16 Arthroscopic Single-Row Subscapularis Tendon Repair

Howard D. Routman and Jack E. Kazanjian

Summary

Arthroscopic rotator cuff repair of the posterosuperior cuff has become the gold standard for soft tissue repairs in the shoulder during the past decade. This has been borne out in the literature with outcomes and healing rates equivalent to open rotator cuff repair. With the technical advances that have been made arthroscopically, the authors believe that these benefits have improved our ability to treat disorders of the subscapularis as well. All-arthroscopic, single-row repair of the subscapularis is achievable for most tears of the subscapularis. This chapter will take a step-by-step approach through the authors preferred approach to this problem from positioning through postsurgical rehabilitation including surgical tips and tricks.

Keywords: arthroscopically, single row, subscapularis repair

16.1 Patient Positioning

? General anesthesia with interscalene block is utilized routinely.

? The patient is positioned in a beach chair position with a pillow under the knees.

? All bony prominences are padded to avoid contact pressure during the procedure.

? A head-holder is used to support and protect the head and spine.

? A commercial beach chair positioner can be used; otherwise, the patient will need to be placed on the lateral edge of the table ensuring adequate access to the shoulder for portal placement.

? Sequential compression devices are applied to the lower extremities.

? The nonoperative arm is positioned in a well-arm holder or secured to the body in a neutral position.

? After positioning is finalized, the bony landmarks of the shoulder are marked and final confirmation that the positioning allows for camera/drill/instrumentation access.

? Examination under anesthesia is performed and the findings documented.

? Clear U-drapes are placed at the medial most aspects of the field, defining the extent of surgical prep.

? The arm, scapula, and chest are prepped in the usual sterile fashion.

? Surgical U-drapes are used proximally to drape the shoulder.

? A waterproof stockinette is used on the arm above the elbow and then the arm is wrapped in Coban, avoiding tightly wrapping this around the ulnar nerve area.

? A pneumatic arm holder is attached to the patient?s arm for positioning during the case.

? Systolic blood pressure is maintained at 90?110 mmHg to maximize intraoperative hemostasis and cerebral oxygenation.

16.2 Surgical Technique

? The anterior and posterior clavicle, coracoid, acromioclavicular joint, and acromion, as well as the anterior and posterior borders of the scapular spine, should be drawn on the skin to assist with portal placement. The location of the conjoined tendon off the tip of the coracoid is noted.

? The shoulder joint is entered with a standard 30� scope via a posterior soft-spot portal. This portal is typically 2 cm inferior and 2 cm medial to the posterolateral corner of the acromion.

? The anterior portal is done via an outside-in technique with an 18-gauge spinal needle. The portal is typically inferior to the palpated coracoid and is just above and lateral to the subscapularis intraoperatively.

? A diagnostic glenohumeral arthroscopy is performed identifying all relevant pathology. The biceps tendon is very frequently subluxed and/or torn. Critical evaluation of preoperative imaging of the biceps with regard to subluxation is important. Only in situations in which the biceps demonstrates that it is in nearly perfect condition should it be spared. For most cases of a known subscapularis tear, a biceps tenotomy is performed initially; later, subpectoral tenodesis can be performed at the end of the procedure if tenotomy is not desired.

? Frequently, a superior rotator cuff tear is encountered during the diagnostic arthroscopy; this makes the subscapularis repair easier as the surgeon can gain access to the joint through the superior defect if needed.

? The subscapularis tear and/or ?comma? tissue can readily be identified with a 30� arthroscope.

? In cases of partial tears, a 70� arthroscope is utilized to determine the size of the tear and whether repair is needed.

? The rotator interval tissue is removed using a shaver, specifically avoiding injury to the ?comma.? The conjoined tendon and coracoid are then identified. At this point, the soft tissue on the posterior coracoid can be released with an electrocautery device to evaluate the bony structure of the undersurface of the coracoid, assess the retro-coracoid space, and determine whether a coracoplasty will be required.

? The undersurface coracoid is subsequently skeletonized being knowledgeable of the relevant adjacent anatomy.

? Even if a coracoplasty is not being performed, this step helps to open up the surgical field for eventual passage and visualization of sutures and makes a difference in suture management.

? If subcoracoid impingement is noted, a gentle posterior coracoplasty can be performed with a bur. Using a 4.2 acromionizer bur working from the anterior portal, a 6- to 8-mm template is created anteriorly and then completed using a cutting block technique posteriorly along the coracoid. A flat surface is created with this technique.

? After adequate retro-coracoid space is confirmed, cannula placement for subscapularis repair is planned.

? A clear cannula can be placed through the portal anteriorly; a second cannula can be placed through the superior rotator cuff tear(if present).

? All secondary portals are performed via an outside-in technique with an 18-gauge spinal needle.

? If the tear is isolated to the subscapularis, a second rotator interval portal can be made adjacent to the superior cuff, just adjacent to the anterolateral corner of the acromion.

? We then switch to a 70� scope for the remainder of the subscapularis procedure.

? A 360� release of the subscapularis is performed utilizing shavers, rasps, liberators, and electrocautery.

? Grasping instruments are then used to assess the tension, mobility, and reparability of the subscapularis.

? Traction sutures can be utilized at this point if needed. The ?comma? tissue is usually robust and is a good traction suture location.

? The lesser tuberosity is then prepared; all soft tissue is removed with a shaver and electrocautery. The tuberosity is then prepared with a rasp, shaver, and bursimilar to standard footprint preparation for posterosuperior repairs. Aggressive bone removal is discouraged, only freshening of the bone bed is needed.

? In cases of complete tears, two double-/triple-loaded anchors are utilized for a total of four to six sutures. For partial repairs, one double-/triple-loaded anchor is utilized.

? Anchor placement is performed through the anterior rotator interval cannula starting inferiorly.

? A 90� lasso device is used to penetrate the subscapularis tissue from the anterior cannula. The passing suture is initially brought out through the anterosuperior cannula. Care should be taken to make sure that the subscapularis is not retracted medial to the joint line when using the lasso device, as inadvertent vascular injury can occur. For retracted tears that have been mobilized, penetration of the tendon should be done with the tendon pulled into the field of view to avoid a blind passage of the penetrating device medially.

? The inferior anchor suture placement is typically in a horizontal mattress pattern.

? Once all sutures are passed, the sutures are then tied from inferior to superior using an arthroscopic knot-tying technique.

? We prefer a sliding-locking knot; however, this is not a critical component of the operation. Any arthroscopic knot that the surgeon is comfortable with would be adequate for repair.

? Traction sutures can be helpful to position the tendon precisely during the tying down of the repair.

? If a full tear is present, a second anchor will frequently be required.

? If a second anchor is placed, sutures are passed as a horizontal mattress pattern with the exception of the superior suture on the upper anchor; this is a simple suture pass that loops over the top of the subscapularis tendon, locking it into place.

? If only one anchor is used (for a partial repair), the pattern of suture placement is horizontal inferiorly with a simple suture superiorly.

? The sutures are tied and the repair is completed.

? The scope is switched backed to a 30� scope to visualize and document the repair.

? All remaining procedures are then completed as needed. See accompanying ? Video 16.1 demonstrating this surgical technique.

image

Video 16.1 Surgical demonstration of an arthroscopic single-row subscalpularis tendon repair technique.

16.3 Surgeon Tips and Tricks

? Portals and cannulas should be placed while using the 30� scope.

? The ?comma? tissue is the superolateral border of the subscapularis, including the coracohumeral ligament and superior glenohumeral ligament and can be used as a traction suture location.

? Be liberal in removing rotator interval tissue for visualization. If there is the need for more than one anchor and more than four limbs of suture to manage the subcoracoid space, this dissection and clearing of this space helps with suture management.

? Preparation and mobilization of the subscapularis tear should be performed with the 70� scope; be aware of relevant anatomy! The axillary artery/nerve and musculocutaneous nerve are all 25 mm from the coracoid.

? 360� release of the subscapularis involves anterior release from the coracoid, posterior release off the glenoid, and a superior release off of the lateral arch/neck of coracoid. Rasps and liberators work well anteriorly and posteriorly; cautery superiorly.

? Avoid dissection medial to the midportion of the coracoid.

? Traction sutures may not be needed. A grasping instrument from one of the portals can be used to assist in mobilization and suture placement.

? One anchor per square centimeter of the tuberosity is needed?two for full tears, one for partial is a good guideline.

? If difficulty is encountered with anchor or pilot-hole creation because of the patient?s head getting in the way, change the rotation of the arm. Consider shoulder flexion, extension, and internal and external rotation changes with a posterior translation on the humerus to achieve an easier passage into the lesser tuberosity.

? Suture management is critical, as the anterior space can be easily congested. Marking the suture pairs and separating the sutures from each individual anchor immediately upon insertion can save a lot of time and frustration.

? Tie each anchor one at a time; it helps reduce the tear and simplifies the procedure.

? If tension is noted on the repair, forward flex and internally rotate the arm.

16.4 Post-Op Rehabilitation

? Initial protection of the repair in an abduction sling for 6 weeks.

? Start formal physical therapy at an average of 4 weeks, being mindful of the tissue quality and tear size.

? Passive range of motion for the first 6 weeks.

? Limit forward flexion to 90�; limit external rotation (ER) to 0�?20� for good quality tissue; however, if tissue quality is poor, more aggressive restrictions can be applied.

? No biceps resistance if tenodesis has been performed for at least 6 weeks.

? At 6 weeks, remove sling and start full active range of motion if tissue quality is good, longer in the sling if the tissue quality is poor.

? At 12 weeks, start resistance.

? At 6 months, unrestricted overhead activities.

16.5 Rationale and Evidence

? The subscapularis is the largest and strongest rotator cuff muscle and plays a very important role for the stability and function of the shoulder joint.1

? Open rotator cuff repair frequently missed the presence of subscapularis tearing, and with the introduction of arthroscopic techniques, the normal and abnormal states of the subscapularis were more easily seen.2

? With advanced imaging, critical physical examination, and arthroscopic visualization, subscapularis tears are no longer the ?forgotten? rotator cuff tear of the shoulder and are more readily recognizable.

? Anatomic repair of the subscapularis should be achievable arthroscopically in the hands of a facile arthroscopist; however, a well-done open subscapularis repair is far better than a poorly done arthroscopic attempt.3 This technique should be approached as any other arthroscopic technique, learning it incrementally and confirming satisfactory execution with open incisions as needed.

? Arthroscopic single-anchor, single-row repair for upper third subscapularis tears has been shown to have good integrity rates on post-repair imaging.4

? Positive clinical subscapularis-specific physical examination findings that are present preoperatively in patients that have a successful repair and rate their results highly may never normalize in some patients.5,6

? Arthroscopic repair of isolated subscapularis repairs has been shown to achieve good results,7 with better outcomes with small full-thickness tears as compared to high-grade partial thickness tears.8

? In a systematic review of arthroscopic subscapularis tear repair surgery, Saltzman, et al9 showed that concomitant treatment of the biceps with tenodesis contributes to better overall results. Surgeons should bear in mind that in the case of a well-repaired subscapularis tear, unaddressed biceps pathology can negatively impact outcomes. Therefore, the threshold for biceps treatment should be considered low in these cases.

References

[1] Keating JF, Waterworth P, Shaw-Dunn J, Crossan J. The relative strengths of the rotator cuff muscles. A cadaver study. J Bone Joint Surg Br. 1993; 75(1):137?140

[2] Bennett WF. Arthroscopic subscapularis repair: a look at primacy from a historical perspective. Arthroscopy. 2014; 30(6):661?664

[3] Mall NA, Chahal J, Heard WM, et al. Outcomes of arthroscopic and open surgical repair of isolated subscapularis tendon tears. Arthroscopy. 2012; 28(9):1306?1314

[4] Rhee YG, Lee YS, Park YB, Kim JY, Han KJ, Yoo JC. The outcomes and affecting factors after arthroscopic isolated subscapularis tendon repair. J Shoulder Elbow Surg. 2017; 26(12):2143?2151

[5] Gerber, Christian, Otmar Hersche, and Alain Farron. ?Isolated rupture of the subscapularis tendon. Results of operative repair.? JBJS 78.7 (1996): 1015?23

[6] Edwards, T. Bradley, et al. ?Repair of tears of the subscapularis.? JBJS 87.4 (2005): 725?730

[7] Lafosse L, Jost B, Reiland Y, Audebert S, Toussaint B, Gobezie R. Structural integrity and clinical outcomes after arthroscopic repair of isolated subscapularis tears. J Bone Joint Surg Am. 2007; 89(6):1184?1193

[8] Katthagen JC, Vap AR, Tahal DS, Horan MP, Millett PJ. Arthroscopic repair of isolated partial- and full-thickness upper third subscapularis tendon tears: Minimum 2-year outcomes after single-anchor repair and biceps tenodesis. Arthroscopy. 2017; 33(7):1286?1293, and Millett PJ

[9] Saltzman BA. Collins MJ, Leroux T, et al. Arthroscopic repair of isolated subscapularis tears: Asystematic review of technique-specific outcomes. Arthroscopy. 2017;33:849?860

Suggested Readings

Burkhart SS, Tehrany AM. Arthroscopic subscapularis tendon repair: Technique and preliminary results. Arthroscopy. 2002; 18(5):454?463

Fox JA, Noerdlinger MA, Romeo AA. Arthroscopic subscapularis repair. Tech Shoulder Elbow Surg. 2003; 4:154?168