D. J. (Daniel John) Cunningham.

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

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flexor hallucis longus

Sustentaculum tali
'lexor hallucis longus tendon (cut)

Posterior talo-calcanean
ligament




Tibio-fibular interosseous
membrane



Distal end of shaft of fibula



Posterior ligament of lateral
malleolus (O. T. Posterior
inferior tibio-fibular ligament)
Distal ligament of the
lateral malleolus
Facet on talus for distal
inferior tibio-fibular
ligament

Posterior talo-fibular
ligament



Calcaneo-fibular ligament



Posterior surface of calcaneus



FIG. 193. -Ankle Joint dissected from behind, with part of the Articular
Capsule removed.



endeavour to trace out the anastomoses between the arteries in
the neighbourhood of the joint, and if possible secure the twigs
from the tibial and deep peroneal nerves which supply the joint.

The Arterial Anastomosis around the Ankle Joint. The

arteries which anastomose around the ankle joint are: (i)
the malleolar branches of the anterior tibial artery, (2) the
perforating branch of the peroneal arteiy, (3) the terminal
part of the peroneal artery. All the vessels are very variable



420



THE INFERIOR EXTREMITY



in size, and the malleolar branches of the anterior tibia!
artery are frequently not injected in ordinary subjects.
The Ligaments of the Ankle Joint are :

1. Capsula articularis.

2. Ligamentum deltoideum.

3. Ligamentum talofibulare anterius.

4. Ligamentum talofibulare posterius.

5. Ligamentum calcaneo-fibulare.

Dissection. After the arterial anastomoses around the ankle
joint have been studied pull aside the remains of the arteries and



Fibula



Posterior ligament of

lateral malleolus (O.T.

Posterior inferior tibio-

fibular ligament)

Articular surface of

talus

Posterior talo-fibular
ligament^
Calcaneo-fibular



Posterior talo-
calcanean ligament
Calcaneus ;



Tibia



Anterior ligament of lateral malleolus
(O.T. Anterior inferior tibio-fibular ligament)

Articular surface of talus

Anterior talo-fibular ligament

Dorsal talo-navicular ligament
Talo-navicular joint

Lateral calcaneo-navicular ligament
Dorsal cuneo-navicular
and cubo-navicular ligamer
Second cuneiform



Third cuneiform



Cuboid



)rsal calcaneo-cuboid ligament
Calcaneo-cuboid joint
Tendon of peronaeus longus
Calcaneo-navicular part of bifurcate ligament
Talo-calcanean joint
Lateral talo-calcanean ligament

FIG. 194. Ligaments on the Lateral Aspect of the Ankle Joint and on
the Dorsum of the Tarsus.




nerves, and clean carefully the anterior and posterior parts of
the capsule, both of which are extremely thin and easily injured.
When the attachments and relations of the anterior and posterior
parts of the capsule have been demonstrated remove both parts
in order to bring the medial and lateral accessory ligaments more
fully into relief.

Capsula Articularis. The anterior and posterior parts of
the fibrous stratum of the articular capsule are very thin.
Medially the fibrous stratum blends with the deep surface of



ANKLE JOINT



421



the deltoid accessory ligament, and laterally it is fused with
the deep surfaces of the anterior and posterior talo-nbular
ligaments, but it has little or no connection with the calcaneo-
fibular ligament. The anterior part of the capsule (O.T.
anterior ligament) extends from the anterior margin of the
distal articular surface of the tibia to the anterior part of the




FIG. 195. Ankle and Tarsal Joints from the Medial Aspect.



1. First tarso-metatarsal joint (opened).

2. Tendon of tibialis anterior muscle

(cut).
^. Medial cuneo-navicular joint (opened).

4. Dorsal cuneo-navicular ligament.

5. Head of talus.

6. Dorsal talo-navicular ligament.

7. Trochlear surface of talus.

8. Medial malleolus.

9. Deltoid ligament of the ankle.



10. Trochlear surface of talus.

IT. Groove for tendon of tibialis posterior

muscle on plantar calcaneo-navicular

ligament.

12. Groove and tunnel for the tendon of

flexor hallucis longus muscle.

13. Calcaneus.

14. Sustentaculum tali.

15. Tendon of tibialis posterior fflmscle (cut).

16. Long plantar ligament.



dorsal surface of the neck of the talus. Therefore a transverse
vertical cut through the dorsum of the foot, immediately in
front of the tibia, will open the ankle joint (see Fig. 197).
The very short posterior part of the capsule (O.T. posterior
ligament) is attached to the margins of the articular surfaces.



422 THE INFERIOR EXTREMITY

The majority of the fibres of both the anterior and posterior
parts of the fibrous stratum of the capsule run transversely.

The Lateral Accessory Bands (O.T. External Lateral
Ligament). The lateral accessory bands of the capsule of
the ankle joint are three in number, (i) The anterior talo-
fibular ligament; (2) the posterior talo-fibular ligament;
(3) the calcaneo-fibular ligament.

The anterior talo-fibular ligament is the most anterior of
the three. It is a flattened band which passes forwards from
the anterior border of the lateral malleolus to the body of
the talus immediately adjacent to the fibular facet.

The posterior talo-fibular ligament is the strongest and the
most posterior of the three bands. It runs almost horizon-
tally, from the deep pit posterior to the distal articular surface
of the fibula to a prominent tubercle on the posterior surface
of the talus.

This tubercle is termed the posterior process of the talus. Generally
in the child, and sometimes in the adult, it is a separate piece of bone,
attached to the talus by a layer of cartilage and the surrounding
periosteum. In such cases it forms a supernumerary tarsal bone which
represents the os trigonuin found in some mammals. If this fact is not
kept in mind a fracture of the talus may be diagnosed when the separate
bone is seen in a radiograph of an injured ankle (Figs. 200, 201).

The calcaneo-fibular ligament is a round, cord -like band
which passes from the distal end of the lateral malleolus to the
lateral surface of the calcaneus.

Ligamentum Deltoideum (O.T. Internal Lateral Lig.).
The deltoid ligament is an accessory band on the medial
side of the joint. It is strong and of triangular form. Its
apex is attached to a shallow pit on the distal end of the
medial malleolus. Its fibres diverge from the apex, and are
attached in a continuous line, from before backwards, to the
navicular bone, the talus, sustentaculum tali of the calcaneus,
and posterior to that to the talus again.

Stratum Synoviale. The synovial layer lines the internal
surface of the fibrous stratum of the capsule described above,
and in some cases it sends a small process proximally
between the tibia and fibula. It is thrown into a transverse
fold anteriorly when the joint is flexed, and into a similar
fold posteriorly when the joint is extended.

Relations. Before the further examination of the joint
is proceeded with, replace the tendons, vessels, and nerves



ANKLE JOINr



423



and note their relations to the anterior and posterior
parts of the articular capsule. Anteriorly, from the medial
to the lateral side lie the tibialis anterior, the flexor hallucis
longus, the anterior
tibial artery, the deep
peroneal nerve, and the
extensor digitorum
longus with the pero-
naeus tertius. The
anastomotic branch of
the peroneal artery
descends across the
anterior talo-fibular liga-
ment lateral to the
peronaeus tertius (Fig.
154). Behind the
joint, from the medial
to the lateral side, the
structures in close rela-
tion with the capsule
are, the tibialis posterior,
the flexor digitorum
longus, the posterior
tibial artery, the tibial
nerve, the flexor hallucis
longus, and the terminal
part of the peroneal
artery. More posteriorly,
separated from the flexor
hallucis longus by a
large pad of fat, is the
tendo calcaneus with
the tendon of the
plantaris on its medial
side. The tendons of
the tibialis posterior




FIG. 196. Frontal Section through the Ankle
Joint, the Tibio-Fibular Syndesmosis, and
the Talo-Calcaneal Joints. The deltoid
ligament, on the medial side, and the
posterior talo-fibular and the calcaneo-
fibular ligaments, on the lateral side, are
shown in the section. The strong inter-
osseous talo - calcanean ligament is seen
forming the lateral boundary of the joint
between the head of the talus and the
sustentaculum tali. The positions of the
distal epiphyseal lines of the tibia and
fibula should be observed.

Light blue = articular cartilage.
Striped blue ligaments.
Green = periosteum.
Red = synovial membrane.



and the flexor digi-
torum longus lie against the superficial surface of the deltoid
ligament, and the tendons of the peronaeus longus and brevis
cross the lateral surface of the calcaneo-fibular ligament.

Dissection. Cut through the anterior talo-fibular ligament,
the calcaneo-fibular ligament, and the greater part of the deltoid

127 a



4 2 4 THE INFERIOR EXTREMITY

ligament, so that the articular surfaces can be separated and
examined.

The Articular Surfaces of the Ankle Joint. The proximal
articular area is formed by the distal surface of the tibia, the
lateral surface of the medial malleolus, and the medial surface
of the lateral malleolus. The three surfaces together form
the boundaries of a socket. It is important to note that the
socket is wider in front than it is behind, and that it is
concave both from side to side and from before backwards.
The distal articular area is formed by the dorsal surface of
the body of the talus and by parts of its medial and lateral
surfaces. It also is broader in front than behind. It is
generally convex both from before backwards and from side
to side, and it fits into the socket formed by the bones of
the leg. When the joint is dorsi-flexed, that is, when the toes
are turned upwards, the broad part of the distal articular
.area rotates backwards into the narrow part of the proximal
articular area and the joint becomes locked. When the joint
is plantar-flexed, that is, when the toes are turned downwards,
the narrow part of the distal articular area moves forwards
into the wide part of the proximal articular area and a small
amount of side to side movement becomes possible.

Movements. The movements which take place at the ankle joint are
(i) dorsal-flexion (sometimes called flexion) ; (2) plantar-flexion (some-
times called extension) ; and (3) a very limited degree of lateral movement
when plantar-flexion is complete. The two principal movements (dorsi-
flexion and plantar-flexion) take place around a horizontal axis, which is
not transverse, but which is directed laterally and posteriorly, so that it
is inclined to the median plane of the body at an angle of about 60
(Krause). This horizontal axis passes through or near the interosseous
canal between the calcaneus and talus (Henle). As the articular cavity
formed by the tibia and fibula, and also the part of the talus which
plays in it, are broader in front than behind, it follows that the
more completely the ankle joint is dorsi-flexed, the more tightly will the
talus be grasped between the two malleoli. In the erect position the talus
is held firmly in the bony socket, and portions of its articular surface project
both in front of and behind the tibia. The line of the centre of gravity
falls anterior to the ankle joint, and as a result the bones are kept firmly
locked. When, on the other hand, the ankle joint is fully plantar-flexed
(as when we rise on tip-toe) the narrower posterior part of the talus is
brought into the socket, and thus a limited amount of lateral movement is
allowed. In dorsi-flexion the calcaneo-fibular and posterior talo-fibular
bands, the greater part of the deltoid ligament, and the posterior part of
the capsule are put on the stretch. In plantar-flexion the anterior talo-
fibular ligament, the anterior fibres of the deltoid ligament, and the anterior
part of the capsule are rendered tense.

The Muscles principally concerned in producing dorsi-flexion of the



ANKLE JOINT 425

foot at the ankle joint are the tibialis anterior, the extensor digitorum longus,
the extensor hallucis longus and the peronseus tertius ; those which
operate as plantar-flexors are the superficial muscles of the calf, the
tibialis posterior, the long flexors of the toes, and the peronseus longus
and brevis.



TlBIO-FIBULAR JOINTS.

The fibula articulates with the tibia by both its proximal
and its distal extremity. The proximal of the two joints, the
articulatio tibiofibularis, is a diarthrodial joint, possessing a
cavity and a capsule with accessory thickenings. The distal
joint is a syndesmosis, the syndesmosis tibiofibularis^ but in
some cases a prolongation of the cavity of the ankle joint
projects between the distal ends of the tibia and fibula
(Fig. 196). The interosseous membrane which occupies the
interval between the bodies of the bones may be regarded as
a ligament common to both joints.

Dissection. Preparatory to the examination of the tibio-
fibular joints the foot must be removed by dividing the remains
of the ligaments on the medial and lateral aspects of the ankle
joint. The muscles also must be detached from both aspects
of the interosseous membrane and from the bones of the leg.
The ligaments may now be defined.

Membrana Interossea Cmris. The interosseous mem-
brane is a strong membrane which stretches across the interval
between the two bones of the leg, and greatly extends the
surface for the origin of muscles. It is attached on the one
hand to the interosseous border of the tibia, and on the other
to the interosseous border of the fibula. It is composed of
strong oblique fibres, which take a direction distally and
laterally from the tibia to the fibula. In the proximal part
of the membrane, immediately distal to the lateral condyle
of the tibia, there is an oval opening for the passage of the
anterior tibial vessels, whilst a small aperture, a short distance
proximal to the ankle joint, marks the point where the
membrane is pierced by the perforating branch of the peroneal
artery.

Articulatio Tibiofibularis (O.T. Superior Tibio-fibular Joint).
At the tibio-fibular joint the bones are held in apposition
by a capsule which is strengthened anteriorly and posteriorly.
The fibres of the strengthening bands pass, distally and
laterally, from the lateral condyle of the tibia to the head



426



THE INFERIOR EXTREMITY



of the fibula. The posterior band is the weaker of the two,
and the tendon of the popliteus with its synovial investment
rests upon its proximal part. The investment is a prolonga-
tion from the synovial layer of the knee joint, and in some
cases it will be found to be directly continuous with the
synovial layer of the capsule of the tibio-fibular joint.

The fibular collateral ligament of the knee joint and the
tendon of the biceps femoris muscle have important relations



Extensor
Anterior ligament of




FIG. 197. Oblique sagittal section through the Foot, along a plane extending
from the centre of the heel behind to the centre of the great toe in
front.

7. Tibialis posterior tendon.

8. Flexor digitorum longus tendon.

9. Plantar calcaneo - navicular liga-

ment.

10. M. quadratus plantae.

11. Lateral plantar vessels and nerve.



1. Flexor hallucis longus.

2. Plantar accessory metatarso-phal-

angeal ligament.

3. Sesamoid bone.

4. Flexor hallucis brevis.

5. Plantar aponeurosis.

6. M. flexor digitorum brevis.



12. Calcaneus.



to the joint. Both are attached to the head of the fibula,
lateral to the joint, and some of the tendinous fibres of the
biceps extend forwards to the lateral condyle of the tibia.
Additional support is thus afforded to the proximal tibio-
fibular joint.

Syndesmosis Tibiofibularis (O.T. Inferior Tibio-fibular
Joint) (Figs. 193 and 196). The distal tibio-fibular articula-
tion is constructed upon a stronger plan than the proximal,
because the strength of the ankle joint very largely depends
upon its security. In some cases a very narrow strip of the



TIBIO-FIBULAR JOINTS 427

distal part of each of the opposing surfaces of the bones is
articular and coated with cartilage continuous with the
cartilage on the distal ends of the tibia and fibula where they
take part in the formation of the ankle joint ; in other cases
articular cartilage is entirely absent. The surfaces of the
proximal part of the syndesmosis are always rough, and are
held together by an exceedingly strong interosseous ligament.

In addition to the important interosseous ligament three
other ligaments are present :

1. Lig. malleoli lateralis anterius (O.T. Ant. inf. tibio-fibular ligament).

2. Lig. malleoli lateralis posterius (O.T. Post. inf. tibio-fibular ligament).

3. Distal ligament of the lateral malleolus.

The anterior and posterior ligaments are flat strong bands
which pass from the tibia to the fibula, in an oblique direc-
tion, laterally and distally.

The distal part of the posterior ligament forms a strong
narrow band of yellowish fibres, which takes a transverse
course on the back of the joint and is firmly attached to
both tibia and fibula, filling up the interval between them.
It constitutes a part of the tibio-fibular socket for the
talus at the ankle joint (Figs. 192 and 193); and on the
proximal aspect of the articular surface of the talus, the
area over which it plays is usually easily distinguished. This
portion of the posterior ligament is called the distal ligament
of the lateral malleolus.

Dissection. To see the interosseous ligament of the tibio-
fibular syndesmosis the bones of the leg may be sawn through
about two inches from the distal end of the tibia, and then
divided with the saw proximo-distally in a vertical-transverse,
or frontal direction. This cut should be planned so as to pass
through the tibio-fibular syndesmosis. The short strong fibres
of the interosseous ligament will then be seen, and also the short
narrow articular interval between the distal portions of the
opposing surfaces of the bones when that interval is present. If
a cavity is present in the distal part of the joint the synovial layer
of the capsule of the ankle joint is prolonged proximally over
w the inner surface of those parts of the ligaments of the tibio-
fibular syndesmosis which help to form the boundaries of the
cavity.



ARTICULATIONS OF THE FOOT.

The articulations of the foot are very numerous. They
consist of:



428 THE INFERIOR EXTREMITY

1. Articulationes intertarseee, tarsometatarsere, and intermetatarsese.

2. Articulationes metatarso-phalangese.

3. Articulationes digitorum pedis.

The bones which enter into these articulations are the
seven tarsal bones, the metatarsal bones, and the phalanges.
The tarsal and metatarsal bones are bound together by inter-
osseous, plantar, and dorsal ligaments, and are disposed in the
form of two arches, viz., a longitudinal and a transverse. The
integrity of these arches is maintained: (i) partly by the
forms of the bones ; (2) partly by the tension of the liga-
ments ; (3) partly by supporting tendons ; and (4) partly by
the tension of the plantar aponeurosis.

The longitudinal arch presents a greater height and a
wider span along the medial than along the lateral side of the
foot. The talus lies at the summit of this arch and forms
its keystone. The posterior pillar of the longitudinal plantar
arch is short and solid, being formed by the calcaneus alone ;
the anterior pillar, much longer, is composed of several bones,
viz., the navicular, the cuboid, the three cuneiforms, and the
metatarsus. Further, the anterior pillar may be considered
as being formed of a medial column composed of the navicular,
the three cuneiform, and the medial three metatarsal bones,
and a lateral column composed of the cuboid and the lateral
two metatarsal bones. The weight of the body is trans-
mitted to the summit of the arch through the talus, and the
most important ligaments concerned in the prevention of
excessive flattening of the arch lie in the plantar concavity ;
they are the plantar calcaneo-navicular, the long plantar liga-
ment, the plantar cakaneo-cuboid ligament. The various slips
of the tendon of the tibialis posterior, as they pass to find
attachment to the different tarsal and metatarsal bones, give
additional support. The plantar aponeurosis is also an import-
ant factor, for, as it extends between the two pillars and is
attached to both, it operates, as the late Sir George Humphry
once pointed out, in the same manner as the " tie-beam " of
a roof. The transverse arch of the foot is seen to best
advantage across the line of the tarso-metatarsal articulations.

Dissection. The muscles and tendons which have hitherto
been only partially detached from the bones of the foot should
now be completely removed and the ligaments defined.

- Taloid Articulations. The talus articulates by means
of the large posterior facet on the plantar surface of its body



JOINTS OF THE FOOT



429



with the corresponding posterior facet on the dorsal surface
of the calcaneus. Its head, on the other hand, is received
into a large socket, which is formed for it by the susten-
taculum tali of the calcaneus, the navicular, and two
ligaments which pass between the calcaneus and the
navicular viz., one below, the plantar calcaneo-navicular,
and anoiher on the lateral side, the calcaneo-navicular part
of the bifurcate ligament. The two taloid articulations are
quite distinct.

The ligaments which hold the talus in its place are five
in number. Four are attached to the calcaneus and one to
the navicular bone. They are :

1. Lig. talo-calcaneum interosseum.

2. Lig. talo-calcaneum laterale.

3. Lig. talo-calcaneum mediale.

4. Lig. talo-calcaneum posterius.

5. Lig. talo-naviculare [dorsale].

The interosseous talo-calcanean ligament is by far the most
powerful. It occupies the tarsal canal, and consists of strong
fibres attached dis-
tally to the groove
between the articu-
lar facets on the
dorsal surface of
the calcaneus, and
proximally to
the corresponding
groove on the
plantar surface of
the talus.

The lateral liga-
ment is a short band
of fibres which pro-
ceeds from the
lateral surface of
the talus to the

lateral Surface of FIG. 198. Talus removed so as to show the
the calcaneus. It socket for its head.

is parallel with the

calcaneo-fibular ligament of the ankle joint, but it is placed

on a deeper plane, and lies somewhat more anteriorly.

The medial talo-calcanean ligament passes distally and




- Posterior surface of navicular
Plantar calcaneo-navicular
ligament

Calcaneo-navicular part
of bifurcate ligament

Facet on calcaneus
for head of talus

Interosseous talo-
calcanean ligament
(cut)

Facet on calcaneus
for body of talus



43 THE INFERIOR EXTREMITY

forwards, from the medial border of the groove on the talus
for the flexor hallucis longus to the sustentaculum tali.

The posterior talo-calcanean ligament passes from the pos-
terior border of the talus to the calcaneus. It closes the
posterior talo-calcanean articulation behind.

The dorsal talo-navicular ligament extends, on the dorsum
of the foot, from the head of the talus to the navicular
bone. It is thin and membranous.

The medial and lateral parts of the capsule of the ankle
joint also help to keep the talus in its place.

Dissection. Divide the various ligaments which hold the
talus in place, and remove the bone. When that has been done
the different parts which form the socket for the head of the
talus can be examined, and it will be obvious that the posterior
talo-calcanean articulation is completely cut off from the anterior
by the strong interosseous talo-calcanean ligament. The great
strength of that ligament can now be appreciated, and the three
facets on the head of the talus studied : (i) a convex 'surf ace
which looks forwards and articulates with the navicular ; (2)
an elongated facet on its plantar aspect (sometimes divided into
two), which rests upon the sustentaculum tali ; and (3) between
i and 2, a triangular facet which corresponds with the dorsal
surface of the plantar calcaneo-navicular ligament. In the
recent state (and indeed usually also in the macerated condition
of the bone) these three facets are very distinctly mapped off
from each other by intervening ridges.

Calcaneo-navicular Ligaments. Although the calcaneus
does not directly articulate with the navicular bone, it is
connected with it by two powerful ligaments, viz., a plantar
calcaneo-navicular ligament and the calcaneo-navicular part
of the bifurcate ligament.

The upper surface of the plantar calcaneo-navicular ligament
(O.T. inferior cakaneo-scaphoid ligament} is brought into view



Online LibraryD. J. (Daniel John) CunninghamCunningham's manual of practical anatomy (Volume 1) → online text (page 42 of 44)