One of the early works dedicated to the experimental study of the
function of the ligamentum capitis femoris (LCF). The author was the first to
propose an original method to visualize the movements of LCF in articulations
without hip dislocation. The article was published in the «Edinburgh Medical
Journal» and also in a separate monograph titled «Anatomical and Physiological
Observations».
XVIII. Demonstration of the use
of the round ligament of the hip joint.
[Communicated to the
British Association, September
1855; to the
Edinburgh Medico-Chirurgical
Society, February 1857 ; and
Reprinted from the
Edinburgh Medical Journal, November
1858.]
Previous writers have
erred regarding the
use of this
important ligament, from
not employing a right
method. By removing
more or less
of the capsular
ligament, they destroyed
a structure which naturally
prevents several motions
from going so far as
to put the round ligament
on the stretch.
They have therefore
attributed to it
uses which it
has not ; while, from
not seeing it
in its natural position,
they have unavoidably
failed to recognize
its true use.
If we sit
down to examine
it in a preparation
in which the
capsular ligament has been
completely divided, the
matter becomes extremely
puzzling, and we
hardly wonder at
the conclusion of our
own
time-honoured Dr Barclay,
that the use
of the round
ligament seemed “ the
restoring the head
of the bone
to a right direction, when
it had partially
quitted, or was
disposed to quit,
the cavity of the acetabulum,
and the maintaining
it in that
direction, so as to replace
the head of
the femur readily
in its socket,
under a variety of
circumstances.” On further
examination, we might
agree with Mr
Mayo, that it
checks rotation inwards
; next with Dr
Knox, that it
checks all the
rotatory movements, simple
or combined. Then, on considering
the anatomy of the ligament,
and G. and
E. Weber’s remarks
and drawing, we
might be persuaded
that these anatomists had
finally proved the
correctness of the
view of various
previous writers, that
this ligament checks
adduction. The more
so, as the Webers’ plausible
theory is, that
by checking adduction,
the ligament serves, when
we stand on
one leg, to
balance or keep
up the trunk,
preventing it from
falling over to
the unsupported side.
But, when we
consider that the
trunk can be
bent over laterally
to a considerable extent,
by a movement of
adduction, and reflect
that this is naturally
prevented by the
abductor muscles, we
shall finally be inclined to
agree with Dr
Knox’s more recent
opinion, expressed in his Manual of Anatomy, that “
the functions of
the round ligament have
not been satisfactorily determined.”
It occurred to
me to expose
the ligament from
behind, by removing the
floor of the acetabulum, while
the capsular ligament was
left entire. The
round ligament could
now be seen
in its natural
position ; and, by putting
the joint through
its various motions,
the condition of
the ligament in
each became a matter
of simple demonstration. I found that
it is not
tight either in
adduction, or in
rotation, inwards or
outwards, all of
which are checked
by parts of
the capsular ligament ; and, that
it is rendered
tight in one position
only,
viz., when rotation
outwards is combined
with flexion.
I now proceed to
show, more particularly,
that the use
of the round
ligament is to
check this combined
movement.
How to expose
the ligament, — With a gouge
and mallet remove the
bone from the
greater part of
the space between
the obturator foramen
and the great
sciatic notch, as
seen in fig.
8. The cut should reach
upwards, so as to encroach
upon the horizontal
ramus of the
pubes, and beyond
the ilio-pectineal line ; approaching as
near as to
about a quarter of
an inch from
the obturator foramen,
where care should
be taken to
avoid injuring the
origins of the
round ligament, which lie
opposite rather more
than the upper
or anterior half
of the obturator
foramen. The opening
should become smaller and
rounder as it
approaches the acetabulum.
The bone is
very thin opposite
the ligament, but so thick
behind and above,
that a sloping
cut is required.
The fatty tissue
and synovial membrane, forming
the Haversian cushion,
being picked away,
the round ligament will
be exposed down
to near its
origin. Any loose
synovial or fatty
tissue on its
surface may be
removed, so as
to expose the fibres of
the ligament proper.
It is now
evident that the
ordinary direction of
the ligament is vertical
; I mean, when the
limb is straight,
as in standing
erect, or as
the body lies
on the table.
Also, that the
ligament, in the
greater part of
its length, is
of a rounded form,
soft or pulpy,
and more or less twisted,
except in that
position which tightens
it, when it assumes the form of a
straight-fibred thick belt.
The depression on
the head of
the femur is
not simply a pit
for the insertion
of the ligament.
Draw two lines
across the middle of
the head, as
in fig. 2,
and it will
be seen that
the pit is
situated in the
lower and posterior
quarter, but only a
little behind and below the
centre. The form
and direction of
the pit may
be now observed ; that it
is elongated, or
ovoid, and that
the long axis
is directed horizontally
backwards, or backwards
and a little downwards. Amid some
varieties as to
size and depth,
the above will be recognized
as the typical
form, if a series
of thigh bones
be examined, especially
before the cartilage
is removed or
dried, the pit
being usually larger
in the natural
state than in
the macerated bone.
Also, that its
posterior termination becomes
shallower and rounded
off at the
edges. The ligament
is not attached
across the breadth
of the pit,
but only to
its anterior end,
the posterior part being a groove,
now seemingly directed
away backwards from
the ligament, but
intended to lodge
it during its
action. The anterior part
we may distinguish
as the pit,
the posterior as
the groove.
The cushioned recess
in the floor
of the acetabulum,
varies a good deal
in form, size,
and direction. Although
it sometimes has a rounded
figure, the examination
of a series of
specimens will show that it
is generally somewhat
square shaped; and,
when the pelvis is
placed with its
natural obliquity, is
usually directed upwards, and,
taking it as a
whole, a little backwards.
This might seem
to indicate, that
the round ligament
naturally lies upwards
and backwards ; but, if
carefully examined, it
will be seen,
that the anterior superior
angle of the
recess is the
highest part, sometimes
considerably prolonged, and that
this part is
vertically above the
notch, or even a
little forward from
its middle. This
high part evidently corresponds
to the high
position of the
ligament, as in
figs. 6 and 8. The posterior
superior corner of the fovea
would seem to
correspond to the
position of the
ligament in rotation
inwards, as in
fig. 3 ; and the
anterior inferior angle,
or near it,
to its position
in rotation outwards,
as in fig.
4. Not unfrequently
the recess presents
a decided notch,
or angle, just
at the latter
part. The recess averages an
inch to an
inch and a quarter,
and the height
generally exceeds the
breadth. From a preparation
before me, it
is evident that
the recess goes a
little higher up
than the ligament
can be carried,
as in fig. 7.
It is probably
more extensive in
other directions as
well, and the
want of these
extreme parts may
account for the
occasional varieties of
form. Whatever the
variety may be,
the typical form is, that
it broadens above
the notch, and
tends to throw
out three angles,
forwards, backwards, and
upwards, of which
the latter is the most
prolonged and most
distant from the
notch, or origin
of the ligament.
The demonstration may
be most conveniently
made, and preserved, on
a ligamentous preparation of
the half pelvis
and upper third
of the thigh
bone, — the capsular ligament
being dissected, but entire. To
prevent mistake, the
pelvis should be
held as in
the subject lying on
the table, and
the exact position
and motion of the
thigh
bone carefully noticed,
especially that it
is not rotated
or flexed unintentionally. I have
confirmed the results
thus obtained, by
exposing the ligament
in a subject, and
putting the entire
undissected limb through its
motions. The removal
of the obturator internus
might have proved some
little source of
fallacy, by allowing rotation inwards
to go too
far, were it
not that the
round ligament is not
rendered tense in
that motion. The
conclusions to be stated are
the result of
experiment with the
undissected limb, as well
as
with the ligamentous
preparation ; while those regarding
the checking structures are
from observations on the ligamentous
preparation. It is
just possible that
these checking structures
may be assisted
passively by some of
the removed muscles.
The joint is,
of course, naturally
steadied by the
opposing groups of
muscles, the force being thrown
on the ligaments
only when the
motion has reached its
extreme.
It is necessary
to premise, that
there are three
special bands, or thickened parts,
with peculiar direction
of fibres, incorporated
in the capsular
ligament. 1. The
Ilio-femoral band, proceeding
from below the
base of the
anterior inferior iliac
spine, broadening out
into a triangular
shape as it
descends to be
attached to nearly
the whole length
of the anterior
inter-trochanteric line. Well
described by the
Webers as of
greater thickness than
the tendo Achillis,
or the ligamentum
patellae, as indeed,
next to the
concealed sacro-iliac, the strongest ligament
in the body,
and, of course,
of corresponding importance.
2. The Pubo-femoral
hand, from the
horizontal ramus of
the pubes, above
or in front
of the cotyloid
notch, downwards and outwards to
the lower roughened
part of the
inter-trochanteric line, about
half an inch
in front of
the trochanter minor.
3. The Ischio-femoral band, a strong
flattened band, proceeding
from the acetabular margin, just
behind the cotyloid
notch, winding upwards
and forwards across
the back of the neck
of the femur,
and inserted into the great
trochanter at the
upper end of
the anterior inter-trochanteric line,
just where the
upper or outer
part of the
ilio-femoral band is attached. The
higher fibres of the ischio-femoral band
join, or descend
from, the ilio-femoral
band, but are
not specially concerned, as
the rest of
the band is,
in checking rotation
inwards.
It will be
granted that a ligament
is not in
use until it is tight ; that,
if a motion be
checked, no matter
by what, before
the round ligament
is tight, that
this ligament has
nothing to do
with checking it ; that, if a
motion goes so far as
to tighten the
round ligament, it is a
function of the
ligament to check,
or assist in
checking, that motion ; and,
finally, if the
ligament can be
made tense in one movement,
and in that
only, that this
is conclusive demonstration of its use. I may
add, that the
condition of the
ligament in several
movements, might lead
the careless observer
to conclude that
it is tight,
when it is
merely extended, or
nearly so, but
not tight. Let
the experimenter begin at
once, by rotating
outwards in the
flexed position, and
he will understand
what tight really
is. In order
to judge of
the degree of
looseness in different
positions, pass a loop
of string round
the ligament, and
try whether it
can be pulled into
an angle off
the head of
the bone, and
feel with the
finger whether it
is pulpy and
round, or flat
and firm.
Condition in the
various movements. — Care must
be taken that the movements be
not confused, especially
that the limb
be not rotated
unintentionally in either
direction. Each movement
is understood to
be carried to the extreme,
and to commence
from the state
of extension.
1. Extension, or
the ordinary position
in standing, and as the subject lies
on the table ; the
limb straight, and
the toes a very little
everted. Ligament directed
vertically upwards, and
loose. Groove directed
downwards and backwards
from it.
2. Flexion. — Carries groove
forwards ; and ligament backwards and
downwards, and renders
it more loose.
3. Abduction. — Brings down
upper attachment of
ligament towards lower, and
makes it entirely
loose. Is checked
especially by pubo-femoral
band.
4. Adduction. See
fig. 5. — Ligament is
carried a little up,
but IS not
made tense; is
round, twisted, and
pulpy, and may
be pulled by
the string away
from the ball
into an angle.
Groove is directed downwards
and backwards from
the ligament. Extreme
attempt at adduction
is checked by
some strongly resisting
structure, but no strain upon
the round ligament.
In the ligamentous
preparation this checking
structure is seen
to be the ilio-femoral band,
especially its lower and
thickest part. In
moderate flexion, adduction
is checked rather
by the u])per
or outer part
of the ilio-femoral
band. In extreme
flexion, adduction is
checked by the
cervix coming against
the pubic part
of the acetabular
edge.
That adduction is
more extensive in
the flexed than
in the extended position, is
well known ; but
that the limits
of the latter
have been greatly
misunderstood by the
Webers, is evident
from their argument,
that although we
can make the
knees touch, we
cannot press them
together without some
degree of flexion
of the hip. This we
cannot do for
the same reason
that bandy-legged persons cannot
even bring the
knees together. The
resistance in either case
is at the
malleoli. But if
one limb be
removed out of
the way, the
body being supported
and prevented from
moving, the other limb can
then be adducted
considerably. This is
better tried on the dead
than on the
living subject ; but, that
extended adduction is not so
early checked, or
early enough to
support the body
on one leg,
as the Webers
suppose, is readily
enough shown in the living body
by standing on
one leg, and
then bending the
body over to the opposite
side. If the
round ligament, or
any other ligament
of the hip,
were of use
in naturally balancing
the body on one leg,
it ought to
prevent the above
mentioned extent of
adduction. It is, of course,
the abductor muscles
which keep up
the body when
the opposite leg
is lifted. These
reasons were enough
to upset the Webers’ view,
however plausible it may at
first seem in
theory, as seen
in fig. 7 ; but
the demonstration settles
the matter, by showing
that
the ligament is
not tight in
extreme adduction.
5. Rotation Inwards. — See fig.
3. — Ligament carried backwards ; is
nearer tight than
in adduction, but
is pulpy, twisted,
and round ; bears
no strain, and
is not the
checking structure. Groove
quite away back
from ligament. Is
checked, in the
extended position, by the ilio-femoral
band ; in the flexed
position, by the
ischio-femoral band.
6. Rotation Outwards. — See fig.
4. — Ligament carried forwards towards
pubic part of
brim of acetabulum.
Is much in
same condition as to
tightness, feel, and
form, as in
rotation inwards ; but now
lies in groove,
or a little forwards
from its lower
end, which is directed obliquely
backwards and downwards.
Rotation outwards is
checked by the
whole front of
the capsular ligament,
the ilio-femoral band
especially resisting. The
ball is pressing
forwards against the
upper part of
the front of
the capsule.
7. Adduction with
Rotation Inwards. — Ligament is
somewhat tight, but
upper part of
it is soft
and round ; not
bearing much, if any
, strain.
8. Adduction with Rotation Outwards. — Ligament much as in the last — that is, in either of the two rotations, combined with adduction, the ligament is somewhat tighter than in either rotation simply, but yet without strain, soft and round.
9. Flexion with Adduction. — Ligament not quite
tight. Groove away
downwards and backwards
from ligament. In
extreme flexion and
adduction the ligament
is loose.
10. Rotation Inwards with Flexion. — Ligament looser than in simple rotation inwards.
11. Rotation Outwards
with Flexion. — See figs.
6 and 8. — Ligament directed upwards,
and more or
less forwards, according
to the less
or greater extent
of flexion. Ligament
flat, straight-fibred, and occupies groove ; completely tense,
and evidently a checking
structure. The effect of
flexion is to
make rotation outwards,
carry the ligament
upwards, instead of
forwards, as in simple
rotation outwards.
In this position
the limb may
now be abducted
and adducted ; the round
ligament still remaining
on the stretch,
as the effect
of these motions,
in this position
of the head
of the femur,
is merely to
carry the pit
forwards and backwards,
the upward strain,
given by rotation outwards
with flexion, still
remaining on the
ligament.
The reason why
the flexed position
enables rotation outwards
to put the round ligament
on the stretch
is evident on
the ligamentous preparation.
Flexion so relaxes
the front of
the capsular ligament that
the latter now
allows rotation outwards
to go much
farther ; the round
ligament then comes
into play, and
is assisted by the
upper or outer
part of the
ilio-femoral band, which,
though at first
relaxed by flexion,
is made tense
again by the
rotation now going
farther.
That the round
ligament is not
by any means
the only check
at this stage
of the movement
might be inferred
from its size,
compared with the
force it would
have to resist,
and is shown
by the fact
that, if the
limb is held
so as to
make the round
ligament tense, and the
ligament
be then divided,
there is no
jerk or yielding.
The other checking
structure is, as
above remarked, the
ilio-femoral band. Of course, if
two ligaments are to be
of use naturally
in checking a motion, they
must become tense
at the same
time ; and the division of
one will not
allow of yielding
unless under a force
sufficient to rupture
the other.
Next to the
position in which
it is truly
tight, the round
ligament approaches the
tight, or extended,
condition in the
following: — 1.
Adduction with flexion.
2. Adduction with
rotation inwards. 3.
Adduction with rotation
outwards ; but in none
of these positions does
it bear the
strain.
Fig. 1. Typical form, size, and direction of cushioned recess in acetabulum.
Fig. 2. Situation,
form, and direction
of the pit
and groove on the head
of the femur.
Figs. 3 to 6 show
the direction and
condition of the
round ligament, and
its relation to
the groove in
different movements. The
pit is larger
than the average,
but not larger
than in the
specimen from which
the diagrams were made.
Fig. 3. As
in rotation inwards.
4. Rotation outwards.
5. Adduction.
6. Rotation outwards
with flexion. The
ligament tense, as
in fig. 8.
Fig. 7. Diagram
showing the vertical
position of the
ligament, and how, theoretically, it
might be expected
to check adduction.
But fig. 6 shows its condition in
extreme adduction.
Fig. 8. The
round ligament is
seen, exposed from
behind, by removing
the floor of
the acetabulum. The
femur is flexed
and rotated outwards,
carrying the ligament
upwards, until it
becomes tense, and
checks the movement.
That the use of the
round ligament is
to prevent or
assist in preventing
dislocation in the
forward and outward
direction, as determined by
rotation outwards in
the flexed position,
is therefore a matter of
fact whether or not we understand why
this movement in particular should
require such a provision
to check it.
But it does not seem
difficult to explain
the why.
A glance at the
skeleton will show
that the acetabulum
and femur are
so directed, that
the head of
the latter has a
natural tendency to
be dislocated forwards
by the outward
rolling of the
limb, as in standing or
walking with the
toes, as they
usually are, more
or less everted.
Indeed, unless in
the rotated inward
position, part of the
ball
lies naturally out
of the socket,
pressing forwards against
the capsular ligament.
The natural tendency,
then, of the
hip joint, from
its necessary mechanism,
is to' dislocate
forwards, although the fact is
that the forward
dislocations are comparatively
rare. Very various
notions are probably
entertained as to
the way in
which the direction
which the dislocation
of the hip
shall take is
determined. The backward
dislocations are not
the most frequent
because the back
of the capsular
ligament is comparatively
thin ; but, rather, the
back of the
capsule is thin
because the ball
does not tend
by the natural
motions of the
limb to throw
itself out backwards,
and because the
front of the
capsule checks rotation
inwards as well
as rotation outwards.
My idea of the matter
is, that the
ordinary backward and
upward direction of
dislocation is determined
simply by the
obliquity of the
shaft of the
femur, the force
driving the bone
out in that
direction ; and we would
expect the accident
as all the
more likely to
occur if the
limb was caught
in the rotated inward
position. Dislocations forward,
on the other
hand, whether pubic
or obturator, we
would expect, theoretically, to
happen from the
limb being wrenched
in the rotated
outward position, carrying the natural
motion so unnaturally
far as to
rupture the thick anterior capsule.
But, whatever may
be the explanation
of the direction
of the different dislocations, it
is evident that
the natural tendency
is for the
bone to throw
itself out of
the socket forwards.
Now, to prevent
this, there are
two strong ligaments.
In the extended
position, as in
standing with the
toes turned more
or less out,
it is checked
by the whole front of the capsular
ligament, including the
entire ilio-femoral band.
But by flexion,
the front of
the capsule is
relaxed, allowing the
outward rotation to
go farther, until
it is checked
by the round ligament, and
by the outer
part of the
ilio-femoral band. The
limb is in
this position when
it is lifted
and advanced in
walking, or in stepping up,
with the toes
everted ; in sitting with
the knees apart, or
with one leg
laid across the
other knee ; or in
the tailor position, or
on horseback. In
all these, and
other allied positions,
the hip joint
is flexed and
rotated outwards, and
the round ligament
is called into
play to prevent
the ball starting
forward from the
socket.
The question occurs.
Whether the ligament
serves a similar purpose in
the lower animals
? It is known
to be present
in nearly all mammals, with a
few well-known exceptions,
among which are
the very variously
limbed orang, elephant,
and seal ; and is
largely developed in
the bird. It may be
simply that a ligament
is placed in
the interior of
the joint to
check over-motion in
that direction in which the
bone is most
liable to leave
the socket. But,
my examination of it
in several quadrupeds,
leads me to
suppose that it is employed
on the same
principle as in man It
has much the
same anatomy within
the joint, only
shorter, which accords
with the seemingly
more limited rotatory
motion of the
quadrupedal hind limb.
In the horse,
a large part of
the ligament leaves
through the notch,
plays round the
transverse ligament, and
passes to meet its fellow
above and in
front of the
symphysis pubis ; but this
does not affect
its position within
the joint. In
the quadruped and
bird, the joint
is naturally in a
state of
acute flexion, moving
backwards to semi-flexion
or partial extension ; so that,
as in the
flexed position in man,
an outward rotatory
motion carries the
ligament upwards, and
this seems to
accord with the
direction of the
ligament, the groove
on the femur,
and the recess
in the acetabulum.
This, however, I state
only as probability,
recollecting that in
each case, as
in man, it
can be actually
determined only by
demonstration by the
method proposed in
this paper.
In conclusion, it
is right to
add, that it
must be now
ten years since I
first employed this
method of demonstrating
the use of the
round
ligament, during which
I have shown it
to many anatomists, and
taught it yearly
in my class.
References
Struthers J. XVIII. Demonstration of the use of the round ligament of the hip joint. In Anatomical and physiological observations (continued). [Edinburgh: s.n.], 1858? [archive.org]
Struthers J. Demonstration of the use of the round ligament of the hip joint. Edinburgh Med J. 1858;4(5)434-42. [ncbi.nlm.nih.gov]
Authors & Affiliations
John Struthers (1823-1899) M.D., F.R.C.S., between 1845 and 1847 was Handyside’s Assistant Demonstrator, Lecturer on Anatomy of Extra-mural School in Edinburgh since 1847, Professor of Anatomy in the University of Aberdeen (1863–1889), President of the Royal College of Surgeons of Edinburgh (1895–1897). journals.sagepub.com
.jpg) |
| Portraits of John Struthers (1850, age 27; 1885, age 62) from work: Keith A. Anatomy in Scotland during the Lifetime of Sir John Struthers (1823-1899): Being the First Sir John Struthers Anatomical Lecture Delivered at the Royal College of Surgeons of Edinburgh, 17th November 1911. Edinburgh Medical Journal. 1912;8(1)7-33. [ncbi.nlm.nih.gov] |
Keywords
ligamentum capitis femoris, ligamentum teres, ligament of head of femur, anatomy, role, experiment, significance
.
NB! Fair practice / use: copied for the purposes of criticism, review, comment, research and private study in accordance with Copyright Laws of the US: 17 U.S.C. §107; Copyright Law of the EU: Dir. 2001/29/EC, art.5/3a,d; Copyright Law of the RU: ГК РФ ст.1274/1.1-2,7
EXPERIMENTS AND OBSERVATIONS
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