Does Surgical Intervention Alter the Natural History of Degenerative Rotator Cuff Tears? Comparative Analysis from a Prospective Longitudinal Study.

INTRODUCTION: The natural history of rotator cuff tears often involves progressive pain development, tear enlargement, and advancing muscle fatty degeneration. Both surgery and conservative management have proven to be effective treatments. Our study purpose was to compare the short to mid-term effects of rotator cuff repair on shoulder function, progression of tear size, and muscle degeneration compared to controls with asymptomatic tears that developed pain and were managed nonoperatively. METHODS: This comparative study consists of two separate longitudinal study arms. The control group consisted of asymptomatic degenerative cuff tears followed until pain development and then managed nonoperatively with continued surveillance. The surgical group consisted of subjects with degenerative tears that failed nonoperative treatment and underwent surgical intervention with a minimum of 2 years follow-up. Outcomes included VAS pain, ASES, AROM, strength, and ultrasonography. RESULTS: There were 83 controls and 65 surgical shoulders. The surgical group was younger at enrollment (58.9±5.3 yr vs. 61.2±7.8 yr, p=0.04). The median follow-up for control subjects after pain development was 5.1 years (IQR 3.6) and the median postoperative follow-up for the surgical group was 3.0 years (IQR 0.2). Baseline tear widths (median 14 mm, IQR 9 vs. 13 mm, IQR 8; p=0.45) and tear lengths (median 14 mm, IQR 13 vs. median 11 mm, IQR 8; p=0.06) were similar between the surgical group and controls. There were no differences in the baseline prevalence of fatty degeneration of the supraspinatus or infraspinatus muscles between groups (p=0.43 and p=0.58, respectively). At final follow-up, the surgical group demonstrated significantly lower VAS pain (0 [IQR 2] vs. 3.5 [IQR 4], p=0.0002), higher composite ASES (95 [IQR 13] vs. 65.8 [IQR 32], p=0.0002) and ADL scores (29 [IQR 4] vs. 22 [IQR 8], p=0.0002), greater abduction strength (69.6 N [SD 29] vs. 35.9 N [SD 29], p=0.0002), greater active forward elevation (155˚ [SD 8] vs. 142˚ [SD 28], p=0.002), greater active external rotation in abduction (mean 98.5˚, SD 12 vs. mean 78.2˚, SD 20; p=0.0002) compared to controls. Additionally, the prevalence of fatty muscle degeneration was lower in the surgical group for the supraspinatus and infraspinatus (25% vs. 41%, p=0.05; 17% vs. 34%, p=0.03; respectively). CONCLUSION: This prospective longitudinal study comparing a surgical cohort undergoing rotator cuff repair with a control group treated nonoperatively supports the notion that surgical intervention has the potential to alter the early natural history of degenerative rotator cuff disease. Patients in the surgical group demonstrated clinically relevant differences in pain and functional outcomes. Surgical intervention was protective against progressive muscle degeneration compared to nonoperative treatment.

Transcriptome sequencing reveals inflammation and macrophage heterogeneity in subacromial bursa from degenerative shoulder disorders.

PURPOSE: We aimed to investigate the transcriptomic alterations that occur in the subacromial bursa (SAB) following degenerative or traumatic shoulder diseases. MATERIALS AND METHODS: RNA sequencing was employed to evaluate the transcriptomic alterations of the SAB in individuals afflicted with degenerative rotator cuff tear (RCT), traumatic RCT and proximal humerus fracture (PHF). To gain insights into the biological significance of differentially expressed genes (DEGs), we conducted an enrichment analysis utilizing Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We further utilized single-cell RNA sequencing datasets of SAB from a recently published study to explore the associated cellular dynamics and alterations. RESULTS: We detected 1,790 up-regulated and 1,964 down-regulated DEGs between degenerative RCT and PHF, 2,085 up-regulated and 1,919 down-regulated DEGs between degenerative RCT and traumatic RCT, and 20 up-regulated and 12 down-regulated DEGs between traumatic RCT and PHF. Given the similar expression pattern between traumatic RCT and PHF, they were integrated as the traumatic group. In comparison with the traumatic group, 1,983 up-regulated and 2,205 down-regulated DEGs were detected in degenerative SAB. Enrichment analysis of up-regulated DEGs uncovered an elevated inflammatory and immunologic responses in degenerative SAB. Single-cell transcriptomic analysis revealed macrophage represented the immune cell with the most DEGs between the degenerative and traumatic RCT. CONCLUSION: Our results revealed that the SAB in degenerative RCT exhibited a different transcriptional signature compared to that in traumatic RCT, and enrichment analysis showed immunologic and inflammatory activations. Macrophages may play a fundamental role in this process.

Effects of Quality of Integrity on Clinical and Structural Outcomes of Rotator Cuff Repair: A Retrospective Cohort Study of 504 Cases.

BACKGROUND: The clinical implications of structural integrity have been a subject of long debate. The oversimplified binary categorization of structural integrity into either healing or retear, along with faulty preoperative baselines for comparison, may contribute to the controversy. PURPOSE: To determine how the quality of structural integrity in a repaired cuff tendon affects both clinical and structural outcomes by dividing the patients into groups based on integrity and using the immediate postoperative baseline (time zero). STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 504 patients with a full-thickness rotator cuff tear who underwent arthroscopic rotator cuff repair and were followed up for at least a year with magnetic resonance imaging (MRI) were included. The quality of structural integrity was graded using the Sugaya classification. To evaluate clinical outcomes, pain, range of motion, strength, functional scores, and overall satisfaction and function were used for within- and between-group analyses at the last follow-up. For the assessment of structural outcomes, the Goutallier classification for fatty infiltration (FI) and the tangent sign, occupation ratio, and normalized cross-sectional area for muscle atrophy (MA) were used. The baselines for these structural measurements were both the preoperative and the time-zero MRI scans. RESULTS: The mean clinical follow-up period was 31.8 ± 27.5 months, and the MRI follow-up period was 10.9 ± 5.3 months. There were 178 (35.3%), 228 (45.2%), 58 (11.5%), 14 (2.8%), and 26 (5.2%) shoulders with Sugaya grades 1, 2, 3, 4, and 5, respectively. Regardless of structural integrity, all clinical outcomes at a mean follow-up of 31.8 months after repair significantly improved compared with those before repair. Only in shoulders with Sugaya grade 1 did the FI of the supraspinatus muscle improve significantly from baseline. FI of the infraspinatus muscle did not change significantly in those with grades 1 and 2 but worsened in those with grades 3 and 5. MA measured using the occupation ratio improved significantly in shoulders with Sugaya grades 1 and 2 but declined in those with grade 5. CONCLUSION: This study established a correlation between improved structural integrity of the repaired cuff tendon and enhanced structural outcomes in rotator cuff muscles. Furthermore, the findings revealed that both FI and MA could be reversed in patients exhibiting high-quality structural integrity. However, these structural improvements were not mirrored in the clinical outcomes.

A modified arthroscopic en masse suture bridge repair is effective for delaminated rotator cuff tears.

PURPOSE: This study aimed to clarify the characteristics of delaminated rotator cuff tears (RCTs) and evaluate the clinical outcomes of a modified arthroscopic en masse suture bridge repair for delaminated RCTs. METHODS: Patients with full-thickness RCTs, who underwent arthroscopic suture bridge repair with a minimum 2-year follow-up, were retrospectively reviewed. Patients were categorized into two groups based on the presence of delamination. Delaminated RCTs were treated using a modified en masse suture bridge technique, while nondelaminated RCTs received a conventional suture bridge technique. Preoperative and postoperative Constant scores and American Shoulder and Elbow Surgeons (ASES) scores were determined to evaluate clinical outcomes. Postoperative magnetic resonance imaging (MRI) was carried out to identify the integrity and retear of the repaired rotator cuff. RESULTS: A total of 172 patients were included in our study cohort, in which 67 (39%) delaminated RCTs were confirmed intraoperatively. The prevalence of delamination was significantly higher in large tears (53/102, 52%) compared to medium tears (14/70, 20%) (p < 0.001). No significant differences in age (n.s.) or gender (n.s.) were observed between the two groups. Both groups showed significant improvements in Constant and ASES scores postoperatively (both p < 0.001), with no significant differences between the groups (n.s.). The retear rates were 2/67 (3.0%) in the delamination group and 3/105 (2.9%) in the nondelamination group, showing no significant difference (n.s.). CONCLUSIONS: The modified arthroscopic en masse suture bridge technique was effective for repairing delaminated RCTs, yielding favourable clinical outcomes comparable to those of nondelaminated tears. LEVEL OF EVIDENCE: Level IV.

Differences in Risk Factors for Rotator Cuff Tears in Young Versus Old Individuals.

Background The etiology of rotator cuff tears is thought to be multifactorial with current literature that varies with regard to identifiable risk factors. The purpose of this retrospective review was to identify risk factors for full-thickness rotator cuff tears and determine whether they differ in young versus older individuals. Methods To determine the presence or absence of a rotator cuff tear, 1,561 patients with a shoulder MRI were reviewed. If a tear was present, it was further classified into a partial or full-thickness tear. Demographic variables and clinical data were collected and analyzed with a two-sided Student's t-test or Wilcoxon rank sum test for continuous variables and a Chi-square test or Fisher's exact test for categorical variables. Age and BMI were dichotomized using receiver operator curves. Results Charlson Comorbidity Index, age, BMI, sex, race, and work status were all factors that variably affected a patient's risk of experiencing a rotator cuff tear, with different factors carrying more influence on outcomes within those who are older versus those who are younger. Gender and race were found to differ as risk factors between young and older individuals. Conclusion We were able to identify risk factors overall associated with increased odds of sustaining a full-thickness rotator cuff tear. Our analyses also showed differences in the effect of gender and race as risk factors between young and older patients with rotator cuff tears. This finding may aid clinicians in counseling patients on more specific risks for their given age.

Qualitative analysis of the Supraspinatus muscle fatty infiltration on MRI - Correlation of the Tangent sign with Goutallier grade at the Y view and Medial Scapular border in large retracted rotator cuff tears.

BACKGROUND: Surgically repairing rotator cuff tears with a higher extent of fatty infiltration is controversial. Current evidence supports performing rotator cuff repair in patients exhibiting Goutallier stage 3-4 fatty infiltration. However, the presence of retraction complicates accurate assessment using the Goutallier Classification, particularly on the lateral Y-view. A shift towards classifying fatty infiltration in more medial regions may enhance the precision of tissue quality quantification. The objective of this study was to analyze the uniformity of fatty infiltration within the entire supraspinatus muscle using the Goutallier Classification across three scapular Y-view sections and to examine the association between Goutallier grade, tangent sign, and modified Patte stage. METHODS: A retrospective evaluation was conducted on preoperative magnetic resonance imaging (MRI) scans from a consecutive series of 97 patients who had previously undergone arthroscopic rotator cuff repairs. Three supraspinatus sections on the MRI sagittal plane were identified: the lateral Y-view (section one), a medial section at the suprascapular notch anatomical landmark (section two), and a section 3 cm medial from the suprascapular notch Medial Scapular Body (section three). Goutallier grade, tangent sign, and modified Patte stage were used to evaluate fatty infiltration, muscle atrophy, and tendon retraction, respectively. RESULTS: Section one had the highest Goutallier grade, while section three had the lowest. Intra-observer rest retest reliability analysis showed excellent consistency in all sections with section one (ICC=0.920, 95% CI), section two (ICC=0.917, 95% CI), and section three (ICC=0.923, 95% CI) for Goutallier grade. Inter-observer reliability analysis also revealed excellent consistency in sections one (ICC=0.951, 95% CI), section two (ICC=0.949, 95% CI), and section three (ICC=0.922, 95% CI) for Goutallier grade. A strong correlation was observed between Goutallier grade and modified Patte stage (τb=0.43-0.56, p=0.001), and between Goutallier grade and tangent sign (τb=0.43-0.54, p=0.001) across all sections. CONCLUSION: The severity of fatty infiltration within the supraspinatus muscle belly is inconsistent, with the lateral portion being the most severe and the medial portion the least severe. Goutallier grade demonstrates a strong correlation with tangent sign and modified Patte stage. This suggests that tendon retraction results in a potential overestimation in the amount of fatty infiltration defining some tears unjustly irreparable when measuring at the traditionally described lateral Y-view position compared with 3cm medial.

Superior Capsular Reconstruction using the Long Head of Biceps Tendon: A Biomechanical Assessment of Tenodesis Location and Angle of Fixation.

BACKGROUND: Massive irreparable rotator cuff tears (MIRCT) treated with superior capsular reconstruction (SCR) using the long head of the biceps tendon have shown satisfactory early results. Different techniques and positions for biceps tenodesis have been described. This study aimed to evaluate the effect of tenodesis location and glenohumeral fixation angle for graft tensioning on the biomechanics of a SCR using a single strand biceps technique. METHODS: Eight cadaveric shoulders were mounted to a custom biomechanical simulator which employed static tone loads to the deltoid and rotator cuff muscles. All cadavers were first tested in the intact condition, and then in the simulated MIRCT condition by sectioning the tendinous insertions of the supraspinatus and upper border of the infraspinatus. SCR using the long head of the biceps tendon was then evaluated. Three biceps tenodesis locations relative to the greater tuberosity (anterior, middle, and posterior) and two glenohumeral fixation angles (0° and 30°) for graft tensioning were tested. An optical tracking system was used to quantify superior-inferior (SI) and anterior-posterior (AP) humeral head translation relative to the glenoid, while the functional abduction force was quantified using a load sensor. All tests were conducted at 0°, 30° and 60° of glenohumeral abduction in a randomized fashion. RESULTS: When assessing isolated superior humeral head migration, all biceps tenodesis locations were effective at decreasing superior migration, with no tenodesis location significantly better than the other (P=0.213). However, biceps grafts tensioned at 30° of glenohumeral abduction were significantly better at reducing proximal humeral migration as compared to graft tensioning at 0° abduction (P=0.008). Posterior humeral head translation observed in the MIRCT condition was significantly reduced when tensioning the biceps tendon at 30° of glenohumeral abduction compared to 0° for all tenodesis locations (P≤0.043). Tenodesis location also significantly influenced posterior humeral head translation (P=0.001), with middle and posterior positions restoring near normal humeral head position when fixed at 30° glenohumeral abduction. All SCR techniques using the biceps tendon improved the functional abduction force relative to the MIRCT condition, although no statistically significant differences were observed relative to the intact condition (P≥0.448). DISCUSSION: SCR using the long head biceps tendon is biomechanically effective in reducing posterosuperior translation of the humeral head in the setting of a MIRCT. Graft tensioning and fixation at 30° of glenohumeral abduction combined with either a middle or posterior tenodesis location on the greater tuberosity most effectively restores near normal time-zero humeral head kinematics.

Comparison of clinical outcomes of anterior combined latissimus dorsi and teres major tendon transfer for anterior superior irreparable rotator cuff tear between young and elderly patients.

Background: Anterior combined latissimus dorsi and teres major (aLDTM) tendon transfer has shown promise as a treatment for anterior superior irreparable rotator cuff tears (ASIRCTs). Our study aimed to compare aLDTM clinical outcomes for ASIRCTs between young and elderly patients. Methods: This retrospective study reviewed data from patients who underwent aLDTM tendon transfer for ASIRCTs. Exclusion criteria were unavailability for assessment, <2-year follow-up, or loss to follow-up. Clinical evaluations included visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE), active range of motion (aROM), strength, and complications. Radiologic assessments included acromiohumeral distance, Hamada classification, and integrity of transferred tendon. Patients were divided into group total (all ages), group old (≥70 years), and group young (≤60 years). Results: A total of 123 patients were enrolled with 39 in group young (mean age, 56.6±4.9 years) and 27 in group old (mean age, 73.6±2.3 years). Postoperatively, both groups showed significant improvements in VAS, ASES, and SANE scores and improved aROM for forward elevation, abduction, and internal rotation. No significant differences were noted between the groups. Strength increment was not significantly different between the groups. In comparison to the total cohort, both group young and group old demonstrated comparable results in VAS, ASES, and SANE scores and in aROM and radiological assessments. Furthermore, similar rates of complications, including re-tears and postoperative infections, were observed across all three groups. Conclusions: Our study highlights the effectiveness of aLDTM transfer for ASIRCTs with minimal glenohumeral arthritis, demonstrating similar outcomes in both Group Young and group old patients. Moreover, patients in these distinct age groups showed comparable clinical results when compared to Group Total. Level of evidence: III.

3D-printed Mg-incorporated PCL-based scaffolds improves rotator cuff tendon-bone healing through regulating macrophage polarization.

Introduction: Rotator cuff tear (RCT) is a common shoulder injury impacting mobility and quality of life, while traditional surgeries often result in poor healing. Tissue engineering offers a promising solution, with poly (ε-caprolactone) (PCL) being favored due to its slow degradation, biocompatibility, and non-toxicity. However, PCL lacks sufficient compression resistance. Incorporating Mg, which promotes bone growth and has antibacterial effects, could enhance RCT repair. Methods: The Mg-incorporated PCL-based scaffolds were fabricated using a 3D printing technique. The scaffolds were incorporated with different percentages of Mg (0%, 5%, 10%, 15%, and 20%). The osteogenic activities and anti-inflammatory properties of the scaffolds were evaluated in vitro using human osteoblasts and macrophages. The tissue ingrowth and biocompatibility of the scaffolds were assessed in vivo using a rat model of RCT repair. The ability of the scaffolds to enhance macrophage polarization towards the M2 subtype and inhibit inflammation signaling activation was also investigated. Results: It was found that when incorporated with 10% Mg, PCL-based scaffolds exhibited the optimal bone repairing ability in vitro and in vivo. The in vitro experiments indicated that the successfully constructed 10 Mg/PCL scaffolds enhance osteogenic activities and anti-inflammatory properties. Besides, the in vivo studies demonstrated that 10 Mg/PCL scaffolds promoted tissue ingrowth and enhanced biocompatibility compared to the control PCL scaffolds. Furthermore, the 10 Mg/PCL scaffolds enhanced the macrophages' ability to polarize towards the M2 subtype and inhibited inflammation signaling activation. Discussion: These findings suggest that 3D-printed Mg-incorporated PCL scaffolds have the potential to improve RCT by enhancing osteogenesis, reducing inflammation, and promoting macrophage polarization. The incorporation of 10% Mg into PCL-based scaffolds provided the optimal combination of properties for RCT repair augmentation. This study highlights the potential of tissue engineering approaches in improving the outcomes of RCT repair and provides a foundation for future clinical applications.

Exosomes derived from tendon stem/progenitor cells enhance tendon-bone interface healing after rotator cuff repair in a rat model.

The rate of retear after surgical repair remains high. Mesenchymal stem cells (MSCs) have been extensively employed in regenerative medicine for several decades. However, safety and ethical concerns constrain their clinical application. Tendon Stem/Progenitor Cells (TSPCs)-derived exosomes have emerged as promising cell-free therapeutic agents. Therefore, urgent studies are needed to investigate whether TSPC-Exos could enhance tendon-bone healing and elucidate the underlying mechanisms. In this study, TSPC-Exos were found to promote the proliferation, migration, and expression of fibrogenesis markers in BMSCs. Furthermore, TSPC-Exos demonstrated an ability to suppress the polarization of M1 macrophages while promoting M2 macrophage polarization. In a rat model of rotator cuff repair, TSPC-Exos modulated inflammation and improved the histological structure of the tendon-bone interface, the biomechanical properties of the repaired tendon, and the function of the joint. Mechanistically, TSPC-Exos exhibited high expression of miR-21a-5p, which regulated the expression of PDCD4. The PDCD4/AKT/mTOR axis was implicated in the therapeutic effects of TSPC-Exos on proliferation, migration, and fibrogenesis in BMSCs. This study introduces a novel approach utilizing TSPC-Exos therapy as a promising strategy for cell-free therapies, potentially benefiting patients with rotator cuff tear in the future.

Rate of graft retear is higher in over-the-top superior capsular reconstruction for massive posterosuperior rotator cuff tears with subscapularis tear.

PURPOSE: To compare side-to-side superior capsular reconstruction (SCR) with over-the-top SCR in terms of functional outcomes, pain relief and allograft survival rates. METHODS: Patients who had undergone arthroscopic dermal allograft SCR for massive irreparable rotator cuff tears and clinical follow-up for ≥2 years were recruited. All patients underwent postoperative assessment with routine radiographic analysis for acromiohumeral distances, ultrasound imaging 1 and 3 months after SCR and magnetic resonance imaging (MRI) at least 12 months after SCR. The outcome measures were visual analogue scale (VAS), American Shoulder and Elbow Surgeons (ASES), Constant and Single Assessment Numeric Evaluation (SANE) scores. RESULTS: SCR was performed in 56 patients including side-to-side SCR in 32 and over-the-top SCR in 24. Postoperative MRI showed that the grafts were intact in 46 patients (82.1%; 26 who underwent side-to-side SCR and 20 who underwent over-the-top SCR). The proportion of nonhealing grafts in the over-the-top group was significantly higher with concomitant subscapularis tears (60% vs. 5.3%; p = 0.02). VAS scores and functional outcomes improved postoperatively in both groups and postoperative VAS (1.4 vs. 1.7; n.s.), Constant (74.8 vs. 76.0; n.s.), mean ASES (87.4 vs. 89.1; n.s.) and mean SANE (81.7 vs. 84.3; n.s.) scores did not differ significantly. CONCLUSION: For massive rotator cuff tears, over-the-top and side-to-side SCR achieve similar pain relief and functional improvement, and the rate of healing allografts is high. However, over-the-top SCR is not recommended for massive posterosuperior rotator cuff tears with repairable subscapularis tendon tears due to a higher nonhealing rate. LEVEL OF EVIDENCE: Level III.

Identification of rare genetic variants for rotator cuff tearing and repair in high-risk pedigrees.

Background: Common genetic variants with small effect sizes have been associated with rotator cuff tearing although very few rare, highly penetrant variants have been identified. The purpose of this pilot study was to identify dominant coding variants that segregated with affected individuals in pedigrees at high risk for rotator cuff tears (RCTs). We hypothesize that rare variants contribute to symptomatic RCTs and that they can be identified in related cases with a full-thickness tear requiring surgical management. Methods: We used the Utah Population Database to identify pedigrees that exhibited a significant excess of individuals who had undergone surgical repair of a full-thickness RCT. We analyzed whole exome sequence analysis to identify rare coding variants in 9 independent affected cousin pairs (first or second cousins) who had undergone arthroscopic surgery for repair of a full-thickness RCT (mean age at diagnosis 68 years). Validation of association of the candidate variants with risk for rotator cuff tearing was accomplished utilizing data from the UK Biobank and a separate cohort of unrelated cases of full-thickness RCTs. Results: A total of 82 rare (minor allele frequency <0.005) coding variants were identified as shared in at least one cousin pair affected with full-thickness rotator cuff tearing belonging to a high-risk pedigree, which included variants in RUNX1, ADAM12, TGFBR2, APBB1, PDLIM7, LTBP1, MAP3K4, and MAP3K1. Analysis of 39 of these variants with data available in the UK Biobank (3899 cases with rotator cuff injury and 11,697 matched controls; mean case age 59.9 years) identified a significant association with the APBB1 gene (OR = 2.37, P = .007, uncorrected). The PDLIM7 allele was found to be in significant excess in RCT cases in a separate cohort of Utah patients with full-thickness RCTs (10 carriers out of 458 independent, unrelated patients; minor allele frequency of 0.022) compared to a minor allele frequency of 0.0058 for the European (non-Finnish) control population rate (749 carriers out of 128612 tested) (chi-square test: 19.3 [P < .001]). Discussion: The analysis of closely related individuals with confirmed full-thickness RCTs from high-risk pedigrees has identified 82 rare, shared candidate genetic predisposition coding variants. Association of the PDLIM7 allele with risk for tear was confirmed in an independent cohort of RCTs. Further analysis of the variant alleles is required for confirmation of these genes in rotator cuff tearing.

Effect of Mobilization With Movement on the Glenohumeral Joint Positional Fault in Subacromial Impingement.

Introduction Subacromial impingement (SAI) is a prevalent shoulder condition characterized by mechanical compression within the subacromial region. It presents with symptoms like shoulder pain and restricted motion, impacting a significant portion of the population. Neer's classification delineates three progressive stages of SAI, ranging from bursa edema to chronic rotator cuff tears. The etiology involves intrinsic and extrinsic factors, leading to altered kinematics and impingement. The study aims to determine the effect of mobilization with movement (MWM) on the glenohumeral joint positional fault in patients with SAI. Materials and methods The study comprised 80 participants diagnosed with SAI, selected based on the inclusion and exclusion criteria, and randomly divided into two groups, each consisting of 40 subjects. Group A received conventional therapy, while Group B received MWM in addition to conventional therapy. Treatment sessions, lasting 45 minutes, were administered five times weekly for four weeks. Pre- and post-treatment assessments included the visual analog scale (VAS), range of motion (ROM), acromion humeral distance (AHD), and acromion tuberosity index (ATI). Results The results demonstrated that there was an extremely significant improvement in VAS, shoulder ROM, and ADH in both groups, with a p-value of 0.0001, except for the ATI, which showed significant improvement in Group B with a p-value of 0.0001 compared to Group A. Conclusions Based on statistical analysis, the study found that MWM significantly improved joint positioning fault and has been beneficial in reducing pain and improving ROM.

Low skeletal muscle mass is associated with inferior preoperative and postoperative shoulder function in elderly rotator cuff tear patients.

BACKGROUND: The age-related loss of skeletal muscle mass is an important characteristic of sarcopenia, an increasingly recognized condition with systemic implications. However, its association with shoulder function in elderly patients with rotator cuff tears (RCT) remains unknown. This study aimed to investigate the relationship between low skeletal muscle mass and shoulder function in elderly RCT patients. METHODS: A retrospective analysis was conducted on RCT patients who underwent chest computed tomography (CT) scans for clinical evaluation. Preoperative CT scan images of the chest were used to calculate the cross-sectional area (CSA) of thoracic muscle at the T4 level. The medical records were reviewed. Shoulder function was assessed using the ASES score and CMS score both preoperatively and at the final follow-up. Data on the preoperative range of motion (ROM) for the affected shoulder, were collected for analysis. Subgroup analyses by sex were also performed. RESULTS: A total of 283 RCT patients, consisting of 95 males and 188 females, with a mean age of 66.22 ± 4.89(range, 60-95 years) years were included in this retrospective study. The low muscle mass group showed significantly higher level of c-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) compared to the normal group(3.75 ± 6.64 mg/L vs. 2.17 ± 2.30 mg/L, p = 0.021; 19.08 ± 12.86 mm/H vs.15.95 ± 10.76 mm/H, p = 0.038; respectively). In the normal group, pre-operative passive ROM, including forward elevation, abduction, lateral rotation, and abductive external rotation, was significantly better than that in the low muscle mass group (127.18 ± 34.87° vs. 89.76 ± 50.61°; 119.83 ± 45.76° vs. 87.16 ± 53.32°; 37.96 ± 28.33° vs. 25.82 ± 27.82°; 47.71 ± 23.56° vs. 30.87 ± 27.76°, all p < 0.01, respectively). Similar results were found in the active ROM of the shoulder. The female low muscle mass group exhibited significantly poorer passive and active ROM (p < 0.05). The post-operative ASES scores and CMS scores of the female low muscle mass group were also statistically worse than those of the female normal group (p < 0.05). CONCLUSIONS: The results of present study revealed that the low skeletal muscle mass is associated with inferior ROM of the shoulder and per- and post-operative shoulder function, especially for elderly female patients.

Effect of magnetic microbeads on sustained and targeted delivery of transforming growth factor-beta-1 for rotator cuff healing in a rat rotator cuff repair model.

Structural failure is a well-established complication of rotator cuff repair procedures. To evaluate the effect of magnetic microbeads, designed for precise drug delivery via magnetic force, on sustained transforming growth factor-beta-1 (TGF-ß1) release and rotator cuff healing in a rat rotator cuff repair model. TGF-ß1 laden microbeads were prepared, and baseline in vitro experiments included the magnetization of the microbeads and TGF-ß1 release tests. In an in vivo experiment using a rat rotator cuff repair model on both shoulders, 72 rats were randomly assigned to three groups (24 per group): group A, conventional repair; group B, repair with and simple TGF-ß1 injection; and group C, repair with magnet insertion into the humeral head and TGF-ß1 laden microbead injection. Delivery of TGF-ß1 was evaluated at 1 and 7 days after the intervention using PCR, Western blot, and immunohistochemistry. At 6 weeks post-intervention, rotator cuff healing was assessed using biomechanical and histological analysis. The in vitro experiments confirmed the magnetization property of the microbeads and sustained delivery of TGF-ß1 for up to 10 days. No difference in the TGF-ß1 expression was found at day 1 in vivo. However, at day 7, group C exhibited a significantly elevated expression of TGF-ß1 in both PCR and Western blot analyses compared to groups A and B (all P < 0.05). Immunohistochemical analysis revealed a higher expression of TGF-ß1 at the repair site in group C on day 7. At 6 weeks, biomechanical analysis demonstrated a significantly higher ultimate failure load in group C than in groups A and B (P < 0.05) and greater stiffness than in group A (P = 0.045). In addition, histological analysis showed denser and more regular collagen fibers with complete continuity to the bone in group C than in groups A and B, a statistically significant difference according to the semi-quantitative scoring system (all P < 0.05). The use of the TGF-ß1 laden magnetic microbeads demonstrated sustained delivery of TGF-ß1 to the repair site, improving rotator cuff healing.

Prospective Evaluation of Normal Supraspinatus Muscle Using Shear Wave Elastography: Comparison With Symptomatic Tendon Tears.

OBJECTIVE: This study aimed to evaluate normal supraspinatus (SS) muscle elasticity using shear wave elastography (SWE) in an asymptomatic group, analyze its correlation with demographic factors and ultrasound (US) grayscale grade, and compare the elasticity between normal SS muscles and symptomatic SS muscles with tendon tears. METHODS: A prospective study was conducted with 101 adult patients with normal SS muscle scheduled for surgery due to a contralateral shoulder with SS tendon tear. Both shoulders underwent US examinations, including SWE. The SWE values, including mean and median elasticity, as well as the elasticity ratio, were analyzed for their correlation with demographic characteristics and grayscale grades. A comparison of SWE values was performed between the normal and symptomatic SS muscle groups. RESULTS: The mean SWE modulus of the normal SS muscle was 27.87 kPa (±49.04), with an elasticity ratio of approximately 1.52 (±0.03). Males exhibited slightly higher elasticity ratios compared with females (1.61 vs 1.45, P = .016). The interobserver agreement for all SWE measurements was excellent (>0.8). Grayscale grade increased with age, showing a similar pattern in females (P < .001). However, no significant correlation was observed between SWE values and grayscale grade in the normal SS muscle group. SWE values in normal SS muscles were significantly lower than those with tendon tears (P < .001). CONCLUSIONS: SWE provides objective measurements of normal SS muscle elasticity. Gender-based variations were observed, with males exhibiting slightly higher elastography ratios. SWE values were significantly lower in asymptomatic SS muscles compared with those with tendon tears.

Scapular morphology does not predict supraspinatus tendon tear propagation following an individualised exercise therapy programme.

Purpose: To determine whether scapular morphology could predict isolated supraspinatus tendon tear propagation after exercise therapy. We hypothesised that a larger critical shoulder angle (CSA) and type III acromial morphology predict a positive change in tear size. Methods: Fifty-nine individuals aged 40-70 years with isolated symptomatic high-grade partial or full-thickness supraspinatus tendon tears were included. Individuals participated in a structured, individualised 12-week exercise therapy programme and underwent ultrasound to measure tear size at baseline and 12 months following therapy. Computed tomography images were segmented to create three-dimensional subject-specific bone models and reviewed by three trained clinicians to measure CSA and to determine acromion morphology based on the Bigliani classification. A binary logistic regression was performed to determine the predictive value of CSA and acromion morphology on tear propagation. Results: The CSA was 30.0 ± 5.4°. Thirty-one individuals (52.5%) had type II acromial morphology, followed by type III and type I morphologies (25.4% and 22.0%, respectively); 81.4% experienced no change in tear size, four (6.8%) individuals experienced tear propagation and seven (11.9%) individuals had a negative change in tear size. No significant difference in tear propagation rates based on CSA or acromion morphology (not significant [NS]) was observed. The model predicted tear size status in 81.4% of cases but only predicted tear propagation 8.3% of the time. Overall, CSA and acromion morphology only predicted 24.3% (R 2 = 0.243) of variance in tear propagation (NS). Conclusions: CSA and acromion morphology were NS predictors of tear propagation of the supraspinatus tendon 12 months following an individualised exercise therapy programme. Level of Evidence: II.

Return to Sports and Activities after Arthroscopic Treatments for Rotator Cuff Lesions in Young Patients Less Than 45-Years-Old: A Systematic Review.

Background: To evaluate the outcomes of arthroscopic treatment of rotator cuff tear (RCT) in individuals under 45 years, focusing on their ability to return to sports (RTS) and work, along with different patient-reported outcomes (PROMs). Methods: Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, this systematic review encompassed articles that studied the outcomes of arthroscopic treatment of RCT in the young population (those under 45 years old). The literature search was conducted in PubMed/Medline and EMBASE until 21 May 2024. The primary outcome was the RTS, with secondary outcomes including the return to work and various PROMs. These PROMs included the American Shoulder and Elbow Surgeons (ASES) score and 10 other PROMs. Results: Out of 6267 articles, 15 met the inclusion criteria, involving 659 patients, predominantly male athletes with a weighted mean age of 28.3 years. The RCT etiology (14 studies) was primarily traumatic (72.3%), followed by chronic microtrauma in overhead athletes (16.8%) and non-traumatic (10.9%). The RTS rate (12 studies) varied between 47% and 100%, with a cumulative rate of 75.2%. The cumulative rate of return to the same or higher RTS level (11 studies) was 56.1%. Excluding non-athletes and patients treated with debridement, the RTS rates increased to 79.8% (143/179) overall, with a 61% (108/177) rate of returning to the same or higher level. The return to work (3 studies) was successful in 90.6% of cases. Postoperative ASES scores (5 studies) improved markedly to a weighted post-operative mean of 75.6, with similar positive trends across other PROMs. Conclusions: Young adults undergoing arthroscopic RCT repair typically experience a 75% RTS rate at any level, and 56.1% RTS at the same level. Excluding non-athletes and debridement patients, RTS rates rise to 79.8% (143/179), with 61% (108/177) achieving the same or higher level. Level of evidence: IV, systematic review including case series.

Effect of Tear Size and Location on Supraspinatus Tendon Strain During Activities of Daily Living and Physiotherapy.

The supraspinatus tendon plays a crucial role in shoulder abduction, making it one of the common structures affected by injury. Clinically, crescent-shaped tears are the most commonly seen tear shape. By developing six specimen-specific, three-dimensional, supraspinatus-infraspinatus finite element model with heterogeneous material properties, this study aimed to examine the changes in tissue deformation (maximum principal strain) of the supraspinatus tendon due to specimen-specific material properties and rotator cuff tear size. FE models with small- and medium-sized full-thickness crescent-shaped tears were subjected to loads seen during activities of daily living and physiotherapy. Six fresh-frozen cadaveric shoulders were dissected to mechanically test the supraspinatus tendon and develop and validate FE models that can be used to assess changes in strain due to small (< 1 cm, equivalent to 20-30% of the tendon width) and medium-sized (1-3 cm, equivalent to 40-50% of the tendon width) tears that are located in the middle and posterior regions of the supraspinatus tendon. FE predictions of maximum principal strain at the tear tips were examined to determine whether failure strain was reached during activities of daily living (drinking and brushing teeth) and physiotherapy exercises (prone abduction and external rotation at 90° abduction). No significant differences were observed between the middle and posterior tear failure loads for small- and medium-sized tears. For prone abduction, there was a potential risk for tear progression (exceeded failure strain) for medium-sized tears in the supraspinatus tendon's middle and posterior regions. For external rotation at 90° abduction, one model with a middle tear and two with posterior tears experienced failure. For all daily activity loads, the strain never exceeded the failure strain. Our three-dimensional supraspinatus-infraspinatus FE model shows that small tears appear unlikely to progress based on the regional strain response; however, medium-sized tears are at higher risk during more strenuous physiotherapy exercises. Furthermore, differences in patient-specific tendon material properties are important in determining whether the tear will progress. Therefore, patient-specific management plans based on tear size may be beneficial to improve clinical outcomes.

3-Dimensional Bioprinting of a Tendon Stem Cell-Derived Exosomes Loaded Scaffold to Bridge the Unrepairable Massive Rotator Cuff Tear.

BACKGROUND: Unrepairable massive rotator cuff tears (UMRCTs) are challenging to surgeons owing to the severely retracted rotator cuff musculotendinous tissues and extreme defects in the rotator cuff tendinous tissues. PURPOSE: To fabricate a tendon stem cell-derived exosomes loaded scaffold (TSC-Exos-S) and investigate its effects on cellular bioactivity in vitro and repair in a rabbit UMRCT model in vivo. STUDY DESIGN: Controlled laboratory study. METHODS: TSC-Exos-S was fabricated by loading TSC-Exos and type 1 collagen (COL-I) into a 3-dimensional bioprinted and polycaprolactone (PCL)-based scaffold. The proliferation, migration, and tenogenic differentiation activities of rabbit bone marrow stem cells (BMSCs) were evaluated in vitro by culturing them in saline, PCL-based scaffold (S), COL-I loaded scaffold (COL-I-S), and TSC-Exos-S. In vivo studies were conducted on a rabbit UMRCT model, where bridging was repaired with S, COL-I-S, TSC-Exos-S, and autologous fascia lata (FL). Histological and biomechanical analyses were performed at 8 and 16 weeks postoperatively. RESULTS: TSC-Exos-S exhibited reliable mechanical strength and subcutaneous degradation, which did not occur before tissue regeneration. TSC-Exos-S significantly promoted the proliferation, migration, and tenogenic differentiation of rabbit BMSCs in vitro. In vivo studies showed that UMRCT repaired with TSC-Exos-S exhibited significant signs of tendinous tissue regeneration at the bridging site with regard to specific collagen staining. Moreover, no significant differences were observed in the histological and biomechanical properties compared with those repaired with autologous FL. CONCLUSION: TSC-Exos-S achieved tendinous tissue regeneration in UMRCT by providing mechanical support and promoting the trend toward tenogenic differentiation. CLINICAL RELEVANCE: The present study proposes a potential strategy for repairing UMRCT with severely retracted musculotendinous tissues and large tendinous tissue defects.