Fibula

The long thin bone

Beside (lateral)tibia
Articulate twice with tibia,once with the talus
The main part in forming the lateral border of the ankle joint
Little wieght

Blood Supply
The blood supply is important for planning free tissue transfer because the fibula is commonly used to reconstruct the mandible. The shaft is supplied in its middle third by a large nutrient vessel from the peroneal artery. It is also perfused from its periosteum which receives many small branches from the peroneal artery. The proximal head and the epiphysis are supplied by a branch of the anterior tibial artery. In harvesting the bone the middle third is always taken and the ends preserved (4cm proximally and 6cm distally)

The fibula is ossified from three centers, one for the shaft, and one for either end.
Ossification begins in the body about the eighth week of fetal life, and extends toward the extremities. At birth the ends are cartilaginous.
Ossification commences in the lower end in the second year, and in the upper about the fourth year. The lower epiphysis, the first to ossify, unites with the body about the twentieth year; the upper epiphysis joins about the twenty-fifth year.

the proximal and distal fibular ends are distinctive and are rarely confused with other bones.
fibular shafts are thin,straight and usually quatrilateral (sometimes rectangular) with sharp crests and corners.they are thus more irregular in cross section than either radial or ulnar shafts.