Anatomy Of Tibia&Fibula

Note: All the notes provided us from gcvs 

recomended book Guide To The Dissection Of Dog By Howard E. Evans, PhD 

Lecture no 7

BONES OF THE PELVIC LIMB(continued)

Veterinary Anatomy  GCVS 1st semester

Tibia

The tibia the shin or leg bone, has a

proximal articular surface that flares out trans-versely and is also broad craniocaudally. It is wider

than the distal end of the femur, with which it

articulates, and is formed largely by two relatively

flat condyles. The medial condyleis separated

from the lateral condyleby the intercondylar em-inence.Both condyles include the articular areas

on their proximal surfaces and the adjacent nonar-ticular parts of the proximal extremity. The lateral

condyle is particularly prominent. It possesses a

facet on its lateral side for articulation with the

A B

Intercondylar eminence Cranial

intercondylar area

Medial condyle

Tibial tuberosity

Cranial border

Tibia

Medial malleolus

Extensor groove

Lateral condyle

Popliteal

sesamoid

Fibula

Head of fibula

Lateral malleolus

Caudal intercondylar area

Medial condyle

Popliteal notch

Tibia

A, Left tibia and fibula, cranial view. B, Articulated left tibia and fibula, caudal view.

Guide to the Dissection of the Dog 48

head of the fibula and provides origin for part of

the peroneus longus and cranial tibial muscles.

A sesamoid bone in the tendon of origin of the

popliteus (seen in radiographs) articulates with

the caudolateral condyle of the tibia. The semi-membranosus is inserted on the medial condyle.

Two biconcave fibrocartilages, the menisci,fill

part of the space between the apposed condyles

of the femur and tibia, making the joint congru-ent. The intercondylar eminenceconsists of two

small, elongated tubercles, which form its highest

part, and a shallow intercondylar area. The cranial

intercondylar areais a depression cranial to the

eminence and in large part between the condyles.

It affords attachment to the cranial parts of the me-nisci and the cranial cruciate ligament. The cau-dal intercondylar areaoccupies a place similar to

that of the cranial area but caudal to the eminence.

It provides attachment for the caudal part of the

medial meniscus. The popliteal notchis caudal

to the caudal intercondylar area and is located be-tween the two condyles. The popliteal vessels pass

through the notch. The tibial tuberosityis the

large quadrangular process on the proximocranial

surface of the tibia. The quadriceps femoris, the

biceps femoris, and the sartorius attach to this tu-berosity by means of the patella and patellar liga-ment. The tibial tuberosity is continued distally by

the cranial border of the tibia.It inclines laterally

on the body. The following muscles attach wholly

or in part to the cranial border of the tibia: biceps

femoris, semitendinosus, gracilis, and sartorius.

The extensor grooveis a small, smooth groove lo-cated at the junction of the lateral condyle and the

tibial tuberosity. The long digital extensor passes

through it.

The bodyis triangular proximally, nearly cylin-drical in the middle, and four sided distally. The

semitendinosus and gracilis are inserted on the

proximal medial surface. The proximal third of

the caudal surface serves for the insertion of the

popliteus medially and for the origins of the deep

digital flexor laterally.

The distal extremity of the tibia is quadrilat-eral in transverse section. The tibial cochlea,the

articular surface, consists of two grooves that

receive the ridges of the proximal trochlea of the

talus. The medial part of the distal extremity of

the tibia is the medial malleolus.The lateral sur-face of the distal extremity articulates with the

fibula by a small facet. No muscles arise from the

distal half of the tibia.

Fibula

The fibula has proximal and distal

extremities and an intermediate body.The proxi-mal extremity, or head,articulates with the lateral

condyle of the tibia. The distal extremity, the lateral

malleolus,has two grooves that contain the tendons

of the fibularis longus,fibularis brevis, and the lat- fibularis brevis, and the lat-  brevis, and the lat-eral digital extensor. These grooves redirect the force

of contraction. On the medial surface of the tibia is

a distinct facet for articulation with the distolateral

surface of the tibia and with the talus.

Posted in: 1st semester