Distal Tibia and Fibula Landmarks

• Anterior Crest of the Tibia:

  • Located on the anterior surface of the tibia, it tapers to a point, a characteristic ridge or border.
  • Acts as a demarcation for bony attachments and separates different leg compartments.

• Interosseous Membrane:

  • Membrane connecting tibia and fibula, limits motion and dissipates forces between these bones.

• Medial Malleolus:

  • A rounded projection on the medial side of the tibia, often mistaken as the "ankle bone."

• Lateral Malleolus:

  • A similar projection on the fibula's lateral side, completes the ankle structure.

Anatomy of the Foot

• Talus:

  • The most superior bone in the foot, articulates with the tibia and fibula, critical for ankle motions (dorsiflexion, plantar flexion).
  • Unique saddle-shaped articular surface called the trochlear surface.

• Calcaneus:

  • The large heel bone beneath the talus, supports significant weight.
  • Notable landmark: Calcaneal Tuberosity where the Achilles tendon inserts.

• Navicular:

  • Located anterior to the talus; important for measuring the medial arch of the foot (navicular height).

• Cuneiform Bones:

  • A group of three bones (medial, intermediate, lateral) contributing to foot architecture.

• Cuboid:

  • The final bone in the foot skeleton, located laterally to the cuneiform bones.

Acronym for Foot Bones

• "Tiger Cubs Need Milk"
  • T = Talus
  • C = Calcaneus
  • N = Navicular
  • M = Medial Cuneiform
  • I = Intermediate Cuneiform
  • L = Lateral Cuneiform
  • C = Cuboid

Phalanges

• Digits: The foot contains five digits identical to the structure of hand bones (tarsals, metatarsals, phalanges).
• Hallux: The big toe, which has no middle phalanx.

Joints of the Foot and Ankle

• Distal Tibiofibular Joint:

  • Joint between the distal ends of the tibia and fibula, supported by ligaments for stability.

• Talocrural Joint:

  • The main joint of the ankle allowing sagittal plane movement (dorsiflexion and plantar flexion).

• Subtalar Joint:

  • Located below the talus, it allows inversion and eversion of the foot.

• Metatarsophalangeal Joints:

  • Connect metatarsals to proximal phalanges, similar to metacarpophalangeal joints in the hand.

• Interphalangeal Joints:

  • Include proximal and distal joints for the digits, with distinction in the big toe.

Stability and Ligaments

• Ligaments at Tibiofibular Joint:

  • Anterior Tibiofibular Ligament: Stabilizes the front of the joint.
  • Posterior Tibiofibular Ligament: Stabilizes the back of the joint.

• Lateral Ankle Ligaments:

  • Anterior Talofibular Ligament (ATFL): Attaches talus to fibula, critical in ankle sprains.
  • Calcaneofibular Ligament (CFL): Connects calcaneus to fibula.
  • Posterior Talofibular Ligament (PTFL): Provides stability from behind.

• Medial Ankle Stability:

  • Deltoid Ligament: A group of ligaments including:
  • Anterior Tibiotalar Ligament
  • Tibionavicular Ligament
  • Tibocalcaneal Ligament
  • Posterior Tibiotalar Ligament

Compartments of the Leg

• Superficial Posterior Compartment:

  • Comprises the gastrocnemius (lateral and medial heads) and the soleus (commonly referred to as triceps surae), sharing an insertion via the Achilles tendon on the calcaneus.

• Deep Posterior Compartment:

  • Contains tibialis posterior, flexor digitorum longus, and flexor hallucis longus.

• Lateral Compartment:

  • Includes peroneus longus and peroneus brevis (also known as fibularis longus and brevis).

• Anterior Compartment:

  • Comprises tibialis anterior, extensor digitorum longus, extensor hallucis longus, and peroneus tertius.