Sample records for tendon tears comparison

  1. Atraumatic quadriceps tendon tear associated with calcific tendonitis.

    PubMed

    Abram, Simon G F; Sharma, Akash D; Arvind, Chinnakonda

    2012-01-01

    Calcific tendonitis of the quadriceps tendon is an uncommon condition. We present the first case of a quadriceps tendon tear associated with calcific tendonitis. In this case, the patient presented with symptoms mimicking a rupture of the quadriceps tendon. This case illustrates that although calcific tendonitis of the quadriceps is a rare condition it is not benign and should be considered when investigating acute symptoms associated with the extensor mechanism of the knee. PMID:23188846

  2. Autologous hamstring tendon used for revision of quadiceps tendon tears.

    PubMed

    McCormick, Frank; Nwachukwu, Benedict U; Kim, Jaehon; Martin, Scott D

    2013-04-01

    A paucity of literature exists on quadriceps tendon reruptures. Failed quadriceps tendon repair can cause significant morbidity and disability. Surgical management of quadriceps tendon rerupture can be challenging due to tissue degeneration, tendon retraction, muscle atrophy, and poor bone fixation. A lack of guidance in the literature exists on the appropriate surgical techniques for managing quadriceps tendon reruptures.This article describes the case of a male recreational athlete with a failed primary quadriceps tendon repair who presented 10 months after rerupture. Examination was significant for morbid obesity, assisted ambulation, and a significant defect at the superior pole of the patella on the affected side. Intraoperative findings were consistent with a 2.0- to 4.5-cm tendon defect across the extensor mechanism with complete retinaculi tears. The authors performed a novel surgical approach for revision of quadriceps tears using a bilateral hamstring autograft through a quadriceps tendon weave and a transosseous patellar repair. Tendon length was restored, and extensor mechanism tension was reapproximated. Postoperatively, the patient achieved a good outcome and had returned to full, painless, sport participation at 2-year follow-up.This surgical technique is suitable for revision quadriceps tendon repairs of large tendon gap defects, repairs desiring tendon-to-bone in-growth, and repairs requiring large-force transmission across the repair. PMID:23590798

  3. Following rotator cuff tears, the remaining (intact) tendons are mechanically altered

    PubMed Central

    Perry, Stephanie M.; Getz, Charles L.; Soslowsky, Louis J.

    2009-01-01

    Although presumed, damage in the remaining (intact) rotator cuff tendons in the presence of an isolated supraspinatus tendon tear or multiple tendon tear has not been well studied. This study utilized an animal model of multiple rotator cuff tendon tears to investigate alterations in the remaining (intact) tendon mechanical properties at 4 and 8 weeks post-injury. Twenty-four animals served as uninjured controls, while seventy-two were divided among the tendon detachment groups (supraspinatus tendon detachment, supraspinatus+infraspinatus tendon detachment, supraspinatus+subscapularis tendon detachment). We found the remaining (intact) rotator cuff tendons have decreased mechanical properties in the presence of rotator cuff tears. Remaining (intact) subscapularis and infraspinatus tendon cross-sectional area increased, while tendon modulus decreased after both one and two tendon tears. Additionally, the remaining (intact) tendon cross-sectional areas continued to increase with time post-injury. These alterations could potentially lead to further tendon damage and tear progression. PMID:19095175

  4. The Effect of Size and Location of Tears in the Supraspinatus Tendon on Potential Tear Propagation.

    PubMed

    Thunes, James; Matthew Miller, R; Pal, Siladitya; Damle, Sameer; Debski, Richard E; Maiti, Spandan

    2015-08-01

    Rotator cuff tears are a common problem in patients over the age of 50?yr. Tear propagation is a potential contributing factor to the failure of physical therapy for treating rotator cuff tears, thus requiring surgical intervention. However, the evolution of tears within the rotator cuff is not well understood yet. The objective of this study is to establish a computational model to quantify initiation of tear propagation in the supraspinatus tendon and examine the effect of tear size and location. A 3D finite element (FE) model of the supraspinatus tendon was constructed from images of a healthy cadaveric tendon. A tear of varying length was placed at six different locations within the tendon. A fiber-reinforced Mooney-Rivlin material model with spatial variation in material properties along the anterior-posterior (AP) axis was utilized to obtain the stress state of the computational model under uniaxial stretch. Material parameters were calibrated by comparing computational and experimental stress-strain response and used to validate the computational model. The stress state of the computational model was contrasted against the spatially varying material strength to predict the critical applied stretch at which a tear starts propagating further. It was found that maximum principal stress (as well as the strain) was localized at the tips of the tear. The computed critical stretch was significantly lower for the posterior tip of the tear than for the anterior tip suggesting a propensity to propagate posteriorly. Onset of tear propagation was strongly correlated with local material strength and stiffness in the vicinity of the tear tip. Further, presence of a stress-shielded zone along the edges of the tear was observed. This study illustrates the complex interplay between geometry and material properties of tendon up to the initiation of tear propagation. Future work will examine the evolution of tears during the propagation process as well as under more complex loading scenarios. PMID:26043431

  5. Diagnosis of Tears of the Quadriceps Tendon of the Knee

    Microsoft Academic Search

    Ibrahim F. Abdelwahab; Antonio Banderali

    OBJECTIVE. The purpose of the study was to evaluate the role of sonography in diagnosing traumatic tears of the quadriceps tendon. More specifically, it was intended to determine the value of sonography in differentiating complete from par- tial tears and thus in directing therapy. Knees of asymptomatic volunteers and patients' contralateral knees were used as normal standards. SUBJECTS AND METHODS.

  6. Reconstruction of a chronic quadriceps tendon tear in a body builder

    Microsoft Academic Search

    Paolo Leopardi; Giovanni di Vico; Donato Rosa; Fabrizio Cigala; Nicola Maffulli

    2006-01-01

    Chronic quadriceps tendon tears are uncommon. We report about a body builder taking a cocktail of anabolic drugs for several years in whom reconstruction of a chronic quadriceps tendon tear was performed using ipsilateral hamstring tendons with good results despite the 7 month delay between injury and surgery. The use of hamstring tendons is a good option for the management of

  7. Medial Biceps Sling Takedown May Be Necessary to Expose an Occult Subscapularis Tendon Tear

    PubMed Central

    Hartzler, Robert U.; Burkhart, Stephen S.

    2014-01-01

    With a systematic approach to diagnosis, including a thorough history, physical examination, advanced imaging, and arthroscopic evaluation, most subscapularis tendon tears may be readily discovered. Occult tears, on the other hand, may escape arthroscopic detection if a high index of suspicion and certain intraoperative examination steps are lacking. We describe an occult tear pattern in which a subscapularis tendon tear was completely hidden by an intact medial biceps tendon sling. Takedown of the sling, which was expendable because a tenodesis was planned, was required to expose this occult tear. Awareness of occult subscapularis tear patterns makes diagnosis and repair possible. PMID:25685681

  8. Simultaneous rupture of bilateral quadriceps tendon and rotator cuff tear: a case report.

    PubMed

    Chen, H T

    2012-03-01

    This is a case report of a patient who sustained both a bilateral quadriceps tendon rupture and a complete rotator cuff tear. Overuse is a known risk factor for rotator cuff tears, but this case suggests that it can also be a risk factor for quadriceps tendon rupture. PMID:23155972

  9. Peroneal tendon tears, surgical management and its complications.

    PubMed

    Cerrato, Rebecca A; Myerson, Mark S

    2009-06-01

    Peroneal tendon injuries in the athlete are recognized with increasing frequency as a pathologic entity. Once considered uncommon, they have been attributed to many cases of persistent lateral ankle symptoms after a "typical" ankle sprain. Acute tears of the peroneus brevis, and less commonly the peroneus longus, have been implicated in sport activities and are often coexistent with peroneal instability. Subluxation typically occurs when the foot is in a dorsiflexed position and the peroneal muscles strongly contract, causing an eversion force simultaneously. Peroneal instability, as well as tearing, has been linked to ballet dancing, skiing, soccer, tennis, American football, running, basketball, and ice skating. This article discusses the mechanism of injury, methods of patient evaluation and management, complications, and outcomes. PMID:19501808

  10. US appearance of partial-thickness supraspinatus tendon tears: Application of the string theory. Pictorial essay

    PubMed Central

    Guerini, H.; Fermand, M.; Godefroy, D.; Feydy, A.; Chevrot, A.; Morvan, G.; Gault, N.; Drapé, J.L.

    2012-01-01

    The supraspinatus tendon is composed of 5 different layers consisting of intertwining bundles. On a front portion of the tendon, the layers become coated bundles which insert on the trochanter. At the insertion, the superficial or bursal surface of the tendon corresponding to the tendon fibers in contact with the subacromial bursa can be distinguished from the deep surface corresponding to the fibers in contact with the glenohumeral joint. A tendon tear may involve partial or total disruption of the tendon fibers and is called full-thickness tear if it affects the entire tendon, and partial-thickness tear if it involves only part of the tendon. Partial-thickness tears of the supraspinatus tendon include lesions of the superficial, deep and central surface or tendon delamination. A contrast enhanced examination requires injection of contrast agent into the joint (arthrography followed by computed tomography (CT) or magnetic resonance imaging (MRI)) to study the deep surface, and injection into the subacromial bursa (bursography followed by CT) to study the superficial surface. MRI and ultrasound (US) examination allow the study of these different tendon layers without the use of contrast agent (which is not possible at CT). PMID:23396264

  11. US appearance of partial-thickness supraspinatus tendon tears: Application of the string theory. Pictorial essay.

    PubMed

    Guerini, H; Fermand, M; Godefroy, D; Feydy, A; Chevrot, A; Morvan, G; Gault, N; Drapé, J L

    2012-02-01

    The supraspinatus tendon is composed of 5 different layers consisting of intertwining bundles. On a front portion of the tendon, the layers become coated bundles which insert on the trochanter. At the insertion, the superficial or bursal surface of the tendon corresponding to the tendon fibers in contact with the subacromial bursa can be distinguished from the deep surface corresponding to the fibers in contact with the glenohumeral joint. A tendon tear may involve partial or total disruption of the tendon fibers and is called full-thickness tear if it affects the entire tendon, and partial-thickness tear if it involves only part of the tendon. Partial-thickness tears of the supraspinatus tendon include lesions of the superficial, deep and central surface or tendon delamination.A contrast enhanced examination requires injection of contrast agent into the joint (arthrography followed by computed tomography (CT) or magnetic resonance imaging (MRI)) to study the deep surface, and injection into the subacromial bursa (bursography followed by CT) to study the superficial surface. MRI and ultrasound (US) examination allow the study of these different tendon layers without the use of contrast agent (which is not possible at CT). PMID:23396264

  12. A review of surgical repair methods and patient outcomes for gluteal tendon tears.

    PubMed

    Ebert, Jay R; Bucher, Thomas A; Ball, Simon V; Janes, Gregory C

    2015-01-01

    Advanced hip imaging and surgical findings have demonstrated that a common cause of greater trochanteric pain syndrome (GTPS) is gluteal tendon tears. Conservative measures are initially employed to treat GTPS and manage gluteal tears, though patients frequently undergo multiple courses of non-operative treatment with only temporary pain relief. Therefore, a number of surgical treatment options for recalcitrant GTPS associated with gluteal tears have been reported. These have included open trans-osseous or bone anchored suture techniques, endoscopic methods and the use of tendon augmentation for repair reinforcement. This review describes the anatomy, pathophysiology and clinical presentation of gluteal tendon tears. Surgical techniques and patient reported outcomes are presented. This review demonstrates that surgical repair can result in improved patient outcomes, irrespective of tear aetiology, and suggests that the patient with "trochanteric bursitis" should be carefully assessed as newer surgical techniques show promise for a condition that historically has been managed conservatively. PMID:25198307

  13. Distinction between supraspinatus, infraspinatus and subscapularis tendon tears with ultrasound in 332 surgically confirmed cases

    Microsoft Academic Search

    Harald Zehetgruber; Thomas Lang; Christian Wurnig

    2002-01-01

    The aim of this retrospective study was to determine the diagnostic value of preoperative ultrasonography for the characterisation of size and location of the involved tendons. in 332 consecutive patients who underwent surgery, all preoperative ultrasonographic reports were reviewed and ultrasound (US) and surgical findings were compared. Ultrasound criteria for cuff tears were complete nonvisualisation of the cuff tendons or

  14. Detection of partial-thickness tears in ligaments and tendons by Stokes-polarimetry imaging

    NASA Astrophysics Data System (ADS)

    Kim, Jihoon; John, Raheel; Walsh, Joseph T.

    2008-02-01

    A Stokes polarimetry imaging (SPI) system utilizes an algorithm developed to construct degree of polarization (DoP) image maps from linearly polarized light illumination. Partial-thickness tears of turkey tendons were imaged by the SPI system in order to examine the feasibility of the system to detect partial-thickness rotator cuff tear or general tendon pathology. The rotating incident polarization angle (IPA) for the linearly polarized light provides a way to analyze different tissue types which may be sensitive to IPA variations. Degree of linear polarization (DoLP) images revealed collagen fiber structure, related to partial-thickness tears, better than standard intensity images. DoLP images also revealed structural changes in tears that are related to the tendon load. DoLP images with red-wavelength-filtered incident light may show tears and related organization of collagen fiber structure at a greater depth from the tendon surface. Degree of circular polarization (DoCP) images exhibited well the horizontal fiber orientation that is not parallel to the vertically aligned collagen fibers of the tendon. The SPI system's DOLP images reveal alterations in tendons and ligaments, which have a tissue matrix consisting largely of collagen, better than intensity images. All polarized images showed modulated intensity as the IPA was varied. The optimal detection of the partial-thickness tendon tears at a certain IPA was observed. The SPI system with varying IPA and spectral information can improve the detection of partial-thickness rotator cuff tears by higher visibility of fiber orientations and thereby improve diagnosis and treatment of tendon related injuries.

  15. Decreased loading following rotator cuff tears leads to improved biceps tendon properties in a rat model

    PubMed Central

    Peltz, Cathryn D.; Hsu, Jason E.; Zgonis, Miltiadis H.; Trasolini, Nicholas A.; Glaser, David L.; Soslowsky, Louis J.

    2010-01-01

    Background The purpose of this study was to elucidate the mechanism of biceps tendon changes following rotator cuff tears. We hypothesized that increased loading on the biceps tendon following rotator cuff tears will result in further detrimental changes while decreased loading will result in increased organization and more normal tendon composition. Additionally, we hypothesized that changes with altered loading will begin at the proximal insertion into bone and progress along the tendon length at later time points. Materials and methods Supraspinatus and infraspinatus tendon detachments in rats were followed by various loading protocols at various time points. Regional changes in cellularity, cell shape, collagen organization, and matrix proteins of the long head of the biceps tendon were determined by histologic measures and immunohistochemistry. Results Increased loading following detachments resulted in more disorganized collagen after only 1 week and compositional changes by 4 weeks. By 8 weeks, decreased loading resulted in increased organization, decreased cellularity, more elongated cell shape and more normal tendon composition. Organizational changes with increased loading began in the intra-articular space and progressed along the tendon length with time. Conclusions Combined with previous findings of decreased mechanics with increased loading, these results indicate increased compressive loading away from the proximal insertion into bone as a mechanism for biceps tendon pathology in the presence of rotator cuff tears. The striking improvements with decreased loading further support increased loading as a mechanism for biceps tendon pathology as removal of this load led to improvements in tendon histology, organization and composition. Level of evidence Basic Science Study PMID:21393021

  16. Partial tear of the quadriceps tendon in a child

    Microsoft Academic Search

    Geetika Khanna; George El-Khoury

    2008-01-01

    We present a case of partial rupture of the quadriceps tendon in an 8-year-old girl. This is one of the youngest patients\\u000a reported with a quadriceps tendon rupture, an entity seen predominantly in middle-aged people. The strength of the muscle\\u000a tendon unit in a child makes tendon injuries extremely unusual as compared to apophyseal avulsions. The MR imaging findings\\u000a of

  17. Ultrasound diagnosis of quadriceps tendon tear in an uncooperative patient.

    PubMed

    Secko, Michael; Diaz, Michelle; Paladino, Lorenzo

    2011-10-01

    A 38-year-old intoxicated man presented to the emergency department with a painful, swollen left knee and inability to ambulate after being tackled to the ground. The patient was uncooperative, and physical examination of the lower extremities was limited by his intoxication. Radiographic examination of the knee was unremarkable. Ultrasound of the knee revealed a quadriceps tendon rupture. The sonographic features of quadriceps tendon rupture are described, as is the role ultrasound plays in the assessment of a swollen, painful knee. PMID:22090751

  18. Quantitative Ultrasound Facilitates the Exploration of Morphological Association of the Long Head Biceps Tendon with Supraspinatus Tendon Full Thickness Tear

    PubMed Central

    Chang, Ke-Vin; Chen, Wen-Shiang; Wang, Tyng-Guey; Hung, Chen-Yu; Chien, Kuo-Liong

    2014-01-01

    Backgrounds Pathology of the long head biceps tendon (LHBT) is associated with rotator cuff tears but whether the LHBT texture changes following supraspinatus tendon full thickness tear (SSFT) can be detected at the extra-articular segment remains unknown. This cross-sectional study aimed to explore the morphological differences of the LHBT in shoulders with and without deficient rotator cuffs by using quantitative ultrasound. Materials and Methods We selected 145 cases with SSFT and 145 age-and- gender-matched controls. The width, thickness, flattening ratio, cross-sectional area, and echogenicity ratio of the LHBT were measured and a general linear model was used to clarify the relationship between rotator cuff pathology and LHBT morphology. The receiver operating characteristic curves of each parameter were constructed for SSFT discrimination and the maximal Youden indexes were used to define the best cut-off points. Results We found increased thickness and cross-sectional area but decreased flattening ratio in shoulders with SSFT, and no between-group differences in the width and echogenicity ratio. The LHBT appearance was modified by biceps peritendinous effusion and medial subluxation, but not by the size of SSFT. The flattening ratio was the best discriminator for SSFT with an area under curve of 0.81 (95% confidence interval, 0.76–0.86). The cut-off values to differentiate between the non-tear and tear groups were 2.00 mm of the thickness, 1.73 of the flattening ratio and 10.53 mm2 of the cross-sectional area. Conclusion Quantitative ultrasound facilitated the detection of the LHBT morphological changes following SSFT and demonstrated its potential utility in discriminating rotator cuff deficiency. PMID:25412357

  19. Peroneal tendon injuries: An evaluation of 49 tears in 41 patients

    Microsoft Academic Search

    Amol Saxena; Andrew Cassidy

    2003-01-01

    Forty-one patients sustaining 49 tears of the peroneal tendons were evaluated prospectively a minimum of 1 year after surgical treatment. Preoperative and postoperative function and activity were assessed by using the American Orthopedic Foot and Ankle (AOFAS) score. Mean age at the time of surgery was 44.0 ± 11.7 years. Mean follow-up after the index surgery was 35.5 ± 22.2

  20. Tendon transfer for irreparable rotator cuff tears: indications and surgical rationale

    PubMed Central

    Merolla, Giovanni; Chillemi, Claudio; Franceschini, Vincenzo; Cerciello, Simone; Ippolito, Giorgio; Paladini, Paolo; Porcellini, Giuseppe

    2014-01-01

    Summary Background: treatment of symptomatic irreparable rotator cuff tears is extremely challenging because, at present, there are no ideal solutions to this problem. Many patients respond favorably to nonsurgical treatment. However, when conservative measures fail to improve the patient’s pain and disability, surgery should be considered. Methods: different surgical techniques are available and the choice of the most appropriate procedure depends on the presenting symptoms, age of the patient, functional demand, medical comorbidities, joint stability and presence of arthritic changes. The transposition of the surrounding muscles to replace the rotator cuff function represents a viable option in the treatment of younger patients without glenohumeral osteoarthritis and with severe functional limitation. Purpose: aim of this study is to give an overview of the currently available evidence regarding tendon transfer procedures for irreparable rotator cuff tears. PMID:25767779

  1. Effect of tear size, corticosteroids and subacromial decompression surgery on the hierarchical structural properties of torn supraspinatus tendons

    PubMed Central

    Tilley, J. M. R.; Murphy, R. J.; Chaudhury, S.; Czernuszka, J. T.; Carr, A. J.

    2014-01-01

    Objectives The effects of disease progression and common tendinopathy treatments on the tissue characteristics of human rotator cuff tendons have not previously been evaluated in detail owing to a lack of suitable sampling techniques. This study evaluated the structural characteristics of torn human supraspinatus tendons across the full disease spectrum, and the short-term effects of subacromial corticosteroid injections (SCIs) and subacromial decompression (SAD) surgery on these structural characteristics. Methods Samples were collected inter-operatively from supraspinatus tendons containing small, medium, large and massive full thickness tears (n = 33). Using a novel minimally invasive biopsy technique, paired samples were also collected from supraspinatus tendons containing partial thickness tears either before and seven weeks after subacromial SCI (n = 11), or before and seven weeks after SAD surgery (n = 14). Macroscopically normal subscapularis tendons of older patients (n = 5, mean age = 74.6 years) and supraspinatus tendons of younger patients (n = 16, mean age = 23.3) served as controls. Ultra- and micro-structural characteristics were assessed using atomic force microscopy and polarised light microscopy respectively. Results Significant structural differences existed between torn and control groups. Differences were identifiable early in the disease spectrum, and increased with increasing tear size. Neither SCI nor SAD surgery altered the structural properties of partially torn tendons seven weeks after treatment. Conclusions These findings may suggest the need for early clinical intervention strategies for torn rotator cuff tendons in order to prevent further degeneration of the tissue as tear size increases. Further work is required to establish the long-term abilities of SCI and SAD to prevent, and even reverse, such degeneration. Cite this article: Bone Joint Res 2014;3:252–61. PMID:25106417

  2. Partial semitendinosus tendon tear in a young athlete: a case report and review of the distal semitendinosus anatomy.

    PubMed

    Sivasundaram, Lakshmanan; Matcuk, George R; White, Eric A; Hatch, George F Rick; Patel, Dakshesh B

    2015-07-01

    Distal semitendinosus tears have been infrequently reported in the radiology literature, and a detailed description of the anatomy and imaging features of these injuries is lacking. The semitendinosus tendon is clinically relevant, as it is frequently grafted in knee ligament reconstructions and plays an important role in performing competitive activities. We present a case of a 31-year old man who developed a partial semitendinosus tear during competitive training. This case highlights the common clinical and imaging findings found with distal semitendinosus tears, and explores the various modalities available to treat this injury. We also review the clinically pertinent anatomy of the distal semitendinosus tendon and discuss the pitfalls that musculoskeletal radiologists may encounter, to avoid misdiagnosing these rare injuries. PMID:25855409

  3. Tears

    MedlinePLUS

    ... as those salty drops that fall from your eyes when you cry. Actually, your tears clean your eyes every time you blink. Tears also keep your eyes moist, which is important for your vision. Tear ...

  4. Effect of return to overuse activity following an isolated supraspinatus tendon tear on adjacent intact tendons and glenoid cartilage in a rat model.

    PubMed

    Reuther, Katherine E; Thomas, Stephen J; Sarver, Joseph J; Tucker, Jennica J; Lee, Chang-Soo; Gray, Chancellor F; Glaser, David L; Soslowsky, Louis J

    2013-05-01

    Rotator cuff tears are common conditions that can alter shoulder mechanics and may lead to damage of intact joint tissues. These injuries are of particular concern in populations who perform tasks requiring repetitive overhead activity (e.g., athletes and laborers) and who are likely to return to aggressive pre-injury activity levels despite limited understanding of the potentially damaging effects on the remaining tissues. Therefore, we investigated the effect of returning to overuse activity following a supraspinatus tear on shoulder function and the mechanical properties of the remaining intact tendons and glenoid cartilage. Forty rats underwent 4 weeks of overuse activity to create a tendinopathic condition followed by detachment of the supraspinatus tendon and were then randomized into two groups: continued overuse or cage activity. Ambulatory measurements were performed throughout the 8 weeks prior to euthaniasia, and properties of the adjacent tendons and cartilage were evaluated. Results demonstrated that shoulder function was not compromised in the return to overuse group. However, alterations of the glenoid cartilage and biceps tendon properties occurred. Our results help define the contributory roles of common mechanical injury mechanisms and provide a framework by which physicians could better prescribe long-term treatment strategies for patients. PMID:23280495

  5. Effect of Return to Overuse Activity Following an Isolated Supraspinatus Tendon Tear on Adjacent Intact Tendons and Glenoid Cartilage in a Rat Model

    PubMed Central

    Reuther, Katherine E.; Thomas, Stephen J.; Sarver, Joseph J.; Tucker, Jennica J.; Lee, Chang-Soo; Gray, Chancellor F.; Glaser, David L.; Soslowsky, Louis J.

    2013-01-01

    Rotator cuff tears are common conditions that can alter shoulder mechanics and may lead to damage of intact joint tissues. These injuries are of particular concern in populations who perform tasks requiring repetitive overhead activity (e.g., athletes and laborers) and who are likely to return to aggressive pre-injury activity levels despite limited understanding of the potentially damaging effects on the remaining tissues. Therefore, we investigated the effect of returning to overuse activity following a supraspinatus tear on shoulder function and the mechanical properties of the remaining intact tendons and glenoid cartilage. Forty rats underwent 4 weeks of overuse activity to create a tendinopathic condition followed by detachment of the supraspinatus tendon and were then randomized into two groups: continued overuse or cage activity. Ambulatory measurements were performed throughout the 8 weeks prior to euthaniasia, and properties of the adjacent tendons and cartilage were evaluated. Results demonstrated that shoulder function was not compromised in the return to overuse group. However, alterations of the glenoid cartilage and biceps tendon properties occurred. Our results help define the contributory roles of common mechanical injury mechanisms and provide a framework by which physicians could better prescribe long-term treatment strategies for patients. PMID:23280495

  6. How do massive immobile rotator cuff tears behave after arthroscopic interval slides? Comparison with mobile tears

    PubMed Central

    FOSSATI, CHIARA; ARRIGONI, PAOLO; RAGONE, VINCENZA; SPENNACCHIO, PIETRO; BANFI, GIUSEPPE; RANDELLI, FILIPPO; RANDELLI, PIETRO

    2014-01-01

    Purpose the aim of this study was to compare clinical outcomes of contracted immobile massive rotator cuff tears mobilised through an arthroscopic interval slide technique versus massive mobile cuff tears directly repaired without any mobilisation. Methods twenty-five patients who underwent arthroscopic repair for massive rotator cuff tears with a minimum of 18 months follow-up were included. The patients were retrospectively divided into two groups. In group 1, a single or double interval slide was performed to achieve adequate tendon mobilisation. In group 2 (control group), massive rotator cuff tears were arthroscopically repaired without any additional release. Patients were evaluated with validated outcomes scores: subjective and objective Constant score, a Visual Analogue Scale (VAS) for pain, and single Assessment Numeric Evaluation (SANE). Results the two groups were comparable in terms of age, gender and involvement of the dominant arm. The mean follow-up duration was 31 months in group 1 and 28 months in group 2 (p = 0.4). The two groups showed no significant differences in SANE and VAS results (group 1: SANE 77%, VAS 1.3; group 2: SANE 88%, VAS 1.6), or in total Constant score (group 1: 66.5 ± 11; group 2: 75 ± 14; p = 0.1) and subjective Constant score (Group 1: 31 ± 5; group 2: 30.8 ± 7; p = 0.9). A significant difference was found for the objective Constant score, which was higher in the control group (group 1: 35.5 ± 7; group 2: 44 ± 8; p = 0.009). Conclusions Subjective clinical outcomes of arthroscopic repair with or without interval slides did not differ and were satisfactory. Objectively, immobile cuff tears showed inferior results. The use of interval slides might be considered a first step or an alternative to more invasive procedures for low demanding patients. Level of evidence Level III, retrospective comparative study. PMID:25606545

  7. Clinics in diagnostic imaging (151). Acromioclavicular joint geyser sign with chronic full-thickness supraspinatus tendon (SST) tear.

    PubMed

    Khor, Andrew Yu Keat; Wong, Steven Bak Siew

    2014-02-01

    An 82-year-old man presented with neck pain, right upper limb radiculopathy and right shoulder pain. Physical examination revealed a soft lump over the right shoulder joint, as well as reduced range of shoulder movements. On magnetic resonance imaging, the soft lump was shown to be a cystic mass over the acromioclavicular joint and was related to a full-thickness supraspinatus tendon tear. This is the classic geyser sign. The pathophysiology and clinical features of the geyser sign, and its imaging features with various imaging modalities, are discussed. PMID:24570312

  8. Incidence of Major Tendon Ruptures and Anterior Cruciate Ligament Tears in US Army Soldiers

    Microsoft Academic Search

    Daniel W. White; Joseph C. Wenke; Dan S. Mosely; Sally B. Mountcastle; Carl J. Basamania

    2007-01-01

    Background: Although a rare event, the prevalence of major tendon rupture has increased in recent decades. Identification of risk factors is important for prevention purposes.Hypothesis: Race is a risk factor for major tendon ruptures.Study Design: Cohort study (prevalence); Level of evidence, 2.Methods: All patients admitted for surgical management of a rupture of a major tendon at Womack Army Medical Center,

  9. Transplantation with allograft for rupture of the flexor hallucis longus tendon with subsequent longitudinal tear of the flexor digitorum longus tendon at the master knot of Henry: a case report.

    PubMed

    Grady, John F; Boumendjel, Yelena; Nguyen, Ngan T; Caldwell, Autumn

    2014-01-01

    A rare case of closed complete rupture of the flexor hallucis longus tendon with subsequent longitudinal tear of the flexor digitorum longus tendon is reported in a marathon runner. This is also a first case report of flexor hallucis longus transplant with cadaveric posterior tibial tendon allograft. Two minimal incisions distal and proximal to the malleolus allowed for tunneling with urethral dilators to open the tendon sheath for transplantation, avoiding the need for a large incision. Postoperatively, the patient regained active flexion at the interphalangeal joint of the left hallux. Four months after surgery, full range of motion was observed and dynamometric exam revealed 68% of the strength of the contralateral side. The patient was able to resume competitive running after the surgery and performed well in her age bracket. PMID:25275740

  10. Simulation of Hot Tearing and Distortion during Casting of Steel: Comparison with Experiments

    E-print Network

    Beckermann, Christoph

    Simulation of Hot Tearing and Distortion during Casting of Steel: Comparison with Experiments C City, IA 52242 Abstract Hot tears are defects that occur during solidification of a casting that is subjected to mechanical restraints. Several key factors are known to aggravate the hot tearing of cast steel

  11. Quadriceps tendon allografts as an alternative to Achilles tendon allografts: a biomechanical comparison.

    PubMed

    Mabe, Isaac; Hunter, Shawn

    2014-12-01

    Quadriceps tendon with a patellar bone block may be a viable alternative to Achilles tendon for anterior cruciate ligament reconstruction (ACL-R) if it is, at a minimum, a biomechanically equivalent graft. The objective of this study was to directly compare the biomechanical properties of quadriceps tendon and Achilles tendon allografts. Quadriceps and Achilles tendon pairs from nine research-consented donors were tested. All specimens were processed to reduce bioburden and terminally sterilized by gamma irradiation. Specimens were subjected to a three phase uniaxial tension test performed in a custom environmental chamber to maintain the specimens at a physiologic temperature (37 ± 2 °C) and misted with a 0.9 % NaCl solution. There were no statistical differences in seven of eight structural and mechanical between the two tendon types. Quadriceps tendons exhibited a significantly higher displacement at maximum load and significantly lower stiffness than Achilles tendons. The results of this study indicated a biomechanical equivalence of aseptically processed, terminally sterilized quadriceps tendon grafts with bone block to Achilles tendon grafts with bone block. The significantly higher displacement at maximum load, and lower stiffness observed for quadriceps tendons may be related to the failure mode. Achilles tendons had a higher bone avulsion rate than quadriceps tendons (86 % compared to 12 %, respectively). This was likely due to observed differences in bone block density between the two tendon types. This research supports the use of quadriceps tendon allografts in lieu of Achilles tendon allografts for ACL-R. PMID:24414293

  12. Allograft reconstruction of peroneus longus and brevis tendons tears arising from a single muscular belly. Case report and surgical technique.

    PubMed

    Pellegrini, Manuel J; Adams, Samuel B; Parekh, Selene G

    2015-03-01

    Anatomic variants of the peroneal tendons may cause tendon disorders. Moreover, there is a lack of evidence on how to address chronic tendon pathology when a variant of the peroneal tendons is causing the patient's symptoms. We present a patient with an uncommon peroneal muscle presentation: a single muscular belly dividing into both the peroneus longus and brevis tendons. After extensive debridement of tendinopathic tissue, primary repair or tenodesis was not possible; therefore a unique solution for this problem was performed, reconstructing both peroneal tendons using a semitendinosus allograft. PMID:25682415

  13. Correlations of isokinetic measurements with tendon healing following open repair of rotator cuff tears

    PubMed Central

    Circi, Esra; Akgun, Rahmi Can; Tarhan, Nefise Cagla; Cetin, Nuri; Akpinar, Sercan; Tuncay, Ismail Cengiz

    2009-01-01

    The aim of this study was to investigate the correlation of tendon integrity following open cuff repairs with functional and isokinetic strength measurements. Twenty-six shoulders of 25 patients were included in this study. At the final follow-up, 14 repairs (53.8%) were intact and 12 repairs (46.2%) had failed on magnetic resonance imaging (MRI). Mean UCLA score at latest follow-up was 28.5 and mean Constant score was 80.3. Constant scores were found to be significantly low for the failed group. Age was found to be significantly related to failed repair. Fatty infiltration stage in the failed repair group was significantly high, and a strong positive correlation for both groups existed pre and postoperatively. When both groups were compared, the failed group was found to have significantly low measurements at extension and internal rotation. Despite high failure rates, functional results were satisfactory. Increased age and fatty infiltration stage decrease success. PMID:19533125

  14. Subscapularis Tendon Repair Using Suture Bridge Technique

    PubMed Central

    Park, Yong Bok; Park, Young Eun; Koh, Kyoung Hwan; Lim, Tae Kang; Shon, Min Soo; Yoo, Jae Chul

    2015-01-01

    The subscapularis tendon plays an essential role in shoulder function. Although subscapularis tendon tears are less common than other rotator cuff tears, tears of the subscapularis tendon have increasingly been recognized with the advent of magnetic resonance imaging and arthroscopy. A suture bridge technique for the treatment of posterosuperior rotator cuff tears has provided the opportunity to improve the pressurized contact area and mean footprint pressure. However, suture bridge fixation of subscapularis tendon tears appears to be technically challenging. We describe an arthroscopic surgical technique for suture bridge repair of subscapularis tendon tears that obtains ideal cuff integrity and footprint restoration. Surgery using such a suture bridge technique is indicated for large tears, such as tears involving the entire first facet or more, tears with a disrupted lateral sling, and combined medium to large supraspinatus/infraspinatus tears. PMID:26052489

  15. Comparison of CO2 laser welding with suture technique for repair of tendons

    NASA Astrophysics Data System (ADS)

    Popovic, Neven A.; Johnstone, Frederic L.; Kilkelly, Francis X.; McKinney, LuAnn; Van De Merwe, Willem P.; Smith, Allan C.

    1995-05-01

    The purpose of this study was to evaluate the efficacy, histology, and strength of laser welding in repair of sharply transected rat Achilles tendons. In 26 adult, male Sprague-Dawley rats, the severed tendons were repaired with a 7-0 nylon, modified Kessler core suture followed by either a running 9-0 nylon epitendinous suture or a circumferential CO2 laser epidendinous weld using 25% human albumin as a solder. All repairs were timed and post- operative tensile strength was analyzed with material testing equipment. In addition, histologic testing was performed on both types of repairs. The mean time to complete the epitendinous repair in the laser group was 3.5 minutes and in the suture group, 8 minutes. The mean ultimate tensile strength in 6 normal tendons was 40.9 Newtons (N) with group standard deviation of 5.2 N. When compared with normal controls, post-operatively both types of tendon repairs resulted in tensile failure at lower forces. The ultimate tensile strength for the epitendinous suture repair and the laser welds were 13% and 6% of normal controls, respectively. Twenty tendons with epidendinous suture repair had mean ultimate tensile strength of 5.4 (+/- 1.2) N, while the 17 tendons with laser wends failed at 2.6 (+/- 0.9) N. Histologic evaluation of tendons repaired with CO2 laser revealed areas of coagulation and edema on the surface of tendon edges. Post-operatively, greater tissue changes were noted in laser treated tendons than those repaired with sutures. Laser welding of epitenon is possible and can be completed faster than the suture repair. The repaired tendon surface appears smoother and less bulky after laser treatment. However, significantly decreased immediate post-operative strength was demonstrated by the use of Kruskal-Wallis one way analysis of variance and Turkey's pairwise comparison.

  16. Infections and Patellar Tendon Ruptures After Anterior Cruciate Ligament ReconstructionA Comparison of Ipsilateral and Contralateral Patellar Tendon Autografts

    Microsoft Academic Search

    Rodney W. Benner; K. Donald Shelbourne; Heather Freeman

    2011-01-01

    Background: No studies document the incidence or results of infections and patellar tendon ruptures after anterior cruciate ligament reconstruction with a contralateral patellar tendon autograft.Purpose: To determine the results of patients who have infections and patellar tendon ruptures after anterior cruciate ligament reconstruction with a patellar tendon autograft and compare the results between ipsilateral and contralateral grafts.Study Design: Cohort study;

  17. Biomechanical comparison of quadriceps tendon fixation with patellar tendon bone plug interference fixation in cruciate ligament reconstruction

    Microsoft Academic Search

    Jeff Brand; Doris Hamilton; Jeff Selby; David Pienkowski; David N. M. Caborn; Darren L. Johnson

    2000-01-01

    Purpose: The purpose of this study was to use current fixation techniques and compare the stiffness and ultimate tensile failure of the tendinous end of the quadriceps tendon (QT) with the bone plug end of the bone–patellar tendon–bone (BPTB) graft using current techniques of fixation. Type of Study: Randomized trial of elderly cadaver knees. Materials and Methods: Tibial and femoral

  18. Quadriceps tendon tear rupture in healthy patients treated with patellar drilling holes: clinical and ultrasonographic analysis after 36 months of follow-up

    PubMed Central

    Verdano, Michele Arcangelo; Zanelli, Matteo; Aliani, Davide; Corsini, Tiziana; Pellegrini, Andrea; Ceccarelli, Francesco

    2014-01-01

    Summary Background: quadriceps tendon subcutaneous rupture is an uncommon injury affecting predominantly middle-aged men as a result of direct or indirect trauma; aim of this work is to evaluate clinical outcome and tendon morphology in patients treated surgically with transpatellar drilling suture. Methods: 20 patients (20 male) with an average age of 54 (42–59) were evaluated with a mean follow-up of 36 months. Measurements of range of motion (ROM) and of tight circumference were collected. Lysholm and Rougraff Score were also performed. All the patients underwent a US evaluation the morphologic changes of the repaired tendon. Results: mean active ROM was 1°–117°; average difference in the circumference of the quadriceps was 2.6% 10 C and 3.3% 15 C. The mean Lysholm Score calculated was 88/100; the mean Rougraff Score 17/25. At ultrasonographic evaluation all tendons were continuous; heterotopic ossification was present in 18 quadriceps tendons. Thickness was augmented in 18 quadriceps tendons and in 5 patellar tendons. Vascularization was always conserved. Lateral subluxation of patella was reported in 1 case. Conclusions: patellar drilling holes repair is a non-demanding procedure, inexpensive and technically uncomplicated. US evaluation confirms tendon healing; tendon remodeling does not affect patient’s clinical outcome and quality of life. Level of incidence: IV PMID:25332935

  19. Location and Initiation of Degenerative Rotator Cuff Tears

    PubMed Central

    Kim, H. Mike; Dahiya, Nirvikar; Teefey, Sharlene A.; Middleton, William D.; Stobbs, Georgia; Steger-May, Karen; Yamaguchi, Ken; Keener, Jay D.

    2010-01-01

    Background: It has been theorized that degenerative rotator cuff tears most commonly involve the supraspinatus tendon, initiating at the anterior portion of the supraspinatus insertion and propagating posteriorly. The purposes of this study were to determine the most common location of degenerative rotator cuff tears and to examine tear location patterns associated with various tear sizes. Methods: Ultrasonograms of 360 shoulders with either a full-thickness rotator cuff tear (272) or a partial-thickness rotator cuff tear (eighty-eight) were obtained to measure the width and length of the tear and the distance from the biceps tendon to the anterior margin of the tear. Tears were grouped on the basis of their size (anteroposterior width) and extent (partial or full-thickness). Each tear was represented numerically as a column of consecutive numbers representing the tear width and distance posterior to the biceps tendon. All tears were pooled to graphically represent the width and location of the tears within groups. Frequency histograms of the pooled data were generated, and the mode was determined for each histogram representing various tear groups. Results: The mean age (and standard deviation) of the 233 subjects (360 shoulders) was 64.7 ± 10.2 years. The mean width and length of the tears were 16.3 ± 12.1 mm and 17.0 ± 13.0 mm, respectively. The mean distance from the biceps tendon to the anterior tear margin was 7.8 ± 5.7 mm (range, 0 to 26 mm). Histograms of the various tear groups invariably showed the location of 15 to 16 mm posterior to the biceps tendon to be the most commonly torn location within the posterior cuff tendons. The histograms of small tears (a width of <10 mm) and partial-thickness tears showed similar distributions of tear locations, indicating that the region approximately 15 mm posterior to the biceps tendon may be where rotator cuff tears most commonly initiate. Conclusions: Degenerative rotator cuff tears most commonly involve a posterior location, near the junction of the supraspinatus and infraspinatus. The patterns of tear location across multiple tear sizes suggest that degenerative cuff tears may initiate in a region 13 to 17 mm posterior to the biceps tendon. Clinical Relevance: The findings of this study speak to the specific location of the most common type of rotator cuff lesions, degenerative rotator cuff tears. PMID:20439653

  20. Biomechanical comparison of stimulated and nonstimulated skeletal muscle pulled to failure

    Microsoft Academic Search

    William E. Garrett; Marc R. Safran; Anthony V. Seaber; Richard R. Glisson; Beth M. Ribbeck

    1987-01-01

    We compared the biomechanical properties of passive and stimulated muscle rapidly lengthened to failure in an experimental animal model. The mechanical param eters compared were force to tear, change in length to tear, site of failure, and energy absorbed by the muscle- tendon unit before failure. Paired comparisons were made between 1) muscles stimulated at 64 Hz (tetanic stimulation) and

  1. Tear System

    MedlinePLUS

    ... or tear drainage. Increased Tear Production and Dry Eyes The eye has two sets of structures that ... and cosmetic surgeon who specializes in the eyelids, orbit, and tear drain system. It’s also important that ...

  2. Imaging of Tendons

    PubMed Central

    Chang, Anthony; Miller, Theodore T.

    2009-01-01

    Both magnetic resonance imaging (MRI) and sonography are well suited to tendon imaging. A normal tendon on MRI demonstrates low signal intensity and on sonography, an echogenic fibrillar pattern. MRI is considered the imaging gold standard, providing an anatomic overview and excellent soft tissue contrast. Sonography is a more rapidly performed examination; it has greater resolution than that of MRI; it allows dynamic evaluation of tendons and muscles; and it can guide percutaneous therapeutic procedures. Moreover, the advent of sonographic extended-field-of-view imaging allows the demonstration of the entire length of a tendon, matching MRI’s ability to display a large anatomic region. Sonography should best be considered a focused examination, concentrating on the area of pain and clinical suspicion of pathology, whereas MRI can provide a global assessment of the region of concern. Both modalities demonstrate high accuracy for abnormalities of various tendons. This article reviews normal tendon anatomy and its imaging appearance, as well as the imaging appearances of tendon degeneration and tear. PMID:23015886

  3. Biochemical markers in the synovial fluid of glenohumeral joints from patients with rotator cuff tear.

    PubMed

    Yoshihara, Y; Hamada, K; Nakajima, T; Fujikawa, K; Fukuda, H

    2001-07-01

    It is known that rotator cuff tears are sometimes accompanied by joint destruction. Our purpose was to elucidate the pathology with this condition. Thirty-two synovial fluid (SF) samples aspirated from the glenohumeral joints of patients with rotator cuff tears, including 7 with partial-thickness and 25 with full-thickness tears of the rotator cuff (10 massive and 15 isolated supraspinatus tendon (SSp) tears), were examined. Collagenase (MMP-1), stromelysin 1 (MMP-3), tissue inhibitor of metalloproteinases-1 (TIMP-1) and carboxy-terminal type II procollagen peptide (pCOL Il-C) were measured in the SF using the respective sandwich enzyme immunoassays. Glycosaminoglycan (GAG) was also quantified with a cationic dye binding method using 1,9-dimethylmethylene blue. Levels of any molecules except pCOL II-C in the SF appeared to be higher in full-thickness tears than those in partial-thickness tears. Moreover, levels of MMP-1, MMP-3 and GAG in the SF were significantly higher in massive tears of the rotator cuff in comparison with those in isolated SSp tears. Such significance was not observed in the levels of TIMP-1 or pCOL II C in the SF. We examined the relation of those levels with operative findings or clinical parameters from full-thickness tears, and observed significant correlations of the tear size with the levels of MMP-1, MMP-3 and GAG in the SF. Although these marker molecules in SF do not always originate from cartilage, our results may indicate the potential for accelerated cartilage-degrading activity in the glenohumeral joint in massive tears of the rotator cuff. PMID:11518264

  4. The effect of flexor tendon repair bulk on tendon gliding during simulated active motion: An in vitro comparison of two-strand and six-strand techniques

    Microsoft Academic Search

    David W Sanders; Andrew D Milne; James A Johnson; Cynthia E Dunning; Robert S Richards; Graham J. W King

    2001-01-01

    The gliding function of 2-strand (Tajima) and 6-strand (Savage) techniques of flexor tendon repair were compared in an in vitro biomechanical model. Stainless steel beads were inserted directly into the metacarpals, phalanges, and flexor digitorum profundus tendons of 22 human cadaver specimens. The FDP tendons were loaded from 5 to 25 N using a pneumatic actuator. The angular rotation and

  5. Outcome of tendon transfer for radial nerve paralysis: Comparison of three methods

    PubMed Central

    Moussavi, Alia Ayatollahi; Saied, Alireza; Karbalaeikhani, Ali

    2011-01-01

    Background: Tendon transfer for radial nerve paralysis has a 100 years history and any set of tendons that can be considered to be useful has been utilized for the purpose. The pronator tress is used for restoration of wrist dorsiflexion, while the flexor carpi radialis, flexor carpiulnaris, and flexor digitorum superficialis are variably used in each for fingers and thumb movements. The present study was a retrospective analysis, designed to compare three methods of tendon transfer for radial nerve palsy. Materials and Methods: 41 patients with irreversible radial nerve paralysis, who had underwent three different types of tendon transfers (using different tendons for transfer) between March 2005 and September 2009, included in the study. The pronator teres was transferred for wrist extention. Flexor carpi ulnaris (group 1, n=18), flexor carpi radialis (group 2, n=10) and flexor digitorum superficialis (group 3, n=13) was used to achieve finger extention. Palmaris longus was used to achieve thumb extention and abduction. At the final examination, related ranges of motions were recorded and the patients were asked about their overall satisfaction with the operation, their ability, and time of return to their previous jobs, and in addition, disabilities of the arm, shoulder and hand (DASH) Score was measured and recorded for each patient. Results: The difference between the groups with regard to DASH score, ability, and time of return to job, satisfaction with the operation, and range of motions was not statistically significant (P>0.05). All of the patients had experienced functional improvement and overall satisfaction rate was 95%. No complication directly attributable to the operation was noted, except for proximal interphalangeal joint flexion contracture in three patents. Conclusion: The tendon transfer for irreversible radial nerve palsy is very successful and probably the success is not related to type of tendon used for transfer. PMID:22144751

  6. Full thickness tears: retaining the cuff.

    PubMed

    Osti, Leonardo; Rizzello, Giacomo; Panascì, Manlio; Denaro, Vincenzo; Maffulli, Nicola

    2011-12-01

    Repair of rotator cuff tears is technically challenging. Full thickness rotator cuff tears have no potential for spontaneous healing, no reliable tendons substitutes are available, and their management is only partially understood. Many factors seem to contribute to the final outcome, and considerable variations in the decision-making process exist. For these reasons, decisions are often taken on the basis of surgeon's clinical experience. Accurate and prompt diagnosis is fundamental to guide correct management, and the tear pattern should be carefully evaluated to planning the most appropriate repair. PMID:22089291

  7. Analysis of sub-surface towing of tendons and comparison of results using WINPOST and ORCAFLEX

    E-print Network

    Mendon, Perdoor Mukthi

    2002-01-01

    During tendon towing the pipe is floating in a horizontal plane parallel to the sea-surface unlike the usual vertical slender members like risers, mooring lines, etc where the pipe/cable is perpendicular to the sea-surface. This change in projection...

  8. Comparison of Aspect Ratio Effects on Neoclassical Tearing Modes Between DIII-D and NSTX

    NASA Astrophysics Data System (ADS)

    La Haye, R. J.; Buttery, R. J.; Gerhardt, S. P.; Sabbagh, S. A.; Brennan, D. P.

    2010-11-01

    Experimental data is analyzed in which m/n=2/1 neoclassical tearing modes self-stabilized; this ``marginal point'' is valuable for evaluating the relative importance of the terms in the balanced Modified Rutherford equation. DIII-D and NSTX have similar cross-sectional area and shape except for the large difference in aspect ratio. The aspect ratio effects for NTMs explicitly occur in the MRE in the destabilizing helically perturbed bootstrap current term, in the small island stabilizing effects, and in the stabilizing curvature term. The marginal island width on NSTX at q95˜8 is about three times the ion banana width. This agrees with the q95˜4 data on DIII-D but is a larger multiple than for DIII-D at q95˜7. The balance in the MRE indicates that while the stabilizing effect of the curvature term in DIII-D is negligible, it is important in NSTX. The temporal behavior of the mode suggests NSTX operates closer to marginal classical tearing stability, but benefits from the stabilizing effect of curvature.

  9. Antibacterial Activity of Rifamycins for M. Smegmatis with Comparison of Oxidation and Binding to Tear Lipocalin

    PubMed Central

    Staudinger, Tamara; Redl, Bernhard; Glasgow, Ben J.

    2014-01-01

    A mutant of Mycobacterium smegmatis is a potential class I model substitute for Mycobacterium tuberculosis. Because not all of the rifamycins have been tested in this organism, we determined bactericidal profiles for the 6 major rifamycin derivatives. The profiles closely mirrored that established for Mycobacterium tuberculosis. Rifalazil was confirmed to be the most potent rifamycin. Because the tuberculous granuloma presents a harshly oxidizing environment we explored the effects of oxidation on rifamycins. Mass spectrometry confirmed that three of the six major rifamycins showed autoxidation in the presence of trace metals. Oxidation could be monitored by distinctive changes including isosbestic points in the ultraviolet-visible spectrum. Oxidation of rifamycins abrogated antimycobacterial activity in Mycobacterium smegmatis. Protection from autoxidation was conferred by binding susceptible rifamycins to tear lipocalin, a promiscuous lipophilic protein. Rifalazil was not susceptible to autoxidation but was insoluble in aqueous. Solubility was enhanced when complexed to tear lipocalin and was accompanied by a spectral red shift. The positive solvatochromism was consistent with robust molecular interaction and binding. Other rifamycins also formed a complex with lipocalin, albeit to a lesser extent. Protection from oxidation and enhancement of solubility with protein binding may have implications for delivery of select rifamycin derivatives. PMID:24530503

  10. Tunnel expansion following anterior cruciate ligament reconstruction: a comparison of hamstring and patellar tendon autografts

    Microsoft Academic Search

    J. C. L’Insalata; Brian Klatt; Freddie H. Fu; Christopher D. Harner

    1997-01-01

    Thirty patients having had anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) autograft\\u000a and thirty patients having had ACL reconstruction with hamstring (HS) autograft were enrolled. All procedures were performed\\u000a using an endoscopic technique with identical postoperative rehabilitation, such that the only variable was the type of graft\\u000a and its fixation. Lateral and 45? posteroanterior (PA) weightbearing radiographs were

  11. Comparison between three methods to value lower tear meniscus measured by image software

    NASA Astrophysics Data System (ADS)

    García-Resúa, Carlos; Pena-Verdeal, Hugo; Lira, Madalena; Oliveira, M. Elisabete Real; Giráldez, María. Jesús; Yebra-Pimentel, Eva

    2013-11-01

    To measure different parameters of lower tear meniscus height (TMH) by using photography with open software of measurement. TMH was addressed from lower eyelid to the top of the meniscus (absolute TMH) and to the brightest meniscus reflex (reflex TMH). 121 young healthy subjects were included in the study. The lower tear meniscus was videotaped by a digital camera attached to a slit lamp. Three videos were recorded in central meniscus portion on three different methods: slit lamp without fluorescein instillation, slit lamp with fluorescein instillation and TearscopeTM without fluorescein instillation. Then, a masked observed obtained an image from each video and measured TMH by using open source software of measurement based on Java (NIH ImageJ). Absolute central (TMH-CA), absolute with fluorescein (TMH-F) and absolute using the Tearscope (TMH-Tc) were compared each other as well as reflex central (TMH-CR) and reflex Tearscope (TMH-TcR). Mean +/- S.D. values of TMH-CA, TMH-CR, TMH-F, TMH-Tc and TMH-TcR of 0.209 +/- 0.049, 0.139 +/- 0.031, 0.222 +/- 0.058, 0.175 +/- 0.045 and 0.109 +/- 0.029 mm, respectively were found. Paired t-test was performed for the relationship between TMH-CA - TMH-CR, TMH-CA - TMH-F, TMH-CA - TMH-Tc, TMH-F - TMH-Tc, TMH-Tc - TMH-TcR and TMH-CR - TMH-TcR. In all cases, it was found a significant difference between both variables (all p < 0.008). This study showed a useful tool to objectively measure TMH by photography. Eye care professionals should maintain the same TMH parameter in the follow-up visits, due to the difference between them.

  12. Clinical comparison of the Autologous Quadriceps Tendon (BQT) and the Autologous Patella Tendon (BPTB) for the reconstruction of the Anterior Cruciate Ligament

    Microsoft Academic Search

    O. Gorschewsky; A. Klakow; A. Pütz; H. Mahn; W. Neumann

    2007-01-01

    The use of the BPTB-autograft is a very common method for ACL reconstruction. Nevertheless, the problem of the typical donor-site-morbidity\\u000a is unresolved. Recently, a transplant of quadriceps tendon, with an attached bone block (BQT) has been increasingly relied\\u000a upon. The purpose of this study was to examine the clinical results of a group of patients after arthroscopic ACL reconstruction\\u000a using

  13. Comparison of superficial digital flexor tendon loading on asphalt and sand in horses at the walk and trot.

    PubMed

    Crevier-Denoix, N; Ravary-Plumioën, B; Vergari, C; Camus, M; Holden-Douilly, L; Falala, S; Jerbi, H; Desquilbet, L; Chateau, H; Denoix, J-M; Pourcelot, P

    2013-12-01

    The incidence of superficial digital flexor tendon (SDFT) injuries is one of the highest of all equine musculoskeletal conditions. Horses with SDFT injuries commonly show no improvement of lameness on soft ground, unlike those suffering from distal bone or joint lesions. The aim of this study was to compare the SDFT loading in five horses at the walk and trot on asphalt and sand using a non-invasive ultrasonic tendon force measurement device. Three horses were equipped with the ultrasonic device, whereas the other two horses were equipped with the ultrasonic device and a dynamometric horseshoe (DHS); the DHS was used to calibrate the measured values of tendon speed of sound (SOS) converted to tendon force, while a previously established ground reaction force pattern was used to calibrate SOS measurements for the other three horses. Although the horses tended to be slower on S, maximal tendon force was higher on sand than on asphalt at the trot (+6%); there was no significant difference between the two surfaces at the walk. The duration of tendon loading was longer on S (+5%) and the area under the tendon force-time curve was larger on S (+10%) at both walk and trot. SDFT loading is significantly affected by the ground surface and the observed increase in SDFT loading on sand compared with asphalt is consistent with clinical observations in horses with SDFT injuries. PMID:24360732

  14. Comparison of tear osmolarity and ocular comfort between daily disposable contact lenses: hilafilcon B hydrogel versus narafilcon A silicone hydrogel.

    PubMed

    Sarac, Ozge; Gurdal, Canan; Bostanc?-Ceran, Basak; Can, Izzet

    2012-06-01

    The aim of this study was to evaluate tear osmolarity and ocular comfort with two different types of hydrogel daily disposable lenses. The right eyes of 15 first-time contact lens users were included in this prospective study. All eyes wore hilafilcon B silicone hydrogel contact lenses for 8 h (group 1). After 1 week without contact lenses, all eyes wore narafilcon A silicone hydrogel contact lenses for 8 h (group 2). Tear osmolarity measurement was performed before and after 4 and 8 h of each contact lens wear. Ocular comfort was assessed after 4 and 8 h of each contact lens wear. In group 1, the mean baseline, 4- and 8-h tear osmolarity values were 293 ± 10.57, 303.00 ± 10.5 mOsm/L (p = 0.023), and 295.0 ± 1.4 mOsm/L (p > 0.05), respectively. In group 2, the mean baseline, 4- and 8-h tear osmolarity values were 294 ± 13.65, 300.9 ± 11.3 mOsm/L (p = 0.007), and 298.80 ± 7.2 mOsm/L (p > 0.05), respectively. In group 1, the mean comfort score was 7.20 ± 0.45 and 8.60 ± 0.45 at 4 and 8 h, respectively (p = 0.038). In group 2, the mean comfort score significantly decreased from 9.80 ± 0.45 to 7.80 ± 0.84 at 4 h (p = 0.039). Both hydrogel and silicone hydrogel daily disposable contact lenses elevated tear osmolarity during 8 h of contact lens wear. The increase in tear osmolarity with both contact lenses was below the cut-off value for dry eye and was not associated with ocular comfort. PMID:22484700

  15. The accuracy of “subacromial grind test” in diagnosis of supraspinatus rotator cuff tears

    PubMed Central

    Sawalha, Seif; Fischer, Jochen

    2015-01-01

    Purpose: The aim of this study is to assess the accuracy of a simple clinical test (subacromial grind test) in diagnosing supraspinatus tendon tears. Patients and Methods: The test is considered positive if palpable crepitus or grinding is detected on passive internal and external rotation of the shoulder while abducted in the scapular plane. Data were collected prospectively on 47 patients undergoing shoulder arthroscopy, and the results of the test and arthroscopy compared. Results: During arthroscopy, 17 patients had full thickness (FT) tears of supraspinatus tendon and 10 had partial thickness tears. For any supraspinatus tear, the sensitivity of the test was 63%, specificity 95%, positive predictive value 94%, negative predictive value 66% and overall accuracy 79%. For FT tears, the sensitivity was 82%, specificity 87%, positive predictive value 78%, negative predictive value 90% and overall accuracy 85%. Conclusion: We found that this is a useful single test for diagnosing FT supraspinatus tears. Level of Evidence: Level IV diagnostic study. PMID:25937713

  16. Human dermal allograft for massive rotator cuff tears.

    PubMed

    Kokkalis, Zinon T; Mavrogenis, Andreas F; Scarlat, Marius; Christodoulou, Michael; Vottis, Christos; Papagelopoulos, Panayiotis J; Sotereanos, Dean G

    2014-12-01

    Previously published studies reported variable results using various suture techniques and reconstruction options for massive rotator cuff tears. Therefore, the current authors retrospectively studied 21 consecutive patients/shoulders with massive rotator cuff tears treated from January 2005 to October 2011 with a human dermal allograft through a mini-open approach. Mean patient age was 58 years (range, 33-72 years). Mean follow-up was 29 months (range, 18-52 months). Ten patients underwent revision repair for a failed rotator cuff repair. The authors measured the tendon gap (mean, 1.7 cm) and acromiohumeral interval (mean, 6.5 mm). They evaluated pain, shoulder range of motion (ROM) and function, patient satisfaction with the operation and outcome, and complications. At last follow-up, all patients experienced significant pain relief (P=.001) and improved ROM (P=.001) and American Shoulder and Elbow Surgeons (ASES) score (P=.001). Eighteen patients reported that they were satisfied or very satisfied and 3 reported that they were not satisfied with the operation and outcome. Comparison of outcomes between patients who underwent primary repair and those who underwent revision repair and between patients who had muscle atrophy and fatty infiltration grades 0 to II and those who had grades III to IV showed no statistically significant differences. A statistically significant correlation was observed between the size of the tendon gap and postoperative pain, ROM (except external rotation), and ASES score (P<.050). No significant correlation was observed between postoperative pain, ROM, and ASES score and the acromiohumeral interval (P>.050). Complications related to the dermal human allograft were not observed. PMID:25437086

  17. The frequency of subscapularis tears in arthroscopic rotator cuff repairs: A retrospective study comparing magnetic resonance imaging and arthroscopic findings

    PubMed Central

    Garavaglia, Guido; Ufenast, Henri; Taverna, Ettore

    2011-01-01

    Purpose: With the advent of arthroscopic shoulder surgery the comprehension and description of rotator cuff tears have strongly evolved. Subscapularis tears are difficult to recognize and are underestimated. Our purpose is to report our observations concerning the relative frequency of subscapularis tears in patients undergoing arthroscopic rotator cuff repair and to compare the arthroscopic observations with the magnetic resonance imaging (MRI) findings. Materials and Methods: Retrospective cohort study including all patients undergoing arthroscopic rotator cuff repair was performed between March 2006 and March 2009 at our institution. Preoperative MRI findings, intraoperative arthroscopic findings, and details of surgical intervention were collected using medical charts. Results: We reviewed the medical charts of a total of 348 consecutive arthroscopic rotator cuff repairs. There were 311 supraspinatus tears (89%), 48 infraspinatus tears (14%), and 129 subscapularis tears (37%). MRI sensitivity and specificity were respectively 0.25 and 0.98 for subscapularis tendon tears, 0.67 and 1.0 for supraspinatus tears and 0.5 and 0.99 for infraspinatus tears. Conclusion: Subscapularis tears are frequent lesions and usually appear concomitantly with supra or infraspinatus lesions. We propose a classification of subscapularis tendon tears, based on our observations of the pathoanatomy of the tears. While concordance with MRI results are good for the supraspinatus, MRI often fails to diagnose the presence of subscapularis tears and infraspinatus tears PMID:22223958

  18. Tear Film Mucins: Front Line Defenders of the Ocular Surface; Comparison with Airway and Gastrointestinal Tract Mucins

    PubMed Central

    Hodges, Robin R.; Dartt, Darlene A.

    2014-01-01

    The ocular surface including the cornea and conjunctiva and its overlying tear film are the first tissues of the eye to interact with the external environment. The tear film is complex containing multiple layers secreted by different glands and tissues. Each layer contains specific molecules and proteins that not only maintain the health of the cells on the ocular surface by providing nourishment and removal of waste products but also protect these cells from environment. A major protective mechanism that the corneal and conjunctival cells have developed is secretion of the innermost layer of the tear film, the mucous layer. Both the cornea and conjunctiva express membrane spanning mucins, whereas the conjunctiva also produces soluble mucins. The mucins present in the tear film serve to maintain the hydration of the ocular surface and to provide lubrication and anti-adhesive properties between the cells of the ocular surface and conjunctiva during the blink. A third function is to contribute to the epithelial barrier to prevent pathogens from binding to the ocular surface. This review will focus on the different types of mucins produced by the corneal and conjunctival epithelia. Also included in this review will be a presentation of the structure of mucins, regulation of mucin production, role of mucins in ocular surface diseases, and the differences in mucin production by the ocular surface, airways and gastrointestinal tract. PMID:23954166

  19. Aspect ratio effects on neoclassical tearing modes from comparison between DIII-D and National Spherical Torus Experiment

    SciTech Connect

    La Haye, R. J.; Buttery, R. J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Gerhardt, S. P. [Princeton Plasma Physics Laboratory, P.O. Box 451 Princeton, New Jersey 08543 (United States); Sabbagh, S. A. [Columbia University, 2960 Broadway, New York, New York 10027-6900 (United States); Brennan, D. P. [University of Tulsa, 800 South Tucker Drive, Tulsa, Oklahoma 74104 (United States)

    2012-06-15

    Neoclassical tearing mode islands are sustained by helically perturbed bootstrap currents arising at finite beta from toroidal effects that trap a fraction of the particles in non-circulating orbits. DIII-D and NSTX are here operated with similar shape and cross-sectional area but almost a factor of two difference in inverse aspect ratio a/R. In these experiments, destabilized n=1 tearing modes were self-stabilized (reached the 'marginal point') by reducing neutral-beam power and thus beta. The measure of the marginal island gives information on the small-island stabilizing physics that in part (with seeding) governs onset. The marginal island width on NSTX is found to be about three times the ion banana width and agrees with that measured in DIII-D, except for DIII-D modes closer to the magnetic axis, which are about two times the ion banana width. There is a balance of the helically perturbed bootstrap term with small island effects with the sum of the classical and curvature terms in the modified Rutherford equation for tearing-mode stability at the experimental marginal point. Empirical evaluation of this sum indicates that while the stabilizing effect of the curvature term is negligible in DIII-D, it is important in NSTX. The mode temporal behavior from the start of neutral-beam injection reduction also suggests that NSTX operates closer to marginal classical tearing stability; this explains why there is little hysteresis in beta between mode onset, saturation, and self-stabilization (while DIII-D has large hysteresis in beta). NIMROD code module component calculations based on DIII-D and NSTX reconstructed experimental equilibria are used to diagnose and confirm the relative importance of the stabilizing curvature effect, an advantage for low aspect ratio; the relatively greater curvature effect makes for less susceptibility to NTM onset even if the classical tearing stability index is near marginal.

  20. Delayed repair of tendon to bone injuries leads to decreased biomechanical properties and bone loss

    Microsoft Academic Search

    L. M. Galatz; S. Y. Rothermich; M. Zaegel; M. J. Silva; N. Havlioglu; S. Thomopoulos

    2005-01-01

    Introduction. Repair of the torn rotator cuff tendon is a common procedure performed in the shoulder. In the clinical setting, a significant delay between rotator cuff tear and subsequent repair often exists. The purpose of this study was to investigate the biomechanical properties and bone density of the tendon to bone repair site after acute and delayed repair.Methods. The supraspinatus

  1. Delaminated tears of the rotator cuff: prevalence, characteristics, and diagnostic accuracy using indirect MR arthrography.

    PubMed

    Choo, Hye Jung; Lee, Sun Joo; Kim, Jung-Han; Kim, Dong Wook; Park, Young-Mi; Kim, Ok Hwa; Kim, Seon Jeong

    2015-02-01

    OBJECTIVE. The purpose of this study was to evaluate the prevalence, radiologic characteristics, and accuracy of diagnosing delaminated tears at the supraspinatus tendon-infraspinatus tendon (SST-IST) on indirect MR arthrography. MATERIALS AND METHODS. Of 531 consecutive shoulders that underwent indirect MR arthrography, 231 shoulders with tears at the SST-IST were included. On the MR images, delaminated tears at the SST-IST, defined as intratendinous horizontal splitting between the articular and bursal layers of the SST-IST with or without different degrees of retraction between the two layers, were identified and classified into six types. Other radiologic findings of the SST-IST, such as the presence of intramuscular cysts, were evaluated. We used video records of 127 arthroscopic surgeries to determine the diagnostic accuracy of indirect MRI for the detection of the delaminated tears at the SST-IST. RESULTS. On MRI, 56% (129/231) of shoulders with SST-IST tears had delaminated tears. Articular-delaminated full-thickness tears (n = 58) and articular-delaminated partial-thickness tears (n = 64) were the most common types. Approximately 82% (36/44) of articular-delaminated full-thickness tears occurring at the SST were combined with articular-delaminated partial-thickness tears at the IST. SST-IST footprint tears and intramuscular cysts were significantly more common in the shoulders with delaminated tears. The sensitivity and specificity of indirect MR arthrography for detection of delaminated tears were 92% and 94%, respectively. CONCLUSION. On indirect MR arthrography, approximately half of the shoulders with SST-IST tears had delaminated tears. The diagnostic accuracy of indirect MR arthrography for detection of delaminated tears was high. PMID:25615759

  2. In vitro evaluation of a novel non-mulberry silk scaffold for use in tendon regeneration.

    PubMed

    Musson, David S; Naot, Dorit; Chhana, Ashika; Matthews, Brya G; McIntosh, Julie D; Lin, Sandy T C; Choi, Ally J; Callon, Karen E; Dunbar, P Rod; Lesage, Stephanie; Coleman, Brendan; Cornish, Jillian

    2015-05-01

    Tearing of the rotator cuff tendon in the shoulder is a significant clinical problem, with large/full-thickness tears present in ?22% of the general population and recurrent tear rates postarthroscopic repair being quoted as high as 94%. Tissue-engineered biomaterials are increasingly being investigated as a means to augment rotator cuff repairs, with the aim of inducing host cell responses to increase tendon tissue regeneration. Silk-derived materials are of particular interest due to the high availability, mechanical strength, and biocompatibility of silks. In this study, Spidrex(®), a novel knitted, non-mulberry silk fibroin scaffold was evaluated in vitro for its potential to improve tendon regeneration. Spidrex was compared with a knitted Bombyx mori silk scaffold, a 3D collagen gel and Fiberwire(®) suture material. Primary human and rat tenocytes successfully adhered to Spidrex and significantly increased in number over a 14 day period (p<0.05), as demonstrated by fluorescent calcein-AM staining and alamarBlue(®) assays. A similar growth pattern was observed with human tenocytes cultured on the B. mori scaffold. Morphologically, human tenocytes elongated along the silk fibers of Spidrex, assuming a tenocytic cell shape, and were less circular with a higher aspect ratio compared with human tenocytes cultured on the B. mori silk scaffold and within the collagen gel (p<0.05). Gene expression analysis by real-time PCR showed that rat tenocytes cultured on Spidrex had increased expression of tenocyte-related genes such as fibromodullin, scleraxis, and tenomodulin (p<0.05). Expression of genes that indicate transdifferentiation toward a chondrocytic or osteoblastic lineage were significantly lower in tenocytes cultured on Spidrex in comparison to the collagen gel (p<0.05). Immunogenicity assessment by the maturation of and cytokine release from primary human dendritic cells demonstrated that Spidrex enhanced dendritic cell maturation in a similar manner to the clinically used suture material Fiberwire, and significantly upregulated the release of proinflammatory cytokines (p<0.05). This suggests that Spidrex may induce an early immune response postimplantation. While further work is required to determine what effect this immune response has on the tendon healing process, our in vitro data suggests that Spidrex may have the cytocompatibility and bioactivity required to support tendon regeneration in vivo. PMID:25604072

  3. Quadriceps and patellar tendon ruptures.

    PubMed

    Lee, Dennis; Stinner, Daniel; Mir, Hassan

    2013-10-01

    The diagnosis of quadriceps and patellar tendon ruptures requires a high index of suspicion and thorough history-taking to assess for medical comorbidities that may predispose patients to tendon degeneration. Radiographic assessment with plain films supplemented by ultrasound and magnetic resonance imaging when the work-up is equivocal further aids diagnosis; however, advanced imaging is often unnecessary in patients with functional extensor mechanism deficits. Acute repair is preferred, and transpatellar bone tunnels serve as the primary form of fixation when the tendon rupture occurs at the patellar insertion, with or without augmentation depending on surgeon preference. Chronic tears and disruptions following total knee arthroplasty are special cases requiring reconstructions with allograft, synthetic mesh, or autograft. Rehabilitation protocols generally allow immediate weight-bearing with the knee locked in extension and crutch support. Limited arc motion is started early with active flexion and passive extension and then advanced progressively, followed by full active range of motion and strengthening. Complications are few but include quadriceps atrophy, knee stiffness, and rerupture. Outcomes are excellent if repair is done acutely, with poorer outcomes associated with delayed repair. PMID:23955186

  4. Tendon, tendon healing, hyperlipidemia and statins

    PubMed Central

    Esenkaya, Irfan; Unay, Koray

    2011-01-01

    Summary Both hyperlipidemia and metabolic syndrome have adverse effect on tendon structure. Atorvastatin is most widely used antihyperlipidemic drug. Statins have adverse effects on the tendon. Many studies have analyzed the relationship between atorvastatin and skeletal muscles. Atorvastatin administered after the surgical repair of a ruptured tendon appears to affect revascularization, collagenization, inflammatory cell infiltration, and collagen construction. Therefore, further investigations on the effects of atorvastatin on tendon healing are needed. PMID:23738266

  5. Tendon injury: from biology to tendon repair.

    PubMed

    Nourissat, Geoffroy; Berenbaum, Francis; Duprez, Delphine

    2015-04-01

    Tendon is a crucial component of the musculoskeletal system. Tendons connect muscle to bone and transmit forces to produce motion. Chronic and acute tendon injuries are very common and result in considerable pain and disability. The management of tendon injuries remains a challenge for clinicians. Effective treatments for tendon injuries are lacking because the understanding of tendon biology lags behind that of the other components of the musculoskeletal system. Animal and cellular models have been developed to study tendon-cell differentiation and tendon repair following injury. These studies have highlighted specific growth factors and transcription factors involved in tenogenesis during developmental and repair processes. Mechanical factors also seem to be essential for tendon development, homeostasis and repair. Mechanical signals are transduced via molecular signalling pathways that trigger adaptive responses in the tendon. Understanding the links between the mechanical and biological parameters involved in tendon development, homeostasis and repair is prerequisite for the identification of effective treatments for chronic and acute tendon injuries. PMID:25734975

  6. Comparison of corneal sensitivity, tear function and corneal staining following laser in situ keratomileusis with two femtosecond laser platforms

    PubMed Central

    Petznick, Andrea; Chew, Annabel; Hall, Reece C; Chan, Cordelia ML; Rosman, Mohamad; Tan, Donald; Tong, Louis; Mehta, Jodhbir S

    2013-01-01

    Purpose To evaluate longitudinal changes in corneal sensitivity, tear function, and corneal staining in patients who underwent laser in situ keratomileusis (LASIK) using two different femtosecond lasers. Methods In a prospective, randomized clinical trial, contralateral eyes of 45 patients underwent flap creation by either VisuMax or IntraLase™ femtosecond laser. Corneal sensitivity, tear break up time (TBUT), Schirmer’s test, and corneal fluorescein staining were assessed preoperatively and at 1 week, 1 month, and 3 months postoperatively. Results There were no statistical differences in any clinical outcome measure between the two femtosecond lasers (P > 0.05), although there was a trend towards slightly lower reductions for corneal sensitivity and TBUT in VisuMax-operated eyes. Overall, corneal sensitivity was significantly reduced at 1 week (P < 0.05), 1 month (P < 0 .001), and 3 months (P < 0.001) postoperatively. A significantly greater reduction of corneal sensitivity was noted in eyes with a myopic spherical equivalent of ?6.00 diopters (D) to ?11.25 D as compared with eyes that had a relatively lower level of myopia of less than ?6.00 D (P < 0.001). TBUT and Schirmer’s test values were significantly diminished at 1 week postoperatively (P < 0.04). Overall, corneal staining was significantly increased at 1 week postoperatively (P < 0.001). The level of myopia did not significantly affect postoperative changes in TBUT, Schirmer’s test values, or corneal staining (P > 0.05). Conclusion This study showed that changes in corneal sensitivity, tear function, and corneal staining were statistically similar in LASIK using VisuMax and IntraLase femtosecond lasers for flap creation. However, the trend towards faster recovery of corneal sensitivity and TBUT observed in VisuMax-operated eyes may be attributable to improved technical specifications. PMID:23576858

  7. Popliteus tendon tenosynovitis.

    PubMed

    Mayfield, G W

    1977-01-01

    This series of case suggests that the entity of tenosynovitis of the popliteus tendon is more common than once recognized. A high index of sucpicion and accurate palpation of the lateral aspect of the knee lead one to the diagnosis. Knowledge of this entity may prevent future misdiagnosis of tear of the lateral meniscus and unnecessary meniscectomy as experienced by Helfet, Holden, and myself. There is a definite correlation with activities requiring downhill walking or running. The runners invariably complained of the oneset of symptoms during downhill running rather than uphill running. Back packing enthusiastscomplained of no symptoms for several days after ascending into the mountains, only to experience the symptoms at the end of a long, rapid descent out of the mountains. The pathomechanics of this inflammation of the popliteus tendon is not fully understood. Preliminary analysis of gait movies suggests that in downhill running there is an increased vector to displace the weight-bearing femur forward on the relatively fixed tibia as the knee is increasingly flexed (Fig. 5). Previously mentioned EMG functional studies indicate that the popliteus muscle is active during this weight-bearing phase of gait and may act to retard the femur from forward displacement on the tibia in conjunction with the quadriceps. More specifically, it may help to retard the lateral femoral condyle from rotating forward off the lateral tibial plateau. Downhill running or walking therefore may cause increased stress on the popliteus muscle-tendon unit in an effort to decelerate the body weight against the altered angle of gravitational pull, with resultant tenosynovitis and symptoms. In this series there were no top flight competitive runners. The typical patient was a 31-year-old physician who was jogging 1 to 5 miles and decided to increase his pace and distance, particularly while jogging downhill. The average age of this series of patients (31 years) at the time of onset, coupled with the fact many of these persons were relatively sedentary until stressing the knee by increased activity, suggests that there will be an increasing number of these patients in the future as jogging and running are prescribed for cardiovascular system conditioning. PMID:848633

  8. Subcoracoid impingement and subscapularis tendon: is there any truth?

    PubMed Central

    Osti, Leonardo; Soldati, Francesco; Del Buono, Angelo; Massari, Leo

    2013-01-01

    Summary Subcoracoid impingement and stenosis have been described related to anterior shoulder pain and subscapularis tendon tears, but the pathogenesis and related treatment of this condition has still not been explained properly. Variability of coracoid morphology has been described and both traumatic and iatrogenic factors can modify it. Some authors referred this to a primary narrow coracohumeral distance with different threshold values defined as increased risk factor for subscapularis and antero-superior RC tear; opposite theories stated that the stenosis is secondary to an anterosuperior translation of the humeral head toward the coracoid due to degenerative changes of the rotator cuff tendons. Limited coracoplasty can be performed when related risk factors are identified; however no clear consensus arises from specific literature review and extensive clinical and instrumental examination of the patient should be performed in order to identify specific risk factors for subscapularis tendon pathology and, subsequently, tailor the proper approach. PMID:23888292

  9. Subcoracoid impingement and subscapularis tendon: is there any truth?

    PubMed

    Osti, Leonardo; Soldati, Francesco; Del Buono, Angelo; Massari, Leo

    2013-04-01

    Subcoracoid impingement and stenosis have been described related to anterior shoulder pain and subscapularis tendon tears, but the pathogenesis and related treatment of this condition has still not been explained properly. Variability of coracoid morphology has been described and both traumatic and iatrogenic factors can modify it. Some authors referred this to a primary narrow coracohumeral distance with different threshold values defined as increased risk factor for subscapularis and antero-superior RC tear; opposite theories stated that the stenosis is secondary to an anterosuperior translation of the humeral head toward the coracoid due to degenerative changes of the rotator cuff tendons. Limited coracoplasty can be performed when related risk factors are identified; however no clear consensus arises from specific literature review and extensive clinical and instrumental examination of the patient should be performed in order to identify specific risk factors for subscapularis tendon pathology and, subsequently, tailor the proper approach. PMID:23888292

  10. Tear analysis and lens–tear interactions

    Microsoft Academic Search

    Aisling M. Mann; Brian J. Tighe

    2007-01-01

    The purpose of this work is to establish the application of a fully automated microfluidic chip based protein separation assay in tear analysis. It is rapid, requires small sample volumes and is vastly superior to, and more convenient than, comparable conventional gel electrophoresis assays. The protein sizing chip technology was applied to three specific fields of analysis. Firstly tear samples

  11. Blocked tear duct

    MedlinePLUS

    A blocked tear duct is a partial or complete blockage in the pathway that carries tears from the surface of the eye into the ... Tears are constantly being made to help protect the surface of your eye. They drain into a ...

  12. Clinical Comparison of Fixation Methods for Patellar Bone Quadriceps Tendon Autografts in Anterior Cruciate Ligament ReconstructionAbsorbable Cross-pins Versus Absorbable Screws

    Microsoft Academic Search

    Ottmar Gorschewsky; Robert Stapf; Laurent Geiser; Ulrich Geitner; Wolfram Neumann

    2007-01-01

    Background: Recently, the use of the quadriceps tendon transplant with bone block (patellar bone quadriceps tendon autografts) for anterior cruciate ligament reconstruction has increasingly been reported.Hypothesis: Clinical results after the implantation of a patellar bone quadriceps tendon autograft fixed with cross-pins or screws will show no significant difference between the 2 techniques with regard to stability, function, and subjective satisfaction.

  13. Characterization of Fluoroquinolone-Induced Achilles Tendon Toxicity in Rats: Comparison of Toxicities of 10 Fluoroquinolones and Effects of Anti-Inflammatory Compounds

    Microsoft Academic Search

    YOKO KASHIDA; MICHIYUKI KATO

    1997-01-01

    Fluoroquinolone antibacterial agents have been reported to induce tendon lesions in juvenile rats. In the present study, we characterized fluoroquinolone-induced Achilles tendon lesions by comparing the effects of 10 fluoroquinolones and examining the potential of one of these antimicrobial agents, pefloxacin, to induce tendon lesions when coadministered with one of nine anti-inflammatory compounds. Among the 10 fluoroquinolones tested, fleroxacin and

  14. BILATERAL PATELLAR TENDON RUPTURE AT DIFFERENT SITES WITHOUT PREDISPOSING SYSTEMIC DISEASE OR STEROID USE

    PubMed Central

    Taylor, Benjamin C.; Tancev, Alex; Fowler, Ty

    2009-01-01

    Simultaneous bilateral patellar tendon ruptures are extremely rare, and even more rare in patients without systemic disease. We describe bilateral simultaneous patellar tendon disruptions in the absence of systemic disease or steroid usage, with one tendon disruption at the inferior pole and the other an intrasubstance tear. The different locations of the ruptures are also exceedingly rare, as only two cases of non-identical ruptures have ever been reported. We also review all bilateral patellar tendon rupture case reports from English and German literature. PMID:19742095

  15. Acute achilles tendon ruptures: a comparison of minimally invasive and open approach repairs followed by early rehabilitation.

    PubMed

    Tejwani, Nirmal C; Lee, James; Weatherall, Justin; Sherman, Orrin

    2014-10-01

    We retrospectively compared the outcomes of early functional weight-bearing after use of 2 different approaches (minimally invasive, standard) for surgical repair of the Achilles tendon. We reviewed the cases of 63 consecutive patients who underwent repair of an acute closed Achilles tendon rupture and had follow-up of at least 6 months. Of these 63 patients, 33 were treated with a minimally invasive posterolateral approach (minimal group), and 30 were treated with a standard posteromedial approach (standard group). Two weeks after surgery, each patient was allowed to weight-bear as tolerated in a controlled ankle movement boot with a 20° heel wedge. At 6 weeks, the patient was placed in a regular shoe with a heel lift. We examined range of motion and incidence of reruptures, sural nerve injuries, and wound complications at 6 weeks and 3 months and calf strength at 6 months. Neither group had any reruptures. Mean incision length was 2.5 cm (minimal group) and 7.2 cm (standard group). One patient (3.2%) in the minimal group and 6 patients (20%) in the standard group developed a superficial wound infection. Four (12.9%) of 31 minimal patients and no standard patients developed a sural nerve deficit. There were statistically significant differences between the groups' wound complication rates (P=.04) and nerve injury rates (P=.043). At final follow-up, the groups did not differ in their functional outcomes (ability to perform a single heel raise, American Orthopaedic Foot and Ankle Society scores). Used after a minimally invasive posterolateral or standard posteromedial approach, early functional weightbearing is an effective and safe method for treating acute ruptures of the Achilles tendon, and it has a lower rate of soft-tissue complications. A standard posteromedial approach has a higher rate of wound complications, and a minimally invasive posterolateral approach has a higher rate of sural nerve injury. PMID:25303448

  16. Diseases of the tendons and tendon sheaths.

    PubMed

    Steiner, Adrian; Anderson, David E; Desrochers, André

    2014-03-01

    Contracted flexor tendon leading to flexural deformity is a common congenital defect in cattle. Arthrogryposis is a congenital syndrome of persistent joint contracture that occurs frequently in Europe as a consequence of Schmallenberg virus infection of the dam. Spastic paresis has a hereditary component, and affected cattle should not be used for breeding purposes. The most common tendon avulsion involves the deep digital flexor tendon. Tendon disruptions may be successfully managed by tenorrhaphy and external coaptation or by external coaptation alone. Medical management alone is unlikely to be effective for purulent tenosynovitis. PMID:24534664

  17. A new tear pattern of the rotator cuff and its treatment: Fosbury flop tears

    PubMed Central

    Lädermann, Alexandre; Denard, Patrick J.; Kolo, Frank C.

    2015-01-01

    Purpose: The purpose of this report is to describe a new full-thickness tear pattern of the posterosuperior rotator cuff with reversal healing. We describe the specific radiologic signs associated with this tear pattern and the arthroscopic rotator cuff repair technique. Materials and Methods: A prospective radiologic and clinical study collected all patients with a magnetic resonance imaging arthrogram that underwent an arthroscopic rotator cuff repair over a 1 year period. Results: Among 97 patients, five demonstrated a tear of the posterosuperior rotator cuff with reversal healing. Characteristic radiographic findings included a thicker tendon than normal, the presence of a stump and accumulation of liquid in the superior-medial part of the subacromial bursa, and adhesions between the supraspinatus tendon and the wall of the subacromial bursa. Conclusion: Avulsion of the posterosuperior rotator cuff with reversal healing on its bursal-side is a less common condition. This type of lesion and distinct radiographic signs that can be recognized to facilitate anatomic repair of the rotator cuff. Level of evidence: Level IV. PMID:25709239

  18. Symptomatic Progression of Asymptomatic Rotator Cuff Tears

    PubMed Central

    Mall, Nathan A.; Kim, H. Mike; Keener, Jay D.; Steger-May, Karen; Teefey, Sharlene A.; Middleton, William D.; Stobbs, Georgia; Yamaguchi, Ken

    2010-01-01

    Background: The purposes of this study were to identify changes in tear dimensions, shoulder function, and glenohumeral kinematics when an asymptomatic rotator cuff tear becomes painful and to identify characteristics of individuals who develop pain compared with those who remain asymptomatic. Methods: A cohort of 195 subjects with an asymptomatic rotator cuff tear was prospectively monitored for pain development and examined annually for changes in various parameters such as tear size, fatty degeneration of the rotator cuff muscle, glenohumeral kinematics, and shoulder function. Forty-four subjects were found to have developed new pain, and the parameters before and after pain development were compared. The forty-four subjects were then compared with a group of fifty-five subjects who remained asymptomatic over a two-year period. Results: With pain development, the size of a full-thickness rotator cuff tear increased significantly, with 18% of the full-thickness tears showing an increase of >5 mm, and 40% of the partial-thickness tears had progressed to a full-thickness tear. In comparison with the assessments made before the onset of pain, the American Shoulder and Elbow Surgeons scores for shoulder function were significantly decreased and all measures of shoulder range of motion were decreased except for external rotation at 90° of abduction. There was an increase in compensatory scapulothoracic motion in relation to the glenohumeral motion during early shoulder abduction with pain development. No significant changes were found in external rotation strength or muscular fatty degeneration. Compared with the subjects who remained asymptomatic, the subjects who developed pain were found to have significantly larger tears at the time of initial enrollment. Conclusions: Pain development in shoulders with an asymptomatic rotator cuff tear is associated with an increase in tear size. Larger tears are more likely to develop pain in the short term than are smaller tears. Further research is warranted to investigate the role of prophylactic treatment of asymptomatic shoulders to avoid the development of pain and loss of shoulder function. Level of Evidence: Prognostic Level III. See Instructions to Authors for a complete description of levels of evidence. PMID:21084574

  19. Biologics for tendon repair.

    PubMed

    Docheva, Denitsa; Müller, Sebastian A; Majewski, Martin; Evans, Christopher H

    2015-04-01

    Tendon injuries are common and present a clinical challenge to orthopedic surgery mainly because these injuries often respond poorly to treatment and require prolonged rehabilitation. Therapeutic options used to repair ruptured tendons have consisted of suture, autografts, allografts, and synthetic prostheses. To date, none of these alternatives has provided a successful long-term solution, and often the restored tendons do not recover their complete strength and functionality. Unfortunately, our understanding of tendon biology lags far behind that of other musculoskeletal tissues, thus impeding the development of new treatment options for tendon conditions. Hence, in this review, after introducing the clinical significance of tendon diseases and the present understanding of tendon biology, we describe and critically assess the current strategies for enhancing tendon repair by biological means. These consist mainly of applying growth factors, stem cells, natural biomaterials and genes, alone or in combination, to the site of tendon damage. A deeper understanding of how tendon tissue and cells operate, combined with practical applications of modern molecular and cellular tools could provide the long awaited breakthrough in designing effective tendon-specific therapeutics and overall improvement of tendon disease management. PMID:25446135

  20. Reconstruction of the anterior cruciate ligament: a comparison between bone-patellar tendon-bone grafts and fourstrand hamstring grafts

    PubMed Central

    Razi, Mohammad; Sarzaeem, Mohammad Mahdi; Kazemian, Gholam Hossein; Najafi, Farideh; Najafi, Mohammad Amin

    2014-01-01

    Background: Disruption of anterior cruciate ligament (ACL) is a common ligamentous injury of the knee. The choice of graft for (ACL) reconstruction remains controversial. This prospective, randomized clinical trial aimed to compare clinical results of bone-patellar tendon-bone (BPTB) grafts and four-strand semitendinosus-gracilis (ST) grafts for ACL reconstruction over a 3-year follow-up interval. Methods: Seventy-one patients with an average age of 29± 4.5yearswere treated for torn ACL between 2008 and 2009. Forty-sixpatients underwent reconstruction with BPTB autograft, and 41 were treated with ST autograft. At the time of final follow-up, 37 patients in patella group and 34 patients in hamstring group were evaluated in terms of return to pre-injury activity level, pain, knee stability, range of motion, IKDC (International Knee Documentation Committee) score and complications. Results: At 36thmonth of follow-up, 34 (92%) and 28 (82%) patients in BPTB and ST group, respectively had good-to-excellent IKDC score (p > 0.05). The activity levels were higher in BPTB group (p> 0.05). At 3rd yearof follow up, the Lachman test was graded normal, for 23 (62%) and 11 (32%) patients in BPTB and ST group, respectively (p=0.019). Regarding the pivot-shift test, 29 (79%) and 15 (44%) patients in patella and hamstring group, respectively had normal test at the latest follow-up (p=0.021).There were no significant differences in terms of thigh circumference difference, effusion, knee range of motion, pain and complications. Conclusion: The results indicate a trend toward increased graft laxity and pivot-shift grades in patients undergoing reconstruction with hamstring autograft compared with patella tendon. However, the two groups had comparable results in terms of activity level and knee function. PMID:25694992

  1. An Unusual Knee Trauma: Combined Rupture of Medial Collateral Ligament and Patellar Tendon

    PubMed Central

    De Baere, T.; De Muylder, J.; Deltour, A.

    2014-01-01

    We present the case of a combined lesion of the medial collateral ligament (MCL) and patellar tendon of the knee in a 45-year-old man, after a fall while skiing. Although there are numerous publications concerning associated tears of MCL and other knee ligaments, a combination of MCL tear with a rupture of the patellar tendon is very rare. After a review of the literature and treatment guidelines about these lesions, the clinical case is described and discussed. This knee trauma was treated with a transosseous reinsertion of the patellar tendon, which was reinforced by an allograft of fascia lata, followed by a direct suture of the MCL, which was reinforced with the lateral semitendinosus tendon. PMID:25202463

  2. Modeling of SMA Tendons for Active Control of Structures

    Microsoft Academic Search

    Alu R. Shahin; Peter H. Meckl; James D. Jones

    1997-01-01

    The use of shape memory alloy (SMA) wires as active tendons to reduce vibra-tion of a building model is analytically investigated. Approximate dynamic equations for one bay of a multi-story building with SMA tendons are derived based on laws of thermodynamics and Brinson's constitutive equations. These equations are used to provide comparisons between us-ing SMA tendons passively and active for

  3. Is ultrasound diagnosis reliable in acute extensor tendon injuries of the knee?

    PubMed

    Swamy, Girish N; Nanjayan, Shashi K; Yallappa, Sachin; Bishnoi, Amit; Pickering, Simon A W

    2012-12-01

    Ruptures of the patellar and quadriceps tendon are rare injuries requiring immediate repair to re-establish knee extensor continuity and allow early motion. Ultrasound is extensively used as a diagnostic tool before surgery on acute traumatic tears of the patellar tendon and quadriceps tendons. The aim of our study was to evaluate the role of sonography in diagnosing quadriceps and patellar tendon rupture and in differentiating partial from complete tears. We conducted a retrospective review of 51 consecutive patients who had a surgical intervention for suspected acute quadriceps and patellar tendon rupture over a 5-year period. Intra-operative findings were compared with pre-operative clinical examination. Radiographs, ultrasound and MRI reports were reviewed. On clinical examination, 22 patients had a suspected patellar tendon rupture and 29 patients had a suspected quadriceps tendon rupture. Diagnosis was confirmed by clinical examination and plain radiographs alone in 13 patients, with additional ultrasound performed in 24 patients and MRI scan performed in 14 patients. There were 8 false positives out of 24 [33.3%] in the ultrasound proven group and 1 false positive out of 13 [7.69%] in the clinical examination and radiographs only group. MRI was 100% accurate. We conclude that ultrasonography is not a reliable method in establishing the diagnosis of acute injuries to the extensor mechanism of the knee, particularly the quadriceps tendon ruptures in the obese and the very muscular patients. If there is clinical ambiguity, MRI scan is a better investigation tool before undertaking surgical treatment. PMID:23409573

  4. Partial-Thickness Rotator Cuff Tears

    PubMed Central

    2011-01-01

    Although the incidence of partial-thickness rotator cuff tears (PTRCTs) was reported to be from 13% to 32% in cadaveric studies, the actual incidence is not yet known. The causes of PTRCTs can be explained by either extrinsic or intrinsic theories. Studies suggest that intrinsic degeneration within the rotator cuff is the principal factor in the pathogenesis of rotator cuff tears. Extrinsic causes include subacromial impingement, acute traumatic events, and repetitive microtrauma. However, acromially initiated rotator cuff pathology does not occur and extrinsic impingement does not cause pathology on the articular side of the tendon. An arthroscopic classification system has been developed based on the location and depth of the tear. These include the articular, bursal, and intratendinous areas. Both ultrasound and magnetic resonance image are reported with a high accuracy of 87%. Conservative treatment, such as subacromial or intra-articular injections and suprascapular nerve block with or without block of the articular branches of the circumflex nerve, should be considered prior to operative treatment for PTRCTs. PMID:21716613

  5. Antimicrobial Compounds in Tears

    PubMed Central

    McDermott, Alison M.

    2013-01-01

    The tear film coats the cornea and conjunctiva and serves several important functions. It provides lubrication, prevents drying of the ocular surface epithelia, helps provide a smooth surface for refracting light, supplies oxygen and is an important component of the innate defense system of the eye providing protection against a range of potential pathogens. This review describes both classic antimicrobial compounds found in tears such as lysozyme and some more recently identified such as members of the cationic antimicrobial peptide family and surfactant protein-D as well as potential new candidate molecules that may contribute to antimicrobial protection. As is readily evident from the literature review herein, tears, like all mucosal fluids, contain a plethora of molecules with known antimicrobial effects. That all of these are active in vivo is debatable as many are present in low concentrations, may be influenced by other tear components such as the ionic environment, and antimicrobial action may be only one of several activities ascribed to the molecule. However, there are many studies showing synergistic/additive interactions between several of the tear antimicrobials and it is highly likely that cooperativity between molecules is the primary way tears are able to afford significant antimicrobial protection to the ocular surface in vivo. In addition to effects on pathogen growth and survival some tear components prevent epithelial cell invasion and promote the epithelial expression of innate defense molecules. Given the protective role of tears a number of scenarios can be envisaged that may affect the amount and/or activity of tear antimicrobials and hence compromise tear immunity. Two such situations, dry eye disease and contact lens wear, are discussed here. PMID:23880529

  6. Bone suture anchors versus the pullout button for repair of distal profundus tendon injuries: A comparison of strength in human cadaveric hands

    Microsoft Academic Search

    Marshall Brustein; James Pellegrini; Jack Choueka; Heather Heminger; Daniel Mass

    2001-01-01

    Avulsion or distal tendon laceration of flexor digitorum profundus (FDP) is classically repaired to the base of the distal phalanx via a pullout suture over a button. Bone suture anchors, used extensively in other surgical areas, have recently been proposed for reattachment of the FDP to the distal phalanx. The FDP tendons of the index, long, and ring fingers in

  7. Recruitment viscoelasticity of the tendon.

    PubMed

    Einat, Raz; Yoram, Lanir

    2009-11-01

    There is still no agreement on the nature of tissues' viscoelasticity and on its reliable modeling. We speculate that disagreements between previous observations stem from difficulties of separating between viscoelastic and preconditioning effects, since both are manifested by similar response features. Here, this and related issues were studied in the tendon as a prototype for other soft tissues. Sheep digital tendons were preconditioned under strain that was higher by 1% than the one used in subsequent testing. Each specimen was then subjected to stress relaxation, and quick release or creep. A stochastic microstructural viscoelastic theory was developed based on the collagen fibers' properties and on their gradual recruitment with stretch. Model parameters were estimated from stress relaxation data and predictions were compared with the creep data. Following its validation, the new recruitment viscoelasticity (RVE) model was compared, both theoretically and experimentally, with the quasilinear viscoelastic (QLV) theory. The applied preconditioning protocol produced subsequent pure viscoelastic response. The proposed RVE model provided excellent fit to both stress relaxation and creep data. Both analytical and numerical comparisons showed that the new RVE theory and the popular QLV one are equivalent under deformation schemes at which no fibers buckle. Otherwise, the equivalence breaks down; QLV may predict negative stress, in contrast to data of the quick release tests, while RVE predicts no such negative stress. The results are consistent with the following conclusions: (1) fully preconditioned tendon exhibits pure viscoelastic response, (2) nonlinearity of the tendon viscoelasticity is induced by gradual recruitment of its fibers, (3) a new structure-based RVE theory is a reliable representation of the tendon viscoelastic properties under both stress relaxation and creep tests, and (4) the QLV theory is equivalent to the RVE one (and valid) only under deformations in which no fibers buckle. The results also suggest that the collagen fibers themselves are linear viscoelastic. PMID:20353259

  8. Bipolar Posterior Deltoid Transfer for Massive Rotator Cuff Tears: A Report on 2 Patients

    PubMed Central

    2015-01-01

    Summary: A transfer of the posterior deltoid innervated by the posterior branch of the axillary nerve and vascularized by the posterior circumflex humeral artery is described for irreparable tears of the supra- and infraspinatus muscle tendons. Functionally useful abduction and flexion were restored in 2 patients. PMID:26090280

  9. Magnetic Resonance Imaging of Rotator Cuff Tears in Shoulder Impingement Syndrome

    PubMed Central

    Freygant, Magdalena; Dziurzy?ska-Bia?ek, Ewa; Guz, Wies?aw; Samojedny, Antoni; Go?ofit, Andrzej; Kostkiewicz, Agnieszka; Terpin, Krzysztof

    2014-01-01

    Summary Background Shoulder joint is a common site of musculoskeletal pain caused, among other things, by rotator cuff tears due to narrowing of subacromial space, acute trauma or chronic shoulder overload. Magnetic resonance imaging (MRI) is an excellent modality for imaging of soft tissues of the shoulder joint considering a possibility of multiplanar image acquisition and non-invasive nature of the study. The aim of this study was to evaluate the prevalence of partial and complete rotator cuff tears in magnetic resonance images of patients with shoulder impingement syndrome and to review the literature on the causes and classification of rotator cuff tears. Material/Methods We retrospectively analyzed the results of 137 shoulder MRI examinations performed in 57 women and 72 men in Magnetic Resonance facility of the Department of Radiology and Diagnostic Imaging at the St. Jadwiga the Queen Regional Hospital No. 2 in Rzeszow between June 2010 and February 2013. Examinations were performed using Philips Achieva 1.5T device, including spin echo and gradient echo sequences with T1-, T2- and PD-weighted as well as fat saturation sequences in transverse, frontal and sagittal oblique planes. Patients were referred from hospital wards as well as from outpatient clinics of the subcarpathian province. Results The most frequently reported injuries included partial supraspinatus tendon tear and complete tearing most commonly involved the supraspinatus muscle tendon. The smallest group comprised patients with complete tear of subscapularis muscle tendon. Among 137 patients in the study population, 129 patients suffered from shoulder pain, including 57 patients who reported a history of trauma. There was 44% women and 56% men in a group of patients with shoulder pain. Posttraumatic shoulder pain was predominantly reported by men, while women comprised a larger group of patients with shoulder pain not preceded by injury. Conclusions Rotator cuff injury is a very common pathology in patients with shoulder impingement syndrome. Isolated supraspinatus tendon injury or complete tearing is most frequent, rather than in conjunction with injuries to other rotator cuff tendons. We did not observe isolated complete tears of infraspinatus and subscapular muscle tendons. PMID:25374626

  10. Patellar tendon reconstruction with semitendinosus-gracilis autograft.

    PubMed

    Harris, Joshua D; Fazalare, Joseph J; Phieffer, Laura S; Flanigan, David C

    2013-12-01

    We present a case of a 24-year-old, otherwise healthy, man who sustained a right knee injury after a fall. A small, comminuted inferior pole patella fracture with medial and lateral retinacular tears was encountered that required a small, nonarticular partial patellectomy and patellar tendon repair. An uneventful postoperative course was complicated by a fall onto a flexed knee and rerupture of the patellar tendon at 3 months following surgery. Intraoperatively, a significant tissue void was seen in the area of the prior repair. The patellar tendon was reconstructed with semitendinosus and gracilis autograft. At 1 year follow-up, the patient had regained a normal gait, had no pain, and had full range-of-motion without extensor lag. PMID:23288729

  11. Nonoperative management of a partial patellar tendon rupture after bone-patellar tendon-bone graft harvest for ACL reconstruction.

    PubMed

    Benner, Rodney W; Shelbourne, K Donald; Freeman, Heather

    2013-12-01

    This is a case report of a young athlete who sustained a partial tear of the patellar tendon after anterior cruciate ligament (ACL) reconstruction with a bone-patellar tendon-bone (BPTB) autograft. The injury, diagnostic workup, and decision-making process that lead to the choice of nonsurgical treatment are described. Furthermore, the rehabilitation process is described in detail. The patient returned to his previous level of sports activity and had a good clinical outcome as measured by range of motion, isokinetic quadriceps muscle strength testing, single leg hop testing, and the modified Noyes survey. In the absence of extensor mechanism incompetence or radiographic evidence of significant patella alta, partial ruptures of the patella tendon after ACL reconstruction using a BPTB autograft may be treated nonoperatively. PMID:23288745

  12. Multilayered Electrospun Scaffolds for Tendon Tissue Engineering

    PubMed Central

    Chainani, Abby; Hippensteel, Kirk J.; Kishan, Alysha; Garrigues, N. William; Ruch, David S.; Guilak, Farshid

    2013-01-01

    Full-thickness rotator cuff tears are one of the most common causes of shoulder pain in people over the age of 65. High retear rates and poor functional outcomes are common after surgical repair, and currently available extracellular matrix scaffold patches have limited abilities to enhance new tendon formation. In this regard, tissue-engineered scaffolds may provide a means to improve repair of rotator cuff tears. Electrospinning provides a versatile method for creating nanofibrous scaffolds with controlled architectures, but several challenges remain in its application to tissue engineering, such as cell infiltration through the full thickness of the scaffold as well as control of cell growth and differentiation. Previous studies have shown that ligament-derived extracellular matrix may enhance differentiation toward a tendon or ligament phenotype by human adipose stem cells (hASCs). In this study, we investigated the use of tendon-derived extracellular matrix (TDM)-coated electrospun multilayered scaffolds compared to fibronectin (FN) or phosphate-buffered saline (PBS) coating for use in rotator cuff tendon tissue engineering. Multilayered poly(?-caprolactone) scaffolds were prepared by sequentially collecting electrospun layers onto the surface of a grounded saline solution into a single scaffold. Scaffolds were then coated with TDM, FN, or PBS and seeded with hASCs. Scaffolds were maintained without exogenous growth factors for 28 days in culture and evaluated for protein content (by immunofluorescence and biochemical assay), markers of tendon differentiation, and tensile mechanical properties. The collagen content was greatest by day 28 in TDM-scaffolds. Gene expression of type I collagen, decorin, and tenascin C increased over time, with no effect of scaffold coating. Sulfated glycosaminoglycan and dsDNA contents increased over time in culture, but there was no effect of scaffold coating. The Young's modulus did not change over time, but yield strain increased with time in culture. Histology demonstrated cell infiltration through the full thickness of all scaffolds and immunofluorescence demonstrated greater expression of type I, but not type III collagen through the full thickness of the scaffold in TDM-scaffolds compared to other treatment groups. Together, these data suggest that nonaligned multilayered electrospun scaffolds permit tenogenic differentiation by hASCs and that TDM may promote some aspects of this differentiation. PMID:23808760

  13. Multilayered electrospun scaffolds for tendon tissue engineering.

    PubMed

    Chainani, Abby; Hippensteel, Kirk J; Kishan, Alysha; Garrigues, N William; Ruch, David S; Guilak, Farshid; Little, Dianne

    2013-12-01

    Full-thickness rotator cuff tears are one of the most common causes of shoulder pain in people over the age of 65. High retear rates and poor functional outcomes are common after surgical repair, and currently available extracellular matrix scaffold patches have limited abilities to enhance new tendon formation. In this regard, tissue-engineered scaffolds may provide a means to improve repair of rotator cuff tears. Electrospinning provides a versatile method for creating nanofibrous scaffolds with controlled architectures, but several challenges remain in its application to tissue engineering, such as cell infiltration through the full thickness of the scaffold as well as control of cell growth and differentiation. Previous studies have shown that ligament-derived extracellular matrix may enhance differentiation toward a tendon or ligament phenotype by human adipose stem cells (hASCs). In this study, we investigated the use of tendon-derived extracellular matrix (TDM)-coated electrospun multilayered scaffolds compared to fibronectin (FN) or phosphate-buffered saline (PBS) coating for use in rotator cuff tendon tissue engineering. Multilayered poly(?-caprolactone) scaffolds were prepared by sequentially collecting electrospun layers onto the surface of a grounded saline solution into a single scaffold. Scaffolds were then coated with TDM, FN, or PBS and seeded with hASCs. Scaffolds were maintained without exogenous growth factors for 28 days in culture and evaluated for protein content (by immunofluorescence and biochemical assay), markers of tendon differentiation, and tensile mechanical properties. The collagen content was greatest by day 28 in TDM-scaffolds. Gene expression of type I collagen, decorin, and tenascin C increased over time, with no effect of scaffold coating. Sulfated glycosaminoglycan and dsDNA contents increased over time in culture, but there was no effect of scaffold coating. The Young's modulus did not change over time, but yield strain increased with time in culture. Histology demonstrated cell infiltration through the full thickness of all scaffolds and immunofluorescence demonstrated greater expression of type I, but not type III collagen through the full thickness of the scaffold in TDM-scaffolds compared to other treatment groups. Together, these data suggest that nonaligned multilayered electrospun scaffolds permit tenogenic differentiation by hASCs and that TDM may promote some aspects of this differentiation. PMID:23808760

  14. Extra-articular Mimickers of Lateral Meniscal Tears

    PubMed Central

    Barker, Joseph U.; Strauss, Eric J.; Lodha, Sameer; Bach, Bernard R.

    2011-01-01

    Context: Lateral meniscus tears are a common entity seen in sports medicine. Although lateral-side knee pain is often the result of a meniscus injury, several extra-articular pathologies share signs and symptoms with a meniscus tear. It is critical for the clinician to be able to identify and understand extra-articular pathologies that can present similar to a lateral meniscus tear. Evidence Acquisition: Data were collected through a thorough review of the literature conducted through a MEDLINE search for all relevant articles between 1980 and February 2010. Study Type: Clinical review. Results: Common extra-articular pathologies that can mimic lateral meniscal tears include iliotibial band syndrome, proximal tibiofibular joint instability, snapping biceps femoris or popliteus tendons, and peroneal nerve compression syndrome or neuritis. The patient history, physical examination features, and radiographic findings can be used to separate these entities from the more common intra-articular knee pathologies. Conclusions: In treating patients who present with lateral-sided knee pain, clinicians should be able to recognize and treat extra-articular pathologies that can present in a similar fashion as lateral meniscus tears. PMID:23015995

  15. Tendon lengthening and transfer.

    PubMed

    Fitoussi, F; Bachy, M

    2015-02-01

    Tendon lengthening and transfer are usually indicated for certain neuromuscular disorders, peripheral or central nerve injury, congenital disorder or direct traumatic or degenerative musculotendinous lesion. In musculotendinous lengthening, technique depends on muscle anatomy, degree of correction required, and the need to avoid excessive loss of force. Lengthening within the muscle or aponeurosis is stable. In the tendon, however, it may provide greater gain but is not stable and requires postoperative immobilization to avoid excessive lengthening. Tendon transfer consists in displacing a muscle's tendon insertion in order to restore function. The muscle to be transferred is chosen according to strength, architecture and course, contraction timing, intended direction, synergy and the joint moment arm to be restored. Functions to be restored have to be prioritized, and alternatives to transfer should be identified. The principles of tendon transfer require preoperative assessment of the quality of the tissue through which the transfer is to pass and of the suppleness of the joints concerned. During the procedure, transfer tension should be optimized and the neurovascular bundle should be protected. The method of fixation, whether tendon-to-bone or tendon-to-tendon suture, should be planned according to local conditions and the surgeon's experience. PMID:25572471

  16. Bilateral simultaneous spontaneous quadriceps tendons rupture A case report studied by magnetic resonance imaging

    Microsoft Academic Search

    Emilio Calvo; Antonio Ferrer; Angel G. Robledo; L. Alvarez; F. Castillo; C. Vallejo

    1997-01-01

    A rare case of bilateral, simultaneous, and spontaneous rupture of the quadriceps tendon in a previous healthy young man is presented. Magnetic resonance imaging (MRI) defined accurately the features of the tear showing different levels of rupture on each side. This finding was especially helpful in preoperative planning.

  17. Human tears contain a chemosignal.

    PubMed

    Gelstein, Shani; Yeshurun, Yaara; Rozenkrantz, Liron; Shushan, Sagit; Frumin, Idan; Roth, Yehudah; Sobel, Noam

    2011-01-14

    Emotional tearing is a poorly understood behavior that is considered uniquely human. In mice, tears serve as a chemosignal. We therefore hypothesized that human tears may similarly serve a chemosignaling function. We found that merely sniffing negative-emotion-related odorless tears obtained from women donors induced reductions in sexual appeal attributed by men to pictures of women's faces. Moreover, after sniffing such tears, men experienced reduced self-rated sexual arousal, reduced physiological measures of arousal, and reduced levels of testosterone. Finally, functional magnetic resonance imaging revealed that sniffing women's tears selectively reduced activity in brain substrates of sexual arousal in men. PMID:21212322

  18. Arthroscopic Repair of Rotator Cuff Tears Using Extracellular Matrix Graft

    PubMed Central

    Gilot, Gregory J.; Attia, Ahmed K.; Alvarez, Andres M.

    2014-01-01

    Despite advances in surgical technology, as well as generally good outcomes, repairs of full-thickness rotator cuff tears show a retear rate of 25% to 57% and may fail to provide full return of function. The repairs tend to fail at the suture-tendon junction, which is due to several factors, including tension at the repair site, quality of the tendon, and defective tissue repair. One strategy to augment repair of large to massive rotator cuff tears is the development of biological scaffold materials, composed of extracellular matrix (ECM). The goal is to strengthen and evenly distribute the mechanical load across the repair site, thus minimizing the rupture risk of the native tendon while providing the biological elements needed for healing. The promising results of ECM-derived materials and their commercial availability have increased their popularity among shoulder surgeons. In contrast to a traditional open or arthroscopically assisted mini-open approach, this completely arthroscopic technique offers the full advantages warranted by the use of a minimally invasive approach. This technical guide describes arthroscopic rotator cuff repair using an ECM graft technique. PMID:25276607

  19. Tendon injuries of the hand

    PubMed Central

    Schöffl, Volker; Heid, Andreas; Küpper, Thomas

    2012-01-01

    Tendon injuries are the second most common injuries of the hand and therefore an important topic in trauma and orthopedic patients. Most injuries are open injuries to the flexor or extensor tendons, but less frequent injuries, e.g., damage to the functional system tendon sheath and pulley or dull avulsions, also need to be considered. After clinical examination, ultrasound and magnetic resonance imaging have proved to be important diagnostic tools. Tendon injuries mostly require surgical repair, dull avulsions of the distal phalanges extensor tendon can receive conservative therapy. Injuries of the flexor tendon sheath or single pulley injuries are treated conservatively and multiple pulley injuries receive surgical repair. In the postoperative course of flexor tendon injuries, the principle of early passive movement is important to trigger an “intrinsic” tendon healing to guarantee a good outcome. Many substances were evaluated to see if they improved tendon healing; however, little evidence was found. Nevertheless, hyaluronic acid may improve intrinsic tendon healing. PMID:22720265

  20. Identification, quantification and comparison of major non-polar lipids in normal and dry eye tear lipidomes by electrospray tandem mass spectrometry

    PubMed Central

    Ham, Bryan M.; Jacob, Jean T.; Keese, Monica M.; Cole, Richard B.

    2008-01-01

    Millions of individuals suffer from a health condition known as keratoconjunctivitis sicca (KCS, also known as ‘dry eye’). Studies have indicated that the lipids in the tear film layer, which covers the outer portion of the eye, may be directly correlated with the existence of dry eye syndrome. By identifying and comparing the major, non-polar lipids in normal eye tears with a dry eye model, it may be possible to identify a symptom of, or a contributing factor to, dry eye. Electrospray tandem mass spectrometry (ES-MS/MS) was used to identify and compare the non-polar lipids, detected as lithium adducts, from normal and dry eye tear samples obtained from rabbits. A limited number of normal human tear samples were also examined for lipid content, and a close resemblance to rabbit was observed. Three distinct regions were delineated in the ES mass spectra of the non polar lipids, m/z 20–500, 500–800 and 800–1100. A common feature noted among identified lipid components was a glycerol backbone with fatty acyl substituents attached. Product ion spectra were obtained for lithiated monoacyl-, 1,2- and 1,3-diacyl- and triacylglyceride standards. Newly proposed structures and fragmentation pathways for the major product ions are presented for the 1,2- and 1,3-diglycerides, and also for the monoglyceride. New approaches to distinguishing asymmetric 1,2-diglycerides and 1,2- from 1,3-diglycerides are proposed. For the rabbit tear samples, the m/z 20–500 range contains monoester diols with empirical formulas CnH2nO4, the m/z 500–800 range includes diesters with empirical formulas CnH2n?2O5 and the m/z 800–1100 range contains triesters with empirical formulas CnH2n?4O6. Also found in the extracts were three isoprene acetals (terpenoids). PMID:15532045

  1. Tear dynamics and dry eye

    Microsoft Academic Search

    Kazuo Tsubota

    1998-01-01

    Tears undergo four processes: production by the lacrimal gland, distribution by blinking, evaporation from the ocular surface and drainage through the nasolacrimal duct. Abnormalities in any of these steps can cause dry eye. There are two kinds of tear production, basic and reflex, which can be distinguished from each other by the Schirmer test with nasal stimulation. Reflex tearing is

  2. Tearing Modes in Tokamaks

    SciTech Connect

    White, R. B. [Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543 (United States)

    2008-05-14

    This lecture gives a basic introduction to magnetic pound elds, magnetic surface destruction, toroidal equilibrium and tearing modes in a tokamak, including the linear and nonlinear development of these modes and their modi pound cation by current drive and bootstrap current, and sawtooth oscillations and disruptions.

  3. Jumper's Knee (Patellar Tendonitis)

    MedlinePLUS

    ... particularly high-jumping), basketball, volleyball, gymnastics, running, and soccer — can put a lot of strain on their ... MCL) Injuries Meniscus Tears Runner's Knee Safety Tips: Soccer Safety Tips: Basketball Osgood-Schlatter Disease Sports and ...

  4. Tear film stability: a review.

    PubMed

    Sweeney, Deborah F; Millar, Thomas J; Raju, Shiwani R

    2013-12-01

    Tear film stability can be assessed via a number of tools designed for clinical as well as research purposes. These techniques can give us insights into the tear film, and allow assessment of conditions that can lead to dry eye symptoms, and in severe cases, to significant ocular surface damage and deterioration of vision. Understanding what drives tear film instability and its assessment is also crucial for evaluating existing and new therapies. This review examines various techniques that are used to assess tear film instability: evaluation of tear break-up time and non-invasive break-time; topographic and interferometric techniques; confocal microscopic methods; aberrometry; and visual function tests. It also describes possible contributions of different tear film components; namely meibomian lipids, ocular mucins and proteins, and factors such as age, contact lens wear, ocular surgery and environmental stimuli, that may influence tear film instability. PMID:23973716

  5. Fibrocartilage in tendons and ligaments — an adaptation to compressive load

    PubMed Central

    BENJAMIN, M.; RALPHS, J. R.

    1998-01-01

    Where tendons and ligaments are subject to compression, they are frequently fibrocartilaginous. This occurs at 2 principal sites: where tendons (and sometimes ligaments) wrap around bony or fibrous pulleys, and in the region where they attach to bone, i.e. at their entheses. Wrap-around tendons are most characteristic of the limbs and are commonly wider at their point of bony contact so that the pressure is reduced. The most fibrocartilaginous tendons are heavily loaded and permanently bent around their pulleys. There is often pronounced interweaving of collagen fibres that prevents the tendons from splaying apart under compression. The fibrocartilage can be located within fascicles, or in endo- or epitenon (where it may protect blood vessels from compression or allow fascicles to slide). Fibrocartilage cells are commonly packed with intermediate filaments which could be involved in transducing mechanical load. The ECM often contains aggrecan which allows the tendon to imbibe water and withstand compression. Type II collagen may also be present, particularly in tendons that are heavily loaded. Fibrocartilage is a dynamic tissue that disappears when the tendons are rerouted surgically and can be maintained in vitro when discs of tendon are compressed. Finite element analyses provide a good correlation between its distribution and levels of compressive stress, but at some locations fibrocartilage is a sign of pathology. Enthesis fibrocartilage is most typical of tendons or ligaments that attach to the epiphyses of long bones where it may also be accompanied by sesamoid and periosteal fibrocartilages. It is characteristic of sites where the angle of attachment changes throughout the range of joint movement and it reduces wear and tear by dissipating stress concentration at the bony interface. There is a good correlation between the distribution of fibrocartilage within an enthesis and the levels of compressive stress. The complex interlocking between calcified fibrocartilage and bone contributes to the mechanical strength of the enthesis and cartilage-like molecules (e.g. aggrecan and type II collagen) in the ECM contribute to its ability to withstand compression. Pathological changes are common and are known as enthesopathies. PMID:10029181

  6. [Repair of Achilles tendon rupture and early rehabilitation].

    PubMed

    Delgado-Brambila, H A; Cristiani, D G; Tinajero, E C; Burgos-Elías, V

    2012-01-01

    The frequency of Achilles tendon tear has increased worldwide. Several factors have been described that help explain the mechanism of injury. The treatment of choice continues to be surgery; conservative treatment is reserved for patients with a high morbidity and mortality. Surgical treatment consists of an open or percutaneous technique. In both modalities we try to achieve prompt mobilization of the operated tendon to obtain better and quicker healing. This prospective study describes our experience with 35 patients enrolled from February 2004 to August 2010. They were treated with open repair, physical rehabilitation and active ankle mobilization before the second postoperative week, and with colchicine. We obtained satisfactory results. Patients recovered complete mobility approximately at postoperative week 6, and from weeks 8 to 10 they could resume their daily work activities and participate in sports and recreational activities. Patients were assessed according to the ATRS classification to measure their clinical results. We had no infections or other major complications. We conclude that the open surgical repair of Achilles tendon tear, prompt mobility, and colchicine provide good results. PMID:23323299

  7. The basic science behind biologic augmentation of tendon-bone healing: a scientific review.

    PubMed

    Weeks, Kenneth D; Dines, Joshua S; Rodeo, Scott A; Bedi, Asheesh

    2014-01-01

    Rotator cuff tears are common musculoskeletal injuries that often require surgical repair. Despite advances in surgical techniques, including progression from a single row of anchors to double-row constructs, recurrent tearing or failure to heal still complicates 10% to 94% of repairs. The surgical treatment of rotator cuff tears is aimed at providing the best mechanical environment for tendon healing. Despite appropriate surgical management and a normal healing response, the resultant tendon healing does not regenerate the tendon-bone architecture initially formed during prenatal development. Instead, a mechanically weaker, fibrovascular scar is formed, leading to suboptimal healing rates and/or higher retear rates. Biologic augmentation strategies aim to improve healing rates by introducing higher concentrations of growth factors and cytokines, mesenchymal stem cells, and enzymatic antagonists to the repair site in the hope of directing a more sophisticated healing response. Biologic augmentation and tissue engineering to improve tendon-to-bone healing remains promising but will require more study before its clinical application is realized. PMID:24720329

  8. Tendon Driven Finger Actuation System

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Reich, David M. (Inventor); Bridgwater, Lyndon (Inventor); Linn, Douglas Martin (Inventor); Askew, Scott R. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Hargrave, Brian (Inventor); Valvo, Michael C. (Inventor); Abdallah, Muhammad E. (Inventor); Permenter, Frank Noble (Inventor); Mehling, Joshua S. (Inventor)

    2013-01-01

    A humanoid robot includes a robotic hand having at least one finger. An actuation system for the robotic finger includes an actuator assembly which is supported by the robot and is spaced apart from the finger. A tendon extends from the actuator assembly to the at least one finger and ends in a tendon terminator. The actuator assembly is operable to actuate the tendon to move the tendon terminator and, thus, the finger.

  9. Bilateral traumatic quadriceps tendon rupture

    Microsoft Academic Search

    C. Holm

    1999-01-01

    Summary  Bilateral quadriceps tendon rupture is a rare condition. In most cases the patients with bilateral quadriceps tendon rupture\\u000a have a general degenerative disease. This case story present a middle-aged male, who became a traumatic bilateral quadriceps\\u000a tendon rupture. Though treated acutely and trained intensively he did not achieve full range of motion.

  10. Flexor Tendon Injuries in Children

    Microsoft Academic Search

    A. O. GROBBELAAR; D. A. HUDSON

    1994-01-01

    Flexor tendon injuries in adults differ from those in children. 38 children (22 male and 16 female) with a mean age of 6.7 years were treated for flexor tendon injuries by primary suture and controlled mobilization between 1985 and 1992. 53 flexor tendons were injured (average 1.5 digits per patient) and the injury most commonly affected the little finger (23

  11. Arthroscopically assisted anterior cruciate ligament reconstruction with the pes anserine tendonsComparison of results in acute and chronic ligament deficiency

    Microsoft Academic Search

    Nicholas A. Sgaglione; Wilson Del Pizzo; James M. Fox; Mark J. Friedman

    1993-01-01

    Fifty anterior cruciate ligament-deficient knees treated consecutively with arthroscopically assisted recon struction using a pes anserine tendon autograft were retrospectively studied. The mean followup was 36.7 months (range, 26 to 58). All patients had reconstruc tion with a double-stranded graft. The mean injury to surgery interval was 9.6 days in 22 patients (acute group) and 22.5 months in 28 patients

  12. Transcriptomic analysis of mouse limb tendon cells during development.

    PubMed

    Havis, Emmanuelle; Bonnin, Marie-Ange; Olivera-Martinez, Isabel; Nazaret, Nicolas; Ruggiu, Mathilde; Weibel, Jennifer; Durand, Charles; Guerquin, Marie-Justine; Bonod-Bidaud, Christelle; Ruggiero, Florence; Schweitzer, Ronen; Duprez, Delphine

    2014-10-01

    The molecular signals driving tendon development are not fully identified. We have undertaken a transcriptome analysis of mouse limb tendon cells that were isolated at different stages of development based on scleraxis (Scx) expression. Microarray comparisons allowed us to establish a list of genes regulated in tendon cells during mouse limb development. Bioinformatics analysis of the tendon transcriptome showed that the two most strongly modified signalling pathways were TGF-? and MAPK. TGF-?/SMAD2/3 gain- and loss-of-function experiments in mouse limb explants and mesenchymal stem cells showed that TGF-? signalling was sufficient and required via SMAD2/3 to drive mouse mesodermal stem cells towards the tendon lineage ex vivo and in vitro. TGF-? was also sufficient for tendon gene expression in late limb explants during tendon differentiation. FGF does not have a tenogenic effect and the inhibition of the ERK MAPK signalling pathway was sufficient to activate Scx in mouse limb mesodermal progenitors and mesenchymal stem cells. PMID:25249460

  13. Molecular targets for tendon neoformation

    PubMed Central

    Aslan, Hadi; Kimelman-Bleich, Nadav; Pelled, Gadi; Gazit, Dan

    2008-01-01

    Tendons and ligaments are unique forms of connective tissue that are considered an integral part of the musculoskeletal system. The ultimate function of tendon is to connect muscles to bones and to conduct the forces generated by muscle contraction into movements of the joints, whereas ligaments connect bone to bone and provide joint stabilization. Unfortunately, the almost acellular and collagen I–rich structure of tendons and ligaments makes them very poorly regenerating tissues. Injured tendons and ligaments are considered a major clinical challenge in orthopedic and sports medicine. This Review discusses the several factors that might serve as molecular targets that upon activation can enhance or lead to tendon neoformation. PMID:18246194

  14. Long Head of the Biceps Pathology Combined with Rotator Cuff Tears

    PubMed Central

    Ditsios, Konstantinos; Agathangelidis, Filon; Boutsiadis, Achilleas; Karataglis, Dimitrios; Papadopoulos, Pericles

    2012-01-01

    The long head of the biceps tendon (LHBT) is an anatomic structure commonly involved in painful shoulder conditions as a result of trauma, degeneration, or overuse. Recent studies have pointed out the close correlation between LHBT lesions and rotator cuff (RCT) tears. Clinicians need to take into account the importance of the LHBT in the presence of other shoulder pathologies. This paper provides an up-to-date overview of recent publications on anatomy, pathophysiology, diagnosis, classification, and current treatment strategies. PMID:23209915

  15. Dacryocystorhynostomy (DCR) - Creating a New Tear Drain

    MedlinePLUS

    ... is a surgery performed to create a new tear drain between the eye and nose when your current tear drain becomes blocked or obstructed. What is the anatomy? The tear drain consists of two small openings called punctum ; ...

  16. Medial Versus Lateral Supraspinatus Tendon Properties: Implications for Double-Row Rotator Cuff Repair

    PubMed Central

    Wang, Vincent M.; Wang, FanChia; McNickle, Allison G.; Friel, Nicole A.; Yanke, Adam B.; Chubinskaya, Susan; Romeo, Anthony A.; Verma, Nikhil N.; Cole, Brian J.

    2013-01-01

    Background Rotator cuff repair re-tear rates range from 25-90% necessitating methods to improve repair strength. While numerous laboratory studies have compared single to double row fixation properties, little is known regarding regional (i.e., medial versus lateral) suture retention properties in both intact and torn tendons. Hypothesis A torn supraspinatus tendon will have reduced suture retention properties on the lateral aspect of the tendon compared to the more medial musculotendinous junction. Study Design Controlled Laboratory Study Methods Human supraspinatus tendons (torn and intact) were randomly assigned for suture retention mechanical testing, ultrastructural collagen fibril analysis, or histology following suture pullout testing. For biomechanical evaluation, sutures were placed either at the musculotendinous junction (medial) or 10 mm from the free margin (lateral), and tendons were elongated to failure. Collagen fibril assessments were performed using transmission electron microscopy (TEM). Results Intact tendons showed no regional differences with respect to suture retention properties. In contrast, among torn tendons the medial region exhibited significantly higher stiffness and work values relative to the lateral region. For the lateral region, work to 10 mm displacement (1592±261 N-mm) and maximum load (265±44 N) for intact tendons were significantly higher (p<0.05) than those of torn tendons (1086±388 N-mm and 177±71 N, respectively). For medial suture placement, maximum load, stiffness and work of intact and torn tendons were similar (p>0.05). Regression analyses for the intact and torn groups revealed generally low correlations between donor age and the three biomechanical indices. For both intact and torn tendons, the mean fibril diameter and area density were greater in the medial region relative to the lateral (p?0.05). In the lateral tendon, but not the medial region, torn specimens showed a significantly lower fibril area fraction (48.3±3.8%) than intact specimens (56.7±3.6%, p<0.05). Conclusions Superior pullout resistance of medial placed sutures may provide a strain shielding effect for the lateral row following double row repair. Larger diameter collagen fibrils as well as greater fibril area fraction in the medial supraspinatus tendon may provide greater resistance to suture migration. Clinical Relevance While clinical factors such as musculotendinous integrity warrant strong consideration for surgical decision making, the present ultrastructural and biomechanical results appear to provide a scientific rationale for double-row rotator cuff repair where sutures are placed more medial at the muscle tendon junction. PMID:20929937

  17. Tear-ducts in wine

    NASA Astrophysics Data System (ADS)

    Bush, John W. M.

    1999-11-01

    We examine the radial spoke pattern evident in the meniscus region in glasses of strong alcoholic beverages exhibiting the `tears-in-wine' phenomenon. We demonstrate that the pattern results from ridge-like elevations of the free surface which are supported by evaporatively-driven Marangoni convection in the meniscus region. Vortices associated with the convective motions are aligned in the radial direction by the surface tension gradient responsible for the generation of tears. The radial flow is focussed into the ridges, which thus serve as the principal conduits of fluid for the tears; consequently, we refer to the ridges as `tear-ducts'. The phenomenon is examined experimentally, and a numerical model of evaporatively-driven Marangoni convection is developed which reproduces the salient features of the tear-duct phenomenon.

  18. Role of Serum Fibrinogen Levels in Patients with Rotator Cuff Tears

    PubMed Central

    Longo, Umile Giuseppe; Petrillo, Stefano; Berton, Alessandra; Spiezia, Filippo; Loppini, Mattia; Maffulli, Nicola; Denaro, Vincenzo

    2014-01-01

    Although rotator cuff (RC) tendinopathy is a frequent pathology of the shoulder, the real understanding of its aetiopathogenesis is still unclear. Several studies showed that RC tendinopathy is more frequent in patients with hyperglycemia, diabetes, obesity, or metabolic syndrome. This paper aims to evaluate the serum concentration of fibrinogen in patients with RC tears. Metabolic disorders have been related to high concentration of serum fibrinogen and the activity of fibrinogen has been proven to be crucial in the development of microvascular damage. Thus, it may produce progression of RC degeneration by reducing the vascular supply of tendons. We report the results of a cross-sectional frequency-matched case-control study comparing the serum concentration of fibrinogen of patients with RC tears with that of a control group of patients without history of RC tears who underwent arthroscopic meniscectomy. We choose to enrol in the control group patients with pathology of the lower limb with a likely mechanic, not metabolic, cause, different from tendon pathology. We found no statistically significant differences in serum concentration of fibrinogen when comparing patients with RC tears and patients who underwent arthroscopic meniscectomy (P = 0.5). Further studies are necessary to clarify the role of fibrinogen in RC disease. PMID:24817887

  19. Parameters influencing prevalence and outcome of tendonitis in Thoroughbred and Arabian racehorses.

    PubMed

    Kalisiak, O

    2012-01-01

    Flexor tendonitis and suspensory desmitis are among most prevalent musculoskeletal injuries observed in racehorses. The aim of this study was to determine which horse and race-related parameters can help to diminish the possibility of injury or--when injury has occurred--to evaluate the potential for the horse to continue a successful career after convalescence. Special attention was given to the comparison of Arabian and Thoroughbred racehorses. 187 horses with ultrasonographically visible lesions were included in the study. Following parameters were analyzed: structure (Superficial Digital Flexor Tendon [SDFT], Deep Digital Flexor Tendon [DDFT], Suspensory Ligament [SL]); percentage of cross sectional area increase; hypoechogenic lesion character; in horses with SDF tendonitis - tendonitis grade according to Genovese. This study showed that Thoroughbreds are more at risk of musculoskeletal problems than Arabian racehorses. In both breeds, the most frequent injuries concern SDFT, then SL. Over 95% of tendonitis concern forelimbs. In Thoroughbreds, the prevalence of tendonitis is higher in bigger horses, in males when compared to females and in fence/steeple racehorses when compared to flat track racehorses. The inside limb is more at risk of SDF tendonitis, when the external limb - of SL desmitis. Tendonitis severity increases with age and is greater in steeplechasers when compared to flat track racehorses. The outcome of tendonitis without hypoechogenic lesion is much better than that with hypoechogenic lesion. Evaluation of hypoechogenic lesion length is an easy and accurate prognosis tool, as the chances of returning to racing drop dramatically with lesions longer than 12 cm. PMID:22708365

  20. NIMROD Simulations of Classical Tearing Modes

    NASA Astrophysics Data System (ADS)

    Kruger, S. E.; Schnack, D. D.

    2002-11-01

    Neoclassical tearing modes have received significant interest in the experimental and theoretical communities because they significantly limit the performance of long-pulse plasma discharges. Many theoretical and experimental questions remain, one of which is the role of the ?' parameter, first introduced in the study of classical tearing modes. To isolate the effects of this parameter experimentally, recent experiments(M.S. Chu and R.J. LaHaye - private communication) that produce tearing modes have been performed in low pressure, Ohmic discharge on the DIII-D tokamak. Using a recent experiment with modern diagnostics and accurate equilibrium reconstruction provides an excellent opportunity for accurate comparison of theory with experiment. Preliminary NIMROD modeling of this experiment based on EFIT equilibrium show that a vacuum region is needed to model this experiment. Because NIMROD is a nonlinear, initial-value code which must allow for a moving separatrix, NIMROD models the ``vacuum'' region as a cold, highly-resistive plasma. Here, we present results from NIMROD's modeling of this experimental discharge using a three-dimensional resistivity which varies with time.

  1. Scaffolds in Tendon Tissue Engineering

    PubMed Central

    Longo, Umile Giuseppe; Lamberti, Alfredo; Petrillo, Stefano; Maffulli, Nicola; Denaro, Vincenzo

    2012-01-01

    Tissue engineering techniques using novel scaffold materials offer potential alternatives for managing tendon disorders. Tissue engineering strategies to improve tendon repair healing include the use of scaffolds, growth factors, cell seeding, or a combination of these approaches. Scaffolds have been the most common strategy investigated to date. Available scaffolds for tendon repair include both biological scaffolds, obtained from mammalian tissues, and synthetic scaffolds, manufactured from chemical compounds. Preliminary studies support the idea that scaffolds can provide an alternative for tendon augmentation with an enormous therapeutic potential. However, available data are lacking to allow definitive conclusion on the use of scaffolds for tendon augmentation. We review the current basic science and clinical understanding in the field of scaffolds and tissue engineering for tendon repair. PMID:22190961

  2. High-intensity focused ultrasound ablation of ex vivo bovine achilles tendon.

    PubMed

    Muratore, Robert; Akabas, Tal; Muratore, Isabella B

    2008-12-01

    Small tears in tendons are a common occurrence in athletes and others involved in strenuous physical activity. Natural healing in damaged tendons can result in disordered regrowth of the underlying collagen matrix of the tendon. These disordered regions are weaker than surrounding ordered regions of normal tendon and are prone to re-injury. Multiple cycles of injury and repair can lead to chronic tendinosis. Current treatment options either are invasive or are relatively ineffective in tendinosis without calcifications. High-intensity focused ultrasound (HIFU) has the potential to treat tendinosis noninvasively. HIFU ablation of tendons is based on a currently-used surgical analog, viz., needle tenotomy. This study tested the ability of HIFU beams to ablate bovine tendons ex vivo. Two ex vivo animal models were employed: a bare bovine Achilles tendon (deep digital flexor) on an acoustically absorbent rubber pad, and a layered model (chicken breast proximal, bovine Achilles tendon central and a glass plate distal to the transducer). The bare-tendon model enables examination of lesion formation under simple, ideal conditions; the layered model enables detection of possible damage to intervening soft tissue and consideration of the possibly confounding effects of distal bone. In both models, the tissues were degassed in normal phosphate-buffered saline. The bare tendon was brought to 23 degrees C or 37 degrees C before insonification; the layered model was brought to 37 degrees C before insonification. The annular array therapy transducer had an outer diameter of 33 mm, a focal length of 35 mm and a 14-mm diameter central hole to admit a confocal diagnostic transducer. The therapy transducer was excited with a continuous sinusoidal wave at 5.25 MHz to produce nominal in situ intensities from 0.23-2.6 kW/cm(2). Insonification times varied from 2-10 s. The focus was set over the range from the proximal tendon surface to 7 mm deep. The angle of incidence ranged from 0 degrees (normal to the tissue surface) to 15 degrees . After insonification, tendons were dissected and photographed, and the dimensions of the lesions were measured. Transmission electron micrographs were obtained from treated and untreated tissue regions. Insonification produced lesions that mimicked the shape of the focal region. When lesions were produced below the proximal tendon surface, no apparent damage to overlying soft tissue was apparent. The low intensities and short durations required for consistent lesion formation, and the relative insensitivity of ablation to small variations in the angle of incidence, highlight the potential of HIFU as a noninvasive treatment option for chronic tendinosis. PMID:18692293

  3. Tear Lipocalin: Structure and Function

    PubMed Central

    Dartt, Darlene A.

    2014-01-01

    Lipocalins are a family of diverse low molecular weight proteins that act extracellularly. They use multiple recognition properties that include: 1) ligand binding to small hydrophobic molecules, 2) macromolecular complexation with other soluble macromolecules, and 3) binding to specific cell surface receptors to deliver cargo. Tear lipocalin (TLC) is a major protein in tears and has a large ligand binding cavity that allows the lipocalin to bind an extensive and diverse set of lipophilic molecules. TLC can also bind to macromolecules including the tear proteins lactoferin and lysozyme. The receptor to which TLC binds is termed tear lipocalin interacting membrane receptor (LIMR). LIMR appears to work by endocytosis. TLC has a variety of suggested functions in tears including regulation of tear viscosity, binding and release of lipids, endonuclease inactivation of viral DNA, binding of microbial siderophores (iron chelators used to deliver essential iron to bacteria), use as a biomarker for dry eye, and possession of anti-inflammatory activity. Additional research is warranted to determine the actual functions of TLC in tears and the presence of its receptor on the ocular surface. PMID:21791187

  4. Chronic retinal detachment and giant retinal tears in 34 dogs: Outcome comparison of no treatment, topical medical therapy, and retinal reattachment after vitrectomy

    PubMed Central

    Grahn, Bruce H.; Barnes, Laura D.; Breaux, Carrie B.; Sandmeyer, Lynne S.

    2007-01-01

    The outcomes of dog’s eyes with chronic (>1 month) retinal detachment and giant retinal tears without therapy were compared with those treated with topical steroids and antiglaucoma medications, and with those that received a vitrectomy, retinal reattachment, endolaser therapy, and silicone oil tamponade. Fourteen of 16 eyes that did not receive therapy developed uveitis and secondary glaucoma, and were enucleated (4) or eviscerated (6); and 2 dogs were euthanized due to blindness and uveitis. Two eyes in 2 dogs remain without treatment, 1 and 3 years later. Fifteen of 19 eyes that received topical therapy developed nonresponsive uveitis and secondary glaucoma, and were enucleated (4) or eviscerated (9), 1 dog that was affected bilaterally was euthanized; and 3 eyes remain on topical anti-inflammatory therapy and the medication has been discontinued on 1 eye. Four of 6 eyes surgically reattached remain without clinical manifestations of uveitis and secondary glaucoma and 3 of these eyes have functional vision. Light microscopic observations completed on failed globes in the 3 groups were similar. PMID:17987965

  5. Achilles tendon injuries in athletes.

    PubMed

    Kvist, M

    1994-09-01

    Two-thirds of Achilles tendon injuries in competitive athletes are paratenonitis and one-fifth are insertional complaints (bursitis and insertion tendinitis). The remaining afflictions consist of pain syndromes of the myotendineal junction and tendinopathies. The majority of Achilles tendon injuries from sport occur in males, mainly because of their higher rates of participation in sport, but also with tendinopathies a gender difference is probably indicated. Athletes in running sports have a high incidence of Achilles tendon overuse injuries. About 75% of total and the majority of partial tendon ruptures are related to sports activities usually involving abrupt repetitive jumping and sprinting movements. Mechanical factors and a sedentary lifestyle play a role in the pathology of these injuries. Achilles tendon overuse injuries occur at a higher rate in older athletes than most other typical overuse injuries. Recreational athletes with a complete Achilles tendon rupture are about 15 years younger than those with other spontaneous tendon ruptures. Following surgery, about 70 to 90% of athletes have a successful comeback after Achilles tendon injury. Surgery is required in about 25% of athletes with Achilles tendon overuse injuries and the frequency of surgery increases with patient age and duration of symptoms as well as occurrence of tendinopathic changes. However, about 20% of injured athletes require a re-operation for Achilles tendon overuse injuries, and about 3 to 5% are compelled to abandon their sports career because of these injuries. Myotendineal junction pain should be treated conservatively. Partial Achilles tendon ruptures are primarily treated conservatively, although the best treatment method of chronic partial rupture seems to be surgery. Complete Achilles tendon ruptures of athletes are treated surgically, because this increases the likelihood of athletes reaching preinjury activity levels and minimises the risk of re-ruptures. Marked forefoot varus is found in athletes with Achilles tendon overuse injuries, reflecting the predisposing role of ankle joint overpronation. Athletes with the major stress in lower extremities have often a limited range of motion in the passive dorsiflexion of the ankle joint and total subtalar joint mobility, which seems to be predisposing factor for these injuries. Various predisposing transient factors are found in about one-third of athletes with Achilles tendon overuse injuries; of these, traumatic factors (mostly minor injuries) predominate. The typical histological features of chronically inflamed paratendineal tissue of the Achilles tendon are profound proliferation of loose, immature connective tissue and marked obliterative and degenerative alterations in the blood vessels. These changes cause continuing leakage of plasma proteins, which may have an important role in the pathophysiology of these injuries. The chronically inflamed paratendineal tissues of the Achilles tendon do not seem to have enough capacity to form mature connective tissue. PMID:7809555

  6. Correlation of acromial morphology with impingement syndrome and rotator cuff tears

    PubMed Central

    2013-01-01

    Background and purpose Indications for acromioplasty are based on clinical symptoms and are generally supported by typical changes in acromial morphology on standard radiographs. We evaluated 5 commonly used radiographic parameters of acromial morphology and assessed the association between different radiographic characteristics on the one hand and subacromial impingement or rotator cuff tears on the other. Patients and methods We measured acromial type (Bigliani), acromial slope (AS), acromial tilt (AT), lateral acromial angle (LAA), and acromion index (AI) on standard radiographs from 50 patients with full-thickness supraspinatus tendon tears, 50 patients with subacromial impingement, and 50 controls without subacromial pathology. Results The acromial type according to Bigliani was not associated with any particular cuff lesion. A statistically significant difference between controls and impingement patients was found for AS. AT of controls was significantly smaller than that of impingement patients and cuff-tear patients. LAA of cuff-tear patients differed significantly from that of controls and impingement patients, but LAA of controls was not significantly different from that of impingement patients. Differences between impingement patients and cuff-tear patients were also significant. AI of controls was significantly lower than of impingement patients and of cuff-tear patients. A good correlation was found between acromial type and AS. Interpretation A low lateral acromial angle and a large lateral extension of the acromion were associated with a higher prevalence of impingement and rotator cuff tears. An extremely hooked anterior acromion with a slope of more than 43° and an LAA of less than 70° only occurred in patients with rotator cuff tears. PMID:23409811

  7. Suture-bridge subscapularis tendon repair technique using low anterior portals.

    PubMed

    Park, Jin-Young; Park, Jun-Suk; Jung, Jae-Kyung; Kumar, Praveen; Oh, Kyung-Soo

    2011-02-01

    A suture-bridge technique has been introduced to facilitate fixation procedures and to achieve increased holding strength in posterosuperior rotator cuff. Based on biomechanical studies, this technique has been suggested as an effective method that could optimize rotator cuff tendon-footprint contact area and mean pressure, as well as holding strength. In this technique, the suture-bridge creation is adapted for arthroscopic subscapularis repair to attain the ideal cuff integrity and footprint restoration. To obtain enough working portals and space, two accessory portals were made on the anterior aspect of the shoulder and use an elevator to retract the conjoined tendons and deltoid muscle. This technique could be useful for the repair of subscapularis tears, which are not easily approached using other arthroscopic techniques. From a biomechanical point of view, the subscapularis tendon could be restored more ideally using the suture-bridge technique. PMID:20890701

  8. Rat rotator cuff muscle responds differently from hindlimb muscle to a combined tendon-nerve injury.

    PubMed

    Davies, Michael R; Ravishankar, Bharat; Laron, Dominique; Kim, Hubert T; Liu, Xuhui; Feeley, Brian T

    2015-07-01

    Rotator cuff tears (RCTs) are among the most common musculoskeletal injuries seen by orthopaedic surgeons. Clinically, massive cuff tears lead to unique pathophysiological changes in rotator cuff muscle, including atrophy, and massive fatty infiltration, which are rarely seen in other skeletal muscles. Studies in a rodent model for RCT have demonstrated that these histologic findings are accompanied by activation of the Akt/mammalian target of rapamycin (mTOR) and transforming growth factor-? (TGF-?) pathways following combined tendon-nerve injury. The purpose of this study was to compare the histologic and molecular features of rotator cuff muscle and gastrocnemius muscle-a major hindlimb muscle, following combined tendon-nerve injury. Six weeks after injury, the rat gastrocnemius did not exhibit notable fatty infiltration compared to the rotator cuff. Likewise, the adipogenic markers SREBP-1 and PPAR? as well as the TGF-? canonical pathway were upregulated in the rotator cuff, but not the gastrocnemius. Our study suggests that the rat rotator cuff and hindlimb muscles differ significantly in their response to a combined tendon-nerve injury. Clinically, these findings highlight the unique response of the rotator cuff to injury, and may begin to explain the poor outcomes of massive RCTs compared to other muscle-tendon injuries. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1046-1053, 2015. PMID:25974842

  9. Comparison of Achilles Tendon Repair Techniques in a Sheep Model Using a Cross-linked Acellular Porcine Dermal Patch and Platelet-rich Plasma Fibrin Matrix for Augmentation

    Microsoft Academic Search

    Tiffany L. Sarrafian; Hali Wang; Eileen S. Hackett; Jian Q. Yao; Mei-Shu Shih; Heather L. Ramsay; A. Simon Turner

    2010-01-01

    The primary goal of this study was to evaluate a cross-linked acellular porcine dermal patch (APD), as well as platelet-rich plasma fibrin matrix (PRPFM), for repair of acute Achilles tendon rupture in a sheep model. The 2 surgically transected tendon ends were reapproximated in groups 1 and 2, whereas a gap was left between the tendon ends in group 3. APD

  10. Outcomes following quadriceps tendon ruptures

    Microsoft Academic Search

    K O'Shea; P Kenny; J Donovan; F Condon; J. P McElwain

    2002-01-01

    Complete rupture of the quadriceps femoris tendon is a well-described injury. There is a scarcity of literature relating to the outcome of patients with this injury after surgery. We undertook a retrospective analysis of patients who had surgical repair of their ruptured quadriceps tendon at our institution over a seven year period-totalling 27 patients. Males were more commonly affected with

  11. Magnetic resonance imaging in acute tendon ruptures

    Microsoft Academic Search

    Richard H. Daffner; Barry L. Riemer; Anthony R. Lupetin; Nilima Dash

    1986-01-01

    The diagnosis of acute tendon ruptures of the extensor mechanism of the knee or the Achilles tendon of the ankle may usually be made by clinical means. Massive soft tissue swelling accompanying these injuries often obscures the findings, however. Magnetic resonance imaging (MRI) can rapidly demonstrate these tendon ruptures. Examples of the use of MRI for quadriceps tendon, and Achilles

  12. Synovial chondromatosis in the quadriceps tendon

    Microsoft Academic Search

    Jeong-Ki Choi; Jae-Hoon Jeong; Chun-Taek Lee; Sung-Jae Kim

    2003-01-01

    We present a case of synovial chondromatosis originating from the quadriceps tendon sheath, which caused a complete quadriceps tendon rupture. The patient was treated using marginal excision. The ruptured quadriceps tendon was repaired. This is the first description of a quadriceps tendon rupture associated with synovial chondromatosis.

  13. Achilles Tendon Rupture

    PubMed Central

    Wertz, Jess; Galli, Melissa; Borchers, James R.

    2013-01-01

    Context: Achilles tendon (AT) rupture in athletes is increasing in incidence and accounts for one of the most devastating sports injuries because of the threat to alter or end a career. Despite the magnitude of this injury, reliable risk assessment has not been clearly defined, and prevention strategies have been limited. The purpose of this review is to identify potential intrinsic and extrinsic risk factors for AT rupture in aerial and ground athletes stated in the current literature. Evidence Acquisition: A MEDLINE search was conducted on AT rupture, or “injury” and “risk factors” and “athletes” from 1980 to 2011. Emphasis was placed on epidemiology, etiology, and review articles focusing on the risk for lower extremity injury in runners and gymnasts. Thirty articles were reviewed, and 22 were included in this assessment. Results: Aerial and ground athletes share many intrinsic risk factors for AT rupture, including overuse and degeneration of the tendon as well as anatomical variations that mechanically put an athlete at risk. Older athletes, athletes atypical in size for their sport, high tensile loads, leg dominance, and fatigue also may increase risk. Aerial athletes tend to have more extrinsic factors that play a role in this injury due to the varying landing surfaces from heights and technical maneuvers performed at various skill levels. Conclusion: Risk assessment for AT rupture in aerial and ground athletes is multivariable and difficult in terms of developing prevention strategies. Quantitative measures of individual risk factors may help identify major contributors to injury. PMID:24427410

  14. Epidemiology of the rotator cuff tears: a new incidence related to thyroid disease

    PubMed Central

    Oliva, Francesco; Osti, Leonardo; Padulo, Johnny; Maffulli, Nicola

    2014-01-01

    Summary Background: in the last years the incidence of rotator cuff tears increased and one main cause still waiting to be clarified. Receptors for thyroid hormones in rotator cuff tendons suggest possible effects on tendons metabolism and status. We undertook a retrospective, observational cohort study of 441 patients who underwent arthroscopic and mini-open repair for non traumatic degenerative rotator cuff tears. Methods: all the patients, predominantly females (63%), were interview to assess the relationship (frequency for class age “20 yrs” and factor analysis) between lesions of the rotator cuff with the following variables: gender, thyroid disease, smoker, taking medications for diabetes, hypertension or high cholesterol; presence of associated conditions (diabetes, hypertension, hypercholesterolemia). Results: thyroid disease is highly frequently (until 63% for 60<80 yrs) in females group independent to the age. Conversely, males showed a high frequency for smoker 37<62% until 80 yrs and 50% hypercholesterolemia over 80 yrs for the clinical variable studied. Conclusions: this is the first clinical report that shown a relationship between thyroid pathologies and non-traumatic rotator cuff tear as increased risk factors. PMID:25489548

  15. Single-Versus Double-Row Arthroscopic Rotator Cuff Repair in Massive Tears

    PubMed Central

    Wang, EnZhi; Wang, Liang; Gao, Peng; Li, ZhongJi; Zhou, Xiao; Wang, SongGang

    2015-01-01

    Background It is a challenge for orthopaedic surgeons to treat massive rotator cuff tears. The optimal management of massive rotator cuff tears remains controversial. Therefore, the goal of this study was to compare arthroscopic single- versus double-row rotator cuff repair with a larger sample size. Material/Methods Of the subjects with massive rotator cuff tears, 146 were treated using single-row repair, and 102 were treated using double-row repair. Pre- and postoperative functional outcomes and radiographic images were collected. The clinical outcomes were evaluated for a minimum of 2 years. Results No significant differences were shown between the groups in terms of functional outcomes. Regarding the integrity of the tendon, a lower rate of post-treatment retear was observed in patients who underwent double-row repair compared with single-row repair. Conclusions The results suggest that double-row repair is relatively superior in shoulder ROM and the strength of tendon compared with single-row repair. Future studies involving more patients in better-designed randomized controlled trials will be required. PMID:26017641

  16. Connecting muscles to tendons: tendons and musculoskeletal development in flies and vertebrates

    E-print Network

    Connecting muscles to tendons: tendons and musculoskeletal development in flies and vertebrates of the musculoskeletal system represents an intricate process of tissue assembly involving heterotypic inductive interactions between tendons, muscles and cartilage. An essential component of all musculoskeletal systems

  17. Congenital Aberrant Tearing: A Re-Look

    PubMed Central

    Miller, Marilyn T.; Strömland, Kerstin; Ventura, Liana

    2008-01-01

    Purpose Congenital aberrant tearing is characterized by tearing when eating (“crocodile tears”), lack of emotional tearing, or both. Most reported cases are associated with Duane syndrome. In our previous studies we observed aberrant tearing in individuals with thalidomide embryopathy and Möbius sequence. This report summarizes the literature on the subject and adds 3 new studies that give information on this unusual condition. Methods Twenty-eight individuals with Möbius sequence were interviewed about tearing symptoms at a support group meeting in Italy. In Sweden 30 adults primarily from the original thalidomide series were reexamined. In this latter study, a Schirmer test was done at baseline and repeated 5 minutes after eating. Twenty families in Brazil who have children with Möbius sequence were questioned about tearing symptoms and exposure to misoprostol during pregnancy. Results In the 28 Italian individuals, either “crocodile tears” or lack of emotional tearing was noted in 7 cases. In the thalidomide study, 10 of 30 patients had tearing when eating and 7 had no emotional tearing. Low Schirmer scores or increased tearing after eating was noted in a few asymptomatic individuals. Among the 20 Brazilian children with Möbius sequence, 10 had some tearing abnormality. Conclusion Congenital anomalous lacrimation is rare but usually associated with Duane syndrome or abduction deficits, as in Möbius sequence and, less frequently, facial nerve palsy. Studies implicate an early insult in development at 4 to 6 weeks. At that time the facial nerve, sixth nerve, and lacrimal nucleus are in close proximity in the embryo. PMID:19277226

  18. Wear and Tear - Mechanical

    NASA Technical Reports Server (NTRS)

    Swanson, Theodore

    2008-01-01

    The focus of this chapter is on the long term wear and tear, or aging, of the mechanical subsystem of a spacecraft. The mechanical subsystem is herein considered to be the primary support structure (as in a skeleton or exoskeleton) upon which all other spacecraft systems rest, and the associated mechanisms. Mechanisms are devices which have some component that moves at least once, in response to some type of passive or active control system. For the structure, aging may proceed as a gradual degradation of mechanical properties and/or function, possibly leading to complete structural failure over an extended period of time. However, over the 50 years of the Space Age such failures appear to be unusual. In contrast, failures for mechanisms are much more frequent and may have a very serious effect on mission performance. Just as on Earth, all moving devices are subject to normal (and possibly accelerated) degradation from mechanical wear due to loss or breakdown of lubricant, misalignment, temperature cycling effects, improper design/selection of materials, fatigue, and a variety of other effects. In space, such environmental factors as severe temperature swings (possibly 100's of degrees C while going in and out of direct solar exposure), hard vacuum, micrometeoroids, wear from operation in a dusty or contaminated environment, and materials degradation from radiation can be much worse. In addition, there are some ground handling issues such as humidity, long term storage, and ground transport which may be of concern. This chapter addresses the elements of the mechanical subsystem subject to wear, and identifies possible causes. The potential impact of such degradation is addressed, albeit with the recognition that the impact of such wear often depends on when it occurs and on what specific components. Most structural elements of the mechanical system typically are conservatively designed (often to a safety factor of greater than approximately 1.25 on yield for unmanned spacecraft) but do not have backup structure due to the added mass this would impose, and also due to the fact that structural elements can be accurately modeled mathematically and in test. Critical mechanisms or devices may have backups, or alternate work-arounds, since characterization of these systems in a 1g environment is less accurate than structure, and repair in-space is often impossible.

  19. Traumatic bilateral quadriceps tendon rupture

    Microsoft Academic Search

    Lars Hansen; Søren Larsen; Troels Laulund

    2001-01-01

    Bilateral spontaneous quadriceps tendon rupture is a very rare event, with only an estimated 40 cases reported in the literature.\\u000a We report a case of bilateral spontaneous quadriceps tendon rupture and review the literature. The reviewed literature recommends\\u000a early repair; therefore, early diagnosis is crucial. Reportedly, up to 50% of spontaneous bilateral quadriceps ruptures are\\u000a misdiagnosed at first, resulting in

  20. Efficacy of a mesenchymal stem cell loaded surgical mesh for tendon repair in rats

    PubMed Central

    2014-01-01

    Objectives The purpose of this study was to investigate the efficacy of a composite surgical mesh for delivery of mesenchymal stem cells (MSCs) in tendon repair. Methods The MSC-loaded mesh composed of a piece of conventional surgical mesh and a layer of scaffold, which supported MSC-embedded alginate gel. A 3-mm defect was surgically created at the Achilles tendon-gastrocnemius/soleus junction in 30 rats. The tendon defects were repaired with either 1) MSC-loaded mesh; or 2) surgical mesh only; or 3) routine surgical suture. Repaired tendons were harvested at days 6 and 14 for histology, which was scored on the bases of collagen organization, vascularity and cellularity, and immunohistochemisty of types I and III collagen. Results In comparison with the other two repair types, at day 6, the MSC-loaded mesh significantly improved the quality of the repaired tendons with dense and parallel collagen bundles, reduced vascularity and increased type I collagen. At day 14, the MSC-loaded mesh repaired tendons had better collagen formation and organization. Conclusion The MSC-loaded mesh enhanced early tendon healing, particularly the quality of collagen bundles. Application of the MSC-loaded mesh, as a new device and MSC delivery vehicle, may benefit to early functional recovery of the ruptured tendon. PMID:24884819

  1. Proximal coracobrachialis tendon rupture, subscapularis tendon rupture, and medial dislocation of the long head of the biceps tendon in an adult after traumatic anterior shoulder dislocation

    PubMed Central

    Saltzman, Bryan M.; Harris, Joshua D.; Forsythe, Brian

    2015-01-01

    Rupture of the coracobrachialis is a rare entity, in isolation or in combination with other muscular or tendinous structures. When described, it is often a result of direct trauma to the anatomic area resulting in rupture of the muscle belly. The authors present a case of a 57-year-old female who suffered a proximal coracobrachialis tendon rupture from its origin at the coracoid process, with concomitant subscapularis tear and medial dislocation of the long head of biceps tendon after first time traumatic anterior shoulder dislocation. Two weeks after injury, magnetic resonance imaging suggested the diagnosis, which was confirmed during combined arthroscopic and open technique. Soft-tissue tenodesis of coracobrachialis to the intact short head of the biceps, tenodesis of the long head of biceps to the intertubercular groove, and double-row anatomic repair of the subscapularis were performed. The patient did well postoperatively, and ultimately at 6 months follow-up, she was without pain, and obtained 160° of active forward elevation, 45° of external rotation, internal rotation to T8, 5/5 subscapularis and biceps strength. Scoring scales had improved from the following preoperative to final follow-up: American Shoulder and Elbow Surgeons, 53.33-98.33; constant, 10-100; visual analogue scale-pain, 4-0. DASH score was 5. PMID:25937715

  2. Finite Element Model of Subsynovial Connective Tissue Deformation due to Tendon Excursion in the Human Carpal Tunnel

    PubMed Central

    Henderson, Jacqueline; Thoreson, Andrew; Yoshii, Yuichi; Zhao, Kristin D.; Amadio, Peter C.; An, Kai-Nan

    2010-01-01

    Carpal Tunnel Syndrome (CTS) is a nerve entrapment disease which has been extensively studied by the engineering and medical community. Although the direct cause is unknown, in vivo and in vitro medical research has shown that tendon excursion creates micro tears in the subsynovial connective tissue (SSCT) surrounding the tendon in the carpal tunnel. One proposed mechanism for the SSCT injury is shearing which is believed to cause fibrosis of the SSCT. Few studies have reported quantitative observations of SSCT response to mechanical loading. Our proposed model is a 2-D section that consists of an FDS tendon, interstitial SSCT and adjacent stationary tendons. We believe that developing this model will allow the most complete quantitative observations of SSCT response to mechanical loading reported thus far. Boundary conditions were applied to the FEA model to simulate single finger flexion. A velocity was applied to the FDS tendon in the model to match loading conditions of the documented cadaver wrist kinematics studies. The cadaveric and FEA displacement results were compared to investigate the magnitude of stiffness required for the SSCT section of the model. The relative motions between the model and cadavers matched more closely than the absolute displacements. Since cadaveric models do not allow identification of the SSCT layers, an FEA model will help determine the displacement and stress experienced by each SSCT layer. Thus, we believe this conceptual model is a first step in understanding how the SSCT layers are recruited during tendon excursion. PMID:20887993

  3. Botulinum toxin is detrimental to repair of a chronic rotator cuff tear in a rabbit model.

    PubMed

    Gilotra, Mohit; Nguyen, Thao; Christian, Matthew; Davis, Derik; Henn, R Frank; Hasan, Syed Ashfaq

    2015-08-01

    Re-tear continues to be a problem after rotator cuff repair. Intramuscular botulinum toxin (Botox) injection can help optimize tension at the repair site to promote healing but could have an adverse effect on the degenerated muscle in a chronic tear. We hypothesized that Botox injection would improve repair characteristics without adverse effect on the muscle in a chronic rotator cuff tear model. The supraspinatus tendon of both shoulders in 14 rabbits underwent delayed repair 12 weeks after transection. One shoulder was treated with intramuscular Botox injection and the other with a saline control injection. Six weeks after repair, outcomes were based on biomechanics, histology, and magnetic resonance imaging. Botox-treated repairs were significantly weaker (2.64?N) than control repairs (5.51?N, p?=?0.03). Eighty percent of Botox-treated repairs and 40% of control repairs healed with some partial defect. Fatty infiltration of the supraspinatus was present in all shoulders (Goutallier Grade 3 or 4) but was increased in the setting of Botox. This study provides additional support for the rabbit supraspinatus model of chronic cuff tear, showing consistent fatty infiltration. Contrary to our hypothesis, Botox had a negative effect on repair strength and might increase fatty infiltration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1152-1157, 2015. PMID:25626677

  4. ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING PATELLAR TENDON AND QUADRICEPS TENDON: A COMPARATIVE STUDY

    Microsoft Academic Search

    Nasser Sarrafan; Seyed Abdolhossein Mehdinasab

    Objective: The goal of this study was to compare the results of knee anterior cruciate ligament reconstruction with the use of patellar tendon and quadriceps tendon. Methodology: In this study 30 patients with rupture of anterior cruciate ligament of knee were compared in two 15-person group with the use of patellar tendon and quadriceps tendon. After precise rehabilitation program for

  5. Reduced Tear Meniscus Dynamics in Dry Eye Patients with Aqueous Tear Deficiency

    PubMed Central

    Yuan, Yimin; Wang, Jianhua; Chen, Qi; Tao, Aizhu; Shen, Meixiao; Shousha, Mohamed Abou

    2010-01-01

    PURPOSE To measure the tear meniscus dynamics in aqueous tear deficiency dry eye patients using optical coherence tomography (OCT). DESIGN Clinical research study of a laboratory technique. METHODS Twenty-five aqueous tear deficiency dry eye patients and thirty healthy subjects were recruited. Upper and lower tear menisci of one randomly selected eye of each participant were imaged during normal and delayed blinking using OCT. Measured parameters included upper tear meniscus height and volume, lower tear meniscus height and volume, the blink outcome defined as the meniscus volume change during blink action, and open eye outcome defined as the meniscus volume change during open eye period. RESULTS During normal blinking, both tear meniscus height and volume before blink in dry eye patients were significantly smaller than those in healthy subjects, except for the upper tear meniscus volume. During normal blinking, the blink outcome and open eye outcome of lower tear meniscus were significantly smaller in dry eye patients compared to healthy subjects. During delayed blinking, the upper and lower tear menisci heights and volumes significantly increased in both groups. However, dry eye patients had smaller increases than healthy subjects. During delayed blinking, the open eye outcomes of upper and lower tear menisci were smaller in dry eye patients than healthy subjects. CONCLUSIONS Dry eye patients appeared to have reduced tear meniscus dynamics during normal blinking and smaller increases of meniscus volume during delayed blinking. Analysis of tear meniscus dynamics may provide more insight in the altered tear system in dry eye patients. PMID:20378096

  6. Prediction of the elastic strain limit of tendons.

    PubMed

    Reyes, A M; Jahr, H; van Schie, H T M; Weinans, H; Zadpoor, A A

    2014-02-01

    The elastic strain limit (ESL) of tendons is the point where maximum elastic modulus is reached, after which micro-damage starts. Study of damage progression in tendons under repetitive (fatigue) loading requires a priori knowledge about ESL. In this study, we propose three different approaches for predicting ESL. First, one single value is assumed to represent the ESL of all tendon specimens. Second, different extrapolation curves are used for extrapolating the initial part of the stress-strain curve. Third, a method based on comparing the shape of the initial part of the stress-strain curve of specimens with a database of stress-strain curves is used. A large number of porcine tendon explants (97) were tested to examine the above-mentioned approaches. The variants of the third approach yielded significantly (p<0.05) smaller error values as compared to the other approaches. The mean absolute percentage error of the best-performing variant of the shape-based comparison was between 8.14±6.44% and 9.96±9.99% depending on the size of the initial part of the stress-strain curves. Interspecies generalizability of the best performing method was also studied by applying it for prediction of the ESL of horse tendons. The ESL of horse tendons was predicted with mean absolute percentage errors ranging between 10.53±7.6% and 19.16±14.31% depending on the size of the initial part of the stress-strain curves and the type of normalization. The results of this study suggest that both ESL and the shape of stress-strain curves may be highly different between different individuals and different anatomical locations. PMID:24362243

  7. Patella baja following chronic quadriceps tendon rupture

    Microsoft Academic Search

    Michael Hockings; John C. Cameron

    2004-01-01

    Patella baja is a complication of chronic quadriceps tendon rupture. In this case we present the treatment of this problem by the proximal transfer of the tibial tubercle allowing an environment in which the quadriceps tendon can heal.

  8. Common Disorders of the Achilles Tendon

    MedlinePLUS

    ... leg and connects the calf muscle to the heel bone. Also called the “heel cord,” the Achilles tendon facilitates walking by helping to raise the heel off the ground. Achilles Tendonitis and Achilles Tendonosis ...

  9. Achilles tendon rupture rehabilitation

    PubMed Central

    Kearney, R. S.; Parsons, N.; Underwood, M.; Costa, M. L.

    2015-01-01

    Objectives The evidence base to inform the management of Achilles tendon rupture is sparse. The objectives of this research were to establish what current practice is in the United Kingdom and explore clinicians’ views on proposed further research in this area. This study was registered with the ISRCTN (ISRCTN68273773) as part of a larger programme of research. Methods We report an online survey of current practice in the United Kingdom, approved by the British Orthopaedic Foot and Ankle Society and completed by 181 of its members. A total of ten of these respondents were invited for a subsequent one-to-one interview to explore clinician views on proposed further research in this area. Results The survey showed wide variations in practice, with patients being managed in plaster cast alone (13%), plaster cast followed by orthoses management (68%), and orthoses alone (19%). Within these categories, further variation existed regarding the individual rehabilitation facets, such as the length of time worn, the foot position within them and weight-bearing status. The subsequent interviews reflected this clinical uncertainty and the pressing need for definitive research. Conclusions The gap in evidence in this area has resulted in practice in the United Kingdom becoming varied and based on individual opinion. Future high-quality randomised trials on this subject are supported by the clinical community. Cite this article: Bone Joint Res 2015;4:65–9 PMID:25868938

  10. Anatomic ACL reconstruction: rectangular tunnel/bone-patellar tendon-bone or triple-bundle/semitendinosus tendon grafting.

    PubMed

    Shino, Konsei; Mae, Tatsuo; Tachibana, Yuta

    2015-05-01

    Anatomic ACL reconstruction is the reasonable approach to restore stability without loss of motion after ACL tear. To mimic the normal ACL like a ribbon, our preferred procedures is the anatomic rectangular tunnel (ART) technique with a bone-patellar tendon-bone (BTB) graft or the anatomic triple bundle (ATB) procedure with a hamstring (HS) tendon graft. It is important to create tunnel apertures inside the attachment areas to lessen the tunnel widening. To identify the crescent-shaped ACL femoral attachment area, the upper cartilage margin, the posterior cartilage margin and the resident's ridge are used as landmarks. To delineate the C-shaped tibial insertion, medial intercondylar ridge, Parson's knob and anterior horn of the lateral meniscus are helpful. In ART-BTB procedure which is suitable for male patients engaged in contact sports, the parallelepiped tunnels with rectangular apertures are made within the femoral and tibial attachment areas. In ATB-HS technique which is mainly applied to female athletes engaged in non-contact sports including skiing or basketball, 2 femoral and 3 tibial round tunnels are created inside the attachment areas. These techniques make it possible for the grafts to run as the native ACL without impingement to the notch or PCL. After femoral fixation with an interference screw or cortical fixation devices including Endobutton, the graft is pretensioned in situ by repetitive manual pulls at 15-20° of flexion, monitoring the graft tension with tensioners on a tensioning boot installed on the calf. Tibial fixation with pullout sutures is achieved using Double Spike Plate and a screw at the pre-determined amount of tension of 10-20N. While better outcomes with less failure rate are being obtained compared to those in the past, higher graft tear rate remains a problem. Improved preventive training may be required to avoid secondary ACL injuries. PMID:25753837

  11. Blood supply of the quadriceps tendon

    Microsoft Academic Search

    W. Petersen; V. Stein; B. Tillmann

    1999-01-01

    Summary  \\u000a Degenerative changes have been considered to be a cause for spontaneous quadriceps tendon rupture. Aim of this study is to\\u000a investigate the microvasculature of the quadriceps tendon by injection techniques and immunohistochemical methods (antibodies\\u000a against laminin) with regard to the pathogenesis of tendon degeneration. The blood supply of the quadriceps tendon arises\\u000a from descending branches of the lateral circumflex

  12. Histologic analysis of ruptured quadriceps tendons

    Microsoft Academic Search

    Per David Trobisch; Matthias Bauman; Kuno Weise; Fabian Stuby; David J. Hak

    2010-01-01

    Quadriceps tendon ruptures are uncommon injuries. Degenerative changes in the tendon are felt to be an important precondition\\u000a for rupture. We retrospectively reviewed 45 quadriceps tendon ruptures in 42 patients. Quadriceps tendon ruptures occurred\\u000a most often in the sixth and seventh decade of life. Men were affected six times as often as women. A tissue sample from the\\u000a rupture-zone was

  13. Silastic tendon graft: its role in neglected tendon repair.

    PubMed

    LaBarbiera, A P; Solitto, R J

    1990-01-01

    A case history is presented of the repair of a neglected traumatic tendon laceration by the use of a permanent Silastic tendon implant, originally manufactured for hand surgery by a staged procedure. Stage I consists of implantation of the Silastic implant and allowance of a 2- to 3-month period for the production of a pseudosheath. Stage II consists of removal of the implant after using it to guide an auto- or allograft, through the newly formed pseudosheath for attachment to the anastomotic sites. PMID:2258563

  14. Staged tendon grafts and soft tissue coverage

    PubMed Central

    Elliot, David

    2011-01-01

    The objective of the two-staged flexor tendon method is to improve the predictability of final results in difficult problems dealing with tendon reconstruction. This article reviews the evolution and benefits of this procedure. It also considers the use of the technique to help deal with problems requiring pulley and skin reconstruction simultaneously with re-constituting the flexor tendon system. PMID:22022043

  15. Management of complications of flexor tendon injuries.

    PubMed

    Pulos, Nicholas; Bozentka, David J

    2015-05-01

    Innovations in operative techniques, biomaterials, and rehabilitation protocols have improved outcomes after treatment of flexor tendon injuries. However, despite these advances, treatment of flexor tendon injuries remains challenging. The purpose of this review is to highlight the complications of flexor tendon injuries and review the management of these complications. PMID:25934203

  16. Biomechanics of tendon injury and repair

    Microsoft Academic Search

    Tony W. Lin; Luis Cardenas; Louis J. Soslowsky

    2004-01-01

    Many clinical and experimental studies have investigated how tendons repair in response to an injury. This body of work has led to a greater understanding of tendon healing mechanisms and subsequently to an improvement in their treatment. In this review paper, characterization of normal and healing tendons is first covered. In addition, the debate between intrinsic and extrinsic healing is

  17. Early active mobilization for extensor tendon injuries

    Microsoft Academic Search

    P. Sylaidis; M. Youatt; A. Logan

    1997-01-01

    Dynamic splinting following extensor tendon repair gives better results than static splinting, but involves cumbersome splints and recommended protocols are often complicated. We prefer controlled active mobilization of extensor tendon repairs without dynamic splinting. Six weeks after repair, excellent or good function was obtained in 22 out of 24 simple extensor tendon injuries and in 11 out of 13 complex

  18. Model of Tearing Mode Suppression by Resonant Magnetic Perturbations in a Tokamak

    NASA Astrophysics Data System (ADS)

    Huang, Wenlong; Zhu, Ping

    2014-10-01

    The conventional error field theory has been extended to model the interaction between tearing mode and resonant magnetic perturbation (RMP) in a tokamak approximated by a screw pinch configuration. The model is applied to the analysis and understanding of the mechanism underlying the tearing mode suppression induced by resonant magnetic perturbation as observed in recent tokamak experiments and simulations. Numerical solutions of the model demonstrate that at lower strength, RMPs are able to reduce the tearing mode amplitude. As the RMP strength increases, the tearing mode is locked in phase and its amplitude jumps to a higher level. Model analysis further reveals that both the tearing mode suppression and the mode locking are achieved through the modulation of the tearing mode rotational frequency using RMPs. The model predictions for the parameter regimes of tearing mode suppression and locking have been examined, and comparisons with recent experimental observations and simulations will be discussed. Supported by Ministry of Science and Technology of P. R. China Grant 2014GB124002.

  19. Achilles tendon reflex measuring system

    NASA Astrophysics Data System (ADS)

    Szebeszczyk, Janina; Straszecka, Joanna

    1995-06-01

    The examination of Achilles tendon reflex is widely used as a simple, noninvasive clinical test in diagnosis and pharmacological therapy monitoring in such diseases as: hypothyroidism, hyperthyroidism, diabetic neuropathy, the lower limbs obstructive angiopathies and intermittent claudication. Presented Achilles tendon reflect measuring system is based on the piezoresistive sensor connected with the cylinder-piston system. To determinate the moment of Achilles tendon stimulation a detecting circuit was used. The outputs of the measuring system are connected to the PC-based data acquisition board. Experimental results showed that the measurement accuracy and repeatability is good enough for diagnostics and therapy monitoring purposes. A user friendly, easy-to-operate measurement system fulfills all the requirements related to recording, presentation and storing of the patients' reflexograms.

  20. Bridging tendon defects using autologous tenocyte engineered tendon in a hen model.

    PubMed

    Cao, Yilin; Liu, Yongtao; Liu, Wei; Shan, Qingxin; Buonocore, Samuel D; Cui, Lei

    2002-10-01

    Tendon defects remain a major concern in plastic surgery because of the limited availability of tendon autografts. Whereas immune rejection prohibits the use of tendon allografts, most prosthetic replacements also fail to achieve a satisfactory long-term result of tendon repair. The tissue engineering technique, however, can generate different tissues using autologous cells and thus may provide an optimal approach to address this concern. The purpose of this study was to test the feasibility of engineering tendon tissues with autologous tenocytes to bridge a tendon defect in either a tendon sheath open model or a partial open model in the hen. In a total of 40 Leghorn hens, flexor tendons were harvested from the left feet and were digested with 0.25% type II collagenase. The isolated tenocytes were expanded in vitro and mixed with unwoven polyglycolic acid fibers to form a cell-scaffold construct in the shape of a tendon. The constructs were wrapped with intestinal submucosa and then cultured in Dulbecco's Modified Eagle Medium plus 10% fetal bovine serum for 1 week before in vivo transplantation. On the feet, a defect of 3 to 4 cm was created at the second flexor digitorum profundus tendon by resecting a tendon fragment. The defects were bridged either with a cell-scaffold construct in the experimental group ( n= 20) or with scaffold material alone in the control group ( n= 20). Specimens were harvested at 8, 12, and 14 weeks postrepair for gross and histologic examination and for biomechanical analysis. In the experimental group, a cordlike tissue bridging the tendon defect was formed at 8 weeks postrepair. At 14 weeks, the engineered tendons resembled the natural tendons grossly in both color and texture. Histologic examination at 8 weeks showed that the neo-tendon contained abundant tenocytes and collagen; most collagen bundles were randomly arranged. The undegraded polyglycolic acid fibers surrounded by inflammatory cells were also observed. At 12 weeks, tenocytes and collagen fibers became longitudinally aligned, with good interface healing to normal tendon. At 14 weeks, the engineered tendons displayed a typical tendon structure hardly distinguishable from that of normal tendons. Biomechanical analysis demonstrated increased breaking strength of the engineered tendons with time, which reached 83 percent of normal tendon strength at 14 weeks. In the control group, polyglycolic acid constructs were mostly degraded at 8 weeks and disappeared at 14 weeks. However, the breaking strength of the scaffold materials accounted for only 9 percent of normal tendon strength. The results of this study indicated that tendon tissue could be engineered in vivo to bridge a tendon defect. The engineered tendons resembled natural tendons not only in gross appearance and histologic structure but also in biomechanical properties. PMID:12360068

  1. Silk and collagen scaffolds for tendon reconstruction.

    PubMed

    Kwon, Soon-Yong; Chung, Jin-Wha; Park, Hee-Jung; Jiang, Yuan-Yuan; Park, Jung-Keug; Seo, Young-Kwon

    2014-04-01

    In this study, silk thread (Bombyx mori) was braided to a tube-like shape and sericin was removed from the silk tube. Thereafter, collagen/chondroitin-6-sulfate solution was poured into the silk tube, and the lyophilization process was performed. To assess the inflammatory response in vivo, raw silk and sericin-free silk tubes were implanted in the subcutaneous layer of mice. After 10 days of in vivo implantation, mild inflammatory responses were observed around the sericin-free silk tubes, and severe inflammation with the presence of neutrophils and macrophages was observed around the raw silk tubes. At 24 weeks post implantation, the regenerated tendon had a thick, cylindrical, grayish fibrous structure and a shiny white appearance, similar to that of the native tendon in the rabbit model of tendon defect. The average tensile strength of the native tendons was 220 ± 20 N, whereas the average tensile strength of the regenerated tendons was 167 ± 30 N and the diameter of the regenerated tendon (3 ± 0.2 mm) was similar to that of the native tendons (4 ± 0.3 mm). Histologically, the regenerated tendon resembled the native tendon, and all the regenerated tissues showed organized bundles of crimped fibers. Masson trichrome staining was performed for detecting collagen synthesis, and it showed that the artificial tendon was replaced by new collagen fibers and extracellular matrix. However, the regenerated tendon showed fibrosis to a certain degree. In conclusion, the artificial tendon, comprising a braided silk tube and lyophilized collagen sponge, was optimal for tendon reconstruction. Thus, this study showed an improved regeneration of neo-tendon tissues, which have the structure and tensile strength of the native tendon, with the use of the combination of collagen and silk scaffold. PMID:24705339

  2. Hyperresistivity due to viscous tearing mode turbulence

    SciTech Connect

    Finn, John M. [T-15, Plasma Theory, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2005-09-15

    The quasilinear hyperresistivity coefficient D{sub H} for flattening a current profile in resistive magnetohydrodynamics is computed. It is found that D{sub H} is independent of {delta}{sup '}, the constant-{psi} matching parameter, for viscous tearing modes. This is in contrast to the situation for inertial tearing modes, for which D{sub H} scales as {delta}{sup '-1/5}. It is reasonable to consider viscous rather than inertial tearing modes for computing D{sub H} because inertial tearing modes cross over to the viscous regime near quasilinear saturation, when their growth rates are sufficiently small. This quasilinear calculation of hyperresistivity related to a spectrum of tearing modes invokes the assumption that the tearing layers overlap. This is in contrast to the usual assumption of overlap of magnetic islands, i.e., magnetic field line chaos.

  3. Tendon Ruptures Associated With Corticosteroid Therapy

    PubMed Central

    Halpern, Alan A.; Horowitz, Bruce G.; Nagel, Donald A.

    1977-01-01

    In five patients, tendon ruptures occurred in association with corticosteroid therapy, either systemic or local infiltration. The chronic nature of the pain in all of these patients suggests that what we often call tendinitis may in fact be early or partial ruptures of tendons. Patients who receive local infiltration of corticosteroids should perhaps be advised of the risk of a ruptured tendon. In addition, particularly when the Achilles tendon is involved, immobilization should be utilized initially for a presumed tendinitis or early rupture, to protect the tendon from further injury. ImagesFigure 1.Figure 2. PMID:919538

  4. Nanoparticle-Induced Superior Hot Tearing Resistance of A206 Alloy

    NASA Astrophysics Data System (ADS)

    Choi, Hongseok; Cho, Woo-hyun; Konishi, Hiromi; Kou, Sindo; Li, Xiaochun

    2013-04-01

    Al- Cu alloys (such as A206) offer high strength and high fracture toughness at both room and elevated temperatures. However, their widespread applications are limited because of their high susceptibility to hot tearing. This article presents a nanotechnology approach to enhance hot-tearing resistance for A206. Specifically, ?-Al2O3 nanoparticles were used, and their effects on the hot-tearing resistance of the as-cast Al-4.5Cu alloy (A206) were investigated. While it is well known that grain refinement can improve the hot-tearing resistance of cast Al alloys, the current study demonstrated that nanoparticles can be much more effective in the case of A206. The hot-tearing susceptibilities (HTSs) of A206 alloy and its Al2O3 nanocomposite were evaluated by constrained rod casting (CRC) with a steel mold. Monolithic A206 and M206 (the Ti-free version of A206) alloys with the B contents of 20, 40, and 300 ppm from an Al-5Ti-1B master alloy addition were also cast under the same conditions for comparison. The results showed that with an addition of 1 wt pct ?-Al2O3 nanoparticles, the extent of hot tearing in A206 alloys was markedly reduced to nearly that of A356, an Al-Si alloy highly resistant to hot tearing. As compared with grain-refined A206 or M206, the hot-tearing resistance of the nanocomposites was significantly better, even though the grain size was not reduced as much. Microstructural analysis suggested that ?-Al2O3 nanoparticles modified the solidification microstructure of the eutectic of ?-Al2Cu and ?-Al, as well as refined primary grains, resulting in the enhancement of the hot-tearing resistance of A206 to a level similar to that of A356 alloy.

  5. Dacryoscintigraphic Findings in the Children with Tearing

    PubMed Central

    Kim, Hyung Chul; Cho, A Ran

    2015-01-01

    Purpose To investigate the diagnostic effectiveness of dacryoscintigraphy in children with tearing; to evaluate tear clearance rate as a diagnostic factor of dacryoscintigraphy in children with tearing; and to analyze the results of treatment according to dacryoscintigraphic findings in children with tearing. Methods Between January 2010 and April 2014, 176 eyes of 88 children with tearing (49 boys and 39 girls; mean age, 23.81 ±14.67 months; range, 12 to 72 months) were studied retrospectively. Of these, 37 of 88 children with tearing were bilateral cases, and 51 were unilateral cases. None of the patients had a history of craniofacial disorder or trauma. The chief complaint of tearing with or without eye discharge and delivery mode, past history of neonatal conjunctivitis, syringing, or probing were collected from parents, grandparents, or previous hospital data. The drainage pattern of the nasolacrimal duct was analyzed, and the clearance rate of 50 µCi 99m technetium pertechnetate was measured by dacryoscintigraphy. Results According to the dacryoscintigraphy results, 98 of 125 eyes (78.4%) with tearing showed nasolacrimal obstruction and 29 of 51 eyes (56.9%) without tearing showed patency. There was a significant difference between tearing eyes and normal eyes (p = 0.001). The clearance rate difference after 3 and 30 minutes was 16.41 ± 15.37% in tearing eyes and 23.57 ±14.15% in normal eyes. There was a significant difference between epiphoric eyes and normal eyes (p = 0.05). Based on the dacryoscintigraphic findings, nasolacrimal-duct obstruction was treated with probing or silicone-tube intubation. The majority of patients showed symptom improvement (75.2%) during the two months of follow-up. Conclusions Dacryoscintigraphy is a non-invasive method of qualitatively and quantitatively diagnosing nasolacrimal duct obstruction in children with tearing. PMID:25646054

  6. Computational modeling of neoclassical and resistive MHD tearing modes in tokamaks

    SciTech Connect

    Gianakon, T.A.; Hegna, C.C.; Callen, J.D.

    1996-06-24

    Numerical studies of the nonlinear evolution of MHD-type tearing modes in three-dimensional toroidal geometry with neoclassical effects are presented. The inclusion of neoclassical physics introduces an additional free-energy source for the nonlinear formation of magnetic islands through the effects of a bootstrap current in Ohm`s law. The neoclassical tearing mode is demonstrated to be destabilized in plasmas which are otherwise {Delta}` stable, albeit once an island width threshold is exceeded. The plasma pressure dynamics and neoclassical tearing growth is shown to be sensitive to the choice of the ratio of the parallel to perpendicular diffusivity ({Chi}{parallel}/{Chi}{perpendicular}). The study is completed with a demonstration and theoretical comparison of the threshold for single helicity neoclassical MHD tearing modes, which is described based on parameter scans of the local pressure gradient, the ratio of perpendicular to parallel pressure diffusivities {Chi}{perpendicular}/{Chi}{parallel}, and the magnitude of an initial seed magnetic perturbation.

  7. Transcription factor EGR1 directs tendon differentiation and promotes tendon repair

    PubMed Central

    Guerquin, Marie-Justine; Charvet, Benjamin; Nourissat, Geoffroy; Havis, Emmanuelle; Ronsin, Olivier; Bonnin, Marie-Ange; Ruggiu, Mathilde; Olivera-Martinez, Isabel; Robert, Nicolas; Lu, Yinhui; Kadler, Karl E.; Baumberger, Tristan; Doursounian, Levon; Berenbaum, Francis; Duprez, Delphine

    2013-01-01

    Tendon formation and repair rely on specific combinations of transcription factors, growth factors, and mechanical parameters that regulate the production and spatial organization of type I collagen. Here, we investigated the function of the zinc finger transcription factor EGR1 in tendon formation, healing, and repair using rodent animal models and mesenchymal stem cells (MSCs). Adult tendons of Egr1–/– mice displayed a deficiency in the expression of tendon genes, including Scx, Col1a1, and Col1a2, and were mechanically weaker compared with their WT littermates. EGR1 was recruited to the Col1a1 and Col2a1 promoters in postnatal mouse tendons in vivo. Egr1 was required for the normal gene response following tendon injury in a mouse model of Achilles tendon healing. Forced Egr1 expression programmed MSCs toward the tendon lineage and promoted the formation of in vitro–engineered tendons from MSCs. The application of EGR1-producing MSCs increased the formation of tendon-like tissues in a rat model of Achilles tendon injury. We provide evidence that the ability of EGR1 to promote tendon differentiation is partially mediated by TGF-?2. This study demonstrates EGR1 involvement in adult tendon formation, healing, and repair and identifies Egr1 as a putative target in tendon repair strategies. PMID:23863709

  8. Anterior cruciate ligament injury: Evaluation of intraarticular reconstruction of acute tears without repairTwo to seven year followup of 155 athletes

    Microsoft Academic Search

    K. Donald Shelbourne; H. Jeffrey Whitaker; John R. McCarroll; Arthur C. Rettig; Lynne D. Hirschman

    1990-01-01

    To evaluate the effectiveness of our treatment regimen, we retrospectively studied the surgically treated knees of 155 athletes, aged 15 to 42 years, who had sustained acute ACL tears. All were treated with ligament excision and intraarticular bone-patellar tendon-bone recon struction followed by early motion with emphasis on full extension. The follow-up period ranged from 2 to 7 years. Of

  9. Tissue engineering for tendon repair

    Microsoft Academic Search

    Pierre-Olivier Bagnaninchi; Ying Yang; Alicia J El Haj; Nicola Maffulli; U Bosch

    2007-01-01

    Tissue engineering aims to induce tissue self-regeneration in vivo or to produce a functional tissue replacement in vitro to be then implanted in the body. To produce a viable and functional tendon, a uniaxially orientated collagen type I matrix has to be generated. Biochemical and physical factors can potentially alter both the production and the organisation of this matrix, and

  10. Tear analysis and lens-tear interactions. Part I. Protein fingerprinting with microfluidic technology.

    PubMed

    Mann, Aisling M; Tighe, Brian J

    2007-07-01

    The purpose of this work is to establish the application of a fully automated microfluidic chip based protein separation assay in tear analysis. It is rapid, requires small sample volumes and is vastly superior to, and more convenient than, comparable conventional gel electrophoresis assays. The protein sizing chip technology was applied to three specific fields of analysis. Firstly tear samples were collected regularly from subjects establishing the baseline effects of tear stimulation, tear state and patient health. Secondly tear samples were taken from lens wearing eyes and thirdly the use of microfluidic technology was assessed as a means to investigate a novel area of tear analysis, which we have termed the 'tear envelope'. Utilising the Agilent 2100 Bioanalyzer in combination with the Protein 200 Plus LabChip kit, these studies investigated tear proteins in the range of 14-200 kDa. Particular attention was paid to the relative concentrations of lysozyme, tear lipocalin, secretory IgA (sIgA), IgG and lactoferrin, together with the overall tear electropherogram 'fingerprint'. Furthermore, whilst lens-tear interaction studies are generally thought of as an investigation into the effects of tears components on the contact lens material, i.e. deposition studies, this report addresses the reverse phenomenon--the effect of the lens, and particularly the newly inserted lens, on the tear fluid composition and dynamics. The use of microfluidic technology provides a significant advance in tear studies and should prove invaluable in tear diagnostics and contact lens performance analysis. PMID:17499010

  11. An alternative cruciate reconstruction graft: The central quadriceps tendon

    Microsoft Academic Search

    John P. Fulkerson; Rolf Langeland

    1995-01-01

    The central quadriceps tendon, above the patella, is thicker and wider than the patella tendon. Using precise technique, one can obtain a tendon graft for cruciate reconstruction with 50% greater mass than a patellar tendon bone-tendonbone graft of similar width. The central quadriceps tendon graft may be harvested by a second surgeon while the first surgeon is simultaneously accomplishing notchplasty

  12. Arthroscopic anterior cruciate ligament reconstruction with quadriceps tendon composite autograft

    Microsoft Academic Search

    Dong-Wook Kim; Jong-Oh Kim; Jae-Doo You; Sung-Jae Kim; Hyun-Kon Kim

    2001-01-01

    At present, no single graft option clearly outperforms another. Autografts (patellar tendon, hamstring) and allografts (Achilles tendon, patellar tendon) are the grafts most often used. However, each grafts has advantages and disadvantages. Quadriceps tendon graft for anterior cruciate ligament reconstruction is not new, but an alternative composite graft is introduced here that consists of quadriceps tendon–patellar bone and bone obtained

  13. Dural tear of unusual cause

    PubMed Central

    Kechna, Hicham; Loutid, Jaouad; Ouzzad, Omar; Hanafi, Sidi Mohamed; Hachimi, Moulay Ahmed

    2015-01-01

    Epidural analgesia is highly recommended in cancer anorectal surgery. In addition to the fight against pain it provides some benefit in allowing early rehabilitation of patients. One of the risks of this practice is the dural tear creating a cerebrospinal fluid leak (CSF) in the epidural space (EPD). Clinical features the typical positional headache, a procession of various more or less severe symptoms: nausea, vomiting, dizziness, visual or hearing impairment or radicular pain. We report a dural of unusual cause secondary of the obstruction of tuohy catheter by vertebral cartilage.

  14. Role of biomechanics in the understanding of normal, injured, and healing ligaments and tendons

    PubMed Central

    Jung, Ho-Joong; Fisher, Matthew B; Woo, Savio L-Y

    2009-01-01

    Ligaments and tendons are soft connective tissues which serve essential roles for biomechanical function of the musculoskeletal system by stabilizing and guiding the motion of diarthrodial joints. Nevertheless, these tissues are frequently injured due to repetition and overuse as well as quick cutting motions that involve acceleration and deceleration. These injuries often upset this balance between mobility and stability of the joint which causes damage to other soft tissues manifested as pain and other morbidity, such as osteoarthritis. The healing of ligament and tendon injuries varies from tissue to tissue. Tendinopathies are ubiquitous and can take up to 12 months for the pain to subside before one could return to normal activity. A ruptured medial collateral ligament (MCL) can generally heal spontaneously; however, its remodeling process takes years and its biomechanical properties remain inferior when compared to the normal MCL. It is also known that a midsubstance anterior cruciate ligament (ACL) tear has limited healing capability, and reconstruction by soft tissue grafts has been regularly performed to regain knee function. However, long term follow-up studies have revealed that 20–25% of patients experience unsatisfactory results. Thus, a better understanding of the function of ligaments and tendons, together with knowledge on their healing potential, may help investigators to develop novel strategies to accelerate and improve the healing process of ligaments and tendons. With thousands of new papers published in the last ten years that involve biomechanics of ligaments and tendons, there is an increasing appreciation of this subject area. Such attention has positively impacted clinical practice. On the other hand, biomechanical data are complex in nature, and there is a danger of misinterpreting them. Thus, in these review, we will provide the readers with a brief overview of ligaments and tendons and refer them to appropriate methodologies used to obtain their biomechanical properties. Specifically, we hope the reader will pay attention to how the properties of these tissues can be altered due to various experimental and biologic factors. Following this background material, we will present how biomechanics can be applied to gain an understanding of the mechanisms as well as clinical management of various ligament and tendon ailments. To conclude, new technology, including imaging and robotics as well as functional tissue engineering, that could form novel treatment strategies to enhance healing of ligament and tendon are presented. PMID:19457264

  15. Greater Tuberosity Osteotomy and Teres Minor Transfer for Irreparable Superior Rotator Cuff Tears

    PubMed Central

    Wolf, Brian R; Bries, Andrew D; Nepola, James V

    2007-01-01

    The purpose of this study was to evaluate the mid- to long- term objective, subjective and radiographic results of patients who underwent anterior-superior transfer of remaining infraspinatus tendon and teres minor tendon for irreparable superior rotator cuff tears. thirteen patients were identified who underwent infraspinatus tendon transfer to a more superior position on the humeral head between January 1, 1990 and december 31, 2001. nine shoulders in eight patients were available for clinical examination, radiographs and questionnaire follow-up at an average of 83.5 ± 31.4 months. radiographic examination revealed 1 fibrous union and 6 united tuberosity osteotomies. Samilson-Prieto grading of radiographs revealed 4 shoulders with mild, and 4 shoulders with moderate, OA. Seven of the patients were satisfied with their shoulder. there were two poor outcomes. Local antero-superior teres minor and residual infraspinatus transfer provides a viable option for irreparable rotator cuff defects. Mid- to long-term satisfactory outcome was achieved in 7 out of 9 shoulders. PMID:17907433

  16. Automatic CAD of meniscal tears on MR imaging: a morphology-based approach

    NASA Astrophysics Data System (ADS)

    Ramakrishna, Bharath; Liu, Weimin; Safdar, Nabile; Siddiqui, Khan; Kim, Woojin; Juluru, Krishna; Chang, Chein-I.; Siegel, Eliot

    2007-03-01

    Knee-related injuries, including meniscal tears, are common in young athletes and require accurate diagnosis and appropriate surgical intervention. Although with proper technique and skill, confidence in the detection of meniscal tears should be high, this task continues to be a challenge for many inexperienced radiologists. The purpose of our study was to automate detection of meniscal tears of the knee using a computer-aided detection (CAD) algorithm. Automated segmentation of the sagittal T1-weighted MR imaging sequences of the knee in 28 patients with diagnoses of meniscal tears was performed using morphologic image processing in a 3-step process including cropping, thresholding, and application of morphological constraints. After meniscal segmentation, abnormal linear meniscal signal was extracted through a second thresholding process. The results of this process were validated by comparison with the interpretations of 2 board-certified musculoskeletal radiologists. The automated meniscal extraction algorithm process was able to successfully perform region of interest selection, thresholding, and object shape constraint tasks to produce a convex image isolating the menisci in more than 69% of the 28 cases. A high correlation was also noted between the CAD algorithm and human observer results in identification of complex meniscal tears. Our initial investigation indicates considerable promise for automatic detection of simple and complex meniscal tears of the knee using the CAD algorithm. This observation poses interesting possibilities for increasing radiologist productivity and confidence, improving patient outcomes, and applying more sophisticated CAD algorithms to orthopedic imaging tasks.

  17. Bifurcated popliteus tendon: a descriptive arthroscopic study

    PubMed Central

    Ginés-Cespedosa, Albert; Monllau, Joan C.

    2008-01-01

    The objective of this study was to confirm the presence and frequency of a bifurcation of the popliteus tendon. The popliteus tendon has received attention due to its important function as a knee stabiliser. Several anatomical variants have recently been reported, one of them being a bifurcated tendon. However, the actual frequency as well as the possible role of this particular variant is still unknown. We prospectively analysed a series of 1,569 arthroscopies between January 2005 to December 2007. Six asymptomatic bifurcated popliteus tendons were found. No alterations in the magnetic resonance imaging were seen and no clinical signs (related to the popliteus tendon) were observed in these patients before surgery. In all cases the morphological variant was found by chance. Our results suggest that the presence of a bifurcated popliteus tendon is a fact and that its frequency, not previously reported, should not be ignored. PMID:18998130

  18. [Effects of Gravity on Attachment of Tendon to Bone

    NASA Technical Reports Server (NTRS)

    Johnson, Roger B.

    1997-01-01

    We have received and processed all samples for either light or scanning electron microscopic analysis and have completed the histomorphometric analysis. We have characterized the changes caused by spaceflight to tendon attachments to the calcaneus, tibia, fibula and femur and compared them to hindlimbs and forelimbs from NIH.RZ. Soleus muscle histomorphometry has also been completed. Our results suggest severe osteoporosis in the femur, fibula and tibia of animals coincident to spaceflight, which had not resolved after 4-5 days following return to earth. This was evident at all sites, including sites of tendon attachments. This atrophy was not evident in the calcaneus. No muscle atrophy was evident. Comparison of scanning photomicrographs of flight animals with other lactating animals demonstrated structural similarities and suggested that it might be worthwhile to assess whether lactation is a factor in development of the osteoporosis in the spaceflight animals. In addition, evaluation of total calcium utilization by spaceflight animals would be beneficial.

  19. [Idiopathic bilateral patellar tendon rupture].

    PubMed

    Choufani, C; Barthélemy, R; Danis, J; Demoures, Th; Rigal, S

    2015-04-01

    In the absence of systemic disease, specific treatment or sport tendonitis, simultaneous bilateral patellar tendon rupture is rare. Often missed on the first glance, it represents a diagnostic difficulty that should not be overlooked at the initial medical visit. The loss of active extension of the lower limb and a radiographic patella alta, even in a bilateral context, should raise suspicion of this diagnosis. It is then necessary to search for predisposing causes and to evoke the differential, or frequently associated, diagnoses. The present report illustrates these diagnostic difficulties and summarizes some clinical considerations that might help to avoid neglecting these different elements at the first medical visit (positive diagnosis, associated lesions, favouring factors). PMID:26054172

  20. Tendon transfers for the drop foot.

    PubMed

    Schweitzer, Karl M; Jones, Carroll P

    2014-03-01

    The paralytic drop foot represents a challenging problem for even the most experienced orthopedic surgeon. Careful patient selection, thorough preoperative examination and planning, and application of tendon transfer biomechanical and physiologic principles outlined in this article can lead to successful results, either through a posterior tibialis tendon transfer, Bridle transfer, or variations on these procedures. Achilles lengthening or gastrocnemius recession may also be needed at the time of tendon transfer. PMID:24548510

  1. Structure and function of tuna tail tendons.

    PubMed

    Shadwick, Robert E; Rapoport, H Scott; Fenger, Joelle M

    2002-12-01

    The caudal tendons in tunas and other scombrid fish link myotomal muscle directly to the caudal fin rays, and thus serve to transfer muscle power to the hydrofoil-like tail during swimming. These robust collagenous tendons have structural and mechanical similarity to tendons found in other vertebrates, notably the leg tendons of terrestrial mammals. Biochemical studies indicate that tuna tendon collagen is composed of the (alpha1)(2),alpha2 heterotrimer that is typical of vertebrate Type I collagen, while tuna skin collagen has the unusual alpha1,alpha2,alpha3 trimer previously described in the skin of some other teleost species. Tuna collagen, like that of other fish, has high solubility due to the presence of an acid-labile intermolecular cross-link. Unlike collagen in mammalian tendons, no differences related to cross-link maturation were detected among tendons in tuna ranging from 0.05 to 72 kg (approx. 0.25-6 years). Tendons excised post-mortem were subjected to load cycling to determine the modulus of elasticity and resilience (mean of 1.3 GPa and 90%, respectively). These material properties compare closely to those of leg tendons from adult mammals that can function as effective biological springs in terrestrial locomotion, but the breaking strength is substantially lower. Peak tendon forces recorded during steady swimming appear to impose strains of much less than 1% of tendon length, and no more than 1.5% during bursts. Thus, the caudal tendons in tunas do not appear to function as elastic storage elements, even at maximal swimming effort. PMID:12485695

  2. Lubricin Surface Modification Improves Tendon Gliding After Tendon Repair in a Canine Model in Vitro

    PubMed Central

    Taguchi, Manabu; Sun, Yu-Long; Zhao, Chunfeng; Zobitz, Mark E.; Cha, Chung-Ja; Jay, Gregory D.; An, Kai-Nan; Amadio, Peter C.

    2011-01-01

    This study investigated the effects of lubricin on the gliding of repaired flexor digitorum profundus (FDP) tendons in vitro. Canine FDP tendons were completely lacerated, repaired with a modified Pennington technique, and treated with one of the following solutions: saline, carbodiimide derivatized gelatin/hyaluronic acid (cd-HA-gelatin), carbodiimide derivatized gelatin to which lubricin was added in a second step (cd-gelatin + lubricin), or carbodiimide derivatized gelatin/HA + lubricin (cd-HA-gelatin + lubricin). After treatment, gliding resistance was measured up to 1,000 cycles of simulated flexion/extension motion. The increase in average and peak gliding resistance in cd-HA-gelatin, cd-gelatin + lubricin, and cd-HA-gelatin + lubricin tendons was less than the control tendons after 1,000 cycles (p < 0.05). The increase in average gliding resistance of cd-HA-gelatin + lubricin treated tendons was also less than that of the cd-HA-gelatin treated tendons (p < 0.05). The surfaces of the repaired tendons and associated pulleys were assessed qualitatively with scanning electron microscopy and appeared smooth after 1,000 cycles of tendon motion for the cd-HA-gelatin, cd-gelatin + lubricin, and cd-HA-gelatin + lubricin treated tendons, while that of the saline control appeared roughened. These results suggest that tendon surface modification can improve tendon gliding ability, with a trend suggesting that lubricin fixed on the repaired tendon may provide additional improvement over that provided by HA and gelatin alone. PMID:18683890

  3. Structure of the human tibialis posterior tendon

    Microsoft Academic Search

    Wolf Petersen; Gerrit Hohmann; Thomas Pufe; Michael Tsokos; Thore Zantop; Friedrich Paulsen; Bernhard Tillmann

    2004-01-01

    Background  The most common site of rupture of the posterior tibial tendon is the retromalleolar region where the tendon changes its direction\\u000a of pull. The aim of this study was to characterize the tissue of the gliding zone of the tibialis posterior tendon to gain\\u000a further knowledge about possible structural causes for spontaneous tendon rupture.\\u000a \\u000a \\u000a \\u000a Methods  Light microscopy, transmission electron microscopy and

  4. Les plaies du tendon patellaire

    PubMed Central

    Mechchat, Atif; Elidrissi, Mohammed; Mardy, Abdelhak; Elayoubi, Abdelghni; Shimi, Mohammed; Elibrahimi, Abdelhalim; Elmrini, Abdelmajid

    2014-01-01

    Les plaies du tendon patellaire sont peu fréquentes et sont peu rapportés dans la littérature, contrairement aux ruptures sous cutanées. Les sections du tendon patellaire nécessitent une réparation immédiate afin de rétablir l'appareil extenseur et de permettre une récupération fonctionnelle précoce. A travers ce travail rétrospectif sur 13 cas, nous analysons les aspects épidémiologiques, thérapeutiques et pronostiques de ce type de pathologie en comparant différents scores. L’âge moyen est de 25 ans avec une prédominance masculine. Les étiologies sont dominées par les accidents de la voie publique (68%) et les agressions par agent tranchant (26%) et contendant (6 %). Tous nos patients ont bénéficié d'un parage chirurgical avec suture tendineuse direct protégée par un laçage au fils d'aciers en légère flexion. La rééducation est débutée après sédation des phénomènes inflammatoires. Au dernier recul les résultats sont excellents et bon à 92%. Nous n'avons pas noté de différence de force musculaire et d'amplitude articulaire entre le genou sain et le genou lésé. Les lésions ouvertes du tendon patellaire est relativement rare. La prise en charge chirurgicale rapide donne des résultats assez satisfaisants. La réparation est généralement renforcée par un semi-tendineux, synthétique ou métallique en forme de cadre de renfort pour faciliter la réadaptation et réduire le risque de récidive après la fin de l'immobilisation. PMID:25170379

  5. Anatomic Reconstruction of Chronic Coracoclavicular Ligament Tears: Arthroscopic-Assisted Approach With Nonrigid Mechanical Fixation and Graft Augmentation

    PubMed Central

    Natera, Luis; Sarasquete Reiriz, Juan; Abat, Ferran

    2014-01-01

    It has recently been suggested that all coracoclavicular ligament tears could be considered for surgery because nonoperative management might result in irreversible changes in the scapular position that could lead to muscle kinematic alterations that would perturb the shoulder girdle function and result in pain. In this technical note we describe an anatomic technique for the treatment of chronic coracoclavicular ligament tears that overcomes the issues related to open surgery, metal hardware, the inferior resistance to secondary displacement of only grafting and nonanatomic techniques, and the saw effect and anterior loop translation that can be seen in systems that surround the base of the coracoid. Our technique incorporates the use of a tendon graft and a nonrigid mechanical stabilizer that protects the graft from stretching during the process of healing and integration into bone, guaranteeing the maintenance of a reduced acromioclavicular joint. PMID:25473611

  6. The bio-tribological properties of anti-adhesive agents commonly used during tendon repair.

    PubMed

    McGonagle, Lorcan; Jones, Michael D; Dowson, Duncan; Theobald, Peter S

    2012-05-01

    Frictional resistance to tendon gliding is minimized by surrounding loose areolar tissue. During periods of prolonged immobilization, for example, post-tendon-repair, adhesions can form between these two adjacent tissues, thereby limiting tendon function. Anti-adhesive agents can be applied during surgery to prevent adhesion formation, whilst reportedly providing some reduction in friction during in vitro tendon-bony pulley investigations. This bio-tribological study evaluates whether application of these agents can improve the lubrication between the tendon and surrounding tissue, thus potentially reducing the risk of re-rupturing the tendon at the repair site. The use of bovine synovial fluid (BSF) enabled an approximation of the in vivo lubrication regime, and subsequent comparison of the performance of three synthetic agents (50?mg/ml 5-fluorouracil; 5?mg/ml hyaluronic acid; ADCON-T/N). Coefficient of friction data was recorded and then compared with the Stribeck curve. BSF generated a fluid film that separated the two surfaces, giving rise to optimal lubrication conditions. This efficient regime was also generated following application of each anti-adhesion agent. The use of phosphate-buffered saline solution in generating only a boundary lubrication regime highlighted the effectiveness of the agents in reducing friction. Hyaluronic acid (5?mg/ml) was marginally deemed the most effective anti-adhesive agent at lubricating the tendon. Subsequently, it is concluded that the application of anti-adhesive agents post-surgery has secondary, tribological benefits that serve to reduce friction, and thus potentially the risk of failure, at the tendon repair site. PMID:22012635

  7. The Mechanical Properties of Rat Tail Tendon

    Microsoft Academic Search

    BERNARD J. RIGBY; OHN D. SPIKES; HENRY EYRING

    1959-01-01

    The load-strain and stress-relaxation behavior of wet rat tail tendon has been examined with respect to the parameters strain, rate of strain- ing, and temperature. It is found that this mechanical behavior is reproducible after resting tile tendon for a few minutes after each extension so long as the strain does not exceed about 4 per cent. If this strain

  8. Simultaneous and spontaneous bilateral quadriceps tendons rupture.

    PubMed

    Celik, Evrim Co?kun; Ozbaydar, Mehmet; Ofluoglu, Demet; Demircay, Emre

    2012-07-01

    Simultaneous and spontaneous bilateral quadriceps tendon rupture is an uncommon injury that is usually seen in association with multiple medical conditions and some medications. We report a case of simultaneous and spontaneous bilateral quadriceps tendon rupture that may be related to the long-term use of a statin. PMID:22561379

  9. Ultrasound Diagnosis of Quadriceps Tendon Rupture

    Microsoft Academic Search

    Brian G. LaRocco; George Zlupko; Paul Sierzenski

    2008-01-01

    Quadriceps tendon ruptures are an uncommon knee injury. The diagnosis is often complicated by a limited examination secondary to edema and pain, the insensitivity of radiographs, and the unavailability of non-emergent magnetic resonance imaging. A delay in diagnosis and treatment has been shown to cause significant morbidity. A case report of bilateral quadriceps tendon rupture is presented demonstrating the utility

  10. Augmentation of tendon-to-bone healing.

    PubMed

    Atesok, Kivanc; Fu, Freddie H; Wolf, Megan R; Ochi, Mitsuo; Jazrawi, Laith M; Doral, M Nedim; Lubowitz, James H; Rodeo, Scott A

    2014-03-19

    Tendon-to-bone healing is vital to the ultimate success of the various surgical procedures performed to repair injured tendons. Achieving tendon-to-bone healing that is functionally and biologically similar to native anatomy can be challenging because of the limited regeneration capacity of the tendon-bone interface. Orthopaedic basic-science research strategies aiming to augment tendon-to-bone healing include the use of osteoinductive growth factors, platelet-rich plasma, gene therapy, enveloping the grafts with periosteum, osteoconductive materials, cell-based therapies, biodegradable scaffolds, and biomimetic patches. Low-intensity pulsed ultrasound and extracorporeal shockwave treatment may affect tendon-to-bone healing by means of mechanical forces that stimulate biological cascades at the insertion site. Application of various loading methods and immobilization times influence the stress forces acting on the recently repaired tendon-to-bone attachment, which eventually may change the biological dynamics of the interface. Other approaches, such as the use of coated sutures and interference screws, aim to deliver biological factors while achieving mechanical stability by means of various fixators. Controlled Level-I human trials are required to confirm the promising results from in vitro or animal research studies elucidating the mechanisms underlying tendon-to-bone healing and to translate these results into clinical practice. PMID:24647509

  11. Ultrasonic evaluation of flood gate tendons

    Microsoft Academic Search

    G. Thomas; A. Brown

    1997-01-01

    Our water resources infrastructure is susceptible to aging degradation just like the rest of this country`s infrastructure. A critical component of the water supply system is the flood gate that controls the outflow from dams.Long steel rods called tendons attach these radial gates to the concrete in the dam. The tendons are typically forty feet long and over one inch

  12. Ultrasonic evaluation of flood gate tendons

    Microsoft Academic Search

    Graham H. Thomas; Albert E. Brown

    1998-01-01

    Our water resources infrastructure is susceptible to aging degradation just like the rest of this country's infrastructure. A critical component of the water supply system is the flood gate that controls the outflow from dams. Long steel rods called tendons attach these radial gates to the concrete in the dam. The tendons are typically forty feet long and over one

  13. Patterns of cellular activation after tendon injury

    Microsoft Academic Search

    U. Khan; J. C. W. Edwards; D. A. McGrouther

    1996-01-01

    Mechanisms which lead to disabling adhesions following flexor tendon surgery of the hand were investigated in a rabbit model which was used to assess the relative response of the cells of the synovial sheath, epitenon and the endotenon to injury. A transverse laceration, cutting through 50% of the tendon, was made just outside the synovial sheath on the flexor aspect

  14. Partial Thickness Rotator Cuff Tears: Current Concepts

    PubMed Central

    Matthewson, Graeme; Beach, Cara J.; Nelson, Atiba A.; Woodmass, Jarret M.; Ono, Yohei; Boorman, Richard S.; Lo, Ian K. Y.; Thornton, Gail M.

    2015-01-01

    Partial thickness rotator cuff tears are a common cause of pain in the adult shoulder. Despite their high prevalence, the diagnosis and treatment of partial thickness rotator cuff tears remains controversial. While recent studies have helped to elucidate the anatomy and natural history of disease progression, the optimal treatment, both nonoperative and operative, is unclear. Although the advent of arthroscopy has improved the accuracy of the diagnosis of partial thickness rotator cuff tears, the number of surgical techniques used to repair these tears has also increased. While multiple repair techniques have been described, there is currently no significant clinical evidence supporting more complex surgical techniques over standard rotator cuff repair. Further research is required to determine the clinical indications for surgical and nonsurgical management, when formal rotator cuff repair is specifically indicated and when biologic adjunctive therapy may be utilized. PMID:26171251

  15. On the tear resistance of skin

    NASA Astrophysics Data System (ADS)

    Yang, Wen; Sherman, Vincent R.; Gludovatz, Bernd; Schaible, Eric; Stewart, Polite; Ritchie, Robert O.; Meyers, Marc A.

    2015-03-01

    Tear resistance is of vital importance in the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. We explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. We express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip.

  16. Partial-thickness rotator cuff tears.

    PubMed

    Matava, Matthew J; Purcell, Derek B; Rudzki, Jonas R

    2005-09-01

    Partial-thickness tears of the rotator cuff have been diagnosed with increased frequency because of a heightened awareness of the condition by clinicians and improved diagnostic methods. Research into the causes, natural history, and optimal treatment of this condition lags behind that of full-thickness tears. However, despite the limitations in the existing literature, there has emerged a consensus among shoulder experts that partial-thickness rotator cuff tears should be aggressively treated in the active athlete because of the unfavorable natural history of these lesions and success of accepted surgical algorithms. This review will provide an overview of the theories regarding the origins of partial-thickness rotator cuff tears, discuss the relative accuracy of accepted diagnostic techniques, and summarize the indications and methods of operative repair with an emphasis on the results of various treatment approaches. PMID:16127127

  17. A comprehensive review of hip labral tears

    Microsoft Academic Search

    Megan M. Groh; Joseph Herrera

    2009-01-01

    The hip labrum has many functions, including shock absorption, joint lubrication, pressure distribution, and aiding in stability,\\u000a with damage to the labrum associated with osteoarthritis. The etiology of labral tears includes trauma, femoroacetabular impingement\\u000a (FAI), capsular laxity\\/hip hypermobility, dysplasia, and degeneration. Labral tears present with anterior hip or groin pain,\\u000a and less commonly buttock pain. Frequently, there are also mechanical

  18. Effect of Ramadan fasting on tear proteins.

    PubMed

    Sariri, Reyhaneh; Varasteh, Abdolali; Sajedi, Reza Hassan

    2010-01-01

    Muslims abstain from eating, drinking and smoking from dawn to sunset during the holy month of Ramadan. Prolonged fasting is thought to be among risk factors for many diseases, e.g., cardiovascular, gastrointestinal and various infectious diseases. It could also play a part in several eye diseases, including dry eye syndrome, glaucoma, and cataract. Toxic and oxidative effects due to increased concentrations of some biochemicals as a result of reduction in tear volume thought to play an important role in damaging ocular tissue. Human tear is an important biological fluid similar to blood in many aspects. Tear film is composed of three basic layers i.e. lipid, aqueous and mucin. The tear film covering the ocular surface presents a mechanical and antimicrobial barrier, and endures an optical refractive surface. The aim of this study was to analyze and compare tear protein of volunteers during fasting. Using two reliable analytical methods, i.e. electrophoresis and high performance liquid chromatography (HPLC), we compared tear protein content of sixty volunteers (35 males and 25 females, 23-27 years old) during fasting in holly month of Ramadan (FAST: n = 62) and one month before Ramadan (CTRL: n = 60). The results showed that some identified tear proteins decreased during fasting. On the other hand, the activity of some enzymes such as lysozyme, lactoferrin and alpha amylase also decreased in fasting samples. Electrophoresis results showed that tear protein patterns in FAST (P < 0.05) were different from those of CTRL. There were a few more protein peaks in the FAST group (P < 0.005) than in CTRL. PMID:21171527

  19. Neoclassical tearing modes in a tokamak

    SciTech Connect

    Hahm, T.S.

    1988-12-01

    Linear tearing instability is studied in the banana collisionality regime in tokamak geometry. Neoclassical effects produce significant modifications of Ohm's law and the vorticity equation, so that the growth rate of tearing modes driven by ..delta..' is dramatically reduced compared to the usual resistive magnetohydrodynamic values. Consequences of this result, regarding the presence of pressure-gradient-driven neoclassical resistive interchange instabilities and the evolution of magnetic islands in the Rutherford regime, are discussed.

  20. Symptoms of Pain Do Not Correlate with Rotator Cuff Tear Severity

    PubMed Central

    Dunn, Warren R.; Kuhn, John E.; Sanders, Rosemary; An, Qi; Baumgarten, Keith M.; Bishop, Julie Y.; Brophy, Robert H.; Carey, James L.; Holloway, G. Brian; Jones, Grant L.; Ma, C. Benjamin; Marx, Robert G.; McCarty, Eric C.; Poddar, Sourav K.; Smith, Matthew V.; Spencer, Edwin E.; Vidal, Armando F.; Wolf, Brian R.; Wright, Rick W.

    2014-01-01

    Background: For many orthopaedic disorders, symptoms correlate with disease severity. The objective of this study was to determine if pain level is related to the severity of rotator cuff disorders. Methods: A cohort of 393 subjects with an atraumatic symptomatic full-thickness rotator-cuff tear treated with physical therapy was studied. Baseline pretreatment data were used to examine the relationship between the severity of rotator cuff disease and pain. Disease severity was determined by evaluating tear size, retraction, superior humeral head migration, and rotator cuff muscle atrophy. Pain was measured on the 10-point visual analog scale (VAS) in the patient-reported American Shoulder and Elbow Surgeons (ASES) score. A linear multiple regression model was constructed with use of the continuous VAS score as the dependent variable and measures of rotator cuff tear severity and other nonanatomic patient factors as the independent variables. Forty-eight percent of the patients were female, and the median age was sixty-one years. The dominant shoulder was involved in 69% of the patients. The duration of symptoms was less than one month for 8% of the patients, one to three months for 22%, four to six months for 20%, seven to twelve months for 15%, and more than a year for 36%. The tear involved only the supraspinatus in 72% of the patients; the supraspinatus and infraspinatus, with or without the teres minor, in 21%; and only the subscapularis in 7%. Humeral head migration was noted in 16%. Tendon retraction was minimal in 48%, midhumeral in 34%, glenohumeral in 13%, and to the glenoid in 5%. The median baseline VAS pain score was 4.4. Results: Multivariable modeling, controlling for other baseline factors, identified increased comorbidities (p = 0.002), lower education level (p = 0.004), and race (p = 0.041) as the only significant factors associated with pain on presentation. No measure of rotator cuff tear severity correlated with pain (p > 0.25). Conclusions: Anatomic features defining the severity of atraumatic rotator cuff tears are not associated with the pain level. Factors associated with pain are comorbidities, lower education level, and race. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence. PMID:24875019

  1. Tear film measurement by optical reflectometry technique

    PubMed Central

    Lu, Hui; Wang, Michael R.; Wang, Jianhua; Shen, Meixiao

    2014-01-01

    Abstract. Evaluation of tear film is performed by an optical reflectometer system with alignment guided by a galvanometer scanner. The reflectometer system utilizes optical fibers to deliver illumination light to the tear film and collect the film reflectance as a function of wavelength. Film thickness is determined by best fitting the reflectance-wavelength curve. The spectral reflectance acquisition time is 15 ms, fast enough for detecting film thickness changes. Fast beam alignment of 1 s is achieved by the galvanometer scanner. The reflectometer was first used to evaluate artificial tear film on a model eye with and without a contact lens. The film thickness and thinning rate have been successfully quantified with the minimum measured thickness of about 0.3 ?m. Tear films in human eyes, with and without a contact lens, have also been evaluated. A high-contrast spectral reflectance signal from the precontact lens tear film is clearly observed, and the thinning dynamics have been easily recorded from 3.69 to 1.31 ?m with lipid layer thickness variation in the range of 41 to 67 nm. The accuracy of the measurement is better than ±0.58% of the film thickness at an estimated tear film refractive index error of ±0.001. The fiber-based reflectometer system is compact and easy to handle. PMID:24500519

  2. A novel fibrocartilaginous tendon from an elasmobranch fish ( Rhinoptera bonasus )

    Microsoft Academic Search

    Adam P. Summers; Magdalena M. Koob-Emunds; Stephen M. Kajiura; Thomas J. Koob

    2003-01-01

    Tendons of the jaw adductor muscles of a hard prey crushing stingray exhibit similar adaptations to compressive and shear loads as those seen in mammalian tendons. Ventral intermandibular tendon from the cownose ray, Rhinoptera bonasus, has a prominent fibrocartilaginous pad that lies between a fibrous region of the tendon and the mineralized tissue of the jaw. Histologically the pad is

  3. Achilles tendon: US diagnosis of pathologic conditions. Work in progress

    SciTech Connect

    Blei, C.L.; Nirschl, R.P.; Grant, E.G.

    1986-06-01

    Twenty-three patients were prospectively examined with ultra-sound (US) for acute or recurrent Achilles tendon symptoms. Three types of pathologic conditions of the Achilles tendon were found: tendinitis/tenosynovitis, acute tendon trauma, and postoperative changes. US appears to enable differentiation of these conditions and to contribute to the diagnosis of a broad range of Achilles tendon disorders.

  4. Endoscopy of the digital flexor tendon sheath in horses.

    PubMed

    Nixon, A J

    1990-01-01

    An arthroscopic procedure for examination of the digital flexor tendons and tendon sheath was developed in 16 equine limbs and 12 horses. Distension of the tendon sheath and insertion of the arthroscope was accomplished through a cul-de-sac on the palmar or plantar surface of the tendon sheath 1 to 2 cm palmar or plantar to the digital neurovascular structures and between the annular ligament and proximal digital annular ligament. A single arthroscope entry point allowed examination of all regions of the tendon sheath cavity and most surfaces of the digital flexor tendons within the sheath. Distal to the fetlock, surgical procedures could be performed through additional entry portals on the lateral, medial, or palmar surfaces of the tendon sheath. The palmar digital vessels and nerves were avoided by palmar placement of the instrument incisions and insertion of a needle before incising the skin. The fetlock canal and proximal regions of the tendon sheath were examined by redirecting the arthroscope. Flexion of the fetlock aided passage of the arthroscope into the proximal tendon sheath regions. Evaluation of the palmar surface of the superficial digital flexor tendon was limited by the midline attachment of the tendon sheath, otherwise the surfaces of the tendons and tendon sheath could be examined with 25 degrees and 70 degrees arthroscopes. The tendon sheath was more tightly invested to the tendons in the proximal regions, limiting the arthroscope movements and second instrument access. PMID:2382395

  5. Influence of running shoes and cross-trainers on Achilles tendon forces during running compared with military boots.

    PubMed

    Sinclair, Jonathan; Taylor, P J; Atkins, S

    2015-06-01

    Military recruits are known to be susceptible to Achilles tendon pathology. The British Army have introduced footwear models, the PT-03 (cross-trainer) and PT1000 (running shoes), in an attempt to reduce the incidence of injuries. The aim of the current investigation was to examine the Achilles tendon forces of the cross-trainer and running shoe in relation to conventional army boots. Ten male participants ran at 4.0?m/s in each footwear condition. Achilles tendon forces were obtained throughout the stance phase of running and compared using repeated-measures ANOVAs. The results showed that the time to peak Achilles tendon force was significantly shorter when running in conventional army boots (0.12?s) in comparison with the cross-trainer (0.13?s) and running shoe (0.13?s). Achilles tendon loading rate was shown to be significantly greater in conventional army boots (38.73?BW/s) in comparison with the cross-trainer (35.14?BW/s) and running shoe (33.57?BW/s). The results of this study suggest that the running shoes and cross-trainer footwear are associated with reductions in Achilles tendon parameters that have been linked to the aetiology of injury, and thus it can be hypothesised that these footwear could be beneficial for military recruits undertaking running exercises. PMID:25428136

  6. Post-LASIK Tear Dysfunction and Dysesthesia

    PubMed Central

    NETTUNE, GREGORY R.; PFLUGFELDER, STEPHEN C.

    2013-01-01

    Symptoms of tear dysfunction after laser in situ keratomileusis (LASIK) occur in nearly all patients and resolve in the vast majority. Although dry eye complaints are a leading cause of patient discomfort and dissatisfaction after LASIK, the symptoms are not uniform, and the disease is not a single entity. Post-LASIK tear dysfunction syndrome or dry eye is a term used to describe a spectrum of disease encompassing transient or persistent post-operative neurotrophic disease, tear instability, true aqueous tear deficiency, and neuropathic pain states. Neural changes in the cornea and neuropathic causes of ocular surface discomfort may play a separate or synergistic role in the development of symptoms in some patients. Most cases of early post-operative dry eye symptoms resolve with appropriate management, which includes optimizing ocular surface health before and after surgery. Severe symptoms or symptoms persisting after 9 months rarely respond satisfactorily to traditional treatment modalities and require aggressive management. This review covers current theories of post-LASIK dry eye disease, pathophysiology, risk factors, and management options for this disease spectrum of post-LASIK tear dysfunction and neuropathic pain. PMID:20712970

  7. Meniscal root tears: significance, diagnosis, and treatment.

    PubMed

    Bhatia, Sanjeev; LaPrade, Christopher M; Ellman, Michael B; LaPrade, Robert F

    2014-12-01

    Meniscal root tears, less common than meniscal body tears and frequently unrecognized, are a subset of meniscal injuries that often result in significant knee joint disorders. The meniscus root attachment aids meniscal function by securing the meniscus in place and allowing for optimal shock-absorbing function in the knee. With root tears, meniscal extrusion often occurs, and the transmission of circumferential hoop stresses is impaired. This alters knee biomechanics and kinematics and significantly increases tibiofemoral contact pressure. In recent years, meniscal root tears, which by definition include direct avulsions off the tibial plateau or radial tears adjacent to the root itself, have attracted attention because of concerns that significant meniscal extrusion dramatically inhibits normal meniscal function, leading to a condition biomechanically similar to a total meniscectomy. Recent literature has highlighted the importance of early diagnosis and treatment; fortunately, these processes have been vastly improved by advances in magnetic resonance imaging and arthroscopy. This article presents a review of the clinically relevant anatomic, biomechanical, and functional descriptions of the meniscus root attachments, as well as current strategies for accurate diagnosis and treatment of common injuries to these meniscus root attachments. PMID:24623276

  8. Multi-layer electrospun membrane mimicking tendon sheath for prevention of tendon adhesions.

    PubMed

    Jiang, Shichao; Yan, Hede; Fan, Dapeng; Song, Jialin; Fan, Cunyi

    2015-01-01

    Defect of the tendon sheath after tendon injury is a main reason for tendon adhesions, but it is a daunting challenge for the biomimetic substitute of the tendon sheath after injury due to its multi-layer membrane-like structure and complex biologic functions. In this study, a multi-layer membrane with celecoxib-loaded poly(l-lactic acid)-polyethylene glycol (PELA) electrospun fibrous membrane as the outer layer, hyaluronic acid (HA) gel as middle layer, and PELA electrospun fibrous membrane as the inner layer was designed. The anti-adhesion efficacy of this multi-layer membrane was compared with a single-layer use in rabbit flexor digitorum profundus tendon model. The surface morphology showed that both PELA fibers and celecoxib-loaded PELA fibers in multi-layer membrane were uniform in size, randomly arrayed, very porous, and smooth without beads. Multi-layer membrane group had fewer peritendinous adhesions and better gliding than the PELA membrane group and control group in gross and histological observation. The similar mechanical characteristic and collagen expression of tendon repair site in the three groups indicated that the multi-layer membrane did not impair tendon healing. Taken together, our results demonstrated that such a biomimetic multi-layer sheath could be used as a potential strategy in clinics for promoting tendon gliding and preventing adhesion without poor tendon healing. PMID:25822877

  9. Transglutaminases expression in human supraspinatus tendon ruptures and in mouse tendons.

    PubMed

    Oliva, Francesco; Zocchi, Loredana; Codispoti, Andrea; Candi, Eleonora; Celi, Monica; Melino, Gerry; Maffulli, Nicola; Tarantino, Umberto

    2009-02-20

    The ethiopathogenesis of rotator cuff disease remains poorly understood. Many studies advocate the importance of extra cellular matrix for the homeostasis of connective tissue. Transglutaminase enzymes family has been studied in the context of connective tissue formation and stabilisation. Here, we investigated transglutaminases expression pattern in biopsies of normal and injured supraspinatus tendons of human shoulders and in the Achilles tendons of transglutaminase 2 knock-out and wild-type mice. Our results show that different transglutaminase family members are differentially expressed in human and mouse tendons, and that transglutaminase 2 is down-regulated at mRNA and protein levels upon human supraspinatus tendon ruptures. PMID:19146825

  10. Position Control of Tendon-Driven Fingers

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E.; Platt, Robert, Jr.; Hargrave, B.; Pementer, Frank

    2011-01-01

    Conventionally, tendon-driven manipulators implement some force control scheme based on tension feedback. This feedback allows the system to ensure that the tendons are maintained taut with proper levels of tensioning at all times. Occasionally, whether it is due to the lack of tension feedback or the inability to implement sufficiently high stiffnesses, a position control scheme is needed. This work compares three position controllers for tendon-driven manipulators. A new controller is introduced that achieves the best overall performance with regards to speed, accuracy, and transient behavior. To compensate for the lack of tension feedback, the controller nominally maintains the internal tension on the tendons by implementing a two-tier architecture with a range-space constraint. These control laws are validated experimentally on the Robonaut-2 humanoid hand. I

  11. Use of tear ring permits repair of sealed module circuitry

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Improved packaging technique for modular electronic circuitry utilizes a tear ring which may be removed for repair and resealed. The tear ring is put over the container and header to which the electronic circuit assembly has been attached.

  12. Acute Patellar Tendon Rupture after Total Knee Arthroplasty Revision.

    PubMed

    Rhee, Seung Joon; Pham, The Hien; Suh, Jeung Tak

    2015-06-01

    Patellar tendon rupture is a catastrophic complication following total knee arthroplasty (TKA). Though revision TKA has been suspected of being a predisposing factor for the occurrence of patellar tendon rupture, there are few reports on patellar tendon rupture after revision TKA. Here, we present a case of acute patellar tendon rupture that occurred after TKA revision. In the patient, the patellar tendon was so thin and could not be repaired, and accordingly was sutured end to end. We used the anterior tibialis tendon allograft to augment the poor quality patellar tendon tissue. Fixation of the allograft was done by using the bone tunnel created through tibial tuberosity and suturing the allograft to the patellar tendon and quadriceps tendon. The patient was instructed to wear a full extension knee splint and was kept non-weight bearing for 6 weeks after operation. Full knee extension could be achieved 6 weeks postoperatively. PMID:26060612

  13. Flexor tendon ruptures secondary to hamate hook fractures.

    PubMed

    Milek, M A; Boulas, H J

    1990-09-01

    Four patients with flexor tendon ruptures secondary to hook of the hamate fracture are described. None of the patients had the diagnosis of fracture made before tendon rupture. All patients were treated with excision of the fractured hook and tendon repair. The tendon repair was usually an end-to-side (Y junction) of the profundus of the small to the profundus of the ring finger. After operation, all patients were free of pain and returned to their preinjury activity levels, but most had some limitation of motion in the digit with the tendon repair. The complication of tendon rupture not uncommonly follows basilar hook of the hamate fractures. Treatment by excision of the fracture and end-to-side tendon repair produces satisfactory results. Range of motion after tendon repair seems to depend more on the patient's age and the amount of inflammation at the site of repair rather than on the method of tendon repair. PMID:2229970

  14. Acute Patellar Tendon Rupture after Total Knee Arthroplasty Revision

    PubMed Central

    Rhee, Seung Joon; Pham, The Hien

    2015-01-01

    Patellar tendon rupture is a catastrophic complication following total knee arthroplasty (TKA). Though revision TKA has been suspected of being a predisposing factor for the occurrence of patellar tendon rupture, there are few reports on patellar tendon rupture after revision TKA. Here, we present a case of acute patellar tendon rupture that occurred after TKA revision. In the patient, the patellar tendon was so thin and could not be repaired, and accordingly was sutured end to end. We used the anterior tibialis tendon allograft to augment the poor quality patellar tendon tissue. Fixation of the allograft was done by using the bone tunnel created through tibial tuberosity and suturing the allograft to the patellar tendon and quadriceps tendon. The patient was instructed to wear a full extension knee splint and was kept non-weight bearing for 6 weeks after operation. Full knee extension could be achieved 6 weeks postoperatively. PMID:26060612

  15. Bilateral quadriceps tendon rupture — A case report

    Microsoft Academic Search

    T. K. Kaar; M. O’Brien; P. Murray; G. B. Mullan

    1993-01-01

    Summary  The diagnosis of rupture of the quadriceps tendon is made relatively infrequently and bilateral simultaneous rupture is a\\u000a rarity. We report a case of spontaneous bilateral rupture of the quadriceps tendon in a patient with documented chronic renal\\u000a insufficiency and secondary hyperparathyroidism. A predisposing cause to the condition as obtained in this case, has been\\u000a described in cases previously published

  16. MRI 'magic angle' imaging of finger tendons.

    PubMed

    Lambe, G; Coutts, G; McArthur, P; Dangerfield, P H

    2006-04-01

    The value of using the technique of magic angle MR imaging to demonstrate finger tendons is explored. Images of fresh frozen cadaveric specimens are presented and the structures that can be visualized in the finger are described. The results suggest that magic angle MR imaging may be a useful non-invasive technique of visualizing the details of the tendons and their surrounds in the hand. PMID:16182418

  17. Traumatic flexor tendon injuries in 27 cattle.

    PubMed

    Anderson, D E; St-Jean, G; Morin, D E; Ducharme, N G; Nelson, D R; Desrochers, A

    1996-01-01

    Information for all cattle with a diagnosis of tendon injury entered into the Veterinary Medical Data Base (VMDB) was retrieved and selected medical records reviewed. The proportional morbidity rate for tendon disruption was 0.89 cattle/1,000 cattle admissions and 95 of 99 cattle survived. Female and dairy cattle had a greater risk of tendon disruption than male or beef cattle, respectively. Also, cattle 6 months to 7 years old had a greater risk than cattle younger than 6 months old. Complete medical records were examined for 27 cattle. Affected cattle were 2.5 +/- 1.8 years old and weighed 593.6 +/- 315.6 kg. Injuries were most commonly caused by accidents involving farm machinery (72%). Unilateral superficial digital flexor tendon injury occurred in 8 cattle (30%); multiple tendon injury occurred in the other 19 cattle (70%). A single limb was involved in 25 cattle, a rear limb was involved in 24 cattle, and an open wound was associated with the injury in 26 cattle. Wounds were identified most commonly at the mid (13 cattle) and proximal metatarsus (4 cattle). Treatment of tendon disruption included tenorrhaphy and casting (9 cattle), external coaptation, alone, (14 cattle), stall confinement, alone, (1 cow), and euthanasia or salvage (3 cattle). External coaptation was maintained for 74.4 +/- 34.3 days, and total confinement period was 88.3 +/- 59.5 days. Short-term complications included severe tendon laxity (one cow) and fatal septic peritonitis (one bull). Twenty-two of 24 cattle treated for tendon disruption survived. Follow-up information was available for 16 cattle; 14 cattle (87%) returned to productivity and 11 of 15 cattle with long-term follow-up (73%) were considered productive. Long-term complications included persistent lameness (56%) and persistent hyperextension of the digits (19%). PMID:8810022

  18. Arthroscopic treatment of a large lateral femoral notch in acute anterior cruciate ligament tear.

    PubMed

    Tauber, Mark; Fox, Michael; Koller, Heiko; Klampfer, Helmut; Resch, Herbert

    2008-11-01

    A 24-year-old professional soccer player suffered an acute anterior cruciate ligament tear associated with a radiologically evident impression fracture of the lateral femoral condyle, the so-called "lateral femoral notch sign". Following MRI validation of the injury with detection of an additional lateral meniscus tear, arthroscopy was carried out 3 days after the injury. Due to the extended impression of about 5 mm, arthroscopically assisted closed reduction of the depression fracture was performed. A 3.2 mm tunnel was drilled at the lateral femoral condyle in a supero-inferior direction using an ACL tibial guide and the depressed area could be restored using an elevator. The resulting subchondral bone defect in the femoral condyle was filled with freeze-dried human cancellous bone allograft. As a one-stage procedure ACL reconstruction was carried out using a hamstring tendon technique. At 1-year follow up the patient has returned to full sporting function, including playing soccer with a radiographically reduced lateral femoral notch sign. PMID:18060552

  19. Arthroscopic treatment options for irreparable rotator cuff tears of the shoulder

    PubMed Central

    Anley, Cameron M; Chan, Samuel KL; Snow, Martyn

    2014-01-01

    The management of patients with irreparable rotator cuff tears remains a challenge for orthopaedic surgeons with the final treatment option in many algorithms being either a reverse shoulder arthroplasty or a tendon transfer. The long term results of these procedures are however still widely debated, especially in younger patients. A variety of arthroscopic treatment options have been proposed for patients with an irreparable rotator cuff tear without the presence of arthritis of the glenohumeral joint. These include a simple debridement with or without a biceps tenotomy, partial rotator cuff repair with or without an interval slide, tuberplasty, graft interposition of the rotator cuff, suprascapular nerve ablation, superior capsule reconstruction and insertion of a biodegradable spacer (Inspace) to depress the humeral head. These options should be considered as part of the treatment algorithm in patients with an irreparable rotator cuff and could be used as either as an interim procedure, delaying the need for more invasive surgery in the physiologically young and active, or as potential definitive procedures in the medically unfit. The aim of this review is to highlight and summarise arthroscopic procedures and the results thereof currently utilised in the management of these challenging patients. PMID:25405083

  20. In vivo identity of tendon stem cells and the roles of stem cells in tendon healing.

    PubMed

    Tan, Qi; Lui, Pauline Po Yee; Lee, Yuk Wa

    2013-12-01

    We investigated the spatial distribution of stem cells in tendons and the roles of stem cells in early tendon repair. The relationship between tendon-derived stem cells (TDSCs) isolated in vitro and tendon stem cells in vivo was also explored. Iododeoxyuridine (IdU) label-retaining method was used for labeling stem cells in rat patellar tendons with and without injury. Co-localization of label-retaining cells (LRCs) with different markers was done by immunofluorescent staining. TDSCs were isolated from patellar tendon mid-substance after IdU pulsing, and the expression of different markers in fresh and expanded cells was done by immunofluorescent staining. More LRCs were found at the peritenon and tendon-bone junction compared with the mid-substance. Some LRCs at the peritenon were located at the perivascular niche. The LRC number and the expression of proliferative, tendon-related, pluripotency, and pericyte-related markers in LRCs in the window wound increased. Most of the freshly isolated TDSCs expressed IdU, and some TDSCs expressed pericyte-related markers, which were lost during expansion. Both freshly isolated and subcultured TDSCs expressed pluripotency markers, which were absent in LRCs in intact tendons. In conclusion, we identified LRCs at the peritenon, mid-substance, and tendon-bone junction. There were both vascular and non-vascular sources of LRCs at the peritenon, while the source of LRCs at the mid-substance was non-vascular. LRCs participated in tendon repair via migration, proliferation, activation for tenogenesis, and increased pluripotency. Some LRCs in the window wound were pericyte like. Most of the mid-substance TDSCs were LRCs. The pluripotency markers and pericyte-related marker in LRCs might be important for function after injury. PMID:23815595

  1. Tearing modes in solar coronal loops

    SciTech Connect

    Hassam, A.B. (Maryland Univ., College Park (USA))

    1990-01-01

    It is shown that solar coronal-like magnetic loops, that is loops emerging from and reentering heavy plasma, are unstable to tearing modes. In particular, the previously made assumption of line tying to the heavy plasma, resulting in stabilization, is shown to be inapplicable because the growth rate is sub-Alfvenic in the entire loop, including the submerged part. In fact, it is shown that the tearing mode may grow faster than ordinarily surmised because the growth rate is determined by the average resistivity along an entire flux line rather than by the resistivity in the corona alone. 12 refs.

  2. Arthroscopic quadriceps tendon repair: two case reports.

    PubMed

    Saito, Hidetomo; Shimada, Yoichi; Yamamura, Toshiaki; Yamada, Shin; Sato, Takahiro; Nozaka, Koji; Kijima, Hiroaki; Saito, Kimio

    2015-01-01

    Recently, although some studies of open repair of the tendon of the quadriceps femoris have been published, there have been no reports in the literature on primary arthroscopic repair. In our present study, we present two cases of quadriceps tendon injury arthroscopically repaired with excellent results. Case 1 involved a 68-year-old man who was injured while shifting his weight to prevent a fall. MRI showed complete rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using both suture anchor and pull-out suture fixation methods via bone tunnels (hereafter, pull-out fixation). Two years after surgery, retearing was not observed on MRI and both Japan Orthopedic Association (JOA) Knee and Lysholm scores had recovered to 100. Case 2 involved a 50-year-old man who was also injured when shifting his weight to prevent a fall. MRI showed incomplete superficial rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using pull-out fixation of six strand sutures. One year after surgery, MRI revealed a healed tendon and his JOA and Lysholm scores were 95 and 100, respectively. Thus, arthroscopic repair may be a useful surgical method for repairing quadriceps tendon injury. PMID:25815224

  3. Arthroscopic Quadriceps Tendon Repair: Two Case Reports

    PubMed Central

    Saito, Hidetomo; Shimada, Yoichi; Yamamura, Toshiaki; Yamada, Shin; Sato, Takahiro; Nozaka, Koji; Kijima, Hiroaki; Saito, Kimio

    2015-01-01

    Recently, although some studies of open repair of the tendon of the quadriceps femoris have been published, there have been no reports in the literature on primary arthroscopic repair. In our present study, we present two cases of quadriceps tendon injury arthroscopically repaired with excellent results. Case 1 involved a 68-year-old man who was injured while shifting his weight to prevent a fall. MRI showed complete rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using both suture anchor and pull-out suture fixation methods via bone tunnels (hereafter, pull-out fixation). Two years after surgery, retearing was not observed on MRI and both Japan Orthopedic Association (JOA) Knee and Lysholm scores had recovered to 100. Case 2 involved a 50-year-old man who was also injured when shifting his weight to prevent a fall. MRI showed incomplete superficial rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using pull-out fixation of six strand sutures. One year after surgery, MRI revealed a healed tendon and his JOA and Lysholm scores were 95 and 100, respectively. Thus, arthroscopic repair may be a useful surgical method for repairing quadriceps tendon injury. PMID:25815224

  4. Laser photoirradiation in digital flexor tendon repair.

    PubMed

    Burt, J D; Siddins, M; Morrison, W A

    2001-09-01

    This study evaluates tendon coaptation using Nd:YAG laser photoirradiation in an in vivo cockerel model. Using the intervinculum segments of the flexor profundus tendons, experimental transactions were performed. Tendon coaptation was then attempted using laser photoirradiation. Tendons were immediately examined for evidence of stable coaptation. After this assessment, specimens were excised and processed for electron microscopic examination and exposure to trypsin digestion. Despite varying multiple laser parameters, tissue welding was not observed. The subsequent functional and ultrastructural observations of irradiated tendon suggest that these changes are those of simple thermal denaturation. The results of this study suggest that when successful tissue welding has been observed in other tissue types, the mechanism is unlikely to be because of formation of intermolecular collagen bonds as hypothesized. An alternative hypothesis is that laser welding reflects photothermal coagulation of cytoplasmic peptides or nucleic acids liberated at the coaptation interface. This may explain the successful welding of cell-rich tissues such as bowel, vas deferens, and arteries and the observed failure of laser welding in collagen-rich but relatively hypocellular tendon. PMID:11698841

  5. Mechanical environment associated with rotator cuff tears

    Microsoft Academic Search

    Zong-Ping Luo; Horng-Chaung Hsu; John J. Grabowski; Bernard F. Morrey; Kai-Nan An

    1998-01-01

    A simplified 2-dimensional finite element model was used to investigate the stress environment in the supraspinatus tendon. The extrafibrillar matrix and collagen fiber were modeled with fiber-reinforced composite elements. The stress was evaluated at humeroscapular elevation angles of 0°, 30°, and 60°. Two acromion conditions were simulated. In the first set of conditions there was no subacromial impingement. In the

  6. Explosive tearing mode reconnection in the magnetospheric tail

    Microsoft Academic Search

    A. A. Galeev; F. V. Coroniti; M. Ashour-Abdalla

    1978-01-01

    A speculative model for the nonlinear phase of the collisionless tearing instability is developed for the case of a single long wavelength tearing mode. Using an energy principle formalism, we find that the nonlinear growth rate is linearly proportional to the mode amplitude. Hence in the nonlinear phase, the tearing mode grows explosively in time, and saturates when the width

  7. Arthroscopic anterior cruciate ligament reconstruction with quadriceps tendon composite autograft.

    PubMed

    Kim, D W; Kim, J O; You, J D; Kim, S J; Kim, H K

    2001-05-01

    At present, no single graft option clearly outperforms another. Autografts (patellar tendon, hamstring) and allografts (Achilles tendon, patellar tendon) are the grafts most often used. However, each grafts has advantages and disadvantages. Quadriceps tendon graft for anterior cruciate ligament reconstruction is not new, but an alternative composite graft is introduced here that consists of quadriceps tendon-patellar bone and bone obtained from a coring reamer used to create the tibial tunnel. This composite graft retains reduced morbidity while allowing the secure bone-to-bone fixation associated with bone-patellar tendon-bone graft. PMID:11337727

  8. Advances in the healing of flexor tendon injuries.

    PubMed

    Sammer, Douglas M; Chung, Kevin C

    2014-05-01

    The intrasynovial flexor tendons of the hand are critical for normal hand function. Injury to these tendons can result in absent finger flexion, and a subsequent loss of overall hand function. The surgical techniques used to repair these tendons have improved in the past few decades, as have the postoperative rehabilitation protocols. In spite of these advances, intrasynovial flexor tendon repairs continue to be plagued by postoperative scar formation, which limits tendon gliding and prevents a full functional recovery. This paper describes the current challenges of flexor tendon repair, and evaluates the most recent advances and strategies for achieving an excellent functional outcome. PMID:24813361

  9. Living with a symptomatic rotator cuff tear ‘bad days, bad nights’: a qualitative study

    PubMed Central

    2014-01-01

    Background Rotator cuff tears are a common cause of shoulder pain. There is an absence of information about symptomatic rotator cuffs from the patients’ perspective; this limits the information clinicians can share with patients and the information that patients can access via sources such as the internet. This study describes the experiences of people with a symptomatic rotator cuff, their symptoms, the impact upon their daily lives and the coping strategies utilised by study participants. Methods An interpretive phenomenological analysis approach was used. 20 participants of the UKUFF trial (The United Kingdom Rotator Cuff Surgery Trial) agreed to participate in in-depth semi-structured interviews about their experiences about living with a symptomatic rotator cuff tear. Interviews were digitally recorded and fully transcribed. Field notes, memos and a reflexive diary were used. Data was coded in accordance with interpretive phenomenological analysis. Peer review, code-recode audits and constant comparison of data, codes and categories occurred throughout. Results The majority of patients described intense pain and severely disturbed sleep. Limited movement and reduced muscle strength were described by some participants. The predominantly adverse impact that a symptomatic rotator cuff tear had upon activities of daily living, leisure activities and occupation was described. The emotional and financial impact and impact upon caring roles were detailed. Coping strategies included attempting to carry on as normally as possible, accepting their condition, using their other arm, using analgesics, aids and adaptions. Conclusions Clinicians need to appreciate and understand the intensity and shocking nature of pain that may be experienced by participants with known rotator cuff tears and understand the detrimental impact tears can have upon all areas of patient’s lives. Clinicians also need to be aware of the potential emotional impact caused by cuff tears and to ensure that patients needing help for conditions such as depression are speedily identified and provided with support, explanation and appropriate treatment. PMID:25008095

  10. Electrolytes and Electrophoretic Studies of Tear Proteins in Tears of Patients with Nasolacrimal Duct Obstruction

    Microsoft Academic Search

    Helen Lew; Young-Soo Yun; Sang-Yeul Lee

    2005-01-01

    This study was performed to determine whether there are differences in tear constituents between normal persons and patients with primary acquired nasolacrimal duct obstruction (PANDO) and to correlate differences in tear composition with the degree of PANDO. We tested 30 normal persons (mean age 42.0 ± 21.4 years) and 34 PANDO patients (mean age 44.8 ± 17.9 years) consisting of

  11. MR imaging-based diagnosis and classification of meniscal tears.

    PubMed

    Nguyen, Jie C; De Smet, Arthur A; Graf, Ben K; Rosas, Humberto G

    2014-01-01

    Magnetic resonance (MR) imaging is currently the modality of choice for detecting meniscal injuries and planning subsequent treatment. A thorough understanding of the imaging protocols, normal meniscal anatomy, surrounding anatomic structures, and anatomic variants and pitfalls is critical to ensure diagnostic accuracy and prevent unnecessary surgery. High-spatial-resolution imaging of the meniscus can be performed using fast spin-echo and three-dimensional MR imaging sequences. Normal anatomic structures that can mimic a tear include the meniscal ligament, meniscofemoral ligaments, popliteomeniscal fascicles, and meniscomeniscal ligament. Anatomic variants and pitfalls that can mimic a tear include discoid meniscus, meniscal flounce, a meniscal ossicle, and chondrocalcinosis. When a meniscal tear is identified, accurate description and classification of the tear pattern can guide the referring clinician in patient education and surgical planning. For example, longitudinal tears are often amenable to repair, whereas horizontal and radial tears may require partial meniscectomy. Tear patterns include horizontal, longitudinal, radial, root, complex, displaced, and bucket-handle tears. Occasionally, meniscal tears can be difficult to detect at imaging; however, secondary indirect signs, such as a parameniscal cyst, meniscal extrusion, or linear subchondral bone marrow edema, should increase the radiologist's suspicion for an underlying tear. Awareness of common diagnostic errors can ensure accurate diagnosis of meniscal tears. Online supplemental material is available for this article. PMID:25019436

  12. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Passive tendon prosthesis. (a) Identification. A passive tendon prosthesis is a device intended to be implanted made of silicon elastomer or a polyester reinforced medical grade silicone elastomer intended for use in the surgical...

  13. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Passive tendon prosthesis. (a) Identification. A passive tendon prosthesis is a device intended to be implanted made of silicon elastomer or a polyester reinforced medical grade silicone elastomer intended for use in the surgical...

  14. Biology and augmentation of tendon-bone insertion repair

    Microsoft Academic Search

    Pauline Po-Yee Lui; Peng Zhang; Kai-Ming Chan; Ling Qin

    2010-01-01

    Surgical reattachment of tendon and bone such as in rotator cuff repair, patellar-patella tendon repair and anterior cruciate ligament (ACL) reconstruction often fails due to the failure of regeneration of the specialized tissue (\\

  15. Robot Arm with Tendon Connector Plate and Linear Actuator

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Bridgwater, Lyndon (Inventor); Nguyen, Vienny (Inventor); Millerman, Alexander (Inventor)

    2014-01-01

    A robotic system includes a tendon-driven end effector, a linear actuator, a flexible tendon, and a plate assembly. The linear actuator assembly has a servo motor and a drive mechanism, the latter of which translates linearly with respect to a drive axis of the servo motor in response to output torque from the servo motor. The tendon connects to the end effector and drive mechanism. The plate assembly is disposed between the linear actuator assembly and the tendon-driven end effector and includes first and second plates. The first plate has a first side that defines a boss with a center opening. The second plate defines an accurate through-slot having tendon guide channels. The first plate defines a through passage for the tendon between the center opening and a second side of the first plate. A looped end of the flexible tendon is received within the tendon guide channels.

  16. Tear function and ocular surface after muller muscle- conjunctival resection

    PubMed Central

    U?urba?, Suat Hayri; Alpay, Atilla; Bahad?r, Burak; U?urba?, S?lay Cantürk

    2014-01-01

    Muller muscle-conjunctival resection (MCR) is a surgical technique to correct mild and moderate ptosis. In this study, tear function tests and ocular surface are evaluated in patients who underwent unilateral surgery. Sixteen patients with normal preoperative tear function who underwent unilateral MCR were evaluated prospectively. The fellow eyes of the patients were taken as the control group. A dry eye assessment questionnaire, Schirmer testing, tear film break-up time, fluorescein stain, Rose-Bengal stain, and conjunctival impression cytology were used to assess the tear film functions and ocular surface changes in the operated and non-operated eyes. There was no statistically significant difference in the tear function tests and goblet cell densities between the operated and non-operated eyes. The results indicate that an MCR procedure has no apparent effect on tear function tests and goblet cell density in patients with normal preoperative tear function. PMID:24088631

  17. A single unit digital flexor tendon prosthesis.

    PubMed

    King, R N; Dunn, H K; Bolstad, K E

    1975-07-01

    Historically, the surgical repair of serious injuries to the flexor tendons of the hand have met with less than satisfactory clinical results. In an attempt to solve this problem, studies have been made on the design and testing of a Dacron polyester tendon prosthesis for complete replacement of the digital flexor tendon. The prosthesis attaches proximally at the anatomical musculotendon junction via collagen ingrowth into a fabric structure and in similar manner distally via bone ingrowth at the anatomical insertion site. These fabrics are continuous with the tendon body of the prosthesis consisting of an inextensible braided cord which is silicone rubber coated to prevent tissue adherence in the glide zone of the tendon bed. An added benefit of the prosthesis is a simple means of length adjustment which can easily be carried out on the operating table. Studies have been performed in both dogs and chickens which indicate that sufficient tissue ingrowth occurs at both the distal and proximal anastomoses for retention of full load bearing capability in these animals and that postoperative adhesions are negligible, if present at all. Full prostheses have been implanted in dogs for periods of over 1 year and chickens for 2 months. The chicken is the preferred animal model as a tendency for extensive scar tissue generation was shown in the dog. Both in vivo mechanical testing and histological characterization have been made on sacrificed animals which have received the full prostheses. PMID:1176499

  18. Supernumerary extensor tendon to the thumb: a case report.

    PubMed

    Cohen, B E; Haber, J L

    1996-01-01

    Anomalies of the dorsal tendons of the hand are not uncommon. Numerous variations in the tendons coursing through the fourth dorsal extensor compartment have been described. We report a rare case of a supernumerary tendon passing through the fourth dorsal compartment and inserting into the distal phalanx of the thumb. We also review the anomalous muscles and tendons that are found in this compartment. PMID:8722996

  19. Structure-function relationships in tendons: a review

    PubMed Central

    Benjamin, M; Kaiser, E; Milz, S

    2008-01-01

    The purpose of the current review is to highlight the structure-function relationship of tendons and related structures to provide an overview for readers whose interest in tendons needs to be underpinned by anatomy. Because of the availability of several recent reviews on tendon development and entheses, the focus of the current work is primarily directed towards what can best be described as the ‘tendon proper’ or the ‘mid-substance’ of tendons. The review covers all levels of tendon structure from the molecular to the gross and deals both with the extracellular matrix and with tendon cells. The latter are often called ‘tenocytes’ and are increasingly recognized as a defined cell population that is functionally and phenotypically distinct from other fibroblast-like cells. This is illustrated by their response to different types of mechanical stress. However, it is not only tendon cells, but tendons as a whole that exhibit distinct structure-function relationships geared to the changing mechanical stresses to which they are subject. This aspect of tendon biology is considered in some detail. Attention is briefly directed to the blood and nerve supply of tendons, for this is an important issue that relates to the intrinsic healing capacity of tendons. Structures closely related to tendons (joint capsules, tendon sheaths, pulleys, retinacula, fat pads and bursae) are also covered and the concept of a ‘supertendon’ is introduced to describe a collection of tendons in which the function of the whole complex exceeds that of its individual members. Finally, attention is drawn to the important relationship between tendons and fascia, highlighted by Wood Jones in his concept of an ‘ectoskeleton’ over half a century ago – work that is often forgotten today. PMID:18304204

  20. Achilles allograft reconstruction of a chronic patellar tendon rupture

    Microsoft Academic Search

    PD McNally; EA Marcelli

    1998-01-01

    Chronic ruptures of the patellar tendon are uncommon injuries. They are technically difficult to repair because of scar formation, poor quality of the remaining tendon, and quadriceps muscle atrophy and contracture. We report the reconstruction of a chronic patellar tendon rupture with an interesting complication, a tibial stress fracture. The reconstruction was performed 3 months after the injury using an

  1. Patellar and quadriceps tendon ru p tures— jumper's knee

    Microsoft Academic Search

    Douglas W. Kelly; Vincent S. Carter; Frank W. Jobe; Robert K. Kerlan

    1984-01-01

    We reviewed 13 patients with end stage jumper's knee, 10 with patellar tendon ruptures, and 3 with ruptures of the quadriceps tendon to evaluate our long-term results in treating these tendon ruptures in an athletic population. The focus was on the natural history, the time until return, and the level of return, to athletic activity. Jumper's knee affected all patients

  2. Repair of quadriceps tendon ruptures using suture anchors

    Microsoft Academic Search

    David P. Richards; F. Alan Barber

    2002-01-01

    The repair of ruptured quadriceps tendon is commonly performed by weaving sutures through the ruptured tendon and then attaching the tendon to the bone by passing these sutures through tunnels in the superior patella. This technical note is the first report we are aware of in the English language literature of a technique that uses suture anchors to attach the

  3. The integrated function of muscles and tendons during locomotion

    Microsoft Academic Search

    Thomas J. Roberts

    2002-01-01

    The mechanical roles of tendon and muscle contractile elements during locomotion are often considered independently, but functionally they are tightly integrated. Tendons can enhance muscle performance for a wide range of locomotor activities because muscle–tendon units shorten and lengthen at velocities that would be mechanically unfavorable for muscle fibers functioning alone. During activities that require little net mechanical power output,

  4. Molecular regulation of tendon cell fate during development.

    PubMed

    Huang, Alice H; Lu, Helen H; Schweitzer, Ronen

    2015-06-01

    Although there have been several advances identifying novel mediators of tendon induction, differentiation, and patterning, much of the basic landscape of tendon biology from developmental stages onward remain almost completely undefined. During the New Frontiers in Tendon Research meeting, a group of developmental biologists with expertise across musculoskeletal disciplines identified key challenges for the tendon development field. The tools generated and the molecular regulators identified in developmental research have enhanced mechanistic studies in tendon injury and repair, both by defining benchmarks for success, as well as informing regenerative strategies. To address the needs of the orthopedic research community, this review will therefore focus on three key areas in tendon development that may have critical implications for the fields of tendon repair/regeneration and tendon tissue engineering, including functional markers of tendon cell identity, signaling regulators of tendon induction and differentiation, and in vitro culture models for tendon cell differentiation. Our goal is to provide a useful list of the currently known molecular players and their function in tendon differentiation within the context of development. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:800-812, 2015. PMID:25664867

  5. An Overview of the Management of Flexor Tendon Injuries

    PubMed Central

    Griffin, M; Hindocha, S; Jordan, D; Saleh, M; Khan, W

    2012-01-01

    Flexor tendon injuries still remain a challenging condition to manage to ensure optimal outcome for the patient. Since the first flexor tendon repair was described by Kirchmayr in 1917, several approaches to flexor tendon injury have enabled successful repairs rates of 70-90%. Primary surgical repair results in better functional outcome compared to secondary repair or tendon graft surgery. Flexor tendon injury repair has been extensively researched and the literature demonstrates successful repair requires minimal gapping at the repair site or interference with tendon vascularity, secure suture knots, smooth junction of tendon end and having sufficient strength for healing. However, the exact surgical approach to achieve success being currently used among surgeons is still controversial. Therefore, this review aims to discuss the results of studies demonstrating the current knowledge regarding the optimal approach for flexor tendon repair. Post-operative rehabilitation for flexor tendon surgery is another area, which has caused extensive debate in hand surgery. The trend to more active mobilisation protocols seems to be favoured but further study in this area is needed to find the protocol, which achieves function and gliding but avoids rupture of the tendons. Lastly despite success following surgery complications commonly still occur post surgery, including adhesion formation, tendon rupture and stiffness of the joints. Therefore, this review aims to discuss the appropriate management of these difficulties post surgery. New techniques in management of flexor tendon will also be discussed including external laser devices, addition of growth factors and cytokines. PMID:22431948

  6. Platelet-rich plasma (prp) and tendon healing: animal model

    Microsoft Academic Search

    J F Kaux; P Drion; J Renouf; F Pascon; V Libertiaux; A Colige; C Le Goff; C Lambert; B Nusgens; A Gothot; S Cescotto; J O Defraigne; M Rickert; J M Crielaard

    2011-01-01

    IntroductionThe tendon is a tissue which does not heal easily. Recently, several studies have demonstrated the positive effects of platelets on the healing process of tendons. A local injection of platelet-rich plasma (PRP), which releases in situ many growth factors, has the potentiality to enhance the tendon healing process. The aim of our experiment was to ascertain by an original

  7. Overuse tendon conditions: Time to change a confusing terminology

    Microsoft Academic Search

    N Maffulli

    1998-01-01

    In overuse clinical conditions in and around tendons, frank inflammation is infrequent, and is associated mostly with tendon ruptures. Tendinosis implies tendon degeneration without clinical or histological signs of intratendinous inflammation, and is not necessarily symptomatic. Patients undergoing an operation for Achilles tendinopathy show similar areas of degeneration. When the term tendinitis is used in a clinical context, it does

  8. BME 315 Biomechanics Experiment 4 Deformation of tendon

    E-print Network

    Lakes, Roderic

    not pull, stretch or manipulate the tendon because small injuries to the fibrous structure will affectBME 315 Biomechanics Experiment 4 Deformation of tendon Pre-lab assignment Review lecture material will be provided in the lab as well. Plan test so that one person or person dissects the tendons from the tail

  9. Measurement of Health Outcomes Following Tendon and Nerve Repair

    Microsoft Academic Search

    Joy C. MacDermid

    2005-01-01

    The World Health Organization's model of health suggests that tendon and nerve injury outcomes can be assessed in terms of impairment, activity limitations, and participation restrictions. A tendon injury results in impairment of motion and strength of affected digits. Literature on outcome of tendon surgery has focused on active motion. Recently developed devices can be used to measure strength impairments

  10. Snapping knee: An unusual biceps femoris tendon injury

    Microsoft Academic Search

    Rajeev Bansal; Chris Taylor; Ashvin L. Pimpalnerkar

    2005-01-01

    We report a case of acute post-traumatic snapping of the biceps femoris tendon following a soccer injury. Surgical stabilisation, achieved by re-routing the tendon insertion through a tunnel in the fibular head, resolved the symptoms after conservative management failed. We believe this is the first report of a ‘snapping knee’ resulting from direct injury to the biceps femoris tendon insertion.

  11. Anatomic foveal reconstruction of the triangular fibrocartilage complex with a tendon graft.

    PubMed

    Bain, Gregory I; McGuire, Duncan; Lee, Yu Chao; Eng, Kevin; Zumstein, Matthias

    2014-06-01

    An acute injury to the triangular fibrocartilage complex (TFCC) with avulsion of the foveal attachment can produce distal radioulnar joint (DRUJ) instability. The avulsed TFCC is translated distally so the footprint will be bathed in synovial fluid from the DRUJ and will become covered in synovitis. If the TFCC fails to heal to the footprint, then persistent instability can occur. The authors describe a surgical technique indicated for the treatment of persistent instability of the DRUJ due to foveal detachment of the TFCC. The procedure utilizes a loop of palmaris longus tendon graft passed through the ulnar aspect of the TFCC and into an osseous tunnel in the distal ulna to reconstruct the foveal attachment. This technique provides stability of the distal ulna to the radius and carpus. We recommend this procedure for chronic instability of the DRUJ due to TFCC avulsion, but recommend that suture repair remain the treatment of choice for acute instability. An arthroscopic assessment includes the trampoline test, hook test, and reverse hook test. DRUJ ballottement under arthroscopic vision details the direction of instability, the functional tear pattern, and unmasks concealed tears. If the reverse hook test demonstrates a functional instability between the TFCC and the radius, then a foveal reconstruction is contraindicated, and a reconstruction that stabilizes the radial and ulnar aspects of the TFCC is required. The foveal reconstruction technique has the advantage of providing a robust anatomically based reconstruction of the TFCC to the fovea, which stabilizes the DRUJ and the ulnocarpal sag. PMID:24694387

  12. Tendon-Derived Stem Cells (TDSCs): From Basic Science to Potential Roles in Tendon Pathology and Tissue Engineering Applications

    Microsoft Academic Search

    Pauline Po Yee Lui; Kai Ming Chan

    Traditionally, tendons are considered to only contain tenocytes that are responsible for the maintenance, repair and remodeling\\u000a of tendons. Stem cells, which are termed tendon-derived stem cells (TDSCs), have recently been identified in tendons. This\\u000a review aims to summarize the current information about the in vitro characteristics of TDSCs, including issues related to TDSC isolation and culture, their cell morphology,

  13. Simultaneous rupture of the quadriceps tendon with contralateral patellar tendon rupture: an unusual case and a review of the literature

    Microsoft Academic Search

    A. Jalgaonkar; A. Rafee; O. Haddo; S. Sarkar

    2008-01-01

    Simultaneous rupture of quadriceps tendon with contralateral patellar tendon is very rare. There are only two case reports\\u000a in English literature. We report the case of a healthy 41-year-old female with simultaneous rupture of her left quadriceps\\u000a tendon and right patellar tendon. There were no known precipitating factors for this injury. Surgical repair and early rehabilitation\\u000a achieved satisfactory outcome.

  14. Skeletal muscle fibrosis and stiffness increase after rotator cuff tendon injury and neuromuscular compromise in a rat model.

    PubMed

    Sato, Eugene J; Killian, Megan L; Choi, Anthony J; Lin, Evie; Esparza, Mary C; Galatz, Leesa M; Thomopoulos, Stavros; Ward, Samuel R

    2014-09-01

    Rotator cuff tears can cause irreversible changes (e.g., fibrosis) to the structure and function of the injured muscle(s). Fibrosis leads to increased muscle stiffness resulting in increased tension at the rotator cuff repair site. This tension influences repairability and healing potential in the clinical setting. However, the micro- and meso-scale structural and molecular sources of these whole-muscle mechanical changes are poorly understood. Here, single muscle fiber and fiber bundle passive mechanical testing was performed on rat supraspinatus and infraspinatus muscles with experimentally induced massive rotator cuff tears (Tenotomy) as well as massive tears with chemical denervation (Tenotomy + BTX) at 8 and 16 weeks post-injury. Titin molecular weight, collagen content, and myosin heavy chain profiles were measured and correlated with mechanical variables. Single fiber stiffness was not different between controls and experimental groups. However, fiber bundle stiffness was significantly increased at 8 weeks in the Tenotomy + BTX group compared to Tenotomy or control groups. Many of the changes were resolved by 16 weeks. Only fiber bundle passive mechanics was weakly correlated with collagen content. These data suggest that tendon injury with concomitant neuromuscular compromise results in extra-cellular matrix production and increases in stiffness of the muscle, potentially complicating subsequent attempts for surgical repair. PMID:24838823

  15. Biodegradable synthetic scaffolds for tendon regeneration

    PubMed Central

    Reverchon, Ernesto; Baldino, Lucia; Cardea, Stefano; De Marco, Iolanda

    2012-01-01

    Summary Tissue regeneration is aimed at producing biological or synthetic scaffolds to be implanted in the body for regenerate functional tissues. Several techniques and materials have been used to obtain biodegradable synthetic scaffolds, on which adhesion, growth, migration and differentiation of human cells has been attempted. Scaffolds for tendon regeneration have been less frequently proposed, because they have a complex hierarchical structure and it is very difficult to mimic their peculiar mechanical properties. In this review, we critically analyzed the proposed materials and fabrication techniques for tendon tissue engineering and we indicated new preparation processes, based on the use of supercritical fluids, to produce scaffolds with characteristics very similar to the native tendon structure. PMID:23738295

  16. [The Achilles tendon in sports].

    PubMed

    Segesser, B; Goesele, A; Renggli, P

    1995-06-01

    Achillodynia is a generic term for various types of ailments in the region of the Achilles tendon. For adequate therapy a specific diagnosis is absolutely necessary. Besides an accurate anamnesis and the right choice of terrain and shoes, as well as a clinical examination where one has to specifically keep an eye on muscular imbalance between the gastrocnemius and the soleus muscle and disorders of the ligamentous control of the calcaneus caused by fibular ligament instabilities, a procedure such as radiology, ultrasound, and MR imaging is inevitable. From the differential diagnosis point of view a distinction between peritendinitis, mechanically triggered bursitis (calcaneal and subachilles), bony alterations of the calcaneus (calcaneus spur, Haglund exostosis persistent nucleus of the apophysis, fatigue fracture, etc) and a partial or total rupture (a one-time occurrence or multiple occurrences) has to be made. Occasionally, entrapment of the ramus calcaneus of the sural nerve causes calcaneal pain. If clinically not confirmed, lumbar pain ought to be taken into consideration (discopathy, Bechterew disease, etc). Metabolic disorders (especially uric acid) and underlying rheumatic diseases must be excluded. The therapy of achillodynia includes local and peroral antiphlogistic medication as a concomitant measure. More important is the causal influence of etiological factors, i.e., the correction of muscular imbalance, ensuring control of the calcaneus through bandages and adjustment of sport shoes, changes in training buildup and exercise intensity, just to mention a few. If necessary, surgically splitting the peritendineum, sanitation of a partial rupture, bursectomy and removal of mechanically obstructive exostosis must be done. PMID:7617382

  17. Simultaneous rupture of the quadriceps tendon with contralateral rupture of the patellar tendon in an otherwise healthy athlete

    Microsoft Academic Search

    N I Munshi; C E Mbubaegbu

    1996-01-01

    A case of a healthy athlete with simultaneous rupture of quadriceps tendon and rupture of the contralateral patella tendon is reported. Both tendons rupturing in the same patient is rare and this is the first reported case in a previously healthy person. Different mechanisms are implicated in the different ruptures. The rarity is because the simultaneous presence of contributory factors

  18. Lubricin in human achilles tendon: The evidence of intratendinous sliding motion and shear force in achilles tendon.

    PubMed

    Sun, Yu-Long; Wei, Zhuang; Zhao, Chunfeng; Jay, Gregory D; Schmid, Thomas M; Amadio, Peter C; An, Kai-Nan

    2015-06-01

    Achilles tendon is one of the most commonly injured tendons. Mechanical force is regarded as a major causative factor. However, the biomechanics of Achilles tendon and mechanical mechanism of the injuries are unclear. Lubricin expresses at regions exposed to sliding motion and shear force in a number of tissues. This study investigated the distribution and concentration of lubricin in human Achilles tendons for better understanding the biomechanics of Achilles tendon. Achilles tendons were harvested from nine cadavers. Lubricin was extracted from various locations proximal to the calcaneal insertion and quantified with ELISA. The distribution of lubricin was investigated with immunohistochemistry. Lubricin was mainly identified at the interfaces of tendon fascicles, especially in the mid-portion of the tendon. The concentration of lubricin in Achilles tendons varied by individual and the distance from its calcaneal insertion. The distal portion of the tendon had a higher concentration of lubricin than the proximal regions of the tendon. This study suggests the presence of intratendinous sliding motion of fascicles and shear force at interfaces of fascicles in human Achilles tendon. Shear force could be an important mechanical factor for the development of Achilles tendinopathy and rupture. PMID:25864860

  19. Tear Dysfunction and the Cornea: LXVII Edward Jackson Memorial Lecture

    PubMed Central

    Pflugfelder, Stephen C.

    2011-01-01

    Purpose To describe the cause and consequence of tear dysfunction related corneal disease. Design Perspective on effects of tear dysfunction on the cornea Methods Evidence is presented on the effects of tear dysfunction on corneal morphology, function and health, as well as efficacy of therapies for tear dysfunction related corneal disease. Results Tear dysfunction is a prevalent eye disease and the most frequent cause for superficial corneal epithelial disease that results in corneal barrier disruption, an irregular optical surface, light scattering, optical aberrations and exposure and sensitization of pain sensing nerve endings (nociceptors). Tear dysfunction related corneal disease causes irritation and visual symptoms, such as photophobia, blurred and fluctuating vision that may decrease quality of life. Dysfunction of one or more components of the lacrimal functional unit results in changes in tear composition, including elevated osmolarity and increased concentrations of matrix metalloproteinases, inflammatory cytokines and chemokines. These tear compositional changes promote disruption of tight junctions, alter differentiation and accelerate death of corneal epithelial cells. Conclusions Corneal epithelial disease resulting from tear dysfunction causes eye irritation and decreases visual function. Clinical and basic research has improved understanding of the pathogenesis of tear dysfunction related corneal epithelial disease, as well as treatment outcomes. PMID:22019306

  20. A Model for Tear Film Thinning With Osmolarity and Fluorescein

    PubMed Central

    Braun, Richard J.; Gewecke, Nicholas R.; Begley, Carolyn G.; King-Smith, P. Ewen; Siddique, Javed I.

    2014-01-01

    Purpose. We developed a mathematical model predicting dynamic changes in fluorescent intensity during tear film thinning in either dilute or quenching regimes and we model concomitant changes in tear film osmolarity. Methods. We solved a mathematical model for the thickness, osmolarity, fluorescein concentration, and fluorescent intensity as a function of time, assuming a flat and spatially uniform tear film. Results. The tear film thins to a steady-state value that depends on the relative importance of the rates of evaporation and osmotic supply, and the resulting increase of osmolarity and fluorescein concentrations are calculated. Depending on the initial thickness, the rate of osmotic supply and the tear film thinning rate, the osmolarity increase may be modest or it may increase by as much as a factor of eight or more from isosmotic levels. Regarding fluorescent intensity, the quenching regime occurs for initial concentrations at or above the critical fluorescein concentration where efficiency dominates, while lower concentrations show little change in fluorescence with tear film thinning. Conclusions. Our model underscores the importance of using fluorescein concentrations at or near the critical concentration clinically so that quenching reflects tear film thinning and breakup. In addition, the model predicts that, depending on tear film and osmotic factors, the osmolarity within the corneal compartment of the tear film may increase markedly during tear film thinning, well above levels that cause marked discomfort. PMID:24458153

  1. Assessment of tear secretions in healthy Indian volunteers.

    PubMed

    Mishra, Panna; Srivastava, Divya; Rajesh Misra; Malik, V K; Trivedi, Vikas

    2014-01-01

    Dry eye syndrome is currently seen with increasing frequency throughout the world including India. An evaluation of tear physiology in the form of tear secretion and tear film stability is the most important aspect of dry eye diagnosis. The aim of this study is to investigate the age and gender related changes in the result of these tear function tests (Schirmers Test and Tear Break up time) in normal Indian population. This cross- sectional observational study included 120 normal subjects (60 Male and 60 females) with no ocular symptoms or ocular surface disorders. Schirmer and tear film break-up time tests were assessed in both eyes of each subject. The study subjects were divided into 4 groups according to their ages (<20 y, 20-40 y, 41-60 y and >60 y) each group was composed of 60 eyes of 30 subjects (15 male and 15 female subjects). The One way ANOVA test and the Statagraphic software was used for statistical analysis. We detected a statistically significant decline in both the tear function tests with increasing age. Tear function tests did not show statistically significant difference according to sex. This study suggests that the age of subjects should be taken into consideration in the evaluation of tear function test results. It is also revealed that Indian population values are different from Caucasian and Chinese values. We propose age specific cut off values of tear function tests in Indian population to aid in the diagnosis of dry eye in Indian conditions. PMID:25509963

  2. Bilateral synchronous rupture of the quadriceps tendon

    Microsoft Academic Search

    P. Ellanti; N. Davarinos; S. Morris; J. Rice

    Background  Bilateral simultaneous rupture of the quadriceps tendon is a rare entity. They are often associated with degenerative changes\\u000a of the tendons and predisposing conditions such as diabetes or excessive steroid use. They most commonly tend to occur in\\u000a patients of 40 years of age or older.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  We describe a case of a 67-year-old man with simultaneous rupture of both

  3. Diagnosing meniscal tears in the emergency department.

    PubMed

    Doherty, Megan; Hoskins, Rebecca

    2015-06-01

    Acute meniscal knee injuries can lead to instability of the joint if they are left untreated, but clinical examinations of patients' acutely injured knees can be challenging because of the pain and swelling involved. Although magnetic resonance imaging and arthroscopy are the gold standard investigations for the diagnosis of meniscal tears they cannot always be carried out in acute or emergency department settings. It is therefore essential that emergency care practitioners have good clinical examination skills to ensure safe and effective patient management, diagnosis, and outcomes, as well as the skills and knowledge required to carry out meniscal tear tests. This article reviews the literature on the most common examination techniques associated with acute injuries, especially meniscal injuries, to knees: joint line tenderness assessment, McMurray's test and the Apley's grind test. It analyses the sensitivity and specificity for each test to help practitioners understand the clinical significance of positive and negative findings. PMID:26050782

  4. Tearing instability in relativistic magnetically dominated plasmas

    E-print Network

    S. S. Komissarov; M. Barkov; M. Lyutikov

    2006-06-21

    Many astrophysical sources of high energy emission, such as black hole magnetospheres, superstrongly magnetized neutron stars (magnetars), and probably relativistic jets in Active Galactic Nuclei and Gamma Ray Bursts involve relativistically magnetically dominated plasma. In such plasma the energy density of magnetic field greatly exceeds the thermal and the rest mass energy density of particles. Therefore the magnetic field is the main reservoir of energy and its dissipation may power the bursting emission from these sources, in close analogy to Solar flares. One of the principal dissipative instabilities that may lead to release of magnetic energy is the tearing instability. In this paper we study, both analytically and numerically, the development of tearing instability in relativistically magnetically-dominated plasma using the framework of resistive magnetodynamics. We confirm and elucidate the previously obtained result on the growth rate of the tearing mode: the shortest growth time is the same as in the case of classical non-relativistic MHD, namely $\\tau =\\sqrt{\\tau_a \\tau_d}$ where $\\tau_a$ is the \\Alfven crossing time and $\\tau_d$ is the resistive time of a current layer.

  5. Tear Film Corneal shape Blink Cycles Reflex Tearing vdW wetting The End? Models for Dynamics of the Human Tear Film

    E-print Network

    Bacuta, Constantin

    have one or more symptoms of dry eye syndrome . Symptoms: Burning/stinging; Blurred vision Irritation computations ­ none today Summary and Future Directions Goal: Quantify tear film dynamics! #12;Tear Film dynamics: Much to understand and quantify! Dry eye syndrome: Common abnormality from insufficient

  6. Effects of reinforcement with the iliotibial tract flap in ACL reconstruction using bone-patellar tendon-bone

    Microsoft Academic Search

    Makato Iwai; Kazuya Sugimoto; Koujirou Okahashi; Yoshinori Takakura; Masayuki Samma; Yoshiyuki Fujisawa

    2005-01-01

    Introduction We attempted to reinforce the transplanted ligament by wrapping it with the iliotibial tract (ITT) flap to get more volume and to protect the graft from impingement in the intercondylar space postoperatively in reconstruction of the anterior cruciate ligament (ACL) using bone-patellar tendon-bone (BTB), and investigated the results in comparison with those of BTB alone. Materials and methods The

  7. Tendon matrix composition and turnover in relation to functional requirements

    PubMed Central

    Birch, Helen L

    2007-01-01

    Tendons are dense regular connective tissue structures that are defined based on their anatomical position of connecting muscle to bone. Despite these obvious commons features tendons from different locations within the body show remarkable variation in terms of their morphological, molecular and mechanical properties which relates to their specialized function. An appreciation of these differences is necessary to understand all aspects of tendon biology in health and disease. In our work, we have used a combination of mechanical assessment, histological measurements and molecular analysis of matrix in functionally distinct tendons to determine relationships between function and structure. We have found significant differences in material and molecular properties between spring-like tendons that are subjected to high strains during locomotion and positional tendons which are subjected to much lower strains. Furthermore, we have data to suggest that not only is the matrix composition different but also the ability of cells to synthesize and degrade the matrix (matrix turnover) varies between tendon types. We propose that these differences relate to the magnitude of strain that the tendon experiences during normal activities in life. Tendon cells may be preprogrammed during embryological development for the strain they will encounter in life or may simply respond to the particular strain environment they are subjected to. The elucidation of controlling mechanisms resulting in tendon cell specialization will have important consequences for cell based therapies and engineering strategies to repair damaged tendons. PMID:17696905

  8. Ocular tear film bubble formation after breath-hold diving.

    PubMed

    Sheard, P W

    2008-01-01

    Bubbles in the ocular tear film have been observed following both dry-chamber, simulated compressed air dives and in-water, recreational compressed air dives. The current paper reports on the formation of tear film bubbles in a breath-hold diver following repeated, extended breath-hold excursions to a maximum depth of -28.5 m. It is believed that this is the first time that ocular tear film bubbles have been reported in breath-hold divers. PMID:18500071

  9. Spondylodiscitis and Achilles tendonitis due to gout.

    PubMed

    Taniguchi, Yoshinori; Matsumoto, Tatsuki; Tsugita, Makoto; Fujimoto, Shimpei; Terada, Yoshio

    2014-11-01

    The patient, a 62-year-old man with a 3-year history of hyperuricemia, presented with severe neck pain, Achilles enthesopathy and polyarthralgia. He consumed alcohol heavily. The biochemical profile was normal except for elevated levels of CRP (3.6 mg/dl; normal < 0.3), uric acid (UA) (10.9 mg/dl; normal 2.5-7.5) and creatinine (1.7 mg/dl; normal 0.5-1.0). Bone scintigraphy showed polyarthritis at the right elbow, wrist and bilateral first MTP joints. Notably, bone scintigraphy with computed tomography also revealed spondylodiscitis of C5-C6, which was confirmed by MRI, and left Achilles tendonitis. Moreover, left Achilles tendonitis was also confirmed by ultrasonography, indicating enthesitis with low-echoic lesion and calcification. Needle aspiration yielded a white viscous liquid, with numerous urate crystals identified on polarized light microscopy. He was diagnosed with gouty arthritis associated with spondylodiscitis and Achilles tendonitis. After the treatment with allopurinol, colchicine and predonisolone, his symptoms were improved, and serum CRP and UA levels were normalized. The cervical spine and Achilles tendon are rare and notable sites of involvements in gout, and differential diagnosis of gouty arthritis from spondyloarthritis, rheumatoid arthritis, tumor, pseudogout, and infection is necessary. When the patient was noted to have neck pain and Achilles enthesopathy, we should always recognize gouty arthritis. PMID:24498865

  10. [The history of flexor tendon surgery].

    PubMed

    Chamay, A

    1997-01-01

    Flexor tendon injuries were already treated in antiquity by Hippocrates, Galien and Avicenne. Since the Renaissance, other surgeons have attempted to repair flexor tendon injuries, but without success due to problems related to unsuitable materials and ignorance of the basic rules of asepsis and the absence of antiseptics until the second half of the 19th century. The first successful flexor tendon grafts in man were performed by K. Biesalski in 1910, E. Lexer in 1912 and L. Mayer in 1916. These three authors published their series of grafts and described in detail the anatomical, physiological and technical principles to be respected. St. Bunnell, in 1918, developed various pull-out direct suture procedures, but faced with the problems of adhesions, he abandoned this technique and proposed not to repair flexors in the digital tunnels but to graft them. He defined the famous zone which he called No man's land, which subsequently became Claude Verdan's zone II, in 1959. In 1960, C. Verdan published his first series of sutures maintained by 2 pins in zone II with comparable results to those obtained after grafting. In 1967, H. Kleinert, with his mobile suture, became the leader of direct tendon repair in zone II. 2-stage grafts were introduced in 1965 under the impetus of J. Hunter, who revised and popularized the studies conducted by A. Bassett and R.E. Caroll in 1950. PMID:9131943

  11. Simultaneous traumatic rupture of the quadriceps tendons.

    PubMed Central

    Young, T B

    1985-01-01

    A case is reported of simultaneous traumatic rupture of quadriceps tendons diagnosed in the accident and emergency department within 2 hours of injury. This is an extremely rare injury and diagnosis is often missed. Possible mechanism of the injury, predisposing factors, guidelines for diagnosis and results of surgical treatment are discussed, and the literature is reviewed. Images Fig. 1 PMID:4015792

  12. Infliximab treatment for resistant Achilles tendonitis.

    PubMed

    Al-Asfar, Said M; Attar, Mohammad; Shacfeh, Hasan

    2009-09-01

    Undifferentiated spondyloarthropathies USPA can sometimes be refractory to usual disease modifying agents. Anti-tumor necrosis factor TNF-alpha agents have been shown to be effective in spondyloarthropathies. Few articles described the efficacy of TNF-alpha antagonists in USPA. Our patient had refractory Achilles tendonitis as an early manifestation of USPA which responded dramatically to infliximab treatment. PMID:19750273

  13. Dynamics of goat distal hind limb muscle–tendon function in response to locomotor grade

    PubMed Central

    McGuigan, M. Polly; Yoo, Edwin; Lee, David V.; Biewener, Andrew A.

    2009-01-01

    Summary The functional roles of the lateral gastrocnemius (LG), medial gastrocnemius (MG) and superficial digital flexor (SDF) muscle–tendon units (MTUs) in domestic goats (N=6) were studied as a function of locomotor grade, testing the hypothesis that changes in distal limb muscle work would reflect changes in mechanical work requirements while goats walked or trotted on the level, 15 deg. decline and 15 deg. incline. As steep terrain-adapted animals, changes in muscle work output are expected to be particularly important for goats. In vivo muscle–tendon forces, fascicle length changes and muscle activation were recorded via tendon force buckles, sonomicrometry and electromyography to evaluate the work performance and elastic energy recovery of the three distal MTUs. These recordings confirmed that fascicle strain and force within goat distal hind limb muscles are adjusted in response to changes in mechanical work demand associated with locomotor grade. In general, muscle work was modulated most consistently by changes in fascicle strain, with increased net shortening (P<0.001) observed as goats switched from decline to level to incline locomotion. Peak muscle stresses increased as goats increased speed from a walk to a trot within each grade condition (P<0.05), and also increased significantly with grade (P<0.05 to P<0.01). Due to the increase in net fascicle shortening and muscle force, net muscle work per cycle also increased significantly (P<0.05 to P<0.005) as goats switched from decline to level to incline conditions (LG work: 20 mJ to 56 mJ to 209 mJ; MG work: –7 mJ to 34 mJ to 179 mJ; SDF work: –42 mJ to 14 mJ to 71 mJ, at a 2.5 ms–1 trot). Although muscle work was modulated in response to changes in grade, the amount of work produced by these three distal pennate muscles was small (being <3%) in comparison with the change in mechanical energy required of the limb as a whole. Elastic energy recovery in the SDF and gastrocnemius (GA) tendons was substantial across all three grades, with the SDF tendon recovering 2.4 times more energy, on average, than the GA tendon. In parallel with the increase in muscle–tendon force, tendon energy recovery also increased as goats increased speed and changed gait, reaching the highest levels when goats trotted on an incline at 2.5 ms–1 (GA: 173 mJ; SDF: 316 mJ). In general, tendon elastic energy exceeded net muscle work across all grade and gait conditions. These results demonstrate, for the first time in a quadruped, similar findings to those observed in ankle extensor muscles in humans, wallabies, turkeys and guinea fowl, suggesting that distal muscle–tendon architecture more generally favors a design for economic force production and tendon elastic energy recovery, with the majority of limb work during incline or decline running performed by larger proximal muscles. PMID:19525436

  14. The role of engineered tendon matrix in the stemness of tendon stem cells in vitro and the promotion of tendon-like tissue formation in vivo.

    PubMed

    Zhang, Jianying; Li, Bin; Wang, James H-C

    2011-10-01

    When injured, tendons tend to heal but with poor structure and compromised function. Tissue engineering is a promising approach to enhancing the quality of healing tendons. Our group and others have identified tendon stem cells (TSCs), a type of tendon-specific stem cells which may be optimal for cellular interventions seeking to restore normal structure and function to injured tendons. However, in vitro expanding of TSCs on regular plastic cell culture dishes only yields a limited number of TSCs before they lose the stemness, i.e., the self-renewal capability and multipotency. In this study, we developed a substrate material for TSCs, engineered tendon matrix (ETM) from decellularized tendon tissues. We showed that ETM in vitro was able to stimulate TSC proliferation and better preserve the stemness of TSCs than plastic culture surfaces. In vivo, implantation of ETM-TSC composite promoted tendon-like tissue formation whereas implantation of TSCs alone led to little such tissue formation. Together, the findings of this study indicate that ETM may be used to effectively expand TSCs in vitro and with TSCs, to enhance repair of injured tendons in vivo. PMID:21703682

  15. Rates of meniscal tearing in patients with chondrocalcinosis.

    PubMed

    Checa, Angel; Chun, William

    2015-03-01

    Internal derangement of the knee secondary to a meniscal tear has been recently observed in patients with chondrocalcinosis. However, there is no data about the prevalence of meniscal tears associated to chondrocalcinosis. Therefore, the aim of this study was to know the rates of meniscal tear in patients with chondrocalcinosis. The study population was a cohort of 1031 consecutive outpatients who underwent arthroscopy of the knee. Meniscal tear was present in 322 patients and 709 patients had intact meniscus. The specific subgroup of interest included 58 knees from 58 patients (25 males and 33 females) with arthroscopic evidences of chondrocalcinosis. Patients with chondrocalcinosis had significantly higher rates of meniscal tear compared to those without chondrocalcinosis (74.1 versus 28.7%, p?tear was 74 and 8%, respectively, in knees with chondrocalcinosis. Relative risk of tear in patients with chondrocalcinosis versus without chondrocalcinosis was 2.58 (95% confidence interval 2.16-3.10). In patients with chondrocalcinosis and meniscal tear, the duration of the disease was about 5.3 (range 1-8)?years versus 4.9 (range 3-7)?years in those patients with chondrocalcinosis and an intact meniscus (p?=?0.75). In conclusion, our findings support that chondrocalcinosis predispose meniscal tearing even in the absence of any traumatic event. Further longitudinal studies are needed to characterize the impact of chondrocalcinosis and meniscal vulnerability. PMID:25431326

  16. Stabilization of tearing modes by oscillating the resonant surface

    NASA Astrophysics Data System (ADS)

    Yang, Xiaoqing; Wang, Shaojie; Yang, Weihong

    2012-07-01

    The effects of the plasma current modulation on the linear instability of the tearing mode are numerically investigated. It is found that the tearing mode can be stabilized if the frequency of the modulation is suitable and the oscillation amplitude of the resonant surface position is large enough. The power needed for the lower-hybrid-current-drive to stabilize the tearing mode by oscillating the position of the resonant surface is comparable to the power consumption of the conventional method of tearing mode stabilization by using the electron-cyclotron-current-drive.

  17. Stabilization of tearing modes by oscillating the resonant surface

    SciTech Connect

    Yang Xiaoqing; Wang Shaojie; Yang Weihong [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)

    2012-07-15

    The effects of the plasma current modulation on the linear instability of the tearing mode are numerically investigated. It is found that the tearing mode can be stabilized if the frequency of the modulation is suitable and the oscillation amplitude of the resonant surface position is large enough. The power needed for the lower-hybrid-current-drive to stabilize the tearing mode by oscillating the position of the resonant surface is comparable to the power consumption of the conventional method of tearing mode stabilization by using the electron-cyclotron-current-drive.

  18. Tear proteins in health, disease, and contact lens wear.

    PubMed

    Sariri, R; Ghafoori, H

    2008-04-01

    Although well known as manifestations of sorrow, emotions, frustration, and blackmail, tears have a more prosaic and important function as a lubricant and as a blood substitute for the cornea. Tears transport oxygen and carbon dioxide and play a central role in the cellular economy of the ocular surface and conjunctiva. In addition to proteins, tears contain lipids and glycoproteins, which increase the wetting effect of the aqueous component and delay evaporation. The total protein concentration of tears is about 10% of that of the plasma. About 80 proteins and polypeptide components have been detected by electrophoresis. Among 30 proteins identified in tears, about 50% are enzymes. Some of the tear enzymes are secreted by the lacrimal glands; others are produced by or released from epithelial cells of the cornea and the conjunctiva. Finally, a few enzymes originate from plasma and appear in tears only in cases with increased permeability of the conjunctival vessels. The aim of this review is to provide clinical and biochemical information about tear enzymes both for ophthalmologists and for biochemists interested in clinical and experimental tear enzymology. PMID:18457567

  19. Lipid peroxidation is increased in tears from the elderly.

    PubMed

    Benlloch-Navarro, Soledad; Franco, Ilenia; Sánchez-Vallejo, Violeta; Silvestre, Dolores; Romero, Francisco Javier; Miranda, María

    2013-10-01

    We describe a procedure in which tears, obtained from Schirmer strips, are used to measure a marker of lipid peroxidation, malondialdehyde (MDA). We also compared the levels of proteins and MDA in tears from two groups of people: young adults (18-30 years old) and elderly adults (65-85 years old), because the data related to total protein concentration of human tears vary widely and because the majority of people over the age of 65 experience some symptoms of dry eyes and this condition has been recognized as an oxidative stress-induced disease. Our results show a significant difference in the protein concentration of the tears taken from the two age categories, younger adults (18-30 years old) and older adults (65-85 years old). Herein, we report for the first time an increase in MDA concentrations determined by HPLC in human tears based on age. It is possible that alterations in the tear lipid layer may lead to an increase in lipid peroxidation. Further studies are needed to understand the nature and function of tear film and stability in order to obtain new methods to analyze tears in patients with different diseases. In this sense, it would be interesting to compare MDA concentration in tears from control subjects and from people with meibomian gland dysfunction. PMID:23906963

  20. Integrated multimodal metrology for objective and noninvasive tear evaluation.

    PubMed

    Kottaiyan, Ranjini; Yoon, Geunyoung; Wang, Qi; Yadav, Rahul; Zavislan, James M; Aquavella, James V

    2012-01-01

    The clinical tests used to assess tear film and diagnose dry eye are invasive and produce results that are different from natural tear characteristics. There is a need to objectively and noninvasively assess tear parameters under controlled environmental circumstances to refine dry eye diagnosis and therapy. We have developed multimodal tear imaging systems integrated in a chamber in which individual environmental factors can be precisely varied to investigate their impacts on tear parameters. With the custom-built high-resolution wavefront sensor combined with placido disc, it is possible to objectively detect two-dimensional tear breakups in real time and evaluate its impact on visual quality. Micrometer ultra-high resolution optical coherence tomography (OCT) enables us to quantify thickness and volume of the tear over the cornea and tear menisci. The ocular surface imaging ellipsometer uses polarized illumination from which both the lipid refractive index and thickness can be measured at a very high resolution. Using an enhanced thermal camera, we measure the ocular surface temperature noninvasively, which makes it possible to study spatial and temporal changes in tear evaporation. The multimodal deployment of these four components in the controlled chamber will assist in better differentiating the various clinical dry eye entities and will lead to the development of specific dry eye treatments. PMID:22330058

  1. In vivo mechanical properties of the human Achilles tendon during one-legged hopping

    Microsoft Academic Search

    G. A. Lichtwark; A. M. Wilson

    2005-01-01

    Compliant tendons act as energy stores, which benefit the energetics and power output of a muscle-tendon unit. However the compliance of tendon and the material properties may vary between individuals and hence alter the energy storing capacity of the tendon. We aimed to determine the in vivo Achilles tendon (AT) stress and strain during one-legged hopping and hence the contribution

  2. Correlations among upper and lower tear menisci, non-invasive tear break-up time and Schirmer's test

    PubMed Central

    Wang, Jianhua; Palakuru, Jayachandra R.; Aquavella, James V.

    2008-01-01

    Purpose The aim was to determine the relationships among tear meniscus parameters, non-invasive tear break-up time (NITBUT), and Schirmer's test. Design Experimental study. Methods Thirty-six subjects were tested on one randomly selected eye. Real-time corneal optical coherence tomography (OCT) was used to image the upper and lower tear menisci during normal and delayed blinking followed by measurement of NITBUT and Schirmer's test. Digital images of the eye were taken for measuring the lid lengths to estimate tear volume in the menisci. Results Compared to normal blinking, significant increases of tear menisci occurred during delayed blinking (post hoc, p < 0.01). NITBUT was weakly but significantly correlated with the height (r = 0.36, P = 0.03) and area (r = 0.37, P = 0.03) of the lower tear meniscus during normal blinks. NITBUT was also correlated with the lower tear meniscus volume (r = 0.45, P < 0.05) and total tear meniscus volume (r = 0.43, P < 0.05) during normal blinking. Schirmer's test was not significantly related to any parameters of the tear menisci, volumes, or NITBUT; however, it was negatively correlated with the age of the subjects (r = -0.47, P = 0.004). The age was negatively correlated with the upper tear meniscus (r ranged from 0.36 to 0.37 for the radius, height and area, P < 0.05) measured during delayed blinking. Conclusions NITBUT appears correlated with the lower tear meniscus during normal blinking, and the Schirmer's test appears not correlated with the non-invasively measured tear meniscus. PMID:18328997

  3. Development of a reinforced electrochemically aligned collagen bioscaffold for tendon tissue engineering applications

    NASA Astrophysics Data System (ADS)

    Uquillas Paredes, Jorge Alfredo

    Type-I collagen is a promising biomaterial that can be used to synthesize bioscaffolds as a strategy to regenerate and repair damaged tendons. The existing in vitro prepared collagen bioscaffolds are in the form of gels, foams, or extruded fibers. These bioscaffolds readily present sites for attachment of biological factors and cells; however, they have extremely poor biomechanical properties in comparison to the properties of native tendons. The biomechanical function of type-I collagen bioscaffolds needs to be elevated to the level of natural tissues for this biomaterial to replace mechanically challenged tendons in a functionally meaningful way. The overall goal of this dissertation is to develop a reinforced electrochemically aligned collagenous bioscaffold for applications in tendon tissue engineering. The bioscaffold is synthesized by a unique electrochemical process via isoelectric focusing (IEF) to attain a very high degree of molecular alignment and packing density. This dissertation presents progress made on four aims: A) development of simple and descriptive electrochemical theory via the mathematical model of IEF and the forces acting on collagen alignment under an electric field; B) optimization of the post-alignment PBS treatment step to achieve d- banding pattern in uncrosslinked electrochemically aligned collagen (ELAC) bioscaffolds; C) optimization of the best crosslinking protocol to produce the strongest possible ELAC biomaterial with excellent cellular compatibility; and D) in vivo evaluation of the biocompatibility and biodegradability properties of electronically aligned collagen bioscaffolds. The results of this dissertation provide strong evidence showing that reinforced ELAC bioscaffolds could be used clinically in the future to repair damaged tendons.

  4. Second Harmonic Generation Confocal Microscopy of Collagen Type I from Rat Tendon Cryosections

    PubMed Central

    Theodossiou, Theodossis A.; Thrasivoulou, Christopher; Ekwobi, Chidi; Becker, David L.

    2006-01-01

    We performed second harmonic generation (SHG) imaging of collagen in rat-tendon cryosections, using femtosecond laser scanning confocal microscopy, both in backscattering and transmission geometries. SHG transmission images of collagen fibers were spatially resolved due to a coherent, directional SHG component. This effect was enhanced with the use of an index-matching fluid (ni = 1.52). The average SHG intensity oscillated with wavelength in the backscattered geometry (isotropic SHG component), whereas the spectral profile was consistent with quasi-phase-matching conditions in transmission geometry (forward propagating, coherent SHG component) around 440 nm (?p = 880 nm). Collagen type I from bovine Achilles tendon was imaged for SHG in the backscattered geometry and its first-order effective nonlinear coefficient was determined (\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\vert}d_{{\\mathrm{eff}}}{\\vert}\\approx 0.085({\\pm}0.025){\\times}10^{-12}{\\mathrm{mV}}^{-1}\\end{equation*}\\end{document}) by comparison to samples of inorganic materials with known effective nonlinear coefficients (LiNbO3 and LiIO3). The SHG spectral response of collagen type I from bovine Achilles tendon matched that of the rat-tendon cryosections in backscattered geometry. Collagen types I, II, and VI powders (nonfibrous) did not show any detectable SHG, indicating a lack of noncentrosymmetric crystalline structure at the molecular level. The various stages of collagen thermal denaturation were investigated in rat-tendon cryosections using SHG and bright-field imaging. Thermal denaturation resulted in the gradual destruction of the SHG signal. PMID:17130233

  5. Bi-fluid and neoclassical effect on a Double-Tearing mode in Tore Supra

    SciTech Connect

    Maget, Patrick, E-mail: patrick.maget@cea.fr; Garbet, Xavier; Février, Olivier; Ségui, Jean-Luc [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France); Lütjens, Hinrich; Luciani, Jean-François [Centre de Physique Théorique, Ecole Polytechnique, CNRS (France)

    2014-06-15

    Tearing modes associated to hollow current profiles are prone to grow in moderate performance plasmas and often constrain the realization of non-inductive discharges in the Tore Supra tokamak, where long pulse duration is performed using Lower Hybrid waves for providing most of the plasma current. The prediction of MHD boundaries in such scenarios is complicated by the importance of diamagnetic effects, combined with curvature stabilization, which determine the stability of these modes. We show that diamagnetic effects, as well as neoclassical forces, are playing a key role in the linear and nonlinear regimes of Double-Tearing Modes on q?=?5/3 and q?=?2 in these experimental conditions. Detailed comparison with experimental measurements, combined with a scaling in plasma resistivity, give constraints about the experimental equilibrium. Resistive-Interchange Modes destabilized by diamagnetic rotation could also play a role in degrading the energy confinement in the negative magnetic shear region.

  6. Surgical Treatment of Combined Posterior Root Tears of the Lateral Meniscus and ACL Tears

    PubMed Central

    Pan, Fengyu; Hua, Shan; Ma, Zhuang

    2015-01-01

    Background The treatment of anterior cruciate ligament (ACL) rupture complicated with posterior lateral meniscus root (PLMR) tears remains controversial. The goal of this study was to evaluate clinical outcomes of PLMR tear refixation versus left untreated at the time of reconstruction. Material/Methods From August 2001 to January 2012, 31 patients who undergone repair of PLMR tears were evaluated and compared with a matched control group with untreated PLMR tears. Clinical evaluation consisted of the Lysholm scale, subjective International Knee Documentation Committee (IKDC) questionnaires, and radiographic evaluation with MRI. Results Regarding to the Lysholm score and the subjective questionnaire score, there were no statistical difference between the 2 groups. However, patients after operative treatment reach higher functional scores and lower rates of osteoarthritis (normal: group A, 80%, and group B, 48%, respectively) with statistical significance (P<0.05) compared to the matched control group. Conclusions Surgical and conservative treatment of the PLMR can both effectively improve knee function. However, a tendency towards higher functional scores and lower rates of osteoarthritis for patients with operative treatment was observed. PMID:25959903

  7. Chronic Achilles Tendon Rupture Reconstructed With Achilles Tendon Allograft and Xenograft Combination.

    PubMed

    Hollawell, Shane; Baione, William

    2014-12-01

    More than 20% of acute Achilles tendon injuries are misdiagnosed, leading to chronic or neglected ruptures. Some controversy exists regarding how to best manage an acute Achilles tendon rupture. However, a general consensus has been reached that chronic rupture with ?3 cm of separation is associated with functional morbidity and, therefore, should be managed operatively. It has been demonstrated that the functional outcomes of surgically treated Achilles ruptures are superior to the nonoperative outcomes in a chronic setting. In the present report, we reviewed 4 patients with chronic Achilles tendon ruptures that were successfully treated with an Achilles tendon interposition allograft and simultaneous augmentation with a xenograft. The median duration of rupture was 11 (range 8 to 16) weeks, the median gap between the proximal and distal segments of the tendon was 4.75 (range 3.5 to 6) cm, and the patients were able to return pain-free to all preinjury activities at a median of 14.5 (range 13.8 to 15.5) weeks, without the need for tendon transfer, lengthening, or additional intervention. The median duration of follow up was 37.25 (range 15.25 to 51.5) months, at which point the mean Foot and Ankle Outcomes Instrument core scale score was 97 ± 1 (mean normative score 53 ± 1), and the Foot and Ankle Outcomes Instrument shoe comfort core scale score was 100 ± 0 (mean normative score 59 ± 0). The combined Achilles allograft plus xenograft augmentation technique appears to be a reasonable option for the surgical treatment of chronic Achilles tendon rupture. PMID:25488191

  8. Superballistic transport in tearing driven magnetic turbulence

    NASA Astrophysics Data System (ADS)

    Zimbardo, G.; Greco, A.; Veltri, P.

    2000-04-01

    Ion transport is studied in a magnetic field reversal with a constant electric field and with a model tearing driven magnetic turbulence. Superdiffusive and superballistic transport regimes are found for the mean square displacements in the plane of the current sheet, ?t?, with anomalous diffusion exponents ? up to 4. It is shown that the jump length l scales as l???, with ? the jump duration and ?>1, and that ? can be interpreted in terms of the Klafter, Blumen, and Shlesinger model [Phys. Rev. A 35, 3081 (1987)] for continuous time random walk. Since velocity increases with the length of the free path, we have accelerated Lévy flights.

  9. Foot posture is associated with morphometry of the peroneus longus muscle, tibialis anterior tendon, and Achilles tendon.

    PubMed

    Murley, G S; Tan, J M; Edwards, R M; De Luca, J; Munteanu, S E; Cook, J L

    2014-06-01

    The aim of this study was to investigate the association between foot type and the morphometry of selected muscles and tendons of the lower limb. Sixty-one healthy participants (31 male, 30 female; aged 27.1 ± 8.8 years) underwent gray-scale musculoskeletal ultrasound examination to determine the anterior-posterior (AP) thickness of tibialis anterior, tibialis posterior, and peroneus longus muscles and tendons as well as the Achilles tendon. Foot type was classified based on arch height and footprint measurements. Potentially confounding variables (height, weight, hip and waist circumference, rearfoot and ankle joint range of motion, and levels of physical activity) were also measured. Multiple linear regression models were used to determine the association between foot type with muscle and tendon morphometry accounting for potentially confounding variables. Foot type was significantly and independently associated with AP thickness of the tibialis anterior tendon, peroneus longus muscle, and Achilles tendon, accounting for approximately 7% to 16% of the variation. Flat-arched feet were associated with a thicker tibialis anterior tendon, a thicker peroneus longus muscle, and a thinner Achilles tendon. Foot type is associated with morphometry of tendons that control sagittal plane motion of the rearfoot; and the peroneus longus muscle that controls frontal plane motion of the rearfoot. These findings may be related to differences in tendon loading during gait. PMID:23301865

  10. The Tensile and Tear Properties of a Biodegradable Polyester Film

    Microsoft Academic Search

    K. E. Nissen; B. H. Stuart; M. G. Stevens; A. T. Baker

    2008-01-01

    The tensile and tear properties of a biodegradable polymer, Biomax®, have been studied in order to assess this material in film applications. While the tensile strength of Biomax® was comparable to that of low-density polyethylene, the tear strength was found to be six times lower. A study of the load-displacement curves revealed a regular variation in load throughout the test,

  11. The influence of nonpolar lipids on tear film dynamics

    NASA Astrophysics Data System (ADS)

    Breward, Chris

    2013-11-01

    We will examine the effects of the presence of nonpolar lipids on the evolution of a tear film during a blink. We will track the thickness of the aqueous tear layer, the thickness of the nonpolar lipid layer, and the concentration of the polar lipids that reside between the two. Our model can be reduced in various limits to previous models for tear dynamics studied. We present numerical solutions for the evolution of the tear film and show how the key parameters play a role in determining how the nonpolar lipid spreads. We will examine the effects of the presence of nonpolar lipids on the evolution of a tear film during a blink. We will track the thickness of the aqueous tear layer, the thickness of the nonpolar lipid layer, and the concentration of the polar lipids that reside between the two. Our model can be reduced in various limits to previous models for tear dynamics studied. We present numerical solutions for the evolution of the tear film and show how the key parameters play a role in determining how the nonpolar lipid spreads. This work was partially supported by Award No. KUK-C1-013-04 made by King Abdullah University of Science and Technology (KAUST).

  12. Cloth Tearing Simulation with Frayed Edges Napaporn METAAPHANON

    E-print Network

    Ouhyoung, Ming

    Cloth Tearing Simulation with Frayed Edges Napaporn METAAPHANON * () E-mail: *{noimeta, ybando,nis}@nis 1 1(a) (a) (b) 1(a) (b) Cloth Tearing Simulation with Frayed Edges. Anderson. "Robust treatment of collisions, contact and friction for cloth animation," ACM Transactions

  13. The effect of line-tying on tearing modes

    SciTech Connect

    Delzanno, Gian Luca; Finn, John M. [T-15 Plasma Theory Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2008-03-15

    Cylindrical magnetohydrodynamic (MHD) constant-{psi} or nonconstant-{psi} tearing modes that are linearly unstable with periodic axial boundary conditions are studied in a line-tied cylinder. Examples of these two respective classes of modes, with m=1 and m=2 (m being the azimuthal mode number), are studied. With a suitable MHD equilibrium, the former modes are marginally stable in ideal MHD for periodic axial boundary conditions, and occur as fast tearing modes (resistive kinks) in the presence of resistivity {eta}. The latter modes are stable in ideal MHD for periodic axial boundary conditions, and with resistivity occur as constant-{psi} tearing modes, unstable in a range of parameters. In both cases, the results for the line-tied modes show the expected tearing scaling with {eta} for very long plasmas, but the scaling becomes {gamma}{proportional_to}{eta} for smaller cylinder lengths L. These results are consistent with the following interpretation: For L{yields}{infinity}, the modes have a tearing width characteristic of tearing, leading to characteristic tearing mode growth. As L decreases, the modes develop a geometric width, which increases as L decreases; the {gamma}{proportional_to}{eta} scaling occurs when L is small enough that the geometric width exceeds the tearing width.

  14. Non-invasive methods of assessing the tear film

    Microsoft Academic Search

    Norihiko Yokoi; Aoi Komuro

    2004-01-01

    The interaction between the tear film and the ocular surface epithelium is crucial for the maintenance of ocular surface health; interference with this relationship may cause dry eye. Several diagnostic techniques have been developed to assess the tear film and diagnose dry eye but many of these tests are invasive and modify the parameter which they are designed to measure.

  15. Rotator cuff tears in the throwing athlete.

    PubMed

    Shaffer, Benjamin; Huttman, Daniel

    2014-06-01

    Tears of the rotator cuff, both partial, and less commonly, full thickness, are relatively common in the throwing athlete. The rotator cuff is subjected to enormous stresses during repetitive overhead activity. The supraphysiological strains, especially when combined with pathology elsewhere in the kinetic chain, can lead to compromise of the cuff fabric, most commonly on the undersurface where tensile overload occurs. Exacerbation by a tight posterior capsular, anterior instability, and internal impingement render the cuff progressively compromised, with intrinsic shear stresses and undersurface fiber failure. Advances in imaging technology, including contrast magnetic resonance imaging, dynamic ultrasound, and arthroscopic visualization have enhanced our understanding of cuff pathology in this athletic population. Unfortunately, this has not yet translated into how to best approach these athletes to return them to their previous level of activity. Nonoperative management remains the mainstay for most throwers, with arthroscopic debridement an effective surgical option for those with refractory symptoms. Despite technological advances in cuff repair in the general population, comparable outcomes have not been achieved in high-level throwers. Widespread appreciation that securing the cuff operatively will likely end an athletes' throwing career has led to adopting a surgical approach that emphasizes debridement over repair for nearly all partial and full-thickness tears. Whether advances in surgical technique will ultimately permit definitive and lasting repairs that allow overhead throwers to return to their previous level of sports remains unknown at this time. PMID:24787724

  16. Subacromial volume and rotator cuff tears

    PubMed Central

    Yi, Anthony; Avramis, Ioannis A; Argintar, Evan H; White, Eric R; Villacis, Diego C; Hatch III, George F Rick

    2015-01-01

    Background: Rotator cuff pathology occurs commonly and its cause is likely multifocal in origin. The development and progression of rotator cuff injury, especially in relation to extrinsic shoulder compression, remain unclear. Traditionally, certain acromial morphologies have been thought to contribute to rotator cuff injury by physically decreasing the subacromial space. The relationship between subacromial space volume and rotator cuff tears (RCT) has, however, never been experimentally confirmed. In this study, we retrospectively compared a control patient population to patients with partial or complete RCTs in an attempt to quantify the relationship between subacromial volume and tear type. Materials and Methods: We retrospectively identified a total of 46 eligible patients who each had shoulder magnetic resonance imaging (MRI) performed from January to December of 2008. These patients were stratified into control, partial RCT, and full-thickness RCT groups. Subacromial volume was estimated for each patient by averaging five sequential MRI measurements of subacromial cross-sectional areas. These volumes were compared between control and experimental groups using the Student's t-test. Results: With the numbers available, there was no statistically significant difference in subacromial volume measured between: the control group and patients diagnosed partial RCT (P > 0.339), the control group and patients with complete RCTs (P > 0.431). Conclusion: We conclude that subacromial volumes cannot be reliably used to predict RCT type. PMID:26015629

  17. Massive Rotator Cuff Tear in an Adolescent Athlete

    PubMed Central

    Turman, Kimberly A.; Anderson, Mark W.; Miller, Mark D.

    2010-01-01

    Full-thickness rotator cuff tears in the young athlete are a rare injury. These injuries typically result from an acute traumatic event in a contact athlete, as opposed to overuse injuries more commonly seen in throwing athletes. Acute tears may be initially overlooked, with the symptoms attributed to other, more common causes, such as cuff contusion or brachial plexus neuropraxia (“stinger” or “burner”). If undiagnosed, the tear may progress to an irreparable state at the time of eventual diagnosis. Therefore, rotator cuff tear must be included in the differential for acute shoulder injuries in the young athlete. This article presents a case of an adolescent athlete with a traumatic, massive rotator cuff tear that was diagnosed and managed promptly with excellent outcome. PMID:23015923

  18. Gender differences in the viscoelastic properties of tendon structures

    Microsoft Academic Search

    Keitaro Kubo; Hiroaki Kanehisa; Tetsuo Fukunaga

    2003-01-01

    .   The purpose of this study was to investigate the differences in the viscoelastic properties of human tendon structures (tendon\\u000a and aponeurosis) in the medial gastrocnemius muscle between men (n=16) and women (n=13). The elongation of the tendon and aponeurosis of the medial gastrocnemius muscle was measured directly by ultrasonography,\\u000a while the subjects performed ramp isometric plantar flexion up to

  19. Tissue engineering of cartilage, tendon and bone

    Microsoft Academic Search

    Hengyun Sun; Wei Liu; Guangdong Zhou; Wenjie Zhang; Lei Cui; Yilin Cao

    2011-01-01

    Tissue engineering aims to produce a functional tissue replacement to repair defects. Tissue reconstruction is an essential\\u000a step toward the clinical application of engineered tissues. Significant progress has recently been achieved in this field.\\u000a In our laboratory, we focus on construction of cartilage, tendon and bone. The purpose of this review was to summarize the\\u000a advances in the engineering of

  20. Quadriceps Tendon Rupture due to Postepileptic Convulsion.

    PubMed

    Balik, Mehmet Sabri; Erkut, Adem; Guvercin, Yilmaz; Sahin, Rifat; Keskin, Davut

    2014-06-01

    We present a case of quadriceps tendon (QT) rupture. QT ruptures can occur in all ages. The cause is mostly traumatic in origin. Spontaneous ruptures that are thought to result from predisposing conditions are rare. Post-convulsion QT ruptures lacking traumas in their history can be overlooked in clinical examinations. This should be born in mind by the attending physician, as early diagnosis and treatment of the condition can lead to satisfactory outcomes. PMID:24944977

  1. Quadriceps Tendon Rupture due to Postepileptic Convulsion

    PubMed Central

    Erkut, Adem; Guvercin, Yilmaz; Sahin, Rifat; Keskin, Davut

    2014-01-01

    We present a case of quadriceps tendon (QT) rupture. QT ruptures can occur in all ages. The cause is mostly traumatic in origin. Spontaneous ruptures that are thought to result from predisposing conditions are rare. Post-convulsion QT ruptures lacking traumas in their history can be overlooked in clinical examinations. This should be born in mind by the attending physician, as early diagnosis and treatment of the condition can lead to satisfactory outcomes. PMID:24944977

  2. Achilles tendon infection due to Mycobacterium chelonae.

    PubMed

    Lui, Tun Hing; Chan, Kwok Bill

    2014-01-01

    Atypical tuberculous tenosynovitis of the foot and ankle is extremely rare. The determination of the Mycobacterium species is essential because resistance of atypical mycobacterial strains to antituberculous drugs is often encountered. We report a case of Mycobacterium chelonae paratendinous and intratendinous infection involving the Achilles tendon. Repeat aggressive irrigation and debridement procedures, coupled with removal of foreign materials and the appropriate use of prolonged antibiotic therapy, can result in a successful long-term outcome. PMID:24529751

  3. Impact of oestrogen deficiency and aging on tendon: concise review

    PubMed Central

    Frizziero, Antonio; Vittadini, Filippo; Gasparre, Giuseppe; Masiero, Stefano

    2014-01-01

    Summary The knowledge about tendons and tenocyte biological behaviour during aging and, especially, oestrogen deficiency is limited. Women differ from men with regard to muscle and tendon, most likely due to differences in sex hormones activity and tissue response. To-date the interest in metabolic factors that may induce tendon disorders is growing. The aim of this paper is to elucidate the current findings in the correlation between oestrogen deficiency, aging and tendon pathology and to encourage future researches to ameliorate assessment and management of tendinopathies in postmenopausal women. PMID:25489550

  4. Reconstruction of neglected patellar tendon ruptures using the quadriceps graft.

    PubMed

    Gomes, João Luiz Ellera; de Oliveira Alves, Jairo André; Zimmermann, José Mauro

    2014-08-01

    Several techniques using different grafts have been described for reconstruction of the patellar tendon after a neglected rupture. Retraction of the quadriceps tendon may compromise repair integrity due to progressive stretching of the graft. The authors present a surgical technique using the central one-third of the quadriceps tendon. This is supported by the fact that the resistance to traction of this segment of the quadriceps tendon equals that of a double-looped semitendinosus graft and that the harvesting of this specific graft promotes muscle inhibition, thus protecting the reconstruction during the recovery period. PMID:25102494

  5. Tendon synovial cells secrete fibronectin in vivo and in vitro

    SciTech Connect

    Banes, A.J.; Link, G.W.; Bevin, A.G.; Peterson, H.D.; Gillespie, Y.; Bynum, D.; Watts, S.; Dahners, L.

    1988-01-01

    The chemistry and cell biology of the tendon have been largely overlooked due to the emphasis on collagen, the principle structural component of the tendon. The tendon must not only transmit the force of muscle contraction to bone to effect movement, but it must also glide simultaneously over extratendonous tissues. Fibronectin is classified as a cell attachment molecule that induces cell spreading and adhesion to substratum. The external surface of intact avian flexor tendon stained positively with antibody to cellular fibronectin. However, if the surface synovial cells were first removed with collagenase, no positive reaction with antifibronectin antibody was detected. Analysis of immunologically stained frozen sections of tendon also revealed fibronectin at the tendon synovium, but little was associated with cells internal in tendon. The staining pattern with isolated, cultured synovial cells and fibroblasts from the tendon interior substantiated the histological observations. Analysis of polyacrylamide gel profiles of /sup 35/S-methionine-labeled proteins synthesized by synovial cells and internal fibroblasts indicated that fibronectin was synthesized principally by synovial cells. Fibronectin at the tendon surface may play a role in cell attachment to prevent cell removal by the friction of gliding. Alternatively, fibronectin, with its binding sites for hyaluronic acid and collagen, may act as a complex for boundary lubrication.

  6. A biomechanical assessment of tendon repair after radiofrequency treatment.

    PubMed

    Tibor, Lisa M; Leek, Bryan T; Chase, Derek C; Healey, Robert M; Linn, Michael S; Tasto, James P; Amiel, David

    2012-09-01

    After acute tendon injury, rapid mobilization prevents adhesions and improves the ultimate strength of the repair. Radiofrequency (RF) ablation is proposed to enhance angiogenesis in the early stages of healing. The mechanism and effect of RF have not yet been described in an animal model of tendon injury. To investigate the biomechanical effect of bipolar RF on acute injury in a rabbit model of partial Achilles tendon transection and suture repair, RF-treated tendon repairs were compared to untreated tendons. Cross-sectional area, Young's modulus, and ultimate tensile strength were determined. At 6 and 12 weeks after repair, RF-treated tendons had significant increases in cross-sectional area (P<.001; P< .0001) and ultimate tensile strength (P<.0001; P<.01). Young modulus of RF-treated tendons was increased at 6 weeks but not at 12 weeks (P<.01) Compared with untreated tendons, RF-treated tendons showed faster return to mechanical integrity. This may allow earlier rehabilitation. PMID:23365813

  7. Low level laser therapy in healing tendon

    NASA Astrophysics Data System (ADS)

    Carvalho, P. T. C.; Batista, Cheila O. C.; Fabíola, C.

    2005-11-01

    This study aims to verify the effects of AsGa Laser in the scarring of tendon lesion in rats with low nourishment condition and to analyze the ideal light density by means of histopathologic findings highlighted by light microscopy. After the proposed nutritional condition was verified the animals were divided into 3 groups denominated as follows: GI control group, GII laser 1 J/sq.cm. and GIII laser 4 J/sq.cm. The lesions were induced by means of routine surgical process for tendon exposure: There was a crushing process with Allis pincers followed by saturated incision. The data obtained in relation to the amount of macrophage, leukocyte, fibroblast, vessel neoformation, fibrosis and collagen were submitted to parametric statistic procedures of variance analysis and "Tukey" Test and the result obtained was p < 0,05. According to the obtained results it can be concluded that low power laser therapy proved to be efficient in tendon repairing even though the animals suffered from malnutrition as well as the 1 J energy density proved to be more efficient in this case.

  8. Retropharyngeal Calcific Tendonitis Mimics a Retropharyngeal Abscess

    PubMed Central

    Wexler, Sonya

    2013-01-01

    Retropharyngeal calcific tendonitis (RCT) is an uncommon, self-limiting condition that is often omitted in the differential diagnosis of a retropharyngeal fluid collection. This condition mimics a retropharyngeal abscess and should be considered when evaluating a fluid collection in the retropharyngeal space. Although calcific tendonitis at other sites has been well described in the medical literature, it appears that this entity has been underreported in the otolaryngology literature where only a few case reports have been identified. Presumably, the actual incidence is higher than the reported incidence, due to lack of familiarity with this disorder. As an otolaryngologist's scope of practice includes the managements of retropharyngeal lesions, it is important for the otolaryngologist to recognize the presentation of acute RCT and be familiar with appropriate treatment strategies. Retropharyngeal calcific tendonitis presents with neck pain, limitation of neck range of motion and includes inflammation, calcifications, and a sterile effusion within the longus colli muscle. Treatment is medical with nonsteroidal anti-inflammatory medications. RCT does not require surgical treatment, and an accurate diagnosis can prevent unnecessary attempts at operative drainage. In this study, we discuss two cases of RCT, summarize the salient features in diagnosis, including key radiologic features, discuss treatment options, and review the literature. PMID:23956905

  9. Tear glucose analysis for the noninvasive detection and monitoring of diabetes mellitus.

    PubMed

    Baca, Justin T; Finegold, David N; Asher, Sanford A

    2007-10-01

    One approach to the noninvasive monitoring of blood glucose concentration is to monitor glucose concentrations in tear fluid. While several methods for sensing glucose in tear fluid have been proposed, controversy remains as to the precise concentrations of tear glucose in normal and diabetic subjects and as to whether tear fluid glucose concentrations correlate with blood glucose concentrations. This review covers the present understanding of the physiology of glucose transport in tears, the regulation of the aqueous tear fraction, and studies of tear glucose concentration over the last 80 years. The various tear collection methods employed greatly influence the measured tear glucose concentrations. Studies that involve mechanical irritation of the conjunctiva during sampling measure the highest tear glucose concentrations, while studies that avoid tear stimulation measure the lowest concentrations. Attempts to monitor tear glucose concentration in situ by using contact lens-based sensing devices are discussed, and new observations are presented of tear glucose concentration obtained by a method designed to avoid tear stimulation. These studies indicate the importance of the sampling method in determining tear glucose concentrations. On the basis of these results, we discuss the future of in vivo tear glucose sensing and outline the studies needed to resolve the remaining questions about the relationship between tear and blood glucose concentrations. PMID:17938838

  10. Spontaneous rupture of the patellar tendon and the contralateral quadriceps tendon, associated with lupus erythematosus: analysis of the literature.

    PubMed

    Karadimas, Efthimios J; Kotzamitelos, Dimitrios; Kakagia, Despoina D; Hatziyiannakis, Athanasios

    2011-01-01

    Bilateral rupture of the patellar tendon is a rare injury. A case of a 67-year-old man with systemic lupus erythematosus under corticosteroid treatment for the last 10 years, who sustained spontaneous rupture of the patellar tendon and the contralateral quadriceps tendon, is herein presented. The patient was operated bilaterally, had an optimal outcome considering his age and the comorbidities, and was followed up for 24 months. PMID:23198218

  11. All-Suture Transosseous Repair for Rotator Cuff Tear Fixation Using Medial Calcar Fixation.

    PubMed

    Aramberri-Gutiérrez, Mikel; Martínez-Menduiña, Amaia; Valencia-Mora, María; Boyle, Simon

    2015-04-01

    We describe an all-suture transosseous repair technique used in the management of rotator cuff tears by means of an all-suture anchor secured on the intra-articular side of the humeral calcar. The technique uses an anterior cruciate ligament guide to ensure accurate positioning of the tunnels, avoiding the articular cartilage and minimizing risk to the neurovascular structures. The distal end of the guide is inserted through a rotator interval portal and passed down to the axillary pouch. The proximal end of the guide is approximated to the greater tuberosity at the cuff footprint, and a complete transosseous tunnel is created with a 2.4-mm drill. An all-suture implant is inserted through this tunnel down to the calcar, and its deployment is visualized under arthroscopy. Gentle traction is applied to the anchor, resulting in a 4-mm concertina of the suture anchor that rests opposed to the medial cortex. The major advantage of this technique is the fixation strength gained from the biomechanically superior cortical bone of the calcar. Furthermore, this method permits greater preservation of bone surface area at the level of the footprint for a larger tendon-to-bone healing surface. This technique also provides an excellent alternative in revision situations. PMID:26052495

  12. All-Suture Transosseous Repair for Rotator Cuff Tear Fixation Using Medial Calcar Fixation

    PubMed Central

    Aramberri-Gutiérrez, Mikel; Martínez-Menduiña, Amaia; Valencia-Mora, María; Boyle, Simon

    2015-01-01

    We describe an all-suture transosseous repair technique used in the management of rotator cuff tears by means of an all-suture anchor secured on the intra-articular side of the humeral calcar. The technique uses an anterior cruciate ligament guide to ensure accurate positioning of the tunnels, avoiding the articular cartilage and minimizing risk to the neurovascular structures. The distal end of the guide is inserted through a rotator interval portal and passed down to the axillary pouch. The proximal end of the guide is approximated to the greater tuberosity at the cuff footprint, and a complete transosseous tunnel is created with a 2.4-mm drill. An all-suture implant is inserted through this tunnel down to the calcar, and its deployment is visualized under arthroscopy. Gentle traction is applied to the anchor, resulting in a 4-mm concertina of the suture anchor that rests opposed to the medial cortex. The major advantage of this technique is the fixation strength gained from the biomechanically superior cortical bone of the calcar. Furthermore, this method permits greater preservation of bone surface area at the level of the footprint for a larger tendon-to-bone healing surface. This technique also provides an excellent alternative in revision situations. PMID:26052495

  13. Arthroscopic Lamina-Specific Double-Row Fixation for Large Delaminated Rotator Cuff Tears

    PubMed Central

    Mori, Daisuke; Funakoshi, Noboru; Yamashita, Fumiharu

    2014-01-01

    Delamination is a commonly observed finding at the time of rotator cuff repair, but few studies have described the surgical techniques used for delaminated rotator cuff tears (RCTs) or their clinical outcomes. We developed a technique using a combination of a double row and an additional row, which we call lamina-specific double-row fixation, for large delaminated RCTs. The lamina-specific double-row technique is performed using an additional row (lamina-specific lateral row) of suture anchors placed between the typical medial and lateral rows of suture anchors. The technique is performed as follows: (1) medial-row sutures are passed through the inferior (articular-side) and superior (bursal-side) layers in a mattress fashion; (2) lamina-specific lateral-row simple sutures are passed through the inferior layer; and (3) lateral-row simple sutures are passed through the superior layer. We believe that this technique offers the following advantages: (1) creation of a larger area of contact between the inferior layer and the footprint, (2) higher initial fixation strength of the articular-side components of the repaired rotator cuff tendon, and (3) an adaptation between the superficial and inferior layers. This technique represents an alternative option in the operative treatment of large delaminated RCTs. PMID:25685671

  14. The Effect of Phospholipids (Surfactant) on Adhesion and Biomechanical Properties of Tendon: A Rat Achilles Tendon Repair Model

    PubMed Central

    Dabak, T. Kursat; Sertkaya, Omer; Acar, Nuray; Donmez, B. Ozgur; Ustunel, Ismail

    2015-01-01

    Adhesion of the tendon is a major challenge for the orthopedic surgeon during tendon repair. Manipulation of biological environment is one of the concepts to prevent adhesion. Lots of biochemicals have been studied for this purpose. We aimed to determine the effect of phospholipids on adhesion and biomechanical properties of tendon in an animal tendon repair model. Seventy-two Wistar rats were divided into 4 groups. Achilles tendons of rats were cut and repaired. Phospholipids were applied at two different dosages. Tendon adhesion was determined histopathologically and biomechanical test was performed. At macroscopic evaluation of adhesion, there are statistically significant differences between multiple-dose phospholipid injection group and Control group and also hyaluronic acid group and Control group (p < 0.008). At microscopic evaluation of adhesion, there was no statistically significant difference (p > 0.008). Ultimate strength was highest at hyaluronic acid injection group and lowest at multiple-dose phospholipid injection group. Single-dose phospholipids (surfactant) application may have a beneficial effect on the tendon adhesion. Although multiple applications of phospholipids seem the most effective regime to reduce the tendon adhesion among groups, it deteriorated the biomechanical properties of tendon.

  15. Treatment of meniscal tears: An evidence based approach

    PubMed Central

    Mordecai, Simon C; Al-Hadithy, Nawfal; Ware, Howard E; Gupte, Chinmay M

    2014-01-01

    Treatment options for meniscal tears fall into three broad categories; non-operative, meniscectomy or meniscal repair. Selecting the most appropriate treatment for a given patient involves both patient factors (e.g., age, co-morbidities and compliance) and tear characteristics (e.g., location of tear/age/reducibility of tear). There is evidence suggesting that degenerative tears in older patients without mechanical symptoms can be effectively treated non-operatively with a structured physical therapy programme as a first line. Even if these patients later require meniscectomy they will still achieve similar functional outcomes than if they had initially been treated surgically. Partial meniscectomy is suitable for symptomatic tears not amenable to repair, and can still preserve meniscal function especially when the peripheral meniscal rim is intact. Meniscal repair shows 80% success at 2 years and is more suitable in younger patients with reducible tears that are peripheral (e.g., nearer the capsular attachment) and horizontal or longitudinal in nature. However, careful patient selection and repair technique is required with good compliance to post-operative rehabilitation, which often consists of bracing and non-weight bearing for 4-6 wk. PMID:25035825

  16. Current-interchange tearing modes: Conversion of interchange-type modes to tearing modes

    SciTech Connect

    Zheng, L. J. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Furukawa, M. [Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8561 (Japan)

    2010-05-15

    It is shown that, in addition to usual neoclassical tearing modes, another type of nonclassical tearing mode exists in tokamaks: viz., current-interchange tearing modes (CITMs). CITMs are directly driven by unstable pressure-driven electromagnetic or electrostatic modes of the interchange type (e.g., interchange/ballooning modes, drift waves, etc.) due to the current gradient in tokamaks. Interchange-type modes exchange not only thermal and magnetic energies between flux tubes but also current. In a plasma with a current (or resistivity) gradient, such an interchange can create a current sheet at a mode resonance surface and result in the excitation of CITMs. Note that the interchange mode (i.e., Rayleigh-Taylor instability) is fundamental to tokamak physics. This new theory has an effect on both resistive magnetohydrodynamic stability and transport theories. Instabilities of the interchange type could be directly converted into CITMs, alternative to forming turbulent eddies through nonlinear coupling as in conventional transport theories. In particular, our CITM theory fills in the component in the transport theory of Rechester and Rosenbluth [Phys. Rev. Lett. 40, 38 (1978)] for the origin of magnetic island structure in axisymmetric tokamaks.

  17. Current-interchange tearing modes: Conversion of interchange-type modes to tearing modes

    NASA Astrophysics Data System (ADS)

    Zheng, L. J.; Furukawa, M.

    2010-05-01

    It is shown that, in addition to usual neoclassical tearing modes, another type of nonclassical tearing mode exists in tokamaks: viz., current-interchange tearing modes (CITMs). CITMs are directly driven by unstable pressure-driven electromagnetic or electrostatic modes of the interchange type (e.g., interchange/ballooning modes, drift waves, etc.) due to the current gradient in tokamaks. Interchange-type modes exchange not only thermal and magnetic energies between flux tubes but also current. In a plasma with a current (or resistivity) gradient, such an interchange can create a current sheet at a mode resonance surface and result in the excitation of CITMs. Note that the interchange mode (i.e., Rayleigh-Taylor instability) is fundamental to tokamak physics. This new theory has an effect on both resistive magnetohydrodynamic stability and transport theories. Instabilities of the interchange type could be directly converted into CITMs, alternative to forming turbulent eddies through nonlinear coupling as in conventional transport theories. In particular, our CITM theory fills in the component in the transport theory of Rechester and Rosenbluth [Phys. Rev. Lett. 40, 38 (1978)] for the origin of magnetic island structure in axisymmetric tokamaks.

  18. Observation of Spontaneous Neoclassical Tearing Modes

    SciTech Connect

    E.D. Fredrickson

    2001-10-03

    We present data in this paper from the Tokamak Fusion Test Reactor (TFTR) which challenges the commonly held belief that extrinsic MHD events such as sawteeth or ELMs [edge localized modes] are required to provide the seed islands that trigger Neoclassical Tearing Modes (NTMs). While sawteeth are reported to provide the trigger for most of the NTMs on DIII-D [at General Atomics in San Diego, California] and ASDEX-U [at Max-Planck-Institut fuer Plasmaphysik in Garching, Germany], the majority of NTMs seen in TFTR occur in plasmas without sawteeth, that is which are above the beta threshold for sawtooth stabilization. Examples of NTMs appearing in the absence of any detectable extrinsic MHD activity will be shown. Conversely, large n=1 modes in plasmas above the NTM beta threshold generally do not trigger NTMs. An alternative mechanism for generating seed islands will be discussed.

  19. Viscoplastic tearing of polyethylene thin film

    NASA Astrophysics Data System (ADS)

    Hegyi, Dezso; Pellegrino, Sergio

    2015-03-01

    Recent advances in noncontact strain measurement techniques and large-strain constitutive modeling of the linear low-density polyethylene film used in NASA superpressure balloons StratoFilm 420 are combined to provide a novel measurement technique for the tear propagation critical value of the J-integral. Previously these measurements required complex test configurations and procedures. It is found that the critical value of the J-integral increases by approximately 50 % when the strain rate is decreased from 1.33×10-4 s-1 to 1.33×10-5 s-1. It is shown that there is good correlation between measurements made on uniaxially loaded dogbone samples and circular diaphragms loaded by pressure, both with a 2-mm-wide slit in the middle. This result indicates that more extensive studies of strain-rate dependence may be made with the simpler, uniaxial test configuration.

  20. Gyrokinetic simulations of the tearing instability

    SciTech Connect

    Numata, Ryusuke [Graduate School of Simulation Studies, University of Hyogo, Kobe, Hyogo 650-0047 (Japan); Center for Multiscale Plasma Dynamics, University of Maryland, College Park, Maryland 20742 (United States); Wolfgang Pauli Institute, University of Vienna, A-1090 Vienna (Austria); Dorland, William [Center for Multiscale Plasma Dynamics, University of Maryland, College Park, Maryland 20742 (United States); Howes, Gregory G. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Loureiro, Nuno F. [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear -- Laboratorio Associado, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, 1049-001 Lisboa (Portugal); Rogers, Barrett N. [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Tatsuno, Tomoya [Center for Multiscale Plasma Dynamics, University of Maryland, College Park, Maryland 20742 (United States); Department of Communication Engineering and Informatics, University of Electro-Communications, Chofu, Tokyo 182-8585 (Japan)

    2011-11-15

    Linear gyrokinetic simulations covering the collisional-collisionless transitional regime of the tearing instability are performed. It is shown that the growth rate scaling with collisionality agrees well with that predicted by a two-fluid theory for a low plasma beta case in which ion kinetic dynamics are negligible. Electron wave-particle interactions (Landau damping), finite Larmor radius, and other kinetic effects invalidate the fluid theory in the collisionless regime, in which a general non-polytropic equation of state for pressure (temperature) perturbations should be considered. We also vary the ratio of the background ion to electron temperatures and show that the scalings expected from existing calculations can be recovered, but only in the limit of very low beta.

  1. Viscoplastic tearing of polyethylene thin film

    NASA Astrophysics Data System (ADS)

    Hegyi, Dezso; Pellegrino, Sergio

    2015-05-01

    Recent advances in noncontact strain measurement techniques and large-strain constitutive modeling of the linear low-density polyethylene film used in NASA superpressure balloons StratoFilm 420 are combined to provide a novel measurement technique for the tear propagation critical value of the J-integral. Previously these measurements required complex test configurations and procedures. It is found that the critical value of the J-integral increases by approximately 50 % when the strain rate is decreased from 1.33×10-4 s-1 to 1.33×10-5 s-1. It is shown that there is good correlation between measurements made on uniaxially loaded dogbone samples and circular diaphragms loaded by pressure, both with a 2-mm-wide slit in the middle. This result indicates that more extensive studies of strain-rate dependence may be made with the simpler, uniaxial test configuration.

  2. The potential of optical coherence tomography in meniscal tear characterization

    NASA Astrophysics Data System (ADS)

    Ling, Hang-yin; Guo, Shuguang; Thieman, Kelley M.; Wise, Brent T.; Pozzi, Antonio; Xie, Huikai; Horodyski, MaryBeth

    2009-02-01

    Meniscal tear is one of the most common knee injuries leading to pain and discomfort. Partial and total meniscectomies have been widely used to treat the avascular meniscal injuries in which tears do not heal spontaneously. However, the meniscectomies would cause an alteration of the tibiofemoral contact mechanics resulting in progressive osteoarthritis (OA). To mitigate the progression of OA, maximal preservation of meniscal tissue is recommended. The clinical challenge is deciding which meniscal tears are amenable to repair and which part of damaged tissues should be removed. Current diagnosis techniques such as arthroscopy and magnetic resonance imaging can provide macrostructural information of menisci, but the microstructural changes that occur prior to the observable meniscal tears cannot be identified by these techniques. Serving as a nondestructive optical biopsy, optical coherence tomography (OCT), a newly developed imaging modality, can provide high resolution, cross-sectional images of tissues and has been shown its capabilty in arthroscopic evaulation of articular cartilage. Our research was to demonstrate the potential of using OCT for nondestructive characterization of the histopathology of different types of meniscal tears from clinical cases in dogs, providing a fundamental understanding of the failure mechanism of meniscal tears. First, cross-sectional images of torn canine menisci obtained from the OCT and scanning electronic microscopy (SEM) were be compared. By studying the organization of collegan fibrils in torn menisci from the SEM images, the feasibility of using OCT to characterize the organization of collegan fibrils was elucidated. Moreover, the crack size of meniscal tears was quantatitively measured from the OCT images. Changes in the crack size of the tear may be useful for understanding the failure mechanism of meniscal tears.

  3. Development of a Hot Tear Indicator for Use in Casting Simulation C. Beckermann

    E-print Network

    Beckermann, Christoph

    1 Development of a Hot Tear Indicator for Use in Casting Simulation C. Monroe C. Beckermann for initiation sites for hot tears in the casting, not a full tear prediction. By evaluating this quantity. Using a simulation study of hot tear castings developed in SFSA literature, conclusions are drawn about

  4. Changes in the tear film and ocular surface from dry eye syndrome

    Microsoft Academic Search

    Michael E Johnson; Paul J Murphy

    2004-01-01

    Dry eye syndrome (DES) refers to a spectrum of ocular surface diseases with diverse and frequently multiple aetiologies. The common feature of the various manifestations of DES is an abnormal tear film. Tear film abnormalities associated with DES are tear deficiency, owing to insufficient supply or excessive loss, and anomalous tear composition. These categorizations are artificial, as in reality both

  5. Ultrasound Diagnosis of Bilateral Quadriceps Tendon Rupture After Statin Use

    PubMed Central

    Nesselroade, Ryan D.; Nickels, Leslie Connor

    2010-01-01

    Simultaneous bilateral quadriceps tendon rupture is a rare injury. We report the case of bilateral quadriceps tendon rupture sustained with minimal force while refereeing a football game. The injury was suspected to be associated with statin use as the patient had no other identifiable risk factors. The diagnosis was confirmed using bedside ultrasound. PMID:21079697

  6. Axisymmetric modeling of prestressing tendons in nuclear containment dome

    Microsoft Academic Search

    Se-Jin Jeon; Chul-Hun Chung

    2005-01-01

    Simple axisymmetric modeling of a nuclear containment building has been often employed in practice to estimate structural behavior for the axisymmetric loadings such as internal pressure. In this case, the prestressing tendons placed in the containment dome should be axisymmetrically approximated, since most dome tendons are not arranged in an axisymmetric manner. Some procedures are proposed that can realistically implement

  7. Bilateral synchronous quadriceps tendon rupture: a case report

    Microsoft Academic Search

    Varatharaj Mounasamy; Robert C. Chadderdon; Candice McDaniel; Mark C. Willis

    2008-01-01

    Bilateral spontaneous rupture of quadriceps tendons is rare and is usually associated with predisposing comorbid conditions.\\u000a We report an uncommon case of bilateral synchronous rupture of the quadriceps tendon after a ground level fall in a 51-year-old\\u000a male, 8 years after renal transplant.

  8. Rupture of the quadriceps tendon after arthroscopic lateral meniscectomy

    Microsoft Academic Search

    Renato Viola; Nicola Marzano; Roberto Vianello

    2001-01-01

    We report a case of complete quadriceps tendon rupture that occured a few days after arthroscopic lateral meniscectomy. Complications following arthroscopy are rare; there have been many reports of quadriceps tendon rupture in the literature, but none by this kind of mechanism.

  9. Simultaneous bilateral quadriceps tendon rupture while playing basketball

    Microsoft Academic Search

    M Shah; N Jooma

    2002-01-01

    Simultaneous bilateral quadriceps tendon rupture is an uncommon injury in healthy people and only a few cases have been reported in athletes. This is the first report of a patient with simultaneous bilateral quadriceps tendon rupture incurred while playing basketball. The injury was surgically repaired and the patient had a good functional outcome.

  10. Diagnostic ultrasound: The appearance of the Achilles tendon following surgery

    Microsoft Academic Search

    David Chapman-Jones

    1996-01-01

    Purpose: To describe the sonographic appearance of the Achilles tendon following surgery. The images presented are from a selection of patients screened for inclusion in a wider study undertaken to evaluate the efficacy of a micro-current treatment regime, contrasted with current conservative management, for the Achilles tendon presenting witj chronic pathology. Twenty per cent of the patients studied reported no

  11. Dorsal dislocation of the lunate with multiple extensor tendon ruptures.

    PubMed

    Schwartz, M G; Green, S M; Coville, F A

    1990-01-01

    An old dorsal lunate dislocation with associated multiple extensor tendon ruptures is described. Treatment consisted of proximal row carpectomy and transfer of the extensor indicis proprius to the distal stumps of the ruptured extensor tendons to the long, ring, and small fingers. PMID:2299153

  12. Relationship between tendon stiffness and failure: a metaanalysis.

    PubMed

    LaCroix, Andrew S; Duenwald-Kuehl, Sarah E; Lakes, Roderic S; Vanderby, Ray

    2013-07-01

    Tendon is a highly specialized, hierarchical tissue designed to transfer forces from muscle to bone; complex viscoelastic and anisotropic behaviors have been extensively characterized for specific subsets of tendons. Reported mechanical data consistently show a pseudoelastic, stress-vs.-strain behavior with a linear slope after an initial toe region. Many studies report a linear, elastic modulus, or Young's modulus (hereafter called elastic modulus) and ultimate stress for their tendon specimens. Individually, these studies are unable to provide a broader, interstudy understanding of tendon mechanical behavior. Herein we present a metaanalysis of pooled mechanical data from a representative sample of tendons from different species. These data include healthy tendons and those altered by injury and healing, genetic modification, allograft preparation, mechanical environment, and age. Fifty studies were selected and analyzed. Despite a wide range of mechanical properties between and within species, elastic modulus and ultimate stress are highly correlated (R(2) = 0.785), suggesting that tendon failure is highly strain-dependent. Furthermore, this relationship was observed to be predictable over controlled ranges of elastic moduli, as would be typical of any individual species. With the knowledge gained through this metaanalysis, noninvasive tools could measure elastic modulus in vivo and reasonably predict ultimate stress (or structural compromise) for diseased or injured tendon. PMID:23599401

  13. Relationship between tendon stiffness and failure: a metaanalysis

    PubMed Central

    LaCroix, Andrew S.; Duenwald-Kuehl, Sarah E.; Lakes, Roderic S.

    2013-01-01

    Tendon is a highly specialized, hierarchical tissue designed to transfer forces from muscle to bone; complex viscoelastic and anisotropic behaviors have been extensively characterized for specific subsets of tendons. Reported mechanical data consistently show a pseudoelastic, stress-vs.-strain behavior with a linear slope after an initial toe region. Many studies report a linear, elastic modulus, or Young's modulus (hereafter called elastic modulus) and ultimate stress for their tendon specimens. Individually, these studies are unable to provide a broader, interstudy understanding of tendon mechanical behavior. Herein we present a metaanalysis of pooled mechanical data from a representative sample of tendons from different species. These data include healthy tendons and those altered by injury and healing, genetic modification, allograft preparation, mechanical environment, and age. Fifty studies were selected and analyzed. Despite a wide range of mechanical properties between and within species, elastic modulus and ultimate stress are highly correlated (R2 = 0.785), suggesting that tendon failure is highly strain-dependent. Furthermore, this relationship was observed to be predictable over controlled ranges of elastic moduli, as would be typical of any individual species. With the knowledge gained through this metaanalysis, noninvasive tools could measure elastic modulus in vivo and reasonably predict ultimate stress (or structural compromise) for diseased or injured tendon. PMID:23599401

  14. Harnessing endogenous stem/progenitor cells for tendon regeneration.

    PubMed

    Lee, Chang H; Lee, Francis Y; Tarafder, Solaiman; Kao, Kristy; Jun, Yena; Yang, Guodong; Mao, Jeremy J

    2015-07-01

    Current stem cell-based strategies for tissue regeneration involve ex vivo manipulation of these cells to confer features of the desired progenitor population. Recently, the concept that endogenous stem/progenitor cells could be used for regenerating tissues has emerged as a promising approach that potentially overcomes the obstacles related to cell transplantation. Here we applied this strategy for the regeneration of injured tendons in a rat model. First, we identified a rare fraction of tendon cells that was positive for the known tendon stem cell marker CD146 and exhibited clonogenic capacity, as well as multilineage differentiation ability. These tendon-resident CD146+ stem/progenitor cells were selectively enriched by connective tissue growth factor delivery (CTGF delivery) in the early phase of tendon healing, followed by tenogenic differentiation in the later phase. The time-controlled proliferation and differentiation of CD146+ stem/progenitor cells by CTGF delivery successfully led to tendon regeneration with densely aligned collagen fibers, normal level of cellularity, and functional restoration. Using siRNA knockdown to evaluate factors involved in tendon generation, we demonstrated that the FAK/ERK1/2 signaling pathway regulates CTGF-induced proliferation and differentiation of CD146+ stem/progenitor cells. Together, our findings support the use of endogenous stem/progenitor cells as a strategy for tendon regeneration without cell transplantation and suggest this approach warrants exploration in other tissues. PMID:26053662

  15. Flexor Tendon Injuries: The Results of Primary Repair

    Microsoft Academic Search

    M. SINGER; S. MALOON

    1988-01-01

    This study is a critical analysis of results obtained following primary repair and post-operative controlled mobilisation of flexor tendon injuries which were treated by registrars with up to six months experience in hand surgery. 70 (55%) of 125 patients who underwent repair of a complete flexor digitorum profundus or flexor pollicis longus tendon injury during a 14-month period attended for

  16. New finding in the radiographic diagnosis of Achilles tendon rupture

    SciTech Connect

    Newmark, H.; Mellon, W.S. Jr.; Malhotra, A.K.; Olken, S.M.; Halls, J.

    1982-06-01

    The authors describe a new radiographic sign of rupture of the Achilles tendon system. It is a fracture, with separation through an osteophyte at the insertion of this tendon. Previously reported signs are also discussed as well as the present case report.

  17. Ultrasonography of chronic tendon injuries in the groin

    Microsoft Academic Search

    Peter Kälebo; Jon Karlsson; Leif Sward; Lars Peterson

    1992-01-01

    Ultrasonography was used in the diagnosis of 36 pa tients with chronic groin pain localized to the tendons of the rectus abdominis, rectus femoris, adductor mus cles, hamstring muscles, and the gluteal muscles. Ab normal findings, such as focal sonolucent areas and discontinuity of tendon fibers, that are indicative of nonhealed partial ruptures were found in 28 patients. These findings

  18. Neutrophils and macrophages accumulate sequentially following Achilles tendon injury

    Microsoft Academic Search

    David Marsolais; Claude H Côté

    2001-01-01

    Structural damage and inflammation occur following tendon injury. The purpose of this study was to determine the time course of inflammatory cell accumulation in two animal models of acute tendinopathy. In the first model, rat Achilles tendons were exposed by blunt dissection, injected with collagenase and sacrificed at 1, 3, 7, 14 and 28 days. In the second model, collagenase

  19. Partial Flexor Tendon Injuries: To Repair or Not

    Microsoft Academic Search

    D. D. MCGEORGE; J. H. STILWELL

    1992-01-01

    The correct management of partially divided flexor tendon injuries is still in dispute. This study compares the results of repair with non-repair in zone 2 injuries. We conclude that tendons divided by 60% or less in cross-sectional area should not be repaired.

  20. Delayed Rupture of Extensor Pollicis Longus Tendon following Closed Injury

    Microsoft Academic Search

    R. G. SIMPSON

    1977-01-01

    Closed rupture of the extensor pollicis longus tendon is most often seen following lower radial fractures, but is uncommon in the absence of fracture. Redden has recently described rupture following rotational injury of the forearm.I wish to record three cases of closed delayed rupture following direct injury to the area of the tendon.

  1. NSAID therapy effects on healing of bone, tendon, and the enthesis

    PubMed Central

    Su, Bailey

    2013-01-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used for the treatment of skeletal injuries. The ability of NSAIDs to reduce pain and inflammation is well-established. However, the effects of NSAID therapy on healing of skeletal injuries is less defined. NSAIDs inhibit cyclooxygenase activity to reduce synthesis of prostaglandins, which are proinflammatory, lipid-signaling molecules. Inhibition of cyclooxygenase activity can impact many physiological processes. The effects of NSAID therapy on healing of bone, tendon, and the tendon-to-bone junction (enthesis) have been studied in animal and cell culture models, but human studies are few. Use of different NSAIDs with different pharmacological properties, differences in dosing regimens, and differences in study models and outcome measures have complicated comparisons between studies. In this review, we summarize the mechanisms by which bone, tendon, and enthesis healing occurs, and describe the effects of NSAID therapy on each of these processes. Determining the impact of NSAID therapy on healing of skeletal tissues will enable clinicians to appropriately manage the patient's condition and improve healing outcomes. PMID:23869068

  2. Specialisation of extracellular matrix for function in tendons and ligaments

    PubMed Central

    Birch, Helen L.; Thorpe, Chavaunne T.; Rumian, Adam P.

    2013-01-01

    Summary Tendons and ligaments are similar structures in terms of their composition, organisation and mechanical properties. The distinction between them stems from their anatomical location; tendons form a link between muscle and bone while ligaments link bones to bones. A range of overlapping functions can be assigned to tendon and ligaments and each structure has specific mechanical properties which appear to be suited for particular in vivo function. The extracellular matrix in tendon and ligament varies in accordance with function, providing appropriate mechanical properties. The most useful framework in which to consider extracellular matrix differences therefore is that of function rather than anatomical location. In this review we discuss what is known about the relationship between functional requirements, structural properties from molecular to gross level, cellular gene expression and matrix turnover. The relevance of this information is considered by reviewing clinical aspects of tendon and ligament repair and reconstructive procedures. PMID:23885341

  3. Achilles tendon sports injuries: a review of classification and treatment.

    PubMed

    Werd, Matthew B

    2007-01-01

    Achilles tendon injuries are among the three most frequent sports-related injuries of the foot and ankle. Proper function of the Achilles tendon is critical to performance in sports. A thorough knowledge of the anatomy and biomechanical function of this tendon is essential to the effective treatment of these injuries. Distinguishing among the various pathologies of the Achilles tendon is an important first step toward successful treatment and return of the athlete to sports activity. The term Achilles tendinitis is a nonspecific diagnosis that does not accurately describe an actual injury. This review is intended to provide the sports medicine physician with a means of classifying Achilles tendon injuries and, thus, arriving at an accurate diagnosis and treatment plan. PMID:17218624

  4. System and Method for Tensioning a Robotically Actuated Tendon

    NASA Technical Reports Server (NTRS)

    Reiland, Matthew J. (Inventor); Diftler, Myron A. (Inventor)

    2013-01-01

    A tendon tensioning system includes a tendon having a proximal end and a distal end, an actuator, and a motor controller. The actuator may include a drive screw and a motor, and may be coupled with the proximal end of the tendon and configured to apply a tension through the tendon in response to an electrical current. The motor controller may be electrically coupled with the actuator, and configured to provide an electrical current having a first amplitude to the actuator until a stall tension is achieved through the tendon; provide a pulse current to the actuator following the achievement of the stall tension, where the amplitude of the pulse current is greater than the first amplitude, and return the motor to a steady state holding current following the conclusion of the pulse current.

  5. Clinical outcomes after repair of quadriceps tendon rupture: a systematic review.

    PubMed

    Ciriello, Vincenzo; Gudipati, Suribabu; Tosounidis, Theodoros; Soucacos, P N; Giannoudis, Peter V

    2012-11-01

    The existing evidence regarding the management of quadriceps tendon rupture remains obscure. The aim of the current review is to investigate the characteristics, the different techniques employed and to analyse the clinical outcomes following surgical repair of quadriceps tendon rupture. An Internet based search of the English literature of the last 25 years was carried out. Case reports and non-clinical studies were excluded. The methodological quality of the included studies was assessed using the Coleman Methodology Score. All data regarding mechanism and site of rupture, type of treatment, time elapsed between diagnosis and repair, patients' satisfaction, clinical outcome, return to pre-injury activities, complications and recurrence rates were extracted and analysed. Out of 474 studies identified, 12 met the inclusion criteria. The average of Coleman Methodology Score was 50.46/100. In total 319 patients were analysed with a mean age of 57 years (16-85). The mean time of follow-up was 47.5 months (3 months to 24 years). The most common mechanism of injury was simple fall (61.5%). Spontaneous ruptures were reported in 3.2% of cases. The most common sites of tear were noted between 1cm and 2 cm of the superior pole of the patella and, in the older people, at the osseotendinous junction. The most frequently used repair technique was patella drill holes (50% of patients). Simple sutures were used in mid-substance ruptures. Several reinforcement techniques were employed in case of poor quality or retraction of the torn ends of tendon. The affected limb was immobilised in a cast for a period of 3-10 weeks. Quadriceps muscular atrophy and muscle strength deficit were present in most of the cases. Worst results were noted in delayed repairs. Reported complications included heterotopic ossifications in 6.9% of patients, deep venous thrombosis or pulmonary embolism in 2.5%, superficial infection in 1.2% and deep infection in 1.1%. It appears that the type of surgical repair does not influence the clinical results. The majority of the studies reported good or excellent ROM and return to the pre-injury activities. The overall rate of re-rupture was 2%. PMID:22959496

  6. Use of a Turndown Quadriceps Tendon Flap for Rupture of the Patellar Tendon After Total Knee Arthroplasty

    Microsoft Academic Search

    Po-Chun Lin; Jun-Wen Wang

    2007-01-01

    Patellar tendon rupture is a devastating complication after total knee arthroplasty. The results of surgical treatment of this complication were discouraging in most of the reports. We describe a case of rupture of patellar tendon 7 weeks after total knee arthroplasty treated with a turndown quadriceps flap and circumferential wiring. Two years and 6 months after operation, the patient had

  7. Simultaneous rupture of the quadriceps tendon and contralateral patellar tendon in a patient with chronic renal failure

    Microsoft Academic Search

    Hasan Hilmi Muratli; Levent Çelebi; Onur Hapa; Ali Biçimo?lu

    2005-01-01

    Simultaneous quadriceps and patellar tendon rupture is rare. Mechanical factors and coexisting systemic and local factors are taken into consideration in the pathogenesis of these ruptures. In patients with some chronic systemic diseases, simultaneous rupture can occur spontaneously or with minor traumas. We present a case of simultaneous quadriceps and patellar tendon rupture in a 21-year-old man with chronic renal

  8. Recurrent patellar tendon rupture in a patient after intramedullary nailing of the tibia: reconstruction using an achilles tendon allograft.

    PubMed

    Jagow, Devin M; Garcia, Branden J; Yacoubian, Stephan V; Yacoubian, Shahan V

    2015-05-01

    Various complications after intramedullary (IM) nailing of the tibia have been reported, the most common of which are anterior knee pain and symptoms similar to patella tendonitis. Complete rupture of the patellar tendon after IM nailing of the tibia has been reported on 2 occasions, in conjunction with predisposing patient factors, such as systemic disease or a proud tibial nail. Patellar tendon ruptures are disabling injuries that can be technically difficult to repair because of the poor quality of remaining tendon tissue, quadriceps muscle atrophy and/or contracture, and scar-tissue formation. Many methods have described the surgical reconstruction of the knee extensor mechanism, which is most commonly performed after total knee arthroplasty. We report the successful surgical and clinical outcome of patellar tendon reconstruction using an Achilles tendon allograft in a patient subject to late and recurrent ruptures after IM nailing of the tibia through a mid-patellar tendon-splitting approach. Seven months after tendon reconstruction, the patient exhibited full knee flexion, an extension lag of 10º, 4/5 quadriceps strength, and return to her baseline ambulatory status. PMID:25950545

  9. Freehand resection of the patella in total knee arthroplasty referencing the attachments of the quadriceps tendon and patellar tendon

    Microsoft Academic Search

    Adolph V. Lombardi; Thomas H. Mallory; Paul D. Maitino; Stephen M. Herrington; Cheryl A. Kefauver

    1998-01-01

    A freehand technique of patellar resurfacing using anatomic references was prospectively evaluated. This technique utilizes an osteotomy beginning at the inferior pole of the patella just posterior to the insertion of the patellar tendon and is carried proximally posterior to the insertion of the quadriceps tendon. Evaluation of 55 total knee arthroplasties in 41 patients showed an average restored patellar

  10. The tear "TROUF" procedure: transconjunctival repositioning of orbital unipedicled fat.

    PubMed

    Kawamoto, Henry K; Bradley, James P

    2003-12-01

    Aging of the lower lid and cheek results in bulging of orbital fat and deepening of the orbital rim groove, known as the "tear trough." As an alternative to orbital fat excision, pedicles of fat can be spread in a submuscular plane to obliterate the groove of the tear trough. In a 1-year period, 25 patients had correction of their tear trough deformities through a transconjunctival approach. This technique included incision of the septum near the arcus marginalis, dissection of a suborbicularis pocket, and placement of medial and central fat pedicles over the orbital rim with buried 5-0 plain gut sutures. Clinically, after a follow-up of 17 to 31 months, there was leveling of the tear trough, smooth contour of the lower lid and cheek, minimal complications, and high patient satisfaction. PMID:14663238

  11. GTC Simulation of Tearing Modes in Fusion Plasmas

    NASA Astrophysics Data System (ADS)

    Liu, Dongjian; Holod, Ihor; Zhang, Wenlu; Lin, Zhihong

    2014-10-01

    In Tokamak discharge, Tearing modes are very important modes which may cause the disruption and sawtooth crash. For the reason, an effective physics model and corresponding simulation code are needed to study these modes. We have modified the fluid-kinetic hybrid electron model used in Gyro-kinetic Toroidal Code (GTC) and developed both resistive and finite mass electron fluid model for tearing mode simulations. Using the model in GTC, we have successfully recovered linear behavior of both the classical resistive tearing mode and the collisonless tearing mode, and verified the capability of GTC to study this mode. The modified GTC may supply a more powerful implement for kinetic-MHD study of Tokamak plasma.

  12. Nonlinear evolution of double tearing modes in tokamaks

    NASA Astrophysics Data System (ADS)

    Fredrickson, E.; Bell, M.; Budny, R. V.; Synakowski, E.

    2000-10-01

    The ?' formalism with neoclassical modifications has proven to be a useful tool in the study of tearing modes in high ?, collisionless plasmas. In this paper the formalism developed for the inclusion of neoclassical effects on tearing modes in monotonic q-profile plasmas is extended to plasmas with hollow current profiles and double rational surfaces. First, the classical formalism of tearing modes in the Rutherford regime in low beta plasmas is extended to q profiles with two rational surfaces and it is shown that this formalism is readily extended to include neoclassical effects. The evolution of a double tearing mode on the Tokamak Fusion Test Reactor is then simulated. Reasonable agreement is found for the outer island, but the stabilizing effect of the neoclassical term is overly large for the inner island.

  13. Scx-Transduced Tendon-Derived Stem Cells (TDSCs) Promoted Better Tendon Repair Compared to Mock-Transduced Cells in a Rat Patellar Tendon Window Injury Model

    PubMed Central

    Lee, Yuk Wa; Wong, Yin Mei

    2014-01-01

    We hypothesized that the transplantation of Scx-transduced tendon-derived stem cells (TDSCs) promoted better tendon repair compared to the transplantation of mock-transduced cells. This study thus aimed to investigate the effect of Scx transduction on the expression of lineage markers in TDSCs and the effect of the resulting cell line in the promotion of tendon repair. Rat non-GFP or GFP-TDSCs were transduced with Scx or empty lentiviral vector (Mock) and selected by blasticidin. The mRNA expressions of Scx and different lineage markers were examined by qRT-PCR. The effect of the transplantation of GFP-TDSC-Scx on tendon repair was then tested in a rat unilateral patellar tendon window injury model. The transplantation of GFP-TDSC-Mock and scaffold-only served as controls. At week 2, 4 and 8 post-transplantation, the repaired patellar tendon was harvested for ex vivo fluorescent imaging, vivaCT imaging, histology, immunohistochemistry and biomechanical test. GFP-TDSC-Scx consistently showed higher expressions of most of tendon- and cartilage- related markers compared to the GFP-TDSC-Mock. However, the effect of Scx transduction on the expressions of bone-related markers was inconclusive. The transplanted GFP-TDSCs could be detected in the window wound at week 2 but not at week 4. Ectopic mineralization was detected in some samples at week 8 but there was no difference among different groups. The GFP-TDSC-Scx group only statistically significantly improved tendon repair histologically and biomechanically compared to the Scaffold-only group and the GFP-TDSC-Mock group at the early stage of tendon repair. There was significant higher expression of collagen type I in the window wound in the GFP-TDSC-Scx group compared to the other two groups at week 2. The transplantation of GFP-TDSC-Scx promoted healing at the early stage of tendon repair in a rat patellar tendon window injury model. PMID:24831949

  14. Multiple tendon rupture in systemic lupus erythematosus: case report and review of the literature

    Microsoft Academic Search

    I Potasman; H M Bassan

    1984-01-01

    Tendon rupture in systemic lupus erythematosus (SLE) is a rare complication that appears to occur in patients receiving corticosteroid therapy. A case is presented with sequential bilateral rupture of Achilles tendon and unilateral rupture of a patellar tendon. Six more published cases are reviewed. Tendon rupture in SLE has affected both males and females between the ages of 24 and

  15. Fgf4 Positively Regulates scleraxis and Tenascin Expression in Chick Limb Tendons

    Microsoft Academic Search

    Frédérique Edom-Vovard; Bernadette Schuler; Marie-Ange Bonnin; Marie-Aimée Teillet; Delphine Duprez

    2002-01-01

    In vertebrates, tendons connect muscles to skeletal elements. Surgical experiments in the chick have underlined developmental interactions between tendons and muscles. Initial formation of tendons occurs autonomously with respect to muscle. However, further tendon development requires the presence of muscle. The molecular signals involved in these interactions remain unknown. In the chick limb, Fgf4 transcripts are located at the extremities

  16. Tear Cathepsin S–A Candidate Biomarker for Sjögren's Syndrome

    PubMed Central

    Hamm-Alvarez, Sarah F.; Janga, Srikanth R.; Edman, Maria C.; Madrigal, Sara; Shah, Mihir; Frousiakis, Starleen E.; Renduchintala, Kavita; Zhu, Jay; Bricel, Seth; Silka, Kimberly; Bach, Dianne; Heur, Martin; Christianakis, Stratos; Arkfeld, Daniel G.; Irvine, John; Mack, Wendy J.; Stohl, William

    2014-01-01

    Objective The diagnosis of Sjögren's Syndrome (SS) in routine practice is largely a clinical one and requires a high index of suspicion by the treating physician. This great dependence upon clinical judgment frequently leads to delayed diagnosis or misdiagnosis. Tear protein profiles have been proposed as simple and reliable biomarkers for SS diagnosis. Given that cathepsin S activity is increased in the lacrimal glands and tears of NOD mice (a murine model of SS), we explored the clinical utility of using tear cathepsin S (CTSS) activity as a biomarker for SS. Methods A method to measure CTSS activity in tears eluted from Schirmer's strips was developed and validated. Schirmer's tests and CTSS activity measurements were performed on 278 female subjects, including patients with SS (n=73), rheumatoid arthritis (n=79), systemic lupus erythematosus (n=40), blepharitis (n=10), non-specific dry eye (n=31), or other autoimmune diseases (n=12), along with 33 healthy controls. Results Median tear CTSS activity in SS patients was 4.1-fold higher than in patients with non-SS autoimmune diseases, 2.1-fold higher than in patients with non-specific dry eye, and 41.1-fold higher than in healthy controls. Tear CTSS levels were equally elevated in primary and secondary SS independent of the Schirmer's strip values or of circulating anti-SSA or anti-SSB autoantibodies. Conclusion Markedly high levels of tear CTSS activity are suggestive of SS. CTSS activity in tears can be measured in a simple, quick, economical, and non-invasive fashion and may serve as a novel biomarker and indicator of autoimmune dacryoadenitis during the workup for SS. PMID:24644101

  17. Computations of the current profile influence on tearing instability

    NASA Technical Reports Server (NTRS)

    Blekher, P. M.; Zuyeva, N. M.; Yurchenko, Z. I.

    1983-01-01

    Results of computations of tearing instability of a plasma column in a strong longitudinal magnetic field are presented for different current profiles. The power current profiles j=j sub 0(1-(r/a)(P))(nu) are considered and analyzed for various values of the parameters p and v. The tearing instability of the smoothed two-step profiles is studied. Optimal smoothed two-step profiles are constructed which are stable with respect to all helical largescale perturbations.

  18. Saturated tearing modes in tokamaks. Renewal proposal, progress report

    SciTech Connect

    Bateman, G.

    1984-01-01

    We have completed a computer code (GTOR) implementing our quasilinear method for determining saturated tearing mode magnetic island widths in axisymmetric toroidal plasmas. With this code we have surveyed the effect of current profile, aspect ratio and plasma elongation on saturated tearing modes. Current peaking within the islands is found to have a particularly large effect. In support of this research, we have developed a direct method for computing Hamada coordinates from harmonics of the inverse Grad-Shafranov equation.

  19. Retinal pigment epithelial tear after photodynamic therapy for choroidal neovascularization

    Microsoft Academic Search

    Faik Gelisken; Werner Inhoffen; Michael Partsch; Ulrike Schneider; Ingrid Kreissig

    2001-01-01

    PURPOSE: To report a case of retinal pigment epithelial tear after photodynamic therapy for choroidal neovascularization.METHODS: Case report. A 74-year-old woman with exudative age-related macular degeneration and classic subfoveal choroidal neovascularization RE underwent photodynamic therapy with verteporfin.RESULTS: Ophthalmoscopy and fluorescein angiography RE disclosed a retinal pigment epithelial tear in the area of photodynamic therapy.CONCLUSION: This case presents the first report

  20. [Regenerative therapy for tendon and ligament disorders in horses. Terminology, production, biologic potential and in vitro effects].

    PubMed

    Geburek, F; Stadler, P

    2011-01-01

    Conventional treatments of equine tendon injuries lead to an unsatisfactory healing process that usually results in a relatively high recurrence rate. Therefore, in recent years so-called regenerative therapeutics were studied scientifically in vitro and in laboratory animals. These include substances that ideally lead to the formation of replacement tissue, which in contrast to the low quality scar, has similar functional properties as the original intact tendon. Currently, a plethora of different substrates is either commercially available or can be produced in practice with the help of kits. The current knowledge on the production and the regenerative potential of nucleated cells like stem cells from bone marrow and fat tissue, of the blood products PRP (platelet rich plasma), ACP (autologous conditioned plasma), ACS (autologous conditioned serum) and of the scaffold substance UBM (urinary bladder matrix) are presented. Finally, the potential of some growth factors and of gene therapy is considered. Currently, it is assumed that the regeneration of tendon tissue is promoted by a complex interaction of scaffolds, growth factors and cells. At present, only very few studies are available which allow a comparison between these substances. Studies on the effect of regenerative substrates on tendons in live horses are presented elsewhere. PMID:22167082

  1. Dysfunctional Tendon Collagen Fibrillogenesis in Collagen VI Null Mice*

    PubMed Central

    Izu, Yayoi; Ansorge, Heather L.; Zhang, Guiyun; Soslowsky, Louis J.; Bonaldo, Paolo; Chu, Mon-Li; Birk, David E.

    2013-01-01

    Tendons are composed of fibroblasts and collagen fibrils. The fibrils are organized uniaxially and grouped together into fibers. Collagen VI is a non-fibrillar collagen expressed in developing and adult tendons. Human collagen VI mutations result in muscular dystrophy, joint hyperlaxity and contractures. The purpose of this study is to determine the functional roles of collagen VI in tendon matrix assembly. During tendon development, collagen VI was expressed throughout the extracellular matrix, but enriched around fibroblasts and their processes. To analyze the functional roles of collagen VI a mouse model with a targeted inactivation of Col6a1 gene was utilized. Ultrastructural analysis of Col6a1?/? versus wild type tendons demonstrated disorganized extracellular micro-domains and collagen fibers in the Col6a1?/? tendon. In the col6a1?/? tendon, fibril structure and diameter distribution was abnormal compared to wild type controls. Col6a1?/? fibrils had smaller diameters and the diameter distributions were shifted significantly toward the smaller diameters. An analysis of fibril density (number/?m2) demonstrated an ~2.5 fold increase in the Col6a1?/? versus wild type tendons. In addition, the fibril arrangement and structure was aberrant in the peri-cellular regions of Col6a1?/? tendons with frequent very large fibrils and twisted fibrils observed restricted to this region. The biomechanical properties were analyzed in mature tendons. A significant decrease in cross sectional area was observed. The percent relaxation, maximum load, maximum stress, stiffness and modulus were analyzed and Col6a1?/? tendons demonstrated a significant reduction in maximum load and stiffness compared to wild type tendons. An increase in matrix metalloproteinase activity was suggested in the absence of collagen VI. This suggests alterations in tenocyte expression due to disruption of cell-matrix interactions. The changes in expression may result in alterations in the peri-cellular environment. In addition, the absence of collagen VI may alter the sequestering of regulatory molecules such as leucine rich proteoglycans. These changes would result in dysfunctional regulation of tendon fibrillogenesis indirectly mediated by collagen VI. PMID:20951202

  2. Tissue engineering in flexor tendon surgery: current state and future advances.

    PubMed

    Galvez, M G; Crowe, C; Farnebo, S; Chang, J

    2014-01-01

    Tissue engineering of flexor tendons addresses a challenge often faced by hand surgeons: the restoration of function and improvement of healing with a limited supply of donor tendons. Creating an engineered tendon construct is dependent upon understanding the normal healing mechanisms of the tendon and tendon sheath. The production of a tendon construct includes: creating a three-dimensional scaffold; seeding cells within the scaffold; encouraging cellular growth within the scaffold while maintaining a gliding surface; and finally ensuring mechanical strength. An effective construct incorporates these factors in its design, with the ultimate goal of creating tendon substitutes that are readily available to the reconstructive hand surgeon. PMID:24262584

  3. Deficits 10-years after Achilles tendon repair.

    PubMed

    Horstmann, T; Lukas, C; Merk, J; Brauner, T; Mündermann, A

    2012-06-01

    The purpose of this study was to determine the long-term impact of surgical repair and subsequent 6-week immobilization of an Achilles tendon rupture on muscle strength, muscle strength endurance and muscle activity. 63 patients participated in this study on average 10.8 ± 3.4 years after surgically repaired Achilles tendon rupture and short-term immobilization. Clinical function was assessed and muscle strength, strength endurance and muscle activity were measured using a dynamometer and electromyography. Ankle ROM, heel height during heel-raise tests and calf circumference were smaller on the injured than on the contralateral side. Ankle torques during the concentric dorsiflexion tasks at 60 °/sec and 180 °/sec and ankle torques during the eccentric plantarflexion task and during the concentric plantarflexion task at 60 °/sec for the injured leg were significantly lower than those for the contralateral leg. The total work during a plantarflexion exercise at 180 °/sec was 14.9% lower in the injured compared to the contralateral leg (p < 0.001). Muscle activity for the gastrocnemius muscle during dorsiflexion tasks was significantly higher in the injured than in the contralateral limb. Limited ankle joint ROM and increased muscle activity in the injured leg suggest compensatory mechanisms to account for differences in muscle morphology and physiology caused by the injury. PMID:22499571

  4. Femoral Press-Fit Fixation of the Hamstring Tendons for Anterior Cruciate Ligament Reconstruction

    Microsoft Academic Search

    Michael Jagodzinski; Vahid Behfar; Christof Hurschler; Knut Albrecht; Christian Krettek; Ulrich Bosch

    2004-01-01

    Background: Press-fit fixation of patellar tendon–bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary. For hamstring tendon grafts, no biomechanical data exist of a press-fit procedure.Hypothesis: Press-fit femoral fixation of hamstring tendons is mechanically equivalent to press-fit patellar tendon–bone fixation.Study Design: Controlled laboratory study.Methods: Patellar and hamstring tendons of 30 human cadavers (age, 53.8 ±

  5. Collagen type V polymorphism in spontaneous quadriceps tendon ruptures.

    PubMed

    Galasso, Olimpio; Iaccino, Enrico; Gallelli, Luca; Perrotta, Ida; Conforti, Francesco; Donato, Giuseppe; Gasparini, Giorgio

    2012-04-01

    Spontaneous simultaneous bilateral quadriceps tendon rupture is associated with multiple medical conditions and pharmacological treatments; however, identifying prior risk factors is impossible in most cases. Achilles tendon and anterior cruciate ligament ruptures are associated with collagen, type V, alpha 1 (COL5A1) polymorphism. This genetic variant may be implicated quadriceps tendon rupture. The COL5A1 encodes the protein for pro-?1 chains of the low-abundance heterotrimeric type V collagen. In most noncartilaginous tissues, type V collagen is a quantitatively minor component of type I collagen that has been implicated in the regulation of the size and configuration of type I collagen fibrils. The functional significance of COL5A1 polymorphism in relation to type V collagen expression or activity has not been determined.This article describes a patient with COL5A1 polymorphism and spontaneous simultaneous quadriceps tendon rupture. However, genetic and histologic studies performed on blood and tendon tissues and 3 consecutive sex- and age-matched controls showed a statistically significant reduction in collagen type V expression and an alteration in collagen structure in the tendon. These findings might explain the pathomechanisms of spontaneous tendon ruptures associated with COL5A1 polymorphism. PMID:22495864

  6. Flexor Digitorum Profundus Tendon Tension during Finger Manipulation

    PubMed Central

    Tanaka, Tatsuro; Amadio, Peter C.; Zhao, Chunfeng; Zobitz, Mark E.; An, Kai-Nan

    2005-01-01

    The purpose of this study was to measure the tension in the flexor digitorum profundus (FDP) tendon in zone II and the digit angle during joint manipulations that replicate rehabilitation protocols. Eight FDP tendons from eight human cadavers were used in this study. The dynamic tension in zone II of the tendon and metacarpophalangeal (MCP) joint angle were measured in various wrist and digit positions. Tension in the FDP tendon increased with MCP joint extension. There was no tension with the finger fully flexed and wrist extended (synergistic motion), but the tendon force reached 1.77 ± 0.43 N with the MCP joint hyperextended 45 degrees with the distal interphalangeal and proximal interphalangeal joints flexed. The combination of wrist extension and MCP joint hyperextension with the distal interphalangeal and proximal interphalangeal joints fully flexed, what the authors term ‘‘modified synergistic motion,’’ produced a modest tendon tension and may be a useful alternative configuration to normal synergistic motion in tendon rehabilitation. PMID:16059854

  7. Temporal Healing in Rat Achilles Tendon: Ultrasound Correlations

    PubMed Central

    Chamberlain, Connie S.; Duenwald-Kuehl, Sarah E.; Okotie, Gregory; Brounts, Sabrina H.; Baer, Geoffrey S.; Vanderby, Ray

    2012-01-01

    The purpose of this study was to explore whether a new ultrasound-based technique correlates with mechanical and biological metrics that describe the tendon healing. Achilles tendons in 32 rats were unilaterally transected and allowed to heal without repair. At 7, 9, 14, or 29 days post-injury, tendons were collected and examined for healing via ultrasound image analysis, mechanical testing, and immunohistochemistry. Consistent with previous studies, we observe that the healing tendons are mechanically inferior (ultimate stress, ultimate load, and normalized stiffness) and biologically altered (cellular and ECM factors) compared to contralateral controls with an incomplete recovery over healing time. Unique to this study, we report: 1) Echo intensity (defined by gray-scale brightness in the ultrasound image) in the healing tissue is related to stress and normalized stiffness. 2) Elongation to failure is relatively constant so that tissue normalized stiffness is linearly correlated with ultimate stress. Together, 1 and 2 suggest a method to quantify mechanical compromise in healing tendons. 3) The amount and type of collagen in healing tendons associates with their strength and normalized stiffness as well as their ultrasound echo intensity. 4) A significant increase of periostin in the healing tissues suggests an important but unexplored role for this ECM protein in tendon healing. PMID:23149902

  8. Preferential tendon stem cell response to growth factor supplementation.

    PubMed

    Holladay, Carolyn; Abbah, Sunny-Akogwu; O'Dowd, Colm; Pandit, Abhay; Zeugolis, Dimitrios I

    2014-01-29

    Tendon injuries are increasingly prevalent around the world, accounting for more than 100 000 new clinical cases/year in the USA alone. Cell-based therapies have been proposed as a therapeutic strategy, with recent data advocating the use of tendon stem cells (TSCs) as a potential cell source with clinical relevance for tendon regeneration. However, their in vitro expansion is problematic, as they lose their multipotency and change their protein expression profile in culture. Herein, we ventured to assess the influence of insulin-like growth factor 1 (IGF-1), growth and differentiation factor-5 (GDF-5) and transforming growth factor-?1 (TGF?1) supplementation in TSC culture. IGF-1 preserved multipotency for up to 28?days. Upregulation of decorin and scleraxis expression was observed as compared to freshly isolated cells. GDF-5 treated cells exhibited reduced differentiation along adipogenic and chondrogenic pathways after 28?days, and decorin, scleraxis and collagen type I expression was increased. After 28?days, TGF?1 supplementation led to increased scleraxis, osteonectin and collagen type II expression. The varied responses to each growth factor may reflect their role in tendon repair, suggesting that: GDF-5 promotes the transition of tendon stem cells towards tenocytes; TGF?1 induces differentiation along several pathways, including a phenotype indicative of fibrocartilage or calcified tendon, common problems in tendon healing; and IGF-1 promotes proliferation and maintenance of TSC phenotypes, thereby creating a population sufficient to have a beneficial effect. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24474722

  9. Current Concepts in Examination and Treatment of Elbow Tendon Injury

    PubMed Central

    Ellenbecker, Todd S.; Nirschl, Robert; Renstrom, Per

    2013-01-01

    Context: Injuries to the tendons of the elbow occur frequently in the overhead athlete, creating a significant loss of function and dilemma to sports medicine professionals. A detailed review of the anatomy, etiology, and pathophysiology of tendon injury coupled with comprehensive evaluation and treatment information is needed for clinicians to optimally design treatment programs for rehabilitation and prevention. Evidence Acquisitions: The PubMed database was searched in January 2012 for English-language articles pertaining to elbow tendon injury. Results: Detailed information on tendon pathophysiology was found along with incidence of elbow injury in overhead athletes. Several evidence-based reviews were identified, providing a thorough review of the recommended rehabilitation for elbow tendon injury. Conclusions: Humeral epicondylitis is an extra-articular tendon injury that is common in athletes subjected to repetitive upper extremity loading. Research is limited on the identification of treatment modalities that can reduce pain and restore function to the elbow. Eccentric exercise has been studied in several investigations and, when coupled with a complete upper extremity strengthening program, can produce positive results in patients with elbow tendon injury. Further research is needed in high-level study to delineate optimal treatment methods. PMID:24427389

  10. Production of a sterilised decellularised tendon allograft for clinical use.

    PubMed

    Huang, Q; Ingham, E; Rooney, P; Kearney, J N

    2013-12-01

    Application of a high-level decontamination or sterilisation procedure and cell removal technique to tendon allograft can reduce the concerns of disease transmission, immune reaction, and may improve remodelling of the graft after implantation. The decellularised matrix can also be used as a matrix for tendon tissue engineering. One such sterilisation factor, Peracetic acid (PAA) has the advantage of not producing harmful reaction residues. The aim of this study was to evaluate the effects of PAA treatment and a cell removal procedure on the production of tendon matrix. Human patellar tendons, thawed from frozen were treated respectively as: Group 1, control with no treatment; Group 2, sterilised with PAA (0.1 % (w/v) PAA for 3 h) Group 3, decellularised (incubation successively in hypotonic buffer, 0.1 % (w/v) sodium dodecyl sulphate, and a nuclease solution); Group 4, decellularised and PAA sterilised. Histological analysis showed that no cells were visible after the decellularisation treatment. The integrity of tendon structure was maintained after decellularisation and PAA sterilisation, however, the collagen waveform was slightly loosened. No contact cytotoxicity was found in any of the groups. Determination of de-natured collagen showed no significant increase when compared with the control. This suggested that the decellularisation and sterilisation processing procedures did not compromise the major properties of the tendon. The sterilised, decellularised tendon could be suitable for clinical use. PMID:23443409

  11. Tendon Basic Science: Development, Repair, Regeneration, and Healing

    PubMed Central

    Andarawis-Puri, Nelly; Flatow, Evan L.; Soslowsky, Louis J.

    2015-01-01

    Tendinopathy and tendon rupture are common and disabling musculoskeletal conditions. Despite the prevalence of these injuries, a limited number of investigators are conducting fundamental, basic science studies focused on understanding processes governing tendinopathies and tendon healing. Development of effective therapeutics is hindered by the lack of fundamental guiding data on the biology of tendon development, signal transduction, mechanotransduction, and basic mechanisms underlying tendon pathogenesis and healing. To propel much needed progress, the New Frontiers in Tendon Research Conference, co-sponsored by NIAMS/NIH, the Orthopaedic Research Society, and the Icahn School of Medicine at Mount Sinai, was held to promote exchange of ideas between tendon researchers and basic science experts from outside the tendon field. Discussed research areas that are underdeveloped and represent major hurdles to the progress of the field will be presented in this review. To address some of these outstanding questions, conference discussions and breakout sessions focused on six topic areas (Cell Biology and Mechanics, Functional Extracellular Matrix, Development, Mechano-biology, Scarless Healing, and Mechanisms of Injury and Repair), which are reviewed in this special issue and briefly presented in this review. Review articles in this special issue summarize the progress in the field and identify essential new research directions. PMID:25764524

  12. The Tendon Injury Response Is Influenced by Decorin and Biglycan

    PubMed Central

    Dunkman, Andrew A.; Buckley, Mark R.; Mienaltowski, Michael J.; Adams, Sheila M.; Thomas, Stephen J.; Satchell, Lauren; Kumar, Akash; Pathmanathan, Lydia; Beason, David P.; Iozzo, Renato V.; Birk, David E.; Soslowsky, Louis J.

    2013-01-01

    Defining the constituent regulatory molecules in tendon is critical to understanding the process of tendon repair and instructive to the development of novel treatment modalities. The purpose of this study is to define the structural, expressional, and mechanical changes in the tendon injury response, and elucidate the roles of two class I small leucine-rich proteoglycans (SLRPs). We utilized biglycan-null, decorin-null and wild type mice with an established patellar tendon injury model. Mechanical testing demonstrated functional changes associated with injury and the incomplete recapitulation of mechanical properties after six weeks. In addition, SLRP deficiency influenced the mechanical properties with a marked lack of improvement between three and six weeks in decorin-null tendons. Morphological analyses of the injury response and role of SLRPs demonstrated alterations in cell density and shape as well as collagen alignment and fibril structure resulting from injury. SLRP gene expression was studied using RT-qPCR with alterations in expression associated with the injured tendons. Our results show that in the absence of biglycan initial healing may be impaired while in the absence of decorin later healing is clearly diminished. This suggests that biglycan and decorin may have sequential roles in the tendon response to injury. PMID:24072490

  13. STRESS CORROSION CRACKING IN TEAR DROP SPECIMENS

    SciTech Connect

    Lam, P; Philip Zapp, P; Jonathan Duffey, J; Kerry Dunn, K

    2009-05-01

    Laboratory tests were conducted to investigate the stress corrosion cracking (SCC) of 304L stainless steel used to construct the containment vessels for the storage of plutonium-bearing materials. The tear drop corrosion specimens each with an autogenous weld in the center were placed in contact with moist plutonium oxide and chloride salt mixtures. Cracking was found in two of the specimens in the heat affected zone (HAZ) at the apex area. Finite element analysis was performed to simulate the specimen fabrication for determining the internal stress which caused SCC to occur. It was found that the tensile stress at the crack initiation site was about 30% lower than the highest stress which had been shifted to the shoulders of the specimen due to the specimen fabrication process. This finding appears to indicate that the SCC initiation took place in favor of the possibly weaker weld/base metal interface at a sufficiently high level of background stress. The base material, even subject to a higher tensile stress, was not cracked. The relieving of tensile stress due to SCC initiation and growth in the HAZ and the weld might have foreclosed the potential for cracking at the specimen shoulders where higher stress was found.

  14. Tendon biomechanics and mechanobiology - a mini-review of basic concepts and recent advancements

    PubMed Central

    Wang, James H-C.; Guo, Qianping; Li, Bin

    2011-01-01

    Due to their unique hierarchical structure and composition, tendons possess characteristic biomechanical properties, including high mechanical strength and viscoelasticity, which enable them to carry and transmit mechanical loads (muscular forces) effectively. Tendons are also mechano-responsive by adaptively changing their structure and function in response to altered mechanical loading conditions. In general, mechanical loading at physiological levels is beneficial to tendons, but excessive loading or disuse of tendons is detrimental. This mechano-adaptability is due to the cells present in tendons. Tendon fibroblasts (tenocytes) are the dominant tendon cells responsible for tendon homeostasis and repair. Tendon stem cells (TSCs), which were recently discovered, also play a vital role in tendon maintenance and repair by virtue of their ability to self-renew and differentiate into tenocytes. TSCs may also be responsible for chronic tendon injury, or tendinopathy, by undergoing aberrant differentiation into non-tenocytes in response to excessive mechanical loading. Thus, it is necessary to devise optimal rehabilitation protocols in order to enhance tendon healing while reducing scar tissue formation and tendon adhesions. Moreover, along with scaffolds that can mimic tendon matrix environments and platelet-rich plasma (PRP), which serves as a source of growth factors, TSCs may be the optimal cell type for enhancing repair of injured tendons. PMID:21925835

  15. Endoscopic Resection of Lipoma of the Patellar Tendon

    PubMed Central

    Lui, Tun Hing; Lee, Man Wai

    2015-01-01

    Synovial lipoma of the patellar tendon is a very rare entity. It can be associated with rupture of the patellar tendon. We present a case of synovial lipoma that was successfully resected endoscopically. The other indications for patellar tendoscopy include chronic patellar tendinitis and tendinosis, recalcitrant bursitis around the tendon, Osgood-Schlatter disease, and jumper's knee. The major potential danger of this endoscopic procedure is iatrogenic damage to the patellar insertion during endoscopic debridement in patients with jumper's knee or the tibial insertion during endoscopic debridement in patients with Osgood-Schlatter disease. PMID:25973368

  16. Tendon transfers in the treatment of the adult flatfoot.

    PubMed

    Backus, Jonathon D; McCormick, Jeremy J

    2014-03-01

    Tendon transfers are critical to successful surgical correction of adult flexible flatfoot deformity and may be beneficial in correcting rigid deformities as well. Patients with refractory stage I and II deformities often require selective osteotomies in addition to tendon transfer. Patients with stage III and IV deformities typically require hindfoot arthrodesis. One of several tendons can be used for transfer based on surgeon's preference. Flexor digitorum longus (FDL) and flexor hallucis longus (FHL) transfers have been shown to have good results. A peroneus brevis transfer is typically used to supplement small FDL or FHL transfer donors or in revision cases. PMID:24548507

  17. Posterior tibial tendon dysfunction in the adult: current concepts.

    PubMed

    Stein, Benjamin E; Schon, Lew C

    2015-01-01

    The management of posterior tibial tendon dysfunction in adults has evolved substantially, and controversy persists regarding a specific recommended algorithm for treatment. The current focus is on early diagnosis and treatment of this disorder with joint-sparing surgeries, such as corrective osteotomies and tendon transfers, when nonsurgical modalities have been exhausted. It is helpful to be familiar with the pertinent pathophysiology and diagnostic pearls associated with posterior tibial tendon dysfunction, its treatment options, pertinent literature, and technique tips for the procedures currently being used. PMID:25745927

  18. Tendon to bone healing and its implications for surgery

    PubMed Central

    Bunker, Daniel Lee John; Ilie, Victor; Ilie, Vladimir; Nicklin, Sean

    2014-01-01

    Summary Entheses are complex structures which act to reduce stress concentrations between tendon and skeleton tissues. Understanding the development and function of the enthesis organ has implications for surgical repair, particularly in regards to healing and the regulation of tendon to bone engraftment. In this paper we review the development and function of entheses as well as the enthesis organ concept. Next we examine the process of tendon to bone healing and how this can be regulated, before addressing implications for surgical repair and post-operative care. PMID:25489553

  19. The long head of the biceps tendon is a suitable cell source for tendon tissue regeneration

    PubMed Central

    Pietschmann, Matthias F.; Gülecyüz, Mehmet F.; Ficklscherer, Andreas; Jansson, Volkmar; Müller, Peter E.

    2014-01-01

    Introduction Tendon tissue engineering (TTE) tries to produce tendinous tissue of high quality to replace dysfunctional tissue. One possible application of TTE might be the replacement of ruptured tissue of the rotator cuff. Autologous tenocytes seem to be most suitable as no differentiation in vitro is necessary. Today it is still uncertain if there is a difference between tendon-derived cells (TDC) of different native tissues. Moreover, the search for suitable scaffolds is another important issue in TTE. Material and methods This study compared TDC of the long head of the biceps tendon (LHB), the anterior cruciate ligament (ACL) and the tendon of the musculus semitendinosus (TMS). The TDC were isolated using the cell migration method. Cell morphology was assessed using light microscopy and gene expression was performed using polymerase chain reaction (PCR). Afterwards, cell seeding efficiency and proliferation were tested on a collagen I scaffold using the WST-1 assay. Results were confirmed using H + E staining. Results The TDC of the LHB showed higher expression levels of collagen type I and decorin (p < 0.01) compared to TDC of other origin. Results showed efficient cell seeding and proliferation within the scaffold. Proliferation within the scaffold was not as high as when cells were cultivated without a scaffold. Conclusions The TDC of the LHB seems to be the most suitable cell source. Further research is necessary to find out if the results can be transferred to an in vivo model. The new collagen I scaffold seems to offer an opportunity to combine good biocompatibility and mechanical strength. PMID:25097592

  20. Technical tips: reconstruction of deep and superficial deltoid ligaments by peroneus longus tendon in stage 4 posterior tibial tendon dysfunction.

    PubMed

    Lui, T H

    2014-12-01

    The deltoid ligament is composed of the superficial and deep layers. Disruption of the deltoid ligament can occur in rotational ankle fracture, chronic ankle instability, or stage 4 posterior tibial tendon dysfunction. Correcting valgus tilt at the time of flatfoot reconstruction in case of stage 4 posterior tibial tendon dysfunction may prevent future collapse and the need for ankle arthrodesis or possibly ankle arthroplasty. We describe a technique of reconstruction of both the superficial and deep deltoid ligaments by peroneus longus tendon. PMID:25457670

  1. 26 CFR 1.1016-3 - Exhaustion, wear and tear, obsolescence, amortization, and depletion for periods since February...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 false Exhaustion, wear and tear, obsolescence, amortization...Application § 1.1016-3 Exhaustion, wear and tear, obsolescence, amortization...property shall be decreased for exhaustion, wear and tear, obsolescence,...

  2. Tear Film Breakup and Structure Studied by Simultaneous Video Recording of Fluorescence and Tear Film Lipid Layer Images

    PubMed Central

    King-Smith, P. Ewen; Reuter, Kathleen S.; Braun, Richard J.; Nichols, Jason J.; Nichols, Kelly K.

    2013-01-01

    Purpose. The thinning of the precorneal tear film between blinks and tear film breakup can be logically analyzed into contributions from three components: evaporation, flow into the cornea, and tangential flow along the corneal surface. Whereas divergent tangential flow contributes to certain types of breakup, it has been argued that evaporation is the main cause of tear thinning and breakup. Because evaporation is controlled by the tear film lipid layer (TFLL) it should therefore be expected that patterns of breakup should match patterns in the TFLL, and this hypothesis is tested in this study. Methods. An optical system is described for simultaneous video imaging of fluorescein tear film breakup and the TFLL. Recordings were made from 85 subjects, including both with healthy and dry eyes. After instillation of 5 ?L2% fluorescein, subjects were asked to blink 1 second after the start of the recording and try to maintain their eyes open for the recording length of 30 or 60 seconds. Results. Areas of tear film thinning and breakup usually matched corresponding features in the TFLL. Whereas thinning and breakup were often matched to thin lipid, surprisingly, the corresponding lipid region was not always thinner than the surrounding lipid. Occasionally, a thin lipid region caused a corresponding region of greater fluorescence (thicker aqueous layer), due to convergent tangential flow. Conclusions. Areas of tear thinning and breakup can generally be matched to corresponding regions of the TFLL as would be expected if breakup is largely due to evaporation. Surprisingly, in some examples, the corresponding lipid area was not thinner and possibly thicker than the surrounding lipid. This indicates that the lipid was a poor barrier to evaporation, perhaps because of deficiency in composition and/or structure. For example, bacterial lipases may have broken down esters into component acids and alcohols, causing a defective TFLL structure with increased evaporation. PMID:23766476

  3. Right ventricular false tendons, a cadaveric approach.

    PubMed

    Loukas, Marios; Wartmann, Christopher T; Tubbs, R Shane; Apaydin, Nihal; Louis, Robert G; Black, Brandie; Jordan, Robert

    2008-06-01

    Left ventricular false tendons (LFTs) have been extensively described and recognized by gross anatomic studies. However, there is very little information available regarding right ventricular false tendons (RFTs). The aim of our study, therefore, was to explore and delineate the morphology, topography and morphometry of the RFTs, and provide a comprehensive picture of their anatomy across a broad range of specimens. We identified 35/100 heart specimens containing right ventricular RFTs and classified them into five types. In Type I (21, 47.7%) the RFTs, was located between the ventricular septum and the anterior papillary muscle; in Type II (11, 22.9%) between ventricular septum and the posterior papillary muscle; in Type III (7, 14.5%) between the anterior leaflet of the tricuspid valve and the right ventricular free wall; in Type IV (5, 10.4%) between the posterior papillary muscle and the ventricular free wall; and lastly, in Type V (4, 8.3%) between the anterior papillary muscle and ventricular free wall. The mean length of the RFTs was 18 +/- 7 mm with a mean diameter of 1.4 +/- 05 mm. Histologic examination with Masson trichrome and PAS revealed that 20 (41.6%) of the 48 RFTs carried conduction tissue fibers. The presence of conduction tissue fibers within the RFTs was limited to Types I, III, and IV. In Types II and V the RFTs resembled fibrous structures in contrast with Type I, II and IV, which were composed more of muscular fibers, including conduction tissue fibers. RFTs containing conduction tissue fibers were identified, which may implicate them in the appearance of arrhythmias. PMID:18283389

  4. Prestressed concrete using KEVLAR reinforced tendons

    SciTech Connect

    Dolan, C.W.

    1989-01-01

    KEVLAR is a high strength, high modulus synthetic fiber manufactured by the E.I. DuPont de Nemours Company. The fiber is resistant to chloride and alkali attack. The resistance is enhanced when the fibers are assembled into a resin matrix and fabricated as rods. These properties suggest that KEVLAR reinforced rods may be a substitute for high strength steel prestress tendons in certain applications such as bridge decks and parking structures. This dissertation presents the background, theoretical development, and experimental investigations of KEVLAR reinforced rod strength, anchorage, fabrication and performance in prestressed concrete structures. The study concludes that KEVLAR has significant potential for these prestressed concrete applications. However, the reliability of the long term anchorage of the KEVLAR reinforced rods must be improved before production applications are undertaken. KEVLAR has a low shear strength compared to its tensile capacity. The anchorage of KEVLAR reinforced rods is sensitive to the shear forces generated in the anchorage assembly. Finite element analyses, using interface elements to simulate the addition of a mold release agent in a conic anchor, predict the behavior of resin socketed anchors. Test results confirm that mold release agents reduce the anchor shear stresses and suggest that moderate strength resins may be used in the anchor. KEVLAR is nearly linearly elastic to failure, yet ductility of a structure is an important design concern. Prestressed concrete beam tests using both bonded and unbonded tendons demonstrated that ductile structural behavior is obtained. Methods of predicting the strength and deflection behavior of the prestressed beams are presented and the theoretical predictions are compared to the experimental results. The overall correlation between predicted and theoretical results is satisfactory.

  5. [Neglected ipsilateral simultaneous ruptures of patellar and quadriceps tendon].

    PubMed

    Karahasano?lu, ?lker; Yolo?lu, Osman; Kerimo?lu, Servet; Turhan, Ahmet U?ur

    2015-01-01

    Neglected patellar and quadriceps tendon rupture is a rare injury, but ipsilateral simultaneous patellar and quadriceps tendon rupture was not described in the literature to our knowledge. In this article, we report a 40-year-old healthy male patient with neglected ipsilateral patellar and quadriceps tendon ruptures treated by peroneus longus tendon autograft. Patient had received some conservative and surgical treatments for patellar fracture before applying to our clinic. After our treatment using peroneus longus autograft and interference nails, patient was immobilized for six weeks in cylindrical cast. Flexion exercises and full weight bearing were started after cast removal. Patient had no complaint at postoperative second year. Patient was a neglected case. Surgical repair and early rehabilitation enabled us to achieve a satisfactory outcome. PMID:25741921

  6. Editorial Commentary: Hamstring Tendon Regeneration After Autograft Harvest.

    PubMed

    Lubowitz, James H

    2015-06-01

    While radiographic and histologic data show features of hamstring tendon regeneration after harvest for ligament reconstruction, we remain skeptical that hamstring regeneration is clinically meaningful. We cannot recommend reharvest for revision surgery. PMID:26048767

  7. Open repair of retracted latissimus dorsi tendon avulsion.

    PubMed

    Ellman, Michael B; Yanke, Adam; Juhan, Tristan; Verma, Nikhil N; Nicholson, Gregory P; Bush-Joseph, Charles; Romeo, Anthony A

    2013-06-01

    Latissimus dorsi avulsion injuries are rarely reported in the literature and are managed with a variety of strategies. Primary anatomical repair of tendon to bone may offer athletes the best chance for successful return to sports. In this article, we describe a surgical technique for safely repairing an acute or chronic, retracted, avulsed latissimus tendon back to its insertion on the medial aspect of the bicipital groove of the proximal humerus. Using 1 low anterior axillary incision and 1 posterior axillary incision for tendon retrieval when retraction is more than 5 cm, this technique allows for direct anatomical repair of a retracted tendon to bone using 3 points of bony fixation supplemented by soft-tissue repair. The technique also minimizes the risks for neurovascular compromise and cosmetic deformity, while decreasing the risk for postinjury strength deficits. PMID:23805423

  8. Management of chronic ruptures of the Achilles tendon.

    PubMed

    Maffulli, Nicola; Ajis, Adam

    2008-06-01

    Chronic ruptures of Achilles tendons are those that present four to six weeks after the original injury. They have become more common as acute Achilles tendon injuries have become more frequent, and they are associated with considerable functional morbidity. Most surgeons agree that chronic ruptures should be managed operatively. Diagnosis is based predominantly on history and clinical examination. Real-time, high-resolution ultrasound and magnetic resonance imaging are helpful in preoperative planning or as a diagnostic aid. Local tissue, local tendons, and allografts can be used to reconstruct the tendon, and end-to-end repair is possible if the gap is <2.5 cm. Compared with acute injuries, chronic injuries are associated with a higher rate of postoperative infection and more prolonged recovery. PMID:18519331

  9. Osmotic pressure induced tensile forces in tendon collagen

    E-print Network

    Masic, Admir

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation ...

  10. Nonlinear optical imaging characteristics in rat tail tendon

    NASA Astrophysics Data System (ADS)

    Liu, N. R.; Zhang, X. Z.; Qiu, Y. S.; Chen, R.

    2013-04-01

    The aim of this study was to examine the characteristics of skeletal muscle fibers in tail tendons, explore the content of intrinsic components at different depths and ascertain the optimum excitation wavelength, which will help to establish a relationship between diagnosis and therapy and the tendon injury. A multiphoton microscopic imaging system was used to achieve the images and spectra via an imaging mode and a Lambda mode, respectively. This work demonstrates that the skeletal muscle fibers of the tail tendon are in good order. Second harmonic generation (SHG) and two-photon excited fluorescence (TPEF) signals originating from certain intrinsic components are varied with depth, and the SHG/TPEF intensity ratios are varied at different excitation wavelengths. Below 800 nm is the optimum for cell TPEF, while above 800 nm is the optimum for SHG. With the development of imaging techniques, a nonlinear optical imaging system will be helpful to represent the functional behaviors of tissue related to tendon injury.

  11. Tearing resistance of some co-polyester sheets

    SciTech Connect

    Kim, Ho Sung; Karger-Kocsis, Jozsef

    2004-06-07

    A three-zone model consisting of initial, evolutionary and stabilised plastic zones for tearing resistance was proposed for polymer sheets. An analysis with the model, based on the essential work of fracture (EWF) approach, was demonstrated to be capable for predicting specific total work of fracture along the tear path across all the plastic zones although accuracy of specific essential work of fracture is subject to improvement. Photo-elastic images were used for identification of plastic deformation sizes and profiles. Fracture mode change during loading was described in relation with the three zones. Tearing fracture behaviour of extruded mono- and bi-layer sheets of different types of amorphous co-polyesters and different thicknesses was investigated. Thick material exhibited higher specific total work of tear fracture than thin mono-layer sheet in the case of amorphous polyethylene terephthalate (PET). This finding was explained in terms of plastic zone size formed along the tear path, i.e., thick material underwent larger plastic deformation than thin material. When PET and polyethylene terephthalate glycol (PETG) were laminated with each other, specific total work of fracture of the bi-layer sheets was not noticeably improved over that of the constituent materials.

  12. Intraocular pressure and tear production in five herbivorous wildlife species.

    PubMed

    Ofri, R; Horowitz, I H; Raz, D; Shvartsman, E; Kass, P H

    2002-08-31

    The intraocular pressure and rate of tear production were measured in 18 addax antelopes (Addax nasomaculatus), four impalas (Aepyceros melampus), 11 wide-lipped rhinoceroses (Ceratotherium simum), 10 white-tailed wildebeests (Connochaetes gnou) and seven scimitar-horned oryxes (Oryx dammah). The animals were anaesthetised with an intramuscular injection of etorphine hydrochloride and acepromazine maleate, and the Schirmer tear test I was used to evaluate tear production, and applanation tonometry was used to evaluate the intraocular pressure. The mean (sd) rate of tear production ranged from 17.6 (3.1) mm/minute in the rhinoceros to 28.8 (8.3) mm/minute in the addax. The intraocular pressure ranged from 8.0 (1.2) mmHg in the impala to 32.1 (10.4) mmHg in the rhinoceros. The rate of tear production in the addax and the intraocular pressure in the rhinoceros appear to be the highest values of these variables to have been reported in any species. PMID:12233828

  13. Direct Repair without Augmentation of Patellar Tendon Avulsion following TKA

    PubMed Central

    Kumar, Nishikant; Yadav, Chandrashekhar; Kumar, Ashok

    2015-01-01

    Complications involving the extensor mechanism after TKA are potentially disastrous. We are reporting a case of patellar tendon rupture from tibial tuberosity following total knee arthroplasty. We managed it by direct repair with fiberwire using Krackow suture technique without augmentation. Our long term result has been very encouraging. Our method is a safe and better method of management of patellar tendon avulsion following TKA when it happens without any tissue loss. PMID:25632362

  14. Structure and Function of Ligaments, Tendons, and Joint Capsule

    Microsoft Academic Search

    Frederick H. Silver; Joseph W. Freeman; Gino Bradica

    For vertebrates to achieve locomotion and to hurl objects efficiently, they must be able to develop muscular forces, store\\u000a elastic energy in tendon, and then transfer this energy to the attached joints. After joint movement has been achieved, excess\\u000a energy dissipates by reverse transmission from the joint to the muscle-tendon unit, where it is dissipated in the muscle.\\u000a Locomotion and

  15. [The effect of repair of paratendon in tendon healing].

    PubMed

    Pan, Z; Wang, C; Zhou, W

    1997-09-01

    In order to investigate the effect of repair of paratendon in tendon healing, two different ways were performed to repair the transected extensor tendons of chick's toe. End to end suture of the extensor tenon was performed in group 1 while the paratendon was also repaired simultaneously in addition to suture of the tendon in group 2. Gross observation and histological examination were undertaken in the 3rd and 6th week after operation. The result showed, in group 1, extensive adhesion and irregular proliferation of fibroblasts was found in the 3rd week, severe adhesion and irregular arrangement of fibroblasts with less collagen fiber was found in the 6th week; while in group 2, smooth and regular "fusiform structure" was formed, slight adhesion and regular proliferation of fibroblasts were found in the 3rd week, adhesion disappeared and the structure of paratendon and tondon recovered in the 6th week. It was concluded that repair of extensor tendon and paratendon simultaneously could promote the intrinsic tendon healing and prevent tendon adhesion. PMID:9867929

  16. The role of thermal conduction in tearing mode theory

    NASA Astrophysics Data System (ADS)

    Connor, J. W.; Ham, C. J.; Hastie, R. J.; Liu, Y. Q.

    2015-06-01

    The role of anisotropic thermal diffusivity in tearing mode stability is analysed in general toroidal geometry following similar techniques to Glasser et al (1975 Phys. Fluids 18 875), although a stronger ordering of the plasma compressibility is required. Resistive layer equations are obtained for a resistive magnetohydrodynamic (MHD) model with anisotropic transport of pressure. A dispersion relation linking the growth rate to the tearing mode stability parameter, ??, characterising the external ideal MHD region, is derived. By using a resistive MHD code modified to include such thermal transport to calculate tearing mode growth rates, this dispersion relation is employed to determine ?? in situations with finite plasma pressure that are stabilised by favourable average curvature when using a simple resistive MHD code. We also demonstrate that the same code can be used to obtain the basis-functions (Ham et al 2012 Plasma Phys. Control. Fusion 54 105014) needed for an alternative approach to calculating ??.

  17. HSV-1 DNA in Tears and Saliva of Normal Adults

    PubMed Central

    Kaufman, Herbert E.; Azcuy, Ann M.; Varnell, Emily D.; Sloop, Gregory D.; Thompson, Hilary W.; Hill, James M.

    2005-01-01

    Purpose. To assess the frequency of shedding of herpes simplex virus type 1 (HSV-1) DNA in tears and saliva of asymptomatic individuals. Methods Fifty subjects without signs of ocular herpetic disease participated. Serum samples from all subjects were tested for HSV IgG antibodies by enzyme-linked immunosorbent assay (ELISA) and for HSV-1 by neutralization assay. HSV-1 DNA copy number and frequency of shedding were determined by real-time polymerase chain reaction (PCR) analysis of tear and saliva samples collected twice daily for 30 consecutive days. Results Thirty-seven (74%) of the 50 subjects were positive for HSV IgG by ELISA. The percentages of positive eye and mouth swabs were approximately equivalent: 33.5% (941/2806) and 37.5% (1020/2723), respectively. However, the percentage of samples with high HSV-1 genome copy numbers was greater in saliva than in tears, which may have been a result of the sample volume collected. Shedding frequency in tears was nearly the same in men (347/1003; 34.6%) and women (594/1705; 34.8%); in saliva, men had a higher frequency of shedding (457/1009; 45.3% vs. 563/1703; 33.1%, men versus women). Overall, 49 (98%) of 50 subjects shed HSV-1 DNA at least once during the course of the 30-day study. Conclusions The percentage of asymptomatic subjects who intermittently shed HSV-1 DNA in tears or saliva was higher than the percentage of subjects with positive ELISA or neutralization antibodies to HSV. Because most HSV transmission occurs during asymptomatic shedding, further knowledge of the prevalence of HSV-1 DNA in tears and saliva is warranted to control its spread. Shedding is simple to study, and its suppression may be an efficient way to evaluate new antivirals in humans. PMID:15623779

  18. Drift resistive interchange and tearing modes in cylindrical geometry

    SciTech Connect

    Finn, J.M.; Manheimer, W.M.; Antonsen, T.M. Jr.

    1982-04-13

    Resistive interchange and tearing modes are studied including the effects of electron parrallel pressure gradient and ion polarization drift (Hall terms) as well as finite plasma compressibility and perpendicular resistivity. It is found that for unfavorable curvature and weak tearing forces (positive but small ..delta..') all modes are stabilized provided the effects of the Hall (drift) terms are large enough. The principal stabilizing influences are plasma compression and coupling to outgoing drift waves. The relevance to reversed field pinch and spheromak experiments is discussed.

  19. Effects of grain refinement and residual elements on hot tearing in aluminum castings

    Microsoft Academic Search

    D. Benny Karunakar; Ram Naresh Rai; Suprakash Patra; G. L. Datta

    2009-01-01

    In the present work, some investigations have been carried out on hot tears in the Al–1 wt.% Sn alloy, with the objective\\u000a of preventing hot tearing in aluminum castings. Al–1Sn alloy is extremely prone to hot tearing due to its long freezing range\\u000a and is an ideal model for studying hot tearing. Experiments were conducted with varying grain refiner (Al–5Ti–1B) percent

  20. Exploring the prevalence of skin tears and skin properties related to skin tears in elderly patients at a long-term medical facility in Japan.

    PubMed

    Koyano, Yuiko; Nakagami, Gojiro; Iizaka, Shinji; Minematsu, Takeo; Noguchi, Hiroshi; Tamai, Nao; Mugita, Yuko; Kitamura, Aya; Tabata, Keiko; Abe, Masatoshi; Murayama, Ryoko; Sugama, Junko; Sanada, Hiromi

    2014-03-28

    The identification of appropriate skin tear prevention guidelines for the elderly requires clinicians to focus on local risk factors such as structural alterations of the epidermis and dermis related to skin tears. The aim of this cross-sectional study is to explore the prevalence of skin tears and to explore skin properties related to skin tears in elderly Japanese patients at a long-term medical facility. After doing the prevalence study, 18 participants with skin tears and 18 without were recruited and an evaluation of their skin properties using 20-MHz ultrasonography, skin blotting and also Corneometer CM-825, Skin-pH-meterPH905, VapoMeter, Moisture Meter-D and CutometerMPA580 was undertaken. A total of 410 patients were examined, the median age was 87?years and 73·2% were women. The prevalence of skin tears was 3·9%, and 50% of skin tears occurred on the dorsal forearm. The changes in skin properties associated with skin tears included increased low-echogenic pixels (LEP) by 20-MHz ultrasonography, decreased type IV collagen and matrix metalloproteinase-2, and increased tumour necrosis factor-? by skin blotting. In conclusion, this study suggests that increased dermal LEP, including solar elastosis, may represent a risk factor for skin tears; this indicates that skin tear risk factors might not only represent chronological ageing but also photoageing. PMID:24674027

  1. Arthroscopic According Subacromial Decompression: Results to the Degree of Rotator Cuff Tear

    Microsoft Academic Search

    James C. Esch; Leonard R. Ozerkis; Norman Kane; Nancy Lilliott

    Summary: We evaluated the results of arthroscopic subacromial decompres- sion according to the degree of rotator cuff tear in 71 patients, available for follow-up for at least 1 year (average 19 months). Of the patients with stage II disease, 82% were satisfied regardless of whether they had no rotator cuff tear (nine of 11) or had a partial tear (28

  2. Study of hot tearing through ingot bending test: thermomechanical and solute transport analysis

    E-print Network

    Boyer, Edmond

    1 Study of hot tearing through ingot bending test: thermomechanical and solute transport analysis.koshikawa@mines-paristech.fr Hot tearing is one of the critical defects in cast products. It takes place close to the end based on tensile stress. In this study, a hot tearing experiment, so-called "bending test", is carried

  3. Actin cytoskeleton contributes to the elastic modulus of embryonic tendon during early development.

    PubMed

    Schiele, Nathan R; von Flotow, Friedrich; Tochka, Zachary L; Hockaday, Laura A; Marturano, Joseph E; Thibodeau, Jeffrey J; Kuo, Catherine K

    2015-06-01

    Tendon injuries are common and heal poorly. Strategies to regenerate or replace injured tendons are challenged by an incomplete understanding of normal tendon development. Our previous study showed that embryonic tendon elastic modulus increases as a function of developmental stage. Inhibition of enzymatic collagen crosslink formation abrogated increases in tendon elastic modulus at late developmental stages, but did not affect increases in elastic modulus of early stage embryonic tendons. Here, we aimed to identify potential contributors to the mechanical properties of these early stage embryonic tendons. We characterized tendon progenitor cells in early stage embryonic tendons, and the influence of actin cytoskeleton disruption on tissue elastic modulus. Cells were closely packed in embryonic tendons, and did not change in density during early development. We observed an organized network of actin filaments that seemed contiguous between adjacent cells. The actin filaments exhibited a crimp pattern with a period and amplitude that matched the crimp of collagen fibers at each developmental stage. Chemical disruption of the actin cytoskeleton decreased tendon tissue elastic modulus, measured by atomic force microscopy. Our results demonstrate that early developmental stage embryonic tendons possess a well organized actin cytoskeleton network that contributes significantly to tendon tissue mechanical properties. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:874-881, 2015. PMID:25721681

  4. Quantification of Total Particulate Matter and Benzene-Soluble Fraction Inhalation Exposures in Roofing Workers Performing Tear-off Activities.

    PubMed

    Hill, Ronald H; Ferraro, John R; Dodson, James L; Hockman, Edwin L; McGovern, Amy E; Fayerweather, William E

    2015-07-01

    Asphalt shingle removal (tear-off) from roofs is a major job task for an estimated 174,000 roofers in the United States. However, a literature search showed that there are no published studies that characterize worker inhalation exposures to asphalt particulates during shingle tear-off. To begin to fill this gap, the present study of inhalation exposures of roofers performing asphalt shingle tear-off was undertaken. The airborne agents of interest were total particulate matter (TP) and organic particulates measured as the benzene-soluble fraction (BSF) of total particulate. The study's objectives were ?to measure the personal breathing zone (PBZ) exposures of roofing tear-off workers to BSF and TP; and ?to assess whether these PBZ exposures are different from ambient levels. Task-based PBZ samples (typical duration 1-5 hours) were collected during asphalt shingle tear-off from roofs near Houston, Texas and Denver, Colorado. Samples were analyzed for TP and BSF using National Institute of Occupational Safety and Health (NIOSH) Method 5042. As controls, area samples (typical duration 3-6 hours) were collected on the ground near the perimeter of the tear-off project Because of the presence of significant sources of inorganic particulates in the work environment, emphasis was placed on the BSF data. No BSF exposure higher than 0.25 mg/m3 was observed, and 69% of the PBZ samples were below the limit of detection (LOD). Due to unforeseen confounding, however, statistical comparisons of on-the-roof PBZ samples with on-the-ground area samples posed some special challenges. This confounding grew out of the interaction of three factors: ?statistical censoring from the left; ?the strong inverse correlation between LOD concentration and sampling duration; and ?variation in sampling durations between on-the-ground area samples and on-the-roof PBZ samples. A general linear model analysis of variance (GLM-ANOVA) was applied to help address the confounding. The results of this analysis indicate that personal sample BSF results were not statistically significantly different from the background/area samples. PMID:26083058

  5. Repopulation of Intrasynovial Flexor Tendon Allograft with Bone Marrow Stromal Cells: An Ex Vivo Model

    PubMed Central

    Amadio, Peter C.; Thoreson, Andrew R.; An, Kai-Nan

    2014-01-01

    Purpose: Delayed healing is a common problem whenever tendon allografts are used for tendon or ligament reconstruction. Repopulating the allograft with host cells may accelerate tendon regeneration, but cell penetration into the allograft tendon is limited. Processing the tendon surface with slits that guide cells into the allograft substrate may improve healing. The purpose of this study was to describe a surface modification of allograft tendon that includes slits to aid cell repopulation and lubrication to enhance tendon gliding. Methods: Canine flexor digitorum profundus tendons were used for this study. Cyclic gliding resistance was measured over 1000 cycles. Tensile stiffness was assessed for normal tendon, tendon decellularized with trypsin and Triton X-100 (decellularized group), tendon decellularized and perforated with multiple slits (MS group) and tendon decellularized, perforated with slits and treated with a carbodiimide-derivatized hyaluronic acid and gelatin (cd-HA-gelatin) surface modification (MS-SM group). To assess tendon repopulation, bone marrow stromal cells (BMSCs) were used in the decellularized and MS groups. DNA concentration and histology were evaluated and compared to normal tendons and nonseeded decellularized tendons. Results: The gliding resistance of the decellularized and MS groups was significantly higher compared with the normal group. There was no significant difference in gliding resistance between the decellularized and MS group. Gliding resistance of the normal group and MS-SM group was not significantly different. The Young's modulus was not significantly different among the four groups. The DNA concentration in the MS group was significantly lower than in normal tendons, but significantly higher than in decellularized tendons, with or without BMSCs. Viable BMSCs were found in the slits after 2 weeks in tissue culture. Conclusions: Tendon slits can successfully harbor BMSCs without compromising their survival and without changing tendon stiffness. Surface modification restores normal gliding function to the slit tendon. Clinical Relevance: A multislit tendon reseeded with BMSCs, with a surface treatment applied to restore gliding properties, may potentially promote tendon revitalization and accelerate healing for tendon or ligament reconstruction applications. PMID:24024566

  6. Markers for the identification of tendon-derived stem cells in vitro and tendon stem cells in situ - update and future development.

    PubMed

    Lui, Pauline Po Yee

    2015-01-01

    The efficacy of tendon-derived stem cells (TDSCs) for the promotion of tendon and tendon-bone junction repair has been reported in animal studies. Modulation of the tendon stem cell niche in vivo has also been reported to influence tendon structure. There is a need to have specific and reliable markers that can define TDSCs in vitro and tendon stem cells in situ for several reasons: to understand the basic biology of TDSCs and their subpopulations in vitro; to understand the identity, niches and functions of tendon/progenitor stem cells in vivo; to meet the governmental regulatory requirements for quality of TDSCs when translating the exciting preclinical findings into clinical trial/practice; and to develop new treatment strategies for mobilizing endogenous stem/progenitor cells in tendon. TDSCs were reported to express the common mesenchymal stem cell (MSC) markers and some embryonic stem cell (ESC) markers, and there were attempts to use these markers to label tendon stem cells in situ. Are these stem cell markers useful for the identification of TDSCs in vitro and tracking of tendon stem cells in situ? This review aims to discuss the values of the panel of MSC, ESC and tendon-related markers for the identification of TDSCs in vitro. Important factors influencing marker expression by TDSCs are discussed. The usefulness and limitations of the panel of MSC, ESC and tendon-related markers for tracking stem cells in tendon, especially tendon stem cells, in situ are then reviewed. Future research directions are proposed. PMID:26031740

  7. Effects of Therapeutic Physical Agents on Achilles Tendon Microcirculation.

    PubMed

    Chang, Yi-Ping; Chiang, Hongsen; Shih, Kao-Shang; Ma, Hsiao-Li; Lin, Leou-Chyr; Hsu, Wei-Li; Huang, Yung-Cheng; Wang, Hsing-Kuo

    2015-07-01

    Study Design Controlled laboratory study. Objectives To measure Achilles tendon microcirculation (total hemoglobin [THb] and oxygen saturation [StO2]) before and after the application of a physical agent in asymptomatic participants, and to compare differences between application location and physical agent dosage. Background Tendon microcirculation can be altered by superficial heating or cryotherapy. Methods Fifty-one healthy adults (median age, 22 years; range, 20-34 years) were recruited and randomly assigned into 1 of 4 groups. Participants in each group received an intervention consisting of 1 of the following 4 physical agents: ultrasound (n = 12), interferential current (n = 14), low-level laser (n = 11), or vibration massage (n = 14). In each group, the selected intervention was applied at 2 different doses (ultrasound, 0.8 or 1.2 W/cm(2); laser, 5.4 or 18 J) or target locations (vibration and electrostimulation, calf muscle or Achilles tendon). For each participant, each dose or target location was randomly applied to 1 randomly selected lower leg (each leg receiving only 1 of the 2 options). Results The StO2 values significantly increased after ultrasound at both doses (P<.008), and the THb value significantly increased for the higher dose only (P<.008). Both THb and StO2 values also significantly increased in response to vibration massage targeting the Achilles tendon (P<.008), and these values were greater than those resulting from the vibration massage applied to the calf muscle (P = .003 and .002, respectively). No significant THb and StO2 differences were found after the application of interferential current or low-level laser. Conclusion Tendon microcirculation increases after ultrasound and vibration massage intervention concentrated on the Achilles tendon. These modalities may be considered for the purpose of temporarily increasing microcirculation in the tendon. J Orthop Sports Phys Ther 2015;45(7):563-569. Epub 3 Jun 2015. doi:10.2519/jospt.2015.5681. PMID:26039223

  8. Quantitative ultrasound (QUS) assessment of tissue properties for Achilles tendons

    NASA Astrophysics Data System (ADS)

    Du, Yi-Chun; Chen, Yung-Fu; Chen, Pei-Jarn; Lin, Yu-Ching; Chen, Tainsong; Lin, Chii-Jeng

    2007-09-01

    Quantitative ultrasound (QUS) techniques have recently been widely applied for the characterization of tissues. For example, they can be used for the quantification of Achilles tendon properties based on the broadband ultrasound attenuation (BUA) and the speed of sound (SOS) when the ultrasound wave passes through the tissues. This study is to develop an integrated system to investigate the properties of Achilles tendons using QUS images from UBIS 5000 (DMS, Montpellier, France) and B-mode ultrasound images from HDI 5000 (ATL, Ultramark, USA). Subjects including young (32 females and 17 males; mean age: 23.7 ± 2.0) and middle-aged groups (8 female and 8 males; mean age: 47.3 ± 8.5 s) were recruited and tested for this study. Only subjects who did not exercise regularly and had no record of tendon injury were studied. The results show that the BUA is significantly higher for the young group (45.2 ± 1.6 dB MHz-1) than the middle-age group (40.5 ± 1.9 dB MHz-1), while the SOS is significantly lower for the young (1601.9 ± 11.2 ms-1) compared to the middle-aged (1624.1 ± 8.7 m s-1). On the other hand, the thicknesses of Achilles tendons for both groups (young: 4.31 ± 0.23 mm; middle age: 4.24 ± 0.23 mm) are very similar. For one patient who had an Achilles tendon lengthening (ATL) surgery, the thickness of the Achilles tendon increased from 4 mm to 4.33 mm after the surgery. In addition, the BUA increased by about 7.2% while the SOS decreased by about 0.6%. In conclusion, noninvasive ultrasonic assessment of Achilles tendons is useful for assisting clinical diagnosis and for the evaluation of a therapeutic regimen.

  9. Tearing instability, Kelvin-Helmholtz instability, and magnetic reconnection

    Microsoft Academic Search

    Q. Chen; A. Otto; L. C. Lee

    1997-01-01

    Two closely related macroscopic instabilities at the magnetospheric boundary layer are the tearing instability and the Kelvin-Helmholtz (KH) instability. It has been suggested that a coupling of these modes may lead to larger reconnection rates and thus may explain magnetic flux transfer events at the dayside magnetopause. In the framework of two-dimensional compressible MHD simulations we study the linear and

  10. A Case of Retinal Tear Associated with Use of Sorafenib

    PubMed Central

    Gaertner, Kelly M.; Caldwell, Stephen H.; Rahma, Osama E.

    2014-01-01

    Inhibition of angiogenesis is a target in the treatment of a variety of malignancies. Sorafenib is an oral inhibitor of multiple tyrosine kinases involved in tumor angiogenesis. A related case of ophthalmologic toxicity has been reported with another vascular endothelial growth factor receptor inhibitor, sunitinib. We report the first case of retinal tear possibly associated with sorafenib. PMID:25105094

  11. Reconnection dynamics with secondary tearing instability in compressible Hall plasmas

    NASA Astrophysics Data System (ADS)

    Ma, Z. W.; Wang, L. C.; Li, L. J.

    2015-06-01

    The dynamics of a secondary tearing instability is systematically investigated based on compressible Hall magnetohydrodynamic. It is found that in the early nonlinear phase of magnetic reconnection before onset of the secondary tearing instability, the geometry of the magnetic field in the reconnection region tends to form a Y-type structure in a weak Hall regime, instead of an X-type structure in a strong Hall regime. A new scaling law is found that the maximum reconnection rate in the early nonlinear stage is proportional to the square of the ion inertial length ( ??di2 ) in the weak Hall regime. In the late nonlinear phase, the thin elongated current sheet associated with the Y-type geometry of the magnetic field breaks up to form a magnetic island due to a secondary tearing instability. After the onset of the secondary tearing mode, the reconnection rate is substantially boosted by the formation of the X-type geometries of magnetic field in the reconnection regions. With a strong Hall effect, the maximum reconnection rate linearly increases with the increase of the ion inertial length ( ??di ).

  12. Understanding and preventing complications in repairing rotator cuff tears.

    PubMed

    Osti, Leonardo; Papalia, Rocco; Del Buono, Angelo; Denaro, Vincenzo; Maffulli, Nicola

    2012-01-01

    Repair of rotator cuff tears is a common procedure. Prior to approaching this surgery, it should be realized that each surgical step can lead to complications, including those related to positioning and anaesthesia. Stiffness, infection and failure of repair are the more frequent complications reported. PMID:21986055

  13. Biceps instability and Slap type II tear in overhead athletes.

    PubMed

    Osti, Leonardo; Soldati, Francesco; Cheli, Andrea; Pari, Carlotta; Massari, Leo; Maffulli, Nicola

    2012-10-01

    Type II lesions are common lesions encountered in overhead athletes with controversies arising in term of timing for treatment, surgical approach, rehabilitation and functional results. The aim of our study was to evaluate the outcomes of arthroscopic repair of type II SLAP tears in overhead athletes, focusing on the time elapsed from diagnosis and treatment, time needed to return to sport, rate of return to sport and to previous level of performance, providing an overview concerning evidence for the effectiveness of different surgical approaches to type II SLAP tears in overhead athletes. A internet search on peer reviewed Journal from 1990, first descriprion of this pathology, to 2012, have been conducted evaluating the outcomes for both isolated Slap II tear overhead athletes and those who presented associated lesions treated. The results have been analyzed according to the scale reported focusing on return to sport and level of activity. Apart from a single study, non prospective level I and II studies were detected. Return to play at the same level ranged form 22% to 94% with different range of technique utilized with the majority of the authors recommending the fixation of these lesions but biceps tenodesis can lead to higher satisfaction racte when directly compated to the anchor fixation. Associated pathologies such as partial or full tickness rotator cuff tear did not clearly affect the outcomes and complications rate. There is no consensus regarding timing and treatment for type II SLAP, especially in overhead athletes who need to regain a high level of performance. PMID:23738307

  14. ANNULAR TEARS AND DISC DEGENERATION IN THE LUMBAR SPINE

    Microsoft Academic Search

    L. OSTI; B. VERNON-ROBERTS; R. MOORE; R. D. FRASER

    Histology suggested that peripheral tears were due to trauma rather than biochemical degradation, and that they developed independently of nuclear degeneration. The association of peripheral annular lesions with low back pain is uncertain but our study suggests that they may have a role in the pathogenesis of discogemc pain. The degenerating human intervertebral disc shows dehydration and fraying of the

  15. From Onions to Shallots: Rewarding Tor Relays with TEARS

    E-print Network

    From Onions to Shallots: Rewarding Tor Relays with TEARS Rob Jansen1 , Andrew Miller2 , Paul and rewards them with anonymous coins called Shallots, proportionally to bandwidth contributed. Shallots may banking using protocols from distributed digital cryp- tocurrency systems like Bitcoin. Shallots

  16. Head Injury Caused by Tear Gas Cartridge in Teenage Population

    Microsoft Academic Search

    A. Wani Abrar; Javeed Zargar; Altaf U. Ramzan; Nayil K. Malik; A. Qayoom; A. R. Kirmani; Furqan A. Nizami; M. A. Wani

    2010-01-01

    Objectives: The aim of this study was to assess the head injury in children caused by an unusual projectile, a tear gas cartridge. The study is the only one on this subject which has been done in a teenage population. Method: This was a prospective study conducted over a period of 4 years in which all the patients aged less

  17. Helical temperature perturbations associated with tearing modes in tokamak plasmas

    E-print Network

    Fitzpatrick, Richard

    conventional magnetic islands. This effect may provide an explanation for some puzzling experimental results. Diamagnetic effects also give rise to island rotation. The uncontrolled growth of tearing islands that a temperature flattened magnetic island possessesa unique ECE signature. The heat flow pattern around

  18. Godel Without (Too Many) Tears 1 Incompleteness the very idea

    E-print Network

    Krajíèek, Jan

    latest versions of these notes, can be found at www.logicmatters.net. 1 Kurt G¨odel (1906G¨odel Without (Too Many) Tears ­ 1 Incompleteness ­ the very idea Peter Smith University of G¨odel's First Incompleteness Theorem · The First Theorem as an incompletability theorem · How did G¨odel

  19. On the energy principle and ion tearing in the magnetotail

    NASA Technical Reports Server (NTRS)

    Brittnacher, M.; Quest, K. B.; Karimabadi, H.

    1994-01-01

    We re-examine the use of the energy principle as applied to the tearing instability in the magnetotail. We demonstrate that when a magnetic field component normal to the current sheet is present, electron pitch-angle diffusion (PAD) either by micro-turbulence or by chaotic orbits cannot remove the strong stabilization of the tearing mode caused by electron compressibility. We find that our conclusions are in agreement with those of Pellat et al. (1991), who argued on the basis of canonical P(sub y) conservation that the stabilization of the ion tearing mode cannot be removed by the introduction of PAD. Our results are at variance with those of Kuznetsova and Zelenyi (1991), who argued that the application of the energy principle used by Pellat et al. (1991) is incorrect, and that tearing is in fact unstable in the limit of strong PAD. We show that the disagreement between these two studies can be traced to an incorrect orbit evaluation first introduced by Coroniti (1980) and subnsequently used by Kuznetsova and Zelenyi (1991).

  20. A fast tearing mode instability driven by agyrotropic electron pressure

    NASA Astrophysics Data System (ADS)

    Hosseinpour, M.

    2014-09-01

    The collisionless plasma environment at the current sheet of the Earth’s magnetotail is subjected to fast dynamic evolutions such as tearing instability. By considering agyrotropic pressure for electron and ion components of a collisionless plasma, we analytically investigate the dynamics of tearing mode instability, in which, breaking the frozen-in condition can either be provided by the electron inertia or by agyrotropic electron pressure. A set of linearized Hall-Magnetohydrodynamic (MHD) equations describes the evolution of tearing mode in a sheared force-free field. The presented scaling analysis shows that if the plasma-? exceeds a specified value, then the main mechanism of magnetic reconnection process is the nongyrotropic electron pressure. In this regime, the role played by agyrotropic ion pressure inside the reconnection layer is out of significance. Therefore, the electron-MHD framework, adequately, describes the dynamics of tearing instability with a growth rate which is much faster compared to the cases with a dominated bulk inertia or a gyrotropic plasma pressure.

  1. Resistive tearing in line-tied magnetic fields: Slab geometry

    Microsoft Academic Search

    M. Velli; A. W. Hood

    1989-01-01

    The resistive tearing-mode instability of a current carrying plasma sheet is investigated including the stabilising photospheric line-tying boundary conditions. This end condition prohibits a single Fourier mode and so requires a series expansion in harmonics of the fundamental sheet excitation. Equilibria in which there exist field lines that do not connect to the photosphere are unstable provided the ratio of

  2. Investigation of tearing modes behavior in predisruption phase

    Microsoft Academic Search

    E. Farshi; N. Brevnov; Y. Gott

    2002-01-01

    The m=2 tearing mode in predisruptive activity with the visible radiation spectrum and the charge exchange neutral have been investigated in the Damavand Tokamak [Amrollahi et al., Plasma Phys. Rep. 23, 561 (1997)]. The oscillations amplitude of the mode has been increased about 500 microseconds before disruption. After that instead of complete ceasing the oscillations, which is observed usually in

  3. Bacteriology and tear protein profiles of the dry eye

    Microsoft Academic Search

    D V Seal; J I McGill; I A Mackie; G M Liakos; P Jacobs; N J Goulding

    1986-01-01

    The concentrations of tear lysozyme, lactoferrin, ceruloplasmin, IgA, and IgG have been estimated in patients with dry eyes at the same time as semiquantitative bacterial culture was performed of the conjunctivae and lids. Staphylococcal isolations were quantified and biotyped. There was no increased conjunctival colonisation by any particular biotype of Staphylococcus aureus or Staph. epidermidis, and similar numbers of conjunctivae

  4. Stop the Tears of Drug and Alcohol Abuse

    ERIC Educational Resources Information Center

    Shimon, Jane; Gibson, Terry-Ann; Spear, Caile

    2009-01-01

    Objectives: By participating in this Stop the Tears teaching strategy, students will be able to: (1) analyze how alcohol and drug abuse could affect their lives as well as the lives of their friends and family and, (2) create a media message, such as a poster, pamphlet, poem, or song, in which alcohol and drug prevention is advocated specific to…

  5. GVHD dry eyes treated with autologous serum tears

    Microsoft Academic Search

    EM Rocha; FSA Pelegrino; CS de Paiva; AC Vigorito; CA de Souza

    2000-01-01

    Two cases of GVHD with severe dry eyes are reported where conventional therapy failed to control ocular signs and symptoms. Autologous serum tears, however, resulted in a beneficial clinical effect with marked attenuation of the symptoms. This therapy proved to be safe during 10 months of treatment. Bone Marrow Transplantation (2000) 25, 1101–1103.

  6. Insidious bilateral infrapatellar tendon rupture in a patient with systemic lupus erythematosus

    Microsoft Academic Search

    L M Cooney; J M Aversa; J H Newman

    1980-01-01

    A patient with systemic lupus erythematosus developed insidious bilateral infrapatellar tendon rupture initially diagnosed as steroid myopathy. Simultaneous loss of extension at the knee due to quadriceps or infrapatellar tendon ruptures is reviewed.

  7. Insidious bilateral infrapatellar tendon rupture in a patient with systemic lupus erythematosus.

    PubMed Central

    Cooney, L M; Aversa, J M; Newman, J H

    1980-01-01

    A patient with systemic lupus erythematosus developed insidious bilateral infrapatellar tendon rupture initially diagnosed as steroid myopathy. Simultaneous loss of extension at the knee due to quadriceps or infrapatellar tendon ruptures is reviewed. Images PMID:7458438

  8. Diclofenac Patch for Treatment of Mild to Moderate Tendonitis or Bursitis

    ClinicalTrials.gov

    2008-08-05

    Rotator Cuff Tendonitis; Bicipital Tendonitis; Subdeltoid Bursitis of the Shoulder; Subacromial Bursitis of the Shoulder; Medial Epicondylitis of the Elbow; Lateral Epicondylitis of the Elbow; DeQuervain's Tenosynovitis of the Wrist

  9. Giant Cell Tumor of Tendon Sheath

    PubMed Central

    Briët, Jan Paul; Becker, Stéphanie JE; Oosterhoff, Thijs CH; Ring, David

    2015-01-01

    Background: Giant cell tumor of tendon sheath (GCTTS) is often thought of as a volar finger mass. We hypothesized that GCTTS are equally common on the dorsal and volar aspects of the hand. In addition, we hypothesized that there are no factors associated with the location (volar versus dorsal) and largest measured dimension of a GCTTS. Methods: A total of 126 patients with a pathological diagnosis of a GCTTS of the hand or finger were reviewed. Basic demographic and GCTTS specific information was obtained. Bivariable analyses were used to assess predicting factors for location (volar or dorsal side) and largest measured diameter of a GCTTS. Results: Seventy-two tumors (57%) were on the volar side of the hand, 47 (37%) were dorsal, 6 (4.8%) were both dorsal and volar, and one was midaxial (0.79%). The most common site of a GCTTS was the index finger (30%). There were no factors significantly associated with the location (volar or dorsal, n=119) of the GCTTS. There were also no factors significantly associated with a larger diameter of a GCTTS. Conclusions: A GCTTS was more frequently seen on the volar aspect of the hand. No significant factors associated with the location or an increased size of a GCTTS were found in this study. PMID:25692164

  10. Anterior Cruciate Ligament Reconstruction Using Achilles Tendon Allograft: an Assessment of Outcome for Patients Age 30 Years and Older

    PubMed Central

    Chehab, Eric L.; Flik, Kyle R.; Vidal, Armando F.; Levinson, Michael; Altchek, David W.; Warren, Russell F.

    2010-01-01

    Achilles allografts have become popular for anterior cruciate ligament (ACL) reconstructions in older patients. Primary ACL reconstructions using Achilles tendon allografts in patients age 30 years and older are successful in restoring the knee to “normal” or “near normal.” During a three-year period, the two senior authors performed 65 primary ACL reconstructions using Achilles tendon allografts in patients aged 30 years and older. Our exclusion criteria were periarticular fracture, ipsilateral/contralateral knee ligament injury, and previous or concomitant osteotomy or cartilage restoration procedure. Each patient was evaluated via physical examination, functional and arthrometric testing, and radiographic and subjective outcome. Knees were considered normal, near normal, or abnormal based on the International Knee Documentation Committee (IKDC) system. Forty-three patients were examined at an average of 33 months (minimum, 24 months) postoperatively. At the time of ACL reconstruction, 35% had normal articular cartilage in all three compartments and 70% had meniscal tears. No re-ruptures occurred. While 24% had mean maximal translation differences less than or equal to 3 mm, none had side-to-side differences greater than 5 mm. Postoperative IKDC, Activities of Daily Living, and Activity Rating Scale scores averaged 88, 94, and 7.7, respectively. Despite the overall favorable outcomes, 29% had worsened radiographic grades at follow-up. Using an Achilles allograft for ACL reconstruction in patients older than 30 years, we restored over 90% of knees to normal or near normal while limiting postoperative complications. Poor subjective results may be related less to instability and more to pain, which may result from progressive arthritis. PMID:22294957

  11. Reconstruction of anterior cruciate ligaments with bone-patellar tendon-bone and achilles tendon allografts.

    PubMed

    Levitt, R L; Malinin, T; Posada, A; Michalow, A

    1994-06-01

    Two hundred fourteen patients had anterior cruciate ligament (ACL) reconstructions performed with banked freeze-dried or frozen allografts using an arthroscopic-assisted technique. Of these, 181 patients were available for follow-up testing and examination. Minimum follow-up time was four years (average, 57 months). All patients were evaluated by using KT-1000 arthrometer and Biodex testing as well as by physical examination. Final results were rated as satisfactory or unsatisfactory by using a modified Feagin knee scoring scale. Patients who were classified as good or excellent were considered to have satisfactory results. Those who were classified as fair or poor were considered to have unsatisfactory results. During the course of the study, 79% of the patients had satisfactory results. The percentage of patients with satisfactory results increased as the study progressed. The surgical technique was modified as new biomechanical principles were applied to ACL reconstruction. Rehabilitation of the patients was also progressively changed from conservative to aggressive. The authors attribute the improvement from 67% of patients with satisfactory results in 1984 to 85% in 1988 at least partially to these modifications. It was concluded that either frozen or freeze-dried aseptically excised and processed bone-patellar tendon-bone and Achilles tendon allografts can serve adequately for the reconstruction of ACLs. Complications may be reduced and clinical end results improved by adherence to an exact, reproducible surgical technique and an aggressive rehabilitation regimen. PMID:8194256

  12. Tears Rendering in Extreme Expression by Using SPH Method and Gravity Parameters

    NASA Astrophysics Data System (ADS)

    Rahim, Mohd Shafry Mohd; Rad, Abdolvahab Ehsani; Rehman, Amjad; Altameem, Ayman

    2014-06-01

    The simulation of fluid generation and the Smooth Particle Hydrodynamic (SPH) method has been discussed as an explanation for extreme expression, followed by tears simulation which includes creating tears using SPH and tears effect rendering. Furthermore, the testing and the evaluation for creating tears simulation with different effects and cases were applied. Accordingly, this paper explains how to control the crying with the facial animation expressions which are used to simulate the extreme expressions. Additionally, the results of various aspects of this study and the different kinds of crying were simulated and explained. Finally, the measurements of frame rates for different parts of tears simulation by using Fraps software have been explored.

  13. Tearing relaxation and the globalization of transport in field-reversed configurations

    SciTech Connect

    Steinhauer, Loren [Redmond Plasma Physics Laboratory, University of Washington, Redmond, Washington 98052 (United States); Barnes, D. C. [Coronado Consulting, 146 Bishop Lamy Rd., Lamy, New Mexico 87540 (United States)

    2009-09-15

    Tearing instability of field-reversed configurations (FRC) is investigated using the method of neighboring equilibria. It is shown that the conducting wall position in experiment lies very close to the location needed for tearing stability. This strongly suggests that vigorous but benign tearing modes, acting globally, are the engine of continual self-organization in FRCs, i.e., tearing relaxation. It also explains the ''profile consistency'' and anomalous loss rate of magnetic flux. In effect, tearing globalizes the effect of edge-driven transport.

  14. An investigation of tendon sheathing filler migration into concrete

    SciTech Connect

    Naus, D.J.; Oland, C.B. [Oak Ridge National Lab., TN (United States)

    1998-03-01

    During some of the inspections at nuclear power plants with prestressed concrete containments, it was observed that the containments has experienced leakage of the tendon sheathing filler (i.e., streaks). The objective of this activity was to provide an indication of the extent of tendon sheathing filler leakage into the concrete and its affects on concrete properties. Literature was reviewed and concrete core samples were obtained from the Trojan Nuclear Plant and tested. The literature primarily addressed effects of crude or lubricating oils that are known to cause concrete damage. However, these materials have significantly different characteristics relative to the materials used as tendon sheathing fillers. Examination and testing of the concrete cores indicated that the appearance of tendon sheathing filler on the concrete surface was due to leakage from the conduits and its subsequent migration through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks and there was no perceptible movement into the concrete. Results of compressive strength testing indicated that the concrete quality was consistent in the containment and that the strength had increased over 40% in 25.4 years relative to the average compressive strength at 28-days age.

  15. A novel fibrocartilaginous tendon from an elasmobranch fish ( Rhinoptera bonasus).

    PubMed

    Summers, Adam P; Koob-Emunds, Magdalena M; Kajiura, Stephen M; Koob, Thomas J

    2003-05-01

    Tendons of the jaw adductor muscles of a hard prey crushing stingray exhibit similar adaptations to compressive and shear loads as those seen in mammalian tendons. Ventral intermandibular tendon from the cownose ray, Rhinoptera bonasus, has a prominent fibrocartilaginous pad that lies between a fibrous region of the tendon and the mineralized tissue of the jaw. Histologically the pad is similar to the fibrocartilaginous meniscus of mammals, and these tissues also share some biochemical traits. Proteoglycan (PG) content in the fibrocartilaginous pad is nearly four times higher than in the linearly arrayed tendinous tissue. The predominant PGs appear to be an aggrecan-like molecule and a decorin-like molecule. The decorin-like molecule is quite small when compared to mammalian decorin (20-80 kDa vs. 100-200 kDa). This study is the first to document adaptations to compressive/shear loading in tendon from a cartilaginous fish, and the similarities to the mammalian condition argue for the early evolution of this reactive ability of tendinous tissue. PMID:12712326

  16. Cell therapies for tendons: old cell choice for modern innovation.

    PubMed

    Petrou, Ilias G; Grognuz, Anthony; Hirt-Burri, Nathalie; Raffoul, Wassim; Applegate, Lee Ann

    2014-01-01

    Although tissue engineering and cell therapies are becoming realistic approaches for medical therapeutics, it is likely that musculoskeletal applications will be among the first to benefit on a large scale. Cell sources for tissue engineering and cell therapies for tendon pathologies are reviewed with an emphasis on small defect tendon injuries as seen in the hand which could adapt well to injectable cell administration. Specifically, cell sources including tenocytes, tendon sheath fibroblasts, bone marrow or adipose-derived stem cells, amniotic cells, placenta cells and platelet-derivatives have been proposed to enhance tendon regeneration. The associated advantages and disadvantages for these different strategies will be discussed and evolving regulatory requirements for cellular therapies will also be addressed. Human progenitor tenocytes, along with their clinical cell banking potential, will be presented as an alternative cell source solution. Similar cell banking techniques have already been described with other progenitor cell types in the 1950's for vaccine production, and these "old" cell types incite potentially interesting therapeutic options that could be improved with modern innovation for tendon regeneration and repair. PMID:25102358

  17. New perspectives in rotator cuff tendon regeneration: review of tissue engineered therapies

    Microsoft Academic Search

    Roberto Rotini; Milena Fini; Gianluca Giavaresi; Alessandro Marinelli; Enrico Guerra; Diego Antonioli; Alessandro Castagna; Roberto Giardino

    2008-01-01

    Tissue engineering may play a major role in the treatment of rotator cuff tendon lesions through replacement of an injured\\u000a tendon segment. Tendons have very poor spontaneous regenerative capabilities, and despite intensive remodelling, complete\\u000a regeneration is never achieved and the strength of tendon and ligaments remains as much as 30% lower than normal even months\\u000a or years following an acute

  18. Reconstruction of chronic patellar tendon rupture with contralateral BTB autograft: a case report

    Microsoft Academic Search

    Miroslav Z. Milankov; Natasa Miljkovic; Milan Stankovic

    2007-01-01

    Chronic patellar tendon rupture is a rare disabling injury that is technically difficult to repair. Many different surgical\\u000a methods have been reported for the reconstruction of chronic patellar tendon ruptures. We are reporting the use of contralateral\\u000a bone-tendon-bone (BTB) autograft for chronic patellar tendon rupture reconstruction followed by double-wire loop reinforcement\\u000a and without postoperative immobilization. One year after the operation,

  19. Double-bundle posterior cruciate ligament reconstruction with quadriceps and semitendinosus tendon grafts

    Microsoft Academic Search

    Chih-Hwa Chen; Wen-Jer Chen; Chun-Hsiung Shih

    2003-01-01

    This study presents a novel arthroscopic technique for double-bundle reconstruction of the posterior cruciate ligament. A quadriceps tendon-patellar bone autograft is used to reconstruct the major anterolateral bundle. An additional double-stranded semitendinosus tendon is used to reconstruct the posteromedial bundle. In 70° of flexion and full extension with anterior drawer force, the quadriceps tendon graft and semitendinosus tendon graft are

  20. Outcome of repaired unstable meniscal tears in children and adolescents

    PubMed Central

    2012-01-01

    Background Unstable meniscal tears are rare injuries in skeletally immature patients. Loss of a meniscus increases the risk of subsequent development of degenerative changes in the knee. This study deals with the outcome of intraarticular meniscal repair and factors that affect healing. Parameters of interest were type and location of the tear and also the influence of simultaneous reconstruction of a ruptured ACL. Methods We investigated the outcome of 25 patients (29 menisci) aged 15 (4–17) years who underwent surgery for full thickness meniscal tears, either as isolated lesions or in combination with ACL ruptures. Intraoperative documentation followed the IKDC 2000 standard. Outcome measurements were the Tegner score (pre- and postoperatively) and the Lysholm score (postoperatively) after an average follow-up period of 2.3 years, with postoperative arthroscopy and MRT in some cases. Results 24 of the 29 meniscal lesions healed (defined as giving an asymptomatic patient) regardless of location or type. 4 patients re-ruptured their menisci (all in the pars intermedia) at an average of 15 months after surgery following a new injury. Mean Lysholm score at follow-up was 95, the Tegner score deteriorated, mean preoperative score: 7.8 (4–10); mean postoperative score: 7.2 (4–10). Patients with simultaneous ACL reconstruction had a better outcome. Interpretation All meniscal tears in the skeletally immature patient are amenable to repair. All recurrent meniscal tears in our patients were located in the pars intermedia; the poorer blood supply in this region may give a higher risk of re-rupture. Simultaneous ACL reconstruction appears to benefit the results of meniscal repair. PMID:22616744

  1. Reconstruction of patellar tendon rupture after anterior cruciate ligament reconstruction: A case report

    Microsoft Academic Search

    Milankov Ziva Miroslav; Semnic Robert; Miljkovi? Natasa; Harhaji Vladimir

    2008-01-01

    Patellar tendon rupture following use of its central third for anterior cruciate ligament (ACL) reconstruction is a rare disabling injury that is technically difficult to repair. We report one case of patellar tendon rupture after harvesting the mid-third for ACL reconstruction. A number of different surgical methods exist for reconstructing patellar tendon ruptures. Here we report a case using a

  2. Simultaneous complete bilateral patellar tendon ruptures: two cases and literature review

    Microsoft Academic Search

    Narayan Hulse; N. Tellisi

    2004-01-01

    Infra-patellar tendon is the least common site for the disruption of extensor mechanism of knee joint. Bilateral simultaneous patellar tendon ruptures are very rare and extremely uncommon in healthy individuals. We report two cases of simultaneous complete bilateral patellar tendon ruptures, one in a healthy adult male and the second in a patient suffering from chronic rheumatoid arthritis. To the

  3. Accelerated corrosion testing, evaluation and durability design of bonded post-tensioned concrete tendons

    Microsoft Academic Search

    Ruben Mario Salas Pereira

    2003-01-01

    In the last few years, the effectiveness of cement grout in galvanized or polyethylene ducts, the most widely used corrosion protection system for multistrand bonded post-tensioned concrete tendons, has been under debate, due to significant tendon corrosion damage, several reported failures of individual tendons as well as a few collapses of non-typical structures. While experience in the USA has been

  4. Evolution of the digital tendon locking mechanism in bats and dermopterans: A phylogenetic perspective

    Microsoft Academic Search

    Nancy B. Simmons; Thomas H. Quinn

    1994-01-01

    A tendon locking mechanism (TLM) in the digits of the feet has been described previously only in bats and birds. In bats, this mechanism typically consists of a patch of tuberculated fibrocartilage cells on the plantar surface of the proximal flexor tendons, and a corresponding plicated portion of the adjacent flexor tendon sheath. The two components mesh together like parts

  5. Continuous Shear Wave Elastography: A New Method to Measure Viscoelastic Properties of Tendons in Vivo.

    PubMed

    Cortes, Daniel H; Suydam, Stephen M; Silbernagel, Karin Grävare; Buchanan, Thomas S; Elliott, Dawn M

    2015-06-01

    Viscoelastic mechanical properties are frequently altered after tendon injuries and during recovery. Therefore, non-invasive measurements of shear viscoelastic properties may help evaluate tendon recovery and compare the effectiveness of different therapies. The objectives of this study were to describe an elastography method for measuring localized viscoelastic properties of tendons and to discuss the initial results in healthy and injured human Achilles and semitendinosus tendons. The technique used an external actuator to generate the shear waves in the tendon at different frequencies and plane wave imaging to measure shear wave displacements. For each of the excitation frequencies, maps of direction-specific wave speeds were calculated using local frequency estimation. Maps of viscoelastic properties were obtained using a pixel-wise curve fit of wave speed and frequency. The method was validated by comparing measurements of wave speed in agarose gels with those obtained using magnetic resonance elastography. Measurements in human healthy Achilles tendons revealed a pronounced increase in wave speed as a function of frequency, which highlights the importance of tendon viscoelasticity. Additionally, the viscoelastic properties of the Achilles tendon were larger than those reported for other tissues. Measurements in a tendinopathic Achilles tendon indicated that it is feasible to quantify local viscoelastic properties. Similarly, measurement in the semitendinosus tendon revealed substantial differences in viscoelastic properties between the healthy and contralateral tendons. Consequently, this technique has the potential to evaluate localized changes in tendon viscoelastic properties caused by injury and during recovery in a clinical setting. PMID:25796414

  6. The wrinkled patellar tendon: an indication of abnormality in the extensor mechanism of the knee

    Microsoft Academic Search

    Robert C. Berlin; E. Mark Levinsohn; Howard Chrisman

    1991-01-01

    Rupture of the quadriceps tendon is an uncommon condition which requires early diagnosis and treatment to avert prolonged disability. In four patients who had surgically confirmed quadriceps tendon rupture, lateral radiographs of the knee and\\/or sagittal magnetic resonance (MR) images demonstrated a corrugated appearance to the patellar tendon. Sagittal MR images of the knee following patellectomy in one patient and

  7. Technical Note: Double tibial tunnel using quadriceps tendon in anterior cruciate ligament reconstruction

    Microsoft Academic Search

    Luigi Pederzini; Ezio Adriani; Carolina Botticella; Massimo Tosi

    2000-01-01

    Summary: To avoid complications related to the use of patellar tendon and hamstring (semitendinosus and gracilis) tendon and to create a more anatomic reconstruction, we present a new technique based on the use of quadriceps tendon placed in a single half femoral tunnel and double tibial tunnels. The graft, harvested by a central longitudinal incision, possesses the following characteristics: (1)

  8. Viscoelastic properties of muscle-tendon unitsThe biomechanical effects of stretching

    Microsoft Academic Search

    Dean C. Taylor; James D. Dalton; Anthony V. Seaber; William E. Garrett

    1990-01-01

    Most muscle stretching studies have focused on defin ing the biomechanical properties of isolated elements of the muscle-tendon unit or on comparing different stretching techniques. We developed an experimental model that was designed to evaluate clinically relevant biomechanical stretching properties in an entire muscle- tendon unit. Our objectives were to characterize the viscoelastic behavior of the muscle-tendon unit and to

  9. Tendon-to-Bone Attachment: From Development to Maturity Elazar Zelzer*1

    E-print Network

    injuries. Unfortunately, the specialized tissue that forms at the attachment of tendon to bone during fetal; Thomopou- los et al., 2002, 2003b). Two examples of tendon­bone junc- tions prone to injury are the rotatorTendon-to-Bone Attachment: From Development to Maturity Elazar Zelzer*1 , Einat Blitz1 , Megan L

  10. SYMPOSIUM: NEW APPROACHES TO ALLOGRAFT TRANSPLANTATION Mechanoactive Scaffold Induces Tendon Remodeling

    E-print Network

    Lu, Helen H.

    SYMPOSIUM: NEW APPROACHES TO ALLOGRAFT TRANSPLANTATION Mechanoactive Scaffold Induces Tendon the scaffold to test the hypothesis that scaffold-induced compression of tendon grafts would result in matrix microscopy and biochemical assays were used to evaluate the effects of scaffold-induced compression on tendon

  11. Surfactant Protein D Is Present in Human Tear Fluid and the Cornea and Inhibits Epithelial Cell Invasion by Pseudomonas aeruginosa

    Microsoft Academic Search

    Minjian Ni; David J. Evans; Samuel Hawgood; E. Margot Anders; Robert A. Sack; Suzanne M. J. Fleiszig

    2005-01-01

    We have previously shown that human tear fluid protects corneal epithelial cells against Pseudomonas aeru- ginosa in vitro and in vivo and that protection does not depend upon tear bacteriostatic activity. We sought to identify the responsible tear component(s). The hypothesis tested was that collectins (collagenous calcium- dependent lectins) were involved. Reflex tear fluid was collected from healthy human subjects

  12. Four Characteristics and a Model of an Effective Tear Film Lipid Layer (TFLL)

    PubMed Central

    King-Smith, P. Ewen; Bailey, Melissa D.; Braun, Richard J.

    2015-01-01

    It is proposed that a normal, effective tear film lipid layer (TFLL) should have the following four characteristics: 1) high evaporation resistance to prevent water loss and consequent hyperosmolarity; 2) respreadability, so it will return to its original state after the compression-expansion cycle of the blink; 3) fluidity sufficient to avoid blocking secretion from meibomian glands; 4) gel-like and incompressible structure that can resist forces that may tend to disrupt it. These characteristics tend to be incompatible; for example, lipids that form good evaporation barriers tend to be disrupted by compression-expansion cycles. It is noted that clues about the function and organization of the TFLL can be obtained by comparison with other biological lipid layers, such as lung surfactant and the lipid evaporation barrier of the skin. In an attempt to satisfy the conflicting characteristics, a “multilamellar sandwich model” of the TFLL is proposed, having features in common with the skin evaporation barrier. PMID:24112227

  13. Co-electrospun dual scaffolding system with potential for muscle-tendon junction tissue engineering.

    PubMed

    Ladd, Mitchell R; Lee, Sang Jin; Stitzel, Joel D; Atala, Anthony; Yoo, James J

    2011-02-01

    Tissue engineering has had successes developing single tissue types, but there is a need for methods that will allow development of composite tissues. For instance, muscle-tendon junctions (MTJ) require a seamless interface to allow force transfer from muscle to tendon. One challenge in engineering MTJs is designing a continuous scaffold suitable for both tissue types. We aimed to create a dual scaffold that exhibits regional mechanical property differences that mimic the trends seen in native MTJ. Poly(?-caprolactone)/collagen and poly(l-lactide)/collagen were co-electrospun onto opposite ends of a mandrel to create a scaffold with 3 regions. Scaffolds were characterized with scanning electron microscopy, tensile testing (uniaxial, cyclic, and video strain), for cytocompatibility using MTS, and seeded with C2C12 myoblasts and NIH3T3 fibroblasts. Native porcine diaphragm MTJs were also analyzed with video strain for comparison. Integrated scaffolds were created with fiber diameters from 452-549 nm. Scaffolds exhibited regional variations in mechanical properties with moduli from 4.490-27.62 MPa and generally withstood cyclic testing, although with hysteresis. Video analysis showed scaffold strain profiles exhibited similar trends to native MTJ. The scaffolds were cytocompatible and accommodated cell attachment and myotube formation. The properties engineered into these scaffolds make them attractive candidates for tissue engineering of MTJs. PMID:21093046

  14. Patellar Tendon Reconstruction in Total Knee Arthroplasty: A New Technique.

    PubMed

    Rajgopal, Ashok; Vasdev, Attique; Dahiya, Vivek

    2014-09-24

    Patellar tendon disruption is one of the most dreaded complications following total knee arthroplasty (TKA) impacting both implant function and implant longevity. To overcome the concerns regarding allografts and improve outcomes with augmentation techniques, we describe a technique, which we have successfully used over the past 4 years with good results. Seven patients underwent reconstruction for patellar tendon disruption using our technique from a cohort of eight patients. Extensor lag improved from a mean of 40 degrees to less than 5 degrees postoperatively. Range of motion improved from a mean of 105 degrees to 115 degrees of flexion. There was improvement in Knee Society Functional Score from a preoperative mean of 30 to 75 points. The Knee Society Pain Score, however, did not show much improvement. We believe our technique to be a solution to the difficult problem of patellar tendon ruptures after TKA and we continue to perform this procedure. PMID:25251879

  15. No man's land revisited: the primary flexor tendon repair controversy.

    PubMed

    Newmeyer, William L; Manske, Paul R

    2004-01-01

    New surgical procedures, novel concepts, and/or the presentation of very good results with an apparently discredited technique meet varying degrees of resistance among the establishment of any profession. In hand surgery this phenomenon was exemplified in a striking fashion with the presentation of a controversial report entitled, "Primary repair of flexor tendons in no man's land" by Kleinert, Kutz, Ashbell, and Martinez of Louisville, KY, at the 1967 American Society for Surgery of the Hand (ASSH) annual meeting. The discussant, Joseph Boyes, expressed such skepticism that a special ASSH committee was appointed to go to Louisville and review the results to determine if they were as good as claimed. They were, and today primary flexor tendon repair is the procedure of choice for most flexor tendon lacerations. PMID:14751095

  16. Stem cell research and clinical development in tendon repair

    PubMed Central

    Filomeno, Paola; Dayan, Victor; Touriño, Cristina

    2012-01-01

    Summary Stem cells are one of the most fascinating areas in regenerative medicine today. They play a crucial role in development and regeneration and are defined as cells that continuously reproduce themselves while maintaining the ability to differentiate into various cell types. Stem cells are found at all developmental stages, from embryonic stem cells (ESCs) which differentiate into all cell types, to adult stem cells (ASCs) which are responsible for tissue regeneration. Studies using animal models have shown promising results following cell therapy for induced injury in musculoskeletal system, including tendon healing, but the results can be variable. Alternative sources for cell therapy in tendon pathology may include ESCs, ASCs (bone marrow, adipose tissue or tendon derived stem cells) or induced pluripotent stem cells (iPSCs). While ethical and safety concerns currently forbid clinical application of ESCs and iPSCs, initial clinical trials with ASCs are promising. PMID:23738298

  17. An Investigation of Tendon Corrosion-Inhibitor Leakage into Concrete

    SciTech Connect

    Costello, J.F.; Naus, D.J.; Oland, C.B.

    1999-07-05

    During inspections performed at US nuclear power plants several years ago, some of the prestressed concrete containment had experienced leakage of the tendon sheathing filler. A study was conducted to indicate the extent of the leakage into the concrete and its potential effects on concrete properties. Concrete core samples were obtained from the Trojan Nuclear Plant. Examination and testing of the core samples indicated that the appearance of tendon sheathing filler on the surface was due to leakage of the filler from the conduits and its subsequent migration to the concrete surface through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks with no perceptible movement into the concrete. Results of compressive strength tests indicated that the concrete quality was consistent in the containment and that the strength had increased relative to the strength at 28 days age.

  18. Ultrasound elasticity imaging of human posterior tibial tendon

    NASA Astrophysics Data System (ADS)

    Gao, Liang

    Posterior tibial tendon dysfunction (PTTD) is a common degenerative condition leading to a severe impairment of gait. There is currently no effective method to determine whether a patient with advanced PTTD would benefit from several months of bracing and physical therapy or ultimately require surgery. Tendon degeneration is closely associated with irreversible degradation of its collagen structure, leading to changes to its mechanical properties. If these properties could be monitored in vivo, it could be used to quantify the severity of tendonosis and help determine the appropriate treatment. Ultrasound elasticity imaging (UEI) is a real-time, noninvasive technique to objectively measure mechanical properties in soft tissue. It consists of acquiring a sequence of ultrasound frames and applying speckle tracking to estimate displacement and strain at each pixel. The goals of my dissertation were to 1) use acoustic simulations to investigate the performance of UEI during tendon deformation with different geometries; 2) develop and validate UEI as a potentially noninvasive technique for quantifying tendon mechanical properties in human cadaver experiments; 3) design a platform for UEI to measure mechanical properties of the PTT in vivo and determine whether there are detectable and quantifiable differences between healthy and diseased tendons. First, ultrasound simulations of tendon deformation were performed using an acoustic modeling program. The effects of different tendon geometries (cylinder and curved cylinder) on the performance of UEI were investigated. Modeling results indicated that UEI accurately estimated the strain in the cylinder geometry, but underestimated in the curved cylinder. The simulation also predicted that the out-of-the-plane motion of the PTT would cause a non-uniform strain pattern within incompressible homogeneous isotropic material. However, to average within a small region of interest determined by principal component analysis (PCA) would improve the estimation. Next, UEI was performed on five human cadaver feet mounted in a materials testing system (MTS) while the PTT was attached to a force actuator. A portable ultrasound scanner collected 2D data during loading cycles. Young's modulus was calculated from the strain, loading force and cross sectional area of the PTT. Average Young's modulus for the five tendons was (0.45+/-0.16GPa) using UEI. This was consistent with simultaneous measurements made by the MTS across the whole tendon (0.52+/-0.18GPa). We also calculated the scaling factor (0.12+/-0.01) between the load on the PTT and the inversion force at the forefoot, a measurable quantity in vivo. This study suggests that UEI could be a reliable in vivo technique for estimating the mechanical properties of the human PTT. Finally, we built a custom ankle inversion platform for in vivo imaging of human subjects (eight healthy volunteers and nine advanced PTTD patients). We found non-linear elastic properties of the PTTD, which could be quantified by the slope between the elastic modulus (E) and the inversion force (F). This slope (DeltaE/DeltaF), or Non-linear Elasticity Parameter (NEP), was significantly different for the two groups: 0.16+/-0.20 MPa/N for healthy tendons and 0.45+/-0.43 MPa/N for PTTD tendons. A receiver operating characteristic (ROC) curve revealed an area under the curve (AUC) of 0.83+/-0.07, which indicated that the classifier system is valid. In summary, the acoustic modeling, cadaveric studies, and in vivo experiments together demonstrated that UEI accurately quantifies tendon mechanical properties. As a valuable clinical tool, UEI also has the potential to help guide treatment decisions for advanced PTTD and other tendinopathies.

  19. ProTec Tear-Offs: A Preliminary Assessment

    SciTech Connect

    Peeler, D

    2005-09-01

    The Savannah River National Laboratory (SRNL) has conducted a series of ''scoping'' tests (referred to as Phase 1) to assess the potential use of a Mylar{reg_sign} tear-off system as a primary or secondary protective barrier to minimize acid etching (''frosting''), accidental scratching, and/or radiation damage for shielded cells windows. Conceptually, thin, multi-layered sheets of Mylar (referred to as a ''tear-off'' system) could be directly applied to the Lexan{reg_sign} sheet or glovebox/hood sash window to serve as a secondary (or primary) barrier. Upon degradation of visual clarity due to accidental scratching, spills/splatters, and/or radiation damage, the outer layer (or sheet) of Mylar could be removed ''refreshing'' or restoring the view. Due to the multi-layer aspect, the remaining Mylar layers would provide continued protection for the window from potential reoccurrences (which could be immediate or after some extended time period). Although the concept of using a tear-off system as a protective barrier was conceptually enticing, potential technical issues were identified and addressed as part of this Phase 1 feasibility study. These included resistance to: (1) acid(s) (concentrated (28.9 M) HF, concentrated (15.9M) HNO{sub 3}, 6M HCl, and 0.6M H{sub 3}BO{sub 3}), (2) base (a simulated sludge with pH of 12.9), (3) gamma radiation (cumulative dose of {approx}200,000 rad), and (4) scratch resistance (simulating accidental scratching with the manipulators). Not only can these four factors play a significant role in determining the visual clarity of the integrated system, they can also contribute to the mechanical integrity issues which could dictate the ability to remove the outer layer when visual clarity has degraded. The results of the Phase 1 study clearly indicate that the Mylar tear-off concept (as a primary or secondary protective barrier) is a potential technical solution to prevent or retard excessive damage that would result from acid etching, base damage (as a result of a sludge spill or splatter), gamma radiation damage, and/or accidental scratching (due to manipulator/tool contact). The short term tests performed in this task showed that Mylar tear-offs can withstand the chemical and physical abuses expected in off-normal shielded cells operations. The ''tear-offs'' not only provide some measure of acid resistance, as reflected by the lack of visual degradation after being exposed to four acids, but also act as a protective barrier to accidental contact with the manipulators and/or tools. The conceptual ''erasing'' of scratches or marks was demonstrated in the shielded cell mock-up facility through the removal, with manipulators, of the outer layer tear-off. The successful removal of the outer layer tear-off with the manipulator, using tabs not specifically designed for remote operations, demonstrates that the system is ''manipulator-friendly'' and could be implemented in the shielded cells. The ability to remove the outer layer tear-off not only regains visual clarity but also reduces waste disposal volumes (i.e., disposal of a thin sheet of Mylar which is ''collapsible'' versus the bulk disposal of a rigid Lexan sheet or glovebox/sash window) which is more cost effective. The ''tear-off'' system could also reduce the number of cell entries needed to replace the Lexan sheet and increase the time interval between glovebox/sash window change outs which can be costly and time consuming. Although the primary focus of this report addresses the application of the Mylar tear-offs on shielded cells windows, the concept is also potentially applicable to glovebox and hood sash windows. In fact, the tear-off concept is potentially applicable to any system where visual clarity is compromised given the environmental conditions of the test. In addition, the tear-offs could be applied to walls or shelves where a protective barrier would reduce deterioration or discoloration. This concept is referred to as the ProTec{trademark} tear-off system as its primary intent is to protect windows or surfaces.

  20. Effects of Notch Shape and Specimen Thickness on Drop-Weight Tear Test Properties of API X70 and X80 Line-Pipe Steels

    Microsoft Academic Search

    Sang Yong Shin; Byoungchul Hwang; Sunghak Lee; Ki Bong Kang

    2007-01-01

    In the present study, effects of notch shape and specimen thickness on drop-weight tear test (DWTT) properties of API X70\\u000a and X80 line-pipe steels fabricated by varying hot-rolling conditions were investigated. The DWTT was conducted on the rolled\\u000a steels, and the results were discussed in comparison with the Charpy V-notch (CVN) impact test and crack-tip opening angle\\u000a (CTOA) test data.

  1. Biologically based strategies to augment rotator cuff tears

    PubMed Central

    Schaer, M.; Schober, M.; Berger, S.; Boileau, P.; Zumstein, M. A.

    2012-01-01

    Lesions of the rotator cuff (RC) are among the most frequent tendon injuries. In spite of the developments in both open and arthroscopic surgery, RC repair still very often fails. In order to reduce the failure rate after surgery, several experimental in vitro and in vivo therapy methods have been developed for biological improvement of the reinsertion. This article provides an overview of the current evidence for augmentation of RC reconstruction with growth factors. Furthermore, potential future therapeutic approaches are discussed. We performed a comprehensive search of the PubMed database using various combinations of the keywords “tendon,” “rotator cuff,” “augmentation,” “growth factor,” “platelet-rich fibrin,” and “platelet-rich plasma” for publications up to 2011. Given the linguistic capabilities of the research team, we considered publications in English, German, French, and Spanish. We excluded literature reviews, case reports, and letters to the editor. PMID:22787334

  2. Verification of gyrokinetic particle simulation of current-driven instability in fusion plasmas. II. Resistive tearing mode

    NASA Astrophysics Data System (ADS)

    Liu, Dongjian; Zhang, Wenlu; McClenaghan, Joseph; Wang, Jiaqi; Lin, Zhihong

    2014-12-01

    Global gyrokinetic particle simulation of resistive tearing modes has been developed and verified in the gyrokinetic toroidal code (GTC). GTC linear simulations in the fluid limit of the kink-tearing and resistive tearing modes in the cylindrical geometry agree well with the resistive magnetohydrodynamic eigenvalue and initial value codes. Ion kinetic effects are found to reduce the radial width of the tearing modes. GTC simulations of the resistive tearing modes in the toroidal geometry find that the toroidicity reduces the growth rates.

  3. PROTEC TM TEAR-OFFS: RESULTS OF LONG TERM TESTING

    SciTech Connect

    Peeler, D

    2008-07-24

    The Savannah River National Laboratory (SRNL) has completed a series of tests (Phases 1 and 2) to assess the potential use of a Mylar{reg_sign} tear-off system as a primary or secondary protective barrier to minimize acid etching ('frosting'), accidental scratching, and/or radiation damage for shielded cells, glovebox, and/or chemical hood windows. Conceptually, thin, multi-layered sheets of Mylar (referred to throughout this report as the ProTec{trademark} tear-off system) can be directly applied to the shielded cell, glovebox, or hood sash window to serve as a secondary (or primary) barrier. Upon degradation of visual clarity due to accidental scratching, spills/splatters, and/or radiation damage, the outer layer (or sheet) of Mylar could be removed refreshing or restoring the view. Due to the multilayer aspect, the remaining Mylar layers would provide continued protection for the window from potential reoccurrences. Although the concept of using a tear-off system as a protective barrier is conceptually enticing, potential technical issues were identified and addressed as part of this phased study to support implementation of this type of system in the Defense Waste Processing Facility (DWPF). Specific test conditions of interest to the DWPF included the performance of the tear-off system exposed to or under the following conditions: (1) acid(s) (concentrated (28.9 M) HF, concentrated (15.9M) HNO{sub 3}, 6M HCl, and 0.6M H{sub 3}BO{sub 3}); (2) base (based on handling of radioactive sludges with pH of {approx}12-13); (3) gamma radiation (due to radioactive sources or materials being used in the analytical cells); (4) scratch resistance (simulating accidental scratching with the manipulators); and (5) in-situ testing (sample coupons exposed to actual field conditions in DWPF). The results of the Phase 1 study indicated that the ProTec tear-off concept (as a primary or secondary protective barrier) is a potential technical solution to prevent or retard excessive damage that would result from acid etching, base damage (as a result of a sludge spill or splatter), gamma radiation damage, and/or accidental scratching (due to manipulator/tool contact). Although identified as a potential solution, the Phase 1 testing was relatively short-term with exposure times up to 1-2 months for the acid and gamma radiation tests. Phase 2 testing included longer exposure times for the acid resistance (up to 456 days) and gamma radiation exposure (700 days with a cumulative gamma dose of {approx}3.1 x 10{sup 5} rad) assessments. The tear-off system continued to perform well in these longer-term acid resistance testing and gamma exposure conditions. Complete removal of the tear-offs after these long-term exposure times indicate that not only could visual clarity be restored but the mechanical integrity could be retained. The results also provided insight into the ability of the ProTec tear-off system to withstand the chemical and physical abuses expected in off-normal shielded cells operations. The conceptual erasing of scratches or marks by excessive manipulator abuse was demonstrated in the SRNL Shielded Cells mock-up facility through the removal of the outer layer tear-off with manipulators. In addition, the Phase 2 testing included an in-situ assessment of a prototype tear-off system in the DWPF Sampling Cells where the system was exposed to actual field conditions including radioactive sources, acidic and basic environments, dusting, and chemical cleaning solutions over a 5-6 month period. DWPF personnel were extremely satisfied with the performance (including the successful removal of 3 layers with manipulators) of the ProTec tear-off system under actual field conditions. The successful removal of the outer layer tear-offs with the manipulator, using tabs not specifically designed for remote operations, demonstrates that the system is 'manipulator-friendly' and could be implemented in a remote environment. The ability to remove the outer layer tear-off not only regains visual clarity but also reduces waste disposal volumes (i.e., dispo

  4. Hi h R l ti O l S fHigh Resolution Ocular Surface OCT to Directly Measure TearOCT to Directly Measure Tear

    E-print Network

    Yoon, Geunyoung

    eye 3-5 µm Tear Film Functions www.artificialtears.net Dry Eye NEI · Smoothens the corneal surface Measure Tear Film Thickness in Human Eyes l i l O ti L b tAdvanced Physiological Optics Laboratory Institute of Optics, Flaum Eye Institute

  5. Dynamics and function of the tear film in relation to the blink cycle.

    PubMed

    Braun, R J; King-Smith, P E; Begley, C G; Li, Longfei; Gewecke, N R

    2015-03-01

    Great strides have recently been made in quantitative measurements of tear film thickness and thinning, mathematical modeling thereof and linking these to sensory perception. This paper summarizes recent progress in these areas and reports on new results. The complete blink cycle is used as a framework that attempts to unify the results that are currently available. Understanding of tear film dynamics is aided by combining information from different imaging methods, including fluorescence, retroillumination and a new high-speed stroboscopic imaging system developed for studying the tear film during the blink cycle. During the downstroke of the blink, lipid is compressed as a thick layer just under the upper lid which is often released as a narrow thick band of lipid at the beginning of the upstroke. "Rippling" of the tear film/air interface due to motion of the tear film over the corneal surface, somewhat like the flow of water in a shallow stream over a rocky streambed, was observed during lid motion and treated theoretically here. New mathematical predictions of tear film osmolarity over the exposed ocular surface and in tear breakup are presented; the latter is closely linked to new in vivo observations. Models include the effects of evaporation, osmotic flow through the cornea and conjunctiva, quenching of fluorescence, tangential flow of aqueous tears and diffusion of tear solutes and fluorescein. These and other combinations of experiment and theory increase our understanding of the fluid dynamics of the tear film and its potential impact on the ocular surface. PMID:25479602

  6. Interferometric measurements of the tear film irregularities on the human cornea

    NASA Astrophysics Data System (ADS)

    Szczesna, Dorota H.; Jaronski, Jaroslaw; Kasprzak, Henryk T.; Stenevi, Ulf

    2005-09-01

    The pre-ocular tear film is the most anterior refractive surface of the eye. Its stability plays an important role in the condition of vision from the optical and physiological point of view. If the eye is opened for a significantly long time or suffers from an anormalities in tear production, there appear isolated dry islands - break-ups - with a random distribution in the continuous lacrimal film. We applied an interferometric method - Lateral Shearing Technique for investigating the tear film stability and the smoothness of the tear film surface. This method is non-invasive and it is characterised by the high accuracy and sensitivity. Interferometry allows dynamic measurements of the tear film stability in real time by observation of interference fringes. The evaporation of tears and appearance of the breakups causes changes in the fringe geometry. Fast Fourier Transform has been used for quantitative assessment of the fringe smoothness and as a consequence of the tear film surface geometry. This paper presents the method used for quantitative evaluation of the tear film distribution on the cornea. Examples of interferograms recorded on eyes of patients with healthy eyes, suffering from dry eye syndrome and wearing contact lenses are also given. With our technique we were able to observe distinct differences in stability of the tear film between healthy and dry eyes, and the tear film on contact lenses.

  7. High strain mechanical loading rapidly induces tendon apoptosis: an ex vivo rat tibialis anterior model

    PubMed Central

    Scott, A; Khan, K; Heer, J; Cook, J; Lian, O; Duronio, V

    2005-01-01

    Objective: To investigate the development of apoptosis after high strain loading of rat tendon. Methods: The right tibialis anterior tendons of three rats were prepared for mechanical loading, and left tendons were prepared identically as non-loaded controls. Tendon was loaded with 20% strain for six hours using a 1 Hz longitudinal sine wave signal. The following were used to assess apoptosis: (a) a monoclonal mouse antibody (F7-26) to label single stranded DNA breaks; (b) a rabbit polyclonal antibody that specifically recognises the cleaved form of caspase-3. Results: Light microscopy confirmed that the high strain protocol induced a stretch overload injury. Control tendons showed little or no staining with the F7-26 antibody, but the loaded tendons displayed numerous apoptotic cells. The percentage of apoptotic cells (20%) in the loaded tendon was significantly greater than in the control tendon (1%) (p = 0.000). The labelled cells colocalised with abnormal nuclear morphology, including nuclear fragmentation. The staining against cleaved caspase-3 was positive in loaded tendons only, and localised both to nucleus and cytoplasm. Conclusion: This experiment extends knowledge of human tendon apoptosis by showing that apoptosis can occur in response to short term, high strain mechanical loading. This is the first report of mechanical loading of intact tendon causing excessive apoptosis. PMID:15849278

  8. Arthroscopic Saucerization and Repair of Discoid Lateral Meniscal Tear

    PubMed Central

    Fields, Logan K.; Caldwell, Paul E.

    2015-01-01

    Meniscal tears are among the most commonly diagnosed knee injuries and often require surgical intervention. Understanding the types of meniscal tears and treatment options is paramount to caring for the young athlete. Sports medicine and arthroscopic physicians now recognize that meniscal preservation in the young athlete is essential to the long-term health and function of the knee. Although uncommon, the discoid lateral meniscus is more prone to injury because of its increased thickness and lack of blood supply. Because of the abnormal development, the peripheral attachments are frequently absent and instability often persists after a partial meniscectomy. If the instability is unrecognized during the initial treatment, a recurrence of pain and mechanical symptoms is likely and a subsequent subtotal meniscectomy may be the only treatment option. With increased awareness, arthroscopic saucerization accompanied by arthroscopically assisted inside-out meniscal repair is a preferable treatment option with an excellent outcome. PMID:26052498

  9. Asymmetric tearing mode in the presence of viscosity

    SciTech Connect

    Militello, F. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Borgogno, D. [Dipartimento di Energetica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Grasso, D. [CNR Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, Dipartimento di Energetica, Politecnico di Torino, 10129 Torino (Italy); Marchetto, C. [Associazione EURATOM-ENEA sulla Fusione, IFP-CNR, Via R. Cozzi 53, 20125 Milano (Italy); Ottaviani, M. [Association EURATOM-CEA, CEA/DSM/IRFM, CEA Cadarache, 13108 St. Paul-lez-Durance (France)

    2011-11-15

    The linear stability of the tearing mode (TM) in a plasma column is investigated in the presence of viscosity and finite equilibrium current density gradients (i.e., asymmetries). It is shown that for low {beta}, both effects are essential in order to properly describe the mode behaviour close to marginality. In particular, the theory introduces a critical threshold for the destabilization, such that the perturbation grows only if {Delta}'>{Delta}'{sub cr}. The value of {Delta}'{sub cr} depends on the equilibrium configuration and on the plasma parameters. Most importantly, {Delta}'{sub cr} can take negative values, thus allowing unstable tearing modes for {Delta}' < 0 (even in the absence of bootstrap current).

  10. The growth of the tearing mode - Boundary and scaling effects

    NASA Technical Reports Server (NTRS)

    Steinolfson, R. S.; Van Hoven, G.

    1983-01-01

    A numerical model of resistive magnetic tearing is developed in order to verify and relate the results of the principal approximations used in analytic analyses and to investigate the solutions and their growth-rate scalings over a large range of primary parameters which include parametric values applicable to the solar atmosphere. The computations cover the linear behavior for a variety of boundary conditions, emphasizing effects which differentiate magnetic tearing in astrophysical situations from that in laboratory devices. Eigenfunction profiles for long and short wavelengths are computed and the applicability of the 'constant psi' approximation is investigated. The growth rate is computed for values of the magnetic Reynolds number up to a trillion and of the dimensionless wavelength parameter down to 0.001. The analysis predicts significant effects due to differing values of the magnetic Reynolds number.

  11. Tear secretion dysfunction among women workers engaged in light-on tests in the TFT-LCD industry

    PubMed Central

    Su, Shih-Bin; Lu, Chih-Wei; Sheen, Jiunn-Woei; Kuo, Shu-Chun; Guo, How-Ran

    2006-01-01

    Background The TFT-LCD (thin film transistor liquid crystal display) industry is rapidly growing in Taiwan and many other countries. A large number of workers, mainly women, are employed in the light-on test process to detect the defects of products. At the light-on test workstation, the operator is generally exposed to low humidity (in the clean room environment), flashing light, and low ambient illumination for long working hours. Many workers complained about eye discomfort, and therefore we conducted a study to evaluate the tear secretion function of light-on test workers of a TFT-LCD company. Methods We recruited workers engaged in light-on tests in the company during their periodical health examination. In addition to a questionnaire survey of demographic characteristics and ophthalmic symptoms, we evaluated the tear secretion function of both eyes of each participant using the Schirmer's lacrimal basal secretion test with anaesthesia. A participant with one or both eyes yielding abnormal test results was defined as a case of tear secretion dysfunction. Results During the study period, a total of 371 light-on test workers received the health examination at the clinic of the park, and 52 of them were excluded due to having ophthalmic diseases and other systemic diseases that may affect ophthalmic function. All the remaining 319 qualified workers agreed to participate in this study, and they were all females working by 4-shift rotations. The average age was 24.2 years old (standard deviation [SD] = 3.8), and the average employment duration was 13.6 months (SD = 5.7). Among the 11 ophthalmic symptoms evaluated, eye dryness was the most prevalent (prevalence = 43.3%). In addition, the prevalence of tear secretion dysfunction in at least one eye was 40.1% (128 cases), and contact lens users had an odds ratio of 1.73 (95% confidence interval = 1.02–2.94) in comparison with non-contact lens users. Comparing the Schirmer's test results of those who also participated in the screening in the previous year, we found 40 of the 156 participants (17.2%) with normal test results in the previous year turned abnormal in 2001. In contrast, only 21 of the 76 participants (9.1%) with abnormal test results in the previous year turned normal, and the difference was statistically significant (p = 0.02 for McNemar's test). Conclusion The prevalence of tear secretion dysfunction in woman workers engaged in light-on tests is high and increases with a one-year duration of employment. The use of contact lens may further increase the risk. PMID:17173696

  12. Tear Film Break-up Time in Bipolar Disorder

    PubMed Central

    Mohammadinia, Mohadeseh; Moghadasin, Maryam; Amiri, Mohammad Aghazade

    2012-01-01

    Objective Ocular dryness is a well-recognized adverse side effect of many topical and systemic medications. In psychiatry, patients who have consumed such drugs as lithium carbonate and sodium valproate frequently experience dry eye symptoms. The purpose of this study was to compare tear film stability between patients who use these drugs with those patients who are not on medication. Methods After obtaining informed consent, the tear film break up time (TBUT) test was performed in 96 eyes of 48 subjects. The subjects were placed in to three groups. Participants included two groups of euthymic bipolar disorder patients (16 cases each) with history of pharmacotherapy for more than two years. Patients in each group were taking only one type of mood stabilizer (lithium carbonate or sodium valproate). In addition,16 age-matched bipolar patients who did not take any topical or systemic medications were included in a control group. Values of TBUT were compared between the three groups using the student's t-test. Results The mean tear film break up time (TBUT) in test groups were 4.88 seconds± 0.34(lithium group), 4.81 seconds ± 1.60 (valproate group) and 15seconds± 2.0(control group), respectively. No statistically significant differences were observed between the first and the second groups in TBUT values, but significant differences were found between the two groups and the control group (P< 0.0001). Conclusion The results of this study show that lithium carbonate and sodium valproate contribute to decrease of tear film break up time, resulting from dryness of the eyes. PMID:23408791

  13. A threshold for excitation of neoclassical tearing modes

    SciTech Connect

    Gorelenkov, N.N.; Zakharov, L.E. [Princeton Univ., NJ (United States). Princeton Plasma Physics Lab.; Gorelenkova, M.V. [Moscow State Univ. (Russian Federation)

    1996-01-01

    Stability criterion is obtained for neoclassical tearing modes. A finite amplitude of magnetic island is required for their excitation. In both collisional and collisionless regimes the threshold is determined by the ratio of the transversal and the parallel transport near the island, when the flattening of the pressure profile eliminates the bootstrap current. A number of TFTR supershots are compared with the theory. Both the stability condition and the critical island width are consistent with experimental data.

  14. Effects of Tear Substitutes on Conjunctival Epithelium of Mice

    Microsoft Academic Search

    Pasquale Aragona; Antonio Micali; Grazia Paladino; Felicia Ferreri; Domenico Puzzolo

    2007-01-01

    Aim: The effects of the administration of three tear substitutes on normal conjunctival epithelium of the mouse, with particular regard to goblet cells, were studied. Methods: Three-month-old Swiss CD 1 mice were divided into four groups of 7 animals each. Group 1 was untreated (control). The other animals were treated with the instillation of 5 drops\\/day for 10 days as

  15. High conductivity magnetic tearing instability. [of neutral plasma sheets

    NASA Technical Reports Server (NTRS)

    Cross, M. A.; Van Hoven, G.

    1976-01-01

    Linearized equations of magnetohydrodynamics are used to investigate the tearing mode, for arbitrary values of the conductivity, through a consideration of the additional effect of the electron-inertia contribution to Ohm's law. A description is provided of the equilibrium and subsequent instability in the magnetohydrodynamic approximation. A method for solving the perturbation equations in the linear approximation is discussed and attention is given to the results in the high conductivity limit.

  16. The effect of line-tying on tearing modes

    Microsoft Academic Search

    Gian Luca Delzanno; John M. Finn

    2008-01-01

    Cylindrical magnetohydrodynamic (MHD) constant-&psgr; or nonconstant-&psgr; tearing modes that are linearly unstable with periodic axial boundary conditions are studied in a line-tied cylinder. Examples of these two respective classes of modes, with m=1 and m=2 (m being the azimuthal mode number), are studied. With a suitable MHD equilibrium, the former modes are marginally stable in ideal MHD for periodic axial

  17. The effect of line-tying on tearing modes

    Microsoft Academic Search

    Gian Luca Delzanno; John M. Finn

    2008-01-01

    Cylindrical magnetohydrodynamic (MHD) constant-psi or nonconstant-psi tearing modes that are linearly unstable with periodic axial boundary conditions are studied in a line-tied cylinder. Examples of these two respective classes of modes, with m=1 and m=2 (m being the azimuthal mode number), are studied. With a suitable MHD equilibrium, the former modes are marginally stable in ideal MHD for periodic axial

  18. Three-dimensional simulations of compressible tearing instability

    SciTech Connect

    Landi, Simone; Londrillo, Pasquale; Velli, Marco; Bettarini, Lapo [Dipartimento di Astronomia a Scienza dello Spazio, Universita degli Studi di Firenze, Largo E. Fermi 2, I-50125 Firenze (Italy); Istituto Nazionale di AstroFisica (INAF) - Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Jet Propulsion Laboratory (JPL), California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States); Dipartimento di Astronomia a Scienza dello Spazio, Universita degli Studi di Firenze, Largo E. Fermi 2, I-50125 Firenze (Italy)

    2008-01-15

    Three-dimensional numerical simulations of the tearing instability in the framework of compressible and resistive magnetohydrodynamics are presented. Simulations have been performed with a novel Eulerian conservative high order code, including an explicit resistivity, which uses implicit high order numerical schemes having higher spectral resolution than classical schemes. The linear and non linear evolution of the tearing instability has been followed for force-free and pressure-balanced initial equilibrium configurations. Pressure equilibrium configurations are subject to a secondary instability which drives the system toward a quasi two dimensional structure oriented perpendicularly to the initial configuration. The development of secondary instabilities is suppressed by a guide field allowing the coalescence instability to fully develop in the system. Force-free initial configurations follow an intermediate path with respect the previous cases: Strong coalescence of magnetic islands, due to the non linear evolution of the tearing instability, is observed before the system enters in a phase dominated by 3D modes. The histories of the differing initial current-sheet equilibria have counterparts in the energy spectra that, for all three cases, are observed to be strongly anisotropic.

  19. Treating Anterior Cruciate Ligament Tears in Skeletally Immature Patients

    PubMed Central

    Vavken, Patrick; Murray, Martha M

    2011-01-01

    Purpose To systematically review the current evidence for conservative and surgical treatment of anterior cruciate ligament (ACL) tears in skeletally immature patients. Methods A systematic search of PubMed, CINAHL, EMBASE, CCTR, and CDSR was performed for surgical and/or conservative treatment of complete ACL tears in immature individuals. Studies with less than six months of follow-up were excluded. Study quality was assessed and data were collected on clinical outcome, growth disturbance, and secondary joint damage. Results We identified 48 studies meeting the inclusion criteria. Conservative treatment was found to result in poor clinical outcomes and a high incidence of secondary defects, including meniscal and cartilage injury. Surgical treatment had only very weak evidence for growth disturbance, yet strong evidence of good postoperative stability and function. No specific surgical treatment showed clearly superior outcomes, yet the studies using physeal-sparing techniques had no reported growth disturbances at all. Conclusions The current best evidence suggests that surgical stabilization should be considered the preferred treatment in immature patients with complete ACL tears. While physeal-sparing techniques are not associated with a risk of growth disturbance, transphyseal reconstruction is an alternative with a beneficial safety profile and a minimal risk of growth disturbance. Conservative treatment commonly leads to meniscal damage and cartilage destruction and should be considered a last resort. Level of Evidence Level IV, systematic review of Level II, III, and IV studies. PMID:21552340

  20. Quasilinear Hall Dynamo Theory For Two-Fluid Tearing Instability

    NASA Astrophysics Data System (ADS)

    Mirnov, V. V.; Hegna, C. C.; Prager, S. C.

    2002-11-01

    A quasilinear theory of the two-fluid Hall dynamo effect is analyzed on the basis of tearing eigenfunctions obtained for force free equilibria with finite ? and uniform mean electron and ion pressures. Previously we have reported the importance of this effect in the case of large values of the stability factor ?'. General theory which is valid for arbitrary ?' is developed in this work. In the range of ? of practical interest the shear Alfven mode is decoupled from fast compressional Alfven and slow magneto-acoustic modes and exhibits dispersion properties typical for kinetic Alfven waves. This drives a tearing instability with the growth rate ?^1/3?_s^2/3 at large ?' and ?s ? ?' at small ?' where ? is electron skin depth and ?s is ion-sound gyroradius. A net dynamo effect producing current parallel to the magnetic field is calculated at ?s >> ? by forming a flux surface average of the quadratic combinations. The results are compared with the case of strong guiding magnetic field where tearing instability is described by resistive MHD. Significant enhancement of the dynamo effect caused by j × B Hall term is found in the narrow electron layer while a smaller enhancement is generated by v × B term (alpha effect) and it is broadened to the scale ?_s. ^* This work is supported by the U.S. Department of Energy

  1. Diagnosis and rehabilitation of gastrocnemius muscle tear: a case report

    PubMed Central

    Nsitem, Virginia

    2013-01-01

    Objective: This case study presents the epidemiology, etiology, diagnostic criteria, and therapeutic interventions for a common clinical condition – gastrocnemius injury. Clinical Features: A 44-year old male presented with acute calf pain with a palpable defect, loss of range of motion, and loss of strength after sustaining a soft tissue injury to the lower leg. The differential diagnosis of tear of the medial head of the gastrocnemius was confirmed by physical examination and diagnostic ultrasound imaging. Intervention and Outcome: The patient was treated over a 6 week period. Initially, rehabilitation was approached using the PRICE principles for symptomatic relief, followed by stretching, strengthening, proprioception, and conditioning exercises. At 9-month follow-up post injury, there was no residual impairment in the gastrocnemius muscle function. Summary: This case demonstrates the importance of epidemiology, clinical assessment, and the use of diagnostic ultrasound and MRI imaging in the diagnosis of a tear of the medial head of the gastrocnemius muscle. With an accurate diagnosis and comprehension of classification of muscle injuries, management of gastrocnemius tears is straightforward. PMID:24302780

  2. Tearing instabilities in the banana-plateau collisionality regime

    SciTech Connect

    Qu, W.X.; Callen, J.D.

    1985-04-01

    Starting from a resistive MHD set of equations and adding neoclassical currents (bootstrap, enhanced polarization and pinch type), we derive the eigenmode equation and relevant dispersion relation for ''neoclassical MHD'' tearing modes in the banana-plateau collisionality regime. The ballooning mode representation and a multiple length scale approximation are utilized. Analysis of the dispersion relation shows that the neoclassical effects on tearing modes are quite strong for ..sqrt..epsilon ..beta../sub p/(1 + nu/sub *//sub e/)/sup -1/ > S/sup -2/5/ (epsilon is the inverse aspect ratio, ..beta../sub p/ is the poloidal beta value, nu/sub *//sub e/ is the electron collisionality factor and S is the neoclassical MHD Reynolds number). The growth rate ..gamma.. and singular layer width deltax are increased typically by more than one order of magnitude from the usual values for epsilon ..beta../sub p/ approx. = 1. For our model, the changes in the tearing modes from the banana-plateau collisionality regime to the usual Pfirsch-Schlueter regime are very clear and natural.

  3. Entry of Four Tetracyclines into Saliva and Tears

    PubMed Central

    Hoeprich, Paul D.; Warshauer, David M.

    1974-01-01

    Although meningococci are susceptible to the tetracyclines by testing in vitro, oxytetracycline (OC) and doxycycline (DC) have failed to eliminate carriage, whereas minocycline (MC) has been effective. Because these congeners differ in lipophilicity, they and tetracycline (TC) were studied in volunteers by assay of serum, saliva, and tears obtained after 5 days of treatment. OC and TC were undetectable or attained concentrations subinhibitory for meningococci in saliva and tears. The concentrations of MC in saliva and tears were equal to or greater than the average minimal inhibitory concentration as long as 12 h post-dose. Near inhibitory concentrations resulted with DC at 100 mg/day; yet, doubling the dose to 100 mg/12 h did not yield concentrations that exceeded the average minimal inhibitory concentration for meningococci. The previous reports of failure or meager entry of DC and MC into saliva probably reflected extraction of these drugs in the paraffin chewed by subjects to stimulate salivary flow. The efficiency of entry of the tetracyclines into the secretions of the noninflamed upper respiratory tract correlates with lipophilicity at physiological pH, enabling prediction of meningococcal chemoprophylactic efficacy. PMID:4840441

  4. Resistive Magnetohydrodynamics Simulations of the Ideal Tearing Mode

    NASA Astrophysics Data System (ADS)

    Landi, S.; Del Zanna, L.; Papini, E.; Pucci, F.; Velli, M.

    2015-06-01

    We study the linear and nonlinear evolution of the tearing instability on thin current sheets by means of two-dimensional numerical simulations, within the framework of compressible, resistive MHD. In particular we analyze the behavior of current sheets whose inverse aspect ratio scales with the Lundquist number S as {{S}-1/3}. This scaling has been recently recognized to yield the threshold separating fast, ideal reconnection, with an evolution and growth that are independent of S provided this is high enough, as it should be natural having the ideal case as a limit for S\\to ? . Our simulations confirm that the tearing instability growth rate can be as fast as ? ? 0.6 {{? }A}-1, where {{? }A} is the ideal Alfvénic time set by the macroscopic scales, for our least diffusive case with S={{10}7}. The expected instability dispersion relation and eigenmodes are also retrieved in the linear regime, for the values of S explored here. Moreover, in the nonlinear stage of the simulations we observe secondary events obeying the same critical scaling with S, here calculated on the local, much smaller lengths, leading to increasingly faster reconnection. These findings strongly support the idea that in a fully dynamic regime, as soon as current sheets develop, thin, and reach this critical threshold in their aspect ratio, the tearing mode is able to trigger plasmoid formation and reconnection on the local (ideal) Alfvénic timescales, as required to explain the explosive flaring activity often observed in solar and astrophysical plasmas.

  5. A Fibre-Reinforced Poroviscoelastic Model Accurately Describes the Biomechanical Behaviour of the Rat Achilles Tendon

    PubMed Central

    Heuijerjans, Ashley; Matikainen, Marko K.; Julkunen, Petro; Eliasson, Pernilla; Aspenberg, Per; Isaksson, Hanna

    2015-01-01

    Background Computational models of Achilles tendons can help understanding how healthy tendons are affected by repetitive loading and how the different tissue constituents contribute to the tendon’s biomechanical response. However, available models of Achilles tendon are limited in their description of the hierarchical multi-structural composition of the tissue. This study hypothesised that a poroviscoelastic fibre-reinforced model, previously successful in capturing cartilage biomechanical behaviour, can depict the biomechanical behaviour of the rat Achilles tendon found experimentally. Materials and Methods We developed a new material model of the Achilles tendon, which considers the tendon’s main constituents namely: water, proteoglycan matrix and collagen fibres. A hyperelastic formulation of the proteoglycan matrix enabled computations of large deformations of the tendon, and collagen fibres were modelled as viscoelastic. Specimen-specific finite element models were created of 9 rat Achilles tendons from an animal experiment and simulations were carried out following a repetitive tensile loading protocol. The material model parameters were calibrated against data from the rats by minimising the root mean squared error (RMS) between experimental force data and model output. Results and Conclusions All specimen models were successfully fitted to experimental data with high accuracy (RMS 0.42-1.02). Additional simulations predicted more compliant and soft tendon behaviour at reduced strain-rates compared to higher strain-rates that produce a stiff and brittle tendon response. Stress-relaxation simulations exhibited strain-dependent stress-relaxation behaviour where larger strains produced slower relaxation rates compared to smaller strain levels. Our simulations showed that the collagen fibres in the Achilles tendon are the main load-bearing component during tensile loading, where the orientation of the collagen fibres plays an important role for the tendon’s viscoelastic response. In conclusion, this model can capture the repetitive loading and unloading behaviour of intact and healthy Achilles tendons, which is a critical first step towards understanding tendon homeostasis and function as this biomechanical response changes in diseased tendons. PMID:26030436

  6. Effect of cyclic tension on lacerated flexor tendons in vitro.

    PubMed

    Tanaka, H; Manske, P R; Pruitt, D L; Larson, B J

    1995-05-01

    The effect of tension on tendon healing was evaluated in vitro using cyclic tension and no tension groups of chicken flexor digitorum profundus tendons and histologic and immunohistologic techniques. A Vitrodyne force-loading machine was used for application of cyclic tension on partially lacerated chicken flexor tendons in culture media. Laceration sites under cyclic tension after 14 days were covered by newly proliferated fibroblasts, aligned in the direction of tension. This new growth was much thicker than that seen in the no tension group at the same time interval. Procollagen synthetic activity began at 3 days of culture in both groups. At 21 days, newly formed fibroblasts in the cyclic tension group were stained positive more strongly at the surface layer than in the deeper layers. In the no tension group, the staining was primarily in the surface layer. Cyclic tension stimulated the intrinsic response of lacerated flexor tendons significantly more than no tension did by enhancing proliferation and migration of fibroblasts, as well as stimulating collagen synthesis. PMID:7642929

  7. FUNCTIONAL RESULTS AFTER SURGICAL REPAIR OF QUADRICEPS TENDON RUPTURE

    Microsoft Academic Search

    T. DE BAERE; B. GEULETTE; L. BARRAS

    2002-01-01

    We present the long-term results of surgical repair of a traumatic rupture of the quadriceps tendon in a group of 24 patients with a mean age of 58 years. There were 21 male and 3 female patients. Fifteen patients were seen for clinical control after a mean follow-up of 75 months and they all presented with some quadriceps muscle atrophy.

  8. Simultaneous bilateral quadriceps tendon rupture in a uremic patient

    Microsoft Academic Search

    Yu-Cheng Pei; Po-Ching Hsieh; Li-Zen Huang; Cheng-Kuen Chiang

    2011-01-01

    Quadriceps is a part of extensor mechanism, and it is a strong muscle bundle for knee joint movement. It rarely ruptures in the general population. We present a case with simultaneous bilateral quadriceps tendon rupture and discuss the causes. A 45-year-old man had a history of end stage renal disease and received regular hemodialysis treatment for more than 12 years.

  9. Laser tissue welding and repair of digital flexor tendons

    NASA Astrophysics Data System (ADS)

    Drew, P. J.; Kiernan, Michael N.; MacGregor, A. D.; Clement, Marc

    1996-01-01

    Injuries involving division of the flexor tendons of the hand are a common surgical problem. Sutured repairs must be strong enough to withstand early active movement. Experiments were designed to assess the strength of bonds formed between tendon sections as a result of heating (1) under controlled conditions in a water bath and (2) using a carbon dioxide laser (laser tissue welding). The load (N) and stress (N/cm2) required to disrupt thermal bonds between bovine tendon sections heated for 4 minutes in water peaked at 62 degrees Celsius (13N, 11.3N/cm2). Further experiments revealed the optimal time period for heating to be 9 minutes (21.5N, 20.6N/cm2). A threshold effect was apparent at these parameters. The in vitro strength of sutured, laser welded and sutured and laser welded tendon repairs was compared in a rabbit model. Laser welding alone did not produce repairs as strong as sutured repairs. It did, however, augment the strength of sutured repair. This effect was maximal at a power of 0.1 W.

  10. Computer modeling of cathodic protection on risers\\/tendons

    Microsoft Academic Search

    H. Osvoll; P. O. Gartland; W. H. Thomason

    1995-01-01

    Computer modeling is gaining popularity in the design and verification of cathodic protection (CP) systems for offshore structures. The work presented in this article expands the use of CP simulation to consider the metallic electrical resistance of risers\\/tendons used with tension leg platforms where anodes are mounted on the hull or subsea structure. The SEACORR\\/CP computer system was used to

  11. Enhancement of acute tendon repair using chitosan matrix.

    PubMed

    Melamed, Eitan; Beutel, Bryan G; Robinson, Dror

    2015-05-01

    Structural failure of rotator cuff repairs has been attributed to multiple factors, including poor repair tissue quality and poor tendon-bone integration. Chitosan gel has been shown to facilitate scarless healing of soft tissues. In the study reported here, we hypothesized that use of a chitosan gel would improve the morphologic appearance of acute rotator cuff repair in a rat model after 12 weeks. Forty Wistar rats were used. In each case, bilateral tenotomy of the supraspinatus tendon was performed, followed by acute repair with sutures. The left shoulder served as a suture-only control, and the right shoulder was augmented with a chitosan gel applied between the ends of the tendon. Histologic analyses were performed to determine the functional and anatomical characteristics of the repair immediately after the operation and 3 days and 1, 2, 4, 6, 8, and 12 weeks after surgery. In the gel-augmented specimens, number of fibroblasts and amount of repair tissue were increased. Compared with the controls, these specimens showed minimal evidence of monocytic infiltration or inflammatory response around the matrix. Structural properties of the augmented shoulder, including pennation angles and fatty atrophy, were significantly improved. These study results showed that use of a chitosan matrix can enhance biological repair of rotator cuff tendons in a rat model. PMID:25950535

  12. BME 315 Biomechanics Experiment 4. Fall 2006. Deformation of tendon

    E-print Network

    Lakes, Roderic

    be easily damaged by even the most superficial cuts. To remove the skin, make an incision longitudinally will have the skin attached; skin must be removed before the tendons can be dissected out. Measure the tail are just below the skin but spaced evenly around the outer circumference of the tail. Therefore they can

  13. Repair of distal biceps tendon ruptures in athletes

    Microsoft Academic Search

    Donald F. DAlessandro; Clarence L. Shields; James E. Tibone; Robert W. Chandler

    1993-01-01

    Ten athletes with distal biceps tendon ruptures that had been anatomically repaired with a double-incision technique were reviewed to determine their functional recovery. All of the patients were men, with an average age of 40 years (range, 25 to 49). Eight of the 10 patients were weight lifters or body builders, and 7 had participated on a competitive level at

  14. An Investigation of Tendon Corrosion-Inhibitor Leakage into Concrete

    Microsoft Academic Search

    J. F. Costello; D. J. Naus; C. B. Oland

    1999-01-01

    During inspections performed at US nuclear power plants several years ago, some of the prestressed concrete containment had experienced leakage of the tendon sheathing filler. A study was conducted to indicate the extent of the leakage into the concrete and its potential effects on concrete properties. Concrete core samples were obtained from the Trojan Nuclear Plant. Examination and testing of

  15. Delayed repair in Achilles tendon rupture. A case report.

    PubMed

    Beckett, D E

    1990-05-01

    Rupture of the Achilles tendon is a significant injury. The management of this problem can be greatly complicated if there is a time delay between the injury and the patient seeking professional care. The author presents such a case and looks at the various philosophies relative to therapy. PMID:2366171

  16. Biaxial tensile testing and constitutive modeling of human supraspinatus tendon.

    PubMed

    Szczesny, Spencer E; Peloquin, John M; Cortes, Daniel H; Kadlowec, Jennifer A; Soslowsky, Louis J; Elliott, Dawn M

    2012-02-01

    The heterogeneous composition and mechanical properties of the supraspinatus tendon offer an opportunity for studying the structure-function relationships of fibrous musculoskeletal connective tissues. Previous uniaxial testing has demonstrated a correlation between the collagen fiber angle distribution and tendon mechanics in response to tensile loading both parallel and transverse to the tendon longitudinal axis. However, the planar mechanics of the supraspinatus tendon may be more appropriately characterized through biaxial tensile testing, which avoids the limitation of nonphysiologic traction-free boundary conditions present during uniaxial testing. Combined with a structural constitutive model, biaxial testing can help identify the specific structural mechanisms underlying the tendon's two-dimensional mechanical behavior. Therefore, the objective of this study was to evaluate the contribution of collagen fiber organization to the planar tensile mechanics of the human supraspinatus tendon by fitting biaxial tensile data with a structural constitutive model that incorporates a sample-specific angular distribution of nonlinear fibers. Regional samples were tested under several biaxial boundary conditions while simultaneously measuring the collagen fiber orientations via polarized light imaging. The histograms of fiber angles were fit with a von Mises probability distribution and input into a hyperelastic constitutive model incorporating the contributions of the uncrimped fibers. Samples with a wide fiber angle distribution produced greater transverse stresses than more highly aligned samples. The structural model fit the longitudinal stresses well (median R(2) ? 0.96) and was validated by successfully predicting the stress response to a mechanical protocol not used for parameter estimation. The transverse stresses were fit less well with greater errors observed for less aligned samples. Sensitivity analyses and relatively affine fiber kinematics suggest that these errors are not due to inaccuracies in measuring the collagen fiber organization. More likely, additional strain energy terms representing fiber-fiber interactions are necessary to provide a closer approximation of the transverse stresses. Nevertheless, this approach demonstrated that the longitudinal tensile mechanics of the supraspinatus tendon are primarily dependent on the moduli, crimp, and angular distribution of its collagen fibers. These results add to the existing knowledge of structure-function relationships in fibrous musculoskeletal tissue, which is valuable for understanding the etiology of degenerative disease, developing effective tissue engineering design strategies, and predicting outcomes of tissue repair. PMID:22482671

  17. A prospective multi-site registry study of a specific protocol of autologous bone marrow concentrate for the treatment of shoulder rotator cuff tears and osteoarthritis

    PubMed Central

    Centeno, Christopher J; Al-Sayegh, Hasan; Bashir, Jamil; Goodyear, Shaun; Freeman, Michael D

    2015-01-01

    Introduction Shoulder pain is a common musculoskeletal complaint in the general population. Bone marrow concentrate (BMC) injections offer promising potential as a minimally invasive approach for treatment of shoulder pain in degenerative disease. In this study, we investigated the clinical outcomes of the BMC injections for treatment of shoulder pain and disability due to osteoarthritis (OA) and rotator cuff tears in a treatment registry population. Methods A total of 115 shoulders in 102 patients were treated with autologous BMC injections for symptomatic OA at the glenohumeral joint and/or rotator cuff tears. Data were collected for factors potentially influencing outcome, including age, sex, body mass index, and the type of condition treated (ie, OA or rotator cuff tear). Clinical outcomes were assessed serially over time using the disabilities of the arm, shoulder and hand score (DASH), the numeric pain scale (NPS), and a subjective improvement rating scale. Baseline scores were compared to the most recent outcome scores at the time of the analysis and adjusted for demographic differences. We reported comparisons of pre- and post-treatment scores, the differences between osteoarthritis and rotator cuff groups, and the predictive effects on the clinical outcomes. Results At the most current follow-up assessment after treatment, the average DASH score decreased (improved) from 36.1 to 17.1 (P<0.001) and the average numeric pain scale value decreased (improved) from 4.3 to 2.4 (P<0.001). These changes were associated with an average subjective improvement of 48.8%. No differences were observed between outcomes among the shoulders treated for OA versus rotator cuff tears, nor did age, sex, or body mass index influence pain or functional outcomes. There were no significant treatment-related adverse events reported. Discussion We observed preliminarily encouraging results following BMC injections for shoulder OA and rotator cuff tears. These results serve as basis for the design of an adequately powered randomized controlled trial.

  18. Tear cytokine response to multipurpose solutions for contact lenses

    PubMed Central

    Kalsow, Carolyn M; Reindel, William T; Merchea, Mohinder M; Bateman, Kirk M; Barr, Joseph T

    2013-01-01

    Purpose An increased risk of corneal infiltrative events has been noted with the use of certain contact lenses and multipurpose solutions (MPS). This study was designed to evaluate tear cytokine assay as a sensitive, objective, and quantitative measure of the ocular surface response to contact lens/MPS and to consider the assay’s clinical relevance in the context of other measures of ocular surface response. Methods Two MPS, ReNu® Fresh™ (RNF) and Opti-Free® RepleniSH (OFR), were used with daily wear silicone hydrogel contact lenses in a randomized, prospective crossover study involving 26 subjects. Clinical data collection (conjunctival hyperemia, ocular surface sensitivity, solution induced corneal staining (SICS) test score, and subjective responses) and tear cytokine assays were conducted masked. Responses were tracked as change from baseline throughout the experimental schedule. Results Similar response patterns for several inflammatory cytokines were seen throughout both phases: subjects who received OFR in Phase I had mean tear concentrations that were generally higher than those of the RNF Phase I group. OFR Phase I subjects had significant (P < 0.01) increases over baseline at day 1 and/or following washout for 13 cytokines (cc chemokine ligands [CCL] 3, CCL5, CCL11, granulocyte-macrophage colony-stimulating factor [GM-CSF], interferon [INF]-?, interleukin [IL]-2, IL-4, IL-5, IL-6, IL-13, IL-15, IL-17, tumor necrosis factor [TNF]-?). These changes were not observed in RNF Phase I subjects, even though SICS test scores increased. Phase I OFR subjects also had increased dryness, while RNF Phase I subjects had decreased bulbar hyperemia. No changes were detected with respect to limbal hyperemia or surface sensitivity thresholds. Conclusion The tear cytokine assay can detect and differentiate contact lens/MPS induced increases in inflammatory cytokines. Changes in cytokine levels were consistent with measurement of hyperemia and dryness but not with SICS scores, thereby suggesting a proinflammatory response to OFR compared to RNF that is not related to SICS test score. Tear cytokine profiles may be useful for reconciling clinical relevance of test results and in revealing signaling involved in the development of corneal infiltrative events. PMID:23847409

  19. Effect of solidified structure on hot tear in Al-Cu alloy

    NASA Astrophysics Data System (ADS)

    Yoshida, Y.; Esaka, H.; Shinozuka, K.

    2015-06-01

    Hot tear is the one of the biggest problems of cast products of aluminum alloy. The effect of solidified structure on the hot tear has not been clear. Therefore, this study has been carried out to correlate solidified structure and hot tear. Al-2.0 wt% Cu alloy was cast at 750 °C in a moldcavity, which could intentionally form hot tear. To change solidified structure, some amount of refiner was added to the molten alloy. Length of hot tear decreased with increasing the amount of refiner. Further, the area of fine eutectic Al2Cu increased as amount of refiner increased. These may indicate that probability of healing increased in case of equiaxed structure. Therefore, the length of hot tear decreased with increasing the amount of refiner. great care should be taken in constructing both.

  20. Study of the tear topography dynamics using a lateral shearing interferometer

    NASA Astrophysics Data System (ADS)

    Dubra, Alfredo; Paterson, Carl; Dainty, Christopher

    2004-12-01

    The dynamics of the pre-corneal tear film topography are studied on 21 subjects with a purpose-built lateral shearing interferometer. Interesting tear topography features such as post-blink undulation, break-up, eyelid-produced bumps/ridges, bubbles and rough pre-contact lens tear surfaces were recorded. Using the calculated tear topography maps, the effects of the tear dynamics in visual performance, refractive surgery and ophthalmic adaptive optics are discussed in terms of wavefront RMS. The potential of lateral shearing interferometry for clinical applications such as dry eye diagnosis and contact lens performance studies is illustrated by the recorded topography features such as post-blink undulation, break-up, eyelid-produced bumps/ridges, bubbles and rough tear surfaces in front of contact lenses.