246 DISSECTION OF THE UPPER LIMB. 



Another strong band (coraco-acromial) passing transversely between 

 the acromion and the coracoid process ; and a small fasciculus (posterior 

 proper ligament), placed over the notch in the superior costa, are then to 

 be defined. 



LIGAMENTS OF THE CLAVICLE AND SCAPULA (fig. 75). The clavicle 

 is connected to the scapula by a distinct joint with the acromion, and by 

 a strong ligament (coraco-clavicular) between it and the coracoid process. 



The coraco-clavicular ligament consists of two parts, each having a 

 different direction and designation. 



The posterior piece ( J ), called conoid from its shape, is fixed by its apex 

 to the posterior and inner part of the coracoid process ; and by its base to 

 the tubercle and the contiguous part of the under surface of the clavicle, 

 at the junction of the outer with the middle third of the bone. 



The anterior part ( 2 ), trapezoid ligament, is larger than the conoid 

 piece : it is connected interiorly to the inner border of the carocoid pro- 

 cess along the hinder half; and superiorly to the line on the under surface 

 of the clavicle which extends outwards from the tubercle before mentioned. 

 The two pieces of the ligament are in apposition posteriorly, but are sepa- 

 rated by an interval in front. . 



Use. Both pieces of the ligament support the scapula in a state of rest : 

 they serve also to restrain the rotatory movements of that bone ; thus 



Fig. 75. 



eg 

 o 



^^fMWy 1. Conoid llgameut. 



2. Trapezoid ligament. 



3. Anterior ligament of Ihe scapula. 



4. Posterior scapular ligament. 



5. Capsule of the shoulder joint. 



6. Tendon of the long head of the bi- 



ceps entering the joint. 



7. Tendon of the subscapular muscle. 

 S. Coraco humeral ligament. 



LIGAMENTS OF THE CLAVICLE AND SCAPULA', AND OF THE SHOULDER JOINT 

 (altered from Bourgery and Jacob). 



when the acromion is rotated down, the motion is checke'd by the trapezoid 

 band ; and when upwards, by the conoid piece. 



Acromio-clavicular articulation. The articular surfaces of the clavicle 

 and acromion process of the scapula are retained in contact by a capsule 

 formed of strong fibres. Some of the fibres are thicker above and below, 

 and are considered to constitute a superior and an inferior ligament. 



An interqrticular jtbro-cartilage generally exists at the upper part of 

 the joint ; but sometimes it forms a complete interarticular septum. If 

 the n'bro-cartSlage is perfect, there are two synoviol membranes present in 

 the joint ; if it is imperfect, there is only one. The joint should be opened 

 to see the cartilage and the synovial membrane. 



Movements. In this articulation there are limited fore and back and up 

 and down movements of the scapula. 



