Tibia :

The tibia is the medial and long bone of the leg. It is homologous with the radius of the upper limb.

It has two ends and one shaft.

Two ends :

1) Upper end

2) Lower end

Upper end :

The upper end has :-

• 1) Medial condyle
• 2) Lateral condyle
• 3) Inter condylar area
• 4) Tibial tuberosity

Shaft of Tibia:

The shaft has three borders and three surfaces.

Three border :   

• 1) Anterior border
• 2) Medial border
• 3) Interosseus border

Three surface:

• 1) Medial surface
• 2)  Lateral surface
• 3) Posterior surface

Lower end : 

The lower end of the slightly expanded. It has five surfaces.

Five Surfaces:  

• 1) Anterior surface.
• 2) Medial Surface
• 3) Lateral surface
• 4)  Posterior surface 
• 5) Inferior surface

                                                                                                   

The Fibula  

Fibula

The fibula is the Lateral and long bone of the leg. It is very thin as compared to tibia. It is homologous with the ulna of the upper limb.

It has two ends and one shaft.

Two ends :   

1)upper end

2) Lower end

Upper end:

The upper end has :    

• 1) Head
• 2) Neck

Shaft : 

It has three borders and three surface.

Three borders :   

• 1) Anterior border
• 2) Posterior border
• 3) Interosseus.

Three surfaces :  

• 1) Medial surface
• 2) Lateral surface
• 3) Posterior surface

Lower end :

The lower end has-

• 1) Lateral malleolus
• 2) Facet
• 3) Malleolar fossa