REGION OF THE ELBOW. 



299 



The bond of union between the fragments is usually so short that it appears to 

 be bony and function is perfect. If the fibrous band is long extension will be incom- 

 plete and weak. 



Fracture of the Coronoid Process and Upper End of the Radius. 

 Fracture of the coronoid process does occur but it is exceedingly rare. The brachi- 

 alis anticus does not insert into its tip, but at the lower part of its anterior surface. 

 The fracture is most liable to occur in cases of luxation, the process being knocked 

 off as the humerus comes forward. 



Fractures of the Head and Neck of the Radius. The head and neck of the 

 radius are rarely fractured. When broken, the line of fracture through the head is 



Triceps extensor muscle 



Ulnar nerve 



Internal condyle 



Site of fracture of olecranon 



Posterior surface of thi 

 upper end of the ulna 



Portion of tendon of triceps which 

 inserts into the olecranon process 



External condyle of humerus 



Portion of the tendon of the triceps 

 which inserts into the posterior 

 surface of the upper fourth of the 

 ulna 



HG. 314. Fracture of the olecranon process, showing the insertion of the triceps muscle into the olecranon and 



upper fourth of the ulna. 



usually longitudinal and a portion of the head is chipped off. The fragment is liable 

 to become displaced, and either creates inflammation and suppuration or becomes 

 fixed and greatly interferes with motion. For these reasons the fractured head has 

 been frequently excised. A similar displacement may occur when the neck of the 

 radius is fractured. 



In this latter injury an anterior angular deformity is said to have been produced 

 by the action of the biceps pulling the lower fragment, to which it is attached, 

 forwards. 



The classical specimen in the Mutter Museum of the College of Physicians of 

 Philadelphia is usually instanced as an example of this action. The possibility of its 

 occurrence suggests the treatment of the injury with the elbow flexed to relax the 

 biceps muscle. 



Epiphyses of the Bones of the Elbow. Traumatic epiphyseal separations 

 are possible, but so rare as to be seldom detected. Supracondylar fractures in 



