Deep learning-based screening tool for rotator cuff tears on shoulder radiography

BACKGROUND

Early diagnosis of rotator cuff tears is essential for appropriate and timely treatment. Although radiography is the most used technique in clinical practice, it is difficult to accurately rule out rotator cuff tears as an initial imaging diagnostic modality. Deep learning-based artificial intelligence has recently been applied in medicine, especially diagnostic imaging. This study aimed to develop a deep learning algorithm as a screening tool for rotator cuff tears based on radiography.

METHODS

We used 2803 shoulder radiographs of the true anteroposterior view to develop the deep learning algorithm. Radiographs were labeled 0 and 1 as intact or low-grade partial-thickness rotator cuff tears and high-grade partial or full-thickness rotator cuff tears, respectively. The diagnosis of rotator cuff tears was determined based on arthroscopic findings. The diagnostic performance of the deep learning algorithm was assessed by calculating the area under the curve (AUC), sensitivity, negative predictive value (NPV), and negative likelihood ratio (LR-) of test datasets with a cutoff value of expected high sensitivity determination based on validation datasets. Furthermore, the diagnostic performance for each rotator cuff tear size was evaluated.

RESULTS

The AUC, sensitivity, NPV, and LR- with expected high sensitivity determination were 0.82, 84/92 (91.3%), 102/110 (92.7%), and 0.16, respectively. The sensitivity, NPV, and LR- for full-thickness rotator cuff tears were 69/73 (94.5%), 102/106 (96.2%), and 0.10, respectively, while the diagnostic performance for partial-thickness rotator cuff tears was low at 15/19 (78.9%), NPV of 102/106 (96.2%) and LR- of 0.39.

CONCLUSIONS

Our algorithm had a high diagnostic performance for full-thickness rotator cuff tears. The deep learning algorithm based on shoulder radiography helps screen rotator cuff tears by setting an appropriate cutoff value.

LEVEL OF EVIDENCE

Level III: Diagnostic Study.

Can coracoacromial ligament degeneration be evaluated with preoperative MRI?

BACKGROUND

Subacromial impingement syndrome is one of the most common causes of painful shoulder in the middle-aged and elderly population. Coracoacromial ligament (CAL) degeneration is a well-known indicator for subacromial impingement.

PURPOSE

To examine the relationship between CAL thickness on preoperative magnetic resonance imaging (MRI), arthroscopic CAL degeneration and types of rotator cuff tears.

MATERIAL AND METHODS

Video records of patients who underwent arthroscopic shoulder surgery between 2015 and 2021 were retrospectively scanned through the hospital information record system. In total, 560 patients were included in this study. Video records of the surgery were used to evaluate the grade of coracoacromial ligament degeneration and the type of cuff tear. Preoperative MRI was used to measure CAL thickness, acromiohumeral distance, critical shoulder angle, acromial index, and acromion angulation.

RESULTS

Significant differences were observed between grades of CAL degeneration in terms of CAL thickness (P < 0.001). As CAL degeneration increases, the mean of CAL thickness decreases. According to the results of post-hoc analysis, the mean CAL thickness of normal patients was significantly higher than those of patients with full-thickness tears (P = 0.024) and massive tears (P <0.001). Patients with articular-side, bursal-side, and full-thickness tears had significantly higher CAL thickness averages than patients with massive tears.

CONCLUSION

This study showed that the CAL thickness decreases on MRI as arthroscopic CAL degeneration increases. High-grade CAL degeneration and therefore subacromial impingement syndrome can be predicted by looking at the CAL thickness in MRI, which is a non-invasive method.

Rotator Cuff Injuries in the Pediatric Population: A Retrospective Review of Patient Characteristics and Treatment at a Single Center

BACKGROUND

As youth participation in contact and overhead sports has increased in recent decades, so has the occurrence of injuries of the shoulder. Rotator cuff injury (RCI) is an infrequent shoulder pathology in pediatric patients and its description in the literature has been scarce. A greater understanding of RCI characteristics and treatment outcomes in children and adolescents would improve our understanding of this pathology and help to better guide clinical decision-making.

HYPOTHESIS

To identify pediatric patients with magnetic resonance imaging-confirmed RCI treated at a single center to summarize injury characteristics, treatment, and outcomes. It was hypothesized that injuries would occur predominantly in overhead throwing athletes and would demonstrate good outcomes among both operatively and nonoperatively treated patients.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 4.

METHODS

A retrospective review of pediatric patients (<18 years old) diagnosed with and treated for an RCI between January 1, 2011 and January 31, 2021. Patient demographics, injury mechanism and type, treatment, and outcomes were collected. Descriptive statistics were performed. Bivariate testing was used to compare operatively and nonoperatively treated cohorts.

RESULTS

A total of 52 pediatric patients treated for a rotator cuff avulsion, partial tear, or complete tear were identified. Mean age was 15 years and 67% of patients were male. Injuries were related most commonly to participation in throwing sports. Operative management occurred in 23% of patients, while 77% were managed nonoperatively. Treatment cohorts differed based on tear type, with all complete tears being managed operatively (P < 0.01). Associated shoulder pathology was common, with the most frequent finding being anterior shoulder instability pathology. Return to play was longer for operatively managed patients (7.1 vs 4.5 months; P < 0.01).

CONCLUSION

The present study expands the limited data available regarding RCIs in pediatric patients. Most injuries are associated with sports and involve the supraspinatus tendon. RCIs were associated with good outcomes and low rates of reinjury in patients managed both nonoperative and operatively. RCI should be considered in throwing athletes with shoulder pain, even in skeletally immature patients.

CLINICAL RELEVANCE

This retrospective study fills the hole in the literature by detailing the patterns associated with RCI characteristics and treatment outcomes. In contrast to studies of adult RCIs, our results suggest that outcomes are good regardless of treatment type.

Higher Upper Subscapularis Goutallier Grade and Coracohumeral Distance Narrowing Are Predictive of Subscapularis Tears in Patients Undergoing Arthroscopic Rotator Cuff Repair

PURPOSE

To evaluate the relation between subscapularis (SSC) Goutallier grade or coracohumeral distance (CHD) and SSC tears, as well as the relation between these radiographic variables and long head of the biceps tendon lesions.

METHODS

A retrospective analysis was conducted on prospectively maintained data on patients who underwent arthroscopic rotator cuff repair of SSC tears between 2011 and 2021 with at least 6 months of follow-up. Patients with identified subscapularis tears during arthroscopy were included. A control group was established by randomly selecting patients without SSC tears from the same study period. Goutallier grading and CHD were obtained from preoperative magnetic resonance imaging (MRI) scans. Receiver operating characteristic analysis was conducted to define optimal cutoff values for these diagnostic measures.

RESULTS

The study included 735 patients with SSC tears and 249 patients in the control group. Comparing subscapularis tear and intact groups' Goutallier grades revealed significant differences in infraspinatus, upper and lower SSC, and overall SSC (P < .001). No significant difference was detected in supraspinatus Goutallier grade (P = .364). An SSC tear was observed in 58.3% (n = 265) of patients with Goutallier grade 0 of the upper SSC, 77.1% (n = 195) of patients with grade 1 changes, 98.7% (n = 155) with grade 2 changes, and 100% of grade 3 or 4 changes. Goutallier grade of the upper SSC showed a significant correlation with tear size (rs = 0.533; P < .01). CHD measurements were lower in individuals with SSC tears compared to those without tears (6.6 ± 1.7 vs 9.6 ± 1.8; P < .001). Upper SSC Goutallier grade >1 had an acceptable area under the curve (AUC) of 0.742. CHD of 7.96 mm or less had an excellent predictive AUC of 0.879.

CONCLUSIONS

Higher Goutallier grade and CHD narrowing are potential associations predictive of SSC tears. Routine MRI assessment of muscle of the upper SSC and the CHD can contribute to the diagnostic accuracy of SSC tears and offer valuable information regarding the severity of such tears.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Magnetic resonance imaging based coracoid process morphology and its associations with isolated subscapularis tendon tears in Chinese patients

OBJECTIVES

This study aims to assess the association between isolated subscapularis tears and coracoid morphology using magnetic resonance imaging (MRI) and to calculate the optimal cut-off values of the significant predictor to predict subscapularis tears.

PATIENTS AND METHODS

Between January 2018 and December 2022, a total of 60 patients (29 males, 31 females; mean age: 58.4±8.4 years; range, 18 to 80 years) diagnosed with subscapularis tendon tears who were treated as Group A and 60 patients (29 males, 31 females; mean age: 46.8±11.5 years; range, 18 to 80 years) without subscapularis tendon tears who were treated as Group B were included. Axial coracoid-humeral distance (aCHD), sagittal coracoid-humeral distance (sCHD), coracoid overlap (CO) and coracoid angle (CA) of all patients were measured. Logistic regression was used to investigate the association between subscapularis tears as variables including aCHD, sCHD, CO and CA. Receiver operating characteristic curve analysis was used to determine the diagnostic values of coracoid morphology for subscapularis tears.

RESULTS

The mean values of CO, aCHD and sCHD in Group A were 22.16 mm, 5.13 mm, and 5.56 mm, respectively. The mean values in Group B were 16.99 mm, 7.18 mm, and 7.29 mm, respectively. The degree of CA in Group A was 95.81 and 111.69 in Group B. The differences in the above measurement values were significant between two Groups. The CO was found to be associated with higher odds of subscapularis tears. The optimal cut-off value of CO was 19.79 mm.

CONCLUSION

Based on our study results, CO is positively associated with isolated subscapularis tears. In addition, coracoid bursa effusion, cysts in the lesser tuberosity or a tear and malposition of long head of the biceps tendon on MRI may predict the presence of a clinically significant subscapularis tear.

Pneumothorax during shoulder surgery

Background

Pneumothorax following shoulder arthroscopy, although rare, is documented in over 30 PubMed case reports as occurring during or within 10 hours post-procedure.

Case Presentation

A fit septuagenarian underwent a two-hour arthroscopic rotator cuff repair with IV anaesthesia and laryngeal mask airway, without a nerve block. With one hour remaining of the operation, the patient had desaturation and hypotension. Lung sliding was absent on ultrasound and x-ray confirmed left-sided tension pneumothorax. Successful thoracic drain insertion and lung re-expansion facilitated his recovery, allowing discharge after 24 hours and symptom-free status at 6 months.

Interpretation

This case highlights pneumothorax as an uncommon yet possible post-arthroscopic event. The speculated aetiology is the surgical procedure, where pump-induced pressure fluctuations may displace air into surrounding tissue. Instances of pneumomediastinum and subcutaneous emphysema without pneumothorax suggest arthroscopic origin of air. Prompt perioperative ultrasound can aid in detecting such critical complications.

Role of Critical Shoulder Angle in Degenerative Type Rotator Cuff Tears: A Turkish Cohort Study

BACKGROUND This retrospective study investigated the association between the critical shoulder angle (CSA) and the development of full-thickness rotator cuff tears (FTRCTs) in the Turkish population. The CSA is an imaging parameter that quantifies the relationship between the inclination of the glenoid and the lateral extension of the acromion in the coronal plane. The CSA is an anatomical measurement, and higher CSA values have been associated with an increased incidence of FTRCTs. However, there is a lack of data on CSA regarding the Turkish population. MATERIAL AND METHODS In this study, CSA measurements were recorded in 2 groups: 50 patients with FTRCT who had arthroscopic repair (group 1) and 50 age- and sex-matched individuals with no FTRCT detected by magnetic resonance imaging (group 2). Sex, age, affected side, dominant side, and smoking status were recorded for each patient. The CSA measurements of the affected sides were performed on true anterior-posterior view radiographs. RESULTS The results showed a statistically significant difference between the mean CSA values of group 1 (37.48°) and group 2 (33.53°), P<0.001. CSA values of 36 and above had a sensitivity of 73.58%, specificity of 74.47%, positive predictive value of 75%, and negative predictive value of 74.47% for detecting FTRCT. CONCLUSIONS CSA measurement on radiographs is a useful diagnostic tool in the Turkish population, and an above-average CSA value is associated with a significantly increased incidence of degenerative-type FTRCT.

Natural History of Quantitative Fatty Infiltration and 3D Muscle Volume After Nonoperative Treatment of Symptomatic Rotator Cuff Tears: A Prospective MRI Study of 79 Patients

BACKGROUND

The severity of fatty infiltration (FI) predicts the treatment outcome of rotator cuff tears. The purpose of this investigation was to quantitatively analyze supraspinatus (SSP) muscle FI and volume at the initial presentation and after a 3-month minimum of conservative management. We hypothesized that progression of FI could be predicted with initial tear size, FI, and muscle volume.

METHODS

Seventy-nine shoulders with rotator cuff tears were prospectively enrolled, and 2 magnetic resonance imaging (MRI) scans with 6-point Dixon sequences were acquired. The fat fraction within the SSP muscle was measured on 3 sagittal slices, and the arithmetic mean was calculated (FI SSP ). Advanced FI SSP was defined as ≥8%, pathological FI SSP was defined as ≥13.5%, and relevant progression was defined as a ≥4.5% increase in FI SSP . Furthermore, muscle volume, tear location, size, and Goutallier grade were evaluated.

RESULTS

Fifty-seven shoulders (72.2%) had normal FI SSP , 13 (16.5%) had advanced FI SSP , and 9 (11.4%) had pathological FI SSP at the initial MRI scan. Eleven shoulders (13.9%) showed a ≥4.5% increase in FI SSP at 19.5 ± 14.7 months, and 17 shoulders (21.5%) showed a ≥5-mm 3 loss of volume at 17.8 ± 15.3 months. Five tears (7.1%) with initially normal or advanced FI SSP turned pathological. These tears, compared with tears that were not pathological, had significantly higher initial mediolateral tear size (24.8 compared with 14.3 mm; p = 0.05), less volume (23.5 compared with 34.2 mm 3 ; p = 0.024), more FI SSP (9.6% compared with 5.6%; p = 0.026), and increased progression of FI SSP (8.6% compared with 0.5%; p < 0.001). An initial mediolateral tear size of ≥20 mm yielded a relevant FI SSP progression rate of 81.8% (odds ratio [OR], 19.0; p < 0.001). Progression rates of 72.7% were found for both initial FI SSP of ≥9.9% (OR, 17.5; p < 0.001) and an initial anteroposterior tear size of ≥17 mm (OR, 8.0; p = 0.003). Combining these parameters in a logistic regression analysis led to an area under the receiver operating characteristic curve (AUC) of 0.913. The correlation between FI SSP progression and the time between MRI scans was weak positive (ρ = 0.31).

CONCLUSIONS

Three risk factors for relevant FI progression, quantifiable on the initial MRI, were identified: ≥20-mm mediolateral tear size, ≥9.9% FI SSP , and ≥17-mm anteroposterior tear size. These thresholds were associated with a higher risk of tear progression: 19 times higher for ≥20-mm mediolateral tear size, 17.5 times higher for ≥9.9% FI SSP , and 8 times higher for ≥17-mm anteroposterior tear size. The presence of all 3 yielded a 91% chance of ≥4.5% progression of FI SSP within a mean of 19.5 months.

LEVEL OF EVIDENCE

Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Intrasynovial autograft for reconstruction of chronic large rotator cuff tears in a rabbit model: biomechanical, computed tomography, and histological results

BACKGROUND

Rotator cuff (RC) tears are a common cause of shoulder dysfunction and pain, posing significant challenges for orthopedic surgeons. Grafts have been proposed as a solution to augment or bridge torn tendons, but optimal clinical outcomes are not always achieved due to poor graft integration, suboptimal mechanical properties, and immunological reactions. The aim of this study was to investigate the biomechanical, CT and histological results of RC reconstruction using an intrasynovial tendon autograft, in a chronic large tear subscapularis rabbit model.

METHODS

Twenty-six adult male Zealand white rabbits were used in this study. Large defects in the subscapularis tendons were produced bilaterally in 20 rabbits. After 6 weeks, secondary procedures were performed to the right shoulder of the rabbits, which were reconstructed with an intrasynovial interposition autograft (graft group). The left shoulder did not undergo any further treatment (defect group). The specimens were randomly divided into two equal time groups and underwent biomechanical testing, CT analysis, and histological evaluation at 6, and 12 weeks after reconstruction. In addition, 6 rabbits that were not operated, were used as a control group.

RESULTS

At 12 weeks post-repair, the graft group exhibited a significant increase in ultimate failure load compared to the defect group (p < 0.05). Furthermore, the 12-week graft group demonstrated comparable stiffness to that of the control group. CT analysis indicated no significant progression of intramuscular fat accumulation in both graft groups, in contrast to the 12-week defect group when compared to the control group. Finally, histological evaluation revealed a gradual integration of the graft with the host tissue at 12 weeks.

CONCLUSION

Our study suggests that intrasynovial flexor tendon autografts hold promise as an effective interposition graft for the reconstruction of chronic large RC tears, as they improve the biomechanical and biological properties of the repaired tendon. Nonetheless, further investigations in preclinical large animal models are warranted to validate and extrapolate these findings to human studies.

Can three-dimensional models enhance understanding and knowledge of rotator cuff tears?

OBJECTIVES

Magnetic resonance imaging (MRI) is currently the standard diagnostic tool for rotator cuff tears. However, its two-dimensional (2D) output, displayed on a monitor, can complicate the interpretation of anatomy. Three-dimensional (3D) imaging may offer a solution to this issue. This study aimed to demonstrate the diagnostic and interpretive value of a 3D model in assessing lesion anatomy. The hypothesis was that 3D models, compared to 2D MRI, can enhance the comprehension and knowledge of rotator cuff injuries, improve the application of classifications for total tears, and provide a more precise definition of the size and type of tear.

METHODS

A prospective single-centre study was conducted. 3D models for rotator cuff tears were created and analysed in conjunction with preoperative MRI for each patient up to 2 months before surgery. The 3D models were based on the preoperative MRI. Collected data included 2D plane measurements by MRI in coronal and sagittal planes, descriptions of 3D lesion geometry (new shapes), 3D measurements in coronal and sagittal planes, arthroscopic classifications of rotator cuff injuries, and arthroscopic measurements in coronal and sagittal planes.

RESULTS

After examining 25 cases, 3D imaging demonstrated similar arthroscopic values post-bursectomy in the sagittal plane (16.70 ​mm for 3D and 18.28 ​mm for post-bursectomy, p-value ​= ​0.189), although these measurements did not align with those of MRI (which underestimated measurements, p-value ​= ​0.010). Both MRI measurement and 3D imaging showed similar measurement accuracy in the coronal plane when compared to arthroscopic measurements taken before and after bursectomy. The creation of 3D objects enabled the analysis of new geometries, including the length, width, and depth of each lesion. These geometries included the rectangle, rectangular trapezoid, scalene trapezoid, irregular pentagon, and irregular hexagon.

CONCLUSIONS

3D models can enhance the understanding and knowledge of rotator cuff injuries. They can be a promising tool for diagnosing and interpreting the anatomy of the injury, particularly in the sagittal plane. The new 3D understanding of the pathological process has led to the description of new geometric features not visible in conventional 2D MRI.

LEVEL OF EVIDENCE

II - Development of diagnostic criteria on consecutive patients (all compared to "gold" standard).

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.

Reverse shoulder arthroplasty for primary glenohumeral osteoarthritis: significantly different characteristics and outcomes in shoulders with intact vs. torn rotator cuff

PURPOSE

To compare outcomes of reverse shoulder arthroplasty (RSA) for primary osteoarthritis (OA) with and without rotator cuff (RC) tears to those with secondary OA due to RC tears.

METHODS

We reviewed records of all patients who received RSA for primary OA or secondary OA. All patients had preoperative radiographs, computed tomographic arthrography (CTA), and/or magnetic resonance imaging (MRI) scans of their shoulders to assess their etiology, glenoid morphology, and fatty infiltration. Pre- and postoperative (at minimum follow-up of 2 years) Constant scores and range of motion were compared between patients who had RSA for primary OA with and without RC tears to those with secondary OA due to RC tears.

RESULTS

Of the initial cohort of 605 shoulders (583 patients), 153 were lost to follow-up (25.3%), 25 required revision with implant removal (4.1%), and 13 died of causes unrelated to the surgery (2.1%), and left a final cohort of 414 patients. Of the final cohort, 97 had primary OA with intact RC, 62 had primary OA with RC tears, and 255 had secondary OA. Postoperative Constant scores were significantly higher for primary OA with intact RC (73.8 ± 14.3), compared with both primary OA with RC tears (66.1 ± 14.6, P < .001) and secondary OA (64.1 ± 14.8, P < .001). There were no differences in pre- or postoperative scores between primary OA with RC tears and secondary OA.

CONCLUSION

At 2 or more years following RSA, Constant scores were significantly higher for primary OA with intact RC, compared to either primary OA with RC tears or secondary OA, whereas there were no differences in pre- or postoperative scores of shoulders that had primary OA with RC tears vs. secondary OA. The authors recommend distinguishing primary OA with intact RC from primary OA with RC tears, as the two have considerably different characteristics and prognosis following RSA.

Fat Fractions of the Rotator Cuff Muscles Acquired With 2-Point Dixon MRI: Predicting Outcome After Arthroscopic Rotator Cuff Repair

OBJECTIVES

The aim of this study was to quantify and compare fat fraction (FF) and muscle volume between patients with failed and intact rotator cuff (RC) repair as well as a control group with nonsurgical conservative treatment to define FF cutoff values for predicting the outcome of RC repair.

MATERIALS AND METHODS

Patients with full-thickness RC tears who received magnetic resonance imaging (MRI) before and after RC repair including a 2-point Dixon sequence were retrospectively screened. Patients with retear of 1 or more tendons diagnosed on MRI (Sugaya IV-V) were enrolled and matched to patients with intact RC repair (Sugaya I-II) and to a third group with conservatively treated RC tears. Two radiologists evaluated morphological features (Cofield, Patte, and Goutallier), as well as the integrity of the RC after repair (Sugaya). Fat fractions were calculated from the 2-point Dixon sequence, and the RC muscles were segmented semiautomatically to calculate FFs and volume for each muscle. Receiver operator characteristics curves were used to determine FF cutoff values that best predict RC retears.

RESULTS

In total, 136 patients were enrolled, consisting of 3 groups: 41 patients had a failed RC repair (58 ± 7 years, 16 women), 50 patients matched into the intact RC repair group, and 45 patients were matched into the conservative treatment group. Receiver operator characteristics curves showed reliable preoperative FF cutoff values for predicting retears at 6.0% for the supraspinatus muscle (0.83 area under the curve [AUC]), 7.4% for the infraspinatus muscle (AUC 0.82), and 8.3% for the subscapularis muscle (0.94 AUC).

CONCLUSIONS

Preoperative quantitative FF calculated from 2-point Dixon MRI can be used to predict the risk of retear after arthroscopic RC repair with cutoff values between 6% and 8.3%.

Clinical Impairments and Rotator Cuff Tendon Pathology in Primary and Intrinsic Secondary Adhesive Capsulitis

OBJECTIVE

This study was conducted to compare the differences in clinical impairments between patients with primary and intrinsic secondary adhesive capsulitis and confirm rotator cuff tendon pathology in intrinsic secondary adhesive capsulitis.

DESIGN

This study included 130 patients with unilateral adhesive capsulitis in freezing or frozen stages. Clinical impairment was evaluated using visual analog scale score, shoulder passive range of motion, Cyriax stage, and Constant-Murley score. Plain radiography, ultrasonography, single-contrast arthrography, and intravenous gadolinium-enhanced magnetic resonance imaging were performed in all patients.

RESULTS

Among 130 patients, 77 patients were diagnosed as primary adhesive capsulitis and 53 patients as intrinsic secondary adhesive capsulitis. Among intrinsic secondary adhesive capsulitis patients, 44 rotator cuff tendon tears, 6 calcific tendinitis, and 3 rotator cuff tendon tears with calcific tendinitis were observed. No significant intergroup difference was observed in all clinical parameters, including shoulder passive range of motion, visual analog scale, Cyriax stage, and Constant-Murley score. The prevalence of subacromial subdeltoid bursitis was significantly higher in intrinsic secondary adhesive capsulitis compared with primary adhesive capsulitis.

CONCLUSIONS

There was no significant difference in all clinical parameters investigated between patients with primary and intrinsic secondary adhesive capsulitis caused by rotator cuff tendon pathology.

Decreased rotator cuff muscle cross-sectional areas in subjects with adhesive capsulitis: a study comparing male and female subjects

OBJECTIVE

To compare rotator cuff (RC) muscle cross-sectional areas (CSA) in subjects with adhesive capsulitis (AC) to age- and sex-matched controls.

MATERIALS AND METHODS

We retrospectively analyzed 97 shoulder MRIs or MR arthrography studies, of which 42 were clinically diagnosed with AC (27 female, 15 male) and 55 were age- and sex-matched controls (38 female, 17 male). All AC subjects underwent imaging ≥ 6 months after symptom onset. All imaging was examined to exclude RC full-thickness tears and prior surgery. A standardized T1 sagittal MR image was segmented in each subject to obtain the CSA of subscapularis (SSC), supraspinatus (SSP), and infraspinatus (ISP) muscles. Differences in CSAs between AC and control subjects were analyzed by sex (females and males separately) and all subjects combined.

RESULTS

AC females had significantly decreased SSC (P = 0.002) and total (P = 0.006) CSAs compared to controls. Male AC subjects showed decreased SSC (P = 0.044), SSP (P = 0.001), and total (P = 0.005) CSAs. Across all subjects, male and female, the AC cohort had significantly decreased SSC (P = 0.019) and total (P = 0.029) CSAs compared to controls.

CONCLUSION

Decreased RC muscle CSAs were present in AC subjects with ≥ 6 months of symptom duration, with decreased SSC and total CSAs in male and female subjects, and decreased SSP CSA in males.

A Machine Learning Model Demonstrates Excellent Performance in Predicting Subscapularis Tears Based on Pre-Operative Imaging Parameters Alone

PURPOSE

To develop a machine learning model capable of identifying subscapularis tears before surgery based on imaging and physical examination findings.

METHODS

Between 2010 and 2020, 202 consecutive shoulders underwent arthroscopic rotator cuff repair by a single surgeon. Patient demographics, physical examination findings (including range of motion, weakness with internal rotation, lift/push-off test, belly press test, and bear hug test), and imaging (including direct and indirect signs of tearing, biceps status, fatty atrophy, cystic changes, and other similar findings) were included for model creation.

RESULTS

Sixty percent of the shoulders had partial or full thickness tears of the subscapularis verified during surgery (83% of these were upper third). Using only preoperative imaging-related parameters, the XGBoost model demonstrated excellent performance at predicting subscapularis tears (c-statistic, 0.84; accuracy, 0.85; F1 score, 0.87). The top 5 features included direct signs related to the presence of tearing as evidenced on magnetic resonance imaging (MRI) (changes in tendon morphology and signal), as well as the quality of the MRI and biceps pathology.

CONCLUSIONS

In this study, machine learning was successful in predicting subscapularis tears by MRI alone in 85% of patients, and this accuracy did not decrease by isolating the model to the top features. The top five features included direct signs related to the presence of tearing as evidenced on MRI (changes in tendon morphology and signal), as well as the quality of the MRI and biceps pathology. Last, in advanced modeling, the addition of physical examination or patient characteristics did not make a significant difference in the predictive ability of this model.

LEVEL OF EVIDENCE

Level III, diagnostic case-control study.

The effect of cuff arthropathy stage on sleep disturbance and kinesiophobia in reverse shoulder arthroplasty patients

BACKGROUND

The current study aimed to determine the changes in pre-and post-operative Pittsburg sleep quality index (PSQI) and Tampa scale of kinesiophobia (TSK) values ​​according to the Hamada classification in patients who underwent reverse shoulder arthroplasty (RSA) for rotator cuff tear arthropathy (RCTA).

METHODS

One hundred and eight patients who underwent RSA for RCTA were reviewed retrospectively. The patients were divided into two groups with low grade (stages 1-2-3) (n = 49) and high grade (stages 4a-4b-5) (n = 59) according to the Hamada classification, which is the radiographic evaluation of RCTA. PSQI and TSK values ​​were calculated preoperatively, and post-operatively at the 6th week, 6th month, and 1st year. The change in PSQI and TSK values ​​between the evaluations and the effect of staging according to the Hamada classification on this change was examined.

RESULTS

When compared in preoperative evaluations, PSQI and TSK scores were found to be lower in low-grade group 1 (7.39 ± 1.56, 51.88 ± 4.62, respectively) than in high-grade group 2 (10.47 ± 2.39, 57.05 ± 3.25, respectively) according to Hamada classification (both p < 0.001). In the postoperative evaluations, PSQI and TSK results decreased gradually compared to the preoperative evaluations, and there was a severe decrease in both parameters between the 6th-week and 6th-month evaluations (both p < 0.001). Preoperatively, 102 (95%) patients had sleep disturbance (PSQI ≥ 6), and 108 (100%) patients had high kinesiophobia (TSK > 37). In the 1st year follow-ups, sleep disturbance was observed in 5 (5%) patients and kinesiophobia in 1 (1%) patient. When the Hamada stages were compared, it was seen that there was a significant difference before the operation (both p < 0.001), but the statistically significant difference disappeared in the PSQI value in the 1st year (p = 0.092) and in the TSK value in the 6th month (p = 0.164) post-operatively. It was observed that Hamada staging caused significant differences in PSQI and TSK values ​​in the preoperative period but did not affect the clinical results after treatment.

CONCLUSIONS

RSA performed based on RCTA improves sleep quality and reduces kinesiophobia. RCTA stage negatively affects PSQI and TSK before the operation but does not show any effect after the treatment.

Can imaging determine if a rotator cuff tear is traumatic?

AIM

We reviewed the last decade of literature to update a previous publication on this topic by the senior author. In New Zealand, traumatic causation has implications for entitlement for treatment though the Accident Compensation Corporation (ACC). Acuity and chronicity may also be relevant in determining repairability.

METHODS

Literature was reviewed regarding acromial morphology, greater tuberosity (GT) cysts, acromiohumeral interval (AHI), fatty degeneration and atrophy, acromioclavicular (AC) arthrosis, tendinopathy, bursal changes and other features.

RESULTS

Some factors can be considered normal for those middle aged and older, including AC arthrosis, type 1 and 2 acromion and tendinopathy. Some factors may indicate acuity, including haemorrhage and debris, GT oedema, mid-substance soft tissue tear, kinking of the tendon and isolated complete subscapularis tears. Other factors may be associated with chronicity, including significant fatty degeneration, positive tangent sign for atrophy, anterior GT cysts, type 3 acromion, critical shoulder angle (CSA) >35 degrees and acromial index (AI) <0.7.

CONCLUSION

A multitude of factors on imaging may infer, to a varying degree, the likelihood of acuity or chronicity. The patient history is also of importance in determining causation.

The association between a rotator cuff tendon tear and a tear of the long head of the biceps tendon: Chart review study

Rotator cuff (RC) and long head of the biceps tendon (LHBT) tears are common shoulder problems presented to the orthopedic clinic. The aim of this study was to assess the association between RC and LHBT tears among a Saudi population sample. A total of 243 patients who were diagnosed with shoulder pain due to RC or LHBT tear between 2016 and 2018 using a magnetic resonance imaging scan were included in this study. Females comprised 66% of the sample, and 59% (n = 143) of the shoulders were on the right side. The mean age of the patients was 58 ± 11 years, ranging from 23 to 88 years. A significant association was detected between the LHBT and RC tears (P < 0.001). Out of 26 cases showing RC and LHBT tears, 81% had a full thickness tear, whereas 19% had a partial tear. The LHBT tears were presented significantly in 48% of cases with at least two completely torn RC compared to 10% in cases with one completely torn RC (P < 0.001). The LHBT tear was significantly observed in shoulders with RC tears including the tendons of subscapularis, supraspinatus, and infraspinatus, but not the teres minor (P < 0.001). Both types of tears were presented significantly in senior patients aged more than 65 years compared to younger patients (P < 0.01). Thus, the LHBT should be assessed carefully in shoulders with more than one RC tear or in chronic cases.

Dyslipidemia may impact initial recovery following arthroscopic rotator cuff repair: a retrospective study

BACKGROUND

The current literature shows that dyslipidemia can lead to a higher incidence of rotator cuff tears (RCTs) and an increased retear rate after repair. We aimed to evaluate the influence of preoperative dyslipidemia on postoperative pain, patient-reported outcomes (PROs), active range of motion (ROM), and structural integrity.

METHODS

A cohort of 111 patients who underwent arthroscopic RCT repair between January 2021 and July 2022, and whose complete preoperative serum lipid data were available within one week prior to surgery was retrospectively reviewed. Dyslipidemia was defined as the presence of an increase or decrease in at least one blood lipid profile (triglycerides, total cholesterol, low-density lipoprotein, high-density lipoprotein, or non-high-density lipoprotein). There were 43 patients in the dyslipidemia group and 68 in the ortholiposis group. Patient evaluations, including pain score, PROs, and ROMs, were conducted preoperatively; at 3 and 6 months postoperatively; and at the last follow-up. Structural integrity was assessed by magnetic resonance imaging (MRI) 6 months after surgery if possible, and Sugaya type 4 or 5 was considered a retear. Propensity score matching (PSM) was used to reduce bias.

RESULTS

The RCT size, surgical technique, preoperative pain status, PROs, and active ROM were comparable between patients with dyslipidemia and those with ortholiposis. Three months after surgery, patients in the dyslipidemia group had worse average PROs (Constant score: P = 0.001; ASES score: P = 0.012; UCLA score: P = 0.015), forward flexion (P = 0.012), and internal rotation (P = 0.001) than patients in the ortholiposis group did. The difference between the two groups persisted after PSM but disappeared at the sixth month after surgery. No significant differences in pain score, PROs, or active ROMs were detected between the dyslipidemia and ortholiposis groups after a mean follow-up of 24 months. Of the 72 patients who underwent MRI, 4 retears (5.6%) were found, and all were in the ortholiposis group. There was no difference in the rate of retears between the two groups (P = 0.291) or with (P = 0.495) PSM.

CONCLUSIONS

In conclusion, we found that perioperative dyslipidemia may impact initial recovery within the first 3 months following arthroscopic rotator cuff repair but may have no effect on pain, PROs, or active ROMs at a mean 2-year follow-up or rotator cuff integrity at 6 months postoperatively. Trail registration Retrospectively registered.

The rat as a novel model for chronic rotator cuff injuries

Chronic rotator cuff injuries (CRCIs) still present a great challenge for orthopaedics surgeons. Many new therapeutic strategies are developed to facilitate repair and improve the healing process. However, there is no reliable animal model for chronic rotator cuff injury research. To present a new valuable rat model for future chronic rotator cuff injuries (CRCIs) repair studies, and describe the changes of CRCIs on the perspectives of histology, behavior and MRI. Sixty male Wistar rats were enrolled and underwent surgery of the left shoulder joint for persistent subacromial impingement. They were randomly divided into experimental group (n = 30, a 3D printed PEEK implant shuttled into the lower surface of the acromion) and sham operation group (n = 30, insert the same implant, but remove it immediately). Analyses of histology, behavior, MRI and inflammatory pain-related genes expression profiles were performed to evaluate the changes of CRCIs. After 2-weeks running, the rats in the experimental group exhibited compensatory gait patterns to protect the injured forelimb from loading after 2-weeks running. After 8-weeks running, the rats in the experimental group showed obvious CRCIs pathological changes: (1) acromion bone hyperplasia and thickening of the cortical bone; (2) supraspinatus muscle tendon of the humeral head: the bursal-side tendon was torn and layered with disordered structure, forming obvious gaps; the humeral-side tendon is partially broken, and has a neatly arranged collagen. Partial fat infiltration is found. The coronal T2-weighted images showed that abnormal tendon-to-bone junctions of the supraspinatus tendon. The signal intensity and continuity were destroyed with contracted tendon. At the nighttime, compared with the sham operation group, the expression level of IL-1β and COX-2 increased significantly (P = 0063, 0.0005) in the experimental group. The expression of COX-2 in experimental group is up-regulated about 1.5 times than that of daytime (P = 0.0011), but the expression of IL-1β, TNF-a, and NGF are all down-regulated (P = 0.0146, 0.0232, 0.0161). This novel rat model of chronic rotator cuff injuries has the similar characteristics with that of human shoulders. And it supplies a cost-effective, reliable animal model for advanced tissue engineered strategies and future therapeutic strategies.

Differences in Clinical Outcomes Between Patients With Retear After Supraspinatus Tendon Repair and Those With Intact Repair at 5-Year Follow-up

BACKGROUND

It is well known that rotator cuff repair is associated with an overall retear rate of 21% to 26%. However, a cuff retear may not necessarily be associated with poor clinical outcomes.

HYPOTHESIS

There would be no difference in clinical outcomes between patients with a cuff retear and those with an intact repair at a midterm follow-up of 5 years.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective study was conducted involving patients who received arthroscopic complete repair of the supraspinatus tendon between January 2009 and December 2017. Patients who did not have a postoperative magnetic resonance imaging (MRI) scan or who had a follow-up of <5 years were excluded. Clinical outcomes, including the visual analog scale (VAS) score, American Shoulder and Elbow Surgeons (ASES) score, and active forward flexion (FF) of the involved shoulder were assessed at the 2-year and 5-year follow-up points.

RESULTS

The study group included 105 patients with a mean follow-up of 85 months. MRI scans were performed at a mean of 20 months. Fourteen full-thickness cuff retears and 91 intact repairs were identified using postoperative MRI scans. Significant improvement in VAS score, ASES score, and FF were found between the preoperative assessment and the 2 designated follow-up points (2 years and 5 years) in both the cuff retear and the intact repair groups (P < .001). The VAS and ASES scores at the 2-year follow-up for the intact repair group were 1.8 ± 2.0 and 80.7 ± 18.1, respectively. The corresponding values for the retear group were 2.3 ± 2.2 and 71.9 ± 19.5, respectively. No significant difference was found between the 2 groups in the VAS and ASES scores at the 2-year follow-up. However, patients with an intact repair had a better VAS score (1.4 ± 1.8; P = .049) and ASES score (81.7 ± 17; P = .019) than those with a cuff retear at the 5-year assessment (3.0 ± 2.8 and 67.1 ± 22.9, respectively). In the intact repair group, 91% of patients achieved the minimal clinically important difference for the 5-year VAS score, compared with 54% in the cuff retear group (P < .001). The corresponding values for the 5-year ASES score were 80% and 54%, respectively (P = .044). FF measurements at the 5-year follow-up in patients with intact repair and those with a cuff retear were 161°± 23° and 144°± 37°, respectively (P = .059). Continuous improvement in VAS score and FF between the 2-year and 5-year follow-up was observed in the intact repair group (P = .005 and P = .04, respectively).

CONCLUSION

The patients with an intact repair had better VAS and ASES scores compared with those who had a cuff retear at a midterm follow-up of 5 years. Between the 2-year and the 5-year follow-up, some further improvement was observed in the VAS score and FF in the intact repair group.

Investigating the multifactorial etiology of supraspinatus tendon tears

The purpose of this study was to develop a multivariable model to determine the extent to which a combination of etiological factors is associated with supraspinatus tendon tears. Fifty-four asymptomatic individuals (55 ± 4 years) underwent testing of their dominant shoulder. Diagnostic ultrasound was used to assess for a supraspinatus tendon tear. The etiological factors investigated included demographics (age and sex), tendon impingement during shoulder motion (via biplane videoradiography), glenohumeral morphology (via computed tomography imaging), family history of a tear (via self-report), occupational shoulder exposure (via shoulder job exposure matrix), and athletic exposure (via self-report). Univariate relationships between etiological predictors and supraspinatus tears were assessed using logistic regression and odds ratios (ORs), while multivariable relationships were assessed using classification and regression tree analysis. Thirteen participants (24.1%) had evidence of a supraspinatus tear. Individuals with a tear had a higher critical shoulder angle (OR 1.2, p = 0.028) and acromial index (OR 1.2, p = 0.016) than individuals without a tear. The multivariable model suggested that a tear in this cohort can be explained with acceptable accuracy (AUROC = 0.731) by the interaction between acromial index and shoulder occupational exposure: a tear is more likely in individuals with a high acromial index (p < 0.001), and in individuals with a low acromial index and high occupational exposure (p < 0.001). The combination of an individual's glenohumeral morphology (acromial index) and occupational shoulder exposure may be important in the development of supraspinatus tears.

Automatic MRI-based rotator cuff muscle segmentation using U-Nets

BACKGROUND

The rotator cuff (RC) is a crucial anatomical element within the shoulder joint, facilitating an extensive array of motions while maintaining joint stability. Comprised of the subscapularis, infraspinatus, supraspinatus, and teres minor muscles, the RC plays an integral role in shoulder functionality. RC injuries represent prevalent, incapacitating conditions that impose a substantial impact on approximately 8% of the adult population in the USA. Segmentation of these muscles provides valuable anatomical information for evaluating muscle quality and allows for better treatment planning.

MATERIALS AND METHODS

We developed a model based on residual deep convolutional encoder-decoder U-net to segment RC muscles on oblique sagittal T1-weighted images MRI. Our data consisted of shoulder MRIs from a cohort of 157 individuals, consisting of individuals without RC tendon tear (N=79) and patients with partial RC tendon tear (N=78). We evaluated different modeling approaches. The performance of the models was evaluated by calculating the Dice coefficient on the hold out test set.

RESULTS

The best-performing model's median Dice coefficient was measured to be 89% (Q1:85%, Q3:96%) for the supraspinatus, 86% (Q1:82%, Q3:88%) for the subscapularis, 86% (Q1:82%, Q3:90%) for the infraspinatus, and 78% (Q1:70%, Q3:81%) for the teres minor muscle, indicating a satisfactory level of accuracy in the model's predictions.

CONCLUSION

Our computational models demonstrated the capability to delineate RC muscles with a level of precision akin to that of experienced radiologists. As hypothesized, the proposed algorithm exhibited superior performance when segmenting muscles with well-defined boundaries, including the supraspinatus, subscapularis, and infraspinatus muscles.