90 CLINICAL APPLIED ANATOMY. 



due to several anatomical causes : first, because the deformity 

 will not have been corrected if impaction has not been reduced ; 

 secondly, because if the fragments have been unimpacted muscular 

 action tends to reproduce the deformity unless the fracture is 

 very carefully set ; and, thirdly, because there is a possibility of 

 the extensor tendons becoming involved in the callus. Most 

 cases, however, even those in which the deformity has not been 

 entirely removed, obtain free movement if massage and manipu- 

 lation are assiduously employed. It is well, generally speaking, 

 that passive movements of the wrist and the more distal joints 

 should be carried out during the whole process of treatment, so 

 as to make the possibility of stiffness remote. 



Separation of the lower radial epiphysis, occurring before the 

 age of seventeen, may be considered as equivalent to a Colles's 

 fracture in young persons. 



Fractures of both Bones of the Forearm. This is most 

 commonly caused by direct violence, and the line of fracture will 

 be transverse and at the same level in both the bones. As a 

 rule it occurs about the middle of the forearm, or a little below 

 this point. When the fracture is situated distal to the insertion of 

 the pronator radii teres, the upper fragment of the radius tends 

 to be drawn into the position which is midway between pronation 

 and supination by the action of the muscle, and the upper end 

 of the lower fragment of the radius is adducted towards the ulna 

 by the pronator quadratus. Owing to this adduction there is 

 always a risk of cross union taking place, and the movements 

 of supination and pronation of the hand lost. 



In fractures of the bone above the pronator radii teres, the 

 upper fragment is supinated by the biceps and supinator brevis, 

 and for this reason it is necessary to set the fracture with the 

 elbow flexed and the hand in the position of full supination, 

 which position is more likely to bring the fragments of the radius 

 together into line. On the other hand, in a fracture below the 

 insertion of the pronator radii teres, a position of the hand 

 midway between pronation and supination is more advantageous. 

 The position secures accurate apposition, seeing that there is 



