Fig. 2.1
(a) Arthroscopic evaluation with the posterior portal (b) Glenoid, labrum and humeral head
By turning the camera viewing angle to the glenoid, it is attempted to understand whether or not there is chondral damage and whether or not the glenoid bone edges intact. Degeneration of the glenoid superior articular surface is evaluated in respect of cartilage loss. It is thicker than the central section. The central glenoid cartilage may sometimes be thin and can therefore be observed as cartilage defect (Fig. 2.2a, b).
Fig. 2.2
(a) Anatomical structures seen from posterior portal (b) Labrum, glenoid, biceps tendon, MGHL and subscapularis tendon
The first things to be visualised within the joint are the triangle formed by the biceps tendon in the superior and the humerus head in the lateral and the subscapularis in the inferior. Of the intra-articular structures, the first to be located is the biceps tendon. On first entry to the joint, the biceps tendon must be identified for orientation purposes. The biceps tendon is visualised from the attachment known as the biceps anchor in the supraglenoid tubercle and superior labrum, along the rotator interval as far as the point where it emerges from the shoulder (Figs. 2.2a, b and 2.3a, b).
Fig. 2.3
(a) Visualization of biceps tendon (b) Biceps groove of humeral head
Then the first area to be identified should be the rotator interval region. Structures in this area are the upper intra-articular tendinous section of the subscapularis muscle, the middle glenohumeral ligament (MGHL), the superior glenohumeral ligament and the subscapular recess. After posterior portal entry, we use a guide needle in the identification of the site of the anterior portal entry in the rotator interval. The anterior portal is located approximately 1 cm lateral to the coracoid process. After opening the anterior portal, a cannula can be placed by widening the portal (Fig. 2.4a, b).
Fig. 2.4
(a) Identification of the rotator interval (b) Anatomic structures of the rotator interval
With the aid of a prop, it is necessary to examine whether or not the biceps tendon has separated from the biceps anchor and whether or not there is full continuity in the bicipital groove at the point of emergence from the joint. Stability of the biceps tendon within the groove is provided by the support formed by the supraspinatus and the subscapularis attachment sites. This structure is also held by the superior glenohumeral ligament and the coracohumeral ligaments. By acting as a pulley, this structure provides stability to the biceps tendon. Treatment should be planned by pathological evaluation of degeneration, tears or dislocations which may be encountered in this area (Figs. 2.5a, b and 2.6a, b).
