2. • The leg has two bones – tibia and fibula. Fibula is very
thin bone compared to tibia and can be expended except
for small length distally. This makes it usable for various
orthopedic procedures. Fibula is homologous with the
ulna. The fibula is a located on the lateral side of the tibia,
with which it is connected above and below. Fibula is the
slenderest of all the long bones.
3. Side Determination
• The upper end, or head, is slightly expanded in all
directions. The lower end or lateral malleolus is expanded
anteroposteriorly and is flattened from side to side
• The medial side of the lower end bears a triangular
articular facet anteriorly, and a deep fossa posteriorly.
5. Upper End of Fibula
• Upper end is slightly expanded in all directions making irregular quadrate
form. Its superior surface bears a circular articular facet directed upward,
forward, and medialward, for articulation with a corresponding surface on the
lateral condyle of the tibia.
• On the lateral side is a thick and rough prominence continued behind into a
pointed eminence, the apex or styloid process, which projects upward from
the posterior part of the head.
6. • Immediately below the head, the fibula constricts and the
part is referred to as neck of fibula.
7. Shaft of Fibula
• The shaft of fibula is slim and its shape is moulded
by attached muscles and therefore shows
considerable variation in its form.
• It has three borders
• -anterior, posterior and interosseus
• and three surface
• – medial, lateral and posterior
8. • The Anterior Border
• It begins just below the anterior aspect of the head. At the lower end, it
divides to enclose an elongated triangular area which is continuous with the
lateral surface of the lateral malleolus.
• The Posterior Border
• It is rounded and its upper end is in line with the styloid process. Below, the
border is continuous with the medial margin of the groove on the back of the
lateral malleolus.
9. • Interosseus or Medial Border
• It lies just medial to the anterior border, but on a more
posterior plane. It ends below at the upper end of a
roughened area above the talar facet of the lateral
malleolus. In its upper two thirds the interosseus border
lies very close to the anterior border and may be
indistinguishable from it.
10. Surfaces of Fibula
• The medial surface
• It lies between the anterior and interosseus borders. In its upper two thirds it
is very narrow, measuring 1 mm or less.
• The lateral surface
• It lies between the anterior and posterior borders. It is twisted backwards in
its lower part.
11. • The posterior surface
• It is the largest of the three surfaces. It lies between the
interosseus and posterior borders. In its upper two thirds it
is divided into two parts by a vertical ridge called the
medial crest.
12.
13. Lower End of Fibula
• It is also called lateral malleolus and along with inferior surface of tibia and
medial malleolus participates in formation of ankle joint.
• The tip of the lateral malleolus is 0.5 cm lower than that of the medial
malleolus, and its anterior surface is 1.5 cm posterior to that of the medial
malleolus. It has the following four surfaces.
• The anterior surface is rough and rounded. The posterior surface is marked
by a groove. The lateral surface is subcutaneous. The medial surface bears a
triangular articular facet for the talus (anteriorly); and the malleolar fossa
(posteriorly).
16. Head of Fibula
• The fibular collateral ligament of the knee joint
• Extensions of origins of:
1. the extensor digitorum
2. the peroneus longus
3. the peroneus longus
4. the soleus
• The capsular ligament of the superior tibio fibular joint – Around the articular
facet.
17. Medial Surface of Fibula
• Origin of the
• Extensor digitorum longus
• Extensor hallucis longus
• Peroneus tertius
18. Lateral Surface of Fibula
• Origin of
– The peroneus longus
– The peroneus brevis
19. Posterior Surface of Fibula
• Tibialis Posterior – The part of the posterior surface
between the medial crest and the interosseus border
• Soleus – Upper one fourth of the part of the posterior
surface between the medial crest and the posterior border
• Flexor hallucis longus – Lower three fourths of the part of
the posterior surface between the medial crest and the
posterior border
20. Anterior Border
• The anterior border of the fibula gives attachment to:
• The anterior intermuscular septum
• The superior extensor retinaculum
• The superior peroneal retinaculum
22. Interosseus border
• Interosseus membrane. The attachment leaves a gap at
the upper end for passage of the anterior tibial vessels.
• Deep transverse fascial septum at the medial crest.
23. Lateral Malleolus
• Anterior talofibular ligament to the anterior surface.
• Inferior transverse tibiofibular ligament (above) and posterior tibiofibular
ligament (below) to the malleolar fossa.
• The capsule of the ankle joint along the edges of the malleolar articular
surface.
• The groove on the posterior surface of the malleolus lodges the tendon of the
peroneus brevis and of the peroneus longus. Longus is superficial and
brevis is deep.
24. Clinical Significance
• Fibula is a common bone to be fractured in ankle fractures and it is very important to restore
normal fibular anatomy in ankle fractures with low fibula fractures.
• The common peroneal nerve can be rolled against the neck of the fibula. This is important
landmark in clinical examination of nerve.
• The fibula is an ideal spare bone for a bone graft and is commonly used in replacing the
length of the bone or serve as to increase graft measure in various bone surgeries.
• The lateral malleolus and the ligaments attached to it are very important in maintaining
stability at the ankle joint
