Fibula

Fibula is one of the two bones located in the lower leg of humans. The other bone in the lower leg is the tibia. The fibula is the smaller of the two bones, and, in proportion to its length, it is the most slender of all the long bones. Its upper extremity is small, placed toward the back of the head of the tibia, below the knee joint and excluded from the formation of this joint. Its lower extremity inclines a little forward, so as to be on a plane anterior to that of the upper end; it projects below the tibia and forms the lateral part of the ankle joint.

Structure

The fibula does not bear any weight. It serves for muscle attachments and, together with the tibia, for the stability of the ankle. The fibula has four borders – the anterior border, the posterior border, the interosseous or medial border and the lateral border. It also has three surfaces – the medial surface, the lateral surface and the posterior surface.

Function

The main function of the fibula is to serve as an attachment for muscles. It does not bear weight. It provides stability for the ankle and support for the muscles of the lower leg, including the gastrocnemius, soleus, peroneus longus, peroneus brevis, tibialis posterior, and flexor hallucis longus muscles.

Clinical significance

Injuries to the fibula and tibia are common and can be caused by high-energy trauma, but isolated injuries to the fibula are rare. The fibula is used as a bone graft in reconstructive surgery, particularly in orthopedic surgery.

See also

• Tibia
• Ankle
• Gastrocnemius
• Soleus
• Peroneus longus
• Peroneus brevis
• Tibialis posterior
• Flexor hallucis longus

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  Fibula - anterior view
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  Fibula