THE SHOULDER-JOINT 



225 



The glenoid ligament (figs. 224 and 227) is a narrow rim of dense fibro-cartilage, 

 which surrounds the edge of and deepens the glenoid socket. It is about a quarter 

 of an inch (6 mm. ) wide above and below, but less at the sides. Its outer edge is 

 inseparably welded, near the bone, with the capsular ligament. Its structure is 

 almost entirely fibrous, with but few cartilage cells intermixed. At the ujjper part 

 of the fossa the biceps tendon is prolonged into the glenoid ligament, the tendon 

 usually dividing and sending fibres right and left into the ligament, which may 

 Avind round nearly the whole circumference of the socket. It may, hoAvever send 

 fil)res into one side only, usually into the outer. 



The articular cartilage covering the glenoid fossa is thicker at the circumfer- 

 ence than in the centre, thus tending to deepen the cavity. It is usually thickest 

 at the lower part of the fossa; over the head of the humerus the cartilage is thickest 

 at and below the centre. 



The synovial membrane lines the glenoid ligament, and is then reflected over 

 the capsule as far as its attachment to the humerus, from which it ascends as far as 

 the edge of the articular cartilage. The tendon of the biceps receives a long tubular 

 sheath, which is continuous with the synovial membrane, V)oth at its attached 

 extremity and at the bicipital groove, but is free in the rest of its extent. The 



Fig. 227. — Biceps Texdox, bifurcating axd Blending on each Side with the 



Glenoid Fibro-cartilage. 



Tendon of biceps 



Tendon of biceps blended with 

 glenoid ligament 



synovial cavity sometimes communicates with the bursa under the subscapularis, and 

 less frequently with one under the infra-spinatus muscle. It also sends a pouch-like 

 prolongation beneath the coracoid process when the fibrous capsule is attached 

 wdde of the margin of the glenoid fossa. A few fringes are seen near the edge 

 of the glenoid cavity, and there is often one which runs down the inner edge of the 

 biceps tendon, extending slightly below it and making a slight groove for the 

 tendon to lie in. 



The transverse humeral ligament (fig. 226) is so closely connected with the 

 capsule of the shoulder that, although it is a proper ligament of the humerus, it 

 may well be described here. It is a strong band of fibrous tissue, Avhich extends 

 between the two tuberosities, roofing in the bicipital canal. It is covered by a thin 

 expansion of the capsule. It is limited to the portion of the bone above the line 

 of the epiphysis. (C. Gordon Brodie. .lourn. Anat. xxiv. 247.) 



The following muscles are in relation with the capsular ligament: above, the 

 supra-spinatus ; externally, the infra-spiiiatiis and teres minor ; below, the long head 

 of the triceps ; internally, the tendon of the subscapularis. The deltoid covers the 

 outer and upper surfaces of the joint, but is separated from the capsule by a bursa, 

 and the tendons of the short rotator muscles. An uj>ward t^lip from the pectoralis 

 15 



