D. J. (Daniel John) Cunningham.

Cunningham's manual of practical anatomy (Volume 1) online

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oblique head of the adductor hallucis. In addition to that
muscle it supplies all the interosseous muscles (with the
exception of those in the fourth space), the transverse head of
the adductor hallucis, and the lateral three lumbrical muscles.
The twig to the second lumbrical takes a recurrent course
round the anterior border of the transverse head of the
adductor hallucis.



SOLE OF THE FOOT



399



Dissection. Detach the transverse head of the adductor
hallucis from its origin and throw it medially, towards the
hallux, to display the transverse ligament of the heads of the
metatarsal bones.

Transverse Ligament of the Heads of the Metatarsal
Bones. The transverse ligament of the heads of the meta-



Nerve to abductor digiti quint i

Lateral plantar artery
Lateral plantar nerve



Lateral plantar nerve,

deep division

Lateral plantar nerve,

superficial division -
Nerve to Mm. interossei of fourth space
Nerve to M. flexor digiti quinti brevi

Plantar arch




Posterior tibial artery

Medial plantar nerve

Lateral plantar nerve

Nerve to M. quadra tus plantae

Nerve to M. abductor hallucis

Nerve to M. flexor digitorum brevis

Medial plantar nerve
Medial plantar artery



Plantar end of dorsalis pedis artery
Nerve to M. flexor hallucis brevis
Nerve to M. lumbricalis i



FIG. 175. Arteries and Nerves of the Sole of the Foot. (Diagram.)
The plantar nerves and their branches are uncoloured.

tarsal bones is a strong fibrous band which stretches across
and is attached to the plantar accessory ligaments of the
five metatarso-phalangeal joints. It differs from the corre-
sponding ligament of the hand, inasmuch as it includes within
its grasp the plantar accessory ligament of the metatarso-
phalangeal joint of the first digit.

Dissection. A satisfactory display of the interosseous muscles
cannot be obtained unless the transverse ligament is divided



400 THE INFERIOR EXTREMITY

between the heads of the various metatarsal bones. The toes
can then be separated more freely from each other, and the
interosseous muscles traced to their insertions. It is well, at
this stage, to reflect the flexor digiti quinti brevis also.

Interosseous Muscles. There are seven interosseous
muscles, three plantar and four dorsal. The plantar inter-
osseous muscles are so placed that they adduct the lateral three
toes towards the middle line of the second toe. They arise
from the plantar aspects and parts of the medial surfaces of
the lateral three metatarsal bones, and each is inserted upon
the medial side of the first phalanx of the corresponding toe.
The dorsal interosseous muscles occupy the four intermetatarsal
spaces, and consequently they must be dissected upon both
plantar and dorsal aspects of the foot. They are arranged so
as to abduct the second, third, and fourth toes from the
middle line of the second toe. Each arises by two heads
from the dorsal parts of the adjacent sides of the metatarsal
bones which bound the cleft in which it lies. They are
inserted as follows : \hz first, upon the medial side of the first
phalanx of the second toe ; the second, upon the lateral side
of the same phalanx ; the third, upon the lateral side of the
first phalanx of the third toe ; and the fourth, upon the lateral
side of the first phalanx of the fourth toe. The slender
tendons of the interosseous muscles are only very slightly
attached to the bases of the proximal phalanges. They are
inserted for the most part into the expansions of the extensor
tendons on the dorsal aspect of the toes (p. 346).

Tendons of the Tibialis Posterior and Peronseus Longus.
Before leaving the sole of the foot the dissector must deter-
mine the precise insertions of the tendons of the tibialis
posterior and of the peronaeus longus. The tendon of the
tibialis posterior is inserted not merely into the tuberosity
of the navicular bone. Fibrous slips are seen to spread out
from it, and these may be traced to every bone of the tarsus,
with the exception of the talus, and also to the bases of the
second, third, and fourth metatarsal bones. As it lies under
and gives support to the head of the talus, the tendon of the
tibialis posterior has developed within it a sesamoid nodule
of fibro-cartilage, and in some cases a sesamoid bone
(Fig. 103).

The tendon of the peronczus longus turns round the
lateral margin of the foot, and runs medially, across the



SOLE OF THE FOOT



401



M. adductor hallucis (oblique head)



sole, in the groove on the plantar surface of the cuboid
bone, to reach the base of the first metatarsal bone. As
it traverses the sole it is enclosed in a fibrous sheath.
The sheath is formed mainly by fibres derived from the
long plantar ligament. Open the sheath, and its smooth,
glistening internal surface will be displayed. The glistening
appearance is due to the mucous layer which lines it
(see p. 354). The
tendon is inserted
into the plantar part
of the base of the
first metatarsal bone,
and also to a slight
degree into the ad-
jacent part of the first
cuneiform bone. In

some cases it sends mlUSfeS Kffl^M M
a slip to the base of
the second metatarsal
bone also. As the
tendon winds round
the cuboid bone it is
thickened, and con-
tains a nodule Of JU=^ \ 7H^F^~^ Flexor hallucis

fibro- cartilage, or a
sesamoid bone.




Tibialis
posterior

Flexor digi-
torum longus



longus



Dissection.

The dissection of

the sole of the foot

is brought to an

end by disarticulat- FIG. 176. The insertions of the Tibialis Posterior

ing the proximal and Peronaeus Longus Muscles in the Right

end of the first Foot. (Paterson.)

metatarsal bone. A

good view is thus obtained of the continuity between the dorsalis

pedis artery and the plantar arch.



ARTICULATIONS.

The dissection of the knee joint, the ankle joint, the tibio-
fibular joints, and the various articulations of the foot, may
now be proceeded with. It is possible that the ligaments may
have become hard and dry. If that is the case, soak the
joints in water for an hour or two.

VOL. I 26



402 THE INFERIOR EXTREMITY



ARTICULATIO GENU (KNEE JOINT).

In the knee-joint three bones are in apposition, viz.,
the distal end of the femur, the proximal end of the
tibia, and the patella. It is the largest and most com-
plicated articulation in the body ; and, when the bones are
examined in the dried skeleton, the joint presents an apparent
insecurity, because the bony surfaces show little adaptation
the one to the other. In reality, however, the knee joint is
very strong, and, on account of the strength of the ligaments
which retain the bones in place, it very rarely suffers dislocation.
The ligaments on the exterior of the joint are :

1. The capsular ligament.

2. Two collateral ligaments fibular and tibial.

3. The ligamentum patellae (or anterior ligament).

4. The oblique popliteal ligament.

Dissection. Before the dissection of the knee joint itself is
commenced, the nerves which supply it, and the arteries which
anastomose around it and provide its blood supply should be
displayed and studied. To a certain extent they can be dissected
simultaneously. The superior, inferior, and middle articular
branches of the tibial nerve, the superior and inferior articular
branches of the common peroneal nerve, and the articular
branch of the obturator nerve were found during the dissection
of the popliteal fossa, each being accompanied by a genicular
branch of the popliteal artery.

Note that the middle genicular branch of the tibial nerve,
the accompanying artery, and the articular branch of the ob-
turator nerve pierce the posterior ligament of the knee joint.
They supply structures inside the capsule, but the demonstra-
tion of their distribution is very difficult, and no attempt must
be made to follow them further at present.

The branches of the femoral nerve to the vastus medialis, the
vastus intermedius, and the vastus lateralis send twigs to the
knee, and twigs of the descending branch of the lateral femoral
circumflex artery descend with the nerve to vastus lateralis to
take part in the anastomosis round the joint. The nerves and
the artery mentioned were found during the dissection of the
thigh. Attempt to trace them now to the knee, and demonstrate,
if possible, the anastomosis of the descending branch of the lateral
femoral circumflex artery with the superior lateral genicular
branch of the popliteal artery, and with the muscular branches
of the arteria genu suprema. Next trace the superior genicular
branches of the popliteal artery and the accompanying nerves.
The medial superior genicular artery, as it leaves the popliteal
fossa, pierces the posterior intermuscular septum of the thigh,
and then passes between the tendon of the adductor magnus
and the femur before it enters the vastus medialis, where it
anastomoses with the adjacent arteries. The lateral superior
genicular artery, and the accompanying nerve, must be followed



KNEE JOINT 403

through the lateral intermuscular septum, and between the
biceps femoris and the bone, into the substance of the vastus
intermedius.

As the inferior genicular vessels and nerves are followed care
must be taken to avoid injury to the collateral ligaments of the
knee joint. Cut through the biceps femoris at the level of the
proximal part of the lateral condyle of the femur, pull the distal
part downwards, and clean the fibular collateral ligament, which
descends from the lateral epicondyle of the femur through the
tendon of the biceps to the head of the fibula (Fig. 178). Then
follow the inferior lateral genicular artery and nerve forward,
between the fibuiar collateral ligament and the fibrous capsule
to the front of the knee. Next throw the tendons of the sartorius,
gracilis, and semitendinosus forwards ; clean the broad tibial
collateral ligament, which descends from the medial epicondyle
of the femur to the medial condyle and the medial surface of the
tibia ; then follow the inferior genicular artery and the accom-
panying nerve along the proximal border of the popliteus to the
point where they disappear under cover of the tibial collateral
ligament below the medial condyle of the tibia. Turn now to
the anterior border of the tibial collateral ligament, and secure
the inferior medial genicular artery as it issues from under cover
of the tibial collateral ligament, and, if possible, display its
anastomoses with the adjacent arteries.

Now turn to the recurrent branches of the anterior tibial
artery. The posterior tibial recurrent artery springs from the
anterior tibial artery at the back of the leg and ascends to the
knee anterior to the popliteus; therefore that muscle must be
reflected. Cut through the narrow part of the muscle, immedi-
ately medial to the proximal tibio-fibular joint, and turn the
medial part to the medial side ; then follow the artery to its
termination and at the same time note the termination of the
nerve to the popliteus ; it enters the anterior surface of the
muscle.

The anterior tibial recurrent artery and the accompanying
branch of the common peroneal nerve were displayed during
the dissection of the anterior and lateral regions of the leg.
Follow them now through the proximal part of the origin of the
tibialis anterior to their terminations.

Anastomosis around the Knee Joint. The most important
of the anastomoses around the knee joint are placed on the
anterior aspect of the articulation, and take the form of
three transverse arches. The most proximal of these arterial
arcades passes through the superficial fibres of the quadriceps
extensor, close to the proximal border of the patella, and is
formed by the union of a branch from the superior lateral
genicular artery with a twig from the articular branch of the
arteria genu suprema. The middle and the distal transverse
arches are both placed under cover of the ligamentum patellae.
The middle arch runs across in the fatty tissue close to the
distal end of the patella. It is formed by the inferior lateral
i 26 a



404



THE INFERIOR EXTREMITY



genicular artery, and a branch which results from the union of
a twig from the arteria genu suprema, and another from the
superior medial genicular artery. The most distal arch lies on
the tibia, immediately above its tuberosity, and results from
the anastomosis of the anterior recurrent tibial and inferior
medial genicular arteries. The proximal and middle of these
transverse arches are connected, on each side of the patella,
by ascending and descending branches, which anastomose
with one another, and thus enclose the patella in an
irregularly quadrilateral arterial framework. From all sides of
this arterial enclosure, twigs are given off which enter small



Deep branch of
arteria genu suprema

M. vastus medialis



Superior medial
artery of the knee



Ligamentum patellae
Medial meniscus



Ligamentum patell

Inferior medial

artery of the knee

Tibial collateral

ligament

Sartorius




M. vastus lateralis



M. rectus femoris
M. biceps femoris

Superior lateral
artery of the knee

Patella

Fibular collateral
ligament

Inferior lateral
artery of the knee

Fibular collateral
ligament

Head of fibula

Anterior recurrent
tibial artery

Anterior tibial artery



FlG. 177. Anastomosis on the front of the Left Knee Joint.



foramina on the anterior surface of the patella to supply the
osseous substance. Six arteries, therefore, take part in the
formation of this system of anastomoses on the front and
lateral aspects of the joint, viz., the musculo-articular branch
of the arteria genu suprema, the two superior and the two
inferior genicular branches of the popliteal, and the anterior
recurrent branch of the anterior tibial. In addition to the
twigs which proceed from these to form the arterial arches,
numerous branches are given which spread over the bones in
the form of a close meshwork. During the dissection of the
articulation these vessels will become apparent.



KNEE JOINT 405

The knee joint is supplied on its posterior aspect by twigs derived from
all the genicular branches of the popliteal. These twigs are variable in
their origin, and the anastomoses which are formed between them are
unimportant and inconstant. They are supplemented by another artery,
the posterior recurrent tibiaL This small vessel ramifies over the distal
part of the oblique popliteal ligament, and inosculates with the two inferior
genicular branches of the popliteal.

The middle genicular artery is destined chiefly for the supply of the
interior of the joint. It pierces the oblique popliteal ligament, passes
forwards between the cruciate ligaments, and ramifies in the fatty tissue
in that situation. Its terminal twigs usually anastomose with the middle
arch in front of the knee joint. It will be dissected, at a later stage, in the
interior of the joint.

Articular Nerves of the Knee Joint. The knee joint is
richly supplied with nerves. No less than ten distinct
branches may be traced to it. The femoral nerve, the
common peroneal, and the tibial nerve trunks contribute
three twigs apiece to this articulation, and the obturator
nerve furnishes a filament to its posterior aspect. The femoral
nerve supplies the joint through branches which proceed from
the nerves to the vastus lateralis, vastus medialis, and to the
musculus articularis genu portion of the vastus intermedius.
These nerves pierce the fibres of the quadriceps muscle, and
are distributed to the proximal and anterior part of the
articulation. The articular branch from the nerve to the
vastus medialis is of larger size than the other two, and
it accompanies an articular branch of the arteria genu
suprema. The common peroneal nerve gives off (i) the
superior and inferior lateral articular nerves, which accompany
the corresponding genicular arteries, and end in fine filaments
which pierce the capsule of the joint; and (2) the recurrent
articular nerve, which accompanies the anterior recurrent
tibial artery. This nerve ends chiefly in the tibialis anterior
muscle ; but a fine twig may reach the distal part of the
anterior aspect of the knee joint. The tibial nerve furnishes the
knee joint with superior and inferior medial articular branches
and a middle articular nerve, which accompany the corre-
sponding genicular arteries. The branch from the obturator
nerve descends on the postero-medial aspect of the popliteal
artery as far as the back of the knee joint. At that point
it leaves the artery and, inclining forwards, breaks up into
several filaments which pierce the oblique popliteal ligament
separately.

Dissection. Remove the popliteal vessels, tibial and common
peroneal nerves, and the muscles surrounding the knee joint,
i 26 &



406



THE INFERIOR EXTREMITY



Portions of the tendons of the biceps femoris, semimembranosus,
sartorius, semitendinosus, gracilis, and popliteus, together with
small pieces of the heads of the gastrocnemius, should be left
in place in order that their connections with the ligaments of
the joint may be studied. The quadriceps extensor may be
divided about three inches proximal to the patella, and the distal
part allowed to remain in position.



Patellar surface of femur



Impression of lateral

meniscus



Lateral tibial surface



Fibular collateral
ligament

Tendon of biceps
femoris

Anterior tibio-

fibular ligament

Fibular collateral

ligament



Opening in inter-
osseous membrane for
anterior tibial vessels




Semilunar facet for
patella

_ Medial tibial
surface



Posterior crucial
ligament



Anterior cruciati
ligament

Transverse ligt.
Medial meniscus



Tibial collateral
ligament



Ligamentum patelh



Medial perpendicular
facet on patella



FIG. 178. Dissection of the interior of the Knee Joint from the front.

Capsula Articularis. The capsule of the knee joint,
together with the tibial collateral ligament and the oblique
popliteal ligament, form a complete investment for the joint.
In some places the fibrous or peripheral part of the capsule
has disappeared and has been replaced either by bone and
cartilage or by tendon, and in other places it has been
strengthened and extended by the incorporation of adjacent
portions of fascia and tendons; thus, anteriorly, the patella



KNEE JOINT 407

entirely replaces a portion of the capsule. Proximal to the
patella the capsule is represented merely by the synovial
stratum covering the posterior surface of the tendon of the
quadriceps muscle ; on the other hand the antero-medial and
the antero-lateral parts of the capsule have been strengthened
by fusion with expansions from the vasti portions of the
quadriceps and with the superjacent parts of the fascia lata.
The position and attachments of the original capsule are still
indicated, in the adult, by the synovial layer which forms
a continuous enclosing membrane except in the region of the
patella.

Ligamentum Patellae. The patellar ligament is situated
in relation to the distal part of the front of the capsule.
It constitutes, at the same time, the tendon of insertion of
the quadriceps extensor muscle and a ligament connecting
the patella with the tuberosity of the tibia. Its anterior
surface and margins should be carefully denned.

The ligament is a strong band, about two inches long,
which is attached proximally to the apex of the patella, and
distally to the smooth proximal part of the tuberosity of
the tibia. Its superficial fibres are directly continuous, over
the surface of the patella, with the central part of the common
tejidon of the quadriceps extensor. Its deep surface is
'separated proximally from the synovial layer by the infra-
patellar pad of fat, and distally it is separated from the
anterior surface of the proximal end of the tibia by the deep
infrapatellar bursa (Fig. 181).

Ligamentum Collaterale Fibulare (O.T. External Lateral
Ligament). The fibular collateral ligament is rounded and
cord -like. It stands well away from the joint cavity, and
takes no part in the formation of the articular capsule. It
is attached proximally to a tubercle on the lateral condyle
of the femur ; distally, it is fixed to the head of the fibula,
anterior to the apex. It is closely associated with the tendon
of the biceps femoris and the tendon of the popliteus. It
splits the tendon of the biceps into two pieces, and extends
between them to its fibular attachment. The tendon of the
popliteus takes origin from the lateral condyle of the femur
distal to and anterior to the femoral attachment of the fibular
collateral ligament. As the tendon runs backwards it lies
under cover of the fibular collateral ligament, but is separated
from it by the articular capsule.
i 26 c



408



THE INFERIOR EXTREMITY



Fibular collateral
ligament
Popliteus

Lateral meniscus



An additional slip is sometimes described as the posterior part of the
fibular collateral ligament. When present it ends above in the capsule,
under cover of the lateral head of the gastrocnemius. Below, it is im-
planted into the apex of the head of the fibula.

Ligamentum Collaterale Tibiale (O.T. Internal Lateral Liga-
ment). The tibial collateral ligament is a long, flat band,
broader in the middle than at either extremity. It springs
from the medial epicondyle of the femur, distal to the adductor
tubercle. As it descends it inclines slightly forwards, and,

finally, it gains attachment to
the margin of the medial
condyle and to the proximal
fourth of the body of the tibia
below the medial condyle.
At the level of the interval
between the femur and the
tibia its deep surface is fused
with and takes part in the
formation of the fibrous stratum
of the articular capsule. The
main part of the tendon of the
semimembranosus extends
forwards, under cover of its
posterior border, to gain an in-
sertion into the medial condyle

of the tibia, whilst, more distally, the inferior medial genicular
vessels are carried forwards between it and the tibia. The
tendons of the sartorius, gracilis, and semitendinosus lie
upon the lower part of its superficial surface, but are separated
from it by an intervening bursa.

The Posterior Part of the Capsule and the Ligamentum
PopliteumObliquum(O.T. Posterior Ligament). The posterior
part of the capsule extends as a continuous sheet across the
posterior aspect of the joint ; laterally it is continuous with
the lateral part of the capsule, which lies medial to the fibular
collateral ligament, and medially it fuses with the deep
surface of the tibial collateral ligament as the latter crosses
the line of the joint. The lateral head of the gastrocnemius
fuses with the proximal part of its lateral portion, and the
tendon of the popliteus passes through the distal part of the
same portion. The medial part of the posterior portion of the
capsule is separated from the medial head of the gastrocnemius




Biceps
femoris



FIG. 179. The Fibular Collateral
Ligament of the Knee Joint.



KNEE JOINT



409



by a bursa which communicates round the medial border of
the gastrocnemius with the bursa between the medial head
of the gastrocnemius and the semimembranosus, and it may
communicate with the cavity of the joint, through an aperture
in the capsule. The medial and lateral parts of the
posterior portion of the capsule, which are covered by




Tendon of adductor,
magnus muscle (cut)

M. gastrocnemius
medial head (cut)
Oblique popliteal
ligament

Bursa beneath tendon
of semimembranosus



Tendon of semimem
branosus muscle (cu

Oblique popliteal liga-
ment

'1 ibial collateral,
ligament



Popliteal fascia
M. popliteus (cut



Popliteal surface of femur



M. plantaris (cut)



M. gastro-
cnemius
lateral head
(cut)



Fibular collateral

ligament

Fibular collateral

ligament
M. popliteus
(cut)

M. biceps
femoris (cut)



Head of fibula



Popliteal surface of tibia



FIG. 1 80. The Knee Joint. Posterior view.

the heads of the gastrocnemius, are thin, but the intermediate
portion, which forms part of the anterior boundary of the
popliteal fossa, is strengthened by a strong oblique band, the
oblique popliteal ligament, which passes upwards and laterally,
from the distal part of the tendon of the semimembranosus
to the medial border of the lateral condyle of the femur.

In addition to the apertures through which the bursa



410 THE INFERIOR EXTREMITY

under cover of the medial head of the gastrocnemius com-
municates with the cavity of the joint, and that through which
the tendon of the popliteus emerges, there are several small
apertures in the posterior part of the capsule for the trans-



Online LibraryD. J. (Daniel John) CunninghamCunningham's manual of practical anatomy (Volume 1) → online text (page 40 of 44)