178 SURGICAL APPLIED ANATOMY. [Chap. XL 



acromion, there is rupture, not only of the capsule, but 

 also to a greater or less extent of the coraco-clavicular 

 ligaments. In the complete dislocation downwards, 

 also, there is a rupture of the capsule, with extensive 

 tearing of the conoid and trapezoid ligaments. These 

 luxations are usually easily reduced, but it will be 

 understood, from the direction of the articular surfaces, 

 that in the displacement upwards it is very difficult 

 to retain the clavicle in situ when once reduced. 



Scapula. At the posterior aspect of the bone 

 the muscles immediately above and below the spine 

 are somewhat precisely bound down by the deep 

 fascia. Thus, the supraspinatus muscle is enclosed in 

 a fascia, that, being attached to the bone all round 

 the origin of the muscle, forms a cavity open only 

 towards the insertion of the muscle. 



The inf raspinatus and teres minor muscles are also 

 enclosed in a distinct, but much denser, fascia that is 

 attached to the bone beyond these muscles, and blends 

 in front with the deltoid sheath so as to form a second 

 enclosed space. The arrangement of these fasciae 

 serves to explain the trifling amount of ecchymosis that 

 usually follows upon fractures of the scapular blade. 

 The extravasation of blood about the fracture is 

 bound down by the fasciae over these muscles, and is 

 unable, therefore, to reach the surface. 



Thus also pus, in the supra- and infraspinous fossse, 

 tends to be pent up, and to come forward in the one 

 case at the insertion of the subscapular muscle, and in 

 the other instance about the insertion of the teres 

 minor.' Owing to the rigidity of the fascia over the 

 inf raspinatus and teres minor muscles, it happens that 

 dense tumours growing from this fascia may readily 

 be mistaken for growths from the bone itself. 



The inferior angle of the scapula is crossed by a 

 part of the latissimus dorsi, and by means of this muscle 

 is retained in contact with the thorax. In certain 



