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1

Intramuscular Rotator Cuff Cysts: Association with Tendon Tears on MRI and Arthroscopy  

Microsoft Academic Search

OBJECTIVE. This study was designed to explore the relationship between intramuscular cysts and rotator cuff tendon tears. CONCLUSION. Intramuscular cysts are strongly associated with rotator cuff tendon tears. Identification of such a cyst should prompt a search for a rotator cuff tear. Findings on MR arthrography and surgery suggest that a delaminating component of the rotator cuff tear may lead

Ara Kassarjian; Martin Torriani; Hugue Ouellette; William E. Palmer

2

MR imaging of delamination tears of the rotator cuff tendons  

Microsoft Academic Search

Objective  The objective was to describe the imaging appearances and location of delamination tears of the rotator cuff tendons on non-contrast\\u000a conventional MR imaging.\\u000a \\u000a \\u000a \\u000a Subjects and methods  This study was reviewed and approved by our Institutional Review Board. The reports of 548 consecutive MR examinations of\\u000a the shoulder were reviewed, looking for mention or description of delamination tears of the rotator cuff.

Daniel M. Walz; Theodore T. Miller; Steven Chen; Josh Hofman

2007-01-01

3

Peroneal tendon tears, surgical management and its complications.  

PubMed

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

Cerrato, Rebecca A; Myerson, Mark S

2009-06-01

4

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

PubMed Central

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

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

2012-01-01

5

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

PubMed

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

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

2012-02-01

6

Expression of Atrophy mRNA Relates to Tendon Tear Size in Supraspinatus Muscle  

PubMed Central

Skeletal muscle atrophy and fatty infiltration develop after tendon tearing. The extent of atrophy serves as one prognostic factor for the outcome of surgical repair of rotator cuff tendon tears. We asked whether mRNA of genes involved in regulation of degradative processes leading to muscle atrophy, ie, FOXOs, MSTN, calpains, cathepsins, and transcripts of the ubiquitin-proteasome pathway, are overexpressed in the supraspinatus muscle in patients with and without rotator cuff tears. We evaluated biopsy specimens collected during surgery of 53 consecutive patients with different sizes of rotator cuff tendon tears and six without tears. The levels of corresponding gene transcripts in total RNA extracts were assessed by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Supraspinatus muscle atrophy was assessed by MRI. The area of muscle tissue (or atrophy), decreased (increased) with increasing tendon tear size. The transcripts of CAPN1, UBE2B, and UBE3A were upregulated more than twofold in massive rotator cuff tears as opposed to smaller tears or patients without tears. These atrophy gene products may be involved in cellular processes that impair functional recovery of affected muscles after surgical rotator cuff repair. However, the damaging effects of gene products in their respective proteolytic processes on muscle structures and proteins remains to be investigated. PMID:18941855

Schmutz, Silvia; Fuchs, Thomas; Regenfelder, Felix; Steinmann, Patrick; Zumstein, M.

2008-01-01

7

Arthroscopic Repair of Full-Thickness Tears of the Supraspinatus: Does the Tendon Really Heal?  

Microsoft Academic Search

Background: Good functional results have been reported for arthroscopic repair of rotator cuff tears, but the rate of tendon-to-bone healing is still unknown. Our hypothesis was that arthroscopic repair of full-thickness supraspinatus tears achieves a rate of complete tendon healing equivalent to those reported in the literature with open or mini-open techniques. Methods: Sixty-five consecutive shoulders with a chronic full-thickness

PASCAL BOILEAU; NICOLAS BRASSART; DUNCAN J. WATKINSON; MICHEL CARLES; ARMODIOS M. HATZIDAKIS; SUMANT G. KRISHNAN

8

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

NASA Astrophysics Data System (ADS)

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.

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

2008-02-01

9

Ultrasound of tendon tears. Part 1: general considerations and upper extremity  

Microsoft Academic Search

The role of ultrasound (US) in assessing musculoskeletal disorders is persistently increasing because of its low cost, readiness, noninvasiveness, and possibility of allowing a dynamic examination. Secondary to increased sport practice, tendon tears are more frequently observed in daily medical practice. They deserve early diagnosis to allow proper treatment that can limit functional impairment. The aim of this review article

Stefano Bianchi; Carlo Martinoli; Ibrahim Fikry Abdelwahab

2005-01-01

10

Abnormal proximal musculotendinous junction of the peroneus brevis muscle as a cause of peroneus brevis tendon tears: a cadaveric study.  

PubMed

Abnormal musculotendinous distal extension of the peroneus brevis has been implicated as a possible cause of peroneus brevis tendon tears. We investigated this relationship in 58 (46 male) fresh human cadavers. Torn lesions were classified according to Sobel et al. Musculotendinous distal extension of the peroneus brevis was measured in each ankle as the vertical distance from the musculotendinous junction of the peroneus brevis to the tip of the fibula. Tendons with and without tears were compared by sex, age at death, height, musculotendinous distal extension of the peroneus brevis, the common sheath bifurcation-fibular tip distance, the peroneus brevis and longus width at the musculotendinous junction, fibular groove depth, peroneal tubercle height, superior-inferior peroneal retinaculum wideness, and the presence of the peroneus quartus or an accessory peroneal muscle. Of 115 evaluable tendons, 15 (13%) had tears. All came from men. The average distance from the musculotendinous junction to the tip of the fibula was 27.0 mm in tendons with tears and 16.4 mm in tendons without (P = .04) Male sex (P = .03), age at death (P = .03), height (P = .04), and fibular groove depth (P = .003) were also related to the presence of tears. Our results do not support a relationship between abnormal musculotendinous distal extension of the peroneus brevis and peroneus brevis tendon tears; rather, proximal extension of the peroneus brevis musculotendinous junction may be related to peroneus brevis tendon tears. PMID:21035039

Unlu, Mehmet Can; Bilgili, Mustafa; Akgun, Isik; Kaynak, Gokhan; Ogut, Tahir; Uzun, Ibrahim

2010-01-01

11

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

PubMed Central

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

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

2014-01-01

12

Semimembranosus tendon avulsion fracture of the posteromedial tibial plateau associated with posterior cruciate ligament tear and capsular rupture.  

PubMed

Semimembranosus tendon avulsion fractures are an uncommon occurrence and are often associated with anterior cruciate ligament (ACL) and medial meniscus tears. We present the imaging features of an unusual case of semimembranosus avulsion fracture of the posteromedial tibial plateau associated with posterior cruciate ligament (PCL) tear, medial meniscus tear, and capsular rupture in a 26-year-old man with a football injury. PMID:24026070

Khoshnoodi, Pooria; Tehranzadeh, Arash D; Dunn, James M; Tehranzadeh, Jamshid

2014-02-01

13

Methicillin-resistant Staphylococcus aureus as a cause of a quadriceps tendon tear.  

PubMed

Methicillin-resistant Staphylococcus aureus (MRSA) is an important causative agent in myositis and pyomyositis, but its involvement in quadriceps tendon tears has not been reported until now. In the case reported here, accurate diagnosis was delayed because of the unique presentation, and the infection was mismanaged with corticosteroids because of the presumptive diagnosis of an inflammatory pathology. Subsequently, aggressive surgical and antibiotic management produced a satisfactory outcome. Early detection and appropriate management of these infections are extremely important in preventing limb- and life-threatening consequences. PMID:23710480

Parikh, Shital N; Bansal, Danesh

2013-05-01

14

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

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

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

15

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 ...

16

Incomplete joint side tear of the subscapularis tendon with a small fragment in an adolescent tennis player: a case report  

PubMed Central

Case In this case report, we presented the case of an adolescent tennis player with avulsion injury of the subscapularis tendon of the right shoulder. Patients A 17-year-old right-hand-dominant male tennis player visited our hospital complaining of pain in the anterior aspect of the right shoulder. We performed X-ray and three-dimensional computed tomography (3D-CT) and magnetic resonance imaging (MRI) scans for the diagnosis. Results Plain radiographs did not reveal the presence of lesion; however, 3D-CT and MRI scans showed a small bony fragment located between the humeral head and the glenoid of the scapula and a high-intensity area of the subscapularis tendon. He was subsequently diagnosed with incomplete joint side tear of the subscapularis tendon with a small bony fragment. Subsequently, we performed arthroscopic excision of the bony fragment and repair of the subscapularis tendon. Conclusions This case highlighted the presence of an injury with minor trauma associated with repeated tennis strokes in a skeletally immature patient. PMID:22812396

2012-01-01

17

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

Microsoft Academic Search

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,

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

2007-01-01

18

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

Microsoft Academic Search

The aim of this study was to investigate the correlation of tendon integrity following open cuff repairs with functional and\\u000a isokinetic strength measurements. Twenty-six shoulders of 25 patients were included in this study. At the final follow-up,\\u000a 14 repairs (53.8%) were intact and 12 repairs (46.2%) had failed on magnetic resonance imaging (MRI). Mean UCLA score at latest\\u000a follow-up was

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

2010-01-01

19

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

PubMed

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

Mabe, Isaac; Hunter, Shawn

2014-12-01

20

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

PubMed Central

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

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

2009-01-01

21

The efficacy of ultrasound in the diagnosis of long head of the biceps tendon pathology.  

PubMed

The use of shoulder ultrasound as an imaging modality has recently gained widespread attention; however, the ability of ultrasound to diagnose long head of the biceps tendon pathology accurately still remains unclear. The biceps tendons in 71 patients were prospectively evaluated by comparison of standard ultrasonographic and arthroscopic examinations. Arthroscopic examination was used as the gold standard comparison. Ultrasound showed a 100% specificity and 96% sensitivity for subluxation or dislocation. Ultrasound detected all complete ruptures of the biceps tendon but detected none of the 23 partial-thickness tears. Overall, ultrasound diagnosed 35 of 36 normal biceps tendons (specificity, 97%) and 17 of 35 abnormal biceps tendons (sensitivity, 49%). Ultrasound can reliably diagnose complete rupture, subluxation, or dislocation of the biceps tendon. It is not reliable for detecting intraarticular partial-thickness tears. PMID:16414462

Armstrong, April; Teefey, Sharlene A; Wu, Thomas; Clark, Aileen M; Middleton, William D; Yamaguchi, Ken; Galatz, Leesa M

2006-01-01

22

Flexor digitorum longus tendon exposure for flatfoot reconstruction: A comparison of two methods in a cadaveric model  

Microsoft Academic Search

BackgroundA novel method for harvesting the flexor digitorum longus (FDL) tendon has been described via a plantar approach based on a surface coordinate. The aim of this investigation is to provide a comparison with the traditional medial midfoot dissection for tendon harvest.

Michael J. Oddy; Mark J. Flowers; Mark B. Davies

2010-01-01

23

Comparison of the Tendon Damage Caused by Four Different Anchor Systems Used in Transtendon Rotator Cuff Repair  

PubMed Central

Objectives. The objective of this study was to compare the damage to the rotator cuff tendons caused by four different anchor systems. Methods. 20 cadaveric human shoulder joints were used for transtendon insertion of four anchor systems. The Healix Peek, Fastin RC, Bio-Corkscrew Suture, and Healix Transtend anchors were inserted through the tendons using standard transtendon procedures. The areas of tendon damage were measured. Results. The areas of tendon damage (mean?±?standard deviation, n = 7) were 29.1?±?4.3?mm2 for the Healix Peek anchor, 20.4?±?2.3?mm2 for the Fastin RC anchor, 23.4?±?1.2?mm2 for the Bio-Corkscrew Suture anchor, 13.7?±?3.2?mm2 for the Healix Transtend anchor inserted directly, and 9.1 ± 2.1?mm2 for the Healix Transtend anchor inserted through the Percannula system (P < 0.001 or P < 0.001, compared to other anchors). Conclusions. In a cadaver transtendon rotator cuff repair model, smaller anchors caused less damage to the tendon tissues. The Healix Transtend implant system caused the least damage to the tendon tissues. Our findings suggest that smaller anchors should be considered when performing transtendon procedures to repair partial rotator cuff tears. PMID:22811923

Zhang, Qing-Song; Liu, Sen; Zhang, Qiuyang; Xue, Yun; Ge, Dongxia; O'Brien, Michael J.; Savoie, Felix H.; You, Zongbing

2012-01-01

24

Arthroscopic treatment of calcific tendonitis.  

PubMed

Calcific tendonitis, or calcifying tendonitis, is a common disorder characterized by the multifocal accumulation of basic calcium phosphate crystals within the rotator cuff tendons. In most cases, the multifocal calcifications are located 1 to 2 cm from the insertion of the supraspinatus tendon on the greater tuberosity. The initial treatment should be nonoperative including oral anti-inflammatory medication and physical therapy. If this is unsuccessful, arthroscopic debridement of the deposit is effective. The technique used is an arthroscopic localization and debridement without associated subacromial decompression. The rotator cuff should be evaluated for partial- and full-thickness tears before and after the debridement of calcifications. If a partial- or full-thickness rotator cuff tendon tear is identified, it should be treated in a fashion consistent with those without associated calcium deposits. In our hands, tears 5 mm or greater in depth are repaired using a tendon-to-tendon or tendon-to-bone technique. Tears with less depth are debrided and then left alone. Arthroscopic debridement of calcific tendonitis can yield excellent functional results and high patient satisfaction. PMID:24904767

Barber, F Alan; Cowden, Courtney H

2014-04-01

25

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

PubMed Central

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

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

2014-01-01

26

Comparison of Medpor Coated Tear Drainage Tube versus Silicon Tear Drainage Tube in Conjunctivodacryocystorhinostomy: Problems and Solutions  

PubMed Central

Purpose. This study aims at comparing two different types of drainage tubes in conjunctivodacryocystorhinostomy, which are used for upper lacrimal system obstruction or damage, with respect to their respective postoperative problems and solutions. Methods. Nineteen eyes of 17 patients who underwent conjunctivodacryocystorhinostomy (CDCR) or conjunctivorhinostomy (CR) surgery with a Medpor coated tear drainage tube or silicon tube placement between October, 2010, and February, 2014, were included in this retrospective comparative study. Results. In the initial surgery, Medpor coated tear drainage tubes were used in 11 eyes by CDCR, whereas silicon tear drainage tubes were implanted into 2 eyes by CR and 6 eyes by CDCR. In group 1, proximal and distal obstructions developed postoperatively in 4 eyes, while 1 eye showed tube malposition and 3 eyes developed luminal obstruction by debris 3 times. In group 2, tube extrusion developed in 4 eyes, whereas tube malposition developed in 6 eyes and luminal obstruction by debris developed in 6 eyes at different times, for a total of 20 times. Conclusions. In our study, the most significant complication we observed in the use of silicon tear drainage tubes was tube extrusion,whereas the leading complication related to the use of Medpor coated tear drainage tubes was tube obstruction. PMID:25379518

Sendul, Selam Yekta; Cagatay, Halil Huseyin; Dirim, Burcu; Demir, Mehmet; Y?ld?z, Ali Atakhan; Acar, Zeynep; Cinar, Sonmez; Guven, Dilek

2014-01-01

27

Imaging of Tendons  

PubMed Central

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

Chang, Anthony; Miller, Theodore T.

2009-01-01

28

Comparison of tenocytes and mesenchymal stem cells seeded on biodegradable scaffolds in a full-size tendon defect model.  

PubMed

In order to investigate cell-based tendon regeneration, a tendon rupture was simulated by utilizing a critical full-size model in female rat achilles tendons. For bridging the defect, polyglycol acid (PGA) and collagen type I scaffolds were used and fixed with a frame suture to ensure postoperatively a functional continuity. Scaffolds were seeded with mesenchymal stem cells (MSC) or tenocytes derived from male animals, while control groups were left without cells. After a healing period of 16 weeks, biomechanical, PCR, histologic, and electron microscopic analyses of the regenerates were performed. Genomic PCR for male-specific gene was used to detect transplanted cells in the regenerates. After 16 weeks, central ossification and tendon-like tissue in the superficial tendon layers were observed in all study groups. Biomechanical test showed that samples loaded with tenocytes had significantly better failure strength/cross-section ratio (P < 0.01) compared to MSC and the control groups whereas maximum failure strength was similar in all groups. Thus, we concluded that the application of tenocytes improves the outcome in this model concerning the grade of ossification and the mechanical properties in comparison to the use of MSC or just scaffold materials. PMID:23090834

Pietschmann, M F; Frankewycz, B; Schmitz, P; Docheva, D; Sievers, B; Jansson, V; Schieker, M; Müller, P E

2013-01-01

29

Comparison of conventional MRI and MR arthrography in the evaluation wrist ligament tears: A preliminary experience  

PubMed Central

Aims: To compare conventional magnetic resonance imaging (MRI) and direct magnetic resonance (MR) arthrography in the evaluation of triangular fibrocartilage complex (TFCC) and intrinsic wrist ligament tears. Materials and Methods: T1-weighted, fat suppressed (FS) proton density plus T2-weighted (FS PD/T2), 3D multiple-echo data image combination (MEDIC) sequences and direct MR arthrography were performed in 53 patients with wrist pain. Images were evaluated for the presence and location of TFCC, scapholunate ligament (SLL) and lunatotriquetral ligament (LTL) tears, and imaging findings were compared with operative findings in 16 patients who underwent arthroscopy or open surgery (gold standard). Results: Sixteen patients underwent arthroscopy/open surgery: 12 TFCC tears were detected arthroscopically out of which 9 were detected on FS PD/T2 sequence, 10 on MEDIC sequence, and all 12 were detected on MR arthrography. The sensitivities of FS PD/T2, MEDIC sequences, and MR arthrography in the detection of TFCC tears were 75%, 83.3%, and 100%, respectively. Out of the eight arthroscopically confirmed SLL tears, three tears were detected on FS PD/T2 sequence, five on MEDIC sequence, and all eight were visualized on MR arthrography. The sensitivities of FS PD/T2, MEDIC sequences, and MR arthrography in detecting SLL tears were 37.5%, 62.5%, and 100%, respectively. One arthroscopically confirmed LTL tear was diagnosed on FS PD/T2 sequence, three on MEDIC sequence, and all five arthroscopically confirmed LTL tears were detected with MR arthrography. The sensitivities of PD, MEDIC sequences, and MR arthrography in detecting LTL tears were 20%, 40%, and 100%, respectively. Conclusions: MR arthrography is the most sensitive and specific imaging modality for the evaluation of wrist ligament tears. PMID:25114389

Pahwa, Shivani; Srivastava, Deep N; Sharma, Raju; Gamanagatti, Shivanand; Kotwal, Prakash P; Sharma, Vijay

2014-01-01

30

Diagnosis of Glenoid Labral TearsA Comparison Between Magnetic Resonance Imaging and Clinical Examinations  

Microsoft Academic Search

We studied 54 patients with shoulder pain secondary to anterior instability or glenoid labral tears refractory to 6 months of conservative management with no evi dence of rotator cuff lesions. All patients had sufficient preoperative clinical data, magnetic resonance imag ing, and shoulder arthroscopy results for analysis. The ability to predict the presence of a glenoid labral tear by physical

Stephen H. Liu; Mark H. Henry; Steven Nuccion; Matthew S. Shapiro; Fred Dorey

1996-01-01

31

Comparison of ophthalmic sponges and extraction buffers for quantifying cytokine profiles in tears using Luminex technology  

PubMed Central

Purpose Evaluating cytokine profiles in tears could shed light on the pathogenesis of various ocular surface diseases. When collecting tears with the methods currently available, it is often not possible to avoid the tear reflex, which may give a different cytokine profile compared to basal tears. More importantly, tear collection with glass capillaries, the most widely used method for taking samples and the best method for avoiding tear reflex, is impractical for remote area field studies because it is tedious and time-consuming for health workers, who cannot collect tears from a large number of patients with this method in one day. Furthermore, this method is uncomfortable for anxious patients and children. Thus, tears are frequently collected using ophthalmic sponges. These sponges have the advantage that they are well tolerated by the patient, especially children, and enable standardization of the tear collection volume. The aim of this study was to compare various ophthalmic sponges and extraction buffers to optimize the tear collection method for field studies for subsequent quantification of cytokines in tears using the Luminex technology. Methods Three ophthalmic sponges, Merocel, Pro-ophta, and Weck-Cel, were tested. Sponges were presoaked with 25 cytokines/chemokines of known concentrations and eluted with seven different extraction buffers (EX1–EX7). To assess possible interference in the assay from the sponges, two standard curves were prepared in parallel: 1) cytokines of known concentrations with the extraction buffers and 2) cytokines of known concentrations loaded onto the sponges with the extraction buffers. Subsequently, a clinical assessment of the chosen sponge-buffer combination was performed with tears collected from four healthy subjects using 1) aspiration and 2) sponges. To quantify cytokine/chemokine recovery and the concentration in the tears, a 25-plex Cytokine Panel and the Luminex xMap were used. This platform enables simultaneous measurement of proinflammatory cytokines, Th1/Th2 distinguishing cytokines, nonspecific acting cytokines, and chemokines. Results We demonstrated the following: (i) 25 cytokines/chemokines expressed highly variable interactions with buffers and matrices. Several buffers enabled recovery of similar cytokine values (regulated and normal T cell expressed and secreted [RANTES], interleukin [IL]-13, IL-6, IL-8, IL-2R, and granulocyte-macrophage colony-stimulating factor [GM-CSF]); others were highly variable (monocyte chemotactic protein-1 [MCP-1], monokine induced by interferon-gamma [MIG], IL-1?, IL-4, IL-7, and eotaxin). (ii) Various extraction buffers displayed significantly different recovery rates on the same sponge for the same cytokine/chemokine. (iii) The highest recovery rates were obtained with the Merocel ophthalmic sponge except for tumor necrosis factor-?: the Weck-Cel ophthalmic sponge showed the best results, either with cytokine standards loaded onto sponges or with tears collected from the inner canthus of the eye, using the sponge. (iv) IL-5, IL-10, and interferon-? were not detected in any tear sample from four normal human subjects. Twenty-two cytokines/chemokines that we detected were extracted from the Merocel sponge to a satisfactory recovery percentage. The recovery of IL-7 was significantly lower in the extracted Merocel sponge compared to the diluted tear samples. The cytokine/chemokine extraction from tears showed the same pattern of extraction that we observed for extracting the standards. Conclusions Simultaneous measurement of various cytokines using ophthalmic sponges yielded diverse results for various cytokines as the level of extraction differs noticeably for certain cytokines. A second set of controls (standard curves “with sponges”) should be used to delineate the extent of extraction for each cytokine to be analyzed. Many cytokines/chemokines were detected in tear samples collected with the Merocel sponge, including many that have been implicated in ocular surface disease. Luminex detection of

Inic-Kanada, Aleksandra; Nussbaumer, Andrea; Montanaro, Jacqueline; Belij, Sandra; Schlacher, Simone; Stein, Elisabeth; Bintner, Nora; Merio, Margarethe; Zlabinger, Gerhard J.

2012-01-01

32

Sodium hyaluronate and polyvinyl alcohol artificial tear preparations. A comparison in patients with keratoconjunctivitis sicca.  

PubMed

An unpreserved artificial tear substitute containing 0.1% sodium hyaluronate was compared with a preparation containing 1.4% polyvinyl alcohol and 0.5% chlorobutanol in a controlled, double-masked, randomized study in patients with moderately severe keratoconjunctivitis sicca. Patients were evaluated initially, at 1, 4, and 8 weeks. The dry-eye status was evaluated by means of tear-film osmolality, tear breakup time, rose bengal staining, Schirmer's test (without anesthesia), and ocular surface-impression cytology. In general, neither preparation was found to be superior to the other. In both study groups, the mean tear-film osmolality and rose bengal staining score improved over the eight-week study, but the degree of squamous metaplasia of the bulbar conjunctival surface, as shown by impression cytology, did not change significantly. PMID:2451494

Nelson, J D; Farris, R L

1988-04-01

33

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

PubMed

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

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

2001-07-01

34

Gap junction protein expression and cellularity: comparison of immature and adult equine digital tendons.  

PubMed

Injury to the energy-storing superficial digital flexor tendon is common in equine athletes and is age-related. Tenocytes in the superficial digital flexor tendon of adult horses appear to have limited ability to respond adaptively to exercise or prevent the accumulation of strain-induced microdamage. It has been suggested that conditioning exercise should be introduced during the growth period, when tenocytes may be more responsive to increased quantities or intensities of mechanical strain. Tenocytes are linked into networks by gap junctions that allow coordination of synthetic activity and facilitate strain-induced collagen synthesis. We hypothesised that there are reductions in cellular expression of the gap junction proteins connexin (Cx) 43 and 32 during maturation and ageing of the superficial digital flexor tendon that do not occur in the non-injury-prone common digital extensor tendon. Cryosections from the superficial digital flexor tendon and common digital extensor tendon of 5 fetuses, 5 foals (1-6 months), 5 young adults (2-7 years) and 5 old horses (18-33 years) were immunofluorescently labelled and quantitative confocal laser microscopy was performed. Expression of Cx43 and Cx32 protein per tenocyte was significantly higher in the fetal group compared with all other age groups in both tendons. The density of tenocytes was found to be highest in immature tissue. Higher levels of cellularity and connexin protein expression in immature tendons are likely to relate to requirements for tissue remodelling and growth. However, if further studies demonstrate that this correlates with greater gap junctional communication efficiency and synthetic responsiveness to mechanical strain in immature compared with adult tendons, it could support the concept of early introduction of controlled exercise as a means of increasing resistance to later injury. PMID:17848160

Stanley, Rachael L; Fleck, Roland A; Becker, David L; Goodship, Allen E; Ralphs, Jim R; Patterson-Kane, Janet C

2007-09-01

35

Peroneus longus tear and its relation to the peroneal tubercle: A review of the literature.  

PubMed

Tear of the peroneal tendon may occur in different anatomical sites. The most prevalent site is around the lateral malleolus. Tear of the peroneus longus at the level of the peroneal tubercle is unusual. Anatomically, the lateral surface of the calcaneous can be divided into thirds. The middle third includes the peroneal tubercle, which separates the peroneus longus tendon from the peroneus brevis. An anatomic variation of the peroneal tubercle may lead to chronic irritation of the peroneus longus tendon that could ultimately cause a longitudinal tear. We conducted this review aiming to clarify the anatomy, biomechanics of the tendon, and the clinical features of tear of the peroneus longus tendon on the lateral surface of the calcaneous due to an enlarged peroneal tubercle. In addition, we reviewed the diagnostic and treatment options of peroneal tendon tears at this site. PMID:23738264

Palmanovich, Ezequiel; Laver, Lior; Brin, Yaron S; Kotz, Evgeny; Hetsroni, Iftach; Mann, Gideon; Nyska, Meir

2011-10-01

36

Isokinetic quadriceps and hamstring muscle strength and knee function 5 years after anterior cruciate ligament reconstruction: comparison between bone-patellar tendon-bone and hamstring tendon autografts  

Microsoft Academic Search

Existing clinical studies have not proven which graft is to be preferred in anterior cruciate ligament (ACL) reconstruction.\\u000a In recent years, bone-patellar tendon-bone and hamstring tendons have been the most frequently used graft types. Muscle strength\\u000a deficit is one of the consequences after ACL reconstruction. The aim of this study was to evaluate possible differences in\\u000a hamstring and quadriceps muscle

Riitta Lautamies; Arsi Harilainen; Jyrki Kettunen; Jerker Sandelin; Urho M. Kujala

2008-01-01

37

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

E-print Network

Statics Method Catenary Cmdsnts: Ful Indude Ley Azimuth Pra-Tension Densgy Pressure Flaw Rats Stalhs Frlcdon (deg) (kN) (Ialm"3) (kNlm"2) (tale) Yea Yas 180. 00 set 0. 000 0. 000 0. 00 0. 00 40 Secgcns: 1 Une Lentgb ~ 600, M m No. Type 1 Tendon... Statics Method Catenary Cmdsnts: Ful Indude Ley Azimuth Pra-Tension Densgy Pressure Flaw Rats Stalhs Frlcdon (deg) (kN) (Ialm"3) (kNlm"2) (tale) Yea Yas 180. 00 set 0. 000 0. 000 0. 00 0. 00 40 Secgcns: 1 Une Lentgb ~ 600, M m No. Type 1 Tendon...

Mendon, Perdoor Mukthi

2012-06-07

38

Comparison of static and dynamic splinting regimens for extensor tendon repairs in zones V to VII.  

PubMed

The aim of this prospective, randomised, controlled trail was to compare two methods of rehabilitating extensor tendon repairs in zones V-VII. Patients who incurred simple and complete lacerations of their extensor tendons in zones V-VII enrolled into the study and underwent either static splinting (n = 25) or dynamic splinting (n = 27) after primary acute repair of tendons. Extension lag, flexion deficit, total active motion (TAM), grip strength, and functional status of upper extremities were measured. TAM was improved in the dynamic group when compared with the static group in the injured digits at 4 weeks (p = 0.001), at 12 weeks (p = 0.05), and at 6 months (p = 0.001). Grip strength outcomes demonstrated improved grip force for the dynamic group when compared with the static group at 12 weeks (p = 0.001). There were no ruptures in either group. Also, a better functional level was found in the dynamic splinting group at 6 months (p = 0.001). The findings of the current study suggest that dynamic splinting of complex lacerations of the extensor tendons in zones V-VII provides improved functional outcomes at 4 and 12 weeks and 6 months when compared with static splinting. PMID:22747353

Kitis, Ali; Ozcan, Ramazan Hakan; Bagdatli, Dilek; Buker, Nihal; Kara, Inci Gokalan

2012-09-01

39

Supraspinatus tears: Propagation and strain alteration  

Microsoft Academic Search

It was hypothesized that there would be an alteration in strain when macroscopically normal supraspinatus tendons were subjected to three patterns of surgically created tear. The propagation of joint-side partial-thickness tears was also examined. Cadaveric shoulders were tested on a purpose-built rig with static loading from 20 to 200 N and during glenohumeral abduction from 0° to 120° with a

Peter Reilly; Andrew A. Amis; Andrew L. Wallace; Roger J. H. Emery

2003-01-01

40

Minimally invasive surgery of the achilles tendon.  

PubMed

Minimally invasive surgical techniques for pathologies of the Achilles tendon (AT) hold the promise to decrease perioperative morbidity, allow faster recovery times, shorten hospital stays, and improve functional outcomes when compared with open procedures, which can lead to difficulty with wound healing because of the tenuous blood supply and increased chance of wound breakdown and infection. This article presents recent advances in the field of minimally invasive AT surgery for tendinopathy, acute ruptures, and chronic tears. All of the techniques described in this article are inexpensive and do not require highly specialized equipment and training. Future randomized controlled trials are required to address the issue of the comparison between open versus minimally invasive AT surgery. PMID:19773054

Maffulli, Nicola; Longo, Umile Giuseppe; Oliva, Francesco; Ronga, Mario; Denaro, Vincenzo

2009-10-01

41

Full thickness tears: retaining the cuff.  

PubMed

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

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

2011-12-01

42

Supraspinatus tears: propagation and strain alteration.  

PubMed

It was hypothesized that there would be an alteration in strain when macroscopically normal supraspinatus tendons were subjected to three patterns of surgically created tear. The propagation of joint-side partial-thickness tears was also examined. Cadaveric shoulders were tested on a purpose-built rig with static loading from 20 to 200 N and during glenohumeral abduction from 0 degrees to 120 degrees with a 100-N tensile load. Differential variable reluctance transducers were used to calculate strain. Six-millimeter-wide midsubstance full-thickness tears (n = 2) caused an increase in bursal-side strain both with abduction 1.93% (90 degrees ) and with loading 0.33% (150 N). Intratendinous delamination (n = 2) increased joint-side strain during abduction and bursal-side strain with loading. A 2-mm-deep tear across the tendon insertion (n = 5) increased the bursal-side strain in abduction by 3.54% (120 degrees ) and with load by 2.53% (200 N). Tear propagation was observed from joint to bursal sides during abduction. Tendon failure occurred at the insertion. PMID:12700564

Reilly, Peter; Amis, Andrew A; Wallace, Andrew L; Emery, Roger J H

2003-01-01

43

Matrix metalloproteases and their inhibitors are altered in torn rotator cuff tendons, but also in the macroscopically and histologically intact portion of those tendons  

PubMed Central

Summary We evaluated whether matrix metalloproteases and their inhibitors are involved in extracellular matrix remodelling and degradation of chronic rotator cuff tears. Tendon samples were harvested from 13 patients who underwent arthroscopic repair of a rotator cuff tear. Supraspinatus specimens were harvested en bloc from the arthroscopically intact middle portion of the tendon, more than 1 cm lateral to the torn edge, from the lateral edge of the tear, and from the superior margin of the macroscopically intact subscapularis tendon, used as control. The collagenases, the stromelysins, and the tissue inhibitors of metalloprotease arrays were analyzed blindly by multiplex sandwich ELISA in each specimen. Histological evidence of tendinopathy was present in all patients with a rotator cuff tear, but not in the macroscopically intact subscapularis tendon. There were significantly increased levels of MMP 1, MMP 2, MMP 3, TIMP-1, and TIMP-2 in all specimens examined, including the macroscopically intact portion of the supraspinatus tendon and the subscapularis (control specimens). The levels of specific matrix metalloproteases and their inhibitors are altered in torn rotator cuff tendons, but also in the macroscopically and histologically intact tendons. These changes extended medially to the site of tendon tear, and to other tendons. PMID:24367772

Castagna, Alessandro; Cesari, Eugenio; Garofalo, Raffaele; Gigante, Antonio; Conti, Marco; Markopoulos, Nikolaos; Maffulli, Nicola

2013-01-01

44

Suture material for flexor tendon repair: 3–0 V-Loc versus 3–0 Stratafix in a biomechanical comparison ex vivo  

PubMed Central

Background Barbed suture material offers the possibility of knotless flexor tendon repair, as suggested in an increasing number of biomechanical studies. There are currently two different absorbable barbed suture products available, V-Loc™ and Stratafix™, and both have not been compared to each other with regard to flexor tendon repair. The purpose of this study was to evaluate both suture materials for primary stability under static and cyclic loading in a biomechanical ex vivo model. Methods Forty fresh porcine flexor digitorum profundus tendons were randomized in two groups. A four-strand modified Kessler suture technique was used to repair the tendon either with a 3–0 V-Loc™ or 3–0 Stratafix™ without a knot. Parameters of interest were mode of failure, 2-mm gap formation force, displacement, stiffness and maximum load under static and cyclic testing. Results The maximum load was 42.3?±?7.2 for the Stratafix™ group and 50.7?±?8.8 N for the V-Loc™ group. Thus, the ultimate tensile strength was significantly higher for V-Loc™ (p?comparison to 26.5?±?2.12 N in the V-Loc™ group (n.s.). Displacement was 2.65?±?0.56 mm in the V-Loc™ group and 2.71?±?0.59 mm in the Stratafix™ group (n.s.). Stiffness was 4.24?±?0.68 (N/mm) in the V-Loc™ group and 3.85?±?0.55 (N/mm) the Stratafix™ group (n.s.). Those measured differences were not significant. Conclusion V-Loc™ demonstrates a higher maximum load in tendon reconstruction. The differences in 2-mm gap formation force, displacement and stiffness were not significant. Hereby, the V-Loc™ has an advantage when used as unidirectional barbed suture for knotless flexor tendon repair. PMID:25205062

2014-01-01

45

Comparison of the Insall–Salvati ratio of the patella in patients with and without an ACL tear  

Microsoft Academic Search

The object of this prospective study is to compare the Insall–Salvati ratio between the patients who have an anterior cruciate ligament (ACL) tear and receive arthroscopic–assistant ACL reconstruction and the patients who have no ACL tear but do have an internal disorder of the knee and receive arthroscopic surgery. We prospectively and consecutively collected into two groups a total of

Chien-Fu Jeff Lin; Jiunn-Jer Wu; Teng-Shung Chen; Tung-Fu Huang

2005-01-01

46

Glenohumeral joint motion after subscapularis tendon repair: an analysis of cadaver shoulder models  

PubMed Central

Background As for the surgical treatment of the rotator cuff tears, the subscapularis tendon tears have recently received much attention for the mini-open or arthroscopic repair. The results of surgical repair for the subscapularis tendon tear are satisfactory, but the range of external rotation is reported to be restricted after the repair. The purpose of this study was to evaluate the range of glenohumeral joint motion after repairs of various sizes of subscapularis tendon tears. Methods Using eight fresh frozen human cadaveric shoulders (mean age at death, 81.5 years), three sizes of subscapularis tendon tear (small, medium, and large) were made and then repaired. With the scapula fixed to the wooden jig, the end-range of glenohumeral motion was measured with passive movement applied through 1.0-Nm torque in the directions of scapular elevation, flexion, abduction, extension, horizontal abduction, and horizontal adduction. The passive end-ranges of external and internal rotation in various positions with rotational torque of 1.0 Nm were also measured. Differences in the ranges among the three type tears were analyzed. Results As tear size increased, range of glenohumeral motion in horizontal abduction after repair decreased gradually and was significantly decreased with the large size tear (P?tear size in every glenohumeral position. The prominent decrease in external rotation (around 40° reduction from intact shoulders) was observed in shoulders after repair of large size tear at 30° to 60° of scapular elevation and abduction. Conclusions As the size of the subscapularis tendon tear increased, the passive ranges of horizontal abduction and external rotation of the glenohumeral joint after repair decreased significantly. In shoulders with a subscapularis tendon tear, it is necessary to consider the reduction of external rotation depending on tear size. PMID:24885276

2014-01-01

47

The Effects of Donor Age and Strain Rate on the Biomechanical Properties of Bone-Patellar Tendon-Bone Allografts  

Microsoft Academic Search

Over 50% of all knee injuries involve partial or com plete tear of the anterior cruciate ligament. Surgical reconstruction of this ligament using an isometrically placed bone-patellar tendon-bone autograft is the cur rent technique of choice; however, harvest of patellar tendon as a free graft can lead to increased morbidity. To address this issue, allogenic patellar tendon grafts have been

Field T. Blevins; Aaron T. Hecker; Gregory T. Bigler; Arthur L. Boland; Wilson C. Hayes

1994-01-01

48

Comparison of Potentials of Stem Cells Isolated from Tendon and Bone Marrow for Musculoskeletal Tissue Engineering  

PubMed Central

The use of tendon-derived stem cells (TDSCs) as a cell source for musculoskeletal tissue engineering has not been compared with that of bone marrow stromal cells (BMSC). This study compared the mesenchymal stem cell (MSC) and embryonic stem cells (ESC) markers, clonogenicity, proliferative capacity, and multilineage differentiation potential of rat TDSC and BMSC in vitro. The MSC and ESC marker profiles of paired TDSC and BMSC were compared using flow cytometry and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Their clonogenicity and proliferative capacity were compared using colony-forming and 5-bromo-2?-deoxyuridine assays, respectively. The expression of tenogenic, osteogenic, and chondrogenic markers at basal state were examined using qRT-PCR. Their osteogenic, chondrogenic, and adipogenic differentiation potentials were compared using standard assays. TDSC and BMSC showed similar expression of CD90 and CD73. TDSC expressed higher levels of Oct4 than BMSC. TDSC exhibited higher clonogenicity, proliferated faster, and expressed higher tenomodulin, scleraxis, collagen 1 ? 1 (Col1A1), decorin, alkaline phosphatase, Col2A1, and biglycan messenger RNA levels than BMSC. There was higher calcium nodule formation and osteogenic marker expression in TDSC than BMSC upon osteogenic induction. More chondrocyte-like cells and higher glycosaminoglycan deposition and chondrogenic marker expression were observed in TDSC than BMSC upon chondrogenic induction. There were more oil droplets and expression of an adipogenic marker in TDSC than BMSC upon adipogenic induction. TDSC expressed higher Oct4 levels, which was reported to positively regulate mesendodermal lineage differentiation, showed higher clonogenicity and proliferative capacity, and had greater tenogenic, osteogenic, chondrogenic, and adipogenic markers and differentiation potential than BMSC. TDSC might be a better cell source than BMSC for musculoskeletal tissue regeneration. PMID:22011320

Tan, Qi; Rui, Yun Feng; Wong, Yin Mei

2012-01-01

49

Achilles Tendonitis  

MedlinePLUS

... strong as they can be. Strong, flexible muscles work more efficiently and put less stress on your tendon. Increase the intensity and length ... as much as possible. Vary your exercise routine. Work different muscle ... or doing activities that put stress on your feet. Wait until all the pain ...

50

Toward an Animal Model of the Human Tear Film: Biochemical Comparison of the Mouse, Canine, Rabbit, and Human Meibomian Lipidomes  

PubMed Central

Purpose. Secretions that are produced by meibomian glands (also known as meibum) are a major source of lipids for the ocular surface of humans and animals alike. Many animal species have been evaluated for their meibomian lipidomes. However, there have been a very small number of studies in which the animals were compared with humans side by side. Therefore, the purpose of this study was to compare meibum collected from humans and three typical laboratory animals, canines, mice, and rabbits, for their meibomian lipid composition in order to determine which animal species most resembles humans. Methods. High pressure liquid chromatography (HPLC) and gas-liquid chromatography (GLC) in combination with mass spectrometry were used to evaluate lipidomes of all tested species. Results. Among three tested animal species, mice were found to be the closest match to humans in terms of their meibomian lipidomes, while canines were the second closest species. The lipids of these three species were close to each other structurally and, for most lipid classes, quantitatively. The rabbit meibomian lipidome, on the other hand, was vastly different from lipidomes of all other tested species. Interestingly, a previously described class of lipids, acylated omega-hydroxy fatty acids (OAHFA), was found to be present in every tested species as the major amphiphilic component of meibum. Conclusions. Our side by side comparison of the rabbit and the human meibum demonstrated their vast differences. Thus, the rabbit seems to be a poor animal model of the human tear film, at least when studying its biochemistry and biophysics. PMID:22918629

Butovich, Igor A.; Lu, Hua; McMahon, Anne; Eule, J. Corinna

2012-01-01

51

Reconstructive surgery for massive rotator cuff tear  

Microsoft Academic Search

Surgical Principles\\u000a \\u000a The rotator cuff is repaired with transosseous sutures if possible. If the defect is too large for direct repair, local muscle\\u000a or tendon transfers are used. An anterior acromioplasty with resection of the coraco-acromial ligament is performed in every\\u000a case. In absolutely irreparable tears the authors recommend an open or arthroscopic debridement combined with an anterior\\u000a acromioplasty and

Peter Habermeyer; Ulrich Brunner; Ernst Wiedemann

1993-01-01

52

Arthroscopic Intratendinous Repair of the Delaminated Partial-Thickness Rotator Cuff Tear in Overhead Athletes  

Microsoft Academic Search

A distinct type of partial-thickness rotator cuff tear has been observed in overhead athletes, characterized by partial failure of the undersurface of the posterior supraspinatus and anterior infraspinatus tendons with intratendinous delamination. We present a technique of percutaneous intratendinous repair using nonabsorbable mattress sutures designed for the management of articular-side delaminated partial-thickness tears. After tear evaluation and preparation, the torn

Stephen F. Brockmeier; Christopher C. Dodson; Seth C. Gamradt; Struan H. Coleman; David W. Altchek

2008-01-01

53

Artificial tears potpourri: a literature review.  

PubMed

Numerous brands and types of artificial tears are available on the market for the treatment of dysfunctional tear syndrome. Past literature has focused on comparing the components of these products on patient's clinical improvement. The wide array of products on the market presents challenges to both clinicians and patients when trying to choose between available tear replacement therapies. Different formulations affect patients based on etiology and severity of disease. In order to provide an unbiased comparison between available tear replacement therapies, we conducted a literature review of existing studies and National Institutes of Health clinical trials on commercially available, brand name artificial tears. Outcomes evaluated in each study, as well as the percent of patients showing clinical and symptomatic improvement, were analyzed. Fifty-one studies evaluating different brands of artificial tears, and their efficacy were identified. Out of the 51 studies, 18 were comparison studies testing brand name artificial tears directly against each other. Nearly all formulations of artificial tears provided significant benefit to patients with dysfunctional tear syndrome, but some proved superior to others. From the study data, a recommended treatment flowchart was derived. PMID:25114502

Moshirfar, Majid; Pierson, Kasey; Hanamaikai, Kamalani; Santiago-Caban, Luis; Muthappan, Valliammai; Passi, Samuel F

2014-01-01

54

Anterior Cruciate Ligament Graft FixationInitial Comparison of Patellar Tendon and Semitendinosus Autografts in Young Fresh Cadavers  

Microsoft Academic Search

The initial biomechanical properties of semitendinosus and patellar tendon autografts and their fixation strengths were investigated. Twenty fresh cadaveric knees from donors under 42 years of age were used in the study. After removing all soft tissues other than the anterior cruciate ligament, we determined the ultimate tensile strength (2195 ± 427 N) and stiffness (306 ± 80 N\\/mm) of

Neville J. Rowden; Doron Sher; Greg J. Rogers; Klaus Schindhelm

1997-01-01

55

Infraspinatus delamination does not affect supraspinatus tear repair.  

PubMed

Supraspinatus full-thickness tears with associated infraspinatus delamination are a frequent lesion, although the results of repair have not been reported. We retrospectively identified 35 patients treated for this cuff lesion among 378 open repaired full-thickness cuff tears. The aim of the study was to assess the subjective, objective, and anatomic outcomes of a subset of patients with supraspinatus tears involving delamination of the whole infraspinatus tendon. Thirty of the 35 patients were reviewed with magnetic resonance imaging at a minimum followup of 2 years (mean, 3.5 years; range, 2-6.5 years). The mean nonweighted Constant-Murley score at followup was 80/100 points, with an average gain of 17 points. Magnetic resonance imaging revealed all supraspinatus tendons but two were continuous. We observed no tear of the infraspinatus tendon, although a persistent delamination was present in 11 cases. One half of the patients had minor weakness in external rotation. One third of the infraspinatus muscles had minor fatty infiltration. Conservation of the infraspinatus tendon after closing the delamination did not seem to compromise the outcome of the supraspinatus repair. Avoiding resection of the infraspinatus delamination and treatment with simple curettage and closure yields satisfactory midterm functional and anatomic results. PMID:17308479

Zilber, Sébastien; Carillon, Yannick; Lapner, Peter C; Walch, Gilles; Nové-Josserand, Laurent

2007-05-01

56

Comparison of partial meniscectomy versus meniscus repair for bucket-handle lateral meniscus tears in anterior cruciate ligament reconstructed knees  

Microsoft Academic Search

Purpose: For patients who underwent anterior cruciate ligament (ACL) reconstruction and had an unstable bucket-handle tear and no other meniscus lesions or articular damage, we sought to determine if repair of the lateral meniscus was superior to partial meniscectomy with regard to subjective and objective results.Type of Study: Retrospective cohort study.Methods: Between 1982 and 1995, 91 patients met the inclusion

K. Donald Shelbourne; Michael D Dersam

2004-01-01

57

Meniscal tears: comparison of the conventional spin-echo and fast spin-echo techniques through image processing  

PubMed Central

Background Conventional spin-echo (PD-CSE) and fast spin-echo (PD-FSE) techniques are frequently used to detect meniscal tears. However, the time delay for imaging with PD-CSE has resulted in its replacement with faster techniques, such as proton density fast spin-echo (PD-FSE), which has become a frequent tool at most diagnostic centres. Qualitative analysis shows that the PD-CSE technique is more sensitive, but other authors have not found significant differences between the aforementioned techniques. Therefore, we performed a quantitative analysis in this study that aims to measure differences in the quality of the images obtained with both techniques. Methods We compared the PD-CSE and PD-FSE techniques by quantitatively analysing the obtained proton density images: the area shown, as well as the brightness and lesion contrast of the obtained image. A set of 100 images from 50 patients thought to contain meniscal tears of the knee were selected. These 100 images were obtained from all individuals using both the PD-CSE and PD-FSE techniques. The images were processed using software developed in Delphi. In addition to these quantifications, three physicians, who are specialists in radiology and capable of analysing magnetic resonance (MR) images of the musculoskeletal system, qualitatively analysed the diagnostic sensitivity of both techniques. Results On average, samples obtained via the PD-CSE technique contained 22% more pixels in the lesion area. The contrast differed by 28%, and the brightness differed by 31%. The two techniques were correlated using Student’s t-test, which showed a statistically significant difference. The specialists detected meniscal tears in 30 of the images obtained via the PD-CSE technique, while only 72% of these cases were detected via the PD-FSE technique. Conclusions The PD-CSE technique was shown to be superior to PD-FSE for all of the evaluated properties, making its selection preferable. PMID:24673813

2014-01-01

58

Subcoracoid impingement and subscapularis tendon: is there any truth?  

PubMed

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

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

2013-04-01

59

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

PubMed

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

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

2014-10-01

60

Tendon Transfer Surgery  

MedlinePLUS

... in hand function occurs. The muscle imbalance or muscle loss due to nervous system disease may be treated with tendon transfers. Common nervous system disorders treated with tendon ... muscle atrophy. Finally, there are some conditions in which ...

61

Extensor Tendon Injuries  

MedlinePLUS

... these small-muscle tendons that allow delicate finger motions and coordination. CAUSES Extensor tendons are just under ... a splint with slings that allows some finger motion, may be used for injuries of this kind. ...

62

Enhancement of rotator cuff tendon–bone healing with injectable periosteum progenitor cells-BMP-2 hydrogel in vivo  

Microsoft Academic Search

Purpose  The fixation and incorporation of ruptured rotator cuff tendon to bone is a major concern in rotator cuff repair surgery.\\u000a Rotator cuff repair usually fails at the tendon–bone interface, especially in case of large or massive tears. To enhance tendon–bone\\u000a healing, an injectable hydrogel made with periosteal progenitor cells(PPCs) and poly (ethylene glycol) diacrylate (PEGDA)\\u000a tethered with bone morphogenic protein-2(BMP-2)

Chih-Hwa Chen; Chih-Hsiang Chang; Kun-Chung Wang; Chun-I Su; Hsien-Tao Liu; Chung-Ming Yu; Chak-Bor Wong; I-Chun Wang; Shu Wen Whu; Hsia-Wei Liu

63

A comparison of different two-dimensional approaches for the determination of the patellar tendon moment arm length.  

PubMed

The purpose of this study was to estimate and compare the moment arm length of the patellar tendon (d) during passive knee extension using three different reference landmarks; instant centre of rotation (ICR), tibiofemoral contact point (TFCP) and geometrical centre of the posterior femoral condyles (GCFC). Measurements were taken on the right leg on seven healthy males during passive knee rotation performed by the motor of a Cybex Norm isokinetic dynamometer. Moment arms lengths were obtained by analysing lateral X-ray images recorded using a GE FlexiView 8800 C-arm videofluoroscopy system. The d-knee joint angle relations with respect to GCFC and ICR were similar, with decreasing values from full knee extension (~5.8 cm for d (GCFC) and ~5.9 cm for d (ICR)) to 90 degrees of knee flexion (~4.8 cm for both d (GCFC) and d (ICR)). However, the d (TFCP)-knee joint angle relation had an ascending-descending shape, with the highest d (TFCP) value (~5 cm) at 60 degrees of knee flexion. There was no significant difference between the GCFC and ICR methods at any knee joint angle. In contrast, there were significant differences (P < 0.01) between d (ICR) and d (TFCP) at 0 degrees , 15 degrees , 30 degrees and 45 degrees of knee flexion and between d (GCFC) and d (TFCP) at 0 degrees , 15 degrees and 30 degrees of knee flexion (P < 0.01). This study shows that when using different knee joint rotation centre definitions, there are significant differences in the estimates of the patellar tendon moment arm length, especially in more extended knee joint positions. These differences can have serious implications for joint modelling and loading applications. PMID:19125279

Tsaopoulos, Dimitrios E; Baltzopoulos, Vasilios; Richards, Paula J; Maganaris, Constantinos N

2009-03-01

64

Neoclassical Tearing Modes  

SciTech Connect

Tearing modes often limit the performance of tokamak plasmas, because the magnetic islands which they generate lead to a loss of confinement, or even a disruption. A particularly dangerous instability is the neoclassical tearing mode, which can grow to a large amplitude because of the amplification effect that the bootstrap current has on an initial 'seed' magnetic island. This paper will address the mechanisms which dominate the neoclassical tearing mode evolution, and thereby identify possible control techniques.

Wilson, H.R. [EURATOM/UKAEA Fusion Association (United Kingdom)

2004-03-15

65

Ultrasound in the diagnosis of posterior tibial tendon pathology.  

PubMed

We retrospectively evaluated the effectiveness of ultrasonography as a diagnostic tool for investigating pathology in the posterior tibial tendon by comparing the preoperative ultrasonograms for 17 patients with their recorded surgical findings. In all cases, the surgical findings confirmed the ultrasonographic diagnoses: 3 inflammations, 4 partial tears, and 10 ruptures. Interestingly, two ruptures had been undiagnosed by magnetic resonance imaging. Ultrasonography, which seems to be a reliable means of visualizing the extent of pathology of the symptomatic posterior tibial tendon, may be a valuable tool in surgical planning. PMID:8886783

Miller, S D; Van Holsbeeck, M; Boruta, P M; Wu, K K; Katcherian, D A

1996-09-01

66

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

PubMed Central

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

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

2014-01-01

67

Antimicrobial compounds in tears.  

PubMed

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

McDermott, Alison M

2013-12-01

68

Arthroscopic double-locked stitch: a new technique for suturing rotator cuff tears.  

PubMed

There are a number of reasons for failed rotator cuff tear repair. In such cases the suture-tendon interface seems to be the most vulnerable area, especially when tendon degeneration is present. We describe a new technique, the arthroscopic double-locked suture, that increases the tendon fixation and has the added benefit of being placed parallel to the blood vessels, therefore avoiding damage to the tendon vascularization. The suture may be achieved by use of knots or knotless anchors and suture passers, without the need for any additional instrumentation. The new technique is especially helpful in cases in which the tendon is retracted and degeneration is present, impeding the use of the double-row technique or its transosseous equivalents. PMID:24904764

Miyazaki, Alberto N; Zanella, Luiz A Z; La Salvia, João C; Fregoneze, Marcelo; Santos, Pedro D; da Silva, Luciana A; Sella, Guilherme do Vall; Checchia, Sergio L

2014-04-01

69

Biomimetic Scaffold Design for Functional and Integrative Tendon Repair  

PubMed Central

Rotator cuff tears represent the most common shoulder injuries in the United States. The debilitating effect of this degenerative condition coupled with the high incidence of failure associated with existing graft choices underscore the clinical need for alternative grafting solutions. The two critical design criteria for the ideal tendon graft would require the graft to not only exhibit physiologically relevant mechanical properties but also be able to facilitate functional graft integration by promoting the regeneration of the native tendon-to-bone interface. Centered on these design goals, this review will highlight current approaches to functional and integrative tendon repair. In particular, the application of biomimetic design principles through the use of nanofiber- and nanocomposite-based scaffolds for tendon tissue engineering will be discussed. This review will begin with nanofiber-based approaches to functional tendon repair, followed by a section highlighting the exciting research on tendon-to-bone interface regeneration, with an emphasis on implementation of strategic biomimicry in nanofiber scaffold design and the concomitant formation of graded multi-tissue systems for integrative soft tissue repair. This review will conclude with a summary and future directions section. PMID:22244070

Zhang, Xinzhi; Bogdanowicz, Danielle; Erisken, Cevat; Lee, Nancy M.; Lu, Helen H.

2012-01-01

70

Bipolar infrapatellar tendon rupture.  

PubMed

Traumatic patella alta in children occurs either distal to the patellar tendon as a tibial tubercle apophyseal fracture or proximally as an osteochondral sleeve fracture of the inferior patellar pole. Acute surgical exploration in a pediatric case of a knee extensor mechanism rupture revealed both proximal and distal (bipolar) patellar tendon pathology. PMID:7790483

Berg, E E

1995-01-01

71

Six surgery-correlated sonographic signs for rotator cuff tears  

Microsoft Academic Search

The purpose of the study is to correlate the sonographic signs of rotator cuff tears (RCTs) with surgical findings, with emphasis on partial-thickness tear. We prospectively performed ultrasonography (US) on 50 patients with suspected RCTs and comparison with operative findings. Six US signs, which included “nonvisualization”, “focal depression”, “focal thinning”, “focal hypoechoic cleft”, “floating bright spots” and “focal heterogeneous hypoechogenicity”

Chao-Hsuan Yen; Hong-Jen Chiou; Yi-Hong Chou; Chuang-Chuen Hsu; Jinn-Jer Wu; Hsiao-Li Ma; Cheng-Yen Chang

2004-01-01

72

Cellular response and extracellular matrix breakdown in rotator cuff tendon rupture  

Microsoft Academic Search

Purpose  The aim of this study was to investigate the relationship between the disruption of ECM and cellular events including autophagic\\u000a cell death, apoptosis and cell differentiation into myofibroblasts in the degenerative rotator cuff tendon.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Tendon samples were collected from 30 patients undergoing surgery for rotator cuff tears. Apoptosis, autophagic cell death\\u000a and myofibroblasts of the tendon cells in the ruptured

Bing Wu; Jimin Chen; Tammyl Dela Rosa; Qian Yu; Allan Wang; Jiake Xu; Ming-Hao Zheng

2011-01-01

73

Acellular flexor tendon allografts: a new horizon for tendon reconstruction.  

PubMed

Flexor tendon injuries continue to pose a significant challenge to the hand surgeon. In particular, chronic tendon ruptures with adhesions of the tendons and sheath, damage or loss of the intrasynovial flexor tendons in zone II, and combined soft tissue and bone injuries present especially difficult problems for restoring satisfactory digital function. This challenge in flexor tendon reconstruction has motivated hand surgeons to explore and develop novel solutions for nearly a century. Recent advances and techniques in processing and decellularizing allograft human flexor tendon constructs may prove to be a new horizon for tendon reconstruction. PMID:23707595

Drake, David B; Tilt, Alexandra C; DeGeorge, Brent R

2013-12-01

74

Allograft tendon for second-stage tendon reconstruction.  

PubMed

Tendons are made of compact dense collagen fibers with only sparse cellularity and naturally low immunogenicity. Allogenic tendons may be preserved through deep freezing methods and retain excellent mechanical properties after revitalization. Allogenic tendons were used in 22 patients (30 tendons) for second-stage tendon reconstruction in the hand. Preliminary results indicate no observable adverse tissue reactions, and functional recovery after tendon grafting does not seem different from reconstruction using tendon autografts. This type of allogenic graft does not seem to produce serious concern as a foreign tissue in the body, at least in the short term. PMID:23101600

Xie, Ren Guo; Tang, Jin Bo

2012-11-01

75

Multilayered electrospun scaffolds for tendon tissue engineering.  

PubMed

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

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

2013-12-01

76

Multilayered Electrospun Scaffolds for Tendon Tissue Engineering  

PubMed Central

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

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

2013-01-01

77

An Artificial Tendon with Durable Muscle Interface  

PubMed Central

A coupling mechanism that can permanently fix a forcefully contracting muscle to a bone anchor or any totally inert prosthesis would meet a serious need in orthopaedics. Our group developed the OrthoCoupler™ device to satisfy these demands. The objective of this study was to test OrthoCoupler’s performance in vitro and in vivo in the goat semitendinosus tendon model. For in vitro evaluation, 40 samples were fatigue-tested, cycling at 10 load levels, n=4 each. For in vivo evaluation, the semitendinosus tendon was removed bilaterally in 8 goats. Left sides were reattached with an OrthoCoupler, and right sides were reattached using the Krackow stitch with #5 braided polyester sutures. Specimens were harvested 60 days post-surgery and assigned for biomechanics and histology. Fatigue strength of the devices in vitro was several times the contractile force of the semitendinosus muscle. The in vivo devices were built equivalent to two of the in vitro devices, providing an additional safety factor. In strength testing at necropsy, suture controls pulled out at 120.5 ± 68.3 N, whereas each OrthoCoupler was still holding after the muscle tore, remotely, at 298±111.3N (mean ± SD)(p<0.0003). Muscle tear strength was reached with the fiber-muscle composite produced in healing still soundly intact. This technology may be of value for orthopaedic challenges in oncology, revision arthroplasty, tendon transfer, and sports-injury reconstruction. PMID:19639642

Melvin, Alan; Litsky, Alan; Mayerson, Joel; Witte, David; Melvin, David; Juncosa-Melvin, Natalia

2010-01-01

78

Tendon Gradient Mineralization for Tendon to Bone Interface Integration  

PubMed Central

Tendon-to-bone integration is a great challenge for tendon or ligament reconstruction regardless of use of autograft or allograft tendons. We mineralized the tendon, thus transforming the tendon-to-bone into a “bone-to-bone” interface for healing. Sixty dog flexor digitorum profundus (FDP) tendons were divided randomly into 5 groups: 1) normal FDP tendon, 2) CaP (Non-extraction and mineralization without fetuin), 3) CaPEXT (Extraction by Na2HPO4 and mineralization without fetuin), 4) CaPFetuin (Non-extraction and mineralization with fetuin), and 5) CaPEXTFetuin (Extraction and mineralization with fetuin). The calcium and phosphate content significantly increased in tendons treated with combination of extraction and fetuin compared to the other treatments. Histology also revealed a dense mineral deposition throughout the tendon outer layers and penetrated into the tendon to a depth of 200 ?m in a graded manner. Compressive moduli were significantly lower in the four mineralized groups compared with normal control group. No significant differences in maximum failure strength or stiffness were found in the suture pull-out test among all groups. Mineralization of tendon alters the interface from tendon to bone into mineralized tendon to bone, which may facilitate tendon-to-bone junction healing following tendon or ligament reconstruction. PMID:23939935

Qu, Jin; Thoreson, Andrew R.; Chen, Qingshan; An, Kai-Nan; Amadio, Peter C.; Zhao, Chunfeng

2014-01-01

79

Bilateral Achilles tendon enlargement.  

PubMed

Cerebrotendinous xanthomatosis is a rare, autosomal-recessive, lipid-storage disease with accumulation of cholestanol in most tissues, particularly within the Achilles tendons. It has been characterized both clinically and biochemically, and recently from the molecular biological aspect as well. Juvenile cataract, childhood diarrhea, mental retardation, cerebellar ataxia, and tendon xanthomas are the most prominent features of this disease. Bilateral symmetrical firm masses of Achilles tendons may be the first symptom the patient recognizes because it can jeopardize his or her ability to walk. However, the treatment strategies for tendon tumors vary. In a recent case, we diagnosed the disease properly, according to the clinical manifestations and the radiological and laboratory examinations. The genetic mutation was characterized by analyzing sterol 27-hydroxylase from the patient's family (located on nucleotide 599) and led to a nonsense mutation. It is a unique type of mutation that has never been reported to our knowledge. Tendon lesions are characterized by the loss of muscle fibers and accumulation of lipid products. To help the patient regain the strength of the Achilles tendon and walking abilities, a large area of tendon tumor was excised, followed by reconstruction with a tibialis posterior allograft, which is the second strongest tendon in the foot and ankle. Although the use of this type of graft is uncommon, the final result was satisfactory. At the 10-month follow-up examination, the patient could walk easily without pain. This case report suggests that the surgical procedure will provide an alternative for the repair of large-area degenerative Achilles tendons. PMID:22146219

Huang, Lu; Miao, Xu-dong; Yang, Di-sheng; Tao, Hui-min

2011-12-01

80

Magnetic Resonance Imaging of Rotator Cuff Tears in Shoulder Impingement Syndrome  

PubMed Central

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

Freygant, Magdalena; Dziurzynska-Bialek, Ewa; Guz, Wieslaw; Samojedny, Antoni; Golofit, Andrzej; Kostkiewicz, Agnieszka; Terpin, Krzysztof

2014-01-01

81

Estimating optimal shoulder immobilization postures following surgical repair of massive rotator cuff tears.  

PubMed

Although shoulder immobilization is commonly prescribed following surgical repair of rotator cuff tears there is no consensus about the best shoulder immobilization postures. A musculoskeletal model was used with a minimax algorithm to estimate optimal post-operative shoulder immobilization postures for massive rotator cuff tears involving the supraspinatus and infraspinatus. An optimal posture was defined as one in which the stresses in the repaired tendons and the angle of humerus elevation were minimized. The optimal post-operative shoulder immobilization postures were with the humerus elevated and externally rotated. Elevation increased with the severity of the tear from 21° to 45° while external rotation decreased slightly from 23° to 18°. The minimax algorithm effectively balanced the competing criteria, resulting in feasible postures that did not overstress the repaired tendons. This method could be used to guide prescription of shoulder immobilization postures for various injuries. PMID:23116766

Jackson, M; Sylvestre, É; Bleau, J; Allard, P; Begon, M

2013-01-01

82

Tears at the rotator cuff footprint: Prevalence and imaging characteristics in 305 MR arthrograms of the shoulder  

Microsoft Academic Search

Objectives  To evaluate the prevalence, imaging characteristics and anatomical distribution of tears at the rotator cuff (RC) footprint\\u000a with MR arthrography (MR-A) of the shoulder.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  MR arthrograms obtained in 305 patients were retrospectively reviewed. Partial articular-sided supraspinatus tendon avulsions\\u000a (PASTA), concealed interstitial delaminations (CID), reverse PASTA lesions and full-thickness tears (FT) at the humeral tendon\\u000a insertion were depicted. Anatomical locations were

Christoph Schaeffeler; Dirk Mueller; Chlodwig Kirchhoff; Petra Wolf; Ernst J. Rummeny; Klaus Woertler

2011-01-01

83

Extra-articular Mimickers of Lateral Meniscal Tears  

PubMed Central

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

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

2011-01-01

84

Posterior Tibial Tendon Dysfunction  

MedlinePLUS

... patients will notice some limitation in activity a er surgery. Anatomy The posterior tibial tendon is one ... the pain to last another 6 months a er treatment starts. Rest Decreasing or even stopping activities ...

85

The tendons: Interventional sonography  

PubMed Central

While blind or fluoroscopically guided infiltration works well for intra-articular injections, injections into the tendon sheath are much more difficult. Ultrasound guidance with high-frequency transducers now allows visualization and infiltration of tendon sheaths. The interventional phase should be preceded by a diagnostic scan. Patients should be questioned to identify possible contraindications to the procedure and informed of the potential risks. Strict asepsis must be maintained for both patient and operator. This review includes separate discussions of the tendons in different areas of the body that are most commonly treated with ultrasound-guided injections, with descriptions of the lesions that are treated and the approach used for each. Interventional sonography is currently the only technique that allows visualization of the tendon being infiltrated. It requires training and experience as well as good knowledge of the indications and equipment used for the procedures, and the anatomy of the areas being treated. PMID:23396899

Campagna, R.; Guerini, H.

2012-01-01

86

Risk factors associated with anal sphincter tear: A comparison of primiparous patients, vaginal births after cesarean deliveries, and patients with previous vaginal delivery  

Microsoft Academic Search

Objective: This study was conducted to identify obstetric risk factors for anal sphincter tear in primiparous patients, patients with a previous cesarean delivery (VBAC), and patients with a previous vaginal delivery (PVD). Study Design: An obstetrics automated record system was accessed to retrospectively review records of all singleton vaginal deliveries at greater than 36 weeks' gestation (excluding breech and stillbirth)

Holly E. Richter; Cynthia G. Brumfield; Suzanne P. Cliver; Kathryn L. Burgio; Cherry L. Neely; R. Edward Varner

2002-01-01

87

Arthroscopic Repair of Rotator Cuff Tears Using Extracellular Matrix Graft  

PubMed Central

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.

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

2014-01-01

88

Jumper's Knee (Patellar Tendonitis)  

MedlinePLUS

... warm-up regimen that involves stretching the quadriceps, hamstring, and calf muscles can help prevent jumper's knee. It's always a good ... Injuries Bursitis Medial Collateral Ligament (MCL) Injuries Meniscus Tears ...

89

[Tear lactoferrin in keratoconjunctivitis sicca].  

PubMed

Keratoconjunctivitis sicca is a commonly encountered disease with decreased lacrimal gland activity. There are several tests to determine the lacrimal gland function, but all have limitations in accuracy, sensitivity or technical difficulty. At present, there is no reliable objective test to render a firm diagnosis of dry eye. Lactoferrin is one of the major proteins secreted by the lacrimal gland. Its concentration was found to correlate well to lacrimal gland activity. In this study we tried to evaluate the diagnostic value of lactoferrin measurement in comparison with other tests for keratoconjunctivitis sicca. Tests including the measurement of tear lactoferrin, Schirmer's-1 test, Schirmer's basal test, tear film break-up time, and rose bengal stain of the cornea were done on 60 healthy eyes and 56 eyes with keratoconjunctivitis sicca. The lactoferrin level was measured by a commercially available "Lactoplate" (Eagle Vision, U.S.A.). It is a plate containing gel loaded with rabbit anti-human-lactoferrin antiserum. Tear-moistened filter paper discs containing lactoferrin were placed on the gel. The lactoferrin concentration could be determined by measuring the concentric ring of precipitate after 72 hours incubation at room temperature. The average concentration of lactoferrin was 1.9 +/- 0.51 mg/ml in the normal group and 1.4 +/- 0.93 mg/ml in the keratoconjunctivitis sicca group. They were significantly different from each other (t-test: p less than 0.05). The results of the other 4 tests also showed a significant difference between the normal and keratoconjunctivitis sicca group, but the lactoferrin measurement had the highest specificity among these 5 tests. Because of the technical simplicity of measurement and its high specificity, lactoferrin measurement could be a valuable tool for the early and accurate diagnosis of keratoconjunctivitis sicca. PMID:2794946

Hu, F R; Wang, T H; Lin, L L; Ko, L S

1989-04-01

90

Giant retinal tears.  

PubMed

Of 94 patients (100 eyes) with giant retinal tears, 71.4% of eyes with nontraumatic breaks were myopic and severe retinal pathologic findings were present in 57.3% of fellow eyes. Fifty-five (58%) of 95 treated eyes were successfully reattached; retinal incarceration, attempted in 19 cases, was successful in five. Serious surgical complications were responsible for failure in nine cases (22.5%). The worst prognostic factor were extension of the tear for over two quadrants, myopia of -10 diopters or more, and the presence of aphakia. PMID:1146947

Kanski, J J

1975-05-01

91

Tears of Wine  

ERIC Educational Resources Information Center

The unique occurrence of the upward motion of a thin film of wine, and its formation into drops inside the wall of a wine glass is explained. Evaporation of alcohol generates a surface tension gradient, moving the film of wine upwards on the internal sides of a wine glass, where it collects and forms into drops or tears.

Gugliotti, Marcos

2004-01-01

92

Tearing Modes in Tokamaks  

SciTech Connect

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.

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

2008-05-14

93

Neuronal regulation of tendon homoeostasis  

PubMed Central

The regulation of tendon homoeostasis, including adaptation to loading, is still not fully understood. Accumulating data, however, demonstrates that in addition to afferent (sensory) functions, the nervous system, via efferent pathways which are associated with through specific neuronal mediators plays an active role in regulating pain, inflammation and tendon homeostasis. This neuronal regulation of intact-, healing- and tendinopathic tendons has been shown to be mediated by three major groups of molecules including opioid, autonomic and excitatory glutamatergic neuroregulators. In intact healthy tendons the neuromediators are found in the surrounding structures: paratenon, endotenon and epitenon, whereas the proper tendon itself is practically devoid of neurovascular supply. This neuroanatomy reflects that normal tendon homoeostasis is regulated from the tendon surroundings. After injury and during tendon repair, however, there is extensive nerve ingrowth into the tendon proper, followed by a time-dependent emergence of sensory, autonomic and glutamatergic mediators, which amplify and fine-tune inflammation and regulate tendon regeneration. In tendinopathic condition, excessive and protracted presence of sensory and glutamatergic neuromediators has been identified, suggesting involvement in inflammatory, nociceptive and hypertrophic (degenerative) tissue responses. Under experimental and clinical conditions of impaired (e.g. diabetes) as well as excessive (e.g. tendinopathy) neuromediator release, dysfunctional tendon homoeostasis develops resulting in chronic pain and gradual degeneration. Thus there is a prospect that in the future pharmacotherapy and tissue engineering approaches targeting neuronal mediators and their receptors may prove to be effective therapies for painful, degenerative and traumatic tendon disorders. PMID:23718724

Ackermann, Paul W

2013-01-01

94

Tear film stability: a review.  

PubMed

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

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

2013-12-01

95

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

PubMed

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 9 fresh frozen cadeveric hands were randomized to 1 of 3 repair techniques after simulated distal avulsion injuries. These were the pullout button using 3-0 monofilament nylon in a 2-strand Bunnell suture pattern, the 1.8 mm Mini QuickAnchor (Mitek Products, Norwood, MA) using 3-0 braided polyester in a 2-strand Bunnell suture pattern, and the Mitek micro anchor using 3-0 braided polyester with a modified 4-strand Becker suture pattern. Nine specimens were loaded to failure, noting maximum load and mode of failure. The 1.3 mm Micro QuickAnchor (Mitek) technique (69.6 +/- 10.8 N) was significantly stronger than the pullout button (43.3 +/- 4.8 N) or the Mini anchor technique (44.6 +/- 12.7 N). The Micro bone suture anchor provides a stronger tendon to bone repair than the pullout button or the Mini anchor. Given the disadvantages of the pullout button, the Micro bone suture anchor with the modified Becker technique is worth consideration as an alternative method to repair distal FDP avulsions. PMID:11418912

Brustein, M; Pellegrini, J; Choueka, J; Heminger, H; Mass, D

2001-05-01

96

All-arthroscopic patch augmentation of a massive rotator cuff tear: surgical technique.  

PubMed

Surgical management of massive rotator cuff tears remains challenging, with failure rates ranging from 20% to 90%. Multiple different arthroscopic and open techniques have been described, but there is no current gold standard. Failure after rotator cuff repair is typically multifactorial; however, failure of tendon-footprint healing is often implicated. Patch augmentation has been described as a possible technique to augment the biology of rotator cuff repair in situations of compromised tendon quality and has shown promising short-term results. The purpose of this article is to describe our preferred surgical technique for arthroscopic rotator cuff repair with patch augmentation. PMID:24400198

Chalmers, Peter N; Frank, Rachel M; Gupta, Anil K; Yanke, Adam B; Trenhaile, Scott W; Romeo, Anthony A; Bach, Bernard R; Verma, Nikhil N

2013-01-01

97

All-Arthroscopic Patch Augmentation of a Massive Rotator Cuff Tear: Surgical Technique  

PubMed Central

Surgical management of massive rotator cuff tears remains challenging, with failure rates ranging from 20% to 90%. Multiple different arthroscopic and open techniques have been described, but there is no current gold standard. Failure after rotator cuff repair is typically multifactorial; however, failure of tendon-footprint healing is often implicated. Patch augmentation has been described as a possible technique to augment the biology of rotator cuff repair in situations of compromised tendon quality and has shown promising short-term results. The purpose of this article is to describe our preferred surgical technique for arthroscopic rotator cuff repair with patch augmentation. PMID:24400198

Chalmers, Peter N.; Frank, Rachel M.; Gupta, Anil K.; Yanke, Adam B.; Trenhaile, Scott W.; Romeo, Anthony A.; Bach, Bernard R.; Verma, Nikhil N.

2013-01-01

98

Transcriptomic analysis of mouse limb tendon cells during development.  

PubMed

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

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

99

Fracture of the coracoid process with acute subscapularis tear without shoulder dislocation  

PubMed Central

Coracoid process fracture is an uncommon injury and can be easily missed. An associated acute subscapularis tear is still rare. Herein, we describe a 61 year old male who fell from a 2 meter height (stair case) and presented with isolated coracoid process fracture with acute subscapularis tear without dislocation of (R) shoulder joint. The plain x-rays, CT scan and MR arthrography comprised the diagnosis. He was operated upon with reattachment of subscapularis to lesser tuberosity and conjoint tendons to pectoralis major. At 6 mo followup he had good range of motion and his MRI revealed complete healing.

Yoo, Jeong Hyun; Min, Byung Cho; Sung, Ki Hyuk; Kim, Joon Yub

2014-01-01

100

Mineral Distributions at the Developing Tendon Enthesis  

PubMed Central

Tendon attaches to bone across a functionally graded interface, “the enthesis”. A gradient of mineral content is believed to play an important role for dissipation of stress concentrations at mature fibrocartilaginous interfaces. Surgical repair of injured tendon to bone often fails, suggesting that the enthesis does not regenerate in a healing setting. Understanding the development and the micro/nano-meter structure of this unique interface may provide novel insights for the improvement of repair strategies. This study monitored the development of transitional tissue at the murine supraspinatus tendon enthesis, which begins postnatally and is completed by postnatal day 28. The micrometer-scale distribution of mineral across the developing enthesis was studied by X-ray micro-computed tomography and Raman microprobe spectroscopy. Analyzed regions were identified and further studied by histomorphometry. The nanometer-scale distribution of mineral and collagen fibrils at the developing interface was studied using transmission electron microscopy (TEM). A zone (?20 µm) exhibiting a gradient in mineral relative to collagen was detected at the leading edge of the hard-soft tissue interface as early as postnatal day 7. Nanocharacterization by TEM suggested that this mineral gradient arose from intrinsic surface roughness on the scale of tens of nanometers at the mineralized front. Microcomputed tomography measurements indicated increases in bone mineral density with time. Raman spectroscopy measurements revealed that the mineral-to-collagen ratio on the mineralized side of the interface was constant throughout postnatal development. An increase in the carbonate concentration of the apatite mineral phase over time suggested possible matrix remodeling during postnatal development. Comparison of Raman-based observations of localized mineral content with histomorphological features indicated that development of the graded mineralized interface is linked to endochondral bone formation near the tendon insertion. These conserved and time-varying aspects of interface composition may have important implications for the growth and mechanical stability of the tendon-to-bone attachment throughout development. PMID:23152788

Schwartz, Andrea G.; Pasteris, Jill D.; Genin, Guy M.; Daulton, Tyrone L.; Thomopoulos, Stavros

2012-01-01

101

Diagnosis and management of superior labral anterior posterior tears in throwing athletes.  

PubMed

Injury to the superior glenoid labrum is increasingly recognized as a significant source of shoulder pain and dysfunction in the throwing athlete. Several theories have been proposed to explain the pathogenesis of superior labral anterior posterior (SLAP) tears. The clinical examination of the superior labrum-biceps tendon complex remains challenging because of a high association of other shoulder injuries in overhead athletes. Many physical examination findings have high sensitivity and low specificity. Advances in soft tissue imaging such as magnetic resonance arthrography allow for improved detection of labrum and biceps tendon lesions, although correlation with history and physical examination is critical to identify symptomatic lesions. Proper treatment of throwers with SLAP tears requires a thorough understanding of the altered biomechanics and the indications for nonoperative management and arthroscopic treatment of these lesions. PMID:23172004

Knesek, Michael; Skendzel, Jack G; Dines, Joshua S; Altchek, David W; Allen, Answorth A; Bedi, Asheesh

2013-02-01

102

Peroneal tendons subluxation.  

PubMed

Subluxation of the peroneal tendons is uncommon. It occurs especially in skiing, soccer, basketball, rugby, ice skating, judo, sprint, water-skiing, mountaineering, and gymnastics. We present an overview of the injury, with the classification commonly used. Many surgical techniques have been described to manage recurrent subluxation of the peroneal tendons, but only Level IV/Grade C evidence has been produced. Thus, randomized controlled trials are necessary to determinate the best surgical management method. It appears that high-demand individuals should be primarily managed surgically, and retinaculoplasty seems to be, when indicated, the best surgical option: it affords less complications and a high rate of return to sports without reducing their activity levels. PMID:19440138

Oliva, Francesco; Del Frate, Dario; Ferran, Nicholas Antonio; Maffulli, Nicola

2009-06-01

103

Scaffolds in Tendon Tissue Engineering  

PubMed Central

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

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

2012-01-01

104

Tear film lipids.  

PubMed

Human meibomian gland secretions (MGS, or meibum) are formed from a complex mixture of lipids of different classes such as wax esters, cholesteryl esters, (O-acyl)-?-hydroxy fatty acids (OAHFA) and their esters, acylglycerols, diacylated diols, free fatty acids, cholesterol, and a smaller amount of other polar and nonpolar lipids, whose chemical nature and the very presence in MGS have been a matter of intense debates. The purpose of this review is to discuss recent results that were obtained using different experimental techniques, estimate limitations of their usability, and discuss their biochemical, biophysical, and physiological implications. To create a lipid map of MGS and tears, the results obtained in the author's laboratory were integrated with available information on chemical composition of MGS and tears. The most informative approaches that are available today to researchers, such as HPLC-MS, GC-MS, and proton NMR, are discussed in details. A map of the meibomian lipidome (as it is seen in reverse phase liquid chromatography/mass spectrometry experiments) is presented. Directions of future efforts in the area are outlined. PMID:23769846

Butovich, Igor A

2013-12-01

105

The Upper Band of the Subscapularis Tendon in the Rat has Altered Mechanical and Histologic Properties  

PubMed Central

Hypothesis/Background The subscapularis is an important mover and stabilizer of the glenohumeral joint and since the advent of shoulder arthroscopy, partial tears are found in 43% of rotator cuff patients. While partial tears to the upper band occur more commonly, little is known about the structure and mechanical behavior of the individual bands. Therefore, the objective of this study was to measure tensile mechanical properties, corresponding collagen fiber alignment, and histology in the upper and lower bands of the rat subscapularis tendon. Materials and Methods Thirty, adult Sprague-Dawley rats were euthanized and subscapularis tendons dissected out for mechanical, organization (n = 24), and histologic assessment (n = 6). Collagen organization was measured with a custom device during mechanical testing. Results Linear-region modulus at the insertion site was significantly lower in the upper band compared to the lower band while no differences were found at the midsubstance location. The upper band was found to be significantly less aligned and demonstrated a more rounded cell shape than the lower band at the insertion site. Discussion This study demonstrated that the two bands of the subscapularis tendon have differential mechanical, organizational, and histological properties. This suggests that a functional deficit exists to the upper band of the subscapularis and may be contributing to the prevalence of partial subscapularis tears. Conclusions Clinicians should be aware that the upper band of the subscapularis tendon may be at higher risk of developing tears due to the decreased mechanical properties and a more disorganized collagen fiber distribution. Level of Evidence Basic Science Study, Biomechanics, Animal Model. PMID:22484390

Thomas, Stephen J.; Miller, Kristin S.; Soslowsky, Louis J.

2011-01-01

106

Tear secretion and tear film function in insulin dependent diabetics  

PubMed Central

BACKGROUND—Diabetic patients often complain of dry eye symptoms, such as burning and/or foreign body sensation. The aim of the present study was to investigate whether diabetes mellitus is correlated with tear film dysfunction and/or tear hyposecretion.?METHODS—In 86 consecutive insulin dependent diabetics with retinopathy and 84 non-diabetic controls (age and sex matched) we performed fluorophotometry of tear secretion, the Schirmer test, and impression cytology of the conjunctival epithelium and determined the tear film break up time.?RESULTS—When compared with the healthy control group diabetics showed decreased Schirmer test readings (?37%, p <0.001) and significantly more frequent and pronounced signs of conjunctival metaplasia. None of the other values differed between groups.?CONCLUSION—In insulin dependent diabetics, reflex tearing was demonstrated to be significantly decreased. In contrast, unstimulated basal tear flow and tear film break up time were found to be normal. However, a majority of insulin dependent diabetics shows distinct signs of conjunctival surface disease.?? PMID:10611093

Goebbels, M.

2000-01-01

107

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

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

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

2010-01-01

108

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

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

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

2007-01-01

109

Development of a mouse model of supraspinatus tendon insertion site healing.  

PubMed

Supraspinatus (SS) tendon tears are common musculoskeletal injuries whose surgical repair exhibits the highest incidence of re-tear of any tendon. Development of therapeutics for improving SS tendon healing is impaired by the lack of a model that allows biological perturbations to identify mechanisms that underlie ineffective healing. The objective of this study was to develop a mouse model of supraspinatus insertion site healing by creating a reproducible SS tendon detachment and surgical repair which can be applied to a wide array of inbred mouse strains and genetic mutants. Anatomical and structural analyses confirmed that the rotator cuff of the mouse is similar to that of human, including the presence of a coracoacromial (CA) arch and an insertion site that exhibits a fibrocartilagenous transition zone. The surgical repair was successfully conducted on seven strains of mice that are commonly used in Orthopaedic Research suggesting that the procedure can be applied to most inbred strains and genetic mutants. The quality of the repair was confirmed with histology through 14 days after surgery in two mouse strains that represent the variation in mouse strains evaluated. The developed mouse model will allow us to investigate mechanisms involved in insertion site healing. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:25-32, 2015. PMID:25231092

Bell, Rebecca; Taub, Peter; Cagle, Paul; Flatow, Evan L; Andarawis-Puri, Nelly

2015-01-01

110

Femoral tunnel-interference screw divergence in anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft: A comparison of two techniques  

PubMed Central

Background: Interference screw is a popular fixation device used to rigidly fix bone-patellar tendon-bone (B-PT-B) graft both in femoral and tibial tunnels in anterior cruciate ligament (ACL) reconstruction. Parallel placement of screw is difficult in transtibially drilled femoral tunnel but always desired as it affects pullout strength of the graft. Commonly, interference screw into the femoral tunnel is inserted through the anteromedial (AM) or accessory AM portal. These portals are not-in-line with the transtibially drilled femoral tunnel. Furthermore, these portals increase the divergence of the interference screw in the femoral tunnel. We hypothesized that interference screw placement through patellar tendon (PT) portal (through donor defect) in transtibially drilled femoral tunnel can be less divergent. We report the prospective randomized study to investigate the difference of divergence of interference screw placed through PT portal and AM portal and its clinical relevance. Materials and Methods: Forty-one patients underwent femoral tunnel B-PT-B graft fixation through AM portal (group 1) and other 41 (group 2) through PT portal. Femoral tunnel-interference screw divergence was measured on postoperative digital lateral X-rays. Ha’s method was used to grade divergence. The clinical outcome was assessed by postoperative intervention knee documentation committee grading (IKDC) and Lysholm score at 2 years followup. Results: Mean tunnel-screw divergence in sagittal plane through AM portal was 13.38° (95% CI: 12.34-14.41) and through PT portal was 7.20° (95% CI: 6.25-8.16) (P<0.0001). In AM portal group, 82.9% patients had divergence in either grade 3 or 4 category, whereas in PT portal group, 82.9% patients were in grade 1 or 2 category (P<0.0001). Mean Lysholm score were 92.8 and 94.5 at two-year follow-up in both groups which were statistically not significant. The International knee documentation committee grades of patients in both groups were similar and had no statistical significance. Conclusion: Femoral interference screw placement through the PT portal leads to significantly less screw divergence as compared with screw placement through the AM portal. However, this difference in divergence is not reflected in clinical outcome. PMID:21559106

Pandey, Vivek; Acharya, Kiran; Rao, Sharath; Rao, Sripathi

2011-01-01

111

Arthroscopic intratendinous repair of the delaminated partial-thickness rotator cuff tear in overhead athletes.  

PubMed

A distinct type of partial-thickness rotator cuff tear has been observed in overhead athletes, characterized by partial failure of the undersurface of the posterior supraspinatus and anterior infraspinatus tendons with intratendinous delamination. We present a technique of percutaneous intratendinous repair using nonabsorbable mattress sutures designed for the management of articular-side delaminated partial-thickness tears. After tear evaluation and preparation, the torn rotator cuff undersurface is held in a reduced position with a grasper through an anterolateral rotator interval portal while viewing intra-articularly. Two spinal needles are then placed percutaneously through the full thickness of the torn and intact rotator cuff. A polydioxanone suture is passed through each needle, retrieved out the anterior portal, and used to shuttle a single nonabsorbable No. 2 suture through the tissue, creating a mattress suture. Multiple mattress sutures can be placed as dictated by tear size and morphology, with suture retrieval and knot securing then proceeding in the subacromial space. We have adopted this approach with the goals of anatomically re-establishing the rotator cuff insertion and sealing the area of intratendinous delamination while preventing significant alteration to the anatomy of the rotator cuff insertion, which could lead to motion deficits, internal impingement, and potential tear recurrence. PMID:18657747

Brockmeier, Stephen F; Dodson, Christopher C; Gamradt, Seth C; Coleman, Struan H; Altchek, David W

2008-08-01

112

Sonographic findings during and after Platelet Rich Plasma injections in tendons  

PubMed Central

Summary Platelet rich plasma has been used in the treatment of tendinopathies, but the sonographic modifications of tendons have received less attention. In this paper we report the results of an ultrasound evaluation, performed during and after plasma injection, in patients with tendinopathy. The sonographic abnormalities and neovascularization were registered in twenty tendons. Three plasma injections (once a week) were performed, and a rehabilitation program was recommended. Pain and patients’ satisfaction were evaluated. During the injections plasma spread along the collagen fibers, and an intratendineous cleft produced by the injected volume was observed. At 12 months two tendons regained a normal echotexture, while neovessels were absent in seven. The remaining tendons showed less abnormalities and neovascularization in comparison with baseline. The clinical improvement was earlier and more consistent. The discrepancy between the ultrasound and clinical results may be explained by the peculiar modalities of tendon healing induced by plasma administration. PMID:24932444

Abate, Michele; Verna, Sandra; Di Gregorio, Patrizia; Salini, Vincenzo; Schiavone, Cosima

2014-01-01

113

Congenital Aberrant Tearing: A Re-Look  

PubMed Central

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

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

2008-01-01

114

Wear and Tear - Mechanical  

NASA Technical Reports Server (NTRS)

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.

Swanson, Theodore

2008-01-01

115

Various patterns of traumatic triangular fibrocartilage complex tear.  

PubMed

We demonstrate various patterns of traumatic triangular fibrocartilage complex (TFCC) tears including some atypical that cannot be categorized under Palmer's classification. TFCC traumatic tears in 173 wrists were examined arthroscopically or macroscopically and divided into disk tears (subdivided into four types: slit tear, flap tear, horizontal tear and tear within the distal radioulnar joint) and peripheral tears (subdivided into six types: ulnocarpal ligament tear, dorsal tear, radial tear, ulnar styloid tear, foveal tear and distal radioulnar ligament tear). Combinations of these types were found in 32 wrists. Wrist arthroscopy revealed various traumatic TFCC tears that do not come under Palmer's classification; therefore establishment of a new classification for traumatic TFCC tears seems to be warranted. PMID:22745082

Abe, Y; Tominaga, Y; Yoshida, K

2012-01-01

116

Position Control of Tendon-Driven Fingers.  

National Technical Information Service (NTIS)

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 i...

B. Hargrave, F. Pementer, M. E. Abdallah, R. Platt

2011-01-01

117

Flexor tendon injuries in the child.  

PubMed

This review aims to highlight the differences in the management of flexor tendon injuries between children and adults. These include differences in epidemiology, anatomy, classification, diagnosis, incisions and skin closure, the size of the flexor tendons, technical aspects of zones I and II repairs, core suture purchase length, rehabilitation, results, and complications of primary flexor tendon repair. Finally, one- versus two-stage flexor tendon reconstruction in children is reviewed. PMID:23855037

Al-Qattan, M M

2014-01-01

118

Investigation of spherical tearing mode  

NASA Technical Reports Server (NTRS)

The purpose of this research was to better understand tearing and reconnection in genuinely three-dimensional configurations. We have identified an equilibrium model that should contain the required features. Three papers have been written and a fourth is in preparation. They are listed in the bibliography.

Greene, John M.; Miller, R. L.

1995-01-01

119

Achilles tendon reflex measuring system  

NASA Astrophysics Data System (ADS)

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.

Szebeszczyk, Janina; Straszecka, Joanna

1995-06-01

120

Common Disorders of the Achilles Tendon  

MedlinePLUS

... tendon is then altered, resulting in continued pain. Athletes are at high risk for developing disorders of the Achilles tendon. Achilles tendonitis and tendonosis are also common in individuals whose work puts stress on their ankles and feet, such as laborers, ...

121

The cell biology of suturing tendons  

Microsoft Academic Search

Trauma by suturing tendon form areas devoid of cells termed “acellular zones” in the matrix. This study aimed to characterise the cellular insult of suturing and acellular zone formation in mouse tendon. Acellular zone formation was evaluated using single grasping sutures placed using flexor tendons with time lapse cell viability imaging for a period of 12h. Both tension and injury

J. K. F. Wong; S. Alyouha; K. E. Kadler; M. W. J. Ferguson; D. A. McGrouther

2010-01-01

122

Passive smoking elevates neurotrophin levels in tears.  

PubMed

The effect of passive smoking on levels of neurotrophin in tears was studied in normal subjects or patients with atopic keratoconjunctivitis (AKC). Basal levels of neurotrophins, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and NT-4, in tears were significantly higher in AKC patients than those in normal subjects. Passive smoking had no effect on levels of neurotrophin in tears of normal subjects, while it elevated levels of NGF, BDNF, NT-3 and NT-4 in tears of AKC patients. These results indicate that passive smoking elevates levels of neurotrophin in tears, which in turn may aggravate AKC. PMID:15222398

Kimata, Hajime

2004-05-01

123

Can PRP effectively treat injured tendons?  

PubMed Central

Summary PRP is widely used to treat tendon and other tissue injuries in orthopaedics and sports medicine; however, the efficacy of PRP treatment on injured tendons is highly controversial. In this commentary, I reason that there are many PRP- and patient-related factors that influence the outcomes of PRP treatment on injured tendons. Therefore, more basic science studies are needed to understand the mechanism of PRP on injured tendons. Finally, I suggest that better understanding of the PRP action mechanism will lead to better use of PRP for the effective treatment of tendon injuries in clinics. PMID:24932445

Wang, James H-C.

2014-01-01

124

Observation of nonlinear neoclassical {nabla}{sub p}-driven tearing modes in TFTR  

SciTech Connect

A quantitative comparison is made between the tearing-type modes observed supershot plasmas and the nonlinear, neoclassical pressure gradient ({nabla}{sub p}) driven tearing mode theory. Good agreement is found on the nonlinear magnetic island evolution of a single helicity mode (m/n = 3/2, 4/3 or 5/4, where m and n are the poloidal and toroidal mode numbers, respectively). Statistical data on the island width and growth rate are also found to be consistent with this theory. The results imply that the supershot plasmas are the classical current-driven tearing modes.

Chang, Z.; Callen, J.D.; Hegna, C.C. [Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering and Engineering Physics; Fredrickson, E.D.; Budny, R.V.; McGuire, K.M.; Zarnstorff, M.C. [Princeton Univ., NJ (United States). Plasma Physics Lab.

1994-08-22

125

Engineering tendon and ligament tissues: present developments towards successful clinical products.  

PubMed

Musculoskeletal diseases are one of the leading causes of disability worldwide. Among them, tendon and ligament injuries represent an important aspect to consider in both athletes and active working people. Tendon and ligament damage is an important cause of joint instability, and progresses into early onset of osteoarthritis, pain, disability and eventually the need for joint replacement surgery. The social and economical burden associated with these medical conditions presents a compelling argument for greater understanding and expanding research on this issue. The particular physiology of tendons and ligaments (avascular, hypocellular and overall structural mechanical features) makes it difficult for currently available treatments to reach a complete and long-term functional repair of the damaged tissue, especially when complete tear occurs. Despite the effort, the treatment modalities for tendon and ligament are suboptimal, which have led to the development of alternative therapies, such as the delivery of growth factors, development of engineered scaffolds or the application of stem cells, which have been approached in this review. PMID:22499564

Rodrigues, Márcia T; Reis, Rui L; Gomes, Manuela E

2013-09-01

126

Hyperuricemic PRP in Tendon Cells  

PubMed Central

Platelet-rich plasma (PRP) is injected within tendons to stimulate healing. Metabolic alterations such as the metabolic syndrome, diabetes, or hyperuricemia could hinder the therapeutic effect of PRP. We hypothesise that tendon cells sense high levels of uric acid and this could modify their response to PRP. Tendon cells were treated with allogeneic PRPs for 96 hours. Hyperuricemic PRP did not hinder the proliferative actions of PRP. The gene expression pattern of inflammatory molecules in response to PRP showed absence of IL-1b and COX1 and modest expression of IL6, IL8, COX2, and TGF-b1. IL8 and IL6 proteins were secreted by tendon cells treated with PRP. The synthesis of IL6 and IL8 proteins induced by PRP is decreased significantly in the presence of hyperuricemia (P = 0.017 and P = 0.012, resp.). Concerning extracellular matrix, PRP-treated tendon cells displayed high type-1 collagen, moderate type-3 collagen, decorin, and hyaluronan synthase-2 expression and modest expression of scleraxis. Hyperuricemia modified the expression pattern of extracellular matrix proteins, upregulating COL1 (P = 0.036) and COMP (P = 0.012) and downregulating HAS2 (P = 0.012). Positive correlations between TGF-b1 and type-1 collagen (R = 0.905, P = 0.002) and aggrecan (R = 0.833, P = 0.010) and negative correlations between TGF-b1 and IL6 synthesis (R = ?0.857, P = 0.007) and COX2 (R = ?0.810, P = 0.015) were found. PMID:25276832

Andia, I.; Rubio-Azpeitia, E.; Maffulli, N.

2014-01-01

127

Tear analysis in contact lens wearers.  

PubMed Central

Tear analysis in contact lens wearers was compared with tear analysis in aphakics without contact lens wear and normal phakic patients. Subjects were divided into five groups: group 1, aphakic without contact lens; group 2, phakic with daily-wear hard contact lens; group 3, phakic with daily-wear soft contact lens; group 4, phakic with extended-wear soft contact lens; and group 5, aphakic with extended-wear soft contact lens. The experimental groups were compared with age- and sex-matched control groups for statistical analysis of tear variables by means of the Student's t-test. The variables measured were tear osmolarity, tear albumin, and lysozyme and lactoferrin concentrations in basal and reflex tears. Highly significant elevations of tear osmolarity were found in aphakic subjects without contact lenses. Less significant differences in tear osmolarity were found in phakic subjects with hard daily-wear lenses or with extended-wear soft lenses. Tear albumin, lysozyme, and lactoferrin in basal and reflex tears were not significantly different in the different groups of contact lens wearers or in the group of aphakic subjects without contact lenses compared with their control groups. Individual variations in tear albumin, lysozyme, and lactoferrin appeared to be responsible for the inability to demonstrate significant differences in tear composition in association with the wearing of different types of contact lenses. Older and aphakic patients demonstrated a tendency to have increased concentrations of proteins in the tears compared with younger, phakic contact lens wearers and normal controls without contact lenses. PMID:3914131

Farris, R L

1985-01-01

128

Human tendon behaviour and adaptation, in vivo  

PubMed Central

Tendon properties contribute to the complex interaction of the central nervous system, muscle–tendon unit and bony structures to produce joint movement. Until recently limited information on human tendon behaviour in vivo was available; however, novel methodological advancements have enabled new insights to be gained in this area. The present review summarizes the progress made with respect to human tendon and aponeurosis function in vivo, and how tendons adapt to ageing, loading and unloading conditions. During low tensile loading or with passive lengthening not only the muscle is elongated, but also the tendon undergoes significant length changes, which may have implications for reflex responses. During active loading, the length change of the tendon far exceeds that of the aponeurosis, indicating that the aponeurosis may more effectively transfer force onto the tendon, which lengthens and stores elastic energy subsequently released during unloading, in a spring-like manner. In fact, data recently obtained in vivo confirm that, during walking, the human Achilles tendon provides elastic strain energy that can decrease the energy cost of locomotion. Also, new experimental evidence shows that, contrary to earlier beliefs, the metabolic activity in human tendon is remarkably high and this affords the tendon the ability to adapt to changing demands. With ageing and disuse there is a reduction in tendon stiffness, which can be mitigated with resistance exercises. Such adaptations seem advantageous for maintaining movement rapidity, reducing tendon stress and risk of injury, and possibly, for enabling muscles to operate closer to the optimum region of the length–tension relationship. PMID:17855761

Magnusson, S Peter; Narici, Marco V; Maganaris, Constantinos N; Kjaer, Michael

2008-01-01

129

Repair of rotator cuff tears in tennis players  

Microsoft Academic Search

Twenty-three tennis players with a symptomatic full- thickness rotator cuff tear underwent anterior acro mioplasty and rotator cuff repair. There were 8 small tears (<1 cm), 5 moderate tears (1 to 3 cm), 2 large tears (3 to 5 cm), and 8 massive tears (>5 cm). The dominant shoulder was involved in all patients and all were unable to play

Louis U. Bigiliani; Jay Kimmel; Peter D. McCann; Ira Wolfe

1992-01-01

130

[Isokinetic assessment with two years follow-up of anterior cruciate ligament reconstruction with patellar tendon or hamstring tendons].  

PubMed

This retrospective multicentric study was designed to assess the outcome of quadriceps and hamstrings muscles two years after Anterior Cruciate Ligament (ACL) reconstruction and compare muscles recovery depending on the type of graft and individual variables like age, gender, level of sport, but also in terms of discomfort, pain and functional score. The results focused on the subjective and objective IKDC scores, SF36, the existence or not of subjective disorders and their location. The review included isokinetic muscle tests concentric and eccentric extensors/flexors but also internal rotators/external rotators with analysis of mean work and mean power. One hundred and twenty-seven patients were included with an average age 29 years (+/-10). They all had an ACL reconstruction with patellar tendon or hamstring tendon with single or double bundles. In the serie, the average muscles deficit at two years was 10% for the flexors and extensors but with a significant dispersion. Significant differences were not noted in the mean values of all parameters in term of sex or age (over 30 years or not), neither the type of sport, nor of clinical assessment (Class A and B of objective IKDC score), nor the existence of anterior knee pain. There was a relationship between the level of extensor or flexor recovery and the quality of functional results with minimal muscle deficits close to 5% if the IKDC score was over 90 and deficits falling to 15% in the group with IKDC score less than 90. The type of reconstruction (patellar tendon versus hamstrings) had an influence on the muscle deficit. For extensors, the recovery was the same in the two groups, more than 90% at two years and the distribution of these two populations by level of deficit was quite the same. For flexors, residual deficits were significantly higher in the hamstrings group on the three studied parameters whatever the speed and the type of contraction (concentric or eccentric) with an average deficit of 14 to 18%, while, in the patellar tendon group, there was a dominance over the opposite side of 2 to 3% in concentric contraction. The hamstrings deficit appears to be "harvest dependent". For internal rotators, a significantly higher deficit is observed in eccentric contraction for the hamstrings group. The residual hamstrings deficits were related to the number of tendons harvested: -7% when there was no harvest, 7% with one tendon harvested and 17% with two tendons harvested. The relationship between the level of recovery of the quadriceps muscle and hamstrings at two years and the quality of functional results incite, regarding the significantly higher deficit of flexors in ACL reconstructions with hamstrings, to change the rehabilitation programs and especially on early rehabilitation of hamstrings in eccentric mode in the early weeks postoperative considering the harvest site as an equivalent of muscle tear. PMID:19046696

Condouret, J; Cohn, J; Ferret, J-M; Lemonsu, A; Vasconcelos, W; Dejour, D; Potel, J-F

2008-12-01

131

Active Achilles tendon kinesitherapy accelerates Achilles tendon repair by promoting neurite regeneration?  

PubMed Central

Active Achilles tendon kinesitherapy facilitates the functional recovery of a ruptured Achilles tendon. However, protein expression during the healing process remains a controversial issue. New Zealand rabbits, aged 14 weeks, underwent tenotomy followed immediately by Achilles tendon microsurgery to repair the Achilles tendon rupture. The tendon was then immobilized or subjected to postoperative early motion treatment (kinesitherapy). Mass spectrography results showed that after 14 days of motion treatment, 18 protein spots were differentially expressed, among which, 12 were up-regulated, consisting of gelsolin isoform b and neurite growth-related protein collapsing response mediator protein 2. Western blot analysis showed that gelsolin isoform b was up-regulated at days 7–21 of motion treatment. These findings suggest that active Achilles tendon kinesitherapy promotes the neurite regeneration of a ruptured Achilles tendon and gelsolin isoform b can be used as a biomarker for Achilles tendon healing after kinesitherapy. PMID:25317130

Jielile, Jiasharete; Aibai, Minawa; Sabirhazi, Gulnur; Shawutali, Nuerai; Tangkejie, Wulanbai; Badelhan, Aynaz; Nuerduola, Yeermike; Satewalede, Turde; Buranbai, Darehan; Hunapia, Beicen; Jialihasi, Ayidaer; Bai, Jingping; Kizaibek, Murat

2012-01-01

132

Active Achilles tendon kinesitherapy accelerates Achilles tendon repair by promoting neurite regeneration.  

PubMed

Active Achilles tendon kinesitherapy facilitates the functional recovery of a ruptured Achilles tendon. However, protein expression during the healing process remains a controversial issue. New Zealand rabbits, aged 14 weeks, underwent tenotomy followed immediately by Achilles tendon microsurgery to repair the Achilles tendon rupture. The tendon was then immobilized or subjected to postoperative early motion treatment (kinesitherapy). Mass spectrography results showed that after 14 days of motion treatment, 18 protein spots were differentially expressed, among which, 12 were up-regulated, consisting of gelsolin isoform b and neurite growth-related protein collapsing response mediator protein 2. Western blot analysis showed that gelsolin isoform b was up-regulated at days 7-21 of motion treatment. These findings suggest that active Achilles tendon kinesitherapy promotes the neurite regeneration of a ruptured Achilles tendon and gelsolin isoform b can be used as a biomarker for Achilles tendon healing after kinesitherapy. PMID:25317130

Jielile, Jiasharete; Aibai, Minawa; Sabirhazi, Gulnur; Shawutali, Nuerai; Tangkejie, Wulanbai; Badelhan, Aynaz; Nuerduola, Yeermike; Satewalede, Turde; Buranbai, Darehan; Hunapia, Beicen; Jialihasi, Ayidaer; Bai, Jingping; Kizaibek, Murat

2012-12-15

133

Flexor tendon injuries in athletes.  

PubMed

Flexor tendon injuries are not common in most sporting venues; however, recognition of the pertinent anatomy, clinical findings, and the utility of diagnostic imaging will assist the clinician in a thorough evaluation of the athlete's hand. Open injuries demand immediate wound care and evaluation as to the integrity of the flexor apparatus; however, closed injuries often present with the challenges of timing: delayed injury presentation and pressures of intervention and return to play. The purpose of this article is to provide a review of the pertinent anatomy of the flexor apparatus of the hand, to identify key aspects of the patient history, clinical evaluation, and diagnostic testing relevant to flexor function, and to discuss treatment options in the setting of injuries to the flexor tendons and flexor pulley system of the hand. PMID:24651291

Neumann, Julie A; Leversedge, Fraser J

2014-03-01

134

Achilles tendon rupture in badminton.  

PubMed Central

The typical badminton player with an Achilles tendon rupture is 36 years old and, despite limbering up, is injured at the rear line in a sudden forward movement. He resumes work within three months and has a slight lack of dorsiflexion in the ankle as the main complication. Most patients resume badminton within one year, but some finish their sports career, mainly due to fear of a new injury. The investigation discusses predisposing factors and prophylactic measures. PMID:2605439

Kaalund, S; Lass, P; Høgsaa, B; Nøhr, M

1989-01-01

135

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

PubMed Central

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

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

2009-01-01

136

Les plaies du tendon patellaire  

PubMed Central

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.

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

2014-01-01

137

Nanoparticle-Induced Superior Hot Tearing Resistance of A206 Alloy  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

138

Crucial transcription factors in tendon development and differentiation: their potential for tendon regeneration.  

PubMed

Tendons that connect muscles to bone are often the targets of sports injuries. The currently unsatisfactory state of tendon repair is largely attributable to the limited understanding of basic tendon biology. A number of tendon lineage-related transcription factors have recently been uncovered and provide clues for the better understanding of tendon development. Scleraxis and Mohawk have been identified as critical transcription factors in tendon development and differentiation. Other transcription factors, such as Sox9 and Egr1/2, have also been recently reported to be involved in tendon development. However, the molecular mechanisms and application of these transcription factors remain largely unclear and this prohibits their use in tendon therapy. Here, we systematically review and analyze recent findings and our own data concerning tendon transcription factors and tendon regeneration. Based on these findings, we provide interaction and temporal programming maps of transcription factors, as a basis for future tendon therapy. Finally, we discuss future directions for tendon regeneration with differentiation and trans-differentiation approaches based on transcription factors. PMID:24705622

Liu, Huanhuan; Zhu, Shouan; Zhang, Can; Lu, Ping; Hu, Jiajie; Yin, Zi; Ma, Yue; Chen, Xiao; OuYang, Hongwei

2014-05-01

139

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

PubMed Central

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

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

140

Advantages of open repair of a foveal tear of the triangular fibrocartilage complex via a palmar surgical approach.  

PubMed

Foveal tears of the triangular fibrocartilage complex (TFCC) can be repaired via a palmar surgical approach. Unlike the dorsal approach, in this method the floor of the extensor carpi ulnaris tendon subsheath and the dorsal superficial limb of the radioulnar ligament do not hinder the view of the fovea. Patients with a fresh or chronic TFCC foveal tear and a positive ulnar fovea sign with its dorsal styloid insertion remaining intact are candidates for this procedure. During operation, the shoulder is positioned at 90 degrees of abduction, and the elbow is flexed at 90 degrees on an arm board. A 4 cm curved skin incision along the flexor carpi ulnaris tendon is made on the anterior aspect of the ulnar fovea. The ulnar fovea is exposed through a transverse capsulotomy of the distal radioulnar joint. The ulnocarpal joint distal to the TFCC is also exposed between the extensor carpi ulnaris tendon subsheath and the ulnotriquetrum ligament. After curettage of the scar tissues at the fovea, the lifted TFCC is sutured onto the fovea using a suture anchor technique. PMID:19956042

Moritomo, Hisao

2009-12-01

141

Knotless anatomic double-layer double-row rotator cuff repair: a novel technique re-establishing footprint and shape of full-thickness tears  

Microsoft Academic Search

The standard technique for restoring footprint after full-thickness tears of the rotator cuff includes double-row or transosseous-equivalent\\u000a techniques. However, the anatomically typical bird’s beak shape and profile of tendon insertion may not be originally restored\\u000a and biomechanics may be altered. In this report, the authors describe a technique that involves creating two intratendinous\\u000a stitches at different levels of the torn

Pierre Hepp; Thomas Engel; Georg Osterhoff; Bastian Marquass; Christoph Josten

2009-01-01

142

Open repair for massive rotator cuff tear with a modified transosseous-equivalent procedure: preliminary results at short-term follow-up  

Microsoft Academic Search

Background  Many surgical procedures have been reported for rotator cuff tears. We adopted the modified transosseous-equivalent procedure,\\u000a also termed “surface-holding repair with transosseous sutures,” and demonstrated that this procedure has a biomechanical advantage\\u000a regarding the concentration of stress on the tendon stump. This study aimed to evaluate the clinical and structural outcomes\\u000a of this technique, which has been demonstrated by postoperative

Hiroshi Yamaguchi; Naoki Suenaga; Naomi Oizumi; Yoshihiro Hosokawa; Fuminori Kanaya

143

Triceps tendon rupture in weight lifters.  

PubMed

Triceps tendon avulsion injuries are rare. We report four weight lifters with triceps tendon raptures, two of whom had received local steroid injections for pain in the triceps. All four patients had taken oral anabolic steroids before injury. All patients had closed avulsion of the triceps tendon from its insertion into the olecranon. Three patients were injured while bench pressing heavy weights, and one patient was injured while swinging a baseball bat. Satisfactory results were achieved after surgical reinsertion of the tendon. PMID:9593095

Sollender, J L; Rayan, G M; Barden, G A

1998-01-01

144

[Effects of Gravity on Attachment of Tendon to Bone  

NASA Technical Reports Server (NTRS)

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.

Johnson, Roger B.

1997-01-01

145

IETI - Isogeometric Tearing and Interconnecting  

PubMed Central

Finite Element Tearing and Interconnecting (FETI) methods are a powerful approach to designing solvers for large-scale problems in computational mechanics. The numerical simulation problem is subdivided into a number of independent sub-problems, which are then coupled in appropriate ways. NURBS- (Non-Uniform Rational B-spline) based isogeometric analysis (IGA) applied to complex geometries requires to represent the computational domain as a collection of several NURBS geometries. Since there is a natural decomposition of the computational domain into several subdomains, NURBS-based IGA is particularly well suited for using FETI methods. This paper proposes the new IsogEometric Tearing and Interconnecting (IETI) method, which combines the advanced solver design of FETI with the exact geometry representation of IGA. We describe the IETI framework for two classes of simple model problems (Poisson and linearized elasticity) and discuss the coupling of the subdomains along interfaces (both for matching interfaces and for interfaces with T-joints, i.e. hanging nodes). Special attention is paid to the construction of a suitable preconditioner for the iterative linear solver used for the interface problem. We report several computational experiments to demonstrate the performance of the proposed IETI method. PMID:24511167

Kleiss, Stefan K.; Pechstein, Clemens; Juttler, Bert; Tomar, Satyendra

2012-01-01

146

Interferometric characterization of tear film dynamics  

NASA Astrophysics Data System (ADS)

The anterior refracting surface of the eye is the thin tear film that forms on the surface of the cornea. When a contact lens is on worn, the tear film covers the contact lens as it would a bare cornea, and is affected by the contact lens material properties. Tear film irregularity can cause both discomfort and vision quality degradation. Under normal conditions, the tear film is less than 10 microns thick and the thickness and topography change in the time between blinks. In order to both better understand the tear film, and to characterize how contact lenses affect tear film behavior, two interferometers were designed and built to separately measure tear film behavior in vitro and in vivo. An in vitro method of characterizing dynamic fluid layers applied to contact lenses mounted on mechanical substrates has been developed using a phase-shifting Twyman-Green interferometer. This interferometer continuously measures light reflected from the surface of the fluid layer, allowing precision analysis of the dynamic fluid layer. Movies showing this fluid layer behavior can be generated. The fluid behavior on the contact lens surface is measured, allowing quantitative analysis beyond what typical contact angle or visual inspection methods provide. The in vivo interferometer is a similar system, with additional modules included to provide capability for human testing. This tear film measurement allows analysis beyond capabilities of typical fluorescein visual inspection or videokeratometry and provides better sensitivity and resolution than shearing interferometry methods.

Primeau, Brian Christopher

147

Arthroscopic surgery for partial rotator cuff tears  

Microsoft Academic Search

Rotator cuff pathology is one of the most common disorders of the shoulder. However, partial rotator cuff tears, treatment, and natural history are still in a state of flux. We believe that partial rotator cuff tears should be treated surgically when the rotator cuff is torn more than 50% of the thickness or when substantial thinning of the rotator cuff

Richard C Lehman; Clayton R Perry

2003-01-01

148

Recent developments in flexor tendon repair techniques and factors influencing strength of the tendon repair.  

PubMed

Over the last decade, both basic researchers and surgeons have sought to identify the most appropriate techniques to be applied in flexor tendon repairs. Recent developments in experimental tendon repairs and clinical outcomes of newer repair techniques have been reviewed in an attempt to comprehensively summarize the most critical mechanical factors affecting the performance of tendon repairs and the surgical factors influencing clinical outcomes. Among them, attention to annular pulleys, the purchase and tension of the core suture, and the direction and curvature of the path of tendon motion have been found to be determining factors in the results of tendon repair. PMID:23792441

Wu, Y F; Tang, J B

2014-01-01

149

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

PubMed Central

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

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

2007-01-01

150

Greater tuberosity osteotomy and teres minor transfer for irreparable superior rotator cuff tears.  

PubMed

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

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

2007-01-01

151

Effect of triggering and entrapment on tendon gliding properties following digital flexor tendon laceration: in vitro study on turkey tendon.  

PubMed

The optimal management of partial flexor tendon laceration is controversial and remains a clinical challenge. Abnormal tendon gliding (triggering and entrapment) was assessed at the A2 pulley in 40 turkey tendons in three groups: intact, partially divided (palmar or lateral), and trimmed. Testing was of gliding resistance and friction coefficient at 30° and 70° of flexion, loaded with 2 and 4 N. We observed for triggering and entrapment. The changes in gliding properties were compared and analysed using Wilcoxon matched pair testing. A significant difference was found in the change in gliding properties of intact to lacerated and lacerated to trimmed tendons and between tendons that glided normally compared with those exhibiting triggering or entrapment. This suggests that palmar and lateral lacerations which, through clinical examination and visualization, are found to glide normally should be treated with early mobilization. However, partial lacerations that exhibit triggering or entrapment should be trimmed. PMID:23735810

Kennedy, J A; Dias, J J

2014-09-01

152

Extensor tendon injury due to repetitive wrist dorsiflexion: morphological study of extensor retinaculum and extensor tendon.  

PubMed

Most etiological studies of extensor tendon injury were based on the normal anatomy of extensor tendon and extensor retinaculum of the wrist. Further understanding of the morphological changes of the extensor tendon and extensor retinaculum during wrist dorsiflexion might contribute to improved and more accurate understanding of the etiology. The morphology of the extensor tendon of the mid-finger and the fourth compartment of the wrist extensor retinaculum was studied by sonography, and the anatomy was studied in 15 extremities from 11 young male cadavers. Compared with anatomical images, ultrasonography provides similar morphological observations of the extensor retinaculum of the wrist and extensor tendon. Ultrasonography findings revealed that as the dorsiflexion angle changed, the extensor retinaculum of the wrist formed different shaped trochleas. The trochlea guides the rotation of the extensor tendon at the wrist, but it does not form a sharp corner with the extensor tendon; thus, the extensor tendon is not compressed. As the dorsiflexion angle increased from 0° to 60°, the length of the trochlea gradually decreases. The shortening of the trochlea length will lead to a smaller frictional contact area between the extensor tendon and the extensor retinaculum. Consequently, the friction is centralized. During wrist dorsiflexion, the extensor retinaculum provides a trochlea for the extensor tendon. Extensor tendon injury of repetitive wrist dorsiflexion might be caused by centralized friction at the small contact area. PMID:24902538

Zhou, Chang-Long; Wang, Xin-Tao; Chi, Zhi-Yong; Yan, Jing-Long

2014-11-01

153

Calcific tendonitis of the tibialis posterior tendon at the navicular attachment  

PubMed Central

Calcific tendinosis (tendonosis/tendonitis) is a condition which results from the deposition of calcium hydroxyapatite crystals in any tendon of the body. Calcific tendonitis usually presents with pain, which can be exacerbated by prolonged use of the affected tendon. We report a case of calcific tendinosis in the posterior tibialis tendon at the navicular insertion. The pathology is rare in the foot, and extremely rare in the tibialis posterior tendon, indeed there are only 2 reported in the published literature. This case report highlights the need to consider calcific tendinosis in the foot despite its rarity. If this diagnosis is considered early, appropriate investigations can then be requested and unnecessary biopsies, use of antibiotics and surgery can be avoided. We also discuss possible causes of calcific tendinosis in the tibialis posterior tendon, the role of imaging modalities and review treatment methods. PMID:22470798

Harries, Luke; Kempson, Susan; Watura, Roland

2011-01-01

154

A proteomic analysis of engineered tendon formation under dynamic mechanical loading in vitro.  

PubMed

Previous studies have demonstrated the beneficial effect of mechanical loading on in vitro tendon engineering. To understand the mechanism, human tenocytes and polyglycolic acid long fibers were used for in vitro tendon engineering in a bioreactor system for 12 weeks with and without dynamic loading. The engineered neo-tendons were subjected to proteomic analysis using mass spectrometry along with shotgun strategy. As expected, mechanical loading resulted in a more mature tendon tissue characterized by a firmer tissue texture and densely deposited matrices which formed longitudinally aligned collagen fibers in a highly compact fashion. In contrast, non-loaded neo-tendon revealed loosely and less deposited matrices in a relatively less organized pattern. Proteins isolated from two groups of tissues exhibited similar distribution of isoeletric point and molecular weight indicating the similarity and comparability of the tissue specimens. Further, proteomic analysis showed that total 758 proteins were identified from both groups with 194 and 177 proteins uniquely presented in loaded and non-loaded tendons, respectively. Comparison of loaded and non-loaded tendons revealed 195 significantly up-regulated proteins and 189 significantly down-regulated proteins. The differentially expressed proteins could generally be classified into the categories of extracellular matrix, intra-cellular signaling, cytoskeleton and inflammatory response. Among them, significantly up-regulated collagens I and VI, MMP-14, WNT5A, microfilament molecules and some inflammatory factors suggest that the possible mechanism for this particular biological phenomenon may involve increased production of tendon specific matrices, enhanced cross-link of collagens and other matrix molecules, proper matrix remodeling for tissue maturation and mechanotransduction (including non-canonical Wnt signal pathway) mediated other biological processes. PMID:21402406

Jiang, Yongkang; Liu, Hongwei; Li, Hong; Wang, Fangjun; Cheng, Kai; Zhou, Guangdong; Zhang, Wenjie; Ye, Mingliang; Cao, Yinlin; Liu, Wei; Zou, Hanfa

2011-06-01

155

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

PubMed

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

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

2012-05-01

156

Estimating upper extremity tendon slack lengths  

Microsoft Academic Search

Tendon slack lengths are used in a dynamic muscle and limb model to animate the upper extremity based on user supplied activation levels. This paper provides tendon slack length estimates for actuators crossing the elbow and inserting on the radius or ulna. These values were not previously available as a complete see for the upper extremity. Muscle parameters used in

Brian R. von Konsky

1995-01-01

157

Mechanical properties of model synthetic tendons.  

PubMed

Model synthetic tendons consisting of 20 vol % of texturized poly(ethylene terephthalate) fibers and of the water-swollen poly(2-hydroxyethyl methacrylate) matrix have the tensile modulus E = 1.5 +/- 0.1 GPa, strength and strain-at-break sigma b = 85 +/- 10 MPa and epsilon b = 0.08 +/- 0.02. The force required for breaking tendons with the diameters 2, 3, 4 mm is, respectively, 300, 500, and 960 N. By these properties model synthetic tendons closely imitate the properties of natural tendons. Long-term (100 min) and repeated short-term (30 times 1 min) creep shows that on loading model tendons lose some 10% of their stiffness, but that the whole deformation is reversible. The shape of the compliance vs. time dependence of synthetic tendons closely resembles the dependence determined for the parent fiber. The stiffness and strength of a tendon are given by those of the fiber bundle used; by varying fiber volume fraction, it is possible to adjust the required mechanical properties of tendons. PMID:7348710

Kolarík, J; Migliaresi, C; Stol, M; Nicolais, L

1981-03-01

158

Unusual rupture of a flexor profundus tendon.  

PubMed

An unusual rupture of a flexor profundus tendon, previously unreported in the literature, is presented. There was avulsion and proximal displacement of a large bone fragment from the palmar base of the distal phalanx and further retraction of the tendon unattached to the bone fragment. PMID:3958452

Langa, V; Posner, M A

1986-03-01

159

Operative and nonoperative treatment options for ACL tears in the adult patient: a conceptual review.  

PubMed

Injury to the anterior cruciate ligament (ACL) is common among athletic individuals. Both nonoperative and operative treatment options exist. The optimal treatment of an adult with an ACL tear depends on several patient-specific factors, including age, occupation, and desired activity level. In less active patients with sedentary jobs, nonoperative management, consisting of physical therapy, bracing, and activity modification can yield successful results. In active patients who want to resume participation in jumping, cutting, or pivoting sports, patients who have physically demanding occupations, or patients who fail a trial of nonoperative management, ACL reconstruction is recommended. Reconstruction utilizing autograft tissue is preferred over allograft, especially in the younger athlete, but allograft tissue is a reasonable option in the older (aged > 40 years) and less active adult, as well. Successful results have been achieved with both patellar tendon and hamstring grafts. The optimal treatment in adult patients with ACL tears should be based on careful consideration of the patient's goals for return to activity, knee-specific comorbidities, such as coexistent meniscal pathology or osteoarthritis, and his or her willingness to follow a detailed rehabilitation regimen. Our article provides an overview of current nonoperative and operative treatment options for adults with ACL tears, considers the outcomes of both nonoperative and operative strategies, and provides general recommendations as to the ideal management for a given patient. PMID:24231595

Bogunovic, Ljiljana; Matava, Matthew J

2013-11-01

160

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

NASA Astrophysics Data System (ADS)

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.

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

2007-03-01

161

Comparative study of tear substitutes and their immediate effect on the precorneal tear film.  

PubMed

Dry eye patients present with instability of the precorneal tear film which breaks up much earlier than normally. The instability of the precorneal tear film leads to dry eye symptoms such as the sensation of sand in the eye, recurrent blurred vision, itching, smartness, and the sensation of dryness. The stability of the precorneal tear film can be evaluated by the break-up-time test (BUT). The aim of treatment of dry eye is to increase the precorneal tear film stability. Tear substitutes are the most frequent medication for dry eye patients, who request life-long treatment. Therefore, we estimated the influence of tear substitutes on the precorneal tear film stability. The influence of unpreserved artificial tear substitute containing 0.1% sodium hyaluronate (Healon 0.1%) was compared with that of 7 different available tear substitute preparations containing preservatives. The results of the present study show that Healon 0.1% has the best influence on the precorneal tear film stability. These data were found to be independent of the viscosity property of Healon 0.1%. PMID:9313790

Avisar, R; Creter, D; Levinsky, H; Savir, H

1997-03-01

162

Distal biceps tendon rupture reconstruction using muscle-splitting double-incision approach  

PubMed Central

AIM: To evaluate the clinical and functional results after repair of distal biceps tendon tears, following the Morrey’s modified double-incision approach. METHODS: We retrospectively reviewed 47 patients with distal rupture of biceps brachii treated between 2003 and 2012 in our Orthopedic Department with muscle-splitting double-incision technique. Outcome measures included the Mayo elbow performance, the DASH questionnaire, patient’s satisfaction, elbow and forearm motion, grip strength and complications occurrence. RESULTS: At an average 18 mo follow-up (range, 7 mo-10 years) the average Mayo elbow performance and DASH score were respectively 97.2 and 4.8. The elbow flexion range was 94%, extension was -2°, supination was 93% and pronation 96% compared with the uninjured limb. The mean grip strength, expressed as percentage of respective contralateral limb, was 83%. The average patient satisfaction rating on a Likert scale (from 0 to 10) was 9.4. The following complications were observed: 3 cases of heterotopic ossification (6.4%), one (2.1%) re-rupture of the tendon at the site of reattachment and 2 cases (4.3%) of posterior interosseous nerve palsy. No complication required further surgical treatment. CONCLUSION: This technique allows an anatomic reattachment of distal biceps tendon at the radial tuberosity providing full functional recovery with low complication rate. PMID:25133147

Tarallo, Luigi; Mugnai, Raffaele; Zambianchi, Francesco; Adani, Roberto; Catani, Fabio

2014-01-01

163

Anterior Cruciate Ligament Reconstruction: Clinical Outcomes of Patella Tendon and Hamstring Tendon Grafts  

PubMed Central

An injury to the ACL can result in significant functional impairment. It has been estimated that more than 100,000 new ACL injuries occur each year. Surgeons employ numerous techniques for reconstruction of the ACL. Of critical importance is the source of the graft to replace the damaged ACL. The graft choices include autografts (the patient's own tissue), allografts (donor tendon), and synthetic/prosthetic ligaments. Tissue harvest sites for autografting include the middle third of the patella tendon, the quadriceps tendon, semitendinosus tendon, gracilis tendon, iliotibial band, tensor fascia lata, and the Achilles tendon. Selection of the type of graft material is predicated upon the tissue's ability to tolerate high levels of stress. Likewise, the clinical presentation and functional outcome is related to the graft material selected. This manuscript specifically examined the patella tendon and hamstring tendon grafts. Numerous manuscripts that studied the outcomes of these graft materials were compiled to help the clinician appreciate the advantages and disadvantages of each of the graft materials. Outcome measures such as thigh circumference, knee range of motion, isokinetic strength, knee stability, pain, and vertical jump/1-leg hop were incorporated. The purpose of this manuscript was to compare and contrast the clinical presentation of patients who underwent an ACL reconstruction using the patella tendon versus the hamstring tendons. This information can be valuable to the clinician when considering the rehabilitation protocol after ACL reconstruction. PMID:24701126

Gulick, Dawn T.; Yoder, Heather N.

2002-01-01

164

Synthetic augmentation for massive rotator cuff tears.  

PubMed

The management of massive, irreparable rotator cuff tears is challenging. They are associated with persistent defects, weakness, and poor outcomes, and can cause an uncoupling of forces across the glenohumeral joint, with unstable shoulder kinematics. There has been much interest in the development of scaffolds to bridge massive rotator cuff tears. As allograft materials may produce inflammatory responses in the host, there is notable interest in developing synthetic grafts for surgical use. Benefits and limitations of the available synthetic scaffolds for augmentation of rotator cuff tears are reported in the present review. PMID:22089286

Longo, Umile Giuseppe; Lamberti, Alfredo; Khan, Wasim S; Maffulli, Nicola; Denaro, Vincenzo

2011-12-01

165

The Factors Affecting the Clinical Outcome and Integrity of Arthroscopically Repaired Rotator Cuff Tears of the Shoulder  

PubMed Central

Background The purpose of this study was to evaluate the functional and anatomic results of arthroscopic rotator cuff repair, and to analyze the factors affecting the integrity of arthroscopically repaired rotator cuff tears of the shoulder. Methods One hundred sixty-nine consecutive shoulders that underwent arthroscopic rotator cuff repair, had a postoperative MRI evaluation and were followed for at least two years were enrolled in this study. The mean age was 57.6 years (range, 38 to 74 years) and the mean follow-up period was 39 months (range, 24 to 83 months). Results The rotator cuff was completely healed in 131 (77.5%) out of 169 shoulders and recurrent tears occurred in 38 shoulders (22.5%). At the last follow-up visit, the mean score for pain during motion was 1.53 (range, 0 to 4) in the completely healed group and 1.59 (range, 0 to 4) in the group with recurrent tears (p = 0.092). The average elevation strength was 7.87 kg (range, 4.96 to 11.62 kg) and 5.25 kg (range, 4.15 to 8.13 kg) and the mean University of California at Los Angeles score was 30.96 (range, 26 to 35) and 30.64 (range, 23 to 34), respectively (p < 0.001, p = 0.798). The complete healing rate was 87.8% in the group less than 50 years of age (49 shoulders), 79.4% in the group over 51 years but less than 60 years of age (68 shoulders), and 65.4% in the group over 61 years of age (52 shoulders, p = 0.049); it was 96.7% in the group with small-sized tears (30 shoulders), 87.3% in the group with medium-sized tears (71 shoulders), and 58.8% in the group with large-sized or massive tears (68 shoulders, p = 0.009). All of the rotator cuffs with a global fatty degeneration index of greater than two preoperatively had recurrent tears. Conclusions Arthroscopic repair of full-thickness rotator cuff tears led to a relatively high rate of recurrent defects. However, the minimum two-year follow up demonstrated excellent pain relief and improvement in the ability to perform the activities of daily living, despite the structural failures. The factors affecting tendon healing were the patient's age, the size and extent of the tear, and the presence of fatty degeneration in the rotator cuff muscle. PMID:19885061

Cho, Nam Su

2009-01-01

166

Tear Film Function in Type 2 Diabetic Patients with Retinopathy  

Microsoft Academic Search

Purpose: To investigate whether diabetes mellitus is correlated with tear film dysfunction. Methods: Tear film function tests including tear film breakup time (BUT), fluorescein staining, Schirmer I test, rose Bengal staining, total tear protein detection, tear sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and TMS-4 corneal topography were performed. A dry-eye questionnaire was used. Results: Compared with the control group

Ling Yu; Xiaoming Chen; Gang Qin; Hanping Xie; Peng Lv

2008-01-01

167

Human Tears Reveal Insights into Corneal Neovascularization  

PubMed Central

Corneal neovascularization results from the encroachment of blood vessels from the surrounding conjunctiva onto the normally avascular cornea. The aim of this study is to identify factors in human tears that are involved in development and/or maintenance of corneal neovascularization in humans. This could allow development of diagnostic tools for monitoring corneal neovascularization and combination monoclonal antibody therapies for its treatment. In an observational case-control study we enrolled a total of 12 patients with corneal neovascularization and 10 healthy volunteers. Basal tears along with reflex tears from the inferior fornix, superior fornix and using a corneal bath were collected along with blood serum samples. From all patients, ocular surface photographs were taken. Concentrations of the pro-angiogenic cytokines interleukin (IL)-6, IL-8, Vascular Endothelial Growth Factor (VEGF), Monocyte Chemoattractant Protein 1 (MCP-1) and Fas Ligand (FasL) were determined in blood and tear samples using a flow cytometric multiplex assay. Our results show that the concentration of pro-angiogenic cytokines in human tears are significantly higher compared to their concentrations in serum, with highest levels found in basal tears. Interestingly, we could detect a significantly higher concentration of IL- 6, IL-8 and VEGF in localized corneal tears of patients with neovascularized corneas when compared to the control group. This is the first study of its kind demonstrating a significant difference of defined factors in tears from patients with neovascularized corneas as compared to healthy controls. These results provide the basis for future research using animal models to further substantiate the role of these cytokines in the establishment and maintenance of corneal neovascularization. PMID:22590547

Wouters, Kristien; Rozema, Jos; Koppen, Carina; Lion, Eva; Cools, Nathalie; Berneman, Zwi; Tassignon, Marie-José

2012-01-01

168

[Diagnosis and treatment of tearing in infancy].  

PubMed

Tearing in infancy is a very frequent symptom, particularly during the first year of life. A definite diagnosis can be made easily, only by questioning the parents about the characteristics and the evolution of the tearing since the birth and with a simple examination. The main causes are congenital nasolacrimal duct obstruction account of his high frequency in infant and congenital glaucoma account of his seriousness. PMID:19324537

Guez, A; Dureau, P

2009-05-01

169

A comprehensive review of hip labral tears  

Microsoft Academic Search

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

Megan M. Groh; Joseph Herrera

2009-01-01

170

Sodium hyaluronate eyedrops enhance tear film stability.  

PubMed

Sodium hyaluronate eyedrops can relieve various dry eye symptoms by prolonging the stability of the precorneal tear film. To determine the most effective concentration of sodium hyaluronate, we studied the concentration-dependent effects of sodium hyaluronate eyedrops on the precorneal tear film breakup time (BUT) in 12 volunteers. These subjects had a BUT of 10 seconds or less and a low tear volume determined with the phenol red thread test. They received four different concentrations of sodium hyaluronate eyedrops (0, 0.05, 0.1 and 0.3%). BUT was measured noninvasively using a non-contact specular microscope before the sodium hyaluronate eyedrop instillation and again after 5, 15, 30, 60, 120 and 180 minutes. The tear film stability period was prolonged significantly with 0.1% and 0.3% eyedrops at all measurement times (P < 0.05), while the eyes treated with 0% and 0.05% eyedrops showed no significant prolongation of tear film stability at any measurement times. The findings of this study confirm that sodium hyaluronate at a concentration of at least 0.1% is required to delay the breakup of the precorneal tear film. PMID:8739501

Hamano, T; Horimoto, K; Lee, M; Komemushi, S

1996-01-01

171

Diet, nutraceuticals and the tear film.  

PubMed

Nutrition disorders and their correlates such as obesity are increasingly prevalent worldwide. A number of studies to date have suggested numerous potential associations between diet and tear film health; this paper will provide a summary of the available literature. The tear film is characterized through its protein and lipid content and through clinical measurements of characteristics such as osmolarity, volume and stability. Malnutrition, protein and vitamin-A deficiencies are extremely deleterious to tear film health and supplementation with oral vitamin A in this setting is of clear benefit. The relative impact of diet on tear film within what would be considered normal ranges of consumption is less clear. A number of population studies have suggested that hyperlipidemia and a diet low in omega-3 fatty acids are risks factor for dry eye disease. Numerous studies have investigated the effectiveness of oral supplementation with antioxidants, omega-3 (e.g. fish oil and linseed oil) and omega-6 (e.g. evening primrose oil) fatty acids in the last 10 years. Taken together, these suggest a small benefit of oral supplementation on tear film volume, stability and decreased ocular symptoms in patients previously diagnosed with diseases involving the ocular surface (e.g. Sjögren's syndrome, meibomian gland dysfunction, dry eye disease) and contact lens wearers suffering from dry eye. More research is required to determine the exact composition, dosage and indications for their use and to fully characterize how these nutraceuticals modulate the tear film. PMID:24012987

Jalbert, Isabelle

2013-12-01

172

Intrasynovial Tendon Graft for Chronic Flexor Tendon Laceration of the Finger: A Case Report  

PubMed Central

We present the case of a patient with flexor digitorum profundus tendon laceration at the A2 pulley level caused by an injury to the base of the right ring finger by a knife. The patient was treated by flexor tendon reconstruction from the palm to the fingertip by using the left second toe flexor tendon as a graft, which improved the active range of motion. Further improvement was achieved by subsequent tenolysis, which eventually restored nearly normal function. Our experience with this case indicates that the intrasynovial tendon is a reasonable graft source for the synovial space in fingers and may enable restoration of excellent postoperative function. PMID:24015158

Sasaki, Jun; Itsubo, Toshiro; Nakamura, Koichi; Hayashi, Masanori; Uchiyama, Shigeharu; Kato, Hiroyuki

2013-01-01

173

Uncommon methods of flexor tendon and tendon-bone repairs and grafting.  

PubMed

The conventional practices used in flexor tendon repair have remained unchanged in many units. Because clinical cases vary considerably, some situations may merit more unusual methods. Here the author describes a few methods that have been used in flexor tendon repair. This article discusses a few methods that are clinically useful in treating some patients but are not commonly described. The newer tendon-bone junction methods exemplified here would likely replace the pull-out suture. Late direct repair and lengthening plasty require the accumulation of clinical experience. Allograft tendon reconstruction has shown successful midterm results, but long-term follow-up is certainly necessary. PMID:23660057

Tang, Jin Bo

2013-05-01

174

IFSSH Flexor Tendon Committee report 2014: from the IFSSH Flexor Tendon Committee (Chairman: Jin Bo Tang).  

PubMed

Hand surgeons continue to search for the best surgical flexor tendon repair and treatment of the tendon sheaths and pulleys, and they are attempting to establish postoperative regimens that fit diverse clinical needs. It is the purpose of this report to present the current views, methods, and suggestions of six senior hand surgeons from six different countries - all experienced in tendon repair and reconstruction. Although certainly there is common ground, the report presents provocative views and approaches. The report reflects an update in the views of the committee. We hope that it is helpful to surgeons and therapists in treating flexor tendon injuries. PMID:23962872

Tang, Jin Bo; Chang, James; Elliot, David; Lalonde, Donald H; Sandow, Michael; Vögelin, Esther

2014-01-01

175

Tendon and Ligament Regeneration and Repair: Clinical Relevance and Developmental Paradigm  

PubMed Central

Tendon and ligament (T/L) are dense connective tissues connecting bone to muscle and bone to bone, respectively. Similar to other musculoskeletal tissues, T/L arise from the somitic mesoderm, but they are derived from a recently discovered somitic compartment, the syndetome. The adjacent sclerotome and myotome provide inductive signals to the interposing syndetome, thereby upregulating the expression of the transcription factor Scleraxis, which in turn leads to further tenogenic and ligamentogenic differentiation. These advances in the understanding of T/L development have been sought to provide a knowledge base for improving the healing of T/L injuries, a common clinical challenge due to the intrinsically poor natural healing response. Specifically, the three most common tendon injuries involve tearing of the rotator cuff of the shoulder, the flexor tendon of the hand, and the Achilles tendon. At present, injuries to these tissues are treated by surgical repair and/or conservative approaches, including biophysical modalities such as physical rehabilitation and cryotherapy. Unfortunately, the healing tissue forms fibrovascular scar and possesses inferior mechanical and biochemical properties as compared to native T/L. Therefore, tissue engineers have sought to improve upon the natural healing response by augmenting the injured tissue with cells, scaffolds, bioactive agents, and mechanical stimulation. These strategies show promise, both in vitro and in vivo, for improving T/L healing. However, several challenges remain in restoring full T/L function following injury, including uncertainties over the optimal combination of these biological agents as well how to best deliver tissue engineered elements to the injury site. A greater understanding of the molecular mechanisms involved in T/L development and natural healing, coupled with the capability of producing complex biomaterials to deliver multiple growth factors with high spatiotemporal resolution and specificity, will allow tissue engineers to more closely recapitulate T/L morphogenesis, thereby offering future patients the prospect of T/L regeneration, as opposed to simple tissue repair. PMID:24078497

Tuan, Rocky S.

2014-01-01

176

Traumatic flexor tendon injuries in 27 cattle.  

PubMed

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

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

1996-01-01

177

Entrapment of the long head of the biceps tendon: the hourglass biceps--a cause of pain and locking of the shoulder.  

PubMed

We describe an unrecognized mechanical condition affecting the long head of the biceps (LHB) tendon with entrapment of the tendon within the joint and subsequent pain and locking of the shoulder on elevation of the arm. We identified 21 patients with a hypertrophic intraarticular portion of the LHB tendon during open surgery (14 patients) or arthroscopic surgery (7 patients). All cases but one were associated with a rotator cuff rupture. Patients were treated by biceps tenotomy (2 patients) or tenodesis (19 patients) after removal of the hypertrophic intraarticular portion of the tendon and appropriate treatment of concomitant lesions. Minimum follow-up was 1 year. All patients presented with anterior shoulder pain and loss of active and passive elevation averaging 10 degrees to 20 degrees. A dynamic intraoperative test, involving forward elevation with the elbow extended, demonstrated entrapment of the tendon within the joint in each case. This test creates a characteristic buckling of the tendon and squeezing of it between the humeral head and the glenoid (hourglass test). The mean Constant score improved from 38 to 76 points at the final follow-up (P <.05). Complete and symmetric elevation was restored in all cases after resection of the intraarticular portion of the LHB tendon. The hourglass biceps is caused by a hypertrophic intraarticular portion of the tendon that is unable to slide into the bicipital groove during elevation of the arm; it can be compared with the condition of trigger finger in the hand. A loss of 10 degrees to 20 degrees of passive elevation, bicipital groove tenderness, and radiographic findings of a hypertrophied tendon can aid in the diagnosis. A definitive diagnosis is made at surgery with the hourglass test: incarceration and squeezing of the tendon within the joint during forward elevation of the arm with the elbow extended. The hourglass biceps is responsible for a mechanical block, which is similar to a locked knee with a bucket-handle meniscal tear. Simple tenotomy cannot resolve this mechanical block. Excision of the intraarticular portion of the LHB tendon, during bipolar biceps tenotomy or tenodesis, must be performed. The hourglass biceps is an addition to the familiar pathologies of the LHB (tenosynovitis, prerupture, rupture, and instability) and should be considered in cases of shoulder pain associated with a loss of elevation. PMID:15111893

Boileau, Pascal; Ahrens, Philip M; Hatzidakis, Armodios M

2004-01-01

178

Mechanical properties of human patellar tendon at the hierarchical levels of tendon and fibril.  

PubMed

Tendons are strong hierarchical structures, but how tensile forces are transmitted between different levels remains incompletely understood. Collagen fibrils are thought to be primary determinants of whole tendon properties, and therefore we hypothesized that the whole human patellar tendon and its distinct collagen fibrils would display similar mechanical properties. Human patellar tendons (n = 5) were mechanically tested in vivo by ultrasonography. Biopsies were obtained from each tendon, and individual collagen fibrils were dissected and tested mechanically by atomic force microscopy. The Young's modulus was 2.0 ± 0.5 GPa, and the toe region reached 3.3 ± 1.9% strain in whole patellar tendons. Based on dry cross-sectional area, the Young's modulus of isolated collagen fibrils was 2.8 ± 0.3 GPa, and the toe region reached 0.86 ± 0.08% strain. The measured fibril modulus was insufficient to account for the modulus of the tendon in vivo when fibril content in the tendon was accounted for. Thus, our original hypothesis was not supported, although the in vitro fibril modulus corresponded well with reported in vitro tendon values. This correspondence together with the fibril modulus not being greater than that of tendon supports that fibrillar rather than interfibrillar properties govern the subfailure tendon response, making the fibrillar level a meaningful target of intervention. The lower modulus found in vitro suggests a possible adverse effect of removing the tissue from its natural environment. In addition to the primary work comparing the two hierarchical levels, we also verified the existence of viscoelastic behavior in isolated human collagen fibrils. PMID:22114175

Svensson, René B; Hansen, Philip; Hassenkam, Tue; Haraldsson, Bjarki T; Aagaard, Per; Kovanen, Vuokko; Krogsgaard, Michael; Kjaer, Michael; Magnusson, S Peter

2012-02-01

179

Contact lens interactions with the tear film.  

PubMed

Biochemical changes brought about by the influence of the contact lens on the tear film are conveniently split into two categories. Firstly, the lens can remove or reduce the levels of specific components in the tear film, and secondly, the lens can augment the tear film, by stimulating the influx of new components or increasing the level of existing components. The most obvious tear film components for study in this context are lipids, proteins, mucins and electrolytes. The interactions are affected by the properties of the lens, the characteristics of the individual wearer and the wear schedule. An additional complicating factor is the fact that the lens is many times thicker than the tear film and any immobilised tear components will be more extensively exposed to oxygen and UV radiation than is the case in the absence of a lens. It is arguably the lipoidal components that are most markedly affected by lens wear, since their immobilisation on the lens surface markedly increases their susceptibility to autoxidative degradation. The limited information that is available highlights the importance of subject specificity and suggests that lipid oxidation phenomena are potentially important in contributing to the 'end of day' discomfort of symptomatic contact lens patients. It is clear that tear lipids, although regarded as relatively inert for many years, are now seen as a reactive and potentially important family of compounds in the search for understanding of contact lens-induced discomfort. The influence of the lens on tear proteins shows the greatest range of complexity. Deposition and denaturation can stimulate immune response, lower molecular weight proteins can be extensively absorbed into the lens matrix and the lens can stimulate cascade or upregulation processes leading either to the generation of additional proteins and peptides or an increase in concentration of existing components. Added to this is the stimulating influence of the lens on vascular leakage leading to the influx of plasma proteins such as albumin. The evidence from studies of mucin expression in tears is not consistent and conclusive. This is in part because sample sources, lens materials and methods of analysis vary considerably, and in some cases the study population numbers are low. Expression levels show mucin and material specificity but clear patterns of behaviour are elusive. The electrolyte composition of tears is significantly different from that of other body fluids. Sodium and potassium dominate but potassium ion concentrations in tears are much higher than in serum levels. Calcium and magnesium concentrations in tears are lower than in serum but closer to interstitial fluids. The contact lens provides the potential for increased osmolarity through enhanced evaporation and differential electrolyte concentrations between the anterior and posterior tear films. Since the changes in ocular biochemistry consequent upon contact lens wear are known to be subject-dependent - as indeed is wearer response to the lens - pre-characterisation of individual participant tear chemistry in clinical studies would enhance understanding of these complex effects. PMID:23886658

Mann, Aisling; Tighe, Brian

2013-12-01

180

The cell biology of suturing tendons  

PubMed Central

Trauma by suturing tendon form areas devoid of cells termed “acellular zones” in the matrix. This study aimed to characterise the cellular insult of suturing and acellular zone formation in mouse tendon. Acellular zone formation was evaluated using single grasping sutures placed using flexor tendons with time lapse cell viability imaging for a period of 12 h. Both tension and injury were required to induce cell death and cell movement in the formation of the acellular zone. DNA fragmentation studies and transmission electron microscopy indicated that cells necrosed. Parallel in vivo studies showed that cell-to-cell contacts were disrupted following grasping by the suture in tensioned tendon. Without tension, cell death was lessened and cell-to-cell contacts remained intact. Quantitative immunohistochemistry and 3D cellular profile mapping of wound healing markers over a one year time course showed that acellular zones arise rapidly and showed no evidence of healing whilst the wound healing response occurred in the surrounding tissues. The acellular zones were also evident in a standard modified “Kessler” clinical repair. In conclusion, the suture repair of injured tendons produces acellular zones, which may potentially cause early tendon failure. PMID:20600895

Wong, J.K.F.; Alyouha, S.; Kadler, K.E.; Ferguson, M.W.J.; McGrouther, D.A.

2010-01-01

181

Evolution of the Achilles tendon: The athlete's Achilles heel?  

PubMed

The Achilles tendon is believed to have first developed two million years ago enabling humans to run twice as fast. However if the Achilles tendon is so important in terms of evolution, then why is this tendon so prone to injury - especially for those more active like athletes. The Achilles tendon had an integral role in evolving apes from a herbivorous diet to early humans who started hunting for food over longer distances, resulting in bipedal locomotion. Evolutionary advantages of the Achilles tendon includes it being the strongest tendon in the body, having an energy-saving mechanism for fast locomotion, allows humans to jump and run, and additionally is a spring and shock absorber during gait. Considering these benefits it is therefore not surprising that studies have shown athletes have thicker Achilles tendons than subjects who are less active. However, contradictory to these findings that show the importance of the Achilles tendon for athletes, it is well known that obtaining an Achilles tendon injury for an athlete can be career-altering. A disadvantage of the Achilles tendon is that the aetiology of its pathology is complicated. Achilles tendon ruptures are believed to be caused by overloading the tensed tendon, like during sports. However studies have also shown athlete Achilles tendon ruptures to have degenerative changes in the tendon. Other flaws of the Achilles tendon are its non-uniform vascularity and incomplete repair system which may suggest the Achilles tendon is on the edge of evolution. Research has shown that there is a genetic influence on the predisposition a person has towards Achilles tendon injuries. So if this tendon is here to stay in our anatomy, and it probably is due to the slow rate of evolution in humans, research in genetic modification could be used to decrease athletes' predisposition to Achilles tendinopathy. PMID:21900004

Malvankar, S; Khan, W S

2011-12-01

182

Relationship between clinical and surgical findings and reparability of large and massive rotator cuff tears: a longitudinal study  

PubMed Central

Background The literature has shown good results with partial repairs of large and massive tears of rotator cuff but the role of factors that affect reparability is less clear. The purpose of this study was twofold, 1) to examine clinical outcomes following complete or partial repair of large or massive full-thickness rotator cuff tear, and 2) to explore the value of clinical and surgical factors in predicting reparability. Methods This was a secondary data analysis of consecutive patients with large or massive rotator cuff tear who required surgical treatment (arthroscopic complete or partial repair) and were followed up for two years. Disability measures included the American Shoulder and Elbow Surgeons (ASES), the relative Constant-Murley score (CMS) and the shortened version of the Western Ontario Rotator Cuff Index (ShortWORC). The relationship between predictors and reparability was examined through logistic regressions and chi-square statistics as appropriate. Within group change over time and between group differences in disability outcomes, range of motion and strength were examined by student’s T-tests and non-parametric statistics. Results One hundred and twenty two patients (41 women, 81 men, mean age 64, SD?=?9) were included in the analysis. There were 86 large (39 fully reparable, 47 partially reparable) and 36 (10 fully reparable, 26 partially reparable) massive tears. Reparability was not associated with age, sex, or pre-operative active flexion or abduction (p?>?0.05) but the fully reparable tear group showed a better pre-operative ASES score (p?=?0.01) and better active external rotation in neutral (p?=?0.01). Reparability was associated with tear shape (p?tendon quality (p?tears is affected by a number of clinical and surgical factors. Patients whose tears could not be fully repaired showed a statistically significant improvement in range of motion, strength and disability at 2 years, although they had slightly inferior results compared to those with complete repairs. PMID:24884835

2014-01-01

183

Study of a low ? classical tearing mode in DIII-D  

NASA Astrophysics Data System (ADS)

The tearing mode stability of low ? plasmas is studied experimentally in the DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] tokamak. The linear and nonlinear characteristics of the plasma are measured and compared with theoretical predictions. In contrast to the neoclassical tearing mode, which occurs at high ? and is dominated by the bootstrap current effect, in the low ? regime the neoclassical bootstrap current effect is minimal. Thus the stability properties are more amenable to comparison with presently available theoretical codes. In the linear phase, the onset of the instability has been found to be predictable from equilibrium reconstruction to agree with the availability of the tearing mode free energy. In the nonlinear phase, the temperature and its fluctuation amplitude and phase have been fitted to the prediction of achieving a perturbed three-dimensional equilibrium with an assumed perturbation eigenfunction.

Chu, M. S.; La Haye, R. J.; Austin, M. E.; Lao, L. L.; Lazarus, E. A.; Pletzer, A.; Ren, C.; Strait, E. J.; Taylor, T. S.; Waelbroeck, F. L.

2002-11-01

184

Bio-engineered synovial membrane to prevent tendon adhesions in rabbit flexor tendon model.  

PubMed

During tendon injuries, the tendon sheath is also damaged. This study aims to test effectiveness of engineered tendon synovial cell biomembrane on prevention of adhesions. Forty New Zealand Rabbits enrolled into four study groups. Engineered synovial sheath was produced by culturing cell suspension on fabricated collagen matrix membrane. Study groups were: tendon repair (group A), tendon repair zone covered with plane matrix (Group B), synovial suspension injection into the zone of repair over matrix (Group C), and biomembrane application (Group D). Biomechanical evaluations of tendon excursion, metacarpophalangeal and proximal interphalangeal joints range of motion, H&E and Alcian Blue with neutral red staining, and adhesion formation graded for histological assessments were studied. Ten non-operated extremities used as control. Tendon excursions and range of motions were significantly higher and close to control group for Group D, p??0.005. Hyaluronic acid synthesis was demonstrated at groups C and D at the zone of injury. Application of synovial cells into the tendon repair zone either by cell suspension or within a biomembrane significantly decreases the adhesion formation. Barrier effect of collagen matrix and restoration of hyaluronic acid synthesis can explain the possible mechanism of action. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 84-90, 2015. PMID:24616375

Baymurat, Alim Can; Ozturk, Akif Muhtar; Yetkin, Haluk; Ergun, Mehmet Ali; Helvac?oglu, Fatma; Ozk?z?lc?k, Asya; Tuzlako?lu, Kadriye; Sener, E Ertugrul; Erdogan, Deniz

2015-01-01

185

The effect of decellularized matrices on human tendon stem/progenitor cell differentiation and tendon repair.  

PubMed

It is reported that decellularized collagen matrices derived from dermal skin and bone have been clinically used for tendon repair. However, the varying biological and physical properties of matrices originating from different tissues may influence the differentiation of tendon stem cells, which has not been systematically evaluated. In this study, the effects of collagenous matrices derived from different tissues (tendon, bone and dermis) on the cell differentiation of human tendon stem/progenitor cells (hTSPCs) were investigated, in the context of tendon repair. It was found that all three matrices supported the adhesion and proliferation of hTSPCs despite differences in topography. Interestingly, tendon-derived decellularized matrix promoted the tendinous phenotype in hTSPCs and inhibited their osteogenesis, even under osteogenic induction conditions, through modulation of the teno- and osteolineage-specific transcription factors Scleraxis and Runx2. Bone-derived decellularized matrix robustly induced osteogenic differentiation of hTSPCs, whereas dermal skin-derived collagen matrix had no apparent effect on hTSPC differentiation. Based on the specific biological function of the tendon-derived decellularized matrix, a tissue-engineered tendon comprising TSPCs and tendon-derived matrix was successfully fabricated for Achilles tendon reconstruction. Implantation of this cell-scaffold construct led to a more mature structure (histology score: 4.08 ± 0.61 vs. 8.51 ± 1.66), larger collagen fibrils (52.2 ± 1.6 nm vs. 47.5 ± 2.8 nm) and stronger mechanical properties (stiffness: 21.68 ± 7.1 Nm m(-1) vs.13.2 ± 5.9 Nm m(-1)) of repaired tendons compared to the control group. The results suggest that stem cells promote the rate of repair of Achilles tendon in the presence of a tendinous matrix. This study thus highlights the potential of decellularized matrix for future tissue engineering applications, as well as developing a practical strategy for functional tendon regeneration by utilizing TSPCs combined with tendon-derived decellularized matrix. PMID:23896565

Yin, Zi; Chen, Xiao; Zhu, Ting; Hu, Jia-jie; Song, Hai-xin; Shen, Wei-liang; Jiang, Liu-yun; Heng, Boon Chin; Ji, Jun-feng; Ouyang, Hong-Wei

2013-12-01

186

Post-LASIK Tear Dysfunction and Dysesthesia  

PubMed Central

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

NETTUNE, GREGORY R.; PFLUGFELDER, STEPHEN C.

2013-01-01

187

Meniscal root tears: significance, diagnosis, and treatment.  

PubMed

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

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

2014-12-01

188

Specialization of tendon mechanical properties results from interfascicular differences.  

PubMed

Tendons transfer force from muscle to bone. Specific tendons, including the equine superficial digital flexor tendon (SDFT), also store and return energy. For efficient function, energy-storing tendons need to be more extensible than positional tendons such as the common digital extensor tendon (CDET), and when tested in vitro have a lower modulus and failure stress, but a higher failure strain. It is not known how differences in matrix organization contribute to distinct mechanical properties in functionally different tendons. We investigated the properties of whole tendons, tendon fascicles and the fascicular interface in the high-strain energy-storing SDFT and low-strain positional CDET. Fascicles failed at lower stresses and strains than tendons. The SDFT was more extensible than the CDET, but SDFT fascicles failed at lower strains than CDET fascicles, resulting in large differences between tendon and fascicle failure strain in the SDFT. At physiological loads, the stiffness at the fascicular interface was lower in the SDFT samples, enabling a greater fascicle sliding that could account for differences in tendon and fascicle failure strain. Sliding between fascicles prior to fascicle extension in the SDFT may allow the large extensions required in energy-storing tendons while protecting fascicles from damage. PMID:22764132

Thorpe, Chavaunne T; Udeze, Chineye P; Birch, Helen L; Clegg, Peter D; Screen, Hazel R C

2012-11-01

189

Presumed hyposecretory/hyperevaporative KCS: tear characteristics.  

PubMed Central

PURPOSE: To characterize patients with ocular surface drying and a diagnosis of keratoconjunctivitis sicca (KCS). METHODS: Patients with a prior diagnosis of KCS and symptoms of dryness or foreign-body sensation who also had vital staining of the interpalpebral fissure ocular surface in the absence of lid and ocular surface inflammation were entered into the study along with normal controls. Patients were segregated into those with "classic" KCS, who did not have concomitant meibomian gland dysfunction (MGD), and those with KCS and MGD. The latter had slit-lamp evidence of difficult-to-express or turbid meibomian secretions upon expression. Patients and normal controls were evaluated for tear volume, flow, and turnover using fluorophotometry; meibomian gland dropout by meibography; evaporation by evaporometry; and tear production by the Schirmer 1 test. RESULTS: All patients with KCS had decreased tear volume, flow, and Schirmer 1 values as well as increased meibomian gland dropout. None of the patient groups were found to have increased tear evaporation compared with normals or other disease subgroups. No correlation between degree of meibomian gland dropout and evaporation was found. The degree of total vital staining or presence of corneal staining correlated with a more severe aqueous deficiency. CONCLUSIONS: Patients with ocular surface drying in the absence of inflammation have decreased tear volume, flow, and Schirmer 1 values as well as increased meibomian gland dropout. The role of meibomian gland dropout or slit-lamp MGD in disease is unclear and in our study specifically did not correlate with increased tear evaporation. PMID:14971572

McCulley, James P; Shine, Ward E; Aronowicz, Joel; Oral, Deniz; Vargas, Jose

2003-01-01

190

The effect of tendon surface treatment on cell attachment for potential enhancement of tendon graft healing: an ex vivo model.  

PubMed

For both tendon allografts and autografts, the surface, initially optimized for gliding, may not be ideal to facilitate tissue integration for graft healing to host tendon or bone. As a prelude to studying tendon-bone integration, we investigated the effect of surface treatments with trypsin or mechanical abrasion on cell attachment to the tendon surface in a canine ex vivo intrasynovial tendon tissue culture model. Intrasynovial tendon allograft surfaces were seeded with cells after the following treatments: (1) no treatment, (2) mechanical abrasion, (3) trypsin, and (4) abrasion and trypsin. The area covered by cells was determined using confocal laser microscopy at one and two weeks. Results were compared to untreated extrasynovial tendon. Additional tendons were characterized with scanning electron microscopy. Tendons with trypsin treatment had significantly more surface coverage with cells than the other groups, after both one and two weeks of culture. In terms of the cellular shape and size, cells on tendons with trypsin treatment spread more and were more polygonal in shape, whereas tendons with mechanical abrasion with/without trypsin treatment contained smaller, more spindle-like cells. Surface roughening can affect cell behavior with topographical stimulation. Trypsin surface digestion exposes a mesh-like structure on the tendon surface, which could enhance cell adherence and, possibly, tendon/bone healing. PMID:22349134

Hashimoto, Takahiro; Sun, Yu-Long; An, Kai-Nan; Amadio, Peter C; Zhao, Chunfeng

2012-12-01

191

Protect Your Tendons: Preventing the Pain of Tendinitis  

MedlinePLUS

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192

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

PubMed

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

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

2014-11-18

193

Arthroscopic treatment options for irreparable rotator cuff tears of the shoulder  

PubMed Central

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.

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

2014-01-01

194

Long-term outcome and structural integrity following open repair of massive rotator cuff tears  

PubMed Central

Background: Surgical repair of massive rotator cuff tears is associated with less favorable clinical results and a higher retear rate than repair of smaller tears, which is attributed to irreversible degenerative changes of the musculotendinous unit. Materials and Methods: During the study period, 25 consecutive patients with a massive rotator cuff tear were enrolled in the study and the tears were repaired with an open suture anchor repair technique. Preoperative and postoperative clinical assessments were performed with the Constant score, the simple shoulder test (SST) and a pain visual analog scale (VAS). At the final follow-up, rotator cuff strength measurement was evaluated and assessment of tendon integrity, fatty degeneration and muscle atrophy was done using a standardized magnetic resonance imaging protocol. Results: The mean follow-up period was 70 months. The mean constant score improved significantly from 42.3 to 73.1 points at the final follow-up. Both the SST and the pain VAS improved significantly from 5.3 to 10.2 points and from 6.3 to 2.1, respectively. The overall retear rate was 44% after 6 years. Patients with an intact repair had better shoulder scores and rotator cuff strength than those with a failed repair, and also the retear group showed a significant clinical improvement (each P<0.05). Rotator cuff strength in all testing positions was significantly reduced for the operated compared to the contralateral shoulder. Muscle atrophy and fatty infiltration of the rotator cuff muscles did not recover in intact repairs, whereas both parameters progressed in retorn cuffs. Conclusions: Open repair of massive rotator tears achieved high patient satisfaction and a good clinical outcome at the long-term follow-up despite a high retear rate. Also, shoulders with retorn cuffs were significantly improved by the procedure. Muscle atrophy and fatty muscle degeneration could not be reversed after repair and rotator cuff strength still did not equal that of the contralateral shoulder after 6 years. Level of evidence: Level IV PMID:22518073

Bartl, Christoph; Kouloumentas, Pannos; Holzapfel, Konstantin; Eichhorn, Stefan; Wortler, Klaus; Imhoff, Andreas; Salzmann, Gian M

2012-01-01

195

Structure-function relationships in tendons: a review  

PubMed Central

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

Benjamin, M; Kaiser, E; Milz, S

2008-01-01

196

[The Achilles tendon in sports].  

PubMed

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

Segesser, B; Goesele, A; Renggli, P

1995-06-01

197

Explosive tearing mode reconnection in the magnetospheric tail  

Microsoft Academic Search

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

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

1978-01-01

198

Snapping knee: An unusual biceps femoris tendon injury  

Microsoft Academic Search

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.

Rajeev Bansal; Chris Taylor; Ashvin L. Pimpalnerkar

2005-01-01

199

An Overview of the Management of Flexor Tendon Injuries  

PubMed Central

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

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

2012-01-01

200

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

Microsoft Academic Search

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

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

201

The integrated function of muscles and tendons during locomotion  

Microsoft Academic Search

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,

Thomas J. Roberts

2002-01-01

202

Changes of tear film and tear secretion after phacoemulsification in diabetic patients  

PubMed Central

Objective: To evaluate tear film stability and tear secretion in patients with diabetes after phacoemulsification. Methods: Twenty-five diabetic cataract patients and 20 age-matched non-diabetic cataract patients as control underwent phacoemulsification. Tear film break-up time (TFBUT), Schirmer I test (SIT), corneal fluorescein staining, and dry eye symptoms were measured pre- and postoperatively. Results: Diabetics had a decreased preoperative TFBUT and SIT. TFBUT was reduced on Day 1 and recovered on Day 180 postoperatively in both groups. SIT was increased after phacoemulsification, but returned to preoperative levels by Day 180 in non-diabetics, whereas it was lower than preoperative level in diabetics. Positive corneal fluorescein staining was elevated in both groups, and returned to preoperative levels only in controls. Dry eye symptoms were similar to fluorescein staining in both groups. Conclusion: Tear secretion was reduced in diabetic cataract patients after phacoemulsification, which worsened dry eye symptoms and predisposed those patients to ocular damage. PMID:18381808

Liu, Xi; Gu, Yang-shun; Xu, Ye-sheng

2008-01-01

203

Arthroscopic Repairs of Triangular Fibrocartilage Complex Tears  

Microsoft Academic Search

Technical advancements in arthroscopic wrist procedures have improved our knowledge of normal and abnormal intraarticular wrist function. Triangular fibrocartilage complex (TFCC) tears from trauma injuries are a common source of ulnar-sided wrist pain. Fortunately, the TFCC is a structure that can be evaluated and treated arthroscopically with results that are comparable to open surgical procedures. Successful arthroscopic repairs of TFCC

Patricia Baehser-Griffith; John M. Bednar; A. Lee Osterman; Randall Culp

1997-01-01

204

Role of lactoferrin in the tear film  

Microsoft Academic Search

The surface of the eye provides an inert barrier against infection. Through its unique combination of antimicrobial action and anti-inflammatory activities lactoferrin (Lf) in the tear film plays an important role in the maintenance of ocular health. In order to maintain clarity the eye must provide immunological defense without immunopathology. Along with physical barriers, soluble plasma factors and other proteins

J. L. Flanagan; M. D. P. Willcox

2009-01-01

205

Living with a symptomatic rotator cuff tear 'bad days, bad nights': a qualitative study  

PubMed Central

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

2014-01-01

206

Effect of timing of surgical SSP tendon repair on muscle alterations.  

PubMed

To investigate the impacts of delayed repairs of a supraspinatus tendon tear on the supraspinatus muscle, we used an animal model data from two previously published studies in which one supraspinatus (SSP) tendon was detached. In one cohort, the rabbits were killed in groups of 10 at 4, 8, and 12?weeks. In the other cohort, a repair was done at these time points, 12 rabbits each, and the animals killed were 12 weeks later. SSP fossa volume (Muscle belly plus extramuscular fat [e-fat] volume), percentage of intramuscular fat (i-fat), and muscle tissue volume (muscle belly volume minus i-fat), as well as CT determination of e-fat and i-fat of both cohorts, were compared. Fossa volume increased (p??0.05), but early repair prevented further volume losses, a fact not seen after 8 and 12?weeks delay of repair. No reversal of e-fat or of i-fat occurred, in fact i-fat almost doubled after 4?weeks delay of repair (p?

Uhthoff, Hans K; Coletta, Elizabeth; Trudel, Guy

2014-11-01

207

Comparative Study on Functional Effects of Allotransplantation of Bone Marrow Stromal Cells and Adipose Derived Stromal Vascular Fraction on Tendon Repair: A Biomechanical Study in Rabbits  

PubMed Central

Objective Tendon never returns to its complete biological and mechanical properties after repair. Bone marrow and, recently, adipose tissue have been used as sources of mesenchymal stem cells which have been proven to enhance tendon healing. In the present study, we compared the effects of allotransplantation of bone marrow derived mesenchymal stromal cells (BMSCs) and adipose derived stromal vascular fraction (SVF) on tendon mechanical properties after experimentally induced flexor tendon transection. Materials and Methods In this experimental study, we used 48 adult male New Zealand white rabbits. Twelve of rabbits were used as donors of bone marrow and adipose tissue, the rest were divided into control and treatment groups. The injury model was a unilateral complete transection of the deep digital flexor tendon. Immediately after suture repair, 4×106cells of either fresh SVF from enzymatic digestion of adipose tissue or cultured BMSCs were intratendinously injected into tendon stumps in the treatment groups. Controls received phosphate-buffered saline (PBS). Immobilization with a cast was continued for two weeks after surgery. Animals were sacrificed three and eight weeks after surgery and tendons underwent mechanical evaluations. The differences among the groups were analyzed using the analysis of variance (ANOVA) test followed by Tukey’s multiple comparisons test. Results Stromal cell transplantation resulted in a significant increase in ultimate and yield loads, energy absorption, and stress of repairs compared to the controls. However, there were no statistically significant changes detected in terms of stiffness. In comparison, we observed no significant differences at the third week between SVF and BMSCs treated tendons in terms of all load related properties. However, at the eighth week SVF transplantation resulted in significantly increased energy absorption, stress and stiffness compared to BMSCs. Conclusion The enhanced biomechanical properties of repairs in this study advocates the application of adipose derived SVF as an excellent source of multipotent cells instead of traditional BMSCs and may seem more encouraging in cell-based therapy for tendon injuries. PMID:25383325

Behfar, Mehdi; Javanmardi, Sara; Sarrafzadeh-Rezaei, Farshid

2014-01-01

208

Microcirculatory effects of topical glyceryl trinitrate on the Achilles tendon microcirculation in patients with previous Achilles tendon rupture.  

PubMed

Topical glyceryl trinitrate treatment has demonstrated short- to mid-term efficacy in chronic noninsertional Achilles tendinopathy. However, the underlying mechanisms are far from being understood. We hypothetized that Achilles tendon capillary blood flow changes immediately after topical glyceryl trinitrate treatment. Fifteen patients (55 + or - 15 years, VAS 5.8 + or - 2.3) with current mid-portion Achilles tendon pain 36 months after open surgical Achilles tendon repair for tendon rupture were included. On the Achilles mid-portion, 1.2 mg topical glyceryl trinitrate was sprayed. Microcirculatory monitoring included capillary blood flow, tendon oxygen saturation and postcapillary venous filling pressures at the insertion and 2, 4 and 6 cm above the insertion using a combined laser Doppler and spectrophotometry system. Baseline capillary blood-flows of the painful versus the uninjured tendon were increased [108 + or - 46 vs. 81 + or - 20 (2 cm above the insertion), 104 + or - 40 vs. 76 + or - 20 (4 cm above the insertion), 111 + or - 53 vs. 90 + or - 21 (6 cm above the insertion, P < 0.05)]. However, topical glyceryl trinitrate did not change capillary blood-flow at 2 and 8-mm tissue depths at the painful Achilles tendon or the healthy tendon. Tendon oxygenation was not changed at the painful or the healthy Achilles tendon. Postcapillary venous filling pressure was reduced at 8 mm at the mid-portion in the painful Achilles tendon only (113 + or - 37 vs. 95 + or - 31, P = 0.030). Acute topical glyceryl trinitrate facilitates capillary venous outflow in painful Achilles tendons. However, capillary blood-flow and tendon oxygenation remain unchanged following acute topical glyceryl trinitrate application. Elevated capillary blood-flow at the entire mid-portion is encountered at baseline in previously ruptured painful Achilles tendons even 3 years after surgical repair of the Achilles tendon indicating an altered microcirculatory flow pattern. PMID:19882141

Osadnik, Rafal; Redeker, Joern; Kraemer, Robert; Vogt, Peter M; Knobloch, Karsten

2010-07-01

209

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

PubMed

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

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

210

A preliminary study of patellar tendon torques during jumping.  

PubMed

The etiology of patellar tendinopathy (jumper's knee) has been attributed to a significant increase in patellar tendon torques associated with jumping. While some investigators have suggested that patellar tendon torques are greater during takeoff, little is known about the relative magnitudes of patellar tendon torques during takeoff and landing. We hypothesized that peak patellar tendon torques are greater in jump takeoff than in landing, and that there is a linear correlation between jump height and peak patellar tendon torque. Seven asymptomatic, recreational male athletes each performed a series of 21 jumps ranging from low to maximal height. A calibrated fiber-optic sensor, implanted transversely within the patellar tendon was used to measure the knee torque during takeoff and landing. There was no significant difference in the peak patellar tendon torque experienced during takeoff and landing within individuals. There was a moderate correlation (r = .64) between maximum takeoff patellar tendon torques and jump height. There was a weak correlation (r = .52) between maximum landing patellar tendon torques and jump height. There was a moderate correlation (r = .67) between maximum 60 degrees/s isokinetic extension torque and maximum jump height. The lack of a strong correlation between jump height and patellar tendon forces during take-off or landing suggests that these forces may be technique dependent. Therefore, modifying takeoff and/or landing techniques could reduce patellar tendon force and potentially lessen the incidence of patellar tendinopathy. PMID:20095457

Elvin, Niell; Elvin, Alex; Scheffer, Cornie; Arnoczky, Steven; Dillon, Edwin; Erasmus, P J

2009-11-01

211

Achilles Tendon Repair, A Modified Technique  

PubMed Central

Background: Wound complications following open repair for acute Achilles tendon ruptures (AATR) remain the subject of significant debate. The aim of this study is to investigate the effects of covering repaired AATR using well-nourished connective tissues (paratenon and deep fascia) to avoid complications after open repair. Methods: In this case series study, open repair was performed for 32 active young patients with AATR. After the tendon was repaired, the deep fascia and paratenon was used to cover the Achilles tendon. Patients were followed for two years and any wound complication was recorded. During the last visit, the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind foot score was completed for all patients. Calf circumference and ankle range of motion were measured and compared with the contralateral side. Patients were asked about returning to previous sports activities and limitations with footwear. Results: Only, one patient developed deep wound infection (3%). None of the patients had any discomfort around the operation area, limitation with footwear, sural nerve injury, re-rupture, and skin adhesion. The AOFAS score averaged 92.5±6. Two patients (7%) were unable to return to previous sports activities because of moderate pain in heavy physical exercises. The calf circumference and ankle ROM were similar between healthy and operated sides. Conclusion: The present study showed that fascial envelope for full covering of the repaired Achilles tendon may help to prevent the occurrence of wound complications. PMID:25207295

Keyhani, Sohrab; Mardani-Kivi, Mohsen; Abbasian, Mohammadreza; Emami-Moghaddam Tehrani, Mohammad; Lahiji, Farivar Abdollahzadeh

2013-01-01

212

Tendon fatigue in response to mechanical loading.  

PubMed

Tendinopathies are commonly attributable to accumulation of sub-rupture fatigue damage from repetitive use. Data is limited to late stage disease from patients undergoing surgery, motivating development of animal models, such as ones utilizing treadmill running or repetitive reaching, to investigate the progression of tendinopathies. We developed an in vivo model using the rat patellar tendon that allows control of the loading directly applied to the tendon. This manuscript discusses the response of tendons to fatigue loading and applications of our model. Briefly, the fatigue life of the tendon was used to define low, moderate and high levels of fatigue loading. Morphological assessment showed a progression from mild kinks to fiber disruption, for low to high level fatigue loading. Collagen expression, 1 and 3 days post loading, showed more modest changes for low and moderate than high level fatigue loading. Protein and mRNA expression of Ineterleukin-1? and MMP-13 were upregulated for moderate but not low level fatigue loading. Moderate level (7200 cycles) and 100 cycles of fatigue loading resulted in a catabolic and anabolic molecular profile respectively, at both 1 and 7 days post loading. Results suggest unique mechanisms for different levels of fatigue loading that are distinct from laceration. PMID:21625047

Andarawis-Puri, N; Flatow, E L

2011-06-01

213

Mechanical compromise of partially lacerated flexor tendons.  

PubMed

Tendons function to transmit loads from muscle to move and stabilize joints and absorb impacts. Functionality of lacerated tendons is diminished, however clinical practice often considers surgical repair only after 50% or more of the tendon is lacerated, the "50% rule." Few studies provide mechanical insight into the 50% rule. In this study cyclic and static stress relaxation tests were performed on porcine flexor tendons before and after a 0.5, 1.0, 2.0, or 2.75?mm deep transverse, midsubstance laceration. Elastic and viscoelastic properties, such as maximum stress, change in stress throughout each test, and stiffness, were measured and compared pre- and post-laceration. Nominal stress and stiffness parameters decreased, albeit disproportionately in magnitude, with increasing percent loss of cross-sectional area. Conversely, mean stress at the residual area (determined using remaining intact area at the laceration cross section) exhibited a marked increase in stress concentration beginning at 47.2% laceration using both specified load and constant strain analyses. The marked increase in stress concentration beginning near 50% laceration provides mechanical insight into the 50% rule. Additionally, a drastic decrease in viscoelastic stress parameters after only an 8.2% laceration suggests that time-dependent mechanisms protecting tissues during impact loadings are highly compromised regardless of laceration size. PMID:23363212

Kondratko, Jaclyn; Duenwald-Kuehl, Sarah; Lakes, Roderic; Vanderby, Ray

2013-01-01

214

On muscle, tendon and high heels.  

PubMed

Wearing high heels (HH) places the calf muscle-tendon unit (MTU) in a shortened position. As muscles and tendons are highly malleable tissues, chronic use of HH might induce structural and functional changes in the calf MTU. To test this hypothesis, 11 women regularly wearing HH and a control group of 9 women were recruited. Gastrocnemius medialis (GM) fascicle length, pennation angle and physiological cross-sectional area (PCSA), the Achilles' tendon (AT) length, cross-sectional area (CSA) and mechanical properties, and the plantarflexion torque-angle and torque-velocity relationships were assessed in both groups. Shorter GM fascicle lengths were observed in the HH group (49.6+/-5.7 mm vs 56.0+/-7.7 mm), resulting in greater tendon-to-fascicle length ratios. Also, because of greater AT CSA, AT stiffness was higher in the HH group (136.2+/-26.5 N mm(-1) vs 111.3+/-20.2 N mm(-1)). However, no differences in the GM PCSA to AT CSA ratio, torque-angle and torque-velocity relationships were found. We conclude that long-term use of high-heeled shoes induces shortening of the GM muscle fascicles and increases AT stiffness, reducing the ankle's active range of motion. Functionally, these two phenomena seem to counteract each other since no significant differences in static or dynamic torques were observed. PMID:20639419

Csapo, R; Maganaris, C N; Seynnes, O R; Narici, M V

2010-08-01

215

Stretch responsiveness of Golgi tendon organs  

Microsoft Academic Search

1.This report describes experiments on Ib afferents from tendon organs of the de-efferented soleus in acutely prepared cats in which: a) contrast was made of responses to passive forces generated by a dynamic stretch and to active forces generated by stimulating either the muscle nerve or small ventral root filaments; and, b) responses to static and dynamic stretch were related

D. G. Stuart; G. E. Goslow; C. G. Mosher; R. M. Reinking

1970-01-01

216

[The history of flexor tendon surgery].  

PubMed

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

Chamay, A

1997-01-01

217

Engaging Stem Cells for Customized Tendon Regeneration  

PubMed Central

The need for a consistent therapeutic approach to tendon injury repair is long overdue. Patients with tendon microtears or full ruptures are eligible for a wide range of invasive and non invasive interventions, often subjectively decided by the physician. Surgery produces the best outcomes, and while studies have been conducted to optimize graft constructs and to track outcomes, the data from these studies have been inconclusive on the whole. What has been established is a clear understanding of healthy tendon architecture and the inherent process of healing. With this knowledge, tissue regeneration efforts have achieved immense progress in scaffold design, cell line selection, and, more recently, the appropriate use of cytokines and growth factors. This paper evaluates the plasticity of bone-marrow-derived stem cells and the elasticity of recently developed biomaterials towards tendon regeneration efforts. Mesenchymal stem cells (MSCs), hematopoietic progenitor cells, and poly(1,8-octanediol co-citrate) scaffolds (POC) are discussed in the context of established grafting strategies. With POC scaffolds to cradle the growth of MSCs and hematopoietic progenitor cells, developing a fibroelastic network guided by cytokines and growth factors may contribute towards consistent graft constructs, enhanced functionality, and better patient outcomes. PMID:22685473

Thaker, Hatim; Sharma, Arun K.

2012-01-01

218

Relationship between compressive loading and ECM changes in tendons  

PubMed Central

Summary Tendons are designed to absorb and transfer large amounts of tensile load. The well organised, strong yet flexible, extracellular matrix allows for this function. Many tendons are also subject to compressive loads, such as at the entheses, as the tendon wraps around bony protuberances or from internal compression during tensile loading or twisting. Tendinopathy, the clinical syndrome of pain and dysfunction in a tendon is usually the result of overload. However, it is not only the tensile overload that should be considered, as it has been shown that compressive loads change tendon structure and that combination loads can induce tendon pathology. This review summarises how load is detected by the tenocytes, how they respond to compressive load and the resulting extracellular matrix changes that occur. Understanding the effect of compression on tendon structure and function may provide directions for future matrix based interventions. PMID:23885340

Docking, Sean; Samiric, Tom; Scase, Ebonie; Purdam, Craig; Cook, Jill

2013-01-01

219

Blood supply of the flexor hallucis longus tendon with regard to dancer's tendinitis: injection and immunohistochemical studies of cadaver tendons.  

PubMed

The flexor hallucis longus is the most common site of lower extremity tendon disorders in ballet dancers. Reduced vascularity is an important factor contributing to tendon degeneration and rupture under strain. A study was conducted on the vascular pattern of the human flexor hallucis longus tendon with injection techniques and immunohistochemically by using antibodies against laminin. Blood supply arose from the posterior tibial and the medial plantar artery. Peritendinous blood vessels penetrated the tendon and anastomosed with a longitudinally oriented intratendinous network. Injection specimens and immunohistochemistry revealed one avascular zone in which the tendon passed behind the talus and a second in which the tendon wrapped around the first metatarsal head. These are the most typical areas for tendon degeneration and rupture. PMID:12956563

Petersen, Wolf; Pufe, Thomas; Zantop, Thore; Paulsen, Friedrich

2003-08-01

220

Immunoglobulins in tear in trachoma patients  

Microsoft Academic Search

Tear immunoglobulin concentrations have been measured in 100 healthy people and 62 patients in different stages of trachoma. In healthy people the average IgA level was 27-8 mg\\/100 ml. There was no significant difference in the IgA level in various age groups and between the sexes. IgG was detected in 92 samples, and it was less than 1 mg\\/100 ml.

D. K. Sen; G. S. Sarin; K. Saha

1977-01-01

221

Sonographic evaluation of digital annular pulley tears  

Microsoft Academic Search

Objective. To evaluate the sonographic (US) appearance of digital annular pulley (DAP) tears in high-level rock climbers. Design and patients. We performed a retrospective analysis of the US examinations of 16 high-level rock climbers with clinical signs of DAP lesions.\\u000a MRI and surgical evaluation were performed in five and three patients respectively. The normal US and MRI appearances of DAP

Carlo Martinoli; Stefano Bianchi; Mario Nebiolo; Lorenzo E. Derchi; Jean F. Garcia

2000-01-01

222

Gastric pentadecapeptide BPC 157 accelerates healing of transected rat Achilles tendon and in vitro stimulates tendocytes growth.  

PubMed

In studies intended to improve healing of transected Achilles tendon, effective was a stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, M.W. 1419). Currently in clinical trials for inflammatory bowel disease (PLD-116, PL 14736, Pliva), it ameliorates internal and external wound healing. In rats, the right Achilles tendon transected (5 mm proximal to its calcaneal insertion) presents with a large tendon defect between cut ends. Agents (/kg b.w., i.p., once time daily) (BPC 157 (dissolved in saline, with no carrier addition) (10 microg, 10 ng or 10 pg) or saline (5.0 ml)), were firstly applied at 30 min after surgery, the last application at 24 h before autopsy. Achilles functional index (AFI) was assessed once time daily. Biomechanical, microscopical and macroscopical assessment was on day 1, 4, 7, 10 and 14. Controls generally have severely compromised healing. In comparison, pentadecapeptide BPC 157 fully improves recovery: (i) biomechanically, increased load of failure, load of failure per area and Young's modulus of elasticity; (ii) functionally, significantly higher AFI-values; (iii) microscopically, more mononuclears and less granulocytes, superior formation of fibroblasts, reticulin and collagen; (iv) macroscopically, smaller size and depth of tendon defect, and subsequently the reestablishment of full tendon integrity. Likewise, unlike TGF-beta, pentadecapeptide BPC 157, presenting with no effect on the growth of cultured cell of its own, consistently opposed 4-hydroxynonenal (HNE), a negative modulator of the growth. HNE-effect is opposed in both combinations: BPC 157+HNE (HNE growth inhibiting effect reversed into growth stimulation of cultured tendocytes) and HNE+BPC 157(abolished inhibiting activity of the aldehyde), both in the presence of serum and serum deprived conditions. In conclusion, these findings, particularly, Achilles tendon transection fully recovered in rats, peptide stability suitable delivery, usefully favor gastric pentadecapeptide BPC 157 in future Achilles tendon therapy. PMID:14554208

Staresinic, M; Sebecic, B; Patrlj, L; Jadrijevic, S; Suknaic, S; Perovic, D; Aralica, G; Zarkovic, N; Borovic, S; Srdjak, M; Hajdarevic, K; Kopljar, M; Batelja, L; Boban-Blagaic, A; Turcic, I; Anic, T; Seiwerth, S; Sikiric, P

2003-11-01

223

Tearing Instability in Relativistic Magnetically Dominated Plasmas  

NASA Astrophysics Data System (ADS)

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 (see also10), 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 ? = ? {? a ? d } where ?a is the Alfvén crossing time and ?d is the resistive time of a current layer. The reason for this coincidence is the close similarity between the governing equations, especially in the quasi-equilibrium approximation. In particular, the role of the mass density of nonrelativistic MHD is played by the mass-energy density of the magnetic field, ? = B2/8?c2.

Barkov, M. V.; Komissarov, S. S.; Lyutikov, M.

2008-09-01

224

Compensatory muscle activation caused by tendon lengthening post-Achilles tendon rupture.  

PubMed

PURPOSE: The purpose of this study was to establish a relationship between the lengthening of the Achilles tendon post-rupture and surgical repair to muscle activation patterns during walking in order to serve as a reference for post-surgical assessment. METHOD: The Achilles tendon lengths were collected from 4 patients with an Achilles tendon rupture 6 and 12 months post-surgery along with 5 healthy controls via ultrasound. EMG was collected from the triceps surae muscles and tibialis anterior during overground walking. RESULTS: Achilles lengths at 6 and 12 months post-surgery were significantly longer (p < 0.05) on the involved side compared to the uninvolved side, but there were no side-to-side differences in the healthy controls. The integrated EMG (iEMG) of the involved side was significantly higher than the uninvolved side in the lateral gastrocnemius at 6 months and for the medial gastrocnemius at 12 months in the patients with Achilles tendon rupture; no side-to-side difference was found in the healthy controls. The triceps surae muscles' activations were fair to moderately correlated to the Achilles lengths (0.38 < r < 0.52). CONCLUSIONS: The increased Achilles tendon length and iEMG from the triceps surae muscles indicate that loss of function is primarily caused by anatomical changes in the tendon and the appearance of muscle weakness is due to a lack of force transmission capability. This study indicates that when aiming for full return of function and strength, an important treatment goal appears to be to minimize tendon elongation. LEVEL OF EVIDENCE: Prognostic prospective case series, Level IV. PMID:23609529

Suydam, Stephen M; Buchanan, Thomas S; Manal, Kurt; Silbernagel, Karin Gravare

2013-04-23

225

Compensatory muscle activation caused by tendon lengthening post Achilles tendon rupture  

PubMed Central

Purpose The purpose of this study was to establish a relationship between the lengthening of the Achilles tendon post rupture and surgical repair to muscle activation patterns during walking in order to serve as a reference for post-surgical assessment. Method The Achilles tendon lengths were collected from 4 patients with an Achilles tendon rupture 6 and 12 month post-surgery along with 5 healthy controls via ultrasound. EMG was collected from the triceps surae muscles and tibialis anterior during over-ground walking. Results Achilles lengths at 6 and 12 months post-surgery were significantly longer (p < 0.05) on the involved side compared to the uninvolved side but there were no side to side differences in the healthy controls. The integrated EMG (iEMG) of the involved side was significantly higher than the uninvolved side in the lateral gastrocnemius at 6 months and for the medial gastrocnemius at 12 months in the patients with Achilles tendon rupture; no side to side difference was found in the healthy controls. The triceps surae muscles’ activations were fair to moderately correlated to the Achilles lengths (0.38 < r < 0.52). Conclusions The increased Achilles tendon length and iEMG from the triceps surae muscles indicate that loss of function is primarily caused by anatomical changes in the tendon and the appearance of muscle weakness is due to a lack of force transmission capability. This study indicates that when aiming for full return of function and strength an important treatment goal appears to be to minimize tendon elongation. Level of evidence Prognostic prospective case series. Level IV. PMID:23609529

Suydam, Stephen M.; Buchanan, Thomas S.; Manal, Kurt; Silbernagel, Karin Gravare

2013-01-01

226

Glycosaminoglycans of human rotator cuff tendons: changes with age and in chronic rotator cuff tendinitis  

Microsoft Academic Search

OBJECTIVES--To analyse the glycosaminoglycans of the adult human rotator cuff tendon matrix, to characterise changes in the glycosaminoglycan composition with age and in chronic rotator cuff tendinitis. METHODS--Rotator cuff (supraspinatus) tendons (n = 84) and common biceps tendons (n = 26) were obtained from cadavers with no history of tendon pathology (age range 11-95 years). Biopsies of rotator cuff tendons

G P Riley; R L Harrall; C R Constant; M D Chard; T E Cawston; B L Hazleman

1994-01-01

227

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

PubMed Central

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

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

2006-01-01

228

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

NASA Astrophysics Data System (ADS)

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.

Uquillas Paredes, Jorge Alfredo

229

Relationships between Biomechanics, Tendon Pathology, and Function in Individuals with Lateral Epicondylosis  

PubMed Central

Study Design Single cohort descriptive and correlational study. Objectives To investigate the relationships between tendon pathology, biomechanical measures, and self-reported pain and function in individuals with chronic lateral epicondylosis. Background Lateral epicondylosis has a multi-factorial etiology and its pathophysiology is not well understood. Consequently, treatment remains challenging and those with lateral epicondylosis are prone to recurrence. While tendon pathology, pain system changes, and motor impairments due to lateral epicondylosis are considered related, their relationships have not been thoroughly investigated. Methods Twenty-six participants with either unilateral (n = 11) or bilateral (n=15) chronic lateral epicondylosis participated in this study. Biomechanical (grip strength, rate of force development, and electromechanical delay), tendon pathology (magnetic resonance imaging [MRI] and ultrasound), and self-reported pain and function (Patient-rated Tennis Elbow Evaluation [PRTEE]) measurements were made. Partial Spearman correlations, adjusting for covariates (age, gender, weight, and height), were used to evaluate the relationship between self-reported pain, function, and biomechanical and tendon pathology measures. Results Statistically significant correlations between biomechanical measures and PTREE measures ranged in magnitude from 0.44 to 0.68 (P<0.05), but no significant correlation was observed between tendon pathology (MRI and ultrasound) measures and PRTEE (r = ?0.02 – 0.31, P>.05). Rate of force development had a stronger correlation (0.54 – 0.68, P<0.05) with self-reported function score than grip strength (r = 0.35 – 0.47, P<.05) or electromechanical delay (r = 0.5, P<.05). Conclusion Biomechanical measures (pain free grip strength, rate of force development, electromechanical delay) have the potential to be used as outcome measures to monitor progress in lateral epicondylosis. In comparison, the imaging measures (MRI and ultrasound) were useful for visualizing the pathophysiology of lateral epicondylosis. However, the severity of the pathophysiology was not related to pain and function, indicating that imaging measures may not provide the best clinical assessment. PMID:23508267

Chourasia, Amrish O.; Buhr, Kevin A.; Rabago, David P.; Kijowski, Richard; Lee, Kenneth S.; Ryan, Michael P.; Grettie-Belling, Jessica M.; Sesto, Mary E

2013-01-01

230

Low frequency pulsed electromagnetic field affects proliferation, tissue-specific gene expression, and cytokines release of human tendon cells.  

PubMed

Low frequency pulsed electromagnetic field (PEMF) has proven to be effective in the modulation of bone and cartilage tissue functional responsiveness, but its effect on tendon tissue and tendon cells (TCs) is still underinvestigated. PEMF treatment (1.5 mT, 75 Hz) was assessed on primary TCs, harvested from semitendinosus and gracilis tendons of eight patients, under different experimental conditions (4, 8, 12 h). Quantitative PCR analyses were conducted to identify the possible effect of PEMF on tendon-specific gene transcription (scleraxis, SCX and type I collagen, COL1A1); the release of pro- and anti-inflammatory cytokines and of vascular endothelial growth factor (VEGF) was also assessed. Our findings show that PEMF exposure is not cytotoxic and is able to stimulate TCs' proliferation. The increase of SCX and COL1A1 in PEMF-treated cells was positively correlated to the treatment length. The release of anti-inflammatory cytokines in TCs treated with PEMF for 8 and 12 h was significantly higher in comparison with untreated cells, while the production of pro-inflammatory cytokines was not affected. A dramatically higher increase of VEGF-A mRNA transcription and of its related protein was observed after PEMF exposure. Our data demonstrated that PEMF positively influence, in a dose-dependent manner, the proliferation, tendon-specific marker expression, and release of anti-inflammatory cytokines and angiogenic factor in a healthy human TCs culture model. PMID:23345006

de Girolamo, L; Stanco, D; Galliera, E; Viganò, M; Colombini, A; Setti, S; Vianello, E; Corsi Romanelli, M M; Sansone, V

2013-07-01

231

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

PubMed

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

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

2014-06-01

232

Study of the tear topography dynamics using a lateral shearing interferometer  

E-print Network

topography/index.htm Abstract: The dynamics of the pre-corneal tear film topography are studied on 21Study of the tear topography dynamics using a lateral shearing interferometer Alfredo Dubra in quantitative tear topography estimation. Based on the reconstructed tear topography maps, the effects of tear

Dainty, Chris

233

Meta-analysis and review on the changes of tear function and corneal sensitivity in diabetic patients.  

PubMed

To perform a comprehensive evaluation and comparison of tear function in diabetic and non-diabetic patients. Research related to tear function in diabetic and non-diabetic patients was gathered using PubMed, EBSCO, OVID. Two reviewers independently conducted the literature search. The quality assessment and the data extraction were performed in accordance with exclusion criteria and cross-checking. RevMan 5.1.7 software was used for the meta-analysis. The tear film break-up time was studied in eight articles with a total of 1449 samples. Through a random-effects model analysis, the combined weighted mean difference (WMD) was -4.44 [-5.87, -3.01]. The time in diabetic patients was shorter than that in the non-diabetic group (p < 0.00001). The basal tear secretion test was studied in seven articles with a total of 949 samples. The combined WMD was -3.96 [-5.70, -2.23], and the difference between the diabetic group and control group was statistically significant (p < 0.00001). The total tear secretion test was studied in five articles with a total of 921 samples. The combined WMD was -3.96 [-7.43, -0.50]. The difference between the diabetic and control groups was statistically significant (p = 0.03). The corneal sensitivity was compared in eight studies with a total of 976 samples. Through a random-effects model analysis, the standardized mean difference (SMD) was -5.14 [-6.99, -3.29]. The corneal sensitivity was lower in diabetic patients than the control group (p < 0.00001). Our study suggests that the tear functions are worse in diabetic patients compared with the control group. Moreover, patients with PDR are more predisposed to impaired tear functions. PMID:23782539

Lv, Hongbin; Li, Ailing; Zhang, Xibo; Xu, Mei; Qiao, Yu; Zhang, Junhui; Yu, Ling

2014-03-01

234

Patient Acceptability of Tear Collection in the Primary Healthcare Setting  

PubMed Central

ABSTRACT Purpose The primary healthcare setting is well placed for health screening. Tear fluid composition gives valuable information about the eye and systemic health, and there is now significant interest in the potential application of tears as a tool for health screening; however, the acceptability of tear collection in the primary healthcare setting as compared with other methods of human sample collection has not been previously addressed. The objective of this study was to evaluate the patient acceptability of tear collection in a primary healthcare setting. Methods This was a cross-sectional study on 383 adult patients seeking primary healthcare, who were not diabetic and were not attending for an eye-related complaint. Tear collection was done using Schirmer strips, and an interviewer-administered questionnaire was conducted to collate information on the pain score (0–10) of the Schirmer tear collection, as well as to score the pain associated with their previous experience of antecubital venous puncture and finger prick test. Results The pain score for Schirmer tear collection was significantly lower (p < 0.001) than antecubital venous puncture but higher (p < 0.001) than finger prick. The pain scores for all three procedures were significantly higher in participants of younger age, female gender, and higher education level. Among the participants, 70% did not mind their tears being collected to screen for eye problems, whereas only 38% did not mind this procedure being performed for general health screening. Nevertheless, 69% of the participants preferred tear to urine collection, and 74% of participants preferred tear to blood collection. Conclusions Tear collection using Schirmer strips is a highly acceptable form of investigation that has the potential for use in health screening in the primary healthcare setting. This study has implications on using tear collection as a method of ocular and systemic health screening in the primary healthcare setting. PMID:24492756

Quah, Joanne Hui Min; Tong, Louis; Barbier, Sylvaine

2014-01-01

235

The Achilles tendon: fundamental properties and mechanisms governing healing  

PubMed Central

Summary This review highlights recent research on Achilles tendon healing, and comments on the current clinical controversy surrounding the diagnosis and treatment of injury. The processes of Achilles tendon healing, as demonstrated through changes in its structure, composition, and biomechanics, are reviewed. Finally, a review of tendon developmental biology and mechano transductive pathways is completed to recognize recent efforts to augment injured Achilles tendons, and to suggest potential future strategies for therapeutic intervention and functional tissue engineering. Despite an abundance of clinical evidence suggesting that current treatments and rehabilitation strategies for Achilles tendon ruptures are equivocal, significant questions remain to fully elucidate the basic science mechanisms governing Achilles tendon injury, healing, treatment, and rehabilitation. PMID:25332943

Freedman, Benjamin R.; Gordon, Joshua A.; Soslowsky, Louis J.

2014-01-01

236

Ligament reconstruction tendon interposition with mersilene augmentation.  

PubMed

Many surgical procedures have been described for the treatment of thumb basilar joint osteoarthritis. Augmentation of the standard ligament reconstruction tendon interposition procedure with the use of a Mersilene suture tape suspension-plasty, to recreate the stability provided by the anterior oblique ligament and increase pinch strength, will be described. Satisfaction with this procedure was evaluated through surveys completed by patients. In addition, independent physical assessments were performed to demonstrate stability, range of motion, and strength. PMID:21358518

Stein, Andrew J; Schofield, Jennifer L; Marsh, Mike; Paulo, Jerry

2011-03-01

237

Hybrid Repair of Large Crescent Rotator Cuff Tears Using a Modified SpeedBridge and Double-Pulley Technique.  

PubMed

An ideal rotator cuff repair maximizes the tendon-bone interface and has adequate biomechanical strength that can withstand a high level of demand. Arthroscopic transosseous-equivalent rotator cuff repairs have become popular and have been shown to be superior to many other methods of fixation. We present an alternative method of repair for large crescent rotator cuff tears that combines 2 well-known methods of fixation: modified SpeedBridge (Arthrex, Naples, FL) and double-pulley techniques. These 2 repair constructs were combined to provide the greatest amount of compression across the footprint while also providing rigid fixation. Ultimately, this can provide an optimal environment for healing in otherwise significant injuries. PMID:25126513

Chauhan, Aakash; Regal, Steven; Frank, Darren A

2014-06-01

238

Low level laser therapy in healing tendon  

NASA Astrophysics Data System (ADS)

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.

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

2005-11-01

239

[Isolated stapedius tendon ossification: a case report].  

PubMed

In this study, a case with bilateral isolated stapedius tendon ossification was reported, since it is a rare clinical condition. A 46-year-old female patient was admitted to our clinic with the complaint of bilateral hearing loss. Tympanic membrane was bilateral normal in color and appearance on otomicroscopic examination. Pure tone air bone gap was between 20-25 dB at 1 kHz and 4 kHz on audiogram bilaterally. Middle ear pressure was normal and stapedius reflex was negative bilaterally. Preoperative diagnosis was otosclerosis. Right exploratory tympanotomy was performed. Isolated stapedius tendon ossification was determined. Normal stapedius movement was achieved by cutting the tendon. Three months later, the same procedure was performed on the left ear. Pure tone air bone gap was bilateral 0 dB at 0.5 kHz, 1 kHz and 2 kHz, and 5-10 dB at 4 kHz on audiogram postoperatively. PMID:21417973

Ulkü, Ca?atay Han

2011-01-01

240

Integrated multimodal metrology for objective and noninvasive tear evaluation.  

PubMed

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

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

2012-01-01

241

Preliminary identification of differentially expressed tear proteins in keratoconus  

PubMed Central

Purpose To examine the proteins differentially expressed in the tear film of people with keratoconus and normal subjects. Methods Unstimulated tears from people with keratoconus (KC) and controls (C) were collected using a capillary tube. Tear proteins from people with KC and controls were partitioned using a novel in-solution electrophoresis, Microflow 10 (ProteomeSep), and analyzed using linear ion trap quadrupole fourier transform mass spectrometry. Spectral counting was used to quantify the individual tear proteins. Results Elevated levels of cathepsin B (threefold) were evident in the tears of people with KC. Polymeric immunoglobulin receptor (ninefold), fibrinogen alpha chain (eightfold), cystatin S (twofold), and cystatin SN (twofold) were reduced in tears from people with KC. Keratin type-1 cytoskeletal-14 and keratin type-2 cytoskeletal-5 were present only in the tears of people with KC. Conclusions The protein changes in tears, that is, the decrease in protease inhibitors and increase in proteases, found in the present and other previously published studies reflect the pathological events involved in KC corneas. Further investigations into tear proteins may help elucidate the underlying molecular mechanisms of KC, which could result in better treatment options. PMID:24194634

Wasinger, Valerie C.; Pye, David C.; Willcox, Mark D. P.

2013-01-01

242

Ethanol treatment of tendon allografts: a potential HIV inactivating procedure  

Microsoft Academic Search

Summary.  \\u000a The penetration rate of ethanol in human tendons was studied to in order to define the conditions which were necessary to\\u000a achieve an inactivating concentration against the Human Immunodeficiency Virus (HIV) within the tendon. The rate of alcohol\\u000a penetration was found to be slow and did not differ with different types of tendons. An average ethanol concentration of 14%

M. Anastasescou; O. Cornu; X. Banse; J. König; A. Hassoun; C. Delloye

1998-01-01

243

Diagnosis and treatment of intraoperative popliteus tendon impingement.  

PubMed

Herein, we describe a simple, effective strategy for diagnosing and treating intraoperative popliteus tendon impingement during total knee arthroplasty (TKA). When lateral impingement is detected intraoperatively during TKA, manual isolation of the popliteus tendon can help determine the cause. Using this technique, the etiology of intraoperative lateral impingement during TKA was never misdiagnosed and the popliteus tendon was never unnecessarily released. The technique described allows for accurate diagnosis of intraoperative lateral impingement during TKA and the prevention of unnecessary popliteus resection. PMID:24474167

Kazakin, Anatoly; Nandi, Sumon; Bono, James

2014-12-01

244

Outflow of tears and its influence on tear secretion and break up time (B.U.T.).  

PubMed

Schirmer's test shows that a retarded outflow of tears causes reduction of the tear secretion. The B.U.T. is independent of the outflow of tears in patients with epiphora (119 eyes with mechanical obstruction, functional obstruction, or normal passage). Mucomimetics prolong the B.U.T. and retard the outflow of tears, whereas ointments reduce both the B.U.T. and the outflow (74 eyes). The B.U.T. becomes reduced when tears are absorbed by filter paper in Schirmer's test, but remains uninfluenced by filter paper inserted in the fornix. The B.U.T. is a valuable clinical test. It is the resultant of many different factors (tear volume, mucus, fat, etc.). PMID:331851

Norn, M S

1977-08-01

245

Mechanical properties of the flexor digitorum profundus tendon attachment.  

PubMed

The current study was performed to determine the strength and rigidity of the intact flexor digitorum profundus (FDP) tendon attachment and compare the rigidity at the attachment site to the rigidity within a more proximal part of the tendon. Eight cadaveric index fingers were tested to failure of the FDP tendon. Lines were drawn on each tendon with India ink stain at the position of the attachment to bone and 5 mm and 10 mm proximally. Each test was recorded using a high resolution video camera. A minimum of six images per test were used for analysis of tissue deformation. The centroid of each line was computationally identified to characterize the deformation of the tendon between the lines. Force vs. deformation curves were generated for the 5 mm region representing the tendon attachment and the 5 mm region adjacent to the attachment. Stiffness measurements were generated for each curve, and normalized by the initial length to determine the rigidity. The failure strength ranged from 263 N to 548 N, with rigidity values ranging from 2201 N/(mm/mm) to 8714 N/(mm/mm) and from 3459 N/(mm/mm) to 6414 N/(mm/mm) for the attachment and the tendon proximal to the attachment, respectively. The rigidity did not vary significantly between the attachment and proximal tendon based on a Wilcoxon signed rank test (p?=?0.2). The measured strength and rigidity establish biomechanical properties for the FDP tendon attachment to bone. PMID:24426675

Felder, Jerrod J; Guseila, Loredana M; Saranathan, Archana; Shary, Timothy J; Lippitt, Steven B; Elias, John J

2013-12-01

246

Mechanical characteristics of native tendon slices for tissue engineering scaffold  

PubMed Central

The purpose of this study was to characterize the mechanical behavior of tendon slices with different thicknesses. Tendon slices of 100, 200, 300, 400, and 500 ?m thickness were mechanically tested. The 300 ?m slices were further tested for strength and modulus after 21,000-cycle fatigue testing under different applied strain levels (0, 1, 3, 5, 8, 10, and 12%). The tendon slice structure, morphology, and viability of bone marrow stromal cells (BMSCs) seeded onto the slices were also examined with histology, scanning electron microscopy, and vital cell labeling, respectively. Tendon slices 300 ?m or more in thickness had similar ultimate tensile strength and Young's modulus to the intact tendon bundle. A strain of 5% or less did not cause any structural damage, nor did it change the mechanical properties of a 300 ?m-thick tendon slice after 21,000-cycle fatigue testing. BMSCs were viable between and on the tendon slices after 2 weeks in tissue culture. This study demonstrated that, if tendon slices are used as a scaffold for tendon tissue engineering, slices 300 ?m or more in thickness would be preferable from a mechanical strength point of view. If mechanical stimulation is performed for seeded-cell preparations, 5% strain or less would be appropriate. PMID:22323314

Qin, Ting-Wu; Chen, Qingshan; Sun, Yu-Long; Steinmann, Scott P.; Amadio, Peter C.; An, Kai-Nan; Zhao, Chunfeng

2014-01-01

247

Tendon transfer options in managing the adult flexible flatfoot.  

PubMed

Patients undergoing surgery for posterior tibial tendon dysfunction may require tendon transfer. The flexor digitorum longus is most commonly transferred, although the flexor hallucis longus and peroneus brevis have also been described in the literature. This article discusses the advantages and disadvantages of the different tendons, the surgical techniques used to perform them, and their results in the literature, concentrating principally on studies in which additional bone procedures were not performed. This article will also discuss the potential role for isolated soft tissue procedures in the treatment of stage 2 posterior tibial tendon dysfunction. PMID:22541521

Aronow, Michael S

2012-06-01

248

Reconstruction of a ruptured patellar tendon using ipsilateral semitendinosus and gracilis tendons with preserved distal insertions: two case reports  

PubMed Central

Background Acute patellar tendon ruptures with poor tissue quality. Ruptures that have been neglected are difficult to repair. Several surgical techniques for the repair of the patellar tendon have been reported, however, these techniques remain difficult because of contractures, adhesions, and atrophy of the quadriceps muscle after surgery. Case presentation We report the cases of 2 Japanese patients (Case 1: a 16-year-old male and Case 2: a 43-year-old male) with patellar tendon ruptures who were treated by reconstruction using semitendinosus-gracilis (STG) tendons with preserved distal insertions. Retaining the original insertion of the STG appears to preserve its viability and provide the revascularization necessary to accelerate healing. Both tendons were placed in front of the patella, in a figure-of-eight fashion, providing stability to the patella. Conclusion Both patients recovered near normal strength and stability of the patellar tendon as well as restoration of function after the operation. PMID:24010848

2013-01-01

249

Repair of Achilles tendon defect with autologous ASCs engineered tendon in a rabbit model.  

PubMed

Adipose derived stem cells (ASCs) are an important cell source for tissue regeneration and have been demonstrated the potential of tenogenic differentiation in vitro. This study explored the feasibility of using ASCs for engineered tendon repair in vivo in a rabbit Achilles tendon model. Total 30 rabbits were involved in this study. A composite tendon scaffold composed of an inner part of polyglycolic acid (PGA) unwoven fibers and an outer part of a net knitted with PGA/PLA (polylactic acid) fibers was used to provide mechanical strength. Autologous ASCs were harvested from nuchal subcutaneous adipose tissues and in vitro expanded. The expanded ASCs were harvested and resuspended in culture medium and evenly seeded onto the scaffold in the experimental group, whereas cell-free scaffolds served as the control group. The constructs of both groups were cultured inside a bioreactor under dynamic stretch for 5 weeks. In each of 30 rabbits, a 2 cm defect was created on right side of Achilles tendon followed by the transplantation of a 3 cm cell-seeded scaffold in the experimental group of 15 rabbits, or by the transplantation of a 3 cm cell-free scaffold in the control group of 15 rabbits. Animals were sacrificed at 12, 21 and 45 weeks post-surgery for gross view, histology, and mechanical analysis. The results showed that short term in vitro culture enabled ASCs to produce matrix on the PGA fibers and the constructs showed tensile strength around 50 MPa in both groups (p > 0.05). With the increase of implantation time, cell-seeded constructs gradually form neo-tendon and became more mature at 45 weeks with histological structure similar to that of native tendon and with the presence of bipolar pattern and D-periodic structure of formed collagen fibrils. Additionally, both collagen fibril diameters and tensile strength increased continuously with significant difference among different time points (p < 0.05). In contrast, cell-free constructs failed to form good quality tendon tissue with fibril structure observable only at 45 weeks. There were significant differences in both collagen fibril diameter and tensile strength between two groups at all examined time points (p < 0.05). The results of this study support that ASCs are likely to be a potential cell source for in vivo tendon engineering and regeneration. PMID:25069604

Deng, Dan; Wang, Wenbo; Wang, Bin; Zhang, Peihua; Zhou, Guangdong; Zhang, Wen Jie; Cao, Yilin; Liu, Wei

2014-10-01

250

Tear Film Interferometry and Corneal Surface Roughness  

PubMed Central

Purpose. Previous studies of optical interference from the whole thickness of the precorneal tear film showed much lower contrast than from the pre–contact lens tear film. It is hypothesized that the recorded low contrast is related to roughness of the corneal surface compared with the smooth contact lens surface. This hypothesis is tested, and characteristics of this roughness are studied. Methods. Reflectance spectra were recorded from 20 healthy individuals using a silicon-based sensor used in previous studies (wavelength range, 562–1030 nm) and an indium-gallium-arsenide (InGaAs) sensor responding at longer wavelengths (912–1712 nm). Interference from the whole thickness of the precorneal tear film caused oscillations in the reflectance spectra. Results. Spectral oscillations recorded with the InGaAs sensor were found to decay as a Gaussian function of wave number (1/wavelength). This is consistent with a rough corneal surface, whose distribution of surface height is also a Gaussian function. Contrast of spectral oscillations for the InGaAs sensor was, on average, approximately four times greater than that for the silicon sensor. Conclusions. For the Gaussian roughness model based on InGaAs spectra, the corneal surface was characterized by a surface height SD of 0.129 ?m. Spectral oscillations recorded with a silicon-based camera can have higher contrast than expected from this Gaussian roughness model, indicating some reflectance from a smoother or more compact surface. The results also indicate that InGaAs cameras could provide whole-thickness interference images of higher contrast than silicon-based cameras. PMID:24692127

King-Smith, P. Ewen; Kimball, Samuel H.; Nichols, Jason J.

2014-01-01

251

In situ microdialysis in tendon tissue: high levels of glutamate, but not prostaglandin E2 in chronic Achilles tendon pain  

Microsoft Academic Search

This investigation was to our knowledge the first to use the microdialysis technique to study concentrations of substances\\u000a in a human tendon. In four patients (mean age 40.7 years) with a painful nodule in the Achilles tendon (chronic Achilles tendinosis)\\u000a and in five controls (mean age 37.2 years) with normal Achilles tendons (confirmed by ultrasonography) the local concentrations\\u000a of glutamate

H. Alfredson; K. Thorsen; R. Lorentzon

1999-01-01

252

The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration.  

PubMed

Pentadecapeptide BPC 157, composed of 15 amino acids, is a partial sequence of body protection compound (BPC) that is discovered in and isolated from human gastric juice. Experimentally it has been demonstrated to accelerate the healing of many different wounds, including transected rat Achilles tendon. This study was designed to investigate the potential mechanism of BPC 157 to enhance healing of injured tendon. The outgrowth of tendon fibroblasts from tendon explants cultured with or without BPC 157 was examined. Results showed that BPC 157 significantly accelerated the outgrowth of tendon explants. Cell proliferation of cultured tendon fibroblasts derived from rat Achilles tendon was not directly affected by BPC 157 as evaluated by MTT assay. However, the survival of BPC 157-treated cells was significantly increased under the H(2)O(2) stress. BPC 157 markedly increased the in vitro migration of tendon fibroblasts in a dose-dependent manner as revealed by transwell filter migration assay. BPC 157 also dose dependently accelerated the spreading of tendon fibroblasts on culture dishes. The F-actin formation as detected by FITC-phalloidin staining was induced in BPC 157-treated fibroblasts. The protein expression and activation of FAK and paxillin were determined by Western blot analysis, and the phosphorylation levels of both FAK and paxillin were dose dependently increased by BPC 157 while the total amounts of protein was unaltered. In conclusion, BPC 157 promotes the ex vivo outgrowth of tendon fibroblasts from tendon explants, cell survival under stress, and the in vitro migration of tendon fibroblasts, which is likely mediated by the activation of the FAK-paxillin pathway. PMID:21030672

Chang, Chung-Hsun; Tsai, Wen-Chung; Lin, Miao-Sui; Hsu, Ya-Hui; Pang, Jong-Hwei Su

2011-03-01

253

[The ACL tear from the pre-operative analysis to a 2-year follow-up, influence of the graft choice on the subjective and objective evaluation].  

PubMed

This study is a synthesis of three series. The first study was prospective on 418 patients with an anterior cruciate ligament (ACL) tear (group I). Two population of ACL ruptures were identified. One population with a postero-lateral bundle preserved in 16%, the mean medial anterior tibial translation side to side was 4.97 mm, the Lachman test was delayed in 40% with no or glide pivot shift in 73%. The second population with a complete ACL tear had a mean medial anterior tibial translation side to side of 7.93 mm, the Lachman test was soft in 98% with gross pivot shift in 80%. The second study was a retrospective study on 258 patients (group II) at 26 months follow-up, it correlated the impact of the type of graft on the clinical objective and subjective results. Twenty-eight percent had anterior knee pain, 33% for the patellar tendon and 25% for the hamstrings, the subjective IKDC was significantly lower for the painful knees, and 68% of the patellar tendon had a hypoesthesia and only 32% for the hamstrings. The ability to walk on the knee was 68% for the hamstrings and 35% for the patellar tendon. The third study was retrospective on 127 patients, 24 months after ACL reconstruction (group III), all were tested on a isokinetic machine for the extensor, the flexor and the internal rotator. In the total population, a 10% extensor and flexor deficit and a 5% rotator deficit was noted. A significant difference between patellar tendon and hamstrings in terms of muscular recovery was found. It pointed out that a more specific rehabilitation should be done on the hamstring group. The muscular recovery was correlated to the highest subjective score. This study allowed the surgeon to be more specific in the ACL tear definition, to adapt the graft choice to the type of sport activity but also to the type of work the patient does and finally to modify the rehabilitation protocol for the hamstring technique. PMID:19046692

Dejour, D; Potel, J-F; Gaudot, F; Panisset, J-C; Condouret, J

2008-12-01

254

Onset Time of Nerve Block: A Comparison of Two Injection Locations in Patients Having Lower Leg/ Foot Surgery  

ClinicalTrials.gov

Strain of Muscle and/or Tendon of Lower Leg; Fracture of Lower Leg; Crushing Injury of Lower Leg; Fracture Malunion - Ankle and/or Foot; Disorder of Joint of Ankle and/or Foot; Complete Tear, Ankle and/or Foot Ligament; Pathological Fracture - Ankle and/or Foot; Loose Body in Joint of Ankle and/or Foot

2014-03-20

255

Repair of a complete anterior cruciate tear using prolotherapy: a case report.  

PubMed

OBJECTIVE AND IMPORTANCE: Surgical reconstruction is considered definitive treatment for anterior cruciate ligament (ACL) tears but precise surgical indications are debated. Some patients are reluctant or inappropriate surgical candidates. Prolotherapy is a non-surgical injection therapy for chronic musculoskeletal pain and instability. This case report documents the non-surgical repair of a torn ACL using prolotherapy and at-home exercise. CLINICAL PRESENTATION AND INTERVENTION: The 18 year old female patient sustained a right knee injury during a downhill skiing accident. Magnetic Resonance Imaging (MRI) revealed a high-grade partial versus complete rupture; Lachman exam findings suggested a complete rupture. She deferred surgical treatment. At 21 weeks post-injury, with unstable gait, inability to climb stairs and more than 1 cm anterior drawer test, she consented to undergo prolotherapy injections. She received 7 prolotherapy sessions over a 15 week period. At-home exercises were initiated at the 3(rd) prolotherapy session. RESULTS: The patient improved. Walking on flat ground improved 4 weeks after initiation of prolotherapy; she could ride a stationary bicycle for 30 minutes by 12 weeks. By 15 weeks, the patient had no instability climbing and descending stairs, the anterior drawer test was negative and MRI showed an intact ACL with fibrosis. Subsequently, she returned to full sport activity. CONCLUSIONS: We document the non-surgical repair of a high-grade partial or complete ACL tear using prolotherapy and at-home exercise. Prolotherapy may be an alternative to surgery in carefully selected patients. This report is consistent with findings of recent pilot-level studies and suggests the need for rigorous clinical trials assessing prolotherapy as treatment for ligament and tendon injury in selected patients. PMID:20802815

Grote, Walter; Delucia, Rosa; Waxman, Robert; Zgierska, Aleksandra; Wilson, John; Rabago, David

2009-12-01

256

Numerical study on the influence of electron cyclotron current drive on tearing mode  

NASA Astrophysics Data System (ADS)

Controlling tearing modes by localized current drive is explored by using numerical simulation with a set of compressible magnetohydrodynamics equations. By examining the effects of different characteristics of driven current, such as density distribution, duration time, and deposition location, it is found that a driven current with larger magnitude and more focused deposition region shows a better suppression effect on the tearing modes. Meanwhile destabilizing effects are also observed when a driven current over a certain magnitude is applied continuously. In comparison with those on the X-point of the magnetic island, the results are better when the current deposition is targeted on the O-point. In addition, the timing control of the current deposition will be also addressed.

Chen, Long; Liu, Jinyuan; Duan, Ping; Mao, Aohua; Sun, Jizhong

2014-10-01

257

All-Arthroscopic Suprapectoral Long Head of Biceps Tendon Tenodesis With Interference Screw-Like Tendon Fixation After Modified Lasso-Loop Stitch Tendon Securing  

PubMed Central

Arthroscopic suprapectoral techniques for tenodesis of the long head of the biceps tendon (LHB) are appropriate for the treatment of proximal biceps lesions. Several types of techniques and fixation devices have been described and evaluated in biomechanical studies regarding primary stability. In this technical note, we describe an all-arthroscopic suprapectoral technique using the 6.25-mm Bio-SwiveLock device (Arthrex, Naples, FL) for an interference screw–like bony fixation after having armed the tendon with a lasso-loop stitch. Both the interference screw fixation and securing of the lasso-loop tendon have been well described and approved in biomechanical tests concerning the primary stability. One advantage of this technique performed from the glenohumeral space, in addition to the strong and secure fixation with ingrowth of the tendon in a bony canal, is the avoidance of touching the soft tissue above the bicipital groove, which results in a smooth fitting of the tendon into its natural canal and therefore avoids mechanical irritation of the stump at the rotator interval. In conclusion, the all-arthroscopic suprapectoral LHB tenodesis performed from the glenohumeral space with the modified lasso-loop stitch for securing of the tendon and the 6.25-mm Bio-SwiveLock suture anchor for interference screw–like bony tendon fixation is an appropriate technique for the treatment of LHB-associated lesions. PMID:23766976

Patzer, Thilo; Kircher, Jorn; Krauspe, Ruediger

2012-01-01

258

Ultrashort echo imaging of cyclically loaded rabbit patellar tendon.  

PubMed

Tendinopathy affects individuals who perform repetitive joint motion. Magnetic resonance imaging (MRI) is frequently used to qualitatively assess tendon health, but quantitative evaluation of inherent MRI properties of loaded tendon has been limited. This study evaluated the effect of cyclic loading on [Formula: see text] values of fresh and frozen rabbit patellar tendons using ultra short echo (UTE) MRI. Eight fresh and 8 frozen rabbit lower extremities had MR scans acquired for tendon [Formula: see text] evaluation. The tendons were then manually cyclically loaded for 100 cycles to 45N at approximately 1Hz. The MR scanning was repeated to reassess the [Formula: see text] values. Analyses were performed to detect differences of tendon [Formula: see text] values between fresh and frozen samples prior to and after loading, and to detect changes of tendon [Formula: see text] values between the unloaded and loaded configurations. No difference of [Formula: see text] was found between the fresh and frozen samples prior to or after loading, p=0.8 and p=0.1, respectively. The tendons had significantly shorter [Formula: see text] values, p=0.023, and reduced [Formula: see text] variability, p=0.04, after cyclic loading. Histologic evaluation confirmed no induced tendon damage from loading. Shorter [Formula: see text] , from stronger spin-spin interactions, may be attributed to greater tissue organization from uncrimping of collagen fibrils and lateral contraction of the tendon during loading. Cyclic tensile loading of tissue reduces patellar tendon [Formula: see text] values and may provide a quantitative metric to assess tissue organization. PMID:25234349

Koff, Matthew F; Pownder, Sarah L; Shah, Parina H; Yang, Lim Wei; Potter, Hollis G

2014-10-17

259

Geometrical influences on neoclassical magnetohydrodynamic tearing modes  

SciTech Connect

The influence of geometry on the pressure drives of nonideal magnetohydrodynamic tearing modes is presented. In order to study the effects of elongation, triangularity, and aspect ratio, three different machines are considered to provide a range of tokamak configurations: Tokamak Fusion Test Reactor (circular) [Fusion Technol. {bold 21}, 1324 (1992)], DIII-D (D-shaped) [{ital Plasma Physics and Controlled Nuclear Fusion Research 1986} (International Atomic Energy Agency, Vienna, 1987), Vol. 1, p. 159], and Pegasus (extremely low aspect ratio) [Fonck {ital et al.}, Bull. Am. Phys. Soc. {bold 41}, 1400 (1996)]. For large aspect ratio tokamaks, shaping does very little to influence the pressure gradient drives, while at low aspect ratios, a very strong sensitivity to the profiles is found. In particular, this sensitivity is connected to the strong dependence on the magnetic shear. This suggests that at low aspect ratio it may be possible to stabilize neoclassical tearing modes by a flattening the q profile near low order rational surfaces (e.g., q=2/1) using a combination of shaping and localized current drive, whereas at large aspect ratio it is more difficult. {copyright} {ital 1998 American Institute of Physics.}

Kruger, S.E.; Hegna, C.C.; Callen, J.D. [Department of Nuclear Engineering and Engineering Physics, 1500 Engineering Drive Madison, Wisconsin 53706-1687 (United States)] [Department of Nuclear Engineering and Engineering Physics, 1500 Engineering Drive Madison, Wisconsin 53706-1687 (United States)

1998-02-01

260

Frequent association of delayed tear clearance in ocular irritation  

PubMed Central

AIM—To explore the pathogenic role of delayed tear clearance.?METHODS—By comparing 10 patients with punctal obstruction and 20 asymptomatic normals, delayed tear clearance was diagnosed in 70 patients without apparent punctal obstruction using fluorescein clearance test.?RESULTS—The majority were older (71.4 (SD 1.2) years) and women (66%). Frequent complaints included redness, itching, mucus discharge, and crusting, which tended to be worse upon awakening. Common associated problems were medicamentosa (13%), drug induced pseudo pemphigoid, ocular hypertension (27%), and glaucoma (7%). Topical non-preserved 1% methylprednisolone resulted in subjective (83%) and objective (80%) improvement and resolution of delayed tear clearance (87%).?CONCLUSION—These results indicate strong association of delayed tear clearance with intrinsically and extrinsically generated ocular surface inflammation. The presence of delayed tear clearance may set up a vicious cycle to aggravate the existing inflammation. Future prospective studies are needed to delineate the pathogenic role of delayed tear clearance in various ocular surface disorders.?? Keywords: medicamentosa; ocular irritation; tear clearance; tear turnover PMID:9797670

Prabhasawat, P.; Tseng, S.

1998-01-01

261

Structural changes in human tear lipocalins associated with lipid binding  

Microsoft Academic Search

Structural and conformational changes in tear lipocalins were detected in association with ligand binding and release. Circular dichroism measurements demonstrated that ligand binding induces ? structure formation, aromatic side chain asymmetry, and a more rigid state in tear lipocalins (TL). The exposure of the tyrosyl component is less in apo-TL than in holo-TL. The sole tryptophan residue, Trp17, is buried

Oktay K. Gasymov; Adil R. Abduragimov; Taleh N. Yusifov; Ben J. Glasgow

1998-01-01

262

49 CFR 173.340 - Tear gas devices.  

...elements unless of a type and design which has been approved by the Associate Administrator. (c) Tear gas grenades, tear gas candles, and similar devices must be packaged in one of the following packagings conforming to the requirements of part 178 of...

2014-10-01

263

Human Tear Film Dynamics with an Overset Grid Method  

E-print Network

Human Tear Film Dynamics with an Overset Grid Method Kara L. Maki1 , R.J. Braun1 , W.D. Henshaw2 University Supported by the NSF #12;What is Human Tear Film? A multilayer structure playing a vital role in health and function of the eye. Typical thickness of each layer in microns. Cornea: Modeled as a flat

Bacuta, Constantin

264

Research on the kelp, Job's tears, and celery compound beverage  

Microsoft Academic Search

With kelp, Job's tears, and celery as main materials, a healthy compound beverage was produced by unit operations of cutting, blanching, slurrying, filtrating, preparing, grinding, Homogenize, sterilization. The formula and suitable stabilizers of compound beverage were obtained by single factor experiments and orthogonal test. The results showed that the formula of compound beverage was kelp juice 15%, job's tears 10%,

Qilong Shi; Ya Zhao

2011-01-01

265

State Secret: North Carolina and the Cherokee Trail of Tears  

ERIC Educational Resources Information Center

This paper is an analytic essay that examines the treatment of the Cherokee Trail of Tears in a North Carolina fourth grade textbook. I begin by offering a satiric look at an imaginary textbook's treatment of the Holocaust that is based closely on the actual narrative of the Trail of Tears written in the fourth grade text. Following this, close…

Bryant, James

2008-01-01

266

Postoperative subcoracoid impingement syndrome in patients with rotator cuff tear  

Microsoft Academic Search

Impingement of the tendinous rotator cuff on the coracoid process (subcoracoid impingement syndrome) has rarely been reported as a cause of pain after surgery for rotator cuff tear. We evaluated clinical features, surgical results, and histopathology findings of resected coracoid processes in patients with subcoracoid impingement syndrome after anterior acromioplasty and management of rotator cuff tear. Pain at the anterior

Naoki Suenaga; Akio Minami; Kiyoshi Kaneda

2000-01-01

267

Effect of airflow exposure on the tear meniscus.  

PubMed

Purpose. To compare the effect of airflow exposure on the tear meniscus and blink frequency in normal and evaporative dry eye subjects. Methods. In 9 normal subjects and 9 short tear breakup time (SBUT) dry eye subjects, lower tear meniscus height (TMH) and area (TMA) and blink frequency were measured with anterior segment optical coherence tomography (OCT) before and after 5 minutes of airflow exposure (1.5 ± 0.5?m/s). Results. In SBUT dry eyes, both TMH and TMA decreased significantly (P = 0.027, P = 0.027) with a significant increase of blink frequency after airflow exposure, while significant increase in TMA was found in normal eyes. Conclusion. Measurement of the tear meniscus with anterior segment OCT seems to be useful as a noninvasive and objective method for evaluating the effect of airflow on tear film. PMID:22570766

Koh, Shizuka; Tung, Cynthia; Kottaiyan, Ranjini; Zavislan, James; Yoon, Geunyoung; Aquavella, James

2012-01-01

268

Effect of Airflow Exposure on the Tear Meniscus  

PubMed Central

Purpose. To compare the effect of airflow exposure on the tear meniscus and blink frequency in normal and evaporative dry eye subjects. Methods. In 9 normal subjects and 9 short tear breakup time (SBUT) dry eye subjects, lower tear meniscus height (TMH) and area (TMA) and blink frequency were measured with anterior segment optical coherence tomography (OCT) before and after 5 minutes of airflow exposure (1.5 ± 0.5?m/s). Results. In SBUT dry eyes, both TMH and TMA decreased significantly (P = 0.027, P = 0.027) with a significant increase of blink frequency after airflow exposure, while significant increase in TMA was found in normal eyes. Conclusion. Measurement of the tear meniscus with anterior segment OCT seems to be useful as a noninvasive and objective method for evaluating the effect of airflow on tear film. PMID:22570766

Koh, Shizuka; Tung, Cynthia; Kottaiyan, Ranjini; Zavislan, James; Yoon, Geunyoung; Aquavella, James

2012-01-01

269

Effect of acute resistance exercise and sex on human patellar tendon structural and regulatory mRNA expression  

PubMed Central

Tendon is mainly composed of collagen and an aqueous matrix of proteoglycans that are regulated by enzymes called matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). Although it is known that resistance exercise (RE) and sex influence tendon metabolism and mechanical properties, it is uncertain what structural and regulatory components contribute to these responses. We measured the mRNA expression of tendon's main fibrillar collagens (type I and type III) and the main proteoglycans (decorin, biglycan, fibromodulin, and versican) and the regulatory enzymes MMP-2, MMP-9, MMP-3, and TIMP-1 at rest and after RE. Patellar tendon biopsy samples were taken from six individuals (3 men and 3 women) before and 4 h after a bout of RE and from a another six individuals (3 men and 3 women) before and 24 h after RE. Resting mRNA expression was used for sex comparisons (6 men and 6 women). Collagen type I, collagen type III, and MMP-2 were downregulated (P < 0.05) 4 h after RE but were unchanged (P > 0.05) 24 h after RE. All other genes remained unchanged (P > 0.05) after RE. Women had higher resting mRNA expression (P < 0.05) of collagen type III and a trend (P = 0.08) toward lower resting expression of MMP-3 than men. All other genes were not influenced (P > 0.05) by sex. Acute RE appears to stimulate a change in collagen type I, collagen type III, and MMP-2 gene regulation in the human patellar tendon. Sex influences the structural and regulatory mRNA expression of tendon. PMID:19023016

Sullivan, Bridget E.; Carroll, Chad C.; Jemiolo, Bozena; Trappe, Scott W.; Magnusson, S. Peter; Døssing, Simon; Kjaer, Michael; Trappe, Todd A.

2009-01-01

270

MAC-EYE: a Tendon Driven Fully Embedded Robot Eye  

E-print Network

MAC-EYE: a Tendon Driven Fully Embedded Robot Eye Dario Biamino, Giorgio Cannata, Marco Maggiali the possibility of designing a robot eye with kinematics and actuation similar to those of the human eye. In particular, we tried to exploit the spherical shape of the eye and to study the feasibility of a tendon based

Cannata, Giorgio

271

Granuloma formation secondary to Achilles tendon repair with nonabsorbable suture  

PubMed Central

INTRODUCTION Several complications can be observed after Achilles tendon repairs. In this study we aimed to report granuloma formation secondary to Achilles tendon repair with Ethibond (Ethicon INC, Somerville, New Jersey) suture. PRESENTATION OF CASE A 31 year-old man operated for Achilles tendon rupture. The Ethibond suture was used for primary repair. The patient attended to polyclinic with the complaints of swelling and discharge around the operation site four months after operation. A mass around distal portion of the Achilles tendon was detected. The granulomatous tissue was excised. Inside the mass Ethibond suture was detected. On histopathologic examination, typical findings of the foreign body reaction were observed. No microorganism was cultivated in the tissue culture. The patient has no complaint on the twelfth month control after surgery. DISCUSSION The results of primary repair of Achilles tendon are good but several complications were reported. In tendon repairs generally nonabsorbable sutures are used. The Ethibond is nonabsorbable, braided suture. In the literature, granuloma formations secondary to the suture materials such as polygylactine and braided polyethylen–polyester after Achilles tendon repair were reported but granuloma secondary to the Ethibond is very rare. CONCLUSION Although Ethibond suture is a strong and safe material for Achilles tendon repairs it may cause soft tissue problems such as granuloma. PMID:25212905

Kara, Adnan; Celik, Haluk; Seker, Ali; Uysal, Mehmet Ali; Uzun, Metin; Malkoc, Melih

2014-01-01

272

Current concepts in the management of tendon disorders.  

PubMed

Primary disorders of tendons are common and constitute a high proportion of referrals to rheumatologists. Certain tendons are particularly vulnerable to degenerative pathology; these include the Achilles, patella, elements of the rotator cuff, forearm extensors, biceps brachi and tibialis posterior tendons. Disorders of these tendons are often chronic and can be difficult to manage successfully in the long term. Significant advances have been made in understanding the pathophysiology of these conditions. Histopathological evidence, together with advances in imaging techniques, has made us more appreciative of the degenerative (rather that inflammatory) nature of these conditions. Additionally the presence of neovascularization is now well-recognized in long-standing tendinopathy. We review the mechanical, vascular and developing neural theories that attempt to explain the aetiology of degenerative tendinopathy. We also explore theories of why specific tendons (such as the Achilles and supraspinatus tendons) are particularly prone to degenerative pathology. Traditionally, treatments have placed a heavy emphasis on anti-inflammatory strategies, which are often inappropriate. Recently, however, significant advances in the practical management of tendon disorders have been made. In particular the advent of 'eccentric loading' training programmes has revolutionized the treatment of Achilles tendinopathy in some patients. This concept is currently being extended to include other commonly injured tendons. Other current treatments are reviewed, as are potential future treatments. PMID:16490749

Rees, J D; Wilson, A M; Wolman, R L

2006-05-01

273

Mechanical strength of repairs of the hip piriformis tendon  

Microsoft Academic Search

Mechanical properties of repairs of the piriformis tendon to the proximal femur were examined in a cadaveric model. Four constructs were separately tested: a suture anchor in the proximal femur, the anchor to suture interface, the suture in tendon interface, and a bone bridge style repair. The weakest interface was the anchor in the bone in cases in which the

Paul S Robinson; Rick Placide; Louis J Soslowsky; Christopher T Born

2004-01-01

274

Ultrasonography of chronic tendon injuries in the groin  

Microsoft Academic Search

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

Peter Kälebo; Jon Karlsson; Leif Sward; Lars Peterson

1992-01-01

275

Prevalence of rotator cuff tears in operative proximal humerus fractures.  

PubMed

Proximal humerus fractures and rotator cuff tears have been shown to have increasing rates with advancing age, theoretically leading to significant overlap in the 2 pathologies. The goal of this study was to examine the prevalence, associated factors, and effect on treatment of rotator cuff tears in surgically treated proximal humerus fractures. A retrospective review was performed of all patients who had surgery for a proximal humerus fracture from January 2007 to June 2012 in the shoulder department of a large academic institution. Patient demographics, the presence and management of rotator cuff tears, and surgical factors were recorded. Regression analysis was performed to determine which factors were associated with rotator cuff tears. This study reviewed 349 fractures in 345 patients. Of these, 30 (8.6%) had concomitant rotator cuff tears. Those with a rotator cuff tear were older (average age, 68.7 vs 63.1 years), were more likely to have had a dislocation (40% vs 12.5%), and were more likely to have undergone subsequent arthroscopic repair or reverse total shoulder arthroplasty than those without a rotator cuff tear. Most (22 of 30) were treated with suture repair at the time of surgery, but 5 patients underwent reverse total shoulder arthroplasty based primarily on the intraoperative finding of a significant rotator cuff tear. A concomitant rotator cuff tear in association with a proximal humerus fracture is relatively common. Rotator cuff tears are associated with older patients and those with a fracture-dislocation. In rare cases, these cases may require the availability of a reverse shoulder prosthesis. PMID:25361372

Choo, Andrew; Sobol, Garret; Maltenfort, Mitchell; Getz, Charles; Abboud, Joseph

2014-11-01

276

Formation of Hot Tear Under Controlled Solidification Conditions  

NASA Astrophysics Data System (ADS)

Aluminum alloy 7050 is known for its superior mechanical properties, and thus finds its application in aerospace industry. Vertical direct-chill (DC) casting process is typically employed for producing such an alloy. Despite its advantages, AA7050 is considered as a "hard-to-cast" alloy because of its propensity to cold cracking. This type of cracks occurs catastrophically and is difficult to predict. Previous research suggested that such a crack could be initiated by undeveloped hot tears (microscopic hot tear) formed during the DC casting process if they reach a certain critical size. However, validation of such a hypothesis has not been done yet. Therefore, a method to produce a hot tear with a controlled size is needed as part of the verification studies. In the current study, we demonstrate a method that has a potential to control the size of the created hot tear in a small-scale solidification process. We found that by changing two variables, cooling rate and displacement compensation rate, the size of the hot tear during solidification can be modified in a controlled way. An X-ray microtomography characterization technique is utilized to quantify the created hot tear. We suggest that feeding and strain rate during DC casting are more important compared with the exerted force on the sample for the formation of a hot tear. In addition, we show that there are four different domains of hot-tear development in the explored experimental window—compression, microscopic hot tear, macroscopic hot tear, and failure. The samples produced in the current study will be used for subsequent experiments that simulate cold-cracking conditions to confirm the earlier proposed model.

Subroto, Tungky; Miroux, Alexis; Bouffier, Lionel; Josserond, Charles; Salvo, Luc; Suéry, Michel; Eskin, Dmitry G.; Katgerman, Laurens

2014-06-01

277

Mechanical model of a single tendon finger  

NASA Astrophysics Data System (ADS)

The mechanical model of a single tendon three phalanxes finger is presented. By means of the model both kinematic and dynamical behavior of the finger itself can be studied. This finger is a part of a more complex mechanical system that consists in a four finger grasping device for robots or in a five finger human hand prosthesis. A first prototype has been realized in our department in order to verify the real behavior of the model. Some results of both kinematic and dynamical behavior are presented.

Rossi, Cesare; Savino, Sergio

2013-10-01

278

Continuum model of tendon pathology - where are we now?  

PubMed Central

Chronic tendon pathology is a common and often disabling condition, the causes of which remain poorly understood. The continuum model of tendon pathology was proposed to provide a model for the staging of tendon pathology and to assist clinicians in managing this often complex condition (Br. J. Sports Med., 43, 2009, 409). The model presents clinical, histological and imaging evidence for the progression of tendon pathology as a three-stage continuum: reactive tendinopathy, tendon disrepair and degenerative tendinopathy. It also provides clinical information to assist in identifying the stage of pathology, in addition to proposed treatment approaches for each stage. The usefulness of such a model is determined by its ability to incorporate and inform new and emerging research. This review examines the degree to which recent research supports or refutes the continuum model and proposes future directions for clinical and research application of the model. PMID:23837792

McCreesh, Karen; Lewis, Jeremy

2013-01-01

279

Specialisation of extracellular matrix for function in tendons and ligaments  

PubMed Central

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

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

2013-01-01

280

Management of Flexor Tendon Lacerations in the Hand  

PubMed Central

Flexor tendon injuries in the hand present a real challenge in treatment. Poorly chosen or poorly executed treatment may lead to a functionless finger at best, impairing total hand function. A variety of approaches to treatment of flexor tendon injuries is available to the specially trained surgeon and a particular method is selected based on the merits of the case in question. Primary tendon repair is a viable choice under the proper conditions, while delayed primary repair allows a somewhat broader application of this technique. Flexor tendon grafting remains a very useful operation for the surgeon caring for tendon injuries of the hand. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7 PMID:359822

Rankin, Edward A.

1978-01-01

281

Surgical management of irreparable rotator cuff tears.  

PubMed

PURPOSE: In this prospective case control study, the effectiveness of surgical management of irreparable rotator cuff tears in terms of patient's status and quality of life was evaluated in two groups of patients: one group receiving arthroscopic debridement associated with acromioplasty and bursectomy and the other receiving an arthroscopic partial repair of the rotator cuff tear. METHODS: Sixty-eight patients (47 males and 21 females) undergoing arthroscopic shoulder surgery for massive irreparable rotator cuff tear were enrolled in our study. Patients were divided into two groups: Group AP (debridement associated with acromioplasty and bursectomy) and Group PR (partial repair). Pre- and post-operative range of motion (ROM), modified-UCLA shoulder score and strength measurement were performed. The RC-QOL was used at the time of the last follow-up to assess patients' perception of their quality of life. RESULTS: The final follow-up was 7.8 (±2.3, range 5-9) years. ROM measures were significantly increased from pre- to post-operative evaluations, with significant intergroup differences (P < 0.001). The overall modified-UCLA shoulder score showed a mean pre-operative value of 7.6 ± 2.6 (95 % CI 6.7-8.5) for Group AP and 8.6 ± 4.1 (95 % CI 7.0-9.9) (n.s.) for Group PR. The post-operative values at the latest follow-up showed a statistically significant improvement in both groups [21.4 ± 3.7 (95 % CI 20.1-22.7) for Group AP and 28.8 ± 4.2 (95 % CI 27.3-30.2) for Group PR] (P < 0.0001), with a significant intergroup difference (P < 0.0001). The RC-QOL demonstrated a statistically significant difference between the groups [Group AP: 61.8 ± 6.1(95 % CI 59.6-63.9); Group PR: 71.2 ± 9.8 (95 % CI 67.7-74.6)] (P < 0.0002). CONCLUSION: Both techniques are effective in reducing patients' symptoms, with higher functional outcomes for partial repair. However, the choice of which technique to undertake should take into account the patients' features concerning the acromio-humeral interval and levels of daily activities. LEVEL OF EVIDENCE: Therapeutic case-control study, Level III. PMID:23212188

Franceschi, Francesco; Papalia, Rocco; Vasta, Sebastiano; Leonardi, Francesco; Maffulli, Nicola; Denaro, Vincenzo

2012-12-01

282

The effect of circumferential taping on flexor tendon pulley failure in rock climbers.  

PubMed

The purpose of this study was to determine whether circumferential taping of the base of the finger increases the A2 pulley's load to failure in a model simulating a rock climber's grip. Nine pairs of fresh-frozen cadaveric hands, 20 to 47 years of age, were rigidly mounted in a specialized jig that maintained the finger in the climber's "crimp" position. Two of the four fingers of each hand were reinforced over the A2 pulley with three wraps of cloth adhesive tape. The flexor digitorum profundus and superficialis tendons were distracted until pulley or tendon failure. Overall, A2 pulley strength was greater in male specimens than in female specimens, and the A2 pulley of the small finger was the weakest tested. The A2 pulley failed simultaneously with the A3 and A4 pulleys in 55% of the tests. In the remaining trials, a single pulley failed initially followed by the remainder of the sheath. Of the 72 fingers studied, complete data were available for comparison of 22 pairs of fingers. No statistically significant difference in load to A2 pulley failure was noted between the taped and untaped finger pairs. Based on our findings we do not support taping the base of the fingers as a prophylactic measure against flexor tendon sheath injury in the climbing athlete. PMID:11032223

Warme, W J; Brooks, D

2000-01-01

283

Anterior cruciate ligament tears: reconstruction and rehabilitation.  

PubMed

Tears of the anterior cruciate ligament (ACL) are common knee injuries experienced by athletes and people with active lifestyles. It is important for members of the healthcare team to take an evidence-based approach to the diagnosis, surgical management, and postoperative rehabilitation of patients with an ACL-deficient knee. Mechanism of ACL injury and diagnostic testing is consistent throughout the literature. Patients frequently opt for ACL reconstruction, and many surgical techniques for ACL reconstruction are available with no clear consensus regarding superiority. Surgeon preference dictates the type of reconstruction and graft choice utilized. No standardized pre- and postoperative rehabilitation protocol exists. However, rehabilitation plays an important role in functional outcomes. A comprehensive rehabilitation program is needed pre- and postoperatively to produce positive patient outcomes. PMID:24457384

Smith, Mary Atkinson; Smith, W Todd; Kosko, Paul

2014-01-01

284

Pain and affective distress before and after ACL surgery: A comparison of amateur and professional male soccer players in the early postoperative period  

Microsoft Academic Search

Pain thresholds and levels of distress before and in the early postoperative period after anterior cruciate ligament surgery were measured in professional and amateur male soccer players and compared. Between June 2005 and March 2007, 30 soccer players (10 amateur, 20 professional) with acute or chronic tears of the anterior cruciate ligament who were scheduled for a bone–tendon–bone ACL reconstruction

Haluk H. Oztekin; Hakan Boya; Ozal Ozcan; Bulent Zeren; Pelin Pinar

2008-01-01

285

Interaction of phospholipid transfer protein with human tear fluid mucins.  

PubMed

In addition to circulation, where it transfers phospholipids between lipoprotein particles, phospholipid transfer protein (PLTP) was also identified as a component of normal tear fluid. The purpose of this study was to clarify the secretion route of tear fluid PLTP and elucidate possible interactions between PLTP and other tear fluid proteins. Human lacrimal gland samples were stained with monoclonal antibodies against PLTP. Heparin-Sepharose (H-S) affinity chromatography was used for specific PLTP binding, and coeluted proteins were identified with MALDI-TOF mass spectrometry or Western blot analysis. Immunoprecipitation assay and blotting with specific antibodies helped to identify and characterize PLTP-mucin interaction in tear fluid. Human tear fluid PLTP is secreted from the lacrimal gland. MALDI-TOF analysis of H-S fractions identified several candidate proteins, but protein-protein interaction assays revealed only ocular mucins as PLTP interaction partners. We suggest a dual role for PLTP in human tear fluid: (1) to scavenge lipophilic substances from ocular mucins and (2) to maintain the stability of the anterior tear lipid film. PLTP may also play a role in the development of ocular surface disease. PMID:20724654

Setälä, Niko L; Holopainen, Juha M; Metso, Jari; Yohannes, Gebrenegus; Hiidenhovi, Jaakko; Andersson, Leif C; Eriksson, Ove; Robciuc, Alexandra; Jauhiainen, Matti

2010-11-01

286

Effect of Saturated Tearing Modes in Tokamak Simulations  

NASA Astrophysics Data System (ADS)

Magnetic islands driven by tearing modes can produce increased radial transport and disruptive instabilities in tokamak discharges. In order to study these phenomena, a quasilinear model for saturated tearing modes, derived for arbitrary aspect ratio and plasma cross-section [1], is implemented in the BALDUR predictive modeling code. The quasilinear tearing mode model is used to compute the widths of saturated tearing mode islands. Neoclassical effects associated with the bootstrap current are added to the quasilinear saturated tearing mode model. The effect of the bootstrap current is to suppress the current density in the islands and, consequently, to produce wider islands. In the BALDUR code, saturated islands are shown to produce localized regions with reduced gradients in the pressure and current density profiles. The quasilinear tearing mode model is also used in a stand-a-lone code to illustrate the effects of plasma profiles and geometry on the widths of the saturated magnetic islands. [1] G. Bateman and R. N. Morris, "Saturated Tearing Modes in Toroidal Geometry," Phys. Fluids 29 (1986) 753. Supported by DOE DE-FG02-92-ER-54141.

Nguyen, C. N.; Bateman, G.; Kritz, A. H.

2003-10-01

287

Human patellar tendon stiffness is restored following graft harvest for anterior cruciate ligament surgery.  

PubMed

Minimising post-operative donor site morbidity is an important consideration when selecting a graft for surgical reconstruction of the torn anterior cruciate ligament (ACL). One of the most common procedures, the bone-patellar tendon-bone (BPTB) graft involves removal of the central third from the tendon. However, it is unknown whether the mechanical properties of the donor site (patellar tendon) recover. The present study investigated the mechanical properties of the human patellar tendon in 12 males (mean+/-S.D. age: 37+/-14 years) who had undergone surgical reconstruction of the ACL using a BPTB graft between 1 and 10 years before the study (operated knee; OP). The uninjured contralateral knee served as a control (CTRL). Patellar tendon mechanical properties were assessed in vivo combining dynamometry with ultrasound imaging. Patellar tendon stiffness was calculated from the gradient of the tendon's force-elongation curve. Tendon stiffness was normalised to the tendon's dimensions to obtain the tendon's Young's modulus. Cross-sectional area (CSA) of OP patellar tendons was larger by 21% than CTRL tendons (P<0.01). Patellar tendon stiffness was not significantly different between OP and CTRL tendons, but the Young's modulus was lower by 24% in OP tendons (P<0.01). A compensatory enlargement of the patellar tendon CSA, presumably due to scar tissue formation, enabled a recovery of tendon stiffness in the OP tendons. The newly formed tendon tissue had inferior properties as indicated by the reduced tendon Young's modulus, but it increased to a level that enabled recovery of tendon stiffness. PMID:19268289

Reeves, Neil D; Maganaris, Constantinos N; Maffulli, Nicola; Rittweger, Joern

2009-05-11

288

Influence of neglecting the curved path of the Achilles tendon on Achilles tendon length change at various ranges of motion.  

PubMed

Achilles tendon length has been measured using a straight-line model. However, this model is associated with a greater measurement error compared with a curved-line model. Therefore, we examined the influence of neglecting the curved path of the Achilles tendon on its length change at various ranges of motion. Ten male subjects participated in this study. First, the location of the Achilles tendon was confirmed by using ultrasonography, and markers were attached on the skin over the Achilles tendon path. Then, the three-dimensional coordinates of each marker at dorsiflexion (DF) 15°, plantarflexion (PF) 0°, PF15°, and PF30° were obtained. Achilles tendon length in the curved-line model was calculated as the sum of the distances among each marker. On the other hand, Achilles tendon length in the straight-line model was calculated as the straight distance between the two most proximal and distal markers projected onto the sagittal plane. The difference of the Achilles tendon length change between curved-line and straight-line models was calculated by subtracting the Achilles tendon length change obtained in curved-line model from that obtained in straight-line model with three different ranges of motion (i.e., PF0°, PF15°, and PF30° from DF15°, respectively). As a result, the difference in Achilles tendon length change between the two models increased significantly as the range of motion increased. In conclusion, neglecting the curved path of the Achilles tendon induces substantial overestimation of its length change when the extent of ankle joint angle change is large. PMID:25303951

Fukutani, Atsuki; Hashizume, Satoru; Kusumoto, Kazuki; Kurihara, Toshiyuki

2014-10-01

289

Estimation of tendon slack lengths of quadriceps based on a least squares optimization  

Microsoft Academic Search

Based on the force transfer relationship from muscle to tendon, a chart determining a normalized tendon force is developed. The experimental data of knee extension moment obtained at maximum isometric contractions are prepared to characterize one's musculo-tendon properties. An optimization algorithm is introduced, which searches the tendon slack lengths of quadriceps by minimizing the differences of calculated knee extension moment

Yoonsu Nam; Woo Eun Lee; Tai Jun Yoon

2008-01-01

290

Establishment of tendon-derived cell lines exhibiting pluripotent mesenchymal stem cell-like property  

Microsoft Academic Search

Development of the musculoskeletal system requires coordinated formation of distinct types of tissues, including bone, cartilage, muscle, and tendon. Compared to muscle, cartilage, and bone, cellular and molecular bases of tendon development have not been well understood due to the lack of tendon cell lines. The purpose of this study was to establish and characterize tendon cell lines. Three clonal

R Salingcarnboriboon; H Yoshitake; K Tsuji; M Obinata; T Amagasa; A Nifuji; M Noda

2003-01-01

291

Les ruptures du tendon du muscle tibial antérieur  

Microsoft Academic Search

In sports medicine, tears of the tibialis anterior are exceptional. We describe our experience with one case. Two types of injury can be observed: true tears involving the main body of the muscle under the pulley or the more distal portion at the insertion and fissurations. These injuries usually occur in a context of longstanding tenosynovitis or tendinopathy and are

M. Raguet

2008-01-01

292

The Role of Thermal Conduction in Tearing Mode Theory  

E-print Network

The role of anisotropic thermal diffusivity on tearing mode stability is analysed in general toroidal geometry. A dispersion relation linking the growth rate to the tearing mode stability parameter, Delta, is derived. By using a resistive MHD code, modified to include such thermal transport, to calculate tearing mode growth rates, the dispersion relation is employed to determine Delta in situations with finite plasma pressure that are stabilised by favourable average curvature in a simple resistive MHD model. We also demonstrate that the same code can also be used to calculate the basis-functions [C J Ham, et al, Plasma Phys. Control. Fusion 54 (2012) 105014] needed to construct Delta.

Connor, J W; Hastie, R J; Liu, Y Q

2014-01-01

293

Non-linear evolution of double tearing modes in tokamaks  

SciTech Connect

The delta prime formalism with neoclassical modifications has proven to be a useful tool in the study of tearing modes in high beta, 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. Then it is shown that this formalism is readily extended to include neoclassical effects.

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

1999-12-17

294

The "turtleneck" pulley plasty for finger flexor tendon repair.  

PubMed

Injuries to the flexor tendons are frequent. Even when correctly treated, they can cause a loss of mobility of the digits secondary to postoperative adhesions. Further, conflicts between the tendon suture and the pulleys can limit the range of motion of the tendon and the flexion of the fingers. We propose a new pulley plasty that permits immediate retraining and avoids conflict with the tendon suture. Ten patients underwent surgery for a tendon injury in zone II, with no lesions of the associated pedicles. The tendons were repaired by a 4-strand stitch technique associated with a continuous peritendinous suture. Pulley plasty was systematically performed on A2, A4, or both. Eight patients recovered a satisfactory range of motion with a finger to palm distance of <1 cm, and 2 others with a distance of <2 cm. Two tenolyses were performed, for which no secondary reconstruction of the pulleys was necessary. This plasty technique is simple to carry out, reliable, and reproducible. Because it facilitates tendon repair and reinforces the existing pulleys, it permits immediate retraining and controlled active mobilization. PMID:24275761

Goubier, Jean-Noel; Lafosse, Thibault; Teboul, Frédéric

2014-03-01

295

The tendon injury response is influenced by decorin and biglycan.  

PubMed

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 6 weeks. In addition, SLRP deficiency influenced the mechanical properties with a marked lack of improvement between 3 and 6 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

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

2014-03-01

296

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

E-print Network

. Introduction Once hot tears occur in steel castings, they must be fixed by welding or the casting must1 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

Beckermann, Christoph

297

The Anterior Cruciate Ligament Tear Rate Varies by Race in Professional Women's Basketball  

Microsoft Academic Search

Background: Female basketball players are more likely to tear their anterior cruciate ligament than are their male counterparts. Many causes are postulated for the difference observed in the rate of anterior cruciate ligament tears between genders. However, little is known about the differences in tears within gender.Hypothesis: The rate of anterior cruciate ligament tears is different in White European American

Thomas H. Trojian; Seamus Collins

2006-01-01

298

The sequelae of salvaged nondegenerative peripheral vertical medial meniscus tears with anterior cruciate ligament reconstruction  

Microsoft Academic Search

Purpose: To determine the clinical sequelae of nondegenerative peripheral vertical medial meniscus tears treated with abrasion and trephination alone (stable tears) or suture repair (unstable tears). Type of Study: Cohort follow-up. Methods: At the time of anterior cruciate ligament reconstruction, 548 patients had nondegenerative peripheral vertical medial meniscus tears that were either left unsutured or repaired. Of 548 menisci, 233

K. Donald Shelbourne; Bart P. Rask

2001-01-01

299

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

PubMed

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

Geburek, F; Stadler, P

2011-01-01

300

Nonoperative treatment of partial-thickness meniscal tears identified during anterior cruciate ligament reconstruction.  

PubMed

The reported incidence and treatment of partial-thickness meniscal tears seen at anterior cruciate ligament (ACL) reconstruction varies widely. The success of nonoperative treatment of partial meniscal tears identified during ACL reconstruction at our institution was reviewed. All incomplete meniscal tears were treated with observation, all full-thickness tears were treated with repair or partial meniscectomy. Partial tears of the lateral meniscus were noted three times more commonly than in the medial meniscus and were seen more acutely after ACL injury than full-thickness tears. At 2-year follow-up, excellent knee function was noted when these tears were treated nonoperatively. PMID:15315046

Zemanovic, Jason R; McAllister, David R; Hame, Sharon L

2004-07-01

301

Allograft anterior tibialis tendon with bioabsorbable interference screw fixation in anterior cruciate ligament reconstruction  

Microsoft Academic Search

For a variety of reasons, bone–patellar tendon–bone and Achilles tendon allografts have been used more commonly in anterior cruciate ligament reconstruction. Soft-tissue allografts used mainly are the semitendinosus, gracilis, and occasionally the quadriceps tendons. The anterior tibialis tendon is a thick, strong tendon that can be prepared with one doubling of the graft, has a large cross-sectional area, and has

David N. M. Caborn; Jeffrey B. Selby

2002-01-01

302

MRI of symptomatic and asymptomatic full-thickness rotator cuff tears  

PubMed Central

Background and purpose Why some full-thickness rotator cuff tears are symptomatic and others are asymptomatic is not understood. By comparing MRI findings in symptomatic and asymptomatic tears, we wanted to identify any tear characteristics that differed between groups. Patients and methods 50 subjects with asymptomatic and 50 subjects with symptomatic full-thickness tears were examined by MRI. Tear characteristics including tear size, tear location, the condition of the long head of the biceps, atrophy, and fatty degeneration of the muscles were compared between groups. Results Single factor logistic regression analysis showed that there were statistically significant associations between symptoms and tear size exceeding 3 cm in the medial-lateral plane, positive tangent sign, and fatty degeneration exceeding grade 1 of the supraspinatus and infraspinatus muscles. Interpretation We found associations between the symptomatic status of a rotator cuff tear and MRI-derived tear characteristics. The causal relationships are unclear. PMID:20450423

Tariq, Rana; Stiris, Morten G; Smith, Hans-J?rgen

2010-01-01

303

Tearing Graphene Sheets From Adhesive Substrates Produces Tapered Nanoribbons  

E-print Network

Thin films Tearing Graphene Sheets From Adhesive Substrates Produces Tapered Nanoribbons Dipanjan Sen, Kostya S. Novoselov, Pedro M. Reis, and Markus J. Buehler* Graphene is a truly two- film materials have been studied extensively, the key mechanical properties of graphene

Entekhabi, Dara

304

Membrane Array Analysis of Tear Proteins in Ocular Cicatricial Pemphigoid  

PubMed Central

Purpose To explore non-invasive, protein-based, membrane array technology as a means to evaluate the global immune and angiogenic profile of tear proteins in patients with active ocular cicatricial pemphigoid (OCP). Methods Forty-three proteins consisting of cytokines, angiogenic/growth factors, and immuno-inflammatory modulators were measured by membrane array in tear samples of four control patients and four OCP patients during active disease and after treatment. Results Signals for several distinct and consistent molecular entities were upregulated in all four active OCP tear samples relative to controls. In particular, IL-8 and MMP-9 were elevated during active disease and decreased following systemic immunomodulatory therapy. Conclusions Protein array analysis may provide a well-tolerated assay to monitor levels of inflammatory markers in the tears of OCP patients in response to therapy. PMID:21552176

Chan, Matilda F.; Sack, Robert; Quigley, David A.; Sathe, Sonal; Vijmasi, Trinka; Li, Shimin; Holsclaw, Douglas; Strauss, Erich C.; McNamara, Nancy A.

2011-01-01

305

Retinal pigment epithelial tear after photodynamic therapy for choroidal neovascularization  

Microsoft Academic Search

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

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

2001-01-01

306

Texture based prelens tear film segmentation in interferometry images  

Microsoft Academic Search

Interferometric imaging has been identified as a novel approach to the evaluation of prelens tear film (PLTF) thickness in\\u000a contact lens patients. In this paper, we present a texture based segmentation approach for the detection of tear film breakup\\u000a regions on interferometry images. First, the textural information was extracted from the studied images using a bank of Gabor\\u000a filters. A

Dijia Wu; Kim L. Boyer; Jason J. Nichols; Peter E. King-Smith

2010-01-01

307

Partial-thickness tears of the rotator cuff  

Microsoft Academic Search

Summary. This review is based on 66 patients with partial-thickness tears of the rotator cuff, verified at operation. Their average\\u000a age was 54 years, and all had symptoms of subacromial impingement. The duration of shoulder pain was for between 2 and 108\\u000a months (mean 11.4 months). Ultrasonography, arthrography and bursography were helpful in establishing the diagnosis. On exploration,\\u000a tears were

H. Fukuda; K. Hamada; T. Nakajima; N. Yamada; A. Tomonaga; M. Goto

1996-01-01

308

Tear osmolarity and dry eye symptoms in diabetics  

PubMed Central

Purpose To assess the relationship between tear osmolarity and dry eye symptoms in patients with diabetes. Patients and methods Fifty patients with diabetes were enrolled. Demographic information and past medical history were recorded. Symptoms were assessed using the ocular surface disease index (OSDI). Tear osmolarity of each eye was measured with the TearLab® Osmolarity System. Results The majority of the subjects were female (76%), African American (56%), and/or had a diagnosis of type 2 diabetes (82%). The mean ± standard deviation (SD) for age was 54.6±13.4, and maximum tear osmolarity was 304.6±12.7 mOsm/L. Men had higher osmolarity than women (mean ± standard error (SE) 311.8±4.0 mOsm/L versus 302.3±1.9 mOsm/L, P=0.02). Age, race, use of artificial tears, years of diabetes, and hemoglobin A1c did not have a statistically significant association with tear osmolarity. Longer duration of diabetes was associated with lower (less severe) OSDI scores (r=?0.35, P=0.01). Higher tear osmolarity was associated with lower (less severe) OSDI scores (r=?0.29, P=0.04). Conclusion Approximately half of the diabetic subjects in our study had elevated tear osmolarity, and half of our population also reported symptoms consistent with dry eye disease. However, the two were slightly inversely related in that those with higher osmolarity reported fewer symptoms. Subjects with a longer duration of diabetes also reported fewer dry eye symptoms. Therefore, health care providers should be aware that patients who are most likely to have ocular surface disease, including those with long-standing diabetes, may not experience symptoms and seek care in a timely manner. PMID:24648714

Fuerst, Nicole; Langelier, Nicole; Massaro-Giordano, Mina; Pistilli, Maxwell; Stasi, Kalliopi; Burns, Carrie; Cardillo, Serena; Bunya, Vatinee Y

2014-01-01

309

Complicated acromioclavicular joint cyst with massive rotator cuff tear.  

PubMed

An acromioclavicular (AC) joint cyst is an unusual presentation of full-thickness rotator cuff tears in patients with degenerative changes of the AC joint. It is important to understand the relationship between AC joint cysts and rotator cuff tears because there is a high recurrence rate if the cyst is treated without addressing the rotator cuff tear. Furthermore, recurrence or draining sinus caused by failure to treat the cyst may lead to infection. To our knowledge, there have been no reports of infected AC joint cyst as a serious complication. We present 2 cases involving an infected AC joint cyst with a massive rotator cuff tear caused by simple cyst excision. When patients have an AC joint cyst, physicians should consider the following points: (1) There is the possibility of an underlying rotator cuff tear, (2) Surgical treatment is indicated for a symptomatic cyst, (3) Aspiration and simple cyst excision are not recommended, because of the potential for postoperative complications such as recurrence, a draining sinus, and infection, and (4) Lateral clavicle resection should be performed if there is an irreparable rotator cuff tear. PMID:24551863

Cho, Chul-Hyun

2014-02-01

310

Nanoscale phase dynamics of the normal tear film.  

PubMed

The tear film is a dynamic multilayered structure. The interactions and the interfacial dynamics between the layers that occur during a blink cycle must be such that they allow for maintenance of a stable tear film. Attempts to understand these dynamics have been limited by the techniques and biomarkers used. Quantum dots (qdots) offer a new potential to monitor the dynamics of the tear film layers in vivo without the drawbacks of previously used methodologies. Indium phosphide-gallium qdots were used to differentially assess the dynamics of the lipid and aqueous layers of the tear film in real time. In the aqueous, qdots dispersed to form a stable local region that was swept away into the upper and lower menisci during a blink. They did not redisperse onto the ocular surface but were progressively removed from the menisci through the puncta. Some of these qdots adhered to the mucin layer on the ocular surface in a meshlike pattern and remained there for five to six blinks before they were removed. The organic qdots dispersed quickly but patchily over the whole outer surface of the tear film. They also strongly marked both eyelid margins and slowly dispersed onto the skin and eyelashes and not through the puncta. Some were trapped in the menisci as blobs that rolled along the meniscus. These data support the view of a distinct three-layered tear film: an inner mucin layer attached to the epithelial cells, a fluid aqueous layer, and an outer viscoelastic lipid layer. PMID:20599525

Khanal, Santosh; Millar, Thomas J

2010-12-01

311

The detection of full thickness rotator cuff tears using ultrasound.  

PubMed

We have examined the accuracy of 143 consecutive ultrasound scans of patients who subsequently underwent shoulder arthroscopy for rotator-cuff disease. All the scans and subsequent surgery were performed by an orthopaedic surgeon using a portable ultrasound scanner in a one-stop clinic. There were 78 full thickness tears which we confirmed by surgery or MRI. Three moderate-size tears were assessed as partial-thickness at ultrasound scan (false negative) giving a sensitivity of 96.2%. One partially torn and two intact cuffs were over-diagnosed as small full-thickness tears by ultrasound scan (false positive) giving a specificity of 95.4%. This gave a positive predictive value of 96.2% and a negative predictive value of 95.4%. Estimation of tear size was more accurate for large and massive tears at 96.5% than for moderate (88.8%) and small tears (91.6%). These results are equivalent to those obtained by several studies undertaken by experienced radiologists. We conclude that ultrasound imaging of the shoulder performed by a sufficiently-trained orthopaedic surgeon is a reliable time-saving practice to identify rotator-cuff integrity. PMID:18591598

Al-Shawi, A; Badge, R; Bunker, T

2008-07-01

312

Cellular therapy in bone-tendon interface regeneration  

PubMed Central

The intrasynovial bone-tendon interface is a gradual transition from soft tissue to bone, with two intervening zones of uncalcified and calcified fibrocartilage. Following injury, the native anatomy is not restored, resulting in inferior mechanical properties and an increased risk of re-injury. Recent in vivo studies provide evidence of improved healing when surgical repair of the bone-tendon interface is augmented with cells capable of undergoing chondrogenesis. In particular, cellular therapy in bone-tendon healing can promote fibrocartilage formation and associated improvements in mechanical properties. Despite these promising results in animal models, cellular therapy in human patients remains largely unexplored. This review highlights the development and structure-function relationship of normal bone-tendon insertions. The natural healing response to injury is discussed, with subsequent review of recent research on cellular approaches for improved healing. Finally, opportunities for translating in vivo findings into clinical practice are identified. PMID:24326955

Rothrauff, Benjamin B; Tuan, Rocky S

2014-01-01

313

Measuring Achilles tendon mechanical properties: a reliable, noninvasive method.  

PubMed

The purpose of this technical report is to describe a cost-effective and highly reliable methodology to measure mechanical and material properties of the Achilles tendon. Subjects are positioned on an isokinetic dynamometer time synchronized to a diagnostic ultrasound device. A tendon fascicle distal to the soleus is visualized during a ramped isometric maximal plantarflexion contraction. Excursion of the fascicle and tendon torque output yield a force-elongation curve in which mechanical characteristics and material properties are derived. Excellent intrasession and intersession reliabilities were observed for both the dynamometer (intraclass correlation coefficient [ICC] 0.99, 0.95) and excursion (ICC 0.99, 0.93) measures. Practical applications for this methodology include examination of training regimes for optimal tendon adaptation and rehabilitation in the presence of tendinopathy. PMID:22561974

Joseph, Michael F; Lillie, Kurtis R; Bergeron, Daniel J; Denegar, Craig R

2012-08-01

314

A model of muscle-tendon function in human walking  

E-print Network

In order to motivate the design of legged machines that walk as humans do, this thesis investigates how leg muscles and tendons work mechanically during level-ground human walking at self-selected speeds. I hypothesize ...

Endo, Ken, Ph. D. Massachusetts Institute of Technology

2012-01-01

315

Fibroma of tendon sheath located within Kager's triangle.  

PubMed

The formation of a fibroma of the tendon sheath, a rare, slow-growing, benign tumor, usually occurs in the upper extremities of young adult males. We present an extremely rare case of a fibroma of the tendon sheath arising adjacent to the Achilles tendon within Kager's triangle in a 41-year-old female. The patient presented with progressive pain localized to the posterior aspect of the left ankle. Complete excision and histopathologic analysis of the fibroma were performed. The patient experienced an uneventful recovery after the intervention and had no evidence of recurrence after 3 months of follow-up. Fibroma of the tendon sheath should be included in the differential diagnosis when a patient presents with a painful soft tissue mass in Kager's triangle. PMID:24556488

Jacobs, Eva; Witlox, Marianne A; Hermus, Joris P S

2014-01-01

316

Uptake swelling and thermal expansion of CFRP tendons  

E-print Network

Carbon-fibre-reinforced polymer (CFRP) tendons can be used as a corrosion-resistant alternative to steel for reinforcing or prestressing concrete in aggressive marine environments. The design lives of many civil marine structures often span decades...

Scott, P.; Lees, Janet M.

2009-08-01

317

Subcutaneous Peroneus Longus Tendon Rupture Associated with OS Peroneum Fracture  

PubMed Central

We report a rare case of subcutaneous peroneus longus tendon rupture associated with os peroneum fracture. Three dimensional computed tomographic scan was useful to understand this disorder. We treated the patient with excision of fractured os peroneum and tenodesis of the proximal stump of the ruptured peroneus longus tendon to the lateral aspect of the calcaneus. Key points In order to understand a rare case of subcutaneous peroneus longus tendon rupture associated with os peroneum fracture, three dimensional computed tomographic scan was useful. The patient was treated with excision of fractured os peroneum and tenodesis of the proximal stump of the ruptured peroneus longus tendon to the lateral aspect of the calcaneus. PMID:24149615

Fujioka, Hiroyuki; Kokubu, Takeshi; Makino, Takeshi; Nagura, Issei; Maeda, Toshihisa; Kurosaka, Masahiro; Okuno, Hiroaki; Yamagiwa, Tokuyoshi; Tanaka, Juichi; Yoshiya, Shinichi

2009-01-01

318

Tendon and ligament adaptation to exercise, immobilization, and remobilization.  

PubMed

This study provides a theoretical and computational basis for understanding and predicting how tendons and ligaments adapt to exercise, immobilization, and remobilization. In a previous study, we introduced a model that described the growth and development of tendons and ligaments. In this study, we use the same model to predict changes in the cross-sectional area, modulus, and strength of tendons and ligaments due to increased or decreased loading. The model predictions are consistent with the results of experimental exercise and immobilization studies performed by other investigators. These results suggest that the same fundamental principles guide both development and adaptation. A basic understanding of these principles can contribute both to prevention of tendon and ligament injuries and to more effective rehabilitation when injury does occur. PMID:10850828

Wren, T A; Beaupré, G S; Carter, D R

2000-01-01

319

STRESS CORROSION CRACKING IN TEAR DROP SPECIMENS  

SciTech Connect

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.

Lam, P; Philip Zapp, P; Jonathan Duffey, J; Kerry Dunn, K

2009-05-01

320

Mechanical properties of the patellar tendon in adults and children.  

PubMed

It is not currently known how the mechanical properties of human tendons change with maturation in the two sexes. To address this, the stiffness and Young's modulus of the patellar tendon were measured in men, women, boys and girls (each group, n=10). Patellar tendon force (F(pt)) was calculated from the measured joint moment during a ramped voluntary isometric knee extension contraction, the antagonist knee extensor muscle co-activation quantified from its electromyographical activity, and the patellar tendon moment arm measured from magnetic resonance images. Tendon elongation was imaged using the sagittal-plane ultrasound scans throughout the contraction. Tendon cross-sectional area was measured at rest from ultrasound scans in the transverse plane. Maximal F(pt) and tendon elongation were (mean+/-SE) 5453+/-307 N and 5+/-0.5 mm for men, 3877+/-307 N and 4.9+/-0.6 mm for women, 2017+/-170 N and 6.2+/-0.5 mm for boys and 2169+/-182 N and 5.9+/-0.7 mm for girls. In all groups, tendon stiffness and Young's modulus were examined at the level that corresponded to the maximal 30% of the weakest participant's F(pt) and stress, respectively; these were 925-1321 N and 11.5-16.5 MPa, respectively. Stiffness was 94% greater in men than boys and 84% greater in women than girls (p<0.01), with no differences between men and women, or boys and girls (men 1076+/-87 N/mm; women 1030+/-139 N/mm; boys 555+/-71 N/mm and girls 561.5+/-57.4 N/mm). Young's modulus was 99% greater in men than boys (p<0.01), and 66% greater in women than girls (p<0.05). There were no differences in modulus between men and women, or boys and girls (men 597+/-49 MPa; women 549+/-70 MPa; boys 255+/-42 MPa and girls 302+/-33 MPa). These findings indicate that the mechanical stiffness of tendon increases with maturation due to an increased Young's modulus and, in females due to a greater increase in tendon cross-sectional area than tendon length. PMID:20045111

O'Brien, Thomas D; Reeves, Neil D; Baltzopoulos, Vasilios; Jones, David A; Maganaris, Constantinos N

2010-04-19

321

Temporal response of canine flexor tendon to limb suspension  

PubMed Central

Tendon disuse, or stress deprivation, frequently accompanies clinical disorders and treatments, yet the metabolism of tendons subject to stress deprivation has rarely been investigated systematically. The effects of stress deprivation on canine flexor tendon were investigated in this study. One adult canine forepaw was suspended for 21 or 42 days. Control forepaws were collected from dogs that had no intervention on their limbs and paws. The expression of collagen I and III was not significantly altered in the tendons disused for 21 days but was significantly decreased at 42 days (P < 0.03). The expression of collagen II, aggrecan, decorin, and fibronectin was significantly decreased in the tendons in the suspended limbs at 21 days (P < 0.002) and further reduced at 42 days. With stress deprivation, the expression of matrix metalloproteinase 2 (MMP2) was significantly increased (P < 0.004) at 21 and 42 days. The expression of MMP3 was significantly decreased at 21 and 42 days (P < 0.03). The expression of MMP13 was not altered with stress deprivation at 21 and 42 days. The expression of MMP14 was significantly increased at 21 days (P = 0.0015) and returned to the control level at 42 days. Tissue inhibitor of metalloproteinase 1 (TIMP1) expression was decreased after the limbs were suspended for 42 days (P = 0.0043), but not 21 days. However, TIMP2 expression was not significantly different from control at 21 or 42 days. Furthermore, the cross-sectional area of the stress-deprived tendons at 42 days was decreased compared with the control group (P < 0.01). The intervention method in this study did not result in any alteration of stiffness of the tendon. Our study demonstrated that stress deprivation decreases the anabolic process and increases the catabolic process of extracellular matrix in flexor tendon. PMID:20947711

Thoreson, Andrew R.; Cha, Stephen S.; Zhao, Chunfeng; An, Kai-Nan; Amadio, Peter C.

2010-01-01

322

Surgical Technique for Combined Dwyer Calcaneal Osteotomy and Peroneal Tendon Repair for Correction of Peroneal Tendon Pathology Associated with Cavus Foot Deformity  

Microsoft Academic Search

Peroneal tendon pathology is commonly seen in patients with underlying pes cavus. The Dwyer calcaneal osteotomy is a useful adjunctive procedure to address the heel varus component of the cavus foot deformity, especially in the presence of concomitant peroneal tendon pathology. The lateralizing heel osteotomy using a wedge resection can effectively reduce future stress on the repaired peroneal tendons, although

Troy J. Boffeli; Rachel C. Collier

323

A new method for estimating subject-specific muscle-tendon parameters of the knee joint actuators: a simulation study.  

PubMed

A new method for the estimation of subject-specific muscle-tendon parameters of the knee actuators based on dynamometry experiments is presented. The algorithm aims at estimating the tendon slack length and the optimal muscle fiber length by minimizing the difference between experimentally reproduced and model-based joint moments. The key innovative features are as follows: (i) the inclusion of a priori physiological knowledge to define a physiologically feasible set, the hot start for the optimization, and constraints for the optimization and (ii) the introduction of a new (affine) transformation of the muscle-tendon parameters, which greatly improves the numerical condition of the optimization. The influence of the initial guess and of measurement noise was studied in a simulation environment, and the performance was compared with that of the method presented earlier by Garner and Pandy for the upper limb. The tendon slack length was estimated for 97.5/63% (extensors/flexors) of all initial guesses within 2% of the ground truth. The optimal fiber length was estimated for 89/90% (extensors/flexors) of all initial guesses within 2% of the ground truth. When 10 Nm measurement noise was added, the mean value of the estimated tendon slack length deviated at most 1.9/1.6% (extensors/flexors) from the ground truth whereas the standard deviations were at most 5.1/3.9%. The mean value of the estimated optimal fiber length deviated at most 4.3/3.0% (extensors/flexors) from the ground truth whereas the standard deviations were at most 10.2/15.5%. In comparison, mean values resulting from the method of Garner and Pandy deviated up to 181% (?±?123%) and 119% (?±?30%) from the ground truth for, respectively, optimal fiber length and tendon slack length of rectus femoris. We concluded that the presented method had a low dependency on the initial guess and outperformed the method of Garner and Pandy in terms of accuracy by at least one order of magnitude when parameters were estimated from noisy data. The improvements open new perspectives for subject-specific modelling of muscles and tendons, which is beneficial for the accuracy of human motion simulations. PMID:24753493

Van Campen, Anke; Pipeleers, Goele; De Groote, Friedl; Jonkers, Ilse; De Schutter, Joris

2014-10-01

324

Strain and elongation of the human semitendinosus muscle - tendon unit.  

PubMed

The semitendinosus (ST) consists of a long distal tendon and it is divided in two parts by a tendinous inscription (TI). The purpose of this study was to quantify strain and elongation of the TI and the distal tendon of ST. Fourteen subjects performed ramp isometric contractions of the knee flexors at 0°, 45° and 90° of knee flexion. Two ultrasound probes were used to visualize the displacement of the distal tendon and selected points across the TI and aponeuroses. Three-way analysis of variance designs indicated that: (a) strain and elongation of the ST distal muscle-tendon junction were higher than that of the aponeurosis - TI junction points (p < 0.05) (b) the long arm of the TI reach strain of 49.86 ± 7.77% which was significantly (p < 0.05) higher than that displayed by the short arm (28.35 ± 0.59%) (c) Strain of tendinous and TI-aponeuroses segments significantly increased from 90° to 0° of knee flexion while the inverse was observed for the TI arm length (p < 0.05). (d) Tendon strain was significantly higher than strain of the TI-aponeuroses segments at 45° and 90° of knee flexion while the opposite was observed at 0° of knee flexion. The arrangement of TI along ST length results in differential local strains, indicating that the mechanical properties of the ST muscle are affected by tendon, aponeuroses and tendinous inscription interactions. PMID:23992632

Kellis, Eleftherios; Patsika, Glykeria; Karagiannidis, Evaggelos

2013-12-01

325

The anatomical footprint of the Achilles tendon: a cadaveric study.  

PubMed

We dissected 12 fresh-frozen leg specimens to identify the insertional footprint of each fascicle of the Achilles tendon on the calcaneum in relation to their corresponding muscles. A further ten embalmed specimens were examined to confirm an observation on the retrocalcaneal bursa. The superficial part of the insertion of the Achilles tendon is represented by fascicles from the medial head of the gastrocnemius muscle, which is inserted over the entire width of the inferior facet of the calcaneal tuberosity. In three specimens this insertion was in continuity with the plantar fascia in the form of periosteum. The deep part of the insertion of the Achilles tendon is made of fascicles from the soleus tendon, which insert on the medial aspect of the middle facet of the calcaneal tuberosity, while the fascicles of the lateral head of the gastrocnemius tendon insert on the lateral aspect of the middle facet of the calcaneal tuberosity. A bicameral retrocalcaneal bursa was present in 15 of the 22 examined specimens. This new observation and description of the insertional footprint of the Achilles tendon and the retrocalcaneal bursa may allow a better understanding of the function of each muscular part of the gastrosoleus complex. This may have clinical relevance in the treatment of Achilles tendinopathies. PMID:25274919

Ballal, M S; Walker, C R; Molloy, A P

2014-10-01

326

Tendon Tissue Engineering: Progress, Challenges, and Translation to the Clinic  

PubMed Central

The tissue engineering field has made great strides in understanding how different aspects of tissue engineered constructs (TECs) and the culture process affect final tendon repair. However, there remain significant challenges in developing strategies that will lead to a clinically effective and commercially successful product. In an effort to increase repair quality, a better understanding of normal development, and how it differs from adult tendon healing, may provide strategies to improve tissue engineering. As tendon tissue engineering continues to improve, the field needs to employ more clinically relevant models of tendon injury such as degenerative tendons. We need to translate successes to larger animal models to begin exploring the clinical implications of our treatments. By advancing the models used to validate our TECs, we can help convince our toughest customer, the surgeon, that our products will be clinically efficacious. As we address these challenges in musculoskeletal tissue engineering, the field still needs to address the commercialization of products developed in the laboratory. TEC commercialization faces numerous challenges because each injury and patient is unique. This review aims to provide tissue engineers with a summary of important issues related to engineering tendon repairs and potential strategies for producing clinically successful products. PMID:21625053

Shearn, Jason T.; Kinneberg, Kirsten R.C.; Dyment, Nathaniel A.; Galloway, Marc T.; Kenter, Keith; Wylie, Christopher; Butler, David L.

2013-01-01

327

Principles and biomechanics of muscle tendon unit transfer: application in temporalis muscle tendon transposition for smile improvement in facial paralysis.  

PubMed

Muscle tendon unit (MTU) transfer is a common procedure performed to restore hand function after peripheral nerve or spinal cord injury. The principles of MTU transfer established for hand surgery can be adopted to optimize the dynamic excursion of the temporalis tendon transfer procedure for facial reanimation. Additionally, the force generating ability of a transferred MTU depends on the ideal length-tension relationship of the donor muscle. There are unclear guideline for selecting the ideal tension at which a transferred MTU will generate maximum force and excursion and current practice often leads to overstretch and suboptimal actin myosin interaction. The use of intraoperative electrical stimulation is an option for determining the ideal tension to optimize excursion of transferred temporalis tendon units in simile restoration. Understanding the biomechanics and principles of MTU and applying it to the temporalis tendon transfer procedure is necessary to improve its use in facial reanimation. PMID:23208742

Boahene, Kofi D O

2013-02-01

328

Subnormal Cytokine Profile in the Tear Fluid of Keratoconus Patients  

PubMed Central

Keratoconus, historically viewed as a non-inflammatory disease, is an ectatic corneal disorder associated with progressive thinning of the corneal stroma. Recently, a few inflammatory mediators have been reported to be elevated in the tear fluid of keratoconus patients. Consequently, we investigated a wide range of inflammation regulating cytokines in the tears and sera of keratoconus and control subjects. Interleukin (IL)-1?, IL-4, IL-6, IL-10, IL-12, IL-13, IL-17, interferon (IFN)-?, chemokine C-C motif ligand 5 (CCL5) and tumor necrosis factor (TNF)-? were tested in tear samples and sera of keratoconus and control individuals by multiplex immuno-bead assays. Selected cytokines were further tested by standard ELISA on pooled tear samples. All cytokines in the sera were generally low, with no significant changes between keratoconus and control subjects. However, in tear fluids, clear differences were detected between the two groups. These differences include increased IL-6, and decreased IL-12, TNF-?, IFN-?, IL-4, IL-13 and CCL5 in keratoconus compared to control tear fluids. The decreases in IL-12, TNF-? and CCL5 were statistically significant, while the IL-13 decrease was statistically significant in the severe keratoconus group only. IL-17 could not be detected by multiplex immuno-bead assay, but showed an increase in keratoconus by conventional ELISA on a limited number of pooled tear samples. Our findings confirm increased IL-6, but dispute earlier reports of increased TNF-?, and suggest a cytokine imbalance in keratoconus disrupting corneal homeostasis. Moreover, an increase in IL-17 suggests tissue degenerative processes at work, contributing to the thinning and weakening of the corneal connective tissue in keratoconus. PMID:21298010

Jun, Albert S.; Cope, Leslie; Speck, Caroline; Feng, Xiaojun; Lee, Seakwoo; Meng, Huan; Hamad, Abdel; Chakravarti, Shukti

2011-01-01

329

Neoclassical tearing modes and their control  

SciTech Connect

A principal pressure limit in tokamaks is set by the onset of neoclassical tearing modes (NTMs), which are destabilized and maintained by helical perturbations to the pressure-gradient driven 'bootstrap' current. The resulting magnetic islands break up the magnetic surfaces that confine the plasma. The NTM is linearly stable but nonlinearly unstable, and generally requires a 'seed' to destabilize a metastable state. In the past decade, NTM physics has been studied and its effects identified as performance degrading in many tokamaks. The validation of NTM physics, suppressing the NTMs, and/or avoiding them altogether are areas of active study and considerable progress. Recent joint experiments give new insight into the underlying physics, seeding, and threshold scaling of NTMs. The physics scales toward increased NTM susceptibility in ITER, underlying the importance of both further study and development of control strategies. These strategies include regulation of 'sawteeth' to reduce seeding, using static 'bumpy' magnetic fields to interfere with the perturbed bootstrap current, and/or applying precisely located microwave power current drive at an island to stabilize (or avoid destabilization of) the NTM. Sustained stable operation without the highly deleterious m=2, n=1 island has been achieved at a pressure consistent with the no-wall n=1 ideal kink limit, by using electron cyclotron current drive at the q=2 rational surface, which is found by real-time accurate equilibrium reconstruction. This improved understanding of NTM physics and stabilization strategies will allow design of NTM control methods for future burning-plasma experiments like ITER.

La Haye, R.J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

2006-05-15

330

Locking finger due to a partial laceration of the flexor digitorum superficialis tendon: a case report.  

PubMed

A 39-year-old woman sustained a small wound on the palm of her right hand, which quickly healed naturally; however, a month later pain and limited range of motion were noted in her right finger. Surgery revealed the radial half of the flexor digitorum superficialis (FDS) tendon was ruptured and formed a flap, which hooked at the entrance of the A1 pulley. The proximal stump was sutured to the remaining ulnar (normal) side of the FDS tendon. Locking occurs between the tendon flap and the tendon sheath; therefore, when there is no fibrous tendon sheath near the partially ruptured tendon, locking will not occur. PMID:25121943

Seki, Yasuhiro; Kuroda, Hiroshi

2014-01-01

331

Elbow tendinopathy and tendon ruptures: epicondylitis, biceps and triceps ruptures.  

PubMed

Lateral and medial epicondylitis are common causes of elbow pain in the general population, with the lateral variety being more common than the medial by a ratio reportedly ranging from 4:1 to 7:1. Initially thought to be an inflammatory condition, epicondylitis has ultimately been shown to result from tendinous microtearing followed by an incomplete reparative response. Numerous nonoperative and operative treatment options have been employed in the treatment of epicondylitis, without the emergence of a single, consistent, universally accepted treatment protocol. Tendon ruptures about the elbow are much less frequent, but result in more significant disability and loss of function. Distal biceps tendon ruptures typically occur in middle-aged males as a result of an event that causes a sudden, eccentric contraction of the biceps. Triceps tendon ruptures are exceedingly rare but usually have a similar etiology with a forceful eccentric contraction of the triceps that causes avulsion of the tendon from the olecranon. The diagnosis of these injuries is not always readily made. Complete ruptures of the biceps or triceps tendons have traditionally been treated surgically with good results. With regard to biceps ruptures, there continues to be debate about the best surgical approach, as well as the best method of fixation of tendon to bone. This article is not meant to be an exhaustive review of the broad topics of elbow tendinopathy and tendon ruptures, but rather is a review of recently published information on the topics that will assist the clinician in diagnosis and management of these conditions. PMID:19258160

Rineer, Craig A; Ruch, David S

2009-03-01

332

Extracellular matrix adaptation of tendon and skeletal muscle to exercise  

PubMed Central

The extracellular matrix (ECM) of connective tissues enables linking to other tissues, and plays a key role in force transmission and tissue structure maintenance in tendons, ligaments, bone and muscle. ECM turnover is influenced by physical activity, and both collagen synthesis and metalloprotease activity increase with mechanical loading. This can be shown by determining propeptide and proteinase activity by microdialysis, as well as by verifying the incorporation of infused stable isotope amino acids in biopsies. Local tissue expression and release of growth factors for ECM such as IGF-1, TGF-beta and IL-6 is enhanced following exercise. For tendons, metabolic activity (e.g. detected by positron emission tomography scanning), circulatory responses (e.g. as measured by near-infrared spectroscopy and dye dilution) and collagen turnover are markedly increased after exercise. Tendon blood flow is regulated by cyclooxygenase-2 (COX-2)-mediated pathways, and glucose uptake is regulated by specific pathways in tendons that differ from those in skeletal muscle. Chronic loading in the form of physical training leads both to increased collagen turnover as well as to some degree of net collagen synthesis. These changes modify the mechanical properties and the viscoelastic characteristics of the tissue, decrease its stress-susceptibility and probably make it more load-resistant. The mechanical properties of tendon fascicles vary within a given human tendon, and even show gender differences. The latter is supported by findings of gender-related differences in the activation of collagen synthesis with exercise. These findings may provide the basis for understanding tissue overloading and injury in both tendons and skeletal muscle. PMID:16637870

Kjær, Michael; Magnusson, Peter; Krogsgaard, Michael; Møller, Jens Boysen; Olesen, Jens; Heinemeier, Katja; Hansen, Mette; Haraldsson, Bjarki; Koskinen, Satu; Esmarck, Birgitte; Langberg, Henning

2006-01-01

333

Reconstruction of anterior cruciate ligaments with bone-patellar tendon-bone and achilles tendon allografts.  

PubMed

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

Levitt, R L; Malinin, T; Posada, A; Michalow, A

1994-06-01

334

The Effects of Dexamethasone on Human Patellar Tendon Stem Cells: Implications for Dexamethasone Treatment of Tendon Injury  

PubMed Central

Injection of Dexamethasone (Dex) is commonly used in clinics to treat tendon injury such as tendinopathy because of its anti-inflammatory capabilities. However, serious adverse effects have been reported as a result of Dex treatment, such as impaired tendon healing and tendon rupture. Using both in vitro and in vivo approaches, this study was to determine the effects of Dex treatment on the proliferation and differentiation of human tendon stem cells (hTSCs), which can directly impact tendon healing. We found that Dex treatment stimulated cell proliferation at lower concentrations (< 1000 nM), whereas a high concentration (1000 nM) decreased cell proliferation. Moreover, at all concentrations used (5, 10, 100, and 1000 nM), Dex treatment induced non-tenocyte differentiation of hTSCs, as evidenced by a change in cell shape, a nearly complete suppression of collagen type I expression, and an upregulation of non-tenocyte related genes (PPAR? and Sox-9), which was especially evident when higher concentrations (> 10 nM) of Dex were used. Implantation of Dex-treated hTSCs for a short time (3 weeks) resulted in the extensive formation of fatty tissues, cartilage-like tissues, and bony tissues. These findings suggest that Dex treatment in clinics may cause a paradoxical effect on the injured tendons it is supposed to treat: by inducing non-tenocyte differentiation of hTSCs, Dex treatment depletes the stem cell pool and leads to the formation of non-tendinous tissues (e.g. fatty and cartilage-like tissues), which make tendon susceptible to rupture. PMID:22886634

Zhang, Jianying; Keenan, Camille; Wang, James H-C.

2012-01-01

335

Accuracy of low-field MRI on meniscal tears.  

PubMed

This study aimed to verify the accuracy of low-field-intensity magnetic resonance imaging (MRI) in diagnosing meniscus tears. A total of 171 patients were examined through low-field-intensity MRI to detect meniscus injuries. These patients were then diagnosed through arthroscopy. Examination results were recorded and compared. The accuracy of the diagnosis for internal and external meniscus tears through low-field-intensity MRI was 95.91% and 95.91%, respectively, the sensitivities were 95.60% and 96.47%, respectively, and the specificities were 96.25% and 95.35%, respectively. Low-field-intensity MRI is an accurate and cost-effective method for diagnosing meniscus tears. PMID:25036170

Chen, H N; Dong, Q R; Wang, Y

2014-01-01

336

An investigation of tendon sheathing filler migration into concrete  

SciTech Connect

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.

Naus, D.J.; Oland, C.B. [Oak Ridge National Lab., TN (United States)

1998-03-01

337

Technical and biological modifications for enhanced flexor tendon repair.  

PubMed

Clinical outcomes after intrasynovial flexor tendon repair have been substantially improved over the past 2 decades through advances in tendon suture techniques and postoperative rehabilitation methods. Nevertheless, complications such as repair site elongation (i.e., gap formation) and rupture continue to occur frequently. Experimental studies have shown that repair site strength fails to increase in the first 3 weeks after tendon suture. After 3 weeks, the strength and rigidity of the repair site improve significantly, a process that continues for several months. Formation of a repair site gap during the early rehabilitation period has been shown to considerably delay the accrual of repair site strength over time. Thus, it is of prime importance that the method of tendon suture achieves and maintains a stiff and strong repair site during the early healing interval by maintaining close approximation of the tendon stumps and by stimulating, where possible, the intrinsic repair response. In this review, we describe recent efforts to enhance the integrity of the immature repair site. We focus on 2 major areas of advancement: surgical technique modifications and manipulation of the biologic and biochemical environment. PMID:20513584

Kim, H Mike; Nelson, Gregory; Thomopoulos, Stavros; Silva, Matthew J; Das, Rosalina; Gelberman, Richard H

2010-06-01

338

Long Head of the Biceps Tendon Allis Clamp Evaluation Technique  

PubMed Central

Disorders of the long head of the biceps brachii are a common finding in conjunction with other causes of shoulder pathology. Nonoperative means as first-line treatment are often successful; however, surgery can be indicated for refractory tendinopathy. There is debate as to the best surgical treatment of the long head of the biceps tendon (LHBT) with different types of arthroscopic and open techniques. The decision on what treatment option to perform is often made at the time of surgery after arthroscopic evaluation of the LHBT. Certain examples of tendon disease are easily visible intra-articularly; however, a large portion of the tendon is not intra-articular and not readily viewed during routine arthroscopy. This study describes a simple arthroscopic technique for evaluation of an increased portion of the LHBT using an Allis clamp. The clamp is inserted through the anterior portal, placed around the LHBT, and rotated such that the tendon is wrapped around itself, bringing the distal tendon into the joint for arthroscopic viewing. This procedure is a routine part of our assessment of the LHBT during arthroscopy. PMID:25276608

Parada, Stephen A.; Dilisio, Matthew F.; Miller, Lindsay R.; Higgins, Laurence D.

2014-01-01

339

77 FR 69508 - Inservice Inspection of Prestressed Concrete Containment Structures With Grouted Tendons  

Federal Register 2010, 2011, 2012, 2013

...Inservice Inspection of Prestressed Concrete Containment Structures With Grouted Tendons...Inservice Inspection of Prestressed Concrete Containment Structures with Grouted Tendons...surveillance program for prestressed concrete containment structures with grouted...

2012-11-19

340

The behavior of rotator cuff tendon cells in three-dimensional culture  

E-print Network

The rotator cuff is composed of the supraspinatus, infraspinatus, subcapularis, and teres minor tendons. Rotator cuff injuries are common athletic and occupational injuries that surgery cannot fully repair. Therefore tendon ...

Gill, Harmeet (Harmeet Kaur)

2007-01-01

341

Diclofenac Patch for Treatment of Mild to Moderate Tendonitis or Bursitis  

ClinicalTrials.gov

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

2008-08-05

342

Hot Tearing Characteristics of Binary Mg-Gd Alloy Castings  

NASA Astrophysics Data System (ADS)

Hot tearing characteristics of Mg- xGd ( x = 1, 2, 5 and 10 wt pct) binary alloys have been studied in a constrained rod casting apparatus attached with a load cell and data acquisition system. The onset temperature of the hot tearing was identified from the force drop in the force-temperature-time curve, and the corresponding onset solid fraction was obtained from the fraction solid-temperature curve derived using Scheil non-equilibrium solidification model. The results indicate that the onset solid fraction for the hot tear decreased as the Gd content increased. The susceptibility defined by the total tear volume measurements by the X-ray micro-tomography technique indicates that the susceptibility increased with increase in Gd content to reach a maximum at 2 pct and then reduced with further increase in Gd to reach a minimum with 10 pct Gd. The high susceptibility observed in Mg-2 pct Gd was attributed to its cellular or columnar grain structure, which facilitated easy tear propagation, high strain at the onset with little amount of remaining liquid. In contrast, the lowest susceptibility of Mg-10 pct Gd was related to its equiaxed grain structure, which effectively accommodated the strain during solidification by reorienting themselves and the ability of the Gd-rich liquid to partially or completely refill the tear at the end of solidification. The results also indicate that the increase in mold temperature [723 K (450 °C)] significantly reduced the total crack volume and hence reduced the susceptibility, which was attributed to the increase in the hot spot size and lesser total stain at the hot spot region.

Srinivasan, Amirthalingam; Wang, Zhi; Huang, Yuanding; Beckmann, Felix; Kainer, Karl Ulrich; Hort, Norbert

2013-05-01

343

Lysozyme Activity in the Serum, Saliva and Tears of Germfree and Conventional Rats and Mice.  

National Technical Information Service (NTIS)

Lysozyme levels in serum, saliva and tears of germfree, gnotobiotic, conventionalized as well as conventionally-reared rats and mice were studied. The results showed that lysozyme levels in serum and tears were quite similar in these groups. However, the ...

D. R. Makulu, M. Wagner

1967-01-01

344

Successful treatment of crocodile tears by injection of botulinum toxin into the lacrimal gland  

Microsoft Academic Search

ObjectivePathologic lacrimation (crocodile tears) is a rare but stigmatizing symptom after facial nerve paralysis. The aim of this pilot study was to examine whether botulinum toxin injection into the lacrimal gland is effective in reducing pathologic tear secretion.

Randolf Riemann; Stefan Pfennigsdorf; Elke Riemann; Markus Naumann

1999-01-01

345

ACL Tear Won't Keep Most College Athletes from Returning to Play  

MedlinePLUS

... this page, please enable JavaScript. ACL Tear Won't Keep Most College Athletes From Returning to Play: ... debilitating injury, but an ACL tear typically doesn't mean the end of a college athlete's career, ...

346

Rest length and compliance of non-immobilised and immobilised rabbit soleus muscle and tendon  

Microsoft Academic Search

The first aim of this study was to measure the contributions of muscle and tendon to the total compliance of resting muscle-tendon\\u000a units. A second aim was to determine whether the decrease in muscle-tendon unit rest length produced by prolonged immobilisation\\u000a in a shortened position is mediated primarily by adaptations of the muscle or tendon. One ankle joint from each

R. D. Herbert; J. Crosbie

1997-01-01

347

Measurement of frog semitendinosus force, tendon load-deformation and load-strain properties  

Microsoft Academic Search

The authors previously studied the mechanics of the Rana pipiens semitendinosus (ST) muscle, assuming zero tendon compliance. The tendon of this muscle is relatively short, perhaps justifying the assumption. A study is reported here of the load-deformation and load-strain properties of these tendons. The tendon slack length was measured at 2.2 ?m. In this case, the muscle force was not

M. E. Leonard; R. L. Lieber

1989-01-01

348

The Achilles Tendon Insertion is Crescent-shaped: An In Vitro Anatomic Investigation  

Microsoft Academic Search

Anatomic and operative textbooks and current literature do not clearly describe the Achilles tendon interface to the calcaneal\\u000a tuberosity. We dissected 51 specimens to identify the detailed anatomy of the Achilles tendon insertion. Achilles tendon fascicles\\u000a expanded from the anterior aspect of the distal Achilles tendon over the retrocalcaneal bursa to the anterior part of the\\u000a Haglund’s tuberosity in nearly

Heinz Lohrer; Sabine Arentz; Tanja Nauck; Nadja V. Dorn-Lange; Moritz A. Konerding

2008-01-01

349

Cross-sectional anatomy of the bicipital tuberosity and biceps brachii tendon insertion: relevance to anatomic tendon repair.  

PubMed

This study evaluated the insertional anatomy and orientation of the biceps tuberosity and tendon to assess the anatomic validity of repairs made with 1 incision vs 2 incisions. Computed axial tomography was used to image 30 cadaver radii, and each tendon insertion was measured with a digital micrometer. Specimens were sectioned and imaged with Faxitron radiography (Faxitron X-Ray Corp, Wheeling, IL) to determine the angular orientation of the biceps tendon insertion relative to the tuberosity apex. The tuberosity axis of orientation averaged 65 degrees (range, 15 degrees -120 degrees ) of pronation from anterior, with angular orientation encompassing a mean 59 degrees (range, 15 degrees -100 degrees ) arc with the midpoint of the insertion averaging 50 degrees (range, -5 degrees to 105 degrees ). Most biceps tendons inserted on the anterior aspect of the apex of the tuberosity, with an average width of 7 mm and length of 22 mm. The biceps tuberosity is oriented in more pronation than is typically described, prohibiting anatomic reinsertion of the tendon in 35% of specimens with current single-incision techniques. PMID:18325797

Forthman, Christopher L; Zimmerman, Ryan M; Sullivan, Michael J; Gabel, Gerard T

2008-01-01

350

An Investigation of Tendon Corrosion-Inhibitor Leakage into Concrete  

SciTech Connect

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.

Costello, J.F.; Naus, D.J.; Oland, C.B.

1999-07-05

351

Rupture of the peroneus tertius tendon in 27 horses  

PubMed Central

Abstract The purpose of the study was to identify factors influencing the outcome and prognosis of rupture of the tendon of the peroneus tertius muscle in 27 horses. Information on history, physical examination findings, diagnosis, treatment, and final outcome was summarized from medical records. Long-term follow-up information on horses was obtained by telephone survey. A stepwise logistic regression model was used to analyze factors influencing the outcome. Rupture occurred in the midbody of the tendon in 11 horses, at the insertion site in 11 horses, and at the origin in 2 horses. Overall, 18/23 (78.3%) horses returned to their previous level of exercise, 5/23 (21.7%) horses were euthanized due to persistent lameness. If the horse was racing at the time of injury or had an additional structure injured besides the peroneus tertius tendon, it was less likely to return to its intended use. PMID:16048009

2005-01-01

352

Could Ossification of the Achilles Tendon Have a Hereditary Component?  

PubMed Central

Ossification of the Achilles tendon (OTA) is an unusual clinical condition. It is characterized by the presence of an ossified mass within the fibrocartilaginous substance of the Achilles tendon. The etiology of the ossification of the Achilles tendon is unknown. Review of the literature suggests that its etiology is multifactorial. The major contributing factors are trauma and surgery with other minor causes such as systemic diseases, metabolic conditions, and infections. To our knowledge, no previous reports suggest any genetic/hereditary predisposition in OAT. We report 3 siblings who have OAT with no history of any of the aforementioned predisposing factors. Could OAT have a hereditary component as one of its etiologies? PMID:23738172

Cortbaoui, Chawki

2013-01-01

353

Meniscus tear developed by pulling of the anomalous insertion of medial meniscus on anterior cruciate ligament  

Microsoft Academic Search

There is no report regarding a medial meniscus tear arising from an anomalous insertion of medial meniscus on the ACL, which\\u000a seemed to be developed by the same mechanism as ACL tear. A case of a combined medial meniscus tear with ACL tear in the presence\\u000a of an anomalous insertion of the medial meniscus on the ACL is reported.

Joon Ho Wang; Andrew K. Wong; James R. Romanowski; Freddie H. Fu

354

Estimation of hamstring tendon slack length for knee flexor moment approximations  

Microsoft Academic Search

This paper presents a model to estimate hamstring tendon slack length for knee flexor moment approximations. The muscle force is very sensitive to the tendon slack length. To predict a tendon slack length, exact muscle parameters are needed. But it is difficult to measure all of the muscle parameters from human body. So we propose the algorithm which finds the

Hyun Woo Uhm; Han Soon Choi; Yoonsu Nam

2009-01-01

355

Estimation of tendon slack length of knee extension\\/flexion muscle  

Microsoft Academic Search

In this paper, we consider about a model to estimate the knee joint extension\\/flexion moment using the angle of the joints and EMG signal. We need exact muscle-tendon parameters for exact estimation of knee moment. But It is very difficult. The muscle force is sensitive to the tendon slack length. So, we developed the algorithm which finds the tendon slack

Woo-Eun Lee; Hyun-Woo Uhm; Yoon-Su Nam

2008-01-01

356

Is There a Role for Ultrasound and Electrical Stimulation Following Injury to Tendon and Nerve?  

Microsoft Academic Search

Ultrasound (US) and electrical stimulation have been widely used in hand therapy to promote recovery after nerve and tendon injuries. There is support for the use of low-dosage continuous wave and pulsed US for carpal tunnel syndrome and tendonitis. Iontophoresis with dexamethasone sodium phosphate can relieve pain in acute elbow tendonitis, but there is no support for phonophoresis for any

Susan L. Michlovitz

2005-01-01

357

Striated muscle fiber apoptosis after experimental tendon lesion in a rat model  

PubMed Central

Tendon lesions induce muscular atrophy, the nature of which has not yet been clearly related to lesion etiology and entity. In the present study, tendon and muscle alterations were assessed after experimental tendon lesion of the Infraspinatus muscle in young rats. The consequences of lesions differed on the basis of both extension and injured tissue vascularization, that is apoptosis and/or degeneration, differing mainly by energy demands: apoptosis requires high energy levels (proportional to vascular supply), but degeneration does not. It is well known that tendons are poorly supplied with blood compared with muscular masses, which are abundantly vascularized. Five weeks after tendon surgical section, tendon/muscle samples were taken for TUNEL and transmission electron microscopy. The structural results reported here identified different tendon/muscle alterations: degeneration of tendon without signs of apoptosis, and atrophy of muscle fibers due only to apoptosis. This led to the formulation of the following hypothetical sequence of events: a tendon lesion, not recovering quickly due to the poor tendon blood supply, results in degeneration of the injured tendon, which, in turn, induces a partial disuse of the muscle mass, which consequently atrophies (proportionally to the severity of tendon lesion) by striated muscular fiber apoptosis. The authors suggest that the different behavior of the two tissues depends on the marked difference in their vascularization. PMID:22881388

Palumbo, Carla; Rovesta, Claudio; Ferretti, Marzia

2012-01-01

358

A partially biodegradable material device for repair and reconstruction of injured tendons  

Microsoft Academic Search

We assessed the applicability of a partially biodegrad able synthetic material composed of polyglycolic acid (PGA) and dacron to repair or replace severely injured tendons. Adult rabbits underwent complete laceration and repair of one Achilles tendon. Group 1 (N = 8) had end to end tenorrhaphy with size 0 braided polyester suture, and Group 2 (N = 16) tendons were

William G. Rodkey; H. Edward Cabaud; John A. Feagin; Paul C. Perlik

1985-01-01

359

Posterior horn lateral meniscal tears simulating meniscofemoral ligament attachment in the setting of ACL tear: MRI findings  

Microsoft Academic Search

Purpose  We have noted apparent far lateral meniscal attachment of the meniscofemoral ligament (MFL) with an anterior cruciate ligament\\u000a (ACL) tear. This study evaluates MFL attachment and association with posterior horn lateral meniscus (PHLM) tear.\\u000a \\u000a \\u000a \\u000a Materials and methods  Nine months of knee arthroscopy reports were reviewed to classify the PHLM and ACL as torn or normal. After excluding those\\u000a with prior knee

Lawrence S. Park; Jon A. Jacobson; David A. Jamadar; Elaine Caoili; Monica Kalume-Brigido; Edward Wojtys

2007-01-01

360

Development of a Hot Tear Indicator for Steel Castings C. Monroe, C. Beckermann  

E-print Network

Development of a Hot Tear Indicator for Steel Castings C. Monroe, C. Beckermann Department, Casting Simulation, Steel Abstract A hot tear indicator based on the physics of solidification, not a full tear predictor. Simulation results for various "T" shaped steel castings show good agreement

Beckermann, Christoph

361

41International Journal of Metalcasting/Fall 08 Prediction of Hot tear formation in a  

E-print Network

abstract A viscoplastic deformation model considering material damage is used to predict hot tear evolution viscoplastic model that calculates deformation and damage is used to predict hot tears in AZ91D magnesium alloy 41International Journal of Metalcasting/Fall 08 Prediction of Hot tear formation in a magnesium

Beckermann, Christoph

362

Validation of the Thessaly test for detecting meniscal tears in anterior cruciate deficient knees  

Microsoft Academic Search

Meniscal injuries are frequently associated with anterior cruciate ligament (ACL) tears. Clinical tests that are useful for detecting meniscal tears may not be valid in this setting. The Thessaly test, a newly described dynamic clinical examination, has been shown to have a very high diagnostic accuracy for detecting meniscal tears. This study evaluates the accuracy of the Thessaly test in

Fardin Mirzatolooei; Zahra Yekta; Mojgan Bayazidchi; Solmaz Ershadi; Ahmadreza Afshar

2010-01-01

363

Tear Film Dynamics on an Eye-shaped Domain I: Pressure Boundary Conditions  

E-print Network

Tear Film Dynamics on an Eye-shaped Domain I: Pressure Boundary Conditions April 13, 2009 Kara L Abstract We study the relaxation of a model for the human tear film after a blink using lubrication theory connectivity around the lid margins. 1 #12;1 Introduction Human tear film plays an essential role in the health

Bacuta, Constantin

364

[Psoas haematoma due to irritation of the psoas tendon].  

PubMed

Irritation of the tendon of the musculus iliopsoas after total hip replacement is a rare complication. In connection with the irritation of the iliopsoas tendon only one case report of a psoas haematoma due to anticoagulation has been published. We assume that these kinds of haematomas are more frequent than described. We report on 2 cases of haematoma caused by an iliopsoas impingement after total hip replacement. In one case a lesion of the femoral nerve was observed. Surgical treatment was composed of the revision of the acetabular component. PMID:24129721

Lausmann, C; Mathonia, P; Plötz, W

2013-10-01

365

Mineralization of dentin, bone and tendon in vitro  

Microsoft Academic Search

Bovine dentin, bone, and tendon slices, and rat bone, readily mineralize to variable degrees after demineralization by (EDTA)\\u000a at pH 7.4, but they fail to mineralize after demineralzation with acetic acid (HAc) at pH 3.0. The demineralized dentin, but\\u000a neither bone nor tendon, contained organically bound phosphate. The EDTA-demineralized dentin contained less phosphate than\\u000a HAc-demineralized dentin. HAc-demineralized rat dentin contained

C. V. DeSteno; F. Feagin; W. T. Butler

1975-01-01

366

First-order finite-Larmor-radius effects on magnetic tearing in pinch configurations  

SciTech Connect

The linear and nonlinear evolution of a single-helicity tearing mode in a cylindrical, force-free pinch are investigated using a fluid model with first-order finite-Larmor-radius corrections. Linear results computed with the nimrod[nonideal magnetohydrodynamics (MHD) with rotation, open discussion] code [Sovinec et al., J. Comput. Phys. 195, 355 (2004)] produce a regime at small {rho}{sub s} where the growth rate is reduced relative to resistive MHD, though the Hall term is not significant. The leading order contributions from ion gyroviscosity may be expressed as a drift associated with {nabla}B{sub 0} and poloidal curvature for experimentally relevant {beta}=0.1, S{approx}10{sup 5}-10{sup 6} force-free equilibria. The heuristic analytical dispersion relation, {gamma}{sup 4}({gamma}-i{omega}{sub *gv})={gamma}{sub MHD}{sup 5} where {omega}{sub *gv} is the gyroviscous drift frequency, confirms numerical results. The behavior of our cylindrical computations at large {rho}{sub s} corroborates previous analytic slab studies where an enhanced growth rate and radially localized Hall dynamo are predicted. Similar to previous drift-tearing results, nonlinear computations with cold ions demonstrate that the Hall dynamo is small when the island width is large in comparison with the scale for electron-ion coupling. The saturation is then determined by the resistive MHD physics. However, with warm ions the gyroviscous stress supplements the nonlinear Lorentz force, and the saturated island width is reduced.

King, J. R.; Mirnov, V. V. [Center for Magnetic Self-Organization and Center for Plasma Theory and Computation, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Sovinec, C. R. [Center for Magnetic Self-Organization and Center for Plasma Theory and Computation, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Department of Engineering-Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States)

2011-04-15

367

Multi-Device Scaling of Neoclassical Tearing Mode Onset with Beta  

SciTech Connect

The islands from tearing modes driven unstable and sustained by helically perturbed neo-classical bootstrap current at high beta often provide the practical limit to long-pulse, high confinement tokamak operation [1,2]. The discharges studied are ELMy H-mode single-null divertor (SND) at q{sub 95} {approx}> 3. Periodic sawteeth with m/n = 1/1 and 2/2 are observed to induce m/n = 3/2 neoclassical tearing modes (NTMs) in the tokamaks Asdex-Upgrade [3], DIII-D [4] and JET [5]; confinement can drop by up to 30%, constituting a ''soft'' beta limit. Data for the onset of these modes was obtained by slowly raising beta on a time scale longer than the sawteeth period and observing the beta value at onset. Comparison of the measured critical beta to a model for the critical beta is made in terms of dimensionless parameters. This modeling is then used for extrapolation/prediction to a reactor-grade tokamak.

La Haye, R.J.; Buttery, R.J.; Guenter, S.; Huysmans, G.T.A.; Wilson, H.R.

1999-07-01

368

First-order finite-Larmor-radius effects on magnetic tearing in pinch configurations  

NASA Astrophysics Data System (ADS)

The linear and nonlinear evolution of a single-helicity tearing mode in a cylindrical, force-free pinch are investigated using a fluid model with first-order finite-Larmor-radius corrections. Linear results computed with the nimrod [nonideal magnetohydrodynamics (MHD) with rotation, open discussion] code [Sovinec et al., J. Comput. Phys. 195, 355 (2004)] produce a regime at small ?s where the growth rate is reduced relative to resistive MHD, though the Hall term is not significant. The leading order contributions from ion gyroviscosity may be expressed as a drift associated with ?B0 and poloidal curvature for experimentally relevant ? =0.1, S ~105-106 force-free equilibria. The heuristic analytical dispersion relation, ?4(?-i?*gv)=?MHD5 where ?*gv is the gyroviscous drift frequency, confirms numerical results. The behavior of our cylindrical computations at large ?s corroborates previous analytic slab studies where an enhanced growth rate and radially localized Hall dynamo are predicted. Similar to previous drift-tearing results, nonlinear computations with cold ions demonstrate that the Hall dynamo is small when the island width is large in comparison with the scale for electron-ion coupling. The saturation is then determined by the resistive MHD physics. However, with warm ions the gyroviscous stress supplements the nonlinear Lorentz force, and the saturated island width is reduced.

King, J. R.; Sovinec, C. R.; Mirnov, V. V.

2011-04-01

369

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

E-print Network

, P.E. King-Smith4 , W.D. Henshaw5 , G.B. McFadden6 , R. Usha7 , D.M. Anderson8 and K.N. Winter8 1 of the Human Tear Film R.J. Braun1 , K.L Maki2 , A. Heryudono3 , T.A. Driscoll1 , L.P. Cook1 , P. Ucciferro1

Bacuta, Constantin

370

Immunoglobulin concentrations in human tears in ocular diseases  

Microsoft Academic Search

Immunoglobulin concentrations in human tears were determined in 165 patients with different eye diseases by a standard radial immunodiffusion method. IgA was present in all the samples in measurable quantity. The mean IgA values were significantly higher than the controls in patients with acute bacterial conjunctivitis, keratomalacia, corneal graft reaction, blepharoconjunctivitis, and acute keratoconjunctivitis. The values in the patients with

D K Sen; G S Sarin

1979-01-01

371

A fast tearing mode instability driven by agyrotropic electron pressure  

NASA Astrophysics Data System (ADS)

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.

Hosseinpour, M.

2014-09-01

372

Triplane ankle fracture with deltoid ligament tear and syndesmotic disruption  

PubMed Central

In patients with immature skeletons, ligamentous injuries rarely accompany ankle fractures. In this article, we report about deltoid ligament tears and syndesmotic disruptions accompanying triplane ankle fractures in two children, and make recommendations as to the evaluation and treatment of children with such injuries. PMID:19308597

2008-01-01

373

Nuclear envelope breakdown: actin' quick to tear down the wall.  

PubMed

Nuclear envelope breakdown in metazoan cells is thought to be facilitated by microtubules, which pull on the nuclear membranes. Unexpectedly, an F-actin meshwork helps to tear down the large nucleus of starfish oocytes and to prevent chromosome loss in meiosis. PMID:25004364

Mogessie, Binyam; Schuh, Melina

2014-07-01

374

Neoclassical Tearing Modes in Tokamak Fusion Test Reactor Experiments  

E-print Network

auxiliary heating, where plasma temperature is relatively low, tearing modes are believed to be mainly driven by the current gradient rJ, J is the inductive current and the magnetic islands are believed heating schemes, plasma temperature increases and the plasmas becomes more collisionless. When the ion

375

Groups Without Tears: Mining Social Topologies from Email  

E-print Network

, that represent the structure and content of a person's social network as a first-class object. We contributeGroups Without Tears: Mining Social Topologies from Email Diana MacLean Sudheendra Hangal Seng Keat, lam, jheer}@cs.stanford.edu ABSTRACT As people accumulate hundreds of "friends" in social me- dia

Heer, Jeffrey

376

Interference and model study of the human tear film  

NASA Astrophysics Data System (ADS)

The main purpose of this dissertation was to elaborate a new method for in vivo observation and stability measurements of the human tear film. Presented method is based on interference phenomenon of the coherent laser light. The quantitative estimation of observed interference fringe pattern deterioration was given. The estimation is based on Fourier spectrum analysis of the interferogram. The prototype of the interferometer together with dedicated software was constructed and some preliminary measurements of the tear film stability on the cornea and contact lens were performed. Several methods were proposed for reconstruction of the corneal topography from recorded interferograms by use of Twyman-Green interferometer. Several interferograms of the human cornea in vivo were recorded. The depth and profile of the tear film break-up were found by analyzing the sequence of the interferograms. The estimations of influence of the tear film break-up on the point spread function and modulation transfer function calculated for the optical model of eye, were presented.

Licznerski, Tomasz Jacek

377

49 CFR 173.340 - Tear gas devices.  

Code of Federal Regulations, 2010 CFR

...elements must be packed in one outer drum, and the gross weight of the drum may not exceed 35 kg (77 pounds). (3) In a UN 4G fiberboard box with inside tear gas devices meeting Specifications 2P or 2Q. Each inside packaging must be placed in...

2010-10-01

378

49 CFR 173.340 - Tear gas devices.  

Code of Federal Regulations, 2012 CFR

...elements must be packed in one outer drum, and the gross weight of the drum may not exceed 35 kg (77 pounds). (3) In a UN 4G fiberboard box with inside tear gas devices meeting Specifications 2P or 2Q. Each inside packaging must be placed in...

2012-10-01

379

49 CFR 173.340 - Tear gas devices.  

Code of Federal Regulations, 2011 CFR

...elements must be packed in one outer drum, and the gross weight of the drum may not exceed 35 kg (77 pounds). (3) In a UN 4G fiberboard box with inside tear gas devices meeting Specifications 2P or 2Q. Each inside packaging must be placed in...

2011-10-01

380

49 CFR 173.340 - Tear gas devices.  

Code of Federal Regulations, 2013 CFR

...elements must be packed in one outer drum, and the gross weight of the drum may not exceed 35 kg (77 pounds). (3) In a UN 4G fiberboard box with inside tear gas devices meeting Specifications 2P or 2Q. Each inside packaging must be placed in...

2013-10-01

381

Management of Meniscus Tears That Extend Into the Avascular Region  

Microsoft Academic Search

The value of the menisci for normal function of the knee joint is well documented. Meniscectomy often results in noteworthy damage to the knee joint, including deterioration of articular cartilage surfaces and subchondral bone sclerosis. Early investigations of meniscus repair that focused on simple longitudinal tears located in the periphery or outer one-third region reported high success rates. More recently,

Frank R. Noyes; Sue D. Barber-Westin

382

Gyrokinetic analysis of tearing instabilities in a collisionless plasma  

SciTech Connect

Using a gyrokinetic description, an analytic investigation of tearing instabilities is carried out for a collisionless tokamak plasma, with particular emphasis on delineating the effects associated with Landau and {nabla}B resonances. The linear characteristics of {Delta}{sup '}-driven tearing modes are studied by including short wavelength variations across the confining magnetic field and long wavelength variations along the field. For the case when electrons are adiabatic and ions are fluidlike, the dispersion relation is solved analytically for mode widths lying between electron and ion excursion lengths. It is shown that electron Landau damping effect can significantly influence the tearing mode growth rate by making it proportional to ({Delta}{sup '}){sup 1/2} in contrast to earlier kinetic results, which show a linear dependence on {Delta}{sup '}. The growth rate can further slow down when compressional mode coupling effects are taken into account. Likewise, analytic conditions for the growth of the gyrokinetic tearing mode in the presence of electron {nabla}B resonance effect are obtained for both the {Delta}{sup '} driven global mode as well as the large {Delta}{sup '} branch of this instability and expressions for the real frequency and growth rate of the modes are given. Our analytic results, besides providing physical insights into the influence of these 'resonance' effects, can also serve as useful benchmark signatures to look for in large scale numerical gyrokinetic simulations.

Sundaram, A. K. [917 Shenandoah Way, Greenwood, Indiana 46143 (United States); Sen, A. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2011-03-15

383

Localized tearing modes in the magnetotail driven by curvature effects  

NASA Technical Reports Server (NTRS)

The stability of collisionless tearing modes is examined in the presence of curvature drift resonances and the trapped particle effects. A kinetic description for both electrons and ions is employed to investigate the stability of a two-dimensional equilibrium model. The main features of the study are to treat the ion dynamics properly by incorporating effects associated with particle trajectories in the tail fields and to include the linear coupling of trapped particle modes. Generalized dispersion relations are derived in several parameter regimes by considering two important sublayers of the reconnecting region. For a typical choice of parameters appropriate to the current sheet region, we demonstrate that localized tearing modes driven by ion curvature drift resonance effects are excited in the current sheet region with growth time of the order of a few seconds. Also, we examine nonlocal characteristics of tearing modes driven by curvature effects and show that modes growing in a fraction of a second arise when mode widths are larger than the current sheet width. Further, we show that trapped particle effects, in an interesting frequency regime, significantly enhance the growth rate of the tearing mode. The relevance of this theory for substorm onset phase and other features of the substorms is briefly discussed.

Sundaram, A. K.; Fairfield, D. H.

1995-01-01

384

Central aponeurosis tears of the rectus femoris: sonographic findings  

Microsoft Academic Search

Objective. The purpose of this study was to review the normal and sonographic (US) anatomy of the central aponeurosis of the rectus femoris muscle, describe the sonographic appearance of its tears and correlate it with the MR findings. Design and patients. The rectus femoris internal architecture was evaluated by cadaveric dissection. To correlate the sonographic normal findings with cadaveric data,

Stefano Bianchi; Carlo Martinoli; Nyali Peiris Waser; Maria Pia Bianchi-Zamorani; Egisto Federici; Jean Fasel

2002-01-01

385

Biceps instability and Slap type II tear in overhead athletes  

PubMed Central

Summary 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

Osti, Leonardo; Soldati, Francesco; Cheli, Andrea; Pari, Carlotta; Massari, Leo; Maffulli, Nicola

2012-01-01

386

ANNULAR TEARS AND DISC DEGENERATION IN THE LUMBAR SPINE  

Microsoft Academic Search

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

L. OSTI; B. VERNON-ROBERTS; R. MOORE; R. D. FRASER

387

Biceps instability and Slap type II tear in overhead athletes.  

PubMed

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

Osti, Leonardo; Soldati, Francesco; Cheli, Andrea; Pari, Carlotta; Massari, Leo; Maffulli, Nicola

2012-10-01

388

Understanding and preventing complications in repairing rotator cuff tears.  

PubMed

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

Osti, Leonardo; Papalia, Rocco; Del Buono, Angelo; Denaro, Vincenzo; Maffulli, Nicola

2012-01-01

389

Groups Without Tears: Mining Social Topologies from Email  

E-print Network

an algorithm for creating social topologies by mining com- munication history and identifying likely groups evolved from recreational to socially essential; media-sharing plat- forms such as Flickr and LastGroups Without Tears: Mining Social Topologies from Email Diana MacLean Sudheendra Hangal Seng Keat

Pratt, Vaughan

390

Transtendon rotator-cuff repair of partial-thickness articular surface tears can lead to medial rotator-cuff failure  

PubMed Central

Purpose The purpose of this study was to evaluate clinical and anatomic outcomes of patients following transtendon rotator-cuff repair of partial articular supraspinatus tendon avulsion (PASTA) lesions. Patients and methods Patients in the senior author’s practice who had isolated PASTA lesions treated by transtendon rotator-cuff repair were included (n=8) and retrospectively reviewed. All patients were evaluated preoperatively and at a mean of 21.2 months (±9.7 months) postoperatively using standardized clinical evaluation (physical exam, American Shoulder and Elbow Surgeons, and Simple Shoulder Test). All patients underwent postoperative imaging with a magnetic resonance imaging arthrogram. Results There was a significant improvement in American Shoulder and Elbow Surgeons (42.7±17.5 to 86.9±25.2) and Simple Shoulder Test (4.6±3.2 to 10.1±3.8) scores from pre- to postoperative, respectively. Postoperative imaging demonstrated full-thickness medial cuff tearing in seven patients, and one patient with a persistent partial articular surface defect. Conclusion Transtendon repair of PASTA lesions may lead to improvements in clinical outcome. However, postoperative imaging demonstrated a high incidence of full-thickness rotator-cuff defects following repair. PMID:25114604

Woods, Tom C; Carroll, Michael J; Nelson, Atiba A; More, Kristie D; Berdusco, Randa; Sohmer, Stephen; Boorman, Richard S; Lo, Ian KY

2014-01-01

391

Outcome of repaired unstable meniscal tears in children and adolescents  

PubMed Central

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

2012-01-01

392

Tears Rendering in Extreme Expression by Using SPH Method and Gravity Parameters  

NASA Astrophysics Data System (ADS)

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.

Rahim, Mohd Shafry Mohd; Rad, Abdolvahab Ehsani; Rehman, Amjad; Altameem, Ayman

2014-06-01

393

Quantification of tear proteins and sPLA2-IIa alteration in patients with allergic conjunctivitis  

PubMed Central

Purpose Allergic conjunctivitis (AC) has been reported to induce the instability of the tear film. The tear protein and the lipid layer play important roles in maintaining the tear film. The aim of this study was to quantify the alteration of the major tear protein components and a lipid related protein secretory type IIa phospholipase A2 (sPLA2-IIa) in tears of seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC) patients. Methods Twenty-one SAC and PAC patients and thirteen normal controls completed a symptom questionnaire and underwent regular ocular examination. SAC and PAC patients were diagnosed based on the clinical presentation and elevated serum IgE levels. Schirmer test paper was used to collect tear samples from SAC and PAC patients and normal controls. Soybean trypsin inhibitor (SBTI) was used as an internal standard to analyze tear samples in 15% SDS–PAGE gel. Total tear protein and its major components from the SAC and PAC patients and normal controls were quantified by band densitometry. The major tear protein bands were determined by MALDI-TOF/TOF spectrum analysis. Western blot was used to detect the content of sPLA2-IIa in tears of allergic conjunctivitis patients and normal controls. Results Schirmer test scores were more than 10 mm in all the SAC and PAC patients and control subjects. The tear film breakup time of SAC and PAC patients was much shorter than that of the normal controls. We obtained 15 bands of tear protein by one dimensional SDS–PAGE, in which 14 bands were determined by mass-spectrum analysis. The band densitometry analysis revealed that the total tear protein concentration was much higher in SAC and PAC patients than in normal controls (p<0.05). The quantity of tear protein band 4 (serum albumin precursor), band 6 (Ig gamma-2), band 9 (leukocyte elastase inhibitor) were also significantly higher in AC patients (p<0.05). Content of sPLA2-IIa, as shown by western blot, was much higher in AC patients than in controls. Conclusions The total tear protein concentration and some of the major tear protein components was increased in tears of SAC and PAC patients. In addition, the content of sPLA2-IIa in tears of SAC and PAC patients was elevated. The tear protein changes in SAC and PAC patients may contribute to instability of tear film. PMID:21042565

Li, Kaijun; Liu, Xialin; Chen, Ziyan; Huang, Qiang

2010-01-01

394

Tearing relaxation and the globalization of transport in field-reversed configurations  

SciTech Connect

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.

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

395

Abnormal tenocyte morphology is more prevalent than collagen disruption in asymptomatic athletes' patellar tendons.  

PubMed

This study investigated the prevalence of each of the four features of patellar tendinosis in asymptomatic athletic subjects undergoing patellar tendon anterior cruciate ligament (ACL) reconstruction. Fifty subjects (39 males and 11 females) undergoing ACL reconstruction using a patellar tendon graft were screened for previous tendon symptoms, training and playing history and had their patellar tendons examined with ultrasound prior to surgery. During surgery, a small piece of proximal posterocentral tendon was harvested, fixed and examined under light microscopy. Histopathological changes were graded for severity. Results demonstrate that 18 tendons were abnormal on light microscopy and 32 were normal. There were no differences between subjects with and without pathology in respect of training, recovery after surgery and basic anthropometric measures. Three tendons were abnormal on ultrasound but only one had proximal and central changes. Tendons showed a consistent series of changes. Tenocyte changes were found in all but one of the abnormal tendons. In all but one of the tendons with increased ground substance there were tenocyte changes, and collagen separation was always associated with both tenocyte changes and increased ground substance. No tendons demonstrated neovascularization. It appears that cellular changes must be present if there is an increase in ground substance, or collagen and vascular changes. Further research is required to confirm these findings. PMID:15013093

Cook, J L; Feller, J A; Bonar, S F; Khan, K M

2004-03-01

396

Fusimotor activity and the tendon jerk in the anaesthetised cat  

Microsoft Academic Search

This is a study of the tendon jerk reflex elicited by a brief stretch applied to the triceps surae muscle group in the chloralose-anaesthetised cat. The size of the recorded reflex depended on stretch parameters (optimum at 300 µm amplitude at a rate of 100 mm\\/s) and on how the muscle had been conditioned. A reflex elicited after a conditioning

S. A. Wood; D. L. Morgan; J. E. Gregory; U. Proske

1994-01-01

397

Bilateral patellar tendon disruption--a professional predisposition?  

PubMed Central

A healthy 37-year-old male carpet fitter sustained an injury to both knees while playing football. The clinical signs of patellar tendon disruption were not obvious because of gross skin thickening as a result of his profession, however, the diagnosis was confirmed by ultrasound scan. PMID:7894815

Sochart, D H; Shravat, B P

1994-01-01

398

Tendon organs as monitors of muscle damage from eccentric contractions  

Microsoft Academic Search

Eccentric contractions, where the active muscle is stretched, can lead to muscle damage. One of the signs of damage is a rise in the whole-muscle passive tension. Here we have asked, how many eccentric contractions are necessary to produce a measurable rise in passive tension and can this be detected by the muscle's tension sensors, the tendon organs? Responses of

J. E. Gregory; D. L. Morgan; U. Proske

2003-01-01

399

Ciprofloxacin-induced tendinopathy of the gluteal tendons.  

PubMed

Fluoroquinolone-induced tendinopathy most commonly affects the Achilles tendon; however, involvement of several other tendons has been described. This is a case report of ciprofloxacin-induced tendinopathy of the gluteal tendons with MRI findings. An obese 25-year-old woman with no significant past medical history was diagnosed with acute pyelonephritis and was treated with intravenous ciprofloxacin. Shortly after her first dose of ciprofloxacin, she developed severe left hip pain and decreased range of motion. MRI of the hips showed bilateral tendinopathy of the gluteal muscle insertion. A diagnosis of ciprofloxacin-induced tendinopathy was made based on her MRI and a Naranjo score of 7. Ciprofloxacin was stopped and her pain quickly resolved. Fluoroquinolones cause tendinopathy in 0.14 % to 0.4 % of patients using these agents. Fluoroquinolone-associated tendinopathy is a serious adverse reaction that can affect many tendons and should be considered in any patient presenting with new musculoskeletal complaints and in whom there is a history of fluoroquinolone use within the preceding 6 months. PMID:25047394

Shimatsu, Kaumakaokalani; Subramaniam, Somasundaram; Sim, Helen; Aronowitz, Paul

2014-11-01

400

Mineralized fibroma of the tendon sheath presenting as a bursitis.  

PubMed

We report on the clinical, imaging-including ultrasound, computed tomography, and magnetic resonance imaging-and histological features of a fibroma of the tendon sheath with mineralized chondroid and osseous metaplasia, presenting as a semimembranosus bursitis. The anatomical characteristics of the semimembranosus bursa are demonstrated by dissection in a cadaveric specimen and correlated with the imaging findings in our patient. PMID:18685844

Le Corroller, Thomas; Bouvier-Labit, Corinne; Sbihi, Abderrahmane; Champsaur, Pierre

2008-12-01

401

Wrist tendon forces during different dynamic wrist motions  

PubMed Central

Purpose A common treatment of arthritis of the first carpometacarpal joint requires all or a portion of the flexor carpi radialis tendon (FCR) to be used as an interpositional graft. The purpose of this study was to examine the in vitro tendon forces in six wrist flexor and extensors to determine if their force contribution changes during different dynamic wrist motions along with a specific application to the FCR. Methods Sixty two fresh frozen cadaver wrists were tested in a wrist joint motion simulator. During wrist flexion-extension, radioulnar deviation, dart throwing and circumduction motions, the peak and average tendon forces were determined for the extensor carpi ulnaris, extensor carpi radialis brevis and longus, abductor pollicis longus, flexor carpi radialis and flexor carpi ulnaris. Results During a dart throwing motion, the mean and peak FCR forces were statistically less than during the other 3 motions. Conversely, the mean and peak flexor carpi ulnaris forces were statistically greater during the dart throwing motion than during the other 3 motions. Discussion Patients who have undergone a surgical procedure in which all or a portion of the FCR has been harvested, may experience a decrease in wrist strength with wrist motion as the FCR tendon normally applies force during wrist motion. The motion least likely to be affected by such surgery is the dart throwing motion when the force on the remaining FCR is minimized. PMID:20353863

Werner, Frederick W.; Short, Walter H.; Palmer, Andrew K.; Sutton, Levi G.

2010-01-01

402

Three tendon transfer methods in reconstruction of ulnar nerve palsy  

Microsoft Academic Search

Purpose: This study was designed to investigate the efficacy of 3 different tendon transfer techniques in restoring grip strength, correcting claw hand deformity, and improving hand function after irreparable ulnar nerve palsy. Method: A total of 44 patients were assessed 14 to 96 months after surgery. Twenty-four patients were reconstructed with the flexor digitorum 4-tail (FDS 4-tail) procedure, 11 with

Türker Özkan; Ka?an Özer; Ayan Gülgönen

2003-01-01

403

Synthetic Collagen Fascicles for the Regeneration of Tendon Tissue  

E-print Network

that the resulting post-fabrication type-I collagen structure retains the essential phase behaviour, alignment and spectral characteristics of aligned native type-I collagen. We have also shown that both ovine tendon fibroblasts and human white blood cells in whole...

Kew, SJ; Gwynne, JH; Enea, D; Brooks, R; Rushton, N; Best, Serena Michelle; Cameron, Ruth Elizabeth

2012-01-01

404

Some effects of Bunnell suture on otherwise uninjured tendons in subhuman primates.  

PubMed

An experimental study was performed in rhesus monkeys (M. mulatta) to examine the contribution of Bunnell tendon suture to the production of postoperative tendon adhesions. It was found that Bunnell suture used with atraumatic technique caused a significant depression of in vitro tendon surface plasminogen activator activity, allowing the in vivo persistence and fibrous organization of fibrinous postoperative adhesions to sutured areas. Bunnell suture also produced coagulation necrosis of the sutured area of tendon. Collagen, which replaced the destroyed areas, was oriented randomly and frequently was continuous with surface tendon adhesions to surrounding connective tissues. Bunnell suture appears to be a cause of tendon adhesions in subhuman primates. The importance of fibrin and depressed local fibrinolysis in the relationship of tendon ischemia and adhesion formation is discussed. PMID:411189

Buckman, R F; Hufnagel, H V; Olivier, G; Buckman, P D; Zuidema, G D

1977-11-01

405

Bilateral, Simultaneous Medial Meniscus Bucket Handle Tears in a 23-Year-Old Female  

PubMed Central

Traumatic tears of the meniscus are well reported in the literature. Rarely, bilateral meniscal tears occur. A PubMed search found that only three cases of bilateral medial meniscus bucket handle type tears have been reported. Treatment options range from partial meniscectomy to repair of the meniscal tear. Repair is reported to be more successful in the vascular red-red or red-white zones. We present the case of a 23-year-old female who sustained simultaneous bilateral medial meniscus bucket handle type tears in an automobile accident. She was treated in a staged fashion with knee arthroscopy. Her meniscus tears were both found to be in the vascularized zone and meniscal tear repair was conducted. At two weeks postoperatively, she had excellent resolution of her symptoms and has returned to pain-free weight-bearing. She has remained pain-free at six-month follow-up. PMID:25302127

Limbert, Andrew

2014-01-01

406

Cellular response of healing tissue to DegraPol tube implantation in rabbit Achilles tendon rupture repair: an in vivo histomorphometric study.  

PubMed

In tendon rupture repair, improvements such as higher primary repair strength, anti-adhesion and accelerated healing are needed. We developed a potential carrier system of an electrospun DegraPol tube, which was tightly implanted around a transected and conventionally sutured rabbit Achilles tendon. Histomorphometric analysis of the tendon tissue 12?weeks postoperation showed that the tenocyte density, tenocyte morphology and number of inflammation zones were statistically equivalent, whether or not DegraPol tube was implanted; only the collagen fibres were slightly less parallelly orientated in the tube-treated case. Comparison of rabbits that were operated on both hind legs with ones that were operated on only one hind leg showed that there were significantly more inflammation zones in the two-leg cases compared to the one-leg cases, while the implantation of a DegraPol tube had no such adverse effects. These findings are a prerequisite for using DegraPol tube as a carrier system for growth factors, cytokines or stem cells in order to accelerate the healing process of tendon tissue. PMID:22294461

Buschmann, Johanna; Meier-Bürgisser, Gabriella; Bonavoglia, Eliana; Neuenschwander, Peter; Milleret, Vincent; Giovanoli, Pietro; Calcagni, Maurizio

2013-05-01

407

ProTec Tear-Offs: A Preliminary Assessment  

SciTech Connect

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