There are two disease-specific outcome measures designed for rotator cuff pathology, including the Western Ontario Rotator Cuff (WORC) Index and the Rotator Cuff Quality of Life score. To date, the WORC Index has been used more extensively and has undergone more vigorous validation, with some suggesting that it is the most responsive to detecting changes in outcomes following rotator cuff repair surgery. Although disease-specific outcome measures are important tools, the more widespread use of general shoulder outcome measures that have been further validated to specifically assess rotator cuff disease, including the ASES, SST, and DASH, has limited the adoption of rotator cuff–specific outcome measures.

The shoulder activity level is a relatively new but important outcome measure developed to be used in addition to generalized health and shoulder outcome measures. The shoulder activity level takes into account patients who may decrease their activity due to their shoulder disease but still score highly on traditional tests focused on pain. Although not widely adopted yet, this validated outcome measure will become important in assessing patients with higher functional levels.

Advances in shoulder arthroscopy from the original cadaveric study by Burman in 1931 allowed for development of the miniopen repair technique, at times referred to as the arthroscopically assisted repair technique, which was popularized by Levy and colleagues. Using this technique, arthroscopy served primarily as a diagnostic tool, identifying and localizing the rotator cuff tear to allow smaller incisions and preserve the deltoid origin during the miniopen repair. Importantly, the use of arthroscopy in combination with miniopen repair techniques also identified concomitant shoulder pathology that could be addressed at the time of surgery. Levy’s early results were promising and supported by subsequent studies that noted significant improvements in pain and function, even in the overhead athlete where return to sport was achieved more frequently than in those treated with open repair techniques. Despite the technical advances, it was also during this time period that the literature consistently pointed out inferior outcomes following repair of large tears with both open and miniopen techniques.

As arthroscopic technology continued to advance, surgeons familiar with the technique began to experiment further with techniques that would limit dissection and exposure during rotator cuff repair while still providing the same diagnostic advantages of the miniopen repair technique. However, repairing rotator cuff tears using suture-based techniques through small portal incisions presented several new challenges. The first published description of an all-arthroscopic knot was published by Thal in 1993. This technical pearl was followed by further advances, including improvements in anchor fixation, evolution of knot-tying techniques, techniques for arthroscopic margin convergence and interval slides, and eventually Lo and Burkhart’s original double-row repair technique description. Today, arthroscopic rotator cuff repair is the preferred technique by over 70% of practicing shoulder surgeons across the United States, with successful mid- and long-term clinical results reported. Additionally, several authors have reported more optimistic results for large or massive rotator cuff tears repaired using arthroscopic techniques, potentially due to the improved ability to visualize and mobilize the rotator cuff from multiple angles using arthroscopic techniques as compared with the concerns with large or massive tears reported during open rotator cuff repair.

The first published description of the double-row suture anchor technique was provided by Lo and Burkhart in 2003. Since that time, the double- versus single-row debate has dominated the literature, with biomechanical studies, randomized controlled trials, and eventually systematic reviews and metaanalyses taking aim at the question. The description of the double-row technique in 2003 was prompted by improved knowledge of the rotator cuff footprint as well as concern with reported retear rates as high as 94% for massive tears treated with the single-row technique. Early biomechanical studies showed improved fixation strength, load to failure, and decreased gap formation with double-row repairs as compared with single-row repairs. Early clinical studies were promising, with retear rates less than 20% reported, but comparative studies often failed to note a difference in clinical outcomes, including retear rates, between single- and double-row repair.

Despite the previously discussed advances in rotator cuff repair technique, healing of the rotator cuff after repair remains an issue. Nonhealed rotator cuff repairs are referred to as repair failures, structural failures, or tears with loss of structural integrity throughout the literature. Repair failures, as we refer to nonhealed rotator cuff repairs throughout this section, have been well documented, particularly for large or massive rotator cuff tears, where failure rates ranging from 41% to 69% are frequently cited, with a single study reporting a 94% failure rate. Although failure rates of large tears typically receive the most attention, even small tears demonstrate a consistent failure rate, which appears to plague both open and arthroscopic approaches. Although assessing the structural integrity of rotator cuff repairs, and thus determining repair failure, remains an important outcome measure, understanding the natural history of these so-called repair failures is important. Jost and colleagues presented the long-term outcomes of patients with repair failures with an average follow-up of 7.6 years. In their study, repair failures remained smaller than the original tears, were capable of spontaneous healing, and were generally well tolerated, without deterioration of clinical results compared with earlier postoperative time points. The authors described their findings in contrast to the outcomes of rotator cuff debridement, where deteriorating clinical outcomes are reported, and untreated tears, where propagation of tears and thus increase in tear size is common and spontaneous healing is not seen. However, the authors did caution that despite the consistent clinical results, some structural concerns, including superior migration of the humeral head and increased fatty degeneration, were seen at a higher rate than in individuals without repair failure. Although previous studies had recognized similar clinical outcomes for patients with intact repairs and those with repair failures, the long-term results reported by Jost et al. described a different natural history for these tears as compared with untreated tears while also leading some to question whether structural integrity of the repaired rotator cuff really mattered.