Fibula

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Fibula
Fibula - anterior view.png
Position of fibula in human (shown in red)
Braus 1921 293.png
Cross section of human lower leg, showing fibula in centre (latin terminology)
Latin(os) fibula
Gray'sp.260
ArticulationsSuperior and inferior tibiofibular joint
MeSHFibula
TAA02.5.07.001
FMAFMA:24479
Anatomical terms of bone
 
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For the ancient jewelry type, see Fibula (brooch).
Fibula
Fibula - anterior view.png
Position of fibula in human (shown in red)
Braus 1921 293.png
Cross section of human lower leg, showing fibula in centre (latin terminology)
Latin(os) fibula
Gray'sp.260
ArticulationsSuperior and inferior tibiofibular joint
MeSHFibula
TAA02.5.07.001
FMAFMA:24479
Anatomical terms of bone

The fibula (/ˈfɪbjələ/[1][2]) or calf bone is a leg bone located on the lateral side of the tibia, with which it is connected above and below. It is the smaller of the two bones, and, in proportion to its length, the slenderest of all the long bones. Its upper extremity is small, placed toward the back of the head of the tibia, below the level of 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[edit]

The bone has the following components:

Blood supply[edit]

The blood supply is important for planning free tissue transfer because the fibula is commonly used to reconstruct the mandible. The shaft is supplied in its middle third by a large nutrient vessel from the fibular artery. It is also perfused from its periosteum which receives many small branches from the fibular artery. The proximal head and the epiphysis are supplied by a branch of the anterior tibial artery. In harvesting the bone the middle third is always taken and the ends preserved (4 cm proximally and 6 cm distally)

Development[edit]

The fibula is ossified from three centers, one for the shaft, and one for either end. Ossification begins in the body about the eighth week of fetal life, and extends toward the extremities. At birth the ends are cartilaginous.

Ossification commences in the lower end in the second year, and in the upper about the fourth year. The lower epiphysis, the first to ossify, unites with the body about the twentieth year; the upper epiphysis joins about the twenty-fifth year.

Function[edit]

The fibula does not carry any significant load (weight) of the body. It extends past the lower end of the tibia and forms the outer part of the ankle providing stability to this joint. It has grooves for certain ligaments which gives them leverage and multiplies the muscle force. It provides an attachment points for the following muscles:

Muscle attachments (seen from the front)
Muscle attachments (seen from the back)
MuscleDirectionAttachment[3]
Biceps femoris muscleInsertionHead of fibula
Extensor hallucis longus muscleOriginMedial side of fibula
Extensor digitorum longus muscleOriginProximal part of the medial side of fibulua
Fibularis tertiusOriginDistal part of the medial side of fibulua
Fibularis longusOriginHead and the lateral side of fibula
Fibularis brevisOriginDistal 2/3 of the lateral side of fibula
Soleus muscleOriginProximal 1/3 of the posterior side of fibula
Tibialis posterior muscleOriginLateral part of the posterior side of fibula
Flexor hallucis longus muscleOriginPosterior side of fibula

History[edit]

Etymology[edit]

The word fibula can be dated back to c. 1670 to describe a clasp or brooch – see fibula (brooch) – and was first used in English for the smaller bone in the lower leg c. 1706. It derives from Latin fībula, also meaning a clasp or brooch. The bone was so called because it resembles a clasp like a modern safety pin.[4]

In other animals[edit]

Because the fibula bears relatively little weight in comparison with the tibia, it is typically narrower in all but the most primitive tetrapods. In many animals, it still articulates with the posterior part of the lower extremity of the femur, but this feature is frequently lost (as it is in humans). In some animals, the reduction of the fibula has proceeded even further than it has in humans, with the loss of the tarsal articulation, and, in extreme cases (such as the horse), partial fusion with the tibia.[5]

See also[edit]

This article uses anatomical terminology; for an overview, see anatomical terminology.

References[edit]

This article incorporates text from a public domain edition of Gray's Anatomy.

  1. ^ OED 2nd edition, 1989.
  2. ^ Entry "fibula" in Merriam-Webster Online Dictionary.
  3. ^ Bojsen-Møller, Finn; Simonsen, Erik B.; Tranum-Jensen, Jørgen (2001). Bevægeapparatets anatomi [Anatomy of the Locomotive Apparatus] (in Danish) (12th ed.). pp. 364–367. ISBN 978-87-628-0307-7. 
  4. ^ etymonline.com
  5. ^ Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. p. 205. ISBN 0-03-910284-X. 

Additional Images[edit]

External links[edit]