D. J. (Daniel John) Cunningham.

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to gain attachment to the pubic tubercle and to the
ligamentum lacunare, and so forms the proximal boundary
of the fossa. The distal end of the margo falciformis also
turns medially, forming the inferior cornu, which lies posterior
to the upper end of the great saphenous vein, on the medial
side of which it terminates by blending with \\\z pectineal part
of the fascia lata, so called because it ascends superficial to
the pectineus muscle to the pectineal line of the pubis
(Figs. 1 06, 113). The manner in which the fascia lata
surrounds the muscles of the proximal part of the inferior
extremity, so that the iliac portion lies anterior to the
femoral sheath and the pectineal portion passes posterior to
the sheath, is shown in the section represented in Fig. 113.

The fossa ovalis is closed by the cribriform fascia, a thin
stratum of the fascia lata which passes from the falciform
margin and the cornua to the pectineal fascia. The cribri-
form fascia is pierced by the great saphenous vein, the

i 15 a



230 THE INFERIOR EXTREMITY

superficial external pudendal and superficial epigastric arteries,
and by the efferent lymph vessels from the subinguinal glands
on their way to join the deeper subinguinal glands, which
lie in the femoral sheath.

Vena Saphena Magna (O.T. Internal Saphenous Vein).
The great saphenous vein is the largest superficial vein of the
inferior extremity. It commences on the dorsum of the foot,
passes anterior to the medial malleolus and ascends through
the leg across the medial surface of the distal third of the
tibia, and then along the medial margin of the tibia. It
enters the area of dissection at present under consideration
at the level of the tuberosity of the tibia, ascends in the
posterior part of the medial genicular region, then, inclining
forwards and laterally, it passes upwards to the fossa ovalis,
where it pierces the fascia cribrosa and the femoral sheath,
and terminates in the femoral vein. In its course through
the thigh it communicates through the deep fascia with
the deep veins, and it receives the following tributaries : ( i )
The lateral femoral circumflex vein^ from the anterior and
lateral parts of the thigh. (2) The medial femoral circumflex
vein, which commences at the back of the knee where it
frequently communicates with the small saphenous vein. The
medial femoral circumflex vein runs upwards, curves round
the medial side of the thigh and joins the great saphenous
vein mid-way between the hip and the knee. (3) The external
superficial pudendal vein. (4) The superficial epigastric
vein ; and (5) the superficial circumflex vein. The last three
tributaries join the great saphenous vein immediately before
it passes through the fossa ovalis. There are several valves
in the interior of the great saphenous vein which help to
divide the column of blood into sections, and so reduce the
pressure on the walls of the distal part of the vein.

Nervi Gutanei. The cutaneous nerves met with in the
area of the present dissection are :

( Ilio-inguinal nerve.
From the lumbar plexus, j Lumbo-inguinal nerve.

(_ Lateral cutaneous nerve of the thigh.

( Intermediate cutaneous nerve of the thigh.
From the femoral nerve, -I Medial cutaneous nerve of the thigh.

( Saphenous nerve.

They have already been found and cleaned. Now their
positions and distributions should be more fully studied.



THE THIGH 231

N. Ilio-inguinalis. The ilio-inguinal nerve escapes from
the subcutaneous inguinal ring (O.T. ext. abdominal) in
company with the spermatic funiculus. Most of its branches
go either to the scrotum or to the labium majus, but some
are distributed to the skin of the adjacent part of the thigh.

N. Lumboinguinalis (O.T. Crural branch of Genito-crural).
The lumbo-inguinal nerve pierces the fascia lata a little
way distal to the inguinal ligament, and to the lateral side
of the falciform margin of the fossa ovalis. It supplies a
limited area of skin on the proximal part of the anterior
aspect of the thigh. With a little care a communication
between this nerve and the intermediate cutaneous nerve of
the thigh may be made out (Fig. 106).

N. Femoris Lateralis (O.T. External Cutaneous). The
lateral cutaneous nerve of the thigh is distributed on the lateral
area of the thigh. It pierces the fascia lata in two parts. Of
these, one the posterior division appears about two inches
distal to the anterior superior spine of the ilium, and proceeds
posteriorly and distally; some twigs of it may be followed to the
lower part of the gluteal region. The anterior division comes
to the surface about two inches more distally. It is the larger
of the two, and has a wide area of distribution. It may ex-
tend to the knee. Previous to its division the lateral cutaneous
nerve of the thigh lies in a prominent ridge of the fascia lata
which descends vertically from the anterior superior spine of
the ilium. This must be slit up to expose the nerve.

The intermediate and medial cutaneous nerves belong to the "anterior
cutaneous branches of the femoral nerve," but for convenience and for the
purposes of more precise description, they are defined by special names.

The intermediate cutaneous nerve of the thigh (O.T.

middle cutaneous nerve), a branch of the femoral nerve, pierces
the fascia lata in the middle line of the thigh about three or
four inches distal to the inguinal ligament. It appears usually
as two branches which perforate the fascia at two points
a short distance from each other. Both branches extend
distally to the knee, which they reach on its medial aspect.

The medial cutaneous nerve of the thigh (O.T. internal
cutaneous nerve\ a branch of the femoral nerve, like the
lateral cutaneous nerve of the thigh and the inter-
mediate cutaneous nerve, divides into two portions an
anterior and a posterior which perforate the deep fascia
on the medial aspect of the thigh, and at some distance
1156



THE INFERIOR EXTREMITY



from each other. The anterior division makes its appear-

ance through the fascia lata
in the distal third of the
thigh, anterior to the great
saphenous vein. It de-
scends towards the knee,
and its terminal branches
turn forwards and laterally
to the anterior aspect of
the patella. The posterior
division reaches the surface
on the medial side of the
knee, behind the great
saphenous vein, and pro-
ceeds distally to supply
the integument on the
medial side of the proxi-
mal part of the leg. But
the main stem of the medial
cutaneous nerve, before it
divides, also sends a few
twigs through the fascia
lata to reach the skin on
the proximal part of the
medial aspect of the thigh.
These make their appear-
ance along the line of the
great saphenous vein.

N. Saphenus (O.T. Long
Saphenous). The saphen-
ous nerve becomes cuta-
neous on the medial side of
the knee by perforating the
fascia between the tendons
of the sartorius and gracilis
muscles. The guide to it

is the saphenous branch
FIG. io 7 .-Cutaneous Nerves on the Front f



Lateral cutaneous
nerve of the thigh

Ilio-inguinal nerve -~
Lumbo-inguinal

nerve

Branch from
medial cutaneous^
nerve of the thigh
Intermediate cuta-
neous nerve
of the thigh
Medial cutaneous -
nerve of the thigh



Great saphenous
vein



Anterior part of
medial cutaneous
nerve of the thigh



Infrapatellar branch
of saphenous nerve



Great saphenous _

vein



Saphenous nerve



Superficial peroneal

nerve (O.T. musculo-

cutaneous)



Deep peroneal nerve
(O.T. ant. tibial)



of the Inferior Extremity.



, supremo,

*. '

which descends alongside

of it. It follows the course of the great saphenous vein into
the leg. Before it pierces the fascia it gives off an infra-
patellar branch.



THE THIGH 233

The infrapatellar branch pierces the sartorius muscle and
the fascia lata on the medial side of the knee, and turns
laterally towards the anterior aspect of the joint, distal to the
level of the patella (Fig. 107).

Patellar Plexus. Twigs of four of the cutaneous nerves
of the thigh have been traced to the skin of the knee, viz.,
the anterior division of the lateral cutaneous nerve of the thigh,
the intermediate cutaneous, the anterior division of the medial
cutaneous, and the saphenous nerve. These nerves communi-
cate with each other and form an interlacement which is situated
over the patella, the ligamentum patellae, and proximal part of
the tibia. The interlacement is termed the patellar plexus.

On the medial side of the thigh two minute cutaneous nerve twigs some-
times make their appearance which do not belong to any of the above
main cutaneous trunks. One appears distal to the ilio-inguinal nerve, and
is a twig from the perineal branch of the posterior cutaneous nerve of the
thigh ; the other pierces the deep fascia at the middle of the medial area of
the thigh, and comes from the obturator nerve.

Dissection. After the cutaneous nerves have been cleaned
the remains of the superficial fascia must be removed in order
that the fascia lata may be studied.

Fascia Lata. This is the name which is given to that
portion of the general fascial investment of the inferior
extremity which clothes the thigh and preserves its figure.
Only a portion of it is displayed at present, but the dissector
should obtain a general idea of its attachments and parts
before proceeding further with the dissection of the anterior
femoral region. One of its striking features is the marked
difference in strength which it shows in the lateral and
medial aspects of the thigh. In the lateral side of the limb
it is generally so dense and strong that it appears to be more
aponeurotic than fascial in its character, whilst, in addition, a
special band called the tractus ilio-tibialis is formed in it. The
tractus ilio-tibialis extends from the crest of the ilium to the
lateral condyle of the tibia and the head of the fibula, and
into it are inserted the tensor fasciae latae and the greater part
of the glutssus maximus muscle ; its distal part, therefore,
serves as an aponeurotic tendon by means of which the two
muscles gain insertion into the lateral condyle of the tibia
and the head of the fibula. The ilio-tibial tract serves as a
powerful brace, on the lateral aspect of the limb, which, in
the erect posture, helps to steady the pelvis and at the same
time keep the knee joint firmly extended. On the medial



234 THE INFERIOR EXTREMITY

side of the thigh the fascia lata is so exceedingly delicate and
thin that the subjacent muscular fibres shine through it, and
it is very apt to be removed with the superficial fascia unless
care is exercised in the dissection.

Proximally, around the root of the limb, the fascia lata is
attached to the inguinal ligament and the bones of the pelvis.
Thus, posteriorly, it is continuous with the fascia of the buttock,
and through that it is fixed to the coccyx, sacrum, and crest of
the ilium. On the lateral side it is attached to the crest of the
ilium ; and on the medial side, to the body of the pubis, the
margin of the pubic arch, and to the tuberosity of the ischium.

Anteriorly, its proximal attach-
ment is complicated by the
presence of the fossa ovalis.
That aperture separates the
fascia lata into a lateral or iliac
portion and a medial or pectineal
portion, now known as the fascia
pectinea. The subdivision ex-
tends distally only to the distal
border of the fossa ovalis. The
iliac portion is attached along the
FIG. 108. Diagram to show the whole length of the inguinal liga-
arrangement of the three inter- ment Its me dial CrCSCCntic
muscular septa and the three , , , c -,

osteo-fascial compartments of mar g m bounds the fossa ovahs
the thigh. (After Turner. ) laterally and forms its falciform

a. Medial intermuscular septum. edge. The COH1U SUpCHUS of

c. S^^^SS^S^ that e d g e blends with the lig.

lacunare (O.T. Gimbernat's liga-
ment) an expansion of the medial end of the inguinal
ligament. Its inferior cornu joins the pectineal portion of
the fascia lata. The fascia pectinea clothes the proximal
portions of the adductor longus and pectineus muscles. It
recedes from the surface as it is traced laterally, passes
posterior to the sheath of the femoral vessels, and blends
with the capsule of the hip joint, with the deep intermuscular
septa, and with the fascia iliaca, which covers the ilio-psoas
muscle (Fig. 113). To the medial side of the femoral vessels
the fascia pectinea is attached proximally to the pectineal
line of the pubic bone. The fascia cribrosa, as previously
stated, is to be regarded as a thin piece of the fascia lata,
stretched across the fossa ovalis. Laterally, it is continuous




THE THIGH 235

with the falciform edge of the iliac portion of the fascia ;
medially, it blends with the front of the fascia pectinea.

In the neighbourhood of the knee the fascia lata is con-
tinuous posteriorly with the popliteal fascia, whilst on the
sides and front of the joint it is attached to the various bony
prominences and to the different tendons in those localities,
and it helps to strengthen and support the capsule of the
knee joint.

Septa Intermuscularia (Intermuscular Septa). The fascia
lata has other offices to perform besides that of forming a
continuous investment for the thigh. From its deep surface
processes pass off which penetrate the limb and constitute
sheaths for the muscles and other structures. Three of
the processes, which are especially strong, form distinct septa
or partitions which reach the femur and are attached to the
linea aspera on its posterior aspect. These partitions are
termed the intermuscular septa, and are so disposed that
they intervene between the three great groups of muscles in
the thigh. The lateral intermuscular septum is placed between
the extensor muscles in the anterior area of the thigh and
the hamstring muscles in the posterior region ; the medial
intermuscular septum intervenes between the extensor muscles
and the adductor muscles in the medial region ; whilst the
posterior intermuscular septum, weak and inconspicuous in
comparison with the other two, is interposed between the
adductor and the hamstring muscles. The three septal
partitions will be disclosed in the subsequent dissection.
In the meantime, merely note that the medial and the
lateral septa show on the surface of the fascia, in the distal
part of the thigh, as white lines. By means of the three septa
the thigh is divided into three osteo-fascial compartments, viz.,
an anterior, containing the extensor muscles and the femoral
nerve ; a posterior, holding the hamstrings and the sciatic
nerve ; and a medial, for the adductors with the obturator
nerve (Fig. 108).

Bursse Patellares (Patellar Bursse). Several mucous bursae
are situated in the patellar region. Those which lie superficially
may be investigated now, and the more deeply placed bursae
should be examined at later stages of the dissection, as
opportunity occurs.

The bursae are (i) The subcutaneous prepatellar bursa, which
lies immediately beneath the skin opposite the distal part



236 THE INFERIOR EXTREMITY

of the patella. (2) The subfascial prepatellar bursa, situated
between the fascia lata superficially and the proximal part of
the patella and the adjacent part of the tendon of the
quadriceps deeply ; this bursa may be displayed by an incision
made through the fascia lata in the area indicated. (3) The
subtendinous prepatellar bursa, lying between the superficial
fibres of the tendon of the quadriceps and the periosteum of
the anterior surface of the patella. (4) The suprapatellar bursa.
This lies proximal to the patella, behind the tendon of the
quadriceps and in front of the distal part of the anterior
surface of the femur it usually communicates with the
cavity of the knee joint. (5) The subcutaneous infra-
patellar bursa, placed directly beneath the skin, anterior to the
proximal part of the ligamentum patellae. (6) The deep infra-
patellar bursa, which is placed between the ligamentum
patellae and the anterior surface of the proximal part of the
tibia. The suprapatellar bursa and the deep infrapatellar
bursae are practically always present, but one or more of the
subcutaneous and subfascial bursse may be absent. Not un-
commonly a subfascial and an adjacent subcutaneous bursa
may communicate through an aperture in the deep fascia.
The subcutaneous bursae are often destroyed during the
reflection of the skin, but the deeper bursae can usually be
found, if looked for carefully, in the situations mentioned
above.



DEEP DISSECTION OF THE ANTERIOR AND MEDIAL
PARTS OF THE THIGH.

In the course of the deep dissection of the anterior and
medial femoral regions the following structures will be met
with and must be examined :

1. The femoral sheath.

2. Nervus lumboinguinalis.

3. Nervus cutaneus femoris lateralis.

4. M. sartorius.

5. Nervus femoralis and its rami.

6. Arteria femoralis and its rami.

7. Vena femoralis.

8. M. ilio-psoas.

M. rectus femoris.



M. vastus medialis.



THE THIGH



237



10. M. articularis genu.

11. M. tensor fasciae latae.

12. Deep part of the tractus ilio-tibialis fasciae latse.

13. The intermuscular septa, lateral and medial.

Ligament Inguinale (O.T. Poupart's Ligament) and Liga-
mentum Lacunare (O.T. Gimbernat's Ligament). Although
both of these ligaments belong more to the abdominal wall



Sheath of rectus



Aponeurosis of external oblique




Inguinal ligament



ubcutaneous
inguinal ring
Reflex inguinal
ligament
Lacunar ligament



FIG. 109. Dissection to show the connections of the Inguinal Ligament.

than to the thigh, it is essential that the dissector of the
inferior extremity should obtain some knowledge of their
connections before he proceeds further with his dissection.
The inguinal ligament is merely the thickened lower border
of the aponeurosis of the external oblique muscle of the
abdominal wall folded backwards upon itself. Therefore it
presents a rounded surface towards the thigh, and a grooved
surface towards the cavity of the abdomen. Its lateral
extremity is fixed to the anterior superior spine of the
ilium. Medially, it has a double attachment, viz. (i) to the



238 THE INFERIOR EXTREMITY

pubic tubercle, (2) through the medium of the lacunar ligament
to the medial part of the pectineal line. The inguinal
ligament pursues an oblique course between its iliac and pubic
attachments, and at the same time describes a gentle curve, the
convexity of which is turned distally. By its distal border it
affords attachment to the iliac part of the fascia lata, and
when that is divided it loses its curvature.

The ligamentum lacunare (O.T. Gimbernafs ligament) is a
small triangular piece of aponeurosis which occupies the interval
between the medial part of the inguinal ligament and the medial
inch of the pectineal line being attached by its margins to
both. Its base, which looks laterally, is sharp, crescentic, and
free, and abuts against the femoral sheath. The lacunar
ligament occupies a very oblique plane ; its femoral surface
looks distally and laterally, whilst its abdominal surface is
directed upwards and medially (Fig. 109).

Dissection. The exposure of the femoral sheath is the next
step in the dissection of the thigh. To display it the iliac portion
of the fascia lata must be partially reflected. Divide the superior
horn of the lateral crescentic margin of the fossa ovalis, and
then carry the knife laterally along the lower border of the
inguinal ligament, so as to sever the attachment of the fascia
lata to that thickened band. The incision should extend to
within an inch of the anterior superior spine of the ilium. The
piece of fascia marked out by the incision above, and by the
lateral free margin of the fossa ovalis medially, must be carefully
raised from the subjacent femoral sheath and thrown distally
and laterally. On the removal of a little loose fat, the femoral
sheath will be brought into view as it enters the thigh under
the inguinal ligament. Isolate it carefully from adjacent and
surrounding parts, by carrying the handle of the knife gently
round it as far as possible. Insinuate the handle of the knife, first
between the sheath and the inguinal ligament, next between
the sheath and the lacunar ligament^ which lies medial to it,
and finally behind the sheath along the front of the pectineal
fascia. Laterally and posteriorly the sheath is fused with the
iliac fascia 1 on the psoas muscle, and in that situation it will
be necessary to use the edge of the knife before the sheath can
be isolated (Fig. in).

Femoral Sheath. The funnel-shaped appearance of the
femoral sheath will now be apparent the wide mouth of
the membranous tube is directed upwards towards the
abdomen, whilst the narrow distal part gradually closes

1 Do not confuse the iliac fascia with the iliac part of (he fascia lata.
The iliac fascia is a fascia which descends from the abdomen on the anterior
surfaces of the psoas and iliacus muscles. The iliac part of the fascia lata is
part of the deep fascia of the thigh (see p. 229).



THE THIGH 239

upon the vessels, and fuses with their coats about the
level of the distal limit of the fossa ovalis. It should be
noticed that the sides of the funnel -shaped sheath do
not slope equally towards one another. The lateral border
of the sheath is nearly vertical in its direction, whilst the
medial wall proceeds very obliquely distally and laterally.
If the dissection has been successfully performed, the
lumbo-inguinal nerve should be seen piercing the lateral
wall of the sheath, whilst the great saphenous vein and
some lymph vessels perforate its anterior wall. Further, if
the subject is spare and the fasciae well marked, the dissector
will in all probability notice that the anterior wall of the
sheath, in its proximal part, is strengthened by some transverse
fibres which pursue an arched course across it. To those
fibres the name of deep femoral arch is given, in contra-
distinction to the term superficial femoral arch, which is
sometimes applied to the inguinal ligament. The deep
femoral arch springs from the deep surface of the inguinal
ligament about its middle, then traverses the front of the
sheath, and expanding somewhat, is attached by its medial
extremity to the pectineal line of the pubic bone behind the
lacunar ligament.

Constitution of the Femoral Sheath. The sources from
which the femoral sheath is derived, and the manner in
which it is formed, must next be considered. The considera-
tion entails the study of some of the structures concerned in
the construction of the abdominal wall, and it is possible
that the dissection of the abdomen will not be in a sufficiently
advanced state for their examination.

A small portion of the medial part of the interval
between the inguinal ligament and the hip bone is filled
up by the lacunar ligament. Immediately to the lateral
side of the lacunar ligament the femoral vessels, enclosed
within the femoral sheath, enter the thigh from the
abdominal cavity, whilst still more laterally the interval is
occupied by the ilio-psoas muscle. Three nerves also find
their way into the thigh through the interval, viz., the lumbo-
inguinal nerve, which passes distally in the femoral sheath ;
the femoral (O.T. anterior crural) nerve, which occupies the
interval between the psoas and iliacus muscles ; and the lateral
cutaneous nerve of the thigh, which runs behind the inguinal
ligament, close to its iliac attachment (Fig. in).



2 4



THE INFERIOR EXTREMITY



The arrangement of the fascial lining of the abdominal
cavity, with reference to this interval of communication
between abdomen and thigh, also requires attention. The
lower part of the posterior wall of the abdomen, immedi-
ately above the thigh, is formed by the iliacus and psoas
muscles. These are covered by that part of the fascial
lining of the abdomen which receives the name of the fascia

Transversalis fascia

Transversus abdomini^
1 Internal oblique
^"External ob



Skin
Camper's fascia

Superficial epi-
gastric vein

Aponeurosis of external
oblique

Scarpa's fascia "
Inguinal ligament
Transversalis fascia
Cribriform fascia

Fascia lata



Great saphenous vein



Inguinal canal

Transversalis fascia

Inguinal ligament




Ilio- psoas
I ^//^V^External iliac vein

^yv Iliac fascia

Femoral vein



FIG. no. Diagram of the Fasciae and Muscles of the Inguinal and
Subinguinal Regions in the line of the Fossa Ovalis.

iltaca. 1 The anterior wall of the abdomen is lined, in like
manner, by a portion of the general lining, termed the fascia



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