The anterior or axillary border is limited above by the glenoid cavity, and below by the inferior angle of the scapula. It is much thicker than either of the others, and its thick ness increases towards its upper extremity, where, close to the glenoid cavity, there is a rough surface which gives attachment to the long head of the triceps muscle ; inferior to this, the edge affords insertion to the teres minor muscle, and still lower down to the teres major.
The superior and posterior angle is formed by the junction of the cervical and vertebral bor ders; it is a little less than a right angle, and is chiefly remarkable for affording insertion to the levator anguli scapulae muscle. The inferior angle, formed by the union of the axillary and vertebral borders, is very acute; the bone here is very thick and spongy; part of the latissimus dorsi glides over this angle, and sometimes some of its fibres are inserted into it. It is only this portion of the muscle which separates this part of the scapula from the common inte guments, and to this superficial position is at tributed the more frequent occurrence of frac tures from direct violence in this- than in any other portion of the bone.
The angle between the cervical and axillary borders is truncated, and presents many points of great interest. We here notice an articular concavity, destined to contribute to the for mation of the shoulder-joint, commonly known under the name of the glenoid cavity, (sinus articularis.) This cavity, which is a very superficial one, is oval; the long axis of the oval being vertical in its direction, the acute extremity of the oval is situated superiorly, and here the edge of the bone is cut and rounded off towards the posterior part, where is inserted the tendon of the biceps. The cavity is surrounded by a thick lip of bone, to which in the recent state the fibro-cartilage, called glenoid ligament, is applied. At the internal or anterior part of this border, is a notch for the passage of the tendon of the sub scapularis muscle. The aspect of the glenoid cavity when the scapula is quiescent is outwards and slightly upwards and forwards. This cavity is connected with the rest of the bone by a thick but contracted portion denominated the neck of the scapula. The neck of the scapula is
surmounted by a remarkable curved process, called the caracoid process, (Kop4, corvus.) This process, well compared to a semiflexed finger, is directed forwards and outwards, it is connected to the scapula by a thick portion, which seems to arise by two roots, one posterior, thick and rough, lying immediately in front of the notch in the cervical border, the other anterior and thin, and connected with the apex of the glenoid cavity. The concave surface of the corticoid process is directed downwards and outwards, and in the recent state projects over the upper and internal part of the shoul dcr-joint : its convex surface is rough, and has inserted into it the ligaments by which the clavicle is tied to it. The corticoid process affords attachment by its internal edge to the pectoralis minor muscle; to its outer edge is affixed the ligament which, with the acromion process, completes the osseo-ligamentous arch over the shoulder-joint, and by its summit it gives insertion to the short head of the biceps and to the coraco•bmchialis.
It remains only to examine the surfaces of this bone. The anterior surface forms in the greatest part of its extent a shallow fossa, fossa suhscapularis, which is limited above and be hind by the superior and posterior margins of the bone, and in front by a smooth and rounded ridge, which extends from the glenoid cavity to the inferior angle. This fossa is frequently intersected in various directions by bony ridges. Cruveilhier remarks, that in a well-formed per son, this surface ought to be exactly adapted to the thorax; but when the chest is contracted, as in phthisical patients, the scapula not par ticipating to a proportionate extent in the con traction, there follows such a change of re lation that the scapula: become very prominent behind, and are in some degree detached from the ribs like wings, whence the expression scapula alata, applied to the projection of the shoulders in phthisical patients. The whole fossa has lodged in and inserted into it the subscapularis muscle, whence its name. At the superior posterior angle and the inferior one, are rough surfaces into which are inserted the superior and inferior fibres of the serrates magnus muscle.