Fibula

The fibula (Latin fibula ( f ) " tacking needle ", " clip " ) is next to the shinbone ( tibia ) on which it rests laterally on the outside, one of the two bones of the lower leg. The fibula is the thinner of the two bones and a typical long bone.

Fibula in mammals

Head

The thickened upper end of the fibula ( fibular head ), runs upward into a tip (apex capitis) from. He is ( articular facies capitis fibulae ) at the central periphery by a three-sided, curved inward ( concave ) articular surface connected to the shin bone, but is not connected to the thigh bone (femur). In ruminants, the fibula head is fused with the lateral tibial condyle ( lateral condyle of the tibia ), ie the articulation canceled.

Shaft

The long and very thin compared to the tibia and fibula shaft ( corpus fibulae ) is located laterally on the tibia. He does not show very pronounced edges ( Margo medialis, lateralis and Margo Margo interosseous ), the body in three areas (facies medialis, facies lateralis and facies posterior) divide. In ruminants, the shaft is completely regressed, in horses it extends only to the middle of the lower leg. The gap between the tibia and fibula shaft ( interosseous space cruris) is spanned by strong connective tissue fibers ( interosseous membrane ) by a band adhesion ( syndesmosis ).

Bottom

The thickened lower end of the fibula forms the outer ankle ( lateral malleolus ). About his outside draws a furrow ( sulcus lateralis malleolus ) for the tendon of the peroneus. An articular surface (facies articular malleoli ) lying on its inner side to connect to the ankle bone ( talus ) and thus to the formation of the ankle and behind her a pit ( fossa malleoli lateralis), attach to the bands. In ruminants, a separate bone (Os malleolare ) is formed as remnants of the largely rudimentary fibula. In horses, the lower end of the fibula is fully merged with the tibia, so that in this species the fibula is formed only in the upper half of the lower leg as a separate bones.

Right fibula ( shin ), back

Function

Fibula has no functional influence on the knee joint, but forms with its lower end, a portion of the ankle joint. It derives from there the forces acting on the leg forces over the upper tibia fibula joint ( articulatio tibiofibularis proximalis ) and the Tape adhesion between the two bones ( interosseous membrane ) to the tibia and thus to the thigh bone ( femur).

Diseases

A fracture of the fibula ( fibular fracture, Pott's fracture) rarely occurs. It is treated surgically by osteosynthesis with metal plates and screws or by intramedullary nailing.

The Fibulaaplasie, also called fibular hemimelia is a malformation in the fibula is not formed. Usually only one limb is affected.

• Bones of the lower extremity