Elicitation of Inhibitory Effects for AGE-Induced Oxidative Stress in Rotator Cuff-Derived Cells by Apocynin.

Advanced glycation end-products (AGEs) play a critical supportive role during musculoskeletal disorders via glycosylation and oxidative stress. Though apocynin, identified as a potent and selective inhibitor of NADPH oxidase, has been reported to be involved in pathogen-induced reactive oxygen species (ROS), its role in age-related rotator cuff degeneration has not been well clarified. Therefore, this study aims to evaluate the in vitro effects of apocynin on human rotator cuff-derived cells. Twelve patients with rotator cuff tears (RCTs) participated in the study. Supraspinatus tendons from patients with RCTs were collected and cultured. After the preparation of RC-derived cells, they were divided into four groups (control group, control + apocynin group, AGEs group, AGEs + apocynin group), and gene marker expression, cell viability, and intracellular ROS production were evaluated. The gene expression of NOX, IL-6, and the receptor for AGEs (RAGE) was significantly decreased by apocynin. We also examined the effect of apocynin in vitro. The results showed that ROS induction and increasing apoptotic cells after treatment of AGEs were significantly decreased, and cell viability increased considerably. These results suggest that apocynin can effectively reduce AGE-induced oxidative stress by inhibiting NOX activation. Thus, apocynin is a potential prodrug in preventing degenerative changes of the rotor cuff.

Foveal Triangular Fibrocartilage Complex Tear Repair with Nonabsorbent Suture Tape.

PURPOSE: Arthroscopic repair is performed for fovea injuries of the triangular fibrocartilage complex (TFCC) when instability of the distal radioulnar joint results in pain, decreased grip strength, and mechanical symptoms. During TFCC repair, reconstruction of its attachment to the fovea is important. Nonabsorbent suture tapes have gained attention for ligament repair in the trapeziometacarpal joint, scapholunate ligament, and thumb metacarpophalangeal ligament. However, there are no reports of TFCC repair using suture tapes. We evaluated the early postoperative results of this approach. METHODS: Participants underwent arthroscopic suture tape repair of foveal TFCC tears and were observed for more than 1 year. All repairs were performed using suture tapes and an outside-in technique with a bone tunnel from the ulnar shaft to the fovea. The postoperative complications, postoperative wrist range of motion, grip strength, and the Modified Mayo Score were evaluated. RESULTS: Arthroscopic repair with a suture tape was performed for 20 hands using the outside-in technique. The ranges of motion for the operated and nonoperated hands were comparable 1 year after surgery (pronation, 84° ± 4°; supination, 83° ± 4°). The mean grip strength improved from 65% ± 13% before surgery to 89% ± 9% after a year. The mean Modified Mayo Score improved from 58 ± 11 before surgery to 91 ± 8 after a year. Postoperative complications included abnormal sensation of the dorsal ulnar side in 2 hands. CONCLUSIONS: After using a suture tape to attach the TFCC to the fovea, satisfactory function was achieved in the early postoperative period with grip strength restoration. For the repair of foveal TFCC tears, attachment to the ulnar fovea is important, and repair by a suture tape may be useful. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Degree of Accuracy With Which Deep Learning for Ultrasound Images Identifies Osteochondritis Dissecans of the Humeral Capitellum.

BACKGROUND: Medical screening using ultrasonography (US) has been performed on young baseball players for early detection of osteochondritis dissecans (OCD) of the humeral capitellum. Deep learning (DL) and artificial intelligence (AI) techniques are widely adopted in the medical imaging research field. PURPOSE/HYPOTHESIS: The purpose of this study was to calculate the diagnostic accuracy using DL for US images of OCD. We hypothesized that using DL for US imaging would improve the prediction accuracy of OCD. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 2. METHODS: A total of 40 elbows (mean age of patients, 12.1 years) that were suspected of having OCD at a medical checkup and later confirmed by radiographs and magnetic resonance imaging were included in the study. The affected elbows were used as the OCD group and the contralateral elbows as the control group. From US videos, 100 images per elbow were captured from different angles, and 4000 images of the elbows were prepared for both groups. Of these, 80% were randomly selected by DL models and used as training data; the remaining were used as test data. Transfer learning was conducted using 3 pretrained DL models. The confusion matrix and the area under the receiver operating characteristic curve (AUC) were used to evaluate the model, and the visualization of the areas deemed important by the DL models was also performed. Furthermore, OCD regions were detected using an automatic image recognition model based on DL. RESULTS: Classification of the OCD image by the DL model was performed; the best accuracy score was 0.87; the recall was 1.00. AUC was high for all DL models. Visualization of important features showed that AI predicted the presence of OCD by focusing on the irregularity or discontinuity of the surface of subchondral bone. In the detection of OCD task, the mean average precision was 0.83. CONCLUSION: The DL on US images identified OCD with high accuracy. The important features detected by the DL models correspond to the areas used by clinicians in screening the US images. The OCD was also detected with high accuracy using the object detection model. The AI model may be used in medical screening for OCD.

Total knee arthroplasty for severe valgus deformity of the knee with extra-articular deformities of the femur and tibia using a 3-dimensional image matching software system.

INTRODUCTION AND IMPORTANCE: Knee osteoarthritis with femoral and/or tibial extra-articular deformities makes total knee arthroplasty (TKA) technically difficult to perform, especially using intramedullary-based instrumentation systems. The Athena Knee 3-dimensional (3-D) image matching software is effective for TKA with an extra-articular deformity, especially in case of using a long-stem prosthesis or not available computer-assisted navigation systems. CASE PRESENTATION: A 79-year-old woman presented with right knee pain secondary to a progressive valgus deformity and gait disturbance. She had experienced a supracondylar femoral fracture fifteen years ago, and a tibial shaft fracture ten years ago on the same side; both of fractures were treated surgically. She had a severe valgus knee deformity and extra-articular deformity of femur and tibia, and valgus stress test detected medial knee instability. The range of motion was 0° in extension and 75° in flexion. Severe medial knee laxity compelled us to use a constrained and long-stem prosthesis, resulting in the use of an intramedullary guided system. The 3-D software system helped us to determine the amount of bone to cut as well as the appropriate entry points for the intramedullary rods and mechanical axis restoration. At two years after surgery, knee range of motion improved to 90° in flexion, and walking ability had also advanced from the use of two crutches to that of a T cane. CONCLUSION: The 3-D image matching software system for preoperative planning was useful for TKA with extra-articular deformity, especially in the case of a long-stem prosthesis without using a navigation system.

Sex Is Associated with the Success or Failure of Manipulation Alone for Joint Stiffness Associated with Rotator Cuff Repair.

Purpose: One-stage arthroscopic rotator cuff repair with manipulation has been recently performed for rotator cuff tears with shoulder stiffness, whereas some patients require capsular release due to severe stiffness that is difficult to treat with manipulation. The purpose of this study was to analyze patient backgrounds and related factors of success or failure of manipulation alone for the treatment of shoulder stiffness associated with rotator cuff tears. Methods: This study included 64 patients with rotator cuff tears and shoulder stiffness who underwent arthroscopic rotator cuff repair with manipulation alone or with manipulation and capsular release of the glenohumeral joint at our institution between January 2015 and September 2019. The patients were divided into two groups: those whose shoulder stiffness could be improved by manipulation alone (Manipulation group) and those whose stiffness could not be improved by manipulation alone and required capsular release (Capsular release addition group). Analysis was performed between the two groups regarding patient backgrounds and related factors, including rotator cuff tear morphology and range of motions pre- and postoperatively. Results: Exactly 45 patients and 19 patients were included in Manipulation group and Capsular release addition group, respectively. A comparison between the two groups showed that patient age (p = 0.0040), sex (p = 0.0005), and injury due to trauma (p = 0.0018) were significantly related to the success or failure of manipulation alone. Multivariate logistic regression analysis on these three factors showed that sex (odds ratio, 5.5; p = 0.048) was significantly associated with the success or failure of manipulation alone. In both groups, the passive ROM of all patients improved at the last postoperative follow-up compared to their pre-operative values (p < 0.001), except for internal rotation in the Capsular release addition group (p = 0.49). Conclusion: Young male patients who have shoulder stiffness associated with rotator cuff tears should be considered for arthroscopic capsular release rather than manipulation.

Assessment of the Ulnar Collateral Ligament of the Elbow Using Ultrasonic Shear Wave Elastography in Professional Baseball Players.

Background: Injury to the ulnar collateral ligament (UCL) of the elbow can cause chronic pain and loss of throwing ability. Ultrasonic shear wave elastography (SWE) is a new imaging method that can be used for quantitative assessment of tissue elasticity. Purpose: To evaluate the properties of the UCL in professional baseball players using SWE. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This study included 35 professional baseball players (mean age, 23.0 years) without elbow injuries. Both elbows of each player were examined using ultrasound, and comparisons between the dominant and nondominant arms were conducted. The thickness of the anterior bundle of the UCL at its midportion was measured in the resting position on ultrasound. We also measured the difference in the ulnohumeral joint space with and without gravity stress on the forearm. Tissue elasticity was evaluated using a built-in software program. The relationship between UCL elasticity and ultrasound findings was analyzed using the Pearson correlation coefficient. Results: The mean ± SD thickness of the UCL was significantly greater in the dominant arm versus the nondominant arm (6.0 ± 1.4 vs 5.3 ± 1.3 mm; P = .004). The mean joint space difference was significantly wider in the dominant arm as compared with the nondominant arm (0.81 ± 0.42 vs 0.52 ± 0.31 mm; P = .002), and the mean UCL elasticity was lower in the dominant arm than in the nondominant arm (34.9 ± 11.6 vs 43.3 ± 10.6 kPa; P = .002). UCL elasticity was negatively correlated with UCL thickness (r = -0.27; P = .02) and joint space difference (r = -0.34; P = .003). Conclusion: In professional baseball players, the elbow UCL of the dominant arm demonstrated increased thickness, with a larger joint space gap on gravity stress and lower elasticity in SWE as compared with the nondominant arm. Greater medial joint laxity can be predicted by assessing the elasticity of the UCL using SWE.

Efficacy of Abductor Pollicis Longus Suspension Arthroplasty Combined With Mini TightRope for Osteoarthritis of Thumb Carpometacarpal Joint.

BACKGROUND: We aimed to evaluate the efficacy of abductor pollicis longus (APL) suspension arthroplasty with trapeziectomy combined with first and second metacarpal fixation using suture button device. METHODS: Thirteen patients (14 thumbs) who underwent APL suspension arthroplasty combined with suture button device for osteoarthritis of the carpometacarpal joint of the thumb (Eaton grade III: 6 and IV: 8 thumbs) at our institution between 2015 and 2019 and were followed up for more than 24 months were included in the study. Preoperative and postoperative range of motion (ROM) of radial and palmar abduction, grip and key pinch strength, visual analog scale (VAS) scores for pain, and the trapezial space ratio (TSR) on radiographic images before and after surgery were statistically examined. RESULTS: The mean age of the patients was 59.6 ± 8.1 years, and the mean follow-up period was 45.4 ± 12.2 months. While grip and pinch strength did not significantly change between preoperative and final follow-up measurements, the ROM of radial and palmar abduction and the VAS score at the latest follow-up were significantly better than the preoperative values (P < .05). The mean TSR immediately after surgery and at the latest follow-up was 0.28 ± 0.089 and 0.22 ± 0.084, respectively, indicating a mean reduction rate of 23.3 ± 15.2%. CONCLUSIONS: This surgical technique showed significant improvement in the ROM of radial and palmar abduction and the VAS score for pain, and the combined fixation of the first and second metacarpals with suture button device suppressed the subsidence of the first metacarpal.

Novel therapy using a fish scale collagen scaffold for rotator cuff healing in rat models.

BACKGROUND: Large and massive rotator cuff tears are challenging for surgeons because of postoperative complications such as repaired site retears. Recently, collagen extracted from fish scales has gained more attention because fish byproducts are considered a safer collagen source than other animal-derived scaffolds. This study aimed to evaluate the biological efficacy of tilapia scale-derived collagen scaffolds for rotator cuff repair in rat models. METHODS: The infraspinatus tendon was resected from the greater tuberosity of Sprague-Dawley rats. In the control group, the tendon edge was sutured directly to the humeral head. In the augmentation group, the repaired site was augmented with a tilapia scale-derived collagen scaffold. Histologic examinations were performed at 2 and 4 weeks postoperatively via safranin O and immunofluorescence staining (isolectin B4 and type II collagen) in the bone-tendon junction. For mechanical analysis, the ultimate failure load of the tendon-humeral head complex was evaluated at 6 weeks postoperatively. RESULTS: During safranin O staining, the repaired enthesis demonstrated greater proteoglycan staining in the augmentation group than in the control group at 4 weeks postoperatively. Compared to controls, the augmentation group had significantly higher vascular staining with isolectin B4 at 2 and 4 weeks postoperatively, type II collagen expression at 4 weeks postoperatively, and ultimate failure load at 6 weeks postoperatively. CONCLUSION: Augmentation therapy using tilapia scale-derived type I collagen scaffolds promoted angiogenesis and fibrocartilage regeneration at the enthesis and provided higher mechanical strength than controls.

Using deep learning for ultrasound images to diagnose carpal tunnel syndrome with high accuracy.

Recently, deep learning (DL) algorithms have been adapted for the diagnosis of medical images. The purpose of this study was to detect image features using DL without measuring median nerve cross-sectional area (CSA) in ultrasonography (US) images of carpal tunnel syndrome (CTS) and calculate the diagnostic accuracy from the confusion matrix obtained. US images of 50 hands without CTS and 50 hands diagnosed with CTS were used in this study. The short-axis image of the median nerve was visualized, and 5000 images of both groups were prepared. Forty hands in each group were used as training data for the DL algorithm, while the remainder were used as test data. Transfer learning was performed using three pre-trained models. The confusion matrix and receiver operating characteristic curves were used to evaluate diagnostic accuracy. Furthermore, regions where DL was determined to be important were visualized. The highest score had an accuracy of 0.96, precision of 0.99 and recall of 0.94. Visualization of the important features revealed that the DL models focused on the epineurium of the median nerve and the surrounding soft tissue. The proposed technique enables the accurate prediction of CTS without measurement of the CSA.

Quercetin treatment protects the Achilles tendons of rats from oxidative stress induced by hyperglycemia.

BACKGROUND: Quercetin, a flavonoid abundantly in vegetables and fruits, exerts antioxidant and anti-inflammatory effects. We investigated the protective effects of quercetin against oxidative stress in the Achilles tendons of diabetic rats. METHODS: Cells were collected from the Achilles tendons of Sprague-Dawley rats and cultured under four conditions: regular glucose (RG) without quercetin (Quer-), RG with quercetin (Quer +), high-glucose (HG) Quer-, and HG Quer + . The expression of genes related to NADPH oxidase (NOX) and inflammation, reactive oxygen species accumulation, and apoptosis rates was analyzed. Additionally, diabetic rats were divided into two groups and subjected to quercetin (group Q) or no quercetin (group C) treatment. Histological evaluation and expression analysis of relevant genes in the Achilles tendon were performed. RESULTS: In rat tendon-derived cells, the expression of Nox1, Nox4, and Il6; reactive oxygen species accumulation; and apoptosis rates were significantly decreased by quercetin treatment in the HG group. The collagen fiber arrangement was significantly disorganized in the diabetic rat Achilles tendons in group C compared with that in group Q. The mRNA and protein expression levels of NOX1 and NOX4 were significantly decreased upon quercetin treatment. Furthermore, the expression of Il6, type III collagen, Mmp2, and Timp2 was significantly decreased, whereas that of type I collagen was significantly increased in group Q compared with that in group C. CONCLUSIONS: Quercetin treatment decreases NOX expression and thus exerts antioxidant and anti-inflammatory effects in the Achilles tendons of diabetic rats. Quercetin treatment may be effective against diabetic tendinopathy.

Biochemical Markers of Aging (Advanced Glycation End Products) and Degeneration Are Increased in Type 3 Rotator Cuff Tendon Stumps With Increased Signal Intensity Changes on MRI.

BACKGROUND: Advanced glycation end products (AGEs) are end products of protein glycation that bind to the receptor for AGEs (RAGE) and activate nicotinamide adenine dinucleotide phosphate oxidase (NOX), resulting in increased oxidative stress and rotator cuff fragility. Stump classification using the signal intensity ratio of the tendon rupture site to the deltoid muscle in the coronal view of T2-weighted fat-suppressed magnetic resonance imaging (MRI) scans is an indicator of clinical outcomes after rotator cuff repair surgery. Comparing the signal intensities of the deltoid (D) and rotator cuff tears (C), Ishitani et al. classified C/D <0.8 as type 1, 0.8 to 1.3 as type 2, and >1.3 as type 3. HYPOTHESIS/PURPOSE: It was hypothesized that the oxidative stress and collagen degeneration that occur in the rotator cuff due to accumulation of AGEs can be assessed on MRI scans (stump classification). Therefore, this study aimed to compare AGE-related factors in the rotator cuff tear site tissues based on stump classification. STUDY DESIGN: Descriptive laboratory study. METHODS: The authors included 30 patients (11 with type 1, 9 with type 2, and 10 with type 3; mean age, 62.3 years) who underwent surgery for complete rotator cuff tears at our hospital. Tendon tissue was harvested from the torn rotator cuff site during surgery for tissue and cell evaluation. RESULTS: There was no significant difference in the mean age according to stump classification. The number of patients with diabetes was significantly larger in type 3 than in the other types (P < .05). Tissue evaluation showed significantly higher expression of AGE and RAGE staining in type 3 than in the other types (~6.7-fold; P < .01). Cell evaluation showed that the expression rates of reactive oxygen species and apoptosis were significantly higher in type 3 than in the other types (~4.3-fold; P < .01). Gene expression by real-time polymerase chain reaction showed significantly higher RAGE (~5.1-fold), NOX (~5.3-fold), and IL (~3.0-fold) in type 3 than in the other types (P < .05). CONCLUSION: Stump classification type 3 exhibited the highest accumulation of AGEs and the highest oxidative stress and apoptosis, suggesting a high degree of degeneration and inflammation. Imaging based on stump classification reflects the degeneration and fragility of the torn rotator cuff site. CLINICAL RELEVANCE: This study provides evidence of a relationship between stump classification, which reflects rotator cuff fragility on MRI, and pathologies related to advanced glycation end products.

Influence of Diabetes-Induced Glycation and Oxidative Stress on the Human Rotator Cuff.

Most shoulder rotator cuff tears (RCTs) are caused by non-traumatic age-related rotator cuff degeneration, of which hyperglycemia is a risk factor due to its glycation reaction and oxidative stress. We aimed to identify the influence of diabetes-induced glycation and oxidative stress in patients with non-traumatic shoulder RCTs. Twenty patients, aged over 50 years, with non-traumatic shoulder RCTs participated in this study. Patients with a history of diabetes mellitus or preoperative HbA1c ≥ 6.5% were assigned to the diabetic group (n = 10), and the rest to the non-diabetic group (n = 10). Cell proliferation; expression of genes related to oxidative stress, glycation reaction, inflammation, and collagen; intracellular reactive oxygen species (ROS) levels; and apoptosis rates were analyzed. The diabetic group had significantly lower cell proliferation than the non-diabetic group. In the diabetic group, the mRNA expression levels of NOX1, NOX4, IL6, RAGE, type III collagen, MMP2, TIMP1, and TIMP2 were significantly higher; type I collagen expression was significantly lower; and the rate of ROS-positive cells and apoptotic cells, as well as the expression of advanced glycation end-products (AGEs) and the receptor for AGEs (RAGE), was significantly higher. In conclusion, hyperglycemia caused by diabetes mellitus increased AGE and RAGE expression, and led to increased NOX expression, ROS production, and apoptosis in the human rotator cuff. This provides scope to find a preventive treatment for non-traumatic RCTs by inhibiting glycation and oxidative stress.

Ultrasound With Artificial Intelligence Models Predicted Palmer 1B Triangular Fibrocartilage Complex Injuries.

PURPOSE: To calculate the diagnostic accuracy from the confusion matrix using deep learning (DL) on ultrasound (US) images of Palmer 1B triangular fibrocartilage complex (TFCC) injury. METHODS: Twenty-nine wrists of 15 healthy volunteers (11 men; mean age, 34.9 years ± 9.7) (control group) and 20 wrists of 17 patients (11 men; mean age 41.0 years ± 12.2) with TFCC injury (Palmer type IB) (injury group) were included in the study. The diagnosis of Palmer 1B TFCC injury was made using magnetic resonance imaging, computed tomography arthrography, and intraoperative arthroscopic findings. In total, 2,000 images were provided to each group, 80% of which were randomly selected by AI and used as training data; the remaining data were used as test data. Transfer learning was conducted using a pretrained 3 separate models (GoogLeNet, ResNet50, ResNet101). Model evaluation was performed using a confusion matrix. The area under a receiver operating characteristic curve was also calculated. The occlusion sensitivity was used to visualize the important features. RESULTS: For the prediction of TFCC injury by the DL model, the best score of accuracy was 0.85 in GoogLeNet, a recall was 1.0 in ResNet50 and ResNet101, and a specificity was 0.78 in GoogLeNet. In predicting the TFCC injury for the test data, the best score of the AUC was 0.97 on ResNet101. Visualization of important features showed that AI predicted the presence of injury by focusing on the morphology of the articular disc. CONCLUSIONS: US images using the DL model predicted Palmer 1B TFCC injury with high accuracy, with the best scores of 0.85 for accuracy on GoogLeNet, 1.00 for sensitivity on ResNet50 and ResNet101, and 0.78 for specificity on GoogLeNet. The use of DL for US imaging of Palmer 1B TFCC injury predicted the injury as well as magnetic resonance imaging and computed tomography arthrography LEVEL OF EVIDENCE: IV; retrospective case series study.

Antioxidant effect of nicotinamide mononucleotide in tendinopathy.

BACKGROUND: A link between tendinopathy and oxidative stress has been recently reported. Nicotinamide mononucleotide (NMN) is a precursor of nicotinamide adenine dinucleotide, which plays an important role in cell redox homeostasis. The aim of this study was to evaluate the antioxidant effect of NMN on tendinopathy in vitro and in vivo. METHODS: Tenocytes from healthy Sprague-Dawley rats were cultured in regular glucose (RG) and high-glucose (HG) conditions with or without NMN, and were divided into four groups: RG NMN(-), RG NMN(+), HG NMN(-), and HG NMN(+). Cell viability, reactive oxygen species (ROS) accumulation, apoptotic rate, and mRNA expression of nicotinamide adenine dinucleotide phosphate oxidase (NOX)1, NOX4, interleukin (IL)6, sirtuin (SIRT)1, and SIRT6 were investigated. In addition, rats with collagenase-induced tendinopathy were treated with or without NMN. Immunostaining of NOX1 and NOX4; mRNA expression of SIRT1, SIRT6, and IL6; and superoxide dismutase (SOD) activity measurements in the Achilles tendon were performed. RESULTS: NMN increased the expression of SIRT1 and SIRT6 in rat tenocytes, but decreased the levels of NOX1, NOX4, IL6, ROS, and apoptosis. In Achilles tendons with collagenase-induced tendinopathy, NMN increased the mRNA expression of SIRT1 and SIRT6, as well as SOD activity; while suppressing protein expression of NOX1 and NOX4, and mRNA expression of IL6. CONCLUSION: The in vitro and in vivo results of this study show that NMN exerts an antioxidant effect on tendinopathy by promoting the expression of SIRT while inhibiting that of NOX.

Advanced glycation end products are associated with limited range of motion of the shoulder joint in patients with rotator cuff tears associated with diabetes mellitus.

BACKGROUND: Most degenerative rotator cuff tears (RCTs) are associated with a limited range of motion (ROM) of the shoulder joint. Additionally, patients with diabetes mellitus (DM) show a higher frequency of limited ROM. Recently, advanced glycation end products (AGEs) of proteins have been observed to cause tissue fibrosis, primarily through abnormal collagen cross-linking and oxidative stress. In this study, we investigated the effect of AGEs on ROM limitation in the shoulder capsule and its relationship with DM in the patients with RCTs. METHODS: Sixteen patients (eight in the DM and non-DM groups) who underwent arthroscopic surgery for RCT with limited shoulder ROM were included in this study. AGE-related pathologies in both groups were compared, and the relationship between AGE accumulation and shoulder joint ROM was evaluated. Shoulder capsule tissue was harvested and subjected to histological and in vitro evaluation. RESULTS: The DM group displayed high levels of AGEs and reactive oxygen species (ROS), and reduced cell viability. There was a significant positive correlation between ROS expression, apoptosis, and preoperative hemoglobin A1c. ROS expression, apoptosis, and ROM of the shoulder joint showed a negative correlation. The NADPH oxidase (NOX) expression and collagen III/I ratio were significantly higher in the DM group than in the non-DM group. CONCLUSIONS: The DM group showed significant AGEs deposition in the shoulder capsule. Additionally, there was a significant association between AGEs and ROM limitation. Collectively, the findings suggest that the oxidative stress induced by AGEs deposition, which leads to fibrosis and local inflammation, might contribute to the limited ROM of the shoulder joint in patients with RCTs accompanied by DM.

Diagnosis of Cubital Tunnel Syndrome Using Deep Learning on Ultrasonographic Images.

Although electromyography is the routine diagnostic method for cubital tunnel syndrome (CuTS), imaging diagnosis by measuring cross-sectional area (CSA) with ultrasonography (US) has also been attempted in recent years. In this study, deep learning (DL), an artificial intelligence (AI) method, was used on US images, and its diagnostic performance for detecting CuTS was investigated. Elbow images of 30 healthy volunteers and 30 patients diagnosed with CuTS were used. Three thousand US images were prepared per each group to visualize the short axis of the ulnar nerve. Transfer learning was performed on 5000 randomly selected training images using three pre-trained models, and the remaining images were used for testing. The model was evaluated by analyzing a confusion matrix and the area under the receiver operating characteristic curve. Occlusion sensitivity and locally interpretable model-agnostic explanations were used to visualize the features deemed important by the AI. The highest score had an accuracy of 0.90, a precision of 0.86, a recall of 1.00, and an F-measure of 0.92. Visualization results show that the DL models focused on the epineurium of the ulnar nerve and the surrounding soft tissue. The proposed technique enables the accurate prediction of CuTS without the need to measure CSA.

Motion Analysis of Triangular Fibrocartilage Complex by Using Ultrasonography Images: Preliminary Analysis.

The triangular fibrocartilage complex (TFCC) is a significant stabilizer of the distal radioulnar joint. Diagnosing TFCC injury is currently difficult, but ultrasonography (US) has emerged as a low-cost, minimally invasive diagnostic tool. We aimed to quantitatively analyze TFCC by performing motion analysis by using US. Twelve healthy volunteers, comprising 24 wrists (control group), and 15 patients with TFCC Palmer type 1B injuries (injury group) participated. The US transducer was positioned between the ulnar styloid process and triquetrum and was tilted ulnarly 30° from the vertical line. The wrist was then actively moved from 10° of radial deviation to 20° of ulnar deviation in a 60-rounds-per-minute rhythm that was paced by a metronome. The articular disc displacement velocity magnitude was analyzed by using particle image velocimetry fluid measurement software. The mean area of the articular discs was larger on ulnar deviation in the control group. The mean articular disc area on radial deviation was larger in the injury group. The average articular disc velocity magnitude for the injury group was significantly higher than that for the control group. The results suggest that patients with TFCC injury lose articular disc cushioning and static stability, and subsequent abnormal motion can be analyzed by using US.

Accuracy and reliability of tridimensional electromagnetic sensor system for elbow ROM measurement.

BACKGROUND: While the precise measurement of the range of motion (ROM) of the elbow joint is important for clinical assessment and rehabilitation, problems include low accuracy and reproducibility in goniometer measurements due to the influence of soft tissue. The purpose of this study was to validate elbow joint motion analysis using a three-dimensional electromagnetic sensor system (EMS). METHODS: The accuracy and reproducibility of the EMS system were evaluated at four angles (0°, 45°, 90°, and 135°) using a model bone of the humerus and forearm. In addition, the maximum extension and maximum flexion of six elbows of six healthy volunteers were assessed by radiographic and EMS measurements. Accuracy was assessed by calculating the mean value of the measurement angle, standard deviation, Pearson's correlation coefficient, and the Bland-Altman method. Reproducibility was assessed by calculating the intra-rater and inter-rater reliabilities using intraclass correlation coefficients. RESULTS: In the model bone evaluation, the mean angles of the EMS measurement were 1.2° ± 2.0°, 45.4° ± 2.1°, 91.7° ± 2.4°, and 134.6° ± 2.7° at 0°, 45°, 90°, and 135°, respectively. In the in vivo evaluation, the elbow angles at the maximum extension with the EMS and radiographic angles were 4.7° ± 3.0° and 2.7° ± 2.0°, respectively, and the angles at maximum flexion were 131.8° ± 13.0° and 130.8° ± 4.5°, respectively. There were statistically significant correlations between the EMS and radiographic measurements; the Bland-Altman plots indicated that the two methods were almost in agreement for both extension and flexion. CONCLUSIONS: This method of measuring ROM of the elbow joint using EMS showed high accuracy, reliability, and reproducibility. The current results demonstrated the possibility of using the electromagnetic system to provide an accurate evaluation of the elbow joint in clinical settings.

Influence of adiponectin and inflammatory cytokines in fatty degenerative atrophic muscle.

Tendon rupture and nerve injury cause fatty infiltration of the skeletal muscle, and the adipokines secreted from the infiltrated adipocytes are known to contribute to chronic inflammation. Therefore, in this study, we evaluated the effects of the adipokines on chronic inflammation using a rat sciatic nerve-crushed injury model. In vitro and in vivo experiments showed that the expression of adiponectin was decreased (0.3-fold) and the expression of Il6 (~ 3.8-fold) and Tnf (~ 6.2-fold) was increased in the nerve-crushed group compared to that in the control group. It was also observed that the administration of an adiponectin receptor agonist decreased the levels of Il6 (0.38-fold) and Tnf (0.28-fold) and improved cellular viability (~ 1.9-fold) in vitro. Additionally, in the fatty infiltrated skeletal muscle, low adiponectin levels were found to be associated with chronic inflammation. Therefore, the local administration of adiponectin receptor agonists would prevent chronic inflammation.