under radiographic control or registration pro-
`cedures, nor any additional computerized
`equipment is needed intraoperatively. Mechan-
`ical guides for drills, saws, chisels, or milling
`tools are adaptable or integrated into these indi-
`vidual templates in predefined positions for
`different types of interventions. Moreover, in-
`dividual templates also can be used for fixation
`of a reference base for standard tool guides or
`other devices in a defined position on bone.
`The individual templates can be autoclaved
`and delivered to the operating room with the
`conventional instrument sets. The feasibility
`and adaptability of this approach has been
`shown on anatomic models and in cadaver tests
`
`-29-
`
`

`
`30 Radermacher et al
`
`Fig 1. Pedicle screw placement: (A) the principle
`of individual templates based on preoperative CT
`imaging and computer based planning; (B) com-
`puter assisted planning of a pedicle screw place-
`ment with the DISOS planning system: (C)
`interactive specification of the reference contact
`face; (D) formclosed intraoperative fitting of the
`template; and (E) radiographic control of the
`placement of 5-mm rods in the pedicles without
`any perforation in situ.
`
`for various appli~ations.~0J4~'6 Results of in
`vitro studies on accuracy have been reported in
`previous publications.12J6
`Among the applications of this technique
`are pedicle screw placement (especially in sco-
`liosis therapy; Fig 2); repositioning os-
`teotomies in spine surgery; puncture of a cystic
`cavity in the femoral head; intertrochanteric
`repositioning osteotomy; initial reference os-
`teotomies for total knee replacement (espe-
`cially in the case of pathologic deformations);
`periacetabular repositioning osteotomies; open
`door decompression in the cervical spine;
`transcorporal decompression in the cervical
`spine; and decompression in the lumbal spine.
`
`Clinical Orthopaedics
`and Related Research
`
`To depict the spectrum and potential of
`various implementations of the principle of
`individual templates, four typical examples
`will be described in more detail, with empha-
`sis on the clinical application of triple repo-
`sitioning osteotomies for the treatment of ac-
`etabular dysplasia. 1 2 ~ 4 ~ 8 , 2 0 2 2
`
`PEDICLE SCREW PLACEMENT
`
`The selection of a pedicle screw of the appro-
`priate length and caliber and its accurate fixa-
`tion in the cortical bone of the pedicles and the
`vertebral body is essential for good anchoring.
`Perforations are the major specific complica-
`tion of pedicle screw placements, implying a
`hgh risk of bone weakening or lesions of the
`spinal cord, nerve roots, or blood vessels.3J To
`monitor
`the placement of
`the piloting
`Kirschner wire and finally the screw, as many
`as four to five radiographs in different planes
`are recommended per screw placement.3 The
`authors selected this application for their initial
`investigations of the principle of individual
`templates12J3 (Fig 1). Human anatomic speci-
`mens of lumbar spines were scanned with CT
`(slices 2-mm thick and 2-mm apart). The im-
`age data were transferred to the personal com-
`puter based DISOS planning workstation
`(Gemetec mbH, Aachen, Germany). Based on
`three-dimensional reconstructions automati-
`cally provided by the system, the surgeon se-
`lects an appropriate screw and defines its opti-
`mal placement (Fig IB). The position and
`orientation of the related drill guide then is
`specified and can be incorporated into the indi-
`vidual template. To provide shape based intra-
`operative matching, small reference contact
`faces to the vertebral bone have to be specified
`on the display in the vicinity of the transverse
`process, the arch, or the spinous process. To
`this end, the surgeon interactively selects and
`positions an appropriate template within the
`three-dimensional view of the vertebral bone
`structure (Fig 1C). The surgeon is supported by
`the system, which automatically constrains the
`positioning to the direction of the defined bore
`axis and evaluates the quality of the contact
`
`-30-
`
`

`
`Number 354
`September, 1998
`
`Surgery With Image Based Individual Templates
`
`31
`
`Fig 2A-B. Total knee arthroplasty: (A) laboratory investigation on a plastic bone model (1): individ-
`ual template guiding the reference osteotomy (3) in tibial bone, optional fixation with a bone pin (4);
`(B) customized reference contact face (5) and copying profile (6) limiting cutting depth (7) to the dor-
`sal contour (6) of tibial bone.
`
`face. Afterward, the system automatically gen-
`erates the manufacturing program and cus-
`tomizes the semifinished template with its inte-
`grated drilling guides. Intraoperatively, the
`defined position of the bore is reproduced by
`placing the self locating template where it fits
`exactly on the bone. Additionally, an optional
`radiographic control of the position of the
`stainless steel drilling guide is possible, be-
`cause the plastic material of the template body
`is radiolucent. In two cadaver studies, in which
`one macerated specimen and one specimen
`with soft tissue were used, 5-mm bores have
`been reproduced exactly according to the pre-
`operative planning without any perforation in
`situ.
`
`TOTAL KNEE ARTHROPLASTY
`
`In total knee arthroplasty accurate placement
`of implant components with respect to the
`individual mechanical axis of the leg is es-
`sential. Conventionally, modular mechanical
`devices corresponding to the intrinsic shape
`of the implant components are used to guide
`the osteotomies and bores for the preparation
`of the implant’s seat. By mounting these
`conventional tool guide systems on an indi-
`vidual template as a basic customized refer-
`ence, it is possible to reproduce the preoper-
`atively planned position exactly even in the
`
`case of severely deformed bone. Moreover,
`for preservation of the posterior cruciate lig-
`aments and the nerves and vessels in the hol-
`low of the knee, not only the reference sur-
`face of the bone but also a copying surface
`limiting the cutting depth to the dorsal con-
`tour of the tibia can be molded into the tem-
`plate (Fig 2B). The geometry of the saw has
`to be known and a calibrated copying cam
`has to be mounted on the conventional saw.
`Figure 2 shows a feasibility study with a
`CT image based individual template for the
`reference tibial cut for total knee replacement
`on a plastic bone model.15 The geometry of
`the cut with its position, orientation, and limi-
`tations was planned on the basis of CT images
`(slices 2-mm thick and 2-mm apart). In addi-
`tion, topograms could be used to identify the
`bone axis. A conventional saw guide can be
`mounted on the individual template, which
`serves as a reference base for subsequent
`work on the bone. The template has been cus-
`tomized in the areas of the reference surface
`and the individual copying profile corre-
`sponding to the dorsal contour of the tibial
`bone within the cut plane. The accuracy of the
`reproduction was measured directly on the
`bone model using a conventional precision
`goniometer and a caliper gauge. The prede-
`fined cut plane and the position of the copying
`profile limiting the cutting depth were repro-
`
`-31-
`
`

`
`32 Radermacher et al
`duced with an accuracy better than 1 mm in
`all directions and 1" inclination in the sagittal
`and transverse planes.
`
`OPEN DOOR DECOMPRESSION IN
`CERVICAL SPINE
`
`The authors investigated the possibility of ap-
`plying this principle to open door decompres-
`sion in the cervical spine, which involves
`even more delicate constraints on the required
`accuracy of imaging, planning, and imple-
`mentation.14.15 The task is to mill away one
`side of the lamina completely and to preserve
`the anterior cortical layer on the other side,
`which acts as a hinge for the dorsal open door
`laminoplasty. Figure 3 shows a corresponding
`design of an individual template and the plan-
`ning and intraoperative implementation in the
`framework of a cadaver study.13J4 Applying
`the principle of copying profiles, a miniatur-
`ized copying cam corresponding to the geom-
`etry of the milling tool was mounted on a
`standard micromilling machine, with a sliding
`jig plate to guide the micromill perpendicular
`to the template. A bore with a defined depth
`was provided in the template for a final on site
`calibration of the length of the milling tool
`with respect to the copying cam. Then, both
`laminotomies were performed within less
`than 10 minutes, subsequently removing sev-
`eral layers of bone to less then 1 mm on the
`left side and approximately 1 mm on the right
`side. The micromilling tool was guided by the
`copying profile, leaving the anterior cortical
`hinge of the right lamina intact. It perforated
`only slightly at two points on the left side
`without damaging the dura (Fig 3E-F).
`
`TRIPLE OSTEOTOMY OF PELVIC
`BONE FOR THE TREATMENT OF A
`DYSPLASTIC HIP JOINT
`
`Periacetabular triple osteotomy for the treat-
`ment of hip dysplasia was chosen as the first
`exemplary clinical application of individual
`templates.14J6Jg In acetabular dysplasia the
`task is to enlarge the weightbearing part of the
`
`Clinical Orthopaedics
`and Related Research
`
`acetabulum covering the femoral head to re-
`duce the pressure on this area to physiologic
`limits. The major therapeutic goals are relief
`from pain and prevention of premature os-
`teoarthrosis.
`Using the operative procedure reported by
`Tonnis20 and Tonnis and coworkers,21 the ac-
`etabulum has to be mobilized by three os-
`teotomies, which have to be performed in a
`defined position and orientation in relation to
`the acetabulum. If the distance from the ac-
`etabulum is too short there is a higher risk of
`avascular necrosis, and if the acetabular frag-
`ment becomes too large its free rotation may
`be impeded.21 Moreover, the inclination of
`the cut planes influences the ability to rotate
`the fragment freely in a specific direction.
`Conventionally, the three osteotomies have to
`be performed under repeated radiographic
`control. The ischial osteotomy has to meet
`the obturator foramen and preserve the sciatic
`nerve and the sacral ligaments. Although the
`public osteotomy is less critical, it is directly
`adjacent to the femoral vein. For the manipu-
`lation and repositioning of the acetabulum, a
`Schanz screw has to be fixed on the acetabu-
`lar fragment. The final iliac osteotomy has to
`meet the distal part of the incisura ischiadica.
`This is the longest and most difficult os-
`teotomy and has the greatest influence on the
`mobility of the acetabular fragment and the
`initial stability of the fixation.
`For the repositioning of the acetabulum,
`empiric standard values still are based on bi-
`planar xray projections in the anteroposterior
`(AP) and faux profile planes. According to
`Tonnis et al2I lateral center edge and anterior
`center edge