252 



APPLIED ANATOMY. 



and the attachments of the muscles to the greater and lesser tuberosities divided and 

 the tendon of the biceps luxated inward, the head is thrust directly upward and out 

 of the wound and sawed off as low as desired. 



Immediately below the lower edge of the tuberosities is the surgical neck. On 

 it anteriorly winds the anterior circumflex artery, and posteriorly the circumflex (axil- 

 lary) nerve and posterior circumflex artery. These should not be disturbed, for the 

 artery will bleed and injury of the nerve will cause paralysis of the deltoid muscle. 



Posterior and transverse incisions have been suggested for this operation but 

 they are not to be advised. The circumflex nerve and posterior circumflex artery 

 are almost certain to be injured and the functions of the deltoid are liable to be 

 seriously impaired or altogether lost. 



If more access is desired than can be obtained by a straight incision as directed, 

 the deltoid can be detached from its origin along the outer end of the clavicle and 



Acromion process 



Subscapularis tendon and capsule 

 Lesser tuberosity 

 Deltoid muscle 



Bicipital groove 



FIG. 265. Resection of the shoulder- joint. The arm has been rotated outward so as to put the tendon of the 

 subscapularis on the stretch. The long tendon of the biceps has been dislocated from the bicipital groove and is 

 held to the inner side by a hook. 



acromion process and turned down. This does not interfere with its nerve supply. 

 The circumflex nerve going to the muscle crosses the humerus at about the junction 

 of the upper and middle thirds of the deltoid or a finger's breadth above its middle. 

 After resection of the bone the deltoid can again be brought up and sewed to its pre- 

 vious attachment. 



The character of the operation depends on the nature and extent of the disease. 

 The operator should be familiar with the epiphyseal line, which runs from the inside 

 upward and outward in the line of the anatomical neck as far as the middle of the 

 bone, and then slopes slightly downward and outward to reach the surface almost on 

 a level with the lower (inner) edge of the articular surface. As this is the site of 

 most active growth of the humerus in young subjects this epiphyseal cartilage should 

 be spared as much as possible. 



The disability arising from a free resection is so great, owing to the loss of 

 movements resulting from the detachment of muscles and interference with the 

 epiphyseal cartilage, that formal resections are rarely performed, but, instead, the 

 diseased parts are simply gouged away and as much allowed to remain as possible. 



