MR Imaging of Rotator Cuff Injury: What the Clinician Needs to Know

MRI-based automated multitask deep learning system to evaluate supraspinatus tendon injuries

OBJECTIVE

To establish an automated, multitask, MRI-based deep learning system for the detailed evaluation of supraspinatus tendon (SST) injuries.

METHODS

According to arthroscopy findings, 3087 patients were divided into normal, degenerative, and tear groups (groups 0-2). Group 2 was further divided into bursal-side, articular-side, intratendinous, and full-thickness tear groups (groups 2.1-2.4), and external validation was performed with 573 patients. Visual geometry group network 16 (VGG16) was used for preliminary image screening. Then, the rotator cuff multitask learning (RC-MTL) model performed multitask classification (classifiers 1-4). A multistage decision model produced the final output. Model performance was evaluated by receiver operating characteristic (ROC) curve analysis and calculation of related parameters. McNemar's test was used to compare the differences in the diagnostic effects between radiologists and the model. The intraclass correlation coefficient (ICC) was used to assess the radiologists' reliability. p < 0.05 indicated statistical significance.

RESULTS

In the in-group dataset, the area under the ROC curve (AUC) of VGG16 was 0.92, and the average AUCs of RC-MTL classifiers 1-4 were 0.99, 0.98, 0.97, and 0.97, respectively. The average AUC of the automated multitask deep learning system for groups 0-2.4 was 0.98 and 0.97 in the in-group and out-group datasets, respectively. The ICCs of the radiologists were 0.97-0.99. The automated multitask deep learning system outperformed the radiologists in classifying groups 0-2.4 in both the in-group and out-group datasets (p < 0.001).

CONCLUSION

The MRI-based automated multitask deep learning system performed well in diagnosing SST injuries and is comparable to experienced radiologists.

CLINICAL RELEVANCE STATEMENT

Our study established an automated multitask deep learning system to evaluate supraspinatus tendon (SST) injuries and further determine the location of SST tears. The model can potentially improve radiologists' diagnostic efficiency, reduce diagnostic variability, and accurately assess SST injuries.

KEY POINTS

• A detailed classification of supraspinatus tendon tears can help clinical decision-making. • Deep learning enables the detailed classification of supraspinatus tendon injuries. • The proposed automated multitask deep learning system is comparable to radiologists.

Machine-learning models for diagnosis of rotator cuff tears in osteoporosis patients based on anteroposterior X-rays of the shoulder joint

OBJECTIVE

This study aims to diagnose Rotator Cuff Tears (RCT) and classify the severity of RCT in patients with Osteoporosis (OP) through the analysis of shoulder joint anteroposterior (AP) X-ray-based localized proximal humeral bone mineral density (BMD) measurements and clinical information based on machine learning (ML) models.

METHODS

A retrospective cohort of 89 patients was analyzed, including 63 with both OP and RCT (OPRCT) and 26 with OP only. The study analyzed a series of shoulder radiographs from April 2021 to April 2023. Grayscale values were measured after plotting ROIs based on AP X-rays of shoulder joint. Five kinds of ML models were developed and compared based on their performance in predicting the occurrence and severity of RCT from ROIs' greyscale values and clinical information (age, gender, advantage side, lumbar BMD, and acromion morphology (AM)). Further analysis using SHAP values illustrated the significant impact of selected features on model predictions.

RESULTS

R1-6 had a positive correlation with BMD respectively. The nine variables, including greyscale R1-6, age, BMD, and AM, were used in the prediction models. The RF model was determined to be superior in effectively diagnosing RCT in OP patients, with high AUC scores of 0.998, 0.889, and 0.95 in the training, validation, and testing sets, respectively. SHAP values revealed that the most influential factors on the diagnostic outcomes were the grayscale values of all cancellous bones in ROIs. A column-line graph prediction model based on nine variables was constructed, and DCA curves indicated that RCT prediction in OP patients was favored based on this model. Furthermore, the RF model was also the most superior in predicting the types of RCT within the OPRCT group, with an accuracy of 86.364% and 73.684% in the training and test sets, respectively. SHAP values indicated that the most significant factor affecting the predictive outcomes was the AM, followed by the grayscale values of the greater tubercle, among others.

CONCLUSIONS

ML models, particularly the RF algorithm, show significant promise in diagnosing RCT occurrence and severity in OP patients using conventional shoulder X-rays based on the nine variables. This method presents a cost-effective, accessible, and non-invasive diagnostic strategy that has the potential to substantially enhance the early detection and management of RCT in OP patient population.

Single slice MR image estimation of 3D supraspinatus intramuscular fatty infiltration in older adults: relevance for clinical practice and research

OBJECTIVE

(1) To compare older adults stratified by supraspinatus tendon tear status (STT status)-no tear (Intact), partial-thickness (PT) tear, full-thickness (FT) tear-by 3D Dixon fat fraction (3D-FF); 2D fat fraction (2D-FF); and 2D Goutallier grade (2D-GG) at the Y-shaped view, and 1.4 cm and 2.8 cm medial to the Y-shaped view. Stratified by STT status to determine (2) correlation of 3D-FF with 2D-FF and 2D-GG and (3) inter-rater reliability at and medial to the Y-shaped view.

MATERIALS AND METHODS

Forty-five volunteers ≥ 60 years recruited prospectively received shoulder MRI. 3D-FF and 2D-FF were measured on 6-point-Dixon MRI by three trainees. Goutallier grade was assessed on T1-weighted MRI by three fellowship-trained diagnostic radiologists. Descriptive, reliability, and correlation analyses were performed.

RESULTS

Groups showed no difference in age. The FT group showed higher (p < 0.05) mean 3D-FF (14.09% ± 10.99%), mean 2D-FF (1.4 cm medial to Y-shaped view, 14.91% ± 12.11%; 2.8 cm medial to Y-shaped view, 13.32% ± 9.48%), and mean 2D-GG (Y-shaped view, 1.71 ± 0.78; 1.4 cm medial to Y-shaped view, 1.71 ± 0.69; 2.8 cm medial to Y-shaped view, 1.71 ± 0.72), relative to Intact/PT groups. 3D-FF showed strong correlation with 2D-FF among all groups/all analyses (rho, 0.80-0.98; p < 0.001). 3D-FF showed strong correlation with 2D-GG for all FT group analyses (rho, 0.85-0.91; p < 0.05). 3D-FF showed moderate-to-strong correlation considering all Intact/PT group analyses (rho, 0.51-0.79; p < 0.50). Dixon fat fraction showed excellent reliability for all groups (≥ 0.884, intraclass correlation coefficient). Goutallier grade showed excellent reliability for FT group (0.771, weighted Fleiss's kappa) but poor (0.294) and fair (0.502) for Intact and PT groups, respectively.

CONCLUSION

Single slice MR image estimation of 3D supraspinatus intramuscular fatty infiltration has merit for continued use in clinical populations requiring potential rotator-cuff-repair surgery. However, Dixon fat fraction should be prioritized for use in research over Goutallier grade due to superior reliability.

Deep-learning-based image quality enhancement of CT-like MR imaging in patients with suspected traumatic shoulder injury

PURPOSE

To evaluate the diagnostic performance of CT-like MR images reconstructed with an algorithm combining compressed sense (CS) with deep learning (DL) in patients with suspected osseous shoulder injury compared to conventional CS-reconstructed images.

METHODS

Thirty-two patients (12 women, mean age 46 ± 14.9 years) with suspected traumatic shoulder injury were prospectively enrolled into the study. All patients received MR imaging of the shoulder, including a CT-like 3D T1-weighted gradient-echo (T1 GRE) sequence and in case of suspected fracture a conventional CT. An automated DL-based algorithm, combining CS and DL (CS DL) was used to reconstruct images of the same k-space data as used for CS reconstructions. Two musculoskeletal radiologists assessed the images for osseous pathologies, image quality and visibility of anatomical landmarks using a 5-point Likert scale. Moreover, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.

RESULTS

Compared to CT, all acute fractures (n = 23) and osseous pathologies were detected accurately on the CS only and CS DL images with almost perfect agreement between the CS DL and CS only images (κ 0.95 (95 %confidence interval 0.82-1.00). Image quality as well as the visibility of the fracture lines, bone fragments and glenoid borders were overall rated significantly higher for the CS DL reconstructions than the CS only images (CS DL range 3.7-4.9 and CS only range 3.2-3.8, P = 0.01-0.04). Significantly higher SNR and CNR values were observed for the CS DL reconstructions (P = 0.02-0.03).

CONCLUSION

Evaluation of traumatic shoulder pathologies is feasible using a DL-based algorithm for reconstruction of high-resolution CT-like MR imaging.

Advancements in the diagnosis and management of rotator cuff tears. The role of artificial intelligence

Background

This review examined the role of artificial intelligence (AI) in the diagnosis and management of rotator cuff tears (RCTs).

Methods

A literature search was conducted in October 2023 using PubMed (MEDLINE), SCOPUS, and EMBASE databases, included only peer-reviewed studies. Relevant articles on AI technology in RCTs. A critical analysis of the relevant literature was conducted.

Results

AI is transforming RCTs management through faster and more precise identification and assessment using algorithms that facilitate segmentation, quantification, and classification of the RCTs across various imaging modalities. Precise algorithms focusing on preoperative factors to assess RCTs reparability have been developed for personalized treatment planning and outcome prediction. AI also aids in exercise classification and promotes patient adherence during at-home physiotherapy. Despite promising advancements, challenges in data quality and symptom integration persist. Future research should include refining AI algorithms, expanding their integration into various imaging techniques, and exploring their roles in postoperative care and surgical decision-making.

Conclusions

AI-driven solutions improve diagnostic accuracy and have the potential to influence treatment planning and postoperative outcomes through the automated RCTs analysis of medical imaging. Integration of high-quality datasets and clinical symptoms into AI models can enhance their reliability. Current AI algorithms can also be refined, integrated into other imaging techniques, and explored further in surgical decision-making and postoperative care.

Deep-Learning-Based Automated Rotator Cuff Tear Screening in Three Planes of Shoulder MRI

This study aimed to develop a screening model for rotator cuff tear detection in all three planes of routine shoulder MRI using a deep neural network. A total of 794 shoulder MRI scans (374 men and 420 women; aged 59 ± 11 years) were utilized. Three musculoskeletal radiologists labeled the rotator cuff tear. The YOLO v8 rotator cuff tear detection model was then trained; training was performed with all imaging planes simultaneously and with axial, coronal, and sagittal images separately. The performances of the models were evaluated and compared using receiver operating curves and the area under the curve (AUC). The AUC was the highest when using all imaging planes (0.94; p < 0.05). Among a single imaging plane, the axial plane showed the best performance (AUC: 0.71), followed by the sagittal (AUC: 0.70) and coronal (AUC: 0.68) imaging planes. The sensitivity and accuracy were also the highest in the model with all-plane training (0.98 and 0.96, respectively). Thus, deep-learning-based automatic rotator cuff tear detection can be useful for detecting torn areas in various regions of the rotator cuff in all three imaging planes.

Evaluation of the acromion variants in MRI and their association with rotator cuff injuries in non-traumatic patients

Purpose

Understanding demographic and MRI parameters with determinant role in rotator cuff tearing (RCT) is required to predict outcomes and select more appropriate treatment in patients with non-traumatic shoulder pain. This study aimed to survey the association of rotator cuff tears with these factors.

Methods

We performed this cross-sectional study on patients referred to Kashani Hospital with non-traumatic shoulder pain suspected of rotator cuff injuries from April 2020 to February 2021. We obtained their demographic data and MRI from electronic hospital records. After that, two radiologists reviewed MRI and recorded data. We employed the SPSS 23 software to organize the obtained results and statistical evaluations.

Results

371 subjects, with the age of 48.61 ± 14.89 years, were included in our study, and 50% of them were male. The flat and down-sloping acromion and partial tearing of the supra and infraspinatus tendons were more frequent than the others. Gender could not consider as a determinant factor for the severity of tendon injuries, acromion types and variants. The relation of age to acromion morphology and the tendinopathy severity was significant. Remarkably, down-sloping acromion was higher at all the acromion shapes; however, it makes no difference in the level of supra and infraspinatus involvement. Moreover, we found that partial tearing was higher in all acromion types, except concave. This distribution was significant only for supraspinatus tears.

Conclusion

The clinical decision is the most important step in patients with RCT and MRI prognostic factors, which are helpful to improve the management of the cases. RCT in older patients and down-slope acromion was more severe than the others. According to the previous studies, acromion morphology (as an important determinant factor) in RCT could be influenced by age, as well.

Shoulder pain, health-related quality of life and physical function in community-dwelling older adults

The impact of shoulder pain on health-related quality of life and physical function among community-dwelling older adults (>60 years) not seeking medical care is not well understood. Forty-four community-dwelling older adult volunteers with low comorbidity were stratified into two groups by the presence (n = 18) or absence (n = 26) of shoulder pain. Participants completed the 36-Item Short Form and American Shoulder and Elbow Surgeon surveys and received shoulder range of motion and magnetic resonance imaging testing. Participants with shoulder pain perceived more difficulty accomplishing usual tasks secondary to their physical and emotion health and displayed inferior shoulder function, relative to participants without shoulder pain. This study suggests that shoulder pain reduces quality of life and physical function in the population of community-dwelling older adults not seeking medical evaluation for their symptoms.

[Translated article] Correlation between the incidence of rotator cuff lesion in traumatic unilateral anterior glenohumeral dislocation and the contralateral shoulder

INTRODUCTION

Anterior glenohumeral dislocation in patients older than 60 years is related to rotator cuff lesion because of its pre-existing degenerative condition. However, in this age group, the scientific evidence fails to elucidate whether rotator cuff lesions are the cause or consequence of recurrent shoulder instability. The objective of this paper is to describe the prevalence of rotator cuff injuries in a series of consecutive shoulders in patients older than 60 years who suffered a first episode of traumatic glenohumeral dislocation, and its correlation with rotator cuff injuries in both shoulders.

METHODS

Retrospectively, 35 patients over 60 years of age who had a first episode of unilateral traumatic anterior glenohumeral dislocation and who had MRI of both shoulders were studied, evaluating both shoulders with MRI to determine the structural damage correlation of the rotator cuff and long head of the biceps between them.

RESULTS

When assessing the existence of partial or complete injury to the supraspinatus and infraspinatus tendons, the concordance on the affected and healthy sides, we have shown concordant results on both sides in 88.6 and 85.7%, respectively. The Kappa concordance coefficient was 0.72 for supraspinatus and infraspinatus tendons tear. Of the total of 35 cases evaluated, 8 (22.8%) presented at least some alteration in the tendon of the long head of the biceps on the affected side and only one (2.9%) on the healthy side, where the Kappa coefficient of concordance was 0.18. Of the 35 cases evaluated, 9 (25.7%) presented at least some retraction in the tendon of the subscapularis muscle on the affected side, while no participant showed signs of retraction in the tendon of this muscle on the healthy side.

CONCLUSIONS

Our study has found a high correlation of the presence of a postero-superior rotator cuff injury after presenting a glenohumeral dislocation between the shoulder that has suffered the event and the presumably healthy contralateral shoulder. Nevertheless, we have not found this same correlation with subscapularis tendon injury and medial biceps dislocation.

Evaluation of a deep learning-based reconstruction method for denoising and image enhancement of shoulder MRI in patients with shoulder pain

OBJECTIVES

To evaluate the diagnostic performance of an automated reconstruction algorithm combining MR imaging acquired using compressed SENSE (CS) with deep learning (DL) in order to reconstruct denoised high-quality images from undersampled MR images in patients with shoulder pain.

METHODS

Prospectively, thirty-eight patients (14 women, mean age 40.0 ± 15.2 years) with shoulder pain underwent morphological MRI using a pseudo-random, density-weighted k-space scheme with an acceleration factor of 2.5 using CS only. An automated DL-based algorithm (CS DL) was used to create reconstructions of the same k-space data as used for CS reconstructions. Images were analyzed by two radiologists and assessed for pathologies, image quality, and visibility of anatomical landmarks using a 4-point Likert scale.

RESULTS

Overall agreement for the detection of pathologies between the CS DL reconstructions and CS images was substantial to almost perfect (κ 0.95 (95% confidence interval 0.82-1.00)). Image quality and the visibility of the rotator cuff, articular cartilage, and axillary recess were overall rated significantly higher for CS DL images compared to CS (p < 0.03). Contrast-to-noise ratios were significantly higher for cartilage/fluid (CS DL 198 ± 24.3, CS 130 ± 32.2, p = 0.02) and ligament/fluid (CS DL 184 ± 17.3, CS 141 ± 23.5, p = 0.03) and SNR values were significantly higher for ligaments and muscle of the CS DL reconstructions (p < 0.04).

CONCLUSION

Evaluation of shoulder pathologies was feasible using a DL-based algorithm for MRI reconstruction and denoising. In clinical routine, CS DL may be beneficial in particular for reducing image noise and may be useful for the detection and better discrimination of discrete pathologies. Assessment of shoulder pathologies was feasible with improved image quality as well as higher SNR using a compressed sensing deep learning-based framework for image reconstructions and denoising.

KEY POINTS

• Automated deep learning-based reconstructions showed a significant increase in signal-to-noise ratio and contrast-to-noise ratio (p < 0.04) with only a slight increase of reconstruction time of 40 s compared to CS. • All pathologies were accurately detected with no loss of diagnostic information or prolongation of the scan time. • Significant improvements of the image quality as well as the visibility of the rotator cuff, articular cartilage, and axillary recess were detected.

Development and clinical validation of deep learning for auto-diagnosis of supraspinatus tears

BACKGROUND

Accurately diagnosing supraspinatus tears based on magnetic resonance imaging (MRI) is challenging and time-combusting due to the experience level variability of the musculoskeletal radiologists and orthopedic surgeons. We developed a deep learning-based model for automatically diagnosing supraspinatus tears (STs) using shoulder MRI and validated its feasibility in clinical practice.

MATERIALS AND METHODS

A total of 701 shoulder MRI data (2804 images) were retrospectively collected for model training and internal test. An additional 69 shoulder MRIs (276 images) were collected from patients who underwent shoulder arthroplasty and constituted the surgery test set for clinical validation. Two advanced convolutional neural networks (CNN) based on Xception were trained and optimized to detect STs. The diagnostic performance of the CNN was evaluated according to its sensitivity, specificity, precision, accuracy, and F1 score. Subgroup analyses were performed to verify its robustness, and we also compared the CNN's performance with that of 4 radiologists and 4 orthopedic surgeons on the surgery and internal test sets.

RESULTS

Optimal diagnostic performance was achieved on the 2D model, from which F1-scores of 0.824 and 0.75, and areas under the ROC curves of 0.921 (95% confidence interval, 0.841-1.000) and 0.882 (0.817-0.947) were observed on the surgery and internal test sets. For the subgroup analysis, the 2D CNN model demonstrated a sensitivity of 0.33-1.000 and 0.625-1.000 for different degrees of tears on the surgery and internal test sets, and there was no significant performance difference between 1.5 and 3.0 T data. Compared with eight clinicians, the 2D CNN model exhibited better diagnostic performance than the junior clinicians and was equivalent to senior clinicians.

CONCLUSIONS

The proposed 2D CNN model realized the adequate and efficient automatic diagnoses of STs, which achieved a comparable performance of junior musculoskeletal radiologists and orthopedic surgeons. It might be conducive to assisting poor-experienced radiologists, especially in community scenarios lacking consulting experts.

Deep Learning Diagnosis and Classification of Rotator Cuff Tears on Shoulder MRI

BACKGROUND

Detection of rotator cuff tears, a common cause of shoulder disability, can be time-consuming and subject to reader variability. Deep learning (DL) has the potential to increase radiologist accuracy and consistency.

PURPOSE

The aim of this study was to develop a prototype DL model for detection and classification of rotator cuff tears on shoulder magnetic resonance imaging into no tear, partial-thickness tear, or full-thickness tear.

MATERIALS AND METHODS

This Health Insurance Portability and Accountability Act-compliant, institutional review board-approved study included a total of 11,925 noncontrast shoulder magnetic resonance imaging scans from 2 institutions, with 11,405 for development and 520 dedicated for final testing. A DL ensemble algorithm was developed that used 4 series as input from each examination: fluid-sensitive sequences in 3 planes and a sagittal oblique T1-weighted sequence. Radiology reports served as ground truth for training with categories of no tear, partial tear, or full-thickness tear. A multireader study was conducted for the test set ground truth, which was determined by the majority vote of 3 readers per case. The ensemble comprised 4 parallel 3D ResNet50 convolutional neural network architectures trained via transfer learning and then adapted to the targeted domain. The final tear-type prediction was determined as the class with the highest probability, after averaging the class probabilities of the 4 individual models.

RESULTS

The AUC overall for supraspinatus, infraspinatus, and subscapularis tendon tears was 0.93, 0.89, and 0.90, respectively. The model performed best for full-thickness supraspinatus, infraspinatus, and subscapularis tears with AUCs of 0.98, 0.99, and 0.95, respectively. Multisequence input demonstrated higher AUCs than single-sequence input for infraspinatus and subscapularis tendon tears, whereas coronal oblique fluid-sensitive and multisequence input showed similar AUCs for supraspinatus tendon tears. Model accuracy for tear types and overall accuracy were similar to that of the clinical readers.

CONCLUSIONS

Deep learning diagnosis of rotator cuff tears is feasible with excellent diagnostic performance, particularly for full-thickness tears, with model accuracy similar to subspecialty-trained musculoskeletal radiologists.

Detection of the rotator cuff tears using a novel convolutional neural network from magnetic resonance image (MRI)

The rotator cuff tear is a common situation for basketballers, handballers, or other athletes that strongly use their shoulders. This injury can be diagnosed precisely from a magnetic resonance (MR) image. In this paper, a novel deep learning-based framework is proposed to diagnose rotator cuff tear from MRI images of patients suspected of the rotator cuff tear. First, we collected 150 shoulders MRI images from two classes of rotator cuff tear patients and healthy ones with the same numbers. These images were observed by an orthopedic specialist and then tagged and used as input in the various configurations of the Convolutional Neural Network (CNN). At this stage, five different configurations of convolutional networks have been examined. Then, in the next step, the selected network with the highest accuracy is used to extract the deep features and classify the two classes of rotator cuff tear and healthy. Also, MRI images are feed to two quick pre-trained CNNs (MobileNetv2 and SqueezeNet) to compare with the proposed CNN. Finally, the evaluation is performed using the 5-fold cross-validation method. Also, a specific Graphical User Interface (GUI) was designed in the MATLAB environment for simplicity, which allows for testing by detecting the image class. The proposed CNN achieved higher accuracy than the two mentioned pre-trained CNNs. The average accuracy, precision, sensitivity, and specificity achieved by the best selected CNN configuration are equal to 92.67%, 91.13%, 91.75%, and 92.22%, respectively. The deep learning algorithm could accurately rule out significant rotator cuff tear based on shoulder MRI.

Interpositional scaffold anchor rotator cuff footprint tear repair: excellent survival, healing, and early outcomes

PURPOSE

Shoulder function limitation duration after a full-thickness rotator cuff tendon (RCT) tear may influence post-repair healing and outcomes. A suture anchor was developed to improve footprint repair fixation and healing through biological fluid delivery and scaffold augmentation. The primary multicenter study objective was to evaluate RCT repair failure rate based on 6-month MRI examination, and device survival at 1-year follow-up. The secondary objective was to compare the clinical outcomes of subjects with shorter- and longer-term shoulder function limitation duration.

METHODS

Seventy-one subjects (46 men) with moderate-to-large RCT tears (1.5-4 cm), at a median 61 years of age (range = 40-76), participated in this study. Pre-repair RCT tear location/size and 6-month healing status were confirmed by an independent radiologist. Subjects with shorter- (Group 1: 17.8 ± 21 days, n = 37) and longer-term (Group 2: 185.4 ± 89 days, n = 34) shoulder function limitation durations were also compared over 1 year for active mobility, strength, American Shoulder and Elbow Surgeon's Shoulder Score (ASES score), Veterans RAND 12 Item Health Survey (VR-12), and visual analog scale (VAS) pain and instability scores.

RESULTS

Three of the 52 subjects [5.8%] who underwent 6-month MRI experienced a re-tear at the original RCT footprint repair site. By the 1-year follow-up, overall anchor survival was 97%. Although Group 2 displayed lower ASES and VR-12 scores pre-repair (ASES = 40.1 ± 17 vs. 47.9 ± 17; VR-12 physical health (PH) = 37.2 ± 9 vs. 41.4 ± 8) (p ≤ 0.048), at 3-month post-RCT repair (ASES = 61.3 ± 19 vs. 71.3 ± 20; VR-12 PH = 40.8 ± 8 vs. 46.8 ± 9) (p ≤ 0.038), and at 6-month post-RCT repair (ASES = 77.4 ± 18 vs. 87.8 ± 13; VR-12 PH = 48.9 ± 11 vs. 54.0 ± 9) (p ≤ 0.045), by 1-year post-RCT repair, groups did not differ (n.s.). Between-groups VR-12 mental health score differences were not evident at any time period (n.s.). Shoulder pain and instability VAS scores also did not differ (n.s.), displaying comparable improvement between groups from pre-RCT repair to 1-year post-RCT repair. Groups had comparable active shoulder mobility and strength recovery at each follow-up (n.s.).

CONCLUSION

At 6-month post-RCT repair, only 3/52 of patients [5.8%] had a footprint re-tear, and at 1-year follow-up, overall anchor survival was 97%. Use of this scaffold anchor was associated with excellent early clinical outcomes regardless of shoulder function impairment duration.

LEVEL OF EVIDENCE

II.

Handheld Ultrasound Does not Replace Magnetic Resonance Imaging for Diagnosis of Rotator Cuff Tears

Purpose

The purpose of this study was to examine the reliability and validity of handheld ultrasound (HHUS) alone versus conventional ultrasound (US) or magnetic resonance imaging (MRI) for diagnosis of rotator cuff tears and versus MRI plus computed tomography (CT) for diagnosis of fatty infiltration.

Methods

Adult patients with shoulder complaints were included in this study. HHUS of the shoulder was performed twice by an orthopedic surgeon and once by a radiologist. RCTs, tear width, retraction and FI were measured. Inter- and intrarater reliability of the HHUS was calculated using a Cohen's kappa coefficient. Criterion and concurrent validity were calculated using a Spearman's correlation coefficient.

Results

Sixty-one patients (64 shoulders) were included in this study. Intra-rater agreement of HHUS for assessment of RCTs (к = 0.914, supraspinatus) and FI (к = 0.844, supraspinatus) was moderate to strong. Interrater agreement was none to minimal for the diagnosis of RCTs (к = 0.465, supraspinatus) and FI (к = 0.346, supraspinatus). Concurrent validity of HHUS compared to MRI was fair for diagnosis of RCTs (r = 0.377, supraspinatus) and fair-to-moderate FI (r = 0.608, supraspinatus). HHUS shows a sensitivity of 81.1% and specificity of 62.5% for diagnosis of supraspinatus tears, 60% and 93.1% for subscapularis tears, 55.6% and 88.9% for infraspinatus tears.

Conclusions

On the basis of findings in this study, we conclude that HHUS is an aid in diagnosis of RCTs and higher degrees of FI in patients who are not obese, but it does not replace MRI as the gold standard. Further clinical studies on the application of HHUS comparing HHUS devices in larger patient populations and healthy patients are required to identify its utility in clinical practice.

Level of Evidence

Level III.

ViVGG19: Novel exemplar deep feature extraction-based shoulder rotator cuff tear and biceps tendinosis detection using magnetic resonance images

BACKGROUND AND PURPOSE

Rotator cuff tear (RCT) and biceps tendinosis (BT) are the two most common shoulder disorders worldwide. These disorders can be diagnosed using magnetic resonance imaging (MRI), but the expert interpretation is manual, time-consuming, and subjected to human errors. Therefore, a fixed-size feature extraction model was created to objectively and accurately perform automated binary classification of RCT vs. normal and BT vs. normal on MRI images.

MATERIALS AND METHODS

We have developed an exemplar deep feature extraction model to diagnose RCT and BT disorders. The model was tested on a new MR image dataset comprising transverse, sagittal, and coronal MRI images of the shoulder that had been organized into three cases. BT was studied on transverse MRI images (Case 1), while RCT was studied on sagittal (Case 2) and coronal MRI images (Case 3). Our model comprised deep feature generation using a pre-trained VGG19, feature selection using iterative neighborhood component analysis (INCA), and classification using shallow standard classifiers k-nearest neighbors (KNN), support vector machine (SVM), and artificial neural network (ANN). In the feature extraction phase, two fully connected layers were used to extract deep features from the original image, and sixteen fixed-size patches obtained by the division of the original image. This model was named Vision VGG19 (ViVGG), analogous to vision transformers (ViT). The feature vector is extracted from the raw image dataset, and 16 feature vectors are extracted from each fixed-size patch. Seventeen feature vectors obtained from each image are obtained from fc6 and fc7 layers of the pre-trained VGG19, are merged to obtain final feature vector. INCA was used to choose the top features from the created features, and the chosen features were classified using shallow classifiers.

RESULTS

We defined three cases to evaluate the proposed ViVGG19 to diagnose RT and BCT disorders. Our proposed ViVGG19 model achieved more than 99% accuracy using the KNN classifier.

CONCLUSIONS

ViVGG19 is a very effective model for detecting RCT and BT disorders on shoulder MRI images. The developed automated system is ready to be tested with a bigger diverse database obtained from different medical centers.

Correlation between the incidence of rotator cuff lesion in traumatic unilateral anterior glenohumeral dislocation and the contralateral shoulder

INTRODUCTION

Anterior glenohumeral dislocation in patients older than 60 years is related to rotator cuff lesion because of its pre-existing degenerative condition. However, in this age group, the scientific evidence fails to elucidate whether rotator cuff lesions are the cause or consequence of recurrent shoulder instability. The objective of this paper is to describe the prevalence of rotator cuff injuries in a series of consecutive shoulders in patients older than 60 years who suffered a first episode of traumatic glenohumeral dislocation, and its correlation with rotator cuff injuries in both shoulders.

METHODS

Retrospectively, 35 patients over 60 years of age who had a first episode of unilateral traumatic anterior glenohumeral dislocation and who had MRI of both shoulders were studied, evaluating both shoulders with MRI to determine the structural damage correlation of the rotator cuff and long head of the biceps between them.

RESULTS

When assessing the existence of partial or complete injury to the supraspinatus and infraspinatus tendons, the concordance on the affected and healthy sides, we have shown concordant results on both sides in 88.6 and 85.7%, respectively. The Kappa concordance coefficient was 0.72 for supraspinatus and infraspinatus tendons tear. Of the total of 35 cases evaluated, 8 (22.8%) presented at least some alteration in the tendon of the long head of the biceps on the affected side and only one (2.9%) on the healthy side, where the Kappa coefficient of concordance was 0.18. Of the 35 cases evaluated, 9 (25.7%) presented at least some retraction in the tendon of the subscapularis muscle on the affected side, while no participant showed signs of retraction in the tendon of this muscle on the healthy side.

CONCLUSIONS

Our study has found a high correlation of the presence of a postero-superior rotator cuff injury after presenting a glenohumeral dislocation between the shoulder that has suffered the event and the presumably healthy contralateral shoulder. Nevertheless, we have not found this same correlation with subscapularis tendon injury and medial biceps dislocation.

MRI evaluation of shoulder pathologies in wheelchair users with spinal cord injury and the relation to shoulder pain

OBJECTIVE

To describe the number, specifics and co-occurrence of shoulder pathologies detected by MRI in manual wheelchair users with spinal cord injury and to evaluate the association between shoulder pathologies and presence of shoulder pain.

DESIGN

Cross-sectional observation study.

SETTING

Community.

PARTICIPANTS

Fifty-one wheelchair-dependent persons with spinal cord injury (44 males, 7 females, median age 50 years (IQR 14), median time since injury 24 years (IQR 16)) were allocated to pain or no-pain group based on the Wheelchair User Shoulder Pain Index.

INTERVENTIONS

Not applicable.

OUTCOME MEASURES

All persons underwent shoulder MRI. Pathologies were scored blinded by two experienced radiologists. Participant characteristics, number and severity of shoulder pathologies were analyzed descriptively. Logistic regression was performed to evaluate the association between MRI findings and shoulder pain.

RESULTS

The median number of co-occurring MRI findings per person ranged from 0 to 19 (out of 31 possible findings). The cluster of MRI findings occurring most often together were tendon tears of supraspinatus (present in 84%), subscapularis (69%) and biceps (67%) and osteoarthritis of acromioclavicular joint (80%). When correcting for age and time since injury, the logistic regression showed no statistically significant correlation between the individual pathologies and shoulder pain.

CONCLUSION

MRI findings of shoulder pathology are very frequent in persons with and without shoulder pain. Therefore, when diagnosing the cause of shoulder pain and planning interventions, health care professionals should keep this finding in mind and MRI should not be interpreted without careful consideration of clinical history and functional testing.

Arthroscopic Anchorless Transosseous Rotator Cuff Repair Produces Equivalent Clinical Outcomes and Imaging Results as a Standard Suture Bridge Technique with Anchors

Purpose

To compare the clinical and imaging outcome of arthroscopic transosseous (TO)-equivalent rotator cuff repair (RCR) with anchors with arthroscopic anchorless TO RCR at a minimum of 2 years postoperatively.

Methods

The study population included patients who underwent RCR using either an anchorless TO technique with a TO suture passing device (group A) and those who were matched for tear size and underwent RCR using suture anchors for repair (group B). The inclusion criterion was an easily reducible rotator cuff tear with a sagittal extension of 2 to 4 cm. After a minimum of 2 years, clinical outcome scores and magnetic resonance imaging were obtained. Tendon quality and footprint integration were evaluated using the Sugaya classification.

Results

Seventy patients were included. A total of 45 were in group A and 25 were in group B. Group A had 2 bone tunnels and 4 sutures using an X-box configuration, and group B had a suture bridge construct of 4 anchors. Group A and B had identical anteroposterior tear size and were comparable for age. The Constant score improved from 50 ± 17.4 to 88 ± 8.6 in group A versus 48 ± 14.5 to 87 ± 7.2 in B. The Subjective Shoulder Value rose from 47 ± 19.1 to 95 ± 7.4 in group A vs from 47 ± 19.4 to 95 ± 7.6 in B. Neither the preoperative (P ≥ .502) nor postoperative scores (P ≥ .29) showed a significant difference. Magnetic resonance imaging showed 2 small retears in group A and one in B, resulting in an identical 4% retear rate. The mean Sugaya type was 2.02 versus 2.24 (P = .206) for groups A versus B.

Conclusions

Anchorless TO RCR is a valid alternative to suture anchor techniques. Clinical outcome data showed comparable results for both techniques after a follow-up of 2 years. The healing results as observed on magnetic resonance imaging were also equivalent for both groups.

Level of Evidence

Level III, retrospective comparative study.

Rotator Cuff Injury and Repair

Rotator cuff pathology is a commonly encountered clinical and radiologic entity that can manifest as tendinopathy or tearing. Magnetic resonance imaging (MRI) and ultrasonography offer similar sensitivity and specificity for the evaluation of the native rotator cuff, and the chosen modality may vary, depending on local practice and accessibility. MR arthrography is frequently used in the postoperative setting as a problem-solving tool. Key findings to include in the preoperative MRI report include the size and location of the tear, thickness of the tendon involved (partial versus full thickness), and overall tendon quality. The report should also address features associated with poor surgical outcomes, such as fatty atrophy, a decreased acromiohumeral interval, and evidence of rotator cuff arthropathy. Musculoskeletal radiologists should be familiar with the various surgical techniques and expected postoperative imaging appearance of rotator cuff repairs. Imaging also plays a role in identifying recurrent tearing, graft failure, hardware loosening, infection, and other complications.

Recommended Musculoskeletal and Sports Ultrasound Terminology: A Delphi-Based Consensus Statement

OBJECTIVES

The current lack of agreement regarding standardized terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice, and research. This consensus was developed to provide a reference to improve clarity and consistency in communication.

METHODS

A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus which was defined as group level agreement >80%.

RESULTS

Content was organized into seven general topics including: 1) General Definitions, 2) Equipment and Transducer Manipulation, 3) Anatomic and Descriptive Terminology, 4) Pathology, 5) Procedural Terminology, 6) Image Labeling, and 7) Documentation. Terms and definitions which reached consensus agreement are presented herein.

CONCLUSIONS

The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients, and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

Supraspinatus pathology on MRI is associated with degree of weakness on dynamic clinical strength testing

OBJECTIVE

To analyze shoulder strength and function in patients presenting with possible supraspinatus pathology and to ascertain if these clinical findings are associated with severity of supraspinatus pathology on MRI.

MATERIALS AND METHODS

In total, 171 patients with presumptive rotator cuff pathology and with preserved strength on standard rotator cuff examination were prospectively recruited. Patients were subjected to bilateral shoulder strength testing employing dynamometry; this included isometric strength testing at 90° of abduction, followed by eccentric assessment of isotonic strength from full abduction through the full range of motion until the arm rested at the patient's side. We calculated absolute strength and symptomatic-to-asymptomatic arm (S/A) strength ratios. On subsequent shoulder MRI, supraspinatus pathology was designated into one of seven categories. The association between strength measurements and MRI findings was analyzed.

RESULTS

Increasing lesion severity on MRI was associated with both decreasing absolute strength (no tear [59.9 N] to full-thickness tear [44.2 N]; P = 0.036) and decreasing S/A strength ratios during isotonic testing (no tear [91.9%] to full-thickness tear [65.3%]; P = 0.022). In contrast, there were no significant relationships between imaging severity and absolute strength or S/A strength ratios on isometric testing.

CONCLUSION

Severity of supraspinatus pathology on MRI was associated with dynamic clinical function. These results validate the clinical correlation between MRI designations of supraspinatus pathology and function and suggest the need for future work to investigate utility of dynamic (versus isometric) rotator cuff physical examination maneuvers.

[Postoperative imaging of the shoulder]

BACKGROUND

Imaging of the postoperative shoulder joint includes complex, diagnostically challenging changes regarding the anatomical structures.

OBJECTIVES

Case-based presentation of common surgical procedures, expected postoperative findings, and typical complications.

MATERIALS AND METHODS

Interdisciplinary evaluation of (didactically instructive) cases and discussion of pertinent literature and expert opinions.

RESULTS

Presentation of normal postoperative findings and complications after subacromial decompression, surgical treatment of rotator cuff lesions, SLAP (superior labral anterior to posterior) lesions/lesions of the long biceps tendon, Bankart lesions as well as instability-related procedures and after shoulder arthroplasty. Discussion of the appropriate use of imaging methods with a focus on magnetic resonance imaging (MRI), which are supplemented by computed tomography (CT), and conventional x‑ray images.

CONCLUSION

The broad spectrum of complex findings as well as the evermore developing and thereby changing surgical procedures result in significant challenges in the radiological evaluation of the postoperative shoulder joint. To differentiate physiological reactions from pathological changes it is necessary to have general knowledge of the common surgical procedures, expected postoperative findings and possible complications. A variety imaging modalities can be used to further advance diagnostic precision.

Assessment of Acute Lesions of the Biceps Pulley in Patients with Traumatic Shoulder Dislocation Using MR Imaging

Background: Shoulder dislocations represent common injuries and are often combined with rotator cuff tears and potentially damage to the biceps pulley. Purpose: To assess the occurrence and type of biceps pulley lesions in patients after traumatic anterior shoulder dislocation using 3T MRI. Methods: Thirty-three consecutive patients were enrolled between June 2021 and March 2022 (14 women, mean age 48.0 ± 19 years). All patients underwent MR imaging at 3 T within one week. Images were analyzed for the presence and type of pulley tears, subluxation/dislocation of the LHBT, rotator cuff lesions, joint effusion, labral lesions, and osseous defects. Results: Seventeen patients (52%) with traumatic anterior shoulder dislocation demonstrated biceps pulley lesions. Of those, eleven patients (33%) showed a combined tear of the sGHL and CHL. All seventeen patients with lesions of the biceps pulley showed associated partial tearing of the rotator cuff, whereas three patients showed an additional subluxation of the LHBT. Patients with pulley lesions after dislocations were significantly older than those without (mean age 52 ± 12 years vs. 44 ± 14 years, p = 0.023). Conclusion: Our results suggest an increased awareness for lesions of the biceps pulley in acute traumatic shoulder dislocation, particularly in patients over 45 years.

Insurance status is not a predictor of rotator cuff tear magnitude

Background

Rotator cuff tear (RCT) chronicity is an important factor in considering treatment options and outcomes for surgical repair. Many factors may contribute to delayed treatment, including timely access to care due to insurance status. The purpose of this study was to evaluate the relationship between the magnitude of RCT on presentation and insurance status. We hypothesize that publicly insured patients will have a greater incidence of chronic RCTs and shoulder pathology on initial presentation.

Methods

Retrospective chart review of patients undergoing RCT repair at an academic tertiary care institution from 2005 to 2019. Demographic data, including age, race, sex, and insurance carrier, were collected. Insurance carriers were categorized into public (Medicare and Medicaid) or private insurance coverage. Individual magnetic resonance imagings were then reviewed by a board-certified musculoskeletal radiologist for supraspinatus (SS), infraspinatus (IS), subscapularis, and biceps tendon tears, as well as acromioclavicular arthritis. In addition, rotator cuff atrophy was evaluated by the scapular ratio. Univariate analysis of variance and logistic regression analyses were used to compare demographics and rotator cuff pathology between those with Medicaid and Medicare, as well as between publicly and privately insured patients.

Results

Of the 492 patients in this study, 192 had private insurance, and 300 had public insurance (Medicaid: 50 and Medicare: 250). Insurance status was not found to be associated with differences in RCTs between Medicare and Medicaid patients. Those with Medicaid or Medicare (public), presented more frequently with SS or IS atrophy (SS atrophy, P = .002; IS atrophy, P = .039) than those with private insurance. However, after adjusting for age, no significant differences in rotator cuff tendon tear or atrophy frequencies were found between insurance groups.

Conclusions

Patients with private and public insurance tend to present with similar chronicity and magnitude of RCTs. Insurance status does not appear to influence timely access to surgical care for patients with RCTs at an academic medical center.

Factors Associated with Shoulder Range of Motion After Arthroscopic Rotator Cuff Repair: A Hospital‐Based Prospective Study

Objective

To assess the factors associated with outcomes of arthroscopic surgical repair of rotator cuff tears (RCTs).

Method

This prospective study recruited patients, at least 18 years old, who underwent arthroscopic rotator cuff repair for full‐thickness RCTs at the First People's Hospital of Hangzhou Xiaoshan between July 2019 and October 2020. Patient demographics, lifestyle habits, and medical histories were collected preoperatively; RCT sizes and affected tendons were determined intraoperatively. Outcomes were assessed by shoulder range of motion (ROM) determinations 1.5 and 3 months postoperatively. The factors associated with ROM were determined using a binary logistic regression analysis, and the results were expressed as adjusted relative risks (RRs) and 95% confidence intervals (CIs).

Results

A total of 132 patients with RCTs underwent arthroscopic surgery. Five were lost to follow‐up, leaving 127 patients (mean age, 59 years; 58.3% women) who were included in the study analysis. The majority of the patients (54.5%) had RCTs that were classified as large or massive, and approximately 20% had tears involving multiple tendons; 80.3% of the patients had tears involving only a single tendon. Moreover, 29.9% of the patients had hypertension and 11.0% had diabetes. Among the patients, 23.0% were smokers and 34.6% drank alcohol. According to the multivariate analysis, none of the assessed factors were associated with shoulder ROM at the 1.5‐month follow‐up. At the 3‐month follow‐up, RCTs involving a single tendon demonstrated 3‐fold better abduction (RR = 4.00; 95% CI, 1.30–12.33; P = 0.016) and 3.15‐fold better internal rotation (RR = 3.15; 95% CI, 1.19–8.36; P = 0.021) than did RCTs involving multiple tendons. Patients who did not drink alcohol demonstrated 6.08‐fold better anteflexion (RR = 7.08; 95% CI, 2.11–23.73; P = 0.002) and nearly 4‐fold better abduction (RR = 4.97; 95% CI, 1.62–15.23; P = 0.005) than patients who drank alcohol.

Conclusion

To improve outcomes, the results indicate that more targeted measures should be directed toward patients with multiple‐tendon RCTs and that preoperative alcohol abstinence education is needed for patients with RCTs.

Factors Influencing the Size of a Non-Traumatic Full-Thickness Rotator Cuff Tear: Focusing on Socioeconomic Factors

This study aimed to identify the risk factors for non-traumatic rotator cuff tears in Korean adult patients who underwent surgical treatment, focusing on socioeconomic factors. A retrospective study was conducted with 659 patients who were diagnosed with a full rotator cuff tear and underwent surgical treatment. The outcome variable was the rotator cuff tear size (mm), as indicated by preoperative magnetic resonance imaging. Socioeconomic variables included occupation, education level, insurance type, and residential area. Univariate analyses were used to evaluate the relation between tear size and independent variables, and multivariate regression was used to estimate the effects of socioeconomic factors on tear size after adjusting for other variables. Significant differences were found in mean tear size according to age, occupation, residence area, and symptom duration (p < 0.05) in multivariate regression analysis. Rural residents had a 2.12 mm larger tear size than urban residents. Compared to National Health Insurance patients, the tear size of Medicaid beneficiaries was significantly larger (6.79 mm) in urban areas. The larger the rotator cuff tear, the greater the risk of retear and poor shoulder function. Therefore, policy efforts are required to expand access to medical care for the vulnerable.

Usefulness of ultrasound in diagnosing long head of the biceps tendon malposition in patients with rotator cuff tears

PURPOSE

This study aimed to determine the role of preoperative shoulder ultrasonography (SUS) in detecting positional abnormalities of the long head of the biceps tendon (LHBT) and predicting subscapularis (SSC) tears in patients with rotator cuff injuries.

METHODS

A total of 331 patients (365 shoulders) who had undergone arthroscopic shoulder surgery for the treatment of rotator cuff tears were included in the study. Their preoperative SUS and magnetic resonance imaging (MRI) findings were examined retrospectively to assess the presence of LHBT abnormalities at the bicipital groove. Using arthroscopic findings as the standard of reference, the sensitivity, specificity, and diagnostic accuracy of SUS and MRI were calculated for detection of LHBT malposition. Furthermore, the correlation between SSC rupture and preoperative LHBT condition was evaluated by MRI and SUS.

RESULTS

LHBT malposition was preoperatively diagnosed with a sensitivity of 92%, specificity of 90%, and accuracy of 91% with SUS, and a sensitivity of 74%, specificity of 84%, and accuracy of 80% with MRI. Preoperative SUS was significantly superior to MRI in terms of sensitivity, specificity, and accuracy (p < 0.001 each). Further, the preoperative SUS LHBT findings could predict well the presence or absence of intraoperative SSC rupture (odds ratio: 1.73, p < 0.001).

CONCLUSION

SUS is a useful diagnostic modality for preoperative detection of LHBT malposition and prediction of SSC tears in patients with rotator cuff tears.

Advantages of 3-dimensional Measurements for Supraspinatus Intramuscular Fatty Evaluation in Patients With Medium to Massive Rotator Cuff Tears: Comparison With a Single Sagittal Slice

BACKGROUND

Fatty infiltration of the rotator cuff muscles is highly related to poor outcomes after rotator cuff tears. Fat fraction (FF) based on traditional 2-dimensional measurements (2D-FF) from a single sagittal Y-view slice cannot determine intramuscular FF in the rotator cuff muscles; the newly developed 3-dimensional method (3D-FF) is supposed to precede 2D measurements for intramuscular FF evaluation in accuracy and reliability.

PURPOSE

(1) To measure 3D-FF and (2) to compare 3D-FF and 2D-FF in terms of quantitative values and intra- and interobserver agreement.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Six-point Dixon magnetic resonance imaging was performed in patients with full-thickness supraspinatus tears. 2D-FF was calculated on a single sagittal Y-view. Semiautomatic segmentation software (ITK-SNAP) was used to reconstruct 3D volumes of the supraspinatus muscle and fat. 3D-FF was obtained by dividing the fat volume by the total volume of the supraspinatus muscle. A paired t test was used to compare the individual differences between 2D-FF and 3D-FF results. Linear regression and Bland-Altman analyses were performed to determine the agreement between 2D-FF and 3D-FF. Intraclass correlation coefficients (ICCs) were calculated to determine intra- and interobserver agreement.

RESULTS

The 3D muscular and fatty models presented an inhomogeneous distribution of intramuscular fat in the supraspinatus, indicating the superiority of 3D-FF over 2D-FF in capturing all muscle morphologic information. 2D-FF was significantly higher than 3D-FF in the supraspinatus with large (19.5% ± 5.9% vs 16.2% ± 3.7%; P = .002) and massive (34.8% ± 13.3% vs 26.2% ± 9.4%; P < .001) rotator cuff tears. 2D-FF overestimated the FF compared with 3D-FF by >50% in 14.7% of all patients and by >15% in 67.6% of patients with large or massive RCTs. The discrepancy between 2D-FF and 3D-FF increased with increasing mean FF. The intra- and interobserver agreement of 3D-FF (ICCs, 0.89-0.99 and 0.89-0.95) was superior to that of 2D-FF (ICCs, 0.71-0.95 and 0.64-0.79).

CONCLUSION

3D-FF indicated an inhomogeneous distribution of intramuscular fat by capturing all muscle and fat morphologic information. In patients with large and massive rotator cuff tears, 2D-FF of the supraspinatus was significantly higher than 3D-FF. 3D-FF was more reliable than 2D-FF for estimating fatty infiltration in the supraspinatus, with better intra- and interobserver agreement.

Recommended musculoskeletal and sports ultrasound terminology: a Delphi-based consensus statement

The current lack of agreement regarding standardised terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice and research. This consensus was developed to provide a reference to improve clarity and consistency in communication. A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus, which was defined as group level agreement of >80%. Content was organised into seven general topics including: (1) general definitions, (2) equipment and transducer manipulation, (3) anatomical and descriptive terminology, (4) pathology, (5) procedural terminology, (6) image labelling and (7) documentation. Terms and definitions which reached consensus agreement are presented herein. The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

Role of Magnetic Resonance Imaging in the Evaluation of Rotator Cuff Tears

Background

Magnetic resonance imaging (MRI), with the advent of surface coils, is becoming the modality of choice for imaging soft tissues around the shoulder joint. Good knowledge regarding the MR characteristics of rotator cuff tendons, acromion, and the abnormalities in these tendons is necessary for appropriate diagnosis.

Methods

This was a hospital-based descriptive, analytical and prospective study conducted at our tertiary care hospital. The study was performed on 50 patients with rotator cuff lesions detected on MRI of the shoulder joint.

Results

The age distribution found in the study is between 19 and 66 years with mean being 43 ± 14.8 years. The peak incidence was found in the fifth and sixth decades of life. Gender-wise distribution of rotator cuff pathologies has shown no significant gender variation. The pain was the most common presenting complaint. An abnormal supraspinatus tendon was seen in 82% of the 50 study patients, making it the most commonly affected tendons, followed by subscapularis and infraspinatus tendons. No apparent teres minor pathology was identified in the study patients. The most common pathology affecting the supraspinatus tendon was tendinosis (38%) closely followed by a partial tear (36%). Among the partial tears, the articular surface type of tear was the most common. About 52% patients had type II (curved) acromion; making it the most common type of acromion followed by type III (hook), supraspinatus tendinopathy was more common in type II acromion. A reduction in the acromiohumeral distance can cause supraspinatus tendinosis and also makes it more susceptible to tear. About 45.5% showed supraspinatus tendon tears when the acromiohumeral distance was less than 8mm as compared to 13.6% when more than 10mm. Only 4.2% had normal supraspinatus tendon in patients with this distance less than 7mm.

Conclusion

MRI provides valuable information to the orthopaedic surgeon regarding the status of tendons, bones, and joints. In order to choose the appropriate course of action, it is crucial first to identify the issue and report relevant data from rotator cuff imaging. A full grasp of the rotator cuff's architecture and function, as well as the repercussions of rotator cuff diseases, is required.

Management of Acute Rotator Cuff Tears

Acute, traumatic rotator cuff tears typically occur in younger patients with a fall on an outstretched hand, grabbing an object to catch oneself when falling, or a glenohumeral dislocation. These tears are best evaluated with MRI. Partial-thickness tears may be managed nonoperatively with physical therapy, NSAIDs, and injections. Full-thickness tears in most patients should be managed with surgical repair as soon as possible, with better outcomes shown when repaired within 4 months of injury.

Can ultrasound suffice for triaging patients requiring surgical correction of rotator cuff tears—a comparative evaluation of ultrasound and magnetic resonance imaging

Background

Objectives: To comparatively evaluate the role of ultrasound and MRI in rotator cuff and biceps tendon pathologies and to establish ultrasound as a consistently reproducible, quick and accurate primary investigation modality sufficient to triage patients requiring surgical correction of full thickness rotator cuff tears. Methods: Fifty patients, clinically suspected to have rotator cuff and/or biceps tendon pathologies, with no contraindications to MRI, were evaluated by US and MRI, in a prospective cross-sectional observational study. US was done with high-frequency linear probe, and MRI was done on a 1.5-T scanner using T1 oblique sagittal, proton density (PD)/T2 fat-suppressed (FS) oblique sagittal, T1 axial, PD/T2 FS axial, T1 oblique coronal, T2 oblique coronal and PD FS oblique coronal sequences. Statistical testing was conducted with the statistical package for the social science system version SPSS 17.0. The sensitivity, specificity, PPV, NPV and accuracy were also calculated to analyze the diagnostic accuracy of US findings correlating with MRI findings. A p value less than 0.05 was taken to indicate a significant difference.

Results

Mean age was 45 years; 74% patients were males; 77% females and 60% males had tears. Majority of patients with rotator cuff tears were in the sixth decade of life. The frequency of tears was higher among older patients. Fourteen percent of patients had full thickness tears while 64% had partial thickness tears. US was comparable to MRI for detection of full thickness tears with overall sensitivity, specificity, PPV and accuracy of 93.8%, 100%, 100% and 98.2%, respectively (p value < 0.001). For partial thickness tears, US had overall sensitivity, specificity, PPV and accuracy of 75.6%, 82.6%, 89.5% and 78%, respectively (p value < 0.001), as compared to MRI. Subacromial-subdeltoid bursal effusion and long head of biceps tendon sheath effusion were common associated, though, non-specific findings.

Conclusion

Ultrasound findings in our study were found to be in significant correlation with findings on MRI in detection of rotator cuff tears. US was equivalent to MRI in detection of full thickness tears and fairly accurate for partial thickness tears. Therefore, US should be considered as the first line of investigation for rotator cuff pathologies.

Reliability of supraspinatus intramuscular fatty infiltration estimates on T1-weighted MRI in potential candidates for rotator cuff repair surgery: full-thickness tear versus high-grade partial-thickness tear

OBJECTIVE

Patients with supraspinatus high-grade partial-thickness tear or full-thickness tear are potential candidates for rotator cuff repair surgery. We sought (1) to compare supraspinatus intramuscular fatty infiltration between these groups by Goutallier grade, fuzzy C-means and an orthopaedic surgeon visible percentage estimate, (2) and to determine the reliability of each method.

MATERIALS AND METHODS

We performed a retrospective cross-sectional study of supraspinatus intramuscular fatty infiltration on T1-weighted MR images for 93 shoulders with either supraspinatus partial-thickness tear > 50% tendon thickness or full-thickness tear by Goutallier grade, fuzzy C-means and an orthopaedic surgeon visible percentage estimate, by two observers for each method. Descriptive statistics were performed to compare groups. Inter- and intra-observer reliability was determined. Correlative analysis among the three methods was performed.

RESULTS

Significant differences of mean supraspinatus intramuscular fatty infiltration were present when comparing supraspinatus high-grade partial-thickness tear versus full-thickness tears by Goutallier grade (p = 0.004), fuzzy C-means (p = 0.002) and orthopaedic surgeon visible percentage estimate (p = 0.001). There was no significant difference for age (55.0 ± 11.1 years versus 56.1 ± 9.6 years) or sex (35.4% male versus 47.8% male) for supraspinatus high-grade partial-thickness tear and full-thickness tear, respectively. A significant difference existed among the subgroup of full-thickness tears stratified by tear size by all three methods (p < 0.020). Inter- and intra-observer reliability was Goutallier grade 0.590 and 0.624, fuzzy C-means 0.768 and 0.925 and orthopaedic surgeon visible percentage estimate 0.858 and 0.686, respectively. For shoulders with mean Goutallier grade ≥ 2.0, inter-observer reliability was 0.878 and 0.802 for fuzzy C-means and orthopaedic surgeon visible percentage estimate, respectively. A strong correlation was present among the three methods of supraspinatus FI analysis (rho ≥ 0.72).

CONCLUSION

Supraspinatus full-thickness tears have higher amounts of intramuscular fatty infiltration compared to high-grade partial-thickness tear. Quantitative fuzzy C-means shows excellent inter-observer reliability for estimating supraspinatus intramuscular fat. Experienced orthopaedic surgeons' semi-quantitative estimation of supraspinatus visible intramuscular fat may offer improved reliability as compared to semi-quantitative Goutallier grade.

Magnetic resonance imaging of deltoid muscle/tendon tears: a descriptive study

OBJECTIVE

To describe the MRI features of deltoid tears and to evaluate tear characteristics in patient groups based on history of trauma and rotator cuff tear (RCT).

MATERIALS AND METHODS

The records of patients who underwent shoulder MRI at our institution between July 2007 and June 2018 were retrospectively reviewed to identify deltoid tears, and patients were divided into groups based on history of recent trauma and presence of RCT. Images were reviewed to identify the location and size of the deltoid tear; the presence or absence of RCT, muscle atrophy, tendon retraction, humeral head subluxation, soft tissue edema, and additional pathologies were also noted. Medical records were reviewed for information about history of steroid injection, previous rotator cuff surgery, and treatments used.

RESULTS

Among 69 patients with deltoid tears (45 men; mean age, 65.2 years; range, 19-89 years), patients with RCTs and no trauma had the highest frequency of deltoid tears in the middle portion (p = 0.005). Only patients with RCTs had undergone steroid injection or rotator cuff surgery. Two patients had deltoid tear without RCT and without recent trauma; these patients demonstrated evidence of calcific tendinopathy and chronic subacromial-subdeltoid bursitis.

CONCLUSION

The middle (acromial) portion of the deltoid is more frequently affected in patients with RCTs than in those with trauma. Although deltoid tears are commonly associated with RCT, calcific tendinopathy and chronic bursitis may also be seen in patients with deltoid tears.

A 5-Year Follow-up of Patients Treated for Full-Thickness Rotator Cuff Tears: A Prospective Cohort Study

Background:

The evidence in support of operative versus nonoperative management of rotator cuff tears (RCTs) is limited, based primarily on observational studies of lower scientific merit.

Purpose:

To (1) compare the efficacy of operative versus nonoperative management of full-thickness RCTs across time and (2) detect variables that predict success within each group.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

We included patients with symptomatic full-thickness RCTs who were enrolled in an institutional shoulder registry. Patient enrollment began in 2009 and continued until early 2018. The following outcome measures were collected at baseline, then 6 months, 1 year, and annually up to 5 years postoperatively: Western Ontario Rotator Cuff Index (WORC), American Shoulder and Elbow Surgeons (ASES) score, Veterans RAND 12-Item Health Survey (VR-12) mental and physical component subscales (MCS and PCS, respectively), 100-point Single Assessment Numeric Evaluation (SANE) rating, and 100-point visual analog scale (VAS) for pain and for patient satisfaction. We performed regression models for all outcome variables across all 5 years of follow-up and included the following predictor variables: treatment type (operative vs nonoperative), sex, age, symptom duration, smoking status, diabetes status, injury side, and obesity status.

Results:

A total of 595 patients were included. Longitudinal mixed-effects regression revealed that patients who received operative treatment did better across time on all outcomes. Women (n = 242; 40.7%) did not fare as well as did men on the ASES, WORC, or VR-12 PCS. Older patients tended to improve less on the VR-12 PCS and more on the VR12-MCS. Patients with longer symptom duration at baseline had better scores across time on the ASES, WORC, VAS for pain, and SANE. Current or recent smokers and patients with diabetes tended to have lower scores on all measures across time. For changes in scores from baseline, patients in the operative group improved to a larger degree out to 3 years compared with those in the nonoperative group.

Conclusion:

Patients with RCTs tended to improve regardless of whether they received operative or nonoperative treatment, but patients who underwent operative treatment improved faster. There appear to be several predictors of improved and worsened outcomes for patients with RCTs undergoing operative or nonoperative treatment.

Quadrilateral space region inflammation and other incidental findings on shoulder MRI following recent COVID-19 vaccination: Three case reports

We present 3 cases reporting the normal appearance of the post COVID-19 vaccination on shoulder MRI exams. All 3 patients were imaged 1 to 5 days post-vaccination for unrelated MSK shoulder symptoms, and none reported any symptoms besides mild shoulder discomfort for a day or 2 following vaccine administration. All 3 patients demonstrated characteristic deltoid edema, quadrilateral space region edema and axillary nodal prominence. Vessel prominence with t2 and t1 increased signal draining to the approximate location of the quadrilateral space and axilla was an associated feature. The normal appearance of the covid-19 vaccine on shoulder MRI has not been previously described, and recognition by the radiologist will prevent erroneous differential diagnosis, unnecessary medical workups, and detract from the clinically relevant pathological imaging findings in patients with shoulder pain.

Hernando M, Abascal F, Cerezal L. Myotendinous junction tear of the anterior bundle of the supraspinatus muscle—a rare pattern of injury involving rotator cuff muscles

Myotendinous junction injuries are rare and often present with distinctive imaging findings that should be differentiated from purely tendinous degenerative ruptures.

Myotendinous junction tears are common in the lower limb but rarely involve rotator cuff muscles. Considering rotator cuff muscles, the infraspinatus and supraspinatus muscles are the most frequently implicated.

The intrinsic anatomy of the supraspinatus muscle gives it a greater contractile force and consequently a propensity for rupture. It is composed of two bundles: anterior and posterior (with the latest further divided in a deep anterior, a medial and a superficial posterior portion). These two components have distinctive anatomy with the anterior bundle having a long intramuscular tendon and bipennate configuration and the posterior bundle having a smaller intramuscular tendon and parallel muscle fibres. This distinctive anatomy grants a greater contractile force to the anterior bundle of the supraspinatus muscle and for this reason it is more prone to myotendinous rupture.

This type of injury has been associated with a rapid progression to severe fatty infiltration and should be differentiated from purely tendinous tears that are more frequent and associated with degenerative changes. Myotendinous tears occur centrally located in the muscle belly and are not associated with full thickness tears of the distal tendon attachment.

Threshold-based quantification of fatty degeneration in the supraspinatus muscle on MRI as an alternative method to Goutallier classification and single-voxel MR spectroscopy

Background

Conventional fat quantification methods for rotator cuff muscles have various limitations, such as inconsistent reliabilities of the Goutallier grades and need for advanced techniques in quantitative MRI sequences. We aimed to examine a threshold-based fat quantification method in the supraspinatus muscle on standard T1-weighted MR images and compare the threshold-based method with Goutallier grades and MR spectroscopy.

Methods

We retrospectively examined 38 symptomatic patients, who underwent T1 and T2-weighted fast spin-echo MR imaging and a single voxel spin-echo MR spectroscopy. The supraspinatus muscle and fossa were manually segmented in T1-weighted sagittal images and clustering-based thresholding was applied to quantify the fat fractions in the segmented areas using custom MATLAB software. Threshold-based fat fractions were compared with the Goutallier grades and MR spectroscopy fat/water ratios. A one-way analysis of variance and Pearson correlation were tested in the MATLAB software.

Results

Inter-observer reliability of threshold-based fat fractions for the supraspinatus muscle and fossa were 0.977 and 0.990 respectively, whereas the reliability of the Goutallier grading was 0.798. Threshold-based fat fractions in the supraspinatus fossa were significantly different between various Goutallier grades (one-way ANOVA, p < 0.001). Threshold-based fat fractions in the supraspinatus muscle strongly correlated with the MR spectroscopy fat/water ratio (Pearson correlation R-square = 0.83).

Conclusions

Threshold-based fat quantification on standard T1-weighted MR images was highly reliable and produced comparable results to conventional Goutallier grades and MR spectroscopy fat/water ratios and could serve as an alternative method for accurate fat quantification in rotator cuff muscles.

MR Imaging of the Rotator Cuff

The cause of rotator cuff tears is multifactorial with both intrinsic and extrinsic contributing factors. Understanding the normal MR anatomy of the rotator cuff and using an appropriate search pattern can help readers identify common pathologic conditions. Accurate designation using classification systems for tear thickness, size, and degree of retraction and muscle fatty infiltration and atrophy are important in guiding surgical management. Knowledge of common disease locations for the rotator cuff tendons can help focus reader searches and increase sensitivity.

MRI Findings Predictive of Shoulder Stiffness in Patients With Full-Thickness Rotator Cuff Tears

OBJECTIVE. The objective of our study was to evaluate the relationship between stiff shoulder in patients with a full-thickness rotator cuff tear and MRI findings, especially joint capsule abnormality. MATERIALS AND METHODS. This study included 106 patients with small to large (≤ 5 cm) full-thickness rotator cuff tears. Joint capsule edema and thickness in the axillary recess, obliteration of the subcoracoid fat triangle, fatty degeneration of the torn rotator cuff muscle, and degree of retraction were assessed by two radiologists. The size and location of tears were determined by MRI findings and operative report. Associations between MRI findings and preoperative passive range of motion (ROM) were assessed by simple and multiple linear regression analyses and proportional odds logistic regression analysis. RESULTS. There was a significant, negative linear correlation between limited ROM at forward elevation and thickness of the joint capsule in the glenoid portion of the axillary recess (p = 0.018), external rotation and joint capsule edema in the humeral portion of the axillary recess (p = 0.011), and internal rotation and joint capsule edema in the glenoid portion of the axillary recess (p = 0.007). Male sex (p = 0.041) and posterosuperior rotator cuff tear (p = 0.030) were independent predictors of shoulder ROM on external rotation. Degree of fatty degeneration (p = 0.003) was another independent predictor of shoulder ROM on internal rotation. CONCLUSION. MRI findings-especially joint capsule edema and thickness at the axillary recess-can be useful in predicting shoulder stiffness in patients with rotator cuff tear.

Rethinking Patellar Tendinopathy and Partial Patellar Tendon Tears: A Novel Classification System

BACKGROUND

Patellar tendinopathy is an overuse injury of the patellar tendon frequently affecting athletes involved in jumping sports. The tendinopathy may progress to partial patellar tendon tears (PPTTs). Current classifications of patellar tendinopathy are based on symptoms and do not provide satisfactory evidence-based treatment guidelines.

PURPOSE

To define the relationship between PPTT characteristics and treatment guidelines, as well as to develop a magnetic resonance imaging (MRI)-based classification system for partial patellar tendon injuries.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

MRI characteristics and clinical treatment outcomes were retrospectively reviewed for 85 patients with patellar tendinopathy, as well as 86 physically active control participants who underwent MRI of the knee for other conditions. A total of 56 patients had a PPTT and underwent further evaluation for tear size and location. The relationship between tear characteristics and clinical outcome was defined with use of statistical comparisons and univariate and logistic regression models.

RESULTS

Of the 85 patients, 56 had partial-thickness patellar tendon tears. Of these tears, 91% involved the posterior and posteromedial regions of the proximal tendon. On axial MRI views, patients with a partial tear had a mean tendon thickness of 10 mm, as compared with 6.2 mm for those without (P < .001). Eleven patients underwent surgery for their partial-thickness tear. All of these patients had a tear >50% of tendon thickness (median thickness of tear, 10.3 mm) on axial views. Logistic regression showed that tendon thickness >8.8 mm correlated with the presence of a partial tear, while tendon thickness >11.45 mm and tear thickness >55.7% predicted surgical management.

CONCLUSION

Partial-thickness tears are located posterior or posteromedially in the proximal patellar tendon. The most sensitive predictor for detecting the presence of a partial tear was patellar tendon thickness, in which thickness >8.8 mm was strongly correlated with a tear of the tendon. Tracking thickness changes on axial MRI may predict the effectiveness of nonoperative therapy: athletes with patellar tendon thickness >11.5 mm and/or >50% tear thickness on axial MRI were less likely to improve with nonoperative treatment. A novel proposed classification system for partial tears, the Popkin-Golman classification, can be used to guide treatment decisions for these patients.

Arthroscopic rotator cuff repair: magnetic resonance arthrogram assessment of tendon healing

BACKGROUND

Many poor outcomes after arthroscopic rotator cuff (RC) repair relate to failure of tendon healing. The purposes of this study were to provide a better understanding of the magnetic resonance arthrography (MRA) characteristics of the RC tendon repair site after arthroscopic RC repair and to examine how these findings influence patient-reported outcome measures (PROMs) and the presence of persistent symptoms.

METHODS

We reviewed 48 shoulders (13 female and 35 male patients; average age, 53.8 years) at a minimum of 6 months (average, 11.4 months) after arthroscopic RC repair (average tear size, 2.2 cm). All patients completed PROMs and underwent MRA assessment. Detailed analysis of the RC repair site was undertaken, with findings correlated with clinical outcomes and PROMs.

RESULTS

The average preoperative American Shoulder and Elbow Surgeons (ASES) score of 39.5 improved to 92.8 (P < .001). All but 6 patients (87.5%) had increased signal intensity of the involved tendon, with interstitial splits and/or delamination in 65.6%. These changes had no effect on PROMs or patient satisfaction. Significant partial-thickness tears (>50%) were observed in 7 patients (14.6%), with no effect on outcomes (average ASES score of 95.2 and satisfaction score of 9). There were 2 recurrent full-thickness tears (4.2%), and 4 patients (8.3%) had a failure in continuity. The average ASES score in these 6 cases of failure was 76 (P < .001).

CONCLUSIONS

Structural abnormalities on MRA are common after RC repair but do not always result in clinical failure. However, our results suggest that an ASES score of less than 80 may be useful when considering postoperative imaging, especially in a patient with ongoing pain more than 6 months after surgery.

Imaging the Postsurgical Upper Limb: The Radiologist Perspective

Imaging has a paramount role in postsurgical assessment. Radiologists need to be familiar with the different surgical procedures to be able to identify expected postsurgical appearances and also detect potential complications. This article reviews the indications, normal expected postsurgical appearances, and complications of the most frequently used surgical procedures in the shoulder, elbow, and wrist. The emphasis is on points that should not be overlooked in the surgical planning.

Diagnostic and therapeutic musculoskeletal ultrasound applications of the shoulder

High frequency ultrasound is a valuable tool for assessing soft tissue injuries about the shoulder. It has advantages over other imaging modalities including relatively low cost, portability, and dynamic real-time visualization. It has a high sensitivity for identifying tendon degeneration, bursitis, and rotator cuff tears. Ultrasound is also an excellent modality for diagnostic and therapeutic needle-guided procedures. A detailed knowledge of shoulder anatomy and transducer positioning is required for obtaining adequate diagnostic value from ultrasound. This Monograph is designed to help develop scanning protocols for optimizing image acquisition for musculoskeletal assessment of the shoulder. Muscle Nerve, 2019.

Leucine attenuates muscle atrophy and autophagosome formation by activating PI3K/AKT/mTOR signaling pathway in rotator cuff tears

Rotator cuff tears (RCTs), the most common tendon injury, are always accompanied by muscle atrophy, which is characterized by excessive protein degradation. Autophagy-lysosome systems are the crucial proteolytic pathways and are activated in atrophying muscle. Thus, inhibition of the autophagy-lysosome pathway might be an alternative way to minimize skeletal muscle atrophy. In this present study, combined with a tendon transection-induced rat model of massive rotator cuff tears, HE staining and transmission electron microscopy methods, we found leucine supplementation effectively prevented muscle atrophy, muscle injury and autophagosome formation. Utilizing immunoblotting, we discovered that leucine supplementation is able to inhibit the rise in autophagy-related protein expression (including LC3, Atrogin-1, MuRF1, Bnip3 and FoxO3) driven by tendon transection. The PI3K/AKT/mTOR pathway that was essential in autophagosome formation and autophagy was blocked in atrophying muscle and reactivated in the presence of leucine. Once administrated with LY294002 (PI3K inhibitor) and Rapamycin (mTOR inhibitor), leucine mediated by the anti-atrophic effects was nearly blunted. These results suggest that leucine potentially attenuates tendon transection-induced muscle atrophy through autophagy inhibition via activating the PI3K/AKT/mTOR pathway.

Preoperative MRI Shoulder Findings Associated with Clinical Outcome 1 Year after Rotator Cuff Repair

Background Investigation of the use of preoperative MRI for providing prognostic information regarding clinical outcome following rotator cuff repair has been limited. Purpose To determine whether patients with more severe rotator cuff tears of the shoulder at preoperative MRI have a greater degree of residual pain and disability after rotator cuff repair. Materials and Methods This retrospective study included a cohort of 141 patients who underwent surgical repair of a full-thickness rotator cuff tear at a single institution between April 16, 2012, and September 3, 2015. The mean patient age was 56.8 years, and there were 100 men (mean age, 56.1 years) and 41 women (mean age, 56.3 years). Patients completed the Disabilities of the Arm, Shoulder, and Hand (DASH) survey (lower score indicates less pain and disability) before and 1 year after surgery. One musculoskeletal radiologist blinded to the DASH scores measured the maximal anterior-posterior width and medial-lateral retraction of the rotator cuff tear on the preoperative MRI and assessed tendon degeneration and composite muscle atrophy and fatty infiltration using categorical grading scales (grade 0 indicates no tendon degeneration or muscle atrophy and fatty infiltration, and higher grades indicate incrementally more severe tendon degeneration or muscle atrophy and fatty infiltration). Generalized estimating equation models were used to determine the association between preoperative MRI findings and the postoperative DASH score. Results There was a significant positive association (P < .05) between the measured tear width (estimate, 2.05), measured tear retraction (estimate, 3.52), and tendon degeneration grade (estimate, 1.59) and the postoperative DASH score. There was no significant association (P = .49) between the composite muscle atrophy and fatty infiltration grade (estimate, 0.31) and the postoperative DASH score. Conclusion Patients with larger rotator cuff tears, more tendon retraction, and more severe tendon degeneration have worse clinical outcome scores 1 year after rotator cuff repair. © RSNA, 2019.

Reduced mitochondrial lipid oxidation leads to fat accumulation in myosteatosis

Myosteatosis is the pathologic accumulation of lipid that can occur in conjunction with atrophy and fibrosis following skeletal muscle injury. Little is known about the mechanisms by which lipid accumulates in myosteatosis, but many clinical studies have demonstrated that the degree of lipid infiltration negatively correlates with muscle function and regeneration. Our objective was to determine the pathologic changes that result in lipid accumulation in injured muscle fibers. We used a rat model of rotator cuff injury in this study because the rotator cuff muscle group is particularly prone to the development of myosteatosis after injury. Muscles were collected from uninjured controls or 10, 30, or 60 d after injury and analyzed using a combination of muscle fiber contractility assessments, RNA sequencing, and undirected metabolomics, lipidomics, and proteomics, along with bioinformatics techniques to identify potential pathways and cellular processes that are dysregulated after rotator cuff tear. Bioinformatics analyses indicated that mitochondrial function was likely disrupted after injury. Based on these findings and given the role that mitochondria play in lipid metabolism, we then performed targeted biochemical and imaging studies and determined that mitochondrial dysfunction and reduced fatty acid oxidation likely leads to the accumulation of lipid in myosteatosis.-Gumucio, J. P., Qasawa, A. H., Ferrara, P. J., Malik, A. N., Funai, K., McDonagh, B., Mendias, C. L. Reduced mitochondrial lipid oxidation leads to fat accumulation in myosteatosis.