Influence of Frequent Corticosteroid Local Injections on the Expression of Genes and Proteins Related to Fatty Infiltration, Muscle Atrophy, Inflammation, and Fibrosis in Patients With Chronic Rotator Cuff Tears: A Pilot Study.

Background: The effect of local corticosteroid (CS) injections on rotator cuff muscles remains poorly defined, despite the significance of muscle quality as a crucial prognostic factor for patients with rotator cuff tears (RCTs). Purpose: To compare alterations in gene and protein expression patterns in the rotator cuff muscles of patients with RCTs who received frequent joint CS injections with alterations in those without a history of CS injections. Study Design: Controlled laboratory study. Methods: A total of 24 rotator cuff muscle samples with medium-sized tears from 12 patients with a frequent joint CS injection history (steroid group; 7 men and 5 women who had received ≥5 injections with at least 1 within the previous 3 months; mean age, 63.0 ± 7.2 years) and 12 age- and sex-matched control patients without a history of CS injections (no-steroid group) were acquired. Alterations in the expression of genes and proteins associated with adipogenesis, myogenesis, inflammation, and muscle fibrosis were compared between the groups using quantitative reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry. Statistical analysis included comparison of group means using the Mann-Whitney U test, chi-square test, or Fisher exact test and logistic regression for multivariate analysis. Results: In the steroid group, the mRNA expression levels of adipogenic CCAAT/enhancer-binding protein alpha (C/EBPα; P = .008) and muscle atrophy-related genes (atrogin; P = .019) were significantly higher, and those of myogenic differentiation 1 (MyoD; P = .035), inflammatory interleukin 6 (IL-6; P = .035), and high mobility group box 1 (P = .003) were significantly lower compared with the no-steroid group. In addition, MyoD (P = .041) and IL-6 (P = .026) expression were decreased in the steroid versus no-steroid group. Immunohistochemistry revealed increased expression of C/EBPα and atrogin and decreased expression of MyoD and IL-6 in the steroid versus no-steroid group. Conclusion: Patients with RCTs and a history of frequent CS injections exhibited an upregulation of adipogenic and muscle atrophy-related genes and proteins within the rotator cuff muscles and a downregulation in the expression of myogenic and inflammatory genes and proteins in the same muscles. Clinical Relevance: These altered gene and protein expressions by frequent local CS injections may cause poor outcomes in patients with RCTs.

Latarjet procedure for failed Bankart repair provides better stability and return to sports, but worse postoperative pain and external rotation limitations with more complications, compared to revision Bankart repair: a systematic review and meta-analysis.

PURPOSE: This study aimed to compare the clinical results of revision Bankart repair versus the Latarjet procedure for failed Bankart repair. METHODS: A literature search was performed in databases, such as Pubmed, Embase, and Scopus Library. The studies were appraised using the Methodological Index for Non-randomized Studies tool. Studies for failed Bankart repair with revision Bankart repair or Latarjet procedure were included. The pain VAS, ROWE score, rate of return to sports and preinjury level of sports, recurrent instability, range of motion, and complications were compared. Additionally, the pain VAS, ROWE score, forward flexion, and external rotation at side were subjected to a meta-analysis. RESULTS: Twenty-four articles were included in the systematic review. The functional outcomes in terms of the ROWE score, recurrent instability, return to sports, and the preinjury level of sports was better in the Latarjet procedure group than those in the revision Bankart repair group (ROWE score, 91 vs. 86.7; recurrent instability rate, 3.5% vs. 14.4%; return to sports rate, 100% vs. 87.9%; return to preinjury level of sports rate, 89.9% vs. 74.9%; all P < 0.001). However, the results of postoperative pain and the postoperative limitation of external rotation at side were worse in the Latarjet procedure group than those in the revision Bankart repair group (pain VAS, 1.4 vs. 0.8; postoperative external rotation at side, 38° vs. 60°; all P < 0.001). In addition, the majority of the complications occurred in the Latarjet procedure group. In the meta-analysis, the postoperative ROWE score was significantly higher in the Latarjet procedure group than that in the revision Bankart group (revision Bankart repair: 95% CI 88.9-80.9, I2 = 65.70; Latarjet procedure: 95% CI 95.8-88.1, I2 = 93.37; P = 0.014). However, the pain VAS, forward flexion, and external rotation at side did not reach the significant level in the meta-analysis. CONCLUSION: Compared with revision Bankart repair, the Latarjet procedure for failed Bankart repair showed better ROWE scores, stability, and return to sports or preinjury level of sports; however, the postoperative pain and the limitation of external rotation at side were worse with more complications. IRB NO: KUMC 2022-01-024. LEVEL OF EVIDENCE: Level IV.

Does Complete Footprint Coverage Affect Outcomes After Conventional Arthroscopic Repair of Large-Sized Rotator Cuff Tears?

Background: In large-sized rotator cuff tears, tendon repair with incomplete footprint coverage is performed frequently as a way of tension-free or low-tension repair. Purpose: To compare clinical outcomes after arthroscopic repair of large-sized rotator cuff tears between patients with complete versus incomplete footprint coverage. Study Design: Cohort study; Level of evidence, 3. Methods: Among 297 patients who underwent arthroscopic surgery for a large-sized rotator cuff tear, we selected 58 patients (<50% coverage; mean age, 63.34 ± 6.8 years; 34 men and 24 women) with incomplete footprint coverage. Using propensity score matching, another 58 patients with complete footprint coverage (mean age, 63.4 ± 8.03 years; 34 men and 24 women) were selected after 1:1 matching for age, sex, and tear size-the main demographic and prognostic factors of outcomes after rotator cuff repair. Clinical outcomes were compared on magnetic resonance imaging or ultrasonography at minimum of 6 months postoperatively, and functional outcomes were compared using range of motion and pain visual analog scale; American Shoulder and Elbow Surgeons; Constant; University of California, Los Angeles; and Simple Shoulder Test scores at a minimum of 2 years postoperatively. Results: A total of 18 patients in the incomplete footprint coverage group (31.0%) and 20 patients in the complete footprint coverage group (34.5%) showed healing failure, with no significant difference between groups (P = .843). In addition, there were no differences in functional outcomes between groups (P > .05 for all). Conclusion: Whether the rotator cuff footprint was completely covered did not affect clinical outcomes in conventional arthroscopic repair of large-sized rotator cuff tears.

Relationship between fatty infiltration and gene expression in patients with medium rotator cuff tear.

BACKGROUND: Fatty infiltration (FI) is a key prognostic factor that affects outcomes after rotator cuff repair and is radiologically evaluated using the Goutallier classification. The purpose of this study was to assess alterations in gene and protein expression according to the Goutallier classification in the supraspinatus muscle and any relationships among various gene expression profiles. METHODS: Twenty-four samples of the supraspinatus muscle from 12 patients with a high FI grade (grade 3 or 4) and 12 patients with a low FI grade (grade 1 or 2) with medium-sized tears were acquired during arthroscopic surgery. Alterations in the expression of genes and proteins associated with adipogenesis, fibrosis, inflammation, and muscle atrophy were compared between the high- and low-FI groups using reverse-transcription quantitative polymerase chain reaction, Western blotting, and immunohistochemistry. RESULTS: mRNA expression of not only the adipogenic genes (peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α; P < .001 and P = .020) but also the fibrosis-related gene (α-smooth muscle actin; P < .001), inflammation-related genes (interleukin [IL]-1ß and tumor necrosis factor α; P = .041 and P = .039), and muscle atrophy-related genes (atrogin 1 and myostatin; P = .006 and P < .001) was higher in the high-FI group compared with that in the low-FI group. In addition, adipogenic gene expression was significantly correlated with the expression of other categories of genes (all P < .05, except atrogin 1). A correlation of gene and protein expression was observed for IL-1ß (P = .027) and myostatin (P = .029). CONCLUSIONS: The radiologic grading of FI was associated with the expression of various genes, including adipogenic, fibrotic, inflammatory, and atrophy-related genes, and these genes were closely correlated with each other in terms of expression. This information could be helpful in patient counseling.

Automated rotator cuff tear classification using 3D convolutional neural network.

Rotator cuff tear (RCT) is one of the most common shoulder injuries. When diagnosing RCT, skilled orthopedists visually interpret magnetic resonance imaging (MRI) scan data. For automated and accurate diagnosis of RCT, we propose a full 3D convolutional neural network (CNN) based method using deep learning. This 3D CNN automatically diagnoses the presence or absence of an RCT, classifies the tear size, and provides 3D visualization of the tear location. To train the 3D CNN, the Voxception-ResNet (VRN) structure was used. This architecture uses 3D convolution filters, so it is advantageous in extracting information from 3D data compared with 2D-based CNNs or traditional diagnosis methods. MRI data from 2,124 patients were used to train and test the VRN-based 3D CNN. The network is trained to classify RCT into five classes (None, Partial, Small, Medium, Large-to-Massive). A 3D class activation map (CAM) was visualized by volume rendering to show the localization and size information of RCT in 3D. A comparative experiment was performed for the proposed method and clinical experts by using randomly selected 200 test set data, which had been separated from training set. The VRN-based 3D CNN outperformed orthopedists specialized in shoulder and general orthopedists in binary accuracy (92.5% vs. 76.4% and 68.2%), top-1 accuracy (69.0% vs. 45.8% and 30.5%), top-1±1 accuracy (87.5% vs. 79.8% and 71.0%), sensitivity (0.94 vs. 0.86 and 0.90), and specificity (0.90 vs. 0.58 and 0.29). The generated 3D CAM provided effective information regarding the 3D location and size of the tear. Given these results, the proposed method demonstrates the feasibility of artificial intelligence that can assist in clinical RCT diagnosis.