The visualization of minor tendon defects of the SSC tendon can be demanding. Cranial medial partial lesions can easily be overlooked (Fig. 7.2). Furthermore, in the case of advanced ruptures (≥2 stage Patte classification), visualization and mobilization of the tendon can be difficult due to the spatial narrowness in the ventral compartment. A completely torn SSC tendon is usually retracted medially and often intergrown with the capsuloligamentary structures (superior or medial glenohumeral ligament [SGHL/MGHL] and coracohumeral ligament [CHL]). Furthermore, accompanying torn structures of the pulley system and the supraspinatus can be adherent to a scar plate. This is interpreted as a so-called “comma-sign” and serves on the one hand as a guiding structure of the lateral edge of the tear and on the other hand it must not be misinterpreted as an intact tendon (Fig. 7.3).

In the literature the healing rate after SSC is indicated between 89% and 95% [5–7]. The causes for a failure of the rotator cuff reconstruction are manifold and include a failure of the anchors, too much tension of the attached tendon or biological failure while degenerative conditions of the tendon. The most important precondition for adequate reconstruction is the sufficient visualization and release of the torn subscapularis tendon, to ensure tension-free refixation. After the establishment of the anteroinferior and anterolateral portal, the subsequent synovectomy of the rotator interval for better visualization is done. The mobilization of complex tendon tears (adhesions to medium glenohumeral ligament, MGHL) with extensive 270° tenolysis is performed as previously described from intra- and extraarticular including the visualization of the coracoidal arch. Care is taken to respect the two muscular nerve branches into the SSC muscle. To ensure sufficient preparation, the reduction of the tendon is verified with an arthroscopic tissue forceps and subsequently a traction suture for the reconstruction management is shuttled through the tendon (Figs. 7.4, 7.5, and 7.6). The lateral tension on the traction suture, which is guided through the superolateral portal, allows better mobilization of the tendon and better addressing of adhesions. As known from rotator cuff reconstruction, a high tension of the reduced tendon goes along with increased failure rate [8]. Although in general, the double row technique in the refixation of the rotator cuff (mostly supraspinatus tendon) has an advantage in biomechanical studies in regard to the pull-out strength, there is no significant advantage in regard of clinical scores [9]. A biomechanical study was also able to achieve a more stable refixation within the double row technique during isolated SSC tendon examination [9]. However, there are equivalent clinical outcomes for single and double row techniques for isolated SSC tendon ruptures [10, 11]. The footprint of the tubercle minus should be prepared from torn tendon tissue and the bone should be very carefully shaped with the acromionizer depending on the bone quality (in the case of excessive weakening of the cortical bone the stability of the anchors may be adversely affected) so that an adequate osteointegration can be ensured. In addition to the used anchor technique, the correct placement of the portals is important. The entrance level and the possible working radius should be checked with a needle in outside-in technique. Inaccurate positioning of the portals makes it more difficult to handle the reconstruction on the one hand, and the exact anchor fixation on the other. An anchor inserted too shallow can pull out of the bone and lead to the failure of the reconstruction. The stability of the anchor must therefore always be checked by an axial pull on the sutures before reattachment of the tendon. There are several methods to shuttle the sutures of the anchors through the tendon. On one hand this can be done by a lasso-type suture shuttling (e.g. cannulated needle), with an arthroscopic shuttling device (Clever Hock [DePuy Synthes] or BirdBeak [Arthrex]) or with a suture passer needle. The perforation hole of arthroscopic penetrator device is obviously larger than a needle, although no comparative biomechanical studies are available. Another aspect that can make the operative procedure more difficult and may cause inadequate reconstruction is that by opening the rotator interval the soft tissue swelling increases with the operation time and can limit the overview especially in the ventral aspect of the shoulder.