RADIO-ULNAR ARTICULATIONS. 



297 



JOINTS AND LIGAMENTS BETWEEN RADIUS AND ULNA. 



Thigse include, — 



1. Superior Radio-Ulnar Articulation 



Orbicular Ligament ; 



2. Inferior Radio-Ulnar Articulation : 



Triangular Cartilage ; 



3. Ligaments uniting the Shafts : 



Interosseous Membrane ; Oblique Ligament 



Capsular Ligament. 

 Capsular Ligament. 



The superior radio-ulnar joint' (Figs. 311, 312) is between the circum- 

 ference of the head of the radius and the lesser sigmoid cavity of the ulna extended 

 into a circle by the orbicular ligament. The articular ends of the bones are coated 



Fig. 311. 



External condyle 



Orbicular ligament surrounding head 

 of radius 



Tuberosity of radius 



Internal condyle 



Coronoid process 



■' I Oblique ligament 



Radius 



Superior radio-ulnar articulation, anterior aspect. The capsule of the elbow has been removed. 



with cartilage requiring no particular description. The orbicular ligament^ (Fig- 

 311) surrounds the head of the radius, springing from the two ends of the lesser sig- 

 moid cavity and from the lines running down from them. This band embraces the 

 head tightly, but is separated from it by the cavity of the joint, and is lined with 



' Artie, radioulnaris proximalis. " Lig. annulare radii. 



