Background: This study aimed to investigate changes in gene expression related to matrix synthesis in individuals with fullthickness rotator cuff tears (RCTs) and normal tendon tissues. The study also aimed to examine the differences in gene expression according to 4 distinct tear sizes. Methods: A total of 12 patients with full-thickness RCTs were included in the study, all of whom underwent arthroscopic rotator cuff repair. The RCTs were stratified by size into small, medium, large, and massive. Tendon samples were harvested from the midpoint between the lateral end of the torn tendon and the musculotendinous junction. Subsequent analysis of the tissue samples revealed the mRNA expression levels of 11 collagen types, 6 proteoglycans, and 8 glycoproteins through real-time polymerase chain reaction techniques. For control purposes, supraspinatus tendon tissue was sourced from 3 patients who had proximal humerus fractures but did not present with RCTs. Results: Among the 11 collagens and 14 non-collagenous protein (NCP) genes examined in this study, COL3A1 and COL10A1 showed a significant increase, whereas COL4A1 and COL14A1 showed a tendency to decrease compared to those in the normal group. ACAN significantly increased by 8.92-fold (p < 0.001) compared to that in the normal group, whereas DCN and LUM showed a tendency to decrease. FN1 and TNC increased significantly by 3.47-fold (p = 0.003) and 5.38-fold (p = 0.005), respectively, and the genes ELN, LAMA2, and THBS1 were all significantly reduced compared to those in the normal group. In the NCPs, almost all the genes with increased expression levels had the highest level in small size RCTs, and gene expression decreased as the size increased. The 3 proteoglycans (ACAN, BGN, and FMOD) showed the highest levels of expression in small size RCTs compared to those in the normal group, and 5 glycoproteins (COMP, FBN1, FN1, HAPLN1, and TNC) also showed the highest expression in small size RCTs. Conclusions We confirmed that most of the detected extracellular matrix gene expression changes were related to the size of the full-thickness RCTs. In NCPs, gene expression was increased in small-size tears, and gene expression levels were significantly reduced when the size increased.

Background: To investigate the feasibility of the antegrade supraspinatus advancement (ASSA), which could be executed entirely arthroscopically without requiring a medial incision; to evaluate the impact of the ASSA on the lateral excursion of the torn end of the supraspinatus in retracted irreducible rotator cuff tears (RIRCTs); and to assess the safety and efficacy of arthroscopic rotator cuff repair with the ASSA. Methods: A total of 57 patients with RIRCTs who underwent the ASSA and were followed up for at least a year with magnetic resonance imaging (MRI) were included. The RIRCT was defined as the lateral excursion grade C (coverage less than the medial half of the greater tuberosity) or D (exposure of the glenohumeral joint). Clinical outcomes assessed nerve injury, pain, range of motion, strength, functional scores, and overall satisfaction and function. Structural outcomes evaluated the retear rate, fatty infiltration, and muscle atrophy of the rotator cuff muscles. The baseline for these structural measurements was time-zero MRIs. Results: The ASSA was feasibly performed all arthroscopically without a medial incision. There was no suprascapular nerve injury during the follow-up. The ASSA increased lateral excursion of the torn end in 86% of the patients from C or D to A or B. The ASSA significantly reduced pain and improved function of the shoulder at the final follow-up. All 11 patients who had had pseudoparalysis prior to repair regained the ability to raise their arm. The retear rate after the ASSA was 18.4%. Conclusions This study demonstrated that the ASSA can be safely and effectively performed all arthroscopically, significantly increasing the lateral excursion of the supraspinatus, thereby ensuring successful rotator cuff repair. This leads to a superior quality of repair, which consequently results in better clinical and structural outcomes, including the reversal of pseudoparalysis.

Background: This study aimed to investigate changes in gene expression related to matrix synthesis in individuals with fullthickness rotator cuff tears (RCTs) and normal tendon tissues. The study also aimed to examine the differences in gene expression according to 4 distinct tear sizes. Methods: A total of 12 patients with full-thickness RCTs were included in the study, all of whom underwent arthroscopic rotator cuff repair. The RCTs were stratified by size into small, medium, large, and massive. Tendon samples were harvested from the midpoint between the lateral end of the torn tendon and the musculotendinous junction. Subsequent analysis of the tissue samples revealed the mRNA expression levels of 11 collagen types, 6 proteoglycans, and 8 glycoproteins through real-time polymerase chain reaction techniques. For control purposes, supraspinatus tendon tissue was sourced from 3 patients who had proximal humerus fractures but did not present with RCTs. Results: Among the 11 collagens and 14 non-collagenous protein (NCP) genes examined in this study, COL3A1 and COL10A1 showed a significant increase, whereas COL4A1 and COL14A1 showed a tendency to decrease compared to those in the normal group. ACAN significantly increased by 8.92-fold (p < 0.001) compared to that in the normal group, whereas DCN and LUM showed a tendency to decrease. FN1 and TNC increased significantly by 3.47-fold (p = 0.003) and 5.38-fold (p = 0.005), respectively, and the genes ELN, LAMA2, and THBS1 were all significantly reduced compared to those in the normal group. In the NCPs, almost all the genes with increased expression levels had the highest level in small size RCTs, and gene expression decreased as the size increased. The 3 proteoglycans (ACAN, BGN, and FMOD) showed the highest levels of expression in small size RCTs compared to those in the normal group, and 5 glycoproteins (COMP, FBN1, FN1, HAPLN1, and TNC) also showed the highest expression in small size RCTs. Conclusions We confirmed that most of the detected extracellular matrix gene expression changes were related to the size of the full-thickness RCTs. In NCPs, gene expression was increased in small-size tears, and gene expression levels were significantly reduced when the size increased.

Background: To investigate the feasibility of the antegrade supraspinatus advancement (ASSA), which could be executed entirely arthroscopically without requiring a medial incision; to evaluate the impact of the ASSA on the lateral excursion of the torn end of the supraspinatus in retracted irreducible rotator cuff tears (RIRCTs); and to assess the safety and efficacy of arthroscopic rotator cuff repair with the ASSA. Methods: A total of 57 patients with RIRCTs who underwent the ASSA and were followed up for at least a year with magnetic resonance imaging (MRI) were included. The RIRCT was defined as the lateral excursion grade C (coverage less than the medial half of the greater tuberosity) or D (exposure of the glenohumeral joint). Clinical outcomes assessed nerve injury, pain, range of motion, strength, functional scores, and overall satisfaction and function. Structural outcomes evaluated the retear rate, fatty infiltration, and muscle atrophy of the rotator cuff muscles. The baseline for these structural measurements was time-zero MRIs. Results: The ASSA was feasibly performed all arthroscopically without a medial incision. There was no suprascapular nerve injury during the follow-up. The ASSA increased lateral excursion of the torn end in 86% of the patients from C or D to A or B. The ASSA significantly reduced pain and improved function of the shoulder at the final follow-up. All 11 patients who had had pseudoparalysis prior to repair regained the ability to raise their arm. The retear rate after the ASSA was 18.4%. Conclusions This study demonstrated that the ASSA can be safely and effectively performed all arthroscopically, significantly increasing the lateral excursion of the supraspinatus, thereby ensuring successful rotator cuff repair. This leads to a superior quality of repair, which consequently results in better clinical and structural outcomes, including the reversal of pseudoparalysis.

Background: This study aimed to investigate changes in gene expression related to matrix synthesis in individuals with fullthickness rotator cuff tears (RCTs) and normal tendon tissues. The study also aimed to examine the differences in gene expression according to 4 distinct tear sizes. Methods: A total of 12 patients with full-thickness RCTs were included in the study, all of whom underwent arthroscopic rotator cuff repair. The RCTs were stratified by size into small, medium, large, and massive. Tendon samples were harvested from the midpoint between the lateral end of the torn tendon and the musculotendinous junction. Subsequent analysis of the tissue samples revealed the mRNA expression levels of 11 collagen types, 6 proteoglycans, and 8 glycoproteins through real-time polymerase chain reaction techniques. For control purposes, supraspinatus tendon tissue was sourced from 3 patients who had proximal humerus fractures but did not present with RCTs. Results: Among the 11 collagens and 14 non-collagenous protein (NCP) genes examined in this study, COL3A1 and COL10A1 showed a significant increase, whereas COL4A1 and COL14A1 showed a tendency to decrease compared to those in the normal group. ACAN significantly increased by 8.92-fold (p < 0.001) compared to that in the normal group, whereas DCN and LUM showed a tendency to decrease. FN1 and TNC increased significantly by 3.47-fold (p = 0.003) and 5.38-fold (p = 0.005), respectively, and the genes ELN, LAMA2, and THBS1 were all significantly reduced compared to those in the normal group. In the NCPs, almost all the genes with increased expression levels had the highest level in small size RCTs, and gene expression decreased as the size increased. The 3 proteoglycans (ACAN, BGN, and FMOD) showed the highest levels of expression in small size RCTs compared to those in the normal group, and 5 glycoproteins (COMP, FBN1, FN1, HAPLN1, and TNC) also showed the highest expression in small size RCTs. Conclusions We confirmed that most of the detected extracellular matrix gene expression changes were related to the size of the full-thickness RCTs. In NCPs, gene expression was increased in small-size tears, and gene expression levels were significantly reduced when the size increased.

Background: To investigate the feasibility of the antegrade supraspinatus advancement (ASSA), which could be executed entirely arthroscopically without requiring a medial incision; to evaluate the impact of the ASSA on the lateral excursion of the torn end of the supraspinatus in retracted irreducible rotator cuff tears (RIRCTs); and to assess the safety and efficacy of arthroscopic rotator cuff repair with the ASSA. Methods: A total of 57 patients with RIRCTs who underwent the ASSA and were followed up for at least a year with magnetic resonance imaging (MRI) were included. The RIRCT was defined as the lateral excursion grade C (coverage less than the medial half of the greater tuberosity) or D (exposure of the glenohumeral joint). Clinical outcomes assessed nerve injury, pain, range of motion, strength, functional scores, and overall satisfaction and function. Structural outcomes evaluated the retear rate, fatty infiltration, and muscle atrophy of the rotator cuff muscles. The baseline for these structural measurements was time-zero MRIs. Results: The ASSA was feasibly performed all arthroscopically without a medial incision. There was no suprascapular nerve injury during the follow-up. The ASSA increased lateral excursion of the torn end in 86% of the patients from C or D to A or B. The ASSA significantly reduced pain and improved function of the shoulder at the final follow-up. All 11 patients who had had pseudoparalysis prior to repair regained the ability to raise their arm. The retear rate after the ASSA was 18.4%. Conclusions This study demonstrated that the ASSA can be safely and effectively performed all arthroscopically, significantly increasing the lateral excursion of the supraspinatus, thereby ensuring successful rotator cuff repair. This leads to a superior quality of repair, which consequently results in better clinical and structural outcomes, including the reversal of pseudoparalysis.

Background: This study aimed to investigate changes in gene expression related to matrix synthesis in individuals with fullthickness rotator cuff tears (RCTs) and normal tendon tissues. The study also aimed to examine the differences in gene expression according to 4 distinct tear sizes. Methods: A total of 12 patients with full-thickness RCTs were included in the study, all of whom underwent arthroscopic rotator cuff repair. The RCTs were stratified by size into small, medium, large, and massive. Tendon samples were harvested from the midpoint between the lateral end of the torn tendon and the musculotendinous junction. Subsequent analysis of the tissue samples revealed the mRNA expression levels of 11 collagen types, 6 proteoglycans, and 8 glycoproteins through real-time polymerase chain reaction techniques. For control purposes, supraspinatus tendon tissue was sourced from 3 patients who had proximal humerus fractures but did not present with RCTs. Results: Among the 11 collagens and 14 non-collagenous protein (NCP) genes examined in this study, COL3A1 and COL10A1 showed a significant increase, whereas COL4A1 and COL14A1 showed a tendency to decrease compared to those in the normal group. ACAN significantly increased by 8.92-fold (p < 0.001) compared to that in the normal group, whereas DCN and LUM showed a tendency to decrease. FN1 and TNC increased significantly by 3.47-fold (p = 0.003) and 5.38-fold (p = 0.005), respectively, and the genes ELN, LAMA2, and THBS1 were all significantly reduced compared to those in the normal group. In the NCPs, almost all the genes with increased expression levels had the highest level in small size RCTs, and gene expression decreased as the size increased. The 3 proteoglycans (ACAN, BGN, and FMOD) showed the highest levels of expression in small size RCTs compared to those in the normal group, and 5 glycoproteins (COMP, FBN1, FN1, HAPLN1, and TNC) also showed the highest expression in small size RCTs. Conclusions We confirmed that most of the detected extracellular matrix gene expression changes were related to the size of the full-thickness RCTs. In NCPs, gene expression was increased in small-size tears, and gene expression levels were significantly reduced when the size increased.

Background: To investigate the feasibility of the antegrade supraspinatus advancement (ASSA), which could be executed entirely arthroscopically without requiring a medial incision; to evaluate the impact of the ASSA on the lateral excursion of the torn end of the supraspinatus in retracted irreducible rotator cuff tears (RIRCTs); and to assess the safety and efficacy of arthroscopic rotator cuff repair with the ASSA. Methods: A total of 57 patients with RIRCTs who underwent the ASSA and were followed up for at least a year with magnetic resonance imaging (MRI) were included. The RIRCT was defined as the lateral excursion grade C (coverage less than the medial half of the greater tuberosity) or D (exposure of the glenohumeral joint). Clinical outcomes assessed nerve injury, pain, range of motion, strength, functional scores, and overall satisfaction and function. Structural outcomes evaluated the retear rate, fatty infiltration, and muscle atrophy of the rotator cuff muscles. The baseline for these structural measurements was time-zero MRIs. Results: The ASSA was feasibly performed all arthroscopically without a medial incision. There was no suprascapular nerve injury during the follow-up. The ASSA increased lateral excursion of the torn end in 86% of the patients from C or D to A or B. The ASSA significantly reduced pain and improved function of the shoulder at the final follow-up. All 11 patients who had had pseudoparalysis prior to repair regained the ability to raise their arm. The retear rate after the ASSA was 18.4%. Conclusions This study demonstrated that the ASSA can be safely and effectively performed all arthroscopically, significantly increasing the lateral excursion of the supraspinatus, thereby ensuring successful rotator cuff repair. This leads to a superior quality of repair, which consequently results in better clinical and structural outcomes, including the reversal of pseudoparalysis.

BACKGROUND: Tendinopathy is a chronic tendon disease. Mesenchymal stem cells (MSCs), known for their antiinflammatory properties, may lose effectiveness with extensive culturing. Previous research introduced ‘‘small umbilical cord–derived fast proliferating cells’’ (smumf cells), isolated using a novel minimal cube explant method. These cells maintained their MSC characteristics through long-term culture. Thus, the purpose of the present study was to assess the anti-inflammatory effects of late-passage smumf cells at P10 on tenocytes derived from degenerative rotator cuff tears in a tendinopathic environment. METHODS: The mRNA expression with respect to aging of MSCs and secretion of growth factors (GFs) by smumf cells at P10 were measured. mRNA and protein synthesis in tenocytes with respect to the tenocyte phenotype, inflammatory cytokines, and matrix- degradation enzymes were measured. The inflammatory signal pathways involving nuclear factor kappa B (NF-jB) and mitogen-activated protein kinase (MAPK) in tenocytes were also investigated. The proliferative response of degenerative tenocytes to co-culture with smumf cells over 7 days in varying IL-1β induced tendinopathic environments was investigated. RESULTS smumf cells at P10 showed no signs of aging compared to those at P3. smumf cells at P10, secreting 2,043 pg/ ml of hepatocyte growth factor (HGF), showed a 1.88-fold (p = .002) increase in HGF secretion in a tendinopathic environment. Degenerative tenocytes co-cultured with smumf cells showed significantly increased protein expression levels of collagen type I (Col I) and the Col I/III ratio by 1.46-fold (p < .001) and 1.66-fold (p < .001), respectively. The smumf cells at P10 reduced both mRNA and protein expression levels of matrix metalloproteinases-1, -2, -3, -8, -9, and -13 in tenocytes and attenuated NF-jB (phosphorylated IjBa/IjBa and phosphorylated p65/p65) and MAPK (phosphorylated p38/p38 and phosphorylated JNK/JNK) pathways activated by IL-1β. Removal of IL-1β from the co-culture accelerated the growth of tenocytes by 1.42-fold (p < .001). Removal of IL-1β accelerated tenocyte growth in co-cultures.CONCULSION Late-passage smumf cells exert anti-inflammatory effects on tenocytes derived from degenerative rotator cuff tears under a tendinopathic environment, primarily through the secretion of growth factors (GFs).

BACKGROUND: Tendinopathy is a chronic tendon disease. Mesenchymal stem cells (MSCs), known for their antiinflammatory properties, may lose effectiveness with extensive culturing. Previous research introduced ‘‘small umbilical cord–derived fast proliferating cells’’ (smumf cells), isolated using a novel minimal cube explant method. These cells maintained their MSC characteristics through long-term culture. Thus, the purpose of the present study was to assess the anti-inflammatory effects of late-passage smumf cells at P10 on tenocytes derived from degenerative rotator cuff tears in a tendinopathic environment. METHODS: The mRNA expression with respect to aging of MSCs and secretion of growth factors (GFs) by smumf cells at P10 were measured. mRNA and protein synthesis in tenocytes with respect to the tenocyte phenotype, inflammatory cytokines, and matrix- degradation enzymes were measured. The inflammatory signal pathways involving nuclear factor kappa B (NF-jB) and mitogen-activated protein kinase (MAPK) in tenocytes were also investigated. The proliferative response of degenerative tenocytes to co-culture with smumf cells over 7 days in varying IL-1β induced tendinopathic environments was investigated. RESULTS smumf cells at P10 showed no signs of aging compared to those at P3. smumf cells at P10, secreting 2,043 pg/ ml of hepatocyte growth factor (HGF), showed a 1.88-fold (p = .002) increase in HGF secretion in a tendinopathic environment. Degenerative tenocytes co-cultured with smumf cells showed significantly increased protein expression levels of collagen type I (Col I) and the Col I/III ratio by 1.46-fold (p < .001) and 1.66-fold (p < .001), respectively. The smumf cells at P10 reduced both mRNA and protein expression levels of matrix metalloproteinases-1, -2, -3, -8, -9, and -13 in tenocytes and attenuated NF-jB (phosphorylated IjBa/IjBa and phosphorylated p65/p65) and MAPK (phosphorylated p38/p38 and phosphorylated JNK/JNK) pathways activated by IL-1β. Removal of IL-1β from the co-culture accelerated the growth of tenocytes by 1.42-fold (p < .001). Removal of IL-1β accelerated tenocyte growth in co-cultures.CONCULSION Late-passage smumf cells exert anti-inflammatory effects on tenocytes derived from degenerative rotator cuff tears under a tendinopathic environment, primarily through the secretion of growth factors (GFs).