D. J. (Daniel John) Cunningham.

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Tibia



Fibula



Posterior
tibial artery



Anterior
tibial artery



FIG. 135. Radiograph of the Knee Region of an injected inferior extremity.
(Major T. Rankine. )



PLATE XXII



Femur




Superior
lateral gen
cular arter



Medial con-
dyle of femur



Lateral co
dyle of fem




Lateral coi
dyle of tibi



FIG. 136. Radiograph of the Knee Region of an injected inferior extremity.

(Major T. Rankine.)



POPLITEAL FOSSA 315

motic peroneal nerve, and the lateral cutaneous nerve of the
calf, which supplies the skin on the anterior and lateral aspect of
the proximal part of the leg. They frequently take origin by a
common stem. The anastomotic peroneal nerve arises from the
common peroneal trunk in the popliteal fossa, and is continued
distally over the lateral head of the gastrocnemius. It ulti-
mately unites with the medial cutaneous nerve of the calf to
form the nervus suralis.

The articular branches are three in number. They are
the superior and inferior lateral articular branches and the
recurrent articular nerve. The first two accompany the
superior and inferior lateral genicular branches of the popliteal
artery respectively. They are of small size and are difficult
to find. The recurrent articular nerve which springs from
the termination of the common peroneal nerve will be dis-
sected at a later stage (p. 356).

Arteria Poplitea. The popliteal artery is the continuation
of the femoral artery, and is therefore part of the great arterial
trunk of the lower limb. It begins at the opening in the
adductor magnus, where the femoral artery ends ; and it
terminates at the distal border of the popliteus muscle by
dividing into the anterior and posterior tibial arteries. The
division is hidden from view, at the present stage of the
dissection, by the proximal border of the soleus muscle, but
it will be exposed when the leg is dissected.

The course which the popliteal artery takes through the
popliteal fossa is not straight. At first it descends vertically
and so reaches the middle of the fossa between the
condyles of the femur. From that point to its termina-
tion it inclines obliquely, distally and laterally. Throughout
the greater part of its length it is placed deeply. In the
proximal part of the fossa it is covered by the semimem-
branosus, but where it lies in the interval between the two
condyles, although it is placed deeply in the fat of the
fossa, it is covered merely by the integuments and fasciae
of the tibial nerve, and the popliteal vein. That part of
the vessel is very short, however, not more than about
25 mm. ; then it passes between and anterior to the two
heads of the gastrocnemius, is crossed by the plantaris,
and finally, at its termination, it sinks under cover of the
proximal border of the soleus. Throughout its whole course
the popliteal artery rests against the floor of the popliteal



THE INFERIOR EXTREMITY



fossa. In its proximal part it is separated from the femur

by some fatty tissue ; at
the level of the interval
between the condyles of
the femur it crosses the
oblique ligament of the
knee joint ; and, in the
distal part of the fossa, it
is in contact with the
fascia covering the pop-
liteus muscle.

The popliteal vein lies in
a more superficial plane,
inferior lateral and crosses the artery. In
tery the proximal part of the
fossa it is placed upon the
lateral side of the artery,
whilst in the distal part
it is situated upon its
medial side. The two
vessels, however, are in
close association through-
out, and are bound together
by a dense fibrous sheath.

The tibial nerve is super-
ficial to both vessels, and
crosses both from the lateral
to the medial side; in
the proximal part of the

fossa it lies lateral to the vein, but in the distal part it lies

on the medial side. Figs. 132, 133, 134.
The branches of the popliteal artery are :

1. Muscular.

2. Cutaneous.

3. Genicular.

The muscular branches consist of a proximal and a distal
set. The proximal branches are distributed to the hamstring
muscles near their insertions. The distal branches, termed
the sural arteries, end chiefly in the two heads of the
gastrocnemius ; but twigs go also to the soleus and plantaris.

The cutaneous branch, called the superficial sural, frequently




Adductor magnus
Popliteal vein

Popliteal artery



Superior medial
genicular artery

Superior lateral
genicular artery



Head of fibula

Inferior medial
genicular artery

Popliteus



Soleus



FIG. 137. Right Popliteal Artery and
its Branches.



POPLITEAL FOSSA 317

arises from one of the sural muscular branches, and supplies
the integument over the proximal part of the calf of the leg.
It lies in the groove between the two heads of the gastro-
cnemius, with the medial cutaneous nerve of the calf.

The genicular arteries are five in number, viz., two superior,
two inferior, and one middle or azygos.

Arterise Genu Superiores (Superior Articular Arteries).
The two superior genicular arteries spring from the main trunk
in the interval between the condyles of the femur. One pro-
ceeds from each side of the popliteal artery, and they are called
medial and lateral, according to the direction which they take.
They were found resting directly upon the popliteal surface
of the femur, and will be observed to incline slightly upwards,
and then to wind round the bone immediately proximal
to the condyles. The lateral artery is the larger of the two.
The student is apt to mistake a muscular branch for one or
other of these vessels ; but their close apposition to the
femur should in all cases be sufficient to distinguish them.

The superior lateral genicular artery runs laterally under
cover of the biceps femoris, and disappears from the popliteal
fossa by piercing the lateral intermuscular septum and enter-
ing the substance of the vastus intermedius. The superior
medial genicular artery proceeds medially under cover of the
semimembranosus, and leaves the popliteal fossa by piercing
the posterior intermuscular septum ; then it passes forwards,
under cover of the tendon of the adductor magnus, to reach
the deep surface of the vastus medialis.

Arterise Genu Inferiores (Inferior Articular Arteries).
The two inferior genicular arteries arise from the popliteal as
it lies against the distal part of the oblique popliteal ligament.
The lateral inferior genicular artery takes a transverse course
laterally, under cover of the plantaris and lateral head of the
gastrocnemius, to gain a point on the lateral side of the knee,
immediately proximal to the head of the fibula. It proceeds
onwards under cover of the fibular collateral ligament of the
knee joint. The medial inferior genicular artery takes an
oblique course, distally and medially, under cover of the medial
head of the gastrocnemius, and along the proximal border of
the popliteus muscle, to gain the medial side of the tibia
distal to the medial condyle. There it turns forwards under
cover of the tibial collateral ligament of the knee.

Arteria Genu Media (O.T. Azygos Articular Artery). The



318 THE INFERIOR EXTREMITY

middle genicular artery springs from the popliteal as it lies
upon the oblique popliteal ligament of the knee joint. It
pierces that ligament to reach the cruciate ligaments and the
synovial layer.

Vena Poplitea. The popliteal vein is formed, near the
distal border of the popliteus muscle, by the union of the
venae comites of the anterior and posterior tibial arteries.
It runs proximally through the popliteal fossa, and, entering
the adductor canal, through the opening in the adductor
magnus, it becomes the femoral vein. The relations which
it presents to the popliteal artery have already been detailed.
In addition to tributaries corresponding to branches of the
artery, it receives the small saphenous vein, which has been
seen piercing the popliteal fascia to join it. By slitting it
open with the scissors the dissector will see that it possesses
three (sometimes four) valves in its interior.

The Genicular Branch of the Obturator Nerve. This slender
continuation of the posterior division of the obturator nerve
usually lies upon the posterior aspect of the popliteal artery.
It enters the popliteal fossa by piercing the distal fibres of
the adductor magnus ; and it enters the knee joint after
passing through the oblique popliteal ligament.



BACK OF THE THIGH.

The dissection of the back of the thigh must be com-
pleted on the fifth day. The following are the structures
which are to be displayed :

1. Superficial fascia.

2. Cutaneous nerves.

3. Deep fascia.

/"Biceps femoris.

Mnc^c J Semitendinosus.

4. Muscles, 1 Semimembranosus>

^Adductor magnus.
N /Posterior cutaneous of thigh.

^_ oCltltlC.

6. Arteries, Four perforating.

Dissection. Reflection of Skin. A vertical incision must be
made, in the median line of the thigh, through the belt of skin
which still encircles the limb posteriorly. The two flaps can
then be reflected, the one laterally, and the other medially.

Superficial Tascia Cutaneous Nerves. The superficial



BACK OF THE THIGH 319

fascia of the back of the thigh presents no features of special
interest, but in it there ramify cutaneous nerves derived from
four sources, ( i ) from the posterior cutaneous nerve of the thigh,
(2) from the lateral cutaneous nerve of the thigh, (3) from the
posterior branch of the medial cutaneous nerve, and (4) from the
obturator nerve.

Dissection. The branches of the posterior cutaneous nerve
of the thigh must be sought in the superficial fascia along the
middle of the back of thigh ; they vary in number, and they pierce
the deep fascia at varying levels (Fig. 127). The search for them
will be facilitated if the dissector pulls gently on the trunk of
the nerve where it is already exposed in the lower part of the
gluteal region. The branches of the lateral and medial cutaneous
nerves should be followed from the portions of those nerves
which were displayed when the front and medial sides of the
thigh were dissected (pp. 227, 248). No time need be lost in
seeking for the cutaneous branch of the obturator nerve, for it
is not only very variable in size and position, but also it is not
uncommonly absent. When present it lies usually in the distal
and medial part of the posterior area of the thigh.

When the cutaneous nerves of the back of the thigh have
been studied the remains of the superficial fascia must be re-
moved to display the deep fascia.

Deep Fascia. The deep fascia of the back of the thigh
is thin but fairly strong. It consists of longitudinal fibres
blended with transverse fibres which serve to bind the ham-
string muscles together.

Dissection. Divide the deep fascia by a longitudinal incision
running along the middle of the back of the thigh, and be careful
not to injure the posterior cutaneous nerve of the thigh, which
lies immediately under cover of the fascia. Turn the two flaps
of deep fascia aside, and then follow and clean the posterior
cutaneous nerve which is now exposed in the whole of its length.

After the trunk of the posterior cutaneous nerve of the thigh
has been secured clean the posterior surfaces of the hamstring
muscles. They are three in number, the biceps femoris, the
semitendinosus, and the semimembranosus. The long head of the
biceps springs from the posterior part of the tuberosity of the
ischium, by means of a tendon common to it and the semi-
tendinosus. It is recognised by the fact that it runs distally and
laterally, whilst the semitendinosus and semimembranosus run
distally and medially. The short head arises from the body
of the femur. Pull the long head of the biceps medially to
expose the sciatic nerve, which lies deep (anterior) to it ; then
follow the lateral border of the sciatic nerve to secure the branch
which goes from it to the short head of the biceps. Next pull
the sciatic nerve laterally and clean the branches which pass
from it to the long head of the biceps, the semitendinosus, the
semimembranosus, and the adductor magnus. As a rule there
is one branch to the long head of the biceps, a branch which



320 THE INFERIOR EXTREMITY

divides to supply the semimembranosus and the adductor magnus,



W. CLUTAELS
MEDIUS



Muscular branch ^p
of profunda artery
Second perforating
artery



Common peroneal
nerve

Popliteal artery

Anastomotic branch of

peroneal nerve

Superior latera

genicular arten




Medial femoral
circumflex artery



M. biceps femoris (long head)



Third perforating artery
Tibial nerve (cut)



Genicular branch of obturator nerve
Popliteal artery



Superior medial genicular artery



/ M. gastrocnemius



FIG. 138. Dissection of the Posterior Region ot the Thigh.

and there are two branches to the semitendinosus, an upper and
a lower. The lower branch to the semitendinosus will be found



BACK OF THE THIGH 321

about the middle of the thigh ; the other branches arise about
the level of the ischial tuberosity.

As the nerves to the muscles are being followed ; arteries will
be found piercing the adductor magnus and passing into the
hamstring muscles ; they are branches of the profunda artery.
As many of them as possible should be preserved and cleaned.
After the nerves and arteries have been secured, pull the long
head of the biceps and the semitendinosus laterally, and clean
the semimembranosus, which lies on a deeper plane.

M. Biceps Femoris. The biceps femoris arises by two
heads a long or ischial^ and a sfwrt or femoral^ and is
inserted, chiefly, into the head of the fibula. The long head
arises from the ischium by a tendon, common to it and the
semitendinosus (Fig. 128, p. 286), which is implanted into the
medial of the two impressions on the upper part of the
ischial tuberosity. Some fibres from the sacro- tuberous
ligament are continued into it. The short head arises from
the back of the femur, distal to the insertion of the glutaeus
maximus, viz., from the lateral lip of the linea aspera, from
the proximal half of the lateral supracondylar ridge, and
from the lateral intermuscular septum. Its parallel fibres
run obliquely distally and laterally, and join the anterior and
medial surface of the tendon of insertion. This tendon, on
the lateral aspect of the knee joint, is split into an anterior
and a posterior part by the fibular collateral ligament. Both
parts are inserted into the upper aspect of the head of
the fibula anterior to the apex capituli, but, in addition, the
posterior part sends an aponeurotic expansion to the deep
fascia of the leg, and by means of a similar expansion the
anterior part gains attachment to the lateral condyle of the
tibia. Each head of the biceps femoris receives its nerve
supply from the sciatic nerve. The twigs to the long head
are derived from the tibial part of the sciatic nerve, and
that to the short head from the common peroneal part.
Both heads flex the knee joint and rotate the leg laterally.
The long head is also an extensor of the hip joint.

M. Semitendinosus. The semitendinosus muscle arises
from the medial impression on the superior part of the tuberosity
of the ischium by a tendon common to it and the long head of
the biceps femoris (Fig. 128, p. 286). The muscular belly
ends, in the distal third of the thigh, in a long cylindrical tendon
which passes downwards on the semimembranosus muscle.
At the medial side of the knee the tendon bends forwards,

VOL. i 21



3 22



THE INFERIOR EXTREMITY



crosses the tibial collateral ligament of the knee joint, and,
becoming flattened, is inserted into the proximal part of the
medial surface of the body of the tibia, near the anterior
crest of that bone, and immediately distal to the tendon of
the gracilis. From its distal border aponeurotic fibres pass
into the deep fascia of the leg ; its proximal border is adherent
to the gracilis for about half an inch from its insertion, and
both tendons are concealed by the expanded insertion of the
sartorius. A mucous bursa lies between the three tendons
and the tibial collateral ligament of the knee joint.



Biceps femoris ,

Fibular collateral
ligament"



Extensor digitorum
longus




... Semitendinosus



FIG. 139. Anterior aspect of Proximal Portions of Bones of Leg with
Attachments of Muscles mapped out.

The muscular belly of the semitendinosus is divided into
proximal and distal parts by a very oblique tendinous inter-
section, and each part receives a branch from the sciatic
nerve. The muscle is a flexor of the knee, a medial rotator
of the leg, and an extensor of the hip joint.

M. Semimembranosus. The semimembranosus muscle
arises from the lateral impression on the upper part of the
tuberosity of the ischium (Fig. 128, p. 286). The tendon of
origin is broad at its attachment to the bone, and narrows as
it passes medially anterior to the origin of the biceps femoris;
it then expands again, and, passing distally and medially,
anterior to the semitendinosus, is folded in such a manner



BACK OF THE THIGH 323

as to form a groove, in which the semitendinosus lies. The
tendon of insertion is attached chiefly to the floor of the
groove on the back of the medial condyle of the tibia, under
cover of the tibial collateral ligament of the knee joint. Three
additional attachments, however, must be noted. These are
effected by aponeurotic extensions from the tendon of in-
sertion (i) to the back of the capsule of the knee joint,
forming a considerable part of the oblique popliteal ligament ;
(2) to the surface of the popliteus muscle, which is covered
by the expansion ; and (3) to the tibial collateral ligament of
the knee joint. The semimembranosus is supplied by the
sciatic nerve. Its actions are the same as those of the
semitendinosus (see p. 322).

Nervus Ischiadicus (O.T. Great Sciatic Nerve). The
sciatic nerve commences at the lower border of the greater
sciatic foramen, and usually terminates about the middle of the
thigh, but occasionally at a higher level, by dividing into the
tibial nerve and common peroneal nerve. Its relations in
the gluteal region have already been studied. In the thigh
it lies on the posterior surface of the adductor magnus muscle,
and is covered by the long head of the biceps femoris. It
gives branches to both heads of the biceps, to the semi-
tendinosus, to the semimembranosus, and to the adductor
magnus ; the branches to the two last-named muscles arise
by a common trunk. In a few cases it gives off a long
articular twig, which enters the popliteal fossa and takes the
place of the lateral superior articular nerve, which, as a rule,
is a branch of the common peroneal nerve.

Dissection. To bring the adductor magnus more fully into
view, and to facilitate the cleaning of its posterior surface, and
at the same time to follow the terminal parts of the perforating
arteries, the hamstring muscles should be detached from their
origins and thrown distally. First detach the common tendon
of the biceps femoris and semitendinosus from the ischial tuber-
osity. When that has been done the exact attachment of the
semimembranosus is displayed, and after that muscle has been
again examined, under the present more advantageous circum-
stances, it also must be detached from its origin and turned
distally. The posterior surface of the adductor magnus will
then be fully exposed, and its attachment to the femur and its
relations to the perforating arteries can be studied.

Arterise Perforantes. Four perforating arteries will be
found in the posterior part of the thigh between the adductor
magnus muscle and the femur, close to the linea aspera.

i 21 a



3 2 4 THE INFERIOR EXTREMITY

They are branches of the profunda femoris and are called
first, second, third, and fourth, according to the level at which
they appear, proximo-distally. The fourth is the terminal
branch of the profunda, it makes its appearance about 25 mm.
(one inch) proximal to the opening in the adductor magnus
muscle through which the popliteal artery enters the popliteal
fossa. The perforating arteries and their branches must
be thoroughly cleaned, together with the apertures in the
adductor magnus through which they pass. It will then be
seen that they do not pierce the fleshy substance of the
muscle, for behind each is a tendinous arch, and the arteries
reach the posterior region of the thigh by passing between
the arches and the linea aspera, to which the piers of the
arches are attached.

The openings are in the same line with and are in all
respects analogous to the large opening in the adductor
magnus muscle for the popliteal artery. The result obtained
is the same in each case ; when the muscle contracts, the
vessels are protected from pressure.

After passing the tendinous arches the perforating arteries
wind round the posterior border of the femur on their way
to the vastus lateralis muscle, in which they end, and in
which they anastomose with branches of the lateral femoral
circumflex artery. The highest perforating artery pierces the
insertion of the glutaeus maximus before it reaches the vastus
lateralis, and the lower three pierce the femoral head of the
biceps femoris and the lateral intermuscular septum.

Anastomoses on the Posterior Aspect of the Thigh. In a
well -injected subject a chain of arterial anastomoses can be
traced from the gluteal region to the popliteal fossa, and
the present is the best time to examine it. Commencing
proximally, in the gluteal region, the superior gluteal artery
is found anastomosing with the inferior gluteal, and the
inferior gluteal with the terminal branches of the medial
femoral circumflex artery. In the posterior part of the thigh
the chain of anastomoses is carried distally by the medial and
lateral femoral circumflex arteries anastomosing with the first
perforating artery, and by anastomoses between the perforating
arteries. The chain is completed distally by anastomoses
between the most distal perforating arteries and the muscular
branches given from the popliteal artery to the hamstring
muscles.



HIP JOINT 325

Dissection. At the end of the fifth day after the subject
has been placed upon its face, the dissector must paint the various
parts in the gluteal and thigh regions with the preservative
solution, replace them in position, and fix the skin flaps over
them with a few points of suture. On the morning of the follow-
ing day he will find the body replaced upon its back, with the
pelvis and thorax supported by blocks, and he must at once
proceed to study any part of the medial region of the thigh
previously left undissected, and to examine the hip joint.

Articulatio Coxae (Hip Joint). The hip joint is the most
perfect example of an enarthrosis or ball-and-socket joint in
the body. It does not allow so free a range of movement
as that which takes place at the shoulder joint, but what
it loses in this respect it gains in strength and stability. Its
great strength and security depend (i) upon the depth of
the acetabulum and the thorough manner in which the head
of the femur is received into it; (2) upon the tension and
power of the ligaments; (3) upon the length and oblique
direction of the neck of the femur; (4) upon atmospheric
pressure and upon the strength of the surrounding muscles.

The ligaments in connection with the hip joint are :



1. Capsula articularis.

Lig. ilio-femorale.
Lig. ischio-capsulare.
Lig. pubo-capsulare.

2. Ligamentum teres.



3. Labrum glenoidale.



4. Lig. transversum acetabuli.



The capsule and the ligamentum teres are attached
to both bones entering into the construction of the joint.
The transverse ligament and the labrum glenoidale are
connected with the hip bone only; the former partially
fills the acetabular notch, whilst the latter surrounds the cir-
cumference of the acetabulum in a ring-like fashion, and serves
to deepen it still further.

Capsula Articularis. The fibrous stratum of the articular
capsule is exceedingly strong, and surrounds the joint on all
sides. Proximally^ it is attached around the acetabulum ; above
and posteriorly, directly to the hip bone, just beyond the rim of
the cavity ; anteriorly, to the superficial aspect of the labrum
glenoidale ; and below, to the transverse ligament. Distally,
it clasps the neck of the femur; anteriorly, it is attached
to the whole length of the intertrochanteric line, and to the
root of the greater trochanter ; this attachment is very firm
and strong ; posteriorly, it falls short of the intertrochanteric



326



THE INFERIOR EXTREMITY



crest by about half an inch, and its attachment to the distal
part of the posterior surface of the neck of the femur is weak.



Online LibraryD. J. (Daniel John) CunninghamCunningham's manual of practical anatomy (Volume 1) → online text (page 32 of 44)