Ankle Joint and joints of foot Lecture – Anatomy Lectures – MBBS Lectures

Ankle Joint

• The ankle joint is a hinged synovial joint.
• It connects:
  •  with the distal ends of the tibia and fibula
  • The proximal end of the talus
• The talus is able to move on a transverse axis in a hingelike manner.
• The shape of the bones and the strength of the ligaments and the surrounding tendons make this joint strong and stable.

Articulating Surfaces

• Distal end of tibia and fibula(along with the inferior transverse part of the posterior tibiofibular ligament)
• Trochlea of talus
• Medial and lateral mallolus
• The tibia articulates with the talus in two places:
  • 1. Its inferior surface forms the roof of the malleolar mortise, transferring the body’s weight to the talus.
  • 2. Its medial malleolus articulates with the medial surface of the talus.
• The articular surfaces are covered with hyaline cartilage.

Stability OF THE ANKLE JOINT

• The malleoli grip the talus tightly as it rocks in the mortise during movements of the joint.
• The grip of the malleoli on the trochlea is strongest during dorsiflexion of the foot (as when during tug-of-war) because this movement forces the wider, anterior part of the trochlea posteriorly between the malleoli, spreading the tibia and fibula slightly apart.
•  This spreading is limited especially by the strong interosseous tibiofibular ligament as well as the anterior and posterior tibiofibular ligaments that unite the tibia and fibula
• The interosseous ligament is deeply placed between the nearly congruent surfaces of the tibia and fibula
•  The ankle joint is relatively unstable during plantarflexion because the trochlea is narrower posteriorly and, therefore, lies relatively loosely within the mortise. It is during plantarflexion that most injuries of the ankle occur (usually as a result of sudden, unexpected,inversion of the foot)

Ligaments of ankle joint

• The medial, or deltoid, ligament is strong and is attached by its apex to the tip of the medial malleolus
  •  Below, the deep fibers are attached to the nonarticular area on the medial surface of the body of the talus
  •  the superficial fibers are attached to the medial side of the talus, the sustentaculum tali, the plantar calcaneonavicular ligament, and the tuberosity of the navicular bone.
•  The lateral ligament is weaker than the medial ligament and consists of three bands.
•  The anterior talofibular ligament  runs from the lateral malleolus to the lateral surface of the talus.
• The calcaneofibular ligament  runs from the tip of the lateral malleolus downward and backward to the lateral surface of the calcaneum.
•  The posterior talofibular ligament  runs from the lateral malleolus to the posterior tubercle of the talus.

Ankle Joint

• Capsule:
  •  The capsule encloses the joint and is attached to the bones near their articular margins.
• Synovial Membrane:
  • The synovial membrane lines the capsule.
• BLOOD SUPPLY OF ANKLE JOINT
  • The arteries are derived from malleolar branches of the fibular and anterior and posterior tibial arteries
•  NERVE SUPPLY OF ANKLE JOINT
  • The nerves are derived from the tibial nerve and the deep fibular nerve, a division of the common fibular nerve

Movements of Ankle Joint

• Dorsiflexion (toes pointing upward) and plantar flexion (toes pointing downward)
•  The movements of inversion and eversion take place at the tarsal joints and not at the ankle joint.

• Dorsiflexion is performed by the tibialis anterior, extensor hallucis longus, extensor digitorum longus, andperoneus tertius.
• It is limited by the tension of the tendo calcaneus, the posterior fibers of the medial ligament, and the calcaneofibular ligament

• Plantar flexion is performed by the gastrocnemius, soleus, plantaris, peroneus longus, peroneus brevis, tibialis posterior, flexor digitorum longus, and flexor hallucis longus.
•  It is limited by the tension of the opposing muscles, the anterior fibers of the medial ligament, and the anterior talofibular ligament.

Relations of Ankle Joint

• Anteriorly:
  •   tibialis anterior,  extensor hallucis longus,  anterior tibial vessels,  deep peroneal nerve,  extensor digitorum longus, and peroneus tertius
•  Posteriorly:
  •  tendo calcaneus and plantaris
•  Posterolaterally (behind the lateral malleolus):
  •  peroneus longus and brevis
•  Posteromedially (behind the medial malleolus):
  •  tibialis posterior,  flexor digitorum longus,  posterior tibial vessels,  tibial nerve, and  flexor hallucis longus

Joints of Foot

• Tarsal Joints
  • Subtalar Joint
  • Talocalcaneonavicular Joint
  • Calcaneocuboid Joint
  • Cuneonavicular Joint
  • Cuboideonavicular Joint
  • Intercuneiform and Cuneocuboid Joints

• Tarsometatarsal and Intermetatarsal Joints
• Metatarsophalangeal and Interphalangeal Joints

• Subtalar Joint:
  •  it is the posterior joint between the talus and the calcaneum.
•  Articulation:
  •  it is between the inferior surface of the body of the talus and the facet on the middle of the upper surface of the calcaneum
  •  The articular surfaces are covered with hyaline cartilage.
•  Type:
  •  These joints are synovial, of the plane variety.
•  Capsule:
  • The capsule encloses the joint and is attached to the margins of the articular areas of the two bones.
•  Ligaments:
  •  Medial and lateral (talocalcaneal) ligaments strengthen the capsule. The interosseous (talocalcaneal) ligament ) is strong and is the main bond of union between the two bones. It is attached above to the sulcus tali and below to the sulcus calcanei.
• Synovial Membrane
  •  The synovial membrane lines the capsule.
•  Movements
  •  Gliding and rotatory movements are possible

• Talocalcaneonavicular Joint:
  •  it is the anterior joint between the talus and the calcaneum and also involves the navicular bone 
• Articulation:
  •  it is between the rounded head of the talus, the upper surface of the sustentaculum tali, and the posterior concave surface of the navicular bone. The articular surfaces are covered with hyaline cartilage.
•  Type: synovial joint.
• Capsule:  incompletely encloses the joint.
• Ligaments :
  • The plantar calcaneonavicular ligament is strong and runs from the anterior margin of the sustentaculum tali to the inferior surface and tuberosity of the navicular bone. The superior surface of the ligament is covered with fibrocartilage and supports the head of the talus.
•  Synovial Membrane:  lines the capsule.
• Movements :Gliding and rotatory movements are possible.

• Calcaneocuboid Joint:
•  Articulation:
  •  Articulation is between the anterior end of the calcaneum and the posterior surface of the cuboid  The articular surfaces are covered with hyaline cartilage.
• Type:  synovial joint  of  plane variety.
•  Capsule: The capsule encloses the joint.
•  Ligaments: The bifurcated ligament is a strong ligament on the upper surface of the joint . It is Y shaped, and the stem is attached to the upper surface of the anterior part of the calcaneum. The lateral limb is attached to the upper surface of the cuboid, and the medial limb to the upper surface of the navicular bone.
•  The long plantar ligament is a strong ligament on the lower surface of the joint  It is attached to the undersurface of the calcaneum behind and to the undersurface of the cuboid and the bases of the third, fourth, and fifth metatarsal bones in front. It bridges over the groove for the peroneus longus tendon, converting it into a tunnel.
•  The short plantar ligament is a wide, strong ligament that is attached to the anterior tubercle on the undersurface of the calcaneum and to the adjoining part of the cuboid bone
•  Synovial Membrane: The synovial membrane lines the capsule.

• Movements in the Subtalar, Talocalcaneonavicular, and Calcaneocuboid Joints
• Inversion is the movement of the foot so that the sole faces medially. Eversion is the opposite movement of the foot so that the sole faces in the lateral direction.

Clinical

• Acute Sprains of the “Lateral Ankle”
  •   usually caused by excessive inversion of the foot with plantar flexion of the ankle. The anterior talofibular ligament and the calcaneofibular ligament are partially torn, giving rise to great pain and local swelling.
• Acute Sprains of the “Medial Ankle”
  • less common than those of the lateral ankle.
  •  may occur to the medial or deltoid ligament as a result of excessive eversion. The great strength of the medial ligament usually results in the ligament pulling off the tip of the medial malleolus.

• Pott fracture:
  • dislocation of the ankle occurs when the foot is forcibly everted .
  •  This action pulls on the extremely strong medial ligament, often tearing off the medial malleolus. The talus then moves laterally, shearing off the lateral malleolus or, more commonly, breaking the fibula superior to the tibiofibular syndesmosis.
  • If the tibia is carried anteriorly, the posterior margin of the distal end of the tibia is also sheared off by the talus, producing a “ trimalleolar fracture.” In applying this term to this injury, the entire distal end of the tibia is erroneously considered to be a “ malleolus.”

• Hallux valgus:

 it is a lateral deviation of the great toe at the metatarsophalangeal joint, is a common condition. Its incidence is greater in women than in men and is associated with badly fitting shoes. It is often accompanied by the presence of a short 1st metatarsal bone. Once the deformity is established, it is progressively worsened by the pull of the flexor hallucis longus and extensor hallucis longus muscles. Later, osteoarthritic changes occur in the metatarsophalangeal joint, which then becomes stiff and painful; the condition is then known as hallux rigidus

• Hammer Toe:
  • In this condition,the proximal phalanx is permanently  dorsiflexed (hyperextended) at the metatarsophalangeal joint, and the middle phalanx strongly plantarflexed at the proximal interphalangeal joint. The distal phalanx of the digit is often also hyperextended. This gives the digit (usually the 2nd) a hammer-like appearance . This deformity of one or more toes may result from weakness of the lumbrical and interosseous muscles, which flex the metatarsophalangeal joints and extend the interphalangeal joints.