Full Thickness Posterior Rotator Cuff Tear

Tear Pattern Recognition

One of the major advancements of arthroscopy has been the ability to more thoroughly evaluate rotator cuff tears compared to a traditional open approach. This has led to recognition of four major types of rotator cuff tears: (1) crescent tears, (2) U-shaped tears, (3) L-shaped tears, and (4) massive contracted tears. Recognition of these distinct tear patterns is crucial because the tear pattern dictates the repair pattern. Anatomic reconstruction of the posterosuperior footprint is important to restore external rotation strength and balance force couples, and repairing tears according to their tear pattern can lead to excellent results ( ).

Crescent-shaped tears are the simplest of all tears. These tears have good medial-to-lateral mobility and can be repaired directly to bone with minimal tension. Essentially, all crescent-shaped tears are repaired with a double-row construct.

In contrast, U-shaped rotator cuff tears extend much farther medially. The apex of the tear is usually adjacent to the glenoid rim medially. These tears demonstrate significant mobility in the anterior-to-posterior direction and should be initially repaired in a side-to-side fashion using margin convergence sutures. Failure in recognizing this tear pattern will result in overwhelming tensile stresses if an attempt is made to repair a lateral bone bed. However, sequential medial to lateral suturing of the anterior and posterior leaflets causes the free margin of the rotator cuff to converge toward the bone bed on the humerus. The free margin of the tear is then directly repaired to bone in a tension-free manner. This technique both allows repair of possible irreparable tears and minimizes strain on the repair site ( ).

L-shaped and reverse L-shaped tears have a leaflet that is more mobile than the other leaflet. In these cases, side-to-side suturing along the longitudinal split is required followed by repair to the greater tuberosity bone bed. The use of traction stitches is useful in assisting reduction and repair of these more complex tear patterns.

Massive contracted tears have limited mobility in both the anteroposterior and medial-lateral planes. These tears typically require advanced mobilization techniques such as interval slides to achieve repair. Based on their limited mobility and frequent tendon loss, these are often best addressed with a single-row or load-sharing rip-stop (LSRS) repair.

Importance of the Subscapularis

Although this chapter focuses on posterosuperior tears, one must not neglect the subscapularis tendon. The subscapularis generates the largest amount of force of any rotator cuff muscle and is generally believed to be the most important single rotator cuff muscle because it is the only anterior muscle that can balance the posterior forces of the rotator cuff. In addition, the anterior attachment of the rotator cable extends to the upper subscapularis insertion. Therefore repair of the upper subscapularis decreases the stress on the adjacent repair of the supraspinatus, thereby protecting the supraspinatus repair. After the subscapularis has been repaired, the comma sign is very useful in locating the anterolateral corner of the supraspinatus tendon, to which it remains attached. For these reasons, we strongly recommend repairing all subscapularis tears before proceeding with arthroscopic repair of the supraspinatus and infraspinatus tendons.

Angle

The angle of visualization is influenced by the position of the patient, the angle of the arthroscope, and the position of the portal the surgeon is viewing through. We perform rotator cuff repairs in the lateral decubitus position. The arm is held in 20 to 30 degrees of abduction combined with 20 degrees of forward flexion with 5 to 10 lb of lateral weight suspended from a standard arthroscopic boom. We palpate the “soft spot” created by the glenoid medially and humeral head laterally and insert the arthroscope below the equator of the glenohumeral joint at about 7 o’clock. We have found that the often-used posterior portal tends to move too superior as soft tissue swelling increases and provides a poor angle of approach to the subacromial space. Therefore we avoid this by placing our skin incision more inferiorly. We also use 30- and 70-degree scopes interchangeably during the case.

Bone-Bed Preparation

A complete bursectomy is essential in all rotator cuff repair cases for two reasons. First, it is essential to see the entire rotator cuff margin to recognize the tear pattern. This includes removing all bursal leaders that attach to the internal deltoid fascia. We routinely release the internal deltoid fascia to achieve greater freedom for the instruments to move. Second, it removes the pain-generating cytokines that reside in the inflamed bursa in the subacromial space. With bone preparation, it is useful to remove all soft tissues from the greater tuberosity with an electrocautery device and then lightly use a high-speed bur to create a uniformly bleeding bone bed to facilitate healing.

Suture-Bridging Double-Row Repair

The original double-row repair was described as two independent rows of anchors. The technique has progressed to linking of the medial and lateral row anchors, which has improved biomechanical properties and decreased retear rates ( Fig. 7A.1 ) ( )

The tear is initially visualized through a posterior subacromial viewing portal with a 30-degree arthroscope. A 70-degree arthroscope is also often helpful, particularly for lateral row placement. Additionally, the scope may be placed in the lateral viewing portal as necessary to better visualize the posteromedial aspect of the footprint. The medial anchors are placed through separate percutaneous portals. This allows the proper angle of approach and aids in suture management. A threaded double-loaded anchor (5.5-mm BioComposite Corkscrew FT; Arthrex, Naples, FL) is placed anteromedially adjacent to the articular margin and approximately 5 mm posterior the bicipital groove. A second anchor is placed posteromedially.

Medial mattress sutures are then passed with a self-retrieving antegrade suture passer. The mattress sutures should be evenly spaced to prevent suture cut-out. We have a simple way of restoring the normal length–tendon relationship, even in tendon loss, to achieve anatomic repair with normal biomechanics. In the setting of a mobile tear, an anatomic and properly tensioned double-row repair can be obtained if the surgeon passes the medial-row sutures 2 to 3 mm lateral to musculotendinous junction. This always restores proper length–tendon relationship. In the case of tendon loss in which only a single-row repair is possible, anchors are placed slightly lateral to the articular margin. In such cases of single-row repair, the sutures are placed more lateral, 6 to 7 mm from the musculotendinous junction. This allows the musculotendinous junction to be within 2 mm of the articular margin, preventing overtensioning and reducing the probability of retear.

Traditionally, only one suture pair from each anchor is used for the SutureBridge, but the use of the second suture pair may add fixation in poor quality tendons. The mattress sutures are tied with a static six-throw surgeon’s knot using a double-diameter knot pusher (Surgeon’s Sixth Finger; Arthrex). After each pair is tied, the suture limbs are preserved by retrieving them out the same portal used for anchor insertion. The lateral row is then established by crisscrossing the medial row suture limbs. One limb from each medial row anchor is retrieved out the lateral cannula and the combined suture limbs are secured with two 4.75- or 5.5-mm BioComposite SwiveLock C anchors (Arthrex). The sutures are tensioned through the cannula before inserting the anchor to determine the appropriate location of the lateral anchors. The lateral anchors are placed on the metaphyseal cortex lateral to the “corner” of the greater tuberosity. One anchor is placed anteriorly and another posteriorly. The sutures are cut flush with the anchor for a low-profile knotless lateral repair.

Knotless Double-Row Rotator Cuff Repair

In the setting of good-quality tissue, we use a knotless technique ( Video 7A.1 ). The steps in the repair are essentially the same as previously described. Medial threaded anchors (BioComposite SwiveLock C; Arthrex) preloaded with a 2-mm suture tape (FiberTape; Arthrex) are placed adjacent to the articular margin.

• Video 7A.1

  SpeedBridge™ with medial double pulley.

One of two techniques is then used for suture passage depending on the desired construct. The medial anchors have #2 safety sutures in the anchor eyelet that may be incorporated into the repair. We often use these to create a broad double-mattress suture between the two anchors using a double-pulley technique. The suture tape and safety sutures from one anchor are retrieved out the lateral working portal. The free end of a FiberLink suture (Arthrex) is loaded onto an antegrade suture passer and passed through the rotator cuff. The sutures from the anchor are then passed through the opposite end of the FiberLink, which is a closed loop. The free end of the FiberLink is then retrieved out the portal used for anchor placement and used to shuttle the sutures through the rotator cuff. These steps are repeated for the other anchor.

Next one #2 suture from each anchor is retrieved out the lateral portal. A six-throw surgeon’s knot is tied over an instrument and limbs are cut. Pulling the opposite limbs of the #2 sutures delivers the knot into the subacromial space so that it rests over one of the anchors. The remaining two #2 suture limbs are then retrieved and tied with a static knot (a sliding knot cannot be used since the previous knot prevents sliding) over the opposite anchor. This medial double-mattress creates a medial seal between the rotator cuff and the glenohumeral joint.

Before lateral fixation, the tendon repair is assessed for dog ears. The same FiberLink used for shuttling can be used to create cinch loops at the anterior and posterior margins of the tear to reduce dog ears and reinforce the rotator cable attachments. Finally, the suture tape limbs (and dog-ear sutures if placed) are crisscrossed and secured laterally with two knotless anchors as previously described ( Figs. 7A.2 and 7A.3 ).

If tissue quality is excellent, a completely knotless technique can be used. In this setting, the medial #2 safety sutures are removed and the suture tapes alone are passed through the rotator cuff in the standard fashion. Because the limbs of these tapes come prewedged into a single limb at the end of the suture, a shuttling technique is not required in this case.

Interval Slides and Other Advanced Mobilization Techniques

Although partial rotator cuff repairs have been shown to work very well with regard to improving pain and function in the short term, a complete anatomic rotator cuff repair is desirable, particularly in younger patients. In two separate studies, showed that an anatomic repair of a massive rotator cuff tear is possible even in the setting of pseudoparalysis and results in restoration of the cable region with resultant improvement in function in 90% of cases or greater. It is critical to exhaust all efforts to mobilize the rotator cuff in the medial to lateral and anterior to posterior planes based on the tear pattern. Most massive rotator cuff tears may be reparable without releases after properly evaluating for the natural mobility. One of the keys in repairing massive tears is to first address and repair the subscapularis tendon, which is torn in the majority of massive rotator cuff tears. We also perform a limited subacromial decompression that preserves the coracoacromial arch. The other major key to success is to excavate the tendon and bursal leaders. This requires visualization of the scapular spine and clearing of the posterolateral gutter. While viewing through the lateral portal using a combination of motorized shaver and cautery placed through the posterior portal, the scapular spine is exposed. Bouncing the shaver off the scapular spine to enter the space ensures protection of the underlying rotator cuff. The scapular spine is a keel-shaped structure that delineates the interval between the supraspinatus and the infraspinatus tendons. Work can then be carried laterally to safely remove bursal leaders or false cuff that inserts on the deltoid.

The need for interval slides is based on the mobility of the rotator cuff tendon margins. When a tear has been determined to be irreparable despite standard releases, interval slides should be considered to improve mobility. The decision is based on a number of factors, including patient age, symptoms, tissue quality, and initial tear mobility. This is particularly relevant in patients with greater than 50% fatty atrophy on magnetic resonance imaging ( ).

Two slides are relevant to repairs of the posterior rotator cuff: the anterior interval slide in continuity and the posterior interval slide. The anterior interval slide is a release of the anterior leading edge of the supraspinatus tendon from the rotator interval. Our preferred method (anterior interval slide in continuity) is to use an electrocautery to release the coracohumeral ligament from the base of the coracoid while preserving the comma tissue ( ). This preserves the tissue adjacent to the anterior leading edge of the subscapularis. The anterior interval slide typically provides an additional 1 cm of excursion, and we use this in nearly all massive tears. The release is typically done while viewing with a 70-degree arthroscope through a posterior portal and working through an anterosuperolateral portal.

In contrast, the posterior slide is a release of the posterior edge of the supraspinatus from the infraspinatus. Our experience has been that the posterior interval slide provides more mobility than the anterior interval slide, with up to 4 cm of increased excursion noted after performing the slide. The posterior interval slide is performed while viewing through a lateral portal with a 30-degree arthroscope or from a posterior portal while viewing with a 70-degree arthroscope. Traction stitches are placed in the supraspinatus and infraspinatus tendons. A spinal needle is used to identify the correct angle approach in line with the posterior interval and toward the scapular spine. An arthroscopic scissor is then introduced and begins the posterior interval slide along the lateral margin of the rotator cuff directing the tendon incision toward the base of the scapular spine. The release is continued toward the scapular spine until the perineural fat pad lateral to the spine is encountered. This identifies the proximity of the suprascapular nerve. With an isolated posterior interval slide only, the mobility of the infraspinatus tendon is usually sufficiently improved to permit for repair to bone. After repair of the tendon to bone, the separation between the supraspinatus and infraspinatus is closed with margin convergence sutures, which reduces strain, thereby protecting the tendon–bone repair interface during critical phases of healing.

Diamondback Repair

The repair pattern must be adapted to the tear pattern. As such, in the setting of a large uncovered footprint from anterior to posterior, additional lateral or medial anchors may be placed as needed. One adaptation is the Diamondback repair. This repair was developed by the senior author (SSB) as an enhanced suture bridging repair construct that provides twice as many linked diagonal compression sutures with three times the number of intersection points.

Two medial double-loaded anchors (5.5-mm BioComposite Corkscrew FT; Arthrex) are placed just lateral to the articular margin in the fashion described previously for the knotted suture-bridging technique. All eight suture limbs are passed in a mattress fashion 2 to 3 mm lateral to the musculotendinous junction. The four central limbs are used in a double-pulley technique to create broad double-mattress sutures. The first two suture limbs are cut short, but the tails of the second pair are preserved. Mattress sutures are tied with the anterior-most two limbs and repeated posteriorly. A total of 3 BioComposite SwiveLock C anchors are placed laterally accepting two suture limbs for each SwiveLock in a crisscross fashion creating a diamondback pattern of repair. Biomechanical testing of the diamondback configuration demonstrated the highest initial footprint contact area and lowest decrease in contact pressure over time when compared with single- and double-row repairs ( )

Load-Sharing Rip-Stop Technique for Massive Rotator Cuff Repair

A Load-Sharing Rip-Stop technique (LSRS) technique was developed by the authors that combines the advantages of a wide rip-stop suture tape and load-sharing properties of a double-row repair ( ). demonstrated that a rip-stop suture with a double-loaded anchor had load to failure equivalent to a modified Mason-Allen stitch. This construct is particularly useful for cases in which there is limited medial tendon that precludes a standard double-row repair.

While viewing through a posterior portal, a FiberTape suture is passed through the rotator cuff as an inverted mattress stitch placed 3 mm lateral to the musculotendinous junction. If the tear has a large anterior-to-posterior dimension, then a second FiberTape may be placed in similar fashion. The limbs are retrieved out of an accessory portal. These rip-stop suture tapes must not be tensioned and repaired to bone until after the sutures from the medial anchors have been passed circumferentially around them.

Next, two double-loaded 5.5-mm anchors are placed anteromedially and posteromedially along the articular margin. Beginning posteriorly, the sutures are passed from the medial anchors as simple stiches that penetrate the rotator cuff medial to the rip-stop suture. After the medial sutures are passed, the FiberTape rip-stop sutures are retrieved from an accessory portal and secured laterally with two knotless suture anchors, making sure they encircle the sutures from the medial anchors.

Finally, simple sutures from the medial anchors are retrieved, and static knots are tied. It is important to delay knot tying until after the rip-stop stitch is secured laterally. This is done for two reasons. First, it is important to have a firm, taut rip stop. Second, the FiberTape serves to unload the medial sutures because the rip-stop construct is secured laterally to an anchor.

were the first to report a biomechanical study of an LSRS construct for repair of tissue-deficient rotator cuff tears. The mean load to failure for LSRS was nearly twice that for a single-row repair construct. The LSRS construct is the authors’ preferred method for massive rotator cuff repair with poor tissue quality in which a double-row repair is not possible because of limited mobility.