Sample records for partial-thickness supraspinatus tendon

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Emergency department diagnosis of supraspinatus tendon calcification and shoulder impingement syndrome using bedside ultrasonography

    PubMed Central

    2013-01-01

    A 45-year-old woman presented to the emergency department with a 2-day history of severe left shoulder pain made worse with movement. Emergency department (ED) bedside point-of-care static and dynamic ultrasound examination of the supraspinatus tendon revealed supraspinatus tendon calcification with impingement syndrome, and the patient was urgently referred to orthopedics after ED pain control was achieved. Bedside shoulder and supraspinatus tendon evaluation with static and dynamic ultrasonography can assist in the rapid diagnosis of supraspinatus tendon calcification and supraspinatus tendon impingement syndrome in the emergency department. PMID:23398632

  9. 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

  10. 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?supraspinatus tears would remain isolated to the supraspinatus tendon during activities of daily living. PMID:24985532

  11. 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

  12. 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

  13. Collagen Fiber Re-Alignment in a Neonatal Developmental Mouse Supraspinatus Tendon Model

    PubMed Central

    Miller, Kristin S.; Connizzo, Brianne K.; Soslowsky, Louis J.

    2012-01-01

    Collagen fiber re-alignment is one postulated mechanism of tendon structural response to load. While collagen fiber distribution has been shown to vary by tendon location in the supraspinatus tendon, changes in local re-alignment behavior have not been examined throughout postnatal development. Postnatal tendons, with immature collagen fibrils, may respond to load in a much different manner than collagen fibers with mature fiber-fiber and fiber-matrix connections. Local collagen fiber re-alignment is quantified throughout tensile mechanical testing in a developmental mouse supraspinatus tendon model and corresponding mechanical properties measured. Collagen fiber re-alignment occurred during preconditioning for 28 day old tendons, at the toe-region for 10 day tendons and at the linear-region for 4 day tendon midsubstance. Mechanical properties increased with developmental age. Linear modulus was lower at the insertion site compared to the midsubstance location at all time points. Local differences in collagen fiber distributions were found at 10 and 28 days for all mechanical testing points (except the 10 day transition point). This study found that collagen fiber re-alignment depends on developmental age and suggests that collagen fibrillogenesis may influence the tendon’s ability to structurally respond to load. Additionally, results indicate that the insertion site and tendon midsubstance locations develop differently. PMID:22183194

  14. Effect of dihydrotestosterone on cultured human tenocytes from intact supraspinatus tendon

    Microsoft Academic Search

    Vincenzo Denaro; Laura Ruzzini; Umile Giuseppe Longo; Francesco Franceschi; Barbara De Paola; Achille Cittadini; Nicola Maffulli; Alessandro Sgambato

    2010-01-01

    The role of hormones in the pathogenesis of tendinopathy is not well recognised, even though the use of anabolic steroids\\u000a is correlated with a higher incidence of spontaneous tendon ruptures. The aim of this study was to investigate the effects\\u000a of dihydrotestosterone (DHT) on human tenocyte cultures from the intact supraspinatus tendon of male subjects. Cultured human\\u000a tenocytes were seeded

  15. Repaired Supraspinatus Tendons in Clinically Improving Patients: Early Postoperative Findings and Interval Changes on MRI

    PubMed Central

    Lee, Jung Eun; Ryu, Kyung Nam; Rhee, Yong Girl; Yoon, So Hee; Park, So Young; Jin, Wook

    2015-01-01

    Objective To demonstrate and further determine the incidences of repaired supraspinatus tendons on early postoperative magnetic resonance imaging (MRI) findings in clinically improving patients and to evaluate interval changes on follow-up MRIs. Materials and Methods Fifty patients, who showed symptomatic and functional improvements after supraspinatus tendon repair surgery and who underwent postoperative MRI twice with a time interval, were included. The first and the second postoperative MRIs were obtained a mean of 4.4 and 11.5 months after surgery, respectively. The signal intensity (SI) patterns of the repaired tendon on T2-weighted images from the first MRI were classified into three types of heterogeneous high SI with fluid-like bright high foci (type I), heterogeneous high SI without fluid-like bright high foci (type II), and heterogeneous or homogeneous low SI (type III). Interval changes in the SI pattern, tendon thickness, and rotator cuff interval thickness between the two postoperative MRIs were evaluated. Results The SI patterns on the first MRI were type I or II in 45 tendons (90%) and type III in five (10%). SI decreased significantly on the second MRI (p < 0.050). The mean thickness of repaired tendons and rotator cuff intervals also decreased significantly (p < 0.050). Conclusion Repaired supraspinatus tendons exhibited high SI in 90% of clinically improving patients on MRI performed during the early postsurgical period. The increased SI and thickness of the repaired tendon decreased on the later MRI, suggesting a gradual healing process rather than a retear. PMID:25741199

  16. 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

  17. 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

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

    PubMed Central

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

    2014-01-01

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

  19. 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

  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

  1. Cell-based tissue engineering augments tendon-to-bone healing in a rat supraspinatus model.

    PubMed

    Loeffler, Bryan J; Scannell, Brian P; Peindl, Richard D; Connor, Patrick; Davis, Daniel E; Hoelscher, Gretchen L; Norton, H James; Hanley, Edward N; Gruber, Helen E

    2013-03-01

    Rotator cuff pathology causes substantial pain/disability and health care costs. Cell-based tissue engineering offers promise for improved outcomes in tendon to bone healing. Cells from the tendon-bone interface were used here to amplify surgical defect healing in a rat model. Cells from tendon-to-bone interface of the rotator cuff were seeded in sponges and implanted into critical rotator cuff defects: Group I, control; II, surgical defect only; III, suture-repaired defect; IV, surgical defect, repair with sponge only; V, surgical defect, repair with sponge with cells. Three, 6-, and 12-week results were assessed for histologic features. At 3 weeks, histologic indices in Group V were significantly increased versus other treatment groups. Group V (12 weeks) showed significantly improved collagen organization versus other treatment groups; there was no difference in collagen organization in Group I versus V. In summary, increased cellularity, inflammation, vascularity, and collagen organization were present at 3 weeks; increased collagen organization at 12 weeks in Group V provides evidence for improved healing with cells. Data further support the utility of tendon-bone interface cells in rotator cuff healing. PMID:23070709

  2. The “Double-Pulley” Technique for Arthroscopic Fixation of Partial Articular-Side Bony Avulsion of the Supraspinatus Tendon: A Rare Case of Bony PASTA Lesion

    PubMed Central

    Murena, Luigi; Canton, Gianluca; Falvo, Daniele A.; Genovese, Eugenio A.; Surace, Michele F.; Cherubino, Paolo

    2012-01-01

    We report the use of the double-pulley technique for arthroscopic fixation of the bony PASTA (partial articular surface tendon avulsion) lesion. Arthroscopic examination documented a 15-mm-long and 8-mm-wide comminuted bony avulsion with 2 main fragments. Two double-loaded suture anchors were placed with a transtendinous technique at the anterior and posterior edges of the lesion respecting the tendon insertion to the avulsed fragment. The medial sutures were retrieved through the intact supraspinatus tendon medially to the fracture. The sutures were initially coupled in a double-pulley configuration generating 2 sutures oriented from anterior to posterior; then a simple suture for each anchor oriented from medial to lateral was obtained. At the end of the procedure, the adequacy of reduction and stability of the fragments were confirmed. At 2 months from surgery, radiographic healing of the fracture was noted and integrity of the supraspinatus tendon insertion to the footprint was confirmed by arthro–magnetic resonance imaging, with full recovery of daily activities and complete active range of motion confirmed at 6 and 12 months. The double-pulley technique allows optimal reduction of bony fragments and reconstruction of normal footprint anatomy even in comminuted fractures. Moreover, it creates a waterproof reduction of the fragments, protecting the fracture site from synovial fluid. PMID:23767005

  3. The "Double-Pulley" Technique for Arthroscopic Fixation of Partial Articular-Side Bony Avulsion of the Supraspinatus Tendon: A Rare Case of Bony PASTA Lesion.

    PubMed

    Murena, Luigi; Canton, Gianluca; Falvo, Daniele A; Genovese, Eugenio A; Surace, Michele F; Cherubino, Paolo

    2013-02-01

    We report the use of the double-pulley technique for arthroscopic fixation of the bony PASTA (partial articular surface tendon avulsion) lesion. Arthroscopic examination documented a 15-mm-long and 8-mm-wide comminuted bony avulsion with 2 main fragments. Two double-loaded suture anchors were placed with a transtendinous technique at the anterior and posterior edges of the lesion respecting the tendon insertion to the avulsed fragment. The medial sutures were retrieved through the intact supraspinatus tendon medially to the fracture. The sutures were initially coupled in a double-pulley configuration generating 2 sutures oriented from anterior to posterior; then a simple suture for each anchor oriented from medial to lateral was obtained. At the end of the procedure, the adequacy of reduction and stability of the fragments were confirmed. At 2 months from surgery, radiographic healing of the fracture was noted and integrity of the supraspinatus tendon insertion to the footprint was confirmed by arthro-magnetic resonance imaging, with full recovery of daily activities and complete active range of motion confirmed at 6 and 12 months. The double-pulley technique allows optimal reduction of bony fragments and reconstruction of normal footprint anatomy even in comminuted fractures. Moreover, it creates a waterproof reduction of the fragments, protecting the fracture site from synovial fluid. PMID:23767005

  4. Supraspinatus tendon US morphology in basketball players: correlation with main pathologic models of secondary impingement syndrome in young overhead athletes. Preliminary report

    Microsoft Academic Search

    R. Girometti; A. De Candia; M. Sbuelz; F. Toso; C. Zuiani; M. Bazzocchi

    2006-01-01

    Purpose.  The purpose of this study was to investigate supraspinatus tendon sonographic morphology in a population of young overhead\\u000a athletes in correlation with main pathologic models of secondary shoulder impingement syndrome.\\u000a \\u000a \\u000a \\u000a Subjects and methods.  Between April and May 2004, 20 subjects (ten professional basketball players and ten non-athlete controls of the same age,\\u000a weight and height ranges) underwent bilateral, standardised, sonographic sholulder

  5. Delayed tendon reattachment does not reverse atrophy and fat accumulation of the supraspinatus – an experimental study in rabbits

    Microsoft Academic Search

    Fujio Matsumoto; Hans K. Uhthoff; Guy Trudel; Joachim F. Loehr

    2002-01-01

    Muscle atrophy and fat accumulation occur after rotator cuff tearing. Whether these changes are reversible after a successful repair is still unknown. Imaging allows only a semi-quantitative assessment of muscle atrophy and fat deposition. As only experimental studies permit a quantification of both, a unilateral detachment and wrapping in a polyvinylidine fluoride membrane of the supraspinatus was done in 22

  6. [Extracorporeal shockwave therapy (ESWT) as therapeutic option in supraspinatus tendon syndrome? One year results of a placebo controlled study].

    PubMed

    Schmitt, J; Tosch, A; Hünerkopf, M; Haake, M

    2002-07-01

    Extracorporeal shock wave therapy (ESWT) is seen as a therapeutic option in the treatment of chronic supraspinatus tendinitis by some authors. To test whether ESWT comprising 3 x 2000 pulses with the positive energy flux density ED+ of 0.33 mJ/mm2 is clinically superior to a sham ESWT treatment, a prospective, randomized, single-blinded, placebo-controlled study with an independent observer was performed. Forty patients were treated either by verum ESWT or sham ESWT under local anesthesia. Target criteria were the age-corrected Constant score, pain at rest and during activity on a visual analogue scale, and subjective improvement. Patients who reported no subjective improvement after 12 weeks were deblinded and received verum ESWT if they had belonged to the placebo group (partial crossover). The results of the verum group lie within the range of results for ESWT published by other authors. Patients in the placebo group with local anesthetic showed equally good results. At 12 weeks, and 1 year after intervention, no difference could be found between the verum and placebo groups regarding Constant score, pain, shoulder function, or subjective improvement. The nonresponders to the placebo ESWT continued to show no improvement after receiving verum ESWT. This contradicts a specific ESWT effect. Based on the results of this placebo-controlled study, ESWT appears to have no clinically relevant effect on supraspinatus tendinitis. The study underlines the importance of a control group in evaluating new treatment methods for diseases with unknown natural history. PMID:12219663

  7. 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

  8. 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

  9. 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

  10. 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 ...

  11. An Acute, Traumatic Supraspinatus Lesion in an Intercollegiate Football Player: A Case Report

    PubMed Central

    Gorse, Keith M.; Myers, Joseph B.; Radelet, Marirose; Scovazzo, Mary Lynn; D'Alessandro, Donald

    2000-01-01

    Objective: To describe the evaluation, management, and rehabilitation of an acute, supraspinatus tendon injury in an intercollegiate football player. Background: While attempting to block a defender, a 19-year-old collegiate football player slipped on the artificial turf and landed on his right elbow, causing an injury to his right shoulder. The athlete was initially seen by the head athletic trainer and then referred to the team physician for further evaluation. Differential Diagnosis: acromioclavicular joint sprain, brachial plexopathy, subacromial impingement syndrome, supraspinatus lesion. Treatment: The athlete was managed surgically with an open acromioplasty and a 3-bone tunnel repair of the supraspinatus tendon. After surgery, the athlete underwent a 4-month rehabilitation protocol in preparation for return to competition. Uniqueness: This case involved a teenage athlete rather than the older individuals who normally sustain rotator cuff lesions. Also, the mechanism was a compressive force on the supraspinatus tendon rather than the tensile force common to rotator cuff lesions. Conclusions: By presenting this case report, we hope to give sports medicine clinicians a better understanding of rotator cuff injuries and how to successfully manage and rehabilitate supraspinatus lesions. ImagesFigure 1.Figure 2. PMID:16558631

  12. 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

  13. 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

  14. Acromiohumeral distance and acromial shape assessed by three-dimensional computed tomography in patients with supraspinatus outlet syndrome

    Microsoft Academic Search

    E.-M. Lochmüller; H. Anetzberger; U. Maier; P. Habermeyer; M. Müller-Gerbl

    1997-01-01

    Summary  \\u000a Mechanical irritations of the supraspinatus tendon due to a reduction of the subacromial space are considered to be a potential\\u000a cause of supraspinatus outlet syndrome. The aim of the current study was, therefore, to provide a method of improved measurement\\u000a of the acromiohumeral distance and the evaluation of the acromial shape. In seven patients aged 50–60 years with unilateral

  15. 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

  16. 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

  17. 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

  18. 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 ...

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

    PubMed Central

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

    2014-01-01

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

  20. Effects of selective paralysis of the supraspinatus muscle using botulinum neurotoxin a in rotator cuff healing in rats.

    PubMed

    Ficklscherer, Andreas; Hartl, Tessa-Katharina; Scharf, Markus; Sievers, Birte; Schröder, Christian; Milz, Stefan; Niethammer, Thomas; Pietschmann, Matthias F; Müller, Peter E

    2013-05-01

    We hypothesized that a temporary rotator cuff paralysis using botulinum-neurotoxin A (BoNtA) would lead to an improved tendon-to-bone healing after repair of supraspinatus lesions. One hundred sixty Sprague-Dawley rats were randomly assigned to either the BoNtA or the control (saline) group. BoNtA/saline-solution was injected into the supraspinatus muscle 1 week prior to surgery. A supraspinatus defect was made; we distinguished between a lesion with normal and increased repair load. Furthermore, one subgroup had the operated shoulder immobilized in a cast. Histologic analysis and biomechanical testing followed. Specimens from the BoNtA-group, which were treated with an increased repair load, showed less cellularity and more organization in the interface tissue compared to the saline control group. In addition, we found that the collagen 1-3 quotient in the BoNtA specimen was significantly (p?=?0.0051) higher than in the control group. Ultimate load at failure between the groups was not significantly different (p?>?0.05). We did not observe any significant differences between the mobilized and immobilized specimen (p?=?0.2079). The study shows that tendon-to-bone healing after rotator cuff repair can be altered positively using BoNtA pre-operatively. Tears with increased repair load seem to benefit the most-at least histologically. PMID:23239559

  1. The bony partial articular surface tendon avulsion lesion: an arthroscopic technique for fixation of the partially avulsed greater tuberosity fracture.

    PubMed

    Bhatia, Deepak N; de Beer, Joe F; van Rooyen, Karin S

    2007-07-01

    The partial articular surface tendon avulsion (PASTA) is a common lesion that involves the supraspinatus tendon in most cases. We present an arthroscopic fixation technique for a previously undescribed lesion that may be considered a variant of the PASTA. The lesion involves a partial avulsion of the greater tuberosity with an intact deep insertion of the supraspinatus tendon into the fractured bone fragment and an intact superficial insertion of the supraspinatus into the unavulsed lateral aspect of the greater tuberosity: a "bony PASTA" lesion. The surgical technique involves the use of a 70 degree arthroscope to provide an "end-on" view of the pathology. A superior-medial transmuscular portal is used for anchor insertion and suture management; the portal avoids damage to the intact tendinous insertion of the supraspinatus, which can occur during transtendon anchor/screw insertion. Abduction of the arm to 50 degrees, after creation of the portal and passage of the cannula, permits an optimal "deadman" angle of anchor placement. An angled suture grasper is used to retrieve the 4 suture strands from the double-loaded suture anchor through the intact superficial and deep supraspinatus tendon fibers along the length of the fracture; these are tied as 2 mattress sutures over the tendon fibers in the subacromial space by use of sliding-locking knots. Adequacy of reduction is confirmed by intra-articular arthroscopic observation during movement of the extremity through its complete range of motion. PMID:17637417

  2. 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 ...

  3. Novel characteristics of normal supraspinatus insertion in rats: an ultrastructural analysis using three-dimensional reconstruction using focused ion beam/scanning electron microscope tomography

    PubMed Central

    Kanazawa, Tomonoshin; Gotoh, Masafumi; Ohta, Keisuke; Shiba, Naoto; Nakamura, Kei-ichiro

    2014-01-01

    Summary Background: the histological architecture of the insertion after a rotator cuff repair is completely different from that of normal tendon-bone insertions. Analysis of normal insertions by electron microscopy may enhance the understanding of the pathophysiology of tendon-to-bone healing after rotator cuff repair. The present study examined the normal supraspinatus insertion in rats using a new three-dimensional (3D) electron microscopic method, focused ion beam/scanning electron microscope (FIB/SEM) tomography. Methods: normal supraspinatus insertion of adult Sprague-Dawley rats was analyzed. FIB/SEM tomography was performed on the entire insertion. The obtained serial images were reconstructed, and the 3D cellular morphology and organization of collagen bundles was observed. Results: the cellular shapes between the tendon-cartilage interface were successfully reconstructed. The cells in the cartilage region were spherical without any cellular processes, while the cells in the intermediate region had some cellular processes oriented longitudinally along the collagen bundles. In addition, these 2 regions were smoothly transferred under ultrastructural resolution. Conclusions: structures at the normal insertion gradually changed from the fibrous cartilage to the tendon midsubstance, which may contribute to the biomechanical strength of the site. These novel cell characteristics may provide necessary knowledge for better regeneration of tendon-to-bone insertions after rotator cuff repair. PMID:25332933

  4. Honey compared with silver sulphadiazine in the treatment of superficial partial-thickness burns.

    PubMed

    Malik, Kamran Ishaque; Malik, M A Nasir; Aslam, Azhar

    2010-10-01

    Burn injury is associated with a high incidence of death and disability; yet, its management remains problematic and costly. We conducted this clinical study to evaluate the efficacy of honey in the treatment of superficial and partial-thickness burns covering less than 40% of body surface area and compared its results with those of silver sulphadiazine (SSD). In this randomised comparative clinical trial, carried out Burn Center of POF Hospital, Wah Cantt, Pakistan, from May 2007 to February 2008, 150 patients of all ages having similar types of superficial and partial-thickness burns at two sites on different parts of body were included. Each patient had one burn site treated with honey and one treated with topical SSD, randomly. The rate of re-epithelialization and healing of superficial and partial-thickness burns was significantly faster in the sites treated with honey than in the sites treated with SSD (13·47 ± 4·06 versus 15·62 ± 4·40 days, respectively: P < 0·0001). The site treated with honey healed completely in less than 21 days versus 24 days for the site treated with SSD. Six patients had positive culture for Pseudomonas aeroginsa in honey-treated site, whereas 27 patients had positive culture in SSD-treated site. The results clearly showed greater efficacy of honey over SSD cream for treating superficial and partial-thickness burns. PMID:20649832

  5. Microsurgical Aesthetic Treatment of Gingival Fenestration by a Coronally Repositioned Partial Thickness Graft: A Case Report

    PubMed Central

    Patel, Punit Vaibhav; Kumar, Naresh; Durrani, Farhan

    2013-01-01

    Gingival fenestration is a rare pathological entity, scarcely described in the literature. The present paper has reported a case of a 22-year-old male patient with a “Gingival fenestration” in the lower left central incisor. The lesion was successfully treated using a coronally positioned partial thickness graft under 4 X magnification, with excellent aesthetic results. PMID:24392432

  6. Effectiveness of Biobrane for treatment of partial-thickness burns in children

    PubMed Central

    Lesher, Aaron P.; Curry, Ryan H.; Evans, Jill; Smith, Valerie A.; Fitzgerald, Michael T.; Cina, Robert A.; Streck, Christian J.; Hebra, Andre V.

    2014-01-01

    Purpose Wound care for partial-thickness burns should alleviate pain, decrease hospital length of stay, and be readily applied to a variety of wounds. The effectiveness of Biobrane (UDL Laboratories, Rockford, IL) is compared with that of Beta Glucan Collagen (BGC; Brennan Medical, St. Paul, MN) in a retrospective cohort study. Methods A retrospective chart review of all children treated at a tertiary care pediatric hospital between 2003 and 2009 identified patients with partial-thickness burns treated with Biobrane. These patients were compared with historical controls treated with BGC. Results A total of 235 children between the ages of 4 weeks and 18 years with an average of 6.0% body surface area partial-thickness burns were treated with Biobrane. In a multivariate statistical analysis, patients treated with Biobrane healed significantly faster than those treated with BGC (Biobrane vs BGC: median, 9 vs 13 days; P = .019; hazard ratio, 1.68). In addition, patients who required inpatient treatment trended toward having shorter length of hospital stay in the Biobrane group (2.6 vs 4.1 days, P = .079). Conclusion Partial-thickness burn care consists of early debridement and application of a burn wound dressing. Biobrane dressings result in faster healing compared with BGC and may decrease hospital length of stay for patients requiring inpatient admission. PMID:21929986

  7. Effect of 1partial thickness actuation on stress concentration reduction near a hole

    NASA Technical Reports Server (NTRS)

    Sensharma, P. K.; Kadivar, M. H.; Haftka, R. T.

    1994-01-01

    Recently, there has been much interest in adaptive structures that can respond to a varying environment by changing their properties. Piezoelectric materials and shape memory alloys (SMA) are often used as partial thickness actuators to create such adaptivity by applied energy, usually electric curent. These actuators can be used to inducce strains in a structure and reduce stresses in regions of high stress concentration. Two of the present authors show that axisymmetric actuation strains applied troughout the thickness of a plate with a hole can reduce the stress concentration factor (SCF) in an isotropic plate from 3 to 2. However, in most cases actuators are expected to be bonded to or embedded in the plate, so that the actuation strains are applied in the actuators and not directly in the plate. The objective of this note is to show that such partial-thickness actuation cannot be used to reduce the stress concentration factor with axisymmetric actuations strain distribution.

  8. The optimal duration and delay of first aid treatment for deep partial thickness burn injuries

    Microsoft Academic Search

    Leila Cuttle; Margit Kempf; Pei-Yun Liu; Olena Kravchuk; Roy M. Kimble

    2010-01-01

    Using our porcine model of deep dermal partial thickness burn injury, various durations (10min, 20min, 30min or 1h) and delays (immediate, 10min, 1h, 3h) of 15°C running water first aid were applied to burns and compared to untreated controls. The subdermal temperatures were monitored during the treatment and wounds observed weekly for 6 weeks, for re-epithelialisation, wound surface area and

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

    PubMed Central

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

    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 during shoulder surgery (n = 31) were analysed for calcium content by atomic absorption spectroscopy, phosphorous content using a spectrophotometric assay, and matrix composition (collagen, glycosaminoglycans and DNA) using standard biochemical techniques. RESULTS: We established baseline values of calcium concentration in macroscopically normal cadaver tendons (mean 1.1 (SD 0.35) micrograms/mg dry wt, n = 60) and found that 33% (nine of 27) of ruptured tendons from patients with 'degenerative tendinitis' contained an excess of calcium (more than 2SD greater than the normal sample mean). Five of these specimens had increased concentrations of phosphorous and calcium:phosphorous (molar) ratios consistent with a variety of possible calcium crystals, including calcium pyrophosphate, hydroxyapatite, and tricalcium phosphate, in addition to mixed or amorphous calcium phosphate deposits. Four of these specimens contained normal concentrations of phosphorous, consistent with deposits of calcium oxalate or calcium carbonate, although this was not confirmed biochemically. In contrast, surgical specimens (n = 4) from patients with 'calcifying tendinitis' (radiographically detected calcium deposits) all contained salts with a mineral composition consistent with hydroxyapatite. The presence and identity of crystal deposits was subsequently confirmed in five specimens by radiographic microanalysis. Analysis of the tendon matrix demonstrated a number of significant differences between normal and degenerate (ruptured) tendons, including a reduction in collagen content, an increase in sulphated glycosaminoglycans (predominantly dermatan sulphate) and an increase in DNA (cellular) content. However, there were no significant differences between degenerate tendons that were 'calcified' and those degenerate specimens that contained normal concentrations of calcium. CONCLUSIONS: Although there was a relatively high prevalence of calcium salts in degenerate tendons, which might contribute to the pathological process (such as increased matrix collagen degradation), these data are consistent with the hypothesis that 'dystrophic calcification' of degenerate tendon matrix is a pathological entity distinct from cell mediated 'calcifying tendinitis'. Calcification is probably one possible outcome (or end point) of chronic tendon injury, although the possibility exists that in many cases, the presence of calcium salts may contribute to the tendon matrix degeneration. PMID:8712860

  10. ERK2 dependent signaling contributes to wound healing after a partial-thickness burn

    SciTech Connect

    Satoh, Yasushi [Department of Biochemistry, National Defense Medical College, 3-2 Namiki, Tokorozawa 359-8513 (Japan)], E-mail: ys@ndmc.ac.jp; Saitoh, Daizoh [Division of Traumatology, Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa 359-8513 (Japan); Takeuchi, Atsuya; Ojima, Kenichiro; Kouzu, Keita; Kawakami, Saki [Department of Biochemistry, National Defense Medical College, 3-2 Namiki, Tokorozawa 359-8513 (Japan); Ito, Masataka [Department of Developmental Anatomy and Regenerative Biology, National Defense Medical College, 3-2 Namiki, Tokorozawa 359-8513 (Japan); Ishihara, Masayuki [Division of Biomedical Engineering, Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa 359-8513 (Japan); Sato, Shunichi [Division of Biomedical Information Science, Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa 359-8513 (Japan); Takishima, Kunio [Department of Biochemistry, National Defense Medical College, 3-2 Namiki, Tokorozawa 359-8513 (Japan)

    2009-03-27

    Burn healing is a complex physiological process involving multiple cell activities, such as cell proliferation, migration and differentiation. Although extracellular signal-regulated kinases (ERK) have a pivotal role in regulating a variety of cellular responses, little is known about the individual functions of ERK isoform for healing in vivo. This study investigated the role of ERK2 in burn healing. To assess this, Erk2{sup +/-} mice generated by gene targeting were used. The resultant mice exhibited significant delay in re-epithelization of partial-thickness burns in the skin in comparison to wild-type. An in vitro proliferation assay revealed that keratinocytes from Erk2{sup +/-} mice grew significantly slower than those prepared from wild-type. These results highlight the importance of ERK2 in the process of burn healing.

  11. ggstThe role of tendon microcirculation in Achilles and patellar tendinopathy

    PubMed Central

    Knobloch, Karsten

    2008-01-01

    Tendinopathy is of distinct interest as it describes a painful tendon disease with local tenderness, swelling and pain associated with sonographic features such as hypoechogenic texture and diameter enlargement. Recent research elucidated microcirculatory changes in tendinopathy using laser Doppler flowmetry and spectrophotometry such as at the Achilles tendon, the patellar tendon as well as at the elbow and the wrist level. Tendon capillary blood flow is increased at the point of pain. Tendon oxygen saturation as well as tendon postcapillary venous filling pressures, determined non-invasively using combined Laser Doppler flowmetry and spectrophotometry, can quantify, in real-time, how tendon microcirculation changes over with pathology or in response to a given therapy. Tendon oxygen saturation can be increased by repetitive, intermittent short-term ice applications in Achilles tendons; this corresponds to 'ischemic preconditioning', a method used to train tissue to sustain ischemic damage. On the other hand, decreasing tendon oxygenation may reflect local acidosis and deteriorating tendon metabolism. Painful eccentric training, a common therapy for Achilles, patellar, supraspinatus and wrist tendinopathy decreases abnormal capillary tendon flow without compromising local tendon oxygenation. Combining an Achilles pneumatic wrap with eccentric training changes tendon microcirculation in a different way than does eccentric training alone; both approaches reduce pain in Achilles tendinopathy. The microcirculatory effects of measures such as extracorporeal shock wave therapy as well as topical nitroglycerine application are to be studied in tendinopathy as well as the critical question of dosage and maintenance. Interestingly it seems that injection therapy using color Doppler for targeting the area of neovascularisation yields to good clinical results with polidocanol sclerosing therapy, but also with a combination of epinephrine and lidocaine. PMID:18447938

  12. 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

  13. 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

  14. Arthroscopic Debridement and Acromioplasty Versus Mini-Open Repair in the Treatment of Significant Partial-Thickness Rotator Cuff Tears

    Microsoft Academic Search

    Stephen C. Weber

    1999-01-01

    Summary: Partial tears of the rotator cuff, especially of the articular side, have received attention only with the recent ability of magnetic resonance imaging (MRI) and arthroscopy to diagnose these lesions. Several early reports showed nearly 100% success in managing these lesions with arthroscopic debridement with or without acromioplasty. This series compares 32 patients with significant partial-thickness rotator cuff tears

  15. Effect of Extracorporeal Shock Wave Treatment on Deep Partial-Thickness Burn Injury in Rats: A Pilot Study

    PubMed Central

    Kamelger, Florian Stefan; Jeschke, Johannes; Piza-Katzer, Hildegunde

    2014-01-01

    Extracorporeal shock wave therapy (ESWT) enhances tissue vascularization and neoangiogenesis. Recent animal studies showed improved soft tissue regeneration using ESWT. In most cases, deep partial-thickness burns require skin grafting; the outcome is often unsatisfactory in function and aesthetic appearance. The aim of this study was to demonstrate the effect of ESWT on skin regeneration after deep partial-thickness burns. Under general anesthesia, two standardized deep partial-thickness burns were induced on the back of 30 male Wistar rats. Immediately after the burn, ESWT was given to rats of group 1 (N = 15), but not to group 2 (N = 15). On days 5, 10, and 15, five rats of each group were analyzed. Reepithelialization rate was defined, perfusion units were measured, and histological analysis was performed. Digital photography was used for visual documentation. A wound score system was used. ESWT enhanced the percentage of wound closure in group 1 as compared to group 2 (P < 0.05). The reepithelialization rate was improved significantly on day 15 (P < 0.05). The wound score showed a significant increase in the ESWT group. ESWT improves skin regeneration of deep partial-thickness burns in rats. It may be a suitable and cost effective treatment alternative in this type of burn wounds in the future. PMID:25431664

  16. Characterization of a new in vitro model for studies of reepithelialization in human partial thickness wounds.

    PubMed

    Jansson, K; Kratz, G; Haegerstrand, A

    1996-10-01

    Reepithelialization of artificial partial thickness wounds made in biopsies of human skin was determined after 3, 5, or 7 d of incubation, submerged or elevated to the air-liquid interface. The biopsies were reepithelialized within 5-7 d, with a more complete epidermal healing in wounds exposed to air. Both types of wounds showed similar time-course in deposition of basement membrane components, as detected by immunofluorescence labeling. Laminin and collagen type VII were deposited underneath the migrating tips, whereas collagen type IV was detected after reepithelialization. Markers of terminal differentiation showed a pattern close to normal in the air-liquid incubated wounds after reepithelialization. Involucrin was detected in the suprabasal regions of the migrating epidermis and thereafter in the upper half of neo-epidermis in the air-liquid incubated wound. Filaggrin could not be detected in the submerged wounds at any time during healing, whereas wounds exposed to air showed a well-differentiated epidermis by Day 7. Tritiated thymidine-incorporation indicated proliferation of epidermal and dermal cells during reepithelialization and a maintained viability, as shown by cultivation of endothelial- and fibroblast-like cells obtained from the dermis 7 d after wounding. Reepithelialization in this human in vitro model is supported by a matrix close to normal with the possibility of extracellular influences and cell-cell interactions and, in addition, the technique is simple and reproducible. Therefore, we suggest this model for studies of regeneration in culture and as a complement to in vivo studies on epidermal healing. PMID:8946225

  17. 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

  18. Comparison of three different dressings for partial thickness burns in children: study protocol for a randomised controlled trial

    PubMed Central

    2013-01-01

    Background In the paediatric population, pain and distress associated with burn injuries during wound care procedures remain a constant challenge. Although silver dressings are the gold standard for burn care in Australasia, very few high-level trials have been conducted that compare silver dressings to determine which will provide the best level of care clinically. Therefore, for paediatric patients in particular, identifying silver dressings that are associated with lower levels of pain and rapid wound re-epithelialisation is imperative. This study will determine whether there is a difference in time to re-epithelialisation and pain and distress experienced during wound care procedures among Acticoat™, Acticoat™ combined with Mepitel™ and Mepilex Ag™ dressings for acute, paediatric partial thickness burns. Methods/Design Children aged 0 to 15 years with an acute partial thickness (superficial partial to deep partial thickness inclusive) burn injury and a burn total body surface area of ?10% will be eligible for the trial. Patients will be randomised to one of the three dressing groups: (1) Acticoat™ or (2) Acticoat™ combined with Mepitel™ or (3) Mepilex Ag™. A minimum of 28 participants will be recruited for each treatment group. Primary measures of pain, distress and healing will be repeated at each dressing change until complete wound re-epithelialisation occurs or skin grafting is required. Additional data collected will include infection status at each dressing change, physical function, scar outcome and scar management requirements, cost effectiveness of each dressing and staff perspectives of the dressings. Discussion The results of this study will determine the effects of three commonly used silver and silicone burn dressing combinations on the rate of wound re-epithelialisation and pain experienced during dressing procedures in acute, paediatric partial thickness burn injuries. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12613000105741 PMID:24274190

  19. Muscle loading is necessary for the formation of a functional tendon enthesis.

    PubMed

    Schwartz, A G; Lipner, J H; Pasteris, J D; Genin, G M; Thomopoulos, S

    2013-07-01

    Muscle forces are essential for skeletal patterning during development. Eliminating muscle forces, e.g., through paralysis, leads to bone and joint deformities. Botulinum toxin (BtxA)-induced paralysis of mouse rotator cuffs throughout postnatal development closely mimics neonatal brachial plexus palsy, a significant clinical condition in infants. In these mice, the tendon-to-bone attachment (i.e., the tendon enthesis) presents defects in mineral accumulation and fibrocartilage formation, presumably impairing the function of the tissue. The objective of the current study was to investigate the functional consequences of muscle unloading using BtxA on the developing supraspinatus tendon enthesis. We found that the maximum endurable load and stiffness of the supraspinatus tendon attachment decreased after four and eight weeks of post-natal BtxA-muscle unloading relative to controls. Tendon cross-sectional area was not significantly reduced by BtxA-unloading, while, strength, modulus, and toughness were decreased in the BtxA-unloaded group compared to controls, indicating a decrease in tissue quality. Polarized-light microscopy and Raman microprobe analysis were used to determine collagen fiber alignment and mineral characteristics, respectively, in the tendon enthesis that might contribute to the reduced biomechanical performance in BtxA-unloaded shoulders. Collagen fiber alignment was significantly reduced in BtxA-unloaded shoulders. The mineral-to-matrix ratio in mineralized fibrocartilage was not affected by loading. However, the crystallographic atomic order of the hydroxylapatite phase (a measure of crystallinity) was reduced and the amount of carbonate (substituting for phosphate) in the hydroxylapatite crystals was increased. Taken together, these micrometer-scale structural and compositional changes partly explain the observed decreases in the mechanical functionality of the tendon enthesis in the absence of muscle loading. PMID:23542869

  20. Do Functional Keratin Dressings Accelerate Epithelialization in Human Partial Thickness Wounds? A Randomized Controlled Trial on Skin Graft Donor Sites

    PubMed Central

    Davidson, Andrew; Jina, N. Hamesh; Marsh, Clive; Than, Martin; Simcock, Jeremy W.

    2013-01-01

    Objective: To determine if the experimental (keratin-based) dressing accelerates epithelialization rates during healing of partial-thickness wounds, relative to a Standard Care dressing. Method: A randomized control trial was conducted using a Standard Care dressing side by side with the experimental dressing on a sample (n=26) of partial-thickness donor site wounds. The proximal/distal placement of the control and treatment was randomized. Percentage epithelialization after approximately 7 days was estimated from which time to fully epithelialize can be inferred. Patients were grouped into “young” (?50 y/o) and “old” (>50 y/o). Results: For the “old” patients (n=15), the median epithelialization percentage at 7 days is 5% and was significantly (P=.023) greater for the experimental dressing. For the “young” patients (n=11), the median epithelialization percentage at 7 days was 80% and there is no significant difference between the experimental and Standard Care control dressings. Conclusions: The experimental dressing significantly increases the rate of epithelialization of acute, traumatic partial-thickness wounds in older patients. We suggest that the dressing may be clinically useful in similar situations where epithelialization may be delayed because of patient or wound characteristics. PMID:24058716

  1. 3D Shape Analysis of the Supraspinatus Muscle Aaron D. Ward1

    E-print Network

    Hamarneh, Ghassan

    of several muscles making up the rotator cuff in the shoulder (figure 1). Disorders of the supraspinatus for the evaluation of the rotator cuff, MR has an exceptionally high accuracy which has been accepted as a standard.ashry@gmail.com, mark.schweitzer@nyumc.org Abstract. Pathology of the supraspinatus muscle can involve tearing, which

  2. Lateral Patellofemoral Ligament Reconstruction Using a Quadriceps Tendon Graft.

    PubMed

    Saper, Michael G; Shneider, David A

    2014-08-01

    Medial patellar subluxation (MPS) is normally described after a lateral retinacular release. However, isolated MPS in the absence of a previous lateral release does occur. This type of patellar instability is often overlooked, and a high index of suspicion is needed for appropriate diagnosis and treatment. This report describes a technique developed in response to episodes of isolated MPS. The technique uses a partial-thickness graft from the quadriceps tendon to reconstruct the lateral patellofemoral ligament and provide stability to the lateral side of the patella. PMID:25264506

  3. 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

  4. 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

  5. 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 ...

  6. 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 ...

  7. 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

  8. 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

  9. 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

  10. 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

  11. Overload and neovascularization of shoulder tendons in volleyball players

    PubMed Central

    2012-01-01

    Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p?=?0.01), opposite hitters (55.5%) (p?=?0.02) and libero players (54.4%) (p?=?0.008), whereas there were no differences in setters (56.2%) (p?>?0.05). Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles. PMID:22853746

  12. 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

  13. 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

  14. 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

  15. Comparison of supraspinatus cross-sectional areas according to shoulder abduction angles.

    PubMed

    Kwon, Wonan; Jang, Hyunjeong; Jun, Ilsub

    2015-02-01

    [Purpose] The purpose of this study was to determine the changes in the supraspinatus cross-sectional areas according to shoulder abduction angles, using ultrasonography. [Subjects and Methods] The subjects consisted of 40 individuals (20 males and 20 females). The cross-sectional areas of the supraspinatus of all subjects were measured with ultrasonography at abduction angle of 0°, 30°, 60°, 90°, and 120°. We set four abduction angle levels (I, II, III, and IV), 0° to 30°, 30° to 60°, 60° to 90°, and 90° to 120°, respectively, when determining the largest change in cross-sectional area. [Results] The results revealed that cross-sectional areas of the supraspinatus increased at all levels, but the abduction angle level with the largest increase in cross-sectional area of the supraspinatus was Level III. [Conclusion] The above results indicate that performing exercises at an abduction angle between 60° and 90° will be the most effective for supraspinatus strengthening in clinical practice. PMID:25729211

  16. Comparison of supraspinatus cross-sectional areas according to shoulder abduction angles

    PubMed Central

    Kwon, Wonan; Jang, Hyunjeong; Jun, Ilsub

    2015-01-01

    [Purpose] The purpose of this study was to determine the changes in the supraspinatus cross-sectional areas according to shoulder abduction angles, using ultrasonography. [Subjects and Methods] The subjects consisted of 40 individuals (20 males and 20 females). The cross-sectional areas of the supraspinatus of all subjects were measured with ultrasonography at abduction angle of 0°, 30°, 60°, 90°, and 120°. We set four abduction angle levels (I, II, III, and IV), 0° to 30°, 30° to 60°, 60° to 90°, and 90° to 120°, respectively, when determining the largest change in cross-sectional area. [Results] The results revealed that cross-sectional areas of the supraspinatus increased at all levels, but the abduction angle level with the largest increase in cross-sectional area of the supraspinatus was Level III. [Conclusion] The above results indicate that performing exercises at an abduction angle between 60° and 90° will be the most effective for supraspinatus strengthening in clinical practice. PMID:25729211

  17. 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

  18. 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.

  19. The role of transforming growth factor beta isoforms in tendon-to-bone healing.

    PubMed

    Kim, H Mike; Galatz, Leesa M; Das, Rosalina; Havlioglu, Necat; Rothermich, Stefan Y; Thomopoulos, Stavros

    2011-04-01

    The purpose of this study was to examine the role of two of the three transforming growth factor beta (TGF-?) isoforms at the healing tendon-to-bone insertion. The supraspinatus tendons of 64 rats were transected at their bony insertions and repaired to the humeral head. One shoulder of each rat received an osmotic pump for sustained delivery of the following factors at the repair site: (1) TGF-?1 and neutralizing antibodies to TGF-?2 and 3 (TGF-?1 group), (2) TGF-?3 and neutralizing antibodies to TGF-?1 and 2 (TGF-?3 group), (3) neutralizing antibodies to TGF-?1, 2, and 3 (anti-TGF-? group), and (4) saline (saline group). The contralateral shoulders received saline to serve as paired controls. The repairs were evaluated at multiple time points postmortem using histology-based assays and biomechanical testing. Treated shoulders in the TGF-?1 group showed increased type III collagen production compared to the paired control shoulders, indicative of a scar-mediated response. There was a trend toward reduced mechanical properties in the TGF-?1 group, but these changes did not reach statistical significance. The anti-TGF-? group showed no difference in tissue volume, but significantly inferior mechanical properties, compared to the paired control shoulders. The TGF-?3 group did not show any differences compared to the paired control shoulders. Although TGF-? isoforms play important roles in tendon-to-bone development and healing, application of exogenous TGF-? isoforms and neutralizing antibodies to the subacromial space using osmotic pumps did not improve supraspinatus tendon-to-bone healing. PMID:20615095

  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. 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

  2. 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

  3. Application of a partial-thickness human ex vivo skin culture model in cutaneous wound healing study.

    PubMed

    Xu, Wei; Jong Hong, Seok; Jia, Shengxian; Zhao, Yanan; Galiano, Robert D; Mustoe, Thomas A

    2012-04-01

    A number of in vivo and ex vivo skin models have been applied to human wound healing studies. A reliable skin model, which recapitulates the features of human wound repair, is essential for the clinical and mechanical investigation of human cutaneous wound healing. Full-skin ex vivo culture systems have been used in wound healing studies. However, important structures of the skin, such as the differentiation of keratinocytes and epidermis-dermis junction, are poorly characterized in this model. This study aims to develop an optimized partial-thickness human ex vivo skin culture (HESC) model to maintain human skin characteristics in vitro. During our culture, the basal layer, suprabasal layer, and stratum granulosum layer of epidermis were preserved until day 8. Analyses of hemidesmosome proteins, bullous pemphigoid antigen 1 (BP180) and 2 (BP230), showed that the integrity of the basement membrane of the epidermis was well preserved in the HESC model. In contrast, an organotypic culture with human keratinocytes and fibroblasts failed to show an integrated basement membrane. Maintenance of skin structure by histological analysis and proliferation of epidermal keratinocytes by Ki67 staining were observed in our model for 12 days. Complete re-epithelialization of the wounding area was observed at day 6 post wounding when a superficial incisional wound was created. The expression of Ki-67 and keratin 6, indicators of activated keratinocytes in epidermis, was significantly upregulated and new collagen synthesis was found in the dermis during the wound healing process. As control, we also used organotypic culture in studying the differentiation of the keratinocyte layers and incisional wound repair. It turned out that our model has advantage in these study fields. The results suggest that our HESC model retains important elements of in vivo skin and has significant advantages for the wound healing studies in vitro. PMID:22231737

  4. Role of Endogenous TRPV1 Agonists in a Post-Burn Pain Model of Partial-Thickness Injury

    PubMed Central

    Green, Dustin; Ruparel, Shivani; Roman, Linda; Henry, Michael A.; Hargreaves, Kenneth M.

    2013-01-01

    Oxidized linoleic acid metabolites (OLAMs) are a class of endogenous transient receptor potential vanilloid 1 (TRPV1) channel agonists released upon exposure of tissue to transient noxious temperatures. These lipid compounds also contribute to inflammatory and heat allodynia. As persistent pain after a burn injury represents a significant clinical challenge for treatment, we developed an in vivo rat model of partial thickness cutaneous thermal injury and examined whether TRPV1 and specific OLAM metabolites play a role in mediating post-burn pain injury. This peripheral model of burn injury had marked thermal allodynia peaking at 24 hours post thermal injury, with allodynia being maintained for up to 7 days. Immunohistochemical characterization of tissue taken from injury site revealed an increase of leukocyte/macrophage infiltration that was co-localized with TRPV1-positive fibers. Utilizing this peripheral thermal injury model we found that pharmacological blockade of peripheral TRPV1 receptors reduced thermal allodynia by about 67%. Moreover, there was a significant increase in OLAM levels compared to naïve controls in hindpaw skin biopsies. Additional studies on metabolism of [C14]-linoleic acid in skin biopsies revealed the role of the cytochrome P450 (CYP) system in mediating the metabolism of linoleic acid post thermal injury. Finally, we demonstrated direct inhibition of OLAMs using OLAM antibodies and indirect inhibition using the CYP inhibitor ketoconazole significantly reduced post-burn thermal allodynia. Collectively, these findings point to a novel role of the OLAMs and CYP-related enzymes in generating post-burn allodynia via activation of peripheral TRPV1. PMID:23891895

  5. 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 ...

  6. 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 ...

  7. 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

  8. 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

  9. 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

  10. The efficacy of Helix aspersa Müller extract in the healing of partial thickness burns: a novel treatment for open burn management protocols.

    PubMed

    Tsoutsos, Dimosthenis; Kakagia, Despoina; Tamparopoulos, Konstantinos

    2009-01-01

    Snail extracts have been increasingly used in numerous dermatologic conditions and recent literature attributes healing, soothing and anti-aging properties to them. This study evaluates the efficacy of Helix aspersa extract in an open wound management protocol for deep partial thickness (PT) facial burns and compares it to moist exposure burn ointment(MEBO). A total of 27 adult patients with deep partial thickness facial burns (group A) were treated by application of a snail extract cream twice daily for a maximum period of 14 days or until full epithelialization. Times until debridement and epithelialization of the burn surface were compared with those of 16 patients (group B, control) treated by MEBO. Pain scores were recorded using a visual analogue scale (VAS) on the fourth post-burn day before and 30 min after application. Mean times for eschar detachment were 9 +/- 2 days (group A) and 11 +/- 2 days (group B) (p = 0.003) and for burn surface epithelialization were 11 +/- 2 days and 15 +/- 3 days respectively (p < 0.001). VAS pain scores after application in group A were significantly lower compared to group B (p < 0.001). Helix aspersa extract is a natural, safe and effective alternative treatment in open wound management of partial thickness burns in adults. PMID:19058081

  11. 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

  12. 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

  13. Short and long-term results of clinical effectiveness of sodium hyaluronate injection in supraspinatus tendinitis

    Microsoft Academic Search

    Merih Özgen; Sibel F?rat; Ay?e Sarsan; Oya Topuz; Füsun Ard?ç; Canan Baydemir

    The objective of the study is to evaluate the short- and long-term effect of intraarticular sodium hyaluronate (SH) application\\u000a in patients diagnosed with supraspinatus tendinitis (ST) that have shoulder pain on the clinical symptoms of the patients\\u000a through comparison with conventional physiotherapy methods. A total of 24 patients were included in the study and were randomized\\u000a into two groups.SH injection

  14. A prospective randomized trial comparing silver sulfadiazine cream with a water-soluble polyantimicrobial gel in partial-thickness burn wounds.

    PubMed

    Black, Jonathan S; Drake, David B

    2015-01-01

    The lipid base of silver sulfadiazine (SSD) makes removal of the product painful for the patient and difficult for the physician to accurately assess particularly in partial-thickness burn injuries. As an alternative, a water-soluble antimicrobial gel is used at the University of Virginia. We present a prospective, randomized comparison of these two therapies using pain with dressing changes and time to perform dressing changes as our primary endpoints. Adult inpatients with partial-thickness burn wounds were randomized to begin therapy with either SSD cream or the water-soluble burn wound gel (BWG), and then therapies were alternated daily. Pain assessments, time to complete dressing care, total narcotic medication administered, and the number of personnel required for dressing changes were recorded. Eight patients were enrolled resulting in 13 pairs (26 points) of data comparison between the two therapies. Four of the eight enrolled patients (50%) refused to continue receiving SSD because of pain associated with dressing changes and voluntarily withdrew from the study. The amount of time to perform dressing changes was an average of 79 nurse-minutes longer for SSD. A 6.08 greater morphine equivalent was delivered to those having BWG removed.A water-soluble polyantimicrobial gel was superior to SSD in the parameters measured as exhibited by our patient dropout rate and differential time to perform dressing care. Limiting the time to perform dressing care will reduce the cumulative pain experience, improve patient satisfaction, and reduce the resources to deliver care. PMID:25730540

  15. Management of the Acute Partial-thickness Burned Hand; Moist Exposed Burn Ointment or Silver Sulphadiazine Cream both Combined with a Polyethylene Bag

    PubMed Central

    Allam, A.M.; Mostafa, W.; Zayed, E.; El-Gamaly, J.

    2007-01-01

    Summary Hand burns predominantly affect young adults, and therefore have serious social and financial implications. In the present work, 106 patients with less than 25% body surface area burns and acute partial-thickness burned hands were managed using polyethylene bags and 1% local silver sulphadiazine (SSD) cream or moist exposed burn ointment (MEBO). Females made up 61.3% of the cases and flame burn was the majority cause (54.7%). There were no significant differences between the two groups regarding either the analgesic effect after local ointment application or hand movement inside the polyethylene bag. Local agent crustation over the wound was very evident in the hands managed by local 1% SSD cream (69.81%). On follow-up, the burned hands healed faster using local MEBO (10.48 versus 14.53 days), with fewer post-burn hand deformities and better active hand movements; however, the total cost until complete hand burn wound healing was higher with MEBO than with 1% SSD, although the final results were superior, with early return to work, when MEBO was used. We concluded that the use of MEBO as a topical agent and of polyethylene bags for the dressing of the acute partial-thickness burned hand accelerated healing; daily wound evaluation was easy as there was no crustation over it of the agent. It was more expensive than 1% SSD cream but presented fewer post-burn complications and more rapid healing, with shorter hospital stay. PMID:21991086

  16. 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

  17. 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

  18. 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

  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. Effects of botulinum-toxin-induced paralysis on postnatal development of the supraspinatus muscle

    PubMed Central

    Rosalina, Das; Jason, Rich; Mike, Kim H.; Audrey, McAlinden; Stavros, Thomopoulos

    2013-01-01

    The mechanical environment plays an important role in musculoskeletal tissue development. The present study characterized changes in supraspinatus muscle due to removal of mechanical cues during postnatal development. An intramuscular injection of botulinum toxin type A (BTX) was used to induce and maintain paralysis in the left shoulders of mice since birth while the right shoulders received saline and served as contralateral controls. A separate group of animals was allowed to develop normally without any injections. Muscles were examined postnatally at various time points. The maximum isometric tetanic force generated by the muscle was significantly reduced in the BTX group compared to saline and normal groups. The paralyzed muscles were smaller and showed significant muscle atrophy and fat accumulation on histologic evaluation. Myogenic genes myogenin, myoD1, myf5, myf6 and fast type II myosin heavy chain (MHC) isoform were significantly upregulated while slow type I MHC isoform was significantly downregulated in the BTX group. Adipogenic genes C/EBP?, PPAR?2, leptin and lipoprotein lipase were significantly upregulated in the BTX group. Results indicate that reduced muscle loading secondary to BTX-induced paralysis leads to fat accumulation and muscle degeneration in the developing muscle. Understanding the molecular and compositional changes in developing supraspinatus muscles may be useful for identifying and addressing the pathological changes that occur in shoulder injuries such as neonatal brachial plexus palsy. PMID:20803483

  2. 3D Shape Analysis of the Supraspinatus Muscle: A Clinical Study of the Relationship Between Shape and Pathology1

    E-print Network

    Hamarneh, Ghassan

    to meet this goal. Key Words. Rotator cuff; supraspinatus; shoulder pathology; tear; atrophy; retraction and Objectives. Rotator cuff disorders are prevalent and can cause pain and reduced range of motion and strength. Accurate, noninvasive diagnosis of rotator cuff disorders is therefore important. In this work, we study

  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. 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

  5. Assessment of marginal bone loss using full thickness versus partial thickness flaps for alveolar ridge splitting and immediate implant placement in the anterior maxilla.

    PubMed

    Mounir, M; Beheiri, G; El-Beialy, W

    2014-11-01

    The aim of this study was to evaluate the effectiveness of maintaining the periosteal attachment of the facial and palatal cortical plates on crestal bone loss that occurs at the margin of dental implants placed immediately in split anterior maxillary alveolar ridges. This was a prospective randomized comparative clinical trial. The study population included 22 patients with edentulous anterior maxillary alveolar ridges who presented for treatment during the period March 2012 to September 2013. The selected patients were divided randomly into two equal groups. All patients underwent a maxillary ridge splitting technique; a total of 43 implants were placed immediately. A full thickness mucoperiosteal flap was performed in the control group patients, while a split thickness mucosal flap was done in the study group patients. Assessments included measurements of the linear changes in the marginal bone surrounding the implants immediately postoperative and after 6 months. Measurements were taken from cross-sectional and longitudinal cone beam computed tomography images using special software. The partial thickness flap used in the study group decreased the percentage of bone loss by 9.5% for the labial bone plate, 7.9% for the palatal bone plate, and 3.5% for the mesiodistal bone plate. PMID:24973295

  6. Effect of red and near-infrared wavelengths on low-level laser (light) therapy-induced healing of partial-thickness dermal abrasion in mice.

    PubMed

    Gupta, Asheesh; Dai, Tianhong; Hamblin, Michael R

    2014-01-01

    Low-level laser (light) therapy (LLLT) promotes wound healing, reduces pain and inflammation, and prevents tissue death. Studies have explored the effects of various radiant exposures on the effect of LLLT; however, studies of wavelength dependency in in vivo models are less common. In the present study, the healing effects of LLLT mediated by different wavelengths of light in the red and near-infrared (NIR) wavelength regions (635, 730, 810, and 980 nm) delivered at constant fluence (4 J/cm(2)) and fluence rate (10 mW/cm(2)) were evaluated in a mouse model of partial-thickness dermal abrasion. Wavelengths of 635 and 810 nm were found to be effective in promoting the healing of dermal abrasions. However, treatment using 730- and 980-nm wavelengths showed no sign of stimulated healing. Healing was maximally augmented in mice treated with an 810-nm wavelength, as evidenced by significant wound area reduction (p < 0.05), enhanced collagen accumulation, and complete re-epithelialization as compared to other wavelengths and non-illuminated controls. Significant acceleration of re-epithelialization and cellular proliferation revealed by immunofluorescence staining for cytokeratin-14 and proliferating cell nuclear antigen (p < 0.05) was evident in the 810-nm wavelength compared with other groups. Photobiomodulation mediated by red (635 nm) and NIR (810 nm) light suggests that the biological response of the wound tissue depends on the wavelength employed. The effectiveness of 810-nm wavelength agrees with previous publications and, together with the partial effectiveness of 635 nm and the ineffectiveness of 730 and 980 nm wavelengths, can be explained by the absorption spectrum of cytochrome c oxidase, the candidate mitochondrial chromophore in LLLT. PMID:23619627

  7. Effect of red and near infrared wavelengths on low-level laser (light) therapy induced healing of partial-thickness dermal abrasion in mice

    PubMed Central

    Gupta, Asheesh; Dai, Tianhong; Hamblin, Michael R.

    2013-01-01

    Low-level laser (light) therapy (LLLT) promotes wound healing, reduce pain, inflammation, and prevent tissue death. Studies have explored the effects of various radiant exposures on the effect of LLLT, however studies of wavelength dependency in in vivo models are less common. In the present study, healing effects of LLLT mediated by different wavelengths of light in the red and near infrared (NIR) wavelength region (635, 730, 810 and 980 nm) delivered at constant fluence (4 J/cm2) and fluence rate (10 mW/cm2) were evaluated in a mouse model of partial-thickness dermal abrasion. 635 and 810 nm wavelengths were found to be effective in promoting healing of dermal abrasions. However, treatment using 730 and 980 nm wavelengths showed no sign of stimulated healing. Healing was maximally augmented in mice treated with 810 nm as evidenced by a significant wound area reduction (p < 0.05), enhanced collagen accumulation, and complete re-epithelialization as compared to other wavelengths and non-illuminated controls. A significant acceleration of re-epithelialization and cellular proliferation revealed by immunofluorescence staining for cytokeratin-14 and proliferating cell nuclear antigen (PCNA) (p < 0.05) was evident in 810 nm compared with other groups. Photobiomodulation mediated by red (635 nm) and NIR (810 nm) light suggests that the biological response of the wound tissue depends on the wavelength employed. The effectiveness of 810 nm agrees with previous publications, and together with the partial effectiveness of 635 nm and ineffectiveness of 730 and 980 nm can be explained by the absorption spectrum of cytochrome c oxidase, the candidate mitochondrial chromophore in LLLT. PMID:23619627

  8. 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

  9. 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

  10. 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.

  11. A Bullet in the Supraspinatus Compartment Successfully Removed by Arthroscopy: Case Report and Review of the Literature

    PubMed Central

    Galland, Alexandre; Lunebourg, Alexandre; Airaudi, Stéphane; Gravier, Renaud

    2015-01-01

    Arthroscopic removal of bullet from intra-articular compartment has been described for several joints. Only few reports dealing with this condition in the shoulder have been reported especially for the glenohumeral and the subacromial compartments. We report the story of a fifty-seven-year-old man presenting a bullet in the supraspinatus compartment of his left shoulder successfully removed by arthroscopy. PMID:25699194

  12. Learning Fourier Descriptors for Computer-Aided Diagnosis of the Supraspinatus1

    E-print Network

    Hamarneh, Ghassan

    of the rotator cuff, which is a group of muscles and tendons responsible for shoulder movement and stabilization. Disorders affecting the rotator cuff can cause pain and reduce patient mobility [1], and their occurrence. The standard procedure for the diagnosis of rotator cuff disorders is shoulder arthroscopy, which is a surgery

  13. 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

  14. 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

  15. [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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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

  9. The Changes of Electromyography in the Upper Trapezius and Supraspinatus of Women College Students According to the Method of Bag-carrying and Weight.

    PubMed

    Cho, Sung-Hyoun; Lee, Jung-Ho; Kim, Cheol-Yong

    2013-09-01

    [Purpose] The purpose of this study was to investigate differences in upper extremity muscle activities of women college students' due to method of bag-carrying and weight. [Subjects] Thirty healthy adult females participated in this study. The exclusion criteria were orthopedic or neurologic disease, or a dominant left side. [Methods] Electromyographic activities of the supraspinatus and upper trapezius were recorded bilaterally under two conditions: crossbody bag, ipsilateral bag. [Results] There were no significant differences in the supraspinatus and upper trapezius muscles according to the weight carried; however, there was significant difference in the right supraspinatus and both upper trapezius muscles according to the method of carrying. [Conclusion] An effective backpack safety program for female college students is necessary to educate them how to prevent possible musculoskeletal pain related to the weight carried and the method of carrying from the perspective of an ergonomical approach. PMID:24259929

  10. The Changes of Electromyography in the Upper Trapezius and Supraspinatus of Women College Students According to the Method of Bag-carrying and Weight

    PubMed Central

    Cho, Sung-Hyoun; Lee, Jung-Ho; Kim, Cheol-Yong

    2013-01-01

    [Purpose] The purpose of this study was to investigate differences in upper extremity muscle activities of women college students' due to method of bag-carrying and weight. [Subjects] Thirty healthy adult females participated in this study. The exclusion criteria were orthopedic or neurologic disease, or a dominant left side. [Methods] Electromyographic activities of the supraspinatus and upper trapezius were recorded bilaterally under two conditions: crossbody bag, ipsilateral bag. [Results] There were no significant differences in the supraspinatus and upper trapezius muscles according to the weight carried; however, there was significant difference in the right supraspinatus and both upper trapezius muscles according to the method of carrying. [Conclusion] An effective backpack safety program for female college students is necessary to educate them how to prevent possible musculoskeletal pain related to the weight carried and the method of carrying from the perspective of an ergonomical approach. PMID:24259929

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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. ...

  12. 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

  13. 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

  14. 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

  15. 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

  16. [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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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...

  11. 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 (\\

  12. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  13. 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

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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,

  7. 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

  8. [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

  9. 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

  10. 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

  11. Supraspinatus and infraspinatus weakness in overhead athletes with scapular dyskinesis: strength assessment before and after restoration of scapular musculature balance.

    PubMed

    Merolla, Giovanni; De Santis, Elisa; Campi, Fabrizio; Paladini, Paolo; Porcellini, Giuseppe

    2010-12-01

    A disturbance in scapulohumeral rhythm may cause negative biomechanic effects on rotator cuff (RC). Alteration in scapular motion and shoulder pain can influence RC strength. Purpose of this study was to assess supraspinatus and infraspinatus strength in 29 overhead athletes with scapular dyskinesis, before and after 3 and 6 months of rehabilitation aimed to restore scapular musculature balance. A passive posterior soft tissues stretching was prescribed to balance shoulder mobility. Scapular dyskinesis patterns were evaluated according to Kibler et al. Clinical assessment was performed with the empty can (EC) test and infraspinatus strength test (IST). Strength values were recorded by a dynamometer; scores for pain were assessed with VAS scale. Changes of shoulder IR were measured. The force values increased at 3 months (P < 0.01) and at 6 months (P < 0.01). Changes of glenohumeral IR and decrease in pain scores were found at both follow-up. Outcomes registered on pain and strength confirm the role of a proper scapular position for an optimal length-tension relationship of the RC muscles. These data should encourage those caring for athletes to consider restoring of scapular musculature balance as essential part of the athletic training. PMID:21069487

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  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. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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,

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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,

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. [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

  18. 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 ...

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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...

  20. 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

  1. 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

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

    PubMed Central

    Palumbo, Carla; Rovesta, Claudio; Ferretti, Marzia

    2012-01-01

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

  3. Spontaneous isolated rupture of popliteus tendon presenting as locked knee: case study and literature review

    Microsoft Academic Search

    Ehab Kheir; Ali Ghoz; K. Gorgees; David MacDonald; David Limb; Peter Giannoudis

    2006-01-01

    Traumatic isolated rupture of the popliteus tendon has been described as a rare cause of haemarthrosis of the knee. There has been only one reported case of spontaneous rupture of the popliteus tendon in the English literature before. We present the case of a 70-year-old lady who had spontaneous rupture of the popliteus tendon without history of significant trauma. She

  4. An experimental investigation of friction and wear of polyethylene sheathings of external tendons at deviation points

    Microsoft Academic Search

    Hermann Weiher; Konrad Zilch

    This article is dealing with the experimental inves tigation of friction and wear of polyethylene sheat hings under extreme loading. PE-sheathings are used as corrosion protec tion system of external tendons of post tensioned c oncrete bridges. At deviation points the material is stressed perpen dicular to the axis of the steel tendons. Whilst lo ad is applied the tendons

  5. Ultrasound echo is related to stress and strain in tendon Sarah Duenwald a

    E-print Network

    Lakes, Roderic

    n f o Article history: Accepted 30 September 2010 Keywords: Tendon Ultrasound Echo intensity of tendon in vitro. Porcine digital flexor tendons were cyclically loaded in a mechanical testing system, and is a promising metric to acquire in vivo mechanical data noninvasively. & 2010 Elsevier Ltd. All rights reserved

  6. Autogenous palmaris longus tendon as frontalis suspension material for ptosis correction in children

    Microsoft Academic Search

    Dennis S. C. Lam; Joan S. K. Ng; George P. M. Cheng; Randa T. H. Li

    1998-01-01

    Purpose: To determine the safety and efficacy of autogenous palmaris longus tendon as a sling material in frontalis suspension surgery for ptosis correction in children.Methods: In a prospective study, the authors evaluated 15 frontalis sling suspension surgeries using palmaris longus tendon in 14 consecutive children with congenital ptosis. The method of harvesting the palmaris longus tendon is described in detail.Results:

  7. Early active mobilization of tendon grafts using mesh reinforced suture techniques

    Microsoft Academic Search

    K. L. Silfverskiöld; E. J. May

    1995-01-01

    The flexor digitorum profundus tendon in 11 digits with division of both flexor tendons in zone 2 was reconstructed with a palmaris longus tendon graft in a two-stage procedure. The distal and proximal fixation of the graft was reinforced with a polyester mesh sleeve placed around the ends of the graft during stage 1. All digits were mobilized with a

  8. Cut Palmaris Longus Tendon—To Repair or not to Repair?

    Microsoft Academic Search

    K. SARANGAPANI; H. G. BROWN

    1977-01-01

    It is suggested in certain circumstances, that a divided palmaris longus tendon should be repaired, as it is an ideal choice for a tendon graft, or could be of use as a tendon transfer. The musculotendinous unit may be of use as an autogenous free graft.

  9. Conservative management of partial extensor tendon lacerations greater than half the width of the tendon in manual workers.

    PubMed

    Al-Qattan, Mohammad M

    2015-04-01

    Conservative management (without suturing or splints) of partial extensor tendon lacerations greater than half the width of the tendon has not been previously investigated. In this prospective study, a total of 45 injured tendons (with lacerations involving 55%-90% of the width of the tendon) in 39 patients were treated conservatively. Injury zones I, III, and V of the fingers; and zones I and III of the thumb were excluded. Immediate non-resistive active mobilization was initiated and continued for 4 weeks, followed by resistive exercises. Patients were allowed to go back to work after 6 weeks. There were no cases of ruptures, triggering, infection, or complex regional pain syndrome. At final follow-up (8-9 months after injury), all patients obtained full range of motion with no extension lags. All patients were able to go back to normal duties. We conclude that early active motion without the use of splints or sutures in major extensor tendon lacerations in zones II, IV, VI-VIII of the fingers; and zones II, IV, and V of the thumb is safe. PMID:25749213

  10. Stem cell research and clinical development in tendon repair

    PubMed Central

    Filomeno, Paola; Dayan, Victor; Touriño, Cristina

    2012-01-01

    Summary Stem cells are one of the most fascinating areas in regenerative medicine today. They play a crucial role in development and regeneration and are defined as cells that continuously reproduce themselves while maintaining the ability to differentiate into various cell types. Stem cells are found at all developmental stages, from embryonic stem cells (ESCs) which differentiate into all cell types, to adult stem cells (ASCs) which are responsible for tissue regeneration. Studies using animal models have shown promising results following cell therapy for induced injury in musculoskeletal system, including tendon healing, but the results can be variable. Alternative sources for cell therapy in tendon pathology may include ESCs, ASCs (bone marrow, adipose tissue or tendon derived stem cells) or induced pluripotent stem cells (iPSCs). While ethical and safety concerns currently forbid clinical application of ESCs and iPSCs, initial clinical trials with ASCs are promising. PMID:23738298

  11. 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

  12. 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.

  13. Torque resolver design for tendon-driven manipulators

    SciTech Connect

    Lee, J.J.; Tsai, Lung-Wen

    1992-08-01

    Given a set of desired joint torques in an n-DOF tendon-driven manipulator with n + 1 control tendons, the determination of tendon forces is an indeterminate problem. Usually, the pseudo-inverse technique is used to solve for such a problem. In this paper, rather than using the pseudo-inverse technique is used to solve for such a problem. In this paper, rather than using the pseudo-inverse technique, an efficient methodology for transforming joint torques (n elements) to motor torques (n + 1 elements) has been developed. This technique called ``torque resolver``, utilizes two circuit-like operators to transform torques between the two different vector spaces. It can be easily programmed on a digital computer or implemented into an analog-circuit system. It is hoped that this technique will make real-time computed-torque control feasible. The technique has been demonstrated through the dynamic simulation of a three-DOF manipulator.

  14. Torque resolver design for tendon-driven manipulators

    SciTech Connect

    Lee, J.J.; Tsai, Lung-Wen.

    1992-01-01

    Given a set of desired joint torques in an n-DOF tendon-driven manipulator with n + 1 control tendons, the determination of tendon forces is an indeterminate problem. Usually, the pseudo-inverse technique is used to solve for such a problem. In this paper, rather than using the pseudo-inverse technique is used to solve for such a problem. In this paper, rather than using the pseudo-inverse technique, an efficient methodology for transforming joint torques (n elements) to motor torques (n + 1 elements) has been developed. This technique called torque resolver'', utilizes two circuit-like operators to transform torques between the two different vector spaces. It can be easily programmed on a digital computer or implemented into an analog-circuit system. It is hoped that this technique will make real-time computed-torque control feasible. The technique has been demonstrated through the dynamic simulation of a three-DOF manipulator.

  15. Surgical treatment options for patella tendon rupture, Part I: Acute.

    PubMed

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

    2005-07-01

    Patella tendon rupture is a debilitating injury. Prompt diagnosis and treatment is essential to prevent retraction of the patella with subsequent adhesions and quadriceps contractures. In a young patient with an acute rupture, primary repair usually is possible with various methods described to protect the repair. In acute injuries with inadequate tissue, augmentation with hamstring tendons or allograft generally is necessary. Because of the different types of rupture and the possibility for poor quality tissue, the surgeon should always be prepared to combine different techniques to obtain tthe best repair. Continuous passive motion generally can be initiated early with a secure repair. In patients with a patella tendon ruptured that is promptly diagnosed, securely repaired, and followed closely through their rehabilitation, good results can be expected. PMID:16119282

  16. Stem cell research and clinical development in tendon repair.

    PubMed

    Filomeno, Paola; Dayan, Victor; Touriño, Cristina

    2012-07-01

    Stem cells are one of the most fascinating areas in regenerative medicine today. They play a crucial role in development and regeneration and are defined as cells that continuously reproduce themselves while maintaining the ability to differentiate into various cell types. Stem cells are found at all developmental stages, from embryonic stem cells (ESCs) which differentiate into all cell types, to adult stem cells (ASCs) which are responsible for tissue regeneration. Studies using animal models have shown promising results following cell therapy for induced injury in musculoskeletal system, including tendon healing, but the results can be variable. Alternative sources for cell therapy in tendon pathology may include ESCs, ASCs (bone marrow, adipose tissue or tendon derived stem cells) or induced pluripotent stem cells (iPSCs). While ethical and safety concerns currently forbid clinical application of ESCs and iPSCs, initial clinical trials with ASCs are promising. PMID:23738298

  17. Posterior Tibial Tendon Dysfunction: An Overlooked Cause of Foot Deformity

    PubMed Central

    Bubra, Preet Singh; Keighley, Geffrey; Rateesh, Shruti; Carmody, David

    2015-01-01

    Posterior tibial tendon dysfunction is the most common cause of adult acquired flatfoot. Degenerative changes in this tendon, lead to pain and weakness and if not identified and treated will progress to deformity of the foot and degenerative changes in the surrounding joints. Patients will complain of medial foot pain, weakness, and a slowly progressive foot deformity. A “too many toes” sign may be present and patients will be unable to perform a single heal raise test. Investigations such X-ray, ultrasound and magnetic resonance imaging will help stage the disease and decide on management. The optimal manage may change based on the progression of deformity and stage of disease. Early identification and prompt initiation of treatment can halt progression of the disease. The purpose of this article is to examine the causes, signs, symptoms, examinations, investigations and treatment options for posterior tibial tendon dysfunction.

  18. Ultrasound elasticity imaging of human posterior tibial tendon

    NASA Astrophysics Data System (ADS)

    Gao, Liang

    Posterior tibial tendon dysfunction (PTTD) is a common degenerative condition leading to a severe impairment of gait. There is currently no effective method to determine whether a patient with advanced PTTD would benefit from several months of bracing and physical therapy or ultimately require surgery. Tendon degeneration is closely associated with irreversible degradation of its collagen structure, leading to changes to its mechanical properties. If these properties could be monitored in vivo, it could be used to quantify the severity of tendonosis and help determine the appropriate treatment. Ultrasound elasticity imaging (UEI) is a real-time, noninvasive technique to objectively measure mechanical properties in soft tissue. It consists of acquiring a sequence of ultrasound frames and applying speckle tracking to estimate displacement and strain at each pixel. The goals of my dissertation were to 1) use acoustic simulations to investigate the performance of UEI during tendon deformation with different geometries; 2) develop and validate UEI as a potentially noninvasive technique for quantifying tendon mechanical properties in human cadaver experiments; 3) design a platform for UEI to measure mechanical properties of the PTT in vivo and determine whether there are detectable and quantifiable differences between healthy and diseased tendons. First, ultrasound simulations of tendon deformation were performed using an acoustic modeling program. The effects of different tendon geometries (cylinder and curved cylinder) on the performance of UEI were investigated. Modeling results indicated that UEI accurately estimated the strain in the cylinder geometry, but underestimated in the curved cylinder. The simulation also predicted that the out-of-the-plane motion of the PTT would cause a non-uniform strain pattern within incompressible homogeneous isotropic material. However, to average within a small region of interest determined by principal component analysis (PCA) would improve the estimation. Next, UEI was performed on five human cadaver feet mounted in a materials testing system (MTS) while the PTT was attached to a force actuator. A portable ultrasound scanner collected 2D data during loading cycles. Young's modulus was calculated from the strain, loading force and cross sectional area of the PTT. Average Young's modulus for the five tendons was (0.45+/-0.16GPa) using UEI. This was consistent with simultaneous measurements made by the MTS across the whole tendon (0.52+/-0.18GPa). We also calculated the scaling factor (0.12+/-0.01) between the load on the PTT and the inversion force at the forefoot, a measurable quantity in vivo. This study suggests that UEI could be a reliable in vivo technique for estimating the mechanical properties of the human PTT. Finally, we built a custom ankle inversion platform for in vivo imaging of human subjects (eight healthy volunteers and nine advanced PTTD patients). We found non-linear elastic properties of the PTTD, which could be quantified by the slope between the elastic modulus (E) and the inversion force (F). This slope (DeltaE/DeltaF), or Non-linear Elasticity Parameter (NEP), was significantly different for the two groups: 0.16+/-0.20 MPa/N for healthy tendons and 0.45+/-0.43 MPa/N for PTTD tendons. A receiver operating characteristic (ROC) curve revealed an area under the curve (AUC) of 0.83+/-0.07, which indicated that the classifier system is valid. In summary, the acoustic modeling, cadaveric studies, and in vivo experiments together demonstrated that UEI accurately quantifies tendon mechanical properties. As a valuable clinical tool, UEI also has the potential to help guide treatment decisions for advanced PTTD and other tendinopathies.

  19. Presence of lymphatics in a rat tendon lesion model.

    PubMed

    Tempfer, Herbert; Kaser-Eichberger, Alexandra; Korntner, Stefanie; Lehner, Christine; Kunkel, Nadja; Traweger, Andreas; Trost, Andrea; Strohmaier, Clemens; Bogner, Barbara; Runge, Christian; Bruckner, Daniela; Krefft, Karolina; Heindl, Ludwig M; Reitsamer, Herbert A; Schrödl, Falk

    2015-04-01

    Tendons lack sufficient blood supply and represent a bradytroph tissue with prolonged healing time under pathological conditions. While the role of lymphatics in wound/defect healing in tissues with regular blood supply is well investigated, its involvement in tendon defects is not clear. We here try to identify the role of the lymphatic system in a tendon lesion model with morphological methods. A rat Achilles tendon lesion model (n = 5) was created via surgical intervention. Two weeks after surgery, animals were killed and lesioned site removed and prepared for polarization microscopy (picrosirius red) and immunohistochemistry using the lymphatic markers PROX1, VEGFR3, CCL21, LYVE-1, PDPN, and the vascular marker CD31. Additionally, DAPI was applied. Untreated tendons served as controls, confocal laser-scanning microscopy was used for documentation. At the lesion site, polarization microscopy revealed a structural reintegration while immunohistochemistry detected band-like profiles immunoreactive for PDPN, VEGFR3, CCL21, LYVE1, and CD31, surrounding DAPI-positive nuclei. PROX1-positive nuclei were detected within the lesion forming lines and opposed to each other. These PROX1-positive nuclei were surrounded by LYVE-1- or VEGFR3-positive surfaces. Few CD31-positve profiles contained PROX1-positive nuclei, while the majority of CD31-positive profiles lacked PROX1-positive nuclei. VEGFR3-, PDPN-, and LYVE-1-positive profiles were numerous within the lesion site, but absent in control tissue. Within 2 weeks, a structural rearrangement takes place in this lesion model, with dense lymphatic supply. The role of lymphatics in tendon wound healing is unclear, and proposed model represents a good possibility to study healing dynamics and lymphangiogenesis in a tissue almost completely lacking lymphatics in physiological conditions. PMID:25371325

  20. [Tendon entrapment after forearm distal bones fracture, case report].

    PubMed

    Piquilloud, G; Drapé, J-L; Guerini, H; Le Viet, D

    2011-09-01

    In the aftermath of a forearm trauma, tendon contractures are difficult to diagnose and evoke nerve compression or muscle ischemia (Volkmann's syndrome). One rarely thinks of tendon incarceration within the fracture and the diagnosis is often made long after. During claw fingers retraction, it is known as "false Volkmann's syndrome" (Baudet and Lafond, 1979) or "pseudo Volkmann's syndrome" (Deeney et al., 1998). The authors report the case of ulnar claw fingers retraction, one year after a fracture of both bones of the forearm, treated surgically with recuperation of normal mobility immediately after emergence of the conflict. PMID:21856201

  1. Intermittent dislocation of the flexor hallucis longus tendon.

    PubMed

    Renard, M; Simonet, J; Bencteux, P; Raynaud, P; Biga, N; Thiébot, J

    2003-02-01

    Dislocation of the flexor hallucis longus tendon is an exceptional occurrence. To our knowledge, this is the first case ever reported of an intermittent dislocation in a 17-year-old woman; she was a synchronised swimmer. She consulted for a right internal retro-malleolar syndrome. Voluntary "snap" was triggered by a mechanism which combined maximal ankle dorsiflexion and interphalangeal plantar flexion of the toes. Non-enhanced dynamic helical CT and axial MRI were performed, which revealed the dislocation of the right flexor hallucis longus tendon outside the posterior intertubercular talar groove. Static and dynamic imaging would appear to be required to make this uncommon diagnosis. PMID:12589485

  2. Bilateral carpal tunnel syndrome with anomalous palmaris profundus tendons.

    PubMed

    Razik, Aisha; Avisar, Erez; Sorene, Elliot

    2012-12-01

    This report presents the case of a 44-year-old man who presented with elective bilateral carpal tunnel decompression. At the operation, he was found to have bilateral palmaris profundus tendons within the carpal tunnel, impinging on the median nerve. In releasing both carpal tunnels, the patient's symptoms were alleviated and there was regain of full function. There have been very few documented cases of these anomalous tendons implicated in carpal tunnel syndrome and this case highlights how such anatomical variations are important in the surgical approach to carpal tunnel decompression. PMID:23088639

  3. A 7Year Follow-up of Patellar Tendon and Hamstring Tendon Grafts for Arthroscopic Anterior Cruciate Ligament ReconstructionDifferences and Similarities

    Microsoft Academic Search

    Justin Roe; Leo A. Pinczewski; Vivianne J. Russell; Lucy J. Salmon; Tomomaro Kawamata; Melvin Chew

    2005-01-01

    Background: For arthroscopic anterior cruciate ligament reconstruction, the most commonly used graft constructs are either the hamstring tendon or patellar tendon. Well-controlled, long-term studies are needed to determine the differences between the 2 materials.Hypothesis: There is a difference between hamstring and patellar tendon grafts in the clinical results of anterior cruciate ligament reconstructions at 7 years.Study Design: Cohort study; Level

  4. Histopathological and biomechanical evaluation of tenocyte seeded allografts on rat Achilles tendon regeneration.

    PubMed

    Güngörmü?, Cans?n; Kolankaya, Dürdane; Aydin, Erkin

    2015-05-01

    Tendon injuries in humans as well as in animals' veterinary medicine are problematic because tendon has poor regenerative capacity and complete regeneration of the ruptured tendon is never achieved. In the last decade there has been an increasing need of treatment methods with different approaches. The aim of the current study was to improve the regeneration process of rat Achilles tendon with tenocyte seeded decellularized tendon matrices. For this purpose, Achilles tendons were harvested, decellularized and seeded as a mixture of three consecutive passages of tenocytes at a density of 1 × 10(6) cells/ml. Specifically, cells with different passage numbers were compared with respect to growth characteristics, cellular senescence and collagen/tenocyte marker production before seeding process. The viability of reseeded tendon constructs was followed postoperatively up to 6 months in rat Achilles tendon by histopathological and biomechanical analysis. Our results suggests that tenocyte seeded decellularized tendon matrix can significantly improve the histological and biomechanical properties of tendon repair tissue without causing adverse immune reactions. To the best of our knowledge, this is the first long-term study in the literature which was accomplished to prove the use of decellularized matrix in a clinically relevant model of rat Achilles tendon and the method suggested herein might have important implications for translation into the clinic. PMID:25771002

  5. Ultrasound characteristics of the patellar and quadriceps tendons among young elite athletes.

    PubMed

    Visnes, H; Tegnander, A; Bahr, R

    2015-04-01

    Tendons adapt in response to sports-specific loading, but sometimes develop tendinopathy. If the presence of ultrasound changes like hypoechoic areas and neovascularization in asymptomatic tendons precede (and predict) future tendon problems is unknown. The aim of this prospective cohort study was to investigate the relationship between the development of ultrasound changes in the patellar and quadriceps tendons and symptoms of jumper's knee, as well to examine the medium-term effects of intensive training on tendon thickness among adolescent athletes. Elite junior volleyball athletes were followed with semi-annual ultrasound and clinical examinations (average follow-up: 1.7 years). Of the 141 asymptomatic athletes included, 22 athletes (35 patellar tendons) developed jumper's knee. In a multivariate logistic regression analysis, a baseline finding of a hypoechoic tendon area (odds ratio 3.3, 95% confidence interval 1.1 to 9.2) increased the risk of developing symptoms of jumper's knee. Patellar tendon thickness among healthy athletes did not change (Wilk's lambda, P?=?0.07) while quadriceps tendon thickness increased (P?=?0.001). In conclusion, ultrasound changes at baseline were risk factors for developing symptoms of jumper's knee. Also, among healthy athletes, we observed a 7-11% increase in quadriceps tendon thickness, while there was no increase in patellar tendon thickness. PMID:24612006

  6. In vivo strain of the medial vs. lateral quadriceps tendon in patellofemoral pain syndrome.

    PubMed

    Wilson, Nicole A; Press, Joel M; Zhang, Li-Qun

    2009-08-01

    Patellofemoral pain (PFP) is thought to be related to patellar maltracking due to imbalances in the knee extensor. However, no study has evaluated the in vivo biomechanical properties of the quadriceps tendon in PFP syndrome. Our purpose was to compare the biomechanical properties of the quadriceps tendons in vivo and noninvasively in patients with PFP syndrome to those of control subjects. The null hypothesis was that the quadriceps tendons of PFP subjects would have significantly decreased strain compared with control subjects. Fourteen subjects (7 control, 7 PFP) performed voluntary ramp isometric contractions to a range of torque levels, while quadriceps tendon elongation was measured using ultrasonography. Tendon strain was calculated for the vastus medialis obliquus (VMO) and vastus lateralis (VL) portion of the quadriceps tendon and compared between subjects (control vs. PFP) and within subjects (VMO vs. VL). PFP subjects showed significantly less VMO tendon strain than control subjects (P<0.001), but there was no difference in VL tendon strain between PFP and control subjects (P=0.100). Relative weakness of the VMO is the most likely cause of the decreased tendon strain seen in subjects with PFP. VMO weakness not only explains the decreased medial tendon strain but also explains the presence of increased lateral patellar translation and lateral patellar spin (distal pole rotates laterally) reported in the literature in this population. This technique can potentially be used in a clinical setting to evaluate quadriceps tendon properties and infer the presence of muscle weakness in PFP. PMID:19541742

  7. The Role of Mechanical Loading in Tendon Development, Maintenance, Injury, and Repair

    PubMed Central

    Galloway, Marc T.; Lalley, Andrea L.; Shearn, Jason T.

    2013-01-01

    ? Tendon injuries often result from excessive or insufficient mechanical loading, impairing the ability of the local tendon cell population to maintain normal tendon function. ? The resident cell population composing tendon tissue is mechanosensitive, given that the cells are able to alter the extracellular matrix in response to modifications of the local loading environment. ? Natural tendon healing is insufficient, characterized by improper collagen fibril diameter formation, collagen fibril distribution, and overall fibril misalignment. ? Current tendon repair rehabilitation protocols focus on implementing early, well-controlled eccentric loading exercises to improve repair outcome. ? Tissue engineers look toward incorporating mechanical loading regimens to precondition cell populations for the creation of improved biological augmentations for tendon repair. PMID:24005204

  8. BME 315 Biomechanics Experiment 4. Fall 2006. Deformation of tendon

    E-print Network

    Lakes, Roderic

    be easily damaged by even the most superficial cuts. To remove the skin, make an incision longitudinally will have the skin attached; skin must be removed before the tendons can be dissected out. Measure the tail are just below the skin but spaced evenly around the outer circumference of the tail. Therefore they can

  9. Developmental regulation of somite derivatives: muscle, cartilage and tendon

    Microsoft Academic Search

    Ava E Brent; Clifford J Tabin

    2002-01-01

    Recent research has broadened significantly our understanding of how the somite, a specialized mesodermal structure found in vertebrate embryos, gives rise to the cartilage, muscle and tendon cell lineages. The specification of somite derivatives involves the action of patterning signals secreted from adjacent tissue combined with the activation, in particular somitic compartments, of genes promoting cell lineage specification.

  10. Laser tissue welding and repair of digital flexor tendons

    NASA Astrophysics Data System (ADS)

    Drew, P. J.; Kiernan, Michael N.; MacGregor, A. D.; Clement, Marc

    1996-01-01

    Injuries involving division of the flexor tendons of the hand are a common surgical problem. Sutured repairs must be strong enough to withstand early active movement. Experiments were designed to assess the strength of bonds formed between tendon sections as a result of heating (1) under controlled conditions in a water bath and (2) using a carbon dioxide laser (laser tissue welding). The load (N) and stress (N/cm2) required to disrupt thermal bonds between bovine tendon sections heated for 4 minutes in water peaked at 62 degrees Celsius (13N, 11.3N/cm2). Further experiments revealed the optimal time period for heating to be 9 minutes (21.5N, 20.6N/cm2). A threshold effect was apparent at these parameters. The in vitro strength of sutured, laser welded and sutured and laser welded tendon repairs was compared in a rabbit model. Laser welding alone did not produce repairs as strong as sutured repairs. It did, however, augment the strength of sutured repair. This effect was maximal at a power of 0.1 W.

  11. Orthopedic pitfalls in the ED: Achilles tendon rupture

    Microsoft Academic Search

    Jacob Ufberg; Richard A. Harrigan; Thomas Cruz; Andrew D. Perron

    2004-01-01

    Achilles tendon rupture is a relatively uncommon occurrence in a general ED population. The history can be subtle, and physical findings may not be clear-cut. Prompt diagnosis and treatment of these injuries, however, is important to improved clinical outcome. The emergency physician needs to remain vigilant for this diagnosis to avoid this orthopedic pitfall. This review article examines the clinical

  12. Latissimus dorsi tendon transfers for rotator cuff deficiency

    PubMed Central

    Donaldson, James; Pandit, Adam; Noorani, Ali; Douglas, Tania; Falworth, Mark; Lambert, Simon

    2011-01-01

    Purpose: Latissimus dorsi tendon transfers are increasingly being used around the shoulder. We aim to assess any improvement in pain and function following a latissimus dorsi tendon transfer for massive, irreparable postero-superior cuff deficiency. Materials and Methods: At our institution, between 1996 and 2009, 38 latissimus dorsi tendon transfer procedures were performed. Sixteen of these were for massive irreparable rotator cuff deficiency associated with pain and impaired function. All patients were evaluated by means of interview or postal questionnaire and case note review. Pain and function were assessed using the Stanmore percentage of normal shoulder assessment (SPONSA) score, visual analogue scale and Oxford Shoulder Score. Forward elevation was also assessed and a significant improvement was thought to correlate with the success of the procedure at stabilizing the humeral head upon elevation. Results: Mean follow-up time was 70 months. There was a significant reduction in pain on the visual analogue scale from 6.4 to 3.4 (P < 0.05), an improved SPONSA score from 32.5 to 57.5 (P < 0.05), and an improved Oxford Shoulder Score from 40.75 to 29.6 (P < 0.05). Forward elevation improved from 40° preoperatively to 75° postoperatively (P < 0.05). Conclusion: Our results add to the body of evidence that latissimus dorsi tendon transfers for irreparable postero-superior cuff deficiency in selected patients reduce pain and improve shoulder function in the medium term. Level of Evidence: Level 4. PMID:22223959

  13. Incidence of symptomatic deep venous thrombosis after Achilles tendon rupture.

    PubMed

    Makhdom, Asim M; Cota, Adam; Saran, Neil; Chaytor, Ruth

    2013-01-01

    Deep venous thrombosis (DVT) is a significant source of morbidity and mortality and is associated with many orthopedic procedures. Previous studies have reported highly variable DVT rates in patients with Achilles tendon rupture undergoing operative and nonoperative treatment. We performed a retrospective chart review for all patients who underwent Achilles tendon repair at our institution from January 2006 to February 2012. Patient data were collected from the electronic medical record system. A total of 115 patients were eligible for the present study. Of these patients, 27 (23.47%) with a surgically treated Achilles tendon rupture developed a symptomatic DVT either while waiting for, or after, surgical intervention, with approximately one third of these diagnosed before surgical intervention. Of the 27 patients with DVT, 3 had a proximal DVT and 24 had a distal DVT. One patient developed a pulmonary embolism. The DVT incidence was greater in the 2 older age groups (40 to 59 and 60 to 79 years) compared individually with the younger age group (20 to 39 years; p < .0026 and p < .0014, respectively). We have shown a high incidence of DVT after Achilles tendon rupture. We recommend a high level of suspicion for the signs and symptoms of DVT during the follow-up period. In addition, patient education and early mobilization should be advocated, especially for patients older than 40 years. Additional randomized controlled trials investigating any benefits to pharmaceutical DVT prophylaxis in this population are needed to establish evidence-based recommendations. PMID:23623625

  14. How obesity modifies tendons (implications for athletic activities)

    PubMed Central

    Abate, Michele

    2014-01-01

    Summary Background: obesity is a well recognized risk factor for dysmetabolic and cardiovascular diseases, but can also be associated to musculo-skeletal disorders. Methods: a search of English-language articles was performed using the key search terms “obesity” or “body mass index” combined with “tendon”, or “tendinopathy”, indipendently. Results: several studies show that, in obese subjects, tendons frequently undergo to degeneration, which can progress to a symptomatic stage, with pain and functional impairment. The main histopathologic findings are a relative paucity of small collagen fibrils, expression of an impaired remodeling process, deposition of lipid droplets which can abut to tendolipomatosis, and a disorganized architecture in the tension regions. Both load-bearing and non load-bearing tendons can be affected. This suggests that systemic factors play an important pathogenetic role. Indeed, adipose tissue releases several bioactive peptides and hormones (chemerin, lipocalin, leptin and adiponectin), and cytokines responsible of a systemic state of chronic low grade inflammation. Conclusion: Physical activity is strongly recommended to stop the progression of weight gain or to bring an obese individual into the normal weight range. Therefore, leisure sport activity is useful in obese subjects, but caution is mandatory, because tendons with sub-clinical damage, when submitted to overload, can easily reach the symptomatic threshold. PMID:25489546

  15. Intraarticular fibroma of the tendon sheath of the knee

    Microsoft Academic Search

    Halit Pinar; Mustafa Özkan; Dinç Özaksoy; U?ur Pabuççuo?lu; Devrim Akseki; Osman Karao?lan

    1995-01-01

    Fibroma of the tendon sheath is an uncommon soft-tissue tumor. Intraarticular localization has not been previously reported. The patient presented with unexplained recurrent swelling of the knee not associated with recent trauma. The soft-tissue tumor was identified by magnetic resonance imaging. Arthroscopy confirmed the diagnosis. Arthrotomy was performed because of the large size of the lesion

  16. Allograft reconstruction for symptomatic chronic complete proximal hamstring tendon avulsion.

    PubMed

    Marx, Robert G; Fives, Gregory; Chu, Samuel K; Daluiski, Aaron; Wolfe, Scott W

    2009-01-01

    Complete proximal hamstring tendon avulsion is an uncommon injury that can cause significant disability in young, athletic individuals. Surgical reattachment is recommended and can be performed on a delayed basis if the tissue is sufficiently mobile. We report 2-year follow up for two cases where interpositional allograft tissue was used for reconstruction because the tendon was too retracted for primary repair. Two 30-year-old patients with complete proximal hamstring avulsion at least 2 years earlier reported severe hamstring weakness and restrictions with respect to sport and recreational activities. Proximal hamstring tendon reconstruction with Achilles tendon allograft was performed for both patients. They were immobilized for 8 weeks with the hip in extension and the knee in flexion using a custom orthosis, followed by physical therapy and weight bearing as tolerated. The patients were followed for over 2 years after the surgery and were evaluated with physical examination, isokinetic strength testing and detailed questions about their function. Following the procedure, both patients returned to a more active lifestyle that was greatly improved with respect to participation in sport and function. This procedure should be considered as a salvage operation as the patients did not return to completely normal function and demonstrated hamstring weakness on the operated side. PMID:18682918

  17. Muscle power attenuation by tendon during energy dissipation

    E-print Network

    Konow, Nicolai

    high risk of contraction-associated damage [7,8]. A familiar example is the muscle soreness experiencedMuscle power attenuation by tendon during energy dissipation Nicolai Konow*, Emanuel Azizi, Providence, RI 02912, USA An important function of skeletal muscle is deceleration via active muscle fascicle

  18. Treatment of unfavourable results of flexor tendon surgery: Skin deficiencies

    PubMed Central

    Elliot, David; Giesen, Thomas

    2013-01-01

    We recently reported a small study at the Federation of European Societies for Surgery of the hand, which was entitled ‘What is secondary flexor tendon surgery’? This study concluded that ‘secondary flexor tendon surgery’ was a generic name encompassing a multitude of pathologies. Between 10% and 15% of cases exhibited pathology of the skin and subcutaneous fat and required flap reconstruction of these tissues. Skin replacement may be used prophylactically at primary surgery or become necessary at secondary surgery after release of scar contractures, to achieve cover of vital structures. The long-term problem of skin deficiency relating to flexor tendon function is one of loss of extension from longitudinal scar shortening of the integument, even if the flexor tendons are primarily concerned with bending the digits, not straightening them. This loss of extension can only be tolerated in a hand to a certain degree without significant loss of function. This paper is largely an analysis of the flaps available and suitable for different degrees of skin deficiency and at different places along the course of the flexor system. It attempts to dispel the idea that ‘any flap will do’ provided the flexors are adequately covered. PMID:24501469

  19. Scaphoid Nonunion and Flexor Pollicis Longus Tendon Rupture

    Microsoft Academic Search

    Satoru Saitoh; Yukihiko Hata; Narimichi Murakami; Yukio Nakatsuchi; Hiroshi Seki; Kunio Takaoka

    1999-01-01

    Four patients presented with a rupture of the flexor pollicis longus tendon that was associated with a longstanding scaphoid nonunion. A radiocarpal arthrosis was present in 3 of the 4 patients and a dorsiflexed intercalated segment instability deformity was also seen in 3 of the 4 patients. Three patients underwent surgery consisting of an osteosynthesis with an iliac bone graft

  20. Tuberculosis tenosynovitis of the extensor tendons of the wrist

    PubMed Central

    Mrabet, Dalila; Ouenniche, Kmar; Mizouni, Habiba; Ounaies, Mouna; Khémiri, Chékib; Sahli, Héla; Sellami, Slaheddine

    2011-01-01

    Mycobacterial tuberculous tenosynovitis of the extensor tendon sheath is an extremely rare manifestation of extrapulmonary tuberculosis. The diagnosis may be easily delayed because of its non-specific clinical signs. We report a new case of tuberculous tenosynovitis of the extensor without concomitant pulmonary tuberculosis or documented immunodeficiency. PMID:22679046

  1. Identification of tendon stem\\/progenitor cells and the role of the extracellular matrix in their niche

    Microsoft Academic Search

    Yanming Bi; Driss Ehirchiou; Tina M Kilts; Colette A Inkson; Mildred C Embree; Wataru Sonoyama; Li Li; Arabella I Leet; Byoung-Moo Seo; Li Zhang; Songtao Shi; Marian F Young

    2007-01-01

    The repair of injured tendons remains a great challenge, largely owing to a lack of in-depth characterization of tendon cells and their precursors. We show that human and mouse tendons harbor a unique cell population, termed tendon stem\\/progenitor cells (TSPCs), that has universal stem cell characteristics such as clonogenicity, multipotency and self-renewal capacity. The isolated TSPCs could regenerate tendon-like tissues

  2. Functional Consequence of Distal Brachioradialis Tendon Release: A Biomechanical Study

    PubMed Central

    Tirrell, Timothy F.; Franko, Orrin I.; Bhola, Siddharth; Hentzen, Eric R.; Abrams, Reid A.; Lieber, Richard L.

    2013-01-01

    Purpose Open reduction and internal fixation of distal radius fractures often necessitates release of the brachioradialis from the radial styloid. However, this common procedure has the potential to decrease elbow flexion strength. To determine the potential morbidity associated with brachioradialis release, we measured the change in elbow torque as a function of incremental release of the brachioradialis insertion footprint. Methods In 5 upper extremity cadaveric specimens, the brachioradialis tendon was systematically released from the radius, and the resultant effect on brachioradialis elbow flexion torque was measured. Release distance was defined as the distance between the release point and the tip of the radial styloid. Results Brachioradialis elbow flexion torque dropped to 95%, 90% and 86% of its original value at release distances of 27mm, 46mm, and 52mm, respectively. Importantly, brachioradialis torque remained above 80% of its original value at release distances up to 7 centimeters. Conclusions Our data demonstrate that release of the brachioradialis tendon from its insertion has minor effects on its ability to transmit force to the distal radius. Clinical Relevance These data may imply that release of the distal brachioradialis tendon during distal radius open reduction internal fixation can be performed without meaningful functional consequences to elbow flexion torque. Even at large release distances, overall elbow flexion torque loss after brachioradialis release would be expected to be less than 5% due to the much larger contributions of the biceps and brachialis. Use of the brachioradialis as a tendon transfer donor should not be limited by concerns of elbow flexion loss, and the tendon could be considered as an autograft donor. PMID:23528425

  3. Effect of Achilles tendon vibration on posture in children.

    PubMed

    McKay, Sandra M; Wu, Jianhua; Angulo-Barroso, Rosa M

    2014-05-01

    This study investigated the effect of unilateral Achilles tendon vibration on postural response in children and young adults during standing. Thirty healthy subjects participated in this study including ten 6-year-old children (YC group), ten 10-year-old children (OC group), and ten young adults (YA group). Eight-second vibration was elicited in each trial from a small vibrator attached above the right Achilles tendon when participants stood barefoot on a force platform. Three 40-s trials were collected under both eyes-open and eyes-closed conditions. Center of pressure (COP) was calculated to examine postural response during the pre-vibration, vibration and post-vibration phases. Results show that both the YC and OC groups had a greater COP average velocity than the YA group in all three phases. Tendon vibration induced a directionally specific postural response in all three groups such that the onset of vibration induced a posterior and medial COP shift during the vibration phase, and the offset of vibration induced an anterior and lateral COP shift during the post-vibration phase. Timing of the maximal COP shift was comparable among three groups in both anterior-posterior (AP) and medial-lateral (ML) directions. However, only the OC group showed an adult-like magnitude of the maximal COP shift during the post-vibration phase in the AP direction. These results suggest that 6-year-old children may start showing an adult-like directionally specific response and temporal parameter to tendon vibration during standing; however, the development of an adult-like spatial postural response to tendon vibration may take more than 10 years. PMID:24613462

  4. Two-stage reconstruction for flexor tendon injuries in zone II using a silicone rod and pedicled sublimis tendon graft

    PubMed Central

    Abdul-Kader, Mohammed Heshmat; Amin, Mahmound A. M.

    2010-01-01

    We report the results of staged flexor tendon reconstruction in 12 patients (12 fingers) with neglected or failed primary repair of flexor tendon injuries in zone II. Injuries involved both flexor digitorum profundus (FDP) and flexor digitorum sublimis (FDS), with poor prognosis (Boyes grades II–IV). The procedure included placing a silicone rod and creating a loop between the FDP and FDS in the first stage and reflecting the latter as a pedicled graft through the pseudosheath created around the silicone rod in the second stage. At a mean follow-up of 18 months (range 12–30 months), results were assessed by clinical examination and questionnaire. The mean total active motion of these fingers was 188°. The mean power grip was 80.0% and pinch grip was 76% of the contralateral hand. The rate of excellent and good results was 75% according to the Buck-Gramcko scale. These results were better than the subjective scores given by the patients. Complications included postoperative hematoma in two, infection in one, silicone synovitis in one (after stage I) and three flexion contractures after stage II. This study confirmed the usefulness of two-stage flexor tendon reconstruction using the combined technique as a salvage procedure to restore flexor tendon function with a few complications. PMID:20924443

  5. Classification of rotator cuff tendinopathy using high definition ultrasound

    PubMed Central

    Hinsley, Hannah; Nicholls, Alex; Daines, Michael; Wallace, Gemma; Arden, Nigel; Carr, Andrew

    2014-01-01

    Summary Background: ultrasound is a valid cost effective tool in screening for rotator cuff pathology with high levels of accuracy in detecting full-thickness tears. To date there is no rotator cuff tendinopathy classification using ultrasound. The aims of this study are to define a valid high-definition ultrasound rotator cuff tendinopathy classification, which has discriminate validity between groups based upon anatomical principles. Methods: 464 women, aged 65–87, from an established general population cohort underwent bilateral shoulder ultrasound and musculoskeletal assessment. Sonographer accuracy was established in a separate study by comparing ultrasound findings to the gold standard intra-operative findings. Results: there were 510 normal tendons, 217 abnormal tendons, 77 partial tears, and 124 full-thickness tears. There was no statistical difference in age or the proportion with pain between the abnormal enthesis and partial tear groups, however both groups were statistically older (p<0.001) and had a greater proportion with pain (p<0.001 & p=0.050) than normal tendons. The full-thickness tears were statistically older than normal tendons (p<0.001), but not abnormal/partially torn tendons. The proportion with pain was significantly greater than both groups (p<0.001 & p=0.006). Symptomatic shoulders had a larger median tear size than asymptomatic shoulders (p=0.006). Using tear size as a predictor of pain likelihood, optimum sensitivity and specificity occurred when dividing tears into groups up to 2.5cm and >2.5cm, which corresponds with anatomical descriptions of the width of the supraspinatus tendon. Conclusion: the classification system is as follows: Normal Tendons; Abnormal enthesis/Partial-thickness tear; Single tendon full-thickness tears (0–2.5cm); Multi-tendon full-thickness tears (>2.5cm). PMID:25489559

  6. Tendinopathy of the long head of the biceps tendon: histopathologic analysis of the extra-articular biceps tendon and tenosynovium

    PubMed Central

    Streit, Jonathan J; Shishani, Yousef; Rodgers, Mark; Gobezie, Reuben

    2015-01-01

    Background Bicipital tendinitis is a common cause of anterior shoulder pain, but there is no evidence that acute inflammation of the extra-articular long head of the biceps (LHB) tendon is the root cause of this condition. We evaluated the histologic findings of the extra-articular portion of the LHB tendon and synovial sheath in order to compare those findings to known histologic changes seen in other tendinopathies. Methods Twenty-six consecutive patients (mean age 45.4±13.7 years) underwent an open subpectoral biceps tenodesis for anterior shoulder pain localized to the bicipital groove. Excised tendons were sent for histologic analysis. Specimens were graded using a semiquantitative scoring system to evaluate tenocyte morphology, the presence of ground substance, collagen bundle characteristics, and vascular changes. Results Chronic inflammation was noted in only two of 26 specimens, and no specimen demonstrated acute inflammation. Tenocyte enlargement and proliferation, characterized by increased roundness and size of the cell and nucleus with proteoglycan matrix expansion and myxoid degenerative changes, was found in all 26 specimens. Abundant ground substance, collagen bundle changes, and increased vascularization were visualized in all samples. Conclusion Anterior shoulder pain attributed to the biceps tendon does not appear to be due to an inflammatory process in most cases. The histologic findings of the extra-articular portion of the LHB tendon and synovial sheath are similar to the pathologic findings in de Quervain tenosynovitis at the wrist, and may be due to a chronic degenerative process similar to this and other tendinopathies of the body. PMID:25792859

  7. Biomechanical properties and histology of db/db diabetic mouse Achilles tendon

    PubMed Central

    Boivin, Gregory P.; Elenes, Egleide Y.; Schultze, Andrew K.; Chodavarapu, Harshita; Hunter, Shawn A.; Elased, Khalid M.

    2014-01-01

    Summary Foot ulcers are a severe complication of diabetic patients resulting from nerve and tendon pathologic alterations. In diabetic patients the tendons are thicker, shorter and have increased stiffness. We examined C57BL/KsJ (BKS.Cg-Dock7m +/+ Leprdb/J) (db/db) mice tendons to determine whether they are an animal model for human diabetic tendon changes. We hypothesized that the Achilles tendons of db/db diabetic mice would be thicker, stiffer, fail at lower loads and stresses, and have degenerative changes compared to control mice. Biomechanical and histologic analyses of the Achilles tendons of 16 week old db/db and control male mice were performed. There was a significant increase in tendon diameter and significant decreases in maximum load, tensile stress, stiffness and elastic modulus in tendons from diabetic mice compared to controls. Mild degenerative and neutrophil infiltration was observed near the tendon insertions on the calcaneous in 25% of db/db mice. In summary, hyper-glycemia and obesity lead to severe changes in db/db mice will be a useful model to examine mechanisms for tendon alterations. PMID:25489543

  8. Treatment of peroneal nerve injuries with simultaneous tendon transfer and nerve exploration

    PubMed Central

    2014-01-01

    Background Common peroneal nerve palsy leading to foot drop is difficult to manage and has historically been treated with extended bracing with expectant waiting for return of nerve function. Peroneal nerve exploration has traditionally been avoided except in cases of known traumatic or iatrogenic injury, with tendon transfers being performed in a delayed fashion after exhausting conservative treatment. We present a new strategy for management of foot drop with nerve exploration and concomitant tendon transfer. Method We retrospectively reviewed a series of 12 patients with peroneal nerve palsies that were treated with tendon transfer from 2005 to 2011. Of these patients, seven were treated with simultaneous peroneal nerve exploration and repair at the time of tendon transfer. Results Patients with both nerve repair and tendon transfer had superior functional results with active dorsiflexion in all patients, compared to dorsiflexion in 40% of patients treated with tendon transfers alone. Additionally, 57% of patients treated with nerve repair and tendon transfer were able to achieve enough function to return to running, compared to 20% in patients with tendon transfer alone. No patient had full return of native motor function resulting in excessive dorsiflexion strength. Conclusion The results of our limited case series for this rare condition indicate that simultaneous nerve repair and tendon transfer showed no detrimental results and may provide improved function over tendon transfer alone. PMID:25099247

  9. Biomechanical properties and histology of db/db diabetic mouse Achilles tendon.

    PubMed

    Boivin, Gregory P; Elenes, Egleide Y; Schultze, Andrew K; Chodavarapu, Harshita; Hunter, Shawn A; Elased, Khalid M

    2014-07-01

    Foot ulcers are a severe complication of diabetic patients resulting from nerve and tendon pathologic alterations. In diabetic patients the tendons are thicker, shorter and have increased stiffness. We examined C57BL/KsJ (BKS.Cg-Dock7(m) +/+ Lepr (db) /J) (db/db) mice tendons to determine whether they are an animal model for human diabetic tendon changes. We hypothesized that the Achilles tendons of db/db diabetic mice would be thicker, stiffer, fail at lower loads and stresses, and have degenerative changes compared to control mice. Biomechanical and histologic analyses of the Achilles tendons of 16 week old db/db and control male mice were performed. There was a significant increase in tendon diameter and significant decreases in maximum load, tensile stress, stiffness and elastic modulus in tendons from diabetic mice compared to controls. Mild degenerative and neutrophil infiltration was observed near the tendon insertions on the calcaneous in 25% of db/db mice. In summary, hyper-glycemia and obesity lead to severe changes in db/db mice will be a useful model to examine mechanisms for tendon alterations. PMID:25489543

  10. Functionally distinct tendon fascicles exhibit different creep and stress relaxation behaviour.

    PubMed

    Shepherd, Jennifer H; Legerlotz, Kirsten; Demirci, Taylan; Klemt, Christian; Riley, Graham P; Screen, Hazel R C

    2014-01-01

    Most overuse tendinopathies are thought to be associated with repeated microstrain below the failure threshold, analogous to the fatigue failure that affects materials placed under repetitive loading. Investigating the progression of fatigue damage within tendons is therefore of critical importance. There are obvious challenges associated with the sourcing of human tendon samples for in vitro analysis so animal models are regularly adopted. However, data indicates that fatigue life varies significantly between tendons of different species and with different stresses in life. Positional tendons such as rat tail tendon or the bovine digital extensor are commonly applied in in vitro studies of tendon overuse, but there is no evidence to suggest their behaviour is indicative of the types of human tendon particularly prone to overuse injuries. In this study, the fatigue response of the largely positional digital extensor and the more energy storing deep digital flexor tendon of the bovine hoof were compared to the semitendinosus tendon of the human hamstring. Fascicles from each tendon type were subjected to either stress or strain controlled fatigue loading (cyclic creep or cyclic stress relaxation respectively). Gross fascicle mechanics were monitored after cyclic stress relaxation and the mean number of cycles to failure investigated with creep loading. Bovine extensor fascicles demonstrated the poorest fatigue response, while the energy storing human semitendinosus was the most fatigue resistant. Despite the superior fatigue response of the energy storing tendons, confocal imaging suggested a similar degree of damage in all three tendon types; it appears the more energy storing tendons are better able to withstand damage without detriment to mechanics. PMID:24285289

  11. Concurrent deficits of soleus and gastrocnemius muscle fascicles and Achilles tendon post stroke.

    PubMed

    Zhao, Heng; Ren, Yupeng; Roth, Elliot J; Harvey, Richard L; Zhang, Li-Qun

    2015-04-01

    Calf muscles and Achilles tendon play important roles in functional activities. However, it is not clear how biomechanical properties of the uniarticular soleus (SOL) and biarticular gastrocnemius muscle and Achilles tendon, including the fascicle length, pennation angle, and stiffness, change concurrently post stroke. Biomechanical properties of the medial gastrocnemius (GM) and soleus muscles were evaluated bilaterally in 10 hemiparetic stroke survivors using combined ultrasonography-biomechanical measurements. Biomechanical properties of the Achilles tendon including the length, cross-sectional area (CSA), stiffness, and Young's modulus were evaluated, together with calf muscle biomechanical properties. Gastrocnemius and SOL contributions were separated using flexed and extended knee positions. The impaired side showed decreased fascicle length (GM: 6%, P = 0.002 and SOL: 9%, P = 0.03, at full knee extension and 0° ankle dorsiflexion) and increased fascicular stiffness (GM: 64%, P = 0.005 and SOL: 19%, P = 0.012, at a common 50 N force level). In contrast, Achilles tendon on the impaired side showed changes in the opposite direction as the muscle fascicles with increased tendon length (5%, P < 0.001), decreased tendon CSA (5%, P = 0.04), decreased tendon stiffness (42%, P < 0.001) and Young's modulus (30%, P < 0.001) compared with the unimpaired side. The fascicle and tendon stiffness changes were correlated negatively to the corresponding fascicle and tendon length changes, and decrease in Achilles tendon stiffness was correlated to the increases of SOL and GM fascicular stiffness (P < 0.05). Characterizations of calf muscle fascicles and Achilles tendon biomechanical properties help us better understand concurrent changes of fascicles and tendon as part of the calf muscle-tendon unit and facilitate development of more effective treatments. PMID:25663670

  12. Spontaneous Zone III rupture of the flexor tendons of the ulnar three digits in elderly Korean farmers.

    PubMed

    Lee, G J; Kwak, S; Kim, H K; Ha, S H; Lee, H J; Baek, G H

    2015-03-01

    Spontaneous flexor tendon rupture is a rare condition and the aetiology is not clear. We report 12 elderly Korean farmers with spontaneous flexor tendon ruptures. We found the rupture in the dominant hand in ten patients. A rupture in the little finger was found in all 12 patients (seven with both flexor tendons ruptured and five with only the profundus ruptured), in the ring finger in four patients (the profundus ruptured in all and both flexor tendons in two patients), and in the middle finger a partial rupture of the profundus in one patient. The tendons were ruptured close to the hook of the hamate. Repetitive friction between the flexor tendons and the hamate hook may cause the ruptures. The hamate hook was excised and the ruptured profundus tendons were reconstructed with tendon transfers with quite favourable functional recovery at follow-up of 1 to 2 years. The ruptured superficialis tendons were not reconstructed. Level of Evidence IV. PMID:25005564

  13. Flexor superficialis tendon transfers to the thumb--an alternative to the free tendon graft for treatment of chronic injuries within the digital sheath.

    PubMed

    Posner, M A

    1983-11-01

    Transfer of a flexor digitorum superficialis tendon is an effective procedure in restoring active flexion of the thumb following old lacerations or ruptures of the flexor pollicis longus tendon within the digital sheath when tendon repair or advancement is not possible. The ample length of the transferred tendon and, more importantly, its normal excursion make it the preferred procedure to the alternative tendon graft. The operation is usually carried out as a one-stage procedure, but, if there is severe scarring, it can follow the preliminary insertion of a silicone rod. For 23 patients, the operation was performed in a single stage in 18 and in 5 after insertion of a silicone rod. Postoperative mobility of the interphalangeal joint averaged 53.5 degrees. Mobility of the donor ring finger was complete in all patients. PMID:6643963

  14. Quantitative ultrasound method for assessing stress-strain properties and the cross-sectional area of Achilles tendon

    NASA Astrophysics Data System (ADS)

    Du, Yi-Chun; Chen, Yung-Fu; Li, Chien-Ming; Lin, Chia-Hung; Yang, Chia-En; Wu, Jian-Xing; Chen, Tainsong

    2013-12-01

    The Achilles tendon is one of the most commonly observed tendons injured with a variety of causes, such as trauma, overuse and degeneration, in the human body. Rupture and tendinosis are relatively common for this strong tendon. Stress-strain properties and shape change are important biomechanical properties of the tendon to assess surgical repair or healing progress. Currently, there are rather limited non-invasive methods available for precisely quantifying the in vivo biomechanical properties of the tendons. The aim of this study was to apply quantitative ultrasound (QUS) methods, including ultrasonic attenuation and speed of sound (SOS), to investigate porcine tendons in different stress-strain conditions. In order to find a reliable method to evaluate the change of tendon shape, ultrasound measurement was also utilized for measuring tendon thickness and compared with the change in tendon cross-sectional area under different stress. A total of 15 porcine tendons of hind trotters were examined. The test results show that the attenuation and broadband ultrasound attenuation decreased and the SOS increased by a smaller magnitude as the uniaxial loading of the stress-strain upon tendons increased. Furthermore, the tendon thickness measured with the ultrasound method was significantly correlated with tendon cross-sectional area (Pearson coefficient = 0.86). These results also indicate that attenuation of QUS and ultrasonic thickness measurement are reliable and potential parameters for assessing biomechanical properties of tendons. Further investigations are needed to warrant the application of the proposed method in a clinical setting.

  15. Applied Joint-Space Torque and Stiffness Control of Tendon-Driven Fingers

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E.; Platt, Robert, Jr.; Wampler, Charles W.; Hargrave, Brian

    2010-01-01

    Existing tendon-driven fingers have applied force control through independent tension controllers on each tendon, i.e. in the tendon-space. The coupled kinematics of the tendons, however, cause such controllers to exhibit a transient coupling in their response. This problem can be resolved by alternatively framing the controllers in the joint-space of the manipulator. This work presents a joint-space torque control law that demonstrates both a decoupled and significantly faster response than an equivalent tendon-space formulation. The law also demonstrates greater speed and robustness than comparable PI controllers. In addition, a tension distribution algorithm is presented here to allocate forces from the joints to the tendons. It allocates the tensions so that they satisfy both an upper and lower bound, and it does so without requiring linear programming or open-ended iterations. The control law and tension distribution algorithm are implemented on the robotic hand of Robonaut-2.

  16. Flexor tendon repair after rupture caused by volar plate fixation of the distal radius.

    PubMed

    Rubensson, Carin C; Ydreborg, Karin; Boren, Linda; Karlander, Lars-Erik

    2015-04-01

    Volar plate fixation of unstable fractures of the distal radius is preferred by a majority of surgeons today. One known complication is the rupture of flexor tendons. The aim of this paper is to present flexor tendon ruptures after volar plate fixation analysing the clinical outcome after tendon surgery, aetiology, and methods of prevention. Seventeen consecutive ruptures in 14 patients were included. The incidence was 1.4%. Three patients declined tendon surgery. Eleven patients were treated with a free tendon graft. Only two patients showed excellent results regarding mobility in the thumb and/or fingers. Analysis of radiographs demonstrated sub-optimal placement of plate or screws in all cases. Rupture of a flexor tendon is a serious complication where the functional outcome after surgical reconstruction is uncertain. Early removal of the plate when the placement is sub-optimal or when local volar tenderness appears would probably prevent many ruptures. PMID:25162925

  17. Structure-Function Relationships of Postnatal Tendon Development: A Parallel to Healing

    PubMed Central

    Connizzo, Brianne K.; Yannascoli, Sarah M.; Soslowsky, Louis J.

    2013-01-01

    This review highlights recent research on structure-function relationships in tendon and comments on the parallels between development and healing. The processes of tendon development and collagen fibrillogenesis are reviewed, but due to the abundance of information in this field, this work focuses primarily on characterizing the mechanical behavior of mature and developing tendon, and how the latter parallels healing tendon. The role that extracellular matrix components, mainly collagen, proteoglycans, and collagen cross-links, play in determining the mechanical behavior of tendon will be examined in this review. Specifically, collagen fiber re-alignment and collagen fibril uncrimping relate mechanical behavior to structural alterations during development and during healing. Finally, attention is paid to a number of recent efforts to augment injured tendon and how future efforts could focus on recreating the important structure-function relationships reviewed here. PMID:23357642

  18. Effect of flexor sheath integrity on nutrient uptake by chicken flexor tendons

    SciTech Connect

    Peterson, W.W.; Manske, P.R.; Lesker, P.A.

    1985-12-01

    The effect of varying degrees of flexor sheath integrity (sheath excised, incised, or incised and repaired) on the uptake of /sub 2/H-proline by chicken flexor tendons in Zone II was studied. The tendons were either: normal and uninjured, lacerated and repaired, or uninjured except for vinculum longum ligation. Different degrees of sheath integrity did not influence the uptake of /sub 2/H-proline by the tendons. The tendon does not appear to be dependent on a synovial environment for nutrients and is capable of obtaining these nutrients by diffusion from the surrounding extracellular tissue fluid. Diffusion is the primary nutrient pathway to the flexor tendon in this area, because removing its major vascular attachment (i.e., the vinculum longum) did not effect proline uptake. Careful closure of the sheath with restoration of a synovial environment does not appear to be necessary for tendon nutrition.

  19. Effects of mechanical vibration of the foot sole and ankle tendons on cutaneomuscular responses in man.

    PubMed

    Smith, Andrew C; Mummidisetty, Chaithanya K; Rymer, William Zev; Knikou, Maria

    2013-06-17

    The modulation of cutaneomuscular responses in response to mechanical vibration applied to the foot sole and to the ankle tendons was established in ten healthy subjects. The effects of mechanical vibration applied to the skin adjacent to the tibialis anterior (TA) and Achilles tendons were examined in two subjects. With the subjects seated, mechanical vibration applied to the TA and/or Achilles tendons significantly depressed the cutaneomuscular responses in all subjects, regardless of the frequency (50, 150, 250 Hz) of vibration. Mechanical vibration applied either to the foot sole or to the skin adjacent to the tendons induced no significant effects. The demonstration that mechanical vibration applied to muscle tendons exerts an inhibitory effect on cutaneomuscular responses supports the hypothesis that receptors that mediate body kinesthesia can be used as a vehicle to alter the spinal excitability state. The data suggests that tendon vibration could be utilized in neurological disorders to induce exogenous-mediated potentiation of presynaptic inhibition. PMID:23643990

  20. Tendon Based Full Size Biped Humanoid Robot Walking Platform Design

    NASA Astrophysics Data System (ADS)

    Kuo, Chung-Hsien; Chiou, Kuo-Wei

    Actuators and gear trains of most biped humanoid robots are divergently allocated on the links of two legs. Disadvantages of such a mechanical design are complicated wiring of power cord and sensing/ control signal bundles and imprecise kinetics models of mixed link-and-actuator structures. Based on these drawbacks, this paper proposes a tendon-driven mechanism to develop a lower body structure of a full-size biped humanoid robot. The actuators are compacted as an actuator module, and they are placed at a distal site. A 12 degree-of-freedom mechanical structure is proposed with 100 cm in height and 45 kg in weight. The gait planning module is simulated and evaluated using the Matlab software. At the same time, an ARM7 based controller is developed to automatically generate walking patterns as well as to control the motors. Finally, a tendon-driven biped humanoid robot prototype is realized for practical waling control in the future.

  1. Avoidance of unfavourable results following primary flexor tendon surgery

    PubMed Central

    Elliot, D.; Giesen, T.

    2013-01-01

    This review describes the biological problems faced by those managing primary flexor tendon injuries and explains why these problems still thwart attempts to achieve normal, or near normal, function after this injury, despite a century of surgical effort. It considers the historical background of the early 20th century attempts to improve the results and analyses the clinical usefulness of more recent research into tendon core and circumferential suture modification, including the authors’ work in this field, and changes in post-operative mobilisation over the last 50 years. More recent manipulation of the sheath to improve results and the future possibility of manipulation of adhesions are discussed. It also discusses other factors, e.g., the patient, the experience of the surgeon, the use of therapists, the timing of repair, complex injuries, injuries in zones other than zone 2, which can have a bearing on the results and considers how these can be modified to avoid an unfavourable outcome. PMID:24501468

  2. [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.

  3. Osmotic pressure induced tensile forces in tendon collagen

    NASA Astrophysics Data System (ADS)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J.; Fratzl, Peter

    2015-01-01

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100?MPa, largely surpassing those of about 0.3?MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  4. Double tendon transfer for correction of drop-foot.

    PubMed

    Grauwin, M-Y; Wavreille, G; Fontaine, C

    2015-02-01

    Many conditions can cause foot drop, which makes walking difficult because the foot easily bumps into obstacles, or the knee must be kept more flexed than usual during the swing phase of gait, especially when going up stairs. Several techniques that have been described to correct foot drop rely on bone procedures or tendon transfer, with or without bone fixation. In this article, we describe a simple technique that is heavily used in leprosy-endemic countries and provides long-lasting results. It requires a double tendon transfer through the interosseous membrane of leg; the tibialis posterior and flexor digitorum longus are sutured to the tibialis anterior, and extensor hallucis longus and extensor digitorum longus, respectively, proximally to the extensor retinaculum. PMID:25623271

  5. Osmotic pressure induced tensile forces in tendon collagen

    PubMed Central

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J.; Fratzl, Peter

    2015-01-01

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100?MPa, largely surpassing those of about 0.3?MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone. PMID:25608644

  6. [Diagnosis and treatment of the ruptured Achilles tendon].

    PubMed

    Neumayer, F; Assal, M; Crevoisier, X

    2012-07-25

    The treatment of the recently ruptured Achilles tendon can be conservative or surgical. The conservative treatment may be carried out using either a static cast immobilisation or using a dynamic brace and an early functional rehabilitation. The surgical technique can be either open or mini-invasive. Neglected and ancient ruptures may need to be treated surgically by a tendinoplasty. There is an ongoing discussion about how to manage the recently ruptured Achilles tendon, especially since recent descriptions of conservative-functional treatment procedures and mini-invasive surgical techniques. We present the choice of the different treatment options and the clinical reasoning to identify the best adapted treatment for the individual patient. The ideal treatment option depends on the functional demand and the medical condition of the patient. PMID:22912999

  7. Tendon cell outgrowth rates and morphology associated with kevlar-49.

    PubMed

    Zimmerman, M; Gordon, K E

    1988-12-01

    A rat tendon cell model was used to evaluate the in vitro biocompatibility of kevlar-49. The cell response to kevlar was compared to carbon AS-4 and nylon sutures. Three trials were run and cell growth rates were statistically similar for all the materials tested. A separate experiment was conducted in which the same fiber materials were placed in the same Petri dish. Again, the rates were similar for each material. Finally, the cells were observed with a scanning electron microscope, and the three classic cell morphologies associated with this tendon cell model were observed. Also, cellular attachment to the fiber and cellular encapsulation of the fiber were identical for the three materials tested. Kevlar-49 proved to be comparable to carbon AS4 and nylon sutures in terms of cellular response and cell outgrowth rates. PMID:3235468

  8. Biomimetic sheath membrane via electrospinning for antiadhesion of repaired tendon.

    PubMed

    Liu, Shen; Zhao, Jingwen; Ruan, Hongjiang; Tang, Tingting; Liu, Guangwang; Yu, Degang; Cui, Wenguo; Fan, Cunyi

    2012-11-12

    The hierarchical architecture and complex biologic functions of native sheath make its biomimetic substitute a daunting challenge. In this study, a biomimetic bilayer sheath membrane consisting of hyaluronic acid-loaded poly(?-caprolactone) (HA/PCL) fibrous membrane as the inner layer and PCL fibrous membrane as the outer layer was fabricated by a combination of sequential and microgel electrospinning technologies. This material was characterized by mechanical testing and analysis of morphology, surface wettability, and drug release. Results of an in vitro drug release study showed sustained release. The outer layer had fewer cells proliferating on its surface compared to tissue culture plates or the inner layer. In a chicken model, peritendinous adhesions were reduced and tendon gliding were improved by the application of this sheath membrane. Taken together, our results demonstrate that such a biomimetic bilayer sheath can release HA sustainably as well as promoting tendon gliding and preventing adhesion. PMID:23025492

  9. An Improved Force Feedback Control Algorithm for Active Tendons

    PubMed Central

    Guo, Tieneng; Liu, Zhifeng; Cai, Ligang

    2012-01-01

    An active tendon, consisting of a displacement actuator and a co-located force sensor, has been adopted by many studies to suppress the vibration of large space flexible structures. The damping, provided by the force feedback control algorithm in these studies, is small and can increase, especially for tendons with low axial stiffness. This study introduces an improved force feedback algorithm, which is based on the idea of velocity feedback. The algorithm provides a large damping ratio for space flexible structures and does not require a structure model. The effectiveness of the algorithm is demonstrated on a structure similar to JPL-MPI. The results show that large damping can be achieved for the vibration control of large space structures. PMID:23112660

  10. Palmaris profundus tendon prohibiting endoscopic carpal tunnel release: case report.

    PubMed

    McClelland, Walter B; Means, Kenneth R

    2012-04-01

    Palmaris profundus is an aberrant muscle of forearm and wrist anatomy. It has no discernible function, but its tendon has been implicated as a cause of carpal tunnel syndrome. Previously, all cases of palmaris profundus in the literature have been encountered during either open surgery or cadaveric dissection. We report a case of palmaris profundus encountered during attempted single-portal endoscopic carpal tunnel release, necessitating conversion to an open approach. There was a unique point of tendon insertion onto the undersurface of the transverse carpal ligament, more proximal than what has been previously described in the literature. There were other anomalies present as well, including a persistent median artery and bifid median nerve. Given the volar position of the structure, its proximal point of insertion, and its minimal bulk, we did not feel that this was the cause of our patient's carpal tunnel syndrome. PMID:22397841

  11. The "double wrist flexor" tendon transfer for radial nerve palsy.

    PubMed

    Al-Qattan, Mohammad

    2013-07-01

    In isolated high radial nerve palsy, it is traditionally taught that one should not use both wrist flexors for tendon transfers. Over the last 17 years, the author has encountered 4 unusual cases of high radial nerve palsy with concurrent direct injury to the pronator teres, flexor digitorum superficialis, and the palmaris longus in the proximal forearm. In these cases, the author used both wrist flexors, namely, the flexor carpi radialis to restore wrist extension and the flexor carpi ulnaris to restore finger/thumb extension as well as thumb radial abduction. Despite the major loss of wrist flexion, all patients had a good overall function as per the modified Bincaz scale. It was concluded that this "double wrist flexor" transfer remains to be an acceptable option for high radial nerve palsy when the pronator teres, flexor digitorum superficialis, and the palmaris longus tendons are not available. PMID:23123604

  12. Freeze-Thaw Cycles Enhance Decellularization of Large Tendons

    PubMed Central

    Erbe, Ina; Berner, Dagmar; Kacza, Johannes; Kasper, Cornelia; Pfeiffer, Bastian; Winter, Karsten; Brehm, Walter

    2014-01-01

    The use of decellularized tendon tissue as a scaffold for tendon tissue engineering provides great opportunities for future clinical and current research applications. The aim of this study was to assess the effect of repetitive freeze-thaw cycles and two different detergents, t-octyl-phenoxypolyethoxyethanol (Triton X-100) and sodium dodecyl sulfate (SDS), on decellularization effectiveness and cytocompatibility in large tendons. Freshly collected equine superficial and deep digital flexor tendons were subjected to decellularization according to four different protocols (1 and 2: freeze-thaw cycles combined with either Triton X-100 or SDS; 3 and 4: Triton X-100 or SDS). Decellularization effectiveness was assessed based on the reduction of vital cell counts, histologically visible nuclei, and DNA content. Transmission electron microscopy was performed to evaluate cellular and extracellular matrix integrity. Further, cytocompatibility of scaffolds that had been decellularized according to the protocols including freeze-thaw cycles (protocols 1 and 2) was assessed by seeding the scaffolds with superparamagnetic iron oxide labeled mesenchymal stromal cells and monitoring the cells histologically and by magnetic resonance imaging for two weeks. Decellularization was significantly more effective when using the protocols including freeze-thaw cycles, leaving only roughly 1% residual nuclei and 20% residual DNA, whereas samples that had not undergone additional freeze-thaw cycles contained roughly 20% residual nuclei and 40% residual DNA. No morphological extracellular matrix alterations due to decellularization could be observed. Scaffolds prepared by both protocols including freeze-thaw cycles were cytocompatible, but the cell distribution into the scaffold tended to be better in scaffolds that had been decellularized using freeze-thaw cycles combined with Triton X-100 instead of SDS. PMID:23879725

  13. Management of subcalcaneal pain and Achilles tendonitis with heel inserts

    PubMed Central

    Maclellan, G. E.; Vyvyan, Barbara

    1981-01-01

    Soft tissue symptoms in the leg due to sporting activity are commonly associated with the force of heel strike. Conventional training shoes compromise between comfort and performance; few models are suitably designed for both considerations. Using a visco-elastic polymer insert the symptoms of heel pain and Achilles tendonitis have been largely or completely abolished in a preliminary study. Imagesp117-ap117-bp117-cp118-a PMID:7272653

  14. Aspects of mineral structure in normally calcifying avian tendon.

    PubMed

    Siperko, L M; Landis, W J

    2001-09-01

    Structural characteristics of normally calcifying leg tendons of the domestic turkey Meleagris gallopavo have been observed for the first time by tapping mode atomic force microscopy (TMAFM), and phase as well as corresponding topographic images were acquired to gain insight into the features of mineralizing collagen fibrils and fibers. Analysis of different regions of the tendon has yielded new information concerning the structural interrelationships in vivo between collagen fibrils and fibers and mineral crystals appearing in the form of plates and plate aggregates. TMAFM images show numerous mineralized collagen structures exhibiting characteristic periodicity (54-70 nm), organized with their respective long axes parallel to each other. In some instances, mineral plates (30-40 nm thick) are found interspersed between and in intimate contact with the mineralized collagen. The edges of such plates lie parallel to the neighboring collagen. Many of these plates appear to be aligned to form larger aggregates (475-600 nm long x 75-90 nm thick) that also retain collagen periodicity along their exposed edges. Intrinsic structural properties of the mineralizing avian tendon have not previously been described on the scale reported in this study. These data provide the first visual evidence supporting the concept that larger plates form from parallel association of smaller ones, and the data fill a gap in knowledge between macromolecular- and anatomic-scale studies of the mineralization of avian tendon and connective tissues in general. The observed organization of mineralized collagen, plates, and plate aggregates maintaining a consistently parallel nature demonstrates the means by which increasing structural complexity may be achieved in a calcified tissue over greater levels of hierarchical order. PMID:11722171

  15. Corrosion of steel tendons used in prestressed concrete pressure vessels

    Microsoft Academic Search

    J. C. Griess; D. J. Naus

    2009-01-01

    The purpose of this investigation was to determine the corrosion behavior of a high strength steel (ASTM A416-74 grade 270), typical of those used as tensioning tendons in prestressed concrete pressure vessels, in several corrosive environments and to demonstrate the protection afforded by coating the steel with either of two commercial petroleum-base greases or Portland Cement grout. In addition, the

  16. Corrosion of steel tendons used in prestressed concrete pressure vessels

    Microsoft Academic Search

    J. C. Griess; D. J. Naus

    1980-01-01

    The corrosion behavior of a high-strength steel (Specifications for Uncoated Seven-Wire-Stress-Relieved Strand for Prestressed Concrete (ASTM A 416-74, Grade 270)), typical of those used as tensioning tendons in prestressed concrete pressure vessels was measured in several corrosive environments. The protection obtained by coating the steel with two commercial petroleum-base greases or with Portland cement grout was evaluated. The few reported

  17. 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

  18. Abductor pollicis longus tendon rupture in De Quervain's disease.

    PubMed

    Yuen, A; Coombs, C J

    2006-02-01

    De Quervain's disease is a stenosing tenovaginitis involving the first extensor compartment of the wrist. The similarity of its symptomatology to a number of other conditions and its controversial aetiology are only a few of the barriers which often delay its diagnosis and treatment. We report the first two cases in the literature of abductor pollicus longus tendon rupture in patients with De Quervain's disease who had been treated with conservative methods. The relevant literature is reviewed. PMID:16289720

  19. 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

  20. Fatty Acid Profiles of Supraspinatus, Longissimus lumborum and Semitendinosus Muscles and Serum in Kacang Goats Supplemented with Inorganic Selenium and Iodine.

    PubMed

    Aghwan, Z A; Alimon, A R; Goh, Y M; Nakyinsige, K; Sazili, A Q

    2014-04-01

    Fat and fatty acids in muscle and adipose tissues are among the major factors influencing meat quality particularly nutritional value and palatability. The present study was carried out to examine the effects of supplementing inorganic selenium (Se), iodine (I) and a combination of both on fatty acid compositions in serum, and supraspinatus (SS), longissimus lumborum (LL), and semitendinosus (ST) muscles in goats. Twenty-four, 7 to 8 months old, Kacang male goats with a mean live weight of 22.00±1.17 kg were individually and randomly assigned into four groups of six animals each for 100 d of feeding prior to slaughter. The animals were offered the same concentrate (basal) diet as 1% of body weight with ad libitum amount of fresh guinea grass. The four groups were as follows: T1 (control) - basal diet without supplementation; T2 - basal diet with 0.6 mg Se/kg DM; T3 - basal diet with 0.6 mg I/kg DM; T4 - basal diet with combination of 0.6 mg Se/kg DM and 0.6 mg I/kg DM. The major fatty acids (FAs) detected in the serum were palmitic (C16:0), stearic (C18:0), oleic (C18:1n9) and linoleic (C18:2n-6), while the major FAs in the selected muscles were C16:0, C18:0 and C18:1n9 acids. The main polyunsaturated fatty acids (PUFA) detected in muscles and serum were (CI8:2n-6), linolenic acid (C18:3n-3), and arachidonic acid (C20:4n-6). No significant differences (p>0.05) were observed in the concentration of total saturated fatty acids (SFA) among the four groups. PUFA concentrations in the goats supplemented with Se (T2) were significantly higher (p<0.05) than the goats of the control group (T1). The PUFA: SFA ratio was significantly higher in the animals supplemented with dietary Se (T2) than those of control ones (T1). It is concluded that dietary supplementation of inorganic Se increased the unsaturated fatty acids in muscle. The supplementation of iodine with or without Se had negligible effects on muscle fatty acid content of Kacang crossbred male goats. PMID:25049986

  1. Fatty Acid Profiles of Supraspinatus, Longissimus lumborum and Semitendinosus Muscles and Serum in Kacang Goats Supplemented with Inorganic Selenium and Iodine

    PubMed Central

    Aghwan, Z. A.; Alimon, A. R.; Goh, Y. M.; Nakyinsige, K.; Sazili, A. Q.

    2014-01-01

    Fat and fatty acids in muscle and adipose tissues are among the major factors influencing meat quality particularly nutritional value and palatability. The present study was carried out to examine the effects of supplementing inorganic selenium (Se), iodine (I) and a combination of both on fatty acid compositions in serum, and supraspinatus (SS), longissimus lumborum (LL), and semitendinosus (ST) muscles in goats. Twenty-four, 7 to 8 months old, Kacang male goats with a mean live weight of 22.00±1.17 kg were individually and randomly assigned into four groups of six animals each for 100 d of feeding prior to slaughter. The animals were offered the same concentrate (basal) diet as 1% of body weight with ad libitum amount of fresh guinea grass. The four groups were as follows: T1 (control) - basal diet without supplementation; T2 - basal diet with 0.6 mg Se/kg DM; T3 - basal diet with 0.6 mg I/kg DM; T4 - basal diet with combination of 0.6 mg Se/kg DM and 0.6 mg I/kg DM. The major fatty acids (FAs) detected in the serum were palmitic (C16:0), stearic (C18:0), oleic (C18:1n9) and linoleic (C18:2n-6), while the major FAs in the selected muscles were C16:0, C18:0 and C18:1n9 acids. The main polyunsaturated fatty acids (PUFA) detected in muscles and serum were (CI8:2n-6), linolenic acid (C18:3n-3), and arachidonic acid (C20:4n-6). No significant differences (p>0.05) were observed in the concentration of total saturated fatty acids (SFA) among the four groups. PUFA concentrations in the goats supplemented with Se (T2) were significantly higher (p<0.05) than the goats of the control group (T1). The PUFA: SFA ratio was significantly higher in the animals supplemented with dietary Se (T2) than those of control ones (T1). It is concluded that dietary supplementation of inorganic Se increased the unsaturated fatty acids in muscle. The supplementation of iodine with or without Se had negligible effects on muscle fatty acid content of Kacang crossbred male goats. PMID:25049986

  2. Range of motion, muscle torque and training habits in runners with and without Achilles tendon problems

    Microsoft Academic Search

    Y. Haglund-Åkerlind; E. Eriksson

    1993-01-01

    Achilles tendon injuries are common in runners. The aim of the present study was to analyse the training programme, any Achilles tendon problems, muscle eightness and range of motion of the ankle joint, and concentric and eccentric musle torques of the calf muscles in middle-distance runners with and without Achilles tendon problems. Eighty-three middle-distance runners answered a questionnaire on their

  3. Complications of common hand and wrist surgery procedures: flexor and extensor tendon surgery.

    PubMed

    Fischer, Lauren H; Abzug, Joshua M; Osterman, A Lee; Stern, Peter J; Chang, James

    2014-01-01

    Orthopaedic and hand surgeons frequently treat disorders of the flexor and extensor tendon systems. Common conditions, such as trigger finger, de Quervain tenosynovitis, extensor tendon injury, and zone II flexor tendon injury, can be challenging to treat. Complications that limit normal hand function still occur despite advances in surgical techniques and therapy protocols. It is helpful to be aware of the complications related to the treatment of these hand disorders and understand surgical techniques to minimize their frequency. PMID:24720297

  4. Arthroscopic repair of the subscapularis tendon: indications, limits and technical features

    PubMed Central

    Osti, Leonardo; Soldati, Francesco; Del Buono, Angelo; Buda, Matteo

    2013-01-01

    Summary The rationale to anatomically repair this tendon is to restore the functional biomechanics of the shoulder. Clinical and imaging assessment are required before undertaking arthroscopy. In this way, associated pathologies of the biceps and labrum may be successfully addressed. The arthroscopic repair of the tendon implies to use suture anchors and reinsert the tendon itself over the footprint. Results after arthroscopy are comparable to those observed after open procedures. PMID:24367783

  5. The revascularization of healing flexor tendons in the digital sheath. A vascular injection study in dogs.

    PubMed

    Gelberman, R H; Khabie, V; Cahill, C J

    1991-07-01

    The role of revascularization in the nutritional support of repair of the flexor tendons is not completely understood. To explore the extent to which intrasynovial flexor tendons revascularize after transection and suture, a vascular injection study was carried out in a canine model. The tendons to the second and fifth digits of the forepaw in twelve adult mongrel dogs were transected and repaired. There were twenty-four experimental tendons and twenty-four normal tendons. The limb was placed in a polyurethane shoulder-spica cast, and the paw was treated with immediate protected passive mobilization. At three, seven, ten, seventeen, and twenty-eight days, the animals were killed and the major arteries supplying both the paw that had been operated on (left) and the contralateral normal paw (right) were injected with 200 milliliters of India ink. Segments of repaired and normal tendons were then clarified by a modified Spalteholz technique. The normal tendons demonstrated a well developed mesotenon that provided vascularization of the proximal portion of the flexor digitorum profundus tendon. A consistent three-cubic-millimeter avascular intrasynovial portion of tendon was noted. Distally, vessels arose from the vinculum breve, supplying the terminal twenty millimeters of tendon substance. In the experimental tendons, longitudinal and transverse clarified sections showed consistent revascularization of the site of repair by proximal vessels in the absence of ingrowth of peripheral adhesions. Vessels in the epitenon progressively extended for a distance of ten millimeters, through normally avascular regions, to reach the site of repair by the seventeenth postoperative day. Intratendinous vessels about the site of repair consistently originated from surface vessels, rather than from extensions of pre-existing intratendinous vessels. New vessels penetrated all areas, including the normally avascular volar segments of tendon, irrespective of previous topical zones of avascularity. Proximal vascular plexi were characterized by large tortuous vessels with frequent circuitous branches. More distal vessels had a longitudinally oriented, feathery appearance. PMID:1712787

  6. Development and Evaluation of Multiple Tendon Injury Models in the Mouse

    PubMed Central

    Beason, David P.; Kuntz, Andrew F.; Hsu, Jason E.; Miller, Kristin S.; Soslowsky, Louis J.

    2012-01-01

    The mouse has proven to be an advantageous animal model system in basic science research focused on aiding in development and evaluation of potential treatments; however, the small size of mouse tendons makes consistent and reproducible injury models and subsequent biomechanical evaluation challenging for studying tendon healing. In this study, we investigated the feasibility and reproducibility of multiple mouse tendon injury models. Our hypothesis was that incisional (using a blade) and excisional (using a biopsy punch) injuries would result in consistent differences in tendon material properties. At 16 weeks of age, 17 C57BL/6 mice underwent surgery to create defects in the flexor digitorum longus, Achilles, or patellar tendon. Each animal received 1–2 full-thickness, central-width incisional or excisional injuries per limb; at least one tendon per limb remained uninjured. The injuries were distributed such that each tendon type had comparable numbers of uninjured, incisionally-injured, and excisionally-injured specimens. Three weeks after injury, all animals were euthanized and tendons were harvested for mechanical testing. As hypothesized, differences were detected for all three different tendon types at three weeks post-injury. While all models created injuries that produced predictable outcomes, the patellar tendon model was the most consistent in terms of number and size of significant differences in injured tendons compared to native properties, as well as in the overall variance in the data. This finding provides support for its use in fundamental tendon healing studies; however, future work may use any of these models, based on their appropriateness for the specific question under study. PMID:22405494

  7. Strain Behavior of the Distal Achilles TendonImplications for Insertional Achilles Tendinopathy

    Microsoft Academic Search

    Jeffrey Lyman; Paul S. Weinhold; Louis C. Almekinders

    2004-01-01

    Background: The changes associated with Achilles insertional tendinopathy (AIT) are seen in the anterior portion of the Achilles tendon near its calcaneal insertion. Strain behavior of this portion of the tendon was evaluated.Hypothesis: The highest strains are in the anterior portion of the tendon.Study Design: Controlled laboratory study.Methods: Six cadaveric legs were tested. While moving through a functional range of

  8. Acute Simultaneous Ruptures of the Anterior Cruciate Ligament and Patellar Tendon

    PubMed Central

    Lee, Gwang Chul; Park, Sung-Hae

    2014-01-01

    Acute simultaneous rupture of the anterior cruciate ligament (ACL) and patellar tendon is a rare injury. We present a case report of a 32-year-old male patient with ruptured ACL and ipsilateral patellar tendon rupture sustained while playing baseball. Surgery was performed on the patellar tendon and the ACL simultaneously. The clinical and radiological outcomes of the treatment were successful. We present this case with a review of the literatures. PMID:24639949

  9. Biomechanical and structural response of healing Achilles tendon to fatigue loading following acute injury.

    PubMed

    Freedman, Benjamin R; Sarver, Joseph J; Buckley, Mark R; Voleti, Pramod B; Soslowsky, Louis J

    2014-06-27

    Achilles tendon injuries affect both athletes and the general population, and their incidence is rising. In particular, the Achilles tendon is subject to dynamic loading at or near failure loads during activity, and fatigue induced damage is likely a contributing factor to ultimate tendon failure. Unfortunately, little is known about how injured Achilles tendons respond mechanically and structurally to fatigue loading during healing. Knowledge of these properties remains critical to best evaluate tendon damage induction and the ability of the tendon to maintain mechanical properties with repeated loading. Thus, this study investigated the mechanical and structural changes in healing mouse Achilles tendons during fatigue loading. Twenty four mice received bilateral full thickness, partial width excisional injuries to their Achilles tendons (IACUC approved) and twelve tendons from six uninjured mice were used as controls. Tendons were fatigue loaded to assess mechanical and structural properties simultaneously after 0, 1, 3, and 6 weeks of healing using an integrated polarized light system. Results showed that the number of cycles to failure decreased dramatically (37-fold, p<0.005) due to injury, but increased throughout healing, ultimately recovering after 6 weeks. The tangent stiffness, hysteresis, and dynamic modulus did not improve with healing (p<0.005). Linear regression analysis was used to determine relationships between mechanical and structural properties. Of tendon structural properties, the apparent birefringence was able to best predict dynamic modulus (R(2)=0.88-0.92) throughout healing and fatigue life. This study reinforces the concept that fatigue loading is a sensitive metric to assess tendon healing and demonstrates potential structural metrics to predict mechanical properties. PMID:24280564

  10. Early Motion After Quadriceps and Patellar Tendon RepairsOutcomes With Single-Suture Augmentation

    Microsoft Academic Search

    Jesse L. West; James S. Keene; Lee D. Kaplan

    2008-01-01

    Background: Complications of immobilization after quadriceps and patellar tendon repairs include decreased patellar mobility, limited flexion, persistent pain, muscle weakness, and patella baja. In contrast, early motion limits muscle atrophy, accelerates tendon healing, and prevents joint stiffness.Hypothesis: Quadriceps and patellar tendon repairs protected with a “relaxing suture” are strong enough to safely permit early motion, full weightbearing, and brace-free ambulation.Study

  11. Effects of various decellularization methods on histological and biomechanical properties of rabbit tendons

    PubMed Central

    XING, SHUXING; LIU, CONG; XU, BING; CHEN, JIANCHANG; YIN, DONGFENG; ZHANG, CHUNHAO

    2014-01-01

    The aim of the present study was to investigate the effects of various decellularization methods on the histological and biomechanical properties of rabbit tendons. In total, six chemical reagents, including 1% t-octyl-phenoxypolyethoxyethanol (Triton-X 100), 0.5% sodium dodecyl sulfate (SDS), 1% tri-n-butyl phosphate (TnBP), 1% Triton-X 100 + 0.5% SDS, 1% TnBP + 0.5% SDS and 1% TnBP + 1% Triton-X 100, were used on rabbit semitendinosus muscles and flexor digitorum tendons for 24 h to remove cells. Hematoxylin and eosin staining was applied for histological observation, while tension testing was used for biomechanical studies. The effects of the various decellularization methods on the histological structure and biomechanical properties of rabbit tendons were evaluated. A group of fresh tendons treated with phosphate-buffered saline served as controls. The various decellularization methods resulted in different effects on the tendons. All the treatment groups exhibited a decrease in tendon biomechanical properties, but no statistically significant differences were observed among the experimental groups. The extensibility of the 1% TnBP-treated group was found to be greater than that of the other groups; however, the difference was not statistically significant. Histologically, the 1% TnBP + 0.5% SDS treatment was shown to have the least impact on the rabbit tendon structure, with good decellularization and no clear cellular remnants observed. The 1% Triton-X 100 + 0.5% SDS treatment had a pronounced effect on the tendon collagen structure and a number of collagen ruptures were observed. Overall, 1% TnBP + 0.5% SDS was found to be the most effective compared with the other treatments, as this treatment preserved the tendon collagen structure while completely removing the cells. Tendons treated with 1% TnBP + 0.5% SDS were histologically similar to normal tendon tissue and biomechanically similar to the tendons in the control group. PMID:25009631

  12. Experimental and theoretical studies on composite steel–concrete box beams with external tendons

    Microsoft Academic Search

    Nan Zhang; Chung C. Fu

    2009-01-01

    Composite steel–concrete box beams with and without external tendons were tested to their ultimate strength. The effects of external tendons on structural performance of composite steel–concrete beams were investigated in detail. Experimental results proved that, due to the action of external prestressing tendons, the ultimate strength of a composite steel–concrete box beam increased by 27.72%, the elastic limit of a

  13. A simplified method for repair of distal biceps tendon ruptures.

    PubMed

    Sotereanos, D G; Pierce, T D; Varitimidis, S E

    2000-01-01

    Repair of distal biceps brachii tendon ruptures is recommended for active individuals desiring maximum return of elbow supination and flexion strength. A 2-incision method of repair has been most popular but carries a risk of radioulnar synostosis. In the past, repair through a single anterior incision required more dissection and risked injury to the posterior interosseous nerve. The authors present a simplified method for the repair of distal biceps tendon ruptures through a single anterior incision. The use of suture anchors provides secure fixation to the radius with minimal volar dissection. This method was used successfully in 16 patients, 8 acutely (<6 weeks) and 8 chronically, with excellent functional results. Patients who received acute repairs regained elbow strength and power; patients who received chronic repairs showed slight deficits of supination strength (16%) and flexion power (14%). Of 10 chronic ruptures treated, only 2 tendons could not be mobilized back to the radial tuberosity and had to be transferred to the brachialis. There were no failures and no complications of radioulnar synostosis or posterior interosseous nerve palsy. The single anterior incision approach in which suture anchors are used is recommended as an alternative to the traditional 2-incision method. PMID:10888168

  14. [Proximal and distal ruptures of the biceps brachii tendon].

    PubMed

    Klonz, A; Loitz, D; Reilmann, H

    2003-09-01

    Proximal ruptures. Ruptures of the long head of the M. biceps humeri are commonly caused by degenerative changes within the tendon. Non-operative treatment gives good results, the loss of power regarding elbow flexion and supination amounts to only 8-21%. Refixation may be indicated for cosmetic reasons and offers a small but evident improvement of flexion and supination power. Deformity of the slipped muscle can be corrected effectively. Residual complaints after conservative treatment often result from associated subacromial problems. Distal ruptures. Ruptures of the distal tendon should be treated operatively. The loss of power after conservative treatment is evident (30-40% for flexion, >50% for supination). Extra-anatomical tenodesis to the brachialis muscle or anatomical fixation to the radial tuberosity can be applied. Flexion power and cosmesis can be addressed by both techniques. If supination strength is to be restored, the tendon has to be fixed anatomically. Preparation of the tuberosity bears the risk of heterotopic ossification or nerve damage. Mini-open techniques, using only a limited anterior approach, may decrease risks. PMID:14959750

  15. Outcome of early active mobilization after extensor tendon repair

    PubMed Central

    Saini, Narender; Sharma, Mohan; Sharma, VD; Patni, Purnima

    2008-01-01

    Background: Traditionally the repaired extensor tendons have been treated postoperatively in static splints for several weeks, leading to formation of adhesions and prolonged rehabilitation. Early mobilization using dynamic splints is common, but associated with many shortcomings. We attempted to study the results of early active mobilization, using a simple static splint, and easy-to-follow rehabilitation plan. Materials and Methods: In a prospective study 26 cases of cut extensor tendons in Zone V to VIII were treated with primary or delayed primary repair. Following this, early active mobilization was undertaken, using an easy-to-follow rehabilitation plan. The results were assessed according to the criteria of Dargan at six weeks and one year. Results: All the 26 patients were followed up for one year. 20 out of 26 patients were below 30 years of age, involving the dominant hand more commonly (16 patients, 62%). Agriculture instruments were the most common mode of injury (13 patients, 50%). The common site for injury was extensor zone VI (42%, n = 11). Conclusion: Rehabilitation done for repaired extensor tendon injuries by active mobilization plan using a simple static splint has shown good results. PMID:19753162

  16. Effects of trypsinization and mineralization on intrasynovial tendon allograft healing to bone.

    PubMed

    Qu, Jin; van Alphen, Nick A; Thoreson, Andrew R; Chen, Qingshan; An, Kai-Nan; Amadio, Peter C; Schmid, Thomas M; Zhao, Chunfeng

    2015-04-01

    The purpose of the current study was to develop a novel technology to enhance tendon-to-bone interface healing by trypsinizing and mineralizing (TM) an intrasynovial tendon allograft in a rabbit bone tunnel model. Eight rabbit flexor digitorum profundus (FDP) tendons were used to optimize the trypsinization process. An additional 24 FDP tendons were stratified into control and TM groups; in each group, 4 tendons were used for in vitro evaluation of TM and 8 were transplanted into proximal tibial bone tunnels in rabbits. The samples were evaluated histologically and with mechanical testing at postoperative week 8. Maximum failure strength and linear stiffness were not significantly different between the control and TM tendons. A thin fibrous band of scar tissue formed at the graft-to-bone interface in the control group. However, only the TM group showed obvious new bone formation inside the tendon graft and a visible fibrocartilage layer at the bone tunnel entrance. This study is the first to explore effects of TM on the intrasynovial allograft healing to a bone tunnel. TM showed beneficial effects on chondrogenesis, osteogenesis, and integration of the intrasynovial tendon graft, but mechanical strength was the same as the control tendons in this short-term in vivo study. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:468-474, 2015. PMID:25611186

  17. Overweight and obesity alters the cumulative transverse strain in the Achilles tendon immediately following exercise.

    PubMed

    Wearing, Scott C; Hooper, Sue L; Grigg, Nicole L; Nolan, Gregory; Smeathers, James E

    2013-07-01

    This research evaluated the effect of obesity on the acute cumulative transverse strain of the Achilles tendon in response to exercise. Twenty healthy adult males were categorized into 'low normal-weight' (BMI <23 kg m(-2)) and 'overweight' (BMI >27.5 kg m(-2)) groups based on intermediate cut-off points recommended by the World Health Organization. Longitudinal sonograms of the right Achilles tendon were acquired immediately prior and following weight-bearing ankle exercises. Achilles tendon thickness was measured 20-mm proximal to the calcaneal insertion and transverse tendon strain was calculated as the natural log of the ratio of post- to pre-exercise tendon thickness. The Achilles tendon was thicker in the overweight group both prior to (t18 = -2.91, P = 0.009) and following (t18 = -4.87, P < 0.001) exercise. The acute transverse strain response of the Achilles tendon in the overweight group (-10.7 ± 2.5%), however, was almost half that of the 'low normal-weight' (-19.5 ± 7.4%) group (t18 = -3.56, P = 0.004). These findings suggest that obesity is associated with structural changes in tendon that impairs intra-tendinous fluid movement in response to load and provides new insights into the link between tendon pathology and overweight and obesity. PMID:23768275

  18. Magnetic resonance imagination of the peroneus longus tendon after anterior cruciate ligament reconstruction.

    PubMed

    Kerimo?lu, Servet; Ko?ucu, Polat; Livao?lu, Murat; Yükünç, Ismail; Turhan, Ahmet U?ur

    2009-01-01

    Several studies report that tendons can regenerate after harvesting. These studies have been performed especially in patellar and hamstring tendons. At our institution, 10 cm length of full thickness peroneus longus tendon has been harvested to reconstruct torn anterior cruciate ligament since 1997 as a different graft source. The aim of this study was to investigate whether the peroneus longus tendon used the anterior cruciate ligament reconstruction has a regeneration potential or not. Twelve patients, who had originally undergone harvesting of the peroneus longus tendon for the primary surgery of the anterior cruciate ligament reconstruction, underwent magnetic resonance imaging (MRI). Images of both legs were acquired simultaneously with the use of the scanner's extremity coil, as we aimed to compare harvested peroneus longus tendon with the other leg's peroneus longus tendon (healthy side) for evaluation of the regeneration potential. The average age of the patients was 31 years. There were eight right and four left legs. The average time interval was 52 months between ligament surgery and MRI. In all patients, a varying amount of the regeneration of the peroneus longus tendon was seen on the MRI images. Although the extent of PLT regeneration in proximal sections seemed better than in mid- and distal sections, there was no statistical difference between sections (P = 0.130). These data show that the peroneus longus tendon has a regeneration potential after harvesting for anterior cruciate ligament reconstruction. PMID:18818901

  19. Simultaneous bilateral Achilles tendon ruptures associated with statin medication despite regular rock climbing exercise

    Microsoft Academic Search

    Michael R. Carmont; Adrian M. Highland; Christopher M. Blundell; Mark B. Davies

    2009-01-01

    IntroductionRuptures of the Achilles tendon are common however simultaneous ruptures occur less frequently. Eccentric loading exercise programmes have been used to successfully treat Achilles tendinopathy.

  20. Gliding resistance and modifications of gliding surface of tendon: clinical perspectives.

    PubMed

    Amadio, Peter C

    2013-05-01

    The smooth gliding of the normal human digital flexor is maintained by synovial fluid lubrication and lubricants bound to the tendon surface. This system can be disrupted by degenerative conditions such as trigger finger, or by trauma. The resistance to tendon gliding after surgical repair of the lacerated digital flexor tendon relates to location of suture knots, exposure of suture materials, and type of surgical repair and materials. Restoration of a functioning gliding surface after injury can be helped by using low-friction, high-strength suture designs, therapy that enables gliding, and the addition of lubricants to the tendon surface. PMID:23660052

  1. [Experimental study in vivo on implantation of autogenous tendon cells after combining culture with carbon fibers].

    PubMed

    Zhang, Q; Yang, Z; Peng, W

    1997-05-01

    In order to investigate the possibility of repairing injuried tendon with living artificial tendon, after combining culture, subcultured autogenous tendon cells with carbon fibers were implanted into the calcaneous tendon of rabbits. In different stages, the synthesis of type I collagen and their relevant morphological changes were observed. The results showed as follows: after implantation, tendon cells continued proliferating. Four weeks after implantation, tendon cells were detached from the carbon fibers and proliferated and produced collagen among the carbon fibers. The collagen fibrils were linked with each other to formed a dense structure. In the linkage site, the collagen fibrils originated from the implants joined to that from the ruptured end of the tendon, which meaned that the implant was healed with the recipient tendon. Observed under scanning electronic microscope, the tendon cells were lined among the carbon fibers evenly and in order, the collagen fibrils joined each other and formed an network, the fibrils were lined parallel to the carbon fibers. Under transparent electron microscope, the nucleolus were clear and organelle were abundant. PMID:9867920

  2. Clinical Allograft of a Calcaneal Tendon in a Rhesus Macaque (Macaca mulatta)

    PubMed Central

    Lemoy, Marie-Josee; Summers, Laura; Colagross-Schouten, Angela

    2014-01-01

    A 5.5-y-old male rhesus monkey (Macaca mulatta) housed in an outdoor field cage presented for severe trauma involving the left calcaneal tendon. Part of the management of this wound included an allograft of the calcaneal tendon from an animal that was euthanized for medical reasons. This case report describes the successful medical and surgical management of a macaque with a significant void of the calcaneal tendon. To our knowledge, this report is the first description of a successful tendon allograft in a rhesus macaque for clinical purposes. PMID:25255076

  3. Scleraxis expression is coordinately regulated in a murine model of patellar tendon injury.

    PubMed

    Scott, Alexander; Sampaio, Arthur; Abraham, Thomas; Duronio, Chris; Underhill, Tully M

    2011-02-01

    This study investigated the expression of Scleraxis in a murine model of patellar tendon injury in which the central third of the patellar tendon was unilaterally injured. The presence of tendon pathology was assessed using dual photon microscopy, conventional histology and microCT. Tendon pathology was also quantified noninvasively over a 12-week period using high-frequency ultrasound and laser Doppler flowmetry. Gene expression (Scx, Tnmd, and Col1a1) was determined at defined end-points (1, 4, 8, and 12 weeks) using qPCR on RNA from individual patellar tendons on injured and uninjured sides. There was significant development of tendon pathology as gauged by ultrasound and laser Doppler over 12 weeks. Injured tendons demonstrated significant histological and microCT evidence of pathological change, and disorganized collagen with reduced density. The expression of Scx and Col1a1 was unchanged at 1 week, significantly upregulated at 4 and 8 weeks, and had returned to baseline by 12 weeks. Tnmd expression was unchanged at 1 week, and significantly increased at 4, 8, and 12 weeks. Patellar tendon injury was associated with marked increases in the expression of Scx, Tnmd, and Col1a1. Our data suggest new roles for Scleraxis in coordinating the response to injury in the pathogenesis of tendon disorders. PMID:20740671

  4. The effect of the Achilles tendon on trabecular structure in the primate calcaneus.

    PubMed

    Kuo, Sharon; Desilva, Jeremy M; Devlin, Maureen J; McDonald, Gabriel; Morgan, Elise F

    2013-10-01

    Humans possess the longest Achilles tendon relative to total muscle length of any primate, an anatomy that is beneficial for bipedal locomotion. Reconstructing the evolutionary history of the Achilles tendon has been challenging, in part because soft tissue does not fossilize. The only skeletal evidence for Achilles tendon anatomy in extinct taxa is the insertion site on the calcaneal tuber, which is rarely preserved in the fossil record and, when present, is equivocal for reconstructing tendon morphology. In this study, we used high-resolution three-dimensional microcomputed tomography (micro-CT) to quantify the microstructure of the trabecular bone underlying the Achilles tendon insertion site in baboons, gibbons, chimpanzees, and humans to test the hypothesis that trabecular orientation differs among primates with different tendon morphologies. Surprisingly, despite their very different Achilles tendon lengths, we were unable to find differences between the trabecular properties of chimpanzee and human calcanei in this specific region. There were regional differences within the calcaneus in the degree of anisotropy (DA) in both chimpanzees and humans, though the patterns were similar between the two species (higher DA inferiorly in the calcaneal tuber). Our results suggest that while trabecular bone within the calcaneus varies, it does not respond to the variation of Achilles tendon morphology across taxa in the way we hypothesized. These results imply that internal bone architecture may not be informative for reconstructing Achilles tendon anatomy in early hominins. PMID:23821323

  5. A brief review of extensor tendon injuries specific to the pediatric patient.

    PubMed

    Dwyer, C Liam; Ramirez, Rey N; Lubahn, John D

    2015-03-01

    Extensor tendon injuries in the pediatric population require careful evaluation and treatment. This article focuses on the differences in injury type and treatment of pediatric versus adult extensor tendon injuries. A detailed history and physical examination is crucial in the management of extensor tendon injuries of the young patient. Treatment of pediatric extensor tendon injuries depends largely on the site of injury. A majority of these injuries may be treated with splinting or primary repair. Treatment methods that require high compliance must be adjusted for the young child. PMID:25767417

  6. Immediate and short-term effects of exercise on tendon structure: biochemical, biomechanical and imaging responses.

    PubMed

    Tardioli, Alex; Malliaras, Peter; Maffulli, Nicola

    2012-09-01

    Introduction Tendons are metabolically active structures, and their biochemical, biomechanical and structural properties adapt to chronic exercise. However, abnormal adaptations may lead to the development of tendinopathy and pain. Acute and subacute adaptations might contribute to tendon pathology. Sources of data A systematic search of peer-reviewed articles was performed using a wide range of electronic databases. A total of 61 publications were selected. Areas of agreement Exercise induces acute responses in collagen turnover, blood flow, glucose, lactate and other inflammatory products (e.g. prostaglandins and interleukins). Mechanical properties are influenced by activity duration and intensity. Acute bouts of exercise affect tendon structure, with some of the changes resembling those reported in pathological tendons. Areas of controversy Given the variation in study designs, measured parameters and outcomes, it remains debatable how acute exercise influences overall tendon properties. There is discrepancy regarding which investigation modality and settings provide optimal assessment of each parameter. Growing points There is a need for greater homogeneity between study designs, including subject consortium and age, exercise protocols and time frames for parameter assessing. Areas timely for developing research Innovative methods, measuring each parameter simultaneously, would allow a greater understanding of how and when changes occur. This methodology is key to revealing pathological processes and pathways that alter tendon properties according to various activities. Optimal tendon properties differ between activities: more compliant tendons are beneficial for slow stretch shortening cycle (SSC) activities such as countermovement jumps, whereas stiffer tendons are considered beneficial for fast SSC movements such as sprinting. PMID:22279080

  7. 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

  8. 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

  9. Experimental study of the effects of helium-neon laser radiation on repair of injured tendon

    NASA Astrophysics Data System (ADS)

    Xu, Yong-Qing; Li, Zhu-Yi; Weng, Long-Jiang; An, Mei; Li, Kai-Yun; Chen, Shao-Rong; Wang, Jian-Xin; Lu, Yu

    1993-03-01

    Despite extensive research into the biology of tendon healing, predictably restoring normal function to a digit after a flexor tendon laceration remains one of the most difficult problems facing the hand surgeon. The challenge of simultaneously achieving tendon healing while minimizing the peritendinous scar formation, which limits tendon gliding, has captured the attention of investigators for many years. It has been said that low-power density helium-neon laser radiation had effects on anti-inflammation, detumescence, progressive wound healing, and reducing intestinal adhesions. This experimental study aims at whether helium-neon laser can reduce injured tendon adhesions and improve functional recovery of the injured tendon. Fifty white Leghorn hens were used. Ten were randomly assigned as a normal control group, the other forty were used in the operation. After anesthetizing them with Amytal, a half of the profundus tendons of the second and third foretoes on both sides of the feet were cut. Postoperatively, the hens moved freely in the cages. One side of the toes operated on were randomly chosen as a treatment group, the other side served as an untreated control group. The injured tendon toes in the treatment group were irradiated for twenty minutes daily with a fiber light needle of helium-neon laser therapeutic apparatus (wavelength, 6328 angstroms) at a constant power density of 12.74 mW/cm2, the first exposure taking place 24 hours after the operation. The longest course of treatment was 3 weeks. The control group was not irradiated. At 3 days, 1, 2, 3, and 5 weeks after surgery, 8 hens were sacrificed and their tendons were examined. The experimental results: (1) active, passive flexion and tendon gliding functional recovery were significantly better in the treatment group (p < 0.01); (2) width and thickness of the tendon at the cut site were significantly smaller in the treatment group (p < 0.01); (3) degrees of tendon adhesions were significantly lighter in the treatment group (p < 0.05). The experimental results demonstrate helium-neon laser radiation had significant effects on anti-inflammation, detumescence, progressive hematoma absorbing, inhibiting the tendon extrinsic healing, reducing tendon adhesions, improving the tendon intrinsic healing, i.e., stimulating epitenon and endotenon cells proliferation and migrating into the gap, stimulating collagen synthesis in the tendon gap, and enhancing the late remodeling of fibrous peritendonous adhesion.

  10. Open re-rupture of the Achilles tendon after surgical treatment

    PubMed Central

    Hanada, Mitsuru; Takahashi, Masaaki; Matsuyama, Yukihiro

    2011-01-01

    The rate of re-rupture of Achilles tendon after surgical treatment were reported to 1.7–5.6% previously. Re-rupture of Achilles tendon generally occurs subcutaneously. We experienced two rare cases of the open re-ruptures of Achilles tendon with a transverse wound perpendicular to the primary surgical incision. Re-rupture occurred 4 and 13 weeks after surgical treatment. We suggest that open re-rupture correlates more closely with skin scaring and shortening. Another factor may be adhesion between the subcutaneous scar and the suture of the paratenon and Achilles tendon with post-operative immobilization. PMID:24765375

  11. Study of optical properties and proteoglycan content of tendons by polarization sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Yang, Ying; Rupani, Asha; Bagnaninchi, Pierre; Wimpenny, Ian; Weightman, Alan

    2012-08-01

    The highly orientated collagen fibers in tendons play a critical role for transferring tensile stress, and they demonstrate birefringent optical properties. However, the influence that proteoglycans (PGs) have on the optical properties of tendons is yet to be fully elucidated. PGs are the essential components of the tendon extracellular matrix; the changes in their quantities and compositions have been associated with tendinopathies. In this study, polarization sensitive optical coherence tomography (PS-OCT) has been used to reveal the relationship between PG content/location and birefringence properties of tendons. Fresh chicken tendons were imaged at regular intervals by PS-OCT and polarization light microscopy during the extraction of PGs, using guanidine hydrochloride (GuHCl). Complementary time-lapsed images taken from the two modalities mutually demonstrated that the extraction of PGs disturbed the local organization of collagen bundles. This corresponded with a decrease in birefringence and associated banding pattern observed by PS-OCT. Furthermore, this study revealed there was a higher concentration of PGs in the outer sheath region than in the fascicles, and therefore the change in birefringence was reduced when extraction was performed on unsheathed tendons. The results provide new insights of tendon structure and the role of PGs on the structural stability of tendons, which also demonstrates the great potential for using PS-OCT as a diagnostic tool to examine tendon pathology.

  12. [Aggravated reduction of the posterior malleolar fracture due to incarceration of the flexor digitorum longus tendon].

    PubMed

    Mennenga, U; Mendel, T; Ullrich, B W; Hofmann, G O

    2015-03-01

    The indications for stabilization of the posterior malleolus (Volkmann triangle) while fixing ankle fractures are controversially discussed. Detailed descriptions of possible obstacles to reduction are scarce. The following case describes the difficulty of reduction of the posterior malleolus caused by interposition of the flexor digitorum longus tendon. The fracture line of the posterior malleolus passed in an atypical manner vertically to the posterior-medial tibial margin with direct contact to the anatomical pathway of the tendon. The impaction of the tendon was already present in the computed tomography (CT) scan taken preoperatively but the tendon hindering malleolar reduction was first realized during surgery after several unsuccessful attempts at repositioning. PMID:25135703

  13. Tendon proper- and peritenon-derived progenitor cells have unique tenogenic properties

    PubMed Central

    2014-01-01

    Introduction Multipotent progenitor populations exist within the tendon proper and peritenon of the Achilles tendon. Progenitor populations derived from the tendon proper and peritenon are enriched with distinct cell types that are distinguished by expression of markers of tendon and vascular or pericyte origins, respectively. The objective of this study was to discern the unique tenogenic properties of tendon proper- and peritenon-derived progenitors within an in vitro model. We hypothesized that progenitors from each region contribute differently to tendon formation; thus, when incorporated into a regenerative model, progenitors from each region will respond uniquely. Moreover, we hypothesized that cell populations like progenitors were capable of stimulating tenogenic differentiation, so we generated conditioned media from these cell types to analyze their stimulatory potentials. Methods Isolated progenitors were seeded within fibrinogen/thrombin gel-based constructs with or without supplementation with recombinant growth/differentiation factor-5 (GDF5). Early and late in culture, gene expression of differentiation markers and matrix assembly genes was analyzed. Tendon construct ultrastructure was also compared after 45 days. Moreover, conditioned media from tendon proper-derived progenitors, peritenon-derived progenitors, or tenocytes was applied to each of the three cell types to determine paracrine stimulatory effects of the factors secreted from each of the respective cell types. Results The cell orientation, extracellular domain and fibril organization of constructs were comparable to embryonic tendon. The tendon proper-derived progenitors produced a more tendon-like construct than the peritenon-derived progenitors. Seeded tendon proper-derived progenitors expressed greater levels of tenogenic markers and matrix assembly genes, relative to peritenon-derived progenitors. However, GDF5 supplementation improved expression of matrix assembly genes in peritenon progenitors and structurally led to increased mean fibril diameters. It also was found that peritenon-derived progenitors secrete factor(s) stimulatory to tenocytes and tendon proper progenitors. Conclusions Data demonstrate that, relative to peritenon-derived progenitors, tendon proper progenitors have greater potential for forming functional tendon-like tissue. Furthermore, factors secreted by peritenon-derived progenitors suggest a trophic role for this cell type as well. Thus, these findings highlight the synergistic potential of including these progenitor populations in restorative tendon engineering strategies. PMID:25005797

  14. SHEAR CARRYING CAPACITY OF SEGMENTAL CONCRETE BEAMS WITH DRAPED EXTERNAL TENDONS

    NASA Astrophysics Data System (ADS)

    Nguyen, Dinh Hung; Matsumoto, Koji; Watanabe, Ken; Hasegawa, Tsuyoshi; Niwa, Junichiro

    This study presents an investigation of the shear be havior of segmental concrete beams with draped external tendons. Deviator force and transfer mechanism of prestressing force from an anchorage that affect the shear failure mechanism have been examined base d on the results of experimental procedure and FEM with different location of deviator and inclined angle of draped tendons. The modified model proposed by authors has been extended for segmental concrete beam s with draped external tendons with considering the effect of deviator force and transfer mechanism of prestressing force from the anchorage. The results from the extended modified model for draped external tendons had a good agreement with experimental results.

  15. 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

  16. A new technique for repair of acute or chronic extensor tendon injuries in zone 1.

    PubMed

    Gu, Y P; Zhu, S M

    2012-05-01

    We describe a new surgical technique for the treatment of lacerations of the extensor tendon in zone I, which involves a tenodesis using a length of palmaris longus tendon one-quarter of its width. After exposing the dorsal aspect of the distal interphalangeal joint and harvesting the tendon, a 1.5 mm drill bit is passed through the insertion of the extensor tendon into the distal phalanx where it penetrates through the skin of the pulp of the digit. The palmaris longus tendon is threaded through the drill hole from dorsal to ventral and the ventral end is tied in a simple knot and trimmed. The palmaris longus tendon is then sutured to the extensor tendon close to its insertion, and also at the middle of the middle phalanx. The operation was undertaken on 67 patients: 27 with an acute injury and 40 patients with a chronic mallet deformity. One finger (or the thumb) was involved in each patient. At a mean follow-up of 12 months (6 to 18), 66 patients (98.5%) received excellent or good results according to both the American Society for Surgery of the Hand (ASSH) classification and Miller's classification. Tenodesis using palmaris longus tendon after complete division of an extensor tendon in zone 1 is a reliable form of treatment for isolated acute or chronic ruptures. PMID:22529089

  17. Heterotopic mineralization (ossification or calcification) in tendinopathy or following surgical tendon trauma

    PubMed Central

    O'Brien, Etienne J O; Frank, Cyril B; Shrive, Nigel G; Hallgrímsson, Benedikt; Hart, David A

    2012-01-01

    Heterotopic tendon mineralization (ossification or calcification), which may be a feature of tendinopathy or which may develop following surgical trauma (repair or graft harvest), has not received much attention. The purpose of this article is to review the prevalence, mechanisms and consequences of heterotopic tendon mineralization and to identify the gaps in our current understanding. We focus on endochondral heterotopic ossification and draw on knowledge of the mechanisms of this process in other tissues and conditions. Finally, we introduce a novel murine Achilles tendon needle injury model, which will enable us to further study the mechanisms and biomechanical consequences of tendon mineralization. PMID:22974213

  18. Flexor tendon healing within the tendon sheath using bioabsorbable poly-L/D-lactide 96/4 suture. A histological in vivo study with rabbits.

    PubMed

    Viinikainen, Anna; Göransson, Harry; Taskinen, Hanna-Stina; Röyttä, Matias; Kellomäki, Minna; Törmälä, Pertti; Rokkanen, Pentti

    2014-05-01

    The bioabsorbable poly-L/D-lactide (PLDLA) 96/4 suture has good biomechanical and knot properties, and sufficient tensile strength half-life for flexor tendon repair. In the present study, the biocompatibility of PLDLA suture was compared with that of coated braided polyester suture in the rabbit flexor digitorum profundus tendon repaired within the tendon sheath. Postoperative unrestricted active mobilization was allowed. The tendons were studied histologically after 1-, 3-, 6-, 12-, 26-, and 52-week follow-ups. No differences were found in the biocompatibility between the suture materials, with only scattered multinuclear giant cells near the sutures in both groups from 6 weeks onwards. At 52 weeks, most of the PLDLA material was absorbed and the histological structure of the tendon appeared normal, whereas in the polyester repairs the suture knots filled the repair site, causing bulking of the tendon surface, and the collagen alignment appeared disoriented. The results suggest that the PLDLA 96/4 is a suitable suture material for flexor tendon repair. PMID:24477875

  19. In situ tibialis posterior to flexor digitorum longus tendon transfer for tibialis posterior tendon dysfunction: a simplified surgical approach with outcome of 11 patients.

    PubMed

    Feldman, N J; Oloff, L M; Schulhofer, S D

    2001-01-01

    Outcomes for 11 patients who underwent an in situ tibialis posterior tendon to flexor digitorum longus tendon side-to-side anastamosis as the sole procedure for stage 2 tibialis posterior tendon dysfunction were reviewed. The average follow-up was 34.4 months. Using the American Orthopedic Foot and Ankle Society hindfoot rating scale, a mean improvement of 39.3 points was achieved, with preoperative scores of 38.8 improving to 78.1 postoperatively. Good to excellent results were achieved in nine patients. The in situ side-to-side anastamosis is technically easier to perform, has less tissue trauma, and compares favorably with other soft-tissue procedures and reconstructions for stage 2 tibialis posterior tendon dysfunction. Performing this transfer alone, while leaving the flexor digitorum longus tendon intact, theoretically provides a stronger transfer as the length-tension relationship of the flexor digitorum longus tendon is maintained near its physiologic level. The procedure can consistently restore inversion ability to the rearfoot and stop the progression of tibialis posterior tendon dysfunction. PMID:11202763

  20. The influence of tendon compliance on muscle power output and efficiency during cyclic contractions.

    PubMed

    Lichtwark, G A; Barclay, C J

    2010-03-01

    Muscle power output and efficiency during cyclical contractions are influenced by the timing and duration of stimulation of the muscle and the interaction of the muscle with its mechanical environment. It has been suggested that tendon compliance may reduce the energy required for power production from the muscle by reducing the required shortening of the muscle fibres. Theoretically this may allow the muscle to maintain both high power output and efficiency during cyclical contraction; however, this has yet to be demonstrated experimentally. To investigate how tendon compliance might act to increase muscle power output and/or efficiency, we attached artificial tendons of varying compliance to muscle fibre bundles in vitro and measured power output and mechanical efficiency during stretch-shorten cycles (2 Hz) with a range of stretch amplitudes and stimulation patterns. The results showed that peak power, average power output and efficiency (none of which can have direct contributions from the compliant tendon) all increased with increasing tendon compliance, presumably due to the tendon acting to minimise muscle energy use by allowing the muscle fibres to shorten at optimal speeds. Matching highly compliant tendons with a sufficiently large amplitude length change and appropriate stimulation pattern significantly increased the net muscle efficiency compared with stiff tendons acting at the same frequency. The maximum efficiency for compliant tendons was also similar to the highest value measured under constant velocity and force conditions, which suggests that tendon compliance can maximise muscle efficiency in the conditions tested here. These results provide experimental evidence that during constrained cyclical contractions, muscle power and efficiency can be enhanced with compliant tendons. PMID:20154185

  1. The Location-Specific Role of Proteoglycans in the Flexor Carpi Ulnaris Tendon

    PubMed Central

    Buckley, Mark R.; Huffman, George R.; Iozzo, Renato V.; Birk, David E.; Soslowsky, Louis J.

    2015-01-01

    Tendons like the flexor carpi ulnaris (FCU) that contain region-specific distributions of proteoglycans (PGs) as a result of the heterogeneous, multi-axial loads they are subjected to in vivo provide valuable models for understanding structure-function relationships in connective tissues. However, the contributions of specific PGs to FCU tendon mechanical properties are unknown. Therefore, the objective of this study was to determine how the location-dependent, viscoelastic mechanical properties of the FCU tendon are impacted individually by PG-associated glycosaminoglycans (GAGs) and by two small leucine-rich proteoglycans (SLRPs), biglycan and decorin. Full length FCU tendons from biglycan- and decorin-null mice were compared to wild type mice to evaluate the effects of specific SLRPs, while chondroitinase ABC digestion of isolated specimens removed from the tendon midsubstance was used to determine how chontroitin/dermatan sulfate (CS/DS) GAGs impact mechanics in mature FCU tendons. A novel combined genetic knockout/ digestion technique also was employed to compare SLRP-null and wild-type tendons in the absence of CS/DS GAGs that may impact properties in the mature state. In all genotypes, mechanical properties in the FCU tendon midsubstance were not affected by GAG digestion. Full-length tendons exhibited complex, multi-axial deformation under tension that may be associated with their in vivo loading environment. Mechanical properties were adversely affected by the absence of biglycan, and a decreased modulus localized in the center of the tendon was measured. These results help elucidate the role that local alterations in proteoglycan levels may play in processes that adversely impact tendon functionality including injury and pathology. PMID:23941206

  2. Closed rupture of flexor tendon by hyperextension mechanism in wrist level (zone V): a report of three cases.

    PubMed

    Nho, Jae-Hwi; Lee, Tae-Kyung; Kim, Byung-Sung; Yoon, Hong-Kee; Gong, Hyun Sik; Suh, You-Sung

    2013-07-01

    Closed flexor tendon ruptures due to trauma without external wound are rare. When the flexor tendon has excessive loading, failure occurs at the tendon insertion or its origin from the bone. It is likely to result in avulsion fracture rather than rupture of the proper portion of the tendon by forceful grasping with hyperextension. However, we have experienced three cases of closed flexor tendon ruptures at zone V, caused by forceful grasping or hyperextension mechanism against resistance. On physical examination, these patients could not flex interphalangeal joint of thumb or distal interphalangeal joint of the fifth finger. All patients underwent MRI or ultrasonography to find out the location of loss in continuity of the flexor tendons before the operation. After identifying the location, flexor tendon repair or tendon graft using palmaris longus were performed. PMID:23604791

  3. Effects of Stress Deprivation on Lubricin Synthesis and Gliding of Flexor Tendons in a Canine Model in Vivo

    PubMed Central

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

    2013-01-01

    Background: Lubricin facilitates boundary lubrication of cartilage. The synthesis of lubricin in cartilage is regulated by mechanical stimuli, especially shear force. Lubricin is also found in flexor tendons. However, little is known about the effect of mechanical loading on lubricin synthesis in tendons or about the function of lubricin in flexor tendons. The purpose of this study was to investigate the relationship of mechanical loading to lubricin expression and gliding resistance of flexor tendons. Methods: Flexor tendons were harvested from canine forepaws that had been suspended without weight-bearing for twenty-one days and from the contralateral forepaws that had been allowed free motion. Lubricin expression in each flexor tendon was investigated with real-time RT-PCR (reverse transcription polymerase chain reaction) and immunohistochemistry. Lubricin in the flexor tendon was extracted and quantified with ELISA (enzyme-linked immunosorbent assay). The friction between the flexor tendon and the proximal pulley was measured. Results: The non-weight-bearing flexor tendons had a 40% reduction of lubricin expression (p < 0.01) and content (p < 0.01) compared with the flexor tendons in the contralateral limb. However, the gliding resistance of the tendons in the non-weight-bearing limb was the same as that of the tendons on the contralateral, weight-bearing side. Conclusions: Mechanical loading affected lubricin expression in flexor tendons, resulting in a 40% reduction of lubricin content, but these changes did not affect the gliding resistance of the flexor tendons. Clinical Relevance: The gliding resistance of flexor tendons was not affected after a period of limited motion. This suggests that physical activity after a short period of limited motion does not lead to wear of intact tendons and their surrounding tissue. PMID:23389791

  4. 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

  5. Effect of simultaneous vibrations to two tendons on velocity of the induced illusory movement

    Microsoft Academic Search

    Hiroaki Yaguchi; Osamu Fukayama; Takafumi Suzuki; Kunihiko Mabuchi

    2010-01-01

    A typical prosthetic limb has sensory shortcomings, one of which is lack of kinesthesia. Conventional methods to evoke kinesthesia, which would be required for a precise control of prosthetic limbs, include tendon vibration and skin stretch, but these produce only the sensation of small movements. In this study, tendon vibration is extended to evoke sensations of a more rapid movement.

  6. Positioning Techniques to Reduce the Occurrence of DeQuervain's Tendonitis in Nursing Mothers

    ERIC Educational Resources Information Center

    Virzi, Alison

    2010-01-01

    DeQuervain's tendonitis is an inflammation of two tendons: the extensor pollicis brevis and the abductor pollicis longus as they cross in the first dorsal compartment of the wrist. Symptoms include pain, swelling along the radial aspect of the wrist, and a decrease in thumb motion. A positive Finkelstein's test at examination is seen. Frequently…

  7. The series-elastic shock absorber: tendons attenuate muscle power during eccentric actions

    E-print Network

    Azizi, Manny

    The series-elastic shock absorber: tendons attenuate muscle power during eccentric actions Thomas J. The series-elastic shock absorber: tendons attenuate muscle power during eccentric actions. J Appl Phys- iol contractions, when muscles absorb energy. Force, length, and power were measured in the lateral gastrocnemius

  8. Investigation of 2D and 3D electrospun scaffolds intended for tendon repair.

    PubMed

    Bosworth, L A; Alam, N; Wong, J K; Downes, S

    2013-06-01

    Two-dimensional (2D) electrospun fibre mats have been investigated as fibrous sheets intended as biomaterials scaffolds for tissue repair. It is recognised that tissues are three-dimensional (3D) structures and that optimisation of the fabrication process should include both 2D and 3D scaffolds. Understanding the relative merits of the architecture of 2D and 3D scaffolds for tendon repair is required. This study investigated three different electrospun scaffolds based on poly(?-caprolactone) fibres intended for repair of injured tendons, referred to as; 2D random sheet, 2D aligned sheet and 3D bundles. 2D aligned fibres and 3D bundles mimicked the parallel arrangement of collagen fibres in natural tendon and 3D bundles further replicated the tertiary layer of a tendon's hierarchical configuration. 3D bundles demonstrated greatest tensile properties, being significantly stronger and stiffer than 2D aligned and 2D random fibres. All scaffolds supported adhesion and proliferation of tendon fibroblasts. Furthermore, 2D aligned sheets and 3D bundles allowed guidance of the cells into a parallel, longitudinal arrangement, which is similar to tendon cells in the native tissue. With their superior physical properties and ability to better replicate tendon tissue, the 3D electrospun scaffolds warrant greater investigation as synthetic grafts in tendon repair. PMID:23504088

  9. Immediate Free Ankle Motion After Surgical Repair of Acute Achilles Tendon Ruptures

    Microsoft Academic Search

    Sven-A. Sölveborn; Anders Moberg

    1994-01-01

    We prospectively studied 17 consecutively treated pa tients (15 men and 2 women) who had surgically treated subcutaneous, complete and acute Achilles tendon rup tures. The patients underwent a new postoperative regi men that allowed free ankle motion in a patellar tendon bearing plaster cast with a protecting frame under the foot making weightbearing possible immediately after surgery. Evaluation was

  10. Stochastic interdigitation as a toughening mechanism at the interface between tendon and bone.

    PubMed

    Hu, Yizhong; Birman, Victor; Demyier-Black, Alix; Schwartz, Andrea G; Thomopoulos, Stavros; Genin, Guy M

    2015-01-20

    Reattachment and healing of tendon to bone poses a persistent clinical challenge and often results in poor outcomes, in part because the mechanisms that imbue the uninjured tendon-to-bone attachment with toughness are not known. One feature of typical tendon-to-bone surgical repairs is direct attachment of tendon to smooth bone. The native tendon-to-bone attachment, however, presents a rough mineralized interface that might serve an important role in stress transfer between tendon and bone. In this study, we examined the effects of interfacial roughness and interdigital stochasticity on the strength and toughness of a bimaterial interface. Closed form linear approximations of the amplification of stresses at the rough interface were derived and applied in a two-dimensional unit-cell model. Results demonstrated that roughness may serve to increase the toughness of the tendon-to-bone insertion site at the expense of its strength. Results further suggested that the natural tendon-to-bone attachment presents roughness for which the gain in toughness outweighs the loss in strength. More generally, our results suggest a pathway for stochasticity to improve surgical reattachment strategies and structural engineering attachments. PMID:25606690

  11. A tendon-driven glove to restore finger function for disabled

    Microsoft Academic Search

    Shunji Moromugi; Kousuke Kawakami; Katsutoshi Nakamura; Taichi Sakamoto; Takakazu Ishimatsu

    2009-01-01

    An innovative glove system actuated by electric motors has been developed to restore finger functions for disabled people. This glove system is composed of a leather glove having external tendons built-in, an actuation unit and a sensor to detect user's intentions for finger operations. Fingers are operated by actuation of the thin tendons made of polyethylene. The driving force of

  12. Principles of tendon reconstruction following complex trauma of the upper limb.

    PubMed

    Chattopadhyay, Arhana; McGoldrick, Rory; Umansky, Elise; Chang, James

    2015-02-01

    Reconstruction of tendons following complex trauma to the upper limb presents unique clinical and research challenges. In this article, the authors review the principles guiding preoperative assessment, surgical reconstruction, and postoperative rehabilitation and management of the upper extremity. Tissue engineering approaches to address tissue shortages for tendon reconstruction are also discussed. PMID:25685101

  13. Model-based segmentation of flexor tendons from magnetic resonance images of finger joints

    Microsoft Academic Search

    H. C. Chen; C. K. Chen; T. H. Yang; L. C. Kuo; I. M. Jou; F. C. Su; Y. N. Sun

    2011-01-01

    Trigger finger is a common hand disease, causing swelling, painful popping and clicking in moving the affected finger joint. To better evaluate patients with trigger finger, segmentation of flexor tendons from magnetic resonance (MR) images of finger joints, which can offer detailed structural information of tendons to clinicians, is essential. This paper presents a novel model-based method with three stages

  14. Fast, strong and compliant pneumatic actuation for dexterous tendon-driven hands

    E-print Network

    Todorov, Emanuel

    Fast, strong and compliant pneumatic actuation for dexterous tendon-driven hands Vikash Kumar, Zhe Xu and Emanuel Todorov Abstract--We describe a pneumatic actuation system for dexterous robotic hands for dexterous manipulation, yet it has never before been achieved with a tendon-driven system, let alone

  15. Tendon injuries induced by exercise and anabolic steroids in experimental mice

    Microsoft Academic Search

    H. Michna

    1987-01-01

    The purpose of this study was to examine the effect of anabolic steroid hormones and exercise training on skeletal tendons. Female mice were exercised for 1 and 10 weeks in an endurance running programme on a treadmill. The altered ultrastructure of tendons caused by simultaneously administered anabolic steroid hormone was investigated by electron microscopy. A stereoscopic analysis of collagen fibrils

  16. TENDON TRANSFER TO RECONSTRUCT WRIST EXTENSION IN CHILDREN WITH OBSTETRIC BRACHIAL PLEXUS PALSY

    Microsoft Academic Search

    M. M. Al-QATTAN

    2003-01-01

    This study reports on 20 children with obstetric brachial plexus palsy who underwent a tendon transfer to reconstruct wrist extension. The mean age at the time of tendon transfer was 8 years. There were seven patients with Erb's palsy and the remaining 13 had total palsy. The flexor carpi ulnaris was utilized 15 times and the flexor carpi radialis five

  17. Surgical Repair of Chronic Complete Hamstring Tendon Rupture in the Adult Patient

    Microsoft Academic Search

    Mervyn J. Cross; Ronald Vandersluis; David Wood; Margaret Banff

    1998-01-01

    Complete rupture of the hamstring tendons in the adult is a rare injury. This report discusses complete rupture of the hamstring tendons in nine patients treated by late operative repair. All patients were referred from outside centers for a second opinion after failed non-operative treatment. The diagnosis was made quite easily on clinical grounds and was confirmed at surgery. Surgical

  18. Repair of a deep digital tendon deficit in a horse using a polypropylene implant.

    PubMed Central

    Crawford, W H; Ingle, J E

    1997-01-01

    A yearling horse was treated for a chronic wound with a 4 cm deficit in the deep digital tendon. The gap in the tendon was bridged with paired polypropylene braided implants designed for use as a ligament augmentation device. Uncomplicated healing and return to function occurred. Images Figure 1. PMID:9167878

  19. Human Leg Model Predicts Ankle Muscle-Tendon Morphology, State, Roles and Energetics in Walking

    E-print Network

    Herr, Hugh

    Human Leg Model Predicts Ankle Muscle-Tendon Morphology, State, Roles and Energetics in Walking to be established. Here we develop a computational framework to address how the ankle joint actuation problem-tendon morphology and neural activations enable a metabolically optimal realization of biological ankle mechanics

  20. Mechanical evaluation of a soft tissue interference screw in free tendon anterior cruciate ligament graft fixation.

    PubMed

    Nagarkatti, D G; McKeon, B P; Donahue, B S; Fulkerson, J P

    2001-01-01

    In this study of bioabsorbable screw fixation of free tendon grafts used in anterior cruciate ligament reconstruction, we performed load-to-failure and cyclic loading of tendon fixation in porcine bone. Bone density measurements from dual photon absorptometry scans were obtained to correlate bone density with fixation failure. The average density of porcine bone (1.42 g/cm2) was similar to that of young human bone (1.30 g/cm2) and significantly higher than that of elderly human cadaveric bone specimens (0.30 g/cm2). Cyclic loading was performed on free tendon grafts fixed with a bioabsorbable screw alone and on grafts fixed with a bioabsorbable screw and an anchor (polylactic acid ball or cortical bone disk). Stiffness of fixation increased substantially with the addition of a cortical bone disk anchor or polylactic acid ball compared with the interference screw alone. Tensile fixation strength of central quadriceps free tendon and hamstring tendon grafts were significantly superior in porcine bone of density similar to young human bone than in elderly human cadaveric bone. The bioabsorbable interference screw yielded loads at failure comparable with traditional bone-tendon-bone and hamstring tendon fixation when controlled for bone density. The addition of a cortical bone disk anchor provided the most optimal fixation of free tendon with the bioabsorbable screw and reduced slippage with cyclic loading to a very low level. PMID:11206259

  1. Patella fracture and proximal patellar tendon rupture following arthroscopic anterior cruciate ligament reconstruction.

    PubMed

    Miller, M D; Nichols, T; Butler, C A

    1999-09-01

    The central one-third bone-patella tendon-bone graft is a popular choice for arthroscopic anterior cruciate ligament reconstruction. Complications following graft harvesting are unusual, but several reports have been published. We report an unusual case involving a simultaneous patella fracture and patellar tendon rupture that occurred 6 weeks postoperatively. PMID:10495182

  2. Complete Subscapularis Tendon Visualization and Axillary Nerve Identification by Arthroscopic Technique

    Microsoft Academic Search

    Gianezio Paribelli; Stefano Boschi

    2005-01-01

    The authors explain how one can view the greatest part of the subscapularis tendon from the subacromial aspect. From the articular aspect, it is possible to see only about one third of its entire surface. We also describe the standardized surgical technique used to obtain this visualization. To visualize the greatest possible surface of the tendon, it is necessary to

  3. Posterior tibial tendon entrapment within an intact ankle mortise: a case report.

    PubMed

    Hunter, Allison M; Bowlin, Christopher

    2015-01-01

    The present case report demonstrates a rare finding associated with irreducible ankle fracture dislocations. To our knowledge, posterior tibial tendon entrapment with an intact ankle mortise has not yet been documented in published studies. In the case of our patient, a high-energy, 12-ft fall resulted in a comminuted intra-articular fracture of the medial malleolus, confirmed by the initial radiographs. Preoperative magnetic resonance imaging showed the Achilles tendon to be ruptured and the posterior tibial tendon to be both displaced and entrapped between the medial malleolar fracture fragments, preventing initial closed reduction. At operative repair for the ruptured Achilles tendon and the medial malleolus fracture, the posterior tibial tendon was removed from the fracture site and was found to be intact with no evidence of laceration or rupture. The tendon was returned back to its anatomic position, and the tendon sheath was reapproximated. Although uncommon, it is important that entrapment of the posterior tibial tendon be considered in cases of irreducible ankle fracture. This injury type can be addressed during open reduction internal fixation to achieve reduction. PMID:25441277

  4. TEST ON PRESTRESSED CONCRETE BEAM WITH AFRP SPIRAL CONFINEMENT AND EXTERNAL ARAMID TENDONS

    E-print Network

    Burgoyne, Chris

    TEST ON PRESTRESSED CONCRETE BEAM WITH AFRP SPIRAL CONFINEMENT AND EXTERNAL ARAMID TENDONS C. J concrete beam. Aramid Fibre Reinforced Polymers (AFRP) are used to make compression confinement in the form of interlocking circular spirals, while external tendons are made from parallel-lay aramid ropes. The response

  5. Structure and functional evaluation of tendon-skeletal muscle constructs engineered in vitro.

    PubMed

    Larkin, Lisa M; Calve, Sarah; Kostrominova, Tatiana Y; Arruda, Ellen M

    2006-11-01

    During muscle contraction, the integrity of the myotendinous junction (MTJ) is important for the transmission of force from muscle to tendon. We evaluated the contractile and structural characteristics of 3-dimensional (3-D) skeletal muscle constructs co-cultured with engineered self-organized tendon constructs (n = 4), or segments of adult (n = 4) or fetal (n = 5) rat-tail tendon. We hypothesized that the co-culture of tendon and muscle would produce constructs with viable muscle-tendon interfaces that remain intact during generation of force. Construct diameter (lm) and maximum isometric force (microN) were measured, and specific force (kPa) was determined. After measure of force, constructs were loaded at a constant strain rate until failure and surface strains were recorded optically across the tendon, the muscle and the interface and used to determine the tangent modulus (passive stiffness) of the construct. Frozen samples were used for Trichrome Masson staining and immunofluorescent analysis of the MTJ-specific protein paxillin. No differences were observed between the groups with respect to diameter, maximum force, or specific force. The MTJ was robust and withstood tensile loading beyond the physiological strain range. The majority of the constructs failed in the muscle region. At the MTJ, there is an increase in the expression and localization of paxillin. In conclusion, using 3 sources of tendon tissue, we successfully engineered 3-D muscle-tendon constructs with functionally viable MTJ, characterized by structural features and protein expression patterns resembling neonatal MTJs in vivo. PMID:17518629

  6. Revision ACL reconstruction using doubled semitendinosus and gracilis tendons: a follow-up study

    Microsoft Academic Search

    A. Ferretti; F. Conteduca; E. Monaco; A. De Carli; C. D’Arrigo

    2004-01-01

    Few papers report the results of revision ACL reconstruction with hamstrings tendons. We report our results with revision anterior cruciate ligament (ACL) surgery using a doubled gracilis and semitendinosus tendons (DGST) graft, in association with an exta-articular procedure. Twelve patients underwent ACL revision surgery using autogenous homolateral DGST graft in association with an extra-articular procedure and were evaluated at a

  7. Ultrasonographic Tendon Alteration in Relation to Parathyroid Dysfunction in Chronic Hemodialysis Patients

    PubMed Central

    Hussein, Dahlia A; El-Azizi, Noran O; Abdel Meged, Ali H; Al-Hoseiny, Sameh A; Hamada, Abdelhady M; Sabry, Moshira H

    2015-01-01

    OBJECTIVE To find the nature of tendon involvement in chronic kidney disease (CKD) patients on regular hemodialysis (RD), and its relationship to parathyroid hormone (PTH) level using ultrasonography (US). METHOD A total of 50 CKD patients on RD subjected to musculoskeletal examination of knee and ankle, laboratory evaluation, and US of quadriceps tendon and Achilles tendon were involved. RESULTS Ankle joint tenderness was the most frequent sign on examination. US of the Achilles tendons showed tenderness during probing in 44% patients, calcific deposition in 24% patients, abnormal peritendon tissue in 20% patients, and abnormal anteroposterior (A-P) middle and distal one-third thicknesses of the Achilles tendon in 20% and 18% patients, respectively. PTH positively correlated with the duration of dialysis, serum phosphorus level, presence of calcific deposit, and increased thickness of the Achilles tendon. CONCLUSION The most common ultrasonographic finding in CKD patients on RD was Achilles tendon tenderness during probing. PTH level positively correlated with the duration of dialysis, presence of calcific deposit, and increased thickness of Achilles tendon. PMID:25674023

  8. DEFINITIVE RESULTS OF THE SICM MULTICENTER STUDY ON TENDON ADHESIONS IN ZONE II OF THE HAND

    Microsoft Academic Search

    M. RICCIO; A. ATZEI; G. PAJARDI; P. FASOLO; B. BATTISTON; M. DEL BENE; C. CERUSO; M. ALTISSIMI; M. CORRADI; F. CATALANO; L. VAIENTI

    SUMMARY Purpose: Injuries of hand involving zone II are burdened by a significant number of treatment failures due to the development of adherences that prevent normal gliding of tendons. Surgical adherences are the result of the physiolo- gical process of tendon healing during the first 14 days following surgery. Due to the high frequency of hand trau- mas and the

  9. SERVICEABILITY OF CONCRETE BEAMS PRESTRESSED BY FmRE REINFORCED PLASTIC TENDONS

    E-print Network

    SERVICEABILITY OF CONCRETE BEAMS PRESTRESSED BY FmRE REINFORCED PLASTIC TENDONS by AMR A: SERVICEABILITY OF CONCRETE BEAMS PRESTRESSED BY CARBON FIBRE REINFORCED PLASTIC TENDONS Submitted by: AMR A reinforced plastic, CFRP, as prestressing reinforcement for concrete structures, has increased rapidly

  10. Rehabilitation of the upper extremity following nerve and tendon reconstruction: when and how.

    PubMed

    Novak, Christine B; von der Heyde, Rebecca L

    2015-02-01

    Following upper extremity nerve and tendon reconstruction, rehabilitation is necessary to achieve optimal function and outcome. In this review, the authors present current evidence and literature regarding the strategies and techniques of rehabilitation following peripheral nerve and tendon reconstruction. PMID:25685106

  11. Finite element formulation for geometric and material nonlinear analysis of beams prestressed with external slipping tendons

    Microsoft Academic Search

    Alessandro Zona; Laura Ragni; Andrea Dall’Asta

    2008-01-01

    In this paper a finite element formulation of a geometric and material nonlinear analytical model for externally prestressed beams is illustrated. Differently from existing methods starting from the linear theory and then including the tendon eccentricity variation, the analytical model adopted is based on a nonlinear kinematical theory. Thus a complete description of the nonlinear interactions between tendon and beam

  12. The Incidence of a Palmaris Longus Tendon in Patients with Dupuytren’s Disease

    Microsoft Academic Search

    B. W. E. M. POWELL; N. R. McLEAN; J. V. JEFFS

    1986-01-01

    The incidence of a palmaris longus tendon in patients with Dupuytren’s disease is significantly greater than in a control group with normal hands (p = 0.014).If a patient has a palmaris longus tendon, then there is a highly significant chance of Dupuytren’s disease developing in that hand (p<0.00l).

  13. The Two-Stage Free Flexor Tendon Grafting of the Hand

    Microsoft Academic Search

    Martin Langer; Erwin Brug

    2001-01-01

    Objective Reconstruction of prehension after remote flexor tendon injury or flexor tendon destruction after disease or infection. Indications Absence of passive motion of proximal and distal interphalangeal joints. Uncooperative patient. Children under 5 years of age. Acute local or serious systemic infection. Injury of both digital nerves; circulatory disturbances. Surgical Technique Stage 1: plexus block. Tourniquet. Bruner skin incision. Exploration

  14. A Comparative Study on Tendon Transfer Surgery in Patients with Radial Nerve Palsy

    PubMed Central

    Yavari, Masoud; Abdolrazaghi, Hossein Ali; Riahi, Azadeh

    2014-01-01

    BACKGROUND Lesions in peripheral nerves are highly prevalent in the upper extremity. The present study compares different tendon transfer surgeries in patients with radial nerve palsy. METHODS Fifty patients with radial nerve palsy were randomly selected among patients who referred to Tehran 15th Khordad Hospital during 2006-2011. They were divided into two groups of 17 and 33 subjects. Single tendon transfer surgery was performed on 33 and ternary tendon transfer surgery on 17 patients and were compared. RESULTS No significant difference was noticed in the range of motion of metacarpophalangeal joint, proximal interphalangeal joint and distal interphalangeal joint joints between the two groups. There was also no significant difference in the results of single tendon and ternary tendon transfer surgeries between the two groups. There was no need to sacrifice three tendons in tendon transfer surgeries on patients with radial nerve palsy. CONCLUSION Single tendon transfer surgery may help establishing a finger extension while indicates to its considerable advantages of surgical simplicity, shorter surgery time, less complications and surgery scars. PMID:25489524

  15. TGF-? Superfamily Signaling in Muscle and Tendon Adaptation to Resistance Exercise.

    PubMed

    Gumucio, Jonathan P; Sugg, Kristoffer B; Mendias, Christopher L

    2015-04-01

    Numerous studies in muscle and tendon have identified a central role of the transforming growth factor-? (TGF-?) superfamily of cytokines in the regulation of extracellular matrix growth and remodeling, protein degradation, and cell proliferation and differentiation. We provide a novel framework for TGF-? and myostatin signaling in controlling the coordinated adaptation of both skeletal muscle and tendon tissue to resistance training. PMID:25607281

  16. 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

  17. Rupture sous-cutanée du tendon long extenseur du pouce: à propos de 5 cas

    PubMed Central

    Abdelillah, Rachid; Abbassi, Najib; Erraji, Moncef; Abdeljawad, Najib; Yacoubi, Hicham; Daoudi, Abdelkrim

    2014-01-01

    La rupture spontanée du muscle long extenseur du pouce (EPL) du tendon au niveau du poignet est rare et principalement rapportés après fracture du radius distal à tubercule de Lister, dans la synovite, ténosynovite ou la polyarthrite rhumatoïde. Nous rapportons 5 cas de rupture spontanée du tendon long extenseur du pouce, traités par une greffe ou un transfert tendineux. PMID:25317233

  18. The role of recreational sport activity in Achilles tendon ruptureA clinical, pathoanatomical, and sociological study of 292 cases

    Microsoft Academic Search

    L. Jozsa; M. Kvist; B. J. Balint; A. Reffy; M. Jarvinen; M. Lehto; M. Barzo

    1989-01-01

    During the last few decades, the incidence of tendon ruptures has increased in civilized countries. Our ma terial comprises 749 patients who had 832 tendon ruptures treated surgically between 1972 and 1985. There were no competitive athletes among the patients studied. There were 292 single ruptures of the Achilles tendon, 274 of the proximal biceps brachii, 113 of the extensor

  19. Closed rupture of the flexor digitorum profundus tendon of the little finger caused by calcification of the triangular-fibrocartilage

    Microsoft Academic Search

    A. Fukui; A. Kido; Y. Inada; Y. Mii; S. Tamai

    1996-01-01

    A case of rupture of flexor digitorum profundus tendon of the little finger caused by calcification of the triangular fibrocartilage (TFC) is reported. At operation, a round defect of the TFC and rupture of the flexor digitorum profundus tendon (FDP) of the little finger were observed. The defect of TFC was repaired using the palmaris tendon and FDP of the

  20. A Novel Arthroscopic Inside-Out Repair Technique for PASTA Lesions

    PubMed Central

    Caldwell, Lindsey S.; Cooper, Anna R.; Elfar, John C.

    2014-01-01

    There is no current consensus in the literature on the optimal technique for surgical treatment of partial articular-sided supraspinatus tendon avulsion (PASTA) lesions, although most techniques described to date require takedown of the partially torn tendon or passage of an anchor through the already damaged tendon. We describe a novel inside-out repair technique for partial articular surface supraspinatus tears that does not require further disruption of the partially torn tendon by passage of an anchor. PMID:25473607

  1. Focal Experimental Injury Leads to Widespread Gene Expression and Histologic Changes in Equine Flexor Tendons

    PubMed Central

    Jacobsen, Else; Dart, Andrew J.; Mondori, Takamitsu; Horadogoda, Neil; Jeffcott, Leo B.; Little, Christopher B.; Smith, Margaret M.

    2015-01-01

    It is not known how extensively a localised flexor tendon injury affects the entire tendon. This study examined the extent of and relationship between histopathologic and gene expression changes in equine superficial digital flexor tendon after a surgical injury. One forelimb tendon was hemi-transected in six horses, and in three other horses, one tendon underwent a sham operation. After euthanasia at six weeks, transected and control (sham and non-operated contralateral) tendons were regionally sampled (medial and lateral halves each divided into six 3cm regions) for histologic (scoring and immunohistochemistry) and gene expression (real time PCR) analysis of extracellular matrix changes. The histopathology score was significantly higher in transected tendons compared to control tendons in all regions except for the most distal (P ? 0.03) with no differences between overstressed (medial) and stress-deprived (lateral) tendon halves. Proteoglycan scores were increased by transection in all but the most proximal region (P < 0.02), with increased immunostaining for aggrecan, biglycan and versican. After correcting for location within the tendon, gene expression for aggrecan, versican, biglycan, lumican, collagen types I, II and III, MMP14 and TIMP1 was increased in transected tendons compared with control tendons (P < 0.02) and decreased for ADAMTS4, MMP3 and TIMP3 (P < 0.001). Aggrecan, biglycan, fibromodulin, and collagen types I and III expression positively correlated with all histopathology scores (P < 0.001), whereas lumican, ADAMTS4 and MMP14 expression positively correlated only with collagen fiber malalignment (P < 0.001). In summary, histologic and associated gene expression changes were significant and widespread six weeks after injury to the equine SDFT, suggesting rapid and active development of tendinopathy throughout the entire length of the tendon. These extensive changes distant to the focal injury may contribute to poor functional outcomes and re-injury in clinical cases. Our data suggest that successful treatments of focal injuries will need to address pathology in the entire tendon, and that better methods to monitor the development and resolution of tendinopathy are required. PMID:25837713

  2. Focal experimental injury leads to widespread gene expression and histologic changes in equine flexor tendons.

    PubMed

    Jacobsen, Else; Dart, Andrew J; Mondori, Takamitsu; Horadogoda, Neil; Jeffcott, Leo B; Little, Christopher B; Smith, Margaret M

    2015-01-01

    It is not known how extensively a localised flexor tendon injury affects the entire tendon. This study examined the extent of and relationship between histopathologic and gene expression changes in equine superficial digital flexor tendon after a surgical injury. One forelimb tendon was hemi-transected in six horses, and in three other horses, one tendon underwent a sham operation. After euthanasia at six weeks, transected and control (sham and non-operated contralateral) tendons were regionally sampled (medial and lateral halves each divided into six 3cm regions) for histologic (scoring and immunohistochemistry) and gene expression (real time PCR) analysis of extracellular matrix changes. The histopathology score was significantly higher in transected tendons compared to control tendons in all regions except for the most distal (P ? 0.03) with no differences between overstressed (medial) and stress-deprived (lateral) tendon halves. Proteoglycan scores were increased by transection in all but the most proximal region (P < 0.02), with increased immunostaining for aggrecan, biglycan and versican. After correcting for location within the tendon, gene expression for aggrecan, versican, biglycan, lumican, collagen types I, II and III, MMP14 and TIMP1 was increased in transected tendons compared with control tendons (P < 0.02) and decreased for ADAMTS4, MMP3 and TIMP3 (P < 0.001). Aggrecan, biglycan, fibromodulin, and collagen types I and III expression positively correlated with all histopathology scores (P < 0.001), whereas lumican, ADAMTS4 and MMP14 expression positively correlated only with collagen fiber malalignment (P < 0.001). In summary, histologic and associated gene expression changes were significant and widespread six weeks after injury to the equine SDFT, suggesting rapid and active development of tendinopathy throughout the entire length of the tendon. These extensive changes distant to the focal injury may contribute to poor functional outcomes and re-injury in clinical cases. Our data suggest that successful treatments of focal injuries will need to address pathology in the entire tendon, and that better methods to monitor the development and resolution of tendinopathy are required. PMID:25837713

  3. Regional Differences in Stem Cell/Progenitor Cell Populations from the Mouse Achilles Tendon

    PubMed Central

    Adams, Sheila M.

    2013-01-01

    Specific niches may affect how cells from different regions contribute to tendon biology, particularly in regard to the healing of certain tendinopathies. The objectives of this study are to determine whether distinct subpopulations of stem/progenitor cells are found within the tendon proper and the epi- and paratenon, the peritenon, as well as to characterize these stem/progenitor cell populations. In this study, we hypothesized that tendon stem/progenitor cells exist in each region, that these populations possess distinct features, and that these populations while multipotent could have differing potentials. To test this hypothesis, stem/progenitor cells were isolated and characterized from the peritenon and tendon proper of mouse Achilles tendons. Colony-forming unit and multipotency assays, as well as flow cytometry, and real-time quantitative polymerase chain reaction analyses of stem cell markers were performed. Significantly, more stem/progenitor cell colonies were observed from cells derived from the tendon proper relative to the peritenon. Analysis of surface markers for stem/progenitor cells from both regions indicated that they were Sca1+ (stem cell marker), Cd90+ and Cd44+ (fibroblast markers), Cd18? (leukocyte marker), Cd34? (hematopoietic and vascular marker), and Cd133? (perivascular marker). Tendon proper stem/progenitor cells had increased expression levels for tenomodulin (Tnmd) and scleraxis (Scx), indicative of enrichment of stem/progenitor cells of a tendon origin. In contrast, cells of the peritenon demonstrated relative increases in the vascular (endomucin) and pericyte (Cd133) markers relative to cells from the tendon proper. Stem/progenitor cells from both regions were multipotent (adipogenic, chondrogenic, osteogenic, and tenogenic). These findings demonstrated that different progenitor populations exist within discrete niches of the Achilles tendon—tendon proper versus peritenon. Overall, these data support the hypothesis that the progenitor pools from both regions have distinct properties and contain enriched progenitor subpopulations of different origins. Moreover, in considering their roles in tendon healing more broadly, they are potential cell sources that may differentially contribute to intrinsic and extrinsic tendon repair mechanisms. That is, intrinsic repair may require a progenitor class with predominant tendon marker expression, while extrinsic repair may involve a progenitor class recruited from perivascular cells of the peritenon. PMID:22871316

  4. Variability in Hoffmann and tendon reflexes in healthy male subjects

    NASA Technical Reports Server (NTRS)

    Good, E.; Do, S.; Jaweed, M.

    1992-01-01

    There is a time dependent decrease in amplitude of H- and T-reflexes during Zero-G exposure and subsequently an increase in the amplitude of the H-reflex 2-4 hours after return to a 1-G environment. These alterations have been attributed to the adaptation of the human neurosensory system to gravity. The Hoffman reflex (H-reflex) is an acknowledged method to determine the integrity of the monosynaptic reflex arc. However deep tendon reflexes (DTR's or T-reflexes), elicited by striking the tendon also utilize the entire reflex arc. The objective of this study was to compare the variability in latency and amplitude of the two reflexes in healthy subjects. Methods: Nine healthy male subjects, 27-43 years in age, 161-175 cm in height plus 60-86 Kg in weight, underwent weekly testing for four weeks with a Dan-Tec EMG counterpoint EMG system. Subjects were studied prone and surface EMG electrodes were placed on the right and left soleus muscles. The H-reflex was obtained by stimulating the tibial nerve in the politeal fossa with a 0.2 msec square wave pulse delivered at 2 Hz until the maximum H-reflex was obtained. The T-reflex was invoked by tapping the achilles tendon with a self triggering reflex hammer connected to the EMG system. The latencies and amplitudes for the H- and T-reflexes were measured. Results: These data indicate that the amplitudes of these reflexes varied considerably. However, latencies to invoked responses were consistent. The latency of the T-reflex was approximately 3-5 msec longer than the H-reflex. Conclusion: The T-reflex is easily obtained, requires less time, and is more comfortable to perform. Qualitative data can be obtained by deploying self triggering, force plated reflex hammers both in the 1-G and Zero-G environment.

  5. [Strength required for mobilization of reconstructed flexor tendons in the front paw of the dog].

    PubMed

    Jeremi?, P D; Coli?, M M; Lazovi?, G D

    2009-01-01

    Adhesions of tendons with surrounding tissue, especially in zone II, are frequent complication at the reconstruction of flexor tendons of the hand. Through knowing of biomechanical incidents between the reconstructed flexor tendon and the surrounding tissue we get significant data for post-operative procedures, and that improves the opportunity for obtaining good functional results. By successive loading of operated flexor digitorum profundus in the experimental animals - dogs, medium values of force necessary for mobilization of tendons obtained on 3. post-operative day are 0 = +/- 3.36 N, 5. day 0 = +/- 6.85 N, 10. day 0 = +/- 9.58 N and 15. day 0 = +/- 10.19 N. It can be concluded that peritendon adhesions occur between 3 and 5 post-operative day. In time, the adhesions get stronger and block the movements of the tendon, and growing force is necessary for their mobilization. PMID:19504995

  6. Is initial preservation of deep tendon reflexes in West Nile Virus paralysis a good prognostic sign?

    PubMed Central

    Mojumder, Deb Kumar; Agosto, Melina; Wilms, Henrik; Kim, Jongyeol

    2014-01-01

    Typical West Nile virus paralysis is characterized by muscle weakness, decreased tone, and loss of deep tendon reflexes attributed to destruction of anterior horn cells. Two cases in which deep tendon reflexes were initially preserved in the presence of profound and persistent muscle weakness are presented here. In both cases, deep tendon reflexes were later severely attenuated or lost, while weakness of the involved muscles remained profound and unchanged. Both patients showed good motor recovery at 6 months. Initial preservation of deep tendon reflexes in the presence of persistent muscle weakness indicates that in the early stages of disease, the muscle weakness in these two cases was not caused by destruction of anterior horn cells. Pathology involving anterior horns preceding AHC destruction could potentially disrupt upper motor neuron pathways to anterior horn cells, causing weakness with initial preserved deep tendon reflexes. PMID:25400704

  7. Acute rupture of the tibialis posterior tendon without fracture: a case report.

    PubMed

    Martinelli, Nicolò; Bonifacini, Carlo; Bianchi, Alberto; Moneghini, Laura; Scotto, Gennaro; Sartorelli, Elena

    2014-05-01

    The acute rupture of the tibialis posterior (TP) tendon, compared to an acute rupture of the Achilles tendon, is a quite uncommon disease to be diagnosed in the emergency department setting. In most cases symptoms related to a TP dysfunction, like weakness, pain along the course of the tendon, swelling in the region of the medial malleolus, and the partial or complete loss of the medial arch with a flatfoot deformity precede the complete rupture of the tendon. In this case report, we describe an acute rupture of the TP tendon following a pronation-external rotation injury of the ankle with no association of a medial malleolus fracture and with no history of a prior flatfoot deformity or symptoms. PMID:24901592

  8. Tendon transfer to reconstruct wrist extension in children with obstetric brachial plexus palsy.

    PubMed

    Al-Qattan, M M

    2003-04-01

    This study reports on 20 children with obstetric brachial plexus palsy who underwent a tendon transfer to reconstruct wrist extension. The mean age at the time of tendon transfer was 8 years. There were seven patients with Erb's palsy and the remaining 13 had total palsy. The flexor carpi ulnaris was utilized 15 times and the flexor carpi radialis five times. The transferred tendon was sutured to the tendon of the extensor carpi radialis brevis. The result of the transfer was assessed according to a modified Medical Research Council (MRC) muscle grading system. A good result was obtained in 18 patients (modified MRC grade of 4) and a fair result (modified MRC grade of 3) in two. The choice of tendon transfer to reconstruct the wrist drop deformity in various conditions including adult traumatic brachial plexus injuries is discussed. PMID:12631488

  9. Re-revision of a patellar tendon rupture in a young professional martial arts athlete.

    PubMed

    Vadalà, A; Iorio, R; Bonifazi, A M; Bolle, G; Ferretti, A

    2012-09-01

    A 27-year-old professional martial arts athlete experienced recurrent right knee patellar tendon rupture on three occasions. He underwent two operations for complete patellar tendon rupture: an end-to-end tenorrhaphy the first time, and revision with a bone-patellar-tendon (BPT) allograft. After the third episode, he was referred to our department, where we performed a surgical reconstruction with the use of hamstring pro-patellar tendon, in a figure-of-eight configuration, followed by a careful rehabilitation protocol. Clinical and radiological follow-ups were realized at 1, 3, and 6 months and 1 and 2 years postop, with an accurate physical examination, the use of recognized international outcome scores, and radiograph and MRI studies. As far as we know, this is the first paper to report a re-revision of a patellar tendon rupture. PMID:22008978

  10. 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

  11. Improved Achilles tendon healing by early mechanical loading in a rabbit model

    PubMed Central

    Wang, Jihong; Jiang, Dianming; Wen, Shuzheng; Jing, Shangfei; Fan, Dongsheng; Hao, Zengtao; Han, Chaoqian

    2015-01-01

    Objective: To investigate the structure and the attachment strength of a healing tendon-bone interface and the role of mechanical loading in tendon healing. Methods: Sixty rabbits underwent unilateral detachment and repair of the Achilles tendon. Thirty animals were immobilized (Group A), and the others wereallowed loadingimmediately postoperatively (Group B). Animals were sacrificed at 4 weeks and evaluated for histological and biomechanical testing. Statistical analysis was performed with an independent t test with significance set at P = 0.05. Results: The ultimate stress was greater in group B (4.598 ± 1.321 N/mm2) compared with the control group (3.388 ± 0.994 N/mm2) (P < 0.05). Similarly, a more organized tendon-to-bone interface with a larger area of chondrocytes was found in group B (P < 0.05). Conclusion: Mechanical loading improves the structure and the attachment strength of the healing tendon-to-bone interface. PMID:25785105

  12. Excision of aberrant abductor pollicis longus tendon slips for decompression of de Quervain's disease.

    PubMed

    Okada, M; Kutz, J E

    2011-06-01

    Release or excision of the first extensor compartment is a commonly performed surgical procedure to treat de Quervain's disease. This technique can potentially cause palmar subluxation of the extensor tendons. The abductor pollicis longus (APL) tendon has multiple slips which can be used as a resource for tendon transfer without loss of function. The technique described in this paper is decompression of the first extensor compartment by excision of an aberrant APL tendon slip without releasing the first extensor compartment. This technique was used in 24 wrists in 21 patients, and outcome assessed. All our patients had relief from pain and tenderness. No patients needed immobilization and none had subluxation of the extensor tendons. Patients without workers' compensation returned to work 15 days after surgery. PMID:21372053

  13. Patellar Tendon Versus Hamstring Tendon Autografts for Reconstructing the Anterior Cruciate LigamentA Meta-Analysis Based on Individual Patient Data

    Microsoft Academic Search

    David Jean Biau; Sandrine Katsahian; Jüri Kartus; Arsi Harilainen; Julian A. Feller; Matjaz Sajovic; Lars Ejerhed; Stefano Zaffagnini; Martin Röpke; Rémy Nizard

    2009-01-01

    Background: The best means of ensuring knee stability after anterior cruciate ligament (ACL) reconstruction remains a core debate in sports medicine.Hypothesis: There is no difference between ACL reconstruction with patellar tendon or hamstring tendon autografts with regard to postoperative knee laxity and instability.Study Design: Meta-analysis of individual patient data.Methods: Pooled analysis of individual patient data from 6 published randomized clinical

  14. 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

  15. Repeated freeze-thaw cycles reduce the survival rate of osteocytes in bone-tendon constructs without affecting the mechanical properties of tendons.

    PubMed

    Suto, Kaori; Urabe, Ken; Naruse, Kouji; Uchida, Kentaro; Matsuura, Terumasa; Mikuni-Takagaki, Yuko; Suto, Mitsutoshi; Nemoto, Noriko; Kamiya, Kentaro; Itoman, Moritoshi

    2012-03-01

    Frozen bone-patellar tendon bone allografts are useful in anterior cruciate ligament reconstruction as the freezing procedure kills tissue cells, thereby reducing immunogenicity of the grafts. However, a small portion of cells in human femoral heads treated by standard bone-bank freezing procedures survive, thus limiting the effectiveness of allografts. Here, we characterized the survival rates and mechanisms of cells isolated from rat bones and tendons that were subjected to freeze-thaw treatments, and evaluated the influence of these treatments on the mechanical properties of tendons. After a single freeze-thaw cycle, most cells isolated from frozen bone appeared morphologically as osteocytes and expressed both osteoblast- and osteocyte-related genes. Transmission electron microscopic observation of frozen cells using freeze-substitution revealed that a small number of osteocytes maintained large nuclei with intact double membranes, indicating that these osteocytes in bone matrix were resistant to ice crystal formation. We found that tendon cells were completely killed by a single freeze-thaw cycle, whereas bone cells exhibited a relatively high survival rate, although survival was significantly reduced after three freeze-thaw cycles. In patella tendons, the ultimate stress, Young's modulus, and strain at failure showed no significant differences between untreated tendons and those subjected to five freeze-thaw cycles. In conclusion, we identified that cells surviving after freeze-thaw treatment of rat bones were predominantly osteocytes. We propose that repeated freeze-thaw cycles could be applied for processing bone-tendon constructs prior to grafting as the treatment did not affect the mechanical property of tendons and drastically reduced surviving osteocytes, thereby potentially decreasing allograft immunogenecity. PMID:21116722

  16. 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

  17. Effects of fluoride on in vitro calcification of tendon matrix

    Microsoft Academic Search

    C. L. Wadkins; R. A. Luben

    1978-01-01

    Summary Ca2+ and Pi uptake induced in vitro by a collagenous matrix derived from bovine tendon is inhibited by 1×10?6 to 2×10?5M NaF and stimulated by 2×10?5 to 2×10?3M NaF. Fluoride uptake occurs only over the latter concentrtion range. The uptake of Ca2+, Pi, and F?1 progresses toward a limiting extent at which the molar Ca\\/P and Ca\\/F values are

  18. Superior oblique tendon lengthening for acquired superior oblique overactions.

    PubMed Central

    Manners, R M; O'Flynn, E; Morris, R J

    1994-01-01

    Two patients who presented with compensatory head postures and diplopia are described. They both had marked unilateral superior oblique overaction, in one patient due to a large, incomitant skew deviation. Each underwent a superior oblique tendon lengthening procedure using a segment of silicone 240 retinal band as an expander, in combination with a contralateral superior rectus recession. Both achieved an excellent result with an improvement of the compensatory head posture and an increase in the field of binocular single vision. This surgical procedure is proposed as an option in the management of superior oblique overaction, including certain cases of skew deviation. Images PMID:8199114

  19. A new technique for medial canthal tendon fixation.

    PubMed

    Turgut, Gürsel; Ozkaya, Ozay; Soydan, Ali Tufan; Ba?, Lütfü

    2008-07-01

    Traumas resulting from naso-orbitoethmoidal fractures and tumor surgery of the medial canthal region may cause orbital dystopia. A variety of techniques with many disadvantages, such as detachment and high cost, has been described for reattachment of medial canthal tendon. We present a new technique, namely, unitransnasal canthoplasty, which is easy to apply, cheap, and reliable. Two nonabsorbable sutures were passed through 2 drill holes to the nasal cavity, taken out from the nasal ostium, and were tied up. Upper and lower eyelids were fixed to the ipsilateral nasal bone. PMID:18650751

  20. Nuclear magnetic resonance study of the collagen matrix in tendon

    NASA Astrophysics Data System (ADS)

    Krasnosselskaia, Lada Vadimovna

    Understanding of complex interactions of water with macromolecules is a prerequisite for quantitative musculoskeletal imaging and this dissertation presents a study on NMR characteristics of water in anisotropic environment of the collagen extracellular matrix of tendon. The first chapter of the dissertation analyzes a "magic angle" effect, a well known in clinical practice artifact of a sudden signal increase in normal tendons and ligaments at the orientation of 55° with respect to the static magnetic field of an MRI scanner. The physical basis of the orientation dependence of the free induction decay is studied in ex-vivo mammalian tissue at the field strength of 2 Tesla. Obtained quantitative measures are related to the model of heterogeneous water phases in the collagen extracellular matrix of tendon. A novel effect of central frequency shift of the water signal is reported and hypothesis on the origin of the effect is put forward. Clinical applications of NMR and MRI constantly benefit from adopting methods and techniques from the field of NMR of liquids, solids and liquid crystals. In the second chapter, a pseudo solid echo technique is evaluated for the purpose of detecting slow motions in the collagen matrix at different hydration and temperatures, at the field strength of 11.74 Tesla (500 MHz). The pseudo solid echo is shown capable in detecting motions on the scale of 10-3-10-6 seconds. 1H spin-lattice relaxation study at different levels of hydration and temperatures is presented in the third chapter. Predictions of the molecular model of collagen hydration are verified at the field strength of 11.74 Tesla (500 MHz) and temperature of 6°C, 26°C and 37°C. In the fourth chapter, an efficient adaptive mesh numerical code is developed on the basis of the octal tree data structure for assessment of the bulk magnetic susceptibility effects. The code allows calculation of the microscopic magnetic field as "seen by the nucleus" for uniformly magnetized objects of arbitrary shapes. It is applied to test two hypotheses related to the bulk susceptibility shifts in tendon as it was evidenced by the study described in the first chapter.

  1. Ligament and tendon repair through regeneration using mesenchymal stem cells.

    PubMed

    Ramdass, Bharathi; Koka, Prasad S

    2014-01-01

    One of Nature's gifts to mankind is mesenchymal stem cells (MSC's). They are multipotent in nature and are present literally in every tissue. Since, they possess certain characteristics of stem cells such as self-renewal and differentiation they are known to be one of the key players in normal tissue homeostasis. This novel function of mesenchymal stem cells has been explored by scientists in the field of regenerative medicine. This review gives an insight of the various sources of mesenchymal stem cells available for tissue engineering with regard to tendon and ligament and the mechanism involved during regeneration. PMID:25274564

  2. Hazards of steroid injection: Suppurative extensor tendon rupture

    PubMed Central

    Woon, Colin Yi-Loong; Phoon, Ee-San; Lee, Jonathan Yi-Liang; Ng, Siew-Weng; Teoh, Lam-Chuan

    2010-01-01

    Local steroid injections are often administered in the office setting for treatment of trigger finger, carpal tunnel syndrome, de Quervain's tenosynovitis, and basal joint arthritis. If attention is paid to sterile technique, infectious complications are rare. We present a case of suppurative extensor tenosynovitis arising after local steroid injection for vague symptoms of dorsal hand and wrist pain. The progression of signs and symptoms following injection suggests a natural history involving bacterial superinfection leading to tendon rupture. We discuss the pitfalls of local steroid injection and the appropriate management of infectious extensor tenosynovitis arising in such situations. PMID:20924461

  3. Hazards of steroid injection: Suppurative extensor tendon rupture.

    PubMed

    Woon, Colin Yi-Loong; Phoon, Ee-San; Lee, Jonathan Yi-Liang; Ng, Siew-Weng; Teoh, Lam-Chuan

    2010-01-01

    Local steroid injections are often administered in the office setting for treatment of trigger finger, carpal tunnel syndrome, de Quervain's tenosynovitis, and basal joint arthritis. If attention is paid to sterile technique, infectious complications are rare. We present a case of suppurative extensor tenosynovitis arising after local steroid injection for vague symptoms of dorsal hand and wrist pain. The progression of signs and symptoms following injection suggests a natural history involving bacterial superinfection leading to tendon rupture. We discuss the pitfalls of local steroid injection and the appropriate management of infectious extensor tenosynovitis arising in such situations. PMID:20924461

  4. Common Aches and Pains What You Need To Know andWhat You Need To Know and

    E-print Network

    Goldman, Steven A.

    Shoulder Rotator Cuff Tendonitis Shoulder Impingement BicipitalBicipital Tendonitis Bursitis #12;Sh ldShoulder Rotator Cuff Anatomy ­ SupraspinatusSupraspinatus ­ Infraspinatus ­ Teres MinorTeres Minor ­ Subscapularis) Sternoclavicular joint #12;P t S i l Sh ldPost-Surgical Shoulder Rotator Cuff Repair Shoulder Decompression

  5. 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

  6. The study of optical properties and proteoglycan content of tendons by PS-OCT

    NASA Astrophysics Data System (ADS)

    Yang, Ying; Rupani, Asha; Weightman, Alan; Wimpenny, Ian; Bagnaninchi, Pierre; Ahearne, Mark

    2011-03-01

    Tendons are load-bearing collagenous tissues consisting mainly of type I collagen and various proteoglycans (PGs) including decorin and versican. It is widely accepted that highly orientated collagen fibers in tendons a play critical role for transferring tensile stress and demonstrate birefringent optical properties. However, the influence that proteoglycans have on the optical properties of tendons is yet to be fully elucidated. Tendinopathy (defined as a syndrome of tendon pain, tenderness and swelling that affects the normal function of the tissue) is a common disease associated with sporting injuries or degeneration. PG's are the essential components of the tendon extracellular matrix; changes in their quantities and compositions have been associated with tendinopathy. In this study, polarization sensitive optical coherence tomography (PS-OCT) has been used to reveal the relationship between proteoglycan content/location and birefringent properties of tendons. Tendons dissected from freshly slaughtered chickens were imaged at regular intervals by PS-OCT and polarizing light microscope during the extraction of PGs or glycosaminoglycans using established protocols (guanidine hydrochloride (GuHCl) or proteinase K solution). The macroscopic and microscopic time lapsed images are complimentary; mutually demonstrating that there was a higher concentration of PG's in the outer sheath region than in the fascicles; and the integrity of the sheath affected extraction process and the OCT birefringence bands. Extraction of PGs using GuHCl disturbed the organization of local collagen bundles, which corresponded to a reduction in the frequency of birefringence bands and the band width by PS-OCT. The feature of OCT penetration depth helped us to define the heterogeneous distribution of PG's in tendon, which was complimented by polarizing light microscopy. The results provide new insight of tendon structure and also demonstrate a great potential for using PS-OCT as a diagnostic tool to examine tendon pathology.

  7. 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.

  8. 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

  9. Differences between the Cell Populations from the Peritenon and the Tendon Core with Regard to Their Potential Implication in Tendon Repair

    PubMed Central

    Cadby, Jennifer A.; Buehler, Evelyne; Godbout, Charles; van Weeren, P. René; Snedeker, Jess G.

    2014-01-01

    The role of intrinsic and extrinsic healing in injured tendons is still debated. In this study, we characterized cell plasticity, proliferative capacity, and migration characteristics as proxy measures of healing potential in cells derived from the peritenon (extrinsic healing) and compared these to cells from the tendon core (intrinsic healing). Both cell populations were extracted from horse superficial digital flexor tendon and characterized for tenogenic and matrix remodeling markers as well as for rates of migration and replication. Furthermore, colony-forming unit assays, multipotency assays, and real-time quantitative polymerase chain reaction analyses of markers of osteogenic and adipogenic differentiation after culture in induction media were performed. Finally, cellular capacity for differentiation towards a myofibroblastic phenotype was assessed. Our results demonstrate that both tendon- and peritenon-derived cell populations are capable of adipogenic and osteogenic differentiation, with higher expression of progenitor cell markers in peritenon cells. Cells from the peritenon also migrated faster, replicate more quickly, and show higher differentiation potential toward a myofibroblastic phenotype when compared to cells from the tendon core. Based on these data, we suggest that cells from the peritenon have substantial potential to influence tendon-healing outcome, warranting further scrutiny of their role. PMID:24651449

  10. Effects of running on human Achilles tendon length-tension properties in the free and gastrocnemius components.

    PubMed

    Lichtwark, Glen A; Cresswell, Andrew G; Newsham-West, Richard J

    2013-12-01

    The elastic properties of the human Achilles tendon are important for locomotion; however, in vitro tests suggest that repeated cyclic contractions lead to tendon fatigue - an increase in length in response to stress applied. In vivo experiments have not, however, demonstrated mechanical fatigue in the Achilles tendon, possibly due to the limitations of using two-dimensional ultrasound imaging to assess tendon strain. This study used freehand three-dimensional ultrasound (3DUS) to determine whether the free Achilles tendon (calcaneus to soleus) or the gastrocnemius tendon (calcaneus to gastrocnemius) demonstrated tendon fatigue after running exercise. Participants (N=9) underwent 3DUS scans of the Achilles tendon during isometric contractions at four ankle torque levels (passive, and 14, 42 and 70 N m) before and after a 5 km run at a self-selected pace (10-14 km h(-1)). Running had a significant main effect on the length of the free Achilles tendon (P<0.01) with a small increase in length across the torque range. However, the mean lengthening effect was small (<1%) and was not accompanied by a change in free tendon stiffness. There was no significant change in the length of the gastrocnemius tendon or the free tendon cross-sectional area. While the free tendon was shown to lengthen, the lack of change in stiffness suggests the tendon exhibited mechanical creep rather than fatigue. These effects were much smaller than those predicted from in vitro experiments, possibly due to the different loading profile encountered and the ability of the tendon to repair in vivo. PMID:24031068

  11. Fiber optic micro sensor for the measurement of tendon forces

    PubMed Central

    2012-01-01

    A fiber optic sensor developed for the measurement of tendon forces was designed, numerically modeled, fabricated, and experimentally evaluated. The sensor incorporated fiber Bragg gratings and micro-fabricated stainless steel housings. A fiber Bragg grating is an optical device that is spectrally sensitive to axial strain. Stainless steel housings were designed to convert radial forces applied to the housing into axial forces that could be sensed by the fiber Bragg grating. The metal housings were fabricated by several methods including laser micromachining, swaging, and hydroforming. Designs are presented that allow for simultaneous temperature and force measurements as well as for simultaneous resolution of multi-axis forces. The sensor was experimentally evaluated by hydrostatic loading and in vitro testing. A commercial hydraulic burst tester was used to provide uniform pressures on the sensor in order to establish the linearity, repeatability, and accuracy characteristics of the sensor. The in vitro experiments were performed in excised tendon and in a dynamic gait simulator to simulate biological conditions. In both experimental conditions, the sensor was found to be a sensitive and reliable method for acquiring minimally invasive measurements of soft tissue forces. Our results suggest that this sensor will prove useful in a variety of biomechanical measurements. PMID:23033868

  12. An Isolated Medial Patellofemoral Ligament Reconstruction with Patellar Tendon Autograft

    PubMed Central

    Wito?ski, Dariusz; K?ska, Rafa?; Synder, Marek; Sibi?ski, Marcin

    2013-01-01

    The aim of the study was to evaluate the results of the medial patellofemoral ligament reconstruction with a medial strip of patellar tendon autograft after a minimum 2-year followup. Ten patients (10 knees) were operated on by one surgeon, according to the modified technique, described by Camanho, without any bone plug at free graft end. The mean age of the patients was 27.2 years (ranging from 18 to 42 years). The mean follow-up period was 3 years and 7 months. All patients were reviewed prospectively. At the last follow-up visit, all the patients demonstrated a significant improvement in terms of patellofemoral joint stability, all aspects of the KOOS questionnaire, and Kujala et al.'s score (59.7 points preoperatively and 84.4 points at the last followup). No patient revealed recurrent dislocation. The SF-36 score revealed a significant improvement in bodily pain, general health, physical role functioning, social role functioning, and physical functioning domains. The described MPFL reconstruction with the use of the medial 1/3rd of patella tendon is an effective procedure that gives satisfactorily patellofemoral joint functions, improves the quality of life, and provides much pain relief. It is relatively simple, surgically not extensive, and economically cost-effective procedure. PMID:24224173

  13. Posterior tibial tendon dysfunction: its association with seronegative inflammatory disease.

    PubMed

    Myerson, M; Solomon, G; Shereff, M

    1989-04-01

    Idiopathic inflammation and rupture of the posterior tibial tendon (PTT) has received much attention in the recent literature. In this report of the presentation of PTT dysfunction as a manifestation of seronegative inflammatory disease, we describe the clinical and laboratory features of 76 patients with inflammation and/or rupture of the PTT. Analysis of all patients identified two discrete groups. Group A patients were younger (mean age 39 years) and had multiple manifestations of inflammation at other sites of ligament and tendon attachments (enthesopathy). Other features of a systemic inflammatory disorder such as oral ulcers, conjunctivitis, colitis, and especially psoriasis were common in the latter patients and their families. Group B consisted predominantly of elderly patients (mean age 64 years) with isolated dysfunction of the PTT. These two groups differed widely in the manner of clinical presentation, demographic data, family history, HLA data, and surgical pathology. These distinctions suggest different pathogeneses for posterior tibial tendinitis. Group A demonstrated local manifestations of a systemic inflammatory disease, whereas group B exhibited the effects of mechanical trauma and degeneration. PMID:2731833

  14. Are tendon transfers justified in very old hand radial palsies?

    PubMed

    Martínez-Villén, G; Muñoz-Marín, J; Pérez-Barrero, P

    2012-10-01

    There have been very few reports about results of tendon transfers carried out in very old radial palsies affecting the hand. We present two cases of radial palsy operated 52 and 30 years after the original injury, which also had after-effects in pronosupination due to elbow injuries. In the first patient, with high radial-nerve palsy, we made a triple transfer of the pronator teres to the extensor carpi radialis brevis, the flexor carpi ulnaris to the extensor digitorum communis and the palmaris longus to the extensor pollicis longus. In the second case, which had posterior interosseous nerve palsy, we transferred the flexor carpi radialis to the extensor digitorum communis, and the brachiorradialis to the extensor pollicis longus. The surgical findings showed a 'gelatinous degeneration' in some of the receiving tendons, which did not prevent the sutures from being resistant. The first patient, who had a stiff elbow, with pronosupination blocked since childhood, showed disuse atrophy of the pronator teres, which conditioned a late rupture of the tenomuscular junction and required a second surgery for wrist arthrodesis. Results after postoperative period of 30 months after surgery in the first patient, and 14 months after surgery in the second one, showed functional recovery in finger range of extension, grip and key-pinch strength and a significantly higher QuickDASH score, restoring the natural aesthetical appearance of the limb. This facilitated the return to professional and daily activities, re-establishing a fine ability to grab and release objects. PMID:22771086

  15. Carbon fibres and plasma-preserved tendon allografts for gap repair of flexor tendon in bovines: gross, microscopic and scanning electron microscopic observations.

    PubMed

    Kumar, N; Sharma, A K; Sharma, A K; Kumar, S

    2002-06-01

    The efficacy of carbon fibres and plasma-preserved tendon allografts for gap repair in the superficial digital flexor tendon in the mid-metatarsal region was evaluated in 12 crossbred calves. Experimental tenectomies were performed, followed by implantation of carbon fibres in group I (12 legs) and plasma-preserved tendon allografts in group II (12 legs). Gross observations in group I showed filling of the defect with granulation tissue with more vascularity on day 7, which was less prominent at day 14. On day 30, the neotendon formed was slightly thicker and comparable to normal tendon in appearance and texture. On day 90, it exhibited all the characteristics of a fully developed tendon. Whereas, in group II increased vascularity at the site and encapsulation of the graft with connective tissue in early periods was observed. The gap between graft and host was filled with fibrous connective tissue. Peritendinous adhesions were maximum on day 7 which were gradually reduced in both groups. Microscopically, an acute inflammatory reaction in the periphery of carbon fibres was observed on day 7. Immature fibroblasts were arranged in a haphazard pattern at this stage. By day 14, numerous newly formed capillaries and comparatively more mature fibroblasts were present in between and around the carbon fibres which were aligning parallel to the longitudinal axis of the tendon. By day 30 the healing tissue exhibited longitudinal orientation of collagen fibres and was at a more advance stage of maturation. By day 90, the neotendon formed simulated the picture of normal tendon. In the grafted tendon group, there was normal healing tissue at the functional sites between host and grafted tendon. The fibroblastic activity appeared to be both extrinsic and intrinsic in origin. The connective tissue had invaded the graft to a variable distance and there was resorption of graft which was replaced by newly formed connective tissue on day 90. Scanning electron microscopic observation revealed formation of neotendon between carbon fibre strands, resulting in thickening of the implant. In later stages parallel collagen fibres resembling normal tendon were observed in both groups. PMID:12126142

  16. Regional stiffening with aging in tibialis anterior tendons of mice occurs independent of changes in collagen fibril morphology

    PubMed Central

    Wood, Lauren K.; Arruda, Ellen M.

    2011-01-01

    The incidence of tendon degeneration and rupture increases with advancing age. The mechanisms underlying this increased risk remain unknown but may arise because of age-related changes in tendon mechanical properties and structure. Our purpose was to determine the effect of aging on tendon mechanical properties and collagen fibril morphology. Regional mechanical properties and collagen fibril characteristics were determined along the length of tibialis anterior (TA) tendons from adult (8- to 12-mo-old) and old (28- to 30-mo-old) mice. Tangent modulus of all regions along the tendons increased in old age, but the increase was substantially greater in the proximal region adjacent to the muscle than in the rest of the tendon. Overall end-to-end modulus increased with old age at maximum tendon strain (799 ± 157 vs. 1,419 ± 91 MPa) and at physiologically relevant strain (377 ± 137 vs. 798 ± 104 MPa). Despite the dramatic changes in tendon mechanical properties from adulthood to old age, collagen fibril morphology and packing fraction remained relatively constant in all tendon regions examined. Since tendon properties are influenced by their external loading environment, we also examined the effect of aging on TA muscle contractile properties. Maximum isometric force did not differ between the age groups. We conclude that TA tendons stiffen in a region-dependent manner throughout the life span, but the changes in mechanical properties are not accompanied by corresponding changes in collagen fibril morphology or force-generating capacity of the TA muscle. PMID:21737825

  17. Spatial and Temporal Expression of Molecular Markers and Cell Signals During Normal Development of the Mouse Patellar Tendon

    PubMed Central

    Liu, Chia-Feng; Aschbacher-Smith, Lindsey; Barthelery, Nicolas J.; Dyment, Nathaniel; Butler, David

    2012-01-01

    Tendon injuries are common clinical problems and are difficult to treat. In particular, the tendon-to-bone insertion site, once damaged, does not regenerate its complex zonal arrangement. A potential treatment for tendon injuries is to replace injured tendons with bioengineered tendons. However, the bioengineering of tendon will require a detailed understanding of the normal development of tendon, which is currently lacking. Here, we use the mouse patellar tendon as a model to describe the spatial and temporal pattern of expression of molecular markers for tendon differentiation from late fetal life to 2 weeks after birth. We found that collagen I, fibromodulin, and tenomodulin were expressed throughout the tendon, whereas tenascin-C, biglycan, and cartilage oligomeric protein were concentrated in the insertion site during this period. We also identified signaling pathways that are activated both throughout the developing tendon, for example, transforming growth factor beta and bone morphogenetic protein, and specifically in the insertion site, for example, hedgehog pathway. Using a mouse line expressing green fluorescent protein in all tenocytes, we also found that tenocyte cell proliferation occurs at highest levels during late fetal life, and declines to very low levels by 2 weeks after birth. These data will allow both the functional analysis of specific signaling pathways in tenocyte development and their application to tissue-engineering studies in vitro. PMID:21939397

  18. Fetal and adult fibroblasts display intrinsic differences in tendon tissue engineering and regeneration

    PubMed Central

    Tang, Qiao-Mei; Chen, Jia Lin; Shen, Wei Liang; Yin, Zi; Liu, Huan Huan; Fang, Zhi; Heng, Boon Chin; Ouyang, Hong Wei; Chen, Xiao

    2014-01-01

    Injured adult tendons do not exhibit optimal healing through a regenerative process, whereas fetal tendons can heal in a regenerative fashion without scar formation. Hence, we compared FFs (mouse fetal fibroblasts) and AFs (mouse adult fibroblasts) as seed cells for the fabrication of scaffold-free engineered tendons. Our results demonstrated that FFs had more potential for tendon tissue engineering, as shown by higher levels of tendon-related gene expression. In the in situ AT injury model, the FFs group also demonstrated much better structural and functional properties after healing, with higher levels of collagen deposition and better microstructure repair. Moreover, fetal fibroblasts could increase the recruitment of fibroblast-like cells and reduce the infiltration of inflammatory cells to the injury site during the regeneration process. Our results suggest that the underlying mechanisms of better regeneration with FFs should be elucidated and be used to enhance adult tendon healing. This may assist in the development of future strategies to treat tendon injuries. PMID:24992450

  19. 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

  20. 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