THE ANKLE AND FOOT

THE ANKLE LIGAMENTS (N494, N495)

Lateral Collateral Ligament

Anterior and Posterior Talofibular Ligaments (Talus <====> Fibula)

Calcaneofibular Ligament (Calcaneous <====> Fibula) -- it crosses the Subtalar joint to help support it.

SPRAINED ANKLE:

Often happens by an inversion injury, where the foot is inverted, placing too much pressure on the Anterior Talofibular Ligament, which you can

sometimes see ball up.

Deltoid (Medial) Ligament: Group of four ligaments composing the medial ankle. Various tibiotarsal ligaments.

Transverse Tarsal Joint / Ligament: aka Chopart's Joint. Allows for pronation and supination of the foot. A common point of amputation.

LISFRANC'S JOINT: TARSOMETATARSAL JOINT -- very important joint. Injuries to this area are common.

Fractures of the 2nd metatarsal are common, because the 2nd metatarsal is less mobile because it is inset from the 2nd cuneiform.

Cervical Ligament

Bifurcate Ligament

Long Planter Ligament: Helps maintain the arch of the foot.

Calcaneonavicular (Spring) Ligament: Helps maintain the arch of the foot.

PLANTAR APONEUROSIS: Similar to the palmar aponeurosis, it keeps the skin on the sole of your foot immobile, so you can walk on it.

Origin from Calcaneous Tuberosity.

Inserts on much of the skin of the sole of the foot.

RETINACULA:

PERONEAL RETINACULUM: Lateral side of foot

Contents: Peroneus Longus and Peroneus Brevis tendons.

Continuous with the inferior part of the extensor retinaculum

EXTENSOR RETINACULUM: Along dorsum of foot

It is Y-Shaped, dividing into a superior and inferior portion on the lateral side of the foot. The stem of the Y is on the medial side and is continuous with

the Peroneal Retinaculum.

Contents:

Extensor Digitorum Longus tendon

Extensor Hallucis Longus tendon

Peroneus Tertius tendon

Dorsalis Pedis Artery and Deep Peroneal Nerve pass underneath.

FLEXOR RETINACULUM: On the medial side of the foot, from the medial malleolus to the calcaneous. All of the flexor tendons pass through it as they

wrap around to the plantar aspect of the foot.

Contents: Tom Dick ANd Harry

Tibialis Posterior tendon

Flexor Digitorum Longus tendon

Posterior Tibial Artery

Posterior Tibial Nerve

Flexor Hallucis Longus tendon

TARSAL TUNNEL SYNDROME: Similar to Carpal Tunnel syndrome, compression of the tibial nerve under the flexor retinaculum.

BONES OF THE FOOT (N492, N493):

Calcaneous: The heel. The inferior-most aspect of the foot.

Made primarily of cancellous bone

Has three articular surfaces that articulate with the Talus at the Subtalar joint.

Posterior Articular Surface

Middle Articular Surface

Anterior Articular Surface

Talus: The ankle-region, which articulates with the Tibia.

Articulates with the Tibia, the Fibula, and the Navicular bone.

There are no blood vessels going to the Talus. There are no muscle attachments to the Talus.

A lot of the Talus blood supply comes from the Sinus Tarsi.

Has three facets that articulate with the Calcaneous

Posterior Facet

Middle Facet

Anterior Facet

Tarsal Bones: The analog to the carpal bones in the wrist:

Cuboid Bone: Most lateral, near the 5th digit

Navicular Bone: Most medial and proximal, articulating with the Talus and Calcaneous.

Most prominent of the Tarsal bones.

It has a palpable Navicular Tuberosity.

Lateral, Intermediate, Medial Cuneiform Bones: Most distal and on the lateral side, articulating with the metatarsals.

Metatarsal Bones

Proximal, Middle, Distal Phalanges

ARCHES OF THE FOOT (N495, N496):

The arches:

Medial Longitudinal Arch: Talus is primary connection here.

Lateral Longitudinal Arch:

Transverse Arch: The Peroneus Longus Tendon helps support the Transverse arch of the foot (on the lateral side of the foot).

What keeps the foot arched?

Shape of the bones

Ligaments

Some muscular support

Three Plantar Ligaments help to maintain the Longitudinal Arch:

Calcaneonavicular (Spring) Ligament: Connect navicular bone to the Calcaneus.

Long and Short Plantar Ligaments: Along bottom of foot, help to maintain its arch.

Muscles that help the arch: Flexor Hallucis Longus Tendon connects from the heel to the big toe, holding the two ends of the Medial Arch together.

Flat-Foot Deformity:

The longitudinal arch is lost in some flat-foot deformities.

SUBTALAR JOINT: The joint between the Talus and Calcaneus.

This joint helps you walk on unlevel ground. It accommodates with eversion and inversion of the hindfoot.

Subtalar Arthritis would prevent a person from being able to walk on unlevel ground easily -- no eversion and inversion of hindfoot.

QUADRATUS PLANTAR MUSCLE (2nd layer): CLAW-TOE Deformity results from scarring of this muscle. The Flexor Digitorum longus tendons are just

superficial to this muscle, and they will contract with scarring of this muscle.

This is a common symptom of a compartment syndrome in this compartment in the foot.

Master's Knot of Henry (N497): The crossing of the Flexor Digitorum Longus and Flexor Hallucis Longus tendons, on the medial side of the foot.

The two run together down the medial leg, behind the medial malleolus. After they pass the medial malleolus, they cross.

BUNION: Over-pull and contraction of the Adductor Hallucis (3rd layer) Muscle.'

First toe bends in medially (in valgus)

In surgery, bunions are often fixed by releasing the muscle in the first web-space.

ARTERIES OF THE FOOT

POSTERIOR TIBIAL ARTERY: Follows the posterior tibial nerve, to supply the plantar aspect of the foot

Medial Plantar Artery

Lateral Plantar Artery

PLANTAR ARCH: Is formed by the medial and lateral plantar arteries.

Perforating Branches are sent up between first and second metatarsals, to provide anastomosis between posterior tibial and dorsalis pedis arteries.

If one of the above arteries is cut off, therefore, you can still get blood supply to the foot.

ANTERIOR TIBIAL ARTERY: Turns into the Dorsalis Pedis

Dorsalis Pedis Artery -- supplies the dorsum of the foot. It passes underneath the extensor retinaculum.

This is a good place to feel for pulses, as the artery is very superficial.

Gives off an Arcuate Artery which forms a Dorsal Superficial Arch and in turn gives off Dorsal Metatarsal Arteries.

PERONEAL ARTERY: Normally small, unless one of the above is absent. It normally peters out on top of the calcaneous.

NERVES OF THE FOOT:

TIBIAL NERVE -- Divides into

Medial and Lateral Plantar Nerves -- the primary motor innervation of the foot.

SAPHENOUS NERVE

DEEP PERONEAL NERVE

SUPERFICIAL PERONEAL NERVE

SURAL NERVE

COMPARTMENTS OF THE FOOT:

Medial Compartment

Central Compartment

Lateral Compartment

Interosseus Compartment

CLINICAL -- CALCANEOUS FRACTURES are common with falls.

The calcaneous is largely cancellous rather than cortical bone, which makes it subject to breaking.

Common mode of action: The Talus gets driven inferiorly into the calcaneous.

Boehler's Angle = the angle between the calcaneous and talus. It becomes flattened.

Fractures are most common through the Posterior Facet of the Talus.

If you don't operate you can lose the height of the foot, making it so shoes don't fit very well!

LISFRANC (TARSOMETATARSAL) JOINT FRACTURES -- most commonly occur at the 2nd metatarsal bone, because it is inset next to the 2nd cuneiform.

This is the location of the transverse arch of the foot.

You can get pain in this fracture because the superficial peroneal nerve is directly dorsal to the joint, too.

Chronic pain and arthritis is common with this, and the joint must be fixated to restore anatomical normality.

STRESS FRACTURE: A fracture that doesn't result from trauma, but results from fatigue in a bone. The fracture is usually small and/or diffuse.