Abstract
Massive rotator cuff tears are often chronic in presentation and present with many factors that may inhibit successful repair. Retear rate of large-to-massive rotator cuff tears approaches 70% in the elderly and 45% in the young. Radiographic parameters for tear irreparability have been described. In the setting of irreparability, a number of surgical treatment approaches have been suggested. An ideal treatment should include restoration of joint function and relief of pain. Although muscle transfer remains an option in some, the indications are limited, and technical aspects of the procedures are demanding. Patch interposition (PI) and superior capsular reconstruction (SCR) have become the more commonly used approaches, along with patch augmentation. Biologics tried include extracellular human, porcine and synthetic grafts, as well as autografts using fascial and long head of biceps tendon. Only one outcome study for SCR has been published, but enthusiasm for this technique has grown. Multiple technical papers recently were published popularizing this treatment approach, so we should expect more clinical reports in the future. Few studies have met strict inclusion criteria to fairly compare reverse shoulder arthroplasty with SCR. This review may serve as a baseline comparison between these approaches. In terms of patient-reported outcomes, initial postoperative SCR reports provide very promising data comparable to Reverse Shoulder Arthroplasty (RSA) complication rate. Further studies involving direct comparison, larger cohorts, and longer term follow-up will be necessary to determine the role of each of these treatment strategies in the treatment of massive irreparable rotator cuff tears.
Keywords
Biologics, Massive rotator cuff tear, Patch augmentation, Patch interposition, Superior capsule reconstruction
Introduction
Massive rotator cuff tears are often chronic in presentation and complicated by poor tendon quality, muscular fatty atrophy, tissue retraction, and scarring. For these reasons, successful footprint repair and tendon healing may be difficult and can result in retear rate of large-to-massive rotator cuff tears as high as 70% in the elderly and an approximate 45% retear in massive rotator cuff repairs in younger cohorts Known radiographic parameters for tear irreparability include acromiohumeral interval less than 7 mm, Goutallier grade 3–4 fatty infiltration of the infraspinatus, and a positive supraspinatus tangent sign. Approximately 10%–40% of all rotator cuff tears are massive. In the setting of irreparability, a number of surgical treatment approaches have been suggested.
There are multiple surgical treatment options for the irreparable rotator cuff tear. The patient’s age, integrity of the glenohumeral joint, extent of residual shoulder function, presenting symptoms, medical comorbidities, desired activity level, and rehabilitation requirements are all important considerations. An ideal treatment should include restoration of joint function and relief of pain. Although muscle transfer remains an option in the young, laboring patient, the demanding technical aspects of this procedure, relative perioperative morbidity, and unpredictable functional outcomes, particularly in older patients, limit the indications for this procedure.
Patch interposition (PI) and superior capsular reconstruction (SCR) have become the more commonly used reconstructive approaches Patch augmentation has also been used. Examples tried have included extracellular human, porcine, and synthetic grafts, as well as autografts using fascial and long head of biceps tendon autografts. In the absence of advanced cuff tear arthropathy, there is no clear indication for one reconstructive technique over another, and there is no standard treatment approach to this challenging clinical problem.
Superior Capsule Reconstruction
The treatment of the irreparable cuff tear remains a significant challenge to the shoulder surgeon. Historically, tendon transfers or shoulder hemiarthroplasty were limited goal treatment options. This option may work in older patients; however, in younger and active patients it may not give such good outcomes and may result in higher complications and reoperations rate than in older ones. Some authors suggest that Reverse Shoulder Arthroplasty (RSA) should be advocated in patients older than 65 years. This is one of the reasons why many new techniques are being investigated ( Figs. 7.1 and 7.2 ).
Some studies have evaluated treatment options for the massive irreparable rotator cuff tear in the setting of no or minimal osteoarthritis ( Fig. 7.3 ). The concept of implanting a patch or reconstructing the superior capsule is based on restoring the fulcrum for glenohumeral joint motions. The first reported approach was to fill the gap in irreparable cuff lesions with either biological or artificial grafts. There have been many clinical reports of different patch techniques published; unfortunately, high rate of retears have been also reported. This corresponds with our findings that almost 40% of patch grafts tore during follow-up; on contrary, only 17% reconstructed superior capsules were torn at the last follow-up visit. These results are supported by biomechanical work by Mihata et al. who reported that superior capsule reconstruction normalized superior stability of the shoulder, whereas patch grafts to the torn tendon only partially restored this stability.
The concept of restoring glenohumeral biomechanics with patch techniques and capsule reconstruction was successfully tested on cadavers. This theory is supported in the published clinical outcome studies reported herein, in which in both groups, patch filling and SCR patients had a significant and comparable increase in their ranges of motion to around 150 degrees of flexion and around 40 degrees of external rotation (ER) ( Fig. 7.4 ).
The published patient-reported outcomes did show that SCR is a promising solution. Postoperative change in American Shoulder and Elbow Society score (ASES) score for the SCR cohort was 70 points compared to 43 for patch interposition. Although direct comparisons between the cohorts are limited due to heterogeneity in reported outcome scores and measures, SCR reported more favorable range of motion and functional results than PI approaches. One potential explanation for this finding is the higher graft retear rate in the PI group than in SCR. Admittedly, the complication rate for SCR may prove to be higher with additional outcome studies and length of follow-up.
Patch Augmentation—Extracellular Matrix Patches
Previously, literature has proven that most cuff repair failure occurs at the bone to tendon interface in both large tears and medium-sized tears, which fails. Thus successful tendon repair must produce an environment that can allow tendon to bone healing over a 12-week period, while creating uniform tension over the tendon-bone interface and preserving blood supply. Omae and colleagues looked at the effect of acellular matrix patches on the biomechanics of the rotator cuff repair. In their cadaveric study, using single-row constructs with and without patch augmentation, the augmented groups had better pull out load to failure; however, they had less stiffness than the nonaugmented shoulders. Shea et al. performed another cadaveric test of extracellular matrix (ECM) augmentation and its effect on the strength of the construct. In their study the gap formation as well as load to failure was found to be improved with ECM augmentation, and further they concluded that the addition of the ECM shared about 35% of the load felt on the native tendon. The Shea study was duplicated with similar results 2 years later in a laboratory model ( Fig. 7.5 ).
In vivo studies have also been conducted to assess the effect of the ECM on an augmented rotator cuff tendon repair. In an analysis of 45 patients with massive cuff tears, Snyder and colleagues found that the use of human dermal allograft resulted in improvement of outcome measures which was significant for University of California at Los Angeles score (UCLA), Western Ontario Rotator Cuff score (WORC), and ASES While these results are promising, Burkhart established years earlier that with an arthroscopic repair, massive cuff tears, with fatty changes of their muscle, could still have acceptable outcomes in the majority of cases. Understanding the need for comparative analysis, multiple other studies have sought to answer the question of superiority with augmentation using ECM. In a level II study performed by Barber et al., ECM-augmented repairs were compared to standard double-row repairs of nonaugmented tears of similar size. Their results found that in addition to statistically better outcome scores, as shown in 14.5-month follow-up MRIs, the augmented repairs were healed in 85% versus the nonaugmented healed in just 40% of their cohorts. In another comparative study, Gilot et al. looked at ECM augment versus no augment and used ultrasound to follow-up retear rate, along with patient-reported outcome scores. In their study, follow-up averaged 25 months, and they reported improved outcomes scores with augmentation and decreased retear rate from 26% to 10% with augmentation.
Patch Augmentation—Xenograft and Synthetic Augment
Xenograft and synthetic graft augmentation have also been considered for the massive rotator cuff tear ( Fig. 7.1 ). Porcine dermal xenograft has been used to augment and as interposition graft for massive rotator cuff tears. Outcomes in level IV studies have shown promising short- to intermediate-term results on patient-reported outcomes and healing rates similar to human ECM augments with this technique. Other attempts to augment large rotator cuff repairs have involved the use of synthetic patch graft augmentation. Most use a poly- l -lactic acid bioabsorbable patch. Results of this technique have been encouraging, out to 42 months. However, the retear rate appears to parallel that of nonaugmented massive tear rates, but with good functional outcomes. Ciampi et al. compared the outcomes of synthetic augmented repairs using a polypropylene patch versus augmented with collagen patch versus primary repair and no augment. At 1 year the polypropylene had the lowest retear rate by ultrasound analysis. At 3 years the synthetic augment also outperformed both the collagen augment and the primary repair, with statistical significance ( Fig. 7.5 ).
Patch Augmentation—Cellular Augments
Cellular augmentation has also been implemented in rotator cuff repair. Fascial autograft and allografts have been described as well as long head of biceps tendon autografting. Fascial allograft has shown to provide increased load to failure and longevity that may improve outcomes in massive rotator cuff repairs but warrants more investigation.
Long head of the biceps tendon after tenotomy and tenodesis has been described as an autograft for rotator cuff repair augmentation. The biceps augment has been shown to improve outcome scores and improve tendon healing versus primary repair alone with healing percentage of 58% versus 26% as seen on follow-up MRI. The biceps autograft has also been described as a manner to bridge a tendon gap to augment a repair.