Made available in DSpace on 2014-06-11T19:31:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2001Bitstream added on 2014-06-13T19:01:25Z : No. of bitstreams: 1 silvares_pra_dr_botfm.pdf: 1865578 bytes, checksum: 5944bbb134ed809f3f7170ccdbc6a33a (MD5) / Com o objetivo de se comparar as propriedades mecânicas do ligamento cruzado anterior (LCA), dos 10 mm do terço central do ligamento da patela (LP), e do tendão do músculo semitendíneo triplicado (STT) do mesmo doador, foram realizados ensaios de tração em material obtido de 19 cadáveres humanos. A idade dos doadores foi de 40 11 anos (18-55 anos), sendo 15 (78,9%) masculinos e 4 (21,1%) femininos, 12 brancos (63,1%) e sete negros (36,9%); 10 (52,6%) joelhos do lado esquerdo e 9 (47,4%) do lado direito. Foi obtida a área de secção dos corpos de prova para que, além das propriedades estruturais, também fossem avaliadas as propriedades materiais. Além do diagrama carga-alongamento, foram estudadas as seguintes variáveis: carga máxima (N), alongamento absoluto (mm) e específico (%) na ruptura, limite de proporcionalidade (N) e respectivos alongamentos, tensão na carga máxima(MPa), módulo de elasticidade (MPa), energia na ruptura (Nm) e energia por área (Nm/m2) . A análise estatística comparativa entre os três materiais mostrou que o LP foi superior ao LCA e ao STT, na carga máxima, tensão na carga máxima, módulo de elasticidade, energia, energia por área e limite de proporcionalidade, caracterizando comportamento de maior estabilidade e rigidez. O LCA e STT apresentaram semelhança com relação à carga máxima, tensão na carga máxima, limite de proporcionalidade e módulo de elasticidade. No STT observou-se valor maior em comparação ao LCA para energia e energia por área, na carga máxima. O STT alongou-se mais que o LCA e LP na ruptura e no limite de proporcionalidade. Não houve associação entre idade e carga máxima, tensão, energia e módulo de elasticidade no LCA, LP e STT. Houve associação entre carga máxima e área de secção no LCA e STT. Concluiu-se que o LP e STT têm comportamento mecânico distinto e que o perfil de ambos justifica a utilização como substitutos do LCA. / The material obtained from 19 human cadavers was submitted to traction-testing with the purpose of comparing the mechanical properties of the 10mm-central third of the patellar ligament (PL), triplicate semitendinosus muscle (TSM) and anterior cruciate ligament (ACL). Mean donor age was 40 11 years; 12 whites (63.1%) and 7 blacks (36.9%); 10 (52.6%) left knees and 9 (47.4%) right knees. The cross-sectional area of the test specimens was obtained so that, besides structural properties, material properties could also be evaluated. In addition to the load-strain diagram, the following variables were studied: ultimate load (N), absolute strain (mm) and relative strain (%) at failure load, yield point (N) and its respective strains, stress at ultimate load (MPa), modulus of elasticity (MPa), energy at failure (Nm) and energy per area (Nm/m2). Comparative statistical analysis of the materials revealed that PL was superior to ACL and TSM in ultimate load, stress at ultimate load, modulus of elasticity, energy, energy per area and yield point, thus featuring a behavior of greater stability and rigidity. ACL and TSM showed similar ultimate load, stress at ultimate load, yield point and modulus of elasticity. In TSM, energy and energy per area at ultimate load were higher than in ACL. Strain was greater in TSM than in ACL and PL at failure load and yield point. No association was observed between age and ultimate load, stress, energy and modulus of elasticity in ACL, PL and TSM. Ultimate load and cross-sectional area are associated in ACL and TSM. In conclusion, PL and TSM present distinct mechanical behaviors and their profiles justify their use as ACL replacements.

Orientador: Sérgio Swain Müller / Resumo: Com o objetivo de se comparar as propriedades mecânicas do ligamento cruzado anterior (LCA), dos 10 mm do terço central do ligamento da patela (LP), e do tendão do músculo semitendíneo triplicado (STT) do mesmo doador, foram realizados ensaios de tração em material obtido de 19 cadáveres humanos. A idade dos doadores foi de 40 11 anos (18-55 anos), sendo 15 (78,9%) masculinos e 4 (21,1%) femininos, 12 brancos (63,1%) e sete negros (36,9%); 10 (52,6%) joelhos do lado esquerdo e 9 (47,4%) do lado direito. Foi obtida a área de secção dos corpos de prova para que, além das propriedades estruturais, também fossem avaliadas as propriedades materiais. Além do diagrama carga-alongamento, foram estudadas as seguintes variáveis: carga máxima (N), alongamento absoluto (mm) e específico (%) na ruptura, limite de proporcionalidade (N) e respectivos alongamentos, tensão na carga máxima(MPa), módulo de elasticidade (MPa), energia na ruptura (Nm) e energia por área (Nm/m2) . A análise estatística comparativa entre os três materiais mostrou que o LP foi superior ao LCA e ao STT, na carga máxima, tensão na carga máxima, módulo de elasticidade, energia, energia por área e limite de proporcionalidade, caracterizando comportamento de maior estabilidade e rigidez. O LCA e STT apresentaram semelhança com relação à carga máxima, tensão na carga máxima, limite de proporcionalidade e módulo de elasticidade. No STT observou-se valor maior em comparação ao LCA para energia e energia por área, na carga máxima. O STT alongou-se mais que o LCA e LP na ruptura e no limite de proporcionalidade. Não houve associação entre idade e carga máxima, tensão, energia e módulo de elasticidade no LCA, LP e STT. Houve associação entre carga máxima e área de secção no LCA e STT. Concluiu-se que o LP e STT têm comportamento mecânico distinto e que o perfil de ambos justifica a utilização como substitutos do LCA. / Abstract: The material obtained from 19 human cadavers was submitted to traction-testing with the purpose of comparing the mechanical properties of the 10mm-central third of the patellar ligament (PL), triplicate semitendinosus muscle (TSM) and anterior cruciate ligament (ACL). Mean donor age was 40 11 years; 12 whites (63.1%) and 7 blacks (36.9%); 10 (52.6%) left knees and 9 (47.4%) right knees. The cross-sectional area of the test specimens was obtained so that, besides structural properties, material properties could also be evaluated. In addition to the load-strain diagram, the following variables were studied: ultimate load (N), absolute strain (mm) and relative strain (%) at failure load, yield point (N) and its respective strains, stress at ultimate load (MPa), modulus of elasticity (MPa), energy at failure (Nm) and energy per area (Nm/m2). Comparative statistical analysis of the materials revealed that PL was superior to ACL and TSM in ultimate load, stress at ultimate load, modulus of elasticity, energy, energy per area and yield point, thus featuring a behavior of greater stability and rigidity. ACL and TSM showed similar ultimate load, stress at ultimate load, yield point and modulus of elasticity. In TSM, energy and energy per area at ultimate load were higher than in ACL. Strain was greater in TSM than in ACL and PL at failure load and yield point. No association was observed between age and ultimate load, stress, energy and modulus of elasticity in ACL, PL and TSM. Ultimate load and cross-sectional area are associated in ACL and TSM. In conclusion, PL and TSM present distinct mechanical behaviors and their profiles justify their use as ACL replacements. / Doutor

No description available.

This study quantified mechanical and structural responses to loading conditions at subtendon hierarchical levels. Tensile tests were performed at three strain rates on three groups of rabbit patellar tendon specimens. For each rate, tangent modulus (E) was computed from the stress-strain curves and the following structural responses were evaluated: (i) Area percent of collagen fibrils (FAR) and (ii) Skewness angle formed between proteoglycans and collagen fibrils. For 0.1%/s, 10%/s, and 70%/s, E was 48.8±20.3MPa, 64.7±29.3MPa, and 78.6±31.7MPa, respectively. For control, 0.1%/s, 10%/s, and 70%/s, the mean FAR was 0.7552±0.1476, 0.6628±0.1190, 0.6335±0.1013, and 0.6047±0.0384, respectively; and proteoglycan skewness angles were 14.70º±11.01º, 12.76º±10.13º, 15.08.0º±11.66º, and 16.68º±12.07º, respectively. For increased E, interfibrillar components had less time for effective fluid flow, energy dissipation, and structural rearrangement. The inverse relationship of FAR to strain rate may be due to broken fibrils and the Poisson effect. Proteoglycan skewness angle increase is likely due to stretched fibrils.

Patellar tendinopathy (PT) is a knee injury resulting in pain localized to the patellar tendon. One main factor that causes PT is repetitive overloading of the tendon. Because of this mechanism, PT is commonly seen in "jumping sports" like basketball. This injury can severely impact a player's performance, and in order for a timely return to preinjury activity levels early diagnosis and treatment is important. The standard for the diagnosis of PT is a clinical examination, including a patient history and a physical assessment. Because PT has similar symptoms to injuries of other knee structures like the bursae, fat pad, and patellofemoral joint, imaging is regularly performed to aid in determining the correct diagnosis. One common imaging modality for the patellar tendon is gray-scale ultrasonography (GS-US). However, the accurate detection of PT in GS-US images is grader dependent and requires a high level of expertise. Machine learning (ML) models, which can accurately and objectively perform image classification tasks, could be used as a reliable automated tool to aid clinicians in assessing PT in GS-US images. ML models, like support vector machines (SVMs) and convolutional neural networks (CNNs), use features learned from labelled images, to predict the class of an unlabelled image. SVMs work by creating an optimal hyperplane between classes of labelled data points, and then classifies an unlabelled datapoint depending on which side of the hyperplane it falls. CNNs work by learning the set of features and recognizing what pattern of features describes each class. The objective of this study was to develop a SVM model and a CNN model to classify GS-US images of the patellar tendon as either normal or diseased (PT present), with an accuracy around 83%, the accuracy that experienced clinicians achieved when diagnosing PT in GS-US images that were already clinically diagnosed as either diseased or normal. We will also compare different test designs for each model to determine which achieved the highest accuracy. GS-US images of the patellar tendon were obtained from male and female Virginia Tech collegiate basketball athletes. Each image was labelled by an experienced clinician as either diseased or normal. These images were split into training and testing sets. The SVM and the CNN models were created using Python. For the SVM model, features were extracted from the training set using speeded up robust features (SURF). These features were then used to train the SVM model by calculating the optimal weights for the hyperplane. For the CNN model, the features were learned by layers within the CNN as were the optimal weights for classification. Both of these models were then used to predict the class of the images within the testing set, and the accuracy, sensitivity and precision of the models were calculated. For each model we looked at different test designs. The balanced designs had the same amount of diseased and normal images. The designs with Long images had only images taken in the longitudinal orientation, unlike Long+Trans, which had both longitudinal and transverse images. The designs with Full images contained the patellar tendon and surrounding tissue, whereas the ROI images removed the surrounding tissue. The best designs for the SVM model were the Unbalanced Long designs for both the Full and ROI images. Both designs had an accuracy of 77.5%. The best design for the CNN model was the Balanced Long+Trans Full design, with an accuracy of 80.3%. Both of the models had more difficulty classifying normal images than diseased images. This may be because the diseased images had a well defined feature pattern, while the normal images did not. Overall, the CNN features and classifier achieved a higher accuracy than the SURF features and SVM classifier. The CNN model is only slightly below 83%, the accuracy of an experienced clinician. These are promising results, and as the data set size increases and the models are fine tuned, the accuracy of the model will only continue to increase. / Master of Science / Patellar tendinopathy (PT) is a common knee injury. This injury is frequently seen in sports like basketball, where athletes are regularly jumping and landing, and ultimately applying a lot of force onto the patellar tendon. This injury can severely impact a player's performance, and in order for a timely return to preinjury activity levels early diagnosis and treatment is important. Currently, diagnosis of PT involves a patient history and a physical assessment, and is commonly supplemented by ultrasound imaging. However, clinicians need to have a high level of expertise in order to accurately assess these images for PT. In order to aid in this assessment, a tool like Machine learning (ML) models could be used. ML is becoming more and more prevalent in our every day lives. These models are everywhere, from the facial recognition tool on your phone to the list of recommended items on your Amazon account. ML models can use features learned from labelled images, to predict the class of an unlabeled image. The objective of this study was to develop ML models to classify ultrasound images of the patellar tendon as either normal or diseased (PT present).

No description available.

archives@tulane.edu / The patellar tendon transmits loads from the quadriceps to the tibia promoting locomotion. The main etiological factor behind patellar tendinopathies is thought to be excessive loading and unloading during athletic activity (Pearson & Hussain, 2014). The extracellular matrix (ECM) composition and fibroblast-like tenocytes dictate tendon’s uniaxial mechanical properties (Kannus, 2000). Following injury, a flood of inflammatory cells and spike in certain gene expressions work together to remove damaged tissue, trigger fibroblast proliferation, and deposit a provisional collagen matrix (Thomopoulos et al., 2015). Despite these processes, healed tendons demonstrate significant functional deficits (Mienaltowski et al., 2016). Moreover decrease in cell migration and fiber alignment with age further hampers healing outcomes(Dunkman et al., 2013). Efforts to restore tendon function are impeded by a lack of understanding of the early healing process, which may be age- and sex-dependent (Fryhofer et al., 2016; Mienaltowski et al., 2016). The tendon healing process can be further understood using an agent-based model (ABM). ABMs simulate individual agents and the interactions between them and their environment. This approach has the advantage of building complexity from the ground up, mimicking the underlying tendon physiology (Conte & Paolucci, 2014). Therefore, the objectives of this study were to 1) formulate a literature based ABM of murine patellar tendon healing with varying initial conditions to recapitulate changes observed with aging, and 2) Conduct simulations to determine whether ABM recapitulated salient features of healing, and to make predictions about healing outcomes. / 1 / Jordan Robinson

Patellar Tendinopathy (PT), commonly called "Jumper's Knee", is a condition resulting from repetitive loading of the patellar tendon that presents as anterior knee pain, which is commonly seen in basketball players due to the maneuvers in the sport. Diagnosis of PT often involves a clinical exam followed by ultrasound images for confirmation of the diagnosis to look for key factors of PT. Clinical assessment of ultrasound images of tendons is subjective and requires a high level of experience for reliable interpretation. Thus, there is a need for objective, quantitative methods to assess tendon abnormalities associated with pathology. Ultrasound image texture analysis has emerged as a reliable technique to augment the utility of conventional US imaging, and has recently been shown to distinguish healthy from abnormal tendon and myofascial tissues. The objective of the present study was to conduct image texture analysis to evaluate patellar tendons of collegiate basketball athletes over two seasons. Under an IRB-approved protocol with informed consent, a total of 33 Division 1 collegiate basketball athletes (16 male, 17 female, age 19.9 +/- 1.4 years) underwent clinical evaluation and ultrasound imaging. Four imaging sessions were collected over the course of two years (pre- and post-season). Participants were imaged using a GE LOGIQ S8 (General Electric, USA) ultrasound machine equipped with ML6-15 linear probe. At each imaging session, power Doppler images were collected in the longitudinal and transverse axis, at the proximal, central, and distal regions of the patellar tendon of both knees. Image texture analysis was performed using a custom MATLAB (Mathworks, USA) program to obtain first order (mean, median, variance, skewness, kurtosis, entropy), second order (contrast, energy, and homogeneity), and blob analysis (blob count, BC, and blob area, BA, for 5%, 25%, 50%, 75%, and 95% thresholding values) texture parameters in each image, based upon borders manually drawn by a single researcher. Statistical analysis was conducted to compare imaging sessions (JMP Pro 16, SAS). P-values <0.05 were considered statistically significant. Quantitative texture parameters are able to distinguish characteristics in patellar tendon ultrasound images to distinguish between anatomic region, gender, dominance and pre- to post- season. The 25% and 75% thresholding percentiles effectively showed characteristics of collagen fibers in the patellar tendon. The abnormal diagnosis does not greatly effect texture parameters, which needs to be investigated with more incorporation of grading criteria distinctions and a larger sample size. / Master of Science / Patellar Tendinopathy (PT) is a knee injury that commonly occurs in basketball players. The recovery for PT is often long and the player can still have knee pain when returning to the sport. Diagnosis of PT requires a high level of expertise to consider the patients history, conduct a physical exam and take ultrasound images to look for factors that indicate patellar tendon is damaged. The difficulty of diagnosing PT calls for an objective method to allow for accuracy in assessing patellar tendons. In order to create a more objective measure of ultrasound images, quantitative texture parameters are explored to understand what the brightness values of each pixel and the proximity of pixels together can convey about the image. The objective of this study is to understand what characteristics of the subject (anatomic region, knee dominance, gender, and time point) texture parameters are able to distinguish in patellar tendon ultrasound images.

Syfte: Sammanställa och granska studier gällande postoperativ behandling vid ruptur av ligament patella. Detta för att beskriva effekt och kvalitet på studier om postoperativ behandling. Metod: En beskrivande litteraturstudie valdes som design, med sökorden: patellar ligament, patellar tendon, rupture, knee injuries, surgery. Av totalt 1240 träffar valdes 13 relevanta artiklar publicerade mellan 1999-2013 efter sökningar i databaserna PubMed, PEDro, COCHRANE, SCOPUS, CINAHL, SPORTDiscus och AMED. Artiklarna kvalitetsgranskades enligt PEDro scale. Resultat: Två postoperativa behandlingar beskrevs, tidig och sen mobilisering. Antingen placeras knäleden i ett stabiliserande knäskydd som till en början låser knäleden i full extension eller så påbörjas tidig mobilisering av den opererade knäleden. Ingen signifikant skillnad påvisades mellan tidig och sen mobilisering vad gäller effekten på muskelstyrka, rörelseomfång och återgång till tidigare aktivitetsnivå. Vidare var kvaliteten på de granskade artiklarna genomgående låg (PEDro scale ≤ 5). Konklusion: Ytterligare forskning krävs för att fastställa vilken postoperativ behandling som ger bäst effekt. / Objective: Summarize and examine studies regarding postoperative treatment following rupture of the patellar ligament. Further the aim was to evaluate the effect of the postoperative treatment and the quality of the studies. Method: As design, a descriptive review was chosen, keywords: patellar ligament, patellar tendon, rupture, knee injuries, surgery. From a total of 1240 items, 13 relevant articles published 1999-2013 were selected after search in the databases PubMed, PEDro, COCHRANE, SCOPUS, CINAHL, SPORTDiscus and AMED. The articles were quality-graded according to PEDro scale. Results: Two postoperative treatments were described, early and delayed mobilization. There was no significant difference between them regarding the effect on muscle strength, range of motion and return to preinjury level of activity. The quality-graded articles had overall low quality (PEDro scale ≤ 5). Conclusion: Further researches are required to determine which postoperative treatment has the best effect.

Sammanfattning Syfte och frågeställningar: Syftet med studien var att utvärdera förändringar över tid vid excentrisk träning av quadriceps i en ny dosering i kombination med träning av höft- och bålmuskulatur under 12 veckor vid patellar tendinopti med avseende på a) smärta, b) skattning av symtom, funktion och förmåga att delta i idrott, c) funktionellt hopptest samt c) vävnadsförändringar i patellarsenan. Metod: Studien var en pilotstudie utan kontrollgrupp. Tolv personer som kliniskt diagnostiserats med patellar tendinopati samt hade ultraljudsverifierad tendinos i patellarsenan deltog frivilligt i studien (2 kvinnor och 10 män; medelålder 29,2 år, besvärsduration &gt; tre månader). För att utvärdera träningsinterventionen användes visuell analog skala (VAS) för smärta i vila och under aktivitet, frågeformuläret Victorian Institute of Sport Assessment score (VISA-P) för skattning av symtom, funktion och förmåga att delta i idrott, funktionellt hopptest, one-leg hop for distance (OLH). Undersökning av patellarsenan gjordes med ultraljud och färgdoppler. Utvärdering genomfördes före och efter tolv veckors träningsintervention. Träningsprogrammet innehöll excentrisk träning av quadriceps (bromsande knäböjning på ett ben) stående på en kil inklusive stretch av quadriceps i kombination med träning av höft- och bålmuskulaturen som utfördes tre gånger i veckan under 12 veckor. Signifikansnivå p &lt; 0.05 användes i studien och en tendens inkluderades mellan 0.05 &lt; p &lt; 0.1 Resultat: Efter träningsperioden sågs en signifikant minskning av smärta i vila (VAS från 64 till 11,5) och under aktivitet (från 80 till 21 på VAS skalan) samt en ökad funktion och förmåga att delta i idrott sågs på VISA-P (från 44 till 71,5). En signifikant förbättrings sågs också på funktionellt hopptest på ett ben med en ökad hopplängd (från 103 till 132 cm) efter träningsinterventionen. Ingen signifikant skillnad kunde ses gällande vävnadsförändringar i patellarsenan. Det fanns däremot en tendens (p=.083) till förbättring av senstrukturen i patellarsenan efter träningsinterventionen. Slutsats: Efter tolv veckors intervention sågs en signifikant förbättring med avseende på smärta och funktion vid patellar tendinopati. Dessa resultat bör följas upp för att utvärdera långsiktiga förändringar av träningsinterventionen. Resultaten från denna pilotstudie kan ligga till grund för en kommande randomiserad kontrollerad interventionsstudie. / Abstract Aim: The aim of this study was to evaluate changes over time during eccentric quadriceps training with a previously unstudied exercise dosage in combination with hip and core exercises for a period of 12 weeks in patients with patellar tendinopathy. The outcome measures were: pain, self-evaluated symptoms, functions and ability to participate in sport, functional jumptest and patellar tendon tissue changes. Method: This was an uncontrolled pilot study. Twelve patients diagnosed with patellar tendinopathy using clinical testing and ultrasound imaging participated in the study voluntarily (2 female and 10 men, mean age 29.2 years, duration of symptoms &gt; 3 months). To evaluate the intervention a visual analogue scale (VAS) was used to measure pain at rest and during activity. The Victorian Institute of Sport Assessment score (VISA-P) was used to evaluate self-assessed symptoms, function and ability to participate in sport. One-leg hop test for distance (OLH) was used as a functional test. Changes in the patellar tendon were examined using ultrasound imaging and colour doppler. Measurements took place at baseline and at 12 weeks. The exercise program contained eccentric quadriceps training (drop-squat on one leg) standing on a decline board, quadriceps stretching in combination with hip and core exercises performed 3 times per week for twelve weeks. P-value was set at &lt; 0.05 and a tendency was included between 0.05 &lt; p &lt; 0.1 Results: At 12 weeks a significant reduction of pain was observed at rest (from 64 to 11.5) and during activity (from 80 to 21) as well as improved VISA-P scores (from 44 to 71.5). A significant improvement was observed on the functional hop test (from 103 to 132 cm). No significant changes in the patellar tendon were observed with ultrasound imaging. Although there was a tendency towards structural improvement of the patellar tendon (p=.083) after 12 weeks of intervention. Conclusion: After twelve weeks of intervention a significant improvement was observed with respect to pain and function. It would be of interest to examine long-term changes of this combined training program. These results may be used as a foundation for a future randomised controlled intervention study.