D. J. (Daniel John) Cunningham.

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transversalis. To the lateral side of the femoral vessels these
two fascial layers become continuous with each other, and at
the same time are attached to the back of the inguinal liga-
ment (Fig. 105). It is behind this union that the ilio-psoas,
the femoral nerve, and the lateral cutaneous nerve of the
thigh are carried distally into the thigh. But the external

1 The dissector must bear in mind the distinction between the fascia iliaca
and the iliac portion of the fascia lata. The former is a part of the general
fascial lining of the abdomen, and the latter is a part of the deep fascia of
the thigh.



THE THIGH 241

iliac vessels (which become the femoral vessels in the' thigh),
with the lumbo-inguinal nerve, lie anterior to the fascia iliaca,
or, in other words, within the fascial lining of the abdomen,
and, as they proceed distally behind the inguinal ligament,
they carry with them a funnel-shaped prolongation of the
lining, which is the femoral sheath.

The dissector will now readily understand that the anterior
wall of the sheath is formed of fascia transversalis from



N. cutaneus
femoris lateralis



M. ilio-psoas
Ligamentum
inguinale




A. femoralis
Femoral sheath
V. femoralis
Lig. lacunare
Tuberculum pubicum
M. pectineus



FIG. in. Dissection to show the Femoral Sheath and the other Structures
which pass between the Inguinal Ligament and the Hip Bone.

the anterior wall of the abdomen, while the posterior wall is
formed of fascia iliaca, prolonged distally, from the posterior
abdominal wall (Fig. no).

Posterior Wall of the Femoral Sheath. There are still
some additional facts relating to the posterior wall of the
femoral sheath which require to be mentioned. It is
formed, as stated above, by the fascia iliaca; but as that
enters the thigh it blends with the lateral part of the (Fig. 113)
fascia pectinea, and further, it is firmly fixed in position by
certain connections which it establishes in the thigh. Thus,

VOL. i 16



242 THE INFERIOR EXTREMITY

lateral to the femoral sheath, it is prolonged over the ilio-
psoas muscle ; whilst from its posterior aspect a lamina is
given off which passes posterior to that muscle and joins the
capsule of the hip joint (Fig. 113).

Dissection. The femoral sheath must be opened, in order
that the arrangement of parts inside may be displayed. Make
three vertical and parallel incisions through the anterior wall
one over the femoral artery, which occupies the lateral part of
the sheath, another over the femoral vein in the line of the
great saphenous vein, and the third about half an inch medial
to the second. The first two should begin at the level of the
inguinal ligament, and should extend distally for an inch and a
half. The most medial of the three incisions should commence
at the same level, but should be carried distally only for half an
inch or less.

Interior of the Femoral Sheath. A little dissection will
show that the sheath is subdivided, by two antero-posterior
partitions, into three compartments. The femoral artery and
lumbo-inguinal nerve occupy the most lateral compartment ; the
femoral vein fills up the intermediate compartment ; whilst in
the most medial compartment are lodged a little loose areolar
tissue, a small lymph gland, and some lymph vessels. This
last compartment, from its relation to femoral hernia, has the
special name of femoral canal applied to it.

Canalis Femoralis. The boundaries and extent of the
femoral canal must be very thoroughly studied. The best
way to commence the study is to introduce the little finger
into the canal and push it gently upwards. The length of
the canal is not nearly so great as that of the other two
compartments. Indeed, it is not more than half an inch
long. Distally it is closed, and it rapidly diminishes in
width proximo -distally. Its proximal aperture lies on the
lateral side of the base of the lacunar ligament, and is called
the femoral ring. It is closed by the closely applied extra-
peritoneal fatty tissue of the abdominal wall. The parts
which immediately surround the opening can be readily
detected with the finger : laterally the femoral vein, medially
the sharp crescentic base of the lacunar ligament, anteriorly
the inguinal ligament, and posteriorly the pubic bone covered
by the pectineus muscle. The portion of the extra-peritoneal
fatty tissue which closes the ring is called the septum
femorale. On the abdominal surface of the septum femorale
is the peritoneal lining of the abdominal cavity, and when
examined from above both are seen to be slightly depressed



THE THIGH 243

into the opening so as to produce the appearance of a
dimple.

Femoral Hernia. Femoral hernia is the name applied to a patho-
logical condition which consists of the protrusion of some of the contents
of the abdominal cavity into the thigh. As they descend they pass
behind the inguinal ligament into the femoral canal or most medial
compartment of the femoral sheath. The arrangement of the parts which
occupy the interval between the hip bone and the inguinal ligament
has been carefully considered, and the dissector should therefore be in
a position to understand how the occurrence of such a protrusion is
possible. To the medial side of the femoral sheath the interval is closed
by the lacunar ligament, which, by its strength and firm connections,
constitutes an impassable barrier in that locality. To the lateral side of the
femoral sheath a hernial protrusion is equally impossible. There the fascia
transversalis on the anterior wall of the abdomen becomes continuous with
the fascia iliaca on the posterior wall of the abdomen, and along the line
of union both are firmly attached to the inguinal ligament (Fig. 105).

It is in the region of the femoral sheath, then, that femoral hernia takes
place. The three compartments of th,e sheath open above into the abdominal
cavity, but there is an essential difference between the three openings. The
lateral two, which hold the artery and the vein, are completely filled up by
their contents. The femoral canal, or most medial compartment, is not
completely filled, for it is wider than is necessary for the passage of the
fine lymph vessels which traverse it. Further, its widest part is the upper
opening or femoral ring. It has been noted that that is wide enough to
admit the point of the little finger, and it forms a weak point in the
parietes of the abdomen ; a source of weakness which is greater in the
female than in the male, seeing that in the former the distance between
the iliac spine and the pubic tubercle is proportionally greater, and that,
in consequence, the femoral ring is wider. Femoral hernia, therefore, is
more common in the female (Fig. 105).

When attempts are made to reduce a femoral hernia, it is necessary
that the course which the protrusion has taken should be kept constantly
before the mind of the operator. In the first instance it passes distally
for a short distance in a perpendicular direction. It then turns forwards
and bulges through the fossa ovalis. Should it still continue to enlarge, it
bends upwards over the inguinal ligament, and pushes its way laterally
towards the anterior superior spine of the ilium. The protrusion is thus
bent upon itself, and if it is to be reduced successfully it must be made
to retrace its steps. In other words, it must be drawn down, and
then pushed gently backwards and upwards. The position of the limb
during this procedure must be attended to. When the thigh is fully
extended and rotated laterally all the fascial structures in the neighbour-
hood of the femoral canal are rendered tense. When, on the other hand,
the limb is flexed at the hip-joint and rotated medially, the upper horn
of the margin of the fossa ovalis, and even the lacunar ligament, are
relaxed. That, then, is the position in which the limb should be placed
during the reduction of the hernia.

As the hernia descends it carries before it, in the form of coverings,
the various layers which it meets. First it pushes before it the peritoneum,
and that forms the hernial sac. The other coverings from within outwards
are (i) the septum femorale ; (2) the wall of the femoral sheath ; (3) the
fascia cribrosa ; and lastly, (4) the superficial fascia and skin.

The femoral canal, as already noted, is surrounded by very unyielding
structures. Strangulation due to pressure is, therefore, of very common
I 16 a



244



THE INFERIOR EXTREMITY



occurrence in cases of femoral hernia. The sharp tense base of the lacunar
ligament and the superior cornu of the margin of the fossa ovalis are
especially apt to bring about that condition.

Abnormal Obturator Artery. The account of the surgical anatomy
of femoral hernia cannot be complete without mention of the relation
which the obturator artery frequently bears to the femoral ring. In
two out of every five subjects the obturator artery, on one or on both sides,
takes origin from the inferior epigastric artery. In those cases it passes
posterior to the pubic bone to gain the obturator sulcus in the upper part



Profuncla femoris artery



Lateral circumflex
artery



Intermediate cuta-
neous nerve (O.T.
middle cutaneous)



Lateral cutaneous nerve

Inguinal ligament

Superficial circumflex iliac artery
,*' Femoral nerve

| Superficial epigastric and
superficial pudendal arteries

Deep external
pudendal artery




Adductor brevis
Femoral vein

aphenous



Femoral artery



FIG. 112 Dissection of the Femoral Triangle of the right side



of the obturator foramen, and according to the point at which it arises
from the epigastric trunk, it presents different relations to the femoral
ring. In the majority ot cases it lies in close contact with the external iliac
vein and on the lateral side of the femoral ring. In that position it is in
no danger of being wounded in operations undertaken for the relief of a
strictured femoral hernia. In about thirty-seven per cent. , however, of the
cases in which it exists, the artery is placed less favourably. In those it
either passes medially, across the septum femorale which closes the
opening into the femoral canal, or it arches over it and turns posteriorly,
on the medial side of the ring, upon the deep aspect of the base of the
lacunar ligament. In the latter situation it is in a position of great danger,



THE THIGH 245

seeing that it is the base of the lacunar ligament against which the surgeon's
knife is generally directed for the relief of strictured femoral hernia.

Dissection. The boundaries and contents of the femoral
triangle, which occupies the proximal third of the anterior part
of the thigh, must now be dissected. Commence by cleaning
the medial and lateral boundaries. The lateral boundary is
formed by the proximal third of the sartorius muscle, and the
medial boundary by the medial border of the adductor longus
muscle. To clean a muscle properly the following rules must
be observed : (i) Keep the muscle tense by bending or straighten-
ing the limb or by rotating it. (2) Make all cuts with the scalpel
parallel with muscle fibres. (3) Remove the fascia in one con-
tinuous layer from one border of the muscle to another. (4)
Define very carefully the borders of the muscle.

As the deep fascia is removed the scalpel must cut not only
parallel with the muscle fibres but also against them, in order
that none of the deep fascia may be left on the muscle.

Clean the sartorius first from its origin on the anterior border
of the ilium, below the anterior superior spine, to the point where
it crosses the adductor longus at the junction of the proximal
and middle thirds of the thigh. Begin at its medial or its
lateral border, whichever is more convenient, and take care not
to injure the lateral cutaneous nerve of the thigh, which crosses
superficial to the muscle near its origin, and the intermediate
cutaneous nerve, which either pierces or crosses the muscle near
the middle line of the thigh.

Next clean the pectineal fascia from the anterior surface of
the adductor longus from the point where the muscle arises
from the front of the pubis to the point where it disappears
behind the sartorius at the apex of the femoral trigone.

When the medial and lateral boundaries of the trigone have
been displayed proceed to the dissection of the femoral nerve
and its branches. Place a block under the knee in order to
flex the hip- joint and relax the boundaries and contents of the
triangle, then follow the intermediate cutaneous nerve upwards
to the point where it springs from the front of the trunk of the
femoral nerve, next clean the lateral border of the trunk, and
inserting the handle of a spare scalpel behind the nerve raise it
from the groove between the iliacus and psoas in which it lies.
Leave the spare scalpel behind the nerve trunk and clean its
various branches so far as t they lie in the femoral trigone.
Medial to the intermediate cutaneous nerve lies the medial
cutaneous nerve of the thigh. It springs from the front of the
trunk of the femoral nerve, runs along the lateral border of
the femoral sheath and crosses the front of the femoral artery
at the apex of the trigone. On a plane posterior to the inter-
mediate and medial cutaneous nerves lie the deeper branches of
the femoral nerve. They radiate from the extremity of the
trunk of the nerve and are arranged in the following order from
above and laterally downwards and medially : the nerve to
the rectus femoris, the nerve to the vastus latralis, the nerve
to the vastus intermedius, the nerve to the vastus medialis, and
the saphenous nerve. The nerve to the sartorius is usually a
branch of the intermediate cutaneous nerve. As the muscular
branches are being cleaned take care to avoid injury to the



246 THE INFERIOR EXTREMITY

lateral femoral circumflex artery, which passes laterally either
behind or between the nerves. After the nerves mentioned
have been cleaned pull the trunk of the femoral nerve laterally
and secure the nerve to the pectineus, which springs from the
medial border of the femoral nerve and passes medially behind
the femoral sheath. Follow it as far as possible behind the
sheath and keep it in mind during the next stage of the dis-
section, which includes the removal of the femoral sheath and
the cleaning of the femoral artery and its branches and the
femoral vein and its tributaries. As many of the branches
of the artery as possible should be retained, but small branches
to the muscles may be removed if they obstruct the cleaning
of the larger vessels. The main trunks of the veins must also
be kept and cleaned, but the venae comites of the smaller arteries
should be removed.

Commence with the femoral artery. Trace the superficial
branches already displayed back to their origin from the trunk
as it lies in the femoral sheath, then raise the trunk of the artery
from the sheath, and completely remove that portion of the
sheath which surrounded the artery, but do not forget the nerve
to the pectineus which lies immediately behind the sheath. As
the arterial part of the femoral sheath is removed, find the deep
external pudendal artery, which springs from the proximal part
of the trunk ; then clean the distal part of the femoral artery as
far as the apex of the trigone. First clean the medial side, from
which no important branches arise. Then clean along the lateral
side, from above downwards, and about 50 mm. distal to the
inguinal ligament find the large profunda femoris branch, which
springs from the postero - lateral aspect of the parent trunk.
Follow the profunda artery distally and medially behind the
femoral and profunda veins and secure its first two branches,
the medial and the lateral femoral circumflex arteries. The
medial femoral circumflex artery passes backwards into the
deep part of the trigone ; the lateral femoral circumflex artery
runs laterally, behind or between the muscular branches of the
femoral nerve, to the lateral border of the femoral trigone, where
it breaks up into ascending, transverse and descending branches.
Not uncommonly one or both the femoral circumflex arteries
spring from the trunk of the femoral artery, and the dissector
must be prepared to meet with such variations.

After the arteries are displayed, clean the femoral and pro-
funda veins, both of which lie posterior to the femoral artery
in the distal part of the trigone. As the posterior aspect of the
proximal part of the femoral vein is cleaned the nerve to the
pectineus must be followed to its termination in the pectineus
muscle ; then the remaining parts of the pectineal fascia must
be removed from the pectineus and adductor longus. As that
is done, an interval will come into view between the lower
border of the pectineus and the upper border of the adductor
longus, in which the superficial division of the obturator nerve
should be found. Lastly, the iliac fascia must be cleaned from
the surfaces of the iliacus and psoas, and the fat in the angle
between the psoas and pectineus must be removed.

Trigonum Femorale. The femoral triangle is the name
given to the triangular hollow which lies in the proximal



THE THIGH 247

third of the thigh distal to the inguinal ligament. It
possesses a roof or anterior boundary ; a floor or posterior
boundary ; a medial boundary ; and a lateral boundary ;
a base, which is situated proximally at the junction of the
thigh with the abdomen ; and an apex, which lies distally
at the junction of the proximal and middle thirds of the
thigh (Fig. 1 12).

The lateral boundary is formed by the medial border of
the sartorius muscle as it runs distally and medially across the
thigh from the anterior superior spine of the ilium, and, more
deeply in the distal part of the triangle, by the medial border
of the rectus femoris. The medial boundary is constituted by
the prominent medial border of the adductor longus, and
the two muscles meet below at the front of the apex of the
triangle. The anterior boundary, or roof, is formed by the
iliac part of the fascia lata and the cribriform fascia. It is
perforated by the structures which pass through the fascia
cribrosa (see p. 229), by the lumbo-inguinal nerve, and the
intermediate cutaneous nerve of the thigh, and it is covered
by the superficial fascia and skin. The posterior boundary,
or floor, slopes backwards from the medial and lateral
boundaries ; the triangle is, therefore, triangular in section as
well as in superficial outline. The medial part of the floor is
constituted mainly by the anterior surfaces of the adductor
longus and the pectineus, but, if an interval exists between
the adjacent borders of those two muscles, a part of the
anterior surface of the adductor brevis also appears in the
medial part of the floor. The lateral part of the floor is
formed by the anterior surfaces of the iliacus and the
psoas major. The medial femoral circumflex artery passes
through the floor, between the adjacent borders of the psoas
and the pectineus, and the profunda artery leaves the
triangle by passing behind the upper margin of the adductor
longus, close to the femur ; it is accompanied by the profunda
vein. The apex is bounded medially by the adductor longus,
laterally by the vastus medialis, and anteriorly by the sartorius ;
through it the femoral vessels, accompanied by the saphenous
nerve, pass from the femoral triangle into the adductor canal.
The base is situated at the junction of the thigh with the
abdomen ; it is bounded, superficially, by the inguinal
ligament ; medially, by the lacunar ligament ; laterally, by the
anterior border of the ilium ; and posteriorly, by the pectineus,



248 THE INFERIOR EXTREMITY

the psoas major and the iliacus. Through it pass the femoral
artery and vein, the deep femoral lymph vessels, the femoral
and lumbo-inguinal nerves, and the lateral cutaneous nerve of
the thigh.

Arteria Pudenda Externa Profimda. The deep ex-
ternal pudendal artery is a small twig which arises from the
medial side of the femoral artery, distal to the inguinal liga-
ment. It runs medially, upon the pectineus and adductor
longus muscles, and, after piercing the fascia lata, ends,
according to the sex, in the integument of the scrotum or of
the labium majus pudendi.

Dissection. Before the other contents of the femoral triangle
are studied, complete the dissection of the remains of the anterior
and medial regions of the thigh and knee.

First clean the remainder of the sartorius as far as its inser-
tion into the tibia, but avoid injury to the nerves which lie in
relation with it. The lateral cutaneous nerve of the thigh,
which crosses anterior to the muscle near the anterior superior
spine of the ilium, and the intermediate cutaneous nerve, which
either crosses or pierces it, have already been secured. Below the
apex of the femoral triangle the anterior branch of the medial
cutaneous nerve crosses superficial to the sartorius, and the
posterior branch of the same nerve runs along its posterior border.
A short distance proximal to the knee the infrapatellar branch of
the saphenous nerve pierces it, and the trunk of the saphenous
nerve emerges between its posterior border and the tendon of the
gracilis at the medial side of the knee accompanied by the
saphenous branch of the arteria genu suprema, which serves as a
guide to its position. After the sartorius is displayed, turn to the
tensor fasciae latae, which lies immediately lateral to the proximal
part of the sartorius. At the lateral border of the proximal part
of the sartorius the iliac part of the fascia lata splits into two
layers. One layer passes superficial to the sartorius, and has
been removed to expose the muscle ; the other passes deep to the
tensor fasciae to blend with the tendon of the rectus femoris.
Trace the tensor fasciae to its attachment to the ilio-tibial tract
of the fascia lata, into which it is inserted ; then cut through the
fascia lata vertically, along the anterior border of the ilio-tibial
tract down to the lateral condyle of the tibia. Pull the distal part
of the ilio-tibial tract laterally, and demonstrate the lateral inter-
muscular septum which passes from its deep surface to the
lateral supracondylar ridge of the femur. Now clean away the
whole of the fascia lata between the tensor fasciae latae and the
ilio-tibial tract on the lateral side, and the sartorius on the
medial side. The muscles which will then be brought into
view are the rectus femoris along the middle of the front of the
thigh. It will be recognised by the bipennate arrangement of
its fibres. Between it and the ilio-tibial tract are parts of the
vastus lateralis and vastus intermedius, the latter below the
former ; and between it and the sartorius in the distal third of
the thigh the distal part of the vastus medialis will be seen.



THE THIGH



249



A short distance proximal to the knee the rectus femoris ends
in a tendon which is inserted into the proximal border of the
patella, and the vasti end in aponeurotic expansions which are
attached to the borders of the patella.

Push the proximal part of the sartorius medially, pull the
tensor fasciae laterally, and find its nerve of supply from the



V. circu



mflexa ilium superficialis Fascia cribrose



V. saphena magna
Subinguinal lymph gland
V. epigastrica superficialis
Pectineal part of fascia lata |
N. obturatorius ramus anterior



N. obturatorius ramus posterior



V. femoralis

Margo falciformis
A. femoralis
Iliac fascia
| N. femoralis
| | Psoas bursa
| | ] Iliac part of fascia lata
M. rectus femoris




Tractus ilio-
tibialis
Capsula articularis



Mm. biceps femoris et semitendinosus



Trochanter major

M. semimembranosus . , Collum femoris

A. circumflexa femoris medialis on M. ! Capsula articularis

obdurator externus I N. cutaneus femoris posterior
N. ischiadiacus (peroneal and tibial parts)

FIG. 113. Dissection of an oblique transverse Section through upper part ot
Thigh showing the relation of the Fascia to the Muscles.



superior gluteal nerve. It enters the deep surface of the muscle
a little above the middle of its length. When the nerve is secured,
follow it backwards till it disappears between the adjacent
anterior borders of the glutaeus medius and minimus at the
anterior margin of the greater trochanter ; then clear away the
septum of deep fascia which passes deep to the tensor fascias
to blend medially with the tendon of the rectus femoris and
laterally with the front of the capsule of the hip joint. As the
deep part of the septum is removed, find and clean the ascending
branch of the lateral femoral circumflex artery, and look for



Online LibraryD. J. (Daniel John) CunninghamCunningham's manual of practical anatomy (Volume 1) → online text (page 25 of 44)