Chap, xin.] REGION OF ELBOW. 247 



it is sometimes called, is usually situate a little above 

 the olecranon fossa, where the humeral shaft begins 

 to expand. It is commonly transverse from side to 

 side, and oblique from behind downwards and forwards. 

 It is generally the result of a blow inflicted upon 

 the extremity of the elbow. Probably the tip of 

 the olecranon driven sharply against the bone acts 

 like the point of a wedge, and takes an important 

 share in the production of the fracture. The lower 

 fragment, together with the bones of the fore-arm, is 

 generally carried backwards by the triceps, and 

 upwards by that muscle, the biceps, and the brachialis 

 anticus. The median, or ulnar nerves, especially the 

 latter, may be severely damaged. 



2. The "T-shaped fracture " is but a variety of the 

 lesion just noted. In addition to the transverse 

 fracture above the condyles, there is also a vertical 

 fracture running between the two condyles into the 

 joint. The lower fragment is thus divided into two 

 parts. The displacement is the same. The fracture 

 is very usually due to a fall upon the bent elbow, and 

 here possibly also the tip of the olecranon acts as 

 a wedge, producing the transverse fracture, while the 

 prominent ridge along the middle of the greater 

 sigmoid cavity, acting as a second wedge, produces 

 the vertical fracture into the joint. 



3, 4, and 5, For surgical purposes it is well to 

 limit the term " condyle " to such parts of the 

 extremity of the humerus as are within the capsule, 

 and the term " cpicondyle " to such parts of the lower 

 projections of the bone as are without the joint. 



In the so-called fracture of the inner condyle 

 the line of separation generally commences about half 

 an inch above the tip of the epicondyle (and, therefore, 

 outside the joint), and running obliquely outwards 

 through the olecranon and coronoid fossae, enters the 

 articulation through the centre of the trochlear surface 



