2i8 SURGICAL APPLIED ANATOMY. [Chap. xin. 



only flexion and extension, but also any attempt 

 to wrench the fore-arm laterally from the arm, it 

 happens that it is the ligament that suffers the most 

 often in " sprains " of the elbow. As this ligament 

 is attached to the whole length of the inner border 

 of the olecranon it may assist in preventing separa- 

 tion of the fragments when that process has been 

 fractured. 



Joint disease. In disease of this joint the 

 effusion first, and most distinctly, shows itself by a 

 swelling around the margins of the olecranon. This 

 is explained by the facts that the synovial cavity is 

 here nearest to the surface, and the posterior ligament is 

 lax and thin. Some swelling is also very soon noticed 

 about the line of the radio-humeral joint, and fluctua- 

 tion in this situation serves to distinguish joint effusion 

 from simple enlargement of thebursa beneath the triceps 

 tendon. Deep-seating swelling may be noted about 

 the front of the joint beneath the brachialis anticus, 

 owing to the thinness of the anterior ligament ; and 

 lastly, about the external condyle. The density of 

 the internal ligament prevents a bulging of the 

 synovial membrane on the inner side. When the 

 joint suppurates the pus will most easily reach the 

 surface by travelling upwards and backwards between 

 the humerus and the triceps, and the abscess points, 

 therefore, very commonly at one or other border 

 of that muscle. The pus may escape beneath the 

 brachialis anticus in front, and discharge itself near 

 the insertion of the muscle. When the bone is 

 diseased the sinuses form usually directly over the 

 part attacked. The diseased elbow tends to assume 

 the posture of semi-flexion, and it is interesting to 

 observe that that is the position assumed by the joint 

 when forcible injections are made into its cavity 

 (Braune). The joint, in fact, holds the greatest amount 

 of fluid when it is semi-flexed. As regards muscular 



