Spinal Injection Techniques E-Book

Theodoros Theodoridis

• Herausgeber: Thieme
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 431

Veröffentlichungsjahr: 2019

Beschreibung

Safe and effective injection techniques for the treatment of spinal pain

Written by a multidisciplinary team of experts, Spinal Injection Techniques presents the most effective methods for injecting pharmaceuticals to address acute and chronic pain originating from the cervical spine to the sacrum. This new, second edition has been extensively revised and updated with replacement of many images and addition of an extended chapter with tips and tricks on diagnostic and clinical examination. The authors' emphasis is on techniques that represent viable alternatives to spine surgery and do not rely on diagnostic imaging.

The first section of the book provides a general overview of the basic principles, diagnostics, and causal as well as symptomatic pain therapy for the spine. The second section, created in an atlas format, includes chapters on spinal anatomy and pain signaling, techniques for injection therapy of the cervical, thoracic, and lumbar spine, management of potential complications and side effects, and multimodal spine therapy. Illustrated using real-life photographs from the authors' practice, each technique-related chapter guides the reader step-by-step and with great confidence through the injection procedures.

Highlights:

• Provides detailed coverage of injection therapy using anatomic landmarks, without the use of image guidance
• Features minimally invasive spine therapy for inpatient and outpatient settings, with concomitant pharmaceutical treatments
• Includes essential information on contraindications and patient consent
• More than 500 color illustrations and photographs demonstrating the relevant anatomy, patient positioning, and accurate needle placement

Conceived as a practical guide and useful compendium, Spinal Injection Techniques is invaluable for orthopedists and practitioners in physical medicine and rehabilitatio

Leseprobe

Spinal Injection Techniques

Second Edition

Theodoros Theodoridis, MDHead Physician Spine TherapyDepartment of Minimally Invasive and Surgical Spine TreatmentViktoria ClinicChairmanInstitute for Spine ResearchBochum, Germany

Juergen Kraemer†, MDFormerly Professor EmeritusOrthopedic University ClinicSt. Josef HospitalFormerly ChairmanInstitute for Spine ResearchBochum, Germany

503 illustrations

ThiemeStuttgart • New York • Delhi • Rio de Janeiro

Library of Congress Cataloging-in-Publication Data

Names: Theodoridis, Theodoros, author. | Kraemer, Juergen, 1939-2011, author.

Title: Spinal injection techniques / Theodoros Theodoridis, Juergen Kraemer.

Other titles: Injektionstherapie an der Wirbelsäule. English Description: Second edition. | Stuttgart; New York : Thieme, [2019] | This book is an authorized and revised translation of the 3rd German edition published and copyrighted 2017 by Georg Thieme Verlag, Stuttgart, Germany.

Title of the German edition: Injektionstherapie an der Wirbelsäule. | Includes bibliographical references and index. | Identifiers: LCCN 2019006657 (print) | LCCN 2019007236 (ebook) | ISBN 9783132414488 () | ISBN 9783132414471 (hardcover) | ISBN 9783132414488 (e-book) Subjects: | MESH: –therapy | Injections, Spinal–methods | Anesthesia, Spinal | Pain Management

Classification: LCC RD771.B217 (ebook) | LCC RD771.B217 (print) | NLM WE 720 | DDC 617.5/6406–dc23

LC record available at https://lccn.loc.gov/2019006657

This book is an authorized and revised translation of the 3rd German edition published and copyrighted 2017 by Georg Thieme Verlag, Stuttgart, Germany. Title of the German edition: Injektionstherapie an der Wirbelsäule.

Translator of original first edition: Michele James, Nettetal, Germany New parts and updates translated by: Dr. phil. Karen Leube, Leube Translation and Language Services, Aachen, GermanyPhotos: Rainer Jagusch, Digital image processing

© 2019 by Georg Thieme Verlag KG

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Cover design: Thieme Publishing Group Typesetting by Thomson Digital, India

Printed in Germany by CPI Books                                    5 4 3 2 1

ISBN 978-3-13-241447-1

Also available as an e-book:eISBN 978-3-13-241448-8

Important note: Medicine is an ever-changing science undergoing continual development. Research and clinical experience are continually expanding our knowledge, in particular our knowledge of proper treatment and drug therapy. Insofar as this book mentions any dosage or application, readers may rest assured that the authors, editors, and publishers have made every effort to ensure that such references are in accordance with the state of knowledge at the time of production of the book.

Nevertheless, this does not involve, imply, or express any guarantee or responsibility on the part of the publishers in respect to any dosage instructions and forms of applications stated in the book. Every user is requested to examine carefully the manufacturers’ leaflets accompanying each drug and to check, if necessary in consultation with a physician or specialist, whether the dosage schedules mentioned therein or the contraindications stated by the manufacturers differ from the statements made in the present book. Such examination is particularly important with drugs that are either rarely used or have been newly released on the market. Every dosage schedule or every form of application used is entirely at the user’s own risk and responsibility. The authors and publishers request every user to report to the publishers any discrepancies or inaccuracies noticed. If errors in this work are found after publication, errata will be posted at www.thieme.com on the product description page.

Some of the product names, patents, and registered designs referred to in this book are in fact registered trademarks or proprietary names even though specific reference to this fact is not always made in the text. Therefore, the appearance of a name without designation as proprietary is not to be construed as a representation by the publisher that it is in the public domain.

This book, including all parts thereof, is legally protected by copyright. Any use, exploitation, or commercialization outside the narrow limits set by copyright legislation without the publisher’s consent is illegal and liable to prosecution. This applies in particular to photostat reproduction, copying, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Contents

Foreword

Dr. Cordelia Schott

Foreword

Professor Rüdiger Krauspe

Foreword

Professor Michael Rauschmann

Preface

Contributors

Part I General Section

1 Basic Principles

1.1 Orthopedic Pain Management

Theodoros Theodoridis, Juergen Kraemer

1.2 Epidemiology

Theodoros Theodoridis, Wolfram Teske

1.3 Nociception and Chronification

Theodoros Theodoridis, Juergen Kraemer

2 Diagnostics

2.1 Medical History

Theodoros Theodoridis, Juergen Kraemer

2.2 Clinical Examination

Theodoros Theodoridis, Constantinos Georgallas

2.3 Neurological–Orthopedic Examination 20

Theodoros Theodoridis, Ilias Nastos

2.4 Laboratory Tests

Theodoros Theodoridis, Constantinos Georgallas

2.5 Imaging Techniques

Theodoros Theodoridis

2.6 Trial Measures for the Diagnosis of Pain

Theodoros Theodoridis, Juergen Kraemer

3 Causal Orthopedic Pain Therapy

Theodoros Theodoridis, Juergen Kraemer

3.1 Positioning and Traction

3.2 Orthopedic Aids

3.3 Manual Therapy

3.4 Physical Therapy

3.5 Postural and Behavioral Training (Back School)

3.6 Back School and Orthopedic Pain Therapy

4 Symptomatic Pain Therapy

4.1 Introduction

Theodoros Theodoridis, Juergen Kraemer

4.2 Thermotherapy

Theodoros Theodoridis, Juergen Kraemer

4.3 Massage

Theodoros Theodoridis, Juergen Kraemer

4.4 Electrotherapy

Theodoros Theodoridis, Juergen Kraemer

4.5 Acupuncture

Theodoros Theodoridis, Juergen Kraemer, Constantinos Georgallas

4.6 Therapeutic Local Injection Treatment (TLIT)

Theodoros Theodoridis, Juergen Kraemer

4.7 Orthokine Therapy

Ulrike Theodoridis, Cordelia Schott, Theodoros Theodoridis

4.8 Adverse Effects of Orthokine/Cortisone 43

Theodoros Theodoridis

4.9 Clinical Results

Theodoros Theodoridis

4.10 Conclusion

Theodoros Theodoridis

4.11 Multimodal Medication Concomitant Therapy

Susanne Stehr-Zirngibl

Part II Atlas Section

5 The Spine: Anatomy, Nociception, and the Distribution of Pain Signals

Theodoros Theodoridis, Juergen Kraemer

5.1 Terminology

5.2 Nociception and the Distribution of Pain Signals in the Spine

6 Special Orthopedic Injection Therapy: Contraindications and Patient Information

Theodoros Theodoridis

6.1 Contraindications

6.2 Patient Information

7 Cervical Injection Therapy

7.1 Specialized Cervical Neuroanatomy

Theodoros Theodoridis, Juergen Kraemer

7.2 Basic Therapy for Cervical Pain

Theodoros Theodoridis, Juergen Kraemer

7.3 Special Therapy for Cervical Pain

Theodoros Theodoridis, Juergen Kraemer

7.4 Cervical Injection Therapy

8 Thoracic Injection Therapy

8.1 Specialized Thoracic Neuroanatomy

Theodoros Theodoridis, Juergen Kraemer

8.2 Clinical Picture

Theodoros Theodoridis, Juergen Kraemer

8.3 Thoracic Injection Therapy

Theodoros Theodoridis, Fritjof Bock

9 Lumbar Injection Therapy

Theodoros Theodoridis, Juergen Kraemer

9.1 Specialized Lumbar Neuroanatomy

9.2 Basic Therapy for Lumbar Pain

9.3 Special Therapy for Lumbar Pain

9.4 Exercise Program

9.5 Lumbar Injection Therapy

10 General and Specific Complications and Treatment Measures

10.1 Vasovagal Syncope

Clemens J. H. Sirtl

10.2 Intravascular Administration of Local Anesthetics and Glucocorticoids

Clemens J. H. Sirtl

10.3 Intrathecal Administration of Local Anesthetics and Glucocorticoids

Clemens J. H. Sirtl, Theodoros Theodoridis, Ilias Nastos

10.4 Anaphylactoid Reaction—Anaphylactic Shock

Clemens J. H. Sirtl

10.5 Postdural Puncture Syndrome

Clemens J. H. Sirtl, Theodoros Theodoridis, Ilias Nastos

10.6 Bacterial Infection

Wolfram Teske, Theodoros Theodoridis

10.7 Bleeding

Wolfram Teske, Theodoros Theodoridis

10.8 Special Complications and Side Effects of Cervical Spinal Nerve Analgesia (CSPA)

Theodoros Theodoridis, Wolfram Teske, Juergen Kraemer

10.9 Side Effects and Complications of Cervical Epidural Injections

Lluis Aguilar i Fernàndez, Wolfram Teske, Theodoros Theodoridis

10.10 Side Effects and Complications of Thoracic Injection Techniques

Wolfram Teske

10.11 Side Effects and Complications of Lumbar Spinal Nerve Analgesia

Wolfram Teske, Juergen Kraemer, Cordelia Schott, Theodoros Theodoridis

10.12 Side Effects and Complications of Lumbar Epidural Injections

Wolfram Teske, Cordelia Schott, Theodoros Theodoridis, Juergen Kraemer

10.13 Summary

11 Multimodal Spinal Therapy

Theodoros Theodoridis, Juergen Kraemer

11.1 Outpatient Minimally Invasive Spinal Therapy

Theodoros Theodoridis, Juergen Kraemer

11.2 Inpatient Minimally Invasive Spinal Therapy

Theodoros Theodoridis, Juergen Kraemer

11.3 Multimodal Program

Theodoros Theodoridis, Juergen Kraemer

11.4 Multimodal Pain Management

Susanne Stehr-Zirngibl, Priska Laubenthal

12 Summary

Theodoros Theodoridis

12.1 Cervical Spine

12.2 Thoracic Spine

12.3 Lumbar Spine/Sacrum

12.4 Conclusion

Bibliography

Index

Foreword

Determining appropriate treatment for the cervical, thoracic, and lumbar spine pain is a constant challenge for physicians today. Regardless of the circumstances of our health care system, the lack of funding and concepts, the policy debate associated with back pain, the struggles between the various factions, and multiple treatment guidelines, conservative treatment of spinal disorders is an integral component of orthopedics and trauma surgery and will continue to play a central role in the foreseeable future. The Interdisciplinary Society for Orthopedic and Trauma Surgery/International Musculoskeletal Pain Society (IGOST/IMPS) has conveyed this message in its injection courses from day one. Based on the workof IGOST, as the representative of the DGOOC pain therapy section and of DGOU, this book intends to improve the safety and reliability of back pain therapy.

Policies on “back pain therapy” widely diverge. A whole range of professional societies have stakes in this area. Various treatment and other guidelines are under development, some of them contradictory, causing increasing uncertainty among both patients and treating physicians, and in their wake, legal regulations and restrictions as well as limitations on so-called “therapeutical freedom,” in other words, physicians’ freedom to prescribe what they deem the most appropriate therapy. There are calls for strict monitoring along the lines of evidence-based medicine. At the same time, the fact that commonly used corticoids are not approved as pharmaceuticals for treating spine-related ailments is also the subject of political debate. Discussions are emerging about the required presence or absence of imaging, about which payers have to cover which benefits, and about who is allowed to refer what patient to which treatment provider. In the context of this debate, pain management has advanced and this progress must continue. At the same time, we need to counteract the tendency to declare some 90% of all back pain “unspecific” owing to the fact that treatment providers’ training simply does not permit more detailed differentiation. We also need to prevent excessive use of technical methods and radiological imaging just for the sake of routine or for purely financial reasons, in so doing revoking the spinal therapist’s freedom to render treatment and make decisions. Instead, we must aim to offer curative treatment using targeted, competent, and early therapy management with interdisciplinary treatment approaches in order to prevent back pain from becoming chronic.

Even if one assumes that the body of evidence on spinal injection therapy is inadequate, this does not change the fact that spinal injection therapy is one of the most common and most efficient therapy forms, playing an absolutely key role in daily treatment of back pain patients. Any therapist who has used injection therapy to successfully relieve a patient’s pain in a short period of time knows just how important and how efficient this treatment option is. In many cases, the techniques presented here are indispensable for performing differential diagnosis and/or for treatment planning, including surgical options. Often, using the techniques even allows surgery to be avoided altogether.

During my time working under Professor Juergen Kraemer, I had the privilege to observe the techniques described in this book on a daily basis, to learn, perform, and teach them, and to follow up the treatment successes for many years and report about them in scientific publications. For over 15 years, I have been personally active in the IGOST’s hands-on injection courses. In my daily practice, the injections described here constitute a substantial share of my work. Based on a large part of the life work of my mentor Professor Juergen Kraemer, this book represents the continuation of his ideas about conservative spinal therapy. In this second edition, the authors have lovingly updated and expanded on this legacy.

The therapy presented in this book is considered to be the gold standard for spinal injection therapy in the framework of orthopedics and trauma surgery and ideally complements our IGOST courses. The book’s depiction of the anatomical landmarks and the instructions for locating them make it very useful for spinal therapists performing conservative therapy as well as for surgeons. The book thus joins the ranks of notable reference works that have also been produced with the assistance of IGOST.

I wish this book continued success and the recognition it deserves. In addition, I hope that you as the reader will gain informative insights when studying the book and a great deal of pleasure and success as you implement what you have learned in your everyday practice.

Dr. Cordelia SchottPresident of the Interdisciplinary Societyfor Orthopaedic, Trauma Surgery and GeneralPain Therapy/International MusculoskeletalPain Society (IGOST/IMPS)Head of the German Society for Orthopedicsand Trauma Surgery (DGOOC) “Pain” SectionHead of the German Society for Orthopedicand Trauma (DGOU) “Pain” SectionVice President of the German Society for BackPain Therapy (DGRS)

Foreword

When diagnosing and treating spinal disorders and indicating further diagnostics, such as imaging, carrying out a patient history and a physical examination is key, and this is also true for developing treatment concepts. For degenerative disorders of one or more vertebral motor segments, systematic analysis of all findings is required to diagnose pain-causing factors. In many cases, additional systematic spinal injections are also required. When attempting to force the medical concepts into an evidence-based corset, one comes up against both boundaries and detours, and this is especially true for spinal disorders. On the opposite end of the spectrum, “individualized medicine” is a popular buzzword. This goes to show that “therapeutical freedom” is a valuable asset that must not be undermined either by narrow guidelines or by economic constraints. On the other hand, physicians have to establish a definitive diagnosis before prescribing therapy. The fact that this is not always successful in the case of back pain has too often led to the catch-all diagnosis of “unspecific back pain.” When in-depth clinical and manual therapy and imaging diagnostics are performed and supplemented by laboratory tests as needed, it is indeed possible to distinguish a discogenic pain from a facet syndrome. In addition, myofascial dysfunction as the primary or secondary pain generator can be detected, as can muscle fatigue syndrome with loss of balance (usually sagittal imbalance). Diagnosing pure nerve root syndromes or symptomatic spinal stenosis tends to be one of the easier tasks when performing differential diagnosis of back pain. In many cases, the diagnostic and therapeutic repertoire for spinal disorders includes the different spinal injection techniques. The more targeted the pain treatment, the higher the chances of success and, in turn, the chances of preventing pain from becoming chronic.

For all types of spinal pain, the anatomical structures, physiological and neurophysiological mechanisms of pain generation and transmission, and neuropsychological aspects of pain processing must all be kept in mind, along with patient’s possible desire to acquire disability benefits. This second, completely revised edition of Spinal Injection Techniques offers comprehensive anatomical, physiological, and pharmacological foundations and detailed information about different techniques, supported by a wealth of illustrations that provide three-dimensional enhancement to understanding the anatomy.

The book explains typical indications, positioning of the patient, and all interventions, including provisions for possible complications. The diagrams and illustrations using both skeletal models and anatomical specimens depict the individual techniques used in the different spinal regions. The book, which was originally co-authored by Juergen Kraemer, is now continued by Theodoros Theodoridis in its second, fully revised edition. It is highly recommended as a standard work for all orthopedists and trauma surgeons dealing with the treatment of spinal disorders. It is especially an important companion for colleagues participating in the injection courses offered by the Interdisciplinary Society for Orthopedic and Trauma Surgery Pain Therapy (IGOST) section of the German Society for Orthopedics and Trauma Surgery (DGOOC) and of the German Society for Orthopedics and Trauma (DGOU). It is also recommended as a reference book for all colleagues using injection techniques to treat back pain.

I would like to sincerely thank the authors for their in-depth work in writing this textbook. In German-speaking countries, it is the standard reference work in this area and deservedly enjoys widespread distribution.

Professor Rüdiger KrauspeDGOOC President 2015Head of the Department of OrthopedicsDüsseldorf University Hospital

Foreword

Conservative treatment of spinal disorders is highly significant and should be accorded more importance in the health policy arena. Injection therapies and interventional techniques serve as a link between purely conservative and surgical therapy. When it comes to degenerative spinal disorders, injection therapies are often preferred to surgical procedures. In many cases, these injection techniques are also used for differential diagnosis and for differential indication of planned surgical procedures.

The basis for any injection therapy is the drug that is applied. Local anesthesia did not become established in everyday clinical routine until after the introduction of the local anesthesia Novocaine by Hoechst in 1905, which is considered the dawn of injection therapy. During this period, caudal anesthesia was established, for example. In this context, the invention of the sympathetic nerve block is also noteworthy, as one of the first paraspinal injection techniques.

While today the body of evidence for spinal injection therapy might be considered by some to be inadequate, it should be noted that this form of treating spinal pain syndromes is one of the most common types of therapy and thus immeasurably significant. Any spinal therapist who has relieved a patient’s pain through a successfully placed facet joint injection or infiltration or a correctly placed lumbar spinal nerve analgesia knows just how significant this technique is.

This book, in its second, fully revised and expanded edition, significantly contributes to gaining insights on spinal injection therapies. The book is well structured and clearly divided into two parts. In the first part, the reader is introduced to the foundations of the pathophysiology of pain generation and will learn about the common diagnostic interventions and nonsurgical pain treatments. The second section is devoted to pharmaceutical support using the common pain medications and their modes of action.

The part dedicated to the specifics of spinal injection therapy is divided in a section structured according to the anatomy of the cervical, thoracic, and lumbar spine, and a section describing general and specific complications. The reader is given a highly detailed description of the common injection techniques, taking the anatomical landmarks into consideration. Diagnostic imaging techniques are presented throughout the book in order to enhance the explanation of the anatomical interrelationships.

The richly illustrated book offers readers a manual for locating anatomical structures, even without the use of imaging techniques, and presents a wide variety of therapeutic options involving spinal injections. The authors of this book draw not only on their own vast experience, but also on the experiences of the Interdisciplinary Society for Orthopedic and Trauma Surgery Pain Therapy (IGOST).

This book, now it its second edition, is recommended as a standard reference work for spinal therapists offering conservative treatment. It is also useful for physicians performing spinal surgery, however. The depiction of the anatomical landmarks and the instructions for locating them alone provide valuable diagnostic support.

I would like to thank the authors of this book for their work on the earlier edition and on this revised edition. On behalf of the German Spine Society (DWG), I hope that the readers of this book will gain informative insights and will successfully implement the techniques presented here in their daily practice.

Professor Michael RauschmannPresident of the German Spine Society (DWG) 2015andHead of Spine UnitOrthopaedic University Hospital FriedrichsheimFrankfurt am Main

Preface

Since the publication of the first edition of Spinal Injection Techniques, 11 years have passed.

I am extremely pleased that we have surpassed our original goal of creating a book that simplifies the challenging day-to-day work with our back pain patients in our practices and at the hospital.

At meetings and symposia, as well as during discussions, it has become evident that spinal injection therapy plays a very significant role, especially for the treatment of degenerative spinal disorders. The step-by-step presentation of the injection techniques from the cervical spine to the sacrum, “as in a cookbook,” has made this manual a successful bestseller.

This made writing the revised version all the more challenging, however, especially in light of the passing of my honored co-author and mentor Professor Juergen Kraemer (March 5, 1939, to October 7, 2011).

The structure used in the manual to teach the techniques has remained the same. All of the chapters have been revised, however. They offer tips and tricks for performing a clinical examination and describe and assess risks, errors, and complications associated with planning and performing injection therapy.

The book’s “highlight” is the completely new atlas section. With over 500 new outstanding photographs of injection techniques as shown on a skeletal model, anatomical specimens, and actual patients, the anatomical landmarks are depicted in even more detail than in the previous editions and the special anatomical know-how is presented and conveyed step by step, from palpation to the tip of the cannula.

I would like to express my gratitude to Rainer Jagusch for the excellent quality of the photographs and his unending patience during the photography.

I would also like to thank the team at Thieme Verlag, in particular Silvia Haller, for allowing me to give the book its individual design.

Special thanks go to the Department of Anatomy at the University of Madrid, Spain. Prof. José Ramón Sañudo Tejero and Dr. Marc Rodriguez-Niedenführ provided numerous anatomical specimens, which enabled many relevant details of the special injection techniques to be depicted.

Thank you to all of the employees for all of the updates that were conducted.

I am also grateful to the authors of the forewords: Dr. Cordelia Schott, President of IGOST; Professor Rüdiger Krauspe, President of the DGOOC 2015; and Professor Michael Rauschmann, President of the German Spine Society 2015.

Finally, I would like to thank the patients who were willing to contribute to the compilation of this manual.

The goal of all spinal therapists should be to help their patients get through their pain peaks with minimal medication and other aids. They should do everything in their power to avoid burdens on the patient caused by drugs, radiation, or emotional stress.

In this context, I would like to mention that Professor Juergen Kraemer always made a point of mentioning the spontaneous regression of spinal disorders.

I would like to encourage all spinal therapists offering conservative and surgical interventions to find out all they can about spinal injection techniques without the use of imaging.

I wish you success in all of your endeavors.

Bochum, Spring 2019, Theodoros Theodoridis

Contributors

Lluís Aguilar i Fernàndez, PhDCentro Médico TeknonBarcelona, Spain

Alexandros P. Anastasiadis, MDHelios St. Johannes HospitalDuisburg, Germany

Fritjof Bock, MDPrivate Practice for OrthopedicsRavensburg, Germany

Constantinos Georgallas, MDOrthopedic Private PracticeDr. Theodoridis Viktoria ClinicBochum, Germany

Jana GinglsederRuhr UniversityBochum, Germany

Stefan Heidersdorf, MDPrivate Practice for OrthopedicsHattingen, Germany

Robert Krämer, MDCentro Médico TeknonBarcelona, Spain

Priska Laubenthal, MDEVK Hospital Group Herne—Castrop-RauxelPain AmbulanceCastrop-Rauxel, Germany

Ilias Nastos, MDPrivate Practice for NeurologyBochum, Germany

Marc Rodriguez-Niedenführ, PhDComplutense University of MadridMadrid, Spain

Cordelia Schott, MDPrivate Practice for OrthopedicsEssen, Germany

Clemens J. H. Sirtl, MDSt.-Franziskus-HospitalAnesthesiology, Emergency MedicineWinterberg, Germany

Susanne Stehr-Zirngibl, MDSt. Johannes-HospitalPain Medicine ClinicHagen, Germany

Wolfram Teske, MDSt. Josefs-HospitalOrthopedic ClinicHagen, Germany

Ulrike Theodoridis, MDEvK HattingenHospital for NeurologyHattingen, Germany

Part I

General Section

1 Basic Principles

2 Diagnostics

3 Causal Orthopedic Pain Therapy

4 Symptomatic Pain Therapy

1 Basic Principles

1.1 Orthopedic Pain Management

Note

Orthopedics is the branch of medicine concerned with conditions involving the musculoskeletal system.

As such, it deals with the diseases and injuries found in bones, ligaments, muscles, and joints at every stage of life. Orthopedics is described more precisely in the German Medical Association’s specimen advanced training ordinance for orthopedic and trauma surgery specialists in the version dated June 25, 2010:

“Orthopedics and trauma surgery comprises the prevention, recognition, surgical and conservative treatment, follow-up care, and rehabilitation of injuries and their consequences, as well as congenital and acquired changes, malformations, functional disorders, and diseases of the musculoskeletal organs, taking age-related differences into account.”

“Spinal and joint injection and puncture techniques” are officially defined diagnostic and treatment methods in this area.

The spectrum of orthopedic medicine ranges from malformations of the spine and limbs to inflammatory bone and joint diseases, pediatric orthopedics, musculoskeletal oncology, rehabilitative medicine, and technical orthopedics. It also includes injuries and damage to the musculoskeletal organs caused by wear and tear, as well as the pain states associated with these injuries.

The essential components of conservative orthopedics include not only the treatment of pain but also recovery from musculoskeletal disorders that affect function and form. This includes the use of bandaging, physical agents and electrotherapy, manual therapy, systemic pharmaceutical therapy, local injections, physiotherapy, and orthopedic devices (Orthopädie Memorandum 1998).

Note

Pain can be defined as an unpleasant sensory and emotional experience (Schmidt and Thews 1997).

The International Association for the Study of Pain has agreed on a more extensive definition of pain: “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” (IASP 1986). This definition distinguishes pain from other unpleasant sensations by relating it to physical damage. The second part of the definition acknowledges that pain may be experienced even when no tissue damage can be demonstrated at that instant. This extension of the definition is especially important for pain that is described as chronic.

Further sensory disorders within the musculoskeletal system that possess possible warning functions include the following disorders based on the definitions of Merskey and Bogduk (1994):

Hypoesthesia: reduced sensation to touch.

Anesthesia: loss of sensation.

Anesthesia dolorosa: pain in a numb area.

Paresthesia: abnormal sensation that is either spontaneous or provoked; described as being like ants crawling, pins and needles, or a furry feeling.

Dysesthesia: in contrast to paresthesia, the abnormal spontaneous or provoked sensation is distinctly unpleasant.

Hyperesthesia: increased sensitivity to touch stimuli.

Hyperalgesia: increased sensitivity to pain.

Allodynia: pain that results from a stimulus that is not normally painful.

These sensory disturbances occur in the musculoskeletal system with or without pain, e.g., with nerve root syndromes, with peripheral nerve lesions, and in the area surrounding surgical wounds. Neuropathic pain can also occur here that is triggered by a primary lesion or nervous system dysfunction. Local numbness and sensory disorders often remain as residual symptoms after a subsided nerve compression. They can function as an alarm, e.g., saddle anesthesia caused by cauda equina syndrome.

Acute and chronic pain are not differentiated solely by the duration of the pain. Acute pain in the musculoskeletal system is felt following acute events, e.g., stretching of the joint capsule, muscle tears, or disk prolapse.

Note

Acute pain begins suddenly, gives a warning, and elicits an immediate reaction. In most cases, this reaction involves adopting a relieving posture with an increase in muscle tension so as to combat the cause of the pain.

A chronic pain syndrome or pain chronification in the musculoskeletal system is described as pain that is constantly or intermittently present over a period of at least 3 months. The most common causes are relapsing spinal syndromes with or without radiation into the extremities. The progression from acute to chronic pain is fluid and is referred to as chronification.

Note

Chronification: acute pain → chronic pain.

Within the musculoskeletal system, the chronification of pain is defined as the transition from acute to chronic pain, where pain is present for more than 3 months and has lost its warning function. The patient exhibits an increase in secondary psychological symptoms, with a change in the perception and processing of pain signals. The relationship between the intensity of the pain stimuli (e.g., tissue damage) and the pain reaction is lost.

The degree of chronification is dependent on the following:

The duration of pain.

Pain dispersion.

Response to medication.

The doctor–patient relationship.

Changes in experience and behavior.

Example

Symptoms of lumboischialgia persist for several months during the chronification process. The radiating pain and the area of radiation into the leg change constantly. The patient requires stronger medication to deal with the pain, and ends up by changing doctors.

The pain chronification score proposed by Gerbershagen provides a valuable framework for pain classification (Gerbershagen 1986). The Graded Chronic Pain Scale (GCPS) developed by Von Korff records the pain intensity in the past 3 to 6 months using numeric rating scales from 0 (no pain) to 10 (worst imaginable pain). It records limitation of activities of daily living, leisure time, and work on a scale of 0 (no interference) to 10 (extreme interference) while quantitatively recording the “days in pain” (Von Korff et al 1992).

Note

We speak of a chronic pain syndrome when the perceived pain is largely independent of the original cause of pain and has become an independent disease state.

Concomitant symptoms, such as increased muscle tension, abnormal posture, and psychogenic reactions, become more important. These symptoms may even become a disease in their own right, even when the cause of pain is no longer present.

The impact of chronic pain on the patient is significant. In 2006, Tang and Crane demonstrated that for chronic pain patients the risk of death by suicide was more than twice that of patients with chronic emphysema, heart failure, or depression.

Treating chronic pain is highly significant in terms of health economics. According to a study by Eriksen et al (2003), pain is the reason for 20% of all doctor’s visits. Ten percent of the sales of drugs in industrialized countries involve pain medication. And the costs of treating pain amount to USD 1 trillion annually.

Chronic pain syndrome is also referred to as “pain disease” (e.g., Adler et al 1989; Eggle and Hoffmann 1993) to emphasize that it is the pain itself that has become a disease. One disadvantage of this terminology is that patients are given the impression that because they have a “disease” there is nothing they can do about the pain. It is exactly this interpretation that is detrimental in chronic pain syndrome. In fact, the opposite is true, and patients should be educated in how to actively manage their pain.

Example

The chronic irritation of a nerve root associated with a disk prolapse or due to a lateral spinal canal stenosis is an example of a chronic pain syndrome. The symptoms often remain, even when the cause of pain has been removed (e.g., by surgery). The nervous system has learned to perceive pain (see “Moving from Acute to Chronic Pain: Nociceptor Sensitization,” below).

Orthopedists use a variety of methods to treat pain. Aside from the administration of common analgesics in general pain therapy, other methods specifically related to orthopedics include:

Physical therapy.

Physical agents and electrotherapy.

Manual therapy.

Local injections.

Orthopedic technical aids.

Exercise programs.

Surgery.

Following injury, orthopedic pain therapy is applied directly or indirectly to the somatic source of pain, and is intended to prevent the chronification of pain. The cascade of acute pain to chronic pain and subsequently to a chronic pain syndrome should be halted right from the start. When the initial intervention is unsuccessful, or too late, treatment must increasingly take psychological aspects into consideration. Psychosomatics, psychology, and orthopedics are of equal importance in the treatment of chronic pain, chronic pain syndromes, and somatic psychogenic disorders. Purely psychogenic disorders primarily require the input of a psychologist. At the same time, orthopedic surgeons must rule out primary organic disorders and keep a lookout for secondary functional disorders as required. Chronic pain also has a high socioeconomic relevance and also poses a challenge for the orthopedists in their function as experts (in disability-benefit cases).

1.2Epidemiology

▶ Most common initial disease. The first serious illness of adulthood requiring medical attention generally affects the musculoskeletal system. This includes conditions such as herniated disk, sciatica, and injury-related sequelae, especially involving the knee and foot, as well as first-time symptoms of incipient osteoarthritis (Orthopädie Memorandum 1998).

In Germany, 1.3 million sports-related accidents requiring medical attention occur each year (Gläser and Henke 2014). Among these first-time orthopedic disorders, the spine and knee joint are most frequently involved. The average age of patients with these first-time disorders is 22.8 years (Ludwig et al 1998). The acute initial disorder often develops into chronic pain if the chronification process is not interrupted consequently.

Hospital and pension fund operators’ statistics demonstrate the economic significance of orthopedic disorders as manifested by the relative prevalence and constant increase in spinal and joint disorders, sports injuries, and cases of osteoarthritis and rheumatic diseases (Orthopädie Memorandum 1998).

Note

Painful, degenerative musculoskeletal disorders are widespread disease.

The high prevalence of orthopedic ailments is also reflected in the statistics of days missed from work due to illness. In 2008, one-quarter of all days missed due to illness in Germany were caused by musculoskeletal disorders, one of the main causes, along with respiratory disorders and injuries/poisoning. The diagnosis of “dorsalgia” (ICD-10 M.54) is particularly relevant (SuGA 2008). The average age of patients with the highest number of days missed from work due to illness of the musculoskeletal system is 41 years.

According to the Statistical Yearbook published by the German Federal Statistical Office, painful orthopedic disorders are the most common reason for granting disability benefits and early retirement. The telephone health survey conducted by the Robert Koch Institute in 2004 on behalf of the German government showed a 12-month prevalence of back pain of more than 60% for both men and women, with women affected more frequently than men. According to the last large-scale health survey conducted in Germany in 1998, the annual incidence of back pain even among men under the age of 30 years is 55.4%, while it is 61.3% for women in the same age group. These figures remain constant into old age with only slight deviations (▶ Fig. 1.1).

Fig. 1.1Prevalence of back pain in percent by age group in years. (Reproduced with permission from German National Health Interview and Examination Survey 1998 [No. 7, Fig. 6. Prevalence of back pain, special issue 2002].)

Among the chronic pain disorders, degenerative spinal and joint disorders are not only the most frequent but also increasing at a disproportionate rate. As humans age, the resilience of their musculoskeletal organs decreases. This limits their capacity to walk and stand, culminating in decompensation leading to the need for a wheelchair or to being bedridden. Musculoskeletal pain disorders are contributory cause for activity limitation and the need for nursing care (Orthopädie Memorandum 1998).

Chronic musculoskeletal pain heads the list of disorders and disabilities recognized in Germany to determine the need for nursing care in accordance with the new long-term care insurance (Section 14 (2) of the Social Code).

▶ Prevalence of chronic pain. When patients with musculoskeletal problems first seek medical attention, are temporarily unable to work, or submit a premature application for a pension, chronic pain is often the motivating factor. Functional impairment, deformity, and impaired performance are secondary. When the spine is involved, the problem tends to be low back pain rather than a lack of flexibility. In patients with osteoarthritis of the hip, it is the pain rather than immobility that causes them to seek out a physician.

During our survey, 75.8% of the patients at orthopedic practices reported that they had consulted a physician primarily due to pain. A similar survey of patients at practices of other specialists showed that a much smaller percentage of the patients were primary pain patients (Krämer 1996).

The patient mix at outpatient pain clinics is similar (Hildebrandt 1993; ▶ Fig. 1.2).

Fig. 1.2 Percentage of disorders for which patients seek treatment at outpatient pain clinics. (Reproduced with permission from Hildebrandt 1993).

▶ The spine is the most frequently involved. Painful spinal syndrome affects nearly everyone at some point in their lives.

In early adulthood, this tends to be acute low back and/or shoulder and neck pain that persists for only a matter of days. In most cases, the patient does not consult a doctor or specialist immediately.

One out of three patients develops chronic recurrent pain that requires medical attention (Krämer 1997).

Only 0.25% of all patients with low back and leg pain caused by nerve root compression require surgery in the end (Frymoyer 1992).

The high percentage of spinal disorders in the statistics on disability, pension, hospital treatments, and treatment by physicians reimbursed by statutory insurance providers in Germany has also been reported in the literature (Berger-Schmitt et al 1996; Raspe 1993). In 2006, the cost of treating “dorsopathies” (ICD-10 M45-M54) was EUR 8.3 billion and has shown an increase in recent years (Statistisches Bundesamt 2008).

Statistical surveys conducted at general practitioners’ and orthopedists’ practices as well as at orthopedic outpatient clinics show that spinal pain syndrome is the leading complaint in all areas (Krämer 1997). According to the findings, 1 in 10 patients seeing a general practitioner presents for treatment of spinal pain syndrome. At orthopedic outpatient clinics, the ratio is 1:3, while at orthopedists’ private practices, one in two patients presents with spinal pain syndrome. Among the orthopedic complaints treated on an outpatient basis, spinal pain disorders play a dominant role, accounting for 37.8% of the complaints. ▶ Fig. 1.3 shows the frequency with which the individual parts of the extremities are treated by orthopedic specialists.

Fig. 1.3Distribution of musculoskeletal pain disorders treated at orthopedic specialists’ practices and outpatient clinics. (Reproduced with permission from Krämer 1997.)

Pain syndromes affect individual spinal segments to various extents. The most frequently involved segment is the lumbar spine, at 61.94%, ahead of the cervical spine, at 36.1%. Thoracic spine syndrome, manifesting as intercostal neuralgia, is rare, at only 1.96% (▶ Fig. 1.4). Men (47.2%) are affected by spinal syndromes almost as often as women (52.8%). Women (60.6%) are affected by cervical syndrome more often than men, while men (51.3%) are affected by lumbar syndrome slightly more often than women. Men are more frequently affected than women by severe lumbar syndrome with radicular deficits requiring hospitalization.

Fig. 1.4Prevalence of chronic pain in the individual spinal segments in patients treated on an outpatient basis (Reproduced with permission from Krämer 1997.)

In terms of age, 68% of the patients are between 30 and 60 years, with prevalence peaking among patients between the ages of 40 and 50 years. The frequency and intensity of spinal pain syndrome increase from the age of 50 onwards (Krämer 1997).

Chronic pain involved with painful degenerative disorders affecting the joints of the extremities tends to begin between the ages of 50 and 60 years and then steadily increases thereafter.

1.3Nociception and Chronification

The pain process goes through several phases: from the activation of nociceptors and conduction of nociceptive impulses, to pain perception and muscular and autonomic reactions. The sequencing of painful events in the musculoskeletal system is specific. Musculoskeletal pain arises from mechanically inflammatory, thermal, or chemical stimuli that affect bones, muscles, tendons, and joint capsules. The pain caused by these noxious stimuli is perceived in the cerebrum. At the spinal level, pain stimuli are distributed, for example, to the muscular system and the autonomic nervous system (ANS).

The physiology of musculoskeletal nociception is based on the existence of an extensive, independent peripheral nervous system which is dedicated to the perception of peripheral musculoskeletal pain. The process shown in ▶ Fig. 1.5 occurs when a stimulus sufficient to cause pain irritates a nociceptive system which has not been previously damaged (by being sensitized, or by the development of chronic pain).

Fig. 1.5 Nociception and pain processing in bones, muscles, tendons, and joints. The transitions, for example, from the afferents to the spinal cord are depicted symbolically.

The noxious stimuli, nociceptors, and afferent fibers combine to form the pain-creating complex. Pain signals travel from the spinal cord via the brainstem and to the thalamus. The neural connection of the thalamus with cortical structures is particularly important for pain perception. Centers of the ANS are also involved. Together with the limbic system of the brain (which affects the emotions), the cortex conducts afferents to the anterior horn of the spinal cord with a motor response of the musculoskeletal system to the pain. A multitude of transmitters, modulators, and their corresponding receptors participate in nociceptive processes within the central nervous system (CNS) (Schmidt and Thews 1997).

In musculoskeletal disorders, the original injury occurs in the peripheral tissues and it is here that orthopedic pain therapy starts.

1.3.1Stages in the Development of Pain

Noxious stimuli (1 on ▶ Fig. 1.5) are events or substances that are damaging to tissues, or are a threat to them. They activate the nociceptors in bone, muscles, tendons, and joint capsules. Mechanical, chemical, and thermal exogenous stimuli act first of all on the musculoskeletal system. The direct trigger for muscular reactions as part of the vicious circle of pain and in the presence of continual psychological stress (endogenous pain) is unknown. Nevertheless, the process leading to the perception of pain is the same.

Nociceptors (2 on ▶ Fig. 1.5) are nerve fibers, usually unmyelinated, but also thinly myelinated Aδ-fibers (pain receptors) that are activated when pain stimuli act on the body. The excitation threshold of the nociceptors is exceeded in the presence of tissue-damaging irritants. The receptiveness of the musculoskeletal system to pain stimuli is dependent on the concentration of nociceptors and their thresholds. A nociceptor’s response (the impulse frequency) typically corresponds to the amount of pain stimulus, increasing to the point at which tissue is damaged (Messlinger 1997).

Note

Muscles, periosteum, tendons, and joint capsules contain polymodal nociceptors that react to mechanical, chemical, and thermal stimuli.

Histologically, musculoskeletal nociceptors consist mainly of noncorpuscular (free) nerve endings. They are found on the small blood and lymphatic vessels within the connective tissue spaces and on the nerves themselves, as a so-called endoneurium (Mense 1977).

Note

Pain sensations originating from the musculoskeletal system form the numerically largest group within the somatosensory system because the concentration of nociceptors in periosteum, ligaments, and joint capsules is high.

Pain often accompanies orthopedic disorders in these structures, which are also liable to injury, overloading, and premature wear and tear.

Afferent fibers (3): Pain signals are transmitted via afferent nerve fibers from the nociceptors to the spinal cord. Unlike dorsal column afferents, the afferent axons are thin and myelinated (Aδ-fibers) or unmyelinated (C-fibers). Visceral afferent fibers are also mostly unmyelinated.

Transmission of Nociceptive Signals

Spinal cord (4): Synapses connect the nociceptive afferents (Aδ- and C-fibers) to the neurons of the posterior horn. Impulses occurring at this switch point in the spinal cord result in the release of excitatory neurotransmitters such as L-glutamate and substance P. L-glutamate is believed to be an important transmitter in the CNS (Zieglgänsberger and Tölle 1993). Along with other neuropeptides (e.g., substance P), L-glutamate transmits the excitatory signals from the thin nociceptive nerve fibers to the nerve cells, which in turn transmit information to the spinal cord. The nociceptive influx is transmitted from the spinal cord by the following routes, among others:

Via the spinothalamic tract to the more superiorly lying areas of the brain (limbic system and thalamus).

To segmental neurons that are connected to the motor and autonomic reflex arcs.

The nociceptive spinal cord neurons, the so-called multireceptive neurons, receive a converging influx of signals from multiple afferents from one organ or from different organs, e.g., skin and muscle, skin, and viscera. This arrangement is an important prerequisite for referred pain (Schmidt and Thews 1997). Interneurons in the posterior horn modulate the activity in these multireceptive neurons. Their activity may reduce the transmission of nociceptive signals (gate control theory; Melzack and Wall 1965).

Perception of Pain

Cortex (5): The pain impulse is transmitted to the cortex via the ascending pathways. The CNS is responsible for the integration of pain perception and the reaction to it. Parts of the pain process can be allocated to individual structures within the CNS (Zieglgänsberger and Tölle 1993).

Information about pain is integrated into the regulation of circulation and breathing within the brainstem. It is here that the descending inhibitory systems can be found. These systems play a part in the endogenous regulation of pain in the spinal cord. Inhibitory systems are constantly active in the CNS, regulating sensitivity and reaction readiness. The action of these descending and segmentally inhibitory systems can be strengthened by a variety of pain therapy methods (Zieglgänsberger and Tölle 1993). Endogenous pain inhibition is activated by electrical stimulation (transcutaneous electrical nerve stimulation), morphine, afferent stimulation (acupuncture), psychological influences (stress), and movement such as sports and exercise (Dietrich 2003).

Note

A special aspect of orthopedic pain therapy is the use of movement to reduce pain.

Motor Reaction

Muscle (6): Pain stimuli trigger motor reflexes in the form of postural adaption and protective reflexes. These actions mostly relate primarily to a change in muscle tension. Some of these reflexes are organized at the spinal level, but others are mediated by supraspinal reflex arcs (Schmidt and Thews 1997).

The change in body posture, with increased muscle tension in certain muscle groups and relaxation of other muscle groups, demonstrates a protective mechanism found in the musculoskeletal system. This mechanism aims to prevent pain stimuli irritating nociceptors. When considering orthopedic pain therapy, it makes sense not to treat adaptive changes in posture or muscle tension for a few days when acute pain is present, at least until the influx of pain stimuli has been disrupted and the nociceptors have been eased.

Autonomic Reaction

Autonomic nervous system (ANS) (7): The autonomic reaction to pain stimuli acting on bones, muscles, tendons, and joints is linked to a spinal reflex arc. Pain stimuli affect the ANS in different ways, depending on their origin. In the musculoskeletal system, the effect is primarily in the form of a reflex increase or decrease in blood flow caused by muscular contraction: the physiological muscle pump is affected. Depending on the level of autonomic involvement, changes in skin temperature and moisture levels may occur (via the influence of sweat glands), as well as sensory disorders.

1.3.2Moving from Acute to Chronic Pain: Nociceptor Sensitization

When sufficiently irritated by noxious stimuli, nociceptors send signals to the cortical areas responsible for pain perception. The processing of pain signals and a pain response follows. This process, from pain development to pain perception, can be disrupted at different levels by exogenous and endogenous factors. Exogenous stimuli and endogenous inflammatory mediators such as bradykinin, histamine, prostaglandins, and interleukins can activate nociceptors so strongly—and, moreover, so frequently that the irritation thresholds of the nociceptors are reduced and they become more sensitive.

Pain adaptation does not occur within the musculoskeletal system. This means that it is impossible to get used to shoulder, knee, or back pain. Rather, pain threshold measurements indicate that continuous irritation results in sensitization of nociceptors (Schmidt and Thews 1997). The sensitization of nociceptors can occur with inflammatory processes resulting from a range of causes such as injuries, active arthritis, infections, or rheumatoid arthritis. At the same time, macrophages are activated by the inflammatory process (e.g., via lymphokines) as part of the cellular reaction. This in turn releases antigen stimuli from the T lymphocytes. The macrophages form prostaglandin, leukotrienes, and cytokines, which all pass on the inflammatory reaction to other cells (endothelium, fibroblasts; Zimmermann 1991). The combination of two inflammatory mediators, such as prostaglandin E2 and bradykinin, potentiates the reaction (Mense 1981).

Note

Sensitized nociceptors in the musculoskeletal system react to even the smallest of external influences (e.g., normal joint movement, warmth, cold, temperature change) because of their decreased irritation thresholds.

Some nociceptors become active only when inflammation is present (Schmidt and Thews 1997). These mechanoreceptors, the so-called silent or sleeping nociceptors, first become sensitive to mechanical input under sensitizing conditions such as inflammation (Messlinger 1997).

Neuropeptides, including substance P, calcitonin gene-related peptide, nitric oxide, prostaglandin, and other vasoactive substances, are released from irritated nociceptors (Zimmermann 1991). Nociceptive processing with sensitized nociceptors results in a vicious circle. Permanently sensitized nociceptors produce a continual change in muscle tension, as part of a protective reflex posture. This muscle tension acts in turn as an endogenous irritant to the sensitized nociceptors. Even when the exogenous irritating stimulus is no longer present, this vicious circle remains (▶ Fig. 1.6).

Fig. 1.6 The nociceptive vicious circle. Sensitized nociceptors (2) give rise to permanent muscle contraction (6) via the spinal reflex arc (3 and 4). The muscle spasm is in turn an endogenous stimulus (1a) for the nociceptors (2). This vicious circle can proceed independently without the influence of additional noxious stimuli (1), the participation of higher brain areas (5), or the ANS (7).

The orthopedic approach to pain therapy and the vicious circle of pain deals first of all with the sensitized nociceptors (2) and the afferent fibers (3), and then moves on to pain transmission (4). Its primary role, however, is to influence the motor reaction by reducing muscle tension. It makes sense to make the primary intervention where the nociceptive process starts, before the vicious circle and chronification begin: with the pain stimulus itself and at the nociceptors.

Chronification by Means of Gene Activation

The ability of nerve cells to react more effectively to the same stimulus when it is applied repeatedly is nowadays seen as an important factor in the formation of memory, e.g., movements becoming more selective and economical after they have been practiced. The reaction of nerve cells in the spinal cord to neuropharmacological and molecular biological techniques has been investigated—in particular, how nerve cells “remember” painful stimuli and correspondingly overreact, and how this process can be prevented by the use of medication (e.g., Zieglgänsberger and Tölle 1993; Even 1995; Hunt et al 1995; Tölle et al 1995).

The activation of certain genes is important for chronification. This leads to the new synthesis of receptors and ion channels, and to stimulation or inhibition of the production of individual neurotransmitters. Molecular biology research (e.g., Even 1995; Tölle et al. 1995) demonstrates that the expression of so-called proto-oncogenes (immediate early genes, IEGs) is stimulated by pain stimuli increasing neuronal excitability.

The formation of pain memory is initiated by nerve cells reacting to repeated pain stimuli with neuronal learning. A repeated stimulus of the same strength, or even weaker, causes the dorsal horn neuron to discharge, with continually increasing strength. The pain cells in the CNS react with a higher discharge frequency. Specific types of damage in the musculoskeletal system (such as strains, pressure, and nociceptor and nerve lesions) act as stimuli that can also change the phenotype of the neuron.

The task of orthopedic pain therapy is to eliminate these types of damage with causal therapy such as pain-free positioning, switching off nociception in the periphery, and transmission of pain signals. This prevents or, in some cases, reverses complex adaptive processes at a morphological, neurophysiological, and genetic level.

Note

The chronification process can be prevented and reversed when pain that has not yet become chronic is treated with local anesthetics and an exercise program aimed at reducing pain.

Endogenous opioids that are produced by spontaneously activated spinal cord and cerebellar neurons reduce the expression of the IEG and curb the activation of nerve cells by pain stimuli. This can prevent chronification.

■ Neuropathic Pain

An important fact to bear in mind when addressing the symptoms of nerve root irritation and peripheral nerve compression syndromes is that damaged nerve roots and peripheral nerves discharge spontaneously. This is not the case with intact, undamaged nerves.

Example

The observations of Kuslich and Ulstrom (1990) during intervertebral disk operations under local anesthesia demonstrate neuropathic pain. When they touched the nerve root that had been irritated by the disk prolapse, the patient perceived the same amount of pain as when they touched the vertebral joint capsule (with its high concentration of nociceptors) and the posterior longitudinal ligament. In contrast, nerve roots from neighboring levels that had not been compressed were just as insensitive to being touched with tweezers as structures with a lower concentration of nociceptors, such as ligamenta flava, dura, and epidural fatty tissue.

Nerves become the source of pain without the primary nociceptors playing a part. Nerve fibers that are normally only responsible for relaying feelings of pain send out pain impulses. In contrast to nociceptive pain, the pain caused by the pathophysiological generation of impulses at nociceptive fibers (not at the nociceptors) is called neuralgia, neuralgic pain (Schmidt and Thews 1997), or neuropathic pain (▶ Table 1.1). Neuralgic pain in the musculoskeletal system is fundamentally different from nociceptive pain. The impulse activity originating in the nerve fiber is projected into the entire area supplied by the nerve, as such impulses normally arise from the nociceptors in this area. With neuralgias, the site of the original damage is not identical to the area of pain perception. In the case of lumbar nerve root syndromes, for example, pain can be perceived in the leg via the ventral ramus (see Chapter 9).

Table 1.1

 The differences between nociceptive and neuropathic pain

Nociceptive pain

Neuropathic pain

Characteristics already present

Characteristics develop first

Local sensation of pain

Sensation of radiating pain

Site of damage and area of pain are identical

Site of damage and area of pain are different

Treatment: local anesthesia at the area of pain

Treatment: local anesthesia away from the area of pain

The conversion from pain conductor to source of pain in the musculoskeletal system is a slow process.

Note

The nerve becomes the source of electrical signals. The CNS gradually learns to perceive pain.

A single, short-term compression has no lasting consequences, but repeated, long-term damage results in permanent pain. Nerve pain/neuralgia develops only from long-term irritation. The pain is thus not a static, repetitive event, but rather a complex plastic occurrence with changes to the nerve structures involved.

Short-term contact of the injection needle with the vertebral nerve root, or the intraoperative irritation of not predamaged nerve roots (Kuslich et al 1991) has no lasting consequences, but repeated, long-term damage results in neuralgia. Nerve pain (neuralgia) develops only from long-term irritation (▶ Fig. 1.7).

Fig. 1.7 Neuropathic pain (neuralgia). The pain stimulus (1a) acts directly on the nerve (3). The nerve becomes the source of pain without the nociceptors (2) playing a role. The transmission of pain signals (4), pain perception (5), and motor (6) and autonomic (7) reactions are the same as in nociceptive pain: the nerve becomes a nociceptor.

1.3.3Secondary Pain