272 SURGICAL ANATOMY OF 



monstrated from without inwards, and in the order they 

 would be met with in an operation. 



Surface Mar kings. ^-This region includes the ankle- 

 joint, and the structures immediately surrounding it, 

 and offers for examination two surfaces, an anterior and 

 a posterior. 



Anterior Surface. The two malleoli, of which the in- 

 ternal is the shorter and broader, and the external set 

 more backwards and longer, inclose a space through which 

 pass the extensors of the foot and toes, which are ren- 

 dered evident in their several movements. Beneath the 

 integument and superficial fascia lie, internally, just in 

 front of the malleolus, the internal saphena vein, accom- 

 panied by its nerve ; more externally the musctilo-cuta- 

 neous nerve, whilst passing from behind the outer mal- 

 leolus is the external saphena nerve. The aponeurosis 

 is a strengthened continuation of that of the leg, attached 

 intimately to the malleoli, consisting of a superior fas- 

 ciculus, which binds down the subjacent tendons, just in 

 front of the extremities of the tibia and fibula, and an 

 inferior, which retains them in connection with the tarsus. 

 It forms two distinct septa, commencing internally 1, 

 for the tendon of the tibialis anticus ; 2, for the tendon 

 of the extensor longus digitorum, peroneus tertius, and 

 extensor proprius pollicis, beneath which is the anterior 

 tibial vessels and nerve. These sheaths are lined with 

 separate synovial membranes. 



The posterior surface, or that portion behind the 

 malleoli, is separated by the tendo-Achillis into two 

 hollows. In the outer, beneath the integuments, is the 

 external saphena vein and nerve, lying upon the external 

 annular ligament, which is attached to the outer malleo- 

 lus and outer surface of the os calcis, binding down the 



