Estimating the Thumb Rotation Angle by Using a Tablet Device With a Posture Estimation Artificial Intelligence Model.

MediaPipe Hand (MediaPipe) is an artificial intelligence (AI)-based pose estimation library. In this study, MediaPipe was combined with four machine learning (ML) models to estimate the rotation angle of the thumb. Videos of the right hands of 15 healthy volunteers were recorded and processed into 9000 images. The rotation angle of the thumb (defined as angle θ from the palmar plane, which is defined as 0°) was measured using an angle measuring device, expressed in a radian system. Angle θ was then estimated by the ML model by using parameters calculated from the hand coordinates detected by MediaPipe. The linear regression model showed a root mean square error (RMSE) of 12.23, a mean absolute error (MAE) of 9.9, and a correlation coefficient of 0.91. The ElasticNet model showed an RMSE of 12.23, an MAE of 9.95, and a correlation coefficient of 0.91; the support vector machine (SVM) model showed an RMSE of 4.7, an MAE of 2.5, and a correlation coefficient of 0.99. The LightGBM model achieved high values: an RMSE of 4.58, an MAE of 2.62, and a correlation coefficient of 0.99. Based on these findings, we concluded that the thumb rotation angle can be estimated with high accuracy by combining MediaPipe and ML.

Estimation of Shoulder Joint Rotation Angle Using Tablet Device and Pose Estimation Artificial Intelligence Model.

Traditionally, angle measurements have been performed using a goniometer, but the complex motion of shoulder movement has made these measurements intricate. The angle of rotation of the shoulder is particularly difficult to measure from an upright position because of the complicated base and moving axes. In this study, we attempted to estimate the shoulder joint internal/external rotation angle using the combination of pose estimation artificial intelligence (AI) and a machine learning model. Videos of the right shoulder of 10 healthy volunteers (10 males, mean age 37.7 years, mean height 168.3 cm, mean weight 72.7 kg, mean BMI 25.6) were recorded and processed into 10,608 images. Parameters were created using the coordinates measured from the posture estimation AI, and these were used to train the machine learning model. The measured values from the smartphone's angle device were used as the true values to create a machine learning model. When measuring the parameters at each angle, we compared the performance of the machine learning model using both linear regression and Light GBM. When the pose estimation AI was trained using linear regression, a correlation coefficient of 0.971 was achieved, with a mean absolute error (MAE) of 5.778. When trained with Light GBM, the correlation coefficient was 0.999 and the MAE was 0.945. This method enables the estimation of internal and external rotation angles from a direct-facing position. This approach is considered to be valuable for analyzing motor movements during sports and rehabilitation.

Treatment of Osteoporosis in Men on Androgen Deprivation Therapy in Japan.

Background and Objectives: Androgen deprivation therapy (ADT) for prostate cancer has greatly improved treatment outcomes. As patient survival rates have increased, reports of decreased bone density and increased bone fractures as side effects of ADT have emerged. The prevalence of osteoporosis in Japanese men was 4.6%. The purpose of this study was to evaluate the effect of osteoporosis treatment in prostate cancer patients who underwent ADT in Japan. Materials and Methods: The subjects were 33 male patients who had undergone ADT for prostate cancer, who were noted to have decreased bone density. Mean age was 76.2 ± 7.7 years (64-87). Medications included vitamin D in one case, bisphosphonates (BP) in 27 cases, and denosumab in five cases. The evaluation method examined the rate of change in bone mineral density (BMD) before osteoporosis treatment and 1 year after. For comparison, a group without osteoporosis treatment intervention (n = 33) was selected, and matched for prostate cancer treatment and age. The rate of change in trabecular bone score (TBS) was also calculated. Results: The percentage changes in BMD before and 1 year after treatment were as follows: lumbar spine, 7.1 ± 5.8% in the treatment group versus -3.9 ± 4.1% in the no treatment group; femoral neck, 5.5 ± 6.2% in the treatment group versus -0.9 ± 3.9% in the no treatment group; total femur, 6.6 ± 6.4% in the treatment group versus the no treatment group which was -1.7 ± 3.2%. In all cases, there was a clear significant difference (p < 0.01). The percent change in TBS was further calculated in the same manner. There was no significant difference between the two groups: +1.7 ± 3.8% in the treated group versus +0.3 ± 4.1% in the untreated group. Conclusions: Osteoporosis treatment in Japanese patients with prostate cancer on ADT therapy was found to significantly increase BMD compared to the untreated group. BP and denosumab were found to be very effective in increasing BMD.

Lateral Collateral Ligament Reconstruction Using the Triceps Brachii Fascia for Posterolateral Rotatory Instability in Cubitus Varus: A Report of Two Cases.

A combination of osteotomy and ligament reconstruction is recommended for posterolateral rotatory instability (PLRI) with large cubitus varus deformities. There is a lack of reports regarding ligament donor selection for ligament reconstruction of PLRI with cubitus varus. Two cases of PLRI with cubitus varus have been described. In case one, a 40-year-old woman presented with left elbow pain. She had a cubitus varus deformity, resulting from a childhood elbow fracture. Radiographs showed an 18-degree cubitus varus deformity. A lateral closing wedge osteotomy and double plate osteosynthesis were performed. The lateral collateral ligament (LCL) was reconstructed with autologous triceps fascia. Postoperative radiographs confirmed correction with 10 degrees of the carrying angle (CA). Bone union at the osteotomy site occurred six months later with excellent results. In case two, a 45-year-old man presented an arm with persistent right elbow instability with cubitus varus deformity. This was due to a childhood supracondylar fracture of the right humerus. Radiographs showed a cubitus varus deformity of 25 degrees on the right. The surgical procedure included a lateral wedge osteotomy, double plate fixation, and LCL reconstruction with autologous triceps fascia. Postoperative radiographs confirmed a corrected CA of 5 degrees. Bone union was achieved at the six-month follow-up with satisfactory results. The use of triceps fascia for LCL reconstruction for PLRI due to cubitus varus would provide a minimally invasive and reasonable treatment option.

Clinical outcomes of medialized single-row repair with fascia lata graft augmentation for large and massive rotator cuff tears.

BACKGROUND: A high postoperative retear rate after arthroscopic rotator cuff repair (ARCR) of large and massive tears remains a problem. This study evaluated rotator cuff integrity after ARCR with fascia lata graft augmentation for large and massive rotator cuff tears and compared clinical outcomes between patients with intact repairs and retears. METHODS: Forty-five patients with rotator cuff tears who could not undergo primary repair due to tendon retraction underwent arthroscopic medialized single-row repair with fascia lata graft augmentation. The patients' minimum follow-up was 2 (2-9) years. Supraspinatus cuff integrity was evaluated postoperatively by magnetic resonance imaging. We compared the clinical outcomes of patients with intact repairs vs. retears based on the University of California-Los Angeles (UCLA), Constant, and Japanese Orthopaedic Association (JOA) scores. We also evaluated their range of motion (ROM) and muscle strength. RESULTS: Retears were observed in 11 of 45 patients. UCLA, Constant, and JOA scores significantly improved postoperatively compared to preoperatively in the intact repair (all P < .001) and retear (all P < .036) groups. The intact repair group had significantly higher Constant (75.6 [mean] ± 9.9 [SD] vs. 69.8 ± 7.9; P = .026) and JOA (94.4 ± 6.9 vs. 89.8 ± 5.9; P = .041) scores than the retear group. Forward elevation, abduction, and the strengths of abduction and external rotation significantly improved in the intact repair group (all P < .003) but not in the retear group (all P > .05). The intact repair group had significantly higher postoperative forward flexion (165° ± 15° vs. 154° ± 23°; P = .036), abduction (164° ± 17° vs. 151° ± 26°; P = .029), and abduction strength (3.5 ± 2.2 kg vs. 2.3 ± 1.2 kg; P = .017) than the retear group. In the intact repair group (n = 34), Sugaya type I:II ratio differed significantly between postoperative 3 months (2:32) and 24 months (24:10) (P < .001). Repaired tendon thickness did not decrease significantly between 3 months (7.1 mm) and 2 years (6.9 mm) (P = .543). CONCLUSIONS: ARCR with fascia lata graft augmentation of large and massive rotator cuff tears showed a 24.4% retear rate but significantly improved the clinical scores, ROMs, and muscle strength with excellent cuff integrity in the intact repair group. However, the differences in the Constant and UCLA scores between the intact repair and retear groups were under the minimal clinically important difference, and their clinical significance is uncertain. Our results confirm that ARCR with fascia lata graft augmentation improves patients' postoperative outcomes if the repair site is maintained postoperatively.

Re-tear after arthroscopic rotator cuff tear surgery: risk analysis using machine learning.

BACKGROUND: Postoperative rotator cuff retear after arthroscopic rotator cuff repair (ARCR) is still a major problem. Various risk factors such as age, gender, and tear size have been reported. Recently, magnetic resonance imaging-based stump classification was reported as an index of rotator cuff fragility. Although stump type 3 is reported to have a high retear rate, there are few reports on the risk of postoperative retear based on this classification. Machine learning (ML), an artificial intelligence technique, allows for more flexible predictive models than conventional statistical methods and has been applied to predict clinical outcomes. In this study, we used ML to predict postoperative retear risk after ARCR. METHODS: The retrospective case-control study included 353 patients who underwent surgical treatment for complete rotator cuff tear using the suture-bridge technique. Patients who initially presented with retears and traumatic tears were excluded. In study participants, after the initial tear repair, rotator cuff retears were diagnosed by magnetic resonance imaging; Sugaya classification types IV and V were defined as re-tears. Age, gender, stump classification, tear size, Goutallier classification, presence of diabetes, and hyperlipidemia were used for ML parameters to predict the risk of retear. Using Python's Scikit-learn as an ML library, five different AI models (logistic regression, random forest, AdaBoost, CatBoost, LightGBM) were trained on the existing data, and the prediction models were applied to the test dataset. The performance of these ML models was measured by the area under the receiver operating characteristic curve. Additionally, key features affecting retear were evaluated. RESULTS: The area under the receiver operating characteristic curve for logistic regression was 0.78, random forest 0.82, AdaBoost 0.78, CatBoost 0.83, and LightGBM 0.87, respectively for each model. LightGBM showed the highest score. The important factors for model prediction were age, stump classification, and tear size. CONCLUSIONS: The ML classifier model predicted retears after ARCR with high accuracy, and the AI model showed that the most important characteristics affecting retears were age and imaging findings, including stump classification. This model may be able to predict postoperative rotator cuff retears based on clinical features.

Inter-observer Agreement and Reproducibility of Pertrochanteric Fracture Classification Using Plain Radiograph Versus Computed Tomogram Images: A Study of 523 Patients.

Background A precise preoperative imaging classification system for pertrochanteric fractures is imperative due to the reported unreliability of the current classification system, which relies solely on plain radiographs. This study aims to achieve two primary objectives: (i) elucidate the reproducibility of pertrochanteric fracture evaluation based on the Revised Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) Classification, comparing plain radiographs and computed tomography (CT) scan images, and (ii) investigate the consistency of fracture classification between both imaging modalities. Methods A total of 523 patients (112 males and 411 females, mean age 85 years) who had both preoperative plain radiographic and three-dimensional CT images were enrolled in this study. Following the Revised AO/OTA Classification, three individual observers initially classified the fractures in plain radiograph images as either Stable (A1) or Unstable (A2). Subsequently, they further categorized them into five sub-categories (A1.1, A1.2, A1.3, A2.2, and A2.3). The same classification system was applied to the CT scan images. Inter-observer agreement and consistency of fracture classification between plain radiographs and CT scan images were assessed. Results The inter-observer agreement for fractures classified as stable or unstable using only plain radiographs was found to be fair among the three observers, with a mean κ of 0.397 (95% CI: 0.316-0.478). However, inter-observer agreement improved significantly when using CT scans, with a mean κ of 0.590 (95% CI: 0.518-0.662). Our results demonstrated a consistency level between two graphical modalities ranging from fair to moderate, with κ values of 0.581, 0.383, and 0.335, respectively. It's worth noting that plain radiographic classification occasionally resulted in underestimations, with each observer identifying 16.1%, 34.0%, and 37.9%, respectively, of cases as A1 in plain radiographs that were classified as A2 in CT scans. Conclusions This study reveals a moderate to substantial level of inter-observer agreement for fracture classification when using CT scan images, in contrast to plain radiographs. Fracture evaluation relying solely on plain radiographs sometimes underestimates fracture classification and exhibits less consistency compared to using CT scan images.

Intra-articular site-specific distribution of advanced glycation end products in the shoulder of patients with diabetes mellitus having rotator cuff tears.

BACKGROUND: Advanced glycation end products (AGEs) are compounds formed due to aging and diabetes mellitus (DM). They activate NADPH oxidase (NOX) by binding to their receptors, thereby increasing the production of reactive oxygen species (ROS), which cause oxidative stress. In this study, we investigated the effects of AGEs on the tissues of the shoulder joint (such as rotator cuff synovium, and capsule) in patients with DM having rotator cuff tears. METHODS: This study included eight patients with DM who underwent surgical treatment for rotator cuff tears with contracture. The rotator cuff, synovium, and joint capsule were harvested at the time of surgery and evaluated by hematoxylin-eosin staining. Furthermore, immunostaining was used for evaluating AGEs and receptor for AGEs (RAGE), cell activity, ROS, and apoptosis. Quantitative real-time polymerase chain reaction (qPCR) was employed for the cellular evaluation of NOX, interleukins, RAGE, and collagen. RESULTS: The AGEs and RAGE staining as well as the ratio of ROS and apoptosis were in the following order: rotator cuff > joint capsule > synovium. In contrast, the cellular activity was significantly higher in the synovium than in the other regions. The type I collagen expression (as shown by qPCR) as well as the RAGE and NOX expressions were as follows: rotator cuff > joint capsule > synovium. Conversely, the expression of inflammatory cytokines (i.e., IL-6 and IL-1ß) was higher in the synovium than in the other regions. CONCLUSIONS: Our study is among the first to evaluate the effects of AGEs on each tissue of the shoulder joint in patients with DM having rotator cuff tears and contractures. The accumulation of AGEs in each tissue of the shoulder joint could reveal the locations affected by DM, which can lead to a better understanding of the pathophysiology of DM-related shoulder diseases.

Measurement of Shoulder Abduction Angle with Posture Estimation Artificial Intelligence Model.

Substantial advancements in markerless motion capture accuracy exist, but discrepancies persist when measuring joint angles compared to those taken with a goniometer. This study integrates machine learning techniques with markerless motion capture, with an aim to enhance this accuracy. Two artificial intelligence-based libraries-MediaPipe and LightGBM-were employed in executing markerless motion capture and shoulder abduction angle estimation. The motion of ten healthy volunteers was captured using smartphone cameras with right shoulder abduction angles ranging from 10° to 160°. The cameras were set diagonally at 45°, 30°, 15°, 0°, -15°, or -30° relative to the participant situated at a distance of 3 m. To estimate the abduction angle, machine learning models were developed considering the angle data from the goniometer as the ground truth. The model performance was evaluated using the coefficient of determination R2 and mean absolute percentage error, which were 0.988 and 1.539%, respectively, for the trained model. This approach could estimate the shoulder abduction angle, even if the camera was positioned diagonally with respect to the object. Thus, the proposed models can be utilized for the real-time estimation of shoulder motion during rehabilitation or sports motion.

Diagnosis of Developmental Dysplasia of the Hip by Ultrasound Imaging Using Deep Learning.

BACKGROUND: A timely diagnosis of developmental dysplasia of the hip (DDH) is important for satisfactory clinical outcomes. Ultrasonography is a useful tool for DDH screening; however, it is technically demanding. We hypothesized that deep learning could assist in the diagnosis of DDH. In this study, several deep-learning models were assessed to diagnose DDH on ultrasonograms. This study aimed to evaluate the accuracy of diagnoses made by artificial intelligence (AI) using deep learning on ultrasound images of DDH. METHODS: Infants who were up to 6 months old with suspected DDH were included. DDH diagnosis using ultrasonography was performed according to the Graf classification. Data on 60 infants (64 hips) with DDH and 131 healthy infants (262 hips) obtained from 2016 to 2021 were retrospectively reviewed. For deep learning, a MATLAB deep learning toolbox (MathWorks, Natick, MA, US) was used, and 80% of the images were used as training data, with the rest as validation data. Training images were augmented to increase data variation. In addition, 214 ultrasound images were used as test data to evaluate the AI's accuracy. Pre-trained models (SqueezeNet, MobileNet_v2, and EfficientNet) were used for transfer learning. Model accuracy was evaluated using a confusion matrix. The region of interest of each model was visualized using gradient-weighted class activation mapping (Grad-CAM), occlusion sensitivity, and image LIME. RESULTS: The best scores for accuracy, precision, recall, and F-measure were all 1.0 in each model. In DDH hips, the region of interest for deep learning models was the area lateral to the femoral head, including the labrum and joint capsule. However, for normal hips, the models highlighted the medial and proximal areas where the lower margin of the os ilium and the normal femoral head exist. CONCLUSIONS: Ultrasound imaging with deep learning can assess DDH with high accuracy. This system could be refined for a convenient and accurate diagnosis of DDH. LEVEL OF EVIDENCE: Level-Ⅳ.

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.

Comparative Study of Different Entry Spots on Postoperative Gluteus Medius Muscle Cross-Sectional Area in Patients With Intertrochanteric Fractures Nailing.

Introduction In a preliminary study of cephalo-medullary (CM) nailing in patients with femoral intertrochanteric fractures, the authors of this study found a 25% to 30% decrease in muscle strength, especially abduction force, during the postoperative follow-up period. This decline was partially attributed to the entry point for the nail insertion causing damage to the gluteus medius tendon at the junction of the greater trochanter after reaming. Therefore, we assumed that changing the position of nail insertion to a "bald spot (BS)" could mitigate postoperative functional impairment. Automated computed tomography (CT) imaging of skeletal muscle cross-sectional area (CSA) and adipose tissue ratio (ATR) can show pathological changes on the operated side compared with the non-operated side. In this study, the authors quantified the difference in postoperative CSA and ATR of the gluteus medius muscle after bald spot nailing versus nail insertion through the conventional tip of the greater trochanter. It was hypothesized that bald spot nailing could avoid significant injury to the gluteus medius muscle. Materials and methods Patients with femoral intertrochanteric fractures were grouped according to the site of cephalo-medullary nailing: greater trochanteric tip (TIP) in 27 patients (8 men and 19 women, mean age 84.9±5.1 years) and BS in 16 patients (3 men and 13 women, mean age 86.9±6.2 years). The CSA and ATR of the gluteus medius muscles were assessed in three slices (A, B, and C from proximal to distal). Each slice was manually traced and automatically calculated based on its contour. Adipose tissue (-100 to -50 in Hounsfield units) in the designated area was distinguished by a bimodal image histogram resulting from the distribution of CT numbers of adipose tissue and muscle. The body mass index (BMI) was used to correct the CSA in each patient. Results In the TIP group, the mean CSA values (mm2) from the non-operated/operated sides were as follows: slice A, 2180.2 ± 616.5/1976.3 ± 421.2; slice B, 2112.3 ± 535.7/1857.7 ± 386.7; and slice C: 1671.8 ± 460.0/1404.1 ± 404.3 (p<0.01 in slices A, B, and C). In the BS group, slice A was 2044.1 ± 473.0/2016.9 ± 388.4; slice B was 2073.2 ± 540.7/1848.3 ± 411.1; and slice C was 1659.1 ± 477.2/1468.5 ± 341.7 (p=0.34 in slice A, and p<0.05 in slices B and C, respectively). The mean CSA values (mm2) of the non-operated minus operated side between the TIP/BS groups were as follows: slice A, 241.3 ± 424.3/-11.8 ± 285.6; slice B, 290.3 ± 313.0/211.8 ± 333.2; and slice C, 276.4 ± 270.4/162.8 ± 319.3 (p < 0.05 in slice A, 0.45, 0.24 in slices B, C, respectively). The mean adjusted CSA per BMI values (mm2) of the non-operated minus the operated side between the TIP/BS groups were slice A, 10.6 ± 19.7/-0.4 ± 14.8; slice B, 13.3 ± 15.0/10.1 ± 16.3; and slice C, 13.1 ± 13.4/ 8.7 ± 15.3 (p < 0.05 in slice A and 0.54 and 0.36 in slices B and C, respectively). Conclusion Nail insertion at the bald spot resulted in a significantly smaller decrease in the CSA of the gluteus medius muscle compared with the conventional tip entry. In addition, an examination of BMI-adjusted CSA showed that CSA was maintained in some image slices. These results suggest that nailing from the BS of the greater trochanter can reduce damage to the gluteus medius muscle and highlight the importance of imaging beyond the usual assessment of skeletal changes.

Dynamic Analysis of the Coracohumeral Ligament Using Ultra-Sonography in Shoulder Contracture.

The coracohumeral ligament (CHL) is related to the range of motion of the shoulder joint. The evaluation of the CHL using ultrasonography (US) has been reported on the elastic modulus and thickness of the CHL, but no dynamic evaluation method has been established. We aimed to quantify the movement of the CHL by applying Particle Image Velocimetry (PIV), a technique used in the field of fluid engineering, to cases of shoulder contracture using the US. The subjects were eight patients, with 16 shoulders. The coracoid process was identified from the body surface, and a long-axis US image of the CHL parallel to the subscapularis tendon was drawn. The shoulder joint was moved from 0 degrees of internal/external rotation to 60 degrees of internal rotation at a rhythm of one reciprocation every 2 s. The velocity of the CHL movement was quantified by the PIV method. The mean magnitude velocity of CHL was significantly faster on the healthy side. The maximum magnitude velocity was significantly faster on the healthy side. The results suggest that the PIV method is helpful as a dynamic evaluation method, and in patients with shoulder contracture, the CHL velocity was significantly decreased.

Screening for Osteoporosis from Blood Test Data in Elderly Women Using a Machine Learning Approach.

The diagnosis of osteoporosis is made by measuring bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA). Machine learning, one of the artificial intelligence methods, was used to predict low BMD without using DXA in elderly women. Medical records from 2541 females who visited the osteoporosis clinic were used in this study. As hyperparameters for machine learning, patient age, body mass index (BMI), and blood test data were used. As machine learning models, logistic regression, decision tree, random forest, gradient boosting trees, and lightGBM were used. Each model was trained to classify and predict low-BMD patients. The model performance was compared using a confusion matrix. The accuracy of each trained model was 0.772 in logistic regression, 0.739 in the decision tree, 0.775 in the random forest, 0.800 in gradient boosting, and 0.834 in lightGBM. The area under the curve (AUC) was 0.595 in the decision tree, 0.673 in logistic regression, 0.699 in the random forest, 0.840 in gradient boosting, and 0.961, which was the highest, in the lightGBM model. Important features were BMI, age, and the number of platelets. Shapley additive explanation scores in the lightGBM model showed that BMI, age, and ALT were ranked as important features. Among several machine learning models, the lightGBM model showed the best performance in the present research.

Anatomical Assessment of Cephalic Vein and Superficial Branch of Radial Nerve Using High-Resolution Ultrasound Imaging.

Introduction The superficial branch of the radial nerve (SBRN) has a risk of nerve injury during cephalic vein (CV) cannulation. Due to the lack of imaging study regarding SBRN and CV relationship, we analyzed the anatomical relationship between the SBRN and the CV using ultrasound (US) imaging. Materials and Methods In total, 82 upper limbs of 41 healthy volunteers were analyzed. The SBRN and CV were identified at the following three points in the elbow extension and pronation position: at the radial styloid process (point 1), 5 cm proximal to point 1 (point 2), and 10 cm proximal to point 1 (point 3). Results The distance between the SBRN and CV was 1.1 ± 1.0 mm at point 1, 1.3 ± 1.3 mm at point 2, and 2.1 ± 1.6 mm at point 3. The depth of the SBRN from the surface of the skin was 2.7 ± 0.9 mm at point 1, 3.5 ± 1.1 mm at point 2, and 5.5 ± 1.9 mm at point 3. The percentage of the SBRN that ran beneath the CV was 17.5%, 53.5%, and 92.4% at points 1, 2, and 3, respectively. Conclusion Ultrasonography can reveal the anatomical relationship between the SBRN and CV.

A Demographic Survey of Pertrochanteric Fractures Based on the Revised Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) Classification Using 3D CT Scan Images.

Introduction A demographic survey of femoral pertrochanteric fractures provides several important information for the healthcare system of a country since this fracture is commonly seen in the elderly and has a poor postoperative functional prognosis that is a burden on society. The importance of accurately classifying pertrochanteric fractures as stable or unstable cannot be understated. However, the use of plain radiograph images alone is known to underestimate fracture severity with low inter- or intra-observer agreement. Computed tomography (CT) images offer information for a more accurate classification of pertrochanteric fractures. With this three-dimensional (3D) CT-based study using the revised Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) classification, the purpose of this study is to elucidate the epidemiological demography of patients with pertrochanteric fractures. Material and methods We retrospectively collected 808 patients from five hospitals, classified into two groups: stable (A1) or unstable (A2). Age, gender, fracture laterality, and surgery timing were identified as epidemiological variables. Patients with both preoperative plain radiographs and 3D CT scans were included in the study. The exclusion criteria were AO/OTA A3 type fractures, pathological fractures, previous ipsilateral surgery, 60 years old or younger, and conservatively treated patients. The primary outcome involved detailing the total number of fractures based on classification (A1 or A2) and variables. The secondary outcome involved a comparison between the A1 and A2 groups. Results The mean age of patients at the time of surgery was 85 years (range: 61-103 years). There were 637 female and 171 male patients. There were 463 left-sided fractures and 345 right-sided fractures. Of the 808 patients, 371 (45.9%) were classified to have A1 fractures, and 437 (54.1%) had A2 fractures. The age at surgery, gender, fracture laterality, and surgery timing between the A1 and A2 groups were compared. The mean and standard deviation of the age at surgery for patients in the A1 and A2 groups were 84.9±7.7 and 86.9±6.8, respectively. The number of patients for each age distribution of 61-69, 70-74, 75-79, 80-84, 85-89, 90-94, and 95 or older for the A1 and A2 groups was 18 and 7, 18 and 12, 43 and 44, 76 and 82, 107 and 132, 79 and 110, and 30 and 50, respectively, showing that the difference in categorial distribution was statistically significant (p=0.002). Overall, 278 females and 93 males were classified to have A1 fractures compared with 359 females and 78 males with A2 fractures (p=0.01). There were 166 right-sided and 205 left-sided stable A1 fractures and 179 right-sided and 258 left-sided A2 fractures (not significant (NS)). Among the total number of A1 and A2 surgeries by month, the most were in December with 77 surgeries (37 and 40, respectively), and the least was in June with 37 (18 and 19, respectively). The seasonal classification for A1 and A2 surgeries is as follows: spring with 172 (74 and 98, respectively), summer with 150 (70 and 80, respectively), autumn with 193 (90 and 103, respectively), and winter with 208 (97 and 111, respectively) (NS). Conclusion In this demographic study of 808 patients with pertrochanteric fractures classified by 3D CT images, 371 had A1 fractures and 437 had A2 fractures. A2 fractures were significantly more in females with an age peak of 85-89 years.

Timing of retears after arthroscopic rotator cuff repair and associated factors: a retrospective analysis.

BACKGROUND: Retear after arthroscopic rotator cuff repair (ARCR) remains a complication of important concern. Few reports have evaluated retear timing and its associated patient characteristics in large cohorts. This study aimed to investigate retear timing and patient characteristics and factors associated with this parameter. METHODS: Of the 638 consecutive shoulders that underwent ARCR from August 2009 to November 2019, shoulders with retear complication within 1 year of surgery were included. Retears were defined as type IV or V of the Sugaya's classification, and magnetic resonance imaging was performed at 6 weeks, 3 months, 6 months, and 1 year after surgery. The distribution of patients with retears at the timing of retears was investigated. In addition, patients with retears were classified into the following two groups: early group with retears occurring at 6 weeks and 3 months postoperatively or late group with retears occurring between 6 months and 1 year postoperatively. Associated factors such as sex, age, tear size, pre and postoperative range of motion, surgical technique, and clinical outcome between the two groups were investigated. RESULTS: The 41 shoulders with retears were divided into four groups: 1) within 6 weeks after surgery (n = 9, 22.0%), 2) 6 weeks-to 3 months after surgery (n = 19, 46.3%), 3) 3-6 months after surgery (n = 11, 26.8%), and 4) 6 months-1 year after surgery (n = 2, 4.9%). In addition, there were significantly larger retear sizes in the Sugaya's classification in the early group compared to the late group (P = .013), while there were significantly more males in the late group compared to the early group (P = .030). CONCLUSION: The highest retear rate after ARCR was observed from 6 weeks to 3 months after surgery, with equivalent rates within 6 weeks and from 3 months to 6 months after surgery.

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.

Local application of a transcutaneous carbon dioxide paste prevents excessive scarring and promotes muscle regeneration in a bupivacaine-induced rat model of muscle injury.

In postoperative patients with head and neck cancer, scar tissue formation may interfere with the healing process, resulting in incomplete functional recovery and a reduced quality of life. Percutaneous application of carbon dioxide (CO2 ) has been reported to improve hypoxia, stimulate angiogenesis, and promote fracture repair and muscle damage. However, gaseous CO2 cannot be applied to the head and neck regions. Previously, we developed a paste that holds non-gaseous CO2 in a carrier and can be administered transdermally. Here, we investigated whether this paste could prevent excessive scarring and promote muscle regeneration using a bupivacaine-induced rat model of muscle injury. Forty-eight Sprague Dawley rats were randomly assigned to either a control group or a CO2 group. Both groups underwent surgery to induce muscle injury, but the control group received no treatment, whereas the CO2 group received the CO2 paste daily after surgery. Then, samples of the experimental sites were taken on days 3, 7, 14, and 21 post-surgery to examine the following: (1) inflammatory (interleukin [IL]-1ß, IL-6), and transforming growth factor (TGF)-ß and myogenic (MyoD and myogenin) gene expression by polymerase chain reaction, (2) muscle regeneration with haematoxylin and eosin staining, and (3) MyoD and myogenin protein expression using immunohistochemical staining. Rats in the CO2 group showed higher MyoD and myogenin expression and lower IL-1ß, IL-6, and TGF-ß expression than the control rats. In addition, treated rats showed evidence of accelerated muscle regeneration. Our study demonstrated that the CO2 paste prevents excessive scarring and accelerates muscle regeneration. This action may be exerted through the induction of an artificial Bohr effect, which leads to the upregulation of MyoD and myogenin, and the downregulation of IL-1ß, IL-6, and TGF-ß. The paste is inexpensive and non-invasive. Thus, it may be the treatment of choice for patients with muscle damage.