carpal tunnel syndrome€¦ · carpal tunnel syndrome excerpt of the full publication. excerpt of...

Louis PATRY, Occupational Medecine Physician, ErgonomistMichel ROSSIGNOL, Occupational Medecine Physician, Epidemiologist

Marie-Jeanne COSTA, Nurse, ErgonomistMartine BAILLARGEON, Plastic Surgeon

GUIDE TO THE DIAGNOSIS OFWORK-RELATED MUSCULOSKELETAL

DISORDERS1Work-related musculoskeletal injuries are one of the most common occupational

health problems for which physicians are consulted. There is solid scientific evidence thatthese injuries may be occupational in origin.

This guide was designed to help physicians interpret the results of a medicalexamination. By combining the standard clinical assessment procedure with guidelinesconcerning the identification of etiological factors, it helps physicians identify the causeof injury.

AUTHORS

Louis Patry holds a degree in medicine from Laval University anda diploma in ergonomics from the Conservatoire National des Artset Metiers de Paris (CNAM). He is a specialist in occupational medi-cine, an associate member of the Royal College of Physicians andSurgeons of Canada, a professor in McGill University’s Departmentof Epidemiology and Biostatistics and Occupational Health, and con-sulting physician to the Direction de la santé publique (Public HealthDepartment), first in Québec City and currently at the Montréal-Centre board.

Michel Rossignol holds degrees in biochemistry and medicinefrom the University of Sherbrooke, in epidemiology and communityhealth from McGill University, and in occupational medicine fromJohn Hopkins University. He is a professor in McGill University’sDepartment of Epidemiology and Biostatistics and OccupationalHealth, co-director of the Centre for Clinical Epidemiology of theJewish General Hospital of Montréal, and physician-epidemiologistat the Montréal-Centre board of the Direction de la santé publique(Public Health Department).

Marie-Jeanne Costa holds a nursing degree from the Institutd’études paramédicales de Liège and a degree in ergonomics fromthe École Pratique des Hautes Études de Paris. She is an ergonomicsconsultant and has collaborated on several studies of CTDs. She isparticularly interested in the development of participatory ergonom-ics, specifically in the problem-resolution and diagnostic processes.

Martine Baillargeon holds a degree in medicine from theUniversité de Montréal. She is a plastic surgeon and associate mem-ber of the Royal College of Physicians and Surgeons of Canada.After years of practising surgery she is now consulting physician,mainly in the field of musculoskeletal injuries affecting the upperlimb, at the Montréal-Centre board of the Direction de la santépublique (Public Health Board).

Carpal TunnelSyndrome


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DISORDERS





Canadian Cataloguing in Publication Data

Main entry under title:

Guide to the diagnosis of work-related musculoskeletal injuries

Translation of: Guide pour le diagnostic des lésions musculo-squelettiques attribuables au travail répétitif.

Includes bibliographical references.

Contents: 1. Carpal tunnel syndrome – 2. De Quervain’s tenosynovitis – 3. Shouldertendinitis.

Co-published by: Institut de recherche en santé et en sécurité du travail du Québec.

ISBN 2-921146-70-3 (v. 1) – ISBN 2-921146-71-1 (v. 2) – ISBN 2-921146-72-X (v. 3)

1. Musculoskeletal system – Wounds and injuries – Diagnosis. 2. Overuse injuries –Diagnosis. 3. Carpal tunnel syndrome – Diagnosis. 4. Tenosynovitis – Diagnosis. 5. Tendinitis – Diagnosis. 6. Occupational diseases – Diagnosis. I. Patry, Louis. II. IRSST(Quebec). III. Workplace Safety & Insurance Board.

RC925.7.G8413 1998 616.7’075 C98-940950-3

Translation: Les Services Organon, Steven Sacks

Graphic design: Gérard Beaudry

Illustrations: Marjolaine Rondeau, Medical Illustration Departmentof the Laval University Hospital Centre (CHUL)

Max Stiebel, Instructional Communications Centre (ICC),McGill University

Rear-cover photographs: Gil Jacques

Legal deposit – Bibliothèque nationale du Québec, 1998Legal deposit – National Library of Canada, 1998ISBN 2-921146-70-3 Éditions MultiMondes (Original edition: ISBN 2-921146-37-1)© Éditions MultiMondes, 1998

Éditions MultiMondes Institut de recherche en santé 930, rue Pouliot et en sécurité du travailSainte-Foy (Québec) 505, boul. de Maisonneuve OuestCanada G1V 3N9 Montréal (Québec)Tel.: (418) 651-3885 Canada H3A 3C2Fax: (418) 651-6822 Tel.: (514) 288-1551

Fax: (514) 288-7636

Régie régionale de la santéet des services sociaux – Montréal-CentreDirection de la santé publique1301, rue Sherbrooke EstMontréal (Québec)Canada H2L 1M3Tel.: (514) 528-2400Fax: (514) 528-2459


v

PREFACE

The diagnosis of cumulative trauma disorders (CTDs) presents many unique problems,especially for physicians. The absence of precise criteria upon which to establish a clin-ical diagnosis of CTD or decide whether a musculoskeletal injury is related to occu-pational factors was noted by several members of the advisory committee supportingan international expert group mandated by the IRSST to review the literature on CTDs*.To remedy this situation, in 1992 the IRSST asked a group of researchers to developdiagnostic guides for carpal tunnel syndrome, De Quervain’s tenosynovitis, and ten-dinitis of the shoulder.

The project team was initially composed of Louis Patry, occupational medecine phy-sician and ergonomist, and Michel Rossignol, occupational medecine physician and epi-demiologist, but quickly grew and increased the scope of its expertise through the ad-dition of Marie-Jeanne Costa, a nurse with ergonomics training, and Martine Baillargeon,a plastic surgeon. All four team members participated in the drafting of the guides.

These guides were designed to help physicians arrive at a clinical diagnosis andidentify the most probable etiological agents. It should be noted that these guides werenot designed for administrative or legal purposes and that their reliability has not beenevaluated by the researchers.

The publication of these guides designed specifically for physicians is one more ad-vance in the IRSST’s efforts to shed light on the phenomenon of cumulative traumadisorders and provide specialists with appropriate tools with which to prevent theseinjuries and reduce related risk factors.

Jean Yves Savoie

Director General Institut de recherche en santé et en sécurité du travail du Québec

* Hagberg, M., Silverstein, B., Wells, R., Smith, M.J., Hendrick, H.W., Carayon, P., Pérusse, M. (1995), Work related muscu-loskeletal disorders (WMSDs): a reference book for prevention, scientific editors: Kuorinka, I., Forcier, L., publishers Taylorand Francis, London, 421 pages.


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This guide is the first of a series of practical summaries of current medical knowledgeon musculoskeletal injuries with well-documented occupational etiology, namely:

– carpal tunnel syndrome (CTS)– De Quervain’s tenosynovitis– tendinitis of the shoulder

When occupational in origin, these injuries are often referred to as “CTDs”, a termapplicable to “problems and diseases of the musculoskeletal system that include, amongtheir causes, some factor related to work” (Hagberg et al., 1995). Whatever term is usedto designate them—occupational overuse syndrome (OOS), repetitive strain injuries (RSI)or cumulative trauma disorders (CTDs) in English, troubles musculo-squelettiques (TMS),lésions musculo-squelettiques (LMS), lésions musculo-tendineuses (LMS), lésions mus-culo-tendineuses liées aux tâches répétitives, or pathologies d’hyper-sollicitation inFrench—their defining characteristic is the presence of an injury caused by biomechanicalstrain due to tension, pressure, or friction which is excessively forceful, repetitive, orprolonged.

This guide is designed for physicians who are called upon in the course of theirpractice to diagnose musculoskeletal injuries and establish the extent to which theseinjuries are caused by their patient’s work. Its goal is to help physicians arrive at clin-ical and etiological diagnoses. To this end, the guide first reviews the anatomical, physio-pathological, and etiological knowledge upon which diagnosis depends. This is follo-wed by guidelines for the evaluation of symptoms, the conduct of the clinical examination,and the control of potential risk factors related to the development of the injury.

Musculoskeletal injuries may have many causes. For carpal tunnel syndrome (CTS),De Quervain’s tenosynovitis, and tendinitis of the shoulder, these include not only oc-cupational, sports-related, recreational, and household activities, but also specific healthproblems and conditions. This guide was prepared in response to requests from phy-sicians, increasingly preoccupied by CTDs, for information and support on this sub-ject. Although the approach taken emphasizes the documentation of potential occu-pational risk factors—a subject little discussed in formal medical training—it does notneglect the evaluation of other potential causes of carpal tunnel syndrome.

This guide is meant to be used in a clinical setting. To help physicians collect theinformation they need to diagnosis the injury and establish its causes, it therefore in-cludes a series of questions, presented in readily identifiable text boxes, for them toask their patients. These questions were derived from psycho-physical scales used byergonomists to subjectively evaluate workload (Sinclair, 1992) and medical question-naires developed for the diagnosis of CTS and the evaluation of functional capacity(Katz et al., 1994; Levine et al., 1993; Rossignol et al., 1995).

INTRODUCTION


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Should however a physician remain unable to come to a definitive conclusion aboutthe work-relatedness of an injury after consulting this guide, she or he should continueto seek information which will enable her or him to better evaluate the occupationalmusculoskeletal load to which her or his patient is subjected.

Finally, it should be noted that this guide does not address the issues of multipleinjuries and the psychosocial aspects of musculoskeletal injuries, important as they maybe for the global evaluation of the patient.


TABLE OF CONTENTS

Chapter 1 – General Considerations

Terminology................................................................................................................... 1

Epidemiology................................................................................................................. 1

Anatomical Review........................................................................................................ 1

Pathophysiology ............................................................................................................ 3

Chapter 2 – Etiology

Pathologies that Modify the Shape of the Carpal Tunnel or Increase the Volume of its Contents........................................................................ 5

Systemic Pathologies and Specific Conditions ........................................................... 5

Work-Relatedness of Musculoskeletal Strain................................................................ 5

Compression of the Median Nerve in the Carpal Tunnel .................................... 5

Compression of the Thenar Branch of the Median Nerve................................... 7

Chapter 3 – Differential Diagnosis

Disorders of the Central Nervous System.................................................................... 9

Disorders of the Peripheral Nervous System............................................................... 9

Chapter 4 – Clinical Considerations

Symptoms..................................................................................................................... 11

Location of Symptoms (Where?) .......................................................................... 12

Onset of Symptoms (When?) ............................................................................... 12

Characteristics of Onset (How?)........................................................................... 13

Impact on Activities of Daily Living........................................................................... 14

Chapter 5 – Recording of Information on Exposure Factors

Occupational History .................................................................................................. 15

Previous Work....................................................................................................... 15

Current Work......................................................................................................... 16

Current Work and Organisational Factors ........................................................... 16

Sports-related, Recreational, and Household Activities............................................. 18

Chapter 6 – Clinical Examination

Observation and Palpation ......................................................................................... 19

Provocative Tests ......................................................................................................... 20

Evaluation of Sensitivity .............................................................................................. 21

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Strength Testing ........................................................................................................... 22

Electrophysiologic Tests.............................................................................................. 23

Chapter 7 – Summary of the Evaluation ..................................................................... 25

Chapter 8 – Guidelines for Therapeutic and Preventive Interventions

Therapeutic Guidelines ............................................................................................... 27

Prevention Guidelines................................................................................................. 28

Conclusion........................................................................................................................ 29

Bibliography .................................................................................................................... 31

List of Figures

Figure 1.1 Anatomy of the Carpal Tunnel ..................................................................... 2

Figure 1.2 Sensory Nerve Field....................................................................................... 2

Figure 1.3 Distal Branches of the Median Nerve (Sensory and Motor) ....................... 2

Figure 2.1 Compression of the Thenar Branch.............................................................. 7

Figure 3.1 Sites of Compression of the Median Nerve.................................................. 9

Figure 4.1 Hand and Upper Limb Diagram ................................................................. 12

Figure 6.1 Bony Limits of the Carpal Tunnel............................................................... 19

Figure 6.2 Phalen’s Test................................................................................................. 20

Figure 6.3 Tinel’s Test ................................................................................................... 20

Figure 6.4 Two-point Discrimination Test.................................................................... 21

Figure 6.5 Semmes-Weinstein Test ............................................................................... 21

Figure 6.6 Abductor Pollicis Brevis............................................................................... 22

Figure 6.7 Opponens Pollicis........................................................................................ 22

Figure 8.1 Therapeutic Intervention Flow-chart .......................................................... 27

List of Tables

Table 6.1 Clinical Provocation Tests............................................................................ 20

Table 6.2 Tests of Sensory Function ........................................................................... 21

Table 6.3 Electrophysiologic Tests .............................................................................. 23

Table 8.1 Preventive Approach ................................................................................... 28

List of Boxes

Box 1.1 The Three Stages in the Evolution of the Progressive Form of Carpal Tunnel Syndrome .......................................................................... 3

Box 2.1 High-risk Activities, Movements, and Actions.............................................. 6

Box 4.1 Symptoms Reported by the Patient ............................................................ 11

Box 4.2 Presentation and Clinical Severity of Symptoms........................................ 13


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Box 4.3 Questions about Activities of Daily Living ................................................. 14

Box 5.1 Questions about Previous Work ................................................................. 15

Box 5.2 General Questions about Occupational Activities and Associated Symptoms........................................................................... 16

Box 5.3 Questions about Activities that Cause Pain in the Hands or Wrist........... 17

Box 5.4 Questions about Organizational Factors at Work ...................................... 18

Box 5.5 Questions about Sports-related, Recreational, and Household Activities Involving the Hands or Wrist ...................................................... 18

Box 6.1 Appearance of the Arms, and State of the Wrist and Hand Tissues......... 19

Box 7.1 Clinical Aspects ............................................................................................ 25


1

TERMINOLOGY

The signs and symptoms of sensory and motor dis-orders of the hand in the median nerve field werefirst reported by Paget in 1854 in a patient havingsuffered a fracture of the wrist. The following termswere initially used to describe the observed prob-lems: tardive paralysis of the median nerve, partialatrophy of the thenar eminence, and median neu-ritis. However, it was not until the work of Brainet al. in 1947 and of Phalen et al. in 1950 that theterm carpal tunnel syndrome (CTS) was applied tothese disorders.

EPIDEMIOLOGY

In Québec, the surgery rate in the general popu-lation for carpal tunnel syndrome is approximately0.5 per 1 000 men and 1.1 per 1 000 women. Thehighest rate—2.2 per 1 000—is observed among wo-men aged 50 to 59 years. These rates are com-parable to those reported by Vessey et al. (1990)for England (0.5-1.3) and Liss et al. (1992) forOntario (0.5-3.5). The mean age of onset is 51 yearsin the general population, but only 37.4 yearsamong individuals requesting workers’ compensa-tion (Franklin et al., 1991). In 56.8% of cases, conco-mitant diseases or conditions are present (Stevenset al., 1992); the most common are hormonal di-sorders (6.1%), diabetes (6.1%), pregnancy (4.6%)and thyroid disorders (1.4%).

Franklin et al. (1991) reported a CTS incidencerate of 1.74 per 1 000 compensated workers in thestate of Washington. The risk factors most commonlyobserved were repetitive wrist and forearm move-

ments, holding the wrist at an angle (Armstrong et al., 1979), performing forceful movements(Silverstein et al., 1987), and exposure to segmen-tal vibration and cold. Rossignol et al.’s study (1990)of the occupational variation of the incidence of CTSon the island of Montreal reported that almost halfof the cases (45%) of CTS occurring among manualworkers are work-related. In seven occupational cat-egories, this proportion ranged from 63% to 91%.

ANATOMICAL REVIEW

Anatomy of the Carpal Tunnel

The carpal tunnel (Figure 1.1) is bounded posteri-orly and medially by the carpal bones and anteriorlyby the transverse carpal ligament. The median nerveand nine flexor tendons (four flexor digitorum su-perficialis, four flexor digitorum profundus tendons,and the flexor pollicis longus tendon) run throughthe tunnel.

The pressure inside the tunnel varies as a func-tion of the position of the wrist: it is 2.5 mm Hgwhen the wrist is in the neutral position, but risesto 30 mm Hg when it is completely flexed and32 mm Hg when it is completely extended(Gelberman et al., 1981).

General Considerations1


2

Sensory Innervation

The median nerve usually arises principally fromthe C6, C7, C8, and T1 nerve roots. Its sensory fibresinnervate the palmar aspect of the thumb, index fin-ger, middle finger and radial half of the ring finger,and the dorsal aspect of the tip of these fingers(Figure 1.2). The pad of the index and middle fin-gers constitutes its selective sensory nerve field.

The palmar cutaneous branch of the mediannerve innervates part of the palm and the thenareminence of the hand; its innervation field is indi-cated by the shaded area in Figure 1.2. As it sepa-rates from the main body of the nerve 5-7 cm proxi-mal to the anterior annular ligament of the wrist,it is not compressed in cases of carpal tunnel syn-drome, and sensory function in the palm is usuallypreserved in cases of CTS (Tubiana, 1990; Dawsonet al., 1990).

The autonomic nerve fibres of the median nervecontrol perspiration (Spinner, 1989) and innervatethe superficial palmar arch and the digital vesselsof the thumb, index finger, middle finger, and theradial half of the ring finger.

Guide To The Diagnosis Of Work-RelatedMusculoskeletal Disorders

Motor Innervation

The motor branches of the median nerve innervatethree muscles in the thenar eminence (the abduc-tor pollicis brevis, opponens pollicis, and flexor pol-licis brevis) and the lumbricals of the index andmiddle finger (Figure 1.3). Because variant inner-vation patterns are common, the most reliable in-dicator of motor disorders of the median nerve isweakness of the abductor pollicis brevis (Dawsonet al., 1990).

Median nerve

Tendon of the flexor carpi radialis

Transverse carpal ligament of the wrist

Ulnar nerve

Tendons of the flexor digitorummuscles

Figure 1.1

Anatomy of the Carpal Tunnel

Lumbricals

Thenarmuscles

Transverse carpalligament of the wrist

Figure 1.2

Sensory Nerve Field

Figure 1.3

Distal Branches of the Median Nerve(Sensory and Motor)





DISORDERS1Work-related musculoskeletal injuries are one of the most common occupational

health problems for which physicians are consulted. There is solid scientific evidence thatthese injuries may be occupational in origin.

This guide was designed to help physicians interpret the results of a medicalexamination. By combining the standard clinical assessment procedure with guidelinesconcerning the identification of etiological factors, it helps physicians identify the causeof injury.

AUTHORS

Louis Patry holds a degree in medicine from Laval University anda diploma in ergonomics from the Conservatoire National des Artset Metiers de Paris (CNAM). He is a specialist in occupational medi-cine, an associate member of the Royal College of Physicians andSurgeons of Canada, a professor in McGill University’s Departmentof Epidemiology and Biostatistics and Occupational Health, and con-sulting physician to the Direction de la santé publique (Public HealthDepartment), first in Québec City and currently at the Montréal-Centre board.

Michel Rossignol holds degrees in biochemistry and medicinefrom the University of Sherbrooke, in epidemiology and communityhealth from McGill University, and in occupational medicine fromJohn Hopkins University. He is a professor in McGill University’sDepartment of Epidemiology and Biostatistics and OccupationalHealth, co-director of the Centre for Clinical Epidemiology of theJewish General Hospital of Montréal, and physician-epidemiologistat the Montréal-Centre board of the Direction de la santé publique(Public Health Department).

Marie-Jeanne Costa holds a nursing degree from the Institutd’études paramédicales de Liège and a degree in ergonomics fromthe École Pratique des Hautes Études de Paris. She is an ergonomicsconsultant and has collaborated on several studies of CTDs. She isparticularly interested in the development of participatory ergonom-ics, specifically in the problem-resolution and diagnostic processes.

Martine Baillargeon holds a degree in medicine from theUniversité de Montréal. She is a plastic surgeon and associate mem-ber of the Royal College of Physicians and Surgeons of Canada.After years of practising surgery she is now consulting physician,mainly in the field of musculoskeletal injuries affecting the upperlimb, at the Montréal-Centre board of the Direction de la santépublique (Public Health Board).



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