486 THE INFERIOR EXTREMITY 



experienced on palpation over the attachments of these ligaments 

 (p. 481) but no pain is elicited on examination of the subcutaneous 

 surface of the fibula. Swelling and discoloration are often 

 more marked than they are when a fracture is present. 



A somewhat similar condition results from over-eversion of 

 the foot, but in this case tenderness is experienced over the 

 attachments of the deltoid ligament (p. 481). 



Pott's Fracture. Fracture of the distal part of the fibula 

 is a common accident, as the region is frequently subjected to 

 violence, and the ligaments of the tibio-fibular syndesmosis 

 (p. 482) are stronger than the bone. The term " Pott's Fracture" 

 includes two distinct varieties of injury : (a) fracture of the 

 distal part of the fibula together with injury of the deltoid 

 ligament or medial malleolus, and (b) fractures of the distal 

 extremity of the tibia, together with tearing of the lateral 

 ligament of the ankle or fracture of the lateral malleolus. 



(a) In violent eversion of the foot, the deltoid (internal 

 lateral) ligament is overstretched and may either give way or 

 tear off the medial malleolus. In children, a diastasis of the 

 tibial epiphysis may result. If the violence continues to act 

 the lower part of the lateral surface of the talus is forced against 

 the lateral malleolus and the distal part of the fibular shaft gives 

 way, unless the powerful ligaments of the distal tibio-fibular 

 joint are torn through. The latter condition does occasionally 

 occur, and is indicated by a great increase in the width of the 

 ankle. In these circumstances the talus may be dislocated 

 upwards between the tibia and fibula (Dupuytren's fracture). 



(b) In violent inversion of the foot, the upper part of the 

 lateral surface of the talus is tilted laterally and downwards 

 against the lateral malleolus and the lateral ligament gives way, 

 or the fibula fractures proximal to the tibio - fibular joint. 

 Continuance of the violence forces the medial surface of the 

 talus upwards and medially against the medial malleolus, which 

 gives way, often breaking off an irregular fragment from the 

 distal extremity of the tibia. 



Fractures in this region may be associated with incomplete 

 dislocations of the foot. 



Dislocation of the Talus is rare and is often compound. 



When deformities in this region are being corrected, the 

 knee should be passively flexed to relax the tension of the 

 muscles of the calf. Subsequently the foot should be kept at 

 right angles, for in this position the widest part of the talus 



