Sample records for tendon tears comparison

  1. Surgical treatment of peroneal tendon tears.

    PubMed

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

    2007-12-01

    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

  2. Abductor tendon tears of the hip: evaluation and management.

    PubMed

    Lachiewicz, Paul F

    2011-07-01

    The gluteus medius and minimus muscle-tendon complex is crucial for gait and stability in the hip joint. There are three clinical presentations of abductor tendon tears. Degenerative or traumatic tears of the hip abductor tendons, so-called rotator cuff tears of the hip, are seen in older patients with intractable lateral hip pain and weakness but without arthritis of the hip joint. The second type of tear may be relatively asymptomatic. It is often seen in patients undergoing arthroplasty for femoral neck fracture or elective total hip arthroplasty (THA) for osteoarthritis. The third type of abductor tendon dysfunction occurs with avulsion or failure of repair following THA performed through the anterolateral approach. Abductor tendon tear should be confirmed on MRI. When nonsurgical management is unsuccessful, open repair of the tendons with transosseous sutures is recommended. Good pain relief has been reported following endoscopic repair. Abductor tendon repair has had inconsistent results in persons with avulsion following THA. Reconstruction with a gluteus maximus muscle flap or Achilles tendon allograft has provided promising short-term results in small series. PMID:21724917

  3. Endoscopic Transtendinous Repair for Partial-Thickness Proximal Hamstring Tendon Tears

    PubMed Central

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

    2014-01-01

    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

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

    PubMed Central

    Hartzler, Robert U.; Burkhart, Stephen S.

    2014-01-01

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

  5. Strain distribution due to propagation of tears in the anterior supraspinatus tendon.

    PubMed

    Miller, R Matthew; Fujimaki, Yoshimasa; Araki, Daisuke; Musahl, Volker; Debski, Richard E

    2014-10-01

    Rotator cuff tears are a significant clinical problem. Tears in the anterior supraspinatus might behave differently compared to central tears due to differences in regional structural properties. The objective of this study was to determine strain distributions for anterior supraspinatus tendon tears and the relationship to tear propagation during cyclic loading. It was hypothesized that highest maximum principal strain would be posterior to the tear, and tears would propagate in the direction of the maximum principal strain. Eight human cadaveric supraspinatus tendons with surgically created small tears in the anterior third were tested with increasing levels of cyclic loads. The position of strain markers was recorded on the bursal surface of the tendon to calculate strain. Tendons reached a 2?cm critical tendon retraction at 580?±?181?N. Largest strains were found medial and posterior to the tear (26.1?±?9.4%). In five tendons, the strain direction for the initial (114?±?28°) and final loading sets (86?±?20°) indicated the strain direction shifted from an anterior to posterior orientation (p?tear propagation. Based on the results, anterior supraspinatus tears would remain isolated to the supraspinatus tendon during activities of daily living. PMID:24985532

  6. Supraspinatus tendon organizational and mechanical properties in a chronic rotator cuff tear animal model

    Microsoft Academic Search

    Jonathan A. Gimbel; Jonathan P. Van Kleunen; Samir Mehta; Stephanie M. Perry; Gerald R. Williams; Louis J. Soslowsky

    2004-01-01

    Rotator cuff tears of the shoulder are a common cause of pain and disability. The successful repair of rotator cuff tendon tears depends on the time from onset of injury to the time of surgical repair. However, the effect of time from injury to repair remains poorly understood. A rat model was used to investigate the supraspinatus tendon organizational and

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

    PubMed

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

    2012-02-01

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

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

    PubMed Central

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

    2012-01-01

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

  9. Identification of suitable reference genes for gene expression studies in tendons from patients with rotator cuff tear.

    PubMed

    Leal, Mariana Ferreira; Belangero, Paulo Santoro; Figueiredo, Eduardo Antônio; Cohen, Carina; Loyola, Leonor Casilla; Andreoli, Carlos Vicente; Smith, Marília Cardoso; de Castro Pochini, Alberto; Ejnisman, Benno; Cohen, Moises

    2015-01-01

    Rotator cuff tear is one of the most common causes of shoulder dysfunction. Gene expression analysis may be a useful tool for understanding tendon tears and the failure of cuff healing, and reverse-transcription quantitative polymerase chain reaction (RT-qPCR) has become an effective method for such studies. However, this technique requires the use of suitable reference genes for data normalization. Here, we evaluate the suitability of six reference genes (18S, ACTB, B2M, GAPDH, HPRT1 and TBP) using samples from the rotator cuff tendons of 28 individuals with tendon tears (3 tendons regions) and 8 controls (2 tendon regions); for the tear patients, we evaluated ruptured and non-ruptured tendon samples. The stability of the candidate reference genes was determined using the NormFinder, geNorm, BestKeeper and DataAssist software packages. Overall, HPRT1 was the best single reference gene, and HPRT1+TBP composed the best pair and HPRT1+TBP+ACTB composed the best trio of reference genes from the analysis of different groups, including the simultaneous analysis of all tissue samples. To identify the optimal combination of reference genes, we evaluated the expression of COL1A1 and COL3A1, and no obvious differences were observed when using 2, 3 or 4 reference genes for most of the analyses. However, COL3A1 expression differed between ruptured and non-ruptured (posterior superior region) tendons of patients only when normalized by HPRT1+TBP+B2M and HPRT1+TBP. On the other hand, the comparison between these two groups using the best trio of reference genes (HPRT1+TBP+ACTB) and 4 reference genes did not revealed a significant difference in COL3A1 expression. Consequently, the use of suitable reference genes for a reliable gene expression evaluation by RT-qPCR should consider the type of tendon samples investigated. HPRT1+TBP+ACTB seems to be the best combination of reference genes for the analysis of involving different tendon samples of individuals with rotator cuff tears. PMID:25768100

  10. Identification of Suitable Reference Genes for Gene Expression Studies in Tendons from Patients with Rotator Cuff Tear

    PubMed Central

    Leal, Mariana Ferreira; Belangero, Paulo Santoro; Figueiredo, Eduardo Antônio; Cohen, Carina; Loyola, Leonor Casilla; Andreoli, Carlos Vicente; Smith, Marília Cardoso; de Castro Pochini, Alberto; Ejnisman, Benno; Cohen, Moises

    2015-01-01

    Rotator cuff tear is one of the most common causes of shoulder dysfunction. Gene expression analysis may be a useful tool for understanding tendon tears and the failure of cuff healing, and reverse-transcription quantitative polymerase chain reaction (RT-qPCR) has become an effective method for such studies. However, this technique requires the use of suitable reference genes for data normalization. Here, we evaluate the suitability of six reference genes (18S, ACTB, B2M, GAPDH, HPRT1 and TBP) using samples from the rotator cuff tendons of 28 individuals with tendon tears (3 tendons regions) and 8 controls (2 tendon regions); for the tear patients, we evaluated ruptured and non-ruptured tendon samples. The stability of the candidate reference genes was determined using the NormFinder, geNorm, BestKeeper and DataAssist software packages. Overall, HPRT1 was the best single reference gene, and HPRT1+TBP composed the best pair and HPRT1+TBP+ACTB composed the best trio of reference genes from the analysis of different groups, including the simultaneous analysis of all tissue samples. To identify the optimal combination of reference genes, we evaluated the expression of COL1A1 and COL3A1, and no obvious differences were observed when using 2, 3 or 4 reference genes for most of the analyses. However, COL3A1 expression differed between ruptured and non-ruptured (posterior superior region) tendons of patients only when normalized by HPRT1+TBP+B2M and HPRT1+TBP. On the other hand, the comparison between these two groups using the best trio of reference genes (HPRT1+TBP+ACTB) and 4 reference genes did not revealed a significant difference in COL3A1 expression. Consequently, the use of suitable reference genes for a reliable gene expression evaluation by RT-qPCR should consider the type of tendon samples investigated. HPRT1+TBP+ACTB seems to be the best combination of reference genes for the analysis of involving different tendon samples of individuals with rotator cuff tears. PMID:25768100

  11. Effectiveness of tendon transfers for massive rotator cuff tears: a simulation study

    Microsoft Academic Search

    D. J. Magermans; E. K. J. Chadwick; H. E. J. Veeger; P. M. Rozing; F. C. T van der Helm

    2004-01-01

    Objective. To determine what the most effective tendon transfer is in the case of a dysfunctional rotator cuff.Design. A tendon transfer procedure of latissimus dorsi, teres major or a combination of these two to the insertions of either teres minor, infraspinatus, supraspinatus, or subscapularis is simulated using a biomechanical musculoskeletal model of the upper extremity.Background. Massive rotator cuff tears are

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

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

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

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

    PubMed Central

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

    2014-01-01

    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

  14. Triceps tendon reconstruction using ipsilateral palmaris longus autograft in unrecognized chronic tears.

    PubMed

    Scolaro, John A; Blake, Matthew H; Huffman, G Russell

    2013-01-01

    Injury to the distal triceps tendon is uncommon and can be difficult to diagnose, especially when a partial rupture or tear occurs. In situations where an incomplete disruption to the musculotendinous unit occurs, a palpable defect or clear functional loss may not be present. Advanced imaging techniques, such as magnetic resonance imaging or ultrasound, can be used to confirm the diagnosis and define the extent of injury. The treatment of a complete rupture of the distal triceps tendon is repair or reconstruction, whereas the management of a patient with a partial triceps rupture is related to the pain, functional deficit, and expectations of the patient. This article presents 2 patients with chronic, near complete disruptions of the distal triceps tendon. In both patients, surgical reconstruction of the injured tendon was accomplished using ipsilateral palmaris longus autograft. This technique allows the treating surgeon to harvest the graft from the ipsilateral upper extremity. The palmaris autograft is then used to reconstruct the injured portion of the triceps tendon using a Pulvertaft weave technique through the intact triceps tendon and osseous tunnels within the proximal ulna. This technique allows for easy surgical setup and harvest of autograft tendon and provides a structurally sound technique for a tension-free reconstruction of the injured tendon. It also permits early postoperative elbow range of motion, with active elbow extension allowed at 6 weeks. The authors have used this technique successfully in the treatment of chronic partial tears of the distal triceps tendon. PMID:23276343

  15. Shoulder ultrasound: Diagnostic accuracy for impingement syndrome, rotator cuff tear, and biceps tendon pathology

    Microsoft Academic Search

    John W Read; Mark Perko

    1998-01-01

    We sought to determine the accuracy of ultrasound for the preoperative evaluation of shoulder impingement syndrome, rotator cuff tear, and abnormalities of the long head of the biceps tendon. The findings in 42 consecutive surgical cases were compared with the preoperative sonographic readings. Ultrasound detected all of the 10 full-thickness cuff tears identified at surgery (sensitivity 1.0, specificity 0.97) but

  16. Successful return to high level sports following early surgical repair of complete tears of the proximal hamstring tendons

    Microsoft Academic Search

    Sujith Konan; Fares Haddad

    2010-01-01

    The purpose of this study was to investigate the outcome of surgical management of acute complete proximal hamstring tendon\\u000a tears. This was a prospective review of a case series from a tertiary referral centre. Ten patients presenting with complete\\u000a proximal hamstring tendon tears were confirmed on MRI. All patients underwent surgical exploration and repair of the torn\\u000a tendons with the

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

    PubMed

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

    2010-01-01

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

  18. Clinics in diagnostic imaging. 148. Bursal-sided partial-thickness supraspinatus tendon tear.

    PubMed

    Bhagwani, Sanjeev; Peh, Wilfred C G

    2013-09-01

    Rotator cuff injury comprises a continual spectrum of lesions ranging from tendinopathy, which may progress to partial- or full-thickness tear. This progression may be influenced by the interplay of extrinsic and intrinsic factors. We describe the case of a 29-year-man who presented with right shoulder pain for one year. His initial magnetic resonance (MR) arthrogram showed supraspinatus tendinopathy. Subsequent MR arthrogram, obtained after a road traffic accident, showed a bursal-sided partial-thickness tear of the supraspinatus tendon. In view of his worsening clinical symptoms, surgery was performed ten months later, revealing a full-thickness rotator cuff tear near the tendon insertion, with a tight subacromial space and bony protuberance of the humeral head. The pathogenesis of rotator cuff injuries, the roles of different imaging modalities in the diagnosis of rotator cuff injuries, as well as the advantages and limitations of various radiological modalities, are discussed. PMID:24068062

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

    PubMed

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

    2014-12-18

    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

  20. Acute Concomitant Anterior Cruciate Ligament and Patellar Tendon Tears in a Non-dislocated Knee

    PubMed Central

    Wissman, Robert D.; Vonfischer, Nathaniel; Kempf, Kari

    2012-01-01

    Anterior cruciate ligament (ACL) tears are common and may occur in isolation or with other internal derangements of the joint. Tears of the patellar tendon (PT) occur less frequently and are rarely associated with intra-articular pathology. Acute combined tears of both the ACL and PT are known complications of high-energy traumatic knee dislocations. We present a case of an acute concomitant ACL and PT tears in a low-energy non-dislocated knee. To our knowledge, this injury has only been described in a limited number of case reports in the orthopedic literature. We present the imaging findings of this combined injury and discuss the importance of magnetic resonance (MR) in diagnosis. PMID:22439127

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  4. Abnormal Proximal Musculotendinous Junction of the Peroneus Brevis Muscle as a Cause of Peroneus Brevis Tendon Tears: A Cadaveric Study

    Microsoft Academic Search

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

    2010-01-01

    Abnormal musculotendinous distal extension of the peroneus brevis has been implicated as a possible cause of peroneus brevis tendon tears. We investigated this relationship in 58 (46 male) fresh human cadavers. Torn lesions were classified according to Sobel et al. Musculotendinous distal extension of the peroneus brevis was measured in each ankle as the vertical distance from the musculotendinous junction of

  5. Successful return to high level sports following early surgical repair of complete tears of the proximal hamstring tendons.

    PubMed

    Konan, Sujith; Haddad, Fares

    2010-02-01

    The purpose of this study was to investigate the outcome of surgical management of acute complete proximal hamstring tendon tears. This was a prospective review of a case series from a tertiary referral centre. Ten patients presenting with complete proximal hamstring tendon tears were confirmed on MRI. All patients underwent surgical exploration and repair of the torn tendons with the aim of returning to normal activities and sports. Isokinetic muscle testing was performed using a dynamometer. The Cybex dynamometer (Cybex International, Ronkonkowa, NY) testing revealed almost comparable readings for the operated versus the non-operated side. An average peak torque of the operated hamstring muscles of 82.78% (range 47.16-117.88%), compared to the contralateral leg, was noted at six months. An excellent outcome was found in terms of return to normal activities and sports. Early surgical repair and physiotherapy has been noted to be associated with a good outcome and enables an early return to high level sports after complete tear of the proximal hamstring tendons. PMID:19252829

  6. 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 ...

  7. Intra-articular changes precede extra-articular changes in the biceps tendon following rotator cuff tears in a rat model

    PubMed Central

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

    2011-01-01

    Background Biceps tendon pathology is common with rotator cuff tears. The mechanisms for biceps changes, and therefore its optimal treatment, are unknown. Our objective was to determine the effect of rotator cuff tears on regional biceps tendon pathology. We hypothesized that histological and compositional changes would appear before organizational changes, both would appear before mechanical changes, and changes would begin at the tendon’s insertion site. Methods Sixty-five Sprague-Dawley rats received either detachment of supraspinatus and infraspinatus tendons or sham surgery. Rats were sacrificed at 1, 4 or 8 weeks for regional measurements of histological, compositional, organizational (1, 4 and 8 weeks) or mechanical properties (4 and 8 weeks only). Results One week following tendon detachments, decreased organization and more rounded cell shape were found in the intra-articular space of the biceps tendon. Aggrecan expression was increased along the entire length of the tendon while all other compositional changes were at the tendon’s proximal insertion into bone only. With time, this disorganization and more rounded cell shape extended the length of the tendon. Organizational and cell shape changes also preceded detrimental mechanical changes, as decreased modulus in the intra-articular space was found after 8 weeks. Conclusions Results support a degenerative component to pathology in the biceps tendon. Additionally, changes resembling a tendon exposed to compressive loading occurring first in the intra-articular space indicate that the biceps tendon plays an increased role as a load bearing structure against the humeral head in the presence of rotator cuff tears. PMID:21816629

  8. Surgically Repaired Massive Rotator Cuff Tears: MRI of Tendon Integrity, Muscle Fatty Degeneration, and Muscle Atrophy Correlated with Intraoperative and Clinical Findings

    Microsoft Academic Search

    J. M. Mellado; J. Calmet; M. Olona; C. Esteve; A. Camins; L. Pérez del Palomar; J. Giné; A. Saurí

    OBJECTIVE. Our goal in this study was to evaluate by means of MRI the clinical signif- icance of tendon integrity, muscle fatty degeneration, and muscle atrophy in surgically repaired massive rotator cuff tears and to correlate these and other prognostic factors with intraoperative and clinical findings. MATERIALS AND METHODS. Twenty-eight surgically proven massive rotator cuff tears were retrospectively included in

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

    PubMed

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

    2012-06-01

    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

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

    PubMed Central

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

    2012-01-01

    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

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

    PubMed

    Khor, Andrew Yu Keat; Wong, Steven Bak Siew

    2014-02-01

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

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

    E-print Network

    Beckermann, Christoph

    Simulation of Hot Tearing and Distortion during Casting of Steel: Comparison with Experiments C that is subjected to mechanical restraints. Several key factors are known to aggravate the hot tearing of cast steel and comparison for accurate hot tear prediction. Introduction Hot tearing in any steel casting is disastrous

  13. The effects of chronic unloading and gap formation on tendon-to-bone healing in a rat model of massive rotator cuff tears

    PubMed Central

    Killian, Megan L.; Cavinatto, Leonardo; Shah, Shivam A.; Sato, Eugene J.; Ward, Samuel R.; Havlioglu, Necat; Galatz, Leesa M.; Thomopoulos, Stavros

    2014-01-01

    The objective of this study was to understand the effect of pre-repair rotator cuff chronicity on post-repair healing outcomes using a chronic and acute multi-tendon rat rotator cuff injury model. Full-thickness dual tendon injuries (supra- and infraspinatus) were created unilaterally in adult male Sprague Dawley rats, and left chronically detached for 8 or 16 weeks. After chronic detachment, tears were repaired and acute dual tendon injuries were created and immediately repaired on contralateral shoulders. Tissue level outcomes for bone, tendon, and muscle were assessed 4 or 8 weeks after repair using histology, microcomputed tomography, biomechanical testing, and biochemical assays. Substantial gap formation was seen in 35% of acute repairs and 44% of chronic repairs. Gap formation negatively correlated with mechanical and structural outcomes for both healing time points regardless of injury duration. Bone and histomorphometry, as well as biomechanics, were similar between acute and chronic injury and repair regardless of chronicity and duration of healing. This study was the first to implement a multi-tendon rotator cuff injury with surgical repair following both chronic and acute injuries. Massive tear in a rodent model resulted in gap formation regardless of injury duration which had detrimental effects on repair outcomes. PMID:24243733

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

    PubMed

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

    2015-03-01

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

  15. Reconstruction of Chronic Foveal TFCC Tears with an Autologous Tendon Graft.

    PubMed

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

    2015-02-01

    Background?A triangular fibrocartilage complex (TFCC) injury can produce distal radioulnar joint (DRUJ) instability. If the foveal attachment is avulsed, it translates distally. The footprint is separated from its origin and will become covered in synovitis, preventing healing. The authors describe a surgical technique for the treatment of instability of the DRUJ due to chronic foveal detachment of the TFCC. Technique?The procedure utilizes a loop of autologous palmaris longus tendon graft passed through the ulnar aspect of the TFCC and through an osseous tunnel in the distal ulna to reconstruct the fovel attachment. Patients and Methods?We report on nine patients with a mean age of 42. Median follow-up was 13 months. Results?The median pain scores measured were reduced from 8 to 3 postoperatively, and all had a stable DRUJ. Conclusions?This technique provides stability of the distal ulna to the radius and carpus, with potential for biologic healing through osseous integration. It is a robust, anatomically based reconstruction of the TFCC to the fovea that stabilizes the DRUJ and the ulnar-carpal sag. PMID:25709873

  16. Tendon stem cells: experimental and clinical perspectives in tendon and tendon-bone junction repair

    PubMed Central

    Lui, Pauline Po Yee; Wong, On Tik

    2012-01-01

    Summary Tendon and tendon-bone junction injuries, while heal, have high re-tear rates. Mesenchymal stem cells (MSCs) have great appeal for the promotion of tendon and tendon-bone junction healing because of their high proliferation rate, multi-potency and relative ease of isolation from various tissues. Tendon stem cells have been identified recently and could be an alternative new cell source for tendon and tendon-bone junction repair. In this review, we summarized the in vitro characteristics of tendon stem cells. The evidence supporting the potential use of these cells for tendon and tendon-bone junction repair was presented. In order to therapeutically apply tendon stem cells in the clinical settings, standardization of tendon stem cell culture is essential. Issues relating to the sources, purity, efficacy, safety and delivery of tendon stem cells for tendon and tendon-bone junction repair were summarized and discussed. The direction for future research was suggested. PMID:23738293

  17. Comparison of camel tear proteins between summer and winter

    PubMed Central

    Chen, Ziyan; Shamsi, Farrukh A.; Li, Kaijun; Huang, Qiang; Al-Rajhi, Ali A.; Chaudhry, Imtiaz A.

    2011-01-01

    Purpose Proteins in the tear fluid have positive effects on maintaining the integrity and stabilization of the tear film, which is affected by several environmental factors. The aim of this study is to investigate seasonal variation of protein patterns in camel tears collected during the summer and winter season. Methods Tears from both eyes of 50 clinically normal camels (Camelus dromedarius) were collected in the summer (June – July) and in the winter (December – January) respectively. Pooled tear protein samples from two seasons were separated by SDS–PAGE and two-dimensional electrophoresis (2-DE). Protein spots of differential expression in two season gels were excised and subjected to in-gel digestion and identification by matrix assisted laser desorption/ionization-time of flight/time of flight-mass spectrum (MALDI-TOF/TOF-MS) analysis. Two differentially expressed proteins, lactoferrin (LF) and vitelline membrane outer layer protein 1 homolog (VMO1 homolog), were validated by western blotting. Results Thirteen well resolved bands were detected in SDS–PAGE gels of both summer and winter camel tears. By band densitometry, significantly higher intensities of band 6, 7, 11, and lower intensity of band 13 were observed in the summer group compared to the winter group. In 2-DE profiles of camel tears, four protein spots were found expressed differentially in two seasons. Further protein identification by MALDI-TOF/TOF-MS and confirmation by western blotting indicated that there was a significant decrease in LF (p=0.002) and an increase in VMO1 homolog (p=0.042) in tears in the summer compared to the winter. Conclusions The seasonal variation of camel tear fluids has been found in the composition of proteins, including LF and VMO1 homolog. This result will expand our knowledge of physiologic characteristics of tear fluids and establish a foundation for the mechanistic studies and clinical practices on ocular surface disorders. PMID:21293736

  18. Subscapularis tears.

    PubMed

    Longo, Umile Giuseppe; Berton, Alessandra; Marinozzi, Andrea; Maffulli, Nicola; Denaro, Vincenzo

    2012-01-01

    The subscapularis muscle is the largest and strongest muscle of the rotator cuff. It plays an essential role in the stability and function of the shoulder. Tears of the subscapularis tendon are more frequent than previously estimated. The worldwide use of arthroscopy in rotator cuff surgery has allowed to recognize the true prevalence of subscapularis lesions, as it permits to visualize the articular side where partial tears are usually localized. Subscapularis tears are generally non-traumatic, arising from intrinsic degeneration, subcoracoid and/or anterosuperior impingement. Clinical presentation is usually characterized by history of pain, typically located anteriorly, and difficulty in lifting movements across the chest, or twisting inwards that hinders activities of daily life. Special tests for the diagnosis of subscapularis tears include the lift-off, belly-press, and bear-hug tests. Imaging of the subscapularis tendon may involve plain radiography, magnetic resonance and ultrasound scanning, but MRI better characterizes subscapular tears and coexistent shoulder pathology. The management of subscapularis tears is aimed at restoring the integral role of this muscle in the shoulder. Operative management is indicated for most patients because it is the only one to allow restoration of subscapularis function. Arthroscopic repair can be safely and successfully performed. It requires tendon mobilization to reach the lesser tuberosity. If this is not possible, its footprint can be medialized up to 5-7 mm. Arthroscopic results are encouraging. At intermediate follow-up, improvement in functional scores and patient satisfaction has been reported. Outcomes are comparable to that of open repair, with a very low complication rate and no major intraoperative complications. PMID:21986050

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

    NASA Astrophysics Data System (ADS)

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

    1995-05-01

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

  20. Tendon structure, disease, and imaging

    PubMed Central

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

    2014-01-01

    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

  1. Arthroscopic Treatment of Calcific Tendonitis

    PubMed Central

    Barber, F. Alan; Cowden, Courtney H.

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  4. Arthroscopic Recognition and Repair of the Torn Subscapularis Tendon

    PubMed Central

    Denard, Patrick J.; Burkhart, Stephen S.

    2013-01-01

    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

  5. [Tendinopathy of the gluteus medius tendon].

    PubMed

    Bard, Hervé

    2009-04-20

    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

  6. Coracoclavicular ligament reconstruction: biomechanical comparison of tendon graft repairs to a synthetic double bundle augmentation.

    PubMed

    Wellmann, Mathias; Kempka, Jan P; Schanz, Steffen; Zantop, Thore; Waizy, Hazibullah; Raschke, Michael J; Petersen, Wolf

    2009-05-01

    For currently presented anatomical coracoclavicular ligament repairs issues such as autologous tendon graft versus synthetic suture augmentation and the optimum fixation strategies for both types of reconstruction are not solved. The purpose of the study was to compare the biomechanical properties of different tendon graft repairs to the characteristics of a synthetic polyester augmentation. Four anatomical coracoclavicular ligament repairs were biomechanically tested: 5 mm coracoclavicular tendon loop with suture fixation, tendon loop with flip button fixation, tendon loop with interference screw fixation versus a double 1.0-mm polyester repair with flip button fixation. The biomechanical testing included cyclic superio-inferior loading and a subsequent load to failure protocol. The ultimate failure loads were significantly higher for the double polyester/flip button repair (927 N) compared to all tendon repair techniques (maximum 640 N). In contrast the stiffness level was higher for the tendon repairs compared to the polyester/flip button repair (68.7 N/mm) but strongly dependent on the fixation technique (interference screw 97.2 N/mm, flip button 84.9 N/mm, side to side suture 60.9 N/mm). A synthetic coracoclavicular augmentation using a polyester suture provides adequate structural properties compared to a tendon repair. Therefore the decision for a tendon graft should be made by the necessity of a biologic substrate rather than by the assumption of a biomechanical advantage. PMID:19225755

  7. Achilles Tendonitis

    MedlinePLUS

    ... you ever worry about getting injured while playing sports? If the tendon becomes swollen or irritated due ... Causes Achilles Tendonitis? Achilles tendonitis is a common sports injury caused by repeated or intense strain on ...

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

    PubMed Central

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

    2012-01-01

    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

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

    PubMed

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

    2005-01-01

    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

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

    PubMed

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

    2001-07-01

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

  11. Massive tears of the rotator cuff treated with a deltoid flap

    Microsoft Academic Search

    Eric Vandenbussche; Moncef Bensaïda; Céline Mutschler; Thierry Dart; Bernard Augereau

    2004-01-01

    We retrospectively reviewed the charts of 29 patients younger than 65 years at surgery treated with deltoid flap reconstruction for massive postero-superior rotator cuff tears. All tears involved supraspinatus and infraspinatus tendons and were associated with tendon stump retraction to the glenoid rim, a preservable long biceps tendon, and an intact subscapularis tendon. Mean follow-up was 10.5 years. Patient satisfaction

  12. Endoscopic Repair of a Gluteus Medius Tear at the Musculotendinous Junction

    PubMed Central

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

    2013-01-01

    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

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

    PubMed

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

    2007-09-01

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

  14. Tendon repair

    MedlinePLUS

    ... free) The surgeon makes a cut on the skin over the injured tendon. The damaged or torn ends of the tendon are sewn together. If the tendon has been severely injured, a tendon graft may be needed. In this case, a piece ...

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

    PubMed Central

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

    2011-01-01

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

  16. Ultrasound of tendons and nerves.

    PubMed

    Martinoli, Carlo; Bianchi, Stefano; Dahmane, M'Hamed; Pugliese, Francesca; Bianchi-Zamorani, Maria Pia; Valle, Maura

    2002-01-01

    Tendons and nerves represent probably one of the best application of musculoskeletal US due to the high lesion detection rate and accuracy of US combined with its low cost, wide availability, and ease of use. The refinement of high-frequency broadband linear-array transducers, and sensitive color and power Doppler technology, have improved the ability of US to detect fine textural abnormalities of these structures as well as to identify a variety of pathological conditions. Characteristic echotextural patterns, closely resembling the histological ones, are typically depicted in these structures using high US frequencies. In tendon imaging, US can assess dislocations, degenerative changes and tendon tears, including intrasubstance tears, longitudinal splits, partial and complete rupture, inflammatory conditions and tendon tumors, as well as postoperative findings. In nerve imaging, US can support clinical and electrophysiological testing for detection of compressing lesions caused by nerve entrapment in a variety of osteofibrous tunnels of the limbs and extremities. Congenital anomalies, nerve tears, and neurogenic tumors can also be diagnosed. Overall, US is an effective technique for imaging tendons and nerves. In most cases, a focused US examination can be performed more rapidly and efficiently than MR imaging. PMID:11868073

  17. A comparison of clinical estimation, ultrasonography, magnetic resonance imaging, and arthroscopy in determining the size of rotator cuff tears

    Microsoft Academic Search

    Lawrence Bryant; Ron Shnier; Carl Bryant; George A. C Murrell

    2002-01-01

    This prospective study was undertaken to compare the ability of clinical estimation, diagnostic ultrasonography, magnetic resonance imaging, and arthroscopy to estimate the size of rotator cuff tears. Estimates of rotator cuff tear size were compared with the findings at open operation in 33 consecutive patients with a presumptive diagnosis of rotator cuff tear. Arthroscopy estimates of rotator cuff tear size

  18. Refixation of the supraspinatus tendon in a rat model--influence of continuous growth factor application on tendon structure.

    PubMed

    Buchmann, Stefan; Sandmann, Gunther H; Walz, Lars; Hoppe, Henriette; Beitzel, Knut; Wexel, Gabriele; Tian, Weiwei; Winter, Gerhard; Imhoff, Andreas B

    2013-02-01

    The purpose was to evaluate histological changes of the supraspinatus tendon (SSP) after refixation under continuous growth factor application over 20 days in comparison to the native healing process. In a chronic rat tendon tear model (15 rats/group), a transosseous SSP refixation was performed and growth factors (control, G-CSF, b-FGF, combination) were continuously released into the subacromial space by an osmotic pump. Tendon healing was evaluated histologically by a modified MOVIN-Score, and Collagen I/III content was determined by immunohistology at 6 weeks. A modified MOVIN sum score showed significant lower counts for G-CSF and b-FGF in comparison to the control group (p = 0.050/p = 0.027) and the combined group (p = 0.050/p = 0.043). Collagen III was significantly reduced in the combined group compared to the control group (p = 0.028). Collagen I showed no significant differences. The Collagen I/III ratio was nearly doubled for b-FGF and the combined group compared to the control. At the study endpoint, 33% of pump dislocations were detected. The continuous application of both isolated growth factors (G-CSF/b-FGF) achieved improved tendon-remodeling. However, the continuous application via an osmotic pump showed a relative high dislocation rate when applied in the rat model. PMID:22912341

  19. The Results of Repair of Massive Tears of the Rotator Cuff

    Microsoft Academic Search

    CHRISTIAN GERBER; BRUNO FUCHS; JUERG HODLER

    2000-01-01

    Background: Massive tears of the tendons of the ro- tator cuff cause atrophy and fatty degeneration of the rotator cuff muscles and painful loss of function of the shoulder. Repair of massive rotator cuff tears is often followed by retears of the tendons, additional muscular degeneration, and a poor clinical outcome. The pur- poses of this study were to determine

  20. A 10Year Comparison of Anterior Cruciate Ligament Reconstructions With Hamstring Tendon and Patellar Tendon AutograftA Controlled, Prospective Trial

    Microsoft Academic Search

    Leo A. Pinczewski; Jeffrey Lyman; Lucy J. Salmon; Vivianne J. Russell; Justin Roe; James Linklater

    2007-01-01

    Background: There are no controlled, prospective studies comparing the 10-year outcomes of anterior cruciate ligament (ACL) reconstruction using patellar tendon (PT) and 4-strand hamstring tendon (HT) autografts.Hypothesis: Comparable results are possible with HT and PT autografts.Study Design: Cohort study; Level of evidence, 2.Methods: One hundred eighty ACL-deficient knees that met inclusion criteria underwent ACL reconstruction (90 HT autograft, 90 PT

  1. Comparison of the Clinical Outcomes of Single and Double-row Repairs in Rotator Cuff Tears

    Microsoft Academic Search

    Jin-Young Park; Sang-Hoon Lhee; Jin-Hyung Choi; Hong-Keun Park; Je-Wook Yu; Joong-Bae Seo

    2008-01-01

    Background: Although research has demonstrated the superiority of double-row rotator cuff repair over single-row methods from a biological and mechanical point of view, few studies have compared clinical outcome of the 2 methods, and no articles have been published describing the superiority of double-row methods in clinical aspects.Hypothesis: Arthroscopic double-row repair of a rotator cuff tear has superior clinical outcome

  2. Comparison of tendon tensions estimated from two biomechanical models of the thumb.

    PubMed

    Vigouroux, Laurent; Domalain, Mathieu; Berton, Eric

    2009-08-01

    Despite the paramount function of the thumb in daily life, thumb biomechanical models have been little developed and studied. Moreover, only two studies provided quantitative anthropometric data of tendon moment arms. To investigate thumb tendon tensions, biomechanicians and clinicians have to know the performances and the limits of these two data sets. The aim of this study was thus to compare the results of these two models and evaluate their performances in regard to prior electromyographic measurements (EMG). Thumb posture was recorded during the classical key pinch and pulp pinch grips. Various fingertip forces applied at the distal segment were simulated in a range including extension, adduction, flexion, abduction. Input data of thumb postures and fingertip forces were used to compute tendon tensions with both models. Tendon tensions obtained using these two models were then compared and correlated to EMG measurements provided in the literature. The results showed that both models predicted relevant muscle coordination for five of the nine muscles modelled. Opponent and abductor longus muscle coordinations were badly estimated by both models. Each model was sensible to kinematic errors but not in the same proportion. This study pointed out the advantages/limits of the two models to use them more appropriately for clinical and/or research purposes. PMID:19467660

  3. Diagnosis and treatment of anterosuperior rotator cuff tears

    Microsoft Academic Search

    Jon J. P. Warner; Laurence Higgins; I. M. Parsons; Paul Dowdy

    2001-01-01

    Nineteen of 407 patients who underwent rotator cuff repair surgery over a 6-year period were found to have a tear of the subscapularis in combination with the supraspinatus and infraspinatus tendons. Nine of these patients had an unsuccessful prior surgery, which failed to recognize the extent of the subscapularis component. Surgical repair of the subscapularis tendon required a deltopectoral approach,

  4. Association of osteopenia of the humeral head with full-thickness rotator cuff tears

    Microsoft Academic Search

    Dominik C Meyer; Sandro F Fucentese; Bruno Koller; Christian Gerber

    2004-01-01

    Rotator cuff tendon repair may fail for various reasons. Although the role of repair techniques and of the musculotendinous unit has been studied, there is little information on the quality of the bone to which the tendon is to be repaired. Therefore, 14 cadaveric humeral heads, 7 specimens without and 7 with a full-thickness rotator cuff tendon tear, were quantitatively

  5. Measuring Regional Changes in Damaged Tendon

    NASA Astrophysics Data System (ADS)

    Frisch, Catherine Kayt Vincent

    Mechanical properties of tendon predict tendon health and function, but measuring these properties in vivo is difficult. An ultrasound-based (US) analysis technique called acoustoelastography (AE) uses load-dependent changes in the reflected US signal to estimate tissue stiffness non-invasively. This thesis explores whether AE can provide information about stiffness alteration resulting from tendon tears both ex vivo and in vivo. An ex vivo ovine infraspinatus tendon model suggests that the relative load transmitted by the different tendon layers transmit different fractions of the load and that ultrasound echo intensity change during cyclic loading decreases, becoming less consistent once the tendon is torn. An in vivo human tibialis anterior tendon model using electrically stimulated twitch contractions investigated the feasibility of measuring the effect in vivo. Four of the five subjects showed the expected change and that the muscle contraction times calculated using the average grayscale echo intensity change compared favorably with the times calculated based on the force data. Finally an AE pilot study with patients who had rotator cuff tendon tears found that controlling the applied load and the US view of the system will be crucial to a successful in vivo study.

  6. Comparison of shoulder ultrasound and MR imaging in diagnosing full-thickness rotator cuff tears.

    PubMed

    Chang, Cheng-Yen; Wang, Su-Fang; Chiou, Hong-Jen; Ma, Hsiao-Li; Sun, Ying-Chou; Wu, Hong-Dar

    2002-01-01

    Ultrasound (US) and magnetic resonance imaging (MRI) of 422 cases were evaluated to compare the feasibility in diagnosing full-thickness rotator cuff tears (FTRCTs). On the basis of different US performers, they were divided into two groups: Group 1 performed by a 5-year experience technician and Group 2 performed by a 10-year experience radiologist. Sensitivity, negative predictive value (NPV), accuracy of US, and correlation between the two modalities were better in Group 2. When an expert is available, US can be used for diagnosing FTRCTs; otherwise, MRI should be performed. PMID:11814754

  7. Effect of implanting a soft tissue autograft in a central-third patellar tendon defect: biomechanical and histological comparisons.

    PubMed

    Kinneberg, Kirsten R C; Galloway, Marc T; Butler, David L; Shearn, Jason T

    2011-09-01

    Previous studies by our laboratory have demonstrated that implanting a stiffer tissue engineered construct at surgery is positively correlated with repair tissue stiffness at 12 weeks. The objective of this study was to test this correlation by implanting a construct that matches normal tissue biomechanical properties. To do this, we utilized a soft tissue patellar tendon autograft to repair a central-third patellar tendon defect. Patellar tendon autograft repairs were contrasted against an unfilled defect repaired by natural healing (NH). We hypothesized that after 12 weeks, patellar tendon autograft repairs would have biomechanical properties superior to NH. Bilateral defects were established in the central-third patellar tendon of skeletally mature (one year old), female New Zealand White rabbits (n?=?10). In one limb, the excised tissue, the patellar tendon autograft, was sutured into the defect site. In the contralateral limb, the defect was left empty (natural healing). After 12 weeks of recovery, the animals were euthanized and their limbs were dedicated to biomechanical (n?=?7) or histological (n?=?3) evaluations. Only stiffness was improved by treatment with patellar tendon autograft relative to natural healing (p?=?0.009). Additionally, neither the patellar tendon autograft nor natural healing repairs regenerated a normal zonal insertion site between the tendon and bone. Immunohistochemical staining for collagen type II demonstrated that fibrocartilage-like tissue was regenerated at the tendon-bone interface for both repairs. However, the tissue was disorganized. Insufficient tissue integration at the tendon-to-bone junction led to repair tissue failure at the insertion site during testing. It is important to re-establish the tendon-to-bone insertion site because it provides joint stability and enables force transmission from muscle to tendon and subsequent loading of the tendon. Without loading, tendon mechanical properties deteriorate. Future studies by our laboratory will investigate potential strategies to improve patellar tendon autograft integration into bone using this model. PMID:22010737

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  9. Comparison of femoral fixation methods for anterior cruciate ligament reconstruction with patellar tendon graft: a mechanical analysis in porcine knees.

    PubMed

    Milano, Giuseppe; Mulas, Pier Damiano; Ziranu, Fabio; Deriu, Laura; Fabbriciani, Carlo

    2007-06-01

    The aim of the present study was to evaluate the structural properties of femur-patellar tendon graft complex in anterior cruciate ligament (ACL) reconstruction using different femoral fixation devices. Type of study is biomechanical testing. An ACL reconstruction was performed on 40 cadaver porcine knees, using patellar tendon (PT) graft. Specimens were divided into four groups according to the femoral fixation: interference absorbable screw (Group A), metallic setscrew (Group B), absorbable pins (Group C), and a combination of metallic setscrew and pin (Group D). Other ten knees were used as controls. On each sample, a cyclic loading test, then a load-to-failure test were performed. Elongation after 1,000 loading cycles, ultimate failure load, yield load, stiffness, deformation at the yield point, and mode of failure were recorded. Kruskal-Wallis test and Tukey test were used to compare the differences between groups. The lowest mean elongation after 1,000 load cycles was observed for Group B (1.7 +/- 1.4 mm) and D (1.2 +/- 0.3 mm). Ultimate failure load of Group D (1,021.8 +/- 199.4 N) was comparable with that of normal ACL (1,091.2 +/- 193.3 N) and PT graft (1,140.6 +/- 285.7 N). All other groups were lower than the controls. For mean stiffness, all the groups, excepting for Group D (172.8 +/- 40.4 N/mm), were significantly lower than PT control group (216 +/- 78.4 N/mm). Mode of failure was graft pullout for Groups A and B, distal pin breakage for Group C, and midsubstance graft rupture in 80% of the cases for Group D. Only combined compression and suspension fixation did not show significantly different structural properties in comparison with normal ACL and PT graft. Furthermore, it showed no risk of graft pullout or hardware breakdown in comparison with other fixation devices. PMID:17295042

  10. Tear System

    MedlinePLUS

    ... the eyelids. A thorough examination by an ophthalmic plastic surgeon can determine the cause of tearing and ... a dacryocystorhinostomy or DCR, look for an ophthalmic plastic reconstructive and cosmetic surgeon who specializes in the ...

  11. Minimally invasive A2 flexor tendon pulley and biomechanical comparison with two accepted techniques.

    PubMed

    Mallo, Gregory C; Sless, Yury; Hurst, Lawrence C; Serra-Hsu, Frederick

    2008-09-01

    The increasing popularity of rock climbing and its associated injury of closed traumatic pulley A2 rupture has sparked investigator interest in pulley biomechanics. Biomechanically, the A2 and A4 pulleys are important for preventing bowstringing of the flexor tendon upon digital flexion. The literature is replete with reparative techniques for A2 pulley rupture. These techniques include direct fibrous tissue repair, as well as the use of palmaris longus autograft for single- and double-loop reconstruction. Through a previously undescribed minimally invasive double-anchor technique, we used palmaris longus tendon and 2-mm bioabsorbable suture anchors to reconstruct the A2 pulley at its anatomical location in a cadaver model. Then the ultimate load to failure of this reconstruction was tested against 2 known reconstructive techniques, namely, single-loop and double-loop palmaris repair. There was no significant difference between the strength of the previously described single-loop technique and our novel double-anchor technique. Furthermore, our minimally invasive repair obviated the need for the circumferential dissection and soft tissue trauma associated with the single- and double-loop repairs. PMID:18776779

  12. Functional postoperative treatment of Achilles tendon repair

    Microsoft Academic Search

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

    1992-01-01

    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

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

    PubMed Central

    2014-01-01

    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

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

    PubMed Central

    2014-01-01

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

  15. Do Cells Contribute to Tendon and Ligament Biomechanics?

    PubMed Central

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

    2014-01-01

    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

  16. Comparison of proximal turndown of central slip combined with suture of lateral bands versus free tendon grafting for central slip reconstruction after an open finger injury.

    PubMed

    Li, Ying; Ding, Aizhong; He, Zhimin; Xue, Feng

    2014-03-01

    We randomized patients with open finger injury and central slip insertion defects into a proximal turn-down group (final n = 28) and a palmaris longus tendon graft group (final n = 20). In the proximal turn-down group, the dorsal central slip of the extensor tendon in the proximal phalanx was split, leaving it attached distally. We turned the strip from proximal to distal and fixed it using the distal joint capsule of the proximal interphalangeal joint as the distal insertion of reconstruction, and the extended central slips were then fixed to the middle phalanx. The dorsal traumatic central slip was stitched with lateral bands using 2-0 suture to form a new conjoint tendon. The injured central slip in the comparison group was sutured using autogenous palmaris longus tendon and fixed in drilled holes in the middle phalanx. Outcomes assessment was performed according to Dargan's criteria during postoperative follow-up. Motion range in the proximal turndown group was significantly greater than in the graft group (p < 0.05). We observed no boutonniere deformity in both the proximal turndown and graft group. PMID:24873096

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

    PubMed Central

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

    2013-01-01

    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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  20. Comparison of femoral fixation methods for anterior cruciate ligament reconstruction with patellar tendon graft: a mechanical analysis in porcine knees

    Microsoft Academic Search

    Giuseppe Milano; Pier Damiano Mulas; Fabio Ziranu; Laura Deriu; Carlo Fabbriciani

    2007-01-01

    The aim of the present study was to evaluate the structural properties of femur–patellar tendon graft complex in anterior\\u000a cruciate ligament (ACL) reconstruction using different femoral fixation devices. Type of study is biomechanical testing. An\\u000a ACL reconstruction was performed on 40 cadaver porcine knees, using patellar tendon (PT) graft. Specimens were divided into\\u000a four groups according to the femoral fixation:

  1. Comma Sign–Directed Repair of Anterosuperior Rotator Cuff Tears

    PubMed Central

    Dilisio, Matthew F.; Neyton, Lionel

    2014-01-01

    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. PMID:25685676

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

    PubMed

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

    2012-06-01

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

  3. Arthroscopic repair of large rotator cuff tears using the interval slide technique

    Microsoft Academic Search

    Joseph C Tauro

    2004-01-01

    Purpose: In some cases of larger and chronic rotator cuff tears, the supraspinatus tendon may be held in a retracted position by the contracted tissue of the rotator interval and the attached coracohumeral ligament. This study was performed to evaluate the utility and clinical effectiveness of an arthroscopic release of the rotator interval from the supraspinatus tendon combined with repair

  4. Stem Cell Applications in Tendon Disorders: A Clinical Perspective

    PubMed Central

    Young, Mark

    2012-01-01

    Tendon injuries are a common cause of morbidity and a significant health burden on society. Tendons are structural tissues connecting muscle to bone and are prone to tearing and tendinopathy, an overuse or degenerative condition that is characterized by failed healing and cellular depletion. Current treatments, for tendon tear are conservative, surgical repair or surgical scaffold reconstruction. Tendinopathy is treated by exercises, injection therapies, shock wave treatments or surgical tendon debridement. However, tendons usually heal with fibrosis and scar tissue, which has suboptimal tensile strength and is prone to reinjury, resulting in lifestyle changes with activity restriction. Preclinical studies show that cell therapies have the potential to regenerate rather than repair tendon tissue, a process termed tenogenesis. A number of different cell lines, with varying degrees of differentiation, have being evaluated including stem cells, tendon derived cells and dermal fibroblasts. Even though cellular therapies offer some potential in treating tendon disorders, there have been few published clinical trials to determine the ideal cell source, the number of cells to administer, or the optimal bioscaffold for clinical use. PMID:22448174

  5. Arthroscopic “Interval Slide” in the Repair of Large Rotator Cuff Tears

    Microsoft Academic Search

    Joseph C. Tauro

    1999-01-01

    Summary: An arthroscopic technique for coracohumeral ligament release from a retracted supraspinatus tendon is presented. The procedure is technically simple and can greatly improve the mobility of retracted rotator cuff tears, thus expanding the application of arthroscopic repair to larger tears.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 15, No 5 (July-August), 1999: pp 527–530

  6. An arthroscopic stitch for massive rotator cuff tears: the mac stitch

    Microsoft Academic Search

    John D. MacGillivray; C. Benjamin Ma

    2004-01-01

    Arthroscopic repair of rotator cuff tears has become popular with the advancement in technology and arthroscopic technique. As we attempt to arthroscopically repair larger rotator cuff tears, we are relying more on tissue fixation. The tendon–suture interface has been recognized as the weak link in rotator cuff repair. In this article, we propose the use of the Mac stitch—a simple

  7. A Simple Grafting Method to Repair Irreparable Distal Biceps Tendon

    Microsoft Academic Search

    Martti Vastamäki; Heidi Vastamäki

    2008-01-01

    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

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

    PubMed Central

    Hodges, Robin R.; Dartt, Darlene A.

    2014-01-01

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

  9. MR Imaging of the Shoulder: Appearance of the Supraspinatus Tendon in Asymptomatic Volunteers

    Microsoft Academic Search

    Christian H. Neumann; R. Gary Holt; Lynne S. Steinbach; Anon H. Jahnke; Steve A. Petersen

    MR imaging has been shown to be accurate in the diagnosis of rotator cuff disruption and tear. Uncertainty remains about the significance of Increased signal intensity in the critical zone of the supraspinatus tendon without visible disruption of tendon fibers and about the significance of other secondary findings commonly encountered with rotator cuff abnormalities, such as musculotendinous retraction or obliteration

  10. Mechanical Compromise of Partially Lacerated Flexor Tendons Jaclyn Kondratko1,2, Sarah Duenwald-Kuehl1,2, Roderic Lakes3,4, and Ray Vanderby Jr.

    E-print Network

    Lakes, Roderic

    to a normal tendon until a 50% rotator cuff tear is present and therefore provided a mechanical basis recommendation for many other tendons, such as rotator cuff [17]. However, little evidence is present to confirm a constant load of 31N was applied to normal and 33% cut human cadaver rotator cuff tendons, did not support

  11. Soft-tissue changes in hip abductor muscles and tendons after total hip replacement: comparison between the direct anterior and the transgluteal approaches.

    PubMed

    Bremer, A K; Kalberer, F; Pfirrmann, C W A; Dora, C

    2011-07-01

    The direct anterior approach in total hip replacement anatomically offers the chance to minimise soft-tissue trauma because an intermuscular and internervous plane is explored. This motivated us to abandon our previously used transgluteal approach and to adopt the direct anterior approach for total hip replacement. Using MRI, we performed a retrospective comparative study of the direct anterior approach with the transgluteal approach. There were 25 patients in each group. At one year post-operatively all the patients underwent MRI of their replaced hips. A radiologist graded the changes in the soft-tissue signals in the abductor muscles. The groups were similar in terms of age, gender, body mass index, complexity of the reconstruction and absence of symptoms. Detachment of the abductor insertion, partial tears and tendonitis of gluteus medius and minimus, the presence of peri-trochanteric bursal fluid and fatty atrophy of gluteus medius and minimus were significantly less pronounced and less frequent when the direct anterior approach was used. There was no significant difference in the findings regarding tensor fascia lata between the two approaches. We conclude that use of the direct anterior approach results in a better soft-tissue response as assessed by MRI after total hip replacement. However, the impact on outcome needs to be evaluated further. PMID:21705558

  12. Artificial tears potpourri: a literature review

    PubMed Central

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

    2014-01-01

    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

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

    PubMed

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

    2015-02-01

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

  14. Reversed arthroscopic subacromial decompression for massive rotator cuff tears

    Microsoft Academic Search

    Markus Scheibel; Sven Lichtenberg; Peter Habermeyer

    2004-01-01

    This prospective study evaluates the results of a procedure for massive rotator cuff tears that we term reversed arthroscopic subacromial decompression (ASD). The procedure includes an arthroscopic debridement of the subacromial space and glenohumeral joint, an arthroscopic tuberoplasty, and depending on the pathologic condition of the long head of the biceps, a biceps tendon tenotomy. Reversed ASD avoids a classic

  15. Rotator Cuff Tears

    MedlinePLUS

    ... 2013 by the American Academy of Orthopaedic Surgeons. Rotator Cu? Tears A rotator cu? tear is a common cause of pain and disability ... Surgeons. Cause There are two main causes of rotator cu? tears: injury and degeneration. Acute Tear If you fall ...

  16. Comparison of anterior cruciate ligament reconstruction in male and female athletes using the patellar tendon and hamstring autografts

    Microsoft Academic Search

    Alberto Gobbi; Marcin Domzalski; Jose Pascual

    2004-01-01

    Despite the higher incidence of anterior cruciate ligament (ACL) injuries in female than in male athletes few authors have studied the effects of gender on the outcome of ACL reconstruction. This prospective study compared the results of ACL reconstruction using the patellar tendon and hamstring techniques in men and women. We prospectively followed 80 comparable athletes (46 males, 32 females)

  17. Comparison of Morphology, Orientation, and Migration of Tendon Derived Fibroblasts and Bone Marrow Stromal Cells on Electrochemically Aligned Collagen Constructs

    PubMed Central

    Gurkan, Umut Atakan; Cheng, Xingguo; Kishore, Vipuil; Uquillas, Jorge Alfredo; Akkus, Ozan

    2010-01-01

    There are approximately 33 million injuries involving musculoskeletal tissues (including tendons and ligaments) every year in the United States. In certain cases the tendons and ligaments are damaged irreversibly and require replacements that possess the natural functional properties of these tissues. As a biomaterial, collagen has been a key ingredient in tissue engineering scaffolds. The application range of collagen in tissue engineering would be greatly broadened if the assembly process could be better controlled to facilitate the synthesis of dense, oriented tissue-like constructs. An electrochemical method has recently been developed in our laboratory to form highly oriented and densely packed collagen bundles with mechanical strength approaching that of tendons. However, there is limited information whether this electrochemically aligned collagen bundle (ELAC) presents advantages over randomly oriented bundles in terms of cell response. Therefore, the current study aimed to assess the biocompatibility of the collagen bundles in vitro, and compare tendon derived fibroblasts (TDFs) and bone marrow stromal cells (MSCs) in terms of their ability to populate and migrate on the single and braided ELAC bundles. The results indicated that the ELAC was not cytotoxic; both cell types were able to populate and migrate on the ELAC bundles more efficiently than that observed for random collagen bundles. The braided ELAC constructs were efficiently populated by both TDFs and MSCs in vitro. Therefore, both TDFs and MSCs can be used with the ELAC bundles for tissue engineering purposes. PMID:20694974

  18. Comparison of strength properties of poly-L/D-lactide (PLDLA) 96/4 and polyglyconate (Maxon) sutures: in vitro, in the subcutis, and in the achilles tendon of rabbits.

    PubMed

    Kangas, J; Paasimaa, S; Mäkelä, P; Leppilahti, J; Törmälä, P; Waris, T; Ashammakhi, N

    2001-01-01

    Achilles tendon rupture is a common injury. Absorbable sutures are not commonly used because of their limited strength properties. Recently, sutures with prolonged strength retention properties have been developed. The aim of the study is to test the mechanical properties of recently developed poly-L/D-lactide (PLDLA) sutures in comparison with polyglyconate (Maxon) sutures. PLDLA (0.2 mm thick) and Maxon (4.0) sutures were studied in vitro by immersion in a buffered saline solution (pH 7.4). Tensile strength tests were done on sutures retrieved after 1-26 weeks. In vivo, they were implanted in the subcutis of 32 rabbits. Tensile strength tests were done on sutures retrieved after 1-6 weeks. The sutures were also used to repair the Achilles tendon in rabbits. Maximum force before breaking and percentage elongation of tendons were determined. Although PLDLA had a lower initial tensile strength than Maxon, PLDLA showed more prolonged tensile strength retention than Maxon. Tendons repaired with PLDLA, however, had a lower strength than Maxon-repaired tendons at six weeks (insignificant difference). PLDLA has more prolonged tensile strength properties compared with Maxon. Thus, PLDLA offers an alternative to Maxon in repair of the Achilles tendon. PMID:11153008

  19. Tendon, tendon healing, hyperlipidemia and statins

    PubMed Central

    Esenkaya, Irfan; Unay, Koray

    2011-01-01

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

  20. Quadriceps and patellar tendon ruptures.

    PubMed

    Lee, Dennis; Stinner, Daniel; Mir, Hassan

    2013-10-01

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

  1. Sensitivity of physical examination versus arthroscopy in diagnosing subscapularis tendon injury.

    PubMed

    Faruqui, Sami; Wijdicks, Coen; Foad, Abdullah

    2014-01-01

    The purpose of this study was to examine the accuracy of physical examination in the detection of subscapularis tendon tears and compare it with the gold standard of arthroscopy to determine whether clinical examination can reliably predict the presence of subscapularis tendon tears. This was a retrospective analysis of 52 patients (52 shoulders) who underwent arthroscopic subscapularis tendon repairs between September 2008 and April 2012. Positive findings on any combination of the belly press, lift-off, and bear hug tests constituted a positive physical examination result. There was a positive finding on physical examination in 42 of 52 patients. The sensitivity of the physical examination as a whole was 81%. The literature has shown that the belly press, bear hug, and lift-off tests are specific to the subscapularis tendon. To the authors’ knowledge, this is the first study to evaluate the sensitivity of these 3 separate clinical tests as a composite. Knowledge regarding the sensitivity of the subscapularis-specific physical examination as a composite can lead practitioners to implement all 3 components, even when 1 test has a negative finding, thus promoting a more thorough physical examination. Because unrepaired subscapularis tendon tears can result in poor outcomes in the repair of other rotator cuff tendons, a complete physical examination would be beneficial to patients with shoulder pathology. The authors conclude that physical examination, when performed consistently by an experienced practitioner, can reliably predict the presence of subscapularis tendon tears. PMID:24683653

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

    PubMed Central

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

    2013-01-01

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

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

    Microsoft Academic Search

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

    1993-01-01

    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,

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

    PubMed Central

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

    2013-01-01

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

  5. Magnetic resonance imaging of the elbow. Part II: Abnormalities of the ligaments, tendons, and nerves.

    PubMed

    Kijowski, Richard; Tuite, Michael; Sanford, Matthew

    2005-01-01

    Part II of this comprehensive review on magnetic resonance imaging of the elbow discusses the role of magnetic resonance imaging in evaluating patients with abnormalities of the ligaments, tendons, and nerves of the elbow. Magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the soft tissue structures of the elbow. Magnetic resonance imaging can detect tears of the ulnar collateral ligament and lateral collateral ligament of the elbow with high sensitivity and specificity. Magnetic resonance imaging can determine the extent of tendon pathology in patients with medial epicondylitis and lateral epicondylitis. Magnetic resonance imaging can detect tears of the biceps tendon and triceps tendon and can distinguishing between partial and complete tendon rupture. Magnetic resonance imaging is also helpful in evaluating patients with nerve disorders at the elbow. PMID:15480640

  6. p38 MAPK Signaling in Postnatal Tendon Growth and Remodeling

    PubMed Central

    Schwartz, Andrew J.; Sarver, Dylan C.; Sugg, Kristoffer B.; Dzierzawski, Justin T.; Gumucio, Jonathan P.; Mendias, Christopher L.

    2015-01-01

    Tendon is a dynamic tissue whose structure and function is influenced by mechanical loading, but little is known about the fundamental mechanisms that regulate tendon growth and remodeling in vivo. Data from cultured tendon fibroblasts indicated that the p38 MAPK pathway plays an important role in tendon fibroblast proliferation and collagen synthesis in vitro. To gain greater insight into the mechanisms of tendon growth, and explore the role of p38 MAPK signaling in this process, we tested the hypotheses that inducing plantaris tendon growth through the ablation of the synergist Achilles tendon would result in rapid expansion of a neotendon matrix surrounding the original tendon, and that treatment with the p38 MAPK inhibitor SB203580 would prevent this growth. Rats were treated with vehicle or SB203580, and subjected to synergist ablation by bilateral tenectomy of the Achilles tendon. Changes in histological and biochemical properties of plantaris tendons were analyzed 3, 7, or 28 days after overload, and comparisons were made to non-overloaded animals. By 28 days after overload, tendon mass had increased by 30% compared to non-overloaded samples, and cross-sectional area (CSA) increased by around 50%, with most of the change occurring in the neotendon. The expansion in CSA initially occurred through the synthesis of a hyaluronic acid rich matrix that was progressively replaced with mature collagen. Pericytes were present in areas of active tendon growth, but never in the original tendon ECM. Inhibition of p38 MAPK resulted in a profound decrease in IL6 expression, and had a modest effect on the expression of other ECM and cell proliferation genes, but had a negligible impact on overall tendon growth. The combined results from this study provided novel insights into tendon mechanobiology, and suggest that p38 MAPK signaling does not appear to be necessary for tendon growth in vivo. PMID:25768932

  7. Distal biceps tendon injuries--current treatment options.

    PubMed

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

    2010-01-01

    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

  8. Diseases of the tendons and tendon sheaths.

    PubMed

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

    2014-03-01

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

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

    PubMed Central

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

    2012-01-01

    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

  10. Partial-thickness tears of the gluteus medius: rationale and technique for trans-tendinous endoscopic repair.

    PubMed

    Domb, Benjamin G; Nasser, Rima Michel; Botser, Itamar B

    2010-12-01

    Tears in the gluteus medius and minimus tendons, often misdiagnosed as trochanteric bursitis, have recently emerged as an important cause of recalcitrant greater trochanter pain syndrome. Advances in endoscopic surgery of the hip have created opportunities to better evaluate and treat pathology in the peritrochanteric compartment. We reviewed the literature on trochanteric pain syndrome and gluteus medius tendon injuries. Existing techniques for endoscopic and open gluteus tendon repair and potential challenges in restoration of abductor function were analyzed. Partial-thickness undersurface tears of the gluteus medius were identified as a common pathologic entity. Although these tears are otherwise analogous to partial-thickness tears of the rotator cuff, the lack of arthroscopic access to the deep side of the gluteus medius tendon represents a unique technical challenge. To address the difficulty in visualizing and thus repairing undersurface tears of the gluteus medius, a novel endoscopic trans-tendinous repair technique was developed. The purposes of this article are to review the anatomy, pathology, and existing repair techniques of gluteus medius tendon tears and to describe the rationale and surgical steps for endoscopic trans-tendinous repair. PMID:20951538

  11. Peroneal Tendon Injuries

    MedlinePLUS

    ... ACFAS | Información en Español Advanced Search Home » Foot & Ankle Conditions » Peroneal Tendon Injuries Text Size Print Bookmark ... foot run side-by-side behind the outer ankle bone. One peroneal tendon attaches to the outer ...

  12. Achilles tendon rupture - aftercare

    MedlinePLUS

    Managing Your: Achilles Tendon Rupture. In: Ferri FF, ed. Ferri's Clinical Advisor 2015 . 1st ed. Philadelphia, PA: Mosby Elsevier; 2014: appendix V. Sokolove PE, Barnes DK. Extensor and Flexor Tendon Injuries ...

  13. Streaming tearing mode

    NASA Technical Reports Server (NTRS)

    Shigeta, M.; Sato, T.; Dasgupta, B.

    1985-01-01

    The magnetohydrodynamic stability of streaming tearing mode is investigated numerically. A bulk plasma flow parallel to the antiparallel magnetic field lines and localized in the neutral sheet excites a streaming tearing mode more strongly than the usual tearing mode, particularly for the wavelength of the order of the neutral sheet width (or smaller), which is stable for the usual tearing mode. Interestingly, examination of the eigenfunctions of the velocity perturbation and the magnetic field perturbation indicates that the streaming tearing mode carries more energy in terms of the kinetic energy rather than the magnetic energy. This suggests that the streaming tearing mode instability can be a more feasible mechanism of plasma acceleration than the usual tearing mode instability.

  14. Mallory-Weiss Tear during Esophagogastroduodenoscopy

    PubMed Central

    Kim, Ji Wan; Shim, Chan-Sup; Lee, Tae Yoon; Cheon, Young Koog

    2015-01-01

    Mallory-Weiss tears (MWTs) are mucosal lacerations caused by forceful retching and are typically located at the gastroesophageal junction. Reported cases of MWT with serious complications seen in esophagogastroduodenoscopy are limited. We report MWT in an 81-year-old woman who presented with gastric perforation by esophagogastroduodenoscopy. We discuss and indicate that hiatal hernia, atrophic gastritis and old age may be associated with the gastric perforation in comparison to typical tears occurring at the gastroesophageal junction.

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

    PubMed Central

    2012-01-01

    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

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

    PubMed

    Waibl, Bernhard; Buess, Eduard

    2005-03-01

    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

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

    PubMed Central

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

    2015-01-01

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

  18. Open extensor tendon injuries.

    PubMed

    Amirtharajah, Mohana; Lattanza, Lisa

    2015-02-01

    The extensor tendons in the dorsum of the hand lie relatively superficially, making open injuries to the extensor mechanism a common source of morbidity. These injuries can range from simple clean lacerations to complex open injuries associated with severe skin and soft tissue loss. Although many advances in the treatment of tendon injuries focused on the flexor tendon, the extensor tendon has begun to receive more attention in recent literature. Knowledge of modern repair techniques and rehabilitation protocols may improve patient outcomes. This Current Concepts article summarizes the treatment of open extensor tendon injuries with a focus on the recent literature. PMID:25557773

  19. Achilles tendon disorders.

    PubMed

    Weinfeld, Steven B

    2014-03-01

    Achilles tendon disorders include tendinosis, paratenonitis, insertional tendinitis, retrocalcaneal bursitis, and frank rupture. Patients present with pain and swelling in the posterior aspect of the ankle. Magnetic resonance imaging and ultrasound are helpful in confirming the diagnosis and guiding treatment. Nonsurgical management of Achilles tendon disorders includes nonsteroidal anti-inflammatory drugs, physical therapy, bracing, and footwear modification. Surgical treatment includes debridement of the diseased area of the tendon with direct repair. Tendon transfer may be necessary to augment the strength of the Achilles tendon. PMID:24559878

  20. Prevalence of abductor mechanism tears of the hips in patients with osteoarthritis.

    PubMed

    Howell, G E; Biggs, R E; Bourne, R B

    2001-01-01

    In a prospective study of 176 consecutive patients who underwent total hip arthroplasty for osteoarthritis, we identified 34 (20%) with degenerative pathology of the abductor mechanism. These degenerative tears were commoner in elderly women. The hip capsule usually was involved, but in 6 patients (16%), the gluteus minimus or medius tendons were involved in isolation. These abductor mechanism tears are progressive in nature and the result of degenerative processes. PMID:11172282

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

    PubMed Central

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

    2014-01-01

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

  2. Spontaneous rupture of the gluteus medius and minimus tendons.

    PubMed

    Lonner, Jess H; Van Kleunen, Jonathan P

    2002-10-01

    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

  3. Recruitment viscoelasticity of the tendon.

    PubMed

    Einat, Raz; Yoram, Lanir

    2009-11-01

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

  4. Usefulness of Turbo Spin-Echo MR Imaging in the Evaluation of Meniscal Tears: Comparison with a Conventional Spin-Echo Sequence

    Microsoft Academic Search

    John C. Hunter; Gordon C. Zink-Brody

    ing the usefulness of turbo spin-echo imaging in the evaluation of meniscal tears. We com- pare a turbo spin-echo sequence that has an echo train length of five with a conventional spin- echo sequence for evaluating meniscal tears. SUBJECTS AND METHODS. Forty knees in 39 consecutive patients referred for MR study of the knee were imaged using both conventional spin-echo

  5. Idiopathic Bilateral Bloody Tearing

    PubMed Central

    Beyazy?ld?z, Emrullah; Özdamar, Yasemin; Beyazy?ld?z, Özlem; Yerli, Hasan

    2015-01-01

    Bloody tear is a rare and distinct clinic phenomenon. We report a case presenting with the complaint of recurrent episodes of bilateral bloody tearing. A 16-year-old girl presented to our clinic with complaint of bloody tearing in both eyes for 3 months. Bloody tearing was not associated with her menses. A blood-stained discharge from the punctum was not observed during the compression of both nasolacrimal ducts. Nasolacrimal passage was not obstructed. Imaging studies such as dacryocystography and gradient-echo magnetic resonance imaging (MRI) of nasolacrimal canal were normal. Intranasal endoscopic evaluation was normal. We collected samples from bloody tears two times and pathological examination was performed. Pathological analysis showed lots of squamous cells and no endometrial cells; dysplastic cells were found. Further evaluations for underlying causes were unremarkable. No abnormalities were found in ophthalmologic, radiologic, and pathologic investigations. This condition is likely a rare abnormality and the least recognized aetiology for the idiopathic phenomenon. PMID:25685572

  6. Arthroscopic Double-Locked Stitch: A New Technique for Suturing Rotator Cuff Tears

    PubMed Central

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

    2014-01-01

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

  7. Tendon healing: repair and regeneration.

    PubMed

    Voleti, Pramod B; Buckley, Mark R; Soslowsky, Louis J

    2012-01-01

    Injury and degeneration of tendon, the soft tissue that mechanically links muscle and bone, can cause substantial pain and loss of function. This review discusses the composition and function of healthy tendon and describes the structural, biological, and mechanical changes initiated during the process of tendon healing. Biochemical pathways activated during repair, experimental injury models, and parallels between tendon healing and tendon development are emphasized, and cutting-edge strategies for the enhancement of tendon healing are discussed. PMID:22809137

  8. Tendon and ligament imaging

    PubMed Central

    Hodgson, R J; O'Connor, P J; Grainger, A J

    2012-01-01

    MRI and ultrasound are now widely used for the assessment of tendon and ligament abnormalities. Healthy tendons and ligaments contain high levels of collagen with a structured orientation, which gives rise to their characteristic normal imaging appearances as well as causing particular imaging artefacts. Changes to ligaments and tendons as a result of disease and injury can be demonstrated using both ultrasound and MRI. These have been validated against surgical and histological findings. Novel imaging techniques are being developed that may improve the ability of MRI and ultrasound to assess tendon and ligament disease. PMID:22553301

  9. Biomimetic Scaffold Design for Functional and Integrative Tendon Repair

    PubMed Central

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

    2012-01-01

    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

  10. Margin convergence: A method of reducing strain in massive rotator cuff tears

    Microsoft Academic Search

    Stephen S. Burkhart; K. A. Athanasiou; Michael A. Wirth

    1996-01-01

    Increased security of fixation in rotator cuff repair is usually achieved by increasing the strength of fixation. Paradoxically, the problem can be approached by techniques that decrease the strain at the margins of the tear so that weaker fixation will still be adequate. Such techniques provide greater safety tolerances for the strength characteristics of suture, tendon, and bone. The principle

  11. Double-row fixation of upper subscapularis tears with a single suture anchor.

    PubMed

    Denard, Patrick J; Lädermann, Alexandre; Burkhart, Stephen S

    2011-08-01

    The recognition of and discussion of operative techniques for subscapularis tendon tears have lagged behind those for the posterosuperior rotator cuff. The advancement of shoulder arthroscopy has provided the opportunity to see the articular side of the rotator cuff and has led to increased recognition of subscapularis tears. Double-row fixation of the posterosuperior rotator cuff has become popular because of improved biomechanical strength, footprint restoration, and tendon healing compared with single-row fixation. Double-row fixation of the subscapularis, however, has been challenging because of the small anterior space overlying the subscapularis. Whereas the subacromial space allows freedom of movement, the limited subcoracoid space makes visualization, instrument manipulation, and knot tying more difficult. We describe a new technique for double-row fixation of the upper subscapularis footprint using a knotless technique without an additional anchor, which eases some of the aforementioned difficulties. The technique is indicated for partial- or full-thickness tears of the upper 50% of the subscapularis tendon and therefore applies to the majority of tears involving the subscapularis tendon. PMID:21704472

  12. Fatigue loading of tendon

    PubMed Central

    Shepherd, Jennifer H; Screen, Hazel R C

    2013-01-01

    Tendon injuries, often called tendinopathies, are debilitating and painful conditions, generally considered to develop as a result of tendon overuse. The aetiology of tendinopathy remains poorly understood, and whilst tendon biopsies have provided some information concerning tendon appearance in late-stage disease, there is still little information concerning the mechanical and cellular events associated with disease initiation and progression. Investigating this in situ is challenging, and numerous models have been developed to investigate how overuse may generate tendon fatigue damage and how this may relate to tendinopathy conditions. This article aims to review these models and our current understanding of tendon fatigue damage. We review the strengths and limitations of different methodologies for characterizing tendon fatigue, considering in vitro methods that adopt both viable and non-viable samples, as well as the range of different in vivo approaches. By comparing data across model systems, we review the current understanding of fatigue damage development. Additionally, we compare these findings with data from tendinopathic tissue biopsies to provide some insights into how these models may relate to the aetiology of tendinopathy. Fatigue-induced damage consistently highlights the same microstructural, biological and mechanical changes to the tendon across all model systems and also correlates well with the findings from tendinopathic biopsy tissue. The multiple testing routes support matrix damage as an important contributor to tendinopathic conditions, but cellular responses to fatigue appear complex and often contradictory. PMID:23837793

  13. The palmaris longus tendon

    Microsoft Academic Search

    C. C. Koo; A. H. N. Roberts

    1997-01-01

    The palmaris longus is one of the most variable muscles of the human body. An understanding of its variations is useful as it is often used as a tendon graft and for tendon transfer. We report another interesting variation in its anatomy.

  14. Multilayered Electrospun Scaffolds for Tendon Tissue Engineering

    PubMed Central

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

    2013-01-01

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

  15. An artificial tendon with durable muscle interface.

    PubMed

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

    2010-02-01

    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 eight 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 postsurgery 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 +/- 111.3 N (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

  16. An Artificial Tendon with Durable Muscle Interface

    PubMed Central

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

    2010-01-01

    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

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

    PubMed Central

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

    2014-01-01

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

  18. Effect of mechanical stimulation on bone marrow stromal cell-seeded tendon slice constructs: A potential engineered tendon patch for rotator cuff repair.

    PubMed

    Qin, Ting-Wu; Sun, Yu-Long; Thoreson, Andrew R; Steinmann, Scott P; Amadio, Peter C; An, Kai-Nan; Zhao, Chunfeng

    2015-05-01

    Cell-based tissue engineered tendons have potential to improve clinical outcomes following rotator cuff repair, especially in large or massive rotator cuff tears, which pose a great clinical challenge. The aim of this study was to develop a method of constructing a functional engineered tendon patch for rotator cuff repair with cyclic mechanical stimulation. Decellularized tendon slices (DTSs) were seeded with BMSCs and subjected to cyclic stretching for 1, 3, or 7 days. The mechanical properties, morphologic characteristics and tendon-related gene expression of the constructs were investigated. Viable BMSCs were observed on the DTS after 7 days. BMSCs penetrated into the DTSs and formed dense cell sheets after 7 days of mechanical stretching. Gene expression of type I collagen, decorin, and tenomodulin significantly increased in cyclically stretched BMSC-DTS constructs compared with the unstrained control group (P < 0.05). The ultimate tensile strength and stiffness of the cyclically stretched tendon constructs were similar to the unstrained control group (P > 0.05). In conclusion, mechanical stimulation of BMSC-DTS constructs upregulated expression of tendon-related proteins, promoted cell tenogenic differentiation, facilitated cell infiltration and formation of cell sheets, and retained mechanical properties. The patch could be used as a graft to enhance the surgical repair of rotator cuff tears. PMID:25770996

  19. A new method for knotless fixation of an upper subscapularis tear.

    PubMed

    Denard, Patrick J; Burkhart, Stephen S

    2011-06-01

    The advancement of shoulder arthroscopy has provided the opportunity to see the articular side of the rotator cuff and has led to increased recognition of subscapularis tears. One of the unique challenges to arthroscopic subscapularis repair is the small anterior space overlying the subscapularis. Whereas the subacromial space allows freedom of movement, the limited subcoracoid space makes visualization, instrument manipulation, and knot tying more difficult. We describe a technique for knotless restoration of the upper subscapularis footprint that eases some of the aforementioned difficulties. The technique is indicated for partial- or full-thickness tears of the upper 50% of the subscapularis tendon and therefore applies to the majority of tears involving the subscapularis tendon. PMID:21489743

  20. Mechanical properties of the human achilles tendon

    Microsoft Academic Search

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

    2001-01-01

    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

  1. Magnetic resonance imaging of the elbow. Part II: Abnormalities of the ligaments, tendons, and nerves

    Microsoft Academic Search

    Richard Kijowski; Michael Tuite; Matthew Sanford

    2005-01-01

    Part II of this comprehensive review on magnetic resonance imaging of the elbow discusses the role of magnetic resonance imaging in evaluating patients with abnormalities of the ligaments, tendons, and nerves of the elbow. Magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the soft tissue structures of the elbow. Magnetic resonance imaging can detect tears

  2. Comparison of the clinical effects of carbomer-based lipid-containing gel and hydroxypropyl-guar gel artificial tear formulations in patients with dry eye syndrome: A 4-week, prospective, open-label, randomized, parallel-group, noninferiority study

    Microsoft Academic Search

    Tsung-Jen Wang; I-Jong Wang; Jau-Der Ho; Hsiu-Chu Chou; Szu-Yuan Lin; Man-Ching Huang

    2010-01-01

    Background: Most marketed artificial tears are substitutes for the aqueous layers of the tear film; therefore, frequent instillation of artificial tears is necessary. Newer gel-, cellulose-, and mineral oil-based formulations have been designed to overcome the disadvantages of current aqueous tear substitutes by offering prolonged retention times.Objectives: The aim of this study was to compare the efficacy, safety, and local

  3. Tendon Gradient Mineralization for Tendon to Bone Interface Integration

    PubMed Central

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

    2014-01-01

    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

  4. Tendon injuries of the hand

    PubMed Central

    Schöffl, Volker; Heid, Andreas; Küpper, Thomas

    2012-01-01

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

  5. Extra-articular Mimickers of Lateral Meniscal Tears

    PubMed Central

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

    2011-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  7. Tendon Transfer Surgery

    MedlinePLUS

    ... stroke, traumatic brain injuries, and spinal muscle atrophy. Finally, there are some conditions in which babies are ... therapy to teach you the new tendon function. Finally, exercises will be needed to strengthen the muscle ...

  8. Percutaneous Achilles Tendon Lengthening

    MedlinePLUS

    ... Bulk Allograft Transplantation for Osteochondral Lesions of the Talus Insertional Achilles Tendinosis Surgery Lateral Ankle Ligament Reconstruction ... Ankle Stabilization Mosaicplasty for Osteochondral Lesions of the Talus Peroneus Longus to Achilles Tendon Transfer Pilon Fracture ...

  9. The tendons: Interventional sonography

    PubMed Central

    Campagna, R.; Guerini, H.

    2012-01-01

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

  10. Demonstrating collagen tendon fibril segments involvement in intrinsic tendon repair

    PubMed Central

    Hazard, Sprague W.; Myers, Roland L.; Ehrlich, H. Paul

    2011-01-01

    Severed tendons can undergo regenerative healing, intrinsic tendon repair. Fibrillogenesis of chick tendon involves “collagen fibril segments” (CFS), which are the building blocks of collagen fibers that make up tendon fascicles. The CFS are 10.5 micron in length, composed of tropocollagen monomers arranged in parallel arrays. Rather than incorporating single tropocollagen molecules into growing collagen fibers, incorporating large CFS units is the mechanism for generating collagen fibers. Is intrinsic tendon repair through the reestablishment of tendon embryogenesis? Gentamicin treated 10-day-old chick embryo tendons released CFS were fluorescently tagged with Rhodamine (Rh). Organ cultured severed 14-day-old embryo tendon explants received Rh tagged CFS. At day 4 auto fluorescent tagged CFS were identified at the severed tendon ends by fluorescent microscopy. Accumulation of fluorescent tagged CFS was exclusively localized to the severed ends of tendon explants. Parallels between collagen fiber growth during embryonic fibrillogenesis and tendon repair reveal CFS incorporation is responsible for collagen fibers growth. CFS incorporation into frayed collagen fibers from severed tendons is the proposed mechanism for intrinsic tendon repair, which is an example of regenerative repair. PMID:21855540

  11. Flexor Tendon–Tendon Sheath Interaction After Tendon Grafting: A Biomechanical Study in a Human Model In Vitro

    Microsoft Academic Search

    Jun Nishida; Peter C. Amadio; Paul C. Bettinger; Kai-Nan An

    1999-01-01

    A human cadaver tendon sheath model was used to study the differences in excursion resistance of tendons that might be considered as sources of clinical tendon grafts. The flexor digitorum profundus and superficialis tendons, the extensor indicis proprius tendon used in its normal proximal-distal orientation, the extensor indicis proprius tendon used in a reversed distal–proximal orientation, and the palmaris longus

  12. New Solution for Massive, Irreparable Rotator Cuff Tears: The Subacromial “Biodegradable Spacer”

    PubMed Central

    Savarese, Eugenio; Romeo, Rocco

    2012-01-01

    Massive, irreparable rotator cuff tears are a source of pain and disability. Although most rotator cuff tears can be completely repaired, a significant number are considered massive and irreparable. Numerous operative techniques have been described for the treatment of these kinds of tears including arthroscopic debridement, biceps tenotomy, tendon transfer, grafting, and reverse arthroplasty. We describe a surgical technique using a biodegradable subacromial balloon spacer (InSpace; OrthoSpace, Kfar Saba, Israel) implanted between the humeral head and acromion that permits smooth, frictionless gliding, restoring the shoulder biomechanics. The technique is easy to perform and is less invasive than the conventional surgical techniques available, and it may potentially serve as a bridging option in patients with massive, irreparable tears who are normally candidates for reverse arthroplasty. PMID:23766979

  13. Minimally invasive surgery for Achilles tendon pathologies

    PubMed Central

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

    2010-01-01

    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

  14. Isolated subscapularis repair for massive rotator cuff tear.

    PubMed

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

    2014-11-01

    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

  15. Tears of Wine

    ERIC Educational Resources Information Center

    Gugliotti, Marcos

    2004-01-01

    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.

  16. Endoscopic Repair of Full-Thickness Gluteus Medius Tears

    PubMed Central

    Domb, Benjamin G.; Carreira, Dominic S.

    2013-01-01

    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

  17. Endoscopic repair of full-thickness gluteus medius tears.

    PubMed

    Domb, Benjamin G; Carreira, Dominic S

    2013-05-01

    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

  18. Neuronal regulation of tendon homoeostasis

    PubMed Central

    Ackermann, Paul W

    2013-01-01

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

  19. Ruptures of the distal biceps tendon.

    PubMed

    Ward, James P; Shreve, Mark C; Youm, Thomas; Strauss, Eric J

    2014-01-01

    Distal biceps ruptures occur most commonly in middle-aged males and result from eccentric contraction of the biceps tendon. The injury typically presents with pain and a tearing sensation in the antecubital fossa with resultant weakness in flexion and supination strength. Physical exam maneuvers and diagnostic imaging aid in determining the diagnosis. Nonoperative management is reserved for elderly, low demand patients, while operative intervention is generally pursued for younger patients and can consist of nonanatomic repair to the brachialis or anatomic repair to the radial tuberosity. Anatomic repair through a one-incision or two-incision approach is commonplace, while the nonanatomic repairs are rarely performed. No clear advantage exists in operative management with a one-incision versus two-incision techniques. Chronic ruptures present a more difficult situation, and allograft augmentation is often necessary. Common complications after repair include transient nerve palsy, which often resolves, and heterotopic ossification. Despite these possible complications, most studies suggest that better patient outcomes are obtained with operative, anatomic reattachment of the distal biceps tendon. PMID:25150334

  20. Anterior-Posterior Instability of the Knee Following ACL Reconstruction with Bone-Patellar Tendon-Bone Ligament in Comparison with Four-Strand Hamstrings Autograft

    PubMed Central

    Angoules, A. G.; Balakatounis, K.; Boutsikari, E. C.; Mastrokalos, D.; Papagelopoulos, P. J.

    2013-01-01

    Purpose. To evaluate anterior-posterior knee laxity using two different autografts. Material-Methods. 40 patients, (34 males and 6 women), 17–54 years old (mean: 31), were included in the present study. Group A (4SHS = 20) underwent reconstruction using four-strand hamstrings, and group B (BPBT = 20) underwent reconstruction using bone-patellar tendon-bone autograft. Using the KT-1000 arthrometer, knee instability was calculated in both knees of all patients preoperatively and 3, 6, and 12 months after surgery at the ACL-operated knee. The contralateral healthy knee was used as an internal control group. Results. Anterior-posterior instability using the KT1000 Arthrometer was found to be increased after ACL insufficiency. The recorded laxity improved after arthroscopic ACL reconstruction in both groups. However, statistically significant greater values were detected in the bone-patellar tendon-bone group, which revealed reduction of anteroposterior stability values to an extent, where no statistical significance with the normal values even after 3 months after surgery was observed. Conclusions. Anterior-Posterior instability of the knee improved significantly after arthroscopic ACL reconstruction. The bone-patellar tendon-bone graft provided an obvious greater stability. PMID:23956862

  1. Open Achilles tendon lacerations.

    PubMed

    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

    2015-04-01

    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

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

    PubMed Central

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

    2013-01-01

    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

  3. Transtendon, Double-Row, Transosseous-Equivalent Arthroscopic Repair of Partial-Thickness, Articular-Surface Rotator Cuff Tears

    PubMed Central

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

    2014-01-01

    Arthroscopic transtendinous techniques for the arthroscopic repair of partial-thickness, articular-surface rotator cuff tears offer the advantage of minimizing the disruption of the patient's remaining rotator cuff tendon fibers. In addition, double-row fixation of full-thickness rotator cuff tears has shown biomechanical advantages. We present a novel method combining these 2 techniques for transtendon, double-row, transosseous-equivalent arthroscopic repair of partial-thickness, articular-surface rotator cuff tears. Direct visualization of the reduction of the retracted articular tendon layer to its insertion on the greater tuberosity is the key to the procedure. Linking the medial-row anchors and using a double-row construct provide a stable repair that allows early shoulder motion to minimize the risk of postoperative stiffness. PMID:25473606

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

    PubMed

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

    2014-10-01

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

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

    PubMed

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

    2004-09-01

    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 after tendon release) the muscle had retracted by 1.7+/-0.5 cm (9% of entire length, p<0.0001), the pennation angle had increased from 22+/-2.5 degrees to 50+/-11 degrees (p<0.0001) and the mean muscle fibre length had shortened from 32+/-3 to 16+/-5 mm (50%, p<0.0001). In electron and light microscopy, we found essentially normal muscle fibres with an unaltered fibre diameter and myofibrillar structure, while interstitial fat and fibrous tissue had increased from 3.9% to 45.9% (p<0.0001) of the muscle volume. Geometric modelling showed that the increase of the pennation angle separates the muscle fibre bundles mechanically like limbs of a parallelogram. Infiltrating fat cells fill the created space between the reoriented muscle fibres which may be quantitatively calculated without affecting the structural properties of the muscle cells. Fatty infiltration is therefore not seen as a degenerative process but a necessary rearrangement of the tissue after macroarchitectural changes caused by musculo-tendinous retraction. PMID:15304272

  6. Distal Biceps Brachii Tendon: The Spectrum of Strain

    PubMed Central

    Miller, Ray F.; Cullen, Myron J.; Krein, Ann M.; Miller, Ray F.; Cullen, Myron J.; Krein, Mary M.

    1991-01-01

    An injured tendinous attachment of the distal biceps brachii to the radial tuberosity was diagnosed in fifteen male patients. One additional patient sustained a first-degree strain of the distal biceps musculotendinous junction. Conservative treatment was effective for the two patients representing first-degree strains. Five patients with second-degree, partial tears were treated conservatively and experienced an average recovery time of over one year. Two patients with partial tears required a surgical reattachment of the biceps to the radial tuberosity for relief of symptoms. The Boyd-Anderson technique was used on six patients with complete ruptures. One complete separation was repaired three years post-injury by reattaching the distal biceps tendon to the brachialis. Post-operative Cybex evaluation demonstrated return to near-normal levels of strength, endurance, and total work in both flexion and supination following early reattachment to the radial tuberosity. ImagesFigure 1AFigure 1BFigure 2

  7. 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

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

    2014-01-01

    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

  8. Mineral distributions at the developing tendon enthesis.

    PubMed

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

    2012-01-01

    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

  9. Mineral Distributions at the Developing Tendon Enthesis

    PubMed Central

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

    2012-01-01

    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

  10. Scaffolds in Tendon Tissue Engineering

    PubMed Central

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

    2012-01-01

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

  11. Tear Film Lipids

    PubMed Central

    Butovich, Igor A.

    2013-01-01

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

  12. Arthroscopic Treatment of Subscapularis Calcific Tendonitis

    PubMed Central

    Fields, Logan K.; Muxlow, Chad J.; Caldwell, Paul E.

    2014-01-01

    Rotator cuff tendonitis is a very common diagnosis of the shoulder that usually responds to conservative management. However, calcific tendonitis occurs less frequently and often necessitates surgical intervention. The etiology and treatment options for this disorder remain controversial among orthopaedic shoulder specialists. Calcific tendonitis frequently presents within the supraspinatus tendon and rarely appears within the subscapularis tendon. We present a case and accompanying video technique of arthroscopic treatment of subscapularis calcific tendonitis. PMID:25473608

  13. Linear stability of tearing modes

    SciTech Connect

    Cowley, S.C.; Kulsrud, R.M.; Hahm, T.S.

    1986-05-01

    This paper examines the stability of tearing modes in a sheared slab when the width of the tearing layer is much smaller than the ion Larmor radius. The ion response is nonlocal, and the quasineutrality retains its full integal form. An expansion procedure is introduced to solve the quasineutrality equation in powers of the width of the tearing layer over the ion Larmor radius. The expansion procedure is applied to the collisionless and semi-collisional tearing modes. The first order terms in the expansion we find to be strongly stabilizing. The physics of the mode and of the stabilization is discussed. Tearing modes are observed in experiments even though the slab theory predicts stability. It is proposed that these modes grow from an equilibrium with islands at the rational surfaces. If the equilibrium islands are wider than the ion Larmor radius, the mode is unstable when ..delta..' is positive.

  14. Three Dimensional CT-based Virtual Patellar Resection in Female Patients Undergoing Total Knee Replacement: A Comparison between Tendon and Subchondral Method

    PubMed Central

    Park, Do Young; Ji, Hyung-Min; Kwak, Kyu-Sung; Nair, Surej Gopinathan

    2012-01-01

    Background Due to its small size, variable shape, and lack of distinct anatomical landmarks, osteoarthritic knees make a precise patellar resection extremely difficult. Methods We performed virtual patellar resection with digital software using three dimensional computed tomography scans of knees from 49 patients who underwent primary total knee replacement at our hospital. We compared 2 commonly used resection methods, the tendon method (TM) and the subchondral method, to determine an ideal resection plane with respect to the symmetry and thickness of the patellar remnant. Results The TM gave a thicker resected patella, and a less oval cut surface shape, which gives better coverage for a domed prosthesis. Both methods, however, gave a symmetric resection both superior-inferiorly, as well as mediolaterally. Conclusions Although TM appears statistically better with respect to the thickness and cut surface shape, only further intraoperative studies with long-term clinical follow-up may provide us with the most appropriate patellar resection method. PMID:22949950

  15. Tear Lipocalin: Structure and Function

    PubMed Central

    Dartt, Darlene A.

    2014-01-01

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

  16. Tendon conditioning: artefact or property?

    PubMed Central

    Maganaris, Constantinos N

    2003-01-01

    Isolated tendons subjected to cyclic tensile loads higher than those experienced in the tendons' recent history exhibit 'conditioning', i.e. gradually increasing elongations upon loading and gradually increasing residual elongations after unloading in the first few loading-unloading cycles. The present study examines whether this behaviour is a measurement artefact or an actual time-dependent property. The gastrocnemius tendons of six men who refrained from rigorous physical activities prior to the experiment were loaded cyclically by 10 repeated isometric plantarflexion contractions at 80% of the moment generated during plantarflexion maximal voluntary contraction (MVC). In each contraction, the elongation of the gastrocnemius tendon at 80% of MVC and the residual tendon elongation after relaxation were obtained from the analysis of sonographs recorded during the test. The tendon elongation during activation and the residual tendon elongation after relaxation increased by ca. 5 mm from the first contraction to the tenth contraction, with no changes obtained after the fifth contraction. The behaviour of the tendon in the first five contractions indicates the presence of conditioning. It is therefore concluded that conditioning is a relevant property and not an artefact associated with in vitro testing. This has implications for joint kinematics and muscle excursion. PMID:12952631

  17. Feedback control of dynamo tearing modes in a reversed field pinch: comparison between out-vessel and in-vessel active coils

    NASA Astrophysics Data System (ADS)

    Zanca, P.

    2010-11-01

    In the framework of innovative feedback schemes for control of dynamo tearing modes (TMs) in reversed field pinch (RFP) devices, the possibility of placing active coils between a non-conducting first wall and the vacuum vessel is investigated with a MHD based model. In this formulation the vacuum vessel plays the role of a stabilizing shell. With active coils placed outside the vacuum vessel and magnetic sensors located inside it, a previous study (Zanca 2009 Plasma Phys. Control. Fusion 51 015006) has shown that the ratio between the TM radial field amplitudes at the sensors' radius and at the resonant surface can be made close to but not smaller than the ideal-shell limit. This analysis considered a continuous-time modelling of the feedback. The same model admits a very appealing solution when applied to the in-vessel coil configuration: for high gains the radial field measured by sensors located between the first wall and the coils is reduced virtually to zero and the TM rotation frequency approaches the unperturbed natural value. In this case the feedback would mimic the stabilizing action of an ideal shell placed at the sensor radius. An improvement which makes the model closer to a realistic digital feedback is also presented. This is realized by introducing a discrete-time feedback action which includes a non-zero latency time. Unfortunately, the nice solution for in-vessel coils becomes unstable for realistic TM amplitudes when passing to the discrete-time feedback. In contrast the feedback of out-vessel coils is robust to time discretization, except when the vacuum vessel time constant becomes very small. This analysis indicates that future RFPs should rely on feedback systems of out-vessel coils.

  18. Effect of acute tensile loading on gender-specific tendon structural and mechanical properties.

    PubMed

    Burgess, Katherine E; Graham-Smith, Phillip; Pearson, Stephen J

    2009-04-01

    Stretching is commonly used prior to exercise, as it is thought to reduce the risk of injury, and it is also used in the preconditioning of tendon grafts. As tendon properties have been shown to be different between genders, it is proposed that stretching will differentially affect the structure. Here we examine the effect of acute stretch on the mechanical properties of both male and female medial gastrocnemius tendon. Female [20 years +/- 1 (SEM), n = 17] and male (22 years +/- 1, n = 18) subjects underwent a 5-min passive dorsiflexion stretch. Prior to and post stretch medial gastrocnemius tendon stiffness (K), length (l) and cross-sectional area (csa) were measured using ultrasonography and dynamometry. Stiffness and Young's modulus (epsilon) were significantly reduced with stretch for both genders (p < 0.05). Females showed significantly (p < 0.05) greater pre- to poststretch decreases in K (22.4 vs. 8.8%) and epsilon (20.5 vs. 8.4%) in comparison to males. The present results show that stretching acutely reduces stiffness of the medial gastrocnemius tendon in females and males, with females showing significantly greater change. The observed disparity between genders may be due in part to variations in tendon moment arm and intrinsic differences in tendon composition. These differential changes in tendon mechanical properties have functional, motor control, and injury risk implications, as well as possible implications for preconditioning of tendon grafts. PMID:18942726

  19. Median Nerve as Free Tendon Graft

    Microsoft Academic Search

    1987-01-01

    Four patients are described, all of whom bad tendon injuries in which the median nerve was used as a free tendon graft. Three cases involved the repair of a flexor tendon injury, and one the repair of an extensor tendon. In all cases, reconstruction of the median nerve was performed with a free sural nerve graft. The difficulty was that

  20. Achilles Tendon Rupture

    PubMed Central

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

    2013-01-01

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

  1. Comparison of arthroscopic anterior cruciate ligament reconstruction by bone-patellar tendon-bone graft with or without using interferential screw in general population.

    PubMed

    Arifeen, K N; Chowdhury, A Z; Sakeb, N; Joarder, A I; Salek, A K; Selimullah, A M

    2015-01-01

    Rupture of the Anterior Cruciate Ligament (ACL) is common, resulting reduced quality of life, increasing the meniscal injury risk, knee instability and early degenerative joint disease. Bone-Patellar Tendon-Bone (BPTB) became the gold standard surgery where conservative management failed. Adding interferential screw provides rigid fixation which is important for early accelerated rehabilitation program in athletes but we have carried out this prospective interventional study in Bangabandhu Sheikh Mujib Medical University (BSMMU) and our private settings from January 2007 to December 2011 to assess whether interferential screws provide any clinical and functional advantage in general population. Sixty six male patients of 21-40 years age, with ACL deficient knees were reconstructed with BPTB graft where 40 cases were augmented by interferential screws and 26 cases without and followed up for minimum 2 years. The clinical and functional outcome (by Lysholm Knee Scoring), post-operative knee stability (by clinical tests) and complications were assessed and recorded. There was significant (p<0.05, paired 't' test) improvement of knee function (limp, walking, stair climbing, squatting, thigh atrophy) in both groups but no significant difference between them (p>0.05, chi squared test) regarding clinical, functional outcome and knee stability. The complications were insignificant (p>0.05, chi squared test) in both groups but there were few cases of screw related complications with augmentation and pronounced anterior knee laxity without it. So, ACL reconstruction by BPTB grafts with or without augmentation results consistent and comparable outcome in general population. PMID:25725669

  2. A New Method for Modeling Spatial Prestressing Tendons

    NASA Astrophysics Data System (ADS)

    Li, Yi; Wang, Yuqian; Liu, Gao

    2010-05-01

    As a standard simulation procedure for curved lines and curved surfaces, spline has been widely used in the domain of computer-aided design. This paper presents a simple but relatively accurate procedure for the description of prestressing tendons. Cubic splines instead of conventional parabolic ones are introduced to obtain the characteristic parameters of the curved tendon profiles. The direct internal load method is adopted to obtain the equivalent load and loss of tendon force. In comparison with the traditional methods, Cubic splines needs less parameter for pre-processor and leads to higher accuracy in calculation. The direct internal load method can demonstrate the regularity of prestressing force acting on the structure, which modifies the prevalent equivalent load method. The results of the analysis presented in this paper indicate that the proposed method turns out to be convenient and reasonably accurate in the analysis of prestressed concrete bridges.

  3. 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. ...

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

    PubMed Central

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

    2014-01-01

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

  5. Exercise Therapy for Total Tear of Rotator Cuff: A Case Report

    PubMed Central

    Nejati, Parisa; Akbari, Faramarz

    2013-01-01

    Background Shoulder pain is one of the most common problems in ages older than 60 years of age. Rotator cuff pathology is the most common etiology of shoulder pain. Most of rotator cuff pathologies are treated conservatively in old ages and exercise therapy is not an accepted intervention for management of rotator cuff tear yet. Case presentation The case was a man of 53 years age with shoulder pain who had total tear of supraspinatus tendon and biceps tendinitis in the right shoulder. He had regularly gone swimming, mountain climbing and running in the last 10 years. The case was managed by exercise therapy for 3 months and physical modalities for 20 sessions. Shoulder pain and his function and right shoulder range of motion increased after 3 months. Para clinical findings did not change after treatment, though. The improvements continued 15 months after the beginning of the treatment. Conclusion Exercise therapy was very effective for improving pain and function in total tear of supraspinatus tendon and tendinitis of biceps. PMID:24868434

  6. Management of extensor tendon injuries.

    PubMed

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

    2012-01-01

    Extensor tendon injuries are very common injuries, which inappropriately treated can cause severe lasting impairment for the patient. Assessment and management of flexor tendon injuries has been widely reviewed, unlike extensor injuries. It is clear from the literature that extensor tendon repair should be undertaken immediately but the exact approach depends on the extensor zone. Zone I injuries otherwise known as mallet injuries are often closed and treated with immobilisaton and conservative management where possible. Zone II injuries are again conservatively managed with splinting. Closed Zone III or 'boutonniere' injuries are managed conservatively unless there is evidence of displaced avulsion fractures at the base of the middle phalanx, axial and lateral instability of the PIPJ associated with loss of active or passive extension of the joint or failed non-operative treatment. Open zone III injuries are often treated surgically unless splinting enable the tendons to come together. Zone V injuries, are human bites until proven otherwise requires primary tendon repair after irrigation. Zone VI injuries are close to the thin paratendon and thin subcutaneous tissue which strong core type sutures and then splinting should be placed in extension for 4-6 weeks. Complete lacerations to zone IV and VII involve surgical primary repair followed by 6 weeks of splinting in extension. Zone VIII require multiple figure of eight sutures to repair the muscle bellies and static immobilisation of the wrist in 45 degrees of extension. To date there is little literature documenting the quality of repairing extensor tendon injuries however loss of flexion due to extensor tendon shortening, loss of flexion and extension resulting from adhesions and weakened grip can occur after surgery. This review aims to provide a systematic examination method for assessing extensor injuries, presentation and management of all type of extensor tendon injuries as well as guidance on mobilisation pre and post surgery. PMID:22431949

  7. Arthroscopic transtendinous repair of articular-sided pasta (partial articular supraspinatus tendon avulsion) injury

    PubMed Central

    Wang, Yi; Lu, Liangyu; Lu, Zhe; Xiao, Lei; Kang, Yifan; Wang, Zimin

    2015-01-01

    Objective: To evaluate clinical efficacy of arthroscopic transtendinous repair of partial articular-sided PASTA (partial articular supraspinatus tendon avulsion) injury. Methods: From February 2011 to July 2014, 12 cases of PASTA, aged 29 to 72 years with an average of 52.9 ± 13.3 years, were treated arthoscopically. To repair PASTA, articular-sided rotator cuff tear was explored, injury site was punctured and labeled with PDS absorbable monofilament suture (Ethicon, Somerville, NJ, USA) suture, subacromial bursa was cleaned up with acromioplasty, and integrity of bursa-side rotator cuff was assessed. Then with arthroscope in glenohumeral joint, footprint of the bursa-side supraspinatus tendon was preserved, rivets were introduced into the joint through supraspinatus tendon, joint-side partial tear was sutured, and anatomical reconstruction of the rotator cuff footprint was established. The patients were followed up post-operatively for 12-36 months, average 22 ± 7.3 months. The clinical outcomes were emulated with ASES (American Shoulder and Elbow Surgeons) Shoulder Score system and UCLA (University of California at Los Angeles) Shoulder rating scale. Results: The post-operative ASES score was 89.7 ± 5.6, higher than the pre-operative one 49.8 ± 9.8 (t = 12.25, P <0.0001). While UCLA scale increased from the pre-operative 17.3, ± 3.3 to the post-operative 30.4 ± 3.2 points (t = 9.87, P <0.0001), with a satisfaction rate of 11/12 (91.7%). Conclusion: Trans-tendon repair is ideal for PASTA with advantage of maximal preservation of the normal rotator cuff tissue, anatomical reconstruction of the rotator cuff footprint and stable fixation of tendon-bone interface. PMID:25784979

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

    PubMed Central

    2014-01-01

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

  9. Tear-Duct Obstruction and Surgery

    MedlinePLUS

    ... Trauma to the eye area or an eye injury that lacerates (cuts through) the tear ducts also could block a duct, but reconstructive surgery at the time of the accident or injury may prevent this. Signs of Blocked Tear Ducts ...

  10. Tear exchange and contact lenses: A review

    PubMed Central

    Muntz, Alex; Subbaraman, Lakshman N.; Sorbara, Luigina; Jones, Lyndon

    2015-01-01

    Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design innovations have been proposed, but no substantial improvement in soft lens tear exchange has been reported. Researchers have determined post-lens tear exchange using several methods, notably fluorophotometry. However, due to technological limitations, little remains known about tear hydrodynamics around the lens and, to-date, true tear exchange with contact lenses has not been shown. Further knowledge regarding tear exchange could be vital in aiding better contact lens design, with the prospect of alleviating certain adverse ocular responses. This article reviews the literature to-date on the significance, implications and measurement of tear exchange with contact lenses. PMID:25575892

  11. Wear and Tear - Mechanical

    NASA Technical Reports Server (NTRS)

    Swanson, Theodore

    2008-01-01

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

  12. Stress biomarkers in the tear film

    Microsoft Academic Search

    Linda K Banbury

    2009-01-01

    Tear fluid plays a vital role in protecting the ocular surface and maintaining conditions optimal for ocular health and vision. Tear fluid may also potentially have a role as a diagnostic fluid, in a similar manner to the way in which saliva has increasingly been utilized for diagnostic tests. This study aimed to determine if tear fluid analysis could distinguish

  13. Tearing instability analysis handbook. Formulas and curves

    SciTech Connect

    Tada, H,; Paris, P.C.

    1980-01-01

    Handbook style information is presented for tearing instability formulas on typical test configuration. It is the J-integral resistance (J-R) curve that forms the basis of the tearing stability concept. Stability of crack growth is judged by the tearing modulus criterion.

  14. Tear Water Evaporation and Eye Surface Diseases

    Microsoft Academic Search

    Maurizio Rolando; Miguel F. Refojo; Kenneth R. Kenyon

    1985-01-01

    The water evaporation rate from the tear film of eyes with anterior surface pathology (corneal and\\/or conjunctival scars, meibomitis) was tested by means of the ‘Rolando-Refojo tear evaporimeter’, which allows noninvasive and reproducible test conditions. These eyes show a statistically significant increase in tear evaporation rate compared to normal eyes. The clinical implications of this finding are discussed.

  15. Staged tendon grafts and soft tissue coverage

    PubMed Central

    Elliot, David

    2011-01-01

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

  16. Achilles tendon reflex measuring system

    NASA Astrophysics Data System (ADS)

    Szebeszczyk, Janina; Straszecka, Joanna

    1995-06-01

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

  17. Silk and collagen scaffolds for tendon reconstruction.

    PubMed

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

    2014-04-01

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

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

    PubMed

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

    2002-10-01

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

  19. Mineralization-related modifications in the calcifying tendons of turkey (Meleagris gallopavo).

    PubMed

    Raspanti, Mario; Reguzzoni, Marcella; Protasoni, Marina; Congiu, Terenzio

    2015-04-01

    The tendons of some birds undergo a physiological process of gradual mineralization, usually limited to the central portion of the tendon and resulting in an increase of the elastic modulus and the ultimate strength. The present study was carried out by light microscopy and scanning electron microscopy and was focused on the structural and ultrastructural modifications occurring in this tissue during biomineralization. In comparison with most other tendons, turkey tendons appeared to be more finely subdivided into thinner fascicles and to contain a greater amount of cell-rich endotenon tissue. The most obvious finding, however, was the complete disappearance of the crimps in the calcified portions of the tendon, while they were present with the usual morphology in the non-mineralized portion. The electron microscopy revealed in the mineralized tendon traces of pre-existing crimps, locked in the straightened-out position by the infiltrating mineral phase. This latter was composed of two different types of fine particles, respectively, growing inside and around the collagen fibrils and appearing as tightly packed platelets or as larger, flat platelets regularly arranged in phase with the D-period of collagen. The perifibrillar mineral could play a critical role in the mechanical coupling of adjoining fascicles and in the transmission of tensile loads along the tendon itself. PMID:25698547

  20. Periostin secreted by mesenchymal stem cells supports tendon formation in an ectopic mouse model.

    PubMed

    Noack, Sandra; Seiffart, Virginia; Willbold, Elmar; Laggies, Sandra; Winkel, Andreas; Shahab-Osterloh, Sandra; Flörkemeier, Thilo; Hertwig, Falk; Steinhoff, Christine; Nuber, Ulrike A; Gross, Gerhard; Hoffmann, Andrea

    2014-08-15

    True tendon regeneration in human patients remains a vision of musculoskeletal therapies. In comparison to other mesenchymal lineages the biology of tenogenic differentiation is barely understood. Specifically, easy and efficient protocols are lacking that might enable tendon cell and tissue differentiation based on adult (stem) cell sources. In the murine mesenchymal progenitor cell line C3H10T½, overexpression of the growth factor bone morphogenetic protein 2 (BMP2) and a constitutively active transcription factor, Smad8 L+MH2, mediates tendon cell differentiation in vitro and the formation of tendon-like tissue in vivo. We hypothesized that during this differentiation secreted factors involved in extracellular matrix formation exert a major impact on tendon development. Gene expression analyses revealed four genes encoding secreted factors that are notably upregulated: periostin, C-type lectin domain family 3 (member b), RNase A4, and follistatin-like 1. These factors have not previously been implicated in tendon biology. Among these, periostin showed a specific expression in tenocytes of adult mouse Achilles tendon and in chondrocytes within the nonmineralized fibrocartilage zone of the enthesis with the calcaneus. Overexpression of periostin alone or in combination with constitutively active BMP receptor type in human mesenchymal stem cells and subsequent implantation into ectopic sites in mice demonstrated a reproducible moderate tenogenic capacity that has not been described before. Therefore, periostin may belong to the factors contributing to the development of tenogenic tissue. PMID:24809660

  1. Investigating load relaxation mechanics in tendon.

    PubMed

    Screen, Hazel R C

    2008-01-01

    Tendons are hierarchical fibre composite materials, designed for the efficient transfer of force from muscles to the skeleton. As such, they exhibit high tensile strength, as well as complex viscoelastic and anisotropic characteristics. Although the viscoelastic behaviour has received considerable attention, the mechanisms by which the tendon structure facilitates this behaviour are less well understood. This study examines viscoelasticity within isolated tendon fascicles, using stress relaxation tests to examine how the matrix acts to dissipate load during the relaxation period. The fascicle behaviour during incremental and direct load relaxation tests was examined, using mechanical testing and confocal microscopy to assess the load and structural responses of the tendon, respectively. Results provide further evidence of the highly viscoelastic nature of tendon, and also demonstrate that relaxation behaviour within isolated tendon fascicles is dominated by fibre sliding mechanisms. These data indicate an important functional role for proteoglycans, in controlling the viscoelastic behaviour and the mechanisms of strain transfer within tendon. PMID:19627771

  2. Bioreactor Design for Tendon/Ligament Engineering

    PubMed Central

    Wang, Tao; Gardiner, Bruce S.; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B.; Wang, Allan; Xu, Jiake

    2013-01-01

    Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a suitable culture environment, which mimics the dynamics of the in vivo environment for tendon/ligament maturation. For clinical settings, bioreactors also have the advantages of less-contamination risk, high reproducibility of cell propagation by minimizing manual operation, and a consistent end product. In this review, we identify the key components, design preferences, and criteria that are required for the development of an ideal bioreactor for engineering tendons and ligaments. PMID:23072472

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

    PubMed Central

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

    2013-01-01

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

  4. 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

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

    2012-01-01

    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. PMID:25653763

  5. Snapping knee caused by a popliteomeniscal fascicle tear of the lateral meniscus in a professional Taekwondo athlete.

    PubMed

    Park, Jong-Hoon; Ro, Kyung-Han; Lee, Dae-Hee

    2012-07-01

    A 19-year-old male professional Taekwondo athlete presented with a 2-year history of pain-free snapping of his right knee. He reported that his right knee joint gave way during games and training and that he could induce pain-free snapping between the proximal-to-fibular head and the lateral knee joint line. None of these physical findings suggested a meniscal pathology or ligamentous instability. Routine radiographs were normal. Magnetic resonance imaging of his right knee joint showed that the shape of the lateral meniscus was normal, and no lateral meniscus tears existed. On arthroscopic examination, popliteal hiatus view showed a posterosuperior popliteomeniscal fascicle tear between the posterior horn of the lateral meniscus and the posterior joint capsule just posteromedial to the popliteus tendon. With medial traction by probing, this popliteomeniscal tear made visible the significant subluxation of the posterior horn of the lateral meniscus to the center or anterior half of the tibial plateau. Based on the diagnosis of a posterosuperior popliteomeniscal tear of the right knee, Fast-Fix (Smith & Nephew, Andover, Massachusetts) was used for the direct repair of the peripheral portion of the lateral meniscus and joint capsule, targeting the popliteomeniscal junction. At 24 months postoperatively, the patient was performing athletic exercises relevant to his profession and was taking part in Taekwondo games, with no pain or recurrence of snapping. To the authors' knowledge, this is the first report of snapping of the lateral aspect of the knee due to a popliteomeniscal fascicle tear. PMID:22784909

  6. Repair of rotator cuff tears in tennis players

    Microsoft Academic Search

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

    1992-01-01

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

  7. Immunoassay of tear lysozyme in conjunctival diseases.

    PubMed Central

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

    1982-01-01

    The tear lysozyme content in 111 normal subjects and in 159 patients with various conjunctival diseases was determined by a single radial immunodiffusion technique. Tear lysozyme level in normal people was 1.33/mg/ml. (SI conversion: mg/ml = g/l.) The mean tear lysozyme levels in patients with chronic irritative conjunctivitis (0.97 mg/ml) and nutritional deficiency with epithelial xerosis (0.76 mg/ml) were significantly lower than in the normal controls. The mean tear lysozyme levels in tears from patients with vernal conjuctivitis (1.20 mg/ml), phlyctenular conjunctivitis (1.10 mg/ml), and acute bacterial conjunctivitis (1.48 mg/ml) were not significantly different from those in the normal controls. Superimposition of acute bacterial conjunctivitis on trachoma did not alter the low tear lysozyme level that existed before in these patients. PMID:6812619

  8. Cell and matrix changes associated with pathological calcification of the human rotator cuff tendons.

    PubMed Central

    Archer, R S; Bayley, J I; Archer, C W; Ali, S Y

    1993-01-01

    The causative mechanism of tendon calcification ('calcifying tendinitis') is unknown. In this report, pathological human tendon samples were examined to give morphological and ultrastructural detail of the calcified regions and these findings were compared with those from normal tendon. Selected specimens were cryosectioned to enable histochemical and immunohistochemical comparison of the occurrence and distribution of specific matrix molecules in diseased and normal tendon tissues. The lack of collagen type II and alkaline phosphatase in the pathological regions suggests that the calcification process is not mediated through an endochondral transition. In contrast, the pathological areas were characterised by widespread labelling for chondroitin-4-sulphate/dermatan sulphate and intense pericellular localisation of chondroitin-6-sulphate. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:8509292

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

    PubMed

    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

    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

  10. Two-Staged Reconstruction of the Flexor Pollicis Longus Tendon

    Microsoft Academic Search

    F. UNGLAUB; C. BULTMANN; A. REITER; P. HAHN

    2006-01-01

    The purpose of this study was to evaluate the results of two-stage reconstruction of the flexor pollicis longus (FPL) tendon. Sixteen patients who underwent reconstructive surgery of the FPL tendon were assessed retrospectively. Eight weeks after implantation of a silastic spacer, a tendon graft was used for reconstruction (thirteen palmaris longus tendons, two plantaris tendons, one half of the flexor

  11. Dacryoscintigraphic Findings in the Children with Tearing

    PubMed Central

    Kim, Hyung Chul; Cho, A Ran

    2015-01-01

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

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

    SciTech Connect

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

    1996-06-24

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

  13. 49 CFR 173.340 - Tear gas devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Tear gas devices. 173.340 Section 173.340...REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.340 Tear gas devices. (a) Packagings for tear...

  14. Achilles tendon moment arms: The importance of measuring at constant tendon load when using the tendon excursion method.

    PubMed

    Olszewski, Katarzyna; Dick, Taylor J M; Wakeling, James M

    2015-04-13

    Achilles tendon moment arms are commonly measured using the tendon-excursion technique and ultrasound imaging of the muscle-tendon junction. The tendon-excursion technique relies on the assumption that the tendon load is constant and thus it does not stretch. However, previous studies have not enforced this constraint and thus it is not known how sensitive the estimated Achilles tendon moment arms are to varying load during the measurement process. The aim of this study was to compare estimates of Achilles tendon moment arms when calculated using the different constraints of constant force (and thus tendon stretch), constant joint torque, or contraction effort. Achilles tendon moment arms were measured for the medial and lateral gastrocnemii in 8 healthy male subjects across five different ankle angles (-5° dorsiflexion to 35° plantarflexion), and a range of contraction levels. Moment arms were calculated for three different constraints of constant force, torque, or effort. Moment arms were significantly greater for the lateral gastrocnemius than for the medial gastrocnemius. At low contraction levels, including the passive condition, the moment arms increased with plantarflexion, whereas the moment arms decreased with plantarflexion at higher contraction levels. There was no difference between the calculated moment arms using the constant force and the constant torque methods; however both these methods yielded significantly different moment arms when compared to the commonly used constant effort method. PMID:25700609

  15. Mesenchymal stem cell applications to tendon healing

    PubMed Central

    Chaudhury, Salma

    2012-01-01

    Summary Tendons are often subject to age related degenerative changes that coincide with a diminished regenerative capacity. Torn tendons often heal by forming scar tissue that is structurally weaker than healthy native tendon tissue, predisposing to mechanical failure. There is increasing interest in providing biological stimuli to increase the tendon reparative response. Stem cells in particular are an exciting and promising prospect as they have the potential to provide appropriate cellular signals to encourage neotendon formation during repair rather than scar tissue. Currently, a number of issues need to be investigated further before it can be determined whether stem cells are an effective and safe therapeutic option for encouraging tendon repair. This review explores the in-vitro and invivo evidence assessing the effect of stem cells on tendon healing, as well as the potential clinical applications. PMID:23738300

  16. Extensor-tendons reconstruction using autogenous palmaris longus tendon grafting for rheumatoid arthritis patients

    Microsoft Academic Search

    Po-Jung Chu; Hung-Maan Lee; Yao-Tung Hou; Sheng-Tsai Hung; Jung-Kuei Chen; Jui-Tien Shih

    2008-01-01

    BACKGROUND: The purpose of the study is to retrospectively review the clinical outcome of our study population of middle-aged RA patients who had suffered extensor-tendon rupture. We reported the outcome of autogenous palmaris tendon grafting of multiple extensor tendons at wrist level in 14 middle-aged rheumatoid patients. METHODS: Between Feb. 2000 to Feb. 2004, thirty-six ruptured wrist level extensor tendons

  17. Management of chronic tendon injuries.

    PubMed

    Childress, Marc A; Beutler, Anthony

    2013-04-01

    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

  18. A Somitic Compartment of Tendon Progenitors

    Microsoft Academic Search

    Ava E Brent; Ronen Schweitzer; Clifford J Tabin

    2003-01-01

    We demonstrate that the tendons associated with the axial skeleton derive from a heretofore unappreciated, fourth compartment of the somites. Scleraxis (Scx), a bHLH transcription factor, marks this somitic tendon progenitor population at its inception, and is continuously expressed through differentiation into the mature tendons. Two earlier-formed somitic compartments, the sclerotome and myotome, interact to establish this fourth Scx-positive compartment.

  19. Tendon transfers for the drop foot.

    PubMed

    Schweitzer, Karl M; Jones, Carroll P

    2014-03-01

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

  20. Free tendon interposition grafting for the repair of ruptured extensor tendons in the rheumatoid hand

    Microsoft Academic Search

    J. Mountney; C. M. Blundell; P. McArthur

    1998-01-01

    Sixteen ruptured extensor tendons were repaired in seven rheumatoid hands using autogenous palmaris longus tendon as a free interposition graft. The patients were reviewed at an average of 17 months (range, 5–45) after repair. Subjectively all patients were satisfied with the clinical results, and achieved a return to their level of ability before tendon rupture. A biomechanical model suggests that

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

    NASA Technical Reports Server (NTRS)

    Johnson, Roger B.

    1997-01-01

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

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

    PubMed Central

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

    2007-01-01

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

  3. Partial-Thickness Rotator Cuff Tears

    Microsoft Academic Search

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

    2005-01-01

    Partial-thickness tears of the rotator cuff have been diagnosed with increased frequency because of a heightened awareness of the condition by clinicians and improved diagnostic methods. Research into the causes, natural history, and optimal treatment of this condition lags behind that of full-thickness tears. However, despite the limitations in the existing literature, there has emerged a consensus among shoulder experts

  4. Tears of the pectoralis major muscle

    Microsoft Academic Search

    Stuart C. Zeman; Robert T. Rosenfeld; Paul R. Lipscomb

    1979-01-01

    Nine athletes (men, 22 to 40 years old) who sustained tears of the pectoralis major muscle are described. Four were treated by the authors and five patients' cases were reviewed from records of orthopaedic surgeons for the National Football League. Eight of the nine patients sustained tears from exces sive tension; one was involved in an automobile accident and sustained

  5. Knee Flexion Strength Before and After ACL Reconstruction Using Hamstring Tendon Autografts

    PubMed Central

    Emami Meybodi, Mohammad Kazem; Jannesari, Morteza; Rahim Nia, Alireza; Yaribeygi, Habib; Sobhani Firoozabad, Vahid; Dorostegan, Ahmad

    2013-01-01

    Background Anterior cruciate ligament (ACL) injury is the most common sports injury in both athletes and nonathletes; it can cause disability if not treated correctly. In cases with minor injuries, conservative treatments suffice. But, in cases with ACL tear, surgery by different methods and autografts are indicated. The most prevalent method for ACL reconstruction is the use of hamstring tendon autograft; this requires tendon removal and results in subsequent weakness in patient’s knee flexion strength which can cause dissatisfaction. Objectives In this study we evaluate a common procedure used for treating ACL injuries. Patients and Methods This study was performed at a hospital in Tehran on 30 patients with ACL tears. Patients’ knee flexion strengths before and 2, 4, 6, and 12 months after reconstruction were measured separately at 20, 45, 90, and 110? knee flexion angles, and their means were analyzed using paired t-test. Results In this study, knee flexion strength decreased after ACL reconstruction. The greatest decrease in knee flexion strength was observed at 90 and 110? knee flexion angles. Conclusions Some previous studies have confirmed reduced knee flexion strength following ACL reconstruction at high knee flexion angles. However, some others have denied it. The present study confirmed the reduction in knee flexion strength one year after ACL reconstruction at 90 and 110? flexion angles (P = 0.000). Furthermore, the need for physiotherapy, as a process for rehabilitating these patients was also confirmed. PMID:24350171

  6. IETI – Isogeometric Tearing and Interconnecting

    PubMed Central

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

    2012-01-01

    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

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

    E-print Network

    Bacuta, Constantin

    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

  8. Exercise protocol induces muscle, tendon, and bone adaptations in the rat shoulder

    PubMed Central

    Rooney, Sarah Ilkhanipour; Loro, Emanuele; Sarver, Joseph J.; Peltz, Cathryn D.; Hast, Michael W.; Tseng, Wei-Ju; Kuntz, Andrew F.; Liu, X. Sherry; Khurana, Tejvir S.; Soslowsky, Louis J.

    2014-01-01

    Summary Background: a rat model of supraspinatus overuse has suggested mechanisms governing tendon degeneration; however, delineating which changes are pathologic or simply physiologic adaptations to increased loading remains a question. The objective of this study was to develop and characterize a rat exercise model that induces systemic and local shoulder adaptations without mechanical injury to the supraspinatus tendon. Methods: exercise rats completed a treadmill training protocol for 12 weeks. Body, fat pad, and heart weights were determined. Supraspinatus tendon collagen content, cross-sectional area, and mechanical properties were measured. Supraspinatus muscle cross-sectional area, weight, and the expression of mitochondrial oxidative phosphorylation (OXPHOS) proteins were measured. Humeri were analyzed with ?CT and mechanically tested. Results: exercise decreased fat pad mass. Supraspinatus muscle hypertrophied and had increased OXPHOS proteins. Humerus trabecular bone had increased anisotropic orientation, and cortical bone showed increased bone and tissue mineral density. Importantly, the supraspinatus tendon did not have diminished mechanical properties, indicating that this protocol was not injurious to the tendon. Conclusion: this study establishes the first rat exercise protocol that induces adaptations in the shoulder. Future research can use this as a comparison model to study how the supraspinatus tendon adapts to loading and undergoes degeneration with overuse. PMID:25767777

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

    PubMed

    Bogunovic, Ljiljana; Matava, Matthew J

    2013-11-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2007-03-01

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

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

    PubMed

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

    2012-05-01

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

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

    PubMed

    Zhou, Chang-long; Wang, Xin-tao; Chi, Zhi-yong; Yan, Jing-long

    2014-11-01

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

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

    PubMed

    Kennedy, J A; Dias, J J

    2014-09-01

    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

  14. Calcific tendonitis of the tibialis posterior tendon at the navicular attachment

    PubMed Central

    Harries, Luke; Kempson, Susan; Watura, Roland

    2011-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  16. Augmentation of tendon-to-bone healing.

    PubMed

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

    2014-03-19

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

  17. Rehabilitation Following Zone II Flexor Tendon Repairs.

    PubMed

    Kannas, Stephanie; Jeardeau, Teresa A; Bishop, Allen T

    2015-03-01

    Ongoing clinical and basic research has improved understanding of flexor tendon mechanics and physiology for surgical repair and rehabilitation after a zone II flexor tendon repair. Yet, the ideal surgical repair technique that includes sufficient strength to allow safe immediate active motion of the finger, without excessive repair stiffness, bulk or rough surfaces resulting in excessive resistance to flexion, does not exist. After optimizing the repair, the surgeon and therapist team must select a rehabilitation plan that protects the repair but helps to maintain tendon gliding. There are 3 types of rehabilitation programs for flexor tendon repairs: delayed mobilization, early passive mobilization, or an early active mobilization. No guideline for rehabilitation should be followed exactly. Many factors influence therapy decisions, including repair technique, associated tendon healing, passive versus active range of motion, edema, and tendon adhesions. These factors can assist in guiding rehabilitation progression and promote functional range of motion, safely mobilize the repaired tendon(s) and prevent gapping, rupture, and adhesions. PMID:25700105

  18. Morphology of human palmaris longus tendon

    Microsoft Academic Search

    S P Nicholls; L J Gathercole; J S Shah

    1984-01-01

    A systematic morphological investigation of human palmaris longus tendons by polarisation microscopy and low angle x-ray diffraction is reported. It is shown that contrary to some previously reported observations, and in common with other tension bearing soft collagenous tissues, the fibres in this tendon are crimped. A new method of preparation of the tissue enabling one to see directly the

  19. THE EXTENDED PALMARIS LONGUS TENDON GRAFT

    Microsoft Academic Search

    A. R. TOLAT; J. K. STANLEY

    1993-01-01

    A technique is described of increasing the length of a palmaris longus tendon graft by including palmar aponeurosis. The additional 5 cm is often useful in treating high flexor tendon ruptures, especially at the wrist level, without the need for an additional incision.

  20. HARVEST OF PALMARIS LONGUS TENDON: TECHNIQUE

    Microsoft Academic Search

    W. R. SAEED; S. P. KAY

    1993-01-01

    We present a modification of Bunnell's technique for harvest of the palmaris longus tendon. Using a 0.5 cm distal incision and a proximal stab incision the tendon is harvested with minimal scarring and, in our experience of over 30 cases, no morbidity.

  1. Effect of Pterygium Surgery on Tear Osmolarity

    PubMed Central

    Türky?lmaz, Kemal; Öner, Veysi; Sevim, Mehmet ?ahin; Kurt, Ali; ?ekeryapan, Berrak; Durmu?, Mustafa

    2013-01-01

    Purpose. To investigate changes of dry eye test results in patients who underwent pterygium surgery. Methods. Seventy-four patients who underwent primary pterygium surgery were enrolled in this study. At the baseline, 3-, 12-, and 18-month visits, measurements of tear osmolarity, BUT, and Schirmer test were performed. The patients were divided into 2 groups: Group 1, which consisted of patients in whom pterygium did not recur, and Group 2, which consisted of patients in whom pterygium recurred after surgery. Results. The patients in Group 1 had lower tear osmolarity levels after surgery than those at baseline (all P < 0.001). In Group 2 the tear osmolarity levels did not differ from baseline after 18 months (P = 0.057). The prevalence rates of dry eye syndrome (DES) were lower than that at baseline and 18 months after surgery in Group 1 (P = 0.002). In Group 2, the incidence of DES was lower after 3 months than at baseline (P = 0.03) but was similar to the baseline rate after 12 and 18 months (both P > 0.05). Conclusions. Anormal tear film function associated with pterygium. Pterygium excision improved tear osmolarity and tear film function. However, tear osmolarity deteriorated again with the recurrence of pterygium. PMID:23401743

  2. Ultrasonic evaluation of flood gate tendons

    NASA Astrophysics Data System (ADS)

    Thomas, Graham H.; Brown, Albert E.

    1998-03-01

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

  3. Ultrasonic evaluation of flood gate tendons

    SciTech Connect

    Thomas, G.; Brown, A.

    1997-10-01

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

  4. Gluteal tendon repair augmented with a synthetic ligament: surgical technique and a case series.

    PubMed

    Bucher, Thomas A; Darcy, Peter; Ebert, Jay R; Smith, Anne; Janes, Greg

    2014-01-01

    We describe an augmented surgical repair technique for gluteus minimus and medius tears, along with a supportive case series. A consecutive series of 22 patients presenting with clinical and radiological findings consistent with hip abductor tears, who had undergone failed prior conservative treatments, were prospectively recruited. Patients underwent open bursectomy, Y-iliotibial release, debridement of the diseased tendon, decortication of the trochanteric foot-plate and reattachment augmented with a LARS ligament through a trans-osseous tunnel, together with suture anchors. All patients were assessed pre- and postoperatively to 12 months with the Oxford Hip Score (OHS), the Short-Form Health Survey (SF-36) and a Visual Analogue Pain Scale (VAS), while a satisfaction scale was employed at 12 months. A statistically significant improvement (p<0.05) was observed for all patient reported outcome measures, while all patients were at least 'satisfied' with the procedure at 12 months. One patient reported some lateral hip discomfort at 10 months, and removal of the LARS interference screw provided immediate relief. One patient had a urological catheter-related complication. With no other complications and no clinical failures of the repair, we believe the technique to be safe and reliable, whilst reducing the incidence of re-tears as reported in the existing literature. PMID:24186680

  5. Preparation and characterization of decellularized tendon slices for tendon tissue engineering.

    PubMed

    Ning, Liang-Ju; Zhang, Yi; Chen, Xiao-He; Luo, Jing-Cong; Li, Xiu-Qun; Yang, Zhi-Ming; Qin, Ting-Wu

    2012-06-01

    To develop a naturally derived tendon tissue engineering scaffold with the preservation of the native ultrastructure, tensile strength, and biochemical composition of the tendon extracellular matrix (ECM), decellularized tendon slices (DTSs) were prepared using repetitive freeze/thaw of the intact Achilles tendons, frozen section, and nuclease treatment. The DTSs were characterized in the native ultrastructure, mechanical properties, biochemical composition, and cytocompatibility. Histological examination and DNA quantification analysis confirmed that cells were completely removed from tendon tissue by repetitive freeze/thaw in combination with nuclease treatment 12 h. The intrinsic ultrastructure of tendon tissue was well preserved based on scanning electron microscopy examination. The tensile strength of the DTSs was retained 85.62% of native tendon slice. More than 93% of proteoglycans (fibromodulin, biglycan) and growth factors (TGF-?1, IGF-1, VEGF, and CTGF) inherent in tendon ECM were preserved in the DTSs according to ELISA analysis. Furthermore, the DTSs facilitated attachment and repopulation of NIH-3T3 fibroblasts in vitro. Overall, the DTSs are sheet scaffolds with a combination of elemental mechanical strength and tendon ECM bioactive factors that may have many potential applications in tendon tissue engineering. PMID:22378703

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

    PubMed Central

    Gulick, Dawn T.; Yoder, Heather N.

    2002-01-01

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

  7. Artificial tendons: biomechanical design properties for prosthetic lower limbs

    Microsoft Academic Search

    Glenn K. Klute; Joseph M. Czerniecki; Blake Hannaford

    2000-01-01

    This paper reports on the design of an artificial tendon intended for use in a powered, lower limb prosthesis. To specify performance requirements, the properties of mammalian weight bearing tendons are drawn from the literature and compared with a number of existing tendon models. Based on the data, a mathematical model of an energy storing tendon is proposed and used

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

    Microsoft Academic Search

    S. Malvankar; W. S. Khan

    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

  9. Doppler ultrasound-based measurement of tendon velocity and displacement for application toward detecting user-intended motion.

    PubMed

    Stegman, Kelly J; Park, Edward J; Dechev, Nikolai

    2012-07-01

    The motivation of this research is to non-invasively monitor the wrist tendon's displacement and velocity, for purposes of controlling a prosthetic device. This feasibility study aims to determine if the proposed technique using Doppler ultrasound is able to accurately estimate the tendon's instantaneous velocity and displacement. This study is conducted with a tendon mimicking experiment consisting of two different materials: a commercial ultrasound scanner, and a reference linear motion stage set-up. Audio-based output signals are acquired from the ultrasound scanner, and are processed with our proposed Fourier technique to obtain the tendon's velocity and displacement estimates. We then compare our estimates to an external reference system, and also to the ultrasound scanner's own estimates based on its proprietary software. The proposed tendon motion estimation method has been shown to be repeatable, effective and accurate in comparison to the external reference system, and is generally more accurate than the scanner's own estimates. After establishing this feasibility study, future testing will include cadaver-based studies to test the technique on the human arm tendon anatomy, and later on live human test subjects in order to further refine the proposed method for the novel purpose of detecting user-intended tendon motion for controlling wearable prosthetic devices. PMID:22913101

  10. Tendon rupture associated with simvastatin/ezetimibe therapy.

    PubMed

    Pullatt, Raja C; Gadarla, Mamatha Reddy; Karas, Richard H; Alsheikh-Ali, Alawi A; Thompson, Paul D

    2007-07-01

    A case of spontaneous biceps tendon rupture in a physician during therapy with the combination of simvastatin and ezetimibe (Vytorin) is reported. Rechallenge produced tendinopathy in the contralateral biceps tendon that abated with drug discontinuation. Tendon rupture generally occurs in injured tendons. Physiological repair of an injured tendon requires degradation and remodeling of the extracellular matrix through matrix metalloproteinases (MMPs). Statins are known to inhibit MMPs. It was hypothesized that statins may increase the risk of tendon rupture by altering MMP activity. In conclusion, statins may increase the risk of tendon rupture by altering MMP activity. PMID:17599460

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

    MedlinePLUS

    ... ALL RIGHTS RESERVED. What is DCR? DCR , or dacryocystorhinostomy , is a surgery performed to create a new ... glass and remains permanently in the tear duct. Dacryocystorhinostomy surgery is usually performed as an outpatient procedure. ...

  12. Hall resistive tearing mode: A variational formulation

    NASA Astrophysics Data System (ADS)

    Shivamoggi, B. K.

    2008-09-01

    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.

  13. On the tear resistance of skin

    PubMed Central

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

    2015-01-01

    Tear resistance is of vital importance in the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. We explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. We express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip. PMID:25812485

  14. Managing the injured tendon: current concepts.

    PubMed

    Evans, Roslyn B

    2012-01-01

    Despite advances in understanding of the mechanical aspects of tendon management with improved suture technique and early stress application with postoperative therapy, clinical results remain inconsistent after repair, especially within the synovial regions. Complementary research to enhance the intrinsic pathway of healing, suppress the extrinsic pathway of healing, and manipulate frictional resistance to tendon gliding is now the focus of current basic science research on tendons. In the future, application of these new biologic therapies may increase the "safety zone" (or tolerance for load and excursion without dysfunctional gapping) as therapists apply stress to healing tendons and may alter future rehabilitation protocols by allowing greater angles of motion (and thus tendon excursion), increased external load, and decreased time in protective orthoses (splints). However, at this time, the stronger repair techniques and the application of controlled stress remain the best and most well-supported intervention after tendon injury and repair in the recovery of functional tendon excursion and joint range of motion. The hand therapist's role in this process remains a critical component contributing to satisfactory outcomes. PMID:22326362

  15. THE ROLE OF MECHANOBIOLOGY IN TENDON HEALING

    PubMed Central

    Killian, Megan L.; Cavinatto, Leonardo; Galatz, Leesa M.; Thomopoulos, Stavros

    2011-01-01

    Mechanical cues affect tendon healing, homeostasis, and development in a variety of settings. Alterations in the mechanical environment are known to result in changes in the expression of extracellular matrix proteins, growth factors, transcription factors, and cytokines that can alter tendon structure and cell viability. Loss of muscle force in utero or in the immediate postnatal period delays tendon and enthesis development. The response of healing tendons to mechanical load varies depending on anatomic location. Flexor tendons require motion to prevent adhesion formation, yet excessive force results in gap formation and subsequent weakening of the repair. Excessive motion in the setting of anterior cruciate ligament reconstruction causes accumulation of macrophages, which are detrimental to tendon graft healing. Complete removal of load is detrimental to rotator cuff healing, yet large forces are also harmful. Controlled loading can enhance healing in most settings; however, a fine balance must be reached between loads that are too low (leading to a catabolic state) and too high (leading to micro-damage). This review will summarize existing knowledge of the mechanobiology of tendon development, homeostasis, and healing. PMID:22244066

  16. A comprehensive review of hip labral tears

    Microsoft Academic Search

    Megan M. Groh; Joseph Herrera

    2009-01-01

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

  17. Neoclassical tearing modes in a tokamak

    SciTech Connect

    Hahm, T.S.

    1988-12-01

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

  18. Neoclassical tearing modes in a tokamak

    SciTech Connect

    Hahm, T.S.

    1988-08-01

    Linear tearing instability is studied in the banana collisionality regime in tokamak geometry. Neoclassical effects produce significant modifications of Ohm's law and the vorticity equation so that the growth rate of tearing modes driven by ..delta..' is dramatically reduced compared to the usual resistive MHD value. Consequences of this result, regarding the presence of pressure-gradient-driven neoclassical resistive interchange instabilities and the evolution of magnetic islands in the Rutherford regime, are discussed. 10 refs.

  19. Tear film measurement by optical reflectometry technique.

    PubMed

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

    2014-02-01

    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

  20. Tear film measurement by optical reflectometry technique

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

    Tuan, Rocky S.

    2014-01-01

    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

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

    PubMed

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

    2000-01-01

    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

  3. Stem Cells for Augmenting Tendon Repair

    PubMed Central

    Gulotta, Lawrence V.; Chaudhury, Salma; Wiznia, Daniel

    2012-01-01

    Tendon healing is fraught with complications such as reruptures and adhesion formation due to the formation of scar tissue at the injury site as opposed to the regeneration of native tissue. Stem cells are an attractive option in developing cell-based therapies to improve tendon healing. However, several questions remain to be answered before stem cells can be used clinically. Specifically, the type of stem cell, the amount of cells, and the proper combination of growth factors or mechanical stimuli to induce differentiation all remain to be seen. This paper outlines the current literature on the use of stem cells for tendon augmentation. PMID:22190960

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

    PubMed Central

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

    2014-01-01

    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

  5. Tendonitis

    MedlinePLUS

    ... to you by the American Orthopaedic Society for Sports Medicine. They provide general information only and are not ... fact sheet or learn more about other orthopaedic sports medicine topics, please visit www.sportsmed.org. Copyright © 2013. ...

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

    PubMed

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

    2014-01-01

    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

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

    PubMed Central

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

    2013-01-01

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

  8. Comparison between single-row and double-row rotator cuff repair: a biomechanical study

    Microsoft Academic Search

    Giuseppe Milano; Andrea Grasso; Donatella Zarelli; Laura Deriu; Mario Cillo; Carlo Fabbriciani

    2008-01-01

    The aim of this study was to compare the mechanical behavior under cyclic loading test of single-row and double-row rotator\\u000a cuff repair with suture anchors in an ex-vivo animal model. For the present study, 50 fresh porcine shoulders were used. On\\u000a each shoulder, a crescent-shaped full-thickness tear of the infraspinatus was performed. Width of the tendon tear was 2 cm.\\u000a The

  9. Natural history of asymptomatic rotator cuff tears: A longitudinal analysis of asymptomatic tears detected sonographically

    Microsoft Academic Search

    Ken Yamaguchi; A. Marc Tetro; Oren Blam; Bradley A. Evanoff; Sharlene A. Teefey; William D. Middleton

    2001-01-01

    The purpose of this study was to examine longitudinally the natural history of asymptomatic rotator cuff tears over a 5-year period and to assess the risk for development of symptoms and tear progression. Since 1985 through the present, bilateral sonograms were done on all patients. A review of consecutive sonograms done from 1989 to 1994 revealed 58 potential patients with

  10. Contact lens interactions with the tear film.

    PubMed

    Mann, Aisling; Tighe, Brian

    2013-12-01

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

  11. Position Control of Tendon-Driven Fingers

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  12. [Flexor tendon repair: a short story].

    PubMed

    Moutet, F; Corcella, D; Forli, A; Mesquida, V

    2014-12-01

    This short story of flexor tendon repair aims to illustrate hesitations and wanderings of this surgery. Obviously tendon repair was very early considered, but it developed and diffused rather lately. It became a routine practice only in 20th century. This was due on the one hand, in Occident, to the Galen's dogmatic interdiction, on the other hand, to the repair difficulties of this paradoxical structure. Actually tendon is made of fibroblasts and collagen (sticky substances), and then its only goal is to move. According to this necessity, whatever the used techniques are, gliding is the final purpose. Technical evolutions are illustrated by historical contributions to flexor tendon surgery of several "giants" of hand surgery. PMID:24837978

  13. Tendon and Ligament Fixation to Bone

    Microsoft Academic Search

    Christopher M. Hill; Yuehuei H. An; Frank A. Young

    For the successful transplantation or transposition of ligaments and tendons, fixation techniques are very important. As most\\u000a postsurgical rehabilitation protocols emphasize immediate full range of motion and early return to function, fixation must\\u000a provide adequate strength and stiffness during the early postoperative period. Table 1 lists mechanical properties (failure\\u000a load, ultimate strength, stiffness, and elastic modulus) of ligament, tendon, or

  14. Biological Augmentation of Rotator Cuff Tendon Repair

    Microsoft Academic Search

    David Kovacevic; Scott A. Rodeo

    2008-01-01

    A histologically normal insertion site does not regenerate following rotator cuff tendon-to-bone repair, which is likely due\\u000a to abnormal or insufficient gene expression and\\/or cell differentiation at the repair site. Techniques to manipulate the biologic\\u000a events following tendon repair may improve healing. We used a sheep infraspinatus repair model to evaluate the effect of osteoinductive\\u000a growth factors and BMP-12 on

  15. Right ventricular false tendons, a cadaveric approach

    Microsoft Academic Search

    Marios Loukas; Christopher T. Wartmann; R. Shane Tubbs; Nihal Apaydin; Robert G. Louis Jr; Brandie Black; Robert Jordan

    2008-01-01

    Left ventricular false tendons (LFTs) have been extensively described and recognized by gross anatomic studies. However, there\\u000a is very little information available regarding right ventricular false tendons (RFTs). The aim of our study, therefore, was\\u000a to explore and delineate the morphology, topography and morphometry of the RFTs, and provide a comprehensive picture of their\\u000a anatomy across a broad range of

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

    PubMed

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

    2006-04-01

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

  17. Tension Distribution in a Tendon-Driven Robotic Finger

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    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.

  18. Automatic dynamic tear meniscus measurement in optical coherence tomography

    PubMed Central

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

    2014-01-01

    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

  19. Effect of estrogen on tendon collagen synthesis, tendon structural characteristics, and biomechanical properties in postmenopausal women.

    PubMed

    Hansen, Mette; Kongsgaard, Mads; Holm, Lars; Skovgaard, Dorthe; Magnusson, S Peter; Qvortrup, Klaus; Larsen, Jytte O; Aagaard, Per; Dahl, Morten; Serup, Annette; Frystyk, Jan; Flyvbjerg, Allan; Langberg, Henning; Kjaer, Michael

    2009-04-01

    The knowledge about the effect of estradiol on tendon connective tissue is limited. Therefore, we studied the influence of estradiol on tendon synthesis, structure, and biomechanical properties in postmenopausal women. Nonusers (control, n = 10) or habitual users of oral estradiol replacement therapy (ERT, n = 10) were studied at rest and in response to one-legged resistance exercise. Synthesis of tendon collagen was determined by stable isotope incorporation [fractional synthesis rate (FSR)] and microdialysis technique (NH(2)-terminal propeptide of type I collagen synthesis). Tendon area and fibril characteristics were determined by MRI and transmission electron microscopy, whereas tendon biomechanical properties were measured during isometric maximal voluntary contraction by ultrasound recording. Tendon FSR was markedly higher in ERT users (P < 0.001), whereas no group difference was seen in tendon NH(2)-terminal propeptide of type I collagen synthesis (P = 0.32). In ERT users, positive correlations between serum estradiol (s-estradiol) and tendon synthesis were observed, whereas change in tendon synthesis from rest to exercise was negatively correlated to s-estradiol. Tendon area, fibril density, fibril volume fraction, and fibril mean area did not differ between groups. However, the percentage of medium-sized fibrils was higher in ERT users (P < 0.05), whereas the percentage of large fibrils tended to be greater in control (P = 0.10). A lower Young's modulus (GPa/%) was found in ERT users (P < 0.05). In conclusion, estradiol administration was associated with higher tendon FSR and a higher relative number of smaller fibrils. Whereas this indicates stimulated collagen turnover in the resting state, collagen responses to exercise were negatively associated with s-estradiol. These results indicate a pivotal role for estradiol in maintaining homeostasis of female connective tissue. PMID:18927264

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

    PubMed Central

    Tan, Qi; Lee, Yuk Wa

    2013-01-01

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

  1. Arthroscopic Quadriceps Tendon Repair: Two Case Reports

    PubMed Central

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

    2015-01-01

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

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

    PubMed

    Malvankar, S; Khan, W S

    2011-12-01

    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

  3. Post-LASIK Tear Dysfunction and Dysesthesia

    PubMed Central

    NETTUNE, GREGORY R.; PFLUGFELDER, STEPHEN C.

    2013-01-01

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

  4. Collisionless and Collisional Tearing Mode in Gyrokinetics

    NASA Astrophysics Data System (ADS)

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

    2009-05-01

    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).

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

    PubMed

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

    2015-01-01

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

  6. Rotator cuff tear measurement by arthropneumotomography

    SciTech Connect

    Kilcoyne, R.F.; Matsen, F.A. III

    1983-02-01

    Five years of experience with a method of shoulder arthrography using upright tomography in cases of suspected or known rotator cuff tears has demonstrated its effectiveness. The value of the procedure lies in its ability to demonstrate the size of the cuff tear and the thickness of the remaining cuff tissue. This information provides the surgeon with a preoperative estimate of the difficulty of the repair and the prognosis for a good functional recovery. In 33 cases, there was good correlation between the upright thin-section tomogram findings and the surgical results. The tomograms provided better information about the size of the tear and the quality of the remaining cuff than did plain arthrograms.

  7. Tear Condition Following Unilateral Ptosis Surgery.

    PubMed

    Bagheri, Abbas; Najmi, Hadi; Salim, Reza Erfanian; Yazdani, Shahin

    2014-12-01

    Abstract Purpose: To evaluate changes in tear film condition following unilateral ptosis surgery. Methods: This interventional case series includes patients with unilateral blepharoptosis scheduled for ptosis surgery with no prior history of eye disease and surgery over a 2-year period. Tear film evaluation before surgery were performed, which included Schirmer test with and without anesthesia, and tear break up time (TBUT). Ptosis surgery included levator resection and frontalis sling. The previously mentioned tests were repeated 1, 3, and 6 months after surgery. Subjective symptoms related to dry eye also evaluated before and after surgery. Results: A total of 83 patients including 46 (55.4%) male subjects with mean age of 26.2?±?16.2 years were enrolled in the study. The most common cause of ptosis was congenital in 77 (92.8%) patients. Surgical intervention included levator resection in 56 (67.5%) cases and frontalis sling procedure in 27 (32.5%) cases. The result of surgery was good in 47 (56.6%) patients while under- and overcorrection were observed in 32 (39.8%) and 3 (3.6%) patients, respectively. Schirmer's test with and without anesthesia and TBUT after surgery revealed a decrease in tear quantity and quality after surgery with time. Patients who had subjective complaints from dryness after surgery only had shorter TBUT among the objective signs. Conclusions: Ptosis surgery can decrease the quantity and quality of tears in operated eyes. Since some of these patients may need other types of operations in future, such as refractive or cataract surgery, evaluation of the tear condition before further surgery is prudent. PMID:25474275

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2008-11-01

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

  10. Specialization of tendon mechanical properties results from interfascicular differences

    PubMed Central

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

    2012-01-01

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

  11. Rotator-cuff tear of the hip.

    PubMed

    Bunker, T D; Esler, C N; Leach, W J

    1997-07-01

    We describe an apparently unreported finding during hip operations: a tear at the insertion of gluteus medius and gluteus minimus. This defect may well be known to many surgeons with experience of hip replacement and hemiarthroplasty for fractures of the neck of the femur, but a Medline search has failed to find a previous description. We made a prospective study of 50 consecutive patients with fractures of the neck of the femur to quantify the incidence of this condition: 11 (22%) had such a tear. PMID:9250749

  12. Magnetotail dynamics excited by the streaming tearing mode

    NASA Technical Reports Server (NTRS)

    Sato, T.; Walker, R. J.

    1982-01-01

    Magnetotail reconnection in the presence of plasma streaming parallel to the neutral sheet is modeled. The tearing mode is excited much more violently in the case with parallel plasma flow in the plasma sheet than in the case with no flow. The flow patterns for the nonlinear resistive tearing mode and the streaming tearing mode are much more complex than those for the linear tearing mode. Flow vortices are observed in both cases.

  13. Primary anterior shoulder dislocation and rotator cuff tears

    Microsoft Academic Search

    Roger Berbig; Dominik Weishaupt; Jürg Prim; Osama Shahin

    1999-01-01

    In a prospective controlled study 167 patients with 167 primary traumatic anterior shoulder dislocations underwent early ultrasonographic evaluation for rotator cuff tears. We found 53 (31.7%) full-thickness cuff tears in this group. Compared with a group of 93 healthy volunteers, we found with statistical significance more cuff tears in the patients aged

  14. Exploring Video Streams using Slit-Tear Visualizations

    E-print Network

    Greenberg, Saul

    of the scene. Keywords video analysis, video visualization, video interaction, information visualization ACMExploring Video Streams using Slit- Tear Visualizations Abstract Slit-tear visualizations allow users to selectively visualize pixel paths in a video scene. The slit-tear visualization technique

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

    PubMed Central

    2014-01-01

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

  16. The Effect of Tendon Surface Treatment on Cell Attachment for Potential Enhancement of Tendon Graft Healing: An Ex Vivo Model

    PubMed Central

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

    2012-01-01

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

  17. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3025 Passive tendon prosthesis. (a...new tendon sheath. The device is not intended as a permanent implant nor to function as a replacement for the ligament or...

  18. Biology and augmentation of tendon-bone insertion repair

    Microsoft Academic Search

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

    2010-01-01

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

  19. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  20. Damage Mechanics of Porcine Flexor Tendon: Mechanical Evaluation and Modeling

    E-print Network

    Lakes, Roderic

    Damage Mechanics of Porcine Flexor Tendon: Mechanical Evaluation and Modeling SARAH DUENWALD of this article. Abstract--Porcine flexor tendons underwent cyclic and stress relaxation testing before and after

  1. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  2. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3025 Passive tendon prosthesis. (a) Identification. A passive tendon prosthesis is...

  3. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3025 Passive tendon prosthesis. (a) Identification. A passive tendon prosthesis is...

  4. Robot Arm with Tendon Connector Plate and Linear Actuator

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  5. Tendon crimps and peritendinous tissues responding to tensional forces.

    PubMed

    Franchi, M; Quaranta, M; De Pasquale, V; Macciocca, M; Orsini, E; Trirè, A; Ottani, V; Ruggeri, A

    2007-01-01

    Tendons transmit forces generated from muscle to bone making joint movements possible. Tendon collagen has a complex supramolecular structure forming many hierarchical levels of association; its main functional unit is the collagen fibril forming fibers and fascicles. Since tendons are enclosed by loose connective sheaths in continuity with muscle sheaths, it is likely that tendon sheaths could play a role in absorbing/transmitting the forces created by muscle contraction. In this study rat Achilles tendons were passively stretched in vivo to be observed at polarized light microscope (PLM), scanning electron microscope (SEM) and transmission electron microscope (TEM). At PLM tendon collagen fibers in relaxed rat Achilles tendons ran straight and parallel, showing a periodic crimp pattern. Similarly tendon sheaths showed apparent crimps. At higher magnification SEM and TEM revealed that in each tendon crimp large and heterogeneous collagen fibrils running straight and parallel suddenly changed their direction undergoing localized and variable modifications. These fibril modifications were named fibrillar crimps. Tendon sheaths displayed small and uniform fibrils running parallel with a wavy course without any ultrastructural aspects of crimp. Since in passively stretched Achilles tendons fibrillar crimps were still observed, it is likely that during the tendon stretching, and presumably during the tendon elongation in muscle contraction, the fibrillar crimp may be the real structural component of the tendon crimp acting as shock absorber. The peritendinous sheath can be stretched as tendon, but is not actively involved in the mechanism of shock absorber as the fibrillar crimp. The different functional behaviour of tendons and sheaths may be due to the different structural and molecular arrangement of their fibrils. PMID:17703588

  6. Modified Rerouting Procedure for Failed Peroneal Tendon Dislocation Surgery

    Microsoft Academic Search

    R. Gaulke; F. Hildebrand; M. Panzica; T. Hüfner; C. Krettek

    2010-01-01

    \\u000a Abstract  Recurrent dislocation of the peroneal tendons following operative treatment is relatively uncommon, but can be difficult to\\u000a treat. We asked whether subligamental transposition of the peroneus brevis tendon, fibular grooving, and reattachment of the\\u000a superior peroneal retinaculum for failed peroneal tendon dislocation surgery would achieve a stable fixation of the peroneal\\u000a tendons and whether there would be restrictions of ROM

  7. Mechanical Strength of the Side-to-Side Tendon Attachment for Mismatched Tendon Sizes and Shapes

    PubMed Central

    Fridén, Jan; Tirrell, Timothy F.; Bhola, Siddharth; Lieber, Richard L.

    2015-01-01

    Summary Certain combinations are advised against in tendon transfers due to size or shape mismatches between donor and recipient tendons. In this study, ultimate load, stiffness and Young’s modulus were measured in two tendon-to-tendon attachments with intentionally mismatched donor and recipient tendons - pronator teres (PT)-to-extensor carpi radialis brevis (ECRB) and flexor carpi ulnaris (FCU)-to-extensor digitorum communis (EDC). FCU-EDC attachments failed at higher loads than PT-to-ECRB attachments but they had similar modulus and stiffness values. Ultimate tensile strength of the tendon attachments exceeded the maximum predicted contraction force of any of the affected muscles, with safety factors of 4x and 2x for the FCU-to-EDC and PT-to-ECRB constructs, respectively. This implies that size and shape mismatch should not be a contraindication to tendon attachment in transfers. Further, these safety factors strongly suggest that no postoperative immobilization of these attachments is necessary. PMID:24413573

  8. Evaporation-driven instability of the precorneal tear film.

    PubMed

    Peng, Cheng-Chun; Cerretani, Colin; Braun, Richard J; Radke, C J

    2014-04-01

    Tear-film instability is widely believed to be a signature of eye health. When an interblink is prolonged, randomly distributed ruptures occur in the tear film. "Black spots" and/or "black streaks" appear in 15 to 40 s for normal individuals. For people who suffer from dry eye, tear-film breakup time (BUT) is typically less than a few seconds. To date, however, there is no satisfactory quantitative explanation for the origin of tear rupture. Recently, it was proposed that tear-film breakup is related to locally high evaporative thinning. A spatial variation in the thickness of the tear-film lipid layer (TFLL) may lead to locally elevated evaporation and subsequent tear-film breakup. We examine the local-evaporation-driven tear-film-rupture hypothesis in a one-dimensional (1-D) model for the evolution of a thin aqueous tear film overriding the cornea subject to locally elevated evaporation at its anterior surface and osmotic water influx at its posterior surface. Evaporation rate depends on mass transfer both through the coating lipid layer and through ambient air. We establish that evaporation-driven tear-film breakup can occur under normal conditions but only for higher aqueous evaporation rates. Predicted roles of environmental conditions, such as wind speed and relative humidity, on tear-film stability agree with clinical observations. More importantly, locally elevated evaporation leads to hyperosmolar spots in the tear film and, hence, vulnerability to epithelial irritation. In addition to evaporation rate, tear-film instability depends on the strength of healing flow from the neighboring region outside the breakup region, which is determined by the surface tension at the tear-film surface and by the repulsive thin-film disjoining pressure. This study provides a physically consistent and quantitative explanation for the formation of black streaks and spots in the human tear film during an interblink. PMID:23842140

  9. Spectroscopic evaluation of human tear lipids

    Microsoft Academic Search

    Douglas Borchman; Gary N. Foulks; Marta C. Yappert; Daxin Tang; Donghai V. Ho

    2007-01-01

    Infrared and fluorescence spectroscopies were applied to characterize the molecular conformational\\/structure and dynamics of human meibum (ML) and tear lipids (SSL). ML lipids contained more CC and CH3 moieties than SSL. SSL contained OH groups that were not apparent in the spectra of ML. The CO stretching band observed in the infrared spectra of SSL and ML revealed that the

  10. Immunoglobulins in tears of normal Indian people.

    PubMed Central

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

    1976-01-01

    Immunoglobulin concentrations in tears from 50 healthy Indians aged from 14 to 50 years were measured by a standard immunodiffusion method. The levels of IgA were substantial; those of IgG were very low; and IgD and IgM were not present. The mean IgA level was 24-6 mg/100 ml. PMID:1276121

  11. CORROSION OF POST-TENSIONED TENDONS IN FLORIDA BRIDGES

    Microsoft Academic Search

    Rodney G. Powers; Alberto A. Sagüés; Yash Paul Virmani

    Severe corrosion distress and failures in post-tensioned tendons has been found in two major bridges in the State of Florida. Corrosion distress and complete tendon failure has been identified in horizontally oriented tendons that support pre-cast bridge superstructure box segments. In virtually all instances, the observed corrosion has been associated with the presence of grout voids and visual evidence of

  12. Early active mobilization after second stage flexor tendon grafts

    Microsoft Academic Search

    K. Khan; M. Riaz; M. S. C. Murison; M. D. Brennen

    1997-01-01

    We assessed the results of nine two-stage tendon reconstructions. The tendon graft was the ipsilateral palmaris longus tendon inserted into a tunnel which had been previously created by a silicone spacer. Early active mobilization was commenced 48 hours after surgery according to a previously described protocol (Small et al, 1989). Using the grading system of Kleinert and Verdan (1983) the

  13. 'Bald trochanter' spontaneous rupture of the conjoined tendons of the gluteus medius and minimus presenting as a trochanteric bursitis.

    PubMed

    LaBan, Myron M; Weir, Susan K; Taylor, Ronald S

    2004-10-01

    A 66-yr-old white woman presented with progressive complaints of right lateral hip and thigh pain associated with a disabling limp without an antecedent history of trauma. Physical examination revealed localized pain over the right greater trochanter to palpation. A full pain-free range of motion of the right hip was associated with weakness in the hip abductors. The patient ambulated with a compensated right Trendelenburg gait. Subsequent magnetic resonance imaging demonstrated a trochanteric bursitis and an effusion of the hip and a full-thickness tear of the gluteus medius muscle, with both a disruption and retraction of the tendon of an atretic gluteus minimus muscle. Conjoined tendon pathology of both the gluteus medius and minimus as, revealed by magnetic resonance examination, is probably more frequent than heretofore commonly recognized. In patients presenting with "intractable" complaints of a trochanteric bursitis and an ambulatory limp due to weakness in the hip abductors, imaging studies calling attention to a possible tendon rupture may be diagnostic. PMID:15385792

  14. Flexor tendon repairs: techniques, eponyms, and evidence.

    PubMed

    Chauhan, Aakash; Palmer, Bradley A; Merrell, Gregory A

    2014-09-01

    The evolution in surgical technique and suture technology has provided an abundance of options for flexor tendon repairs. Multiple biomechanical studies have attempted to identify the best surgical technique based on suture properties, technical modifications, and repair configurations. However, the burgeoning amount of research on flexor tendon repairs has made it difficult to follow, and no gold standard has been determined for the optimal repair algorithm. Therefore, it seems that repairs are usually chosen based on a combination of familiarity from training, popularity, and technical difficulty. We will discuss the advantages, disadvantages, and technical aspects of some of the most common core flexor tendon repairs in the literature. We will also highlight the nomenclature carried through the years, drawings of the repairs referred to by that nomenclature, and the data that support those repairs. PMID:25154573

  15. Biodegradable synthetic scaffolds for tendon regeneration

    PubMed Central

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

    2012-01-01

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

  16. 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

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

    2014-01-01

    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

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

    Microsoft Academic Search

    Pauline Po Yee Lui; Kai Ming Chan

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

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

    PubMed

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

    2014-06-01

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

  19. A Comparison of Two Injection Locations in Obese Patients Having Lower Leg/Foot Surgery

    ClinicalTrials.gov

    2014-02-05

    Strain of Muscle and/or Tendon of Lower Leg; Fracture of Lower Leg; Crushing Injury of Lower Leg; Fracture Malunion - 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

  20. Research on reasonable position of FRP tendons in concrete beams prestressed with bonded and\\/or unbonded FRP tendons

    Microsoft Academic Search

    Zuohu Wang; Xiuli Du

    2011-01-01

    Fiber reinforcement polymers (FRPs) have high strength; they are well suited for prestressing tendons in corrosive environment. Concrete structures prestressed with FRP tendons usually exhibit brittle failure models due to the brittle nature of the FRP composites. Based on different mechanical properties of prestressed concrete structures, a combination of bonded and\\/or unbonded prestressing tendons was used in order to improve

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

    PubMed

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

    2014-09-01

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

  2. [Tendon rupture as a complication after osteosynthesis of distal radius].

    PubMed

    Lugger, L J; Pechlaner, S

    1984-10-01

    Close contact between extensor and flexor tendons to the bone structure of the wrist and distal radius shaft implies the possibility of alteration concerning the tendons' slide way and tensile direction in case of osteosynthesis in this region. Even a slightly damaged screw is mechanically capable of irritation and can be made responsible for a scrub-necrosis of an above tendon. The metal implant has to be selected in consideration of both the demands of the fracture and a free and natural tendons pathway. This is discussed by means of two implant-induced scrub necroses of the long pollex extensor and flexor tendon. PMID:6516033

  3. The role of animal models in tendon research

    PubMed Central

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

    2014-01-01

    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

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

    E-print Network

    and the exoskeleton in invertebrates. Here, we discuss recent findings that illuminate musculoskeletal assembly connectivity between muscles and the exoskeleton. Intriguingly, tendon-like cells develop within the ectoderm

  5. Effect of hydrogen peroxide on human tendon allograft.

    PubMed

    Gardner, E M H; VonderHeide, N; Fisher, R; Brooker, G; Yates, P J

    2013-12-01

    Bacterial contamination of tendon allografts at the completion of processing has historically been about 2 %, with tendons that are found to be culture positive being discarded. Treatment of tendon allograft with hydrogen peroxide at the beginning of tissue processing may reduce bacterial contamination, however, the potential side effects of hydrogen peroxide treatment include hydrolysis of the collagen and this may alter the mechanical properties of the graft. Pairs of human tendons were used. One was washed in 3 % hydrogen peroxide for 5 min and the untreated tendon was used as a control. The ultimate tensile strength of the tendons was determined using a material testing machine. A freeze clamp technique was used to hold the tendons securely at the high loads required to cause tendon failure. There was no statistical difference in the ultimate tensile strength between the treated and untreated tendons. Mean strength ranged from Extensor Hallucis Longus at 588 Newtons to Tibialis Posterior at 2,366 Newtons. Hydrogen peroxide washing may reduce bacterial contamination of tendon allograft and does not affect the strength of the tendon. PMID:23681552

  6. Plantar tendons of the foot: MR imaging and US.

    PubMed

    Donovan, Andrea; Rosenberg, Zehava Sadka; Bencardino, Jenny T; Velez, Zoraida Restrepo; Blonder, David B; Ciavarra, Gina A; Adler, Ronald Steven

    2013-01-01

    Tendon disorders along the plantar aspect of the foot may lead to significant symptoms but are often clinically misdiagnosed. Familiarity with the normal anatomy of the plantar tendons and its appearance at magnetic resonance (MR) imaging and ultrasonography (US) is essential for recognizing plantar tendon disorders. At MR imaging, the course of the plantar tendons is optimally visualized with dedicated imaging of the midfoot and forefoot. This imaging should include short-axis images obtained perpendicular to the long axis of the metatarsal shafts, which allows true cross-sectional evaluation of the plantar tendons. Normal plantar tendons appear as low-signal-intensity structures with all MR sequences. At US, accurate evaluation of the tendons requires that the ultrasound beam be perpendicular to the tendon. The normal tendon appears as a compact linear band of echogenic tissue that contains a fine, mixed hypoechoic and hyperechoic internal fibrillar pattern. Tendon injuries can be grouped into six major categories: tendinosis, peritendinosis, tenosynovitis, entrapment, rupture, and instability (subluxation or dislocation) and can be well assessed with both MR imaging and US. The radiologist plays an important role in the diagnosis of plantar tendon disorders, and recognizing their imaging appearances at MR imaging and US is essential. PMID:24224599

  7. Relationship between compressive loading and ECM changes in tendons

    PubMed Central

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

    2013-01-01

    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

  8. Zone I extensor reconstruction with tendon salvaged from another finger.

    PubMed

    Türker, Tolga; Capdarest-Arest, Nicole; Schmahl, Dennis T

    2014-05-01

    Laceration, crush, and avulsion injuries are common acute extensor tendon injuries. Simple lacerations may often be repaired in the emergency room, but crush or avulsion injuries may involve tendon loss and gaps in the extensor tendons. Reconstruction can be difficult. The purpose of this article is to present a salvage technique for reconstruction of large extensor tendon gaps in extensor zone I in patients with severe injuries to multiple fingers. This technique, in which a tendon is transplanted from an unsalvageable finger to another with a terminal tendon gap in the same patient, may be a reasonable remedy for reconstruction of tendon loss or gaps and may offer advantages over other traditional reconstructive techniques in certain cases. PMID:24613590

  9. Abductor pollicis longus tendon division with swan neck thumb deformity.

    PubMed

    Zacharia, Balaji; Puthezhath, Kishore

    2012-08-01

    Swan neck thumb deformity can be caused by osteoarthritis, rheumatoid arthritis, systemic lupus erythematosus, tendon transfers and paralytic diseases. Abductor pollicis longus is one of the major stabilizing tendon of the carpometacarpal joint of thumb. To the best of our knowledge, swan neck thumb deformity owing to division of abductor pollicis longus tendon is rare. In this article, we describe a case of isolated division of abductor pollicis longus tendon presenting with swan-neck deformity of thumb and discuss the mechanism, management and outcome. The patient was treated by repair of the divided tendon using palmaris longus tendon graft. At approximately 107 weeks following treatment, the patient was having full range of thumb movement and the deformity completely disappeared. We also describe the unusual mechanism whereby an isolated division of abductor pollicis longus tendon results in swan neck thumb deformity. Level of clinical evidence IV. PMID:22825877

  10. Variation in the insertion of the palmaris longus tendon.

    PubMed

    Sunil, Vinutha; Rajanna, Shubha; Gitanjali; Kadaba, Jayanthi

    2015-01-01

    The palmaris longus is harvested as a tendon graft in various surgical procedures. We herein report the variations in the insertion of the palmaris longus tendon. During a routine dissection, a rare variation in the insertion of the palmaris longus tendon was observed. In the left forearm, the palmaris longus tendon bifurcated, while in the right forearm, the palmaris longus tendon trifurcated, giving rise to an accessory muscle, which passed superficial to the ulnar artery and ulnar nerve. The accessory muscle was supplied by a deep branch of the ulnar nerve, and the ulnar artery was observed to be tortuous. During reconstructive surgeries, surgeons should bear in mind the accessory muscle. Also, since the palmaris longus muscle provides a very useful graft in tendon surgery, every surgeon should be aware of the variations in the insertion of the palmaris longus tendon. PMID:25640108

  11. Biomechanical Evaluation of 4 Techniques of Distal Biceps Brachii Tendon Repair

    Microsoft Academic Search

    Augustus D. Mazzocca; Kevin J. Burton; Anthony A. Romeo; Stephen Santangelo; Douglas A. Adams; Robert A. Arciero

    2007-01-01

    Background: Recent technical improvements have led the way to a resurgence of the single-incision approach for repair of distal biceps tendon injuries. There has been no biomechanical evaluation of all these techniques with comparison to the standard 2-incision bone tunnel technique.Hypothesis: There will be no difference under cyclic loading and ultimate failure between the 2-incision bone tunnel technique, suture anchor

  12. How tendons buffer energy dissipation by muscle

    PubMed Central

    Roberts, Thomas J.; Konow, Nicolai

    2013-01-01

    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

  13. Prestressed concrete using KEVLAR reinforced tendons

    Microsoft Academic Search

    Dolan

    1989-01-01

    KEVLAR is a high strength, high modulus synthetic fiber manufactured by the E.I. DuPont de Nemours Company. The fiber is resistant to chloride and alkali attack. The resistance is enhanced when the fibers are assembled into a resin matrix and fabricated as rods. These properties suggest that KEVLAR reinforced rods may be a substitute for high strength steel prestress tendons

  14. Achilles tendon pathology, present and future

    Microsoft Academic Search

    N Maffulli

    2011-01-01

    Lecture 18IntroductionThe recent progress in molecular biology, could make possible to identify the factors which influence the metabolism of the tenocytes and promote their natural healing process. The role of growth factors in the healing of tendons, for example, is still unclear, although basic fibroblast growth factor can stimulate healing by promoting cell proliferation and synthesis of the matrix. Gene

  15. Biologics in Achilles tendon healing and repair: a review.

    PubMed

    Shapiro, Evan; Grande, Daniel; Drakos, Mark

    2015-03-01

    Injuries of the Achilles tendon are relatively common with potentially devastating outcomes. Healing Achilles tendons form a fibrovascular scar resulting in a tendon which may be mechanically weaker than the native tendon. The resulting strength deficit causes a high risk for reinjury and other complications. Treatments using biologics aim to restore the normal properties of the native tendon and reduce the risk of rerupture and maximize tendon function. The purpose of this review was to summarize the current findings of various therapies using biologics in an attempt to improve the prognosis of Achilles tendon ruptures and tendinopathies. A PubMed search was performed using specific search terms. The search was open for original manuscripts and review papers limited to publication within the last 10 years. From these searches, papers were included in the review if they investigated the effects of biological augmentation on Achilles tendon repair or healing. Platelet-rich plasma may assist in the healing process of Achilles tendon ruptures, while the evidence to support its use in the treatment of chronic Achilles tendinopathies remains insufficient. The use of growth factors such as hepatocyte growth factor, recombinant human platelet-derived growth factor-BB, interleukin-6, and transforming growth factor beta as well as several bone morphogenetic proteins have shown promising results for Achilles tendon repair. In vitro and preclinical studies have indicated the potential effectiveness of bone marrow aspirate as well. Stem cells also have positive effects on Achilles tendon healing, particularly during the early phases. Polyhydroxyalkanoates (PHA), decellularized tendon tissue, and porcine small intestinal submucosa (SIS) are biomaterials which have shown promising results as scaffolds used in Achilles tendon repair. The application of biological augmentation techniques in Achilles tendon repair appears promising; however, several techniques require further investigation to evaluate their clinical application. PMID:25655258

  16. Characterization of ocular gland morphology and tear composition of pinnipeds

    PubMed Central

    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

    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

  17. Assessment of tear secretions in healthy Indian volunteers.

    PubMed

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

    2014-01-01

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

  18. Diadenosine tetraphosphate contributes to carbachol-induced tear secretion.

    PubMed

    Fonseca, Begoña; Martínez-Águila, Alejandro; Díaz-Hernández, Miguel; Pintor, Jesús

    2015-03-01

    The purpose of this study is to investigate if the cholinergic stimulation by carbachol on tear secretion is a direct process or if it is also mediated by purinergic mechanisms. Experiments were performed in New Zealand male rabbits. The amount of tear secretion was measured with Schirmer's test and then analyzed by a HPLC protocol in order to study the nucleotide levels. Animal eyes were instilled with carbachol (a cholinergic agonist), pirenzepine, gallamine and 4-DAMP (muscarinic antagonists), PPADS, suramin and reactive blue 2 (purinergic antagonists), and a P2Y2 receptor small interfering RNA (siRNA). Tear secretion increased with the instillation of carbachol, approximately 84 % over control values 20 min after the instillation and so did Ap4A and ATP release. When we applied carbachol in the presence of muscarinic antagonists, tear volume only increased to 4 % with atropine, 12 % in the case of pirenzepine, 3 % with gallamine, and 8 % with 4-DAMP. In the presence of carbachol and purinergic antagonists, tear secretion was increased to 12 % (all values compared to basal tear secretion). By analyzing tear secretion induced with carbachol in presence of a P2Y2 receptor siRNA, we found that tear secretion was diminished to 60 %. The inhibition of tear secretion in the presence of carbachol and purinergic antagonists or P2Y2 siRNA occurred with no apparent change in the tear amount of Ap4A. These experiments demonstrated the participation of Ap4A in lacrimal secretion process. PMID:25398705

  19. Immunoglobulins in tear in trachoma patients.

    PubMed Central

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

    1977-01-01

    Tear immunoglobulin concentrations have been measured in 100 healthy people and 62 patients in different stages of trachoma. In healthy people the average IgA level was 27-8 mg/100 ml. There was no significant difference in the IgA level in various age groups and between the sexes. IgG was detected in 92 samples, and it was less than 1 mg/100 ml. IgM in tears was detected in only one sample. IgD was not detected in any specimen. In tracoma cases, the mean IgA level was found to be significantly lower (22-0 mg/100 ml) than in healthy people. There was no significant difference in IgA level between different stages of trachoma, IgG, IgD, and IgM could not be detected in any sample from the trachoma cases. PMID:856248

  20. Collisionless tearing instability in magnetotail plasmas

    NASA Technical Reports Server (NTRS)

    Wang, Xiaogang; Bhattacharjee, A.; Lui, A. T. Y.

    1990-01-01

    The problem of the linear stability of collisionless tearing modes in the earth's magnetotail is revisited. It is found that the collisionless tearing mode is linearly unstable with wavelengths of the order of 10 R(E). It is shown that an important feature neglected in earlier theories is a nonzero equilibrium B(y)-field. The physics of the instability is elucidated in the context of a simple slab model and a sheared parabolic model which is representative of the magnetotail in which all three components of the magnetic field are nonzero. The dispersion equation for the instability is obtained by a boundary-layer analysis. The implications of the theory for recent observations on current disruption and diversion during substorms is discussed.

  1. Tearing of free-standing graphene

    NASA Astrophysics Data System (ADS)

    Moura, M. J. B.; Marder, M.

    2013-09-01

    We examine the fracture mechanics of tearing graphene. We present a molecular dynamics simulation of the propagation of cracks in clamped, free-standing graphene as a function of the out-of-plane force. The geometry is motivated by experimental configurations that expose graphene sheets to out-of-plane forces, such as back-gate voltage. We establish the geometry and basic energetics of failure and obtain approximate analytical expressions for critical crack lengths and forces. We also propose a method to obtain graphene's toughness. We observe that the cracks’ path and the edge structure produced are dependent on the initial crack length. This work may help avoid the tearing of graphene sheets and aid the production of samples with specific edge structures.

  2. Gender-specific in vivo measurement of the structural and mechanical properties of the human patellar tendon.

    PubMed

    Onambélé, Gladys N L; Burgess, Katherine; Pearson, Stephen J

    2007-12-01

    Human patellar tendon stress (sigma), strain (epsilon), stiffness (K), and tensile or Young's modulus (E), are determined in vivo through voluntary isometric contractions monitored with B-mode ultrasonography. The limitations in previous studies are: (1) they have generally not accounted for the fact that the distal attachment of the patellar tendon (the tibial tuberosity) also displaces; thus, they have underestimated epsilon (and, hence, injury risk) while overestimating K; (2) no gender effect has been studied despite the fact that females are seen to have higher incidences of tendon-related injuries. The current investigation therefore aimed to determine the gender specific values of sigma, epsilon, K, and E of the patellar tendon while also accounting for distal displacement of the patellar tendon. Healthy young males (aged 23.1 +/- 1.3 years, n = 10) and females (aged 21.3 +/-0.9 years, n = 10) were tested. The maximal epsilon of the young males was approximately 5-10% higher than that reported in earlier literature. Average female versus male values for epsilon, sigma, K, and E, taken at the same force level as the males for comparison purposes, were respectively 10.6 +/- 1.0 versus 9.0 +/- 1.0%, 36.9 +/- 1.4 versus 28.9 +/- 0.9 MPa, 1053 +/- 108 versus 1652 +/- 216 N x mm(-1), and 0.61 +/- 0.08 versus 0.68 +/- 0.10 GPa (p < 0.05). There are gender differences in tendon structural and mechanical properties. The current methodology may be useful in a clinical context where early prediction of injury risk and/or monitoring of reconstructed tendon needs to be an accurate, objective, and reliable method if optimal functionality is to be achieved. PMID:17568426

  3. Two-staged extensor tendon reconstruction for zone 6 extensor tendon loss of the fingers: indications, technique and results.

    PubMed

    Al-Qattan, M M

    2015-03-01

    Over a 20-year period, six patients (19 tendons) underwent two-staged extensor tendon reconstruction using silicone rods followed by palmaris longus tendon grafts sutured proximally to the divided flexor carpi radialis tendon. All patients were young men (mean age, 22 years) who sustained the injury in car accidents. The soft tissue loss from the dorsum of the hand was associated with extensor tendon loss over the entire zone 6 with or without loss in zone 7. Primary soft tissue coverage was done elsewhere, and patients presented for secondary tendon reconstruction. All patients had supple metacarpophalangeal joints before reconstruction. After the two-staged tendon reconstruction, full or near-full active flexion at the metacarpophalangeal joints was obtained in all patients. However, minor extension lags (10°-15°) at the metacarpophalangeal joints were seen in 15 out of 19 reconstructed fingers. PMID:24369363

  4. Prevalence and possible pathological significance of calcium phosphate salt accumulation in tendon matrix degeneration

    Microsoft Academic Search

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

    1996-01-01

    OBJECTIVES: To investigate the prevalence of calcium phosphate mineral salt accumulation in degenerative supraspinatus 'tendinitis' compared with a normal sample of human tendons, and to determine whether there is an association of calcium salt deposition with pathological changes in the tendon extracellular matrix. METHODS: Cadaver tendons (supraspinatus and common biceps tendons, n = 96) and fragments of supraspinatus tendons obtained

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

    PubMed Central

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

    2006-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  7. Identity of tendon stem cells – how much do we know?

    PubMed Central

    Lui, Pauline Po Yee

    2013-01-01

    Tendon stem cells are multi-potent adult stem cells with broad differentiation plasticity that render them of great importance in cell-based therapies for the repair of tendons. We called them tendon-derived stem cells (TDSCs) to indicate the tissue origin from which the stem cells were isolated in vitro. Based on the work of other sources of MSCs and specific work on TDSCs, some properties of TDSCs have been characterized / implicated in vitro. Despite these findings, tendon stem cells remained controversial cells. This was because MSCs residing in different organs, although very similar, were not identical cells. There is evidence of differences in stem cell-related properties and functions related to tissue origins. Similar to other stem cells, tendon stem cells were identified and characterized in vitro. Their in vivo identities, niche (both anatomical locations and regulators) and roles in tendons were less understood. This review aims to summarize the current evidence of the possible anatomical locations and niche signals regulating the functions of tendon stem cells in vivo. The possible roles of tendon stem cells in tendon healing and non-healing are presented. Finally, the potential strategies for understanding the in vivo identity of tendon stem cells are discussed. PMID:23279609

  8. Tear lipid layer and contact lens comfort: a review.

    PubMed

    Rohit, Athira; Willcox, Mark; Stapleton, Fiona

    2013-05-01

    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

  9. Crimp morphology in relaxed and stretched rat Achilles tendon.

    PubMed

    Franchi, Marco; Fini, Milena; Quaranta, Marilisa; De Pasquale, Viviana; Raspanti, Mario; Giavaresi, Gianluca; Ottani, Vittoria; Ruggeri, Alessandro

    2007-01-01

    Fibrous extracellular matrix of tendon is considered to be an inextensible anatomical structure consisting of type I collagen fibrils arranged in parallel bundles. Under polarized light microscopy the collagen fibre bundles appear crimped with alternating dark and light transverse bands. This study describes the ultrastructure of the collagen fibrils in crimps of both relaxed and in vivo stretched rat Achilles tendon. Under polarized light microscopy crimps of relaxed Achilles tendons appear as isosceles or scalene triangles of different size. Tendon crimps observed via SEM and TEM show the single collagen fibrils that suddenly change their direction containing knots. The fibrils appear partially squeezed in the knots, bent on the same plane like bayonets, or twisted and bent. Moreover some of them lose their D-period, revealing their microfibrillar component. These particular aspects of collagen fibrils inside each tendon crimp have been termed 'fibrillar crimps' and may fulfil the same functional role. When tendon is physiologically stretched in vivo the tendon crimps decrease in number (46.7%) (P<0.01) and appear more flattened with an increase in the crimp top angle (165 degrees in stretched tendons vs. 148 degrees in relaxed tendons, P<0.005). Under SEM and TEM, the 'fibrillar crimps' are still present, never losing their structural identity in straightened collagen fibril bundles of stretched tendons even where tendon crimps are not detectable. These data suggest that the 'fibrillar crimp' may be the true structural component of the tendon crimp acting as a shock absorber during physiological stretching of Achilles tendon. PMID:17229278

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

    ClinicalTrials.gov

    2014-03-20

    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

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

    PubMed

    Lewicky, Yuri M

    2009-10-01

    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

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

    PubMed Central

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

    2014-01-01

    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

  13. Rates of meniscal tearing in patients with chondrocalcinosis.

    PubMed

    Checa, Angel; Chun, William

    2015-03-01

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

  14. Stabilization of tearing modes by oscillating the resonant surface

    SciTech Connect

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

    2012-07-15

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

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

    PubMed

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

    2014-06-01

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

  16. The Achilles tendon: fundamental properties and mechanisms governing healing

    PubMed Central

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

    2014-01-01

    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

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

    SciTech Connect

    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

    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.

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

    SciTech Connect

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

    2014-06-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Maget, Patrick; Lütjens, Hinrich; Luciani, Jean-François; Garbet, Xavier; Février, Olivier; Ségui, Jean-Luc

    2014-06-01

    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.

  1. Triceps tendon rupture: an uncommon orthopaedic condition.

    PubMed

    Bunshah, Jamshed Jal; Raghuwanshi, Sagar; Sharma, Deepak; Pandita, Aakash

    2015-01-01

    Triceps tendon disruption is a rare orthopaedic injury that can lead to poor outcomes if misdiagnosed or managed inappropriately. This case report illustrates the importance of early, precise diagnosis of triceps rupture by clinical and radiological examination with appropriate management. A weightlifter who had fallen while riding his bike presented with pain, swelling around the posterior aspect of the left arm just above the elbow. Physical examination revealed ecchymosis and weakness in elbow extension. A radiograph of the elbow showed a small fleck of bone proximal to the tip of the olecranon. The patient was initially stabilised. Early intervention in the form of primary tendon repair was performed within 3?days and rehabilitation was started. The patient improved significantly to his best possible functional status with Mayo elbow score of 85. Early intervention was the key to better prognosis. PMID:25766435

  2. Anterior cruciate ligament reconstruction with allograft tendons.

    PubMed

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

    2003-01-01

    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

  3. Quadriceps Tendon Rupture due to Postepileptic Convulsion

    PubMed Central

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

    2014-01-01

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

  4. Biomechanical Analysis of Distal Biceps Tendon Repair Methods

    Microsoft Academic Search

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

    2007-01-01

    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.

  5. Low level laser therapy in healing tendon

    NASA Astrophysics Data System (ADS)

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

    2005-11-01

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

  6. Tear Film Interferometry and Corneal Surface Roughness

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  8. Biology and augmentation of tendon-bone insertion repair

    PubMed Central

    2010-01-01

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

  9. Mechanical characteristics of native tendon slices for tissue engineering scaffold.

    PubMed

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

    2012-04-01

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

  10. Smad3 Binds Scleraxis and Mohawk and Regulates Tendon Development

    PubMed Central

    Berthet, Ellora; Chen, Carol; Butcher, Kristin; Schneider, Richard A.; Alliston, Tamara; Amirtharajah, Mohana

    2014-01-01

    TGF? plays a critical role in tendon formation and healing. While its downstream effector Smad3 has been implicated in the healing process, little is known about the role of Smad3 in normal tendon development or tenocyte gene expression. Using mice deficient in Smad3 (Smad3–/–), we show that Smad3 ablation disrupts normal tendon architecture and has a dramatic impact on normal gene and protein expression during development as well as in mature tendon. In developing and adult tendon, loss of Smad3 results in reduced protein expression of the matrix components Collagen 1 and Tenascin-C. Additionally, when compared to wild type, tendon from adult Smad3–/– mice shows a downregulation of key tendon marker genes. Finally, through in vitro work, we have established that Smad3 has the ability to physically interact with the critical transcriptional regulators Scleraxis and Mohawk. Together these results indicate a central role for Smad3 in normal tendon development and in the maintenance of mature tendon. PMID:23653374

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

    PubMed Central

    2013-01-01

    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

  12. Endoscopic Management of Mallory-Weiss Tearing

    PubMed Central

    2015-01-01

    Mallory-Weiss tearing (MWT) is a common cause of non-variceal upper gastrointestinal bleeding. Although the majority of patients with bleeding MWT require no intervention other than hemodynamic supports, spectrum of MWT is wide, and the condition sometimes results in a fatal outcome. Endoscopic management to stop the bleeding may be required during the index endoscopy, especially in those with active bleeding or stigmata of recurrent bleeding. Most commonly used endoscopic treatment for actively bleeding MWT is injection therapy, argon plasma coagulation, hemoclip placement, and band ligation. Selection of the optimal endoscopic hemostasis depends on the physician's ability and patient's clinical status.

  13. Nonlinear growth of strongly unstable tearing modes

    SciTech Connect

    Waelbroeck, F.L.

    1993-11-01

    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.

  14. Apomictic maternal diploids in tetraploid Job's tears.

    PubMed

    Venkateswarlu, J; Rao, P N

    1975-06-01

    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

  15. In vivo passive mechanical behaviour of muscle fascicles and tendons in human gastrocnemius muscle–tendon units

    PubMed Central

    Herbert, Robert D; Clarke, Jillian; Kwah, Li Khim; Diong, Joanna; Martin, Josh; Clarke, Elizabeth C; Bilston, Lynne E; Gandevia, Simon C

    2011-01-01

    Abstract Ultrasound imaging was used to measure the length of muscle fascicles in human gastrocnemius muscles while the muscle was passively lengthened and shortened by moving the ankle. In some subjects the muscle belly ‘buckled’ at short lengths. When the gastrocnemius muscle–tendon unit was passively lengthened from its shortest in vivo length by dorsiflexing the ankle, increases in muscle–tendon length were not initially accompanied by increases in muscle fascicle lengths (fascicle length remained constant), indicating muscle fascicles were slack at short muscle–tendon lengths. The muscle–tendon length at which slack is taken up differs among fascicles: some fascicles begin to lengthen at very short muscle–tendon lengths whereas other fascicles remain slack over a large range of muscle–tendon lengths. This suggests muscle fascicles are progressively ‘recruited’ and contribute sequentially to muscle–tendon stiffness during passive lengthening of the muscle–tendon unit. Even above their slack lengths muscle fascicles contribute only a small part (tendon length. The contribution of muscle fascicles to muscle–tendon length increases with muscle length. The novelty of this work is that it reveals a previously unrecognised phenomenon (buckling at short lengths), posits a new mechanism of passive mechanical properties of muscle (recruitment of muscle fascicles), and confirms with high-resolution measurements that the passive compliance of human gastrocnemius muscle–tendon units is due largely to the tendon. It would be interesting to investigate if adaptations of passive properties of muscles are associated with changes in the distribution of muscle lengths at which fascicles fall slack. PMID:21825027

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

    Microsoft Academic Search

    H. Alfredson; K. Thorsen; R. Lorentzon

    1999-01-01

    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

  17. Spontaneous Rupture of the Patellar Tendon and the Contralateral Quadriceps Tendon, Associated with Lupus Erythematosus: Analysis of the Literature

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2014-10-01

    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

  19. Recurrent subluxation of the peroneal tendons.

    PubMed

    Ferran, Nicholas A; Oliva, Francesco; Maffulli, Nicola

    2006-01-01

    Recurrent peroneal tendon subluxation is an uncommon sports-related injury. The retrofibular groove is formed not by the concavity of the fibula itself, but by a relatively pronounced ridge of collagenous soft tissue blended with the periosteum that extends along the posterolateral lip of the distal fibula. The shape of the groove is primarily determined by this thick fibrocartilagenous periosteal cushion, and not by the bone itself. The superior peroneal retinaculum is extremely variable in width, thickness and insertional patterns. Peroneal tendon subluxation is commonly associated with longitudinal splits in the peroneus brevis tendon and lateral ankle instability. Disruption of the lateral collateral ankle ligaments places considerable strain on the superior peroneal retinaculum. This explains why the two conditions commonly coexist. In recurrent subluxation, patients usually give a history of previous ankle injury, which may have been misdiagnosed as a sprain. An unstable ankle that gives way or is associated with a popping or snapping sensation is another common complaint. The peroneal tendons may actually be seen subluxing anteriorly on the distal fibula during ambulation. The role of imaging has been debated, and the diagnosis and management plan are based on clinical evidence. Conservative management may be attempted in acute dislocations, and can be successful in up to 50% of patients, although there is a trend for operative management in athletes. Recurrent dislocations should be managed surgically. Five basic categories of repair have been described: (i) anatomical reattachment of the retinaculum; (ii) bone-block procedures; (iii) reinforcement of the superior peroneal retinaculum with local tissue transfers; (iv) rerouting the tendons behind the calcaneofibular ligament; and (v) groove deepening procedures. However, it is impossible to determine from the relatively small series which procedure is superior. If an anatomical approach to treating the pathology is utilised, reattachment of the superior retinaculum seems a most appropriate technique. Randomised controlled trials may be the way forward in determining the best surgical management method. However, the relative rarity of the condition and the large number of techniques described make such study difficult. PMID:17004847

  20. Shoulder function after surgical repair of rotator cuff tears

    Microsoft Academic Search

    M Kronberg; P Wahlström; L-Å Broström

    1997-01-01

    Shoulder function was assessed in 37 patients with a mean age of 57 years after acromioplasty and repair of full-thickness rotator cuff tears were performed. The cuff tears were closed without transfer of other muscles or use of synthetic materials. At review 2 years after surgery 32 patients had significant pain relief and improved shoulder function. Range of motion, muscle

  1. Postoperative subcoracoid impingement syndrome in patients with rotator cuff tear

    Microsoft Academic Search

    Naoki Suenaga; Akio Minami; Kiyoshi Kaneda

    2000-01-01

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

  2. Rotator cuff tear —Relationship between clinical and anatomopathological findings

    Microsoft Academic Search

    N. Gschwend; D. Ivoševi?-Radovanovi?; D. Patte

    1987-01-01

    Rotator cuff tears (RCT) are frequent and increase with age. Why do only a relatively small percentage cause a permanent severe handicap justifying surgery? Is there a relationship between size and site of the tear and the clinical symptoms? How do they influence the postoperative result? These questions were answered in a prospective study of 76 operated patients. We adopted

  3. INTERACTION OF TEARING MODES WITH EXTERNAL STRUCTURES IN CYLINDRICAL GEOMETRY

    E-print Network

    Fitzpatrick, Richard

    research. The basic theory of tearing modes is fairly well established. Tearing modes are thought surfaces, where the magneti? winding number, or `safety factor', q takes the rational value mln. The ideal and inertia into account [4].The region of the plasma where ideal MHD breaks down is termed the `inner region

  4. Tearing of Free-Standing Graphene M. J. B. Moura

    E-print Network

    Texas at Austin. University of

    Tearing of Free-Standing Graphene M. J. B. Moura IBM Research - Brazil, Av. Pasteur 138 of tearing graphene. We present a molecular dynamics simulation of the propagation of cracks in clamped, free in the free-standing experimental setup, mostly in an effort to improve electronic properties through absence

  5. ‘Suture-induced tear’ after human meniscal allograft transplantation

    Microsoft Academic Search

    Kwang Am Jung; Su Chan Lee; Seung Hyun Hwang

    2010-01-01

    Meniscal allograft transplantation (MAT) is generally associated with good outcomes. However, the likelihood of a successful outcome is reduced by various complications, and a meniscal tear is one of the most common of these after MAT. Meniscal tears usually occur at the periphery of the meniscal allografts at the capsular junction or the posterior horn, and biomechanical factors, such as

  6. 49 CFR 173.340 - Tear gas devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  7. 49 CFR 173.340 - Tear gas devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  8. 49 CFR 173.340 - Tear gas devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  9. 49 CFR 173.340 - Tear gas devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  10. The fluid mechanics of shear-thinning tear substitutes

    Microsoft Academic Search

    Laurent Jossic; Pauline Lefevre; Clément de Loubens; Albert Magnin; Christophe Corre

    2009-01-01

    Tear substitutes are used to treat dry eye syndrome. Shear-thinning should help to delay the appearance of dry spots and improve comfort. This article discusses a numerical model study of the spreading of shear-thinning tear substitutes during blinking. The Ellis model, which takes account of the Newtonian plateau at low shear rate, was chosen. Flow is governed by the capillary

  11. 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

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

    2014-01-01

    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

  12. Death due to isolated jejunal tear following blunt abdominal trauma.

    PubMed

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

    2014-09-01

    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

  13. Kinetic theory and simulation of collisionless tearing in bifurcated current sheets

    NASA Astrophysics Data System (ADS)

    Matsui, Tatsuki

    Observations from the Earth's geomagnetic tail have established that the current sheet is often bifurcated with two peaks in the current density. These so-called bifurcated current sheets have also been reported in a variety of simulations and often occur in conjunction with significant temperature anisotropy. In this work, a new self-consistent Vlasov equilibrium is developed that permits both the current profile and temperature anisotropy to be independently adjusted. This new equilibrium has a sufficient flexibility to model a wide variety of bifurcated sheets observed in both kinetic simulations and space observations, and transforms continuously back to the standard Harris sheet model with a single peak in the current density. The linear stability of these layers with respect to the tearing mode is examined in the framework of resistive MHD and full Vlasov theory. From the simplified fluid theory, it is demonstrated that a bifurcated current profile has a stabilizing influence on the resistive tearing instability. However, the resistive MHD model is not really appropriate to model the highly collisionless plasma conditions in the magnetosphere. To obtain reliable predictions, Vlasov theory is required and the approach in this thesis employs both standard analytic techniques and a formally exact treatment in which the full orbit integral is numerically evaluated. The resulting linear growth rate for the collisionless tearing instability and the mode structure are verified with 2D full kinetic particle- in-cell simulations. The simplified analytic theory is reasonably accurate in capturing these dependencies for long wavelength modes, but the short wavelength regime generally requires the full numerical treatment to accurately compute the growth rate. The results from these different approaches consistently demonstrate that a bifurcated current profile has a strong stabilizing influence on the collisionless tearing mode in comparison to centrally peaked layers with a similar thickness. In collisionless tearing, electron temperature anisotropy is strongly destabilizing in the limit T e [perpendicular] > T e || and strongly stabilizing when T e [perpendicular] < T e || . Thus, the collisionless tearing instability is determined by the competition between these two influences.

  14. Skin tears: state of the science: consensus statements for the prevention, prediction, assessment, and treatment of skin tears©.

    PubMed

    LeBlanc, Kimberly; Baranoski, Sharon

    2011-09-01

    The appropriate management of patients with skin tears is an ongoing challenge for healthcare professionals. Skins tears are often painful, acute wounds resulting from trauma to the skin and are largely preventable. Healthcare professionals must be able to identify individuals at risk for skin tears and aid in the prevention of these wounds and in their treatment when they occur. Despite preliminary studies that suggest skin tears may be more prevalent than pressure ulcers, there remains a paucity of literature to guide prevention, assessment, and treatment of skin tears. As a result, these wounds are often mismanaged and misdiagnosed, leading to complications, including pain, infection, and delayed wound healing. In addition, skin tears increase caregiver time and facility costs, cause anxiety for patients and families, and may reflect poorly on the quality of care delivered in a facility. In an effort to shift awareness toward this largely unheeded healthcare issue, a consensus panel of 13 internationally recognized key opinion leaders convened to establish consensus statements on the prevention, prediction, assessment, and treatment of skin tears. The initial consensus panel meeting was held in January 2011 and was made possible by an unrestricted educational grant from Hollister Wound Care. This document details the consensus definition and statements, as well as recommendations for future research and steps toward establishing a validated, comprehensive program for managing skin tears. PMID:21876389

  15. Mechanical and functional properties of implanted freeze-dried flexor tendons.

    PubMed

    Webster, D A; Werner, F W

    1983-11-01

    Tendons harvested from donor dogs were freeze-dried and implanted as free allografts in the paws of recipient experimental animals; the tendons were subsequently tested for mechanical properties, clinical function, and histologic appearance. Free tendon autografts, normal tendons in the operated experimental paw, and normal tendons in the unoperated paw were used as controls and compared with the allografts. Mechanically, the free tendon allografts and autografts were similar. The ultimate strength of the two grafts was statistically the same but significantly less, about one-third, than that of normal tendons. The implanted allografts appeared to be tolerated well by the host and to allow flexor tendon function similar to that allowed by autografts. The histologic appearance of the allograft and autograft tendons was similar at three and six months. Freeze-dried flexor tendon allografting is a satisfactory alternative to free tendon autografting. PMID:6627794

  16. Quantifying the deep tendon reflex using varying tendon indentation depths: applications to spasticity.

    PubMed

    Chardon, Matthieu K; Rymer, W Zev; Suresh, Nina L

    2014-03-01

    The deep tendon reflex (DTR) is often utilized to characterize the neuromuscular health of individuals because it is cheap, quick to implement, and requires limited equipment. However, DTR assessment is unreliable and assessor-dependent improve the reliability of the DTR assessment, we devised a novel standardization procedure. Our approach is based on the hypothesis that the neuromuscular state of a muscle changes systematically with respect to the indentation depth of its tendon. We tested the hypothesis by progressively indenting the biceps tendons on each side of nine hemiplegic stroke survivors to different depths, and then superimposing a series of brief controlled taps at each indentation depth to elicit a reflex response. Our results show that there exists a unique indentation depth at which reflex responses are consistently recorded (termed the Reflex Threshold) with increasing amplitude along increasing indentation depth. We further show that the reflex threshold depth is systematically smaller on the affected side of stroke survivors and that it is negatively correlated with the Modified Ashworth Score (VAF 70%). Our procedure also enables measurement of passive mechanical properties at the indentation location. In conclusion, our study shows that controlling for the indentation depth of the tendon of a muscle alters its reflex response predictably. Our novel device and method could be used to estimate neuromuscular changes in muscle (e.g., spasticity). Although some refinement is needed, this method opens the door to more reliable quantification of the DTR. PMID:24621852

  17. Achilles tendon rupture following coblation for insertional Achilles tendinosis.

    PubMed

    Akhtar, M A; Montgomery, H; Shenolikar, A

    2009-03-01

    Radiofrequency microdebridement for Achilles tendinosis is a relatively new technique. We report a case of Achilles tendon rupture in a patient eight weeks after coblation for his right insertional Achilles tendinosis. We believe that this is the first reported case of Achilles tendon rupture following this new treatment of radiofrequency microdebridement for chronic Achilles tendinosis. PMID:20307450

  18. Stiffness of reinforced concrete beams with external tendons

    Microsoft Academic Search

    Bilal El-Ariss

    2004-01-01

    In recent years, external prestressing has become a primary method for strengthening existing concrete structures and has been increasingly used in the construction of newly erected ones, particularly segmental bridges. Analysis of externally prestressed members is more difficult than that of members with internal bonded tendons. This is because external tendons are unbonded to the concrete and the stress in

  19. Achilles tendon rupture and sciatica: a possible correlation

    Microsoft Academic Search

    N. Maffulli; A. S. Irwin; M. G. Kenward; F. Smith; R. W. Porter

    1998-01-01

    The association between Achilles tendon rupture and sciatica was investigated by questionnaire in 138 patients who underwent repair of an Achilles tendon rupture, and in a group of individuals nominated by the patients, matched for age, sex, and occupation. A total of 102 patients (74%) and 128 peer nominated controls (71%) replied to the questionnaire. Of the 102 respondent patients,

  20. Physiological Loading of Tendons Induces Scleraxis Expression in Epitenon Fibroblasts

    PubMed Central

    Mendias, Christopher L; Gumucio, Jonathan P; Bakhurin, Konstantin I; Lynch, Evan B; Brooks, Susan V

    2011-01-01

    Scleraxis is a bHLH transcription factor that plays a central role in promoting fibroblast proliferation and matrix synthesis during the embryonic development of tendons. Mice with a targeted inactivation of scleraxis (Scx?/?) fail to properly form limb tendons, but the role that scleraxis has in regulating the growth and adaptation of tendons of adult organisms is unknown. To determine if scleraxis expression changes in response to a physiological growth stimulus to tendons, we subjected adult mice that express GFP under the control of the scleraxis promoter (ScxGFP) to a six week treadmill training program designed to induce adaptive growth in Achilles tendons. Age matched sedentary ScxGFP mice were used as controls. Scleraxis expression was sparsely observed in the epitenon region of sedentary mice, but in response to treadmill training, scleraxis was robustly expressed in fibroblasts that appeared to be emerging from the epitenon and migrating into the superficial regions of tendon fascicles. Treadmill training also led to an increase in scleraxis, tenomodulin, and type I collagen gene expression as measured by qPCR. These results suggest that in addition to regulating the embryonic formation of limb tendons, scleraxis also appears to play an important role in the adaptation of adult tendons to physiological loading. PMID:21913219

  1. MAC-EYE: a Tendon Driven Fully Embedded Robot Eye

    E-print Network

    Cannata, Giorgio

    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

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

    PubMed

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

    2013-07-01

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

  3. Achilles tendon biomechanics in response to acute intense exercise.

    PubMed

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

    2014-05-01

    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

  4. Management of flexor tendon sheath ganglions: A cost analysis

    Microsoft Academic Search

    James G. Bittner IV; Richard Kang; Peter J. Stern

    2002-01-01

    The purpose of this study was to determine success rates of 1 or more aspirations on flexor tendon sheath ganglions compared with surgical excision and to determine what treatment method is most cost-effective. Data were collected from documented history and physical examinations, operative reports, billing records, and telephone interviews. Of the 259 patients coded as having flexor tendon sheath ganglions,

  5. A study on the vascular supply of the supraspinatus tendon

    Microsoft Academic Search

    S-C Ling; C-F Chen; R-X Wan

    1990-01-01

    Summary The vascular supply of the rotator cuff in 22 adult shoulders was studied by way of mixture infusion of gelatin and India ink and vascular cast, in combination with Scanning Electronic Microscopy of the vascular pattern in the supraspinatus tendon. It was found that the vessels of the supraspinatus tendon mainly derive from the anterior circumflex humeral and suprascapular

  6. Finite element modeling of concrete beams prestressed with external tendons

    Microsoft Academic Search

    Tie-jiong Lou; Yi-qiang Xiang

    2006-01-01

    In this study, a numerical model based on the finite element method incorporating an arc-length solution algorithm for materially and geometrically nonlinear analysis of concrete beams prestressed with external tendons is established. The second-order effects are taken into account. The effects of external tendons are expressed by equivalent nodal loads of the beam element and therefore analysis of externally prestressed

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

    PubMed Central

    Mori, Daisuke; Funakoshi, Noboru; Yamashita, Fumiharu

    2014-01-01

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

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

    PubMed

    De Cupis, Vincenzo; De Cupis, Mauro

    2012-04-01

    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

  9. [Rotator cuff tear of the hip].

    PubMed

    Jeanneret, Luc; Kurmann, Patric T; van Linthoudt, Daniel

    2008-05-14

    We report the observations of two women with a recurrent periarthritis of the hip complicated by a spontaneous rupture of the tendons of the gluteus medius and minimus. These patients usually complain from an acute lateral hip pain and show a Trendelenburg gait. When the rupture is complete, clinical evaluation reveals a drop of the pelvis on the non-stance side and resisted rotation starting from the extreme external rotation position is weak. MRI plays a key role in the diagnosis and the evaluation of a possible surgical repair. Hip rotator-cuff rupture is probably insufficiently diagnosed by ignorance. Nonetheless, optimized handling could relieve the pain of most these patients and improve the disability of some of them. PMID:18561829

  10. Histological and molecular analysis of the biceps tendon long head post-tenotomy.

    PubMed

    Joseph, Michael; Maresh, Carl M; McCarthy, Mary Beth; Kraemer, William J; Ledgard, Felicia; Arciero, Cristina L; Anderson, Jeffrey M; Nindl, Bradley C; Mazzocca, Augustus D

    2009-10-01

    Tendinopathy is a vexing clinical problem as its onset and development is often asymptomatic and unrecognized until tendon rupture. While extensively studied in the rotator cuff, Achilles, and patellar tendons, no study to date has examined the histological and molecular characteristics of the tendinopathic biceps long-head (LHB). The anatomy of the LHB is unique in that it comprises intra- and extra-articular portions, each exposed to differing loading patterns. Eleven LHBs post-tenotomy were sectioned, fixed in formalin, and stained (H and E; Alcian Blue), and gross structural organization of collagen measured using polarized light microscopy. Protein expression of intra- and extra-articular portions of the tenotomized biceps for IGF-I, collagen III, and MMP-1, -2, -3, and -13 was determined with Western blot analyses. The intra-articular LHB exhibited significantly greater histological evidence of tendinopathy inclusive of increased proteoglycan (p < 0.05) and decreased organization as measured by polarized light microscopy (p < 0.01). The intra-articular LHB also had significantly increased expression of collagen type III (p < 0.01) and of MMP-1 and 3 (p < 0.01, p < 0.05 respectively). No significant differences were found for IGF-I or for MMP-2 and -13. The intra-articular LHB exhibited histological characteristics of tendinopathy. Protein expression of the intra-articular LHB did not universally display signs of tendinopathy in comparison to the extra-articular portion of the tendon. PMID:19340876

  11. Continuum model of tendon pathology – where are we now?

    PubMed Central

    McCreesh, Karen; Lewis, Jeremy

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  13. Torque Control of Underactuated Tendon-driven Robotic Fingers

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E. (Inventor); Ihrke, Chris A. (Inventor); Reiland, Matthew J. (Inventor); Wampler, Charles W. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Bridgwater, Lyndon (Inventor)

    2013-01-01

    A robotic system includes a robot having a total number of degrees of freedom (DOF) equal to at least n, an underactuated tendon-driven finger driven by n tendons and n DOF, the finger having at least two joints, being characterized by an asymmetrical joint radius in one embodiment. A controller is in communication with the robot, and controls actuation of the tendon-driven finger using force control. Operating the finger with force control on the tendons, rather than position control, eliminates the unconstrained slack-space that would have otherwise existed. The controller may utilize the asymmetrical joint radii to independently command joint torques. A method of controlling the finger includes commanding either independent or parameterized joint torques to the controller to actuate the fingers via force control on the tendons.

  14. Mechanical model of a single tendon finger

    NASA Astrophysics Data System (ADS)

    Rossi, Cesare; Savino, Sergio

    2013-10-01

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

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

    PubMed Central

    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

    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

  16. Is there an association between an absence of palmaris longus tendon and an absence of plantaris tendon?

    Microsoft Academic Search

    A. L. H. Moss

    1988-01-01

    Tendon grafts are frequently required, particularly in reconstructive hand surgery. Palmaris longus has been the commonest donor tendon but its absence is quoted in the literature to be about 13%. Plantaris is then often sought as a substitute, and although there is less documentation about its incidence of absence, it appears to be not present in about 7% of cadavers.

  17. Altered Fate of Tendon-Derived Stem Cells Isolated from a Failed Tendon-Healing Animal Model of Tendinopathy

    PubMed Central

    Rui, Yun Feng; Wong, Yin Mei; Tan, Qi; Chan, Kai Ming

    2013-01-01

    We hypothesized that altered fate of tendon-derived stem cells (TDSCs) might contribute to chondro-ossification and failed healing in the collagenase-induced (CI) tendon injury model. This study aimed to compare the yield, proliferative capacity, immunophenotypes, senescence, and differentiation potential of TDSCs isolated from healthy (HT) and CI tendons. TDSCs were isolated from CI and healthy Sprague-Dawley rat patellar tendons. The yield, proliferative capacity, immunophenotypes, and senescence of TDSCs (CI) and TDSCs (HT) were compared by colony-forming unit assay, BrdU assay, flow cytometry, and ?-galactosidase activity assay, respectively. Their osteogenic and chondrogenic differentiation potentials and mRNA expression of tendon-related markers were compared using standard assays. More TDSCs, which showed a lower proliferative potential and a higher cellular senescence were present in the CI patellar tendons compared to HT tendons. There was a higher alkaline phosphatase activity and mineralization in TDSCs (CI) in both basal and osteogenic media. More chondrocyte-like cells and higher proteoglycan deposition, Sox9 and collagen type II expression were observed in TDSCs (CI) pellets upon chondrogenic induction. There was a higher protein expression of Sox9, but a lower mRNA expression of Col1a1, Scx, and Tnmd in TDSCs (CI) in a basal medium. In conclusion, TDSCs (CI) showed altered fate, a higher cellular senescence, but a lower proliferative capacity compared to TDSCs (HT), which might contribute to pathological chondro-ossification and failed tendon healing in this animal model. PMID:23106341

  18. Tear gas--harassing agent or toxic chemical weapon

    SciTech Connect

    Hu, H.; Fine, J.; Epstein, P.; Kelsey, K.; Reynolds, P.; Walker, B.

    1989-08-04

    Tear gas has gained widespread acceptance as a means of controlling civilian crowds and subduing barricaded criminals. The most widely used forms of tear gas have been o-chlorobenzylidenemalononitrile and omega-chloroacetophenone. Proponents of their use claim that, if used correctly, the noxious effects of exposure are transient and of no long-term consequences. The use of tear gas in recent situations of civil unrest, however, demonstrates that exposure to the weapon is difficult to control and indiscriminate, and the weapon is often not used correctly. Severe traumatic injury from exploding tear gas bombs as well as lethal toxic injury have been documented. Moreover, available toxicological data are deficient as to the potential of tear gas agents to cause long-term pulmonary, carcinogenic, and reproductive effects. Published and recent unpublished in vitro tests have shown o-chlorobenzylidenemalononitrile to be both clastogenic and mutagenic. Sadly, the nature of its use renders analytic epidemiologic investigation of exposed persons difficult. In 1969, eighty countries voted to include tear gas agents among chemical weapons banned under the Geneva Protocol. There is an ongoing need for investigation into the full toxicological potential of tear gas chemicals and renewed debate on whether their use can be condoned under any circumstances. 48 references.

  19. Observation of Spontaneous Neoclassical Tearing Modes

    SciTech Connect

    E.D. Fredrickson

    2001-10-03

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

  20. Immunoglobulin Concentration in Tears of Contact Lens Wearers

    PubMed Central

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

    2014-01-01

    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. PMID:25667732

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

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

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

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

    PubMed Central

    Lee, Yuk Wa; Wong, Yin Mei

    2014-01-01

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

  3. Changes in aberrations and retinal image quality due to tear film dynamics

    E-print Network

    Yoon, Geunyoung

    the dynamics of the human tear film. ©2006 Optical Society of America OCIS codes: (330.5370) PhysiologicalChanges in aberrations and retinal image quality due to tear film dynamics Kaccie Y. Li changes due to the tear film is essential in improving clinical assessment of the tear film and in vivo

  4. SIMULATION OF POROSITY AND HOT TEARS IN A SQUEEZE CAST MAGNESIUM CONTROL ARM

    E-print Network

    Beckermann, Christoph

    SIMULATION OF POROSITY AND HOT TEARS IN A SQUEEZE CAST MAGNESIUM CONTROL ARM K.D. Carlson1 , C: Magnesium Alloys, Casting, Shrinkage Porosity, Hot Tears, Modeling Abstract Simulations are performed and hot tears in squeeze casting of magnesium alloys. Introduction Both shrinkage porosity and hot tears

  5. Latissimus dorsi tendon transfer: A comparative analysis of primary and salvage reconstruction of massive, irreparable rotator cuff tears

    Microsoft Academic Search

    Jon J. P. Warner; I. M. Parsons

    2001-01-01

    On the basis of a modified Constant scoring system, we compared outcomes for 16 patients who underwent latissimus dorsi transfer as a salvage reconstruction for a failed prior rotator cuff repair with outcomes for 6 patients who underwent a primary reconstruction for an irreparable cuff defect. There was a statistically significant difference in Constant score between groups, which measured 55%

  6. Non-linear evolution of double tearing modes in tokamaks

    SciTech Connect

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

    1999-12-17

    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.

  7. Biomechanical properties of Achilles tendon repair augmented with a bioadhesive-coated scaffold

    Microsoft Academic Search

    Michael Brodie; Laura Vollenweider; John L. Murphy; Fangmin Xu; Arinne Lyman; William D. Lew; Bruce P. Lee

    2011-01-01

    The Achilles tendon is the most frequently ruptured tendon. Both acute and chronic (neglected) tendon ruptures can dramatically affect a patient's quality of life, and require a prolonged period of recovery before return to pre-injury activity levels. This paper describes the use of an adhesive-coated biologic scaffold to augment primary suture repair of transected Achilles tendons. The adhesive portion consisted

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

    PubMed Central

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

    2014-01-01

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

  9. Morphological studies of bone and tendon.

    PubMed

    Doty, S B; Morey-Holton, E R; Durnova, G N; Kaplansky, A S

    1992-08-01

    The Soviet biosatellite COSMOS 2044 carried adult rats on a spaceflight that lasted 13.8 days and was intended to repeat animal studies carried out on COSMOS 1887. Skeletal tissue and tendon from animals flown on COSMOS 2044 were studied by light and electron microscopy, histochemistry, and morphometric techniques. Studies were confined to the bone cells and vasculature from the weight-bearing tibias. Results indicated that vascular changes at the periosteal and subperiosteal region of the tibia were not apparent by light microscopy or histochemistry. However, electron microscopy indicated that vascular inclusions were present in bone samples from the flight animals. A unique combination of microscopy and histochemical techniques indicated that the endosteal osteoblasts from this same mid-diaphyseal region demonstrated a slight (but not statistically significant) reduction in bone cell activity. Electron-microscopic studies of the tendons from metatarsal bones showed a collagen fibril disorganization as a result of spaceflight. Thus changes described for COSMOS 1887 were present in COSMOS 2044, but the changes ascribed to spaceflight were not as evident. PMID:1526935

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

    PubMed

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

    2015-01-01

    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

  11. Surgical considerations for the neglected or chronic Achilles tendon rupture: a combined technique for reconstruction.

    PubMed

    Peterson, Kyle S; Hentges, Matthew J; Catanzariti, Alan R; Mendicino, Michael R; Mendicino, Robert W

    2014-01-01

    The Achilles tendon is among the most commonly injured tendons in the human body. The most common reason for delayed treatment is a missed diagnosis or a deficiency in presentation. The neglected or chronically ruptured Achilles tendon presents a unique treatment challenge. The surgical approach varies greatly depending on the extent of degeneration and the resultant gap between the opposing tendon ends. Most surgeons have recommended the use of a tendon transfer or augmentation to strengthen the Achilles tendon repair. The following technique uses a flexor hallucis longus tendon transfer with gastrocnemius aponeurosis turndown flap augmentation. This technique has been commonly performed by us with success. PMID:24269103

  12. Current Concepts in Examination and Treatment of Elbow Tendon Injury

    PubMed Central

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

    2013-01-01

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

  13. Successful management of bilateral patellar tendon rupture in a dog.

    PubMed

    Shipov, A; Shahar, R; Joseph, R; Milgram, J

    2008-01-01

    A seven-year-old, 41 kg, intact, cross breed dog, was presented with a history of bilateral hind limb lameness after falling from a height of 1 m. Clinical and radiographic findings were consistent with bilateral patellar tendon rupture. Surgical repair was performed bilaterally. The tendons were sutured primarily, and an internal splint of nylon leader was added. Good apposition of the severed tendon ends had been achieved intraoperatively; however, post operative radiographs showed supra-trochlear displacement of both patellae. The casts used to immobilize the stifle joints slipped distally and three days post operatively the tendon repair had broken down, bilaterally. Revision surgery was undertaken and the tendons were re-sutured. Nylon leader was placed through holes that had been drilled in the patellae and tibiae. The stifle joints were immobilized with type I external skeletal fixators (ESFs). Both freeform polymethylmethacrylate (PMMA) connecting bars were found to be broken at the level of the stifle joints two days later, without any disruption of the primary tendon repair. Each connecting bar was replaced with two connecting bars of PMMA reinforced with 3 mm steel wire. The dog was fully weight-bearing with a reduced range of motion in flexion immediately after removal of the ESFs at six weeks and was still sound 18 months post-operatively. Primary tendon repair in combination with adequate immobilization allowed for an excellent outcome in a complicated bilateral pathology. PMID:18545725

  14. Conflicts, snapping and instability of the tendons. Pictorial essay

    PubMed Central

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

    2012-01-01

    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

  15. Tenocyte contraction induces crimp formation in tendon-like tissue.

    PubMed

    Herchenhan, Andreas; Kalson, Nicholas S; Holmes, David F; Hill, Patrick; Kadler, Karl E; Margetts, Lee

    2012-03-01

    Tendons are composed of longitudinally aligned collagen fibrils arranged in bundles with an undulating pattern, called crimp. The crimp structure is established during embryonic development and plays a vital role in the mechanical behaviour of tendon, acting as a shock-absorber during loading. However, the mechanism of crimp formation is unknown, partly because of the difficulties of studying tendon development in vivo. Here, we used a 3D cell culture system in which embryonic tendon fibroblasts synthesise a tendon-like construct comprised of collagen fibrils arranged in parallel bundles. Investigations using polarised light microscopy, scanning electron microscopy and fluorescence microscopy showed that tendon constructs contained a regular pattern of wavy collagen fibrils. Tensile testing indicated that this superstructure was a form of embryonic crimp producing a characteristic toe region in the stress-strain curves. Furthermore, contraction of tendon fibroblasts was the critical factor in the buckling of collagen fibrils during the formation of the crimp structure. Using these biological data, a finite element model was built that mimics the contraction of the tendon fibroblasts and monitors the response of the Extracellular matrix. The results show that the contraction of the fibroblasts is a sufficient mechanical impulse to build a planar wavy pattern. Furthermore, the value of crimp wavelength was determined by the mechanical properties of the collagen fibrils and inter-fibrillar matrix. Increasing fibril stiffness combined with constant matrix stiffness led to an increase in crimp wavelength. The data suggest a novel mechanism of crimp formation, and the finite element model indicates the minimum requirements to generate a crimp structure in embryonic tendon. PMID:21735243

  16. Spatial variations in Achilles tendon shear wave speed.

    PubMed

    DeWall, Ryan J; Slane, Laura C; Lee, Kenneth S; Thelen, Darryl G

    2014-08-22

    Supersonic shear imaging (SSI) is an ultrasound imaging modality that can provide insight into tissue mechanics by measuring shear wave propagation speed, a property that depends on tissue elasticity. SSI has previously been used to characterize the increase in Achilles tendon shear wave speed that occurs with loading, an effect attributable to the strain-stiffening behavior of the tissue. However, little is known about how shear wave speed varies spatially, which is important, given the anatomical variation that occurs between the calcaneus insertion and the gastrocnemius musculotendon junction. The purpose of this study was to investigate spatial variations in shear wave speed along medial and lateral paths of the Achilles tendon for three different ankle postures: resting ankle angle (R, i.e. neutral), plantarflexed (P; R - 15°), and dorsiflexed (D; R+15°). We observed significant spatial and posture variations in tendon shear wave speed in ten healthy young adults. Shear wave speeds in the Achilles free tendon averaged 12 ± 1.2m/s in a resting position, but decreased to 7.2 ± 1.8m/s with passive plantarflexion. Distal tendon shear wave speeds often reached the maximum tracking limit (16.3m/s) of the system when the ankle was in the passively dorsiflexed posture (+15° from R). At a fixed posture, shear wave speeds decreased significantly from the free tendon to the gastrocnemius musculotendon junction, with slightly higher speeds measured on the medial side than on the lateral side. Shear wave speeds were only weakly correlated with the thickness and depth of the tendon, suggesting that the distal-to-proximal variations may reflect greater compliance in the aponeurosis relative to the free tendon. The results highlight the importance of considering both limb posture and transducer positioning when using SSI for biomechanical and clinical assessments of the Achilles tendon. PMID:24933528

  17. Tearing Graphene Sheets From Adhesive Substrates Produces Tapered Nanoribbons

    E-print Network

    Entekhabi, Dara

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

  18. Giant retinal tears. Surgical techniques and results using perfluorocarbon liquids.

    PubMed

    Chang, S; Lincoff, H; Zimmerman, N J; Fuchs, W

    1989-05-01

    Three low-viscosity perfluorocarbon liquids provided an intraoperative tool during vitrectomy to manage giant retinal tears. These clear fluids have a high specific gravity (1.8 to 1.9) and are immiscible with water. In six eyes, the giant tear was less than 180 degrees; in 11 eyes, it was 180 degrees or greater. In all eyes, the tear was unfolded and the retina was flattened while the patient was supine. The perfluorocarbon liquid was aspirated and replaced by air-perfluorocarbon gas mixtures (16 eyes) or silicone oil (one eye) at the end of the operation. The retina was reattached in 16 eyes (94%), with a minimum follow-up period of 6 months. In five eyes (29%), the retina was reattached without scleral buckling. Residual droplets of perfluorocarbon liquid were observed in four patients. These new materials complement present surgical techniques for managing giant retinal tears. PMID:2719587

  19. Treatment Options for Rotator Cuff Tears: A Guide for Adults

    MedlinePLUS

    ... or health care provider about what kind of rehabilitation therapy is best for you. Making a Decision Ask your doctor Given my tear, what benefits and harms for using non-surgical or surgical treatments should I consider? If ...

  20. Looped suture properties: implications for multistranded flexor tendon repair.

    PubMed

    Haddad, R; Peltz, T; Bertollo, N; Walsh, W R; Nicklin, S

    2015-03-01

    Multiple-strand repair techniques are commonly used to repair cut flexor tendons to achieve initial biomechanical strength. Looped sutures achieve multiple strands with fewer passes and less technical complexity. Their biomechanical performance in comparison with an equivalent repair using a single-stranded suture is uncertain. This study examined the mechanical properties of double-stranded loops of 3-0 and 4-0 braided polyester (Ticron) and polypropylene monofilament (Prolene). Double loops were generally less than twice the strength of a single loop. Ticron and Prolene had the same strengths, but Ticron was stiffer. The 4-0 double loops had significantly higher stiffness than 3-0 single loops. Increasing the size of sutures had a larger relative effect on strength than using a double-stranded suture. However, a double-strand loop had a larger effect on increasing stiffness than using a single suture of a larger equivalent size. Looped suture repairs should be compared with standard techniques using a thicker single suture. PMID:25698798

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

    PubMed Central

    Schweitzer, Ronen; Zelzer, Elazar; Volk, Talila

    2010-01-01

    The formation of the musculoskeletal system represents an intricate process of tissue assembly involving heterotypic inductive interactions between tendons, muscles and cartilage. An essential component of all musculoskeletal systems is the anchoring of the force-generating muscles to the solid support of the organism: the skeleton in vertebrates and the exoskeleton in invertebrates. Here, we discuss recent findings that illuminate musculoskeletal assembly in the vertebrate embryo, findings that emphasize the reciprocal interactions between the forming tendons, muscle and cartilage tissues. We also compare these events with those of the corresponding system in the Drosophila embryo, highlighting distinct and common pathways that promote efficient locomotion while preserving the form of the organism. PMID:20699295

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

    PubMed Central

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

    2012-01-01

    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

  3. Bipolar hemiarthroplasty for chronic rotator cuff tear arthropathy

    Microsoft Academic Search

    Ioannis K. Sarris; Nicholas G. Papadimitriou; Dean G. Sotereanos

    2003-01-01

    Massive rotator cuff tears associated with glenohumeral arthritis are currently an unsolvable clinical entity. We review our series of 14 patients with rotator cuff tear arthropathy (RCTA) who underwent a bipolar prosthesis of the shoulder. The average follow up was 27.8 months (range, 24–48 months), and the average age was 71 years (range, 57–84 years). Of these 14 patients, 9

  4. Cytokine changes in tears and relationship to contact lens discomfort

    PubMed Central

    Zhao, Zhenjun; Naduvilath, Thomas; Lazon de la Jara, Percy

    2015-01-01

    Purpose To determine the reproducibility of a multiplex bead assay for measuring cytokines in tears and correlations between ocular discomfort with or without contact lens wear and the concentration of cytokines in tears. Methods Ninety participants (divided into two groups) were enrolled in this prospective study. They were asked to rate their ocular comfort and collect their tears in the morning and just before sleep for 10 days with or without contact lenses. The participants collected their tears using a glass microcapillary tube for both stages. Galyfilcon A lenses were worn on a daily disposable basis during the contact lens stage, and comfort scores and tears were collected before lens insertion and prior to lens removal at the end of the day. Tears were analyzed for cytokine concentrations using a 27-plex multibead assay. Correlations were sought between cytokine concentrations and comfort. Results There was a significant (p<0.022) decrease in ocular comfort over the day with or without lens wear. The magnitude of ocular discomfort was significantly greater (p<0.009) with lens wear. The concentrations of 12 cytokines differed significantly between the groups; thus, these cytokines were not analyzed further. For the remaining 15 cytokines, interleukin-8 (IL-8) was the only cytokine that changed in both groups during the day without (reduced by >-0.5 Log pg/ml, p<0.001) or with lens wear (reduced by >-0.2 Log pg/ml, p<0.001). The change in the vascular endothelial growth factor (VEGF) concentration only in tears was correlated to ocular comfort, but this was not changed by contact lens wear. Conclusions Ocular comfort during the day is magnified by contact lens wear. However, the increase in the change in comfort during lens wear was not associated with changes in 15 cytokines in the tear film. PMID:25814827

  5. Tear osmolarity and dry eye symptoms in diabetics

    PubMed Central

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

    2014-01-01

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

  6. A feasibility study for measuring accurate tendon displacements using an audio-based Fourier analysis of pulsed-wave Doppler ultrasound signals.

    PubMed

    Stegman, K J; Podhorodeski, R P; Park, E J

    2009-01-01

    The accuracy of Pulsed-Wave Doppler Ultrasound displacement measurements of a slow moving "tendon-like" string was investigated in this study. This was accomplished by estimating string displacements using an audio-based Fourier analysis of a Pulsed-Wave Doppler signal from a commercial ultrasound scanner. Our feasibility study showed that the proposed technique is much more accurate at estimating the actual string displacement in comparison to the scanner's onboard software. Furthermore, this study also shows that a real-time Doppler data acquisition from an ultrasound scanner is possible for the ultimate purpose of real-time biological tendon displacement monitoring. PMID:19964755

  7. Tendon to bone healing and its implications for surgery

    PubMed Central

    Bunker, Daniel Lee John; Ilie, Victor; Ilie, Vladimir; Nicklin, Sean

    2014-01-01

    Summary Entheses are complex structures which act to reduce stress concentrations between tendon and skeleton tissues. Understanding the development and function of the enthesis organ has implications for surgical repair, particularly in regards to healing and the regulation of tendon to bone engraftment. In this paper we review the development and function of entheses as well as the enthesis organ concept. Next we examine the process of tendon to bone healing and how this can be regulated, before addressing implications for surgical repair and post-operative care. PMID:25489553

  8. Posterior tibial tendon dysfunction in the adult: current concepts.

    PubMed

    Stein, Benjamin E; Schon, Lew C

    2015-01-01

    The management of posterior tibial tendon dysfunction in adults has evolved substantially, and controversy persists regarding a specific recommended algorithm for treatment. The current focus is on early diagnosis and treatment of this disorder with joint-sparing surgeries, such as corrective osteotomies and tendon transfers, when nonsurgical modalities have been exhausted. It is helpful to be familiar with the pertinent pathophysiology and diagnostic pearls associated with posterior tibial tendon dysfunction, its treatment options, pertinent literature, and technique tips for the procedures currently being used. PMID:25745927

  9. Repair of severe muscle belly lacerations using a tendon graft.

    PubMed

    Botte, M J; Gelberman, R H; Smith, D G; Silver, M A; Gellman, H

    1987-05-01

    Fourteen patients with 58 severe forearm muscle belly lacerations had muscle repair using tendon grafts. At mean follow-up of 14 months, results of manual muscle testing (N = 58) were: grade 5, 42%, grade 4, 14%, grade 3, 9%, grade 2, 9%, grade 1, 12%, and grade 0, 15%. Mean grip strength of the injured extremity, in pounds per square inch, was 33.5 compared with 83.4 on the noninjured side. Tendon excursion and joint mobility were maintained, and there were no postoperative complications. Tendon grafting of severe muscle lacerations is an effective method to overcome extensive defects. PMID:3295003

  10. Tendon transfers in the treatment of the adult flatfoot.

    PubMed

    Backus, Jonathon D; McCormick, Jeremy J

    2014-03-01

    Tendon transfers are critical to successful surgical correction of adult flexible flatfoot deformity and may be beneficial in correcting rigid deformities as well. Patients with refractory stage I and II deformities often require selective osteotomies in addition to tendon transfer. Patients with stage III and IV deformities typically require hindfoot arthrodesis. One of several tendons can be used for transfer based on surgeon's preference. Flexor digitorum longus (FDL) and flexor hallucis longus (FHL) transfers have been shown to have good results. A peroneus brevis transfer is typically used to supplement small FDL or FHL transfer donors or in revision cases. PMID:24548507

  11. Stapedius tendon reconstruction during stapedotomy: technique and results.

    PubMed

    Causse, J B; Vincent, R; Michat, M; Gherini, S

    1997-04-01

    During surgery for otosclerosis, it is common for the surgeon to cut the stapedius tendon. Even without reconstruction of the tendon, the results of this kind of surgery are particularly satisfactory. The stapedial reflex is more important for improving intelligibility of speech in the presence of background noise than for protection against hazardous levels of noise. An intact stapedial reflex improves ones ability to follow speech in the presence of background noise. This report will present a technique to reconstruct the stapedius tendon, along with the results obtained when adding this procedure to stapedotomy surgery. PMID:9127525

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

    PubMed

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

    2005-08-01

    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

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

    PubMed Central

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

    2014-01-01

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

  14. Effect of paratenon and repetitive motion on the gliding resistance of tendon of extrasynovial origin.

    PubMed

    Momose, Toshimitsu; Amadio, Peter C; Zobitz, Mark E; Zhao, Chunfeng; An, Kai-Nan

    2002-05-01

    We measured the gliding resistance of canine and human tendons of intrasynovial origin and tendons of extrasynovial origin with and without paratenon, and investigated the structure of paratenon using scanning electron microscopy. In the canine study, seven intrasynovial flexor digitorum profundus (FDP) tendons, seven extrasynovial fibularis (peroneus) longus (FL) tendons with paratenon, and seven FL tendons without paratenon were used. In the human study, seven intrasynovial FDP tendons and seven extrasynovial palmaris longus (PL) tendons cut in half (one half with paratenon, the other half without paratenon) were used. The gliding resistance of each tendon was measured at 1, 5, 10, 20, 50, and100 flexion/extension cycles. The canine and human FDP tendons maintained a gliding resistance significantly lower than that of the other tendons at all observation points (P < 0.05). In the canine, the gliding resistance of the FL tendon with paratenon was significantly lower than that of the FL tendon without paratenon up to 50 flexion/extension cycles (P < 0.05), but the two were not significantly different at 100 cycles. In the human, the gliding resistance of PL tendons with paratenon was significantly lower than that of the PL tendons without paratenon at all measuring points (P < 0.05). Preservation of paratenon thus appears to decrease the gliding resistance of extrasynovial tendons after repetitive motion in vitro. PMID:11948955

  15. Hi h R l ti O l S fHigh Resolution Ocular Surface OCT to Directly Measure TearOCT to Directly Measure Tear

    E-print Network

    Yoon, Geunyoung

    90 110 130 150 170 Time (s) #12;Tear film imaging on cadaver porcine eye i h l f OCTwith ocularHi h R l ti O l S fHigh Resolution Ocular Surface OCT to Directly Measure TearOCT to Directly Measure Tear Film Thickness in Human Eyes

  16. Cushing, acromegaly, GH deficiency and tendons

    PubMed Central

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

    2014-01-01

    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

  17. Prestressed concrete using KEVLAR reinforced tendons

    SciTech Connect

    Dolan, C.W.

    1989-01-01

    KEVLAR is a high strength, high modulus synthetic fiber manufactured by the E.I. DuPont de Nemours Company. The fiber is resistant to chloride and alkali attack. The resistance is enhanced when the fibers are assembled into a resin matrix and fabricated as rods. These properties suggest that KEVLAR reinforced rods may be a substitute for high strength steel prestress tendons in certain applications such as bridge decks and parking structures. This dissertation presents the background, theoretical development, and experimental investigations of KEVLAR reinforced rod strength, anchorage, fabrication and performance in prestressed concrete structures. The study concludes that KEVLAR has significant potential for these prestressed concrete applications. However, the reliability of the long term anchorage of the KEVLAR reinforced rods must be improved before production applications are undertaken. KEVLAR has a low shear strength compared to its tensile capacity. The anchorage of KEVLAR reinforced rods is sensitive to the shear forces generated in the anchorage assembly. Finite element analyses, using interface elements to simulate the addition of a mold release agent in a conic anchor, predict the behavior of resin socketed anchors. Test results confirm that mold release agents reduce the anchor shear stresses and suggest that moderate strength resins may be used in the anchor. KEVLAR is nearly linearly elastic to failure, yet ductility of a structure is an important design concern. Prestressed concrete beam tests using both bonded and unbonded tendons demonstrated that ductile structural behavior is obtained. Methods of predicting the strength and deflection behavior of the prestressed beams are presented and the theoretical predictions are compared to the experimental results. The overall correlation between predicted and theoretical results is satisfactory.

  18. Localized pulsed magnetic fields for tendonitis therapy.

    PubMed

    Owegi, Robert; Johnson, Mary T

    2006-01-01

    Energy medicine has existed for centuries in some parts of the world, but in recent years, western health care practitioners have taken a heightened interest in these therapies. Treatment by use of pulsed magnetic fields (PMF) is currently being explored in both chronic and inflammatory diseases such as cancer, epilepsy, psoriasis, rheumatoid arthritis, and tendinitis. In the U.S., PMFs have already been approved for use in treatment of bone fractures in humans and clinical trials have been conducted for lower back pain. This study presents a summary of the therapeutic potential of a localized PMF treatment for tendinitis using the Softpulse III system. This system has been used to accelerate wound healing and soft tissue swelling. It generates a specific PMF that induces an electrical field within the tendon. This induced electrical field is thought to influence the healing process by affecting the inflammatory cells that line the tendon sheath. In this study, we have used an established model of tendinitis along with a validated method for appraising edema and gait (Achilles' Functional Index), to test the hypothesis that the proposed PMF signal is effective in reducing the indicators of acute tendinitis injury. These experiments were approved by the Institutional Animal Care and Use Committee. Our findings suggest a role for the treatment of soft tissue injury using the Softpulse III therapeutic device. The symbolic stand point of PMF treatments is to push the need for a revolutionary leap, from the more dominant pharmaceutical and surgical interventions, to the advanced applications of non-invasive therapies that would minimize the medicinal risk of side effects, and eliminate the risk of complicated drug interactions. PMID:16817646

  19. STRESS CORROSION CRACKING IN TEAR DROP SPECIMENS

    SciTech Connect

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

    2009-05-01

    Laboratory tests were conducted to investigate the stress corrosion cracking (SCC) of 304L stainless steel used to construct the containment vessels for the storage of plutonium-bearing materials. The tear drop corrosion specimens each with an autogenous weld in the center were placed in contact with moist plutonium oxide and chloride salt mixtures. Cracking was found in two of the specimens in the heat affected zone (HAZ) at the apex area. Finite element analysis was performed to simulate the specimen fabrication for determining the internal stress which caused SCC to occur. It was found that the tensile stress at the crack initiation site was about 30% lower than the highest stress which had been shifted to the shoulders of the specimen due to the specimen fabrication process. This finding appears to indicate that the SCC initiation took place in favor of the possibly weaker weld/base metal interface at a sufficiently high level of background stress. The base material, even subject to a higher tensile stress, was not cracked. The relieving of tensile stress due to SCC initiation and growth in the HAZ and the weld might have foreclosed the potential for cracking at the specimen shoulders where higher stress was found.

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

    PubMed Central

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

    2014-01-01

    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

  1. Exploring the role of hypercholesterolemia in tendon health and repair

    PubMed Central

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

    2014-01-01

    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

  2. Isolation and growth characteristics of adult human tendon fibroblasts.

    PubMed Central

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

    1987-01-01

    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

  3. Cellular therapy in bone-tendon interface regeneration

    PubMed Central

    Rothrauff, Benjamin B; Tuan, Rocky S

    2014-01-01

    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

  4. Traumatic extensor tendon dislocation in a boxer: a case study.

    PubMed

    Bents, Robert Thurston; Metz, John Patrick; Topper, Steven Mark

    2003-10-01

    An elite collegiate boxer developed extensor tendon subluxation in the small finger of his dominant right hand. He was thought to have a radial sagittal band disruption and was allowed to complete his season with custom padding. Surgical exploration revealed intact sagittal bands with divergent dislocation of the two extensor tendons to the small finger with underlying capsular rupture. These lesions were repaired and he successfully returned to boxing. Soft tissue injuries to the dorsal MCP joint may involve the collateral ligaments, the sagittal bands, the extensor tendons, or the joint capsule. Symptoms usually involve persistent pain, swelling, and tendon subluxation or dislocation. Accurate recognition and treatment is crucial as nonoperative treatment is generally unsuccessful and surgical reconstruction is required for optimal return to function. PMID:14523299

  5. [Neglected ipsilateral simultaneous ruptures of patellar and quadriceps tendon].

    PubMed

    Karahasano?lu, ?lker; Yolo?lu, Osman; Kerimo?lu, Servet; Turhan, Ahmet U?ur

    2015-04-01

    Neglected patellar and quadriceps tendon rupture is a rare injury, but ipsilateral simultaneous patellar and quadriceps tendon rupture was not described in the literature to our knowledge. In this article, we report a 40-year-old healthy male patient with neglected ipsilateral patellar and quadriceps tendon ruptures treated by peroneus longus tendon autograft. Patient had received some conservative and surgical treatments for patellar fracture before applying to our clinic. After our treatment using peroneus longus autograft and interference nails, patient was immobilized for six weeks in cylindrical cast. Flexion exercises and full weight bearing were started after cast removal. Patient had no complaint at postoperative second year. Patient was a neglected case. Surgical repair and early rehabilitation enabled us to achieve a satisfactory outcome. PMID:25741921

  6. A model of muscle-tendon function in human walking

    E-print Network

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

    2012-01-01

    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 ...

  7. Tendon-driven manipulators: Analysis, synthesis, and control

    NASA Astrophysics Data System (ADS)

    Lee, Jyh-Jone

    As the development of light-weight, small volume, and versatile manipulators has grown in the field of robotics, the need for more efficient and relevant power transmission systems in the manipulators has become increasingly apparent. It is clear that the advent of efficient, low friction, and backlash-free actuation systems promises to provide significant gains in manipulator performance. Tendon transmission has been widely used to actuate small volume and light-weight articulated manipulators, such as dextrous mechanical hands, for it permits actuators to be installed remotely from the end-effector, thus reducing the bulk and inertia of the manipulator system. Current research on such actuation systems is accomplished on the basis of specialized designs. The lack of systematic approaches has limited our scope in realizing performance of such transmission systems. Therefore, when associated with systematic methodologies, the study of tendon-driven manipulators promises to be of major importance in the field of robotics. This dissertation is concerned with four issues to enhance our use and understanding of tendon-driven manipulators. First, a systematic approach for the kinematics analysis of tendon-driven manipulators is established. A graph is used to represent the kinematic structure of tendon-driven manipulators. It is shown that the kinematic structure of tendon-driven manipulators is in every way similar to that of epicyclic gear trains. The fundamental circuit equation developed for the kinematic analysis of epicyclic gear trains can thus be applied to this type of mechanism. The displacement equation governing joint angle space and tendon space can easily be obtained. Secondly, the concept of structural isomorphism and the structural characteristics of tendon-driven manipulators are investigated. Based on the explored properties, a methodology for the enumeration of tendon-driven manipulators is developed. By applying the methodology, a class of kinematic structures having pseudo-triangular structure matrix is enumerated. Thirdly, a method for assessing the kinematic/static performance of tendon-driven manipulators is developed. Transmission ellipsoids of the manipulators are investigated. A criterion for differentiating force transmission characteristics and a procedure for identifying least maximum-tendon-force are established.

  8. The flexor tendon pulley system and rock climbing.

    PubMed

    Crowley, Timothy P

    2012-06-01

    Rock climbing has increased in popularity over the past two decades. Closed traumatic rupture of the finger flexor tendon pulleys is rare among the general population but is seen much more commonly in rock climbers. This article reviews the anatomy and biomechanics of the finger flexor tendon pulleys, how they may be injured in rock climbing and how these injuries are best diagnosed and managed. PMID:23730085

  9. Patellar Tendon Ruptures in National Football League Players

    Microsoft Academic Search

    Martin Boublik; Theodore Schlegel; Ryan Koonce; James Genuario; Charles Lind; David Hamming

    2011-01-01

    Background: Although knee injuries are common among professional football players, ruptures of the patellar tendon are relatively rare. Predisposing factors, mechanisms of injury, treatment guidelines, and recovery expectations are not well established in high-level athletes.Hypothesis: Professional football players with isolated rupture of the patellar tendon treated with timely surgical repair will return to their sport.Study Design: Case series; Level of

  10. Temporal response of canine flexor tendon to limb suspension

    PubMed Central

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

    2010-01-01

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

  11. Direct Repair without Augmentation of Patellar Tendon Avulsion following TKA

    PubMed Central

    Kumar, Nishikant; Yadav, Chandrashekhar; Kumar, Ashok

    2015-01-01

    Complications involving the extensor mechanism after TKA are potentially disastrous. We are reporting a case of patellar tendon rupture from tibial tuberosity following total knee arthroplasty. We managed it by direct repair with fiberwire using Krackow suture technique without augmentation. Our long term result has been very encouraging. Our method is a safe and better method of management of patellar tendon avulsion following TKA when it happens without any tissue loss. PMID:25632362

  12. Surface modification counteracts adverse effects associated with immobilization after flexor tendon repair.

    PubMed

    Zhao, Chunfeng; Sun, Yu-Long; Jay, Gregory D; Moran, Steven L; An, Kai-Nan; Amadio, Peter C

    2012-12-01

    Although post-rehabilitation is routinely performed following flexor tendon repair, in some clinical scenarios post-rehabilitation must be delayed. We investigated modification of the tendon surface using carbodiimide derivatized hyaluronic acid and lubricin (cd-HA-Lub) to maintain gliding function following flexor tendon repair with postoperative immobilization in a in vivo canine model. Flexor digitorum profundus tendons from the 2nd and 5th digits of one forepaw of six dogs were transected and repaired. One tendon in each paw was treated with cd-HA-Lub; the other repaired tendon was not treated. Following tendon repair, a forearm cast was applied to fully immobilize the operated forelimb for 10 days, after which the animals were euthanized. Digit normalized work of flexion (nWOF) and tendon gliding resistance were assessed. The nWOF of the FDP tendons treated with cd-HA-Lub was significantly lower than the nWOF of the untreated tendons (p < 0.01). The gliding resistance of cd-HA-Lub treated tendons was also significantly lower than that of the untreated tendons (p < 0.05). Surface treatment with cd-HA-Lub following flexor tendon repair provides an opportunity to improve outcomes for patients in whom the post-operative therapy must be delayed after flexor tendon repair. PMID:22714687

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

    PubMed

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

    2014-10-01

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

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

    PubMed Central

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

    2013-01-01

    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

  15. Distal biceps brachii tendon rupture resulting in acute compartment syndrome.

    PubMed

    Grandizio, Louis C; Suk, Michael; Feltham, Glen T

    2013-11-01

    Distal biceps brachii tendon rupture is an uncommon injury. Compartment syndrome of the upper arm is rarely described in the literature. The diagnosis of upper arm compartment syndrome requires a high index of suspicion, and emergent surgical treatment with fasciotomy in the acute setting is necessary to avoid devastating neurovascular complications. This article reports a case of acute compartment syndrome of the anterior compartment of the upper arm after a complete rupture of the distal biceps brachii tendon. A healthy 45-year-old man presented with increasing arm pain; paresthesia in the lateral antebrachial cutaneous nerve distribution; and a tense, swollen anterior compartment of his upper arm. Side port catheter absolute pressure measurement was 83 mm Hg with a diastolic blood pressure of 92 mm Hg. The patient underwent an emergent fasciotomy and was found to have a complete rupture of his distal biceps brachii tendon. He subsequently underwent distal biceps tendon repair and delayed primary closure of his incision. Postoperatively, his paresthesia improved and he has no neurological deficit. There is a paucity of case reports describing compartment syndrome after rupture of either the proximal or distal end of the biceps brachii tendon, and none of the reports describe compartment syndrome of the upper arm after rupture of the distal biceps tendon. This article highlights an unusual complication of an uncommon injury and reviews diagnostic and treatment principles for the management of acute compartment syndrome of the upper arm. PMID:24200459

  16. Catabolism of aggrecan, decorin and biglycan in tendon.

    PubMed Central

    Rees, S G; Flannery, C R; Little, C B; Hughes, C E; Caterson, B; Dent, C M

    2000-01-01

    We have examined the catabolism of the proteoglycans aggrecan, decorin and biglycan in fresh tendon samples and in explant cultures of tissue from the tensional and compressed regions of young and mature bovine tendons. A panel of well-characterized antibodies that recognize glycosaminoglycan or protein (linear or neoepitope) sequences was used to detect proteoglycans and proteoglycan degradation products that were both retained within the tissue and released into the culture medium. In addition, a reverse-transcriptase-mediated PCR analysis was used to examine the mRNA expression patterns of tendon proteoglycans and aggrecanases. The results of this study indicate a major role for aggrecanase(s) in the catabolism of aggrecan in bovine tendon. The study also provides a characterization of glycosaminoglycan epitopes associated with the proteoglycans of tendon, illustrating age-related changes in the isomers of chondroitin sulphate disaccharides that remain attached to the core protein glycosaminoglycan linkage region after digestion with chondroitinase ABC. Evidence for a rapid turnover of the small proteoglycans decorin and biglycan was also observed, indicating additional molecular pathways that might compromise the integrity of the collagen matrix and potentially contribute to tendon dysfunction after injury and during disease. PMID:10926842

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

    PubMed

    Boahene, Kofi D O

    2013-02-01

    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

  18. Tearing resistance of some co-polyester sheets

    SciTech Connect

    Kim, Ho Sung; Karger-Kocsis, Jozsef

    2004-06-07

    A three-zone model consisting of initial, evolutionary and stabilised plastic zones for tearing resistance was proposed for polymer sheets. An analysis with the model, based on the essential work of fracture (EWF) approach, was demonstrated to be capable for predicting specific total work of fracture along the tear path across all the plastic zones although accuracy of specific essential work of fracture is subject to improvement. Photo-elastic images were used for identification of plastic deformation sizes and profiles. Fracture mode change during loading was described in relation with the three zones. Tearing fracture behaviour of extruded mono- and bi-layer sheets of different types of amorphous co-polyesters and different thicknesses was investigated. Thick material exhibited higher specific total work of tear fracture than thin mono-layer sheet in the case of amorphous polyethylene terephthalate (PET). This finding was explained in terms of plastic zone size formed along the tear path, i.e., thick material underwent larger plastic deformation than thin material. When PET and polyethylene terephthalate glycol (PETG) were laminated with each other, specific total work of fracture of the bi-layer sheets was not noticeably improved over that of the constituent materials.

  19. Intraocular pressure and tear production in five herbivorous wildlife species.

    PubMed

    Ofri, R; Horowitz, I H; Raz, D; Shvartsman, E; Kass, P H

    2002-08-31

    The intraocular pressure and rate of tear production were measured in 18 addax antelopes (Addax nasomaculatus), four impalas (Aepyceros melampus), 11 wide-lipped rhinoceroses (Ceratotherium simum), 10 white-tailed wildebeests (Connochaetes gnou) and seven scimitar-horned oryxes (Oryx dammah). The animals were anaesthetised with an intramuscular injection of etorphine hydrochloride and acepromazine maleate, and the Schirmer tear test I was used to evaluate tear production, and applanation tonometry was used to evaluate the intraocular pressure. The mean (sd) rate of tear production ranged from 17.6 (3.1) mm/minute in the rhinoceros to 28.8 (8.3) mm/minute in the addax. The intraocular pressure ranged from 8.0 (1.2) mmHg in the impala to 32.1 (10.4) mmHg in the rhinoceros. The rate of tear production in the addax and the intraocular pressure in the rhinoceros appear to be the highest values of these variables to have been reported in any species. PMID:12233828

  20. Tear trough deformity: review of anatomy and treatment options.

    PubMed

    Stutman, Ross L; Codner, Mark A

    2012-05-01

    The lower eyelid can be a challenging area in facial rejuvenation. While lower eyelid bags are commonly the reason that patients present for lower eyelid rejuvenation, a separate entity known as a tear trough deformity may occur in conjunction with lower eyelid bags or alone. In this article, the authors outline the current understanding of the tear trough anatomy; describe multiple classification systems, which provide an objective means of evaluating the deformity and aid the surgeon in choosing appropriate treatment options; and review surgical and nonsurgical techniques for correcting the tear trough deformity. Treatment options include hyaluronic acid filler, fat grafting, skeletal implants, and fat transposition. Each procedure is associated with advantages and disadvantages, and each should be considered more complex than traditional lower blepharoplasty alone. While lower blepharoplasty removes excess fat and may tighten the anterior lamella, tear trough procedures require the addition of volume to the underlying depression. These procedures requiring release of the ligamentous structures and orbicularis (of which the tear trough is composed), as well as fat transposition or fat grafting, are associated with additional complications, which are also reviewed. PMID:22523096

  1. The management of chronic rupture of the Achilles tendon: minimally invasive peroneus brevis tendon transfer.

    PubMed

    Maffulli, N; Oliva, F; Costa, V; Del Buono, A

    2015-03-01

    We hypothesised that a minimally invasive peroneus brevis tendon transfer would be effective for the management of a chronic rupture of the Achilles tendon. In 17 patients (three women, 14 men) who underwent minimally invasive transfer and tenodesis of the peroneus brevis to the calcaneum, at a mean follow-up of 4.6 years (2 to 7) the modified Achilles tendon total rupture score (ATRS) was recorded and the maximum circumference of the calf of the operated and contralateral limbs was measured. The strength of isometric plantar flexion of the gastrocsoleus complex and of eversion of the ankle were measured bilaterally. Functional outcomes were classified according to the four-point Boyden scale. At the latest review, the mean maximum circumference of the calf of the operated limb was not significantly different from the pre-operative mean value, (41.4 cm, 32 to 50 vs 40.6 cm, 33 to 46; p = 0.45), and not significantly less than that of the contralateral limb (43.1 cm, 35 to 52; p = 0.16). The mean peak torque (244.6 N, 125 to 367) and the strength of eversion of the operated ankle (149.1 N, 65 to 240) were significantly lower (p < 0.01) than those of the contralateral limb (mean peak torque 289, 145 to 419; strength of eversion: 175.2, 71 to 280). The mean ATRS significantly improved from 58 pre-operatively (35 to 68) to 91 (75 to 97; 95% confidence interval 85.3 to 93.2) at the time of final review. Of 13 patients who practised sport at the time of injury, ten still undertook recreational activities. This procedure may be safely performed, is minimally invasive, and allows most patients to return to pre-injury sport and daily activities. Cite this article: Bone Joint J 2015;97-B:353-7. PMID:25737519

  2. Unloaded rat Achilles tendons continue to grow, but lose viscoelasticity.

    PubMed

    Eliasson, Pernilla; Fahlgren, Anna; Pasternak, Björn; Aspenberg, Per

    2007-08-01

    Tendons can function as springs and thereby preserve energy during cyclic loading. They might also have damping properties, which, hypothetically, could reduce risk of microinjuries due to fatigue at sites of local stress concentration within the tendon. At mechanical testing, damping will appear as hysteresis. How is damping influenced by training or disuse? Does training decrease hysteresis, thereby making the tendon a better spring, or increase hysteresis and thus improve damping? Seventy-eight female 10-wk-old Sprague-Dawley rats were randomized to three groups. Two groups had botulinum toxin injected into the calf muscles to unload the left Achilles tendon through muscle paralysis. One of these groups was given doxycycline, as a systemic matrix metalloproteinase inhibitor. The third group served as loaded controls. The Achilles tendons were harvested after 1 or 6 wk for biomechanical testing. An increase with time was seen in tendon dry weight, wet weight, water content, transverse area, length, stiffness, force at failure, and energy uptake in all three groups (P < 0.001 for each parameter). Disuse had no effect on these parameters. Creep was decreased with time in all groups. The only significant effect of disuse was on hysteresis (P = 0.004) and creep (P = 0.007), which both decreased with disuse compared with control, and on modulus, which was increased (P = 0.008). Normalized glycosaminoglycan content was unaffected by time and disuse. No effect of doxycycline was observed. The results suggest that in growing animals, the tendons continue to grow regardless of mechanical loading history, whereas maintenance of damping properties requires mechanical stimulation. PMID:17412787

  3. Bone loss following tendon laceration, repair and passive mobilization.

    PubMed

    Ditsios, Konstantinos; Boyer, Martin I; Kusano, Nozomu; Gelberman, Richard H; Silva, Matthew J

    2003-11-01

    Little is known about the localized changes in bone mass that occur following tendon or ligament injury. Interruption of normal load transfer at the insertion site will presumably lead to a localized loss of bone, although few data exist to support this claim. To test this hypothesis, we transected the canine flexor digitorum profundus (FDP) tendon from its insertion, and either repaired it using a trans-osseous suture technique or left it unrepaired (laceration only). Post-operatively, forelimbs in the repair group were cast immobilized except for 10 min of daily passive mobilization rehabilitation, whereas in the laceration only group dogs were allowed full weight bearing. At 5-42 days post-injury, we assessed bone mineral density (BMD) using pQCT and osteoclast surface by histomorphometry. We measured significant bone loss in the distal phalanx after combined FDP tendon laceration, repair, and post-operative passive mobilization, with BMD decreases of 20%, 40%, and 41% at 10, 21, and 42 days (p<0.01). Moreover, we observed that passive mobilization and tendon laceration each contributed independently to the observed bone loss. At 42 days, BMD was reduced by 21% in bones that were not injured but were subjected to the post-operative passive mobilization protocol, while BMD was reduced by 28% in bones subjected to tendon laceration and full weight bearing (p<0.01). In both the passive mobilization and laceration specimens, we counted significantly increased osteoclasts after only 7-10 days, and these increases persisted through 42 days (p<0.05). We conclude that rapid and sustained bone resorption leads to significant bone loss in the 6-week period following flexor tendon injury and repair. This bone loss may impact healing by impeding the restoration of a strong tendon-bone interface. PMID:14554210

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

    NASA Astrophysics Data System (ADS)

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

    2007-09-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    Microsoft Academic Search

    Randolf Riemann; Stefan Pfennigsdorf; Elke Riemann; Markus Naumann

    1999-01-01

    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.

  7. Lateral epicondylalgia: midlife crisis of a tendon.

    PubMed

    Luk, James K H; Tsang, Raymond C C; Leung, H B

    2014-04-01

    The pathogenesis and management of lateral epicondylalgia, or tennis elbow, a common ailment affecting middle-aged subjects of both genders continue to provoke controversy. Currently it is thought to be due to local tendon pathology, pain system changes, and motor system impairment. Its diagnosis is usually clinical, based on a classical history, as well as symptoms and signs. In selected cases, additional imaging (X-rays, ultrasound, and magnetic resonance imaging) can help to confirm the diagnosis. Different treatment modalities have been described, including the use of orthotics, non-steroidal anti-inflammatory drugs, steroid injections, topical glyceryl trinitrate, exercise therapy, manual therapy, ultrasound therapy, laser therapy, extracorporeal shockwave therapy, acupuncture, taping, platelet-rich plasma injections, hyaluronan gel injections, botulinum toxin injections, and surgery. Nevertheless, evidence to select the best treatment is lacking and the choice of therapy depends on the experience of the management team, availability of the equipment and expertise, and patient response. This article provides a snapshot of current medical practice for lateral epicondylalgia management. PMID:24584568

  8. mTOR Regulates Fatty Infiltration through SREBP-1 and PPARg after a Combined Massive Rotator Cuff Tear and Suprascapular Nerve Injury in Rats

    PubMed Central

    Joshi, Sunil K.; Liu, Xuhui; Samagh, Sanjum P.; Lovett, David H.; Bodine, Sue C.; Kim, Hubert T.; Feeley, Brian T.

    2015-01-01

    Rotator cuff tears (RCTs) are among the most common injuries seen in orthopedic patients. Chronic tears can result in the development of muscular atrophy and fatty infiltration. Despite the prevalence of RCTs, little is known about the underlying molecular pathways that produce these changes. Recently, we have shown that mammalian target of rapamycin (mTOR) signaling plays an important role in muscle atrophy that results from massive RCTs in a rat model. The purpose of this study was therefore to extend our understanding of mTOR signaling and evaluate its role in fatty infiltration after a combined tendon transection and suprascapular nerve denervation surgery. Akt/mTOR signaling was significantly increased and resulted in the up-regulation of two transcription factors: SREBP-1 and PPAR?. We also saw an increase in expression of adipogenic markers: C/EBP-? and FASN. Upon treatment with rapamycin, an inhibitor of mTOR, we observed a decrease in mTOR signaling, activity of transcription factors, and reduction in fatty infiltration. Therefore, our study suggests that mTOR signaling mediates rotator cuff fatty infiltration via SREBP-1 and PPAR?. Clinically, our finding may alter current treatment methods to address rotator cuff fatty infiltration. © 2012 Orthopaedic Research Society. PMID:23239524

  9. Decision-making in massive rotator cuff tear.

    PubMed

    Thès, André; Hardy, Philippe; Bak, Klaus

    2015-02-01

    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

  10. Anterior versus posterior, and rim-rent rotator cuff tears: prevalence and MR sensitivity

    Microsoft Academic Search

    M. J. Tuite; John R. Turnbull; John F. Orwin

    1998-01-01

    Purpose. To determine the relative distribution of the locations of rotator cuff tears, and the sensitivity of anterior versus posterior\\u000a tears on MR images. Patients and methods. We identified 110 consecutive patients who had a shoulder MR and either a partial-thickness or a small full-thickness rotator\\u000a cuff tear diagnosed at arthroscopy. From the arthroscopy videotapes, we classified the tears as

  11. Effect of tear film break-up on higher-order aberrations measured with wavefront sensor

    Microsoft Academic Search

    Shizuka Koh; Naoyuki Maeda; Teruhito Kuroda; Yuichi Hori; Hitoshi Watanabe; Takashi Fujikado; Yasuo Tano; Yoko Hirohara; Toshifumi Mihashi

    2002-01-01

    PURPOSE: To investigate whether optical wavefront aberrations vary with tear film break-up.DESIGN: Observational case series.METHODS: Higher-order aberrations were examined for 20 eyes of 20 normal subjects with a Hartmann-Shack wavefront sensor before and after tear film break-up.RESULTS: Higher-order aberrations for photopic vision (central 4 mm diameter) after tear film break-up increased 1.44 fold compared to higher-order aberrations before tear film

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

    E-print Network

    Gill, Harmeet (Harmeet Kaur)

    2007-01-01

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

  13. 77 FR 69508 - Inservice Inspection of Prestressed Concrete Containment Structures With Grouted Tendons

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-19

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

  14. Uncovering the cellular and molecular changes in tendon stem/progenitor cells attributed to tendon aging and degeneration

    PubMed Central

    Kohler, Julia; Popov, Cvetan; Klotz, Barbara; Alberton, Paolo; Prall, Wolf Christian; Haasters, Florian; Müller-Deubert, Sigrid; Ebert, Regina; Klein-Hitpass, Ludger; Jakob, Franz; Schieker, Matthias; Docheva, Denitsa

    2013-01-01

    Although the link between altered stem cell properties and tissue aging has been recognized, the molecular and cellular processes of tendon aging have not been elucidated. As tendons contain stem/progenitor cells (TSPC), we investigated whether the molecular and cellular attributes of TSPC alter during tendon aging and degeneration. Comparing TSPC derived from young/healthy (Y-TSPC) and aged/degenerated human Achilles tendon biopsies (A-TSPC), we observed that A-TSPC exhibit a profound self-renewal and clonogenic deficits, while their multipotency was still retained. Senescence analysis showed a premature entry into senescence of the A-TSPC, a finding accompanied by an upregulation of p16INK4A. To identify age-related molecular factors, we performed microarray and gene ontology analyses. These analyses revealed an intriguing transcriptomal shift in A-TSPC, where the most differentially expressed probesets encode for genes regulating cell adhesion, migration, and actin cytoskeleton. Time-lapse analysis showed that A-TSPC exhibit decelerated motion and delayed wound closure concomitant to a higher actin stress fiber content and a slower turnover of actin filaments. Lastly, based on the expression analyses of microarray candidates, we suggest that dysregulated cell–matrix interactions and the ROCK kinase pathway might be key players in TSPC aging. Taken together, we propose that during tendon aging and degeneration, the TSPC pool is becoming exhausted in terms of size and functional fitness. Thus, our study provides the first fundamental basis for further exploration into the molecular mechanisms behind tendon aging and degeneration as well as for the selection of novel tendon-specific therapeutical targets. PMID:23826660

  15. Synthetic collagen fascicles for the regeneration of tendon tissue.

    PubMed

    Kew, S J; Gwynne, J H; Enea, D; Brookes, R; Rushton, N; Best, S M; Cameron, R E

    2012-10-01

    The structure of an ideal scaffold for tendon regeneration must be designed to provide a mechanical, structural and chemotactic microenvironment for native cellular activity to synthesize functional (i.e. load bearing) tissue. Collagen fibre scaffolds for this application have shown some promise to date, although the microstructural control required to mimic the native tendon environment has yet to be achieved allowing for minimal control of critical in vivo properties such as degradation rate and mass transport. In this report we describe the fabrication of a novel multi-fibre collagen fascicle structure, based on type-I collagen with failure stress of 25-49 MPa, approximating the strength and structure of native tendon tissue. We demonstrate a microscopic fabrication process based on the automated assembly of type-I collagen fibres with the ability to produce a controllable fascicle-like, structural motif allowing variable numbers of fibres per fascicle. We have confirmed that the resulting post-fabrication type-I collagen structure retains the essential phase behaviour, alignment and spectral characteristics of aligned native type-I collagen. We have also shown that both ovine tendon fibroblasts and human white blood cells in whole blood readily infiltrate the matrix on a macroscopic scale and that these cells adhere to the fibre surface after seven days in culture. The study has indicated that the synthetic collagen fascicle system may be a suitable biomaterial scaffold to provide a rationally designed implantable matrix material to mediate tendon repair and regeneration. PMID:22728568

  16. Dimensionless scaling of the critical beta for onset of a neoclassical tearing mode

    NASA Astrophysics Data System (ADS)

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

    2000-08-01

    The islands from tearing modes driven unstable and sustained by the helically perturbed neoclassical bootstrap current often provide the practical limit to long-pulse, high confinement tokamak operation. The destabilization of such "metastable" plasmas depends on a "seed" island exceeding a threshold. A database from similar regimes [high confinement H-mode with periodic edge localized modes (ELMs) and periodic central sawteeth] was compiled from the tokamaks ASDEX Upgrade (AUG) [Plasma Phys. Controlled Fusion 41, 767 (1999)], DIII-D [Nucl. Fusion 38, 987 (1998)], and JET (Joint European Torus) [Plasma Phys. Controlled Fusion 41, B1 (1999)]. A comparison is made of the measured critical beta for onset of the m/n=3/2 mode (m and n being the poloidal and toroidal Fourier harmonics, respectively) to a model in terms of dimensionless parameters for the seed and threshold islands. This modeling is then used for extrapolation to a reactor-grade tokamak design such as ITER/FDR (International Thermonuclear Experimental Reactor/Final Design Report) [Nucl. Fusion 39, 2137 (1999)]; this indicates that the seed island from sawteeth could be too small to sufficiently disturb the metastable plasma and excite the m/n=3/2 neoclassical tearing mode.

  17. Kinetic theory and simulation of collisionless tearing in bifurcated current sheets

    SciTech Connect

    Matsui, Tatsuki; Daughton, William [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

    2008-01-15

    Observations from the Earth's geomagnetic tail have established that the current sheet is often bifurcated with two peaks in the current density. These so-called bifurcated current sheets have also been reported in a variety of simulations and often occur in conjunction with significant temperature anisotropy. In this work, a new self-consistent Vlasov equilibrium is developed that permits both the current profile and temperature anisotropy to be independently adjusted. The stability of these layers with respect to the collisionless tearing mode is examined using both standard analytic techniques and a formally exact treatment involving a numerical evaluation of the full orbit integral. The resulting linear growth rate and mode structure are verified with fully kinetic particle-in-cell simulations. These results demonstrate that a bifurcated current profile has a strong stabilizing influence on the tearing mode in comparison to centrally peaked layers with a similar thickness. In contrast, electron temperature anisotropy is strongly destabilizing in the limit T{sub eperpendicular}>T{sub eparallel} and strongly stabilizing when T{sub eperpendicular}

  18. Multi-Device Scaling of Neoclassical Tearing Mode Onset with Beta

    SciTech Connect

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

    1999-07-01

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

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

    SciTech Connect

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

    2011-04-15

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

  20. Biomechanical analysis of bursal-sided partial thickness rotator cuff tears

    E-print Network

    Makhsous, Mohsen

    Biomechanical analysis of bursal-sided partial thickness rotator cuff tears Scott Yang, BSa , Hyung of Shoulder and Elbow Surgery Board of Trustees. Keywords: Rotator cuff; rotator cuff tear; supraspinatus abductor of the arm, and is most commonly torn in partial thickness rotator cuff tears.8 Partial thickness