A two-step neural network-based guiding system for obtaining reliable radiographs for critical shoulder angle measurement.

Background: The critical shoulder angle (CSA) has been reported to be highly associated with rotator cuff tears (RCTs) and an increased risk of RCT re-tears. However, the measurement of the CSA is greatly affected by the malpositioning of the shoulder. To address this issue, a two-step neural network-based guiding system was developed to obtain reliable CSA radiographs, and its feasibility and accuracy was evaluated. Methods: A total of 1,754 shoulder anteroposterior (AP) radiographs were retrospectively acquired to train and validate a two-step neural network-based guiding system to obtain reliable CSA radiographs. The study included patients aged 18 years or older who underwent X-rays and/or computed tomography (CT) scans of the shoulder. Patients who had undergone shoulder surgery, had a confirmed fracture, or were diagnosed with a musculoskeletal tumor or glenoid defect were excluded from the study. The system consisted of a two-step neural network that in the first step, localized the region of interest of the shoulder, and in the second step, classified the radiography according to type [i.e., 'forward' when the non-overlapping coracoid process is above the glenoid rim, 'backward' when the non-overlapping coracoid process is below or aligned with the glenoid rim, a ratio of the transverse to longitudinal diameter of the glenoid projection (RTL) ≤0.25, or a RTL >0.25]. The performance of the model was assessed in an offline, prospective manner, focusing on the sensitivity and specificity for the forward, backward, RTL ≤0.25, or RTL >0.25 types (denoted as SensF, B, -, + and SpecF, B, -, +, respectively), and Cohen's kappa was also reported. Results: Of 273 cases in the offline prospective test, the SensF, SensB, Sens-, and Sens+ were 88.88% [95% confidence interval (CI): 50.67-99.41%], 94.11% (95% CI: 82.77-98.47%), 96.96% (95% CI: 91.94-99.02%), and 95.06% (95% CI: 87.15-98.40%), respectively. The SpecF, SpecB, Spec-, and Spec+ were 98.48% (95% CI: 95.90-99.51%), 99.55% (95% CI: 97.12-99.97%), 95.04% (95% CI: 89.65-97.81%), and 97.39% (93.69-99.03%), respectively. A high classification rate (93.41%; 95% CI: 89.14-96.24%) and almost perfect agreement (Cohen's kappa: 0.903, 95% CI: 0.86-0.95) were achieved. Conclusions: The guiding system can rapidly and accurately classify the types of AP shoulder radiography, thereby guiding the adjustment of patient positioning. This will facilitate the rapid obtainment of reliable CSA radiography to measure the CSA on proper AP radiographs.

Modified Continuous Arthroscopy-Guided Suprascapular Nerve Block for Postoperative Pain Control Following Rotator Cuff Repair: Surgical Technique.

Arthroscopic rotator cuff repair is one of the most painful surgical procedures; patients complain of pain especially during the first 48 hours postoperatively. Pain management is an essential goal to reduce the demand for analgesic agents and patient discomfort. Various methods have been introduced for arthroscopic rotator cuff repair, including continuous arthroscopy-guided suprascapular nerve blocks (SSNB) and interscalene nerve blocks. However, the aforementioned procedures have shown disadvantages such as catheter mobilization, which may cause injury to the artery, a weak analgesic effect, and Horner syndrome, as well as phrenic nerve paralysis. A modification of the continuous arthroscopy-guided SSNB has been introduced at our hospital: the modified continuous arthroscopy-guided SSNB technique. The aim of this technique is to immobilize the catheter to reduce the chance of injury and minimize postsurgical analgesic needs and patient discomfort.

Enhancing prediction of supraspinatus/infraspinatus tendon complex injuries through integration of deep visual features and clinical information: a multicenter two-round assessment study.

OBJECTIVE: Develop and evaluate an ensemble clinical machine learning-deep learning (CML-DL) model integrating deep visual features and clinical data to improve the prediction of supraspinatus/infraspinatus tendon complex (SITC) injuries. METHODS: Patients with suspected SITC injuries were retrospectively recruited from two hospitals, with clinical data and shoulder x-ray radiographs collected. An ensemble CML-DL model was developed for diagnosing normal or insignificant rotator cuff abnormality (NIRCA) and significant rotator cuff tear (SRCT). All patients suspected with SRCT were confirmed by arthroscopy examination. The model's performance was evaluated using sensitivity, specificity, accuracy, and area under the curve (AUC) metrics, and a two-round assessment was conducted to authenticate its clinical applicability. RESULTS: A total of 974 patients were divided into three cohorts: the training cohort (n = 828), the internal validation cohort (n = 89), and the external validation cohort (n = 57). The CML-DL model, which integrates clinical and deep visual features, demonstrated superior performance compared to individual models of either type. The model's sensitivity, specificity, accuracy, and area under curve (95% confidence interval) were 0.880, 0.812, 0.836, and 0.902 (0.858-0.947), respectively. The CML-DL model exhibited higher sensitivity and specificity compared to or on par with the physicians in all validation cohorts. Furthermore, the assistance of the ensemble CML-DL model resulted in a significant improvement in sensitivity for junior physicians in all validation cohorts, without any reduction in specificity. CONCLUSIONS: The ensembled CML-DL model provides a solution to help physicians improve the diagnosis performance of SITC injury, especially for junior physicians with limited expertise. CRITICAL RELEVANCE STATEMENT: The ensembled clinical machine learning-deep learning (CML-DL) model integrating deep visual features and clinical data provides a superior performance in the diagnosis of supraspinatus/infraspinatus tendon complex (SITC) injuries, particularly for junior physicians with limited expertise. KEY POINTS: 1. Integrating clinical and deep visual features improves diagnosing SITC injuries. 2. Ensemble CML-DL model validated for clinical use in two-round assessment. 3. Ensemble model boosts sensitivity in SITC injury diagnosis for junior physicians.

Salvianolic acid B attenuates inflammation and prevent pathologic fibrosis by inhibiting CD36-mediated activation of the PI3K-Akt signaling pathway in frozen shoulder.

Frozen shoulder (FS) is characterized by pain and limited range of motion (ROM). Inflammation and fibrosis are accepted as main pathologic processes associated with the development of FS. However, the intrinsic mechanisms underlying pathologic fibrosis remain unclear. We aimed to elucidate the key molecules involved in pathologic fibrosis and explore new therapeutic targets for FS. Synovial fibroblasts isolated from patient biopsies were identified using immunofluorescence. Western blotting, RT-qPCR, cell adhesion tests, and would-healing assays were used to evaluate the fibrosis-related functions of synovial fibroblasts. Elevated cluster of differentiation 36 (CD36) expression was detected in FS using Western blotting and immunohistochemistry. Salvianolic acid b (SaB) inhibited CD36, blocking synovial fibroblast-induced inflammation and fibrosis. Our RNA-seq data showed that knocking down CD36 dramatically impaired the capacity of synovial fibroblasts for cell adhesion and that the PI3K-Akt signaling pathway may be crucial to the fibrotic process of FS. By up-regulating CD36 and inhibiting the phosphorylation of Akt, we demonstrated that CD36 promotes pathologic fibrosis by activating the PI3k-Akt pathway. Finally, rats treated with SaB had improved ROM and less collagen fiber deposition than the FS model group. Conclusion: SaB attenuates inflammation and inhibited the CD36-mediated activation of the PI3K-Akt signaling pathway to block pathologic fibrosis of FS in vitro and in vivo models.

The Longitude-Latitude-Loop Used for Complex Bankart Lesion Repair: An All-Arthroscopic Technique.

The most frequent operation for anterior shoulder instability is the arthroscopic Bankart repair, which has a positive outcome and a low rate of complications. A variety of restoration procedures have been reported to reconstruct labral height and reproduce a dynamic concavity-compression reaction. The longitude-latitude loop is a knotless high-strength suture method that simultaneously tightens the joint capsule in the warp and weft direction and resists tearing. The suture method is safe and reproducible. This study aimed to present a longitude-latitude loop suture for joint capsule labral complex repair during Bankart arthroscopy surgery.

Arthroscopic Autologous Coracoacromial Ligament Augment Technique for Particle Thickness of Rotator Cuff with at Least Two Years Follow-Up.

OBJECTIVE: Patch technology has been the new technique in the treatment of partial thickness of the rotator cuff tear (PTRCTs) to address the limitation of traditional techniques. Compared with allogeneic patches and artificial materials, coracoacromial ligament is obviously closer to their own biology. The purpose of the study was to evaluate the functional and radiographic outcomes following arthroscopic autologous coracoacromial ligament augment technique for treatment of PTRCTs. METHOD: This study included three female patients with PTRCTs who underwent arthroscopy operation in 2017 with an average age of 51 years (range from 50 to 52 years). The coracoacromial ligament implant was attached to the bursal side surface of the tendon. The clinical results were evaluated by American Shoulder and Elbow Surgeons (ASES) score, Simple Shoulder Test (SST), acromiohumeral distance (AHD) and muscle strength before and 12 months after operation. Magnetic resonance imaging (MRI) was performed 24 months after operation to assess the integrity of the anatomical structure of the original tear site. RESULT: The average ASES score improved significantly from 57.3 preoperatively to 95.0 at 1-year follow-up. The strength improved significantly from grade 3 preoperatively to grade 5 at 1 year. Two of three patients underwent the MRI at 2-year follow-up. Radiographic released the complete healing of rotator cuff tear. No implant-related serious adverse events were reported. CONCLUSION: The new technique of using autogenous coracoacromial ligament patch augment provides good clinical results on patients with PTRCTs.

Biomechanical Analysis of Lark-Loop, Lasso-Loop and Krackow Suture Technique in Tenodesis.

OBJECTIVE: Strong tendon grasping is vital to the success of a tenodesis operation. The purpose of this study was to evaluate the initial tendon-fixation strength of the Lark-Loop technique in arthroscopic suprapectoral biceps tenodesis and compare it with others commonly used techniques. METHODS: Thirty-three porcine superficial flexor digitorum tendons were harvested from a local slaughterhouse and randomly divided into three groups to perform three tendon fixation techniques (Lasso-Loop stich group, Lark-Loop stich group or Krackow stich group; 11 tendons each group) with a No. 2 suture, respectively. Each tendon was pre-tensioned in 5°N for 2 min and then cyclically loaded 5 to 30°N for 500 cycles to assess displacement. After cyclic loading, the tendon was loaded to ultimate tendon-suture configuration failure at the rate of 1 mm/s. Finally, the mode of failure and the construct stiffness of the tendon were recorded and calculated. RESULTS: After cyclical loading, the displacement of the Lark-Loop group was equivalent to the Krakow group (P > 0.9999) but significantly smaller than the Lasso-Loop group (P = 0.0009). The ultimate load to failure for the Lark-Loop was equivalent to the Krakow technique group (P = 0.1463) but significantly greater than the Lasso-Loop group (P < 0.0001). The stiffness for the Lark-Loop was equivalent to the Krakow group (P = 0.4718) but significantly greater than the Lasso-Loop technique group (P < 0.0001). In the Lark-Loop and Krackow group, all the tendons failed by suture breakage, while all the tendons failed by suture cutting through the tendon in the Lasso-Loop technique group. CONCLUSION: Lark-Loop suture technique has biomechanical properties comparable to Krackow and superior to the Lasso-Loop in terms of suture displacement, ultimate load to failure, and stiffness. Therefore, the Lark-Loop suture fixation technique may be beneficial for arthroscopic biceps tenodesis.

The Critical Shoulder Angle Can be Accurately and Reliably Determined from Three-Dimensional Computed Tomography Images.

OBJECTIVE: Anteroposterior (AP) radiographs do not necessarily offer the optimal approach to measuring the critical shoulder angle (CSA) due to the malposition of the scapula. Three-dimensional computed tomography (3D-CT) may offer some advantages, including the ability to rotate the scapula for position alignment and pre-operative planning for reducing CSA. This study aimed to investigate the accuracy and reliability of CSA measurement in 3D-CT and to determine whether there is an association between CSA and rotator cuff tears (RCTs). METHODS: In this retrospective study we identified 200 patients who received shoulder arthroscopy from 2019 to 2021, including 142 patients (81 females, 61 males) with RCTs and 58 patients (14 females, 44 males) with non-RCTs. For each participant, CSA was measured from standard shoulder AP radiographs and anterior views of 3D-CT of the scapula by two independent assessors. Inter- and intra-observer agreements were assessed by the intraclass correlation coefficient (ICC). The relationship between the two measurement methodologies was determined by Spearman's correlation coefficient and Bland-Altman plots. Discriminative capacity was calculated by using receiver operating curve (ROC) analyses in the whole cohort and age sub-groups above and below 45 years. RESULTS: We found perfect inter-observer (ICC >0.96) and intra-observer (ICC >0.97) reliabilities for CSA measurements obtained from the standard AP radiographs and the 3D-CT. There was a strong correlation between the two methods (r = 0.960, P < 0.001). The mean CSA was 31.7° ± 4.2° in the standard AP radiographs and 31.8° ± 4.4° in the 3D-CT (mean difference 0.02°, P = 0.940; bias 0.02°, limits of agreement -2.29° to +2.33°). ROC analysis of the whole cohort showed that the CSA measured in the standard AP radiographs (area under the ROC curve [AUC] = 0.812, P < 0.001) and the 3D-CT (AUC = 0.815, P < 0.001) predicted RCT with high confidence. ROC analysis of patients aged ≥45 years showed that the CSA measured from the standard AP radiographs (AUC = 0.869, P < 0.001) and the 3D-CT (AUC = 0.870, P < 0.001) were very good at predicting RCTs. CONCLUSION: CSA measured from standard AP radiographs and 3D-CT showed high consistency, and the CSA could be accurately and reliably measured using 3D-CT. CSAs measured from standard AP radiographs and 3D-CT could predict RCTs, especially in patients aged ≥45 years.

The high resistance loop (H-loop) technique used for all-inside arthroscopic knotless suprapectoral biceps tenodesis: A case series.

Introduction: Suprapectoral tenodesis is a common technique for the treatment of long head biceps tendon lesions. However, so far, there is no gold standard treatment in all-inside arthroscopy. The purpose of the present study was to introduce and evaluate the functional outcomes of an innovative, all-inside arthroscopic high resistance loop (H-loop, high resistance to tissue cutout and 360° grasping of the tendon) technique for long head of biceps (LHB) tenodesis. Method: From September 2020 to March 2022, a series of cases of 32 consecutive patients (28 rotator cuff tear with LHBT pathology and 4 superior labrum anterior-posterior (SLAP) tears which including 2 type II and 2 type IV) who received LHB tenodesis using all-inside arthroscopic high resistance loop technique were included in this study. The American Shoulder and Elbow Surgeon Score (ASES), Visual Analog Scale (VAS), Simple Shoulder Test Score (SST), Constant-Murley scores, and University of California at Los Angeles Scoring System (UCLA) were used to evaluate the clinical outcomes of patients in preoperative and final follow-up. Meanwhile, postoperative complications were also observed. Result: 32 patients (14 women and 18 men, average age was 55.7 years) underwent all-inside arthroscopic knotless suprapectoral biceps tenodesis using the H-Loop stitch technique. The mean time of follow-up was 16.2 ± 2.6 months. The ASES, VAS, Constant-Murley, SST, and UCLA scores improved from 51.5 ± 15.8, 5.5 ± 1.6, 57.8 ± 14.7, 5.0 ± 2.8, and 16.1 ± 3.8 preoperatively, to 89.1 ± 7.5, 1.0 ± 0.8, 87.3 ± 5.5, 10.4 ± 1.5, and 31.3 ± 2.6 in the last follow-up, respectively (p < 0.001). During the follow-up, no patients in this study experienced postoperative complications such as infection of the wound, injury of nerves, and hardware failure; no patients required revision after their operation. In addition, none of the patients had cramping or a "Popeye" deformity during follow-up. Conclusion: This article presents an innovative, all-arthroscopic H-loop technique for LHB tenodesis. This technique for LHB tenodesis showed favorable functional and cosmetic outcomes, as well as high satisfaction rates. Due to its simplicity of operation and satisfactory preliminary clinical outcomes, H-loop technique is perhaps another option to choose in all-inside arthroscopic LHB tenodesis.

The Lark Loop Used for Proximal Biceps Tenodesis: An All-Arthroscopic Technique.

Long head of the biceps tendinopathy is a common shoulder problem that is difficult to diagnose and treat. Biceps tenodesis is an effective surgical approach target for long head of the biceps tendon lesions. This article describes an all-arthroscopic proximal biceps tenodesis technique. This technique uses a high-strength suture to construct a tear-resistant loop; fixation is achieved with a suture anchor at the proximal aspect of the intertubercular groove or the greater tuberosity. This tenodesis fixation is simple, with no neurovascular injury or humeral fracture risk. In addition, our technique is cost-effective, with no need for specialty sutures.

Young's Modulus of Bilateral Infraspinatus Tendon Measured in Different Postures by Shear Wave Elastography Before and After Exercise.

OBJECTIVE: To investigate the Young's modulus value of infraspinatus tendons using shear wave elastography (SWE) technique in normal adults, and to analyze the influence of gender, postures, exercise, and dominant side on Young's modulus of infraspinatus tendons. METHODS: This is a prospective cross-sectional study. From January 2019 to July 2020, 14 healthy subjects were identified, including seven males and seven females aged between 24 to 34, with a mean age of 27.67 ± 3.08 years. The Young's modulus of their infraspinatus tendons was measured by two operators using SWE in neutral and maximum external rotation positions of both sides before exercise and the dominant side after exercise. The Young's modulus values in different sexes, different postures, before vs after exercise, and dominant vs non-dominant side were statistically analyzed. RESULTS: All 14 subjects completed the data collection process. The mean Young's modulus values of infraspinatus tendon for dominant sides in neutral position were 33.04 ± 3.01 kPa for males and 28.76 ± 3.09 kPa for females. And for non-dominant sides in the neutral position, the values were 33.02 ± 2.38 kPa for males and 28.86 ± 2.47 kPa for females. In the maximum external rotation position, the values for dominant sides were 50.19 ± 4.86 kPa for males and 42.79 ± 4.44 kPa for females, and for non-dominant sides were 50.95 ± 3.24 kPa for males and 42.42 ± 3.66 kPa for females. After exercise, the mean Young's modulus values of infraspinatus tendon for dominant sides in neutral position were 54.56 ± 3.76 kPa for males and 46.66 ± 5.99 kPa for females. And for the maximum external rotation position, the values were 59.13 ± 3.78 kPa for males and 54.49 ± 5.67 kPa for females. The Young's modulus of infraspinatus tendon in the neutral and maximum external rotation positions showed statistically significant differences in males and females, as well as before and after exercise (P < 0.05). However, the difference in Young's modulus between the dominant and non-dominant sides was not statistically significant (P > 0.05). Intergroup reliability between both operators was excellent (ICC > 0.85). CONCLUSION: There are gender-related differences and post-exercise increase in Young's modulus, yet such a difference cannot be witnessed between the dominant and non-dominant sides.

Nomograms for Prediction of Molecular Phenotypes in Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) patients with different molecular phenotypes, including microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and somatic mutations in BRAF and KRAS gene, vary in treatment response and prognosis. However, molecular phenotyping under adequate quality control in a community-based setting may be difficult. We aimed to build the nomograms based on easily accessible clinicopathological characteristics to predict molecular phenotypes. METHODS: Three hundred and six patients with pathologically confirmed stage I-IV CRC were included in the cohort. The assays for MSI, CIMP, and mutations in BRAF and KRAS gene were performed using resected tumor samples. The candidate predictors were identified from clinicopathological variables using multivariate Logistic regression analyses to construct the nomograms that could predict each molecular phenotype. RESULTS: The incidences of MSI, CIMP, BRAF mutation and KRAS mutation were 25.3% (72/285), 2.5% (7/270), 3.4% (10/293), and 34.8% (96/276) respectively. In the multivariate Logistic analysis, poor differentiation and high neutrophil/lymphocyte ratio (NLR) were independently associated with MSI; poor differentiation, high NLR and high carcinoembryonic antigen/tumor size ratio (CSR) were independently associated with CIMP; poor differentiation, lymphovascular invasion and high CSR were independently associated with BRAF mutation; poor differentiation, proximal tumor, mucinous tumor and high NLR were independently associated with KRAS mutation. Four nomograms for MSI, CIMP, BRAF mutation and KRAS mutation were developed based on these independent predictors, the C-indexes of which were 61.22% (95% CI: 60.28-62.16%), 95.57% (95% CI: 95.20-95.94%), 83.56% (95% CI: 81.54-85.58%), and 69.12% (95% CI: 68.30-69.94%) respectively. CONCLUSION: We established four nomograms using easily accessible variables that could well predict the presence of MSI, CIMP, BRAF mutation and KRAS mutation in CRC patients.