THE ELBOW-JOINT 



259 



The posterior portion (fig. 294), thin and membranous, is attached superiorly 

 to the humerus, in much the same inverted V-shaped waj^ as the anterior; ascend- 

 ing from the medial epicondyle, along the medial side of the olecranon fossa- 

 nearly to the top; then, crossing the bottom of the fossa, it descends on the lateral 

 side, skirting the lateral margin of the trochlear surface, and turns laterally along 

 the posterior edge of the capitulum. Inferiorly, it is attached to a slight groove 



Fig. 293. — Medial View of the Elbow-joint. 



Anterior ligament 



Ulnar collateral- 

 ligament 



Annular hgament 



Tendon ot biceps 



Oblique ligament 



Upper edge of in- 

 terosseous mem- 

 brane 



along the superior and lateral surfaces of the olecranon, and the rough surface of 

 the ulna just beyond the radial notch, and to the annular ligament, a few fibres 

 passing on to the neck of the radius. 



It is composed of decussating fibres, most of which pass vertically or obliquely downward, a 

 few taking a transverse course at the summit of the olecranon fossa where the ligament is usually 

 thinnest. 



Fig. 294. — Lateral View of the Elbow-joint. 



Annular ligament 



Radial collateral ligment 



Posteri&r ligament 



The medial portion, the ulnar collateral ligament (fig. 293), is thicker, stronger, 

 and denser than either the anterior or posterior portions. It is triangular in 

 form, its apex being attached to the anterior and under aspect of the medial 

 epicondyle, and to the condyloid edge of the groove between the trochlea and the 

 condyle. The fibres radiate downward from this attachment, the anterior 

 passing forward to be fixed to the rough overhanging medial edge of the coronoid 



