148 CLINICAL APPLIED ANATOMY. 



little distance from the joint proper, may yet give rise to septic 

 arthritis. 



Ischial tuber osity bursa. From prolonged sitting, and parti- 

 cularly when associated with a certain amount of movement 

 upon the seat, the bursa superficial to the tuber ischii becomes 

 chronically inflamed. Hence coachmen, omnibus drivers, 

 weavers with a hand loom, and others with similar occupations 

 are liable to this affection. It is, moreover, not an uncommon 

 site for gummatous disease. 



Trochanter bursa. The bursa lying over the trochanter major 

 of the femur may also become the seat of inflammation, parti- 

 cularly in persons who are thin and who have to lie upon hard 

 substances, or who carry a bag which intermittently rubs over 

 the region of the bursa. 



Psoas bursa. This lies on the front of the hip-joint beneath 

 the psoas and may communicate with the articular cavity. 



Olecranon bursa. The bursa normally found over the lower 

 part of the olecranon process is apt to become irritated and thus 

 inflamed in persons following certain occupations, such as 

 packers and miners. Effusion into this bursa produces a 

 swelling in the middle line posterior to the bone, and obscures 

 the olecranon, instead of the swelling on either side of this 

 process as in synovitis of the elbow. But it is perhaps more 

 commonly the site of acute septic inflammation from punctured 

 wounds, the outcome of falls upon the point of the elbow. In 

 these cases long-continued suppuration, and perhaps even 

 necrosis of the bone, may result unless free discharge of the pus 

 is provided for. 



Sub-deltoid bursa. This bursa is situated between the deltoid 

 and the capsule of the shoulder joint. It may become enlarged 

 as the result of chronic inflammation, and the swelling thereby 

 caused may be mistaken for inflammatory mischief in the 

 shoulder-joint. The position of the bursa, however, indicates 

 that it is unlikely that any fulness can be felt or seen in the 

 axilla, whilst the deltoid appears much more stretched and 

 tense. It should also be remembered that distension of the 



