632 OPEEATIONS ON THE FOOT. 



on the inferior surface ; when the resting takes place only on the 

 toe, ordinarily the tendon is injured, possibly the synovial sheath; 

 in cases where high inflammation exists the pain is very great, the 

 animal walking on three legs only. 



The anatomical examination of the injured part teaches that 

 the most serious punctured wound of the foot is that of the cen- 

 tre of the foot, where the tendon, synovial sac, and where the 

 articulations may have been injured. Forward of this the wound 

 is less serious, even if it involves the bone. Posterior to it, it 

 can only injure the plantar cushion. Under this condition the 

 plantar region of the foot is divided into three zones ; one, ante- 

 rior, from the toe to the point of the frog ; one, middle, extending 

 from the first to the median lacunse of the frog ; and the third, 

 anterior, covering the space left back of this to the heels. 



The most serious of the injuries to which the foot is liable are 

 those caused by foreign bodies which penetrate the middle zone, 

 that being the most complicated portion of the structure. The 

 symptoms wiU vary, according as the wound extends to tlie plan- 

 tar apouevirosis, or only as far as this membrane ; or lacerates the 

 soft surrounding tissues without touching it ; or it goes beyond 

 this and injuries the small sesamoid sheath, or even going deeper, 

 severs the na\icvdar bone, or its ligamentous attachment to the os 

 pedis ; or reaches the last phalangeal articulation. 



A wound of the plantar aponeurosis is always very painful, 

 especially when complicated with necrosis, in which case there is 

 no weight put on the diseased leg, and continual lancinating 

 pains and reacting fever are soon observed. The wound is then 

 fistulous in character, and the suppuration then flowing from it 

 meets with difficulties in its escape, which gives rise to a state of 

 general i nflammation, and the foot becomes hot and very painful 

 If the necrosed scar becomes loose and sloughs off, being de- 

 tached by suppuration, improvement soon ensues, but as the ne- 

 crosis of the tendon has generally a tendency to spread, there is 

 an increase in the character of the symptoms. If the wound 

 extends to the sesamoid sheath from the start, the synovial fluid 

 is observed escaping, first pure, but soon becoming milky and 

 piu'ulent in aspect, if the sheath has become inflamed, and easily 

 coagulated in yellowish clots. The pain is then very great, much 

 more so than when the aponeurosis alone is diseased. At times, 

 by rapid closing of the plantar wound or obstruction of the fis- 



