19 Arthroscopic Transtendon Double-Row Subscapularis Repair with all Suture Medial Row Anchors

Robert A. Duerr, Tyler J. Hunt, and Laurence D. Higgins

Summary

Arthroscopic transtendon double-row subscapularis repair with use of all suture medial row anchors achieves a biomechanically stable anatomic repair. This repair construct provides compression across a large contact area to recreate the subscapularis footprint and optimize tendon-to-bone healing.

Keywords: all-suture anchor, arthroscopic, subscapularis tear, transtendon repair

19.1 Patient Positioning

Our preferred patient position is in beach chair with a hydraulic powered limb positioner (Spider2, Smith & Nephew, Andover, MA).

19.2 Portal Placement

? Initial posterior viewing portal is placed typically 2 cm inferior and 1?2 cm medial to the posterolateral tip of the acromion in the ?soft spot.?

? An anterior working portal is established just lateral to the tip of the coracoid through the rotator interval.

? Accessory percutaneous anterior portals will be used for anchor placement directly over the lesser tuberosity.

? From the subacromial space, the anterolateral portal is established for placement of a traction suture to pull in-line with the subscapularis to enable anatomic reduction to the footprint.

? A lateral portal is also established for viewing the entire subcoracoid space to allow thorough debridement and mobilization of the subscapularis.

19.3 Surgical Technique (Step-by-Step Approach)

? Please see accompanying video for detailed description of the surgical technique. Patient is placed in the beach chair position with an adjustable arm holder.

? Diagnostic arthroscopy is performed through a posterior viewing portal.

? An anterior working portal is established to allow thorough diagnostic evaluation.

? Once a subscapularis tear is confirmed, if the long head of the biceps (LHB) tendon remains, this will be cut to remove it from the bicipital groove and later tenodesed.

? The subacromial space is then entered for placement of anterolateral and lateral portals.

? A traction suture is placed in the subscapularis tendon to facilitate mobilization.

? Mobilization of the subscapularis is achieved using combination of electrocautery and a shaver to debride any fibrous adhesions along the anterior capsule and subcoracoid space.

? This is achieved from both subacromial space while viewing from lateral portal and working through anterior and anterolateral portals and from the intraarticular space while viewing from the posterior portal.

? A 70� lens is often used for improved visualization.

? Care must be taken to stay lateral to the coracoid to avoid neurovascular structures.

? Once the subscapularis has been adequately mobilized to allow anatomic reduction to the footprint, the footprint will be prepared using a bur to remove any remaining soft tissues and create a healthy bleeding bone bed for tendon healing.

? The traction suture is then used to reduce the subscapularis to the footprint and is held in place with a clamp from outside the portal.

? Two spinal needles are used to localize placement of the medial row anchors at the articular margin of the humeral head into the lesser tuberosity.

? A small stab incision is made just inferior to the spinal needle, and a FiberTak (Arthrex, Naples, FL) double-loaded soft anchor is placed percutaneously.

? This anchor is preferred for the transtendon technique because of the small diameter (1.6 mm) drill that is needed. These anchors are loaded with a LabralTape and #2 FiberWire (Arthrex).

? Give a gentle pull on the sutures to ensure the anchor is firmly seated.

? These steps are repeated for placement of the second medial row anchor.

? The sutures from the medial row are then tied in a ?double-pulley? technique.

? One limb of the free suture from each anchor is brought through the anterior portal and a knot is tied extracorporeal.

? The other two suture limbs are then pulled to shuttle this knot into the medial row.

? These limbs are then brought out through the anterior portal, and a static knot is tied to complete the ?double pulley.?

? Attention is then turned to the lateral row of the repair construct.

? One limb of the LabralTape from each medial anchor is then retrieved through the anterior portal.

? A 4.75-mm SwiveLock anchor (Arthrex) is loaded with these two LabralTape sutures.

? The lateral row is placed at the lateral aspect of the lesser tuberosity.

? These steps are repeated for placement of a second lateral row anchor, completing the repair construct.

? The repair can be assessed by taking the arm through a range of motion (ROM) to confirm anatomic reduction of the subscapularis.

19.4 Surgeon Tips and Tricks (Use of Specific Instrumentation)

? This technique can be used for both partial and complete tears of the subscapularis.

? In partial tears involving the superior portion of the subscapularis, it is important to identify and anatomically reduce the stump of the remaining tendon.

? We prefer the beach chair position to allow easy access to the anterior shoulder.

? The adjustable arm positioner (Spider2) is an important tool when planning for subscapularis repair as the arm is internally and externally rotated at different points throughout the procedure.

? Tenotomy or tenodesis of the LHB should be performed with all subscapularis repairs.

? Adequate mobilization of the subscapularis is achieved while viewing from both subacromial and intraarticular spaces.

? Placing the subscapularis on tension during mobilization is important to address adhesions long the anterior glenoid and subcoracoid space.

? Accurate placement of the anterolateral portal inline with the subscapularis to allow for a traction stitch to anatomically reduce the tendon to the footprint is imperative for this transtendon repair technique.

? The FiberTak Soft Anchors are easily placed percutaneously and cause minimal damage to the tendon with a 1.6-mm drill hole.

19.5 Pitfalls and Complications

? Neurovascular structures lie just medial and inferior to the coracoid and are at risk during mobilization of the subscapularis.

? Ensure accurate placement of the medial row anchors to avoid penetration of the humeral head.

? Assess the strength and stability of the repair by taking the arm through a full ROM at the conclusion of the repair.

19.6 Rehabilitation

? See www.bostonshoulderinstitute.com for full details.

? Phase 1: immediate postsurgical phase (weeks 1?4).

? Maintain arm in a sling with abduction pillow at all times and remove only for exercise.

? Cryotherapy to reduce initial inflammation.

? At day 21, may begin pendulum exercises and start passive ROM as tolerated under the direction of the physical therapist.

? Phase 2: Protection phase (weeks 4?10).

? Weeks 4?5: gradually restore full passive ROM.

? May discontinue sling at end of week 6.

? Week 6: begin assisted active ROM (AROM).

? Begin rotator cuff isometrics.

? Initiate AROM exercises.

? Phase 3: Intermediate phase (weeks 10?14).

? Weeks 10?12: full AROM.

? Initiate strengthening program.

? Week 12: begin light functional activities.

? Week 14: progress to fundamental shoulder exercises.

? Phase 4: advanced strengthening phase (weeks 16?22).

? Continue progression of strengthening.

? Advance proprioceptive, neuromuscular activities.

? Phase 5: return to activity phase.

? Gradual return to strenuous work activities.

? Week 26: may initiate interval sport program if appropriate.

19.7 Rationale and Evidence for Approach

? As the anterior force couple of the rotator cuff, the subscapularis plays an important role in shoulder stability and motion, and in isolation was found to produce up to 50% of the rotator cuff force.1

? The subscapularis is unique, in that the upper two-thirds of the insertion consists of a tendinous portion at the lesser tuberosity, and a muscular insertion more distal along the humeral metaphysis.2

? It is this superior tendinous portion that blends with anterior fibers of the supraspinatus tendon and contributes to the rotator interval and biceps pulley.3

? While this superior portion was found to be the strongest of the subscapularis, it is also the most susceptible to injury.4,5

? These tears can be missed or overlooked, as they are most often partial tears, and associated with anterior supraspinatus tears that may mimic the symptoms.6

? As tears of the subscapularis are more commonly recognized, with incidences up to 43% in one series,7 it is important to have a knowledge of techniques that can produce a biomechanically stable repair of this important structure.

? The goals of any rotator cuff repair should be to anatomically reduce the tendon to the footprint, maximize tendon?bone contact area, and utilize a biomechanically stable construct that will prevent gapping and allow tendon-to-bone healing.

? Given the biomechanical importance of the subscapularis, we feel that repair techniques should employ these same strategies that have proven effective in supraspinatus and infraspinatus tendon repair.

? Biomechanical studies have demonstrated the advantages of double-row repair versus single-row repair with regard to restoration of the footprint contact area, ultimate load to failure, and resistance to gap formation.8,9,10,11

? We feel that a double-row construct is appropriate for subscapularis tears to achieve the above-listed goals.

? This technique in particular has several advantages:

? Using a traction stitch allows for anatomic reduction of the tendon prior to placement of the transtendon medial row anchors.

? The double-row construct combined with the medial row ?double pulley? provides a large contact area with compression over the entire footprint.

? The use of a small caliber (1.6 mm) soft anchor causes minimal tendon damage for this transtendon approach.

? Also, the small soft anchor minimizes the loss of the footprint area that may be associated with larger anchors.

? While further biomechanical and clinical studies are needed to confirm the effectiveness of this technique, we feel that in appropriately selected patients, this technique provides a biomechanically stable construct that is advantageous for tendon-to-bone healing with minimal risk of complications (? Video 19.1).

image

Video 19.1 This video demonstrates our preferred technique for arthroscopic transtendon doublerow subscapularis repair. The procedure is on the patient's right shoulder in a beach chair position. The initial view is with a 30 degree lens from a posterior viewing portal. The subscapularis tear is identified and mobilized. Once adequately mobilized the insertion site is prepared and the tendon is held in a reduced position while medial row anchors are placed transtendon. The repair construct is completed using a medial double pulley to compress the tendon and a lateral row in a speed-bridge configuration.

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] Hinton MA, Parker AW, Drez D, Jr, Altcheck D. An anatomic study of the subscapularis tendon and myotendinous junction. J Shoulder Elbow Surg. 1994; 3(4):224?229

[3] Burkhart SS, Esch JC, Jolson RS. The rotator crescent and rotator cable: an anatomic description of the shoulder?s ?suspension bridge?. Arthroscopy. 1993; 9(6):611?616

[4] Arai R, Sugaya H, Mochizuki T, Nimura A, Moriishi J, Akita K. Subscapularis tendon tear: an anatomic and clinical investigation. Arthroscopy. 2008; 24(9):997?1004

[5] Halder A, Zobitz ME, Schultz E, An KN. Structural properties of the subscapularis tendon. J Orthop Res. 2000; 18(5):829?834

[6] Sakurai G, Ozaki J, Tomita Y, Kondo T, Tamai S. Incomplete tears of the subscapularis tendon associated with tears of the supraspinatus tendon: cadaveric and clinical studies. J Shoulder Elbow Surg. 1998; 7(5):510?515

[7] Adams CR, Schoolfield JD, Burkhart SS. The results of arthroscopic subscapularis tendon repairs. Arthroscopy. 2008; 24(12):1381?1389

[8] Tuoheti Y, Itoi E, Yamamoto N, et al. Contact area, contact pressure, and pressure patterns of the tendon-bone interface after rotator cuff repair. Am J Sports Med. 2005; 33(12):1869?1874

[9] Mazzocca AD, Millett PJ, Guanche CA, Santangelo SA, Arciero RA. Arthroscopic single-row versus double-row suture anchor rotator cuff repair. Am J Sports Med. 2005; 33(12):1861?1868

[10] Kim DH, Elattrache NS, Tibone JE, et al. Biomechanical comparison of a single-row versus double-row suture anchor technique for rotator cuff repair. Am J Sports Med. 2006; 34(3):407?414

[11] Smith CD, Alexander S, Hill AM, et al. A biomechanical comparison of single and double-row fixation in arthroscopic rotator cuff repair. J Bone Joint Surg Am. 2006; 88(11):2425?2431