THE
CLINICAL
EXTENSOR A.
JAMES
DIGITORUM
Ross
and
From
Although (Albinus Glasgow
an
1734; 1967)
reference
it
to
most
works,
recorded further
two
anomalous
Wood it has
the
Easteriz
short
TROY,
Geizeral
extensor
THE MANUS
BREVIS
A.
CHESTER
OF
EDINBURGH,
Hospital,
of the
SCOTLAND
Edinburgh
fingers
has
been
1864; Quain 1892; Smith 1897; Cauldwell, only rarely been found in the living subject.
in his study and Kaplan cases
case. In recent
SIGNIFICANCE
of an
years
of the anatomy of the hand. The (1953) noted that it is encountered atavistic
extensor
its presence
brevis
in living
in 1942,
subjects
has
but
been
described
by anatomists
Anson and Wright 1943; Jones (1941) made no
muscle only by
is not mentioned in very rarely. Bunnell
1956
reported,
had
found
although
only
it has
one nearly
always been diagnosed incorrectly as a ganglion or synovial cyst (Jones 1959; Dunn and Evarts 1963; Gagnon and Lavigne 1964; Egawa and Hashimoto 1966; Fortier, Anastasiadis, Martineau and Gagnon 1966; Peeling 1966; Souter 1966). On one occasion a pre-operative diagnosis
to
of
have
patient
rheumatoid
tenovaginitis
the
recognised
to operation. Some authors
comprehensive
have
fifteenth
clinical
made anomaly
reports
present
of earlier
authors
of a smaller
have
tenosynovitis wrist in plaster; all of which
the
relief,
swelling locking
occasional
army
on the dorsum This was treated
complained
hydrocortisone,
recently
previous cases have been to determine management.
right-handed
painful lump appearing his wrist in a door.
of
cases,
have
CASE
A twenty-year-old
extensor the right
(Bingold 1964). Sauser (1935) in a living subject without but
there
appears
encountered
alone appears submitting his to have
what
seems
been
no
to be the
case.
The features of the clinical features and
the
of the
mentioned The
review.
was
presence
and
“
“
similar
lump
summarised
(Table
I) in an effort
to define
REPORT
motor
mechanic
complained
in February
1967
of a
of his right hand after an accident in which he jammed with wax baths without relief. Several weeks later he on
the
dorsum
and was given further a course of penicillin; failed to give permanent
thought
to
treatment which included immobilisation phenylbutazone and local injections relief. Although there were periods
of the
of of
cramp were made worse by of the index and middle fingers
left
heavy work. of the right
hand.
He hand,
He
was
also with
complained the impression
of
that
this was caused by the presence of the swelling. In March 1968, in view of the continued disability and lack of response to treatment, he was referred to hospital. Examination showed an ill-defined swelling on the dorsum of the right
hand,
approximately 4 centimetres long, l5 centimetres wide and 03 centimetre high, the extensor tendons of the index and middle fingers. It was firm, not fluctuant or tender, and was made more prominent by forced extension of the fingers against resistance. There was a similar but less prominent swelling on the dorsum of the left hand in a position situated
between
to the right. The swelling was thought to be an unusual ganglion of the wrist or of the extensor tendons. Findings at operation and progress-In March 1968 the dorsum of the right hand was explored. similar
There
was
extensor
no ganglion,
tendons
and
the
VOL.
51 B,
of
incision NO.
was
3,
AUGUST
but the
index
the and
swelling middle
was fingers.
found
to
No
be an attempt
anomalous was
made
muscle to
excise
between
the
the muscle,
closed. 1969
473
474
J. A.
ROSS
AND
TABLE REPORTED
Case number
Author
McGregor (1926)
2
Sauser
Bunnell
3, 4, 5
I DIGITORUM
BREvIS
MANUS
Male
Unknown
Nil. Discovered at operation for cut tendons on dorsum of hand
Male
Unknown
None
Unknown
Unknown
Unknown
20
Male
Naval cook
years: swelling and diffuse pain in left hand after heavy use
25
(1956)
TROY
Occupation
Unknown
(1935)
OF EXTENSOR
A.
Sex
Age
1
CASES
C.
Unknown
Symptoms
Side
Handswith
affected
symptoms
Unknown
Unknown
Left
-
Unknown
Unknown
(3 cases)
6
Jones
7
Dunn and Evarts(1963)
25
Male
Naval seaman
Bingold (1964)
19
Male
Sprayer
8
(1959)
4years:swelling,discomfort with heavy use such strong gripping
days: right 4-6
Gagnon 9
and
Lavigne
21
Male
Unknown
(first
16
Male
Mechanic
(1966)
Martineau Gagnon
and (1966)
(second
case)
Egawa
12
: I
Male
Labourer
(1966)
41
Female
Unknown
on wrist
Souter (1966)
after
38
Male
Mechanic
pain
29
Male
Unknown
on
.
Left
Left
Both
sides
20
Male
Army mechanic
I
following
heavy
Right
Right
Right
Right
Right
Right
Right
Right
r
use
on dorsum
More
gripping
recently: and
of wrist
with
rest
intermittent
swelling and cramp in right wrist with heavy work. “Locking” of index and middle fingers
THE
Both
after
7 weeks: swelling and discomfort of dorsum of wrist and hand but temporary
13 months: 15
Right
of
at work
: swelling
of hand.
relief Ross and Troy (1969)
in
Onset uncertain : swelling hand with ononlydorsum slight ofdiscomfort
extension
14
sides
work
accident
(1966)
Peeling
increase
painful
Swelling
5 weeks
13
Both
Right
.I
and
Hashimoto
of
impairment movement
manual
23
Left
Right
Since childhood; oval swelling on dorsum of each hand. In recent months:
case)
sides
painful swelling of wrist with
swellings
Fortier, Anastasiadis, I 1
as
over back and wrist
progressive
size and wrist
Fortier, Anastasiadis. Martineau and
Gagnon
years:
of dorsum
(1964)
10
pain hand
Both
JOURNAL
OF
Both
BONE
sides
AND
JOINT
Right
SURGERY
I
TIlE
CLINICAL
SIGNIFICANCE
OF
THE
TABLE REPORTED
Dominant
Clinical
hand
Unknown
CASES
EXTENSOR
Clinical diagnosis
DIGITORUM
not very
muscular.
anomalus brevis”
Unknown
Unknown
Unknown
Elongated swelling on dorsum. Bilateral, soft,
Elongated Unknown
soft,
Unknown
Firm cystic mass between index and middle finger extensor tendons more prominent when wrist extended
Unknown
Soft well-defined swelling on ulnar side of second metacarpal (bilateral)
Swelling
Ganglion
on right
Rheumatoid tenovaginitis
“
“
wrist
Soft oval swelling on dorsum ofhand from carpus along extensor tendon to index finger. No tenderness
Unknown
Fusiform swelling between middle and index extensor tendons,
.
Right
which
Unknown
Unknown
Nil
-
Unknown
Unknown
Division
of extensor
retinaculum
(left)
improvement
but still ached after heavy use of hand
non-tender
Soft elongated swelling attached to extensor indicis tendon (bilateral)
Unknown
of treatment
Result
on left
mass over dorsum of second metacarpal from carpus to midshaft
Right
treatment
Considerable Ganglion
slightly
tender
MANUS
Extensor
.
Swelling visible with contraction, but disappeared with relaxation,
semi-fluctuant
475
MANUS
Unknown
Right
Unknown
BREVIS
Operative
Supernumerary tendons found at operation Hand
BREVIS
I--co,ziiizued
OF EXTENSOR
examination
DIGITORUM
moved
with
Synovial cyst “ of wrist
Synovial cyst “ of tendon
Division of extensor retinaculum
Freedom from all symptoms
Exploration of right hand. Removal of associated ganglion only 2) Muscle excision (right)
Muscle
Bilateral
1) Pain 2) Relief
excision
muscle
continued of pain
Unknown
excision
Traumatic ‘ synovial cyst “
1) Aponeurosis widely split but muscle left i,z situ 2) Muscle excision
Ganglion
Exploration. ? nothing else done
Recovery
uneventful
1) Temporary improvement but tion returned after four formonths opera2) Completely free of symptoms Unknown
Ganglion
Exploration
only
Free of symptoms three weeks later
Ganglion
Exploration
only
Free
them
Swelling deep to radial edge of long wrist extensors I
of symptoms
I
.
.
Right
Ill-defined swelling between index and middle extensor tendons, right larger
VOL.
51 B,
NO.
3,
AUGUST
than
left
1969
I
I
Ganglion
1) Exploration 2) Muscle
only (right)
excision
(right)
1) Symptoms 2) Free
unrelieved
of symptoms
476
J.
The left
wound
healed
hand more hypertrophy.
work
In June swelling
1968
ached
with
the
The
extreme
heavy
except
still
C.
A.
TROY
complained
of the
of
the
on
to hospital
work and that the addition
for
AND
swelling
flexion
manual
unchanged
ROSS
patient
normal.
he was readmitted
prevented
were
but
than
A.
because
right
became
of
index
After
pain.
hand
middle
he used
presumably
disability.
persisting
and
operation
bigger,
He said that
fingers,
the” locking” sensation persisted. of a healed operation incision over
his
due
the
to
that
hand
The clinical the swelling
the still
findings (Fig. 1).
HG
Figure 1-Patient’s at operation. The
Findings was
to
digitorum into the
have
a single
extensor
by the
extensor which
expansion indicis blended
proximal
part
the
posterior
interosseous
The
muscle
point
The seen
incision
musculo-tendinous
it was necessary into two bellies.
the
its
1968 the previous
healed operation scar. Figure 2-View of insertion of the extensor digitorurn
was excised
origin
from
in
of
of the was
2).
The
belly
to the
was
radial
tendon but also visible on either with the ulnar edge of the extensor muscle
and
extended.
on its dorsal
aspect,
The
of the
dorsum
muscle
capitate
bone.
retinaculum. side of the
The extensor
inserted joint
by a long, fine, flat tendon of the middle finger, deep
side
also
was
fleshy,
partly
covered
side of it, and was continued by a fine indicis tendon. A thin nerve entered
and
appeared
to be a terminal
branch
of
being
cut
nerve.
excised
fusion
wound
July
(Fig.
the
to divide the distal part of the extensor The larger ulnar belly lay to the radial
communis tendon for the middle finger and dorsum of the capsule of the metacarpo-phalangeal
to the tendon
hand showing swelling with passes beneath the tendons brevis manus.
June
at operation-In
found
To define this muscle divided
at
right probe
with
healed
1968 he had
by division
of its three
the extensor and the patient
returned
to
indicis
work
attachments,
the
radial
insertion
tendon.
got
complete
and
had
relief
from
his
symptoms.
almost
a full range
patient
is usually
described
extensor
anomalus”
When
of movement
last
of the finger.
DISCUSSION
The digitorum and
“le
anotiialous
brevis muscle
muscle
manus. manieux”
encountered
It has
also
(Gagnon
in
been and
this
called Lavigne
the
“m.
as the (Sauser
extensor 1935)
1964). TIlL
JOURNAL
OF
BONE
AND
JOINT
SURGERY
THE
The structure, migration
found normally of ulno-carpal metacarpal
intrinsic, delamination
OF THE
extensor.
present
The evolutionary morphological patterns
EXTENSOR
significance 1956) and
Glasgow
(1967)
group, this.
and
instability of this deeper which have been described.
the index According
finger, the name extensor indicis brevis to Dunn and Evarts (1963) a fasciculus frequency
in cadavers
In view
been found (McGregor
has
of this
in a careful 1926, Bunnell
Most symptomless Hashimoto years
finger nearly is the most
been
“
for
reported
that the
hands,
and
of presentation. of only seven
three
of these
are
been considered that this atavistic
doubt to the
were
only
muscle
as from fourteen
represents interosseous
explains the variety of index finger are the most be as many variation,
as four separate a single slip to
(Cauldwell not been
1 to 9 per previous
and
they
were
et a!. 1943). reported. cent
clinical
(Dunn
and
cases
have
McGregor (1926) found a was Japanese (Egawa and eight were less than thirty
all manual
as a result of work In four of the patients
known
the
Of these, four are described very briefly condition must often remain symptomless.
known,
discomfort hand.
the right side. symptoms are produced
symptoms
477
MANUS
posterior
has been applied the thumb has
variously that
of the literature. Obviously the
be expected if the muscle causes produced usually in the dominant both
no Slips
view from
of the subjects reviewed were of European origin, but example in a Bantu, and the only female in the series 1966); of the ten male subjects whose age is stated,
old at the time The occupations
BREVIS
has already suggested
as frequent. There may usual. In the commonest
it is surprising
search 1956).
the
layer
“
1963).
entity (1966)
innervation
and to the middle but a solitary one
The
ofthis Souter
favoured
the
common, fasciculi,
Evarts
DIGITORUM
in amphibia, may represent in the human a failure of proximal elements of the antebrachial muscle mass. It may also be an atavistic,
the extensor case supports
of
in the
nerve
SIGNIFICANCE
morphological and phylogenetic by other authors. Bunnell (1942,
in detail
a
CLINICAL
to be right-handed.
workers.
hypertrophy, the muscle All these
As would
symptoms was present
three
presented
and
swelling
are in with
on
When dorsum
of the hand
with
heavy
they
manual
Examination reveals an elongated hand, usually between the middle and but moves with the digital extensor
are
work.
remarkably Sometimes
consistent they
: pain
are noticed
swelling in the proximal index finger extensor tendons. tendons and is made more
only
after
of the
minor
injury.
part of the dorsum of the The swelling is ill-defined prominent by active finger
extension against resistance. It is usually thought to be a ganglion or a pathological thickening of an extensor tendon. The measures employed in treatment have been: 1) None, when the nature ofthe swelling was recognised but there were no symptoms. 2) Exploration only. Of five such operations the result of one is unknown. Of the remaining four, two relieved the symptoms, but two were and
unsuccessful
further
whose firm distal use of the hand. used
in three
atavistic
cases
muscle,
retinaculum. three, which
edge This
operation
was
necessary.
3) Division
of the
extensor
may impinge on the contracting muscle belly and is more likely when there is muscle hypertrophy.
but
in only
complete
one
exposure
was of
it completely which
may
This was done in four cases, but in one were all done because symptoms continued
of symptoms was obtained. appears that if the symptoms warrant operation of the whole muscle. If the possibility of the existence diagnosis is not difficult and operation may be
successful. require the
partial
result is not after inadequate
retinaculum,
thus cause pain This technique
4) Total
ablation
division
of
the
with was of the
extensor
reported. In the other operation, complete
relief
It
the best procedure is probably ablation of such an anomalous muscle is realised, unnecessary. This knowledge may be of
importance.
SUMMARY
1.
A case
of the VOL.
literature
51 B, F
of bilateral
NO.
has 3,
AUGUST
extensordigitorum revealed 1969
fourteen
brevismanuscausingsymptomsisdescribed. previous
cases
in which
the
A review anomaly
was
recognised.
478
2. 3.
J. A. ROSS
The phylogenetic Observations are
young
male
after
heavy
manual
worker
work.
There
who
significance features
complains
is a visible
C. A. TROY
of this atavistic of the condition.
of pain
swelling
with
and the
swelling
physical
structure It usually
on
the
is considered. presents in a
dorsum
characteristics
of the
hand
of a small
fleshy
operation
total
muscle.
extensor
4. Various methods ablation of the muscle We
and morphological made on the clinical
AND
wish
to express
our
of treatment is suggested. thanks
to
Mr
are
discussed.
F. Robbie.
If the
Superintendent
symptoms
Radiographer,
warrant
for
the
photographs.
REFERENCES ALBINUS BINGOLD,
(1734): Annotationes A. C. (1964): An
BUNNELL,
S. (1942):
Surgery
Academicarum. Extensor
Indicis
of
Intrinsic
the
Vol. Brevis. Muscles
IV, Ch. British of the
VI,
Journal Hand
p. 28.
Cited
ofSurgery, other
than
by Peeling, 51, 236. those
W.
Producing
B. (1966). Opposition
of
the Thumb. Journal ofBone andJoint Surgery, 24, 1. BUNNELL, S. (1956): Surgery ofthe Hand. Third edition, p. 4. London: Pitman Medical Publishing Co. Ltd. CAULDWELL, E. W., ANSON, B. J., and WRIGHT, R. R. (1943): The Extensor Indicis Proprius Muscle. A Study of 263 Consecutive Specimens. Quarterly Bulletin of Northwestern University Medical School, 17, 267. DUNN. A. W.. and EVARTS, C. M. (1963): The Extensor Digitorum Brevis Manus Muscle. Clinical Orthopaedics and Related Research, 28, 210. EGAWA, T., and HASHIMOTO, K. (1966): An Anomalous Extensor Indicis Muscle-a Case Report. Bulletin of the Hospitalfor Joint Diseases, 27, 116. FORTIER, M., ANASTASIADIS, C., MARTINEAU, G., and GAGNON, P..A. (1966): Nouvelles observations de muscles manieux. Rappel ontog#{233}nique. anatomique et clinique. L’Union M#{233}dicale du Canada, 95, 198. GAGNON, P.-A.. and LAVIGNE, P. (1964): Le muscle manieux. L’Union M#{233}dicale du Canada, 93, 1556. GLASGOW, E. F. (1967): Bilateral Extensor Digitorum Brevis Manus. MedicalJournal ofAustralia, 2, 24. JONES, B. V. (1959): An Anomalous Extensor Indicis Muscle. Journal ofBone andJoint Surgery, 41-B, 763. JONES, F. W. (1941): The Principles ofAnatomy as Seen in the Hand. Second edition, p. 250. London: Bailli#{234}re, Tindall
and
Cox.
E. B. (1953): Functional and Surgical Anatomy ofthe Hatid, p. 68. Philadelphia: J. B. Lippincott. MCGREGOR, A. L. (1926): A Contribution to the Morphology of the Thumb. Journal ofAnatomy, 60, 259. PEELING, W. B. (1966): Short Extensor Muscles of the Hand. British Journal of Surgery, 53, 359. QUAJN, J. (1892): Elements of Anatomy (edited by E. A. Schafer and G. D. Thane). Tenth edition, Vol. II, Pt. II, p. 234. London: Longmans, Green & Co. SAUSER, G. (1935): Beobachtung zweier Muskelvariet#{228}ten an Lebenden. Wiener Klinische Wochenschr,ft, 48,430. SMITH, E. B. (1897): Some Points in the Anatomy of the Dorsum of the Hand, with Special Reference to the Morphology of the Extensor Brevis Digitorum Manus. Journal of Aizatomy and Physiology, 31, 45. SOUTER, W. A. (1966): The Extensor Digitorum Brevis Manus. British Journal of Surgery, 53, 821. WooD, J. (1864): On Some Varieties in Human Myology. Proceedings of the Royal Society of London, 13, 299. KAPLAN,
THE
JOURNAL
OF
BONE
AND
JOINT
SURGERY
