1 Introduction

Management of large to massive rotator cuff tears (RCTs) remains challenging, particularly when complete anatomic repair cannot be achieved.^1–5 Severe tendon retraction, compromised tissue quality, and progressive muscle degeneration frequently preclude full restoration of the native footprint.^4–7 In this setting, arthroscopic partial repair has been widely adopted as a nonanatomic yet biomechanically meaningful strategy aimed at restoring balanced shoulder force couples, reducing pain, and improving function.⁸ Previous studies have demonstrated that partial repair can yield favorable short-to mid-term clinical outcomes despite incomplete footprint coverage.^3,5,8–10.

However, postoperative structural failure remains a major limitation of partial repair in large to massive RCTs.^2,11–15 High retear rates have been consistently reported, and although early clinical improvement may persist in the presence of structural failure, loss of tendon integrity has been associated with inferior functional outcomes, reduced strength, and diminished durability over time.^3,5,15 Patch augmentation has emerged as a potential adjunct to rotator cuff repair, particularly in cases characterized by poor tissue quality or residual defects.^16–20 By increasing the effective tendon–bone contact area, redistributing mechanical load across the repair construct, and providing a biologic scaffold for tissue integration, patch augmentation may improve healing and reduce the risk of structural failure.^19,21–24.

The purpose of the present study was to evaluate short-term clinical outcomes, complications, and postoperative structural integrity following arthroscopic partial rotator cuff repair with acellular dermal matrix patch augmentation in patients with large to massive RCTs. Secondary objectives included comparison of outcomes according to postoperative rotator cuff integrity. It was hypothesized that patch-augmented partial repair would result in substantial clinical improvement and that preservation of postoperative structural integrity would be associated with superior outcomes.

2 Methods

2.2

2.2 Surgical technique

All procedures were performed arthroscopically by a single senior shoulder surgeon (C.H.B.) with the patient in the lateral decubitus position under brachial plexus block with intravenous sedation. Diagnostic arthroscopy was performed to evaluate the glenohumeral joint, rotator cuff tear, and any associated pathology (Fig. 1A). When present, concomitant lesions—including subscapularis tendon tears (Lafosse²⁵ type ≤3) and pathology of the long head of the biceps tendon—were treated according to established surgical indications. Subscapularis tendon tears were repaired using a double-row suture bridge technique in the subacromial space (n = 38). The long head of the biceps tendon was managed with tenotomy when greater than 50% structural compromise was identified (n = 36).

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Fig. 1 Arthroscopic partial repair of a large to massive rotator cuff tear in the right shoulder. View from the lateral portal demonstrating (A) a retracted rotator cuff tear (white asterisk) displaced to the level of the glenoid; (B) mobilization and partial reduction of the retracted rotator cuff tendon (red arrow) only to the extent that reduction could be achieved without excessive tension; (C) passage of all medial-row anchor sutures through the rotator cuff tendon (white asterisk); and (D) final arthroscopic appearance showing partial rotator cuff repair with acellular dermal matrix patch augmentation (red asterisk).

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Following management of the subscapularis and long head of the biceps tendon, the torn supraspinatus tendon—with or without associated infraspinatus involvement—was released using anterior interval release and coracohumeral ligament release as needed to maximize tendon excursion. Repair was attempted only to the extent that the tendon could be reduced to the greater tuberosity without excessive tension (Fig. 1B). When complete anatomic footprint coverage was not achievable despite adequate mobilization, arthroscopic partial repair with incomplete footprint coverage and patch augmentation was performed. For partial repair, the greater tuberosity footprint was prepared with débridement and decortication to promote biologic healing. Two triple-loaded medial-row suture anchors were placed at the articular margin of the greater tuberosity. All suture limbs were passed through the rotator cuff tendon at evenly spaced intervals and sequentially tied to secure the tendon medially (Fig. 1C). After completion of medial-row knot tying and before lateral-row fixation, an acellular dermal matrix allograft patch was introduced into the subacromial space. The patch was trimmed to match the size and configuration of the residual rotator cuff defect. The suture limbs from the medial-row anchors were then passed through the medial margin of the patch in a mattress fashion, allowing the patch to overlie and reinforce the repaired tendon. Lateral-row fixation was subsequently completed using three knotless anchors positioned along the lateral aspect of the greater tuberosity, creating a suture-bridge construct that secured both the native tendon and the patch (Fig. 1D).

2.4

2.4 Clinical and radiologic evaluation

Clinical outcomes were assessed preoperatively and at final follow-up using the Visual Analog Scale (VAS) for pain, Constant score, American Shoulder and Elbow Surgeons (ASES) score, and Single Assessment Numeric Evaluation (SANE) score. Active ROM, including forward elevation, abduction, and external rotation at the side, was measured using a goniometer. Internal rotation was recorded according to the highest vertebral level reached by the thumb. Forward elevation strength was measured using a handheld dynamometer. All postoperative complications were recorded. Standardized radiographic evaluations, including true anteroposterior, lateral scapular, and axillary lateral views, were obtained preoperatively and at the final follow-up for all patients. Magnetic resonance imaging (MRI) was performed preoperatively to assess rotator cuff tear size and fatty infiltration of the rotator cuff muscles, and postoperatively to evaluate rotator cuff integrity (Fig. 2A). Postoperative rotator cuff integrity was evaluated using the Sugaya²⁶ classification, with types IV and V defined as retears (Fig. 2B).

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Fig. 2 Postoperative magnetic resonance imaging of the right shoulder. (A) Preoperative coronal image demonstrating a torn and retracted supraspinatus tendon (white asterisk); (B) postoperative coronal image demonstrating an intact repaired supraspinatus tendon (white asterisk) with acellular dermal matrix patch augmentation (red asterisk) covering the residual footprint (green arrow).

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For subgroup analyses, patients were stratified according to postoperative rotator cuff integrity. Postoperative integrity was classified as either an intact repair or a retear based on postoperative imaging. Minimal clinically important differences (MCIDs) were evaluated using previously reported threshold values for rotator cuff repair, including 15.2 points for the ASES score, 4.6 points for the Constant score, and 16.9 points for the SANE score.^27,28

3 Results

After exclusion of 16 patients due to loss to follow-up (n = 4), incomplete clinical data (n = 11), or a history of prior shoulder instability surgery (n = 1), a total of 90 patients were included in the final analysis. The mean age was 65.8 ± 7.5 years, and the mean follow-up duration was 26.3 ± 2.1 months (Table I). Significant improvements were observed in all clinical outcome measures at final follow-up compared with preoperative values (Table II). The mean VAS pain score improved from 4.8 ± 1.1 preoperatively to 1.7 ± 1.0 postoperatively (p < .001). Patient-reported outcome measures (PROM) also demonstrated significant improvement, including the Constant score (51.2 ± 9.9 to 71.4 ± 10.6), ASES score (56.3 ± 9.6 to 77.1 ± 11.7), and SANE score (53.8 ± 9.6 to 74.6 ± 11.2) (all p < .001). Active ROM improved significantly in forward elevation, abduction, external rotation at the side, and internal rotation behind the back, and forward elevation strength increased from 46.5 ± 8.0 N to 72.1 ± 16.8 N at final follow-up (p < .001). Postoperative complications included retear in 18 patients (20.0%), shoulder stiffness in 8 patients (8.9%), infection in 2 patients (2.2%), and progression of glenohumeral arthritis in 3 patients (3.3%) (Table III). Among patients who experienced retears, 18 underwent revision rotator cuff repair with patch augmentation, and 8 underwent tendon transfer procedures. The remaining patients did not pursue additional surgical intervention because their symptoms remained tolerable at the time of final evaluation. Three patients with progression of glenohumeral arthritis were among those with retears and subsequently underwent reverse total shoulder arthroplasty at approximately two years of follow-up. Two patients who developed postoperative infection were treated with arthroscopic irrigation and débridement combined with intravenous antibiotic therapy.

In the subgroup analysis based on postoperative rotator cuff integrity (Table IV), patients with intact repairs had significantly lower VAS pain scores and higher Constant, ASES, and SANE scores compared with those who experienced retears at final follow-up (all p < .001). Additionally, patients with intact repairs demonstrated significantly greater improvements in forward elevation, abduction, internal rotation, and forward elevation strength compared with the retear group (all p < .001). Analysis of MCIDs further demonstrated that patients with intact repairs were significantly more likely to achieve clinically meaningful improvement than those with retears (Table V). MCID thresholds were achieved in 100.0% versus 44.4% of patients for the Constant score, 98.6% versus 44.4% for the ASES score, and 98.6% versus 50.0% for the SANE score in the intact and retear groups, respectively (all p < .001).

4 Discussion

The principal finding of the present study was that arthroscopic partial rotator cuff repair with acellular dermal matrix patch augmentation resulted in significant short-term improvements in pain, PROM, ROM, and shoulder strength in patients with large to massive RCTs. Postoperative MRI demonstrated a retear rate of 20.0%. Patients with intact postoperative rotator cuff integrity exhibited superior clinical outcomes, including lower VAS scores, greater PROM, larger improvements in ROM, and higher shoulder strength. Moreover, they were significantly more likely to achieve MCID across multiple outcome measures, highlighting the clinical significance of maintaining structural integrity after patch-augmented partial repair.

Retear rates after rotator cuff repair vary widely depending on tear size and repair technique but are generally high in large to massive RCTs. Cho et al.²⁹ reported a retear rate of 51.2%, and Jo et al.³⁰ reported a rate of 28.5% after primary repair of large RCTs. However, retear rates tend to be substantially higher following partial repair in large to massive rotator cuff tears. A recent systematic review by Baumann et al.² showed a retear rate of 72.5% after partial repair for large to massive RCTs, underscoring the difficulty of achieving durable structural integrity in this patient population. Several studies have demonstrated reduced retear rates following patch-augmented rotator cuff repair for large to massive RCTs. ^{16–19,21,24} For example, Bushnell et al.³¹ reported a 28.6% retear rate at 2 years in a prospective multicenter cohort, Castle et al.³² reported a rate of 11.9%, and Park et al.³³ reported a rate of 25.0%, suggesting that patch augmentation may decrease structural failure. In the present study, arthroscopic partial rotator cuff repair with patch augmentation resulted in a 20.0% retear rate, which is comparable to or lower than previously reported outcomes for large to massive RCTs. A recent systematic review of randomized controlled trials by Orozco et al.²¹ demonstrated that patch augmentation was consistently associated with lower retear rates compared with standard rotator cuff repair, with reported rates ranging from 9.1% to 52.9% in the patch-augmented group versus 34.0% to 65.4% in the non-augmented group. Although improvements in PROMs were less consistent, several studies reported significantly higher Constant and ASES scores in patients who underwent patch augmentation. Similarly, Ciampi et al.³⁴ and Barber et al.²⁴ reported improved postoperative structural integrity and increased tendon thickness on imaging following patch-augmented repair of large rotator cuff tears, suggesting enhanced mechanical durability at the repair site.

The beneficial effects of patch augmentation observed in this study may be explained by several biomechanical and biologic mechanisms reported in the literature. Mechanically, patch augmentation increases the effective tendon–bone contact area and distributes load more evenly across the repair construct, reducing stress concentration at the medial repair site—a well-recognized failure point in large to massive RCTs.^16–20 Denard et al.²⁰ demonstrated that patch augmentation constructs can significantly reduce gap formation and improve load-to-failure characteristics compared with non-augmented repairs, particularly under cyclic loading conditions. Biologically, acellular dermal matrix allografts provide a scaffold that supports cellular infiltration, neovascularization, and collagen deposition, which may enhance tendon–bone healing in the presence of compromised native tissue quality, as described by Adams et al.³⁵ and Barber et al.²⁴ In the context of partial repair, these advantages may be particularly important, as incomplete footprint coverage inherently concentrates stress on a smaller tendon–bone interface. By reinforcing a tension-free partial repair with a patch prior to lateral-row fixation, the technique used in the present study may preserve the biomechanical benefits of partial repair while mitigating its known vulnerability to structural failure. This mechanism is supported by the present findings, which demonstrated that patients with preserved postoperative structural integrity achieved superior pain relief, PROMs, range of motion, and strength compared with those who experienced structural failure.

Several limitations of this study should be acknowledged. First, the retrospective design and lack of a control group limit the ability to draw definitive conclusions regarding the comparative effectiveness of patch augmentation. Second, the relatively short follow-up duration precludes assessment of long-term durability, progression of cuff arthropathy, and late structural deterioration. Third, the absence of a comparison group treated with partial repair alone limits the ability to isolate the specific contribution of the acellular dermal matrix allograft. Fourth, the presence of potential confounding factors, including concomitant subscapularis repair and long head of the biceps tenotomy, may have influenced postoperative clinical outcomes. Finally, all procedures were performed by a single experienced surgeon at a single institution, which may limit the generalizability of the findings.

5 Conclusion

Arthroscopic partial repair with patch augmentation resulted in significant short-term improvements in pain, functional outcomes, ROM, and shoulder strength in patients with large to massive RCTs. Patients with intact repairs demonstrated superior clinical outcomes and achieved higher rates of clinically meaningful improvement compared with those in the retear group.

Guardian/patient's consent

Regarding the manuscript “Middle Trapezius Tendon Transfer for Isolated Irreparable Supraspinatus Tears Shows Favorable Outcomes Despite Subscapularis Tear” as submitted to the Journal of Orthopedics, collectively declares that the requirement for informed consent was waived owing to the retrospective design of the study and the lack of additional harm to the patients.

Ethical statement

This study was conducted in accordance with the Code of Ethics of the World Medical.

Association (Declaration of Helsinki).

Credit author statement

Chang Hee Baek: conceptualization, investigation, methodology, validation, project administration, resources, supervision, validation.

Bo Taek Kim: conceptualization, data curation, formal analysis, investigation, validation, methodology, validation, writing original draft, review/editing final draft.

Jung Gon Kim: conceptualization, formal analysis, investigation, methodology, validation.

Chaemoon Lim: conceptualization, formal analysis, investigation, methodology, validation.

Seung Jin Kim: data curation, formal analysis, investigation, methodology.

Funding or financial disclosures

None.

Funding source

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.