Fig. 25.1
(a, b) Arthroscopic images from the posterior viewing portal demonstrating an upper border tear of the subscapularis (a) before and (b) after a posterior lever push. The posteriorly directed force on the humerus allows the subscapularis tendon to lift away from the lesser tuberosity, revealing the true extent of the pathology
Given the close anatomic relationship of the biceps tendon and pulley to the subscapularis, there is often concomitant pathology. Arai et al. reported that of all biceps tendon lesions, 76% were associated with a subscapularis tear, and all unstable biceps tendons also had subscapularis tears [5]. Another investigation found that a subscapularis tear was significantly associated with biceps tendon lesions [12]. Because of this, and particularly in older patients with degenerative tears, a biceps tenodesis or tenotomy is often performed, especially in light of evidence that tenodesis for tenotomy was associated with improved subjective and objective results in a cohort of patients undergoing subscapularis repair [42].
Once the extent and anatomy of the subscapularis tear has been identified, the surgical construct can be determined. A distinction is made between partial-thickness tears (Fig. 25.2a), small full-thickness tears (Fig. 25.2b), and large full-thickness tears with retraction (Fig. 25.2c). A similar but slightly more detailed classification system which divides the subscapularis insertion on the lesser tuberosity into four distinct facets has been proposed [7]. In general, the author utilizes a single-anchor construct for partial-thickness tears, while a double-row construct is used for small and large full-thickness tears. In the author’s experience, and in agreement with previously published literature [43], most chronic and retracted subscapularis tears can be repaired arthroscopically given appropriate mobilization techniques. Denard et al. have also shown that medialization of the lesser tuberosity footprint by as much as 7 mm does not result in negative clinical consequences [44].
![A428222_1_En_25_Fig2_HTML.gif](https://i0.wp.com/musculoskeletalkey.com/wp-content/uploads/2017/12/A428222_1_En_25_Fig2_HTML.gif?w=960)
![A428222_1_En_25_Fig2_HTML.gif](https://i0.wp.com/musculoskeletalkey.com/wp-content/uploads/2017/12/A428222_1_En_25_Fig2_HTML.gif?w=960)
Fig. 25.2
(a–c) Arthroscopic images from the posterior portal of three different left shoulders demonstrating (a) partial-thickness, (b) small full-thickness, and (c) large and retracted full-thickness tears of the subscapularis
Following assessment of the tear pattern and mobility, an additional anterosuperolateral working portal is created off the edge of the anterolateral acromion using outside-in technique. The portal should allow an approximately 10° angle of approach to the lesser tuberosity and be mostly aligned with the subscapularis tendon. The exception to this has been in the setting of isolated partial-thickness tears where a coracoplasty is not required, and a single-anchor repair is planned. In this circumstance, the author does not create additional anterosuperolateral portal so as to remove the possibility of damage to the anterior aspect of the supraspinatus tendon. For these cases, a larger cannula may be exchanged for the initial smaller cannula placed anteriorly. After preparation of the footprint, a free suture is passed in mattress fashion through the superolateral border of the tendon using a suture-passing device (Fig. 25.3a). The two suture limbs (exiting the anterior aspect of the tendon) are then placed through the eyelet of a knotless suture anchor and secured to the superolateral aspect of the lesser tuberosity footprint (Figs. 25.3b, c).
![A428222_1_En_25_Fig3_HTML.gif](https://i0.wp.com/musculoskeletalkey.com/wp-content/uploads/2017/12/A428222_1_En_25_Fig3_HTML.gif?w=960)
![A428222_1_En_25_Fig3_HTML.gif](https://i0.wp.com/musculoskeletalkey.com/wp-content/uploads/2017/12/A428222_1_En_25_Fig3_HTML.gif?w=960)
Fig. 25.3
(a–c) Arthroscopic images as viewed from the posterior portal demonstrating the steps for repair of a partial-thickness upper border subscapularis tear utilizing single anterior working portal. In this series (a) the free end of the sutures are passed in mattress fashion through the superolateral border of the tendon using a suture-passing device. The two suture limbs are then placed through the eyelet of a knotless suture anchor, and (b) the anchor hole is created. The final construct demonstrates (c) secure fixation of the tendon to the superolateral aspect of the lesser tuberosity footprint
For full-thickness tears, mobilization of the tendon is required, and the additional anterosuperolateral portal is created. Working through this portal, the coracoid tip is identified, paying careful attention to the presence of nearby neurovascular structures, and a window in the rotator interval can be created to give access to the anterior aspect of the tendon. The tip and posterolateral base of the coracoid is skeletonized, proving for and giving access to anterior and superior releases. The need for coracoplasty can be determined at this time. Posterior releases can be achieved using a blunt elevator inserted between the subscapularis and anterior glenoid neck. In chronic and retracted tears, the “comma sign,” a convergence of the superior glenohumeral ligament and coracohumeral ligament, can aid in identification of the superolateral aspect of the torn tendon (Fig. 25.4) [45]. This tissue can hold a traction stitch to aid in releases and mobilization of the tendon and should be preserved in the final repair.
![A428222_1_En_25_Fig4_HTML.gif](https://i0.wp.com/musculoskeletalkey.com/wp-content/uploads/2017/12/A428222_1_En_25_Fig4_HTML.gif?w=960)
![A428222_1_En_25_Fig4_HTML.gif](https://i0.wp.com/musculoskeletalkey.com/wp-content/uploads/2017/12/A428222_1_En_25_Fig4_HTML.gif?w=960)
Fig. 25.4
An arthroscopic image from the posterior viewing portal demonstrating a chronic and retracted subscapularis tear. The grasper is placed through the anterosuperolateral portal and is pulling lateral traction on the tendon, demonstrating the “comma sign,” representing the convergence of the superior glenohumeral ligament and coracohumeral ligament attached to the superolateral border of the tendon
The author’s preferred construct for a full-thickness tear is a double-row knotless repair (Fig. 25.5). Ide et al. reported on a group of patients undergoing subscapularis repairs using either a single-row or double-row technique [46]. While they found that the clinical outcomes for these 61 patients were comparable, subscapularis function and abduction strength were improved in the double-row group, and there was a trend toward a lower failure rate in this same group. For smaller full-thickness tears, a single anchor is placed at the medial aspect of the exposed footprint. For larger tears where more of the footprint is exposed, an inferior and a superior anchor are placed. The anterior portal may need to be adjusted, or a new anterior portal can be created using outside-in technique to allow for appropriate angle for anchor placement. With the use of a grasper or traction stitch through the anterosuperolateral portal to place tension on the subscapularis, a suture-passing device is utilized to pass each suture limb, from inferior to superior, through the tendon in a mattress configuration. Each limb is then secured with a single knotless anchor to the superolateral aspect of the lesser tuberosity footprint. As mentioned, nearly all subscapularis repairs, even with significant fatty infiltration, are able to be repaired with appropriate releases with or without footprint medialization. In the truly irreparable tears, pectoralis major transfer remains an option [47, 48].
![A428222_1_En_25_Fig5_HTML.jpg](https://i0.wp.com/musculoskeletalkey.com/wp-content/uploads/2017/12/A428222_1_En_25_Fig5_HTML.jpg?w=960)
![A428222_1_En_25_Fig5_HTML.jpg](https://i0.wp.com/musculoskeletalkey.com/wp-content/uploads/2017/12/A428222_1_En_25_Fig5_HTML.jpg?w=960)
Fig. 25.5
Schematic drawing of the authors’ preferred method for double-row repair of the large, full-thickness subscapularis repair (Adapted from Ide et al. [46])
25.7 Postoperative Rehabilitation
Postoperatively, patients are placed in a sling for 6 weeks. No weight bearing is allowed during this time. Active motion of the elbow, wrist, and hand is encouraged. In the case of partial-thickness repairs, external rotation is allowed to 30°. For full-thickness tears, external rotation is only allowed to neutral. Forward flexion is limited to 90° and abduction to 60°. At 6 weeks, passive stretching is allowed as well as progression to active range of motion. Strengthening is deferred until 3 months postoperatively.
25.8 Results
Burkhart et al. were some of the first to publish preliminary results of arthroscopic subscapularis repair in 2002, reporting 92% good-to-excellent outcomes [49]. This group followed their cohort and reported intermediate-term results which continued to be significantly improved from preoperative status [50]. Numerous other studies have reported similarly good-to-excellent results with arthroscopic subscapularis repair [51–54], and this method has therefore become current standard of care. The exact technique of the repair (single- versus double-row, stitch configuration) is still controversial; however, early reports indicate a trend toward improved outcomes with a double-row technique [46].
Conclusion
The subscapularis muscle-tendon unit plays a critical role in the stability and kinematics of shoulder function. Recognition of subscapularis tears has increased with the wide adoption of arthroscopic techniques for the treatment of shoulder pathologies. Both physical exam and advanced imaging modalities can be sensitive for the detection of subscapularis pathology; however, one must maintain a high index of clinical suspicion, particularly for partial-thickness tears, which may not be evident on MRI. Conservative treatment is pursued for small chronic tears in older patients, while operative management is the mainstay of treatment for all other categories. While repair techniques and construct configurations are evolving, good-to-excellent results have been reported for arthroscopic subscapularis repair.
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