In fracture neck of fibula, the following nerve is involved

A i.e. Common peroneal nerve Smallar terminal branch of sciatic nerve, the common peroneal (lateral popliteal) nerve arises in the lower third of thigh. It runs down ward through the popliteal fossa (lateral side) closely following the medial border of biceps femoris muscle. It leaves the fossa by crossing superficially the lateral head of the gastrocnemius muscle. It then passes behind the head of the fibula, winds laterally around the neckQ of the bone, pierces the peroneus longus muscle, and divides into two terminal branches superficial and deep peroneal nerve. The common peroneal nerve is extremely vulnerable to injury as it winds around the neck of fibulaQ by direct trauma and fractures. Injury to common peroneal nerve causes foot dropQ. Beware : an isolated fracture of proximal fibula is rare : it may be merely the most visible pa of a more extensive rotational injury of leg involving a serious fracture or ligament injury of the ankle (the Misonneuve fracture). So alsways X - ray the ankle !