The External Fixator: AO/ASIF-Threaded Rod System Spine-Fixator

385 Pages·1985·42.85 MB·English

by  Prof. Dr. Bernhard G. Weber

THE
B.G.Weber
F. Magerl
EXTERNAL FIXATOR
AO/ASIF-Threaded Rod System
Spine-Fixator
With a Chapter by Ch. Brunner
Foreword by A. Sarmiento
With 362 Partly Colored Figures
Springer-Verlag
Berlin Heidelberg New York Tokyo 1985
Prof. Dr. BERNHARD G. WEBER
Dr. FRIEDRICH MAGERL
Dr. CHRISTIAN BRUNNER
Klinik für Orthopädische Chirurgie,
Kantonsspital,
CH-9007 St. Gallen
Translated from the German by
TERRY C. TELGER
Tit1e of the German Edition
B.G. WEBER' F. MAGERL: Fixateur exteme
© Springer-Verlag Berlin Heidelberg 1985
ISBN- 13: 978-3-642-70017-0
ISBN-13: 978-3-642-70017-0 e-ISBN-13:978-3-642-70015-6
DOI: 10.1007/978-3-642-70015-6
Library of Congress Cataloging in Publication Data. Weber, B.G. (Bernhard Georg), 1927- . The external
fixator. Translated from the German with title: Fixateur externe. Ineludes bibliographies and index. 1. External
skeletal fixation (Surgery) 1. Magerl, F. (Friedrich), 1931- . II. Brunner, Christian Ferdinand, 1937-
III. Title. IV. Title: Spine-fixator. [DNLM: 1. Fracture Fixation - methods. WE 185 W373e]
RD103.E88W43 1985 617'.15 84-24045
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© by Springer-Verlag Berlin Heidelberg 1985
Softeover reprint of the hardeover 1st edition 1985
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2124/3130-543210
Foreword
Professor B.G. WEBER has once again and in a very timely fashion produced a superb
book on an orthopaedic subject of great importance. "The Extemal Fixator" is the
most comprehensive text on the subject in orthopaedic literature to date. Professor WEBER
thoroughly discusses extemal fixation with c1arity, organization, profuse illustrations
and roentgenograms.
Professor WEBER acknowledges that the use of extemal fixation in orthopaedic surgery
is not newand traces its history over the years. He points out c1early the fact that
though at various times the "method" has experienced periods of disrepute, modem
sophistication, improved technology and a better understanding of its philosophy have
given the system a newand perhaps permanent place in the armamentarium of the
orthopaedic surgeon.
All methods of treatment have critics as well as supporters, and not infrequently
the strongest criticisms are the result of poor understanding of the philosophy proposed
and its proper implementation. Professor WEBER, in his carefully detailed and well
illustrated book, has made it abundantly c1ear that the use of extemal fixators in the
treatment of fractures must be c1early understood by the orthopaedic surgeon in order
to obtain satisfactory clinical results. His discussion of its philosophy, pathomechanics
and technology are most comprehensive and leave "no stone untumed" and because
of this the book represents a most comprehensive text on the subject.
I have long held the belief that immobilization in the treatment oflong bone fractures
is unphysiological and that fracture care should avoid, as much as possible, rigid fixation
of fracture fragments. I recognize, however, there are situations where the creation of
a healthy environment in which controlled motion is present cannot be attained. Severely
open fractures and certain nonunions are representative examples of that situation. It
is primarily in these circumstances where rigid fixation may be the treatment of choice.
Extemal fixation, as Professor WEBER has so well documented, is an excellent method
to obtain osseous repair while maintaining function and cosmesis.
AUGUSTO SARMIENTO, M.D.
Professor and Chairman
Department of Orthopaedics
University of Southem California
School of Medicine
Preface
The use of an external fixation device for the stabilization of bone fragrnents probably
dates back to LAMBOTTE in 1902. But despite its long history, the external fixator has
not gained the same degree of acceptance in fracture management as the" elosed" meth
ods of BÖHLER, WATSON-JONES and SARMIENTO, or true internaI fixation.
Operative fracture treatment itself was not widely practiced until it was popularized
in 1958 by the Swiss Association for the Study ofInternal Fixation (ASIF). It is important
to note that the principal authors of the ASIF technique, Drs. MÜLLER, ALLGÖWER
and WILLENEGGER, have never represented their technique as the only "correet" one,
and in the preface to their book Technique of Operative Fracture Management (Springer
Verlag, 1963) they state, "We caution very strongly against internaI fixations performed
without proper training, instrumentation and surgical asepsis ... " The potential risks
of internaI fixation have sparked renewed interest in conservative treatment strategies,
with the resuIt that SARMIENTO'S "functional bracing" technique is now practiced as
widely as the ASIF method.
But neither internaI fixation nor functional bracing is adequate for the management
of the highly complex extremity injuries that are being seen with increasing frequency
as a resuIt of motorcyele and other high-speed vehicular accidents (" Honda disease ").
This accounts in large part for the many reeent artieles and books devoted to the subject
of external skeletal fixation (BROOKER, EDWARDS 1979; UHTHOFF 1982; MEARS 1983;
ACKROYD, O'CONNOR, DE BRUYN 1983). The shear volume of these publications suggests
that the external fixator is being "rediscovered" in the English-speaking world after
ANDERSON put the external fixation concept into practice in the United States in 1934.
When the first ASIF book was published in 1963, Dr. MÜLLER and other Swiss
orthopedic surgeons had already been practicing external fixation for some years -
first in reconstructive orthopedics and later fracture management. The threaded-rod
external fixator, for example, is described in the first ASIF book.
At the Department of Orthopedic Surgery of Kantonsspital St. Gallen, Switzerland,
external fixations with the threaded-rod device have become as routine as internaI fixa
tions by the ASIF method. This" routineness" mayexplain why no major publications
on external fixation have yet appeared in Switzerland, and we feel that a text on the
subject is overdue. In the present book we shall examine the use of the external fixator
not only in fracture treatment, but also in other areas of orthopedic surgery.
The following colleagues had a hand in the preparation of the book: Mrs. URSULA
OETLIKER and Mrs. MYRTHA ZWEIFEL, who undertook repeated typescript revisions with
thireless diligence and technical expertise; KATRIN and HORsT SCHUMACHER, who pre
pared the excellent drawings; and Mrs. MARIANNE SCHAFFNER, Mrs. DORIS CLERICI and
Mrs. ANNELISE SPITZ, who prepared the photographic illustrations.
I express special thanks to my elosest medical colleagues: Dr. FRITZ MAGERL, assis
tant department head, who described the spin al external fixation device; and Dr. CHRIS
TIAN BRUNNER, chief of pediatric orthopedics, who wrote a chapter on external fixations
in children and adolescents.
VIII Preface
I am also grateful to my present and former straff eolleagues who "tended to busi
ness" on the c1inieallevel.
In his eapaeity as engineer and manufaeturer, Dr. h.e. ROBERT MATHYS has worked
elosely with the Teehnieal Committee of the ASIF and with us to improve the quality
of the surgieal armamentarium. His work is gratefully aeknowledged.
Finally, I express thanks to the staffat Springer-Verlag, who onee again did outstand
ing work in the publieation of this text.
St. Gallen, Summer, 1984 B.G. WEBER
Contents
Preamble. B.G. WEBER . . . . . . . . . . . . . . . . . . . . . . . . .. 1
The ASIF Threaded External Fixator in General Orthopaedic and Trauma Surgery of
the Extremities
A General Part. B.G. WEBER 4
1 Introduction . . . . . . 4
2 The History of External Fixation 6
3 Bone Healing in the Presenee of an External Fixator 7
3.1 Healing of a Diaphyseal Fraeture 9
3.1.1 Primary Healing of the Cortex 9
3.1.2 Seeondary Healing of the Cortex 9
3.1.3 Nonunion . . . . . . . . . . 12
3.1.3.1 Pathogenesis of Vaseular Nonunion 12
3.1.3.2 Pathogenesis of Avaseular Nonunion 14
3.2 Healing of Caneellous Bone .. .. 14
3.2.1 Primary Healing of Caneellous Bone 14
3.2.2 Seeondary Healing of Caneellous Bone 14
3.2.3 Nonunion of Caneellous Bone 14
3.2.3.1 Pathogenesis of Vaseular Nonunion . 14
3.2.3.2 Pathogenesis of Avaseular Nonunion 14
3.3 Healing of Nonunions . . . . . . 20
3.3.1 Healing of a Vaseular Nonunion 20
3.3.2 Healing of an Avaseular Nonunion 20
3.3.3 Healing of a Nonunion with Bone Loss 20
4 Goals of Treatment with the External Fixator 26
4.1 Lengthening Frame . 26
4.2 Neutralization Frame 26
4.3 Compression Frame 26
4.4 Soft-Tissue Frame 26
B On the Biomechanics of External Fixation. B.G. WEBER 27
1 Intrinsie Stability of the External Fixator . . . . . . 27
2 The External Fixator and Bone as a Composite System 28
2.1 Extemal Fixation without Interfragmental Contaet 28
2.2 Extemal Fixation with Interfragmental Contaet . . 28
2.3 Extemal Fixation with Interfragmental Compression 31
2.4 Biomeehanies and Seleetion of the Frame .... 32
X Contents
3 Stress Transfer with the External Fixator 34
3.1 Stress Transfer with the Neutralization and Lengthening Frame 34
3.2 Stress Transfer in the Presence of Bone Contact 34
3.2.1 Stress Transfer with a Bilateral Compression Frame . 34
3.2.2 Stress Transfer with a Unilateral Compression Frame 34
3.2.2.1 "Prebending" of the Rod . . . . . . . . 34
3.2.2.2 "Prebending" of the Bone . . . . . . . . . . . 37
3.2.2.3 Axial Compression with a "Spreading Rod" . . . 37
4 Means of Augmenting the Stability of the External Fixator 38
4.1 Increasing the Number of Pins or Screws 38
4.2 Placement of the Pins and Screws 38
4.3 Increasing the Number of Rods . 38
4.4 The Double-Frame Configuration 40
4.5 The Biplanar Frame ..... 41
5 Improving the Anchorage of Pins and Screws in Bone 42
6 Restoring the Compressive Strength of Bone in the Absence of Interfragmental
Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.1 Restoring Bone Contact by Shortening .............. 45
6.2 Restoring Bone Contact by Interposing a Pressure-Resistant Bone Graft 46
6.3 Restoring Bone Contact by Adjunctive InternaI Fixation 46
6.3.1 Lag Screw pIus External Fixation . . . . . . . . . 47
6.3.2 AntigIide Plate pIus External Fixation . . . . . . . 48
6.4 Restoring Bone Contact by Cancellous Bone Grafting 49
6.5 Restoring Bone Contact by Transverse Compression 51
6.6 Restoring Bone Contact by Fragment Manipulation . 51
7 Sagittal or "Intermediate" Screw Placement in Unilateral External Fixation of
the Tibia .................. . 52
8 Summary of the Biomechanics of External Fixation 53
8.1 The External Fixator and Bone . 53
8.2 Unilateral or Bilateral Frame . . 53
8.3 Elasticity of the External Fixator 53
e
The Threaded External Fixator. Instrumentation. B.G. WEBER 54
1 Introduction 54
1.1 Requirements of the External Fixator 54
1.2 The External Fixator of the ASIF . . 54
2 The Elements of the Threaded External Fixator 55
2.1 Steinmann Pins . . . . . . . . . . . 55
2.2 Schanz Screws . . . . . . . . . . . 55
2.3 The 4.5-mm and 3.5-mm Cortex Screws 55
2.4 Drill Bits, Drill Sleeyes and Taps 56
2.5 Clamps for Steinmann Pins, Schanz Screws, 4.5-mm and 3.5-mm Cortex
Screws 56
2.6 Threaded Rods 56
2.7 Nuts 56
2.8 Siider Bar 56
Contents XI
2.9 Additional lnstruments and lmplants 58
2.10 Special lnstruments 58
3 The Threaded Minifixator 59
D Operative Technique for the Threaded External Fixator. B.G. WEBER 60
1 The Special Characteristics of the Threaded External Fixator 60
2 Errors of Pin and Screw lnsertion . . 60
2.1 Technique for Steinmann Pins 61
2.2 Technique for Schanz Screws 63
2.3 Technique for Cortex Screws 64
3 Reduction 66
3.1 Concept. 66
3.2 Technique 68
4 The Application of a Bilateral Frame 69
4.1 Pin Placement 69
4.2 Pin lnsertion . . . . 70
4.3 Assembling the Frame 72
4.4 Reinforcing the Frame 72
4.5 Finishing the Frame 72
5 The Application of a Unilateral Frame 74
5.1 Placement of the Schanz Screws 74
5.2 Screw lnsertion . . . . . . . 75
5.3 Assembling the Unilateral Frame 78
5.4 Reinforcing the Frame 79
5.5 Finishing the Frame ..... 79
E Teehniques for Reinforeing the External Fixator. B.G. WEBER 80
1 lncreasing the Number of Rods . . . . . . . . . . . . . 80
2 Mounting Additional Rods in a Perpendicular Configuration 80
3 Stability of the Unilateral Frame .... 81
4 Restoring Bone Contact . . . . . . . . 83
5 Stability Enhancemerit and Frame Design 85
F Situations Requiring a Special Operative Technique. B.G. WEBER 86
1 Stabilization of Short Fragments ............ . 86
2 Diagonal Bracing Rod . . . . . . . . . . . . . . . . . . 87
3 Adding Single Clamps to the Frame, and Transverse Compression 88
G Axial Correetions. B.G. WEBER 89
1 Axial Corrections in the Bilateral Frame . 89
2 Axial Corrections in the Unilateral Frame 93
3 Axial Corrections with the Aid of an External Frame 93
H Loeal Care Following Frame Applleation. B.G. WEBER 94
1 Postoperative Care 94
2 Further Supervision . . . . . . . . . . . . . . . 95
XII Contents
I Duration of External Fixation, and Removal of the External Fixator. B.G. WEBER 96
1 General Duration of External Fixation . . . 96
2 Early Removal of Individual Pins or Screws 96
3 Staged Removal of Combined Frames . . . 97
4 Removal of the External Fixator ..... 97
5 "Dynamization" of External Fixator Frames 99
K Instrumentation Used with the Threaded External Fixator. B.G. WEBER 100
1 General . . . . . . . . . . 100
2 Threaded External Fixator Sets 100
L The Threaded External Fixator in Adults. Clinieal Examples. B.G. WEBER 106
1 Introduction 106
2 Humerus 111
3 Elbow 115
4 Wrist 118
5 Pelvis 125
6 Femur 127
7 Knee 139
8 Tibia 146
9 Ankle 209
10 Soft Tissues 231
M The Threaded External Fixator in Children and Adolescents. CH. BRUNNER 243
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . .. 243
2 The External Fixator for Severe Open Fractures in Children, Infected Fractures
and Infected Nonunions . . . . . . . . . . . . . . . . . . 244
3 Corrective Osteotomies of the Proximal Femur in Small Children 252
3.1 Instrumentation and Technique . . . 252
3.2 The Technique Practiced at our Center 252
3.3 Indications and Examples ..... 254
4 Lengthening Osteotomies in Children and Adolescents 259
4.1 Introduction . . . . . . . . . . . . 259
4.2 Lengthening Osteotomy of the Humerus 259
4.3 Lengthening Osteotomy of the Femur . 261
4.4 Lengthening of the Tibia ..... . 269
5 Corrective Osteotomy for Staged Limb Lengthening 273
5.1 Staged Supracondylar Lengthening of the Femur 273
5.2 Corrective Osteotomy of the Proximal Tibia 275
5.3 Supramalleolar Corrective Osteotomy of the Tibia 281
6 Special Problems 284
N Concluding Remarks. B.G. WEBER .................... 287