Abstracts
Background/objective
In young patients with massive irreparable rotator cuff tears (MRCTs), superior capsular reconstruction (SCR) is a viable surgical treatment option, whereas SCR and reverse shoulder arthroplasty (RSA) are reliable treatments for irreparable MRCTs in patients aged >65 years. This study aimed to compare the outcomes of arthroscopic SCR and RSA in patients with MRCTs without arthritis aged ≥65.
Methods
This retrospective comparative study included 202 patients ≥65 years old with irreparable MRCTs who had undergone either SCR using a 3–4 mm single-layer human acellular dermal matrix or RSA between January 2017 and December 2021. All patients underwent at least 2 years of postoperative follow-up. Propensity score matching was performed based on age, sex, dominant-arm involvement, follow-up duration, body mass index, pseudoparalysis, bone mineral density, global fatty degeneration index, and rotator cuff tear size. A total of 44 matched patients (22 with SCR and 22 with RSA) were included in the analysis. Clinical outcomes were assessed using the visual analog scale (VAS) for pain, American Shoulder and Elbow Surgeons (ASES) score, Constant score, Single Assessment Numeric Evaluation (SANE), and active range of motion (ROM). Postoperative radiological evaluations were performed to assess healing failure.
Results
No significant differences were observed in the preoperative demographic data, clinical outcomes, or active ROM between the SCR and RSA groups. At the final follow-up, significant improvements in pain, ROM, and functional outcomes were observed in both groups. However, the SCR group had significantly higher ASES scores (88.6 ± 7.5 vs. 81.0 ± 12.0; p = 0.02), Constant scores (72.4 ± 8.9 vs. 65.0 ± 7.0; p < 0.01), and SANE scores (87.2 ± 8.4 vs. 81.2 ± 6.8; p = 0.01) than the RSA group. Postoperative active ROM was also superior in the SCR group for forward flexion (157.7 ± 21.2° vs. 141.2 ± 16.0°; p < 0.01) and internal rotation (8.1 ± 1.4 vs. 9.5 ± 2.0; p = 0.01) compared with the RSA group. Healing failure occurred in 6 patients in the SCR group (27.3 %).
Conclusion
SCR and RSA resulted in reliable improvements 2 years post-surgery in patients aged >65 years without glenohumeral joint arthritis. However, SCR provided superior outcomes in terms of forward flexion, internal rotation, and functional scores. These results suggest SCR as a more effective treatment option than RSA for irreparable MRCT in this population.
Level of evidence
Level III, Retrospective comparative study.
Keywords: Clinical outcomes, Propensity score matching, Rotator cuff tear, Reconstruction, Reverse shoulder arthroplasty, Superior capsular
1. Introduction
Irreparable rotator cuff tears (MRCTs), particularly in patients aged ≥65 years old, remain a major clinical challenge due to their high prevalence in this population.1, 2, 3, 4 MRCTs account for approximately 20 % of all rotator cuff and have recurrence rates as high as 80 %.3,5 MRCTs often lead to significant pain, functional impairment, and reduced quality of life owing to their detrimental effects on shoulder stability and biomechanics.6, 7, 8 Although numerous surgical and non-surgical options are available, selecting the most appropriate treatment for patients, particularly those aged ≥65 years old, remains debatable. Although the outcomes of nonoperative treatment are satisfactory, MRCTs that fail to improve with adequate nonoperative treatment necessitate the consideration of various surgical treatment options.1
Surgical options for irreparable MRCTs include arthroscopic partial repair, arthroscopic subacromial débridement, superior capsular reconstruction (SCR), graft augmentation, tendon transfers, and reverse shoulder arthroplasty (RSA).1,3 In elderly patients with MRCTs, surgical decision-making considers the patient's overall functional demands and the structural characteristics of the rotator cuff.4 The presence of significant tendon retraction, fatty infiltration, or associated glenohumeral arthritis often influences the choice of intervention.1,4 RSA is typically preferred for elderly patients with low functional demands, pseudoparalysis, or advanced arthritis as it reliably improves pain and function.9
Conversely, for active patients without glenohumeral arthritis, non-arthroplasty options, such as partial rotator cuff repair, tendon transfers, and SCR, may be preferred to preserve native biomechanics.4 These procedures are particularly suited for individuals with higher functional demands who seek to maintain joint motion without the irreversible changes of arthroplasty.1,6 Among them, SCR has gained attention for its ability to restore superior stability and support functional recovery by reconstructing the capsular structure.
Although RSA is a reliable surgical option for MRCTs, its limitations, including implant-related complications, suboptimal internal rotation results, and long-term durability concerns, have highlighted the advantages of joint-preserving procedures such as arthroscopic SCR.10 Previous comparative studies have evaluated the outcomes of SCR using various graft materials, including fascia lata and dermal; however, human acellular dermal matrix (ADM) offers distinct advantages, including superior biocompatibility, reduced donor site morbidity, and improved ease of handling during surgery.11 Based on its technical simplicity and ease of use, SCR using human ADM offers a joint-preserving alternative to RSA while maintaining a surgical complexity comparable to arthroscopic rotator cuff repair. This makes SCR a more accessible surgical option, particularly in older patients with unique challenges in managing MRCTs.
This study aimed to compare the clinical outcomes of SCR using human ADM and RSA in patients aged ≥65 years old with irreparable MRCTs without glenohumeral arthritis. We hypothesized that SCR would demonstrate comparable or superior outcomes to RSA in terms of pain relief, functional recovery, and range of motion. Our findings will provide evidence to guide surgical decision-making in this population.
2. Material and methods
2.1. Patient selection
This multicenter retrospective study was conducted by two surgeons across two institutions using a standardized protocol. Ethical approval was obtained from the institutional review boards of both institutions (Approval number: XYZ), and the requirement for informed consent was waived due to the retrospective design of the study. Electronic medical records were reviewed to identify patients who underwent arthroscopic SCR using the human ADM or RSA for irreparable MRCTs between January 2017 and December 2021. Inclusion criteria consisted of patients aged ≥65 years old with MRCTs diagnosed via preoperative magnetic resonance imaging (MRI) as substantial tears (>5 cm or involving more than two complete tendons) and without advanced glenohumeral arthritis, classified as Hamada grade 1, 2, or 3 on radiographs. The exclusion criteria were as follows: (1) advanced glenohumeral arthritis (Hamada grade 4 or 5), (2) inflammatory arthritis, (3) age <65 years, (4) history of previous surgery on the affected shoulder, and (5) insufficient follow-up for <2 years. Patients meeting these criteria were enrolled to ensure a homogeneous study population for evaluating the comparative outcomes of SCR and RSA in managing MRCTs.
In this study, pseudoparalysis was defined as the inability to actively elevate the arm above 90° in forward flexion despite preserved passive range of motion.6 Patients were classified as pseudoparalysis based on preoperative clinical evaluation and medical record documentation.
2.2. Propensity score (PS) matching
Propensity score (PS) matching was employed to minimize selection bias and enhance the comparability between patients undergoing SCR and RSA.
The PS of each patient was estimated using logistic regression, incorporating a comprehensive set of covariates considered relevant to surgical decision-making and clinical outcomes. These variables included sex, age, dominant arm involvement, average follow-up duration, body mass index (BMI), pseudoparalysis, bone mineral density (BMD), tear size, and global fatty degeneration index (GFDI), as these factors are known to influence both treatment selection and postoperative outcomes.7,8,12,13 Once the PS was calculated, a greedy nearest-neighbor matching algorithm was applied within a caliper width of .2 standard deviations of the PS to identify the closest match for each patient in the SCR group with a corresponding patient in the RSA group. Matching was performed without replacement to ensure one-to-one pairing, thus optimizing the comparability of baseline characteristics between the two groups.
To verify the effectiveness of the matching process, the balance of covariates between the SCR and RSA groups was evaluated using standardized mean difference (SMD). An absolute SMD of ≤.1 was used as the threshold for excellent balance, while an SMD of ≤.25 was considered acceptable based on established recommendations in the literature. This evaluation ensured that the matched groups were well-balanced and that potential confounders were appropriately controlled. The entire PS-matching process, including logistic regression, matching algorithm implementation, and covariate balance assessment, was performed using R software (version 13.0; R Development Core Team, Vienna, Austria).
2.3. Surgical treatment
Arthroscopic SCR and RSA were performed by two experienced shoulder surgeons using standardized indications and surgical techniques.
2.3.1. Arthroscopic SCR using human ADM
Arthroscopic SCR was conducted under general anesthesia with patients in the lateral decubitus position. The quality and mobility of the rotator cuff tendon apex were assessed for repair using a tendon grasper. SCR was indicated for irreparable MRCTs in which the infraspinatus tendon could be partially repaired, but the supraspinatus tendon was considered irreparable (Fig. 1A). Glenoid-side fixation was achieved using two 3.0-mm double-loaded suture anchors (Gryphon BR, Mitek, MA, USA) inserted via the anterior and Neviaser portals. Depending on the defect size, two or three 4.5-mm double-loaded suture anchors (Healix Advanced BR, Mitek, MA, USA) were placed medially at the greater tuberosity. The suture lines were threaded through the graft outside the joint and introduced into the subacromial space with a grasper. The graft was first secured to the glenoid side using knots and then fixed to the medial row at the greater tuberosity (Fig. 1C). Lateral row fixation was achieved using two knotless anchors (Healix Advanced Knotless; Mitek, MA, USA). Additional sutures were used to attach the graft to the residual stump of the retracted rotator cuff and repair it to the posterior cuff in a side-to-side manner to enhance stability (Fig. 1D).
Fig. 1.
Arthroscopic superior capsular reconstruction (SCR) of the right shoulder joint of a 67-year-old male patient with an irreparable massive rotator cuff tear (MRCT). (A) Arthroscopic view of an MRCT from the posterolateral portal. (B) A ready-to-use human acellular dermal allograft (ADM) with a thickness of 3–4 mm. (C) Human ADM connected to the suture of the suture anchors inserted into the glenoid and proximal humerus. (D) After performing SCR with ADM, arthroscopic findings showed that the glenohumeral joint was completely covered, and the remaining cuff and ADM in the anterior and posterior parts were repaired. ∗ indicates ADM.
2.3.2. RSA
The RSA procedures were performed under general anesthesia with the patients in the beach chair position using a deltopectoral approach. All patients received the same prosthesis (Equinoxe; Exactech, FL, USA). The subscapularis tendon was carefully detached from the lesser tuberosity at the medial aspect of the bicipital groove, and biceps tenodesis was performed. For humeral preparation, the stem was inserted at 20° retroversion. Glenoid implantation involves the preparation of the inferior glenoid rim, allowing placement of the baseplate and glenosphere with an approximately 10° of inferior tilt to optimize stability. After inserting the trial implant, the tension of the conjoined tendon and deltoid contour were verified to ensure proper biomechanical balance. The subscapularis tendon was reattached postoperatively if tissue quality was acceptable.
2.3.3. Postoperative rehabilitation
The postoperative rehabilitation protocols were standardized for the SCR and RSA groups to ensure consistency and comparability during the recovery process. All patients were fitted with a shoulder abduction brace immediately after surgery, worn for six weeks to provide support and promote initial healing. Passive ROM exercises were started on the first postoperative day and limited to movements below the waist to minimize stress at the surgical site. These exercises progressively increased patient tolerance and pain.
Six weeks postoperatively, active-assisted ROM exercises were performed under supervised guidance to improve joint mobility while protecting the repair site. Strengthening exercises began at 12 weeks and included forward flexion and internal and external rotation using elastic resistance bands to restore shoulder strength and stability. Patients were advised to gradually increase their activity levels and encouraged to return to preoperative activities, including recreational sports, by six months postoperatively.
2.4. Clinical assessment
All patients underwent a comprehensive preoperative physical examination of both shoulders and completed standardized questionnaires to collect demographic information, including age, sex, symptom duration, and dominant arm involvement. Clinical assessments were conducted preoperatively, 6 and 12 months postoperatively, and the final follow-up visit. These evaluations included measures of active range of motion (ROM), pain severity using the visual analog scale (VAS), functional outcomes using the American Shoulder and Elbow Surgeons (ASES) and Constant scores, and patient satisfaction using the Single Assessment Numeric Evaluation (SANE) score. The active ROM assessments included forward flexion, side external rotation, and back internal rotation. Internal rotation was evaluated by determining the highest spinal level that the patient could reach with the ipsilateral thumb, with the following numerical values assigned for statistical analysis: 1–12 for the thoracic vertebrae (T1–T12), 13–17 for the lumbar vertebrae (L1–L5), and 18 for the sacrum.
To ensure accuracy and eliminate potential bias, all clinical parameters were recorded by a physician assistant blinded to the study and surgical interventions.
2.5. Radiological evaluation
Radiological evaluations were performed preoperatively and postoperatively to ensure thorough assessment and comparability between the SCR and RSA groups. Preoperative imaging included plain radiographs in anteroposterior (AP), axial, and scapular outlet views to evaluate the bony anatomy and overall joint condition. Additionally, all patients underwent preoperative MRI to assess rotator cuff tear pattern, size, retraction level, fatty infiltration, and muscle atrophy. Tear dimensions were measured with precision. AP tear size was defined as the maximum distance between the anterior and posterior tear margins on oblique sagittal images, whereas mediolateral (ML) tear size was measured as the longest distance between the most medial margin of the retracted cuff and the greater tuberosity on coronal images. Fatty infiltration of the rotator cuff muscles was quantified using the GFDI as previously described.
In patients who underwent SCR, postoperative MRI at six months was used to evaluate graft healing. Graft failure was defined as the presence of full-thickness graft tears on imaging in accordance with established criteria. Following the initial MRI, annual ultrasound examinations were conducted to monitor the long-term graft integrity and detect structural changes.
For patients with RSA, radiographs obtained at the final follow-up were reviewed for complications, including periprosthetic fractures, scapular notching, dislocations, and mechanical baseplate failure. All preoperative and postoperative radiological evaluations were conducted by an independent orthopedic surgeon not involved in the surgical procedures, ensuring unbiased and consistent assessments. This rigorous imaging protocol provides a robust framework for evaluating the structural and functional outcomes of the two surgical techniques.
2.6. Statistical analysis
All statistical analyses were performed using the R software (version 13.0; R Development Core Team, Vienna, Austria). Descriptive statistics are presented as means with standard deviations for continuous variables and as counts with percentages for categorical variables. Paired t-tests were used to compare the pre-and postoperative clinical scores within each group to assess the efficacy of each surgical intervention. Comparisons between groups for continuous variables, such as clinical scores and ROM, were performed using Student's t-test, whereas categorical variables were analyzed using the chi-squared or Fisher's exact test, as appropriate.
PS matching was used to minimize selection bias, and SMDs were used to confirm covariate balance between matched groups, with an SMD of ≤.1 indicating excellent balance. The significance level for all statistical tests was set at p < 0.05. All analyses were two-sided.
3. Results
Between January 2017 and December 2021, a total of 309 patients underwent surgical treatment for irreparable MRCTs at two institutions: 67 underwent arthroscopic SCR and 242 underwent RSA. Thirty-two patients under the age of 65 years, 16 with a history of previous surgery, and 59 patients who were lost to follow-up were excluded from the analysis. Therefore, 202 patients were eligible for PS matching.
PS matching was performed on a 1:1 basis to balance baseline characteristics between the groups. Before matching, significant differences were observed between the SCR and RSA groups in age (p < 0.01), mean follow-up time (p < 0.01), presence of pseudoparalysis (p = 0.02), GFDI (p < 0.01), and AP (p < 0.01) and ML (p = 0.03) tear sizes (Table 1). After matching, 22 pairs of patients were successfully matched with no significant differences in these variables, ensuring well-balanced groups for analysis (Table 2).
Table 1.
Preoperative patient demographics before propensity score matchinga.
| SCR (n = 31) | RSA (n = 172) | p value | |
|---|---|---|---|
| Age, years | 69.4 ± 3.1 | 74.3 ± 4.1 | <.001∗ |
| Sex (male/female), n | 17/14 | 61/111 | .066 |
| Dominant arm involvement, n (%) | 20 (64.5) | 121 (70.3) | .662 |
| Average follow-up, mos | 30.4 ± 6.0 | 39.4 ± 14.3 | <.001∗ |
| BMI | 24.8 ± 2.9 | 25.3 ± 3.2 | .386 |
| Pseudoparalysis, n (%) | 5 (16.1) | 68 (39.5) | .022∗ |
| GDFI | 2.6 ± .8 | 2.8 ± .7 | .266 |
| BMD, T-score | −1.9 ± .6 | −2.1 ± 1.1 | .080∗ |
| GFDI | 1.8 ± .4 | 2.1 ± .7 | <.001∗ |
| Tear size, mm | |||
| AP direction | 32.5 ± 7.0 | 38.2 ± 11.2 | <.001∗ |
| ML direction | 36.8 ± 9.4 | 40.8 ± 9.5 | .032∗ |
∗Statistically significant differences between groups (p < 0.05).
Data are presented as mean ± SD (ranges). SCR, superior capsular reconstruction; RSA, reverse shoulder arthroplasty; BMI, body mass index; BMD, bone mineral density; GFDI, global fatty degeneration index; AP, anterior to posterior; ML, medial to lateral.
Table 2.
Preoperative patient demographics after propensity score matching.
| SCR (n = 22) | RSA (n = 22) | SMD | p value | |
|---|---|---|---|---|
| Age, yearsa | 70.3 ± 3.1 | 71.3 ± 3.9 | .24 | .357 |
| Sex (male/female), na | 13/9 | 12/10 | .09 | >.999 |
| Dominant arm involvement, n (%)a | 17 (77.3) | 19 (86.4) | −.20 | .696 |
| Average follow-up, mosa | 32.0 ± 6.2 | 34.3 ± 16.8 | .16 | .549 |
| BMIa | 24.7 ± 2.7 | 25.0 ± 2.6 | .08 | .739 |
| Pseudoparalysis, n (%)a | 4 (18.2) | 6 (27.3) | −.19 | .719 |
| GDFI | 2.6 ± .8 | 2.8 ± .7 | .266 | |
| BMD, T-scorea | −2.0 ± .7 | −1.8 ± 1.1 | .18 | .479 |
| GFDIa | 1.9 ± .4 | 1.8 ± .6 | −.08 | .725 |
| Tear size (mm) | ||||
| AP directiona | 32.5 ± 7.0 | 38.2 ± 11.2 | .07 | .731 |
| ML directiona | 36.8 ± 9.4 | 40.8 ± 9.5 | .18 | .588 |
aData are presented as mean ± SD (ranges). SCR: superior capsular reconstruction; RSA: reverse shoulder arthroplasty; SMD: standardized mean difference; BMI: body mass index; BMD: bone mineral density; GFDI: global fatty degeneration index; AP: anterior to posterior; ML: medial to lateral.
Variable used for propensity score matching.
Both groups showed significant improvements in pain and functional outcomes at the final follow-up. VAS pain and SANE scores showed significant improvement from preoperative to final follow-up in both groups (p < 0.001). Similarly, the ASES and Constant scores significantly increased from preoperative values in both groups (p < 0.001). Although the preoperative VAS, ASES, and Constant scores were comparable between groups, the SCR group demonstrated superior results at the final follow-up. Specifically, the SCR group had significantly higher ASES (88.6 ± 7.5 vs. 81.0 ± 12.0; p = 0.02) and Constant (72.4 ± 8.9 vs. 65.0 ± 7.0; p < 0.01) scores than the RSA group. In addition, while preoperative SANE scores were similar, the SCR group reported significantly greater patient satisfaction at the final follow-up (87.2 ± 8.4 vs. 81.2 ± 6.8; p = 0.013) (Table 3).
Table 3.
Preoperative and postoperative clinical comparisons between SCR and RSA.
| SCR group (n = 22) | RSA group (n = 22) | p value | |
|---|---|---|---|
| VAS for pain | |||
| Preoperative | 6.0 ± 1.9 | 6.3 ± 2.0 | .588 |
| Postoperative | 1.1 ± 1.0 | 1.3 ± 1.0 | .541 |
| p value | <.001∗ | <.001∗ | |
| ASES score | |||
| Preoperative | 53.7 ± 19.3 | 51.1 ± 19.7 | .656 |
| Postoperative | 88.6 ± 7.5 | 81.0 ± 12.0 | .016∗ |
| p value | <.001∗ | <.001∗ | |
| Constant score | |||
| Preoperative | 41.1 ± 11.7 | 39.7 ± 12.4 | .692 |
| Postoperative | 72.4 ± 8.9 | 65.0 ± 7.0 | .004∗ |
| p value | <.001∗ | <.001∗ | |
| SANE score | |||
| Preoperative | 25.3 ± 8.9 | 25.6 ± 10.2 | .924 |
| Postoperative | 87.2 ± 8.4 | 81.2 ± 6.8 | .013∗ |
| p value | <.001∗ | <.001∗ | |
Data are presented as mean ± SD (range). SCR, superior capsular reconstruction; RSA, reverse shoulder arthroplasty; VAS, visual analog scale; ASES, American Shoulder and Elbow Surgeons; SANE, single-assessment numeric evaluation.
∗Statistically significant differences between groups (p < 0.05).
Active range of motion (ROM) significantly differed between the groups. Although both groups had comparable preoperative ROM, only the SCR group showed significant improvement at the final follow-up. Forward flexion (157.7 ± 21.2° vs. 141.2 ± 16.0°; p = 0.006) and internal rotation (8.1 ± 1.4 vs. 9.5 ± 2.0; p = 0.011) were significantly higher in the SCR group than the RSA group at final follow-up (Table 4).
Table 4.
Preoperative and postoperative shoulder range of motion between SCR and RSA.
| SCR group (n = 22) | RSA group (n = 22) | p value | |
|---|---|---|---|
| Forward flexion,° | |||
| Preoperative | 137.3 ± 21.9 | 134.3 ± 31.7 | .717 |
| Postoperative | 157.7 ± 21.2 | 141.2 ± 16.0 | .006∗ |
| p value | .007∗ | .383 | |
| External rotation,° | |||
| Preoperative | 49.9 ± 15.8 | 47.4 ± 19.8 | .652 |
| Postoperative | 58.0 ± 11.4 | 52.4 ± 8.2 | .071 |
| p value | .048∗ | .273 | |
| Internal rotation† | |||
| Preoperative | 10.3 ± 3.3 | 10.2 ± 2.4 | .876 |
| Postoperative | 8.1 ± 1.4 | 9.5 ± 2.0 | .011∗ |
| p value | .008∗ | .217 | |
∗Statistically significant differences between groups (p < 0.05).
Internal rotation was determined by measuring the highest spinal segment the patient could reach using the thumb. To facilitate statistical analyses, the spinal segment level was converted into continuous numbers; T1-T12 were represented by 1–12, L1-L5 by 13–17, and the sacrum by 18.
aData are presented as mean ± SD (range). SCR, superior capsular reconstruction; RSA, reverse shoulder arthroplasty.
Postoperative MRI revealed a graft healing failure rate of 27.3 % in the SCR group (six patients), with no additional failures observed on subsequent annual ultrasound examinations. Upon review of the preoperative imaging and intraoperative findings, none of the patients had a full-thickness subscapularis tear at the time of surgery. One patient showed intact graft healing but progressed from an untreated partial-thickness subscapularis tear to a near full-thickness tear, as seen on 6-month MRI and confirmed by 1-year ultrasound. In the RSA group, scapular notching was noted in three patients (13.6 %) on final follow-up radiographs; no mechanical implant failures, infections, or neurovascular complications were reported in either group.
4. Discussion
The primary finding of this study was that SCR using both human ADM and RSA significantly improved the clinical outcomes in patients aged ≥65 years old with MRCTs without glenohumeral arthritis. Although both procedures effectively reduced pain and improved functional scores, SCR demonstrated superior recovery of active ROM and overall shoulder function, making it a favorable joint-preserving option for active elderly patients. In contrast, RSA showed limited improvement in ROM.
A previous study showed that SCR using fascia lata autograft and RSA achieved favorable outcomes in patients aged ≥65 years old with MRCTs, with RSA providing faster recovery from pseudoparalysis and significant short-term improvements, while SCR using fascia lata autograft demonstrated superior internal rotation and ASES scores at the final follow-up.10 Another study comparing RSA and rotator cuff repair in MRCTs without osteoarthritis also found that, while both treatments provided significant pain relief and functional improvement, rotator cuff repair yielded superior shoulder function, range of motion, and functional scores.9 These findings are consistent with our results, emphasizing the differential benefits of SCR and RSA in managing MRCTs in elderly patients. Similar to our results, the superior outcomes of SCR in terms of internal rotation and functional scores at final follow-up underscore its potential as a joint-preserving alternative to RSA, particularly in active patients who prioritize ROM and shoulder function. The faster recovery from pseudoparalysis with RSA is consistent with its role in providing reliable and immediate improvements in pain relief and stability, making it an effective option for patients with low functional demands or advanced shoulder dysfunction.
Defining indications for SCR and RSA in elderly patients is critical for optimizing surgical outcomes and addressing evolving patient expectations.1, 4, 14 SCR is particularly suitable for active patients ≥65 years old with MRCTs without advanced glenohumeral arthritis, particularly those with partially repairable infraspinatus tendons and sufficient tissue quality to support graft integration, offering significant advantages in preserving joint biomechanics, improving ROM, and meeting functional demands.1,15 In contrast, RSA is more appropriate for patients with low functional demands, pseudoparalysis, poor tissue quality, or associated glenohumeral arthritis, where reliable pain relief and joint stability were prioritized over joint preservation.4,9 SCR is an effective joint-preserving option for patients aged 65 years with MRCTs.16 Clinical studies have demonstrated significant improvements in functional outcomes, including forward flexion from 82.6° to 141.9° and external rotation from 35.5° to 43.4°, along with pain relief, as reflected by VAS score reduction from 5.4° to 1.3°. The graft healing rates in this population range from 73 % to 87 %, with a low complication rate of approximately 5.6 % and a conversion rate to RSA of 7.1 %.15,17, 18, 19 These results indicate that SCR is suitable for active elderly patients who prioritize ROM and functional independence, particularly in those without advanced glenohumeral arthritis. However, further long-term studies are required to validate the sustainability of these outcomes in aging populations.
The original SCR technique introduced by Mihata et al. utilized a folded fascia lata autograft to achieve a 6–8 mm thickness, providing reliable outcomes for MRCTs by restoring shoulder stability and function.20 A 5-year follow-up study demonstrated significant functional improvements and return to physical activity with no progression of cuff tear arthropathy in cases of successful graft healing.21
However, concerns regarding donor-site complications due to the large incision required for fascia lata harvesting have prompted the exploration of alternatives, particularly for human ADM.11,22 Owing to the characteristics of the human ADM, achieving the same 6–8 mm thickness in a single layer is challenging. Comparative studies have shown that fascia lata allografts and double-layer human ADMs restore superior stability more effectively than single-layer human ADMs, which only provide partial restoration.23,24 Snow et al. reported complete healing in all 18 cases of SCR using double-layer human ADMs over 48 months, whereas single-layer human ADM had a graft failure rate of 27.3 %, consistent with other findings.23 Despite the challenges associated with graft thickness and healing rates, using a single-layer human ADM in SCR remains a reliable and practical option in clinical settings. This approach offers surgical ease and technical simplicity, making it an accessible technique. Furthermore, when effectively restoring the force-coupling mechanism of the rotator cuff, SCR with a single-layer human ADM can provide satisfactory functional outcomes and shoulder stability.
RSA is a reliable surgical option for improving active ROM and providing significant pain relief in patients with MRCTs, particularly in those aged ≥65 years old.25 Rybalko et al. reported that SCR and RSA effectively restored abduction force and humeral head stability in shoulders with irreparable supraspinatus tears. The authors demonstrated that the SCR provided superior passive abduction ROM and restored normal superior humeral migration, whereas the RSA offered greater external rotation and inferior humeral head translation, underscoring the distinct biomechanical benefits of each approach.26 However, in clinical setting, this limitation of RSA in improving internal rotation presents considerable challenges as it directly affects essential activities of daily living, such as dressing, reaching behind the back, and maintaining personal hygiene.10,27 This limitation is particularly pronounced in active elderly patients with higher functional demands and those who aspire to maintain an unrestricted lifestyle.28 For such patients, the inability to restore satisfactory internal rotation can be a major drawback, even with improvements in forward flexion and external rotation. In contrast, studies comparing surgical options for MRCTs have consistently shown that arthroscopic rotator cuff repair and SCR are associated with superior recovery of ROM, including internal rotation, compared to RSA.10,27 These techniques not only preserve joint integrity but also restore the natural biomechanics of the shoulder, leading to greater overall satisfaction in this patient group.29 Therefore, for active elderly patients without advanced osteoarthritis, arthroscopic procedures, such as SCR or partial repair, may be more suitable as they provide more comprehensive ROM recovery and better alignment with the functional and lifestyle expectations of these patients.
Partial repair can contribute to the restoration of the horizontal force coupling. However, due to supraspinatus tendon defects, the normal biomechanics of the shoulder may not be fully restored. In such cases, additional procedures, such as a balloon spacer or SCR, can be considered to address the restoration of vertical force coupling.
HDAs have been proposed as alternatives. These grafts are considered potentially stronger and can virtually eliminate donor site morbidity.30,31 HDAs carry minimal immunological risk, and these grafts have demonstrated effective integration, serving as scaffolds for neovascularization while maintaining structural integrity. The benefits of using this type of graft include the absence of donor-site morbidity, simplicity of preparation, substantial thickness and strength of the construct, and successful biological incorporation. Numerous studies have investigated the biomechanical properties and clinical outcomes of HDAs to demonstrate their efficacy. Several systematic reviews have compared SCR using HDA with fascia lata autografts. Although the healing rate with HDA may be slightly lower, these reviews indicate no significant difference in clinical outcomes between the two techniques.15,22,32,33
In this study, we focused on individuals ≥65 years old, fundamentally shifting the paradigm of performing SCR from the typically physically demanding younger patients. Our selection of the study population was driven by the concept of addressing irreparable MRCTs without the accompanying arthritis. Although RSA has shown relatively favorable outcomes, it fails to completely restore the biomechanics of the normal shoulder. Particularly, the satisfaction of patients without concomitant rotator cuff tear arthropathy may not be as high. Hence, our study began with the notion of conducting SCR procedures in individuals aged ≥65 years old, a relatively older demographic group. Given the potential concerns, such as donor site morbidity, associated with harvesting fascia lata autografts, especially in this age group, we opted to use HDA to perform surgery to address potential issues and streamline the surgical process, including reducing surgical time.
The most significant recent challenge related to SCR revolves around graft thickness. In particular, owing to the characteristics of HDA, it is challenging to achieve the same 6–8 mm thickness as the original concept of a folded fascia lata autograft using a single layer. In a cadaveric study comparing two different graft types for SCR, a fascia lata allograft demonstrated complete restoration of superior stability in the shoulder joint, whereas an HDA achieved only partial stability restoration.24 A previous study assessed three graft types—fascia lata allograft, double-layered HDA, and single-layered HDA—used in SCR. The authors indicated that all three grafts successfully restored superior humeral translation and subacromial contact pressure and influenced the glenohumeral abduction angle to various extents. Notably, fascia lata and double-layer dermal allografts proved to be more effective than single-layer dermal allografts.32 Snow et al. reported satisfactory clinical outcomes in their study of SCR using double-layer-thick HDA over an average of 48 months and indicated that all 18 patients achieved complete healing.23
In this study, SCR was performed using a 3–4 mm single-layer HDA, and graft healing failure occurred in 27.3 % of cases. This incidence is consistent with the findings of other studies.34, 35, 36, 37 Nevertheless, clinical outcomes, range of motion, and satisfaction were maintained at higher levels than RSA for at least two years postoperatively. Although single-layer ADM is biomechanically inferior to double-layer constructs or fascia lata grafts, favorable outcomes were likely achieved through meticulous surgical technique, restoration of the force-coupling mechanism, and a structured rehabilitation protocol.5,10,11,15,17,21 The authors recently shifted to double-layer HDA, anticipating improved results based on the biomechanical and clinical outcomes reported in other studies.
Several biomechanical studies have conducted comparative studies on the SCR and RSA. Rybalko et al.26 investigated the biomechanical effects of shoulder motion on irreparable supraspinatus tears in a cadaver study and found that both procedures restored the abduction force to intact cuff levels, but SCR provided superior passive abduction range of motion (ROM). Similarly, in our study, the group undergoing SCR showed better improvement in forward flexion and internal rotation at the final follow-up compared to the RSA group. Particularly in the RSA group, although there was an improvement in pain reduction and functional scores postoperatively, there was no significant improvement in active range of motion. This implies that in patients with arthritis-free irreparable MRCTs, the preoperative limitations in ROM were not severe, and the biomechanical characteristics of the RSA may not contribute to the recovery of ROM.
The relatively short follow-up period of this study, with a mean duration of 30 months, limits our understanding of the long-term outcomes of SCR and RSA. Although both procedures show favorable short-term results in terms of pain relief, functional recovery, and patient satisfaction, uncertainties remain regarding their durability and effectiveness over extended periods. Specifically, SCR is prone to challenges, such as graft thinning, structural degradation, and delayed failure, which can adversely impact functional outcomes.15,18,19,23,32,35 Although RSA provides excellent improvements in functional outcomes, complications, such as scapular notching, glenoid loosening, and prosthetic dislocation, pose challenges to the long-term durability and mechanical stability of the implant.38 Prospective large-scale studies with extended follow-up durations remain warranted to evaluate the mid- and long-term outcomes of SCR and RSA, investigate patient-specific factors, such as activity level and graft characteristics, and refine surgical decision-making and postoperative strategies to enhance care for patients with MRCTs.
Although six patients in the RSA group were classified as having pseudoparalysis, the mean preoperative forward elevation exceeded 130°, which may appear inconsistent. This discrepancy can be attributed to compensatory scapulothoracic motion during shoulder elevation, potentially leading to an overestimation of true glenohumeral range of motion.6 Additionally, some patients may have initially presented with pseudoparalysis but showed partial improvement in active elevation prior to surgery due to conservative treatment or natural recovery over time.
This study has several limitations. First, the small sample size (22 patients in each group) limited the generalizability of the findings, despite the use of PS-matching to reduce selection bias. Future studies with larger sample sizes and a priori power analyses are warranted to validate these findings and assess their clinical relevance more robustly. Second, the relatively short follow-up period (approximately 30 months) may not capture mid-to long-term outcomes, particularly for SCR, where graft thickness and integrity may decrease over time. Third, the retrospective design inherently carries the risk of unmeasured confounding variables despite efforts to control for key factors. Fourth, although the study was conducted at two institutions, the potential variability in patient selection, management, and rehabilitation protocols might have influenced the results, even though both surgeons were trained at the same institution and used standardized techniques. Fifth, the inclusion criteria focused exclusively on patients aged ≥65 years old without advanced glenohumeral arthritis (Hamada grades 1–3), which limits the applicability of the findings to other patient populations, such as younger individuals or those with more severe arthritis.
5. Conclusion
Although SCR using human ADM and RSA is an effective surgical option for treating MRCTs in patients aged ≥65 years old, SCR has demonstrated superior postoperative shoulder function, particularly in forward flexion and internal rotation. Therefore, SCR may represent a joint-preserving alternative to RSA for active elderly patients without glenohumeral arthritis, with potential advantages in functional recovery and range of motion. However, the potential risk of graft healing failure in SCR should be considered, and further research with larger cohorts and longer follow-up periods remains warranted to evaluate outcome durability and refine the indications for SCR and RSA.
Ethical statement
This study was conducted in accordance with the principles outlined in the Declaration of Helsinki. Ethical approval was obtained from the Institutional Review Board (IRB) of Inje University Ilsan Paik Hospital (IRB No.2024-06-009-001) and National Health Insurance Service Ilsan Hospital (IRB No.NHIMC-2023-02-021). Informed consent was obtained from all participants prior to their inclusion in the study.
Author contribution
Seong Hun Kim: Study design, data collection, and statistical analysis.
Seung Joo Kim: Data collection, interpretation, and manuscript preparation.
Jae-Hoo Lee: Study supervision, manuscript review, and correspondence.
All authors have read and approved the final manuscript.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflict of interest
The authors declare no conflicts of interest related to this study.
Acknowledgment
None.
Data availability
The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.