arthrology and syndesmosis of the leg

PROXIMAL TIBIOFIBULAR JOINT

The proximal tibiofibular joint is located between the head of the fibula and lateral

condyle of the tibia. Structurally it is a planar or gliding synovial joint. Functionally, it is a

diarthrosis. It is reinforced by ligaments. The proximal anterior tibiofibular ligament

reinforces its anterior aspect. The proximal posterior tibiofibular ligament reinforces its

posterior aspect. This articulation undergoes rotational moments and gliding movements

when the distal tibiofibular joint separates. The proximal tibiofibular joint receives arterial

supply from the inferior lateral genicular, anterior tibial recurrent, and the posterior tibial

recurrent arteries. It receives innervation from the common peroneal nerve and the nerve to

popliteus muscle.

MIDDLE TIBIOFIBULAR JOINT

The middle tibiofibular joint is formed by the interosseous membrane as it attaches to

the interosseous borders of both the tibia and fibula. The fibers of the interosseous

membrane pass from proximal medial to distal lateral which allows the fibula to slide slightly

proximal on the tibia. This sliding accompanies a slight separation of the fibula from the

tibia at their distal extremities.

 DISTAL TIBIOFIBULAR JOIN

The distal tibiofibular joint / tibiofibular syndesmosis is located between the fibular

notch of the tibia and the roughened triangular area on the medial aspect of the fibular distal

extremity. It is a syndesmotic fibrous joint, structurally and an amphiarthrotic joint

functionally. The motion usually accompanies inversion and eversion of the foot during

closed kinetic chain motion, when the foot is fixed on the ground. It is reinforced by several

ligaments. The distal tibiofibular joint receives arterial supply from the perforating peroneal,

anterior lateral malleolar and posterior lateral malleolar arteries. It receives innervation from

the deep peroneal, tibial and saphenous nerves.

Distal Anterior Tibiofibular Ligament

- extends from the anterior border of the fibular notch of the tibia to the

anterior border of the fibula and the anterior edge of the triangular area on

the distal extremity of the fibula

- helps to prevent separation of the fibula from the tibia

Interosseous Tibiofibular Ligament

- inferior continuation of the interosseous membrane

- extends from the central part of the fibular notch of the tibia to the central part

of the rough triangular area on the fibular distal extremity

- strongest of the ligaments at this joint

- often is a small synovial extension of the ankle joint within this ligament

- prevents the talus from wedging between the tibia and fibula by preventing

separation of the fibula from the tibia

 Distal Posterior Tibiofibular Ligament

- extends from the posterior border of the fibular notch and the posterior process of the tibia to the posterior edge of the triangular area on the medial aspect of the distal fibula

- very broad ligament which decreases the posterior movement of the talus within the ankle mortise and prevents separation of the fibula from the tibia

Transverse Tibiofibular Ligament / Inferior Transverse Ligament /

Transverse Inferior Posterior Tibiofibular Ligament

- the inferior part of the posterior tibiofibular ligament which blends with the

fibrous capsule of the ankle joint

- has articular cartilage on its deep surface for articulation with the posterior

aspect of the trochlea tali so it forms part of the ankle mortise (ankle joint)

- passes from the posterior process of the tibia to the superior (½ of the)

lateral malleolar fossa of the fibula

Ankle Mortise

- the concavity formed by the distal extremities of the tibia and fibula, and the

transverse tibiofibular ligament

- articulations include the tibial plafond, the lateral malleolar facet, the medial

malleolar facet, and the articular cartilage on the transverse tibiofibular ligament

/ inferior transverse ligament

- the talus fits into this concavity

 Capsule 

- the capsule of the ankle joint attaches at the articular margins of all surfaces of

the ankle joint except the anterior trochlea tali; here it extends to the neck of the

talus to allow ankle plantar flexion (or it could be easily damaged)

- reinforced by ligaments

 Synovial Membrane

- lines all areas of the capsule

- at the junction of the tibia and fibula inferiorly (in the syndesmosis), it extends

slightly proximal to form a small recess in the interosseous tibiofibular ligament

- occasionally this recess is large enough to create a synovial joint between the

distal tibia and fibula

Distal Posterior Tibiofibular Ligament

necessary for ankle joint stability

Posterior Talofibular Ligament

- extends from the lateral tubercle of the posterior process of the talus to

the inferior (½ of the) lateral malleolar fossa of the fibula

- part of the lateral collateral ligament of the ankle joint

Posterior Talotibial Ligament

- this ligament has deep and superficial parts

- extend from the medial malleolar posterior colliculus to the

medial tubercle of the talar posterior process

- part of the medial collateral ligament of the ankle joint

Calcaneofibular Ligament

- an extracapsular ligament

- extends from the summit of the lateral malleolus to the calcaneal lateral

surface, superoposterior to fibular trochlea

- part of the lateral collateral ligament of the ankle

Calcaneotibial Ligament

- extends from the inferior aspect of the medial malleolus, anterior and

posterior colliculi, to the medial surface of the sustentaculum tali

- part of the medial collateral ligament of the ankle

Anterior Talofibular Ligament

- extends from the anterior inferior edge of the lateral malleolus to the

lateral aspect of the talar neck

- part of the lateral collateral ligament of the ankle joint

Anterior Talotibial Ligament

- extends from the inferior medial malleolus, the anterior colliculus, to the

medial aspect of the neck of the talus

- part of the medial collateral ligament of the ankle joint

Lateral Collateral Ligament of the Ankle

- reinforces the ankle joint laterally

- limits inversion of the rearfoot

- consists of 3 separate parts

Anterior Talofibular Ligament

- from the anterior inferior edge of the lateral malleolus to the lateral

aspect of the talar neck; passes primarily medial and slightly anterior

- becomes taut when the ankle joint is plantar flexed

- the most commonly injured ligament in ankle sprains

- prevents anterior displacement of the talus from the ankle mortise and

prevents excessive ankle joint plantar flexion

Calcaneofibular Ligament

- extends from the summit of the lateral malleolus to the lateral aspect

of the calcaneus, just proximal and superior to the peroneal trochlea

- an extracapsular ligament which lies deep to the peroneal tendons

- becomes taut when the ankle joint is dorsiflexed

- forms an angle of approximately 105o with the anterior talofibular

ligament

- limits inversion of the rearfoot and prevents excessive ankle joint

dorsiflexion

Posterior Talofibular Ligament

- from the inferior (1/2 of the) lateral malleolar fossa to the lateral tubercle

of the posterior process of the talus

- taut when the ankle is dorsiflexed

- prevents posterior displacement of the talus from the ankle mortise

and prevents excessive ankle joint dorsiflexion

- rarely torn in ankle sprains as its position is almost horizontal

Medial Collateral Ligament of the Ankle

- also called the Deltoid Ligament

- very thick strong ligament; rarely injured

- reinforces the ankle joint medially

- limits eversion of the rearfoot so usually injured with eversion force

- consists of superficial and deep parts

- descriptions vary from three to five ligaments present, two may be

absent or blended with others

- the common clinical description is 3 ligaments

Anterior Talotibial Ligament

- from the anterior colliculus of the medial malleolus to the

medial aspect of the talar neck

- its fibers often blend with fibers of the tibionavicular ligament

- may be absent

- taut when ankle is plantar flexed

- prevents anterior displacement of the talus from the ankle

mortise and prevents excessive ankle joint plantar flexion

Deep Posterior Talotibial Ligament

- from the posterior colliculus of the medial malleolus to the

medial tubercle of the posterior process of the talus

- a strong thick ligament

- taut when the ankle is dorsiflexed

- prevents posterior displacement of the talus from the ankle

mortise and prevents excessive ankle joint dorsiflexion

Tibionavicular Ligament

- extends from the anterior inferior aspect of the medial malleolus,

anterior colliculus, to the navicular tuberosity where it blends

with the spring ligament / plantar calcaneonavicular ligament

- weakest of the deltoid ligaments

Calcaneotibial Ligament

- extends from the medial malleolar colliculi to the medial surface

of the sustentaculum tali

- lies deep to the tendon of flexor digitorum longus as it passes along the medial edge of the sustentaculum tali

- strongest of the deltoid ligaments

- limits eversion of the calcaneus

Superficial Posterior Talotibial Ligament

- from the posterior inferior aspect of the medial malleolus,

posterior colliculus, to the medial tubercle of the posterior

talar process

- mimics the course of the deep posterior talotibial ligament and

may blend with the fibers of the deep ligament or may be absent

- taut when the ankle is dorsiflexed

- prevents posterior displacement of the talus from the ankle

mortise and prevents excessive ankle joint dorsiflexion