246 SURGICAL APPLIED ANATOMY, [chap. xm. 



Dislocation of the radius forwards. This 

 may be due to direct violence to the bone from behind, 

 or to extreme pronation, or to falls upon the extended 

 and pronated hand. The anterior, external, and 

 annular ligaments ai % e torn. There would seem to be 

 a lack of evidence in support of Hamilton's statement 

 that " sometimes the anterior and external lateral 

 are alone broken, the annular ligament being then 

 sufficiently stretched to allow of the complete disloca- 

 tion." The biceps being relaxed, the pronators act, 

 and the limb is either pronated. or assumes a position 

 midway between pronation and supiiiation. Some 

 stretching of the supiiiator brevis would probably 

 modify the amount of pronation. A difficulty in the 

 reduction is often due to the torn annular ligament 

 coming between the head of the radius and the 

 humeral condyle. 



Sprain ol the elbow. Mr. J. Hutchinson, 

 Jun., has shown that in young children, under five 

 years, forcible traction of the limb in the supinated 

 position may cause the radius to slip downwards, away 

 from the orbicular ligament, which is displaced up- 

 wards. Flexion of the elbow in the pronated position 

 restores the ligament to its normal position. It is 

 clear that this displacement is the anatomical basis 

 of the common sprain of the elbow met with in young 

 children, and usually due to violent traction of the 

 hand. 



Fractures of'the lower end of the liuincrus. 

 These are : (1) A fracture just above the condyles ; 



(2) "the T-shaped fracture" involving the joint; 



(3) fractures of the internal, and (4) of the external 

 condyle ; (5) fracture of the internal epicondyle ; and 

 (6) separation of the lower epiphysis. 



All these fractures are more common in the 

 young. 



1. The fracture " at the base of the condyles,'' as 



