ANATOMY AND PATHOANATOMY

Basic rotator cuff anatomy is covered elsewhere in this text. Here we will focus on the anatomic changes relevant to large tears. Massive retracted tears pose unique anatomic constraints. They are associated with muscle atrophy and eventually fatty infiltration, which progresses with increasing size and duration of the tear. Even with successful repairs, only a portion of the atrophy is reversed and fatty infiltration remains constant. The tendons themselves can become degenerative and fibrotic. Superior migration of the humeral head can occur, making a primary repair even more difficult. Many massive rotator cuff tears can be repaired primarily using interval scar releases and margin convergence. In some cases, the final construct may have significant tension, with poor-quality tissue and even a residual defect. In these cases, it might be beneficial to add a patch augmentation to supplement the repair because the risk for retear is high. When primary repair is impossible, it is important to have the ability to bridge the gap with a biologic augmentation device. Currently, there are no tissue replacement devices approved by the U.S. Food and Drug Administration (FDA) for bridging gaps larger than 1 cm.

HISTORY AND PHYSICAL EXAMINATION

Chronic massive tears usually occur in patients older than 45 years and are less common in the younger patient population. The symptoms include chronic aching and weakness in the shoulder that worsens with abduction and external rotation. Catching, locking, and crepitation may also be present. Symptoms increase noticeably at night and sleep is frequently interrupted. In the most severe cases, shoulder elevation and external rotation are weak or impossible.

A comprehensive examination of the shoulder is necessary for all patients, complete with specific tests for the rotator cuff, starting with inspection and comparison to the unaffected side to evaluate for atrophy of the rotator cuff musculature. Humeral head subluxation and deltoid incompetence are easily assessed on many patients with inspection and palpation. Active and active-assisted range of motion are also tested. Active elevation may be severely limited but passive motion is often preserved.

Muscle testing starts with the arm at the side to test the infraspinatus and subscapularis muscles with internal and external rotation. The subscapularis can also be isolated with the belly press or lift-off test. The supraspinatus is tested with the arm in 60 degrees of abduction and 45 degrees of forward flexion, and the shoulder held in maximum internal rotation. The patient attempts to elevate as the examiner places progressive downward pressure. Impingement and acromioclavicular arthritis often coincide with rotator cuff pathology, so patients undergo specific tests for those entities as part of the complete examination.

DIAGNOSTIC IMAGING

Four standard views of the shoulder are obtained in all patients with rotator cuff problems:

The gold standard for imaging of the soft tissues around the shoulder, including the rotator cuff, is magnetic resonance imaging (MRI). This study provides the most information when a powerful 1.5-T magnet is used, with specialized shoulder coils and current software. Standard three-plane sequences should be obtained for T1- and T2-weighted images. Large full-thickness tears are easily visualized on the T2 coronal oblique images. The T1 sagittal oblique images are useful for visualizing the muscle bellies of the rotator cuff to determine the degree of atrophy. The axial oblique images are useful to evaluate the subscapularis and biceps tendons, because they are often involved in large and massive tears and are best visualized on this sequence.

Often, the treatment of a large or massive rotator cuff tear may follow failed open or arthroscopic surgery. In this case, it is best to obtain MRI images after intra-articular injection of dilute gadolinium-saline solution (1:100). This enhances visualization of intra-articular structures as well as the rotator cuff, biceps tendon, and old anchors in a revision setting. The MRI scan provides the most information to help determine the possibility of a primary repair; however, the decision to repair primarily, augment, or bridge is always made at the time of arthroscopy.

INDICATIONS AND CONTRAINDICATIONS

The indications and contraindications for bridging and augmentation of rotator cuff defects are still being defined. For bridging, the best demographic factor is motivated patients younger than 60 years with massive irreparable tears who have severe disabling pain and well-maintained active motion. An intact biceps tendon is helpful because it facilitates sewing the graft in anteriorly. Fatty infiltration of the rotator cuff musculature and superior migration of the humeral head are acceptable variables. Augmentation is typically used for tears that are at risk for failure with primary repair. These include rotator cuffs with repairs under tension, chronic large tears, fatty degeneration, poor tendon quality, or a small residual defect following a large repair. Age is a confounding variable because older patients are more at risk for retear but are also less likely to incorporate the graft successfully, likely because of the senescence of mesenchymal stem cells.²⁶

Relative contraindications for both procedures include moderate glenohumeral osteoarthritis or rotator cuff arthropathy, immunocompromised state, and heavy smoking. Patients older than 60 years are potential candidates but outcomes may not be equivalent to those in the younger age group.²⁶ Older patients with cuff tears, osteoarthritis, restricted motion, and little pain are not candidates for this procedure. These patients are best served with a reverse total shoulder arthroplasty.

TREATMENT OPTIONS

Treatment options for massive rotator cuff tears are limited in the very young population. Primary repair, either arthroscopically or with a miniopen repair, is possible. Repairing massive tears with compromised tissues dramatically increases the risk of failure with either technique. In this situation, it is best to augment with a biologic scaffold to reinforce the tenuous repair. In our opinion, alternatives to repair, such as reverse total shoulder arthroplasty, latissimus dorsi transfer, glenohumeral joint fusion, and arthroscopic débridement with partial repair, are second attempts, or salvage may be considered if the allograft fails. In addition to other shortcomings, these are all nonanatomic solutions. Latissimus dorsi transfers have demonstrated good results in certain patient populations but the postoperative immobilization is likely tolerated only by the most compliant of patients.^27,28 Reverse total shoulder arthroplasty appears to be a good option for patients older than 70 years with limited function.²⁹ In the younger population, arthroplasty plays a small role because of the possibility of multiple revision surgeries over the long term. Glenohumeral joint arthrodesis sometimes offers excellent pain relief but function is limited when compared with other techniques that preserve the glenohumeral joint.³⁰ For the very young patient, the best option is probably patch augmentation with acellular human dermal matrix (GJA; Wright Medical Technology). There is a burgeoning interest in nonstructural biologic options, including bone morphogenic proteins and growth factors. In the future, these could be added to primary repairs or grafts to improve rotator cuff healing rates.³¹

Patients with large rotator cuff tears, preserved function, and minimal discomfort can be treated conservatively in the short term. Corticosteroid injections combined with physical therapy offer symptomatic relief only. Unfortunately, the natural history predicts that the tear will enlarge and the joint may progress to rotator cuff arthropathy if the tendon is not surgically reattached to the tuberosity. At this point, the best option for most patients is an attempt at repair with an augmentation if necessary.

Arthroscopic Techniques

Patch Augmentation of Rotator Cuff Tears

The technique described here is for augmentation of primarily repaired rotator cuff tears that appear to be at risk for failure. At-risk repairs include those with residual defects, poor-quality tissue, size larger than 3 cm, and previous failed repair attempts. The technique for biologic rotator cuff replacement has been described.²³

Glenohumeral Diagnostic Arthroscopy and Tendon Mobilization.

For all arthroscopic cases, the patient is positioned lateral decubitus on a beanbag. Bony prominences are padded and an axillary roll is placed. The standard position includes 70 degrees of abduction for glenohumeral work, 15 degrees abduction for bursal work, and 45 degrees abduction as the midposition to access the lateral aspect of the tuberosity. After creation of a standard posterior portal and an anterior interval portal, a complete diagnostic examination of the glenohumeral joint is performed, viewing from both portals. The rotator cuff tear is evaluated and débrided with an arthroscopic shaver; the tuberosity may be prepared from within the joint, usually by viewing from the anterior portal and working from the posterior portal. Intra-articular releases are performed to mobilize the tendon, if needed, using the shaver, arthroscopic liberator tool, or radiofrequency wand from the glenohumeral or bursal approach.

Bursal Arthroscopy and Tuberosity Preparation.

A complete diagnostic examination of the bursal space is performed. An additional lateral portal is made at the middle of the tear, followed by complete débridement of bursal scar tissue to ensure complete visualization. An arthroscopic subacromial decompression is performed, if required, taking care to avoid resecting the coracoacromial ligament to prevent anterosuperior escape. The tear is visualized and débrided, and bursal-sided releases are performed with the shaver and electrosurgery to maximize mobilization. The scarred muscle and tendon can also be sharply separated from the acromion before using a shaver or electrosurgical tool. If not completed from the articular side, the tuberosity is gently prepared for rotator cuff repair. This is done with an arthroscopic shaver, removing only a thin layer of cortical bone to create a bleeding surface. The tuberosity must be prepared near the articular margin for the primary repair and up to 1.4 cm away from the tuberosity for lateral fixation for the graft.

Primary Rotator Cuff Repair.

After the tendon and tuberosity are prepared, a primary rotator cuff repair is usually possible. This may require advanced techniques, including releases, side to side sutures, and multiple anchors. It is our practice to repair the tendon in single-row fashion with anchor placement 4 mm from the articular surface. Each anchor holds three sutures, which are passed in simple fashion and tied sequentially. Bone vents are created using a 2-mm punch laterally on the tuberosity to allow marrow elements (e.g., stem cells, blood cells, platelets, growth factors) to contribute to the rotator cuff healing. For the at-risk, tears we proceed with rotator cuff biologic augmentation using acellular human dermal matrix (GJA; Wright Medical Technology).

Graft Measurement.

Accurate measurements of the tear are needed to appropriately size the graft. The knotted suture device allows simple and precise measurement of the dimensions of the tear (Fig. 25-1). It is an arthroscopic measurement tool made of braided suture with knots placed 1 cm apart that can be pulled through a knot pusher. The length is measured between the tip of the knot pusher on one of the knots and a grasper that holds the free end of the device (Fig. 25-2). In the medial to lateral dimension, 1 cm of graft will overlap the tuberosity and an additional 1 cm will overlap the repaired cuff; 6 mm should be added to the mediolateral and anteroposterior dimensions to allow for suture placement 3 mm from each edge.

FIGURE 25-1 The knotted suture device arthroscopic measuring tool is made using a standard arthroscopic knot pusher, grasper, and braided suture, with knots placed at 10-mm increments.

FIGURE 25-2 The knotted suture device is used to measure the anterior to posterior dimension of the tear.

Graft Preparation.

The graft is cut on the back table and the midline of the lateral aspect of the graft is marked with a sterile marking pen. Five short-tail interference knotted (STIK) sutures are then passed with a Keith needle from top to bottom through the anterior, medial, and posterior portions of the graft, 3 mm from the edge. The sutures are passed at the 9, 11, 12, 1, and 3 o’clock positions on the graft (Fig. 25-3). A STIK suture is a permanent braided no. 2 suture with a mulberry interference knot tied at one end, allowing for control of the graft using a single pass of the suture.

FIGURE 25-3 Using the measurements, the graft is cut on the back table. The medial to lateral dimension is 26 mm, allowing 1 cm of graft on either side of the repair. The anterior to posterior dimension is X (the length of the tear) plus 6 mm for placement of STIK sutures 3 mm from either end. STIK sutures are placed as shown and the midline of the lateral edge is marked for orientation.

Suture Passing.

The STIK sutures are passed in order, starting with the anterior suture (9 o’clock) and progressing toward the posterior stitch. All sutures are shuttled with a 45- or 60-degree suture hook to pass Suture Shuttles (Conmed Linvatec, Largo, Fla). The position of the first STIK and each subsequent STIK suture can be estimated using a knotted suture measuring device. All sutures are passed while viewing from the lateral portal and working from the posterior portal. The anterior-most stitch is the exception; it is not easily approached from the posterior portal. Instead, the suture hook is introduced through the anterior portal and passed through the anterior cuff, just anterior to the primary rotator cuff repair. Several inches of suture shuttle are fed into the joint; the suture hook then can be removed and the free end of the shuttle brought out the same anterior cannula. The eyelet is loaded with the corresponding 9 o’clock STIK suture, which can then be shuttled through the tissue. Once passed, the 9 o’clock STIK suture is stored outside the anterior cannula (Fig. 25-4). The remaining STIK sutures can be passed using the suture hook in the posterior cannula. The suture shuttle is retrieved out the anterior cannula and the corresponding STIK sutures shuttled out the posterior cannula (Fig. 25-5). When passing the remaining STIK sutures, it is critical that each subsequent suture be passed lateral to the previous one. This stay lateral technique is critically important when augmenting a rotator cuff repair. For example, the 11 o’clock STIK is passed with a suture hook, grabbing tissue approximately 1 cm medial to the original repair. The shuttle is retrieved on the lateral side of the 9 o’clock STIK suture. The subsequent three STIK sutures are passed in the same fashion, always staying lateral (Fig. 25-6). A crochet hook is used to retrieve and bring the 9 o’clock suture out the posterior cannula with the other four STIK sutures.

FIGURE 25-4 The 9 o’clock STIK suture is passed using a shuttle through the anterior cannula (arrows).

FIGURE 25-5 The second suture shuttle is passed from the posterior portal at the anteromedial position on the graft. The suture shuttle is retrieved into the anterior cannula staying lateral to the prior suture, and then used to shuttle the corresponding 11 o’clock STIK suture.

FIGURE 25-6 All STIK sutures have been passed, staying lateral with each subsequent suture.

Graft Insertion.

Once the five STIK sutures are passed and clamped out the posterior cannula, the graft is ready to be inserted down the anterior cannula. The graft is carefully rolled on itself with the bursal surface remaining inside so that it will face up when the graft is unrolled in the joint. The graft is inserted with a push-pull technique; the folded graft is carefully pushed down the anterior cannula with an arthroscopic grasper and the five STIK suture ends are pulled from the posterior cannula. With the graft in the joint, each STIK suture can be sequentially tensioned to position the graft over the repair site (Fig. 25-7). Each STIK knot can then be retrieved and tied with a sliding locking knot, followed by three alternating half-hitches to secure the graft anteriorly, medially, and posteriorly.

FIGURE 25-7 The graft is inserted by pulling the free ends of the STIK sutures. The STIK sutures can now be retrieved and tied.

Lateral Fixation.

Previously, the tuberosity was prepared for the lateral suture anchors. Two anchors are placed 1 cm lateral to the suture line for the primary repair and placed at the 5 and 7 o’clock positions of the unfolded graft. The anchors can be double- or triple-loaded; abduction of the arm is helpful for placement of these more lateral anchors. Simple sutures are passed through the lateral aspect of the graft and tied arthroscopically. The midline mark on the graft is helpful for orienting suture placement for the lateral anchors (Fig. 25-8).

FIGURE 25-8 The remaining lateral edge is fixed to bone using suture anchors and standard technique.

Rotator Cuff Bridging Reconstruction

If a primary repair is impossible, a good option for some patients is a bridging reconstruction. This procedure is considered off-label for FDA purposes. Similar to an augmentation, the procedure begins with a complete glenohumeral and subacromial diagnostic arthroscopy.

Bursal Arthroscopy and Tuberosity Preparation.

The remaining rotator cuff tendon must be débrided, allowing a clear view of the anterior, posterior, and medial edges. The subacromial bursa is completely removed and releases are performed. The greater tuberosity is gently prepared with a shaver and several bone marrow venting holes are placed with an arthroscopic punch lateral to future anchor placement.

Graft Measurement.

The defect must be precisely measured in two dimensions. The knotted suture device can again be used to measure the defect in the anterior, posterior, medial, and lateral dimensions. These four measurements are used to cut the graft to match on the back table.

Graft Preparation.

The anterior, posterior, and lateral edges of the graft are marked with a sterile marking pen. On the medial edge, four to five STIK sutures are placed 3 to 4 mm from the edge. They are placed from top to bottom 5 mm apart, leaving the knotted ends on the top (smooth side) of the graft. Additional STIK sutures are placed in the anterior and posterior edges of the graft in a similar fashion (Fig. 25-9).

FIGURE 25-9 Orientation of the STIK sutures on the anterior, medial, and posterior edges of the graft.

Anchor Placement.

Two triple-loaded suture anchors are placed percutaneously into the prepared tuberosity 4 to 5 mm lateral to the edge of cartilage. One is placed just posterior to the biceps and a second just anterior to the posterior cuff remnant. When appropriate, one suture from each anchor is passed through the adjacent cuff and biceps. When the anterior suture is tied, it will effect a tenodesis of the biceps in the bicipital groove (Fig. 25-10).

FIGURE 25-10 Placement of the anterior anchor adjacent to the biceps and posterior anchor anterior to the posterior cuff margin. Bone marrow venting holes are lateral to the anchors.

Visualization.

Insert an 8-mm docking cannula in the lateral acromial portal and 7-mm docking cannulas into the anterior and posterior subacromial portals. The scope is maintained in an accessory lateral subacromial portal 2 cm posterior to the 8-mm docking cannula.

Posterior Suture Passing.

Place the graft on a moist towel attached to the arm lateral to the lateral cannula and orient the graft so the posterior edge faces the cannula. Pass a suture-shuttling device through the lateral aspect of the posterior cuff remnant. Retrieve it in the lateral cannula, being careful to stay between the two clusters of sutures from the anchors. The unknotted end of the posterior lateral STIK suture tie is shuttled out the posterior cannula (Fig. 25-11). Working from lateral to medial, the remaining posterior STIK sutures are passed in similar fashion. The shuttle device is always retrieved into the lateral cannula anterior to the previously passed suture to avoid entanglement.

FIGURE 25-11 The suture shuttle device is passed through the posterior cuff and retrieved between the two clusters of anchored sutures.

Medial Suture Passing.

Rotate the graft so that the medial border is facing the cannula. Pass the medial STIK sutures through the medial cuff, working from posterior to anterior. Be sure to retrieve the shuttle between the two clusters of suture anchor sutures. The posterior two or three STIK sutures are best passed working through the posterior portal and the anterior one or two STIK sutures usually require switching to the anterior portal.

Anterior Suture Passing.

Rotate the graft so that the anterior edge faces the lateral cannula and pass the anterior STIK sutures through the anterior edge of tissue, including the biceps tendon when it is present. Work medial to lateral, always taking care to retrieve the shuttle anterior to previously passed sutures in the lateral cannula.

Corner Suture Passing.

With the anterior graft edge still facing the cannula, retrieve the most anterior suture in the anterior anchor out the lateral cannula and pass it through the graft from bottom to top at the anterior lateral corner using a Keith needle. Tie a STIK knot on the upper end of the suture. Rotate the graft so that the posterior edge faces the cannula. Retrieve the most posterior suture from the posterior anchor, pass it through the posterior lateral corner of the graft, and tie a STIK knot on top (Fig. 25-12).

FIGURE 25-12 The posterior anchored suture is retrieved and passed through the posterior lateral corner of the graft with a Keith needle.

Graft Insertion.

Rotate the graft so the medial border faces the cannula and roll it up. Advance the graft through the cannula into the shoulder by pulling on the free ends of the STIK sutures and pushing the graft with a small arthroscopic clamp (Fig. 25-13). Once in the shoulder, pull the slack from all STIK sutures, allowing it to flatten in the cuff defect.

FIGURE 25-13 The graft is inserted by pulling on the free ends of the STIK sutures (arrows) and gently pushing with a small arthroscopic grasper.

Tie STIK Sutures.

Begin tying from posterior to anterior. Retrieve the free ends of all STIK sutures except the most posterior one out the anterior cannula. Retrieve the free and knotted end of the most posterior STIK suture out the posterior cannula and tie it. Continue tying around the posterior, medial, and anterior edges of the graft and then tie the two STIK sutures passed from the anchors (Fig. 25-14).

FIGURE 25-14 The STIK sutures are tied sequentially, starting posterior and progressing along the medial and anterior edges. The anchored STIK sutures are tied last.

Lateral Fixation.

Pass and tie the remaining sutures from the anchors on the lateral edge. Insert additional anchors and pass simple sutures as needed (Fig. 25-15). At the completion of the procedure, turn off the arthroscopic pump and observe the bone marrow as it flows from the vents on the tuberosity, forming a red blanket over the graft—the “crimson duvet” (Fig. 25-16).

FIGURE 25-15 Anchored sutures are passed and tied in simple fashion. Additional anchors are placed if needed.

FIGURE 25-16 The arthroscopic pump is turned off, allowing the “crimson duvet” to blanket the graft.

PEARLS& PITFALLS

1. Identify tears at risk for failure after primary repair (poor tissue quality, residual defect, excessive tension).

2. Excise subacromial bursal tissue completely to optimize visualization throughout the procedure.

3. Lateral decubitus positioning allows safe administration of relatively hypotensive anesthesia.

4. Accurately measure the size of the graft material needed, using a knotted suture device over the primary repair and cutting the graft with 6 mm of additional length and width to allow for suture placement.

5. For the augmentation technique, use STIK sutures to pass through the graft at the 9, 11, 12, 1, and 3 o’clock positions 3 mm from the edge of the graft.

6. When passing the STIK sutures, start with the 9 o’clock position and be sure to stay lateral with each subsequent STIK passage.

7. Keep all sutures parallel and always stay lateral, because precise suture management is critical for success.

8. Graft is carefully rolled and inserted with the push-pull technique.

9. Fluid extravasation must be carefully monitored if a pump is used; pressures should be kept as close to 35 mm Hg as possible.

10. If more than 2 hours have transpired, remove the arm from traction for 30 minutes after the graft enters the shoulder to minimize the risk of traction- or compression-related nerve injury.

11. Practice this technique on a shoulder model (ALEX shoulder model, SCOI’s CLASroom, Orthopaedic Learning Center courses) to master the techniques of staying lateral and keeping sutures parallel prior to attempting this difficult technique on a patient.

POSTOPERATIVE REHABILITATION PROTOCOL

Postoperatively patients are managed exactly as we would manage any large rotator cuff repair. They are immobilized in an Ultra-Sling (Donjoy, Carlsbad, Calif) for 6 weeks. The sling is removed daily to perform Codman pendulum exercises. Formal therapy is begun at 6 weeks, active elevation at 8 weeks, and gentle strengthening at 12 weeks. Presently, our protocol also includes obtaining MRI scans with gadolinium arthrography at 3 months, 12 months, and 2 years to detect any early or late failures of the graft.

SUMMARY AND CONCLUSIONS

More than 80 procedures have been performed at SCOI to date, with very few complications. There has only been one infection in an immunocompromised patient that responded to arthroscopic irrigation, débridement, and antibiotics. The graft itself is acellular, eliminating the possibility of graft rejection. Recently, 2-year follow-up data became available for the first 13 patients treated with GRAFTJACKET bridging technique at our institution.³² Of the 13 patients, 12 were satisfied with their results. Postoperatively, the Constant scores increased to 87.3 from 53.8 preoperatively (P = .0001). The mean modified UCLA score increased to 29.8 from 18.4 (P = .0001). MRI data is also convincing; 12 of 13 patients demonstrated full incorporation of the graft into native tissue at 1 year.³² Currently, a multicenter prospective randomized study is in progress to study GRAFTJACKET allograft augmentation of rotator cuff repairs; however, 2-year follow-up data are not yet available.

At this point, the exact mechanisms for the success of this operation are unknown. Most likely, the graft works to reduce and contain the humeral head into the glenoid (preventing boutonniere deformity) and allowing the deltoid to function more efficiently by maintaining the integrity of the anterior-posterior force couple. It is also possible that attaching the remaining cuff musculature to the humerus supplies some benefit. Continued research and engineering will improve graft options and the ability to regenerate tissue. Further research is needed to determine the ideal fixation configuration, need for other biologic enhancement with growth factors or platelet-rich plasma, and whether there is an age limit for the marrow stem cells to provide in-growth potential to the graft.

Arthroscopic allograft rotator cuff augmentation or bridging reconstruction are technically challenging procedures that require significant preoperative planning and practice. We believe that any surgeon with interest and desire can learn the appropriate steps. We recommend perfecting the technique on an ALEX shoulder model prior to attempting these procedures on a patient. With practice and experience, the individual steps continue to evolve at our institution in efforts to make it more efficient and straightforward. We believe that the future of this technique is bright because it provides an excellent option for patients with complex rotator cuff tears.