Beyond pixel: Superpixel-based MRI segmentation through traditional machine learning and graph convolutional network.

BACKGROUND AND OBJECTIVE: Tendon segmentation is crucial for studying tendon-related pathologies like tendinopathy, tendinosis, etc. This step further enables detailed analysis of specific tendon regions using automated or semi-automated methods. This study specifically aims at the segmentation of Achilles tendon, the largest tendon in the human body. METHODS: This study proposes a comprehensive end-to-end tendon segmentation module composed of a preliminary superpixel-based coarse segmentation preceding the final segmentation task. The final segmentation results are obtained through two distinct approaches. In the first approach, the coarsely generated superpixels are subjected to classification using Random Forest (RF) and Support Vector Machine (SVM) classifiers to classify whether each superpixel belongs to a tendon class or not (resulting in tendon segmentation). In the second approach, the arrangements of superpixels are converted to graphs instead of being treated as conventional image grids. This classification process uses a graph-based convolutional network (GCN) to determine whether each superpixel corresponds to a tendon class or not. RESULTS: All experiments are conducted on a custom-made ankle MRI dataset. The dataset comprises 76 subjects and is divided into two sets: one for training (Dataset 1, trained and evaluated using leave-one-group-out cross-validation) and the other as unseen test data (Dataset 2). Using our first approach, the final test AUC (Area Under the ROC Curve) scores using RF and SVM classifiers on the test data (Dataset 2) are 0.992 and 0.987, respectively, with sensitivities of 0.904 and 0.966. On the other hand, using our second approach (GCN-based node classification), the AUC score for the test set is 0.933 with a sensitivity of 0.899. CONCLUSIONS: Our proposed pipeline demonstrates the efficacy of employing superpixel generation as a coarse segmentation technique for the final tendon segmentation. Whether utilizing RF, SVM-based superpixel classification, or GCN-based classification for tendon segmentation, our system consistently achieves commendable AUC scores, especially the non-graph-based approach. Given the limited dataset, our graph-based method did not perform as well as non-graph-based superpixel classifications; however, the results obtained provide valuable insights into how well the models can distinguish between tendons and non-tendons. This opens up opportunities for further exploration and improvement.

Beyond the Diagnosis: Using Patient Characteristics and Domains of Tendon Health to Identify Latent Subgroups of Achilles Tendinopathy.

OBJECTIVE: To identify latent subgroups among patients with Achilles tendinopathy, describe patient characteristics and clinical attributes that defined each subgroup, and develop a clinical classification model for subgroup membership. DESIGN: Cross-sectional study. METHODS: One hundred forty-five participants (men, n = 73; mean ± SD age, 51 ± 14 years) with clinically diagnosed Achilles tendinopathy completed a baseline evaluation, including demographics and medical history, patient-reported outcome measures, a clinical exam, tendon structure measures via ultrasound imaging and continuous shear-wave elastography, and a functional test battery. Subgroups were identified using mixture modeling. We compared the subgroups using a 1-way analysis-of-variance or chi-square test and the Tukey post hoc test to identify defining attributes. We developed a clinical classification model using logistic regression and receiver operating characteristic curves. RESULTS: Three latent subgroups were identified and named by their distinctive patient characteristics and clinical attributes. The activity-dominant subgroup (n = 67), on average, had the highest physical activity level, function, and quality of life; reported mild symptoms; and was the youngest. The psychosocial-dominant subgroup (n = 56), on average, had the worst symptoms, impaired function, heightened psychological factors, the poorest quality of life, minimal tendon structural alterations, and was obese and predominantly female. The structure-dominant subgroup (n = 22), on average, had the most tendon structural alterations, severe functional deficits, moderate symptoms and psychological factors, reduced quality of life, and was the oldest, obese, and predominantly male. The clinical classification model correctly classified 85% (123/145) of participants. CONCLUSION: Three Achilles tendinopathy subgroups (activity dominant, psychosocial dominant, and structure dominant) differed in patient characteristics and clinical attributes. J Orthop Sports Phys Ther 2021;51(9):440-448. Epub 1 Jun 2021. doi:10.2519/jospt.2021.10271.

Tendinopatía cálcica: etiopatogenia y evaluación por imágenes / Calcific tendinitis: aetiopathogenesis and imaging evaluation

Resumen: La tendinopatía cálcica es causada por el depósito patológico de cristales de hidroxiapatita de calcio en los tendones y es una causa común de dolor en las articulaciones. Afecta más frecuentemente al hombro y la cadera, con hallazgos característicos en imágenes; sin embargo, cualquier tendón puede estar involucrado. Ocasionalmente, la tendinopatía cálcica puede simular patología agresiva, como infección o neoplasia, especialmente en RM. Fisiotpatológicamente, las calcificaciones provendrían de una diferenciación anormal de las células madre del tendón, que comienzan a producir calcio, aunque todavía no es del todo claro. Los radiólogos deben estar familiarizados con los hallazgos de las imágenes para distinguir la tendinopatía cálcica de procesos más agresivos. La aspiración y lavado guiado bajo ecografía es una técnica útil realizada por el radiólogo para el tratamiento de casos sintomáticos. La familiaridad con estos procedimientos y su apariencia en imágenes es un aspecto importante en el manejo de esta enfermedad. El propósito de esta revisión es analizar la etiopatogenia de la tendinopatía cálcica, la evaluación con imágenes en los sitios de presentación más comunes y también en los menos frecuentes, así como el papel que desempeña la ecografía en el tratamiento de la patología.

Abstract: Calcific tendinitis is caused by abnormal deposition of calcium hydroxyapatite crystals in tendons and is a common cause of joint pain. The disease typically affects the shoulder and hip, with characteristic imaging findings; however, any tendon can be involved. Occasionally, calcific tendinitis can mimic aggressive disorders, such as infection and neoplasm, especially on MRI. Apparently, the calcifications come from an abnormal differentiation of the tendon stem cells, which begin to produce calcium. Radiologists should be familiar with the imaging findings to distinguish calcific tendinitis from more aggressive processes. Image-guided percutaneous needle aspiration is a useful technique performed by the radiologist for the treatment of symptomatic cases. Being familiar with these processes and their imaging appearance is an important aspect in the management of this common disease. The purpose of this review is to analyze the pathogenesis of calcium tendinopathy, the evaluation of images in both the most common and less frequent presentation sites, as well as the role played by ultrasound in the treatment of pathology.

Getting tendinopathy treatment (and terminology) right.

Tendinopathy, tendinitis, tendinosis, paratenonitis-they are not synonymous. Here you'll find a review of their pathophysiology and best approaches to treatment.

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.

Radiographic assessment of calcifying tendinitis of the rotator cuff : an inter- and intraobserver study.

The radiographic appearance of calcific tendinitis of the rotator cuff varies according to the stage of the disease. We compared currently used classification systems in a large group of observers to identify the most reliable classification system. Thirty-seven orthopaedic surgeons evaluated shoulder radiographs of 25 patients to classify the stage of the calcific tendinitis according to the classifications by (1) Gärtner and (2) Molé on a Web-based study platform. Inter and intraobserver agreement among observers was measured using the Siegel and Castellan multirater κ. Both classification systems had fair interobserver agreement : κ was 0.25 for the Molé classification and 0.34 for the Gärtner classification. The Gärtner classification was significantly more reliable than the Molé classification. Currently there is no radiographic classification that can serve the purpose of guiding the treatment in a reliable way.

Incidence of Tendinopathy in Team Sports in a Multidisciplinary Sports Club Over 8 Seasons.

Tendinopathy is a critical medical condition that often hinders level of participation for professional and young athletes in many sports. The purpose of the study was to describe the incidence and severity of tendinopathy in a multi-sport club with professional and youth teams. We performed a retrospective epidemiological study. Incidence of tendinopathy in players (n = 3839; 8-38 years, professional and youth) was reviewed over 8 seasons (2008-2016) in 5 team sports: football, basketball, handball, roller hockey, and futsal. Team physicians diagnosed and classified tendinopathies according to anatomical location, sport types, playing category, sex, playing surface, lost training time, and severity (time to return to play). Injuries were coded using OSICS-10, and incidence of tendinopathies were calculated as the number of injuries per 100 players per season. The total relative frequency of tendinopathy (versus total injuries) was 22% (843/3839) over 8 seasons from 360 in youth and 483 in professional teams. The incidence of injury was the highest in professional basketball [69.9, 95%CI: (58.0-81.4)] followed by professional roller hockey [64.4, 95%CI: (47.3-85.6)], and professional futsal [36.2, 95%CI: (27.3-47.1)]. The most incidences commonly affected tendons were the patellar [11.7, 95%CI: (10.0-13.5)] and Achilles [10.3, 95%CI: (8.5-12.5)]. Tendinopathies represent a significant number of injuries in team sports and are more common in professional than youth teams, especially basketball and roller hockey. Additional studies are needed to understand associated time-loss and impact on performance, and to develop prevention strategies for high risk sports.

Achilles Pain, Stiffness, and Muscle Power Deficits: Midportion Achilles Tendinopathy Revision 2018.

The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The purpose of these revised clinical practice guidelines is to review recent peer-reviewed literature and make recommendations related to midportion Achilles tendinopathy. J Orthop Sports Phys Ther 2018;48(5):A1-A38. doi:10.2519/jospt.2018.0302.

Common Running Injuries: Evaluation and Management.

Running is a common form of exercise but predisposes athletes to several running-related injuries. Most running injuries are due to overuse and respond to conservative treatment. Tendinopathies in the patellar, Achilles, and hamstring tendons are common, and are primarily treated with eccentric exercise. Iliotibial band syndrome and patellofemoral pain syndrome are less common than patellar tendinopathy and are treated by strengthening exercises for the core and legs in addition to flexibility exercises. Acute hamstring strains and medial tibial stress syndrome require a period of relative rest, followed by stretching and graded return to activity. Tibial stress fractures require an extended period of relative rest, followed by a more gradual return to activity. Early mobilization improves recovery from ankle sprains, and exercise therapy and functional bracing while running for six to 12 months prevents reinjury. Plantar fasciopathy (plantar fasciitis) can be significantly improved with stretching, heel raises, and orthoses that provide arch support.

El continuum de la patología de tendón: concepto actual e implicaciones clínicas / The continuum of tendon pathology: Current view and clinical implications

El modelo del continuum fue propuesto por Cook y Purdam en 2009 con el propósito de mejorar la comprensión del complejo marco que rodea la patología del tendón. El concepto se basa en las características de los tres estados tisulares del tendón: tendón reactivo, tendinopatía desestructurada y tendinopatía degenerativa. El concepto del continuum se diferencia de las otras propuestas por su visión de cambio continuo de la estructura del tejido tendinoso. Cada fase tiene una presentación clínica característica y un tratamiento específico. Estudios histológicos, por la imagen y clínicos corroboran con evidencia el abordaje de esta patología mediante el concepto del modelo de continuum (AU)

Cook and Purdam first proposed the Continuum model in 2009, with the aim of improving the understanding of the complexity of tendon pathologies. The Continuum is based on three states of tendon structure: reactive tendon, tendon disrepair and degenerative tendon. In contrast to other proposals, the Continuum model describes continuous changes in tendon structure. Each state of tendon structure represents a particular clinical presentation and requires a particular type of management. Evidence seen in histopathological studies, imaging and clinical studies all support the Continuum model for the analysis of tendon pathologies (AU)

Tratamiento por vía artroscópica de la tendinitis calcificada del hombro / Traitement par voie arthroscopique de la tendinite calcifiante de l'épaule / Arthroscopic Treatment of Calcific Tendonitis of the Shoulder

Introducción: la tendinitis calcificada es una afección frecuente en la articulación del hombro, sus principales síntomas y signos son el dolor y la pérdida del movimiento articular, el tratamiento conservador es el pilar fundamental, sin embargo la vía artroscópica es de gran utilidad en caso de fallo del primero. Objetivo: el objetivo de este trabajo es profundizar en aspectos como: síntomas y signos, clasificaciones, modalidades de tratamiento conservador y por último en la perspectiva quirúrgica a través de la vía artroscópica. Método: la búsqueda de la información se realizó en un periodo de tres meses (1ro. de marzo de 2016 al 31 de mayo de 2016) y se emplearon las siguientes palabras: calcific tendinitis y subacromial impingment. A partir de la información obtenida se realizó una revisión bibliográfica de un total de 311 artículos publicados en las bases de datos PubMed, Hinari, SciELO y Medline mediante el gestor de búsqueda y administrador de referencias EndNote, de ellos se utilizaron 51 citas seleccionadas para realizar la revisión, 49 de ellas de los últimos 5 años donde se incluyeron 4 libros. Se presentan los síntomas y signos más importantes de esta entidad, así como las clasificaciones basadas en diferentes parámetros, apoyadas fundamentalmente por medios imaginológicos como la radiografía simple, ultrasonido de alta definición y la imagen de resonancia magnética. Conclusiones: la tendinitis calcificada es una entidad frecuente; aunque el tratamiento más empleado es el conservador, la cirugía por la vía artroscópica ofrece múltiples ventajas(AU)

Background: Calcific tendinitis is a common condition in the shoulder joint, its main symptoms and signs are pain and loss of joint movement, conservative treatment is the fundamental pillar, however the arthroscopic course is very useful in case of the first course fails. Objective: The objective of this work is to delve into aspects such as symptoms and signs, classifications, modalities of conservative treatment and finally in the surgical perspective through the arthroscopic course. Method: the search for the information was carried out in a period of three months (from March 1, 2016 to May 31, 2016) and we used the following words: calcific tendinitis and subacromial impingment. A bibliographic review was conducted for 311 articles published in PubMed, Hinari, SciELO and Medline databases, using EndNote search manager and reference manager. Fifty-one selected citations were used to perform those articles reviewed, 49 of them from the last five years. Four books were included. The most important symptoms and signs of this entity are presented, as well as classifications based on different parameters, mainly supported by imaging such as simple radiography, high definition ultrasound and magnetic resonance imaging. Conclusions: Calcific tendinitis is a common entity; although the conservative treatment is most commonly, arthroscopic surgery offers multiple advantages(AU)

Fondement: La tendinite calcifiante est une affection fréquente de l'articulation de l'épaule. Elle est caractérisée par la douleur et la perte du mouvement articulaire. Son pilier fondamental est le traitement conservateur. Cependant, la voie arthroscopique s'avère très utile en cas d'échec du traitement conservateur. Objectif: Le but de ce travail est d'approfondir des aspects tels que les symptômes et signes, les classifications, les modalités de traitement conservateur, et finalement, du point de vue chirurgical, le traitement par voie arthroscopique. Méthodes: La recherche de l'information a été effectuée dans une période de trois mois (du 1er mars 2016 au 31 mai 2016) et on a utilisé les mots-clés : calcific tendinitis et subacromial impingment. À l'aide du logiciel de gestion des références EndNote, on a réalisé une révision bibliographique d'un total de 311 articles publiés dans les bases de données PubMed, Hinari, SciELO et Medline. Sur 51 citations sélectionnées pour faire la révision, on a utilisé 49 de ces cinq dernières années, y compris quatre livres. Les symptômes et signes les plus importants de cette maladie, ainsi que les classifications basées sur différents paramètres, prouvées notamment par imagerie (radiographie simple, échographie haute définition et IRM), sont présentés. Conclusions: La tendinite calcifiante est une affection fréquente; quoique le traitement conservateur soit le plus souvent employé, la chirurgie par voie arthroscopique offre plusieurs bénéfices(AU)

A Treatment-Based Classification Algorithm to Treat Achilles Tendinopathy: An Exploratory Case Series.

CONTEXT: Achilles tendinopathy is relatively common in both the general and athletic populations. The current gold standard for the treatment of Achilles tendinopathy is eccentric exercise, which can be painful and time consuming. While there is limited research on indirect treatment approaches, it has been proposed that tendinopathy patients do respond to indirect approaches in fewer treatments without provoking pain. OBJECTIVE: To determine the effectiveness of using a treatment-based-classification (TBC) algorithm as a strategy for classifying and treating patients diagnosed with Achilles tendinopathy. PARTICIPANTS: 11 subjects (mean age 28.0 ±15.37 y) diagnosed with Achilles tendinopathy. DESIGN: Case series. SETTING: Participants were evaluated, diagnosed, and treated at multiple clinics. MAIN OUTCOME MEASURES: Numeric Rating Scale (NRS), Disablement in the Physically Active Scale (DPA Scale), Victorian Institute of Sport Assessment-Achilles (VISA-A), Global Rating of Change (GRC), and Nirschl Phase Rating Scale were recorded to establish baseline scores and evaluate participant progress. RESULTS: A repeated-measures ANOVA was conducted to analyze NRS scores from initial exam to discharge and at 1-mo follow-up. Paired t tests were analyzed to determine the effectiveness of using a TBC algorithm from initial exam to discharge on the DPA Scale and VISA-A. Descriptive statistics were evaluated to determine outcomes as reported on the GRC. CONCLUSION: The results of this case series provide evidence that using a TBC algorithm can improve function while decreasing pain and disability in Achilles tendinopathy participants.

Heterogeneous MR arthrography findings in patients with subacromial impingement syndrome - Diagnostic subgroups?

BACKGROUND: Subacromial Impingement Syndrome (SIS) is frequently diagnosed, but treatment results vary greatly. It is increasingly reported that SIS symptoms are caused by various underlying mechanisms that need distinctive treatment strategies. We evaluated a set of specific MRI Arthrography (MRA) characteristics that have been related with underlying mechanisms for SIS in the literature, in patients with SIS. METHODS: In 47 patients diagnosed with SIS, MRA characteristics were evaluated and categorized into categories of potential underlying mechanisms: (1) extrinsic: e.g. acromion shape; (2) intrinsic: e.g. tendinosis; (3) dynamic: e.g. signs of glenohumeral (micro-)instability. Control values were obtained from the literature. With cluster analysis, potential patient subgroups were assessed. RESULTS: In 17 (36.2%) patients originally diagnosed with SIS, specific other conditions were found, including rotator cuff tears and labrum lesions. In the remaining 30, all had positive signs of at least one of the predefined underlying mechanisms. Patients could be categorized into 2 groups: predominantly findings corresponding with extrinsic/structural causes, or with dynamic/(micro)instability. CONCLUSIONS: MRA characteristics in patients with SIS symptoms are heterogeneous and many patients have specific other shoulder conditions causing symptoms. Patients without specific other conditions have MRA characteristics associated with either extrinsic (structural), or dynamic (e.g. micro-instability) underlying mechanisms.

[Tendinitis in athletes: etiology, diagnosis and treatment]. / Tendinopathies du sportif: étiologie, diagnostic et traitement.

Tendinopathy is one of the most common diagnosis in sports. Knowledges about their etiology, the repair process to their diagnosis and their treatment have improved thanks to the development of imaging, especially ultra- sound. The disorder whose etiology could be mechanical or degenerative can cause long- term disability and sometimes the end of the sport carreer. The risk of reccurence is com- mon; this may lead to tendon rupture whose functional effects can be significative. The management should be early: it must respect the deadlines for tendon healing and pro- pose a gradual recovery efforts after elimina tion of the contributing factors involved.

Results of operative treatment for recalcitrant retrocalcaneal bursitis and midportion Achilles tendinopathy in athletes.

BACKGROUND: The results of operative treatment for recalcitrant midportion Achilles tendinopathy and recalcitrant retrocalcaneal bursitis were evaluated using the patient administered, disease specific, and validated VISA-A-G questionnaire. METHODS: A cohort of 89 patients was prospectively followed. These patients underwent operations for sport induced midportion Achilles tendinopathy (39 procedures) or retrocalcaneal bursitis (55 procedures). Depending on the individual intraoperative findings the patients of either disease were treated with two respective operative modifications (tendon repair or no tendon repair). Preoperative and follow-up status (3, 6, and 12 months) were investigated using the VISA-A-G questionnaire. RESULTS: Preoperatively, the four groups scored from 37.0 ± 17.6 to 45.9 ± 15.2 (p = 0.376-0.993) on the VISA-A-G questionnaire. Six and 12 months postoperatively, the VISA-A-G scores improved significantly (p < 0.001). Twelve months postoperatively, the groups' scores were not different (p = 0.100-0.952) and ranged from 80.8 ± 17.9 to 90.3 ± 10.6. CONCLUSION: Retrocalcaneal bursitis and midportion Achilles tendinopathy responded equally well to operative treatment. When repaired, additional tendon lesions did not influence this result. We demand to differentiate not only between midportion Achilles tendinopathy and retrocalcaneal bursitis but also to identify additional Achilles tendon lesions to specifically address these lesions during operative procedures.

Hyaluronan injection therapy for athletic patients with patellar tendinopathy.

BACKGROUND: Patellar tendinopathy produces activity-related pain and focal tenderness at the attachment of the patellar tendon at the lower pole of the patella. It frequently causes a reduction in athletic ability. An injection of hyaluronan was found to be useful for patellar tendinopathy, provided the indication is appropriate, based on the authors' pilot cases. The purpose of this study was to summarize the clinical experience of and to describe the appropriate indication for this injection therapy. METHODS: Fifty patients were treated from January 1999 to December 2006. The observation period averaged 25.7 months (range 6-88). All patients were graded stage 2 or 3 by Blazina's classification. Each treatment was counted separately for 9 patients (10 knees) who had more than one treatment period with 3 months or more between the injections. There were 4 bilaterally injected patients. Patellar tendinopathy was classified into 4 types according to the degree of tenderness and the regions that are tender. Hyaluronan was injected into the interface between the patellar tendon and the infrapatellar fat pad at the proximal insertion, or into the region of maximum tenderness. RESULTS: The total number of injections was 135, and there were an average of 2.0 injections per case (range 1-11). Following treatment, 54 % of the cases were rated in excellent condition, as they were able to return to their previous athletic activities with little difficulty, while 40 % of the cases were rated in good condition-these patients were able to return to their previous sporting activities with some degree of limitation. CONCLUSIONS: Hyaluronan injection therapy for athletic patients with patellar tendinopathy is an optional but effective treatment.

Tendinopatía rotuliana y de tendón aquileano: clasificación orientada en la fisiopatología y tratamiento / Patellar and achilles tendinopathy: classification oriented in physiopathology and treatment

La patología tendinosa provoca dolor y alteración del rendimiento deportivo, la terminología es confusa y lleva a estrategias de tratamiento equivocadas. Se realiza una clasificación fisiopatológica y se presenta un protocolo de tratamiento para cada caso.