354 



THE INFERIOR EXTREMITY 



PERONEAL OR LATERAL CRURAL REGION. 



Before the peroneal region is opened up, the dissector 

 should examine the mucous sheaths of the tendons of the 

 peronaeus longus and brevis. Behind and below the lateral 

 malleolus the two tendons are enclosed in a common sheath, 

 but immediately posterior to the trochlear process of the 

 calcaneus the common sheath is separated into two portions, 



M. extensor digitorum longus 

 tibialis anterior 



Sheath of extensor digitorum longus 

 icath of tibialis anterior 



Tendo calcaneus 

 Retinaculum mm. 

 peronaeorum sup. 



Bursa 



Sheath of 

 peronaeus longus 



Retinaculum mm. 

 peronaeorum inf. 



Abductor digiti quinti 



M. peronceus brevis | M. flexor digiti quinti brevis 



M. extensor digitorum brevis '| M - adductor digiti quinti. 



M. peronoeus tertius 



FIG. 158. Dissection of Leg and Foot showing Mucous Sheath of Tendons. 



one for each tendon (Fig. 158). The upper portion, which 

 surrounds the continuation of the peronaeus brevis tendon, 

 extends forwards almost to the insertion of the tendon into 

 the base of the fifth metatarsal bone. The lower portion, 

 which surrounds the continuation of the peronaeus longus 

 tendon, may accompany that tendon to its insertion into the 

 lateral side of the base of the first metatarsal bone, or it may 

 end, at the lateral border of the cuboid bone, as the tendon 

 turns medially into the sole of the foot. In the latter case 

 the part of the tendon which lies in the sole has a separate 

 mucous sheath. The sheaths should either be inflated, or 



