THE UPPER LIMB 32? 



These surfaces are sometimes partially separated by an inter- 

 articular fibro-cartilage, and the joint is surrounded by a complete 

 capsule, which forms the superior and inferior ligaments. 



The superior and inferior acromio-ciavicular ligaments extend 

 between the contiguous margins of the bones on their upper and 

 under surfaces, the former being strengthened by aponeurotic 

 fibres from the trapezius and deltoid. The interarticular fibro- 

 cartilage, when present, is hmited to the upper part of the joint, 

 where it is attached to the superior ligament. It may divide 

 the joint into two synovial compartments, but there is usually 

 only one. 



The eoraco-clavieular ligament, which is to be regarded as acces- 

 sory to this joint, connects the clavicle with the coracoid process, 



Capsule of Acromio-clavicnlar Joint Coraco-acrombtl ligament 



Trapezoid Ligament 



Conoid Ligament 



Long Head of Biceps - 



Glenoid Lig^aroent 



Capsular Ligament 

 (cut) 



Fig. 183.— The Riglt Glenoid Cavity, and the Adjacent Ligaments, 



and is composed of two parts — conoid and trapezoid. The conoid 

 ligament, internal and posterior in position, is attached below by 

 its apex to an impression at the back part of the antero-internal 

 border of the coracoid process, and above by its base to the conoid 

 tubercle of the clavicle, its direction being upwards and backwards. 

 The trapezoid ligament, external and anterior in position, is some- 

 what quadrilateral. It is attached below to the trapezoid ridge on 

 the back part of the upper surface of the coracoid process, and 

 above to the trapezoid ridge on the under surface of the clavicle, its 

 d.rection being upwards; backwards, and outwards. Between the 

 two ligaments there is a slight interval, in which there may be a 

 bursa. 



Arterial Supply. — The suprascapular and acromio- thoracic arteries. 



Nerve-supply. — ^The suprascapular and circumflex nerves. 



