Fibula

Function

A slim splint beside the tibia bearing almost no weight, yet indispensable: its lateral malleolus is the ankle's key stabiliser against inversion, and eight leg muscles take origin from its shaft.

Landmarks

• Head (peroneal nerve winding around the neck)
• Neck
• Shaft
• Lateral malleolus
• Interosseous border

Articulations (joints)

• Tibia (proximal and distal tibiofibular joints)
• Talus (lateral malleolus of the ankle)

Clinical relevance

The common peroneal nerve curls around the fibular neck — leg-crossing compression causes foot drop. Weber classification of ankle fractures grades fibular fracture height.