The fibula is the lateral bone of the leg. It has an expanded upper end that articulates with the tibia, a shaft with anterior, interosseous and posterior borders, and a lower end called the lateral malleolus. The upper end bears a facet for the tibiofibular joint. The shaft gives attachment to intermuscular septa and ligaments. The lateral malleolus projects below the ankle joint and has facets that articulate with the talus.

1. SM BADAR HAYAT
TUTOR
DEPARTMENT OF ANATOMY
NMCH, JAMUHAR
FIBULA & PATELLA

2. CONTENTS
 Introduction
 Anatomical position
 Side determination
 Parts
 Attachments
 Ossification
 Clinical anatomy

3. Introduction
 It is the lateral bone of
leg and is long but very
slender.
 Its homologous with
the ulna.
 It takes no part in
transmission of body
weight.
 In latin, the term fibula
means “pin”.

4. Anatomical position
 Bone is vertically placed.

5. Side determination
 Head lies above.
 Lower end is expanded
antero-posteriorly but flat
from side to side.
 Medial surface of the lower
end has a triangular facet at
its anterior part while the
malleolar fossa lies below
and behind the facet.

6. Parts
I. Upper end (head)
II. Shaft
III. Lower end (lateral malleolus)

7. Upper end
 It is expanded all
around and overhangs
the shaft on the
posterior and lateral
aspects.
 It bears a circular facet
on its upper surfaces
which articulates with
fibular facet on the
lateral condyle of tibia
forming superior tibio-
fibular joint.

8.  Apex of head (styloid process):
it is a small blunt process,
projecting upwards from
postero-lateral aspect of head .
 Fibular collateral ligament of
knee joint is attached just in
front of the apex
 Neck: the slightly constricted
part just below the head
 It is related on its postero-lateral
aspect to common peroneal
nerve.

9. shaft
 It possesses
3 BORDER ANTERIOR INTEROSSEOUS POSTERIOR
3 SURFACES LATERAL MEDIAL POSTERIOR

10. Borders
1. Anterior :
 Extends from anterior
aspect of the upper end to
the apex of an elongated
triangular area which is
continuous below with the
lateral surface of lateral
malleolus.
 Below, it divides into two
lines between which is the
triangular area.
 To its upper 3/4th is attaced
anterior intermuscular
septum of the leg.

11. Interosseous
 Lies on medial side of
anterior border; in
upper 2/3rd the two
borders lies very close
to each other.
 It divides into two limbs
at the lower fourth to
enclose a rough
triangular area.

12. Posterior
 Begins above from lower part
of the posterior aspect of the
head and below it is
continuous with medial
border of the groove on the
back of lateral malleolus.
 Its upper part is rounded and
not easily recognisable.
 Gives attachment to posterior
intermuscular septum of leg
in its upper 3/4th part.

13. Surfaces
1. Lateral (peroneal) :
 Lies between anterior
and posterior borders.
 Its lower fourth becomes
continuous with the
groove on the back of
lateral malleolus.

14. Medial (extensor)
 Lies between anterior
and interosseous
borders.
 It is very narrow in its
upper part but is wider
below.

15. Posterior
 Lies between interosseous and posterior
borders and is the widest of all surfaces.
 Its faces backwards and medially.
 Medial crest- It is prominent vertical ridge
dividing upper 2/3rd of this surface into
two areas.
 It gives attachment to deep intermuscular
septum.
 Lower part of this surface faces medially
and fits into the fibular notch of tibia.
 It gives attachment to interosseous tibio-
fibular ligament.

16.  A nutrient foramen lies near the middle of
this surface between the medial crest and
interosseous border.
 It is directed downwards, therefore upper
end of the bone is the growing end.
 The nutrient artery is a branch of peroneal
artery.
 Anterior & posterior borders of the rough
triangular area give attachment to anterior
& posterior tibiofibular ligaments.

17. Lower end (lateral malleolus)
 It projects downwards to a lower level
than the medial malleolus and
possesses:
1. Lateral surface : It is subcutaneous,
smooth and convex.
 It forms a bony projection on lateral
aspect of ankle joint.
2. Posterior surface: It has a broad
groove which lodges tendons of
peroneus longus & brevis.
 Lateral border of the groove gives
attachment to superior peroneal
retinaculum.

18. 3. Anterior surface: It is continuous below with the
inferior border and gives attachment to anterior talo-
fibular ligament.
4. Medial surface: It has a triangular facet in front, with its
apex downwards, which articulates with lateral surface
of talus in forming ankle joint.
 Malleolar fossa: It is a rough depressed area behind
the facet. It bears many vascular foramina.
 Upper part of the malleolar fossa gives attachment to
posterior tibio-fibular ligament.
5. Inferior border: It has a small notch in front which
gives attachment to calcaneo-fibular ligament.