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1

Treatment of partial distal biceps tendon tears.  

PubMed

Partial rupture of the distal biceps tendon exhibits features similar to that of complete disruption, including acute antecubital pain, weakness of elbow flexion, and forearm supination, and differs only in the fact that the biceps tendon is still palpable in the partial rupture. There are 2 etiologies, first acute traumatic (such as a sudden eccentric contracture) and second, chronic degenerative tendon disease. For accurate diagnosis, a high index of suspicion must be employed. Initial investigations should include plain x-ray and a magnetic resonance scan. Partial tears <50% may be treated with nonoperative management or with surgical debridement of the surrounding synovitis. Tears >50% should be treated with division of the remaining tendon and surgical repair of the entire tendon as a single unit. Surgical endoscopy provides the ability to further quantify the extent of a distal biceps tear and to treat with debridement. This technique, however, should only be used in experienced hands. PMID:18703975

Bain, Gregory I; Johnson, Luke J; Turner, Perry C

2008-09-01

2

Autologous hamstring tendon used for revision of quadiceps tendon tears.  

PubMed

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

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

2013-04-01

3

Surgical treatment of peroneal tendon tears.  

PubMed

The focus of this article is the diagnosis and treatment of peroneal tendon tears. The article first describes mechanisms of injuries resulting in peroneal brevis and longus tears. Associated pathologies, such as ankle instability, hindfoot varus, hypertrophied peroneal tubercle, are discussed. Following sections on diagnosis and conservative treatment, the article describes operative treatment for isolated peroneus brevis tear, isolated peroneus longus tear, and tears of both the peroneus longus and brevis. The authors also discuss hamstring allograft reconstruction, the silicone rod technique, flexor digitorum longus transfer to the peroneus brevis, and treatment of associated pathology. PMID:17996622

Squires, Natalie; Myerson, Mark S; Gamba, Cesar

2007-12-01

4

Sonography of tears of the distal biceps tendon.  

PubMed

OBJECTIVE. The objective of this study was to describe the sonographic appearance of tears of the distal biceps brachii tendon. CONCLUSION. Sonography can reveal complete and partial tears of the distal biceps tendon, thus providing an alternative technique to MR imaging. PMID:11000169

Miller, T T; Adler, R S

2000-10-01

5

Proximal biceps tendon tear in an adolescent tennis player.  

PubMed

The diagnosis of a torn biceps tendon in athletes who use overhead throwing or swinging motions can be difficult to make because there is no one physical examination finding that will confirm the diagnosis, and because magnetic resonance imaging, although sometimes helpful, does not image the length of the biceps tendon adequately. We report a case of an isolated partial biceps tendon tear in an adolescent female athlete who was diagnosed during arthroscopy after the tendon was pulled into the joint. The tendon was cut and a tenodesis was performed. Two years after the surgical procedure, the patient was without pain and returned to playing tennis at her previous level. PMID:23527332

Johnson, Alan R; Higgins, Brendan T; Teixeira, Rafael P; Garzon-Muvdi, Juan; McFarland, Edward G

2013-03-01

6

Triceps tendon tear in a middle-aged weightlifter.  

PubMed

The patient was a 47-year-old man who was evaluated by a physical therapist for a chief complaint of posterior right elbow pain. The patient routinely participated in weightlifting activities and reported a sudden onset of triceps weakness and posterior elbow pain while performing clap push-ups 3 days prior. A physician assistant ordered radiographs, which were initially interpreted as normal, and routine magnetic resonance imaging for the right elbow. Following examination by a physical therapist, due to concern for a triceps tendon tear, the previously ordered magnetic resonance imaging was expedited, which revealed a partial triceps tendon tear with partial tendon retraction medially. PMID:24175622

Molloy, Joseph M; Aberle, Curtis J; Escobar, Eduardo

2013-11-01

7

Endoscopic transtendinous repair for partial-thickness proximal hamstring tendon tears.  

PubMed

Partial tears of the proximal hamstring tendon can successfully be managed with tendon repair in cases of failed conservative management. As in partial-thickness gluteus medius repair, a transtendinous technique can be used to repair partial-thickness undersurface tears of the hamstring origin. This report details an endoscopic transtendinous approach for the treatment of partial-thickness hamstring tendon tears. PMID:24749032

Jackson, Timothy J; Trenga, Anthony; Lindner, Dror; El-Bitar, Youseff; Domb, Benjamin G

2014-02-01

8

Endoscopic Transtendinous Repair for Partial-Thickness Proximal Hamstring Tendon Tears  

PubMed Central

Partial tears of the proximal hamstring tendon can successfully be managed with tendon repair in cases of failed conservative management. As in partial-thickness gluteus medius repair, a transtendinous technique can be used to repair partial-thickness undersurface tears of the hamstring origin. This report details an endoscopic transtendinous approach for the treatment of partial-thickness hamstring tendon tears. PMID:24749032

Jackson, Timothy J.; Trenga, Anthony; Lindner, Dror; El-Bitar, Youseff; Domb, Benjamin G.

2014-01-01

9

Traumatic Subscapularis Tendon Tear in an Adolescent American Football Player  

PubMed Central

Isolated traumatic subscapularis tendon tears are uncommon at any age. In adolescent patients, this type of injury is even more infrequent and usually presents as a bony avulsion of the lesser tuberosity. This report reviews a case of an adolescent American football player sustaining a posterior impact to an abducted, extended arm that resulted in an isolated subscapularis tendon tear. Magnetic resonance imaging of the shoulder revealed an isolated subscapularis tear retracted 1.6 cm without bony avulsion from the lesser tuberosity. Surgical repair was performed with 2 biocomposite absorbable anchors in the lesser tuberosity. The patient returned to basketball 12 weeks after surgery. This case illustrates that a high index of suspicion is required for an appropriate diagnosis in young athletes. PMID:24427400

Gibson, Margaret E.; Gurley, Daniel; Trenhaile, Scott

2013-01-01

10

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

PubMed Central

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

Hartzler, Robert U.; Burkhart, Stephen S.

2014-01-01

11

Subpectoral Biceps Tenodesis for Bicipital Tendonitis With SLAP Tear.  

PubMed

The purpose of this study was to evaluate the outcomes of patients undergoing subpectoral biceps tenodesis for bicipital tendonitis with a superior labral anterior-posterior (SLAP) tear. Patients undergoing primary subpectoral biceps tenodesis for arthroscopically confirmed SLAP tears with signs or findings of bicipital tendonitis were included. An independent observer collected data prospectively as part of a data repository, which was then analyzed retrospectively. Primary outcome measures were the American Shoulder and Elbow Surgeons (ASES) score and pain relief via visual analog scale (VAS). Secondary outcome measures included the Simple Shoulder Test (SST), Constant, Single Assessment Numeric Evaluation (SANE), and Short Form 12 (SF-12) scores. Twenty-eight patients with a mean±SD age of 43.7±13.4 years and a mean±SD follow-up of 2.0±1.0 years met inclusion criteria. Workers' compensation was involved with 43% of cases, and 46% of the included patients were manual laborers. Eight (32%) patients were athletes, and 88% of the athletes were overhead athletes. Intraoperatively, 15 (54%) patients had type I SLAP tears, 10 (36%) had type II SLAP tears, 1 (3%) had a type III SLAP tear, and 2 (7%) had type IV SLAP tears. Significant improvements were seen in the following outcome measures pre- vs postoperatively: ASES score (58±23 vs 89±18; P=.001), SST score (6.3±3.6 vs 10.6±3.3; P=.001), SANE score (54±24 vs 88±25; P=.003), VAS score (3.8±2.0 vs 1.1±1.8; P=.001), SF-12 overall score (35±6 vs 42±6; P=.001), and SF-12 physical component score (39±6 vs 50±10; P=.001). Overall satisfaction was excellent in 80% of patients. Subpectoral biceps tenodesis demonstrates excellent clinical outcomes in select patients with SLAP tears. [Orthopedics. 2015; 38(1):e48-e53.]. PMID:25611420

Gupta, Anil K; Chalmers, Peter N; Klosterman, Emma L; Harris, Joshua D; Bach, Bernard R; Verma, Nikhil N; Cole, Brian J; Romeo, Anthony A

2015-01-01

12

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.; Drapé, J.L.

2012-01-01

13

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

14

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

15

Diagnostic accuracy in detecting tears in the proximal biceps tendon using standard nonenhancing shoulder MRI  

PubMed Central

Background There is a paucity of data in the literature evaluating the performance of noncontrast MRI in the diagnosis of partial and complete tears of the proximal portion of the long head of the biceps (LHB) tendon. The objective of this study was to evaluate the accuracy of noncontrast magnetic resonance imaging (MRI) compared to arthroscopy for the diagnosis of pathology involving the intra-articular portion of the LHB tendon. Methods We conducted a retrospective review of 66 patients (mean age 57.8 years, range 43–70 years) who underwent shoulder arthroscopy and evaluation of the LHB tendon after having had a noncontrast MRI of the shoulder. Biceps pathology was classified by both MRI and direct arthroscopic visualization as either normal, partial tearing, or complete rupture, and arthroscopy was considered to be the gold standard. We then determined the sensitivity, specificity, and positive- and negative-predictive values of MRI for the detection of partial and complete LHB tears. Results MRI identified 29/66 (43.9%) of patients as having a pathologic lesion of the LHB tendon (19 partial and ten complete tears) while diagnostic arthroscopy identified tears in 59/66 patients (89.4%; 50 partial and 16 complete). The sensitivity and specificity of MRI for detecting partial tearing of the LHB were 27.7% and 84.2%, respectively (positive predictive value =81.2%, negative predictive value =32.0%). The sensitivity and specificity of MRI for complete tears of the LHB were 56.3% and 98.0%, respectively (positive predictive value =90.0%, negative predictive value =87.5%). Conclusion Standard noncontrast MRI of the shoulder is limited in detecting partial tears and complete ruptures of the intra-articular LHB tendon. Surgeons may encounter pathologic lesions of the LHB tendon during arthroscopy that are not visualized on preoperative MRI. PMID:24891814

Dubrow, Samuel A; Streit, Jonathan J; Shishani, Yousef; Robbin, Mark R; Gobezie, Reuben

2014-01-01

16

Distribution and expression of type VI collagen and elastic fibers in human rotator cuff tendon tears.  

PubMed

There is increasing evidence for a progressive extracellular matrix change in rotator cuff disease progression. Directly surrounding the cell is the pericellular matrix, where assembly of matrix aggregates typically occurs making it critical in the response of tendon cells to pathological conditions. Studies in animal models have identified type VI collagen, fibrillin-1 and elastin to be located in the pericellular matrix of tendon and contribute in maintaining the structural and biomechanical integrity of tendon. However, there have been no reports on the localization of these proteins in human tendon biopsies. This study aimed to characterize the distribution of these ECM components in human rotator cuffs and gain greater insight into the relationship of pathology to tear size by analyzing the distribution and expression profiles of these ECM components. Confocal microscopy confirmed the localization of these structural molecules in the pericellular matrix of the human rotator cuff. Tendon degeneration led to an increased visibility of these components with a significant disorganization in the distribution of type VI collagen. At the genetic level, an increase in tear size was linked to an increased transcription of type VI collagen and fibrillin-1 with no significant alteration in the elastin levels. This is the first study to confirm the localization of type VI collagen, elastin and fibrillin-1 in the pericellular region of human supraspinatus tendon and assesses the effect of tendon degeneration on these structures, thus providing a useful insight into the composition of human rotator cuff tears which can be instrumental in predicting disease prognosis. PMID:25166893

Thakkar, Dipti; Grant, Tyler M; Hakimi, Osnat; Carr, Andrew J

2014-01-01

17

Incidence of familial tendon dysfunction in patients with full-thickness rotator cuff tears  

PubMed Central

Background A familial predisposition to the development of rotator cuff tearing has been previously reported. Very little information exists on the development of global tendon dysfunction in patients with rotator cuff tears. The purpose of the current study was to determine the incidence of global tendon dysfunction as well as the need for surgery for tendon dysfunction in patients with rotator cuff tears and their family members and compare them to age-matched controls. Methods Ninety two patients with full-thickness rotator cuff tears and 92 age-matched controls with no history of shoulder dysfunction or surgery responded to several questions regarding tendon diseases in themselves as well as their family members. Individuals were queried regarding the presence of tendon diseases other than the rotator cuff, the need for surgery on these other tendinopathies, the presence of family members having tendinopathies including rotator cuff disease, and the need for family members to have surgery for these problems. Chi-square analysis was performed to compare the incidences between cases and controls (P<0.05 was considered significant). Results The average age of patients in the rotator cuff tear group and control groups were 58.24±7.4 and 58.42±8.5 years, respectively (P=0.876). Results showed 32.3% of patients in the rotator cuff tear group reported that family members had a history of rotator cuff problems or surgery compared to only 18.3% of the controls (P=0.035), and 38.7% of patients in the rotator cuff tear group reported they had a history of other tendon problems compared to only 19.3% of individuals in the control group (P=0.005). Conclusion Individuals with rotator cuff tears report a higher incidence of family members having rotator cuff problems or surgery as well as a higher incidence of other tendinopathies compared to controls. This data further supports a familial predilection for the development of rotator cuff tearing and generalized tendinopathies. PMID:24966704

Tashjian, Robert Z; Saltzman, Erik G; Granger, Erin K; Hung, Man

2014-01-01

18

Influence of tendon tears on ultrasound echo intensity in response to loading.  

PubMed

Acoustoelastic (AE) ultrasound image analysis is a promising non-invasive approach that uses load-dependent echo intensity changes to characterize stiffness of tendinous tissue. The purpose of this study was to investigate whether AE can detect localized changes in tendon stiffness due to partial and full-thickness tendon tears. Ovine infraspinatus tendons with different levels of damage (Intact, 33%, 66% and full thickness cuts initiated on the articular and bursal sides) were cyclically loaded in a mechanical testing system while cine ultrasound images were recorded. The load-induced changes in echo intensity on the bursal and articular side of the tendon were determined. Consistent with AE theory, the undamaged tendons exhibited an increase in echo intensity with tendon loading, reflecting the strain-stiffening behavior of the tissue. In the intact condition, the articular region demonstrated a significantly greater increase in echo intensity during loading than the bursal region. Cuts initiated on the bursal side resulted in a progressive decrease in echo intensity of the adjacent tissue, likely reflecting the reduced load transmission through that region. However, image intensity information was less sensitive for identifying load transmission changes that result from partial thickness cuts initiated on the articular side. We conclude that AE approaches may be useful to quantitatively assess load-dependent changes in tendon stiffness, and that disruption of AE behavior may be indicative of substantial tendon damage. PMID:25468301

Frisch, Kayt E; Marcu, David; Baer, Geoffrey S; Thelen, Darryl G; Vanderby, Ray

2014-12-18

19

Longitudinal split tear of the extensor pollicis brevis tendon: report of 2 cases.  

PubMed

Two patients presented with radial-sided wrist pain and longitudinal split tears of the extensor pollicis brevis tendon. Surgical debridement and repair was performed on the first patient with good results. Early diagnosis in the second patient led to successful treatment with immobilization alone. If diagnostic maneuvers for de Quervain tenosynovitis produce pain in a location other than the radial styloid, advanced imaging should be considered to identify other anatomic causes for the pain. PMID:25446412

Kroonen, Leo T; Ferguson, Christopher; Ketschke, Rhett A

2015-02-01

20

An underdiagnosed hip pathology: apropos of two cases with gluteus medius tendon tears.  

PubMed

Until recently, gluteus medius tendon tears have been the sort of hip pathology that is relatively unknown in the realm of rheumatology. Their diagnosis can pose a serious challenge to physicians, despite diligence. In this report we summarize two relevant cases and put forward some hints for their evaluation. Magnetic resonance imaging is quite beneficial in demonstrating the pathology and ruling out other likely pathologies after a prompt physical examination. Physicians should exercise care and vigilance in order not to overlook these cases, in which prompt physical examination and radiological interventions remain a prerequisite in the diagnostic algorithm. PMID:15459819

Ozçakar, Levent; Erol, Ozlem; Kaymak, Bayram; Aydemir, Nihal

2004-10-01

21

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

PubMed Central

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

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

2014-01-01

22

A lateral meniscus tear incarcerated behind the popliteus tendon: a case report.  

PubMed

A 51-year-old male, sustained an injury to his left knee after being pinned between his motorcycle and a road barrier. In the ER, the patient complained of medial knee pain, and had a significant joint effusion. MRI demonstrated an ACL injury, medial meniscal tear, bone bruising and impaction at the lateral femoral condyle and tibial plateau, and a tear of the posterior horn of the lateral meniscus that was displaced behind the popliteus. Unfortunately, the patient also presented with a deep vein thrombosis and thus could not proceed to the operating room for two months. During this time, scar tissue developed around the lateral meniscus. The purpose of this report is to present an unusual variant of a common injury pattern previously unreported where the posterior horn of the lateral meniscus became incarcerated behind the popliteus tendon and was left in place. It is likely that our patient will develop osteoarthritis in the future, but considering the circumstances he received a favorable early clinical outcome. Early recognition and a mobile fragment are essential restoring a patient's original anatomical features and achieving an optimal clinical outcome. PMID:19897371

Eskander, Mark S; Drew, Jacob M; Osuch, Daniel B; Metzmaker, Jeff

2010-10-01

23

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

24

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 ...

25

Acute traumatic tear of gluteus medius and minimus tendons in a patient without antecedant peritrochanteric hip pain.  

PubMed

Morphologic similarities between the abductor mechanisms of the hip and shoulder have given rise to the term rotator cuff tear of the hip. Although the true incidence of gluteus medius and minimus tears in the general population is unknown, the association between these tears and recalcitrant lateral hip pain has been described as greater trochanteric pain syndrome. Historically, tears of the gluteus medius and minimus have been thought to be attritional, and associated with chronic peritrochanteric pain, found incidentally during fracture fixation or hip arthroplasty, or with failure of abductor repair following arthroplasty utilizing the anterolateral approach. The literature supports favorable clinical outcomes with operative repair utilizing either endoscopic or open techniques. To our knowledge, there has never been a reported case of an acute traumatic tear of the gluteus medius and minimus that occurred without antecedant peritrochanteric hip pain. In this case, the patient was treated with acute open repair of the gluteus medius and minimus tendons within 3 weeks of injury and excellent clinical results were obtained at 6-month follow-up. Of note, the patient was notified and gave consent for his case to be used in publication. PMID:23569702

Stanton, Michael C; Maloney, Michael D; Dehaven, Kenneth E; Giordano, Brian D

2012-06-01

26

Acute Traumatic Tear of Gluteus Medius and Minimus Tendons in a Patient Without Antecedant Peritrochanteric Hip Pain  

PubMed Central

Morphologic similarities between the abductor mechanisms of the hip and shoulder have given rise to the term rotator cuff tear of the hip. Although the true incidence of gluteus medius and minimus tears in the general population is unknown, the association between these tears and recalcitrant lateral hip pain has been described as greater trochanteric pain syndrome. Historically, tears of the gluteus medius and minimus have been thought to be attritional, and associated with chronic peritrochanteric pain, found incidentally during fracture fixation or hip arthroplasty, or with failure of abductor repair following arthroplasty utilizing the anterolateral approach. The literature supports favorable clinical outcomes with operative repair utilizing either endoscopic or open techniques. To our knowledge, there has never been a reported case of an acute traumatic tear of the gluteus medius and minimus that occurred without antecedant peritrochanteric hip pain. In this case, the patient was treated with acute open repair of the gluteus medius and minimus tendons within 3 weeks of injury and excellent clinical results were obtained at 6-month follow-up. Of note, the patient was notified and gave consent for his case to be used in publication. PMID:23569702

Stanton, Michael C.; Maloney, Michael D.; DeHaven, Kenneth E.; Giordano, Brian D.

2012-01-01

27

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

28

Tendonitis  

MedlinePLUS

... References: Ackermann PW, Renstrom P. Tendinopathy in sport. Sports Health. May 2012;4(3):193-201. Sharma P, Maffulli N. Tendon injury and tendinopathy: healing and repair. J Bone Joint Surg . 2005;87A:187-202. TENDONITIS Sports Tips are brought to you by the American ...

29

Rotator Cuff Tears  

MedlinePLUS

... cu? tear most o en occurs within the tendon. Rotator Cu? Tears cont. .org Page ( 3 ) AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information ...

30

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

31

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

PubMed

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

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

2015-03-01

32

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

33

Tendon Disorders.  

PubMed

The clinically important tendons around the elbow include the biceps and triceps brachii and the flexor and extensor muscles of the forearm. Familiarity with the normal magnetic resonance (MR) appearance of these structures facilitates the MR diagnosis of tendon abnormalities. Often referred to as epicondylitis, degeneration of the flexor or extensor groups is a common clinical complaint, treated conservatively and usually not requiring MR imaging. Imaging may play a role in unusual or severe cases; elevated signal in the appropriate common tendon origin is typically seen on T2 weighted images. Significant injury or disruption of the distal biceps or triceps tendons is a rare event, usually related to an acute event. Discontinuity of these tendons is best imaged using sagittal and axial T2 weighted sequences. Partial tears may demonstrate tendon irregularity and elevated signal within and around the tendon. PMID:11387099

Sonin, Andrew

1998-01-01

34

Rotator Cuff Tears: Surgical Treatment Options  

MedlinePLUS

... time, sti? ness will improve with more aggressive therapy and exercise. • Tendon re-tear. There is a chance for re-tear following ... of re-tear. Patients who re-tear their tendons usually do not have greater pain or decreased shoulder function. ... .org Page ( 5 ) AAOS does not ...

35

Intratendinous strain fields of the supraspinatus tendon: Effect of a surgically created articular-surface rotator cuff tear  

Microsoft Academic Search

Articular-surface partial-thickness rotator cuff tears play a significant role in shoulder pathology, but the role of the articular-surface tissue is poorly understood. This investigation assessed the effect of an articular-surface partial-thickness rotator cuff tear on intratendinous strain fields. A magnetic resonance imaging–based technique quantified intratendinous strains in healthy cadaveric shoulders at 15°, 30°, 45°, and 60° of glenohumeral abduction. A

Michael J Bey; Matthew L Ramsey; Louis J Soslowsky

2002-01-01

36

Comparison of Three-Dimensional Isotropic and Two-Dimensional Conventional Indirect MR Arthrography for the Diagnosis of Rotator Cuff Tears  

PubMed Central

Objective To compare the accuracy between a three-dimensional (3D) indirect isotropic T1-weighted fast spin-echo (FSE) magnetic resonance (MR) arthrography and a conventional two-dimensional (2D) T1-weighted sequences of indirect MR arthrography for diagnosing rotator cuff tears. Materials and Methods The study was approved by our Institutional Review Board. In total, 205 patients who had undergone indirect shoulder MR arthrography followed by arthroscopic surgery for 206 shoulders were included in this study. Both conventional 2D T1-weighted FSE sequences and 3D isotropic T1-weighted FSE sequence were performed in all patients. Two radiologists evaluated the images for the presence of full- or partial-thickness tears in the supraspinatus-infraspinatus (SSP-ISP) tendons and tears in the subscapularis (SSC) tendons. Using the arthroscopic findings as the reference standard, the diagnostic performances of both methods were analyzed by the area under the receiver operating characteristic curve (AUC). Results Arthroscopy confirmed 165 SSP-ISP tendon tears and 103 SSC tendon tears. For diagnosing SSP-ISP tendon tears, the AUC values were 0.964 and 0.989 for the 2D sequences and 3D T1-weighted FSE sequence, respectively, in reader I and 0.947 and 0.963, respectively, in reader II. The AUC values for diagnosing SSC tendon tears were 0.921 and 0.925, respectively, for reader I and 0.856 and 0.860, respectively, for reader II. There was no significant difference between the AUC values of the 2D and 3D sequences in either reader for either type of tear. Conclusion 3D indirect isotropic MR arthrography with FSE sequence and the conventional 2D arthrography are not significantly different in terms of accuracy for diagnosing rotator cuff tears. PMID:25469089

Lee, Ji Hyun; Jee, Sukkyung; Kwon, Jong Won; Cha, Jang Gyu; Yoo, Jae Chul

2014-01-01

37

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

NASA Astrophysics Data System (ADS)

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

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

1995-05-01

38

Peroneal Tendon Injuries  

MedlinePLUS

... outside ankle bone Ankle instability or weakness Early treatment of a subluxation is critical, since a tendon that continues to sublux (move out of position) is more likely to tear or rupture. Therefore, if you feel the characteristic ...

39

Tendon structure, disease, and imaging  

PubMed Central

Summary Tendon imaging plays a critical role in evaluating tendon diseases and injuries including mechanical, degenerative, and overuse disease, inflammatory enthesitis, as well as partial and full thickness tears. Ultrasound and magnetic resonance imaging (MRI), each with unique benefits and limitations, are commonly utilized to assist in diagnosing these diseases and conditions. This review delineates important structural properties of tendon and biochemical changes occurring in tendon pathology. This review also examines commonly injured tendons including tendons of the elbow, tendons of the rotator cuff of the shoulder, hip abductor tendons, patellar tendons, and the Achilles tendon to help clinicians better recognize tendon disease. Finally, this paper introduces several emerging imaging techniques including T2 mapping, ultra-short echo time MRI, and sonoelastography as ways in which tendon imaging and evaluation may be improved. PMID:24932450

Weinreb, Jeffrey H.; Sheth, Chirag; Apostolakos, John; McCarthy, Mary-Beth; Barden, Benjamin; Cote, Mark P.; Mazzocca, Augustus D.

2014-01-01

40

Proximal Biceps Tendonitis  

MedlinePLUS

... that arm. But sometimes an injury or small tear in the tendon can cause problems right away. Some of the ... do surgery to repair badly injured proximal biceps tendons, it's usually for adults. Kids and teens ... can include the following: Rest your arm. Stop ...

41

The distal biceps tendon.  

PubMed

Distal biceps tendon ruptures continue to be an important injury seen and treated by upper extremity surgeons. Since the mid-1980s, the emphasis has been placed on techniques that limit complications or improve initial tendon-to-bone fixation strength. Recently, basic science research has expanded the knowledge base regarding the biceps tendon structure, footprint anatomy, and biomechanics. Clinical data have further delineated the results of conservative and surgical management of both partial and complete tears in acute or chronic states. The current literature on the distal biceps tendon is described in detail. PMID:23474326

Schmidt, Christopher C; Jarrett, Claudius D; Brown, Brandon T

2013-04-01

42

Comparison of insall-salvati ratios in children with an acute anterior cruciate ligament tear and a matched control population.  

PubMed

OBJECTIVE. An anterior cruciate ligament (ACL) injury is an increasingly recognized cause of knee pain in young patients and in athletes in particular and can be detected non-invasively with MRI. Anecdotal information suggests that patella alta may be more common in the setting of this injury, but no study has documented this phenomenon. This study sought to test whether an ACL tear is associated with an increased Insall-Salvati ratio suggestive of patella alta. MATERIALS AND METHODS. Measurements of patellar height, patellar tendon length, and the Insall-Salvati ratio obtained from MRI of the knee were compared for 34 children with an arthroscopically proven ACL tear (mean age ± SD, 12.4 ± 1.4 years) and 36 control subjects with normal knee examinations (12.8 ± 2.1 years); these measurements were performed independently by two observers. RESULTS. Patellar tendon length (47.6 ± 6.6 mm vs 40.4 ± 5.7 mm) and patellar position calculated as the Insall-Salvati ratio (1.16 ± 0.16 vs 0.99 ± 0.14) were significantly greater in the knees with an ACL injury than in those without an internal injury, respectively, on MRI (p < 0.001). Patella length was not significantly different between the two groups (patients vs control subjects, 41.1 ± 4.2 mm vs 40.6 ± 2.7 mm, respectively; p = 0.523). There was good to excellent interobserver and intraobserver correlation for all measurements. CONCLUSION. There is a significant association between an ACL tear and increased patellar tendon length with a greater Insall-Salvati ratio. The mechanism for this finding is unclear, but this association provides support to suggest relative patella alta may be a risk factor for ACL injuries in pediatric patients. PMID:25539252

Degnan, Andrew Joseph; Maldjian, Catherine; Adam, Richard J; Fu, Freddie H; Didomenico, Marica

2015-01-01

43

Arthroscopic Recognition and Repair of the Torn Subscapularis Tendon  

PubMed Central

Although the subscapularis has historically received less attention than posterosuperior rotator cuff tears, repair of a torn subscapularis tendon is critically important to restoring anatomy and achieving the best functional outcome possible. Arthroscopic repair begins with proper recognition of the tear. A systematic approach can then be used to arthroscopically repair all types of subscapularis tendon tears, from partial tears to full-thickness tears, as well as those which are retracted and have adhesions medially. Subscapularis footprint restoration can be accomplished with a variety of repair techniques that must be matched to the extent of the tear and mobility of the tendon. PMID:24400185

Denard, Patrick J.; Burkhart, Stephen S.

2013-01-01

44

A pathomechanical concept explains muscle loss and fatty muscular changes following surgical tendon release  

Microsoft Academic Search

Following tendon tear, the musculo-tendinous unit retracts permanently, looses muscle fibre volume and is infiltrated with fat. This is currently considered to be an unexplained degenerative process. In a sheep model of chronic tendon tear with delayed tendon repair (35 weeks after tendon release), we studied the nature of these muscle changes in eight experimental animals. At sacrifice (75 weeks

Dominik C. Meyer; Hans Hoppeler; Brigitte von Rechenberg; Christian Gerber

2004-01-01

45

Proximal biceps tendon: injuries and management.  

PubMed

The long head of the biceps tendon is a known pain generator of the shoulder. There are numerous pathologic entities that may affect this tendon, including tendonitis, partial tearing, and subluxation. These conditions are often associated with rotator cuff tears, especially those involving the subscapularis. Operative interventions include tenotomy and tenodesis. Tenodesis can be preformed in a proximal or distal location. Subpectoral tenodesis may have a lower recurrence rate than proximal-based techniques. PMID:18703976

Friedman, Darren J; Dunn, John C; Higgins, Laurence D; Warner, Jon J P

2008-09-01

46

Sprains, Strains, and Tears  

MedlinePLUS

Sprains, Strains and Tears A sprain is an injury to a ligament, while a strain is an injury to a muscle or tendon. Both can result in significant lost time from sports. SPRAINS A sprain is an injury to a ligament, the ...

47

Achilles Tendonitis  

MedlinePLUS

... told Kim she had Achilles tendonitis. What Is Achilles Tendonitis and Who Gets It? Your Achilles tendon is ... very painful. Continue What Are the Symptoms of Achilles Tendonitis? Most cases of Achilles tendonitis start out slowly, ...

48

Partial rupture of the distal biceps tendon.  

PubMed

Partial rupture of the distal biceps tendon is a relatively rare event, and various degrees of partial tendon tears have been reported. In the current study four patients with partial atraumatic distal biceps tendon tears (mean age, 59 years; range, 40-82 years) are reported. In all four patients, a common clinical pattern emerged. Pain at the insertion of the distal biceps tendon in the radius unrelated to any traumatic event was the main symptom. In all patients the diagnosis was based on magnetic resonance imaging or computed tomography imaging. In three of four patients the partial rupture of the tendon caused a significant bursalike lesion. The typical appearance was a partially ruptured biceps tendon, with contrast enhancement signaling the degree of degeneration, tenosynovitis, and soft tissue swelling extending along the tendon semicircular to the proximal radius. In three patients, conservative treatment was successful. Only one patient needed surgery, with reinsertion of the tendon resulting in total functional recovery. PMID:10818980

Dürr, H R; Stäbler, A; Pfahler, M; Matzko, M; Refior, H J

2000-05-01

49

Biomechanical comparison of stimulated and nonstimulated skeletal muscle pulled to failure  

Microsoft Academic Search

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

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

1987-01-01

50

Clinical and biological aspects of rotator cuff tears  

PubMed Central

Summary Rotator cuff tears are common and are a frequent source of shoulder pain and disability. A wide variation in the prevalence of rotator cuff tears has been reported. The etiology of rotator cuff tear remains multifactorial and attempts to unify intrinsic and extrinsic theories tried to explain the etiopathogenesis of rotator cuff tears. Knowledge of the etiopathogenesis of rotator cuff tears is important to improve our therapies, surgical techniques and promote tendon repair. Several strategies have been proposed to enhance tendon healing and recently research has focused on regenerative therapies, such as Growth Factors (GFs) and Plasma Rich Platelet (PRP), with high expectations of success. PMID:23888289

Giai Via, Alessio; De Cupis, Mauro; Spoliti, Marco; Oliva, Francesco

2013-01-01

51

[Tendinopathy of the gluteus medius tendon].  

PubMed

Tendinopathy of the gluteus medius tendon is the main cause of great trochanter pain syndrom. Recent clinical, ultrasonographic and MRI study, allow to distinguish anterior lesions which concern the lateral part of the gluteus medius tendon, almost always associated with tendinopathy of the gluteus minimus tendon, from tendinopathy of the main tendon of the gluteus medius. Tears of the main tendon of the gluteus medius are the serious disabling consequence of that pathology and must be avoid by early medical and functional treatment with very moderate use of intrabursal corticosteroid injections. In few cases without improvement after medical treatment, surgery is indicated and includes bursectomy of the trochanteric bursa and tendinoplasty. PMID:19462863

Bard, Hervé

2009-04-20

52

[Peroneal tendons do exist, don't they?].  

PubMed

Peroneal tendon disorders are a significant but often overlooked cause of posterolateral ankle and lateral foot pain. When left untreated, peroneal tendon disorders can lead to persistent pain and substantial functional problems. The goals of this review are to develop a current understanding of the regional anatomy, as well as diagnostic evaluation and current treatment options of the peroneal tendon disorders, and to present nowadays preferred surgical techniques for operative management of peroneal tendon disorders. More specific details related to peroneal tendon luxation, intrasheath subluxation of peroneal tendons, peroneal trendinopathy, peroneal tendon tears and painful os peroneum syndrome are reported in this review article. PMID:25632772

Bojani?, Ivan; Dimnjakovi?, Damjan; Smoljanovi?, Tomislav

2014-01-01

53

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

54

[Comparison of local acetylcysteine and artificial tears in the management of dry eye syndrome].  

PubMed

Dry eye syndrome is a common clinical entity causing difficulties to many people, especially the elderly. Standard substitution therapy with artificial tears may frequently prove inadequate, thus any new treatment modality is highly welcome. The syndrome implies lacrimal hyperosmolality, which in turn results in mucus accumulation in the conjunctival sac causing additional irritation. Locally applied acetylcysteine, a mucolytic, regulates mucus secretion and reduces mucus accumulation. The aim of the study was to compare the efficacy of artificial tear therapy and therapy with local acetylcysteine. The study included 32 patients with the symptoms and signs of dry eye attending our department between March 20 and May 9, 2003. All study patients were on long-term substitution therapy with artificial tears. Upon evaluation of subjective discomforts and objective signs, the patients were switched from artificial tear therapy (Isopto-Tears, Alcon, with polyvinyl alcohol as active ingredient) to therapy with locally applied acetylcysteine (Brunac, Bruschettini). All parameters were re-evaluated at 2-week control visit. Thirty of 32 patients (94%) completed the study with control visit. Of these, 18 (60%) patients reported reduction of subjective discomforts, ten (33%) patients observed no change, and two (7%) patients experienced more discomforts with acetylcysteine than with artificial tear therapy. On objective sign evaluation, 12 (40%) patients showed less discomforts, unchanged condition was recorded in 13 (43%) patients, and five (17%) patients had more discomforts as compared with artificial tear therapy. A statistically significant difference (p=0.05) between artificial tear therapy and acetylcysteine therapy was found for the subjective symptom score but not for the objective sign score. Therapy with acetylcysteine proved more efficient than artificial tears in reducing subjective symptoms but had no effect on the objective signs of dry eye syndrome. The advantages of acetylcysteine include more convenient instillation timing (4 times daily) and reduced nocturnal discomfort, whereas shortcomings are the sense of burning on instillation, bad odor, and as yet relatively high price on the Croatian market. PMID:16334742

Pokupec, Rajko; Petricek, Igor; Siki?, Jakov; Bradi?, Mirna; Popovi?-Sui?, Smiljka; Petricek, Goranka

2005-01-01

55

Comparison of therapeutic ultrasound and exercises for augmenting tendon healing in rats  

Microsoft Academic Search

We compared therapeutic ultrasound (US) and exercises on Achilles tendon healing in 49 mature male rats. The medial Achilles tendon of the right leg was transected and the rats were divided into five groups: 1. control (n = 9), 2. 1 W\\/cm2 US (n = 9), 3. 2 W\\/cm® US (n = 10), 4. running (n = 11) and 5.

G. Y. F. Ng; C. O. Y. Ng; E. K. N. See

2004-01-01

56

Disorders of the distal biceps brachii tendon.  

PubMed

Pathologic conditions of the distal biceps brachii tendon are of clinical interest, with partial and complete tears being the most common. However, the anatomy of the distal biceps brachii tendon makes imaging of the distal tendon somewhat difficult. An innovation in patient positioning for magnetic resonance (MR) imaging of the distal biceps tendon was recently described in which the patient lies prone with the arm overhead, the elbow flexed to 90 degrees , and the forearm supinated, so that the thumb points superiorly. The acronym FABS (f lexed elbow, abducted shoulder, forearm supinated) has been used to describe this position. The FABS position creates tension in the tendon and minimizes its obliquity and rotation, resulting in a "true" longitudinal view of the tendon. MR imaging and, to a lesser extent, ultrasonography are useful in visualizing the distal tendon and in detecting other pathologic conditions in the cubital fossa. Partial tears are usually characterized by enlargement and abnormal contour of the tendon, along with abnormal intratendinous signal intensity. In complete tears, there is discontinuity and, if the bicipital aponeurosis is also disrupted, retraction. Imaging with FABS positioning can complement conventional MR imaging, especially in the axial plane, in the assessment of the distal biceps tendon. PMID:16160108

Chew, Michael L; Giuffrè, Bruno M

2005-01-01

57

Endoscopic Repair of a Gluteus Medius Tear at the Musculotendinous Junction  

PubMed Central

Abductor tendon tears are an increasingly recognized clinical entity in patients with lateral thigh pain and weakness. These “rotator cuff tears of the hip” typically result from chronic, nontraumatic rupture of the anterior fibers of the gluteus medius. Although the abductor tendon typically tears from the osseous insertion, the case discussed here ruptured at the musculotendinous junction. This is the first report of this abductor tear subtype and its endoscopic repair. PMID:23875152

Yanke, Adam B.; Hart, Michael A.; McCormick, Frank; Nho, Shane J.

2013-01-01

58

Direct comparison of in vivo Achilles tendon moment arms obtained from ultrasound and MR scans.  

PubMed

Accurate and reliable estimation of muscle moment arms is a prerequisite for the development of musculoskeletal models. Numerous techniques are available to estimate the Achilles tendon moment arm in vivo. The purposes of this study were 1) to compare in vivo Achilles tendon moment arms obtained using the center of rotation (COR) and tendon excursion (TE) methods and 2) to assess the reliability of each method. For the COR method, magnetic resonance (MR) images from nine participants were obtained at ankle angles of -15°, 0°, and +15° and analyzed using Reuleaux' method. For the TE method, the movement of the gastrocnemius medialis-Achilles tendon junction was recorded using ultrasonography as the ankle was passively rotated through its range of motion. The Achilles tendon moment arm was obtained by differentiation of tendon displacement with respect to ankle angular excursion using seven different differentiation techniques. Moment arms obtained using the COR method were significantly greater than those obtained using the TE method (P < 0.01), but results from both methods were well correlated. The coefficient of determination between moment arms derived from the COR and TE methods was highest when tendon displacement was linearly differentiated over a ± 10° interval (R(2) = 0.94). The between-measurement coefficient of variation was 3.9% for the COR method and 4.5-9.7% for the TE method, depending on the differentiation technique. The high reliabilities and strong relationship between methods demonstrate that both methods are robust against their limitations. The large absolute between-method differences (? 25-30%) in moment arms have significant implications for their use in musculoskeletal models. PMID:20847130

Fath, Florian; Blazevich, Anthony J; Waugh, Charlie M; Miller, Stuart C; Korff, Thomas

2010-12-01

59

Tendonitis (image)  

MedlinePLUS

... as a result of injury, overuse, or with aging as the tendon loses elasticity. Any action that places prolonged repetitive strain on the forearm muscles can cause tendonitis. The most common symptom of ...

60

A Prospective Randomized Study of Anterior Cruciate Ligament ReconstructionA Comparison of Patellar Tendon and Quadruple-Strand Semitendinosus\\/Gracilis Tendons Fixed With Bioabsorbable Interference Screws  

Microsoft Academic Search

Background: Debate exists regarding the optimal graft for anterior cruciate ligament reconstruction. Few studies have compared the differences in outcome after reconstruction using similar fixation methods.Hypothesis: Similar outcomes will be seen after anterior cruciate ligament reconstruction with bone-patellar tendon-bone or quadruple-strand semitendinosus\\/gracilis tendons fixed with bioabsorbable interference screws.Study Design: Randomized controlled trial; Level of evidence, 1.Methods: Ninety-nine patients were prospectively

Gregory B. Maletis; Sheri L. Cameron; Joann J. Tengan; Raoul J. Burchette

2007-01-01

61

Quantitative Comparison of Grasp Qualities of Two Tendon-driven Hands Using a Novel Methodology  

E-print Network

and torques that can be resisted in 6-dimensional wrench space (i.e., 3 force dimensions and 3 torque dimensions) [4]. Figure 3: Grasp configurations analyzed. (a) Isometric view of 2-finger grasp. (b) Front" that can be resisted by the grasp [4]. Results: The results for each tendon layout and grasp configuration

Valero-Cuevas, Francisco

62

Comparison of TGF-?1 in tears and corneal haze following Epi-LASIK with and without mitomycin C  

PubMed Central

AIM To compare transforming growth factor-?1 (TGF-?1) levels in tears and the degree of corneal haze formation following epithelial laser in situ keratomileusis (Epi-LASIK) with and without the use of mitomycin C (MMC) and to investigate the effect of MMC on corneal wound healing. METHODS Thirty-two patients (64 eyes) with high myopia underwent Epi-LASIK surgery, and MMC was randomly used in one eye in each patient. The epithelialization process was observed, and the TGF-?1 level in tears was measured at 1 day, 3, and 7 days postoperatively for comparison with baseline. Corneal haze was graded at 1 month, 3, and 6 months after surgery. RESULTS Mean preoperative spherical equivalent refraction was -8.24±2.18D (range -6.00 to -10.50D) in the MMC group and -7.82±1.55D (range -6.00 to -9.75D) in the non-MMC group. There was no significant difference between the two groups (P=0.38). Mean epithelialization time was (5.02±0.68) days in the MMC group and (4.86±0.57) days in the non-MMC group (P=0.31). Tear fluid TGF-?1 levels were similar before surgery (P=0.34), but were significantly higher in the non-MMC group at 1 day, 3, and 7 days postoperatively (P=0.004, 0.008, and 0.012, respectively). Corneal haze scores 1 month after surgery were significantly higher in the non-MMC group (P=0.03), and similar at 3 and 6 months after surgery (P=0.28 and 0.62, respectively). CONCLUSION MMC did not delay epithelialization. In early postoperative period, lower TGF-?1 levels in tears and a lower grade of corneal haze were observed in the MMC group. Our findings suggest that the ability of MMC to inhibit Epi-LASIK-induced haze might be mediated through TGF-?1 suppression. PMID:23826524

Chen, Jing; Chen, Yi; Han, Su-Ning

2013-01-01

63

Gluteus medius tears: an under-diagnosed pathology.  

PubMed

Tears of the gluteus medius tendon contribute to greater trochanteric pain syndrome, but they are often overlooked as a cause of lateral hip pain and tenderness. This review presents the relevant anatomy, pathophysiology, diagnostic workup, differential diagnosis and management of these tears. PMID:21240111

El-Husseiny, Moataz; Patel, Shelain; Rayan, Faizal; Haddad, Fares

2011-01-01

64

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

65

Antibacterial activity of rifamycins for M. smegmatis with comparison of oxidation and binding to tear lipocalin.  

PubMed

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

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

2014-04-01

66

Lateral releases of the subscapularis tendon  

PubMed Central

The technique of arthroscopic subscapularis repair continues to evolve. A three-sided subscapularis release (e.g. anterior, posterior, superior) is commonly advocated for improving tendon excursion to bone. However, a lateral release is commonly required as well, particularly for full thickness, upper subscapularis tears and full thickness, complete subscapularis tears. We describe the techniques to identify and release the lateral subscapularis border, which aids in the completion of other releases. PMID:24403761

Lo, Ian K.Y.; Nelson, Atiba A.; Burkhart, Stephen S

2013-01-01

67

Biomechanical comparison of the four-strand cruciate and Strickland techniques in animal tendons  

PubMed Central

OBJECTIVE: The objective of this study was to compare two four-strand techniques: the traditional Strickland and cruciate techniques. METHODS: Thirty-eight Achilles tendons were removed from 19 rabbits and were assigned to two groups based on suture technique (Group 1, Strickland suture; Group 2, cruciate repair). The sutured tendons were subjected to constant progressive distraction using a universal testing machine (Kratos®). Based on data from the instrument, which were synchronized with the visualized gap at the suture site and at the time of suture rupture, the following data were obtained: maximum load to rupture, maximum deformation or gap, time elapsed until failure, and stiffness. RESULTS: In the statistical analysis, the data were parametric and unpaired, and by Kolmogorov-Smirnov test, the sample distribution was normal. By Student's t-test, there was no significant difference in any of the data: the cruciate repair sutures had slightly better mean stiffness, and the Strickland sutures had longer time-elapsed suture ruptures and higher average maximum deformation. CONCLUSIONS: The cruciate and Strickland techniques for flexor tendon sutures have similar mechanical characteristics in vitro. PMID:24473513

Iamaguchi, Raquel Bernardelli; Villani, William; Rezende, Marcelo Rosa; Wei, Teng Hsiang; Cho, Alvaro B; dos Santos, Gustavo Bispo; Mattar, Rames

2013-01-01

68

Sonographic incidence of tendon microtears in athletes with chronic Achilles tendinosis  

Microsoft Academic Search

OBJECTIVE: To assess the number and distribution of tendon microtears in asymptomatic controls and athletes with chronic Achilles tendinitis or partial thickness tears using high resolution ultrasound. METHODS: The mean number of microtears in three random tendon cross sections were recorded per tendon third in 19 asymptomatic volunteers, 16 athletes with symptomatic chronic Achilles tendinitis, and eight athletes with partial

W. W. Gibbon; J. R. Cooper; G. S. Radcliffe

1999-01-01

69

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

70

Meniscus Tears  

MedlinePLUS

... common sports injury, particularly in contact sports like football and hockey. Meniscus tears can range from minor ... knee while playing a contact sport, such as football, hockey, or rugby, where the knee may be ...

71

Identification and Comparison of the Polar Phospholipids in Normal and Dry Eye Rabbit Tears by MALDI-TOF Mass Spectrometry  

PubMed Central

Purpose To identify and compare the phosphorylated lipids in normal and dry eye rabbit tears using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Methods MALDI-TOF MS studies were performed on tear samples from normal and dry eyes of female New Zealand White rabbits. Experimental dry eye was induced by complete removal of the main and accessory lacrimal glands and nictitating membranes. A solid ionic crystal MALDI matrix of paranitroaniline and butyric acid was used to enhance the mass spectral responses of the phospholipids. In addition, a novel lipid isolation, preconcentration, and clean-up method using pipettes containing immobilized metal ion affinity chromatography (IMAC) medium was used. Results The polar phospholipids present in the normal and dry eye rabbit tears showed both similarities and differences. Species related to platelet-activating factor (PAF) and/or lysophosphatidylcholine (lyso-PC), phosphatidylcholine (PC), and sphingomyelin (SM) were found in both the normal and dry eye rabbit tears. However, the number of types and the concentrations of SM molecules were markedly greater in the dry eye tears than in the normal tears. In addition, phosphatidylserine (PS) species that were readily detectable in dry eye tears were not found in normal tears. Conclusions The combination of immobilized metal ion affinity chromatography and the solid ionic crystal matrix for MALDI enabled the detection and study of phosphorylated lipids in the tears. Specific differences between phospholipid levels in normal and dry eye tears were observable with this methodology. The appearance of various SM species only in the dry eye tears may provide markers for this disease state in the future. PMID:16877399

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

2008-01-01

72

Functional postoperative treatment of Achilles tendon repair  

Microsoft Academic Search

Twenty-one patients with surgically repaired Achilles tendon tears that were treated postoperatively with a functional orthosis rather than routine cast immobiliza tion were evaluated. The orthosis allowed unrestricted plantar flexion and limited dorsiflexion to neutral. Toe- touch weightbearing crutch ambulation was allowed immediately and was gradually increased over the 6 to 8 weeks of treatment. Of the 21 patients, 14

Thomas R. Carter; Peter J. Fowler; Cathy Blokker

1992-01-01

73

Simultaneous bilateral biceps tendon rupture: a case report with practical sonographic diagnosis.  

PubMed

Simultaneous bilateral complete tear of the biceps tendons is a rare clinical entity with challenging treatment approaches. Current diagnostic imaging of rupture of the biceps tendon has reverted to magnetic resonance imaging; however, in the recent years, sonography has been widely used in musculoskeletal practice. The authors present a case of simultaneous bilateral biceps tendon rupture diagnosed on the basis of fundamental sonographic findings of the torn biceps tendons. PMID:25122098

Babaei-Ghazani, Arash; Eftekhar-Sadat, Bina; Ghabili, Kamyar

2015-02-01

74

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

75

Do Cells Contribute to Tendon and Ligament Biomechanics?  

PubMed Central

Introduction Acellular scaffolds are increasingly used for the surgical repair of tendon injury and ligament tears. Despite this increased use, very little data exist directly comparing acellular scaffolds and their native counterparts. Such a comparison would help establish the effectiveness of the acellularization procedure of human tissues. Furthermore, such a comparison would help estimate the influence of cells in ligament and tendon stability and give insight into the effects of acellularization on collagen. Material and Methods Eighteen human iliotibial tract samples were obtained from nine body donors. Nine samples were acellularized with sodium dodecyl sulphate (SDS), while nine counterparts from the same donors remained in the native condition. The ends of all samples were plastinated to minimize material slippage. Their water content was adjusted to 69%, using the osmotic stress technique to exclude water content-related alterations of the mechanical properties. Uniaxial tensile testing was performed to obtain the elastic modulus, ultimate stress and maximum strain. The effectiveness of the acellularization procedure was histologically verified by means of a DNA assay. Results The histology samples showed a complete removal of the cells, an extensive, yet incomplete removal of the DNA content and alterations to the extracellular collagen. Tensile properties of the tract samples such as elastic modulus and ultimate stress were unaffected by acellularization with the exception of maximum strain. Discussion The data indicate that cells influence the mechanical properties of ligaments and tendons in vitro to a negligible extent. Moreover, acellularization with SDS alters material properties to a minor extent, indicating that this method provides a biomechanical match in ligament and tendon reconstruction. However, the given protocol insufficiently removes DNA. This may increase the potential for transplant rejection when acellular tract scaffolds are used in soft tissue repair. Further research will help optimize the SDS-protocol for clinical application. PMID:25126746

Hammer, Niels; Huster, Daniel; Fritsch, Sebastian; Hädrich, Carsten; Koch, Holger; Schmidt, Peter; Sichting, Freddy; Wagner, Martin Franz-Xaver; Boldt, Andreas

2014-01-01

76

Comparison of the effects of first and second generation silicone hydrogel contact lens wear on tear film osmolarity  

PubMed Central

AIM To compare the effects of first and second generation silicone hydrogel (SiH) contact lens wear on tear film osmolarity. METHODS The healthy subjects who have never used contact lenses before were enrolled in the study. Tear film osmolarity values of 16 eyes (group 1) who wore first generation SiH contact lenses were compared with those of 18 eyes (group 2) who wore second generation SiH contact lenses after three months follow-up. RESULTS Before contact lens wear, tear film osmolarity of groups 1 and 2 were 305.02±49.08 milliosmole (mOsm) and 284.66±30.18mOsm, respectively. After three months of contact lens wear, osmolarity values were found 317.74±60.23mOsm in group 1 and 298.40±37.77mOsm in group 2. Although osmolarity values for both groups of SiH contact lens wear after three months periods were slightly higher than before the contact lens wear, the difference was not statistically significant. CONCLUSION Contact lens wear may cause evaporation from the tear film and can increase tear film osmolarity leading to symptoms of dry eye disease. In the current study, there is a tendency to increase tear film osmolarity for both groups of SiH contact lens wear, but the difference is not statistically significant. PMID:24195046

Iskeleli, Guzin; Karakoc, Yunus; Ozkok, Ahmet; Arici, Ceyhun; Ozcan, Omer; Ipcioglu, Osman

2013-01-01

77

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

PubMed

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

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

2013-12-01

78

Comma Sign–Directed Repair of Anterosuperior Rotator Cuff Tears  

PubMed Central

The comma sign was described as an arthroscopic landmark to identify the torn subscapularis stump to mobilize and repair the tendon in anterosuperior rotator cuff tears. It was hypothesized that it is composed of the humeral attachments of the superior glenohumeral and coracohumeral ligaments. This arthroscopic finding has since become accepted orthopaedic nomenclature pathognomonic for subscapularis tears and a key component of subscapularis tear classification. We propose an alternative theory of the pathoanatomy of the comma sign in anterosuperior rotator cuff tears and present the technique of comma sign–directed repairs of combined subscapularis and supraspinatus lesions. After appropriate releases, tendon-to-tendon repair of the distal-superior aspect of the comma sign to the upper border of the remnant subscapularis results in anatomic re-creation of the intra-articular portion of the torn subscapularis with concomitant reduction of the anterior leading edge of the supraspinatus and reconstitution of the rotator cable complex. A tension-free, single-anchor subscapularis repair is then performed to secure the tendon to the lesser tuberosity. After subscapularis repair, the supraspinatus that was previously retracted to the glenoid rim takes the appearance of a crescent-type tear that is easily approximated to its anatomic insertion.

Dilisio, Matthew F.; Neyton, Lionel

2014-01-01

79

Imaging the infrapatellar tendon in the elite athlete.  

PubMed

Extensor mechanism injuries constitute a major cause of anterior knee pain in the elite athlete. Sonography and magnetic resonance imaging (MRI) are the imaging methods of choice when assessing the infrapatellar tendon. A comprehensive imaging review of infrapatellar tendon normal anatomy, tendinopathy, and partial/full-thickness tendon tears is provided. The value of imaging the infrapatellar tendon in clinical practice, including whether sonography can predict symptoms in asymptomatic athletes, is discussed. Acute avulsion fractures, including periosteal sleeve avulsion, and chronic avulsion injuries, including Sinding-Larsen-Johansson and Osgood-Schlatter syndromes, are shown. Mimics of infrapatellar tendon pathology, including infrapatellar plica injury, patellar tendon-lateral femoral condyle friction syndrome, and Hoffa's syndrome, are illustrated. PMID:16784942

Peace, K A L; Lee, J C; Healy, J

2006-07-01

80

Surgical treatment of partial biceps tendon ruptures at the elbow.  

PubMed

We present the treatment and results of a consecutive series of 7 patients (mean age, 42.7 years) with partial ruptures of the distal biceps tendon. All injuries occurred as the result of either heavy labor or weightlifting. Diagnosis in all cases was made with magnetic resonance imaging. After failure of conservative therapy, the patients were treated with repair of the distal biceps tendon. Mean follow-up was 30.6 months (range, 25-39 months). Results were uniformly good, with all patients satisfied with the outcome. All patients maintained their preoperative range of motion, with none reporting significant postoperative pain. The only complication was transient neurapraxias of the lateral antebrachial cutaneous nerve in 2 cases. We conclude that patients presenting with chronic pain in the cubital fossa should be evaluated for possible partial biceps tendon tear. If the diagnosis of partial tendon tear is made, surgical repair is a safe and effective method of treatment. PMID:16517368

Dellaero, David T; Mallon, William J

2006-01-01

81

Human dermal allograft for massive rotator cuff tears.  

PubMed

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

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

2014-12-01

82

A Simple Grafting Method to Repair Irreparable Distal Biceps Tendon  

Microsoft Academic Search

Irreparable distal biceps tendon tears typically are treated using a free tendon graft. We asked whether our new method to\\u000a fix the graft—using two suture anchors—yields similar results to our previous bone canal method. We compared the two methods\\u000a for strength, endurance, and clinical findings. There were two groups, the suture anchor group (Group A, seven patients) and\\u000a the bone

Martti Vastamäki; Heidi Vastamäki

2008-01-01

83

Popliteomeniscal Fascicle Tear: Diagnosis and Operative Technique  

PubMed Central

The occurrence and the consistency of the popliteomeniscal fascicle between the popliteus tendon and the lateral meniscus have been the subject of debate. It is difficult to diagnose and treat popliteomeniscal fascicle tears. Furthermore, popliteomeniscal fascicle tears are difficult to identify with arthroscopy. This article describes the diagnostic factors for popliteomeniscal fascicle tears and the safe, effective operative techniques that can be used for their treatment. We suggest that popliteomeniscal fascicle tears are diagnosed when the following 3 conditions are confirmed: (1) existence of mechanical symptoms such as pain, locking, and giving way in the lateral compartment of the knee; (2) identification of hypermobility of the lateral meniscus through arthroscopic probing; and (3) occurrence of an osteochondral lesion in the posterior area of the lateral femoral condyle. In the case of popliteomeniscal fascicle tears, the tear area can be repaired with a suture hook and polydioxanone with an all-inside technique. If the joint space is narrowing because of soft-tissue tightness, it can be repaired with a zone-specific cannula through an inside-out technique. PMID:23766962

Shin, Hong-Kwan; Lee, Hee-Sung; Lee, Young-Kuk; Bae, Ki-Cheor; Cho, Chul-Hyun; Lee, Kyung-Jae

2012-01-01

84

Pectoralis major tears: anatomy, classification, and diagnosis with ultrasound and MR imaging.  

PubMed

Accurate characterization of pectoralis major tears is important to guide management. Imaging evaluation with ultrasound and MR imaging can be difficult given the complex regional anatomy. In addition, recent literature has redefined the anatomy of the distal pectoralis major. The purpose of this study is to review pectoralis major injuries taking into account new anatomic descriptions using ultrasound and MR imaging, including cadaveric dissection, surgically produced pectoralis tears, and clinical pectoralis tendon tear with surgical correlation. PMID:25200915

Chiavaras, Mary M; Jacobson, Jon A; Smith, Jay; Dahm, Diane L

2015-02-01

85

Influence of nanofibers on growth and gene expression of human tendon derived fibroblast  

Microsoft Academic Search

BACKGROUND: Rotator cuff tears are a common and frequent lesion especially in older patients. The mechanisms of tendon repair are not fully understood. Common therapy options for tendon repair include mini-open or arthroscopic surgery. The use of growth factors in experimental studies is mentioned in the literature. Nanofiber scaffolds, which provide several criteria for the healing process, might be a

Christina Theisen; Susanne Fuchs-Winkelmann; Karola Knappstein; Turgay Efe; Jan Schmitt; Juergen RJ Paletta; Markus D Schofer

2010-01-01

86

Artificial tears potpourri: a literature review  

PubMed Central

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

87

Percutaneous Achilles Tendon Lengthening  

MedlinePLUS

... percutaneous Achilles tendon lengthening, specific complications are rare. Wound problems such as nonhealing incisions or infection can occur. The Achilles tendon can remain tight after surgery. The Achilles tendon can also completely rupture during ...

88

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

89

Open subpectoral biceps tenodesis: reliable treatment for all biceps tendon pathology.  

PubMed

Long head of the biceps (LHB) tendon pathology is a common cause of pain in the shoulder. Pathology encountered includes biceps tendon tears and tendonitis, biceps anchor or superior labral tears, and biceps subluxation or instability. Current surgical treatment options for LHB disorders include tenotomy and tenodesis. Tenodesis prevents cosmetic deformity and biceps cramping with activity. Open subpectoral tenodesis anatomically restores the length-tension relationship of the biceps muscle and removes all diseased biceps from the bicipital groove. The authors present their technique of open subpectoral tenodesis, which demonstrates a high success rate with consistent pain relief and dependable fixation. [Orthopedics. 2015; 38(1):37-41.]. PMID:25611408

Kane, Patrick; Hsaio, Philip; Tucker, Bradford; Freedman, Kevin B

2015-01-01

90

Ultrasound demonstration of distal biceps tendon bifurcation: normal and abnormal findings.  

PubMed

We demonstrate the US appearance of the distal biceps tendon bifurcation in normal cadavers and volunteers and in those affected by various disease processes. Three cadaveric specimens, 30 normal volunteers, and 75 patients were evaluated by means of US. Correlative MR imaging was obtained in normal volunteers and patients. In all cases US demonstrated the distal biceps tendon shaped by two separate tendons belonging to the short and long head of the biceps brachii muscle. Four patients had a complete rupture of the distal insertion of the biceps with retraction of the muscle belly. Four patients had partial tear of the distal biceps tendon with different US appearance. In two patients the partial tear involved the short head of the biceps brachii tendon, while in the other two patients, the long head was involved. Correlative MR imaging is also presented both in normal volunteers and patients. US changed the therapeutic management in the patients with partial tears involving the LH of the biceps. This is the first report in which ultrasound considers the distal biceps tendon bifurcation in detail. Isolated tears of one of these components can be identified by US. Knowledge of the distal biceps tendon bifurcation ultrasonographic anatomy and pathology has important diagnostic and therapeutic implications. PMID:19657654

Tagliafico, Alberto; Michaud, Johan; Capaccio, Enrico; Derchi, Lorenzo E; Martinoli, Carlo

2010-01-01

91

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

PubMed Central

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

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

2013-01-01

92

Effect of Repetition Rate on the Formation of Microtears in Tendon in an In Vivo Cyclical Loading Model  

PubMed Central

We reported previously the formation of microtears in an in vivo loaded Flexor Digitorum Profundus (FDP) rabbit tendon with a repetition rate of 60 repetitions per minute and a peak force of 15% of maximum peak tetanic force for 80 cumulative hours. Tear area as a percent of tendon area, tear density (tears/mm2), and mean tear size (?m2) were higher in tendons from the loaded limb compared to the unloaded control limb. The purpose of the present study was to compare those results to results obtained with a repetition rate of 10 while maintaining the same peak force and force-time integral (n = 8). Due to a strain gradient between the inner and outer sides of the FDP tendon, microtears were quantified in four regions, two regions each along the inner and outer sides of the tendon. The tear area as a percent of total tendon area and the mean tear size were significantly greater in the loaded limb compared to the unloaded limb (p <0.03). However, the effects were less than those observed at 60 repetitions/min. The higher repetition loading pattern resulted in an increase in tear measures in all four regions, while the lower rate produced changes only in the outer regions of the tendon. This finding may establish where the initial sites of damage occur in tendons that insert into bone in a similar arrangement as the FDP. The results suggest that repetition rate or number of loading cycles is associated with increased tendon microtears or fragility in a dose-response pattern. PMID:17516500

Nakama, Leena H.; King, Karen B.; Abrahamsson, Sven; Rempel, David M.

2009-01-01

93

A comparison of patellar tendon autograft and allograft used for anterior cruciate ligament reconstruction in the goat model  

Microsoft Academic Search

Similar-sized patellar tendon autografts and fresh-fro zen allografts were used to reconstruct the anterior cruciate ligament of one knee in 40 female goats. Evaluations of the reconstructions and contralateral controls at the 6-week and 6-month postoperative pe riods included anterior-posterior translation, mechanical properties determined during tensile failure tests, meas urement of cross-sectional area, histology, collagen fibril size and area distribution,

Douglas W. Jackson; Edward S. Grood; Jack D. Goldstein; Mark A. Rosen; Peter R. Kurzweil; John F. Cummings; Timothy M. Simon

1993-01-01

94

Subcoracoid impingement and subscapularis tendon: is there any truth?  

PubMed Central

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

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

2013-01-01

95

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

96

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

Microsoft Academic Search

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

YOKO KASHIDA; MICHIYUKI KATO

1997-01-01

97

Distal biceps tendon injuries--current treatment options.  

PubMed

Three percent of all biceps tendon ruptures occur at the distal aspect, where the tendon inserts into the radial tuberosity. Distal bicep tendon ruptures typically occur in middle-aged males after an eccentric extension load is applied to the elbow. Patients usually complain of a sudden, sharp, and painful tearing sensation in the antecubital region, with a palpable defect. The biceps squeeze and hook tests are specific maneuvers by which to diagnose distal biceps ruptures on physical examination. Magnetic resonance imaging (MRI) or ultrasound maybe be helpful to distinguish between partial and complete tears. Anatomic studies suggest there are two distinct insertions for the short and long heads of the distal biceps. The short head may be a more powerful flexor, and the long head may be a more powerful supinator. Nonoperative treatment typically results in loss of flexion and supination strength and endurance. Early anatomic re-attachment is the goal. Surgical approaches include one- or two-incision techniques, and tendon fixation methods include the use of suture anchors, bone tunnels, an endobutton, or biotenodesis screws. Biomechanical studies have shown that endobuttons have higher load-to-failure strengths, compared to the other fixation methods. However, clinical studies have demonstrated that patients do well regardless of surgical approach or fixation method. Possible complications include nerve injuries, heterotopic ossification, postoperative fracture, tendon rerupture, complex regional pain syndrome, and wound infection. Partial ruptures are significantly less common and initially can be treated conservatively. Chronic tears are more difficult to treat because of possible tendon retraction and poor tissue quality. Tendon grafts using semitendinosus, fascia lata, hamstring, Achilles (calcaneal), or flexor carpi radialis have been successfully used for length restoration in these cases. PMID:20632985

Quach, Tony; Jazayeri, Reza; Sherman, Orrin H; Rosen, Jeffrey E

2010-01-01

98

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

99

Decellularized Tendon Extracellular Matrix—A Valuable Approach for Tendon Reconstruction?  

PubMed Central

Tendon healing is generally a time-consuming process and often leads to a functionally altered reparative tissue. Using degradable scaffolds for tendon reconstruction still remains a compromise in view of the required high mechanical strength of tendons. Regenerative approaches based on natural decellularized allo- or xenogenic tendon extracellular matrix (ECM) have recently started to attract interest. This ECM combines the advantages of its intrinsic mechanical competence with that of providing tenogenic stimuli for immigrating cells mediated, for example, by the growth factors and other mediators entrapped within the natural ECM. A major restriction for their therapeutic application is the mainly cell-associated immunogenicity of xenogenic or allogenic tissues and, in the case of allogenic tissues, also the risk of disease transmission. A survey of approaches for tendon reconstruction using cell-free tendon ECM is presented here, whereby the problems associated with the decellularization procedures, the success of various recellularization strategies, and the applicable cell types will be thoroughly discussed. Encouraging in vivo results using cell-free ECM, as, for instance, in rabbit models, have already been reported. However, in comparison to native tendon, cells remain mostly inhomogeneously distributed in the reseeded ECM and do not align. Hence, future work should focus on the optimization of tendon ECM decellularization and recolonization strategies to restore tendon functionality. PMID:24710540

Schulze-Tanzil, Gundula; Al-Sadi, Onays; Ertel, Wolfgang; Lohan, Anke

2012-01-01

100

Diseases of the tendons and tendon sheaths.  

PubMed

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

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

2014-03-01

101

Posterosuperior rotator cuff tears: classification, pattern recognition, and treatment.  

PubMed

The posterosuperior rotator cuff, composed of the supraspinatus and infraspinatus tendons, is the most common site for full-thickness rotator cuff tears and represents a significant source of shoulder disability worldwide. Recognition of and classification of full-thickness tear patterns are essential in order to optimize surgical treatment and to improve prognosis. Until recently, tear patterns have been described using one- or two-dimensional classification systems. Three-dimensional pattern recognition is critical to achieving the most successful outcome possible. For more complex patterns, a combination of side-to-side stitching, margin convergence, and interval slide techniques may be needed to achieve a tension-free tendon-bone repair. Biomechanical and anatomic evidence supports the use of linked double-row repairs for most full-thickness tears. Although double-row repairs seem to result in improved structural outcomes, clinical evidence has not shown differences in outcomes scores between single-row and double-row repairs. Single-row repair may be performed in partial-thickness, small full-thickness, or very massive, immobile tears, whereas double-row repair may be performed in most other cases. PMID:25063750

Millett, Peter J; Warth, Ryan J

2014-08-01

102

Achilles tendon: US examination  

SciTech Connect

Real-time ultrasonography (US) using linear-array probes and a stand-off pad as a ''waterpath'' was performed to evaluate the Achilles tendon in 67 patients (including 24 athletes) believed to have acute or chronic traumatic or inflammatory pathologic conditions. Tendons in 23 patients appeared normal on US scans. The 44 abnormal tendons comprised five complete and four partial ruptures, seven instances of postoperative change, and 28 cases of tendonitis. US depiction of the inner structure of the tendon resulted in the diagnosis of focal abnormalities, including partial ruptures, nodules, and calcifications. Tendonitis was characterized by enlargement and decreased echogenicity of the tendon. The normal US appearance of the Achilles tendon is described.

Fornage, B.D.

1986-06-01

103

Achilles tendon rupture - aftercare  

MedlinePLUS

The Achilles tendon connects your calf muscles to your heel bone. Together, they help you push your heel off the ... your toes. You use these muscles and your Achilles tendon when you walk, run, and jump. If your ...

104

Partial-thickness articular surface supraspinatus tears: a new transtendon suture technique.  

PubMed

The standard technique for repairing partial-thickness tears of the supraspinatus tendon includes completion of the lesion to a full-thickness tear. Partial articular-side supraspinatus tendon avulsions (PASTA) form a subgroup deserving special consideration. We present a transtendon suture technique that is able to preserve the intact tendon fibers and to achieve firm attachment of the tendon to the humeral footprint using 1 double-loaded bone anchor. The surgical technique is described in detail, and pitfalls and complications are noted. The clinical results of the first 22 consecutive patients are reported, showing an increase in the UCLA score from 17.1 to 31.2 points and a patient satisfaction rate of 91%. PMID:15756195

Waibl, Bernhard; Buess, Eduard

2005-03-01

105

Tenotomy versus Tenodesis in the treatment of the long head of biceps brachii tendon lesions  

PubMed Central

Background The superiority of tenotomy vs. tenodesis for surgery on lesions of the long head of the biceps brachii tendon is still under debate. Indeed, high-quality evidence is lacking, mainly because of methodological problems, such as retrospective design, population sample size or lack of patient randomization. Methods/Design The study will be a two-center, double-blind, randomized, controlled trial to compare patients treated with biceps tenotomy or tenodesis for lesions of the long head of the biceps brachii tendon over a 2-year follow-up period. The study participants will be 128 adults with biceps brachii tendinopathy and supraspinatus tendon tears. The primary end point will be the postoperative difference in the Constant-Murley score (CMS) between the 2 groups at the two-year follow-up. A comparison of the mean improvement with standard age- and gender-related CMS will be performed. The secondary end point will be evaluation of the postoperative general health of patients, as evaluated with Short Form 36 (SF-36) scores. The number and severity of complications associated with use of the different surgical techniques will be assessed. Discussion This study will be the first randomized and appropriately powered clinical trial to directly compare tenotomy and biceps tenodesis. The results of this study will help to establish clinical practice guidelines for patients suffering from lesions of the long head of the biceps brachii tendon, providing important information to patients and health care providers about the possible complications, outcome predictors and effectiveness of the targeted interventions. Trial Registration Current Controlled Trials ISRCTN38839558 PMID:23088416

2012-01-01

106

A comparison of accuracy between clinical examination and magnetic resonance imaging in the diagnosis of meniscal and anterior cruciate ligament tears  

Microsoft Academic Search

A prospective and retrospective study was undertaken to compare the accuracy of magnetic resonance imaging (MRI) with clinical examination in diagnosing meniscal and anterior cruciate ligament (ACL) tears. Pathological findings were then confirmed during arthroscopy. One hundred fifty-four patients clinically diagnosed with a meniscal or ACL tear who ultimately had arthroscopic knee surgery were evaluated; 100 patients underwent clinical examination

Nicholas E. Rose; Stuart M. Gold

1996-01-01

107

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

PubMed Central

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

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

2014-01-01

108

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

109

Biomechanical comparison of hamstring tendon fixation devices for anterior cruciate ligament reconstruction: part 1. Five femoral devices.  

PubMed

We conducted a study to biomechanically compare 5 femoral hamstring tendon fixation devices commonly used in anterior cruciate ligament reconstruction. Quadrupled human semitendinosus-gracilis tendon grafts were fixed into porcine femurs using 5 separate fixation devices. For each device, 10 specimens were tested (1500-cycle loading test at 50-200 N). Specimens surviving the cyclic loading then underwent a single load-to-failure (LTF) test. Failure mode, stiffness, ultimate load, and rigidity were recorded. Two of 10 Delta screw (Arthrex), 10 of 10 Bio-TransFix (Arthrex), 10 of 10 Bone Mulch screw (Arthrotek), 10 of 10 EZLoc (Arthrotek), and 10 of 10 Zip Loop (Arthrotek) devices completed the 1500-cycle loading test. Residual displacement was lowest for Bio-TransFix (4.1 mm) followed by Bone Mulch (5.2 mm), EZLoc (6.4 mm), Zip Loop (6.8 mm), and Delta (8.2 mm). Mean stiffness was significantly (P < .001) higher for Bone Mulch (218 N/mm) than for Bio-TransFix (171 N/mm), EZLoc (122 N/mm), Zip Loop (105 N/mm), or Delta (84 N/mm). Mean LTF was significantly ( P < .001) higher for Bone Mulch (867 N) than for Zip Loop (615 N), Bio-TransFix (552 N), EZLoc (476 N), or Delta (410 N). The Bone Mulch screw demonstrated superior strength in the fixation of hamstring grafts in the femur. Bio-TransFix was close behind. The Delta screw demonstrated poor displacement, stiffness, and LTF. When used as the sole femoral fixation device, a device with low LTF, decreased stiffness, and high residual displacement should be used cautiously in patients undergoing aggressive rehabilitation. PMID:25566554

Scannell, Brian P; Loeffler, Bryan J; Hoenig, Michael; Peindl, Richard D; D'Alessandro, Donald F; Connor, Patrick M; Fleischli, James E

2015-01-01

110

Degenerative disease in rotator cuff tears: what are the biochemical and histological changes?  

PubMed Central

The histopathological changes associated with rotator cuff tears include thinning and disorganization of collagen fibers, the presence of granulation tissue, increased levels of glycosaminoglycans, fibrocartilaginous metaplasia, calcification, fatty infiltration, and necrosis of the tendon margin with cell apoptosis. The biochemical changes include an increase in the expression of matrix metalloproteinases (MMPs) and a decrease in tissue inhibitor of metalloproteinases (TIMP) messenger ribonucleic acid expression. Histological evidence of tendinopathy has been found in patients with rotator cuff tear. Biochemical changes include significant increases in MMP1, MMP2, MMP3, and in TIMP1 and TIMP2 levels, not only at the lateral supraspinatus edge, but also in the macroscopically intact portion of the supraspinatus tendon and in the intact subscapularis. The tissue in the ruptured area of the supraspinatus tendon undergoes marked rearrangement at molecular levels. This involves the activity of MMP1, 2, and 3 and supports a critical role of MMPs in tendon physiology. Intact parts of the torn supraspinatus tendon can present the histopathological changes associated with rotator cuff tears. These findings suggest that biochemical changes can already occur in a macroscopically intact tendon and seem to point to a global degenerative process in the shoulder. PMID:25606538

DE GIORGI, SILVANA; SARACINO, MICHELE; CASTAGNA, ALESSANDRO

2014-01-01

111

Spontaneous rupture of the gluteus medius and minimus tendons.  

PubMed

Tears and tendinopathy of the gluteus medius and minimus are potentially underrecognized clinical sources of hip pain. Magnetic resonance imaging is useful in diagnosing gluteal tears. This entity is frequently a result of predisposing conditions but may arise spontaneously. This clinical problem should be considered in the differential diagnosis of patients presenting with acute hip pain. In this article, we report a case of spontaneous rupture of the gluteus medius and minimus tendons in a previously healthy patient with no prior hip symptoms. PMID:12405564

Lonner, Jess H; Van Kleunen, Jonathan P

2002-10-01

112

Meniscus tears - aftercare  

MedlinePLUS

... of tears, or if you are younger in age, you may need knee arthroscopy (surgery) to repair the meniscus. In this type of surgery, small cuts are made to the knee. A small camera and small surgical tools are inserted to repair the tear.

113

Acromio-clavicular joint cyst associated with a complete rotator cuff tear - a case report.  

PubMed

This case report describes a patient with an acromio-clavicular joint (ACJ) cyst, associated with a complete tear of the supraspinatus tendon, and the related arthropathy. Ultrasound was a suitable imaging modality to make the diagnosis, and rule out other pathologies. Full assessment of the rotator cuff must be carried out in the presence of ACJ cysts due to their common co-existence with large cuff tears. Cyst aspiration is not a suitable treatment, due to the high likelihood of recurrence. Optimal treatment requires management of the underlying rotator cuff tear. PMID:24331701

McCreesh, Karen M; Riley, Sara J; Crotty, James M

2014-10-01

114

Antimicrobial Compounds in Tears  

PubMed Central

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.

2013-01-01

115

Biomimetic scaffold design for functional and integrative tendon repair.  

PubMed

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 underscores the clinical need for alternative grafting solutions. The 2 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 discussion of future directions. PMID:22244070

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

2012-02-01

116

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

117

Glenoid Cartilage Mechanical Properties Decrease after Rotator Cuff Tears in a Rat Model  

PubMed Central

Summary Rotator cuff repairs are commonly performed to reduce pain and restore function. Tears are also treated successfully without surgical intervention; however, the effect that a torn tendon has on the glenohumeral cartilage remains unknown. Clinically, a correlation between massive rotator cuff tears and glenohumeral arthritis has often been observed. This may be due to a disruption in the balance of forces at the shoulder, resulting in migration of the humeral head and subsequently, abnormal loading of the glenoid. Our lab previously demonstrated changes in ambulation and intact tendon mechanical properties following supraspinatus and infraspinatus rotator cuff tendon tears in a rat model. Therefore, the purpose of this study was to investigate the effects of supraspinatus and infraspinatus rotator cuff tears on the glenoid cartilage. Nine rats underwent unilateral detachment of the supraspinatus and infraspinatus tendons and were sacrificed after four weeks. Cartilage thickness significantly decreased in the antero-inferior region of injured shoulders. In addition, equilibrium elastic modulus significantly decreased in the center, antero-superior, antero-inferior, and superior regions. These results suggest that altered loading after rotator cuff injury may lead to damage to the joint with significant pain and dysfunction. Clinically, understanding the mechanical processes involved with joint damage will allow physicians to better advise patients. PMID:22407524

Reuther, Katherine E.; Sarver, Joseph J.; Schultz, Susan M.; Lee, Chang Soo; Sehgal, Chandra M.; Glaser, David L.; Soslowsky, Louis J.

2012-01-01

118

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

2014-01-01

119

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

120

Etiology and pathophysiology of tendon ruptures in sports.  

PubMed

Of all spontaneous tendon ruptures, complete Achilles tendon tears are most closely associated with sports activities (1-3). Schönbauer (3) reported that 75% of all ruptures of the Achilles tendon are related to sports. In Plecko & Passl (2) the number was 60%. In our material of 430 cases, the number of sports-related Achilles ruptures was very similar (62%), while only 2% of ruptures of other tendons were sports-related (P < 0.001) (1). Also, the majority of Achilles reruptures occurred in sports. The ruptures occurred most often in soccer (34%), track and field (16%) and basketball (14%). The distribution of Achilles ruptures according to different sports varies considerably from country to country, according to the national sport traditions. For example, in northern and middle Europe, soccer, tennis, track and field, indoor ball games, downhill skiing, and gymnastics are the most common; and in North America, football, basketball, baseball, tennis and downhill skiing dominate the statistics (1, 2, 4). In sports, some Achilles ruptures are not spontaneous or degeneration-induced but may occur as a consequence of the remarkably high forces that are involved in the performance (2). Ruptures in the high jump or triple jump are good examples. In such cases, failure in the neuromuscular protective mechanisms due to fatigue or disturbed co-ordination can frequently be found. The spontaneous complete rupture of the supraspinatus tendon of the rotator cuff does not occur very frequently in sports. Those sports that include high-energy throwing movements, such as American and Finnish baseball, American football, rugby and discuss and javelin throwing, may, however, produce this injury. Partial tears and inflammations of the rotator cuff complex are much more frequent in throwing sports. The complete rupture of the proximal long head of the biceps brachii tendon is rare among competitive and recreational athletes. In our material, under 2% of these ruptures were associated with sports activities (5). The rupture (avulsion) of the distal tendon of the biceps muscle is rare. In sports, gymnastics, body building and weight lifting have been said to be able to produce this injury (6). In general, complete ruptures of the quadriceps tendon and the patellar tendon occur most often in older individuals. In our study, the mean age of these patients was 65 years (5). However, these injuries do also occur in younger age groups, especially in athletes. In athletes, the rupture most frequently occurs in high-power sports events, such as high jump, basketball and weight lifting, at the age of 15-30 years. A chronic-patellar apicitis (jumper's knee) may predispose rupture of the tendon (7). As is the case with the rotator cuff complex, overuse inflammation and partial tears of the quadriceps and patellar tendons are one of the most characteristic athletic injuries. Complete spontaneous ruptures of other tendons in sports are rare, although the literature does provide case studies from almost every tendon the human body possesses (8-18). PMID:9211611

Kannus, P; Natri, A

1997-04-01

121

Mechanical properties of the human achilles tendon  

Microsoft Academic Search

Objective. To determine whether the human Achilles tendon has higher material properties than other tendons and to test for strain rate sensitivity of the tendon.Design. Mechanical testing of excised tendons.Background. While the human Achilles tendon appears to experience higher in vivo stresses than other tendons, it is not known how the Achilles tendon's material properties compare with the properties of

Tishya A. L Wren; Scott A Yerby; Gary S Beaupré; Dennis R Carter

2001-01-01

122

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

123

Tendon injuries of the hand  

PubMed Central

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

Schöffl, Volker; Heid, Andreas; Küpper, Thomas

2012-01-01

124

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

PubMed Central

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

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

2008-01-01

125

Comparison of a multifilament stainless steel suture with FiberWire for flexor tendon repairs--an in vitro biomechanical study.  

PubMed

Our goal was to investigate and compare the mechanical properties of multifilament stainless steel suture (MFSS) and polyethylene multi-filament core FiberWire in flexor tendon repairs. Flexor digitorum profundus tendons were repaired in human cadaver hands with either a 4-strand cruciate cross-lock repair or 6-strand modified Savage repair using 4-0 and 3-0 multifilament stainless steel or FiberWire. The multifilament stainless steel repairs were as strong as those performed with FiberWire in terms of ultimate load and load at 2 mm gap. This study suggests that MFSS provides as strong a repair as FiberWire. The mode of failure of the MFSS occurred by the suture pulling through the tendon, which suggests an advantage in terms of suture strength. PMID:22745156

McDonald, E; Gordon, J A; Buckley, J M; Gordon, L

2013-05-01

126

Measurement of stress strain and vibrational properties of tendons  

NASA Astrophysics Data System (ADS)

The authors present a new non-intrusive experimental procedure based on laser techniques for the measurement of mechanical properties of tendons. The procedure is based on the measurement of the first resonance frequency of the tendon by laser Doppler vibrometry during in vitro tensile experiments, with the final aim of establishing a measurement procedure to perform the mechanical characterization of tendons by extracting parameters such as the resonance frequency, also achievable during in vivo investigation. The experimental procedure is reported, taking into account the need to simulate the physiological conditions of the Achilles tendon, and the measurement technique used for the non-invasive determination of tendon cross-sectional area during tensile vibration tests at different load levels is described. The test procedure is based on a tensile machine, which measures longitudinal tendons undergoing controlled load conditions. Cross-sectional area is measured using a new non-contact procedure for the measurement of tendon perimeter (repeatability of 99% and accuracy of 2%). For each loading condition, vibration resonance frequency and damping, cross-sectional area and tensile force are measured, allowing thus a mechanical characterization of the tendon. Tendon stress-strain curves are reported. Stress-strain curves have been correlated to the first vibration resonance frequency and damping of the tendon measured using a single-point laser Doppler vibrometer. Moreover, experimental results have been compared with a theoretical model of a vibrating cord showing discrepancies. In vitro tests are reported, demonstrating the validity of the method for the comparison of different aged rabbit tendons.

Revel, Gian Marco; Scalise, Alessandro; Scalise, Lorenzo

2003-08-01

127

Isolated subscapularis repair for massive rotator cuff tear.  

PubMed

The best surgical treatment for an irreparable rotator cuff tear is controversial. In such cases, partial rotator cuff repair, primarily involving the posterior cuff in most reports, has been shown to be beneficial. The authors retrospectively investigated 41 patients who underwent arthroscopic subscapularis-only repair and greater tuberoplasty between April 2003 and August 2009 for massive 3-tendon cuff tears with irreparable supraspinatus and infraspinatus tendons after 3 months of conservative management was unsuccessful. Twenty-five patients (61%) underwent biceps tenotomy, and the remaining 39% had preexisting biceps tenotomy or rupture. The patients were assessed with American Shoulder and Elbow Surgeons (ASES) and Single Assessment Numeric Evaluation (SANE) scores. Of the 41 patients, 34 (83%) were available for a follow-up telephone questionnaire after a minimum of 12 months (mean, 35 months; range, 12-84 months). Mean ASES and SANE scores were 76% and 63%, respectively. Mean postoperative passive range of motion was 156° of forward flexion and 39° of external rotation. Of the patients queried, 74% (25 of 34) were able to actively raise their arms above shoulder level. For those with a positive belly-press test result preoperatively, 22 of 27 patients had a negative test result postoperatively. A total of 3 complications (7.3%) occurred. Workers' compensation claim was a strong predictor of lower shoulder scores. Arthroscopic subscapularis-only repair and greater tuberoplasty may offer a promising and safe method for treating massive rotator cuff tears when the supra-spinatus and infraspinatus tendons are irreparable. Workers' compensation claim may predict lower outcome scores. PMID:25361371

Austin, Luke; Chang, Edward S; Zmistowski, Benjamin; Nydick, Jason; Lazarus, Mark

2014-11-01

128

Minimally invasive surgery for Achilles tendon pathologies  

PubMed Central

Minimally invasive trauma and orthopedic surgery is increasingly common, though technically demanding. Its use for pathologies of the Achilles tendon (AT) hold the promise to allow faster recovery times, shorter hospital stays, and improved functional outcomes when compared to traditional open procedures, which can lead to difficulty with wound healing because of the tenuous blood supply and increased chance of wound breakdown and infection. We present the recent advances in the field of minimally invasive AT surgery for tendinopathy, acute ruptures, chronic tears, and chronic avulsions of the AT. In our hands, minimally invasive surgery has provided similar results to those obtained with open surgery, with decreased perioperative morbidity, decreased duration of hospital stay, and reduced costs. So far, the studies on minimally invasive orthopedic techniques are of moderate scientific quality with short follow-up periods. Multicenter studies with longer follow-up are needed to justify the long-term advantages of these techniques over traditional ones. PMID:24198547

Maffulli, Nicola; Longo, Umile Giuseppe; Spiezia, Filippo; Denaro, Vincenzo

2010-01-01

129

Rehabilitating Psoas Tendonitis: A Case Report  

PubMed Central

This case report describes the examination and physical therapy intervention for a woman with anterior hip pain whose medical diagnosis following magnetic resonance imaging (MRI) was bilateral labral tears and psoas tendinitis. Her physical therapy evaluation revealed findings consistent with psoas tendonitis. Utilizing theories of neuromuscular patterning and knowledge of normal muscle function, the patient was successfully treated in physical therapy following six physical therapy sessions, once a week for 6 weeks. The patient was found to have an overactive psoas muscle, as indicated by hip flexion being the primary mover in her movement patterns, and dysfunctional abdominal and pelvic floor muscles. Functionally based therapeutic exercise and electrical stimulation were used to reeducate the muscles of the abdomen, pelvic floor, and hips in order to create muscular balance and correct muscle dysfunction. PMID:19048347

2008-01-01

130

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

131

Endoscopic Repair of Full-Thickness Gluteus Medius Tears  

PubMed Central

Tears in the gluteus medius and minimus tendons recently have emerged as an important cause of chronic greater trochanteric pain syndrome. Increasing recognition of the gluteal insertion as a cause of chronic pain and weakness, as well as technologic advances in endoscopic hip surgery, has made gluteal insertional repair a rapidly emerging technique in minimally invasive surgery of the hip. We present an endoscopic double-row technique for gluteal insertional repair that allows for visualization, debridement, and repair, re-creating the normal footprint. PMID:23875154

Domb, Benjamin G.; Carreira, Dominic S.

2013-01-01

132

Tendon Driven Finger Actuation System  

NASA Technical Reports Server (NTRS)

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

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

2013-01-01

133

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

134

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. PMID:25404778

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

2014-01-01

135

Biomechanical comparison between BioScrew and titanium alloy interference screws for bone—patellar tendon—bone graft fixation in anterior cruciate ligament reconstruction  

Microsoft Academic Search

This investigation compared the maximum load at failure of BioScrew (Linvatec Corp, Largo, FL) and titanium alloy interference screw femoral fixation using a human cadaveric model that approximated the anatomical orientation and physiological strain rate of in vivo bone—patellar tendon—bone (BPTB) graft loading following anterior cruciate ligament reconstruction. Eighteen fresh-frozen human BPTB allografts (10-mm wide, 10-mm thick, 25-mm long bone

David N. M. Caborn; William P. Urban; Darren L. Johnson; John Nyland; David Pienkowski

1997-01-01

136

Comparison of the effect of intra-tendon applications of recombinant human platelet-derived growth factor-BB, platelet-rich plasma, steroids in a rat achilles tendon collagenase model.  

PubMed

This study compared the effect of intra-tendon (IT) delivery of recombinant human platelet-derived growth factor-BB (rhPDGF-BB), platelet-rich plasma (PRP) and corticosteroids in a rat tendinopathy model. Seven days after collagenase induction of tendinopathy, a 30-µl IT injection was administered. Treatments included: saline; 3 µg rhPDGF-BB; 10 µg rhPDGF-BB; PRP; and 300 µg triamcinolone acetonide (TCA). Outcomes were assessed 7 and 21 days after treatment. All groups exhibited good to excellent repair. Relative to saline, cell proliferation increased 65% in the 10 µg rhPDGF-BB group and decreased 74% in the TCA group; inflammation decreased 65% in the TCA group. At 7 days, maximum load-to-failure was increased in the 3 µg rhPDGF-BB group relative to saline, PRP, and TCA (p < 0.025). On day 21, maximum load-to-rupture was increased in the 10 µg rhPDGF-BB group relative to saline, PRP, and TCA (p < 0.035) and in the 3 µg rhPDGF-BB group compared to saline and TCA (p < 0.027). Stiffness in the 10 µg rhPDGF-BB group was increased compared to saline, PRP, and TCA (p < 0.038). Histology demonstrated similar repair in all groups. PRP and TCA did not improve mechanical properties compared to saline. Injections of rhPDGF-BB increased maximum load-to-failure (3 and 10 µg) and stiffness (10 µg) relative to controls and commonly used treatments. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:145-150, 2014. PMID:24018586

Solchaga, Luis A; Bendele, Alison; Shah, Vivek; Snel, Leo B; Kestler, Hans K; Dines, Joshua S; Hee, Christopher K

2014-01-01

137

Autologous tenocyte implantation, a novel treatment for partial-thickness rotator cuff tear and tendinopathy in an elite athlete  

PubMed Central

Tendinopathy and small partial-thickness tears of the rotator cuff tendon are common presentations in sports medicine. No promising treatment has yet been established. Corticosteroid injections may improve symptoms in the short term but do not primarily treat the tendon pathology. Ultrasound-guided autologous tenocyte implantation (ATI) is a novel bioengineered treatment approach for treating tendinopathy. We report the first clinical case of ATI in a 20-year-old elite gymnast with a rotator cuff tendon injury. The patient presented with 12?months of increasing pain during gymnastics being unable to perform most skills. At 1?year after ATI the patient reported substantial improvement of clinical symptoms. Pretreatment and follow-up MRIs were reported and scored independently by two experienced musculoskeletal radiologists. Tendinopathy was improved and the partial-thickness tear healed on 3?T MRI. The patient was able to return to national-level competition. PMID:23314880

Wang, Allan W; Bauer, Stefan; Goonatillake, Matthew; Breidahl, William; Zheng, Ming-Hao

2013-01-01

138

Open Achilles tendon lacerations.  

PubMed

In contrast to closed Achilles tendon ruptures, open injuries are rarely reported in the literature. This paper provides information about open Achilles tendon wounds that are eventually seen in the Middle East. The reporting unit, Hamad Medical Corporation, is one of the biggest trauma centers in the Gulf area and the major health provider in Qatar. This is a retrospective study including patients admitted and operated for open Achilles tendon injuries between January 2011 and December 2013. Two hundred and five cases of open Achilles tendon lacerations were operated in Hamad General Hospital in this period. Forty-eight cases showed partial injuries, and the remaining are complete tendons cut. In the same period, fifty-one closed ruptured Achilles tendons were operated in the same trauma unit. In the majority of cases, the open injury resulted from a slip in the floor-leveled traditional toilette seats. Local damage to the toilette seats resulted in sharp edges causing the laceration of the heel if the patient was slipping over the wet floor. This occurrence is the cause in the vast majority of the cases. Wounds were located 1-5 cm proximal to tendon insertion. Standard treatment principles were applied. This included thorough irrigation in the emergency room, intravenous antibiotics, surgical debridement and primary repair within 24 h. Patients were kept in the hospital 1-7 days for intravenous antibiotics and possible dressing changes. Postoperatively below knee slabs were applied in the majority of patients and were kept for about 4 weeks followed by gradual weight bearing and range of motion exercises. Outpatients follow up in 1-2 weeks. Further follow-up visits at around 2-, 4-, 8- and 12-week intervals until complete wound healing and satisfactory rehabilitation outcome. Sixteen cases needed a second procedure. A high incidence of Achilles tendon open injuries is reported. This seems to be related to partially damaged floor-level toilettes in the typical Middle-East lavatory. The surgical treatment resulted in excellent outcome in the vast majority of the cases. Low incidence of complications resulted despite dramatic injury pattern. PMID:25337957

Said, M Nader; Al Ateeq Al Dosari, Mohamed; Al Subaii, Nasser; Kawas, Alaa; Al Mas, Ali; Al Ser, Yaser; Abuodeh, Yousef; Shakil, Malik; Habash, Ali; Mukhter, Khalid

2014-10-22

139

Outlet Biceps Tenodesis: A New Technique for Treatment of Biceps Long Head Tendon Injury  

PubMed Central

Degeneration and tearing of the long head of the biceps brachii tendon (LHBT) are common intra-articular findings, and surgical intervention including tenodesis or tenotomy is beneficial. A new arthroscopic shoulder technique may be performed through an anterior portal while one is viewing from a posterior portal: (1) Visualize the intra-articular biceps tendon. (2) Identify the segment of the LHBT to be enlarged. (3) Use a tissue modulation wand to enlarge the tendon. (4) Evaluate the diameter of the enlarged segment. It should be twice the original diameter. (5) Cut the biceps tendon at the proximal end of the enlarged segment. (6) View the tendon within the tunnel. (7) Identify and cut the remaining stump of the biceps tendon. Seventeen cadaveric shoulders were used to compare the pullout force, stiffness, and displacement of outlet tenodesis versus tenotomy. There was a significant increase in pullout force for the outlet tenodesis group when compared with tenotomy. This technique is used to operatively treat LHBT intra-articular pathology in patients who would benefit from tenotomy and traditional biceps tenodesis and may minimize the retraction of the biceps tendon distally. PMID:23875155

Lemos, David; Esquivel, Amanda; Duncan, Douglas; Marsh, Stephanie; Lemos, Stephen

2013-01-01

140

Percutaneous Achilles tendon repair  

Microsoft Academic Search

Fourteen patients underwent percutaneous Achilles tendon repairs between 1982 and 1989 for ruptures approximately 2 to 8 cm from the calcaneal insertion. They were evaluated subjectively (questionnaires) and objectively (physical examinations, Cybex II dynamom eter). The minimum follow-up time was 2 years with an average of 3.8 years. Subjectively, all of the patients were satisfied with their overall results. Objectively,

Robert E. Fitzgibbons; John Hefferon; James Hill

1993-01-01

141

Long Head of the Biceps Pathology Combined with Rotator Cuff Tears  

PubMed Central

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

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

2012-01-01

142

Humeral head cysts: association with rotator cuff tears and age.  

PubMed

The objective of this study was to retrospectively evaluate the prevalence of the cystic changes at rotator cuff footprint on proximal humeral tuberosities and investigate their relationship with rotator cuff tears and patient age. Magnetic resonance (MR) images of 657 patients who underwent shoulder arthroscopy for treatment of rotator cuff disorders were reviewed to localize the cystic changes at anterior (supraspinatus insertion) and posterior (infraspinatus insertion) aspects of greater tuberosity (GT) and lesser tuberosity (subscapularis insertion). Preoperative MR reports as well as cyst size and locations on MR images were correlated with arthroscopic records of rotator cuff pathology (tear type, size, location and tendon involvement) and patient age. The prevalence of cystic changes was 9.1% (60 patients) in the study population. Anterior GT cysts were found in 56% of patients and were strongly associated with full-thickness (p<.001) and articular-sided partial-thickness rotator cuff tears (p=.02). Posterior GT and lesser tuberosity cysts were found in 27 and 17% of patients, respectively, and were not significantly related to rotator cuff tears, although there was an increased trend of posterior cysts in patients with infraspinatus tears (p=.09). A significant relation was found between patient age and the cyst size (p=.01), while none of the cyst localizations were statistically related to age. Anterior GT cysts were more common in this patient group and demonstrated a strong association with rotator cuff disorders regardless of age. Posterior GT and lesser tuberosity cysts were less common and showed no association with rotator cuff pathology or patient age. PMID:23748696

Suluova, Fatih; Kanatli, Ulunay; Ozturk, Burak Yagmur; Esen, Erdinc; Bolukbasi, Selcuk

2014-07-01

143

A Comparison of the Fixation Strengths Provided by Different Intraosseous Tendon Lengths during Anterior Cruciate Ligament Reconstruction: A Biomechanical Study in a Porcine Tibial Model  

PubMed Central

Background The purpose of this study was to determine the tibial fixation strength provided by different intraosseous soft tissue graft lengths within the tibial tunnel. Methods Porcine tibial bones and digital flexor tendons were used for testing. Bone mineral densities of proximal tibial medial condyles were measured, and two-strand tendon bundles of 8 mm diameter were used. An intraosseous graft length of 2 cm was used in group 1 (n = 10), and a graft length of 4 cm was used in group 2 (n = 10). Tunnels were 4 cm in length and 8 mm in diameter. Tibial fixation was performed using a suture tied around a screw post with a washer and an additionally inserted 7 × 20 mm bioabsorbable screw. After applying preconditioning loading of 10 cycles, 1,000 cycles between 70-220 N were applied at a frequency of 1 Hz. Graft slippage and total graft movement were recorded. Ultimate tensile strength was measured by pull-out testing at an Instron crosshead speed of 1,000 mm/min. Results No significant intergroup difference was found for total graft movement after cyclic loading (slippage in group 1, 1.2 mm and group 2, 1.2 mm, respectively, p = 0.917; and total graft movement in group 1, 3.3 mm and group 2, 2.7 mm, respectively, p = 0.199). However, mean ultimate tensile strength in group 2 was significantly higher than that in group 1 (group 1, 649.9 N; group 2, 938 N; p = 0.008). Conclusions In a porcine model, ultimate tensile strength was greater for a 4 cm long intraosseous flexor tendon in the tibial tunnel. However, no intergroup difference in graft slippage or total graft movement was observed. The results show that a 2 cm intraosseous graft length in the tibial tunnel is safe and has sufficient strength (> 450 N) for adequate rehabilitation after anterior cruciate ligament reconstruction. PMID:24900898

Yang, Dong-Lyul; Cheon, Sang-Ho; Oh, Chang-Wug

2014-01-01

144

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

145

Shoulder labral pathomechanics with rotator cuff tears.  

PubMed

Rotator cuff tears (RCTs), the most common injury of the shoulder, are often accompanied by tears in the superior glenoid labrum. We evaluated whether superior humeral head (HH) motion secondary to RCTs and loading of the long head of the biceps tendon (LHBT) are implicated in the development of this associated superior labral pathology. Additionally, we determined the efficacy of a finite element model (FEM) for predicting the mechanics of the labrum. The HH was oriented at 30° of glenohumeral abduction and neutral rotation with 50N compressive force. Loads of 0N or 22N were applied to the LHBT. The HH was translated superiorly by 5mm to simulate superior instability caused by RCTs. Superior displacement of the labrum was affected by translation of the HH (P<0.0001), position along the labrum (P<0.0001), and interaction between the location on the labrum and LHBT tension (P<0.05). The displacements predicted by the FEM were compared with mechanical tests from 6 cadaveric specimens and all were within 1 SD of the mean. A hyperelastic constitutive law for the labrum was a better predictor of labral behavior than the elastic law and insensitive to ±1 SD variations in material properties. Peak strains were observed at the glenoid-labrum interface below the LHBT attachment consistent with the common location of labral pathology. These results suggest that pathomechanics of the shoulder secondary to RCTs (e.g., superior HH translation) and LHBT loading play significant roles in the pathologic changes seen in the superior labrum. PMID:24636720

Hwang, Eunjoo; Carpenter, James E; Hughes, Richard E; Palmer, Mark L

2014-05-01

146

High-Resolution US and MR Imaging of Peroneal Tendon Injuries.  

PubMed

Injuries of the peroneal tendon complex are common and should be considered in every patient who presents with chronic lateral ankle pain. These injuries occur as a result of trauma (including ankle sprains), in tendons with preexisting tendonopathy, and with repetitive microtrauma due to instability. The peroneus brevis and peroneus longus tendons are rarely torn simultaneously. Several anatomic variants, including a flat or convex fibular retromalleolar groove, hypertrophy of the peroneal tubercle at the lateral aspect of the calcaneus, an accessory peroneus quartus muscle, a low-lying peroneus brevis muscle belly, and an os peroneum, may predispose to peroneal tendon injuries. High-resolution 1.5-T and 3-T magnetic resonance (MR) imaging with use of dedicated extremity coils and high-resolution ultrasonography (US) with high-frequency linear transducers and dynamic imaging are proved to adequately depict the peroneal tendons for evaluation and can aid the orthopedic surgeon in injury management. An understanding of current treatment approaches for partial- and full-thickness peroneal tendon tears, subluxation and dislocation of these tendons with superior peroneal retinaculum ( SPR superior peroneal retinaculum ) injuries, intrasheath subluxations, and peroneal tendonopathy and tenosynovitis can help physicians achieve a favorable outcome. Patients with low functional demands do well with conservative treatment, while those with high functional demands may benefit from surgery if nonsurgical treatment is unsuccessful. Radiologists should recognize the normal anatomy and specific pathologic conditions of the peroneal tendons at US and MR imaging and understand the various treatment options for peroneal tendon and SPR superior peroneal retinaculum injuries. Online supplemental material is available for this article. (©)RSNA, 2015. PMID:25590397

Taljanovic, Mihra S; Alcala, Jennifer N; Gimber, Lana H; Rieke, Joshua D; Chilvers, Margaret M; Latt, L Daniel

2015-01-01

147

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

148

Common Disorders of the Achilles Tendon  

MedlinePLUS

... helping to raise the heel off the ground. Achilles Tendonitis and Achilles Tendonosis Two common disorders that occur in the heel cord are Achilles tendonitis and Achilles tendonosis. Achilles tendonitis is an inflammation ...

149

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

150

Skin tears: prevention and treatment.  

PubMed

While skin tears are common among the elderly in general, and residents of long-term care facilities in particular, there has been limited research into their treatment. Many facilities voluntarily track skin tears, and some states require facilities to report these events. Risk factors include age, xerosis (abnormal eye, skin, or mouth dryness), need for help in activities of daily living, presence of senile purpura, visual impairment, and poor nutrition. Plans to prevent skin tears that employ skin sleeves, padded side rails, gentle skin cleansers, moisturizing lotions, as well as staff education, can decrease by half the number of skin tears incurred in a long-term care facility. Although the treatment process seems simple, it is time consuming and can be painful for the patient. Residents with dementia or agitation often try to remove bulky dressings used to cover skin tears. Dressing changes may injure the fragile wound via skin stripping. PMID:18764669

Wick, Jeannette Y; Zanni, Guido R

2008-07-01

151

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

152

Biomechanical comparison between single-bundle and double-bundle anterior cruciate ligament reconstruction with hamstring tendon under cyclic loading condition  

PubMed Central

Purpose The purpose of this study was to compare the anterior tibial translation (ATT) of the anterior cruciate ligament (ACL) reconstructed-knee between single-bundle and double-bundle ACL reconstruction under cyclic loading. Methods Single-bundle and double-bundle reconstructions of the knee were performed sequentially in randomized order on the same side using eight human amputated knees. After each reconstruction, the reconstructed-knee was subjected to 500-cycles of 0 to 100-N anterior tibial loads using a material testing machine. The ATT before and after cyclic loading and “laxity increase”, which indicated a permanent elongation of the graft construct, was also determined. Results The ATT after cyclic loading increased in both single-bundle and double-bundle reconstruction techniques compared to that without cyclic loading. Changes in ATT before and after cyclic loading were 3.9?±?0.9 mm and 2.9?±?0.6 mm respectively, and were significantly different. Laxity increase was also significantly different (4.3?±?0.9 mm and 3.2?±?0.8 mm respectively). Although no graft rupture or graft fixation failure was found during cyclic loading, the graft deviated into an eccentric position within the tunnel. Conclusions Although ATT was significantly increased in both single-bundle and double-bundle reconstruction with hamstring tendon after cyclic loading test, there was significant difference. Double-bundle reconstruction might be superior to prevent increasing ATT under cyclic loading. Deformation of hamstring tendon after cyclic loading might result in deterioration of knee stability after ACL reconstruction, and is one of disadvantages of soft tissue graft. PMID:22747942

2012-01-01

153

Tear Lipocalin: Structure and Function  

PubMed Central

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

Dartt, Darlene A.

2014-01-01

154

Hamstring tendon graft for anterior cruciate ligament reconstruction.  

PubMed

In an age of increasing emphasis on sports, the most common contact injury of the lower extremity is anterior cruciate ligament (ACL) rupture. The classic history of an ACL injury is a sudden twisting of the knee accompanied by a popping or snapping sound. The patient usually complains of a feeling of hesitation, instability, or giving way of the knee. By the end of the day, the patient's knee will be swollen and unstable. There are many ways that the ACL can rupture, but a common method is a contact injury in which a valgus force is applied to the flexed, rotated externally knee. This can produce tears to the ACL, medial collateral ligament, and menisci. Noncontact injuries, such as those incurred while skiing or jumping, occur when the knee is extended and the tibia is internally rotated on the femur. There are several methods of repairing a ruptured ACL, such as using an allograft or autograft of the patella tendon or a hamstring tendon graft for the repair. This article focuses on the use of a hamstring tendon graft for ACL reconstruction and how to care for patients undergoing this procedure. PMID:12382466

Boni, Deborah M; Herriott, George E

2002-10-01

155

Lactoferrin levels in normal human tears  

Microsoft Academic Search

Using commercially available reagents we developed an enzyme-linked immunosorbent assay to measure lactoferrin in normal human tears. Tears obtained from 38 normal human subjects contained a mean lactoferrin content of 2.2 mg\\/ml (g\\/l). No differences in the mean level of lactoferrin were found when tears were collected by either Schirmer tear strips or by glass capillaries after short tear gas

A Kijlstra; S H Jeurissen; K M Koning

1983-01-01

156

[Perinatal neonatal lesions: retrovaginal tears].  

PubMed

Neonatal injuries produced during the childbirth or in the maneuvers of resuscitation they have a high morbidity and suppose the 8th reason of mortality in newborns. The aim of this article is to check our casuistry in the last 10 years and to present a case report of rectovaginal tear with the possible therapeutic options published in the literature. There were gathered a total of 8 perinatal neonatal injuries, being the majority of them clause-contused (5) in hairy leather, pinna and thorax. Other cases were affecting the perine: an anal tear and two rectovaginal tears; one of these patients needed colostomy and surgical repair of the perine. Only a small percentage of the perinatal neonatal injuries are valued by the paediatric surgeon. Some of them are serious and can have important consequences. The colostomy and primary or secondary closing is a therapeutic sure option in rectovaginal tears. PMID:22295663

Tirado Pascual, M; Primelles Díaz, A; Sánchez Díaz, F; Pérez Rodríguez, J; Rodríguez, Argos

2011-08-01

157

Flexor tendon injury, repair and rehabilitation.  

PubMed

Injuries to the flexor tendons remain among the most difficult problems in hand surgery. Historically, lacerations to the intrasynovial portion of the flexor tendons were thought to be unsuitable for primary repair. Despite continuing advances in our knowledge of flexor tendon biology, repair, and rehabilitation, good results following primary repair of flexor tendons remain challenging to achieve. PMID:25435036

Lutsky, Kevin F; Giang, Eric L; Matzon, Jonas L

2015-01-01

158

Achilles Tendon Rupture  

PubMed Central

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

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

2013-01-01

159

Tear lipocalin is the major endonuclease in tears  

PubMed Central

Purpose Human endonucleases are integral to apoptosis in which unwanted or potentially harmful cells are eliminated. The rapid turnover of ocular surface epithelium and microbial colonization of the eyelids are continual sources of DNA in tears. Here, we determine the principal sources of endonuclease activity in tears. Methods Endonucleases in human tears were identified after Sephadex G100 gel filtration. DNA hydrolyzing activity was measured by the conversion pUC19 plasmid DNA to its circular form in agarose gels. Fractions with endonuclease activity were further isolated using a combination ConA-Sepharose DNA, oligo (dT) cellulose, and anion exchange chromatographies. The molecular weights of the DNA hydrolyzing proteins were estimated in zymograms and by calibration of size exclusion chromatography. DNase activities were characterized for activity at a variety of pH and ion concentrations as well as in the presence of inhibitors including NiCl2, ZnCl2, G-actin, and aurintricarboxylic acid (ATA). To determine the mode of hydrolysis, the cleaved ends of the DNA digested by tear DNases were analyzed by 3? and 5? end labeling using either terminal deoxynucleotidyl transferase or polynucleotide kinase with or without pretreatment with alkaline phosphatase. Results Tear lipocalin (TL) accounts for over 75% of the DNA catalytic activity in tears while a second endonuclease, ~34 kDa, is responsible for less than 24% of the activity. Both are Mg2+ dependent enzyme endonucleases that are enhanced by Ca2+, active at physiologic pH, inhibited by aurintricarboxylic acid, and catalyze hydrolysis of DNA to produce 3?-OH/5?P ends. However, the two enzymes can be distinguished by the inhibitory effect of NiCl2 and the sizes of the cleaved DNA fragments. Conclusions Two magnesium dependent extracellular endonucleases were identified in tears that are different from other major human extracellular nucleases. TL is the principal endonuclease in human tear fluid. Tear endonucleases have unique characteristics that differ from other known human endonucleases. PMID:18334931

Yusifov, Taleh N.; Abduragimov, Adil R.; Narsinh, Kiran; Gasymov, Oktay K.

2008-01-01

160

Surgical treatment of partial distal biceps tendon ruptures through a single posterior incision.  

PubMed

The purpose of this study was to describe a novel technique for repair of partial distal biceps tendon ruptures through a single posterior incision. Eight patients with partial distal biceps tendon ruptures had the tear confirmed and repaired through a single posterior incision. All were men. The mean age was 50 years (range, 36-60 years). Postoperatively, immediate active and passive motion was instituted. Seven of eight patients returned to their previous professions. The mean postoperative American Shoulder and Elbow Surgeons elbow score was 96 (range, 89-100). Six of the patients were completely satisfied, and all were much improved. There were no complications. Surgical confirmation and repair of symptomatic partial distal biceps tendon ruptures can be performed through a single posterior incision. The morbidity of the anterior exposure can be avoided and the tendon readily explored and reattached with excellent patient outcomes. The security of repairing the tendon directly into a trough in bone and suturing over cortical bone permits immediate rehabilitation without immobilization in a cast or splint. PMID:14564267

Kelly, Edward W; Steinmann, Scott; O'Driscoll, Shawn W

2003-01-01

161

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

162

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

PubMed Central

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

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

2014-01-01

163

Posterior Tibial Tendon Dysfunction (PTTD)  

MedlinePLUS

... ACFAS | Información en Español Advanced Search Home » Foot & Ankle Conditions » Posterior Tibial Tendon Dysfunction (PTTD) Text Size ... the arch, and an inward rolling of the ankle. As the condition progresses, the symptoms will change. ...

164

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

PubMed Central

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

2014-01-01

165

Comparative analysis of the microstructure of the hamstring tendons: an electron microscopic, histologic, and morphologic study.  

PubMed

Semitendinosus and gracilis tendons taken from 25 cadaveric knees were investigated using light and electron microscopy, immunohistochemistry, and morphometry. Thickness of the collagen fibrils, fibril/interstitium ratio, density of blood vessels, density of fibroblasts, and distribution of the collagen fibrils (types I, III, and V collagen and elastic fibers) were analyzed. It was hypothesized that the difference in biomechanical stability between the gracilis and semitendinosus tendons could be reflected by different morphologic features. The results of this study showed that the gracilis tendon, in comparison with the semitendinosus tendon, provides a significantly higher fibril/interstitium ratio and a higher density of collagen III fibers. Conversely, the semitendinosus tendon provides a higher density of blood vessels and collagen I fibers. No differences regarding the density of fibroblasts, thickness of collagen fibrils, and elastic and type V collagen fibers were found. In conclusion, the gracilis tendon graft can provide approximately 15% more collagen than the semitendinosus tendon graft with the same thickness. This fact can play an important role for better biomechanical stability of the gracilis tendon. PMID:18851799

Hadjicostas, Panayiotis T; Soucacos, Panayotis N; Koleganova, Nadezda; Piecha, Grzegorz; Krohmer, Gerhard; Berger, Irina

2008-01-01

166

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

167

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

PubMed Central

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

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

2010-01-01

168

Calcium-phosphate-hybridized tendon directly promotes regeneration of tendon-bone insertion.  

PubMed

We developed a novel technique to improve tendon-bone attachment by hybridizing calcium phosphate (CaP) with tendons using an alternate soaking process. We characterized the deposited CaP on or in tendons and determined the healing process of anterior cruciate ligament (ACL) grafts by implanting CaP-hybridized free tendons in bone tunnels intra-articularly. Tendons to be implanted were alternately soaked 10 times in a Ca-containing solution and a PO(4)-containing solution for 30 s each. Treated tendons had ash contents threefold that of untreated tendons. Low-crystallinity apatite was found on or in treated tendons. In animal experiments, the CaP-hybridized tendon exhibited osteoclasts at the tendon-bone interface at 5 days after operation. At 2 weeks after operation, there were more osteoclasts and osteoblasts around the tendon than at 5 days after operation. Directly bonded areas were partially found between the implanted tendon and newly formed bone. The formation of a cartilage layer was partially apparent at 3 weeks after operation. The newly formed bone was observed almost around the tendon. We conclude that CaP-hybridized tendons clearly enhance the healing process of ACL grafts at the tendon-bone interface and regenerate a direct insertion-like formation of tendons similar to a normal healthy ACL insertion within 3 weeks after operation. PMID:15227677

Mutsuzaki, Hirotaka; Sakane, Masataka; Nakajima, Hiromi; Ito, Atsuo; Hattori, Shinya; Miyanaga, Yutaka; Ochiai, Naoyuki; Tanaka, Junzo

2004-08-01

169

Prediction of the elastic strain limit of tendons.  

PubMed

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

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

2014-02-01

170

Determination of ofloxacin in tear by HPLC-ESI-MS/MS method: comparison of ophthalmic drug release between a new mucoadhesive chitosan films and a conventional eye drop formulation in rabbit model.  

PubMed

Ofloxacin, second-generation fluoroquinolone derivative, is one of the most commonly used to treat and prevent superficial ocular infection in animals and human beings. However, poor bioavailability, rapid elimination, and non compliance by patients are several problems associated with ocular route. Ophthalmic controlled drug delivery offers the potential to enhance the efficacy of treatment for pathological conditions, while reducing the side effects and the toxicity associated with frequent applications. Specific analytical methods to determine drugs in eye are needed to analyze and compare the new controlled release ocular devices with those conventional eye drops. The topical eye administration of ophthalmic drugs induces lachrymation, and the tear promotes a drug wash out. Quantify drugs in tear is a good tool to study their kinetic comportment in the eye. A liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method for quantitation of ofloxacin in rabbits' tears was developed and validated. The tear was collected with tear strips, extracted by a liquid extraction procedure and then separated on an ACE C(18) column with a mobile phase composed of 0.15% aqueous formic acid and methanol (60:40, v/v). Calibration curve was constructed over the range of 10-5000 ng/mL for ofloxacin. The mean R.S.D. values for the intra-run and inter-run precision were 5.15% and 4.35%, respectively. The mean accuracy value was 100.16%. The validated method was successfully applied to determine the ofloxacin concentration in tears of rabbits treated with a mucoadhesive chitosan films and a conventional eye drop formulation. PMID:22673938

Byrro, Ricardo Martins Duarte; de Oliveira Fulgêncio, Gustavo; da Silva Cunha, Armando; César, Isabela Costa; Chellini, Paula Rocha; Pianetti, Gerson Antônio

2012-11-01

171

Triceps tendon rupture in weight lifters  

Microsoft Academic Search

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

Jonathan L Sollender; Ghazi M Rayan; Glen A Barden

1998-01-01

172

Exercise therapy for the conservative management of full thickness tears of the rotator cuff: a systematic review  

PubMed Central

Purpose: To review the evidence for the effectiveness of therapeutic exercise for the treatment of full thickness (including massive and inoperable) tears of the rotator cuff. Relevance: There is little consensus as to the most effective treatment of full thickness and massive tears of the rotator cuff. There is consensus that the outcome of rotator cuff tendon surgery in the elderly is generally very poor. As such, exercise therapy is usually recommended for this patient group. Although commonly prescribed, the evidence to support this approach is equivocal. The aim of this study was to conduct a systematic review of the literature to determine the efficacy of exercise therapy for the management of full thickness rotator cuff tears. Methods: A systematic review was conducted to synthesise the available research literature on the effectiveness of exercise therapy for full thickness tears of the rotator cuff. Data source: Reports up to and including September 2006 were located from MEDLINE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), AMED, EMBASE, the Cochrane Database of Systematic Reviews and the Physiotherapy Evidence Database (PEDro) using the terms “rotator cuff” and “tear/s” and “exercise” or “physiotherapy” or “physical therapy” or “rehabilitation”. Study selection: Studies were included if they related to full thickness rotator cuff tears and exercise. Data extraction: Two independent reviewers assessed the methodological quality of the studies. Differences were resolved by consensus. Analysis/Data synthesis: Ten studies met the inclusion criteria: eight were observational case series and two were single case studies. There were no randomised clinical trials. Results: Four studies were specific to massive rotator cuff tears. One study had a sub?group with massive cuff tears and five studies were not specific as to the size of the full thickness tear. Due to the heterogeneity of outcome measures used, it was not possible to combine results. In all studies an improvement in outcome scores was reported. Exercise programmes were well documented in five studies. Conclusions: No randomised controlled trials met the inclusion criteria and the evaluation has been based on observational studies of lower scientific merit. The findings suggest that some evidence exists to support the use of exercise in the management of full thickness rotator cuff tears. There is a definite need for well?planned randomised controlled trials investigating the efficacy of exercise in the management of full thickness and massive rotator cuff tears. PMID:17264144

Ainsworth, Roberta; Lewis, Jeremy S

2007-01-01

173

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

174

Silk and collagen scaffolds for tendon reconstruction.  

PubMed

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

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

2014-04-01

175

Magnetic resonance imaging appearance of the shoulder after subacromial injection with corticosteroids can mimic a rotator cuff tear.  

PubMed

Subacromial injections have been used to treat rotator cuff problems. Previous studies have noted the difficulty in performing accurate injections into this area. In addition, one must also question the effects that misplaced corticosteroids could have on the surrounding tissues. In this case, a 51-year-old woman presented with several weeks of left shoulder pain and was diagnosed with rotator cuff tendonitis. After a subacromial injection with betamethasone and lidocaine, the patient noted 3 weeks of near complete pain relief, followed by a return of her symptoms. A magnetic resonance imaging scan obtained 7 weeks after the injection showed a full-thickness tear of the supraspinatus tendon. Five weeks later, the patient underwent arthroscopic evaluation of the shoulder and subacromial decompression. The rotator cuff tendons were noted to be intact and normal in appearance. The patient eventually had full resolution of her symptoms. Six months postoperatively, she underwent a new scan that showed a normal supraspinatus tendon. Apparently, the subacromial injection penetrated the anterior half of the supraspinatus tendon, causing a transient effect and signal change. One should use caution in the interpretation of magnetic resonance imaging scans of the shoulder soon after the injection of corticosteroids. PMID:18589276

Borick, Jay M; Kurzweil, Peter R

2008-07-01

176

REHABILITATION OF A PARTIALLY TORN DISTAL TRICEPS TENDON AFTER PLATELET RICH PLASMA INJECTION: A CASE REPORT  

PubMed Central

Background: Platelet Rich Plasma (PRP) is an emerging non?surgical intervention used for the treatment of tendon and ligament pathology. Despite the growing popularity of PRP in musculoskeletal medicine, there is a paucity of research that describes appropriate rehabilitation procedures following this intervention. Case Description: This case report presents the rehabilitation strategy used following a PRP injection for a patient with a partially torn distal triceps tendon who previously failed physical therapy interventions. Outcome: The patient returned to light weight training and coaching activity after completing 15 visits over a 3 month period. One month after discharge, the patient reported pain?free activities of daily living and a return to previously performed gym activities. Discussion: PRP presents a viable treatment option for individuals who are recalcitrant to conservative interventions yet elect to avoid more invasive surgical measures. Despite the growing popularity of PRP, a paucity of evidence exists to guide physical therapists in the rehabilitation process of these patients. The rehabilitation strategies used in a patient who had a PRP injection for a partial triceps tendon tear are outlined. Although this case report highlights a successful rehabilitation outcome, future research regarding the concomitant effects of PRP injection and rehabilitation for tendon pathology are needed. Level of Evidence: 4?Case Report PMID:23772345

Kolber, Morey J.; Salamh, Paul A.; Hanney, William J.

2013-01-01

177

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

178

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

179

Comparison of hyaluronic acid-containing topical eye drops with carbomer-based topical ocular gel as a tear replacement in canine keratoconjunctivitis sicca: A prospective study in twenty five dogs  

PubMed Central

The aim of this study was to evaluate the efficacy of a hyaluronic acid containing eye drop in ameliorating ocular surface pathology and discomfort in canine keratoconjunctivitis sicca (KCS). Twenty five dogs with KCS treated with a topical carbomer (CA)-based tear replacement gel were moved to treatment with a hyaluronic acid (HA)-containing tear replacement eye drop. Dogs were subject to a full ophthalmic examination at the beginning of the study and after two and four weeks of treatment, Schirmer tear tests (STTs) were performed at each examination. Conjunctival hyperemia, ocular discharge and ocular irritation were evaluated and scored on a 0-3 semi-quantitative scale. Values were compared before and after 4 weeks of treatment using a paired t-test. Evaluation scores were compared using the Wilcoxon signed rank test. The transfer from CA-based to HA-containing tear replacement significantly decreased the conjunctival hyperemia score from 2.12 ± 0.73 to 1.26 ± 0.59 and ocular discomfort was lowered from 2.11 ± 0.97 to 0.93 ± 0.75. Ocular discharge was reduced from a score of 1.04 ± 0.82 to 0.70 ± 0.53, however, the decrease did not reach statistical significance. Schirmer tear test was increased with statistical significance (p < 0.001) but given that the increase was only from 5.42 ± 3.50 to 6.19 ± 3.86 mm min-1; this was not considered clinically significant. This study demonstrated that HA-containing eye drops used twice daily in dogs with KCS had greater ameliorative effects on ocular surface health and discomfort than did CA-based topical gels used as or more frequently.

Williams, David; Middleton, Sheldon; Fattahian, Hamidreza; Moridpour, Roozbeh

2012-01-01

180

Work-related lesions of the supraspinatus tendon: a case–control study  

Microsoft Academic Search

Objectives  To examine the dose–response relationship between cumulative duration of work with highly elevated arms (work above shoulder\\u000a level) as well as of manual material handling and ruptures of the supraspinatus tendon in a population-based case–control\\u000a study.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  In 14 radiologic practices, we recruited 483 male patients aged 25–65 with radiographically confirmed partial (n = 385) or total (n = 98) supraspinatus tears associated with shoulder

Andreas Seidler; Ulrich Bolm-Audorff; Gabriela Petereit-Haack; Elke Ball; Magdalena Klupp; Noëlle Krauss; Gine Elsner

2011-01-01

181

Hamstring tendon harvesting--Effect of harvester on tendon characteristics and soft tissue disruption; cadaver study.  

PubMed

The purpose of this study was to determine whether the type of hamstring tendon harvester used can influence harvested tendon characteristics and soft tissue disruption. We compared two different types of tendon harvesters with regard to the length of tendon obtained and soft tissue disruption during hamstring tendon harvesting. Thirty six semitendinosus and gracilis tendons were harvested using either a closed stripper or a blade harvester in 18 paired knees from nine human fresh cadavers. Use of the blade harvester gave longer lengths of usable tendon whilst minimising the stripping of muscle and of any non-usable tendon. Our results suggest that the type of harvester per se can influence the length of tendon harvested as well as soft tissue disruption. Requesting such data from the industry prior to deciding which harvester to use seems desirable. PMID:19272780

Charalambous, C P; Alvi, F; Phaltankar, P; Gagey, O

2009-06-01

182

Tearing modes and canonical profiles  

NASA Astrophysics Data System (ADS)

The stability of tearing modes for current profiles satisfying the principle of profile consistency proposed by B Coppi (1980 Comments Plasma Phys. Contr. Fusion 5 261) is investigated in a "straight" tokamak and compared with recent experimental data from JET (M F F Nave et al 1992 Nucl. Fusion 32 825). Stability diagrams in the parametric space qa vs qa0 (= qa/q0) and li vs qa, where qa, q0 and li stand for the safety factor at the column radius and on the axis and the internal inductance, respectively, for tearing modes associated with equilibrium profiles satisfying such a constraint, reveal that disruptions occur mainly in the unstable region of the diagram common to modes m/n = 2/1 and 3/2, suggesting that they may be triggered by their respective islands overlap. It is also shown that the experimental electron temperature profile which are linearly unstable to tearing modes still keep an underlying canonical shape if the quasilinear growth of the magnetic islands saturates before islands overlapping. Neoclassical correction to parallel resistivity is also considered and discussed.

Tomimura, A.; Galvão, R. M. O.

1995-06-01

183

Risk Factors for Giant Retinal Tears  

PubMed Central

Purpose To evaluate the risk factors associated with giant retinal tears. Methods This retrospective study was performed on medical records of 150 patients who had undergone retinal detachment surgery. Age, sex, history of trauma, lens status (phakic, pseudophakic, or aphakic), and high myopia were evaluated in association with giant retinal tears. Results Of 150 patients with retinal detachments, 99 subjects (66%) were older than 30 years while 51 (34%) were 30 years of age or younger. Overall, 26 (17.3%) patients had giant retinal tears. Controlling for all variables, only age had a significant correlation with giant retinal tears. Each year of advancing age was associated with a 6% decrease in the incidence of giant retinal tears. Conclusion Young age is a significant risk factor for development of giant retinal tears. PMID:22737369

Mehdizadeh, Morteza; Afarid, Mehrdad; Haqiqi, Mohammad Shabanpour

2010-01-01

184

Hyperuricemic PRP in tendon cells.  

PubMed

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

185

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

186

Therapeutic potential of mesenchymal stem cells to treat Achilles tendon injuries.  

PubMed

Rupture of the Achilles tendon diminishes quality of life. The gold-standard therapy is a surgical suture, but this presents complications, including wound formation and inflammation. These complications spurred evaluation of the therapeutic potential of mesenchymal stem cells (MSCs) from adipose tissue. New Zealand rabbits were divided into 6 groups (three treatments with two time points each) evaluated at either 14 or 28 days after surgery: cross section of the Achilles tendon (CSAT); CSAT + Suture; and CSAT + MSC. A comparison between all groups at both time points showed a statistically significant increase in capillaries and in the structural organization of collagen in the healed tendon in the CSAT + Suture and CSAT + MSC groups at the 14-day assessment. Comparison between the two time points within the same group showed a statistically significant decrease in the inflammatory process and an increase in the structural organization of collagen in the CSAT and CSAT + MSC groups. A study of the genomic integrity of the cells suggested a linear correlation between an increase of injuries and culture time. Thus, MSC transplantation is a good alternative for treatment of Achilles tendon ruptures because it may be conducted without surgery and tendon suture and, therefore, has no risk of adverse effects resulting from the surgical wound or inflammation caused by nonabsorbable sutures. Furthermore, this alternative treatment exhibits a better capacity for wound healing and maintaining the original tendon architecture, depending on the arrangement of the collagen fibers, and has important therapeutic potential. PMID:25511027

Vieira, M H C; Oliveira, R J; Eça, L P M; Pereira, I S O; Hermeto, L C; Matuo, R; Fernandes, W S; Silva, R A; Antoniolli, A C M B

2014-01-01

187

Dacryoscintigraphic Findings in the Children with Tearing  

PubMed Central

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

Kim, Hyung Chul; Cho, A Ran

2015-01-01

188

Computational modeling of neoclassical and resistive MHD tearing modes in tokamaks  

SciTech Connect

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

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

1996-06-24

189

Mucus-stimulating factor in tears.  

PubMed

Mechanisms responsible for regulation of tear film mucus are poorly understood. Humoral factors responsible for stimulation of mucus secretion can be studied in vitro by using the free-swimming urn cell, a normal component of the coelomic fluid of the marine invertebrate Sipunculus nudus. With this system, a tear mucus-stimulating factor was found in normal human tears but was markedly decreased in patients with dry eye syndromes. It is suggested that a mucus-stimulating factor exists in normal human tears and that a decrease in this substance may be instrumental in the pathophysiology of certain dry eye syndromes. PMID:7358498

Franklin, R M; Bang, B G

1980-04-01

190

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

191

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

192

Intrarectal tear from water skiing.  

PubMed

We report a case of intrarectal tear and hemorrhage after a fall while water skiing. The injury resulted from rectal douche, or jet enema, which is dangerous because of the high pressure of the water jets forced into the rectum. The patient, a middle-aged woman, had colonoscopy, which revealed a deep rectal laceration. During subsequent colostomy, a full-thickness laceration and an extensive pelvic and retroperitoneal hematoma with some free blood were found. The patient's recovery was uneventful, and she subsequently had reanastomosis of her colostomy. We recommend protective apparel to prevent these injuries. PMID:1595660

Lee, R Y; Miller, S; Thorpe, C

1992-05-01

193

Neovascularisation in Achilles tendons with painful tendinosis but not in normal tendons: an ultrasonographic investigation  

Microsoft Academic Search

Chronic Achilles tendinosis is a condition with unknown aetiology and pathogenesis, most often, but not always, associated with painful nodular thickening of the tendon. In this investigation, 28 tendons (21 patients) with a painful nodule located at the 2-6 cm level in the tendon, and 20 normal (pain-free) tendons, were examined with grey-scale ultrasonography combined with colour Doppler examination. In

Lars Öhberg; Ronny Lorentzon; Håkan Alfredson

2001-01-01

194

[Primary flexor tendons repair in zone 2].  

PubMed

Primary flexor tendon repair is still challenging even in the most experienced hands. With atraumatic surgery, the goal is to suture the tendon in a way that it will be strong enough to allow for tendon gliding without the risk of rupture or adhesions during the 12 weeks needed for the tendon to heal. After reviewing the zone 2 anatomy, the authors describe the state of art for flexor tendon repair along with their personal preferences. Although suture methods and postoperative rehabilitation programs are not universal, most specialized teams now use multistrand suturing techniques with at least 4 stands along with protected and controlled early active mobilization. Although the published rates of failure of the repair or postoperative adhesions with stiffness have decreased, these complications are still a concern. They will continue to pose a challenge for scientists performing research into the mechanics and biology of flexor tendon repairs, especially in zone 2. PMID:25442406

Bellemère, P; Ardouin, L

2014-12-01

195

Management of chronic tendon injuries.  

PubMed

Chronic tendon injuries present unique management challenges. The assumption that these injuries result from ongoing inflammation has caused physicians to rely on treatments demonstrated to be ineffective in the long term. Nonsteroidal anti-inflammatory drugs should be limited in the treatment of these injuries. Corticosteroid injections should be considered for temporizing pain relief only for rotator cuff tendinopathy. For chronic Achilles tendinopathy (symptoms lasting longer than six weeks), an intense eccentric strengthening program of the gastrocnemius/ soleus complex improved pain and function between 60 and 90 percent in randomized trials. Evidence also supports eccentric exercise as a first-line option for chronic patellar tendon injuries. Other modalities such as prolotherapy, topical nitroglycerin, iontophoresis, phonophoresis, therapeutic ultrasound, extracorporeal shock wave therapy, and low-level laser therapy have less evidence of effectiveness but are reasonable second-line alternatives to surgery for patients who have persistent pain despite appropriate rehabilitative exercise. PMID:23547590

Childress, Marc A; Beutler, Anthony

2013-04-01

196

Extensor tendon injuries in athletes.  

PubMed

Extensor tendon injuries of the hand and wrist in high-level athletes can cause a delay in return to play and permanently affect their performance. Given the inherent demand for a speedy and complete recovery, orthopedic surgeons must have an understanding of how to best direct an athlete's treatment for these injuries. The extensor anatomy is very intricate and a thorough understanding of the anatomy can help with both diagnosis and treatment. However, untreated or poorly managed injuries are at risk of leading to chronic deformities. We will discuss the diagnosis and management of the most common extensor tendon injuries and tendinopathies of the hand found in athletes: mallet fingers, swan-neck deformities, boutonniere deformities, central slip ruptures, sagittal band ruptures, intersection syndrome, extensor carpi ulnaris tendinitis, and extensor carpi ulnaris subluxation. PMID:24651290

Chauhan, Aakash; Jacobs, Bruce; Andoga, Alexandra; Baratz, Mark E

2014-03-01

197

Achilles tendon rupture in athletes.  

PubMed

Achilles tendon ruptures commonly affect middle-aged athletes and can result in considerable functional impairment. While the cause is multifactorial, the greatest risk is present for athletes involved in sports that involve sudden acceleration and deceleration. A thorough history and physical examination can accurately yield a diagnosis, but when question remains, magnetic resonance imaging is superior to ultrasound-guided evaluation. The best evidence available suggests that operative treatment has a lower rate of rerupture, a higher rate of return to the same level of sport participation, and a higher complication rate, if an open technique is used. Percutaneous methods of fixation have lower complication rates without an increase in the rate of rerupture when compared with open methods. Augmentation of an Achilles tendon repair has demonstrated no clinical benefit. Rehabilitation with early mobilization leads to improved patient-reported outcomes. PMID:19843435

Deangelis, Joseph P; Wilson, Kristina M; Cox, Charles L; Diamond, Alex B; Thomson, A Brian

2009-01-01

198

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

199

Structure and function of tuna tail tendons.  

PubMed

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

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

2002-12-01

200

[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

201

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. PMID:25170379

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

2014-01-01

202

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; Jüttler, Bert; Tomar, Satyendra

2012-01-01

203

IETI - Isogeometric Tearing and Interconnecting.  

PubMed

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; Jüttler, Bert; Tomar, Satyendra

2012-11-01

204

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

E-print Network

Tear Film Corneal shape Blink Cycles Reflex Tearing vdW wetting The End? Models for Dynamics of the Human Tear Film R.J. Braun1 , K.L Maki2 , A. Heryudono3 , T.A. Driscoll1 , L.P. Cook1 , P. Ucciferro1 Sciences, George Mason U Supported by the NSF #12;Tear Film Corneal shape Blink Cycles Reflex Tearing vd

Bacuta, Constantin

205

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

206

Thermographic and microscopic evaluation of LARS knee ligament tearing.  

PubMed

Damage to knee articular ligaments causes important functional problems and adversely affects particularly the stability of the knee joint. Several methods were developed in order to repair damage to the anterior cruciate ligament (ACL), which employ autografts, allografts, as well as synthetic ligaments. One such synthetic scaffold, the ligament advanced reinforcement system (LARS) synthetic ligament is made of non-absorbing polyethylene terephthalate fibers whose structure allow tissue ingrowths in the intra-articular part, improving the stability of the joint. The LARS ligament is nowadays widely used in modern knee surgery in the Europe, Canada, China or Japan. This paper evaluates LARS ligament from two perspectives. The first regards a study done by the Orthopedics Clinic II, Timisoara, Romania, which compared results obtained by employing two techniques of ACL repair - the Bone-Tendon-Bone (BTB) or LARS arthroscopic, intra-articular techniques. This study found that patients treated with the BTB technique presented with an IKDC score of 45.82±1.14 units preoperative, with increasing values in the first nine months after each implant post-surgical ligament restoration, reaching an average value of 75.92±2.88 units postoperative. Patients treated with the LARS technique presented with an IKDC score of 43.64±1.11 units preoperative, and a score of 77.32±2.71 units postoperative. The second perspective describes the thermographic and microscopic analysis of an artificial knee ligament tearing or loosening. The objective of the study was to obtain information regarding the design of artificial ligaments in order to expand their lifespan and avoid complications such as recurring synovitis, osteoarthritis and trauma of the knee joint. Thermographic data has shown that tearing begins from the inside out, thus improving the inner design of the ligament would probably enhance its durability. An optical microscope was employed to obtain images of structural damage in the inner layers, for use in further analysis of the tears. In conclusion, the LARS artificial ligament, like the BTB technique, displays both advantages and disadvantages. It is important to understand that these two options of ACL lesion repair are not competing. LARS could, in addition to its use in primary ACL ruptures, be utilized in revisions of autologous graft rupture post primary ACL repair. PMID:25607412

P?tra?cu, Jenel Marian; Amarandei, Mihaela; Kun, Karla Noemy; Borug?, Ovidiu; Totorean, Alina; Andor, Bogdan; Florescu, Sorin

2014-01-01

207

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

208

Tendon mineralization is accelerated bilaterally and creep of contralateral tendons is increased after unilateral needle injury of murine achilles tendons.  

PubMed

Heterotopic mineralization may result in tendon weakness, but effects on other biomechanical responses have not been reported. We used a needle injury, which accelerates spontaneous mineralization of murine Achilles tendons, to test two hypotheses: that injured tendons would demonstrate altered biomechanical responses; and that unilateral injury would accelerate mineralization bilaterally. Mice underwent left hind (LH) injury (I; n?=?11) and were euthanized after 20 weeks along with non-injured controls (C; n?=?9). All hind limbs were examined by micro computed tomography followed by biomechanical testing (I?=?7 and C?=?6). No differences were found in the biomechanical responses of injured tendons compared with controls. However, the right hind (RH) tendons contralateral to the LH injury exhibited greater static creep strain and total creep strain compared with those LH tendons (p???0.045) and RH tendons from controls (p???0.043). RH limb lesions of injured mice were three times larger compared with controls (p?=?0.030). Therefore, despite extensive mineralization, changes to the responses we measured were limited or absent 20 weeks postinjury. These results also suggest that bilateral occurrence should be considered where tendon mineralization is identified clinically. This experimental system may be useful to study the mechanisms of bilateral new bone formation in tendinopathy and other conditions. PMID:23754538

O'Brien, Etienne John Ogilvy; Shrive, Nigel G; Rosvold, Joshua M; Thornton, Gail M; Frank, Cyril B; Hart, David A

2013-10-01

209

Subscapularis Tendon Integrity: An Examination of Shoulder Index Tests  

PubMed Central

Abstract Reference: Hegedus EJ, Goode A, Campbell S, et al. Physical examination tests of the shoulder: a systematic review with meta-analysis of individual tests. Br J Sports Med. 2008;42(2):80–92. Clinical Question: The systematic review focused on various index tests for the shoulder. We concentrated on the subscapularis tendon results to determine the accuracy of reported index tests for clinically diagnosing subscapularis integrity. Data Sources: Studies were identified by an OVID search using MEDLINE, SPORTDiscus, and CINHAL databases (1966–2006) and a hand search by 2 authors (E.J.H. and S.C.). Primary search terms were shoulder, examination, and diagnosis. In addition to the database searches, personal files were hand searched by one of the authors (E.J.H.) for publications, posters, and abstracts. The reference lists in review articles were cross-checked, and all individual names of each special test were queried using MEDLINE and PubMed. Study Selection: The search was limited to English-language journals. Studies were eligible for inclusion if the criterion standard was surgery, magnetic resonance imaging, or injection (subacromial or acromioclavicular joint); at least 1 physical examination test or special test was studied; and one of the paired statistics of sensitivity and specificity was reported or could be determined. Excluded were studies in which the index test was performed under anesthesia or in cadavers, studies in which the index test was assigned the status of composite physical examination, and review articles. Studies were grouped according to the subscapularis index test assessed: lift off, internal-rotation lag sign, Napoleon sign, bear hug, belly off, and belly press. Data Extraction: Studies were selected in a 2-stage process. First, all abstracts and articles found through the search process were independently reviewed by 2 authors (E.J.H. and S.C.). Disagreement on inclusion of an article was resolved by consensus. Second, each selected study was assessed by each reviewer independently. A third reviewer made the final decision on any disagreements for the selected studies. The primary outcome measures were sensitivity and specificity and positive and negative likelihood ratios. The quality of a study was determined by assessing its internal and external validity. Validity was determined by the primary author (E.J.H.) using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) statement. Our work required data extraction from the original articles, which we used to generate 2 × 2 contingency tables for each index test. Pooled indices of clinical usefulness were then determined for each index test. Main Results: The specific search criteria identified 922 articles for review. Of these, 4 met the inclusion and exclusion criteria for subscapularis tendon tears, resulting in the number of studies assessing each index test as follows: 4 for lift off, 2 for internal-rotation lag sign, 2 for Napoleon sign, 1 for bear hug, 1 for belly off, and 1 for belly press. Subscapularis tears were identified by the criterion standard of surgery to visually assess the torn fibers. Across all 4 studies, a total of 304 shoulders were examined, 95 of which had a subscapularis tear (45 full thickness, 50 partial thickness), and 106 were injury free. Indices of clinical usefulness for full-thickness and partial-thickness subscapularis tears are reported in Tables 1 and 2, respectively. PMID:20617916

Rigsby, Ruel; Sitler, Michael; Kelly, John D.

2010-01-01

210

Single-stage reconstruction of flexor tendons with vascularized tendon transfers.  

PubMed

The reconstruction of finger flexor tendons with vascularized flexor digitorum superficialis (FDS) tendon grafts (flaps) based on the ulnar vessels as a single stage is not a popular technique. We reviewed 40 flexor tendon reconstructions (four flexor pollicis longus and 36 finger flexors) with vascularized FDS tendon grafts in 38 consecutive patients. The donor tendons were transferred based on the ulnar vessels as a single-stage procedure (37 pedicled flaps, three free flaps). Four patients required composite tendon and skin island transfer. Minimum follow-up was 12 months, and functional results were evaluated using a total active range of motion score. Multiple linear regression analysis was performed to evaluate the factors that could be associated with the postoperative total active range of motion. The average postoperative total active range of motion (excluding the thumbs) was 178.05° (SD 50°). The total active range of motion was significantly lower for patients who were reconstructed with free flaps and for those who required composite tendon and skin island flap. Age, right or left hand, donor/motor tendon and pulley reconstruction had no linear effect on total active range of motion. Overall results were comparable with a published series on staged tendon grafting but with a lower complication rate. Vascularized pedicled tendon grafts/flaps are useful in the reconstruction of defects of finger flexor tendons in a single stage, although its role in the reconstructive armamentarium remains to be clearly established. PMID:24436359

Cavadas, P C; Pérez-García, A; Thione, A; Lorca-García, C

2014-01-15

211

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

212

Anatomic reconstruction of chronic coracoclavicular ligament tears: arthroscopic-assisted approach with nonrigid mechanical fixation and graft augmentation.  

PubMed

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

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

2014-10-01

213

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

PubMed Central

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

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

2014-01-01

214

Flexor tendon repair using a stainless steel external splint. Biomechanical study on human cadaver flexor tendons.  

PubMed

A stainless steel external tendon splint was used in repair of cadaver tendons and compared with standard tendon repairs with suture. The splint was combined with a Kessler repair and tested against the Kessler, Becker, and Savage repairs in fresh human cadaver flexor digitorum profundus tendons. Biomechanical testing was done on a tensile testing machine, and load-displacement curves were generated. The repairs using the external tendon splint demonstrated a range of improvement of 32 to 146% in mean maximal tensile strength and a 20 to 185% improvement of mean ultimate tensile strength compared with all other repairs. The external tendon splint is relatively easy to apply to a tendon. The repair is strengthened and becomes capable of withstanding early active range of motion exercises. In vivo testing will be needed to assess the potential clinical usefulness of such a device. PMID:10672797

Gordon, L; Dysarz, F A; Venkateswara, K T; Mok, A P; Ritchie, R O; Rabinowitz, S

1999-12-01

215

[Indentation of large retinal tears (author's transl)].  

PubMed

According to us large retinal tears are between 20 degrees and 70 degrees in their largest dimension, which excludes true giant tears. Study of the data collected on 42 patients has shown us the following facts:--these retinal tears occur in phakic and often highly myopic eyes;--our global success rate is 73,8%;--tears smaller than 2 to 3 papillary diameters radially are on the whole easy to indent and failures are quite often related to a surgical fault;--tears wider than 3 papillary diameters radially are on the whole difficult to indent and failures are not always related to an obvious surgical fault, fishmouth phenomenon plays an important role;--in every case presence of blood in the vitreous seems to be unfavourable to the prognosis;--use of episcleral pockets solves must of times surgical problems related to fishmouth or tear dimension;--post operative intern limiting membrane retraction is frequent (10% vs 5,7% for all the retinal tears and detachments cured in the same period of time). PMID:501045

Forest, A; Girard, P; Cohen, M L; Biojout, G; Pasticier, A

1979-01-01

216

Augmentation of tendon-to-bone healing.  

PubMed

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

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

2014-03-19

217

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

218

Ultrasonic evaluation of flood gate tendons  

SciTech Connect

Our water resources infrastructure is susceptible to aging degradation just like the rest of this country`s infrastructure. A critical component of the water supply system is the flood gate that controls the outflow from dams.Long steel rods called tendons attach these radial gates to the concrete in the dam. The tendons are typically forty feet long and over one inch in diameter. Moisture may seep into the grout around the tendons and cause corrosion. Lawrence Livermore National Laboratory is working with the California Department of Water Resources to develop advanced ultrasonic techniques for nondestructively inspecting their tendons. A unique transducer was designed and fabricated to interrogate the entire tendon. A robust,portable unit was assembled that included a computer controlled data acquisition system and specialized data processing software to analyze the ultrasonic signals. This system was tested on laboratory specimens and is presently being fielded at two dam sites.

Thomas, G.; Brown, A.

1997-10-01

219

The tear ferning test: a simple clinical technique to evaluate the ocular tear film.  

PubMed

A healthy tear film is very important for many major functions of the ocular surface. Dry eye disease is a significant clinical problem that needs to be solved but the poor correlation between clinical signs and reported symptoms makes it difficult for the clinician to apply a scientific basis to his clinical management. The problem is compounded by the difficulties of evaluating the tear film due to its transparency, small volume and complex composition. Practical insight into tear film composition would be very useful to the clinician for patient diagnosis and treatment but detailed analysis is restricted to expensive, laboratory-based systems. There is a pressing need for a simple test. The tear ferning test is a laboratory test but it has the potential to be applied in the clinic setting to investigate the tear film in a simple way. Drying a small sample of tear fluid onto a clean, glass microscope slide produces a characteristic crystallisation pattern, described as a 'tear fern'. This test is currently not widely used because of some limitations that need to be overcome but several studies have demonstrated its potential. Such limitations need to be resolved so that tear ferning could be used in the clinic setting to assess the tear film. PMID:25138744

Masmali, Ali M; Purslow, Christine; Murphy, Paul J

2014-09-01

220

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

SciTech Connect

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

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

1986-06-01

221

Hall resistive tearing mode: A variational formulation  

NASA Astrophysics Data System (ADS)

A unified linear tearing-mode formulation is given incorporating both resistivity and Hall effects. A variational method is used that appears to be best suited to deal with the difficulties peculiar to the triple-deck structure associated with the Hall resistive tearing mode but also to lead to a convenient analytical dispersion relation for the Hall resisitive tearing mode. This analytical dispersion relation: a) recovers the Furth-Killeen-Rosenbluth (Phys. Fluids, 6 (1963) 459) result for the resistive branch; b) gives a growth rate for the Hall branch which appears to be consistent with the growth rate of the electron-inertia-driven tearing mode given previously (Coppi B., Phys. Lett. A, 11 (1964) 226); c) recovers the scaling relation for the transition from the resisitive regime to the Hall regime numerically established by Fitzpatrick (Phys. Plasmas, 11 (2004) 937) in a driven Hall resistive reconnection situation.

Shivamoggi, B. K.

2008-09-01

222

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

223

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

224

Tear film measurement by optical reflectometry technique  

PubMed Central

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

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

2014-01-01

225

Tear film measurement by optical reflectometry technique.  

PubMed

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

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

2014-02-01

226

Patellar tendonitis and anterior knee pain.  

PubMed

Patellar tendonitis or "jumper's knee" is an important cause of anterior knee pain. The natural history, classification of the lesion, and treatment methods, however, remain controversial. This article presents a retrospective review of 40 patients (50 knees) with various stages of patellar tendonitis and examines the etiology, presentation, clinical picture, investigation, and results of conservative treatment. Twenty-nine men and 11 women ranging in age from 17-48 years comprised the study population. Ten patients had bilateral involvement. The overall evaluation of patients' treatment was 70% with normal or nearly normal results and 30% with abnormal or very abnormal results; most required surgical treatment in the form of arthroscopy, anterior compartment decompression, and patellar tendon exploration. Thirty-seven percent of the patients had a previous history of anterior knee pain (25% had Osgood-Schlatter disease and 12.5% had anterior knee pain). Patellar tendon involvement is appraised according to a new concept. Since patellar tendonitis is part of the wider picture of anterior knee pain, patellar tendonitis is classified as primary or secondary according to presentation, magnetic resonance imaging in general, and the pathology of the patellar tendon in particular. Treatment is planned accordingly. PMID:10323501

Duri, Z A; Aichroth, P M; Wilkins, R; Jones, J

1999-01-01

227

Biological Augmentation of Rotator Cuff Tendon Repair  

PubMed Central

A histologically normal insertion site does not regenerate following rotator cuff tendon-to-bone repair, which is likely due to abnormal or insufficient gene expression and/or cell differentiation at the repair site. Techniques to manipulate the biologic events following tendon repair may improve healing. We used a sheep infraspinatus repair model to evaluate the effect of osteoinductive growth factors and BMP-12 on tendon-to-bone healing. Magnetic resonance imaging and histology showed increased formation of new bone and fibrocartilage at the healing tendon attachment site in the treated animals, and biomechanical testing showed improved load-to-failure. Other techniques with potential to augment repair site biology include use of platelets isolated from autologous blood to deliver growth factors to a tendon repair site. Modalities that improve local vascularity, such as pulsed ultrasound, have the potential to augment rotator cuff healing. Important information about the biology of tendon healing can also be gained from studies of substances that inhibit healing, such as nicotine and antiinflammatory medications. Future approaches may include the use of stem cells and transcription factors to induce formation of the native tendon-bone insertion site after rotator cuff repair surgery. PMID:18264850

Kovacevic, David

2008-01-01

228

Bilateral cadaveric Achilles tendon graft in reconstruction after Achilles tendon tumor resection.  

PubMed

The standard approach to reconstruction after resection of a diffuse-type tenosynovial giant cell tumor is a local patch with free flaps. However, in cases in which the Achilles tendon involvement is extensive, and the entire tendon must be removed, an autologous flap graft might not be adequate to allow a return to function. We report a case of a 52-year-old female patient who developed bilateral tumors of the Achilles tendon, with a 10-year duration. By the time, she sought medical help, both Achilles tendons required removal. We chose to use Achilles tendon allografts to replace the Achilles tendons. Postoperatively, the patient did well. The allograft shortened the recovery time, and the patient regained full ankle range of motion. PMID:22857848

Yang, Maowei; Wang, Zhenpeng; Li, Yuanzhou; Guo, Baolei

2013-01-01

229

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

230

Arthroscopy-assisted anterior cruciate ligament reconstruction with patellar tendon or hamstring autografts.  

PubMed

Isolated ACL reconstructions were performed in 138 patients between 1994 and 1998. Patellar bone-patellar tendon-bone, and hamstring tendon autografts were used in 88 patients, and allografts were used in 50 patients. Eighty-eight knees of 88 patients with autograft reconstructions (17 female, 71 male) were included in this study and evaluation of the patients with allograft reconstruction reported separately. The mean age at the time of the operation was 32 years. All ACL reconstructions were performed arthroscopically. Twenty-seven bone-patellar tendon-bone, and 61 hamstring tendon autografts were used. The mean follow-up was 29 months. In the postoperative course the Lachman test was negative in 62 patients, 1+ in 22 patients, and 2+ in 4 patients. In 17 patients, anterior drawer sign were 1+ in comparison to the contralateral side. Pivot shift test was moderately positive only in 5 cases in the bone-patellar tendon-bone and hamstring tendon autograft groups postoperatively. There were 3 patients with subjective "giving way" symptoms. Second look arthroscopy revealed rupture of the neo-ligament. Arthroscopic washout and debridement were performed, and no revision ligamentoplasties were performed. Two of these patients improved with accelerated proprioceptive physical therapy, and one had to decrease his previous level of activity. There were no cases of arthrofibrosis, infection, or extension lag. Clinical results of patellar bone-tendon-bone and hamstring groups did not show any significant clinical difference. Avoiding the disturbance of the extensor mechanism of the knee is probably the most significant advantage of the hamstring autograft. PMID:10983256

Doral, M N; Leblebicioglu, G; Atay, O A; Baydar, M L; Tetik, O; Atik, S

2000-01-01

231

Biochemical and morphological alterations in the Achilles tendon of mdx mice.  

PubMed

Dystrophin-deficient muscles have repeated cycles of necrosis and regeneration, being susceptible to injury induced by muscle contractions. Some studies have demonstrated that tendons are also affected in mdx mice, based especially on the changes in biomechanical properties arising from the respective linked muscles. However, most studies have focused only on alterations in the myotendinous junction. Thus, the purpose of this work was to study biochemical and morphological alterations in the Achilles tendons of 60-day-old mdx mice. Hydroxyproline quantification, showed higher collagen concentration in the mdx mice as compared with the control. No difference between the tendons of both groups was found in the noncollagenous proteins dosage, and in the amount of collagen type III detected in the western blotting analysis. The zymography for gelatinases detection showed higher amounts of metaloproteinase-2 (active isoform) and of metalloproteinase-9 (latent isoform) in the mdx mice. Measurements of birefringence, using polarization microscopy, showed higher molecular organization of the collagen fibers in the tendons of mdx mice in comparison to the control group, with presence of larger areas of crimp. Ponceau SS-stained tendon sections showed stronger staining of the extracellular matrix in the mdx groups. Toluidine blue-stained sections showed more intense basophilia in tendons of the control group. In morphometry, a higher number of inflammatory cells was detected in the epitendon of mdx group. In conclusion, the Achilles tendon of 60-day-old mdx mice presents higher collagen concentration and organization of the collagen fibers, enhanced metalloproteinase-2 activity, as well as prominent presence of inflammatory cells and lesser proteoglycans. Microsc. Res. Tech. 78:85-93, 2015. © 2014 Wiley Periodicals, Inc. PMID:25327690

De Aro, Andrea Aparecida; Da Ré Guerra, Flávia; Marretto Esquisatto, Marcelo Augusto; Nakagaki, Wilson Romero; Gomes, Laurecir; Pimentel, Edson Rosa

2015-01-01

232

Outcome and Structural Integrity of Rotator Cuff after Arthroscopic Treatment of Large and Massive Tears with Double Row Technique: A 2-Year Followup  

PubMed Central

Purpose. The purpose of this study was to evaluate the functional outcome and the tendon healing after arthroscopic double row rotator cuff repair of large and massive rotator cuff tears. Methods. 82 patients with a full-thickness large and massive rotator cuff tear underwent arthroscopic repair with double row technique. Results were evaluated by use of the UCLA, ASES, and Constant questionnaires, the Shoulder Strength Index (SSI), and range of motion. Follow-up time was 2 years. Magnetic resonance imaging (MRI) studies were performed on each shoulder preoperatively and 2 years after repair. Results. 100% of the patients were followed up. UCLA, ASES, and Constant questionnaires showed significant improvement compared with preoperatively (P < 0.001). Range of motion and SSI in flexion, abduction, and internal and external rotation also showed significant improvement (P < 0.001). MRI studies showed 24 cases of tear after repair (29%). Only 8 cases were a full-thickness tear. Conclusions. At two years of followup, in large and massive rotator cuff tears, an arthroscopic double row rotator cuff repair technique produces an excellent functional outcome and structural integrity. PMID:23533788

Carbonel, Ignacio; Martínez, Angel A.; Aldea, Elisa; Ripalda, Jorge

2013-01-01

233

Tendon-Holding Capacities of Two Newly Designed Implants for Tendon Repair: An Experimental Study on the Flexor Digitorum Profundus Tendon of Sheep  

PubMed Central

Background: Two main factors determine the strength of tendon repair; the tensile strength of material and the gripping capacity of a suture configuration. Different repair techniques and suture materials were developed to increase the strength of repairs but none of techniques and suture materials seem to provide enough tensile strength with safety margins for early active mobilization. In order to overcome this problem tendon suturing implants are being developed. We designed two different suturing implants. The aim of this study was to measure tendon-holding capacities of these implants biomechanically and to compare them with frequently used suture techniques Materials and Methods: In this study we used 64 sheep flexor digitorum profundus tendons. Four study groups were formed and each group had 16 tendons. We applied model 1 and model 2 implant to the first 2 groups and Bunnell and locking-loop techniques to the 3rd and 4th groups respectively by using 5 Ticron sutures. Results: In 13 tendons in group 1 and 15 tendons in group 2 and in all tendons in group 3 and 4, implants and sutures pulled out of the tendon in longitudinal axis at the point of maximum load. The mean tensile strengths were the largest in group 1 and smallest in group 3. Conclusion: In conclusion, the new stainless steel tendon suturing implants applied from outside the tendons using steel wires enable a biomechanically stronger repair with less tendon trauma when compared to previously developed tendon repair implants and the traditional suturing techniques. PMID:25067965

A??r, ?smail; Aytekin, Mahmut Nedim; Ba?ç?, Onur; Çayp?nar, Bar??; Erol, Bülent

2014-01-01

234

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

235

Fiber Bragg grating displacement sensor for movement measurement of tendons and ligaments  

NASA Astrophysics Data System (ADS)

Biomechanical studies often involve measurements of the strains developed in tendons or ligaments in posture or locomotion. Fiber-optic sensors present an attractive option for the measurement of strains in tendons and ligaments because of their low cost, ease of implementation, and increased accuracy compared with other implantable transducers. A new displacement sensor based on a fiber Bragg grating and shape memory alloy technology is proposed for the monitoring of tendon and ligament strains in different postures and in locomotion. After sensor calibration in the laboratory, a comparison of the fiber sensors and traditional camera displacement sensors was carried out to evaluate the performance of the fiber sensor during the application of tension to the Achilles tendon. Additional experiments were performed in cadaver knees to assess the suitability of these fiber sensors to measure ligament deformation in a variety of simulated postures. The results demonstrate that the proposed fiber Bragg grating sensor is a highly accurate, easily implantable, and minimally invasive method of measuring tendon and ligament displacement.

Ren, Liang; Song, Gangbing; Conditt, Michael; Noble, Philip C.; Li, Hongnan

2007-10-01

236

Image analysis of tendon helical superstructure using interference and polarized light microscopy.  

PubMed

Wave-like structures (WLS also known as crimp) have generally been reported to be planar structures. However, there is evidence that a helical superstructure, rather than a planar one, should be considered. Conditions dictated by supramolecular chemistry, molecular recognition and self-assembly favor the idea of a helical arrangement for collagen bundles in a supramolecular structure. The aim of this work is to provide additional data in support of a helical superstructure for collagen bundles in tendons. Cryosections of fixed flexor bovine tendons and sections of resin-embedded peeled rat tail were studied using polarized light, interference, and phase contrast microscopy. Image analysis was used to find appropriate mathematical descriptors for WLS. Interference colors due to the dispersion of birefringence allowed the detection of a gradual, intertwined twisted fiber organization in WLS, as the angle of the tendon axis was rotated relative to the polarizers. Helical movements of the images of the WLS bands were produced using animation methods. Interference microscopy revealed interference colors associated with different orientations and dry mass concentrations in the fibers, especially in tendon cross-sections, which also exhibited Maltese-cross birefringence images. Similar images were detected by interference microscopy, suggesting a spiral organization of fibers in the section plane. The helical orientation of the fibers was detected by focusing through different planes of sections. Based on a comparison of this superstructure with mesophases, the twisted grain boundary concept is considered to be the most appropriate for the classification of tendon WLS. PMID:14680929

de Campos Vidal, Benedicto

2003-01-01

237

Automatic dynamic tear meniscus measurement in optical coherence tomography  

PubMed Central

An image processing algorithm is developed for quantitative assessment of tear meniscus dynamics from continuous optical coherence tomography (OCT) measurements. Clinical utility of dynamic OCT tear meniscus measurement is assessed in studies of tear meniscus parameters. The results indicate that any apparent changes in the early post-blink phase meniscus parameters are essentially related to the longitudinal movements of the eye and not to the formation of tear meniscus corresponding to tear film build-up. Dynamic acquisition of tear film meniscus is essential for providing reliable estimates of its parameters such as height, depth, and area. PMID:25136499

Bartuzel, Maciej M.; Szczesna-Iskander, Dorota H.; Iskander, D. Robert

2014-01-01

238

Tension Distribution in a Tendon-Driven Robotic Finger  

NASA Technical Reports Server (NTRS)

A method is provided for distributing tension among tendons of a tendon-driven finger in a robotic system, wherein the finger characterized by n degrees of freedom and n+1 tendons. The method includes determining a maximum functional tension and a minimum functional tension of each tendon of the finger, and then using a controller to distribute tension among the tendons, such that each tendon is assigned a tension value less than the maximum functional tension and greater than or equal to the minimum functional tension. The method satisfies the minimum functional tension while minimizing the internal tension in the robotic system, and satisfies the maximum functional tension without introducing a coupled disturbance to the joint torques. A robotic system includes a robot having at least one tendon-driven finger characterized by n degrees of freedom and n+1 tendons, and a controller having an algorithm for controlling the tendons as set forth above.

Abdallah, Muhammad E. (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor)

2013-01-01

239

In Vivo Identity of Tendon Stem Cells and the Roles of Stem Cells in Tendon Healing  

PubMed Central

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

Tan, Qi; Lee, Yuk Wa

2013-01-01

240

Collisionless and Collisional Tearing Mode in Gyrokinetics  

NASA Astrophysics Data System (ADS)

We present numerical results of linear tearing mode simulations for collisionless and collisional regimes in a strong guide magnetic field limit using the AstroGK astrophysical gyrokinetics code. In the collisionless regime, the two-fluid effect, instead of the resistivity, mediates reconnection. Mirnov et al. and Fitzpatrick et al. have derived linear and nonlinear versions of reduced two-fluid models for the tearing mode in the presence of the guide field^1,2. We compare numerically obtained tearing mode growth rate with those theories. For the collisional regime, we compare gyrokinetic simulation results with the classical tearing mode theory by Furth, Kileen, and Rosenbluth, and with a fluid simulation. This benchmarks recently implemented resistivity term in the code. AstroGK can smoothly connect those two regimes. We also discuss the scaling of the growth rate against the collisionality in the intermediate regime, and how the kinetic effects play roles in the tearing mode. 1. V. V. Mirnov, C. C. Hegna, and S. C. Prager, Phys. Plasmas 11, 4468, (2004). 2. R. Fitzpatrick and F. Porcelli, Phys. Plasmas 11, 4713 (2004).

Numata, Ryusuke; Tatsuno, Tomoya; Dorland, William; Rogers, Barret

2009-05-01

241

Laser photoirradiation in digital flexor tendon repair.  

PubMed

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

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

2001-09-01

242

Posterior tibial tendon dysfunction: a review.  

PubMed

Posterior tibial tendon dysfunction is a progressive deformity that can result in the development of a pathologic flatfoot deformity. Numerous publications have studied the effects of clinical interventions at specific stages of progression of posterior tibial tendon dysfunction, but there is still uncertainty regarding the clinical identification of the condition. It is clear that more information regarding the etiology, progression, and risk factors of posterior tibial tendon dysfunction is required. Clear evidence exists that suggests that the quality of life for patients with posterior tibial tendon dysfunction is significantly affected. Furthermore, evidence suggests that early conservative intervention can significantly improve quality of life regarding disability, function, and pain. This would suggest that significant cost burden reductions could be made by improving awareness of the condition, which would improve early diagnosis. Early conservative intervention may help reduce the number of patients requiring surgery. This review focuses on the etiologic factors, epidemiologic features, and pathogenesis of posterior tibial tendon dysfunction. It aims to analyze, discuss, and debate the current understanding of this condition using the available literature. In addition, there is a discussion of the evidence base surrounding disease characteristics associated with the different clinical stages of posterior tibial tendon dysfunction. PMID:21406702

Durrant, Beverley; Chockalingam, Nachiappan; Hashmi, Farina

2011-01-01

243

Functional morphology of the supraspinatus tendon.  

PubMed

Grossly normal supraspinatus tendons were analyzed by stereomicroscope dissection and three-dimensional serial-section reconstruction. Four structurally independent subunits were identified: the tendon proper extended from the musculotendinous junction to approximately 2.0 cm medial to the greater tuberosity. It was composed of parallel collagen fascicles oriented along the tensional axis and separated by a prominent endotenon region. There was no interdigitation of fascicles, and an 18% incidence of fascicle convergence as the fascicles coursed from muscle toward greater tuberosity. The attachment fibrocartilage extended from the tendon proper to the greater tuberosity, consisted of a complex basket-weave of collagen fibers, and stained diffusely with alcian blue. The densely packed unidirectional collagen fibers of the rotator cable extended from the coracohumeral (CH) ligament posteriorly to the infraspinatus, coursing both superficial and deep to the tendon proper. The capsule was composed of thin collagen sheets each with uniform fiber alignment that differed slightly between sheets. These data describe a specialized tendon capable of internally compensating for changing joint angles through fascicles which are structurally independent and can slide past one another. The tendon attachment exhibits a structure adapted to tensional load dispersion and resistance to compression. PMID:12382954

Fallon, Jonathan; Blevins, Field T; Vogel, Kathryn; Trotter, John

2002-09-01

244

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

245

Comparison between surgery and physiotherapy in the treatment of small and medium-sized tears of the rotator cuff: A randomised controlled study of 103 patients with one-year follow-up.  

PubMed

In order to compare the outcome from surgical repair and physiotherapy, 103 patients with symptomatic small and medium-sized tears of the rotator cuff were randomly allocated to one of the two approaches. The primary outcome measure was the Constant score, and secondary outcome measures included the self-report section of the American Shoulder and Elbow Surgeons score, the Short Form 36 Health Survey and subscores for shoulder movement, pain, strength and patient satisfaction. Scores were taken at baseline and after six and 12 months by a blinded assessor. Nine patients (18%) with insufficient benefit from physiotherapy after at least 15 treatment sessions underwent secondary surgical treatment. Analysis of between-group differences showed better results for the surgery group on the Constant scale (difference 13.0 points, p - 0.002), on the American Shoulder and Elbow surgeons scale (difference 16.1 points, p < 0.0005), for pain-free abduction (difference 28.8 degrees , p = 0.003) and for reduction in pain (difference on a visual analogue scale -1.7 cm, p < 0.0005). PMID:20044684

Moosmayer, S; Lund, G; Seljom, U; Svege, I; Hennig, T; Tariq, R; Smith, H-J

2010-01-01

246

Patellar tendon length after anterior cruciate ligament reconstruction: a comparative magnetic resonance imaging study between patellar and hamstring tendon autografts.  

PubMed

Patellar tendon shortening after anterior cruciate ligament reconstruction may be associated with anterior knee pain or patellofemoral arthritis. The present study was designed to compare postoperative changes in patellar tendon length after anterior cruciate ligament reconstruction between patellar tendon and hamstring tendon autograft. Magnetic resonance images of both knees (operated and healthy) and functional outcome were documented at least 1 year postoperatively in 16 patellar tendon harvested patients and in 32 hamstrings harvested patients. Patellar tendon length, patella length and Insall-Salvati ratio were measured. The operated knee values were compared to the respective values of the non-operated control knees. A significant 4.2 mm or 9.7% patellar tendon shortening in patellar tendon group and a non-significant 1.14 mm or 2.6% shortening in hamstrings group was detected. No significant difference was detected in terms of major shortening-patella baja-(6% for the patellar tendon group vs. 0% for the hamstring group). There was no significant difference in anterior knee problems between the two groups as evidenced by the Shelbourne score (94 for the patellar tendon group vs. 98 for the hamstring group). Harvesting of the patellar tendon for anterior cruciate ligament reconstruction resulted in a significant shortening of the remaining tendon. In contrast harvesting of the hamstring tendons did not affect significantly the patellar tendon length. However, the incidence of patella baja and overall functional outcome was not significantly different between the two groups. PMID:17225175

Hantes, Michael E; Zachos, Vasilios C; Bargiotas, Konstantinos A; Basdekis, Georgios K; Karantanas, Apostolos H; Malizos, Konstantinos N

2007-06-01

247

Tear film dynamics with evaporation and osmolarity  

NASA Astrophysics Data System (ADS)

We consider a model problem for the evaporation and breakup up of tear film. The model includes the effects of surface tension, Marangoni stresses, insoluble surfactant transport, evaporation, osmolarity transport, osmosis and wetting of corneal surface. Evaporation is made dependent on surface concentration in order to mimic the lipid layer of the tear film when there is a single fluid layer in the model. In many cases for a single layer, the Marangoni effect seems to eliminate a localized area of increased evaporation due to reduced surfactant concentration. In this model the osmolarity in the tear film increases because of average evaporation rate rather than by a locally increased evaporation rate. If time permits, the effect of having a second fluid layer, representing the lipid layer, will be explored as well.

Siddique, Javed; Braun, Richard

2011-11-01

248

Arthroscopic Percutaneous Repair of Anterosuperior Rotator Cuff Tear Including Biceps Long Head: A 2-Year Follow-up  

PubMed Central

Background To report the results of an arthroscopic percutaneous repair technique for partial-thickness tears of the anterosuperior cuff combined with a biceps lesion. Methods The inclusion criteria were evidence of the upper subscapularis tendon tear and an articular side partial-thickness tear of the supraspinatus tendon, degeneration of the biceps long head or degenerative superior labrum anterior-posterior, above lesions treated by arthroscopic percutaneous repair, and follow-up duration > 24 months after the operation. American Shoulder and Elbow Surgeons (ASES) score, constant score, the pain level on a visual analogue scale, ranges of motion and strength were assessed. Results The mean (± standard deviation) age of the 20 enrolled patients was 56.0 ± 7.7 years. The forward flexion strength increased from 26.3 ± 6.7 Nm preoperatively to 38.9 ± 5.1 Nm at final follow-up. External and internal rotation strength was also significantly increased (14.2 ± 1.7 to 19.1 ± 3.03 Nm, 12.3 ± 3.2 to 18.1 ± 2.8 Nm, respectively). Significant improvement was observed in ASES and constant scores at 3 months, 1 year and the time of final follow-up when compared with preoperative scores (p < 0.001). The mean subjective shoulder value was 86% (range, 78% to 97%). Conclusions The implementation of complete rotator cuff repair with concomitant tenodesis of the biceps long head using arthroscopic percutaneous repair achieved full recovery of normal rotator cuff function, maximum therapeutic efficacy, and patient satisfaction. PMID:23205238

Kim, Do-Young; Lee, Sang-Soo; Seo, Eun-Min; Hwang, Jung-Taek; Kwon, Sun-Chang; Lee, Jae-Won

2012-01-01

249

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

250

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

PubMed

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

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

2008-11-01

251

Elastographic characteristics of the metacarpal tendons in horses without clinical evidence of tendon injury.  

PubMed

Tendon and ligament injuries are common causes of impaired performance in equine athletes. Gray-scale ultrasonography is the current standard method for diagnosing and monitoring these injuries, however this modality only provides morphologic information. Elastography is an ultrasound technique that allows detection and measurement of tissue strain, and may provide valuable mechanical information about equine tendon and ligament injuries. The purpose of this study was to determine the feasibility, reproducibility, and repeatability of elastography; and to describe elastographic characteristics of metacarpal tendons in sound horses. Nineteen legs for 17 clinically sound horses without evidence of musculoskeletal pathology were included. Elastographic images of the superficial and deep digital flexor tendons and the branches of the suspensory ligament (tendon of the interosseous muscle) were described quantitatively and qualitatively. There was no statistically significant difference between operators (P = 0.86) nor within operators (P = 0.93). For qualitative assessments, reproducibility (0.46) was moderate and repeatability (0.78) was good. Similar to human Achilles tendons, equine tendons were classified as predominantly hard using elastography. There was no statistically significant difference in stiffness of the flexor tendons (P = 0.96). No significant difference in stiffness was found with altered leg position during standing (P = 0.84) and while nonweight bearing (P = 0.61). The flexor tendons were softer when imaged in longitudinal versus transverse planes (P < 0.01) however, the suspensory branches were not (P = 0.67). Findings supported future clinical application of elastography as a noninvasive "stall-side" imaging modality for evaluation of the tendons and ligaments of the distal forelimb in horses. PMID:24103015

Lustgarten, Meghann; Redding, W Rich; Labens, Raphael; Morgan, Michel; Davis, Weston; Seiler, Gabriela S

2014-01-01

252

Clinic and electromyographic results of latissimus dorsi transfer for irreparable posterosuperior rotator cuff tears.  

PubMed

BackgroundThis study examines the clinical and electromyographic results of latissimus dorsi transfer (LDT) using a combined open and arthroscopic technique for the treatment of symptomatic irreparable posterosuperior rotator cuff tears.MethodsBetween 2006 and 2009, LDT was performed in 14 patients (mean age 59 years) with massive and symptomatic irreparable posterosuperior rotator cuff tear. The patients were examined preoperatively and postoperatively with mean follow-up of 52 months using the Constant score, and the integrity of the latissimus dorsi (LD) transfer was assessed by ultrasound in all cases and by MRI in ten cases. The functional activity of the LD transfer was compared to the non-operated side using surface electromyography.ResultsAll patients demonstrated a significant improvement in the Constant score (p =0.001), from a preoperative score of 33 points (range 10¿55 points) to a postoperative score of 59 points (range 13¿80 points). The subjective assessment score was good to excellent in 12 patients (85%), and 11 patients (78%) would be willing to undergo surgery again. Integrity of the transferred tissue was confirmed in 13 of the 14 cases using ultrasound and MRI. Surface electromyographic signal showed increased activation of the transferred latissimus dorsi when performing active movements of external rotation (p =0.002) and abduction-elevation (p =0.009).ConclusionsOur results indicate that LDT significantly improves function and diminishes pain in patients with a massive posterosuperior rotator cuff tear. The combined open and arthroscopic technique preserves the deltoid muscle and controls the LD tendon reinsertion. Surface electromyographic signal confirms the active function of the transferred muscle. PMID:25380558

De Casas, Ricardo; Lois, Matías; Cidoncha, Myriam; Valadron, Miguel

2014-11-01

253

49 CFR 173.340 - Tear gas devices.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Tear gas devices. 173.340 Section 173...REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.340 Tear gas devices. (a) Packagings for tear gas devices must be approved prior...

2010-10-01

254

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

255

Quantitative tear lysozyme assay: a new technique for transporting specimens.  

PubMed Central

We have developed a method for assaying the concentration of tear lysozyme using eluates of tear fluid collected on filter paper discs. Specimens can be stored and transported to remote laboratories for assay. We have shown that the 'indirect' or eluate method gives statistically comparable results to the 'direct' method using fresh, neat tear fluid. Images PMID:7426595

Seal, D V; Mackie, I A; Coakes, R L; Farooqi, B

1980-01-01

256

21 CFR 888.3025 - Passive tendon prosthesis.  

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

2014-04-01

257

21 CFR 888.3025 - Passive tendon prosthesis.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

258

21 CFR 888.3025 - Passive tendon prosthesis.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

259

Temperture anisotropy effect on the tearing mode  

Microsoft Academic Search

Previous study of the Plasma temperature anisotropy in the current sheet have shown that alphaj > 1 (alphaj = Tj,perp\\/Tj,para , j = ion or electron) significantly enhances the growth rate of tearing instability (TI), and the maximum growth wave length shift for shorter by the linear theory [Chen & Palmadesso, Phys. Fluds 1984; Ambrosiano, Geophys. Res. 1986]. Recent result

K. Haijima; K. Tanaka; M. Fujimoto; I. Shinohara

2006-01-01

260

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

261

Compaction Drilling Does Not Increase the Initial Fixation Strength of the Hamstring Tendon Graft in Anterior Cruciate Ligament Reconstruction in a Cadaver Model  

Microsoft Academic Search

Background: Compaction of the bone tunnel walls has been proposed to increase the fixation strength of soft tissue grafts fixed with an interference screw in anterior cruciate ligament reconstructions.Hypothesis: Compaction drilling does not increase the initial fixation strength of the hamstring tendon graft in comparison with conventional extraction drilling.Study Design: Randomized experimental study.Methods: Initial fixation strength of quadrupled hamstring tendon

Janne T. Nurmi; Pekka Kannus; Harri Sievänen; Markku Järvinen; Teppo L. N. Järvinen

2003-01-01

262

Use of platelet-rich plasma to enhance tendon function and cellularity.  

PubMed

Clinical studies have shown inconsistent healing with subjective improvement after use of platelet-rich plasma (PRP) for tendinosis and partial tendon tears. We conducted a study to assess changes after injecting PRP into an intact rabbit patellar tendon (PT) model. In the study group (n = 10), an incision was made over the PT and PRP was injected into multiple sites on the PT. The control group (n = 8) was injected with saline. PTs were harvested 7 and 28 days after injection. Hematoxylin-eosin staining showed hypercellularity in the PRP group at 7 days, but the effect was not as marked at 28 days. At 7 days, polarized microscopy showed increased crimp density of collagen in the PRP group, compared with the control group, demonstrating up-regulation in collagen matrix. Cellular proliferation measured by tritiated thymidine was also significantly increased (P = .02) in the PRP group, compared with the control group, but the difference was not as significant at 28 days. At 7 and 28 days, there were no significant changes in basic fibroblast growth factor, insulin-like growth factor, vascular endothelial growth factor, or platelet-derived growth factor with 2B chains. Injection of PRP into rabbit PT enhances collagen remodeling and hypercellularity with increased metabolic activity, which could have a positive effect on healing. PMID:23710476

Lane, John G; Healey, Robert M; Chase, Derek C; Amiel, David

2013-05-01

263

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

264

In vivo achilles tendon loading' during jumping in humans  

Microsoft Academic Search

Elastic behaviour of the human tendomuscular system during jumping was investigated by determination of the in vivo Achilles tendon force. A buckle-type transducer was implanted under local anaesthesia around the right Achilles tendon of an adult subject. After calibration, the Achilles tendon force was recorded together with the triceps surae muscle electromyogram activity and high speed filming and ground reaction

Senshi Fukashiro; Paavo V. Komi; Markku Järvinen; Mitsumasa Miyashita

1995-01-01

265

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:24611149

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

2014-01-01

266

Biodegradable synthetic scaffolds for tendon regeneration  

PubMed Central

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

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

2012-01-01

267

MR imaging-based diagnosis and classification of meniscal tears.  

PubMed

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

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

2014-01-01

268

Structure-strength relations in mammalian tendon.  

PubMed Central

The stress-strain relations in mammalian tendon are analyzed in terms of the structure and mechanics of its constituents. The model considers the tensile and bending strength of the collagen fibers, the tensile strength of the elastin fibers, and the interaction between the matrix and the collagen fibers. The stress-strain relations are solved through variational considerations by assuming that the fibermaxtrix interactions can be modeled as beam on elastic foundation. The tissue thus modeled is a hyperelastic material. It is further shown that on the basis of the model, the dominant parameters to the tendon's behavior can be evaluated from simple tensile tests. PMID:728528

Lanir, Y

1978-01-01

269

The role of animal models in tendon research  

PubMed Central

Tendinopathy is a debilitating musculoskeletal condition which can cause significant pain and lead to complete rupture of the tendon, which often requires surgical repair. Due in part to the large spectrum of tendon pathologies, these disorders continue to be a clinical challenge. Animal models are often used in this field of research as they offer an attractive framework to examine the cascade of processes that occur throughout both tendon pathology and repair. This review discusses the structural, mechanical, and biological changes that occur throughout tendon pathology in animal models, as well as strategies for the improvement of tendon healing. Cite this article: Bone Joint Res 2014;3:193–202. PMID:24958818

Hast, M. W.; Zuskov, A.; Soslowsky, L. J.

2014-01-01

270

Spontaneous "spaghetti" flexor tendon ruptures in the rheumatoid wrist.  

PubMed

A 54-year-old woman who had been treated for rheumatoid arthritis for 12 years developed spontaneous multiple flexor tendon ruptures during a 5-month period. Radiography revealed volar subluxation of the lunate bone. Surgery was performed 5 months after the first onset of tendon rupture. All eight flexors, except the flexor pollicis longus tendons, had ruptured, and the damage resembled spaghetti. Four flexor digitorum profundus tendons were reconstructed by bridge graft using their respective sublimis tendons. Wrist joint fusion and tenolysis were performed 3 months after the first operation. Each finger achieved a good range of motion 2 years and 6 months after the second operation. PMID:17143686

Hashizume, Hiroyuki; Nishida, Keiichiro; Fujiwara, Kazuo; Inoue, Hajime

2004-01-01

271

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

272

Simultaneous reconstruction of quadriceps tendon rupture after TKA and neglected Achilles tendon rupture.  

PubMed

We report a case of simultaneous reconstruction of a quadriceps tendon rupture after total knee arthroplasty (TKA) and neglected Achilles tendon rupture, which occurred before TKA with an ipsilateral hamstring autograft. A 64-year-old woman presented with persistent right knee pain. She also had right heel pain and had received multiple steroid injections at the knee joint and heel. On examination, she showed osteoarthritis in the medial and lateral compartments of the knee joint and an Achilles tendon rupture in the ipsilateral limb. There was skin dimpling and the proximal portion of tendon was migrated. We performed TKA, and the postoperative course was satisfactory. She returned 3 months postoperatively, however, with skin dimpling around the suprapatellar area and weakness of knee extension. Her ankle symptoms were also aggravated because she could not use the knee joint freely. We performed simultaneous reconstruction of the quadriceps tendon and the Achilles tendon using an ipsilateral hamstring autograft.Hamstring autograft offers a good alternative treatment option for rupture repair, particularly with concommitant ruptures of multiple sites when primary repair is not possible or the viability of repaired tissue is poor. PMID:20506939

Lee, Yong Seuk; Min, Byoung-Hyun; Han, Kyeong-Jin; Cho, Jae Ho; Han, Seung Hwan; Lee, Doo-Hyung; Oh, Kyung Soo

2010-05-01

273

Tear Dysfunction and the Cornea: LXVII Edward Jackson Memorial Lecture  

PubMed Central

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

Pflugfelder, Stephen C.

2011-01-01

274

Characterization of ocular gland morphology and tear composition of pinnipeds  

PubMed Central

Objective The importance of tear film integrity to ocular health in terrestrial mammals is well established, however, in marine mammals, the role of the tear film in protection of the ocular surface is not known. In an effort to better understand the function of tears in maintaining health of the marine mammal eye surface, we examined ocular glands of the California sea lion, and began to characterize the biochemical nature of the tear film of pinnipeds. Procedures Glands dissected from California sea lion eyelids and adnexa were examined for gross morphology, sectioned for microscopic analysis, and stained with haematoxylin and eosin. The tear film was examined using interferometry. Tears were collected from humans and pinnipeds for analysis of protein and carbohydrate content. Results The sea lion has sebaceous glands in the lid, but these glands are different in size and orientation compared to typical meibomian glands of terrestrial mammals. Two other accessory ocular glands located dorsotemporally and medially appeared to be identical in morphology, with tubulo-acinar morphology. An outer lipid layer on the ocular surface of the sea lion was not detected using interferometry, consistent with the absence of typical meibomian glands. Similar to human tears, the tears of pinnipeds contain several proteins but the ratio of carbohydrate to protein was greater than that in human tears. Conclusions Our findings indicate that the ocular gland architecture and biochemical nature of the tear film of pinnipeds have evolved to adapt to the challenges of an aquatic environment. PMID:23067374

Davis, Robin Kelleher; Doane, Marshall G.; Knop, Erich; Knop, Nadja; Dubielzig, Richard R.; Colitz, Carmen M. H.; Argüeso, Pablo; Sullivan, David A.

2012-01-01

275

Spondylodiscitis and Achilles tendonitis due to gout.  

PubMed

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

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

2014-11-01

276

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

277

How tendons buffer energy dissipation by muscle  

PubMed Central

To decelerate the body and limbs, muscles actively lengthen to dissipate energy. During rapid energy-dissipating events, tendons buffer the work done on muscle by temporarily storing elastic energy, then releasing this energy to do work on the muscle. This elastic mechanism may reduce the risk of muscle damage by reducing peak forces and lengthening rates of active muscle. PMID:23873133

Roberts, Thomas J.; Konow, Nicolai

2013-01-01

278

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

279

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

280

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

PubMed Central

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

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

2009-01-01

281

ACL Tears in Collegiate Wrestlers  

PubMed Central

Six NCAA Division I wrestlers at The University of Iowa tore an anterior cruciate ligament (ACL) during the 2002-03 season. In comparison, between the years of 1993 and 2002, only five wrestlers sustained the same injury. Retrospective review and video data analysis were performed. All six were injured while their knee was near terminal extension and in a vulnerable position. Eighty-three percent of all injuries occurred during takedowns. Five of the six wrestlers' mechanism of injury involved rotation and stress on the weight-bearing knee. Eighty-three percent sustained their injuries while their foot was firmly planted on the ground. Five of the injuries occurred in competition. Of the six wrestlers injured, four underwent immediate rehabilitation in hope of wrestling that same season. Three ultimately needed surgery and one continued to wrestle in the same season without having surgery. Of the five wrestlers who underwent surgical reconstruction of their ACL, each had bone-patellar-bone grafts. PMID:16089088

Lightfoot, Andrew J; McKinley, Todd; Doyle, Matthew; Amendola, Annunziato

2005-01-01

282

Versican splice variant messenger RNA expression in normal human Achilles tendon and tendinopathies  

Microsoft Academic Search

Objectives. Versican is the principal large proteoglycan expressed in mid-tendon, but its role in tendon pathology is unknown. Our objective was to define the expression of versican isoform splice variant messenger ribonucleic acid (mRNA) in normal Achilles tendons, in chronic painful tendinopathy and in ruptured tendons. Methods. Total RNA isolated from frozen tendon samples (normal n ¼ 14; chronic painful

A. N. Corps; A. H. N. Robinson; T. Movin; M. L. Costa; D. C. Ireland; B. L. Hazleman; G. P. Riley

2004-01-01

283

Tear lipid layer and contact lens comfort: a review.  

PubMed

This review describes the impact of contact lens wear on the tear film lipid layer and how changes in the lipid layer might modulate contact lens-related discomfort. Relevant clinical, functional, and biochemical aspects of the tear film lipid layer are reviewed. Contact lens wear modulates these aspects of the lipid layer, specifically the prelens lipid layer thickness is reduced; tear evaporation rate is increased; tear breakup time is reduced; and the concentration of lipid components such as cholesterol esters, wax esters, and phospholipids varies. The full implications of these changes are unclear; however, there is some evidence that contact lens-related discomfort is associated with a thinner prelens lipid layer, increased lipid degradation, and greater secretory phospholipase A2 activity. Certain fatty acids appear to be associated with maintaining the structural stability of the tear film but their role in retarding tear evaporation and modulating contact lens-related discomfort remains to be elucidated. PMID:23584045

Rohit, Athira; Willcox, Mark; Stapleton, Fiona

2013-05-01

284

Posterolateral reconstruction using split achilles tendon allograft  

Microsoft Academic Search

Injury to the cruciate ligaments of the knee commonly occurs in association with posterolateral instability, which can cause severe functional disability including varus, posterior translation, and external rotational instability. Failure to diagnose and treat an injury of the posterolateral corner in a patient who has a tear of the cruciate ligament can also result in the failure of the reconstructed

Myung Chul Lee; Yoon Keun Park; Sang-Hoon Lee; Hyunchul Jo; Sang Cheol Seong

2003-01-01

285

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

286

Design and performance of a fiber bragg grating displacement sensor for movement measurement of tendon and ligament  

NASA Astrophysics Data System (ADS)

Biomechanical studies often involve measurements of the strains developed in tendons or ligaments in posture or locomotion. Fiber optic sensors present an attractive option for measurement of strains in tendons and ligaments due to their low cost, ease of implementation, and increased accuracy compared to other implantable transducers. A new displacement sensor based on fiber Bragg grating and shape memory alloy technology is proposed for the monitoring of tendon and ligament strains in different postures and in locomotion. After sensor calibration in the laboratory, a comparison test between the fiber sensors and traditional camera displacement sensors was carried out to evaluate the performance of the fiber sensor during application of tension to the Achilles tendon. Additional experiments were performed in cadaver knees to assess the suitability of these fiber sensors for measuring ligament deformation in a variety of simulated postures. The results demonstrate that the proposed fiber Bragg grating sensor is a high-accuracy, easily implantable, and minimally invasive method of measuring tendon and ligament displacement.

Ren, Liang; Song, Gangbing; Conditt, Michael; Noble, Philip C.; Li, Hongnan

2007-04-01

287

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

288

"V"ictory transosseous equivalent suture configuration for arthroscopic rotator cuff tear repairs of iatrogenically completed PASTA lesions and full-thickness "U"-shaped tears.  

PubMed

The cost of numerous anchors in rotator cuff surgery is high from both an economic standpoint as well as a physiologic one. More anchors means increased cost and increased surgical time; additionally, the greater number of anchors placed, the greater the expense on the native bone that they inevitably replace. It is therefore in the surgeon's and patient's best interest to use the appropriate number of anchors, no more and no less, with the appropriate number being that which allows for strong, stable fixation with minimal gap formation and maximal healing potential and recovery. The transosseous equivalent repair technique described herein uses a single double-loaded bioabsorbable suture anchor placed along the medial border of the rotator cuff foot print and the humeral head articular cartilage margin followed by 1 pushlock (Arthrex, Naples, Florida) anchor placed laterally on the vertical aspect of the greater tuberosity. It is designed for small to medium "U"-shaped tears and for iatrogenically completed partial articular supraspinatus tendon avulsions of moderate to large size, the so-called PASTA lesion. The use of selective knot placement allows for the conversion of a linear construct into a "V" configuration, optimizing repair strength and allowing for earlier rehabilitation while maximizing the healing biology seen with increased footprint contact dimensions and less repair gap formation. PMID:19824586

Lewicky, Yuri M

2009-10-01

289

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

PubMed Central

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.

2014-01-01

290

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

291

The Relationship between Meniscal Tears and Meniscal Position  

PubMed Central

Objective: To investigate how different types of meniscal tears predispose to different patterns of meniscal position in subjects with and without symptomatic knee osteoarthritis (OA). Methods: A cross-sectional analysis of 161 women participating in an observational study to evaluate knee OA progression was performed using baseline MRI data. Meniscal morphologic features were scored in three separate locations. Meniscal position measures were determined for extrusion and proportion of coverage. Analysis was performed using multiple linear regression models treating each tear type as an individual variable with a binary response. Results: Complex tears, cysts and maceration of the medial meniscus were associated with more medial (p=0.0004, p=0.004, p <0.0001, respectively) and anterior extrusion (p =0.03, p=0.03, p<0.0001, respectively) than normal menisci. Horizontal tears of the lateral meniscus had more lateral (p=0.005) and anterior extrusion (p<0.0001) than normal menisci. Anterior and body tears of the medial meniscus were associated with more anterior extrusion (p=0.0006, p=0.01, respectively), whereas meniscal body tears alone had more medial extrusion than normal menisci (p= 0.0002). Meniscal body tears of the lateral meniscus had more lateral extrusion than normal menisci (p=0.01). Conclusion: Anterior horn and meniscal body tears and the more severe macerated and complex tear types predisposed to more medial meniscal extrusion. Laterally, only meniscal body and horizontal tears significantly affected extrusion, potentially reflecting a lower overall prevalence of lateral meniscal tears. These results may have important implications in identifying tear types associated with more meniscal dysfunction, with the ultimate goal of identifying those at greatest risk for knee OA progression. PMID:22870457

Allen, Deborah M.; Li, Ling; Crema, Michel D.; Marra, Monica D.; Guermazi, Ali; Wyman, Brad T.; Le Graverand, Marie-Pierre Hellio; Englund, Martin; Brandt, Kenneth D.; Hunter, David J.

2010-01-01

292

Sphincter tears in primiparous women: is age a factor?  

Microsoft Academic Search

Anal sphincter tears during vaginal delivery may result in serious sequelae. We examined whether younger primiparous patients\\u000a were at increased risk for sphincter tears during vaginal delivery. Data from an obstetric automated record were analyzed.\\u000a Primiparous women delivering term infants (n?=?5,937) were included to test for an association between age and sphincter tear rates. Three age groups were considered:\\u000a young

C. Bryce Bowling; Thomas L. Wheeler II; Kimberly A. Gerten; Victoria R. Chapman; Kathryn L. Burgio; Holly E. Richter

2009-01-01

293

Effect of tendon tensioning: an in vitro study in porcine extensor tendons.  

PubMed

Graft tensioning is a controversial issue in anterior cruciate ligament reconstruction (ACLR) that has not achieved consensus between peers. The purpose of this study is to determine if after tensioning tendon length and resistance to maximal load changes. We performed an in vitro study with 50 porcine extensors tendons. The first group (P=25) was tensioned with 80 N (19.97 lb) for 10 min, using an ACL graft preparation board. The second group (C=25) was used as control and was not tensioned. The average initial (groups P and C) and post tensioning tendon length (group C) were measured; the average initial and post tensioning tendon diameter were measured as well. All samples were fixated in a tube-clamp system connected to a tension sensor. The samples were stressed with continuous and progressive tension until ultimate failure at maximum load (UFML) occurs. The initial mean length was: P before tensioning=13.4 mm+/-1.4 mm (range 10.5-16.5); P after tensioning=13.8 mm+/-1.4 mm (range 11.5-16.5); C=13 mm+/-1.35 mm (p=0.005). The mean diameter was: P=5.6 mm (4.5-6); C=5.5 mm (range 4.5-6) (p>0.05). The UFML was: P=189.7 N (114-336); C=229.9 N (143-365) (p=0.029). Tendon tensioning with 80 N for 10 min produced 3% average elongation. These could be beneficial in ACLR since tendon tensioning decreases elongation of the graft after fixation. Regardless, tendon tensioning is not innocuous since it diminishes their resistance when continuously stressed until complete failure occurs. PMID:19744857

Figueroa, David; Calvo, Rafael; Vaisman, Alex; Meleán, Patricio; Figueroa, Francisco

2010-06-01

294

Stabilization of tearing modes by oscillating the resonant surface  

SciTech Connect

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

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

2012-07-15

295

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

296

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

SciTech Connect

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; Mao, Aohua; Sun, Jizhong, E-mail: jsun@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Duan, Ping [Department of Physics, Dalian Maritime University, Dalian 116026 (China)

2014-10-15

297

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

SciTech Connect

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

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

2014-06-15

298

Effects of different extents of pulley release on tendon excursion efficiency and tendon moment arms.  

PubMed

To compare the excursion efficiency and moment arms of flexor digitorum superficialis (FDS) and profundus (FDP) among different conditions of pulley integrity related to trigger finger treatment, cadaveric fingers were first tested with an intact pulley system, and then the first (A1) and second (A2) annular pulleys were released gradually from the proximal to distal part. Linear position sensors and a motion capture system were used to measure the tendon excursion and joint rotation simultaneously. The tendon excursion efficiency was defined as the range of motion of the involved joints per unit of tendon excursion, and the tendon moment arm was determined by the slope of the linear fitting result of tendon excursion versus metacarpophalangeal (MCP) joint rotation. No significant differences were found between the release of the A1 pulley and the release extending to half the proximal part of the A2 pulley in the FDP excursion efficiency and the moment arms of FDS and FDP with respect to the MCP joint. These results imply that the release could extend to half the proximal A2 pulley, if necessary, without significantly decreasing the FDP excursion efficiency and increasing the moment arms of FDS and FDP with respect to the MCP joint. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:224-228, 2015. PMID:25297915

Lu, Szu-Ching; Yang, Tai-Hua; Kuo, Li-Chieh; Jou, I-Ming; Sun, Yung-Nien; Su, Fong-Chin

2015-02-01

299

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

300

Exploring the application of stem cells in tendon repair and regeneration.  

E-print Network

clinical studies met the inclusion criteria. Preclinical studies have shown that stem cells are able to survive and differentiate into tendon cells when placed into a new tendon environment, leading to regeneration and biomechanical benefit to the tendon...

Ahmad, Z; Wardale, J; Brooks, R; Henson, F; Noorani, A; Rushton, N

2012-07-28

301

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

Federal Register 2010, 2011, 2012, 2013

...Prestressed Concrete Containment Structures With Grouted Tendons AGENCY...Prestressed Concrete Containment Structures with Grouted Tendons...prestressed concrete containment structures with grouted tendons. ADDRESSES...postulated accidents, and data that the staff needs in...

2012-11-19

302

Bifurcated intraarticular long head of biceps tendon  

PubMed Central

Though rare, many anomalous origins of long head of the biceps tendon (LHBT) have been reported in the literature. Anatomic variations commonly explained are a third humeral head, anomalous insertion, congenital absence and adherence to the rotator cuff. We report a rare case who underwent shoulder arthroscopy with impingement symptoms where in LHBT was found to be bifurcated with a part attached to superior labrum and the other part to the posterior capsule of joint. Furthermore, intraarticular portion of LHBT was adherent to the undersurface of the supraspinatus tendon. Awareness of such an anatomical aberration during the shoulder arthroscopy is of great importance as it can potentially avoid unnecessary confusion and surgery. PMID:25143652

Pandey, Vivek; van Laarhoven, Simon Nurettin; Arora, Gaurav; Rao, Sripathi

2014-01-01

303

Anterior cruciate ligament reconstruction with allograft tendons.  

PubMed

Allograft tissue allows reconstruction of the ACL without the donor site morbidity that can be caused by autograft harvesting. Patients who must kneel as a part of their occupation or chosen sport are particularly good candidates for allograft reconstruction. Patients over 45 years of age and those requiring revision ACL surgery can also benefit from the use and availability of allograft tendons. In some cases, patients or surgeons may opt for allograft tendons to maximize the result or morbidity ratio. Despite advances in cadaver screening and graft preparation, there remain risks of disease transmission and joint infection after allograft implantation. Detailed explanation and informed consent is vitally important in cases in which allograft tissue is used. PMID:12735200

Strickland, Sabrina M; MacGillivray, John D; Warren, Russell F

2003-01-01

304

Percutaneous & Mini Invasive Achilles tendon repair  

PubMed Central

Rupture of the Achilles tendon is a considerable cause of morbidity with reduced function following injury. Recent studies have shown little difference in outcome between the techniques of open and non-operative treatment using an early active rehabilitation programme. Meta-analyses have shown that non-operative management has increased risk of re-rupture whereas surgical intervention has risks of complications related to the wound and iatrogenic nerve injury. Minimally invasive surgery has been adopted as a way of reducing infections rates and wound breakdown however avoiding iatrogenic nerve injury must be considered. We discuss the techniques and outcomes of percutaneous and minimally invasive repairs of the Achilles tendon. PMID:22082172

2011-01-01

305

MRI and surgical findings in deltoid ligament tears.  

PubMed

OBJECTIVE. The objectives of our study were to determine the accuracy of new MRI criteria in detecting tears of the superficial deltoid ligament of the ankle, the accuracy of established criteria for detecting deep deltoid ligament tears, the most common location of super-ficial deltoid ligament tears, and the frequency of other injuries associated with deltoid tears. MATERIALS AND METHODS. A chart review yielded 89 cases over a 3-year interval in which ankle MRI was followed by open or arthroscopic surgery and the surgical report described findings in the deltoid ligament. One case was excluded because the MRI study was technically inadequate. MRI and surgical reports were then compared for the presence and location of deltoid ligament tears. RESULTS. MRI findings of focal detachment of the superficial deltoid origin or detachment of the fascial sleeve of the medial malleolus yielded a sensitivity for superficial deltoid ligament tears of 83.3% (45/54) and specificity of 93.9% (31/33). Eight of nine prospectively missed tears were visible on retrospective review. All superficial deltoid tears involved the origin of the ligament from the medial malleolus, and six involved mid or distal bundles of the superficial deltoid as well. MRI findings of discontinuity or nonvisualization of discrete fibers yielded a sensitivity for deep deltoid ligament tears of 96.3% (26/27) and specificity of 97.9% (46/47). CONCLUSION. MRI has a high accuracy for deltoid ligament tears in consecutive cases prospectively evaluated by musculoskeletal radiologists. The location of superficial deltoid ligament tears differed in our series from findings previously reported in the imaging literature. PMID:25539277

Crim, Julia; Longenecker, Loren G

2015-01-01

306

Biomechanical Analysis of Distal Biceps Tendon Repair Methods  

Microsoft Academic Search

Background: The 1-incision and 2-incision techniques are commonly used methods to repair a distal biceps rupture, and they differ in the location of reinsertion of tendon into bone.Hypothesis: The native distal biceps brachii tendon inserts on the posterior-ulnar aspect of the bicipital tuberosity, which functions as a cam, increasing the tendon's moment arm during its principal action of forearm supination.

Jon Henry; Jeff Feinblatt; Christopher C. Kaeding; James Latshaw; Alan Litsky; Roman Sibel; Julie A. Stephens; Grant L. Jones

2007-01-01

307

Surgical treatment of partial Achilles tendon rupture  

Microsoft Academic Search

Fifty-four patients with a total of 58 partial ruptures of the Achilles tendon were treated surgically. The postoperative observation time ranged from 8 months to 7 years. Forty-six patients indicated that they were pleased with the results, 8 were satisfied, and 3 were unsatisfied (one died during the interim). Thirty-seven of the 44 patients who had been engaged in competitive

Tor Finn Denstad; Asbjørn Roaas

1979-01-01

308

Quadriceps Tendon Rupture due to Postepileptic Convulsion  

PubMed Central

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

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

2014-01-01

309

Achilles tendon infection due to Mycobacterium chelonae.  

PubMed

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

Lui, Tun Hing; Chan, Kwok Bill

2014-01-01

310

Nonlinear growth of strongly unstable tearing modes  

SciTech Connect

Rutherford`s theory of the tearing instability is extended to cases where current nonlinearities are important, such as long wavelength modes in current slabs and the m = 1 instability in tokamaks with moderately large aspect-ratios. Of particular interest is the possibility that the associated magnetic islands, as a result of secondary instabilities, have a singular response to the Ohmic diffusion of the current. A family of islands is used to test this possibility; it is found that the response remains bounded.

Waelbroeck, F.L.

1993-11-01

311

Apomictic maternal diploids in tetraploid Job's tears.  

PubMed

Two cases of reversion to diploidy were observed in autotetraploid Job's tears (Coix lacryma-jobi L. 4n = 40) out of a total of 1,112 plants examined over a period of 7 years. One of these was a trisomie (2n = 21) and the other a disomic (2n = 20), derived from apomictic development ofn+1 andn maternal gametes of the tetraploid, respectively. In some respects both these derivatives differed from the original diploid that gave rise to the tetraploid through colchicine treatment. The potentialities of such reversions in the evolution of new diploid races are discussed. PMID:24419473

Venkateswarlu, J; Rao, P N

1975-06-01

312

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

313

Evolutionary transformations of myoseptal tendons in gnathostomes.  

PubMed Central

Axial undulations in fishes are powered by a series of three-dimensionally folded myomeres separated by sheets of connective tissue, the myosepta. Myosepta have been hypothesized to function as transmitters of muscular forces to axial structures during swimming, but the difficulty of studying these delicate complex structures has precluded a more complete understanding of myoseptal mechanics. We have developed a new combination of techniques for visualizing the three-dimensional morphology of myosepta, and here we present their collagen-fibre architecture based on examination of 62 species representing all of the major clades of notochordates. In all gnathostome fishes, each myoseptum bears a set of six specifically arranged tendons. Because these tendons are not present outside the gnathostomes (i.e. they are absent from lampreys, hagfishes and lancelets), they represent evolutionary novelties of the gnathostome ancestor. This arrangement has remained unchanged throughout 400 Myr of gnathostome evolution, changing only on the transition to land. The high uniformity of myoseptal architecture in gnathostome fishes indicates functional significance and may be a key to understanding general principles of fish swimming mechanics. In the design of future experiments or biomechanical models, myosepta have to be regarded as tendons that can distribute forces in specific directions. PMID:12816635

Gemballa, Sven; Ebmeyer, Leoni; Hagen, Katja; Hannich, Tobias; Hoja, Kathrin; Rolf, Mara; Treiber, Kerstin; Vogel, Felix; Weitbrecht, Gerd

2003-01-01

314

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

315

Prevention of Tendon Adhesions by ERK2 Small Interfering RNAs  

PubMed Central

Tendon adhesions are one of the most concerning complications after surgical repair of flexor tendon injury. Extracellular signal-regulated kinase (ERK) 2 plays crucial roles in fibroblast proliferation and collagen expression which contributes to the formation of tendon adhesions after flexor tendon surgery. Using a chicken model, we have examined the effects of a small interfering RNA (siRNA) targeting ERK2 delivered by a lentiviral system on tendon adhesion formation with an adhesion scoring system, histological assessment, and biomechanical evaluation. It was found that ERK2 siRNA effectively suppressed the increase of fibroblasts and the formation of tendon adhesions (p < 0.05 compared with the control group). Moreover, no statistically significant reduction in breaking force was detected between the ERK2 siRNA group and the control group. These results show that the lentiviral-mediated siRNA system is effective in preventing tendon adhesion formation but not to tendon healing, and may be used for tendon repair after confirmation and improvement by future detailed studies. PMID:23429276

Ruan, Hongjiang; Liu, Shen; Li, Fengfeng; Li, Xujun; Fan, Cunyi

2013-01-01

316

Biology and augmentation of tendon-bone insertion repair  

PubMed Central

Surgical reattachment of tendon and bone such as in rotator cuff repair, patellar-patella tendon repair and anterior cruciate ligament (ACL) reconstruction often fails due to the failure of regeneration of the specialized tissue ("enthesis") which connects tendon to bone. Tendon-to-bone healing taking place between inhomogenous tissues is a slow process compared to healing within homogenous tissue, such as tendon to tendon or bone to bone healing. Therefore special attention must be paid to augment tendon to bone insertion (TBI) healing. Apart from surgical fixation, biological and biophysical interventions have been studied aiming at regeneration of TBI healing complex, especially the regeneration of interpositioned fibrocartilage and new bone at the healing junction. This paper described the biology and the factors influencing TBI healing using patella-patellar tendon (PPT) healing and tendon graft to bone tunnel healing in ACL reconstruction as examples. Recent development in the improvement of TBI healing and directions for future studies were also reviewed and discussed. PMID:20727196

2010-01-01

317

Impact of oestrogen deficiency and aging on tendon: concise review  

PubMed Central

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

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

2014-01-01

318

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

319

Habitual loading results in tendon hypertrophy and increased stiffness of the human patellar tendon.  

PubMed

The purpose of this study was to examine patellar tendon (PT) size and mechanical properties in subjects with a side-to-side strength difference of > or =15% due to sport-induced loading. Seven elite fencers and badminton players were included. Cross-sectional area (CSA) of the PT obtained from MRI and ultrasonography-based measurement of tibial and patellar movement together with PT force during isometric contractions were used to estimate mechanical properties of the PT bilaterally. We found that distal tendon and PT, but not mid-tendon, CSA were greater on the lead extremity compared with the nonlead extremity (distal: 139 +/- 11 vs. 116 +/- 7 mm(2); mid-tendon: 85 +/- 5 vs. 77 +/- 3 mm(2); proximal: 106 +/- 7 vs. 83 +/- 4 mm(2); P < 0.05). Distal tendon CSA was greater than proximal and mid-tendon CSA on both the lead and nonlead extremity (P < 0.05). For a given common force, stress was lower on the lead extremity (52.9 +/- 4.8 MPa) compared with the nonlead extremity (66.0 +/- 8.0 MPa; P < 0.05). PT stiffness was also higher in the lead extremity (4,766 +/- 716 N/mm) compared with the nonlead extremity (3,494 +/- 446 N/mm) (P < 0.05), whereas the modulus did not differ (lead 2.27 +/- 0.27 GPa vs. nonlead 2.16 +/- 0.28 GPa) at a common force. These data show that a habitual loading is associated with a significant increase in PT size and mechanical properties. PMID:18556433

Couppé, C; Kongsgaard, M; Aagaard, P; Hansen, P; Bojsen-Moller, J; Kjaer, M; Magnusson, S P

2008-09-01

320

Outcome following addition of peroneus brevis tendon transfer to treatment of acquired posterior tibial tendon insufficiency.  

PubMed

The flexor digitorum longus, the tendon most often used for transfer in posterior tibial tendon insufficiency, is one-half to one-third the size of the posterior tibial tendon. Occasionally it may be particularly small or may have been previously used for transfer. In these cases, the senior author has felt that the addition of a transfer of the Peroneus Brevis (PBr) tendon may be helpful in maintaining sufficient tendon and muscle mass to rebalance the foot. Thirteen patients who underwent this procedure were retrospectively identified and matched by age and length of follow-up to patients who underwent a more standard tendon transfer operation minus the addition of the PBr transfer. Pain and functional status were then assessed by the American Orthopaedic Foot and Ankle Society's ankle/hindfoot rating scale. Each patient was tested by an independent physical therapist to evaluate inversion and eversion strength. The mean duration of follow-up was 20.6 months (12 to 34 months). The average AOFAS score of the PBr group was 75.8 compared to 71.5 for the standard control group. There was no significant difference between the groups when inversion or eversion strengths were compared. Inversion strength and eversion strength was rated good or excellent (4 or 5) in 12 out of 13 of the PBr transfer group patients. No major complications were encountered in either group. Although it does not increase inversion strength, a PBr transfer can be used to augment a small FDL without causing significant eversion weakness. This can be useful when the FDL is particularly small or in revision surgery. PMID:11354442

Song, S J; Deland, J T

2001-04-01

321

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

322

New developments in assessing hot tearing in magnesium alloy castings  

Microsoft Academic Search

High performance magnesium parts produced by permanent mold casting often exhibit hot tear defects. Theoretical prediction of hot tears in magnesium alloys has reached only limited success and further research is necessary to enhance understanding of the fundamental mechanisms associated with the formation of this defect.In this research, numerical modeling of the casting process enabled identification of casting regions susceptible

L. Bichler; C. Ravindran

2010-01-01

323

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

324

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

325

Tendon-to-bone healing using autologous bone marrow-derived mesenchymal stem cells in ACL reconstruction without a tibial bone tunnel-A histological study-  

PubMed Central

Summary Background: after anterior cruciate ligament (ACL) reconstruction, it is necessary to integrate free tendon graft biologically to the bone. In the present study, to verify whether a structure identical to the normal ligament-bone insertion could be regenerated at the tendon-bone interface without bone tunnel, we designed ACL reconstruction model without a tibial bone tunnel. Moreover, to enhance the integration process in this model, bone marrow-derived mesenchymal stem cells (bMSCs) were transplanted, and histological changes investigated. Our first hypothesis was that the grafted tendon would be anchored at part of the tendon-bone interface even if a bone tunnel was not created. Second hypothesis was that application of bMSCs at the tendon-bone interface would yield results histologically superior to those in controls. Methods: bilateral ACL reconstruction using our originally designed method was performed. Autologous bMSCs with the carrier were transplanted between the bottom of the grafted tendon and the bone pit of the tibia in the experimental limb, whereas the control limb received the carrier only. At 4 and 8 weeks after the operation, histological comparison between bMSCs and the control group was carried out. Results/Conclusions: even in our present ACL reconstruction model without a tibial bone tunnel, integration via chondroid tissue was seen at part of the tendon-bone interface. However, there were no appreciable differences between the groups. In ACL reconstruction, to enhance the tendon-bone integration without a bone tunnel would lead to save the graft length and prevent from bone tunnel complications (ex. Bone-tunnel enlargement after surgery). PMID:25332936

Kanazawa, Tomonoshin; Soejima, Takashi; Noguchi, Kouji; Tabuchi, Kousuke; Noyama, Megumi; Nakamura, Kei-ichiro; Shiba, Naoto

2014-01-01

326

Death due to isolated jejunal tear following blunt abdominal trauma.  

PubMed

Small intestinal injury following blunt abdominal trauma has been widely reported. Isolated jejunal tear which is caused by blunt abdominal trauma is rare and is most often seen in road traffic accidents. Here, we report a case of isolated jejunal tear in a 24-year-old male truck driver. He was admitted to a tertiary care hospital in a South Indian Metropolitan city with complaints of acute abdominal pain and tiredness following alleged accidental blunt trauma sustained to abdomen due to steering wheel impact. An isolated jejunal tear and adjacent mesenteric contusion and tear were missed by the treating physician even after preliminary investigations, and thus, the conservative management was instituted. The condition deteriorated gradually, and he succumbed to death. The autopsy revealed transverse tear of jejunum almost involving whole of its circumference on the antimesenteric border and peritonitis. Proper use of radio-diagnostic techniques and timely undertaken explorative laparotomy would have saved the life. PMID:24547969

Hugar, Basappa S; Yajaman, Girishchandra P; Kainoor, Sunilkumar; Shetty, Akshith Raj S

2014-09-01

327

The development of zebrafish tendon and ligament progenitors.  

PubMed

Despite the importance of tendons and ligaments for transmitting movement and providing stability to the musculoskeletal system, their development is considerably less well understood than that of the tissues they serve to connect. Zebrafish have been widely used to address questions in muscle and skeletal development, yet few studies describe their tendon and ligament tissues. We have analyzed in zebrafish the expression of several genes known to be enriched in mammalian tendons and ligaments, including scleraxis (scx), collagen 1a2 (col1a2) and tenomodulin (tnmd), or in the tendon-like myosepta of the zebrafish (xirp2a). Co-expression studies with muscle and cartilage markers demonstrate the presence of scxa, col1a2 and tnmd at sites between the developing muscle and cartilage, and xirp2a at the myotendinous junctions. We determined that the zebrafish craniofacial tendon and ligament progenitors are neural crest derived, as in mammals. Cranial and fin tendon progenitors can be induced in the absence of differentiated muscle or cartilage, although neighboring muscle and cartilage are required for tendon cell maintenance and organization, respectively. By contrast, myoseptal scxa expression requires muscle for its initiation. Together, these data suggest a conserved role for muscle in tendon development. Based on the similarities in gene expression, morphology, collagen ultrastructural arrangement and developmental regulation with that of mammalian tendons, we conclude that the zebrafish tendon populations are homologous to their force-transmitting counterparts in higher vertebrates. Within this context, the zebrafish model can be used to provide new avenues for studying tendon biology in a vertebrate genetic system. PMID:24803652

Chen, Jessica W; Galloway, Jenna L

2014-05-01

328

Massive cuff tears treated with arthroscopically assisted latissimus dorsi transfer. Surgical technique  

PubMed Central

Summary Latissimus dorsi transfer is our preferred treatment for active disabled patients with a posterosuperior massive cuff tear. We present an arthroscopically assisted technique which avoids an incision through the deltoid obtaining a better and faster clinical outcome. The patient is placed in lateral decubitus. After the arthroscopic evaluation of the lesion through a posterior and a posterolateral portal, with the limb in traction we perform the preparation of the greater tuberosity of the humerus. We place the arm in abduction and internal rotation and we proceed to the harvest of the latissimus dorsi and the tendon preparation by stitching the two sides using very resistant sutures. After restoring limb traction, under arthroscopic visualization, we pass a curved grasper through the posterolateral portal by going to the armpit in the space between the teres minor and the posterior deltoid. Once the grasper has exited the access at the level of the axilla we fix two drainage transparent tubes, each with a wire inside, and, withdrawing it back, we shuttle the two tubes in the subacromial space. After tensioning the suture wires from the anterior portals these are assembled in a knotless anchor of 5.5 mm that we place in the prepared site on the greater tuberosity of the humerus. A shoulder brace at 15° of abduction and neutral rotation protect the patient for the first month post-surgery but physical therapy can immediately start. PMID:23738290

De Cupis, Vincenzo; De Cupis, Mauro

2012-01-01

329

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

PubMed Central

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

Mori, Daisuke; Funakoshi, Noboru; Yamashita, Fumiharu

2014-01-01

330

Massive cuff tears treated with arthroscopically assisted latissimus dorsi transfer. Surgical technique.  

PubMed

Latissimus dorsi transfer is our preferred treatment for active disabled patients with a posterosuperior massive cuff tear. We present an arthroscopically assisted technique which avoids an incision through the deltoid obtaining a better and faster clinical outcome. The patient is placed in lateral decubitus. After the arthroscopic evaluation of the lesion through a posterior and a posterolateral portal, with the limb in traction we perform the preparation of the greater tuberosity of the humerus. We place the arm in abduction and internal rotation and we proceed to the harvest of the latissimus dorsi and the tendon preparation by stitching the two sides using very resistant sutures. After restoring limb traction, under arthroscopic visualization, we pass a curved grasper through the posterolateral portal by going to the armpit in the space between the teres minor and the posterior deltoid. Once the grasper has exited the access at the level of the axilla we fix two drainage transparent tubes, each with a wire inside, and, withdrawing it back, we shuttle the two tubes in the subacromial space. After tensioning the suture wires from the anterior portals these are assembled in a knotless anchor of 5.5 mm that we place in the prepared site on the greater tuberosity of the humerus. A shoulder brace at 15° of abduction and neutral rotation protect the patient for the first month post-surgery but physical therapy can immediately start. PMID:23738290

De Cupis, Vincenzo; De Cupis, Mauro

2012-04-01

331

MR Imaging of Disorders of the Achilles Tendon  

Microsoft Academic Search

he Achilles tendon is among the most frequently injured tendons of the body with a variety of types of traumatic and overuse conditions affecting it. These conditions are common, often come to clinical attention, and are frequently imaged. The pathophysiology of Achilles disorders is complex, and the nomenclature is irregularly applied; this leads to miscommunication be- tween clinicians and radiologists

Mark E. Schweitzer; David Karasick

332

Platelet concentrate injection improves Achilles tendon repair in rats  

Microsoft Academic Search

Background Blood platelets release a cocktail of growth factors when activated, some of which are thought to initi- ate and stimulate repair. Experiment and findings We studied whether a plate- let concentrate injection would improve Achilles tendon repair in an established rat model. The Achilles tendon was transected and a 3 mm segment removed. After 6h, a platelet concentrate was

Per Aspenberg; Olena Virchenko

2004-01-01

333

New finding in the radiographic diagnosis of Achilles tendon rupture  

SciTech Connect

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

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

1982-06-01

334

Muscle power attenuation by tendon during energy dissipation.  

PubMed

An important function of skeletal muscle is deceleration via active muscle fascicle lengthening, which dissipates movement energy. The mechanical interplay between muscle contraction and tendon elasticity is critical when muscles produce energy. However, the role of tendon elasticity during muscular energy dissipation remains unknown. We tested the hypothesis that tendon elasticity functions as a mechanical buffer, preventing high (and probably damaging) velocities and powers during active muscle fascicle lengthening. We directly measured lateral gastrocnemius muscle force and length in wild turkeys during controlled landings requiring rapid energy dissipation. Muscle-tendon unit (MTU) strain was measured via video kinematics, independent of muscle fascicle strain (measured via sonomicrometry). We found that rapid MTU lengthening immediately following impact involved little or no muscle fascicle lengthening. Therefore, joint flexion had to be accommodated by tendon stretch. After the early contact period, muscle fascicles lengthened and absorbed energy. This late lengthening occurred after most of the joint flexion, and was thus mainly driven by tendon recoil. Temporary tendon energy storage led to a significant reduction in muscle fascicle lengthening velocity and the rate of energy absorption. We conclude that tendons function as power attenuators that probably protect muscles against damage from rapid and forceful lengthening during energy dissipation. PMID:21957134

Konow, Nicolai; Azizi, Emanuel; Roberts, Thomas J

2012-03-22

335

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

336

Tendon xanthomas as indicators of atherosclerotic burden on coronary arteries  

PubMed Central

The presence of tendon xanthomas is an almost certain indicator of familial hypercholesterolemia (FH). They also reflect coronary atherosclerotic burden and therefore must be treated aggressively. Tendon xanthomas also occur in two rare conditions, cerebrotendinous xanthomatosis and sitosterolemia, which are not easily confused with FH, can be easily differentiated with clinical history and biochemical tests. PMID:23993019

Patil, Shivanand; Kharge, Jayashree; Bagi, Vittal; Ramalingam, Rangaraj

2013-01-01

337

Achilles tendon biomechanics in response to acute intense exercise.  

PubMed

Achilles tendinopathy is a common disorder and is more prevalent in men. Although differences in tendon mechanics between men and women have been reported, understanding of tendon mechanics in young active people is limited. Moreover, there is limited understanding of changes in tendon mechanics in response to acute exercise. Our purpose was to compare Achilles tendon mechanics in active young adult men and women at rest and after light and strenuous activity in the form of repeated jumping with an added load. Participants consisted of 17 men and 14 women (18-30 years) who were classified as being at least moderately physically active as defined by the International Physical Activity Questionnaire. Tendon force/elongation measures were obtained during an isometric plantarflexion contraction on an isokinetic dynamometer with simultaneous ultrasound imaging of the Achilles tendon approximate to the soleus myotendinous junction. Data were collected at rest, after a 10-minute treadmill walk, and after a fatigue protocol of 100 toe jumps performed in a Smith machine, with a load equaling 20% of body mass. We found greater tendon elongation, decreased stiffness, and lower Young's modulus only in women after the jumping exercise. Force and stress were not different between groups but decreased subsequent to the jumping exercise bout. In general, women had greater elongation and strain, less stiffness, and a lower Young's modulus during plantarflexor contraction. These data demonstrate differences in tendon mechanics between men and women and suggest a potential protective mechanism explaining the lower incidence of Achilles tendinopathy in women. PMID:24552794

Joseph, Michael F; Lillie, Kurtis R; Bergeron, Daniel J; Cota, Kevin C; Yoon, Joseph S; Kraemer, William J; Denegar, Craig R

2014-05-01

338

Transfer bond stresses generated between FRP tendons and concrete  

E-print Network

Transfer bond stresses generated between FRP tendons and concrete J. M. LeesÃ? and C. J. Burgoyne such as fibre-reinforced plastics (FRPs) are lightweight, strong, and, for the most part, non-corrodible. Hence, the use of FRPs as prestressing tendons for concrete represents a viable, durable alternative

Burgoyne, Chris

339

Review article: Treatment for Achilles tendon ruptures in athletes.  

PubMed

Treatment for Achilles tendon ruptures in athletes is controversial. Surgical fixation has lower rates of re-rupture and confers increased strength and function, whereas conservative treatment has lower risks of wound complications. We review the literature on the optimal treatment for Achilles tendon rupture in athletes. PMID:24014791

Stavrou, Maria; Seraphim, Andreas; Al-Hadithy, Nawfal; Mordecai, Simon C

2013-08-01

340

Fibroma of tendon sheath of the infrapatellar fat pad  

Microsoft Academic Search

We report on a 13-year-old boy who was found to have a fibroma of the tendon sheath associated with the patellar tendon and\\u000a within Hoffa’s fat pad of the knee. This benign tumor has never been described in this location previously. The MRI characteristics\\u000a are correlated with the histologic findings.

John Hur; Timothy A. Damron; Andrei I. Vermont; Sharad C. Mathur

1999-01-01

341

Muscle power attenuation by tendon during energy dissipation  

PubMed Central

An important function of skeletal muscle is deceleration via active muscle fascicle lengthening, which dissipates movement energy. The mechanical interplay between muscle contraction and tendon elasticity is critical when muscles produce energy. However, the role of tendon elasticity during muscular energy dissipation remains unknown. We tested the hypothesis that tendon elasticity functions as a mechanical buffer, preventing high (and probably damaging) velocities and powers during active muscle fascicle lengthening. We directly measured lateral gastrocnemius muscle force and length in wild turkeys during controlled landings requiring rapid energy dissipation. Muscle-tendon unit (MTU) strain was measured via video kinematics, independent of muscle fascicle strain (measured via sonomicrometry). We found that rapid MTU lengthening immediately following impact involved little or no muscle fascicle lengthening. Therefore, joint flexion had to be accommodated by tendon stretch. After the early contact period, muscle fascicles lengthened and absorbed energy. This late lengthening occurred after most of the joint flexion, and was thus mainly driven by tendon recoil. Temporary tendon energy storage led to a significant reduction in muscle fascicle lengthening velocity and the rate of energy absorption. We conclude that tendons function as power attenuators that probably protect muscles against damage from rapid and forceful lengthening during energy dissipation. PMID:21957134

Konow, Nicolai; Azizi, Emanuel; Roberts, Thomas J.

2012-01-01

342

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

PubMed Central

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

Su, Bailey

2013-01-01

343

Force Model for Control of Tendon Driven Hands  

NASA Technical Reports Server (NTRS)

Knowing the tendon forces generated for a given task such as grasping via a model, an artificial hand can be controlled. A two-dimensional force model for the index finger was developed. This system is assumed to be in static equilibrium, therefore, the equations of equilibrium were applied at each joint. Constraint equations describing the tendon branch connectivity were used. Gaussian elimination was used to solve for the unknowns of the Linear system. Results from initial work on estimating tendon forces in post-operative hands during active motion therapy were discussed. The results are important for understanding the effects of hand position on tendon tension, elastic effects on tendon tension, and overall functional anatomy of the hand.

Pena, Edward; Thompson, David E.

1997-01-01

344

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

345

Characterization of human tear proteome using multiple proteomic analysis techniques.  

PubMed

Tear proteome profiling may generate useful information for the understanding of the interaction between an eye and its contacting objects, such as a contact lens or a lens implant. This is important for designing improved eye-care devices and maintaining the health of an eye. Proteome profiles of tear fluids may also be used for disease diagnosis and prognosis. However, only a small volume of tear fluid (<5 microL) can be collected in a clinical laboratory under normal operational conditions, which makes proteome profiling a challenge. In this work we apply several proteomic analysis techniques, including gel-based and solution-based approaches with LC-ESI and LC-MALDI MS and MS/MS to gauge the relative merits of producing proteome profiles and to generate as broad a coverage of the tear proteome as possible from this small amount of sample. It is shown that a total of 54 proteins can be confidently identified using less than 5 microL of tear fluid. Of these, 44 proteins can be detected by LC-MALDI MS alone with a consumption of 2 microL of tear fluid. Furthermore, LC-MALDI can be used to determine post-translational modifications (PTMs), such as glycosylation and phosphorylation, without any sample enrichment or treatment. This work represents one of the most extensive proteome profiles (i.e., proteins identified and PTMs characterized) generated from tear fluids using clinically relevant amounts of sample. PMID:16335950

Li, Nan; Wang, Nan; Zheng, Jing; Liu, X Michael; Lever, O William; Erickson, Paul M; Li, Liang

2005-01-01

346

Observation of Spontaneous Neoclassical Tearing Modes  

SciTech Connect

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

E.D. Fredrickson

2001-10-03

347

Immunoglobulin Concentration in Tears of Contact Lens Wearers  

PubMed Central

Purpose: To evaluate changes in the concentration of tear immunoglobulins in contact lens wearers. Methods: A total of 45 cases including 23 contact lens wearers (43 eyes) and 22 age and sex matched healthy controls having no ocular pathology were studied for immunoglobulins (IgA, IgG, IgM) in their tears by single radial immunodiffusion method. Results: Most of the cases used soft (56.6%) and semi-soft gas permeable (30.4%) contact lenses. Tear IgM was detected in only 17.4% and tear IgG in 43.6% of contact lens wearers, while in controls IgG was detected in 9.1% but none of the controls had IgM. There was a significant rise in total tear IgA (13.17 ± 4.44 mg/dl) in contact lens wearer as compared to controls (8.93 ± 3.79 mg/dl). Rise of tear IgA was more in symptomatic patients (15.38 ± 5.28 mg/dl) and in those wearing hard (19.73 ± 5.43 mg/dl) and semi-soft contact lenses (13.31 ± 5.43 mg/dl). A significant increase in tear IgA was noticed in subjects wearing lenses for >3 years (15.69 ± 5.39 mg/dl). About 43.4% of lens wearers were symptomatic and 80% of their lenses showed deposits and/or haziness. All cases with IgM in tear were symptomatic. Conclusion: The relation of immunoglobulin concentration with increasing duration of wear and material of contact lens shows that tear immunoglobulin rise accrues due to mechanical stimulation, hence contact lenses should not be used for a long period and lenses of hard nature should be discouraged. The maintenance, cleaning and deproteinization of the lenses are of high importance to avoid immunostimulation.

Maurya, Rajendra P.; Bhushan, Prashant; Singh, Virendra P.; Singh, Mahendra K.; Kumar, Prakash; Bhatia, Ravindra P.S.; Singh, Usha

2014-01-01

348

The potential of optical coherence tomography in meniscal tear characterization  

NASA Astrophysics Data System (ADS)

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

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

2009-02-01

349

Vascular Endothelial Growth Factor-111 (VEGF-111) and tendon healing: preliminary results in a rat model of tendon injury  

PubMed Central

Summary Tendon lesions are among the most frequent musculoskeletal pathologies. Vascular endothelial growth factor (VEGF) is known to regulate angiogenesis. VEGF-111, a biologically active and proteolysis-resistant splice variant of this family, was recently identified. This study aimed at evaluating whether VEGF-111 could have a therapeutic interest in tendon pathologies. Surgical section of one Achilles tendon of rats was performed before a local injection of either saline or VEGF-111. After 5, 15 and 30 days, the Achilles tendons of 10 rats of both groups were sampled and submitted to a biomechanical tensile test. The force necessary to induce tendon rupture was greater for tendons of the VEGF-111 group (p<0.05) while the section areas of the tendons were similar. The mechanical stress was similar at 5 and 15 days in the both groups but was improved for the VEGF-111 group at day 30 (p <0.001). No difference was observed in the mRNA expression of collagen III, tenomodulin and MMP-9. In conclusion, we observed that a local injection of VEGF-111 improves the early phases of the healing process of rat tendons after a surgical section. Further confirmatory experimentations are needed to consolidate our results. PMID:24932443

Kaux, Jean-François; Janssen, Lauriane; Drion, Pierre; Nusgens, Betty; Libertiaux, Vincent; Pascon, Frédéric; Heyeres, Antoine; Hoffmann, Audrey; Lambert, Charles; Le Goff, Caroline; Denoël, Vincent; Defraigne, Jean-Olivier; Rickert, Markus; Crielaard, Jean-Michel; Colige, Alain

2014-01-01

350

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

351

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

352

Achilles Tendon Length and Medial Gastrocnemius Architecture in Children With Cerebral Palsy  

E-print Network

Achilles Tendon Length and Medial Gastrocnemius Architecture in Children With Cerebral Palsy. Methods: Ultrasound was used to measure Achilles tendon length and muscle-tendon architectural parameters and Scheffe post hoc tests. Results: The CP groups had longer Achilles tendons and shorter muscle bellies than

Valero-Cuevas, Francisco

353

Effects of Creep and Cyclic Loading on the Mechanical Properties and Failure of Human Achilles Tendons  

E-print Network

, Stanford, CA (Received 9 September 2002; accepted 18 February 2003) Abstract--The Achilles tendon is one understood. This study examines the ex vivo mechanical behavior of excised human Achilles tendons to elucidate the relationships between mechanical loading and Achilles tendon injury. Eighteen tendons

Stanford University

354

In-vivo measurements of the tear film on a cornea and a contact lens by use of interferometry  

NASA Astrophysics Data System (ADS)

The tear film fulfills several important functions in the eye. Apart of its physiologic functions like maintaining a moist environment for the epithelial cells of the cornea and conjunctiva, bacterial properties, transporting metabolic products etc., this film causes that the corneal surface has the optical quality. This smooth surface allows to apply interferometry for measurements. The paper presents tear's layer distribution on the soft contact lens and the cornea in comparison. Tv frame speed registration in the Twyman- Green interferometer was used to observe an unstable biomedical objects like the eye. The proposed method has the advantage of being noncontact and applies the low energy laser beam in interferometric set-up. This provides non- invasive testing of human cornea in vivo and enables observation the kinetics of its tear layer deterioration. The evaluation of non-invasive tear breakup time is possible by use of proposed setup. Further analysis of recorded interferograms helps to examine the matter of the breakup process and can be used for detection of the 'dry eye' symptoms.

Licznerski, Tomasz J.; Kasprzak, Henryk T.; Kowalik, Waldemar

1996-12-01

355

Murine patellar tendon biomechanical properties and regional strain patterns during natural tendon-to-bone healing after acute injury.  

PubMed

Tendon-to-bone healing following acute injury is generally poor and often fails to restore normal tendon biomechanical properties. In recent years, the murine patellar tendon (PT) has become an important model system for studying tendon healing and repair due to its genetic tractability and accessible location within the knee. However, the mechanical properties of native murine PT, specifically the regional differences in tissue strains during loading, and the biomechanical outcomes of natural PT-to-bone healing have not been well characterized. Thus, in this study, we analyzed the global biomechanical properties and regional strain patterns of both normal and naturally healing murine PT at three time points (2, 5, and 8 weeks) following acute surgical rupture of the tibial enthesis. Normal murine PT exhibited distinct regional variations in tissue strain, with the insertion region experiencing approximately 2.5 times greater strain than the midsubstance at failure (10.80±2.52% vs. 4.11±1.40%; mean±SEM). Injured tendons showed reduced structural (ultimate load and linear stiffness) and material (ultimate stress and linear modulus) properties compared to both normal and contralateral sham-operated tendons at all healing time points. Injured tendons also displayed increased local strain in the insertion region compared to contralateral shams at both physiologic and failure load levels. 93.3% of injured tendons failed at the tibial insertion, compared to only 60% and 66.7% of normal and sham tendons, respectively. These results indicate that 8 weeks of natural tendon-to-bone healing does not restore normal biomechanical function to the murine PT following injury. PMID:24210849

Gilday, Steven D; Casstevens, E Chris; Kenter, Keith; Shearn, Jason T; Butler, David L

2014-06-27

356

Low-level laser therapy in IL-1?, COX-2, and PGE2 modulation in partially injured Achilles tendon.  

PubMed

This study evaluated IL-1?, COX-2, and PGE2 modulation in partially injured Achilles tendons treated with low-level laser therapy (LLLT). Sixty-five male Wistar rats were used. Sixty were submitted to a direct injury on Achilles tendon and then distributed into six groups: LASER 1 (a single LLLT application), LASER 3 (three LLLT applications), and LASER 7 (seven LLLT applications) and Sham 1, 3, and 7 (the same injury but LLLT applications were simulated). The five remaining animals were allocated at control group (no procedure performed). LLLT (780 nm) was applied with 70 mW of mean power and 17.5 J/cm(2) of fluency for 10 s, once a day. The tendons were surgically removed and assessed immunohistochemically for IL-1?, COX-2, and PGE2. In comparisons with control (IL-1?: 100.5?±?92.5 / COX-2: 180.1?±?97.1 / PGE2: 187.8?±?128.8) IL-1? exhibited (mean?±?SD) near-normal level (p?>?0.05) at LASER 3 (142.0?±?162.4). COX-2 and PGE2 exhibited near-normal levels (p?>?0.05) at LASER 3 (COX-2: 176.9?±?75.4 / PGE2: 297.2?±?259.6) and LASER 7 (COX-2: 259.2?±?190.4 / PGE2: 587.1?±?409.7). LLLT decreased Achilles tendon's inflammatory process. PMID:25070591

de Jesus, Julio Fernandes; Spadacci-Morena, Diva Denelle; Dos Anjos Rabelo, Nayra Deise; Pinfildi, Carlos Eduardo; Fukuda, Thiago Yukio; Plapler, Helio

2015-01-01

357

[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

358

Quantification of regional blood flow to canine flexor tendons  

SciTech Connect

Although the blood supply and the microcirculation of flexor tendons have been studied and defined extensively using qualitative methods, the quantitative assessment of blood flow has been lacking because of the limitations of the available experimental techniques. The authors studied the regional blood supply to the flexor tendons of dogs by the technique of radionuclide-labeled microspheres. Seven adult mongrel dogs were used. Microsphere injection and tissue-counting techniques previously used for other tissues were applied. Samples of proximal, isthmus, and distal portions of the profundus and superficialis flexor tendons were harvested from each digital unit of available limbs from each dog. Mean (+/- SE) flows (ml/100 g dry tissue/min) were proximal profundus 1.78 +/- 0.60 and superficialis 7.10 +/- 1.50. The differences were significant. The study suggests that regional variation in blood flow to canine digital flexor tendons exists, so that a single value for blood flow to these tendons is not relevant. Furthermore, the study supports the concept of dual (vascular and synovial) nutrition to the digital flexor tendons in dogs. These observations may have implications regarding tendon repair techniques.

Weidman, K.A.; Simonet, W.T.; Wood, M.B.; Cooney, W.P.; Ilstrup, D.M.

1984-01-01

359

Sutured tendon repair; a multi-scale finite element model.  

PubMed

Following rupture, tendons are sutured to reapproximate the severed ends and permit healing. Several repair techniques are employed clinically, with recent focus towards high-strength sutures, permitting early active mobilisation thus improving resultant joint mobility. However, the arrangement of suture repairs locally alters the loading environment experienced by the tendon. The extent of the augmented stress distribution and its effect on the tissue is unknown. Stress distribution cannot be established using traditional tensile testing, in vivo, or ex vivo study of suture repairs. We have developed a 3D finite element model of a Kessler suture repair employing multiscale modelling to represent tendon microstructure and incorporate its highly orthotropic behaviour into the tissue description. This was informed by ex vivo tensile testing of porcine flexor digitorum profundus tendon. The transverse modulus of the tendon was 0.2551 [Formula: see text] 0.0818 MPa and 0.1035 [Formula: see text] 0.0454 MPa in proximal and distal tendon samples, respectively, and the interfibrillar tissue modulus ranged from 0.1021 to 0.0416 MPa. We observed an elliptically shaped region of high stress around the suture anchor, consistent with a known region of acellularity which develop 72 h post-operatively and remain for at least a year. We also observed a stress shielded region close to the severed tendon ends, which may impair collagen fibre realignment during the remodelling stage of repair due to the lack of tensile stress. PMID:24840732

Rawson, Shelley D; Margetts, Lee; Wong, Jason K F; Cartmell, Sarah H

2015-01-01

360

Current Concepts in Examination and Treatment of Elbow Tendon Injury  

PubMed Central

Context: Injuries to the tendons of the elbow occur frequently in the overhead athlete, creating a significant loss of function and dilemma to sports medicine professionals. A detailed review of the anatomy, etiology, and pathophysiology of tendon injury coupled with comprehensive evaluation and treatment information is needed for clinicians to optimally design treatment programs for rehabilitation and prevention. Evidence Acquisitions: The PubMed database was searched in January 2012 for English-language articles pertaining to elbow tendon injury. Results: Detailed information on tendon pathophysiology was found along with incidence of elbow injury in overhead athletes. Several evidence-based reviews were identified, providing a thorough review of the recommended rehabilitation for elbow tendon injury. Conclusions: Humeral epicondylitis is an extra-articular tendon injury that is common in athletes subjected to repetitive upper extremity loading. Research is limited on the identification of treatment modalities that can reduce pain and restore function to the elbow. Eccentric exercise has been studied in several investigations and, when coupled with a complete upper extremity strengthening program, can produce positive results in patients with elbow tendon injury. Further research is needed in high-level study to delineate optimal treatment methods. PMID:24427389

Ellenbecker, Todd S.; Nirschl, Robert; Renstrom, Per

2013-01-01

361

Production of a sterilised decellularised tendon allograft for clinical use.  

PubMed

Application of a high-level decontamination or sterilisation procedure and cell removal technique to tendon allograft can reduce the concerns of disease transmission, immune reaction, and may improve remodelling of the graft after implantation. The decellularised matrix can also be used as a matrix for tendon tissue engineering. One such sterilisation factor, Peracetic acid (PAA) has the advantage of not producing harmful reaction residues. The aim of this study was to evaluate the effects of PAA treatment and a cell removal procedure on the production of tendon matrix. Human patellar tendons, thawed from frozen were treated respectively as: Group 1, control with no treatment; Group 2, sterilised with PAA (0.1 % (w/v) PAA for 3 h) Group 3, decellularised (incubation successively in hypotonic buffer, 0.1 % (w/v) sodium dodecyl sulphate, and a nuclease solution); Group 4, decellularised and PAA sterilised. Histological analysis showed that no cells were visible after the decellularisation treatment. The integrity of tendon structure was maintained after decellularisation and PAA sterilisation, however, the collagen waveform was slightly loosened. No contact cytotoxicity was found in any of the groups. Determination of de-natured collagen showed no significant increase when compared with the control. This suggested that the decellularisation and sterilisation processing procedures did not compromise the major properties of the tendon. The sterilised, decellularised tendon could be suitable for clinical use. PMID:23443409

Huang, Q; Ingham, E; Rooney, P; Kearney, J N

2013-12-01

362

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

363

Preferential tendon stem cell response to growth factor supplementation.  

PubMed

Tendon injuries are increasingly prevalent around the world, accounting for more than 100 000 new clinical cases/year in the USA alone. Cell-based therapies have been proposed as a therapeutic strategy, with recent data advocating the use of tendon stem cells (TSCs) as a potential cell source with clinical relevance for tendon regeneration. However, their in vitro expansion is problematic, as they lose their multipotency and change their protein expression profile in culture. Herein, we ventured to assess the influence of insulin-like growth factor 1 (IGF-1), growth and differentiation factor-5 (GDF-5) and transforming growth factor-?1 (TGF?1) supplementation in TSC culture. IGF-1 preserved multipotency for up to 28?days. Upregulation of decorin and scleraxis expression was observed as compared to freshly isolated cells. GDF-5 treated cells exhibited reduced differentiation along adipogenic and chondrogenic pathways after 28?days, and decorin, scleraxis and collagen type I expression was increased. After 28?days, TGF?1 supplementation led to increased scleraxis, osteonectin and collagen type II expression. The varied responses to each growth factor may reflect their role in tendon repair, suggesting that: GDF-5 promotes the transition of tendon stem cells towards tenocytes; TGF?1 induces differentiation along several pathways, including a phenotype indicative of fibrocartilage or calcified tendon, common problems in tendon healing; and IGF-1 promotes proliferation and maintenance of TSC phenotypes, thereby creating a population sufficient to have a beneficial effect. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24474722

Holladay, Carolyn; Abbah, Sunny-Akogwu; O'Dowd, Colm; Pandit, Abhay; Zeugolis, Dimitrios I

2014-01-29

364

Conflicts, snapping and instability of the tendons. Pictorial essay  

PubMed Central

Conflicts, snapping and instability of the tendons are common, and ultrasound (US) is the method of choice for evidencing these conditions thanks to the possibility to perform dynamic maneuvers during imaging studies. A conflict can occur between a tendon and a bone structure, other tendons, the retinacula or pulleys. Snapping can occur due to instability caused by rupture of the retinaculum, conflict between a thickened retinaculum and a bone prominence or due to an abnormal position of the tendon. Instability can occur due to insufficient ability of the retinaculum to keep the tendons in the bone groove or its failure to hold the tendons applied to the bone. The technique for evidencing conflicts, snapping and instability of the tendons is very demanding because it requires a thorough knowledge of the US appearance and dynamic maneuvers. However, at the present time US examination completed with dynamic maneuvers is the investigation of choice for evidencing these disorders and providing the clinicians with the necessary information. PMID:23396604

Fantino, Olivier; Borne, J.; Bordet, Bertrand

2012-01-01

365

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

366

Multiple tendon xanthomas in patient with heterozygous familial hypercholesterolaemia: sonographic and MRI findings.  

PubMed

Tendon xanthomas are a component of familial hypercholesterolaemia, which is a hereditary disease and characterised by elevated low-density lipo protein cholesterol plasma levels and premature coronary artery disease. Tendon xanthomas are diagnostic for heterozygous familial hypercholesterolaemia (HFH) and they mostly occur in Achilles tendon. Sonography and MRI are superior to clinical assessment and are useful in detecting tendon xanthomas. In this report, we present ultrasonographic and MRI findings of multiple tendon xanthomas in a case of HFH. PMID:24252837

Dagistan, Emine; Canan, Arzu; Kizildag, Betul; Barut, Abdullah Yuksel

2013-01-01

367

Comparing and contrasting methods for tenodesis of the ruptured distal biceps tendon.  

PubMed

The evidence is clear that anatomic reinsertion is the best treatment for an active, compliant patient with an acute distal biceps rupture or a subacute rupture without significant proximal retraction of the tendon. Patients with partial tears and chronic ruptures require surgical attention when persistently symptomatic. Biceps tenodesis through dual incisions or a single anterior incision is a safe, highly reliable, and effective operation. The posterior interosseous nerve is potentially at risk with either approach. This risk is minimized by avoiding exposure and retraction of the nerve. Heterotopic ossification and subsequent proximal radio-ulnar synostosis are reported complications of the two-incision technique. The incidence of this devastating complication has been reduced, but not eliminated, by using a limited posterior forearm muscle-splitting incision and by not exposing the ulna. It is the authors' belief that a single anterior incision with suture anchor fixation of the distal biceps (in the manner described herein) is the surgical treatment of choice for most distal biceps ruptures. Compared with the two-incision method, the posterior interosseous nerve is at no more risk and the chance of heterotopic ossification is diminished. The secure fixation obtained and the limited surgical exposure required allow for early mobilization and rapid return of function. PMID:12143413

Morrison, Keith D; Hunt, Thomas R

2002-02-01

368

Peripheral tears of triangular fibrocartilage complex: results of primary repair  

Microsoft Academic Search

In 16 patients with ulnar wrist pain, we performed primary arthroscopic or open repair of the peripheral rim tears of the triangular fibrocartilage complex (TFCC) (14 ulnar, 4 volar, and 3 radial tears). The wrist function was assessed before and 1 year after the repair using the Mayo-modified wrist score. The average pain score improved from 9.1NJ.0 to 21.2Lj.5, the

Chen-Hsi Chou; Tu-Sheng Lee

2001-01-01

369

Saccharification of Job's Tears Flour during Fermentation of Aspergillus oryzae  

Microsoft Academic Search

The effects of pH, initial substrate concentration and addition of sodium chloride on saccharification of Job's tears flour during fermen tation of Aspergillus oryzae were examined. The result of proximate analysis of Job's Tears flo ur showed that it contained 64.3% carbohydrate, 12.4% protein, 4.8% fat, 6.6% insolub le fiber, 1.7% ash and 10.2% moisture. The saccharification rate based on

Sasivimol Chuen-Im Ahmed; Wanida Chiansanoi; Sivatat Cosa

370

Imaging horse tendons using multimodal 2-photon microscopy.  

PubMed

Injuries and damage to tendons plague both human and equine athletes. At the site of injuries, various cells congregate to repair and re-structure the collagen. Treatments for collagen injury range from simple procedures such as icing and pharmaceutical treatments to more complex surgeries and the implantation of stem cells. Regardless of the treatment, the level of mechanical stimulation incurred by the recovering tendon is crucial. However, for a given tendon injury, it is not known precisely how much of a load should be applied for an effective recovery. Both too much and too little loading of the tendon could be detrimental during recovery. A mapping of the complex local environment imparted to any cell present at the site of a tendon injury may however, convey fundamental insights related to their decision making as a function of applied load. Therefore, fundamentally knowing how cells translate mechanical cues from their external environment into signals regulating their functions during repair is crucial to more effectively treat these types of injuries. In this paper, we studied systems of tendons with a variety of 2-photon-based imaging techniques to examine the local mechanical environment of cells in both normal and injured tendons. These tendons were chemically treated to instigate various extents of injury and in some cases, were injected with stem cells. The results related by each imaging technique distinguish with high contrast and resolution multiple morphologies of the cells' nuclei and the alignment of the collagen during injury. The incorporation of 2-photon FLIM into this study probed new features in the local environment of the nuclei that were not apparent with steady-state imaging. Overall, this paper focuses on horse tendon injury pattern and analysis with different 2-photon confocal modalities useful for wide variety of application in damaged tissues. PMID:23871762

Sivaguru, Mayandi; Eichorst, John Paul; Durgam, Sushmitha; Fried, Glenn A; Stewart, Allison A; Stewart, Matthew C

2014-03-15

371

The effect of core and epitendinous suture modifications on repair of intrasynovial flexor tendons in an in-vivo canine model  

PubMed Central

Purpose To determine in-vivo effects of modifications to core and epitendinous suture techniques in a canine intrasynovial flexor tendon repair model using clinically relevant rehabilitation. Our null hypothesis was that gap formation and rupture rates would remain consistent across repair techniques. Methods We evaluated gap formation and rupture in 75 adult mongrel dogs that underwent repair of intrasynovial flexor tendon lacerations followed by standardized post-operative therapy. The current suture technique was a 4-0, 8-strand core suture with a purchase of 1.2 cm and a 5-0, epitendinous suture repair with a 2 mm purchase length and depth. Gap and failure were compared by chi-squared analysis to a historical group of in-vivo repairs (n=76) from the same canine model using 8-strand core suture repair with purchase of 0.75 cm and 6-0 epitendinous suture with a 1 mm purchase length and depth. Results Ninety-three percent of tendons (n = 70) demonstrated gapping of <3 mm using the current suture technique. Five percent of tendons (n = 4) had a gap of 3 mm or greater, and there was 1 repair site failure. This was significantly improved over the comparison group of historical 8-strand core repair technique which resulted in 82% (n = 62) and 81% (n=112) of repairs with a gap of <3 mm and 7 failures (9%). Conclusions In an in-vivo model, current modifications of suture techniques for intrasynovial flexor tendon repair demonstrated significant improvements in gap formation and rupture compared to a similar technique using shorter purchase lengths and shallower purchase depth. Clinical Relevance Suggested repair modifications for the treatment of Zone 2 flexor tendon transections demonstrate improvements in gap formation and tendon rupture in-vivo. PMID:23174065

Fufa, Duretti T; Osei, Daniel A; Calfee, Ryan P; Silva, Matthew J; Thomopoulos, Stavros; Gelberman, Richard H

2012-01-01

372

Surgical treatment options for patella tendon rupture, part II: chronic.  

PubMed

Patella tendon rupture is a debilitating injury that often occurs in the setting of preexisting tendon degeneration. Prompt diagnosis and treatment is essential to prevent retraction of the patella with subsequent adhesions and quadriceps contractures. In the setting of a chronic rupture, augmentation with hamstring tendons or allograft reconstruction generally is necessary. Patients who undergo delayed repair are at risk for a compromised result secondary to loss of full knee flexion and decreased quadriceps strength, although a functional extensor mechanism is likely to be reestablished. Overall the results of chronic repair are less satisfactory than the acute repair, but still provide an extensor mechanism for the patient and thus provide function. PMID:16119741

Greis, Patrick E; Lahav, Amit; Holmstrom, Michael C

2005-08-01

373

Acute and chronic Achilles tendon ruptures in athletes.  

PubMed

The Achilles tendon is the most injured tendon of athletes in the lower extremities and is the most common tendon to rupture spontaneously. Operative repair provides earlier return to sporting activities and lesser rate of rerupture. The general goal is to attempt anastomosis of the acute ruptured ends; however, delayed ruptures may require more extensive procedures. New surgical approaches, including percutaneous and mini-open techniques, are being introduced to potentially diminish perioperative complications. Advent of early protective range of motion and rehabilitation has shown a potential for earlier return to sporting activities for Achilles ruptures. PMID:21276522

Thompson, Jonathan; Baravarian, Bob

2011-01-01

374

The long head of the biceps tendon is a suitable cell source for tendon tissue regeneration  

PubMed Central

Introduction Tendon tissue engineering (TTE) tries to produce tendinous tissue of high quality to replace dysfunctional tissue. One possible application of TTE might be the replacement of ruptured tissue of the rotator cuff. Autologous tenocytes seem to be most suitable as no differentiation in vitro is necessary. Today it is still uncertain if there is a difference between tendon-derived cells (TDC) of different native tissues. Moreover, the search for suitable scaffolds is another important issue in TTE. Material and methods This study compared TDC of the long head of the biceps tendon (LHB), the anterior cruciate ligament (ACL) and the tendon of the musculus semitendinosus (TMS). The TDC were isolated using the cell migration method. Cell morphology was assessed using light microscopy and gene expression was performed using polymerase chain reaction (PCR). Afterwards, cell seeding efficiency and proliferation were tested on a collagen I scaffold using the WST-1 assay. Results were confirmed using H + E staining. Results The TDC of the LHB showed higher expression levels of collagen type I and decorin (p < 0.01) compared to TDC of other origin. Results showed efficient cell seeding and proliferation within the scaffold. Proliferation within the scaffold was not as high as when cells were cultivated without a scaffold. Conclusions The TDC of the LHB seems to be the most suitable cell source. Further research is necessary to find out if the results can be transferred to an in vivo model. The new collagen I scaffold seems to offer an opportunity to combine good biocompatibility and mechanical strength. PMID:25097592

Pietschmann, Matthias F.; Gülecyüz, Mehmet F.; Ficklscherer, Andreas; Jansson, Volkmar; Müller, Peter E.

2014-01-01

375

Human iPSC-Derived Neural Crest Stem Cells Promote Tendon Repair in a Rat Patellar Tendon Window Defect Model  

PubMed Central

Induced pluripotent stem cells (iPSCs) hold great potential for cell therapy and tissue engineering. Neural crest stem cells (NCSCs) are multipotent that are capable of differentiating into mesenchymal lineages. In this study, we investigated whether iPSC-derived NCSCs (iPSC-NCSCs) have potential for tendon repair. Human iPSC-NCSCs were suspended in fibrin gel and transplanted into a rat patellar tendon window defect. At 4 weeks post-transplantation, macroscopical observation showed that the repair of iPSC-NCSC-treated tendons was superior to that of non-iPSC-NCSC-treated tendons. Histological and mechanical examinations revealed that iPSC-NCSCs treatment significantly enhanced tendon healing as indicated by the improvement in matrix synthesis and mechanical properties. Furthermore, transplanted iPSC-NCSCs produced fetal tendon-related matrix proteins, stem cell recruitment factors, and tenogenic differentiation factors, and accelerated the host endogenous repair process. This study demonstrates a potential strategy of employing iPSC-derived NCSCs for tendon tissue engineering. PMID:23815150

Xu, Wei; Wang, Yequan; Liu, Erfu; Sun, Yanjun; Luo, Ziwei; Xu, Zhiling; Liu, Wanqian; Zhong, Li; Lv, Yonggang; Wang, Aijun; Tang, Zhenyu; Li, Song

2013-01-01

376

bFGF and PDGF-BB for Tendon Repair: Controlled Release and Biologic Activity by Tendon Fibroblasts In Vitro  

PubMed Central

Flexor tendon injuries are often encountered clinically and typically require surgical repair. Return of function after repair is limited due to adhesion formation, which leads to reduced tendon gliding, and due to a lack of repair site strength, which leads to repair site gap formation or rupture. The application of the growth factors basic fibroblastic growth factor (bFGF) and platelet derived growth factor BB (PDGF-BB) has been shown to have the potential to enhance tendon healing. The objectives of this study were to examine: (1) the conditions over which delivery of bFGF can be controlled from a heparin-binding delivery system (HBDS) and (2) the effect of bFGF and PDGF-BB released from this system on tendon fibroblast proliferation and matrix gene expression in vitro over a 10-day interval. Delivery of bFGF was controlled using a HBDS. Fibrin matrices containing the HBDS retained bFGF better than did matrices lacking the delivery system over the 10-day period studied. Delivery of bFGF and PDGF-BB using the HBDS stimulated tendon fibroblast proliferation and promoted changes in the expression of matrix genes related to tendon gliding, strength, and remodeling. Both growth factors may be effective in enhancing tendon healing in vivo. PMID:19937274

Thomopoulos, Stavros; Das, Rosalina; Sakiyama-Elbert, Shelly; Silva, Matthew J.; Charlton, Nichole; Gelberman, Richard H.

2010-01-01

377

Inuence of bone mineral density, age, and strain rate on the failure mode of human Achilles tendons  

E-print Network

Achilles tendons fail. Design. Dual-energy X-ray absorptiometry and mechanical testing of excised Achilles tendon-calcaneus specimens. Background. The Achilles tendon can fail by tendon rupture or bony avulsion treatments selected. Methods. Excised human Achilles tendons were loaded to failure at strain rates of 1% sÃ?1

Stanford University

378

Tearing mode analysis in cylindrical tokamaks, revisited  

NASA Astrophysics Data System (ADS)

A ? ' shooting code has been developed to investigate tokamak tearing mode stability in a classical cylindrical tokamak geometry. Though this shooting type code is only applicable for large aspect ratio tokamaks and thus single or a few Fourier modes, it is still compact, intuitively straightforward, and has fast convergence. The analysis is reviewed and the numerical results for the stability criteria have been compared to Furth et al.(H. P. Furth, P. H. Rutherford, and H. Selberg, Phys. Fluids 16) 1054 (1973) and Wesson(J. Wesson, Tokamaks), (Cambridge Press, Cambridge, 1987), p. 146. results. The numerical algorithm of the shooting code is discussed in detail in connection with the singularities at the boundary and the mode rational surfaces. The effects of finite magnetic island width, which has shown to be stabilizing the mode is discussed. The attempt to include toroidal geometry(C. C. Hegna and J. D. Callen, Phys. Plasmas 1), 2310 (1994). from an equilibrium code RSTEQ as well as Pfircsh-Schlüter contribution will be exhibited.

Nishimura, Y.; Hegna, C. C.; Callen, J. D.

1997-11-01

379

Stage IV posterior tibial tendon rupture.  

PubMed

Adult acquired flatfoot deformity progresses through well defined stages as set out by Johnson and Strom. Myerson modified this classification system with the addition of a fourth, more advanced stage of the disease. This stage describes the involvement of the tibiotalar joint in addition to the hindfoot malalignment seen in stages II and III. This most advanced stage is comprised of a hindfoot valgus deformity, resulting from degeneration of the posterior tibial tendon, with associated valgus tilting of the talus within the mortise. The deformity at the tibiotalar joint may or may not be rigid. Although rigid deformities are still best treated with fusions of the ankle and hindfoot, supple tibiotalar deformity may be treated with joint sparing procedures involving reconstructive procedures of the foot and deltoid ligaments. PMID:17561206

Bluman, Eric M; Myerson, Mark S

2007-06-01

380

Cushing, acromegaly, GH deficiency and tendons  

PubMed Central

Summary Cushing’s syndrome, induced by an endogenous or exogenous cortisol excess, and acromegaly, the clinical syndrome caused by growth hormone (GH) excess in adulthood, as well as the disease induced by GH deficiency (GHD), represent perfect models for the evaluation of the effects induced by chronic exposure in vivo, respectively, to cortisol and GH/IGF-1 excess or deficiency on the complex structure of the tendons as well as on the related post-traumatic repair mechanism. Although the literature is still scant, here in main scientific evidence on this topic is summarized in order to provide suggestions about the management of the above mentioned illnesses, to translate such information in the field of sports medicine and/or traumatology, and to increase and to disseminate knowledge on this misunderstood theme. PMID:25489551

Galdiero, Mariano; Auriemma, Renata S.; Pivonello, Rosario; Colao, Annamaria

2014-01-01

381

Reconstruction of the coracoclavicular and acromioclavicular ligaments with semitendinosus tendon graft: a pilot study  

PubMed Central

Purpose this study was conducted to assess the safety and efficacy of a new surgical technique for anatomical reconstruction of the coracoclavicular (CC) and acromioclavicular (AC) ligaments using one single-strand semitendinosus tendon graft. Methods eighteen patients affected by chronic type III–V AC joint dislocations were included in the present study between January 2010 and March 2012. All underwent the same surgical operation and rehabilitation protocol. The semitendinosus tendon was harvested from the ipsilateral knee. The CC and AC ligaments were reconstructed using the graft passed beneath the coracoid and through bone tunnels in the clavicle and in the acromion. The graft was secured with non-absorbable sutures. Radiographic recurrence of AC joint dislocation was the primary outcome. Clinical outcome was assessed using the DASH score and normalized Constant score. Wilcoxon’s signed-rank test was used for comparison between pre- and postoperative results. Significance was set at p ? 0.05. Results the mean follow-up duration was 26.4±2.3 months (range: 24–30 months). On X-ray evaluation, only two patients (11%) showed asymptomatic recurrence of AC joint instability. Comparison between pre- and postoperative DASH and Constant scores showed significant clinical improvement (p<0.001). Conclusion anatomical reconstruction of CC and AC ligaments using an autologous semitendinosus tendon graft for the treatment of AC joint dislocation provided good and reliable clinical and radiological results with a low failure rate at short-term follow-up. Level of evidence level IV, therapeutic case series. PMID:25606535

SACCOMANNO, MARISTELLA F.; FODALE, MARIO; CAPASSO, LUIGI; CAZZATO, GIANPIERO; MILANO, GIUSEPPE

2014-01-01

382

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

383

Isolation and growth characteristics of adult human tendon fibroblasts.  

PubMed Central

An explant method for the isolation of fibroblasts from adult human tendon is described. Cells were successfully isolated from 22 out of 27 common biceps tendons obtained from cadaveric donors (age range 11-83 years). The fibroblasts could be maintained in culture using standard methods and morphologically resembled those of synovial rather than dermal origin. Growth characteristics of 12 cell lines were assessed by deoxyribose nucleic acid (DNA) synthesis using [3H]thymidine incorporation in response to stimulation by fetal calf serum. Cells obtained separately from superficial and deep parts of the tendons produced almost identical responses. No significant reduction in growth response with increasing age was found when related to the age of the donor. Therefore this study did not show any age related defect in the short term tendon fibroblast replicative responses to serum. Images PMID:3592800

Chard, M D; Wright, J K; Hazleman, B L

1987-01-01

384

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

385

Exploring the role of hypercholesterolemia in tendon health and repair  

PubMed Central

Summary High cholesterol remains a significant healthcare problem, as more than 13% of adults in the U.S. are affected by hypercholesterolemia. The detrimental effects the disease has on cardiovascular health are well-documented, but the effects on the musculoskeletal system, and more specifically on tendons, have not been thoroughly examined. This paper provides an overview of work performed in our lab with various animal models to elucidate the relationship between high cholesterol and tendon biomechanical integrity and ability to heal. These studies highlight the complexity of relationships between multiple factors that influence tendon biomechanics, and it has offered a better understanding of the implications of high cholesterol on healthy and healing tendons. PMID:25489542

Hast, Michael W.; Abboud, Joseph A.; Soslowsky, Louis J.

2014-01-01

386

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

387

AN IN VIVO METHOD TO QUANTIFY BIOMECHANCAL COMPROMISE IN TENDON  

E-print Network

ultrasound echo intensities. We demonstrate our method on tendinopathy regions in human Achilles tendons or the exterior region of normal tissue. After objectively bounding the tendinopathy, PES segments and tracks

Sethares, William A.

388

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

389

Direct Repair without Augmentation of Patellar Tendon Avulsion following TKA  

PubMed Central

Complications involving the extensor mechanism after TKA are potentially disastrous. We are reporting a case of patellar tendon rupture from tibial tuberosity following total knee arthroplasty. We managed it by direct repair with fiberwire using Krackow suture technique without augmentation. Our long term result has been very encouraging. Our method is a safe and better method of management of patellar tendon avulsion following TKA when it happens without any tissue loss.

Kumar, Nishikant; Yadav, Chandrashekhar; Kumar, Ashok

2015-01-01

390

Individual muscle contributions to the in vivo achilles tendon force  

Microsoft Academic Search

Objective. To ascertain the possibility of non-uniform stress within the achilles tendon due to individual force contributions of the triceps surae.Design. Calculation of non-uniform stress through discrepancies in moments about the ankle joint. Background. Non-uniform stress over the cross-sectional area have been implied in the etiology of achilles tendon injury and may influence functional aspects. However, this has not been

A. N. Arndt; P. V. Komi; G.-P. Brüggemann; J. Lukkariniemi

1998-01-01

391

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

392

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

393

Tendon tissue engineering: progress, challenges, and translation to the clinic.  

PubMed

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, J T; Kinneberg, K R; Dyment, N A; Galloway, M T; Kenter, K; Wylie, C; Butler, D L

2011-06-01

394

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

395

Tear Film Breakup and Structure Studied by Simultaneous Video Recording of Fluorescence and Tear Film Lipid Layer Images  

PubMed Central

Purpose. The thinning of the precorneal tear film between blinks and tear film breakup can be logically analyzed into contributions from three components: evaporation, flow into the cornea, and tangential flow along the corneal surface. Whereas divergent tangential flow contributes to certain types of breakup, it has been argued that evaporation is the main cause of tear thinning and breakup. Because evaporation is controlled by the tear film lipid layer (TFLL) it should therefore be expected that patterns of breakup should match patterns in the TFLL, and this hypothesis is tested in this study. Methods. An optical system is described for simultaneous video imaging of fluorescein tear film breakup and the TFLL. Recordings were made from 85 subjects, including both with healthy and dry eyes. After instillation of 5 ?L2% fluorescein, subjects were asked to blink 1 second after the start of the recording and try to maintain their eyes open for the recording length of 30 or 60 seconds. Results. Areas of tear film thinning and breakup usually matched corresponding features in the TFLL. Whereas thinning and breakup were often matched to thin lipid, surprisingly, the corresponding lipid region was not always thinner than the surrounding lipid. Occasionally, a thin lipid region caused a corresponding region of greater fluorescence (thicker aqueous layer), due to convergent tangential flow. Conclusions. Areas of tear thinning and breakup can generally be matched to corresponding regions of the TFLL as would be expected if breakup is largely due to evaporation. Surprisingly, in some examples, the corresponding lipid area was not thinner and possibly thicker than the surrounding lipid. This indicates that the lipid was a poor barrier to evaporation, perhaps because of deficiency in composition and/or structure. For example, bacterial lipases may have broken down esters into component acids and alcohols, causing a defective TFLL structure with increased evaporation. PMID:23766476

King-Smith, P. Ewen; Reuter, Kathleen S.; Braun, Richard J.; Nichols, Jason J.; Nichols, Kelly K.

2013-01-01

396

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

397

Attrition or rupture of digital extensor tendons due to carpal boss: report of 2 cases.  

PubMed

We present 2 cases that demonstrate the potential for tendon involvement in the presence of a carpal boss. In the first, a patient presented with tendon rupture without antecedent pain. In the second, pain and tendon irritation prompted magnetic resonance imaging that revealed tendon fraying, which was confirmed at surgery. These cases illustrate the potential for tendinous sequelae of a carpal boss. Advanced imaging may be considered when tendon irritation is clinically suspected. Attention to the possibility of tendon rupture in the setting of an otherwise asymptomatic carpal boss is advised. PMID:24674613

Ghatan, Andrew C; Carlson, Erik J; Athanasian, Edward A; Weiland, Andrew J

2014-05-01

398

Molecular Organization of the Tear Fluid Lipid Layer  

PubMed Central

The tear fluid protects the corneal epithelium from drying out as well as from invasion by pathogens. It also provides cell nutrients. Similarly to lung surfactant, it is composed of an aqueous phase covered by a lipid layer. Here we describe the molecular organization of the anterior lipid layer of the tear film. Artificial tear fluid lipid layers (ATFLLs) composed of egg yolk phosphatidylcholine (60 mol %), free fatty acids (20 mol %), cholesteryl oleate (10 mol %), and triglycerides (10 mol %) were deposited on the air-water interface and their physico-chemical behavior was compared to egg-yolk phosphatidylcholine monolayers by using Langmuir-film balance techniques, x-ray diffraction, and imaging techniques as well as in silico molecular level simulations. At low surface pressures, ATFLLs were organized at the air-water interface as heterogeneous monomolecular films. Upon compression the ATFLLs collapsed toward the air phase and formed hemispherelike lipid aggregates. This transition was reversible upon relaxation. These results were confirmed by molecular-level simulations of ATFLL, which further provided molecular-scale insight into the molecular distributions inside and dynamics of the tear film. Similar type of behavior is observed in lung surfactant but the folding takes place toward the aqueous phase. The results provide novel information of the function of lipids in the tear fluid. PMID:20959097

Kulovesi, Pipsa; Telenius, Jelena; Koivuniemi, Artturi; Brezesinski, Gerald; Rantamäki, Antti; Viitala, Tapani; Puukilainen, Esa; Ritala, Mikko; Wiedmer, Susanne K.; Vattulainen, Ilpo; Holopainen, Juha M.

2010-01-01

399

Medial Posterior Meniscal Root Tears Are Associated with Development or Worsening of Medial Tibiofemoral Cartilage Damage: The Multicenter Osteoarthritis Study  

PubMed Central

Purpose: To assess the association of meniscal root tear with the development or worsening of tibiofemoral cartilage damage. Materials and Methods: Institutional review board approval and written informed consent from all subjects were obtained. A total of 596 knees with radiographically depicted osteoarthritis were randomly selected from the Multicenter Osteoarthritis study cohort. Cartilage damage was semiquantitatively assessed by using the Whole-Organ Magnetic Resonance Imaging Score (WORMS) system (grades 0–6). Subjects were separated into three groups: root tear only, meniscal tear without root tear, and neither meniscal nor root tear. A log-binomial regression model was used to calculate the relative risks for knees to develop incident or progressing cartilage damage in the root tear group and the meniscal tear group, with the no tear group serving as a reference. Results: In the medial tibiofemoral joint, there were 37 knees with isolated medial posterior root tear, 294 with meniscal tear without root tear, and 264 without meniscal or root tear. There were only two lateral posterior root tears, and no anterior root tears were found. Thus, the focus was on the medial posterior root tear. The frequency of severe cartilage damage (WORMS ?5) was higher in the group with root tear than in the group without root or meniscal tear (76.7% vs 19.7%, P < .0001) but not in the group with meniscal but no root tear (76.7% vs 65.2%, P = .055). Longitudinal analyses included 33 knees with isolated medial posterior root tear, 270 with meniscal tear, and 245 with no tear. Adjusted relative risk of cartilage loss was 2.03 (95% confidence interval [CI]: 1.18, 3.48) for the root tear group and 1.84 (95% CI: 1.32, 2.58) for the meniscal tear group. Conclusion: Isolated medial posterior meniscal root tear is associated with incident and progressive medial tibiofemoral cartilage loss. © RSNA, 2013 PMID:23696679

Hayashi, Daichi; Jarraya, Mohamed; Roemer, Frank W.; Zhang, Yuqing; Niu, Jingbo; Crema, Michel D.; Englund, Martin; Lynch, John A.; Nevitt, Michael C.; Torner, James C.; Lewis, Cora E.; Felson, David T.

2013-01-01

400

Evidence of Neoclassical Toroidal Viscosity on the Neoclassical Tearing Modes in TCV tokamak  

NASA Astrophysics Data System (ADS)

The interplay between the plasma toroidal rotation and the onset of magnetohydrodynamics instabilities, such as the Neoclassical Tearing Modes (NTMs), is an important issue for tokamak performance. An interesting mechanism characterizing this interaction is the breaking of axisymmetry due to the NTM helical structure, which is the source of a magnetic viscous drag parallel to the toroidal field. This effect, known as Neoclassical Toroidal Viscosity (NTV) depends on magnetic island width, and is responsible of the nearly global slowing down of the toroidal velocity across the profile. In the TCV tokamak the spontaneous plasma toroidal rotation profile, observed even in absence of other external momentum sources [1], can be modified by nearly central electron cyclotron heating (ECH) with a slight poloidal asymmetry and current drive (ECCD) [1,2,3]. The evidence of NTV effect on the plasma toroidal velocity profile of TCV is apparent as a pronounced flattening at the onset of m/n=3/2 and 2/1 tearing instabilities in the neoclassical regime in TCV discharges (Ip~150 kA, ne_av~2 1019 m-3 Te~3 keV) with 1.5 MW EC ramp up/down phases. Comparison of the measured and calculated toroidal plasma velocity is performed using the NTV formulation [4,5] applicable in the collisionless regimes. The different aspects of the NTM onset associated both with the ECH-coECCD effect on the current profile and with NTV observed in several TCV discharges are discussed, in the frame of classical and neoclassical tearing modes theory applied to 3/2 and 2/1 modes.

Nowak, S.; Lazzaro, E.; Sauter, O.; Canal, G.; Duval, B.; Federspiel, L.; Karpushov, A. N.; Kim, D.; Reimerdes, H.; Rossel, J.; Wagner, D.; the Tcv Team

2012-12-01

401

A Disposable Tear Glucose Biosensor—Part 3: Assessment of Enzymatic Specificity  

PubMed Central

Background A concept for a tear glucose sensor based on amperometric measurement of enzymatic oxidation of glucose was previously presented, using glucose dehydrogenase flavin adenine dinucleotide (GDH-FAD) as the enzyme. Glucose dehydrogenase flavin adenine dinucleotide is further characterized in this article and evaluated for suitability in glucose-sensing applications in purified tear-like saline, with specific attention to the effect of interfering substances only. These interferents are specifically saccharides that could interact with the enzymatic activity seen in the sensor's performance. Methods Bench top amperometric glucose assays were performed using an assay solution of GDH-FAD and ferricyanide redox mediator with samples of glucose, mannose, lactose, maltose, galactose, fructose, sucrose, and xylose at varying concentrations to evaluate specificity, linear dynamic range, signal size, and signal-to-noise ratio. A comparison study was done by substituting an equivalent activity unit concentration of glucose oxidase (GOx) for GDH-FAD. Results Glucose dehydrogenase flavin adenine dinucleotide was found to be more sensitive than GOx, producing larger oxidation currents than GOx on an identical glucose concentration gradient, and GDH-FAD exhibited larger slope response (-5.65 × 10-7 versus -3.11 × 10-7 A/mM), signal-to-noise ratio (18.04 versus 2.62), and linear dynamic range (0–30 versus 0–10 mM), and lower background signal (-7.12 versus -261.63 nA) than GOx under the same assay conditions. GDH-FAD responds equally to glucose and xylose but is otherwise specific for glucose. Conclusion Glucose dehydrogenase flavin adenine dinucleotide compares favorably with GOx in many sensor-relevant attributes and may enable measurement of glucose concentrations both higher and lower than those measurable by GOx. GDH-FAD is a viable enzyme to use in the proposed amperometric tear glucose sensor system and perhaps also in detecting extreme hypoglycemia or hyperglycemia in blood. PMID:22027303

Lan, Kenneth; McAferty, Kenyon; Shah, Pankti; Lieberman, Erica; Patel, Dharmendra R; Cook, Curtiss B; La Belle, Jeffrey T

2011-01-01

402

Modelling the evaporation of a tear film over a contact lens.  

PubMed

A contact lens (CL) separates the tear film into a pre-lens tear film (PrLTF), the fluid layer between the CL and the outside environment, and a post-lens tear film (PoLTF), the fluid layer between the CL and the cornea. We examine a model for evaporation of a PrLTF on a modern permeable CL allowing fluid transfer between the PrLTF and the PoLTF. Evaporation depletes the PrLTF, and continued evaporation causes depletion of the PoLTF via fluid loss through the CL. Governing equations include Navier-Stokes, heat and Darcy's equations for the fluid flow and heat transfer in the PrLTF and porous layer. The PoLTF is modelled by a fixed pressure condition on the posterior surface of the CL. The original model is simplified using lubrication theory for the PrLTF and CL applied to a sagittal plane through the eye. We obtain a partial differential equation (PDE) for the PrLTF thickness that is first-order in time and fourth-order in space. This model incorporates evaporation, conjoining pressure effects in the PrLTF, capillarity and heat transfer. For a planar film, we find that this PDE can be reduced to an ordinary differential equation (ODE) that can be solved analytically or numerically. This reduced model allows for interpretation of the various system parameters and captures most of the basic physics contained in the model. Comparisons of ODE and PDE models, including estimates for the loss of fluid through the lens due to evaporation, are given. PMID:24521538

Talbott, Kevin; Xu, Amber; Anderson, Daniel M; Seshaiyer, Padmanabhan

2014-02-11

403

Repopulation of Intrasynovial Flexor Tendon Allograft with Bone Marrow Stromal Cells: An Ex Vivo Model  

PubMed Central

Purpose: Delayed healing is a common problem whenever tendon allografts are used for tendon or ligament reconstruction. Repopulating the allograft with host cells may accelerate tendon regeneration, but cell penetration into the allograft tendon is limited. Processing the tendon surface with slits that guide cells into the allograft substrate may improve healing. The purpose of this study was to describe a surface modification of allograft tendon that includes slits to aid cell repopulation and lubrication to enhance tendon gliding. Methods: Canine flexor digitorum profundus tendons were used for this study. Cyclic gliding resistance was measured over 1000 cycles. Tensile stiffness was assessed for normal tendon, tendon decellularized with trypsin and Triton X-100 (decellularized group), tendon decellularized and perforated with multiple slits (MS group) and tendon decellularized, perforated with slits and treated with a carbodiimide-derivatized hyaluronic acid and gelatin (cd-HA-gelatin) surface modification (MS-SM group). To assess tendon repopulation, bone marrow stromal cells (BMSCs) were used in the decellularized and MS groups. DNA concentration and histology were evaluated and compared to normal tendons and nonseeded decellularized tendons. Results: The gliding resistance of the decellularized and MS groups was significantly higher compared with the normal group. There was no significant difference in gliding resistance between the decellularized and MS group. Gliding resistance of the normal group and MS-SM group was not significantly different. The Young's modulus was not significantly different among the four groups. The DNA concentration in the MS group was significantly lower than in normal tendons, but significantly higher than in decellularized tendons, with or without BMSCs. Viable BMSCs were found in the slits after 2 weeks in tissue culture. Conclusions: Tendon slits can successfully harbor BMSCs without compromising their survival and without changing tendon stiffness. Surface modification restores normal gliding function to the slit tendon. Clinical Relevance: A multislit tendon reseeded with BMSCs, with a surface treatment applied to restore gliding properties, may potentially promote tendon revitalization and accelerate healing for tendon or ligament reconstruction applications. PMID:24024566

Amadio, Peter C.; Thoreson, Andrew R.; An, Kai-Nan

2014-01-01

404

Quantitative ultrasound (QUS) assessment of tissue properties for Achilles tendons  

NASA Astrophysics Data System (ADS)

Quantitative ultrasound (QUS) techniques have recently been widely applied for the characterization of tissues. For example, they can be used for the quantification of Achilles tendon properties based on the broadband ultrasound attenuation (BUA) and the speed of sound (SOS) when the ultrasound wave passes through the tissues. This study is to develop an integrated system to investigate the properties of Achilles tendons using QUS images from UBIS 5000 (DMS, Montpellier, France) and B-mode ultrasound images from HDI 5000 (ATL, Ultramark, USA). Subjects including young (32 females and 17 males; mean age: 23.7 ± 2.0) and middle-aged groups (8 female and 8 males; mean age: 47.3 ± 8.5 s) were recruited and tested for this study. Only subjects who did not exercise regularly and had no record of tendon injury were studied. The results show that the BUA is significantly higher for the young group (45.2 ± 1.6 dB MHz-1) than the middle-age group (40.5 ± 1.9 dB MHz-1), while the SOS is significantly lower for the young (1601.9 ± 11.2 ms-1) compared to the middle-aged (1624.1 ± 8.7 m s-1). On the other hand, the thicknesses of Achilles tendons for both groups (young: 4.31 ± 0.23 mm; middle age: 4.24 ± 0.23 mm) are very similar. For one patient who had an Achilles tendon lengthening (ATL) surgery, the thickness of the Achilles tendon increased from 4 mm to 4.33 mm after the surgery. In addition, the BUA increased by about 7.2% while the SOS decreased by about 0.6%. In conclusion, noninvasive ultrasonic assessment of Achilles tendons is useful for assisting clinical diagnosis and for the evaluation of a therapeutic regimen.

Du, Yi-Chun; Chen, Yung-Fu; Chen, Pei-Jarn; Lin, Yu-Ching; Chen, Tainsong; Lin, Chii-Jeng

2007-09-01

405

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

406

Introducing a New Parameter for the Assessment of the Tear Film Lipid Layer  

E-print Network

with the osmolarity of the tear film. Without the correction for the eyelid opening, the correlations decrease osmolarity of the tear film and inflammation of the ocular surface.''12 Symptoms of discomfort, dryness

Haslwanter, Thomas

407

Evaluation of tear film proteinases in horses with ulcerative keratitis.  

PubMed

Ulcerative keratitis is a common and potentially blinding ocular disease of horses, capable of progressing to corneal perforation in as little as 24 h. This rapid stromal degeneration is mediated in part by exogenous and endogenous proteinases. We measured and compared the concentrations of two matrix metalloproteinases (MMP-2 and MMP-9) and a serine proteinase (neutrophil elastase) present in the precorneal tear film of normal horses and horses with rapidly progressing ulcerative keratitis. Precorneal tear film samples were collected from 23 ulcerated and 21 unaffected eyes of 23 horses with unilateral ulcerative keratitis, and from 33 normal eyes of 17 control horses. MMP-2, MMP-9, and neutrophil elastase were identified by casein and gelatin zymography and quantified by computerized image analysis. Median MMP-9 levels were significantly higher in the precorneal tear film of young control horses vs. older control horses (P = 0.005). Median MMP-2, MMP-9, and neutrophil elastase levels were significantly higher in the precorneal tear film of ulcerated eyes when compared to age-matched normal controls (P = 0.004, P = 0.001, and P = 0.012, respectively). Median MMP-2 levels were also significantly higher in the precorneal tear film of contralateral eyes of affected horses when compared to age-matched normal controls (P = 0.004). No significant differences in median proteinase levels were detected between 'sterile' ulcers and those from which bacteria or mixed infections (bacteria and fungi) were isolated. However, median MMP-2 and neutrophil elastase levels were significantly higher in the precorneal tear film of eyes with 'sterile' ulcers when compared with ulcerated eyes from which fungi were isolated (P < 0.05). The results of this study support the use of topical antiproteinase therapy which targets both MMPs and serine proteinases in progressive equine ulcerative keratitis. PMID:11397292

Strubbe, D.T.; Brooks, D.E.; Schultz, G.S.; Willis-Goulet, H.; Gelatt, K.N.; Andrew, S.E.; Kallberg, M.E.; MacKay, E.O.; Collante, W.R.

2000-01-01

408

Patient Satisfaction after Arthroscopic Repair of Acetabular Labral Tears  

PubMed Central

Background Acetabular labral tear is a main cause of hip pain and disability, often requiring surgical treatment. Improvements of hip arthroscopic technique have produced positive outcomes after labral repair with arthroscopy. The purpose of this study was to determine clinical outcomes and patient satisfaction after arthroscopic repair of acetabular labral tear. Methods We interviewed 21 patients (10 men and 11 women; mean age, 36 years [range, 22 to 57 years]) with acetabular labral tears that had been repaired arthroscopically in terms of satisfaction of the procedure. In addition, clinical outcome was assessed using visual analog scale (VAS) score, University of California, Los Angeles (UCLA) activity, Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, and Harris hip score, and radiologic outcome was assessed using serial radiography. The patients were followed for 24-50 months. Results The mean Harris hip score was 73 points (range, 64 to 84 points) preoperatively and 83 points (range, 66 to 95 points) postoperatively. Fifteen hips (71%) were rated excellent and good. The mean WOMAC osteoarthritis index and VAS scores were improved at final follow-up. UCLA activity at the latest follow-up improved in 16 patients. The Tonnis grade of osteoarthritis at the latest follow-up did not change in all patients. Eighteen of the patients (86%) were satisfied with the procedure. Conclusions High rate of satisfaction after arthroscopic repair of acetabular labral tears is an encouraging outcome. Arthroscopic treatment of labral tears might be a useful technique in patients with hip pathologies, such as femoroacetabular impingement with labral tears. PMID:24900896

Ha, Yong-Chan; Shin, Yong-Eun

2014-01-01

409

Decision-making in massive rotator cuff tear.  

PubMed

Treatment of massive rotator cuff tears has developed over many years ranging from conservative treatment to open and arthroscopic repair, muscle transfers and reversed arthroplasty. The evolution of more advanced techniques in arthroscopic repair has changed the treatment approach and improved the prognosis for functional outcome despite low healing rates. Due to this rapid development, our evidence-based knowledge today is mainly founded in Level 3 and Level 4 studies. Based on the literature, the current knowledge on treatment of symptomatic massive rotator cuff tears is proposed in an algorithm. Level of evidence V. PMID:25502477

Thès, André; Hardy, Philippe; Bak, Klaus

2015-02-01

410

Electron diamagnetism and toroidal coupling of tearing modes  

SciTech Connect

Using a simple model for the layer of the tearing mode, we demonstrate that toroidally coupled tearing modes with two rational surfaces are most unstable when the ..omega..*'s of the electrons at the rational surfaces are equal. The onset of instability may then occur because of the tuning of ..omega..* rather than the passage of ..delta..'-like quantities through zero. This mechanism for the onset of instability is sharp since the resonance is narrow. The effect of toroidal rotation is also discussed. 7 refs., 2 figs.

Cowley, S.C.; Hastie, R.J.

1987-10-01

411

Clinical characteristics of conjunctivochalasis with or without aqueous tear deficiency  

PubMed Central

Aim: To show characteristic ocular surface findings caused by conjunctivochalasis (CCh) in dry eye patients with or without aqueous tear deficiency (ATD). Design: Comparative non-interventional cases. Patients and methods: Clinical data of five ATD patients without CCh (group A), eight CCh patients with ATD (group B), and eight CCh patients without ATD (group C) were retrospectively reviewed. Presence or absence of CCh was determined by fluorescein staining to outline tear meniscus and conjunctival folds with an enhancing filter. Dry eye symptoms, history of subconjunctival haemorrhage, meibum expression, tear break up time, fluorescein and rose bengal staining, and fluorescein clearance test, and other abnormal ocular surface findings were measured. Results: CCh patients were significantly older (p?=?0.001). In pure ATD, the principal symptom of dryness became worse as the day progressed. In contrast, blurry vision, burning sensation, and dryness became worse during reading in all CCh patients (p?=?0.0008) or worse in the morning upon awakening in the majority patients with CCh only (p?=?0.02). Besides the interpalpebral exposure, which was noted in ATD, positive fluorescein or rose bengal staining was noted in the redundant conjunctival folds and the non-exposure zone in CCh (p?=?0.0008). Redundant conjunctival folds were present in both lower and upper bulbar conjunctiva, obliterating both lower and upper tear meniscuses, and spatially correlated with anterior migration of the mucocutaneous junction in CCh. Delayed tear clearance was significantly more prevalent in CCh than ATD (p?=?0.0008). Vigorous blinking worsened in CCh but not in ATD (p?=?0.0008). Lacrimal puncta were swollen in groups B and C, but not in group A (p?=?0.04). Conclusions: CCh is not restricted to the lower bulbar conjunctiva, and contributes to pathogenesis of dry eye by obliterating both lower and upper tear meniscus, causing unstable tear film and by creating delayed tear clearance. Dry eye symptoms were worsened by downgaze during reading and by vigorous blinking. Other characteristic signs including subconjunctival haemorrhage, swollen puncta, anterior migration of the mucocutaneous junction, and patterns of dye staining also help distinguish dry eye associated with CCh from that caused by ATD alone. PMID:14977775

Di Pascuale, M A; Espana, E M; Kawakita, T; Tseng, S C G

2004-01-01