92 THE SUPERIOR EXTREMITY 



accompanies the transverse artery of the scapula, but it 

 enters the supraspinous fossa by passing through the scapular 

 notch, under cover of the upper transverse ligament of the 

 scapula. It supplies the supraspinatus, and ends in the infra- 

 spinatus muscle. It usually sends two articular twigs to the 

 posterior aspect of the shoulder-joint, viz., one while in the 

 supraspinous fossa and the second as it lies in the infra- 

 spinous fossa. 



The ligaments which connect the clavicle with the scapula 

 should now be examined; they are (i) the coraco-clavicular 

 ligament, which is found between the clavicle and the coracoid 

 process of the scapula and the capsule of the acromio- 

 clavicular joint. 



Dissection. Clean the surfaces and borders of the coraco- 

 clavicular ligament, and note that it consists of two segments 

 a medial segment called the conoid ligament and a lateral 

 segment called the trapezoid ligament. The two segments 

 meet at an angle which is open in front, and in the angle a small 

 bursa is sometimes found. After the coraco-clavicular ligament 

 has been fully defined, remove the remains of the deltoid and 

 trapezius muscles from the capsule of the acromio-clavicular 

 joint and clean the external surface of the capsule. 



Lig. Coracoclaviculare. The coraco - clavicular ligament 

 is a powerful ligament which binds the inferior surface of the 

 clavicle to the coracoid process. It consists of two parts, 

 which are termed the conoid and the trapezoid ligaments. 



The ligamentum conoideum lies posterior and medial to 

 the lig. trapezoideum. It is broad above, where it is attached 

 to the coracoid tubercle of the clavicle (Fig. 10, p. 21), and 

 somewhat narrower below, at its attachment to the bend of 

 the coracoid process. The ligamentum trapezoideum is a 

 flatter band. Above, it is attached along the trapezoid line 

 of the clavicle (Fig. 10, p. 21), whilst below it is fixed to the 

 upper aspect of the coracoid process. 



The coraco-clavicular ligament helps to prevent dislocation 

 of the acromial end of the clavicle, and, to a certain extent, 

 it limits the movements of the acromio-clavicular joint. It 

 is therefore an accessory ligament of that joint. It is the 

 main medium by which the scapula, and, indirectly, the other 

 parts of the superior extremity, are suspended from the 

 clavicle. If it is cut when the body is erect, the superior 

 extremity as a whole at once falls, and the same thing occurs 



