THE FOOT. 57 



of the scaphoid bone ; the gap between it and the sustenta- 

 culum tali being filled by the calcaneo-scaphoid ligament 

 and the tendon of the tibialis posticus, in which there is often 

 a sesamoid bone ; 5, the internal cuneiform bone ; 6, the 

 projection of the first metatarsal bone ; 7, the sesamoid bones 

 of the great toe. 



Along the outer side of the foot we can feel I, the 

 external tuberosity of the os calcis ; 2, the external mal- 

 leolus ; 3, the peroneal tubercle of the os calcis, one inch 

 below the malleolus, with the long peroneal tendon below it, 

 and the short one above it ; 4, the projection of the base of 

 the fifth metatarsal bone. 



125. Lines of joints. In fat persons the following rules 

 for finding the joints may be of service as regards the surgery 

 of the foot : 



The level of the ankle joint lies about half an inch above 

 the end of the inner malleolus. This is worth remembering 

 in performing ' Syme's ' amputation. 



The tubercle of the scaphoid bone is the best guide to the 

 astragalo-scaphoid joint which lies immediately behind it ; 

 and the plane of this joint is in the same line as that of the 

 calcaneo-cuboid. Thus a line drawn transversely over the 

 dorsum of the foot, behind the tubercle of the scaphoid, 

 would strike both the joints opened in 'Chopart's' opera- 

 tion. 



Place your thumb on the tubercle of the scaphoid, and 

 measure about one inch and a half in front : here you find 

 the joint between the internal cuneiform bone and the meta- 

 tarsal bone of the great toe. This point is useful in Lisfranc's 

 operation, which consists in the removal of the metatarsal 

 bones. 



The line of the calcaneo-cuboid joint lies midway between 

 the external malleolus and the (tarsal) end of the metatarsal 

 bone of the little toe. 



The projection of the fifth metatarsal bone is the guide to 

 the joint between it and the cuboid. 



Notice that the line of the joints between the metatarsal 

 bones and the first phalanges lies a full inch farther back than 



