138 SCAPULO-CLAVICULAR LIGAMENTS. 



ligaments ; it divides the joint into two cavities, which are lined by 

 distinct synovia! membranes. This cartilage is sometimes pierced through 

 its centre, and not unfrequently deficient, to a greater or less extent, 

 in its lower part. 



Fig. 63.* 



2. Scapulo'davicular Articulation. The ligaments of the scapular 

 end of the clavicle are, the 



Superior acromio-clavicular, 

 Inferior acromio-clavicular, 

 Coraco-clavicular (trapezoid and conoid), 

 Interarticular fibro-cartilage, 

 Two synovial membranes. 



The superior acromio-clavicular ligament is a moderately thick plane 

 of superimposed fibres passing between the extremity of the clavicle 

 and the acromion, upon the upper surface of the joint. 



The inferior acromio-clavicular ligament is a thin plane situated 

 upon the under surface. These two ligaments are continuous with 

 each other in front anfl. behind, and form a complete capsule around 

 the joint. 



The coraco-clavicular ligament (trapezoid, conoid) is a thick fasci- 

 culus of ligamentous fibres, passing obliquely between the base of the 

 coracoid process and the under surface of the clavicle, and holding the 

 end of the clavicle in firm connection with the scapula. When seen 

 from before, it has a quadrilateral form : hence it is named trapezoid ; 

 and, examined from behind, it has a triangular form, the base being 

 upwards ; hence another name, conoid. 



The interarlicular fibro-cartilage is often indistinct, from having 



* The ligaments of the sterno-clavicular and costo-sternal articulations. 1. 

 The anterior sterno-clavicular ligament. 2. The inter-clavicular ligament. 

 3. The costo-clavicular or rhomboid ligament, seen on both sides. 4. The 

 interarticular fibro-cartilage, brought into view by the removal of the anterior 

 and posterior ligaments. 5. The anterior costo-sternal ligaments of the first 

 and second ribs. 



