Fibula: Difference between revisions

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The lower leg is made up by two bones - the [[tibia]] and fibula.  The fibula's role is to act as an attachment for muscles, as well as providing stability of the [[Ankle Joint|ankle]] joint.
There are two bones in the lower leg - the [[tibia]] and fibula.  The fibula plays a key role in muscle attachment and contributes to the stability of the [[Ankle Joint|ankle]] joint.


=== Structure<ref name=":0">Moore KL, Dalley AF, Agur AMR. Clinial oriented anatomy. Philadelphia: Wolters Kluwer, 2010.
=== Structure ===
</ref> ===
The fibula is the thinner and posteriolaterally situated of the two lower leg bones.  These two bones are connected by the tibiofibular syndesmosis, which includes the interosseous membrane.<ref name=":0">Moore KL, Dalley AF, Agur AMR. Clinial oriented anatomy. Philadelphia: Wolters Kluwer, 2010.
The fibula is the thinner and posteriolaterally situated of the two lower leg bones.  These two bones are connected by the tibiofibular syndesmosis, which includes the interosseous membrane.
</ref>


'''Proximal:'''  A enlarged pointed head and small neck form the proximal part of the fibula.
'''Proximal:'''  The proximal part of the fibula features an enlarged pointed head and a small neck.


'''Shaft:'''  The shaft is twisted in form and triangular in cross-section. It consists of the anterior, interosseous and posterior borders, as well as medial, posterior and lateral surfaces. It is the main area for muscle attachments.
'''Shaft:'''  The shaft of the fibula is twisted and triangular in cross-section. It has anterior, interosseous, and posterior borders, as well as medial, posterior, and lateral surfaces. This area is the primary site for muscle attachments.


'''Distal:'''  The distal part of the fibula enlarges to form the lateral malleolus inferiolaterally and form part of the ankle joint.  
'''Distal:'''  At the distal end, the fibula extends to form the lateral malleolus, an important structure in the ankle joint, positioned inferiolaterally.  


== Function<ref name=":0" /> ==
== Function ==
The fibula's role is to act as and attachment for muscles, as well as providing stability of the ankle joint.  The fibula is a non-weight-bearing bone.
The fibula's role is to act as an attachment for muscles, as well as providing stability of the ankle joint.  Although it is less involved in weight-bearing compared to the tibia, it still supports a small portion of body weight, especially when the knee is flexed.<ref name=":0" />


=== Articulations<ref name=":0" /> ===
=== Articulations ===
'''Proximal:'''  The fibular head articulates with the fibular facet on the lateral tibial condyle to form the proximal tibiofibular joint.
'''Proximal:'''  The fibular head articulates with the lateral tibial condyle at the fibular facet, forming the proximal tibiofibular joint, a syndesmotic joint.<ref name=":0" />


'''Distal:'''  The lateral malleolus articulates with the a) fibular notch of the tibia  to form the distal tibiofibular joint and b) talus to form the superior part of the ankle joint
'''Distal:'''  The lateral malleolus articulates with the fibular notch of the tibia  to form the distal tibiofibular joint and the talus to form the superior part of the ankle joint


=== Muscle attachments<ref name=":0" /> ===
=== Muscle attachments ===
The fibula acts as an proximal attachment for the following muscles:
The fibula provides proximal attachment for the following muscles:<ref name=":0" />
* '''Extensor digitorum longus:'''  Superior 3/4 of medial border
* '''Extensor digitorum longus:'''  Superior 3/4 of medial border
* '''Extensor hallucis longus:'''  Middle of anterior surface
* '''Extensor hallucis longus:'''  Middle of anterior surface
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<nowiki>*</nowiki>Take note that above only describes fibular attachments, and that all of these muscles also has other areas of attachments not mentioned in this page.
<nowiki>*</nowiki>Take note that above only describes fibular attachments, and that all of these muscles also has other areas of attachments not mentioned in this page.


== Injuries<ref name=":0" /> ==
== Injuries ==
'''Fractures:'''
'''Fractures:'''


The most common area for [[Fibular Fracture|fibula]] fractures are 2-6cm proximal to the distal end of the fibula. It is also often linked to [[Ankle & Foot Fractures|ankle]] fractures.
The most common area for [[Fibular Fracture|fibula]] fractures are 2-6cm proximal to the distal end of the fibula. It is also often linked to [[Ankle & Foot Fractures|ankle]] fractures.<ref name=":0" />


== Surface Anatomy ==
== Surface Anatomy ==
* '''Fibula head:''' Very superficial. Palpable at the posteriolateral aspect of the knee on the level of the tibial tuberosity.
* '''Fibula head''': Very superficial and palpable at the posteriolateral aspect of the knee, level with the tibial tuberosity.
* '''Fibula neck:''' Distal to lateral part of fibula head.
* '''Fibula neck''': Situated distal to the lateral part of the fibula head.
* '''Fibula shaft:''' Distal 1/4 is palpable.
* '''Fibula shaft''': The distal 1/4 is palpable.
* '''Medial malleolus:''' Superficial prominence on lateral side of ankle.
* '''Lateral malleolus''': A superficial prominence on the lateral side of the ankle, distinct from the medial malleolus of the tibia.


== Resources  ==
== Resources  ==

Revision as of 12:22, 10 January 2024

Original Editor - Leana Louw

Top Contributors - Leana Louw and Kim Jackson  

Description[edit | edit source]

Fibula 360 view bigger.gif


There are two bones in the lower leg - the tibia and fibula. The fibula plays a key role in muscle attachment and contributes to the stability of the ankle joint.

Structure[edit | edit source]

The fibula is the thinner and posteriolaterally situated of the two lower leg bones. These two bones are connected by the tibiofibular syndesmosis, which includes the interosseous membrane.[1]

Proximal: The proximal part of the fibula features an enlarged pointed head and a small neck.

Shaft: The shaft of the fibula is twisted and triangular in cross-section. It has anterior, interosseous, and posterior borders, as well as medial, posterior, and lateral surfaces. This area is the primary site for muscle attachments.

Distal: At the distal end, the fibula extends to form the lateral malleolus, an important structure in the ankle joint, positioned inferiolaterally.

Function[edit | edit source]

The fibula's role is to act as an attachment for muscles, as well as providing stability of the ankle joint. Although it is less involved in weight-bearing compared to the tibia, it still supports a small portion of body weight, especially when the knee is flexed.[1]

Articulations[edit | edit source]

Proximal: The fibular head articulates with the lateral tibial condyle at the fibular facet, forming the proximal tibiofibular joint, a syndesmotic joint.[1]

Distal: The lateral malleolus articulates with the fibular notch of the tibia to form the distal tibiofibular joint and the talus to form the superior part of the ankle joint

Muscle attachments[edit | edit source]

The fibula provides proximal attachment for the following muscles:[1]

  • Extensor digitorum longus: Superior 3/4 of medial border
  • Extensor hallucis longus: Middle of anterior surface
  • Fibularis tertius: Inferior 1/3 of anterior surface
  • Fibularis longus: Fibular head and superior 2/3 of lateral surface
  • Fibularis brevis: Inferior 2/3 of lateral surface
  • Soleus: Fibular head (posterior) and superior 1/4 of posterior surface
  • Flexor hallucis longus: Inferior 2/3 of posterior surface
  • Flexor digitorum longus: Via tendon
  • Tibialis posterior: Posterior surface

*Take note that above only describes fibular attachments, and that all of these muscles also has other areas of attachments not mentioned in this page.

Injuries[edit | edit source]

Fractures:

The most common area for fibula fractures are 2-6cm proximal to the distal end of the fibula. It is also often linked to ankle fractures.[1]

Surface Anatomy[edit | edit source]

  • Fibula head: Very superficial and palpable at the posteriolateral aspect of the knee, level with the tibial tuberosity.
  • Fibula neck: Situated distal to the lateral part of the fibula head.
  • Fibula shaft: The distal 1/4 is palpable.
  • Lateral malleolus: A superficial prominence on the lateral side of the ankle, distinct from the medial malleolus of the tibia.

Resources[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 Moore KL, Dalley AF, Agur AMR. Clinial oriented anatomy. Philadelphia: Wolters Kluwer, 2010.