00:01
So here we can see,
as we go to the ankle joint, this anterior
tibiofibular ligament, and here we can see
the posterior tibiofibular ligament. And here
we can see the two articular facets of the lateral
malleolus and the medial malleolus here.
00:17
So this is where we’re going to have the
articulation with the trochlear surface
on the talus, and we can see that here. So the
joint capsule for the ankle joint is relatively
thin anteriorly and posteriorly enabling dorsiflexion
and plantarflexion to occur. There are heavy
supports lateral and medially via collateral
ligaments as we’ll see. Superiorly, the
joint capsule attaches to the articular margins
of the tibia and fibula. And inferiorly, they
attach to the talus away from those articular
surfaces. The articulations at the ankle joint
are the distal tibia and fibula with the trochlea
of the talus. So here we can see the talus,
and here we have this smooth trochlear surface.
And the distal end of the tibia and fibula
form a deep socket, and this is known as the
malleolar mortise. So with the medial malleolus
and the lateral malleolus bulging away from
the distal ends of the tibia and the fibula,
they form this mortise, and that sits on the
rounded superior surface of the talus.
01:32
Here, we can see the fibula medial surface of
the lateral malleolus with the lateral talus.
01:40
So here, we can see this medial surface of
the lateral malleolus is going to articulate
with the lateral surface of the talus. The
roof of the malleolar mortise is going to
go to the talus. So here we see the roof of the
malleolar mortise, and that’s articulating
directly on top of the talus. And the medial
malleolus, which we can see here, is going
to articulate with the medial talus. During
dorsiflexion, the joint is more stable as
the anterior talus is wider driving into the
tibia and fibula. Here, if you see, the anterior
talus is wider and it tapers away posteriorly
into this thinner region. With dorsiflexion,
the malleolar mortise is going to be sitting
against this wider anterior portion, and this
wedges into this malleolar mortise, with the
anterior and posterior tibiofibular ligaments
holding the joint tightly in position. So
with dorsiflexion, the joint becomes a lot
more stable due to the wider anterior aspect
of the talus. If we carry on looking at the
ankle joint, we can see that it’s supported
by a number of ligaments. Here again, we can
see the posterior talofibular ligament, and
we can also see we have a series of medial
and lateral deltoid ligaments. So if we look at
the ligaments of the ankle joint, the lateral
ligament is formed by three separate ligaments.
We have the anterior talofibular. Here, we
can see the anterior talofibular. This is
running from the lateral malleolus to the
neck of the talus, and it’s weak, a flat
band. We also have the posterior talofibular
ligament. We can see it here. And this is
running from the malleolus of the fibula to
the lateral tubercle of the talus. It is a thick
strong band. It is the posterior talofibular.
03:52
We can also see the calcaneofibular. Here,
we can see the calcaneofibular ligament.
04:00
And that’s running from the lateral malleolus,
the distal end of the fibula to the lateral
aspect of the calcaneus. And here we have
a rounded cord. So the lateral ligaments,
we’ve got these three separate ligaments:
anterior talofibular, posterior talofibular,
and calcaneofibular. If we look at the medial
or deltoid ligament, then this is a large
strong ligament that originates from the medial
malleolus part of the tibia. It spreads out
distally to the talus, the calcaneus, the
navicular, and it serves to stabilize the
ankle joint during eversion. Remember, this
was when your foot is lifted so that your
little toe is lifting upwards and your big toe
is flat on the floor. We have a few ligaments
that make up this medial one. We have the
tibionavicular ligament. So here, we can see
the tibionavicular ligament just running down
here. It’s very small, running from the
tibia to the navicular bone. Here, we
can see the tibiocalcaneal ligament.
05:11
So it’s running down from the tibia to the calcaneus.
Between them, we can see the anterior tibiotalar
ligament running from the tibia to the talus.
And most posteriorly, we can see the posterior
tibiotalar ligament. So we have these ligaments
that are reinforcing the medial aspects of
the joint. And this is important during eversion.
Remember, when your little toe is lifted up
and the medial aspect of your ankle is stretched,
and this can help to control that aspect of
the ankle joint.