THE REGION OF THE ANKLE AND FOOT 489 



can then be turned down from the lateral, posterior, and medial 

 aspects of the calcaneus. 



Ossification of the Tarsus. At birth, ossific centres are 

 present in the calcaneus, the talus and the cuboid. The lateral 

 cuneiform begins to ossify during the first year, the middle 

 cuneiform during the second year, and the medial cuneiform 



FIG. 145. Normal Ankle-joint. Lateral View. 

 calcanean epiphysis. 



Observe the 



and the navicular during the third or fourth year. A secondary 

 centre appears in the cartilaginous posterior extremity of the 

 calcaneus during the eighth year, and forms an epiphysis which 

 unites with the body of the bone between the ages of sixteen and 

 twenty. A separate centre for the posterior process (external 

 tubercle) of the talus is sometimes present, and it may remain 

 separate, being then known as the os trigonum (Fig. 146). 



Fractures of the tarsal bones may occur when the patient, 



