Peroneus longus tendon lengthening as an adjuvant measure in cavus foot surgery.

Lengthening of the peroneus longus tendon is very important when performing cavus foot surgery. This tendon directly affects all three components (varus heel, increased arch height, and forefoot adduction) of the idiopathic cavus foot which can be accounted for by increased strength and activity of the peroneus muscle. The deforming force is removed or weakened according to the degree, duration and rigidity of the cavus foot by lengthening or transferring the tendon.