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Sample records for partial-thickness supraspinatus tendon

  1. Effect of partial-thickness tear on loading capacities of the supraspinatus tendon: a finite element analysis.

    PubMed

    Engelhardt, Christoph; Ingram, David; Müllhaupt, Philippe; Farron, Alain; Becce, Fabio; Pioletti, Dominique; Terrier, Alexandre

    2016-06-01

    Partial-thickness tears of the supraspinatus tendon frequently occur at its insertion on the greater tubercule of the humerus, causing pain and reduced strength and range of motion. The goal of this work was to quantify the loss of loading capacity due to tendon tears at the insertion area. A finite element model of the supraspinatus tendon was developed using in vivo magnetic resonance images data. The tendon was represented by an anisotropic hyperelastic constitutive law identified with experimental measurements. A failure criterion was proposed and calibrated with experimental data. A partial-thickness tear was gradually increased, starting from the deep articular-sided fibres. For different values of tendon tear thickness, the tendon was mechanically loaded up to failure. The numerical model predicted a loss in loading capacity of the tendon as the tear thickness progressed. Tendon failure was more likely when the tendon tear exceeded 20%. The predictions of the model were consistent with experimental studies. Partial-thickness tears below 40% tear are sufficiently stable to persist physiotherapeutic exercises. Above 60% tear surgery should be considered to restore shoulder strength. PMID:26290956

  2. Effect of Supraspinatus Tendon Injury on Supraspinatus and Infraspinatus Muscle Passive Tension and Associated Biochemistry

    PubMed Central

    Silldorff, Morgan D.; Choo, Alexander D.; Choi, Anthony J.; Lin, Evie; Carr, J. Austin; Lieber, Richard L.; Lane, John G.; Ward, Samuel R.

    2014-01-01

    Background: Injury to the supraspinatus and infraspinatus tendons and the associated atrophic changes to the muscle remain a common clinical problem. Specifically, increased muscle stiffness has been implicated in failure of the repair and poor functional outcomes. We present a comparison of the passive mechanical properties and associated biochemical studies from patients with and without torn supraspinatus tendons. Methods: Muscle biopsy samples (n = 40) were obtained from twenty patients undergoing arthroscopic shoulder surgery. Passive mechanical tests of both individual fibers and fiber bundles as well as analysis of titin molecular weight and collagen content were performed. Results: At the fiber-bundle level, a significant increase in passive modulus was observed between intact supraspinatus samples (mean [and standard error], 237.41 ± 59.78 kPa) and torn supraspinatus samples (515.74 ± 65.48 kPa) (p < 0.05), a finding that was not observed at the single fiber level. Within the torn samples, elastic moduli in the supraspinatus were greater than in the infraspinatus at both the single fiber and the fiber-bundle level. There was a significant positive correlation between bundle elastic modulus and collagen content (r2 = 0.465) in the supraspinatus muscle as well as a significant positive correlation between tear size and bundle elastic modulus (r2 = 0.702) in the torn supraspinatus samples. Conclusions: Supraspinatus muscle passive tension increases in a tendon tear size-dependent manner after tendon injury. The increase in muscle stiffness appears to originate outside the muscle cell, in the extracellular matrix. Clinical Relevance: Muscle stiffness after rotator cuff tendon injury is more severe with large tears. This finding supports the concept of early intervention, when tendon tears are smaller, and interventions targeting the extracellular matrix. PMID:25320205

  3. Supraspinatus Intramuscular Calcified Hematoma or Necrosis Associated with Tendon Tear

    PubMed Central

    Lädermann, Alexandre; Genevay, Muriel; Abrassart, Sophie; Schwitzguébel, Adrien Jean-Pierre

    2015-01-01

    Introduction. Rotator cuff intramuscular calcification is a rare condition usually caused by heterotopic ossification and myositis ossificans. Case Presentation. We describe a patient with voluminous calcified mass entrapped in supraspinatus muscle associated with corresponding tendon tear. Histological examination corresponded to a calcified hematoma or necrosis. Patient was surgically managed with open excision of the calcified hematoma and rotator cuff arthroscopic repair. At 6 months, supraspinatus muscle was healed, and functional outcome was good. Discussion and Conclusion. We hypothesized that supraspinatus intramuscular calcified hematoma was responsible for mechanical stress on the tendon. This association has never been described. PMID:26380138

  4. 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.

  5. Genetic Response of Rat Supraspinatus Tendon and Muscle to Exercise

    PubMed Central

    Rooney, Sarah Ilkhanipour; Tobias, John W.; Bhatt, Pankti R.; Kuntz, Andrew F.; Soslowsky, Louis J.

    2015-01-01

    Inflammation is a complex, biologic event that aims to protect and repair tissue. Previous studies suggest that inflammation is critical to induce a healing response following acute injury; however, whether similar inflammatory responses occur as a result of beneficial, non-injurious loading is unknown. The objective of this study was to screen for alterations in a subset of inflammatory and extracellular matrix genes to identify the responses of rat supraspinatus tendon and muscle to a known, non-injurious loading condition. We sought to define how a subset of genes representative of specific inflammation and matrix turnover pathways is altered in supraspinatus tendon and muscle 1) acutely following a single loading bout and 2) chronically following repeated loading bouts. In this study, Sprague-Dawley rats in the acute group ran a single bout of non-injurious exercise on a flat treadmill (10 m/min, 1 hour) and were sacrificed 12 or 24 hours after. Rats in the chronic group ran 5 days/wk for 1 or 8 weeks. A control group maintained normal cage activity. Supraspinatus muscle and tendon were harvested for RNA extractions, and a custom Panomics QuantiGene 2.0 multiplex assay was used to detect 48 target and 3 housekeeping genes. Muscle/tendon and acute/chronic groups had distinct gene expression. Components of the arachidonic acid cascade and matrix metalloproteinases and their inhibitors were altered with acute and chronic exercise. Collagen expression increased. Using a previously validated model of non-injurious exercise, we have shown that supraspinatus tendon and muscle respond to acute and chronic exercise by regulating inflammatory- and matrix turnover-related genes, suggesting that these pathways are involved in the beneficial adaptations to exercise. PMID:26447778

  6. 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

  7. Collagen fiber re-alignment in a neonatal developmental mouse supraspinatus tendon model.

    PubMed

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

    2012-05-01

    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 (SST), 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 SST 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

  8. 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

  9. In Situ Fibril Stretch and Sliding is Location-Dependent in Mouse Supraspinatus Tendons

    PubMed Central

    Connizzo, Brianne K.; Sarver, Joseph J.; Han, Lin; Soslowsky, Louis J.

    2014-01-01

    Tendons are able to transmit high loads efficiently due to their finely optimized hierarchical collagen structure. Two mechanisms by which tendons respond to load are collagen fibril sliding and deformation (stretch). While many studies have demonstrated that regional variations in tendon structure, composition, and organization contribute to the full tendon’s mechanical response, the location-dependent response to loading at the fibril level has not been investigated. In addition, the instantaneous response of fibrils to loading, which is clinically relevant for repetitive stretch or fatigue injuries, has also not been studied. Therefore, the purpose of this study was to quantify the instantaneous response of collagen fibrils throughout a mechanical loading protocol, both in the insertion site and in the midsubstance of the mouse supraspinatus tendon. Utilizing a novel atomic force microscopy-based imaging technique, tendons at various strain levels were directly visualized and analyzed for changes in fibril d-period with increasing tendon strain. At the insertion site, d-period significantly increased from 0% to 1% tendon strain, increased again from 3% to 5% strain, and decreased after 5% strain. At the midsubstance, d-period increased from 0% to 1% strain and then decreased after 7% strain. In addition, fibril d-period heterogeneity (fibril sliding) was present, primarily at 3% strain with a large majority occurring in the tendon midsubstance. This study builds upon previous work by adding information on the instantaneous and regional-dependent fibrillar response to mechanical loading and presents data proposing that collagen fibril sliding and stretch are directly related to tissue organization and function. PMID:25468300

  10. Effects of crystalline glucocorticoid triamcinolone acetonide on cultered human supraspinatus tendon cells

    PubMed Central

    Gehwolf, Renate; Lehner, Christine; Wagner, Andrea; Mtsariashvili, Maia; Bauer, Hans-Christian; Resch, Herbert; Tauber, Mark

    2009-01-01

    Background Rotator cuff tears are a common cause of shoulder pain and impairment. Subacromial glucocorticoid injections are widely used for treatment of epiphenomenons of chronic impingement syndrome with the possible side effects of tendon rupture and impaired tendon healing. Methods Using qRT-PCR, western blot, immunoflourescence, and measurement of 3H-thymidine uptake we investigated the effects of the crystalline glucocorticoid triamcinolone acetonide (TAA) when added to the culture medium of isolated human rotator cuff tendon cells. Results After 2 weeks of incubation, the cells had lost their fibroblastic appearance and parallel orientation, which is characteristic of cellular degeneration in vivo. Moreover, expression and secretion of collagen I was strongly reduced, and there was a decrease in proliferation rate. Cell migration was blocked and the rate of expression of the matrix metalloproteinases MMP2, MMP8, MMP9, and MMP13 was reduced, but expression of TIMP1 (a tissue inhibitor of MMPs) was upregulated, indicating a reduction in the cellular capacity for tendon repair. In addition, changes in cellular differentiation were observed: the number of adipocytes increased and levels of the protein Sox9—a marker of differentiating and mature chondrocytes—were elevated in triamcinolone acetonide treated cells. Interpretation These results may indicate that the use of TAA is one reason for weaker mechanical tendon properties and for the high rate of re-rupture after supraspinatus tendon repair. PMID:19421912

  11. Repair versus shaving of partial-thickness articular-sided tears of the upper subscapularis tendon. A prospective randomized controlled trial

    PubMed Central

    RANDELLI, PIETRO; ARRIGONI, PAOLO; ALIPRANDI, ALBERTO; SDAO, SILVANA; RAGONE, VINCENZA; D’AMBROSI, RICCARDO; RANDELLI, FILIPPO; CABITZA, PAOLO; BANFI, GIUSEPPE

    2015-01-01

    Purpose the purpose of this study was to evaluate whether treating partial-thickness articular-sided tears of the upper subscapularis (SSC) tendon with a dedicated suture anchor would result in an internal rotation strength improvement compared with simple shaving of the SSC tendon and footprint. Methods twenty-six patients with a limited SSC tendon tear (equal or inferior to the most superior centimeter) in association with a posterosuperior cuff lesion were prospectively randomized to two treatments: repair with a dedicated suture anchor versus shaving of the tendon and footprint. The patients also underwent long head of the biceps (LHB) treatment and posterosuperior cuff tear repair. In each patient the following parameters were measured both preoperatively and at a minimum follow-up of 2.5 years: strength in internal rotation in the bear-hug testing position (using a digital tensiometer), DASH score and Constant scores. MRI assessment of tendon healing was performed at the final follow-up. Results twenty of the 26 patients (76%) were reviewed after a mean follow-up time of 42 months: 11 patients had undergone SSC tendon repair and nine simple shaving. At final follow-up no significant differences were found between the repaired and shaving group in strength in internal rotation (9.5 ± 3.8 kg versus 10.3±5.4 kg; p=0.7). The DASH score and Constant score also failed to show significant differences between the two groups. Furthermore, no significant difference in SSC tendon healing rate was observed on MRI evaluation. Conclusions partial-thickness articular-sided tear of the upper SSC tendon in association with a posterosuperior rotator cuff repair and LHB treatment, when limited to the superior centimeter of the SSC tendon, shows a comparable performance in terms of strength in internal rotation either after simple shaving or a tendon-to-bone repair. Level of evidence Level II, prospective comparative study. PMID:26889466

  12. Morphology of the humeral insertion of the supraspinatus and infraspinatus tendons: Application to rotator cuff repair.

    PubMed

    Lumsdaine, William; Smith, Adam; Walker, Rowan G; Benz, Daniel; Mohammed, Khalid D; Stewart, Fiona

    2015-09-01

    In shoulder surgery, a precise understanding of anatomical relationships is required for accurate reconstruction. Reports in recent literature have challenged the traditional definitions of the humeral footprints of the supraspinatus and infraspinatus tendons. This study aims to precisely delineate these footprints. The rotator cuffs of 54 shoulders from 27 Australian Caucasoid donor cadavers were examined. The tendinous portions were dissected down to their region/footprint of attachment upon the humerus. Measurements of those footprints, upon the greater and lesser tuberosities, were made. Those measurements were statistically analyzed for any association with age, sex, height, or side. Twenty-seven cadavers had an average age at death of 74.9 (± 12.8), 56% were male, average height was 168 (± 8.6) cm. Due to premorbid fracture, or degeneration, 11 shoulders were excluded. The footprint of the supraspinatus was triangular, with a medial, anteroposterior length of 20.4 ± 4.2 mm. Its lateral anteroposterior length was 6.3 ± 1.6 mm and its maximal mediolateral width was 6.6 ± 2.7 mm. Its calculated area was 122.0 ± 66.6 mm(2). The footprint of the infraspinatus was trapezoidal, with a medial anteroposterior length 22.6 ± 3.0 mm. Its lateral anteroposterior length was 25.4 ± 3.3mm and its maximal mediolateral width was 12.0 ± 2.7 mm. Its calculated area was 294.9 ± 74.1 mm(2). There was no statistical correlation between size of the footprint and age, sex, side, or height. The humeral footprints of the supraspinatus and infraspinatus tendons upon the greater tuberosity were distinct. The lateral border of the infraspinatus' humeral attachment extended much farther anteriorly upon the highest facet of the greater tuberosity than in traditional descriptions. PMID:25914209

  13. Repair of large supraspinatus rotator-cuff defects by infraspinatus and subscapularis tendon transfers in a cadaver model

    PubMed Central

    Kasten, Philip; Loew, Markus

    2006-01-01

    Transosseous repair of a supraspinatus tendon (SSP) defect (Patte size II) can be difficult if the tendon is retracted and the muscle atrophied. In this situation alternatives are margin convergence techniques, local tendon transfers or distant tendon transfers in massive tears. The object of this study was to compare two local tendon transfers in terms of the feasibility of the shift, the area covered by the shift and the force needed to accomplish the shift. Thirteen fresh-frozen cadaver shoulders were used. First a supraspinatus defect extending to the apex of the humeral head (Patte size II) was created. Transosseous repair was attempted with the infraspintus (ISP) and with the subscapularis (SCP) in all cases; repair was successful in all ISP cases, while use of the SCP resulted in a successful repair in only 8 of the 13 (61.5%). A significantly (P=0.012) larger defect area was covered by the ISP transfer than by the SCP shift: 89.7±8.5% versus 31.2±31.1% of the original defect, respectively. The tensile force needed to accomplish the shift was significantly (P=0.004) lower when the ISP was used (15±11 N) than with the SCP (37.1±15 N). In this cadaver model the ISP shift proved more favourable than the SCP shift for covering a Patte size II SSP defect. PMID:16691385

  14. Lysylhydroxylation and non-reducible crosslinking of human supraspinatus tendon collagen: changes with age and in chronic rotator cuff tendinitis

    PubMed Central

    Bank, R.; TeKoppele, J.; Oostingh, G.; Hazleman, B.; Riley, G.

    1999-01-01

    OBJECTIVES—To investigate age related and site specific variations in turnover and chemistry of the collagen network in healthy tendons as well as the role of collagen remodelling in the degeneration of the supraspinatus tendon (ST-D) in rotator cuff tendinitis.?METHODS—Collagen content and the amount of hydroxylysine (Hyl), hydroxylysylpyridinoline (HP), lysylpyridinoline (LP), and the degree of non-enzymatic glycation (pentosidine) were investigated in ST-D and in normal human supraspinatus (ST-N) and biceps brachii tendons (BT-N) by high-performance liquid chromatography.?RESULTS—In BT-N, tendons that served as control tissue as it shows rarely matrix abnormalities, pentosidine levels rise linearly with age (20-90 years), indicating little tissue remodelling (resulting in an undisturbed accumulation of pentosidine). A similar accumulation was observed in ST-N up to 50 years. At older ages, little pentosidine accumulation was observed and pentosidine levels showed large interindividual variability. This was interpreted as remodelling of collagen in normal ST after age 50 years because of microruptures (thus diluting old collagen with newly synthesised collagen). All degenerate ST samples showed decreased pentosidine levels compared with age matched controls, indicating extensive remodelling in an attempt to repair the tendon defect. Collagen content and the amount of Hyl, HP, and LP of ST-N and BT-N did not change with age. With the exception of collagen content, which did not differ, all parameters were significantly (p<0.001) lower in BT-N. The ST-D samples had a reduced collagen content and had higher Hyl, HP, and LP levels than ST-N (p<0.001).?CONCLUSIONS—Inasmuch as Hyl, HP, and LP levels in ST-N did not change with age, tissue remodelling as a consequence of microruptures does not seem to affect the quality of the tendon collagen. On the other hand, the clearly different profile of post-translational modifications in ST-D indicates that the newly deposited collagen network in degenerated tendons is qualitatively different. It is concluded that in ST-D the previously functional and carefully constructed matrix is replaced by aberrant collagen. This may result in a mechanically less stable tendon; as the supraspinatus is constantly subjected to considerable forces this could explain why tendinitis is mostly of a chronic nature.?? Keywords: collagen; tendons; crosslinks; pentosidine PMID:10343538

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

    PubMed

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

    2013-05-01

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

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

    PubMed Central

    Khor, Andrew Yu Keat; Wong, Steven Bak Siew

    2014-01-01

    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

  17. 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

  18. Collagen V-heterozygous and -null supraspinatus tendons exhibit altered dynamic mechanical behaviour at multiple hierarchical scales.

    PubMed

    Connizzo, Brianne K; Han, Lin; Birk, David E; Soslowsky, Louis J

    2016-02-01

    Tendons function using a unique set of mechanical properties governed by the extracellular matrix and its ability to respond to varied multi-axial loads. Reduction of collagen V expression, such as in classic Ehlers-Danlos syndrome, results in altered fibril morphology and altered macroscale mechanical function in both clinical and animal studies, yet the mechanism by which changes at the fibril level lead to macroscale functional changes has not yet been investigated. This study addresses this by defining the multiscale mechanical response of wild-type, collagen V-heterozygous and -null supraspinatus tendons. Tendons were subjected to mechanical testing and analysed for macroscale properties, as well as microscale (fibre re-alignment) and nanoscale (fibril deformation and sliding) responses. In many macroscale parameters, results showed a dose-dependent response with severely decreased properties in the null group. In addition, both heterozygous and null groups responded to load faster than in wild-type tendons via earlier fibre re-alignment and fibril stretch. However, the heterozygous group exhibited increased fibril sliding, while the null group exhibited no fibril sliding. These studies demonstrate that dynamic responses play an important role in determining overall function and that collagen V is a critical regulator in the development of these relationships. PMID:26855746

  19. Examining differences in local collagen fiber crimp frequency throughout mechanical testing in a developmental mouse supraspinatus tendon model.

    PubMed

    Miller, Kristin S; Connizzo, Brianne K; Feeney, Elizabeth; Tucker, Jennica J; Soslowsky, Louis J

    2012-04-01

    Crimp morphology is believed to be related to tendon mechanical behavior. While crimp has been extensively studied at slack or nondescript load conditions in tendon, few studies have examined crimp at specific, quantifiable loading conditions. Additionally, the effect of the number of cycles of preconditioning on collagen fiber crimp behavior has not been examined. Further, the dependence of collagen fiber crimp behavior on location and developmental age has not been examined in the supraspinatus tendon. Local collagen fiber crimp frequency is quantified throughout tensile mechanical testing using a flash freezing method immediately following the designated loading protocol. Samples are analyzed quantitatively using custom software and semi-quantitatively using a previously established method to validate the quantitative software. Local collagen fiber crimp frequency values are compared throughout the mechanical test to determine where collagen fiber frequency changed. Additionally, the effect of the number of preconditioning cycles is examined compared to the preload and toe-region frequencies to determine if increasing the number of preconditioning cycles affects crimp behavior. Changes in crimp frequency with age and location are also examined. Decreases in collagen fiber crimp frequency were found at the toe-region at all ages. Significant differences in collagen fiber crimp frequency were found between the preload and after preconditioning points at 28 days. No changes in collagen fiber crimp frequency were found between locations or between 10 and 28 days old. Local collagen fiber crimp frequency throughout mechanical testing in a postnatal developmental mouse SST model was measured. Results confirmed that the uncrimping of collagen fibers occurs primarily in the toe-region and may contribute to the tendon's nonlinear behavior. Additionally, results identified changes in collagen fiber crimp frequency with an increasing number of preconditioning cycles at 28 days, which may have implications on the measurement of mechanical properties and identifying a proper reference configuration. PMID:22667679

  20. 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

  1. Partial Thickness Rotator Cuff Tears: Current Concepts

    PubMed Central

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

    2015-01-01

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

  2. Single ultrasound-guided platelet-rich plasma injection for treatment of supraspinatus tendinopathy in dogs

    PubMed Central

    Ho, Louisa K.; Baltzer, Wendy I.; Nemanic, Sarah; Stieger-Vanegas, Susanne M.

    2015-01-01

    The effect of a single platelet-rich plasma injection for supraspinatus tendinopathy was assessed in 10 dogs. Subjective (owner-assessed) improvement in lameness and function were seen in 40% of dogs with improved tendon heterogeneity and echogenicity in 60%. There were no significant changes in gait reaction forces 6 wk after treatment. PMID:26246631

  3. 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

  4. Subchondral mineralization patterns of the glenoid after tear of the supraspinatus.

    PubMed

    Anetzberger, H; Schulz, C; Pfahler, M; Refior, H J; Müller-Gerbl, M

    2002-11-01

    Clinical experience has shown that in many cases of rupture of the supraspinatus tendon the head of the humerus shifts upward against the acromion. This implicates alterations in the stress acting on the joint surface. Accordingly, this should be reflected by changes in the distribution of the subchondral mineralization on the glenoid. Computed tomography osteoabsorptiometry was used to evaluate the distribution patterns on the subchondral bone plate of the glenoid in 67 human shoulders. The position of the two most frequent density maxima was determined by a standard procedure. In macroscopically normal specimens (n = 24) every case had an anterosuperior density maximum and the majority (75%) also had a posterior positioned maximum. In some instances a third maximum, placed centrally (17%) or in an anteroinferior position (4%) was seen. In shoulders with a torn supraspinatus tendon (n = 43) a third density maximum frequently appeared in the center of the glenoid (42%); however, most notable was a significant change of the posterior maximum position toward central and superior. With increasing size of the tendon defect an extension of the shift of the posterior maximum (superiorly and centrally) was observed in contrast to the constant anterior maximum. The changes in the distribution of glenoid subchondral bone mineralization in shoulders with a supraspinatus tear must be regarded as a morphologic parameter for the altered long-term stress acting on the joint surface. PMID:12439268

  5. Change in the Pathologic Supraspinatus: A Three-Dimensional Model of Fiber Bundle Architecture within Anterior and Posterior Regions.

    PubMed

    Kim, Soo Y; Sachdeva, Rohit; Li, Zi; Lee, Dongwoon; Rosser, Benjamin W C

    2015-01-01

    Supraspinatus tendon tears are common and lead to changes in the muscle architecture. To date, these changes have not been investigated for the distinct regions and parts of the pathologic supraspinatus. The purpose of this study was to create a novel three-dimensional (3D) model of the muscle architecture throughout the supraspinatus and to compare the architecture between muscle regions and parts in relation to tear severity. Twelve cadaveric specimens with varying degrees of tendon tears were used. Three-dimensional coordinates of fiber bundles were collected in situ using serial dissection and digitization. Data were reconstructed and modeled in 3D using Maya. Fiber bundle length (FBL) and pennation angle (PA) were computed and analyzed. FBL was significantly shorter in specimens with large retracted tears compared to smaller tears, with the deeper fibers being significantly shorter than other parts in the anterior region. PA was significantly greater in specimens with large retracted tears, with the superficial fibers often demonstrating the largest PA. The posterior region was absent in two specimens with extensive tears. Architectural changes associated with tendon tears affect the regions and varying depths of supraspinatus differently. The results provide important insights on residual function of the pathologic muscle, and the 3D model includes detailed data that can be used in future modeling studies. PMID:26413533

  6. Change in the Pathologic Supraspinatus: A Three-Dimensional Model of Fiber Bundle Architecture within Anterior and Posterior Regions

    PubMed Central

    Kim, Soo Y.; Sachdeva, Rohit; Li, Zi; Lee, Dongwoon; Rosser, Benjamin W. C.

    2015-01-01

    Supraspinatus tendon tears are common and lead to changes in the muscle architecture. To date, these changes have not been investigated for the distinct regions and parts of the pathologic supraspinatus. The purpose of this study was to create a novel three-dimensional (3D) model of the muscle architecture throughout the supraspinatus and to compare the architecture between muscle regions and parts in relation to tear severity. Twelve cadaveric specimens with varying degrees of tendon tears were used. Three-dimensional coordinates of fiber bundles were collected in situ using serial dissection and digitization. Data were reconstructed and modeled in 3D using Maya. Fiber bundle length (FBL) and pennation angle (PA) were computed and analyzed. FBL was significantly shorter in specimens with large retracted tears compared to smaller tears, with the deeper fibers being significantly shorter than other parts in the anterior region. PA was significantly greater in specimens with large retracted tears, with the superficial fibers often demonstrating the largest PA. The posterior region was absent in two specimens with extensive tears. Architectural changes associated with tendon tears affect the regions and varying depths of supraspinatus differently. The results provide important insights on residual function of the pathologic muscle, and the 3D model includes detailed data that can be used in future modeling studies. PMID:26413533

  7. EVALUATION OF THE EXTRACELLULAR MATRIX OF INJURED SUPRASPINATUS IN RATS

    PubMed Central

    Almeida, Luiz Henrique Oliveira; Ikemoto, Roberto; Mader, Ana Maria; Pinhal, Maria Aparecida Silva; Munhoz, Bruna; Murachovsky, Joel

    2016-01-01

    ABSTRACT Objective: To evaluate the evolution of injuries of the supraspinatus muscle by immunohistochemistry (IHC) and anatomopathological analysis in animal model (Wistar rats). Methods: Twenty-five Wistar rats were submitted to complete injury of the supraspinatus tendon, then subsequently sacrificed in groups of five animals at the following periods: immediately after the injury, 24h after the injury, 48h after, 30 days after and three months after the injury. All groups underwent histological and IHC analysis. Results: Regarding vascular proliferation and inflammatory infiltrate, we found a statistically significant difference between groups 1(control group) and 2 (24h after injury). IHC analysis showed that expression of vascular endothelial growth factor (VEGF) showed a statistically significant difference between groups 1 and 2, and collagen type 1 (Col-1) evaluation presented a statistically significant difference between groups 1 and 4. Conclusion: We observed changes in the extracellular matrix components compatible with remodeling and healing. Remodeling is more intense 24h after injury. However, VEGF and Col-1 are substantially increased at 24h and 30 days after the injury, respectively. Level of Evidence I, Experimental Study. PMID:26997907

  8. Distal Triceps Tendon Injuries.

    PubMed

    Keener, Jay D; Sethi, Paul M

    2015-11-01

    Acute triceps ruptures are an uncommon entity, occurring mainly in athletes, weight lifters (especially those taking anabolic steroids), and following elbow trauma. Accurate diagnosis is made clinically, although MRI may aid in confirmation and surgical planning. Acute ruptures are classified on an anatomic basis based on tear location and the degree of tendon involvement. Most complete tears are treated surgically in medically fit patients. Partial-thickness tears are managed according to the tear severity, functional demands, and response to conservative treatment. We favor an anatomic footprint repair of the triceps to provide optimal tendon to bone healing and, ultimately, functional outcome. PMID:26498552

  9. Innervation pattern of the suprascapular nerve within supraspinatus: a three-dimensional computer modeling study.

    PubMed

    Hermenegildo, J A; Roberts, S L; Kim, S Y

    2014-05-01

    The relationship between the innervation pattern of the suprascapular nerve (SSN) and the muscle architecture of supraspinatus has not been thoroughly investigated. The supraspinatus is composed of two architecturally distinct regions: anterior and posterior. Each of these regions is further subdivided into three parts: superficial, middle and deep. The purpose of this study was to investigate the course of the SSN throughout the volume of supraspinatus and to relate the intramuscular branches to the distinct regions and parts of the supraspinatus. The SSN was dissected in thirty formalin embalmed cadaveric specimens and digitized throughout the muscle volume in six of those specimens. The digitized data were modeled using Autodesk(®) Maya(®) 2011. The three-dimensional (3D) models were used to relate the intramuscular innervation pattern to the muscle and tendon architecture defined by Kim et al. (2007, Clin Anat 20:648-655). The SSN bifurcated into two main trunks: medial and lateral. All parts of the anterior region were predominantly innervated by the medial trunk and its proximal and medial branches, whereas all parts of the posterior region predominantly by the lateral trunk and its posterolateral and/or posteromedial branches. The posterior region also received innervation from the proximal branch of the medial trunk in half of the specimens. These findings provide evidence that the anterior and posterior regions are distinct with respect to their innervation. The 3D map of the innervation pattern will aid in planning future clinical studies investigating muscle activation patterns and provide insight into possible injury of the nerve with supraspinatus pathology and surgical techniques. PMID:23649406

  10. Tenascin-C and human tendon degeneration.

    PubMed

    Riley, G P; Harrall, R L; Cawston, T E; Hazleman, B L; Mackie, E J

    1996-09-01

    We investigated the distribution of tenascin in supraspinatus tendons to determine whether an alteration in tenascin expression was associated with human tendon degeneration. Tenascin was present in all of the tendons studied, although with two distinct patterns of expression. First, tenascin was associated with organized, fibrous regions of the tendon matrix that were typical of the normal tendon structure. This distribution is consistent with a role for tenascin in collagen fibril organization, perhaps maintaining the interface between fibrils and adjacent structures. Second, although tenascin was generally absent from poorly organized matrix in degenerate tendons, it was strongly associated with some rounded cells in disorganized fibrocartilaginous regions that were more abundant in pathological specimens. Tenascin was also found around infiltrating blood vessels, with more intense staining associated with a mononuclear cell infiltrate. Western blotting of tendon extracts showed differences in tenascin isoform expression, with only the small (200-kd) tenascin isoform found in normal tendons. Degenerate tendons also expressed the 300-kd isoform, consistent with a role for the larger tenascin isoform in tendon disease, potentially stimulating tenocyte proliferation, cell rounding, and fibrocartilaginous change. Proteolytic fragments of tenascin were detected but only in ruptured tendons, an indication of matrix remodeling in degenerate tendons, with fragment sizes consistent with the activity of matrix metalloproteinase enzymes. PMID:8780397

  11. Reliability of MRI assessment of supraspinatus tendinopathy

    PubMed Central

    Sein, Mya Lay; Walton, Judie; Linklater, James; Harris, Craig; Dugal, Tej; Appleyard, Richard; Kirkbride, Brent; Kuah, Donald; Murrell, George A C

    2007-01-01

    Objective To determine the interobserver and intraobserver reliability of the interpretation of MRIs for supraspinatus tendinosis. Methods In the interobserver trial, the MRIs of 52 athletes' shoulders were observed by 3 observers on one occasion within a 2?month period. All 52 images were read by the most experienced musculoskeletal radiologist on 3 different occasions on separate days without access to the previous readings for the intraobserver trial. Supraspinatus tendinosis was graded using a modified 4?point scale from grades 0 to grade 3. Results The grading of MRI?determined supraspinatus tendinosis was reliable, having an intraclass correlation (ICC) of 0.85 when assessed by the single well?trained observer. Interobserver reliability was only fair to good (ICC?=?0.55). Conclusions Supraspinatus tendinosis can be accurately identified on MRI with little variation by a single well?trained observer. Interobserver reliability was only fair to good. Our data indicated that the reliability of the assessment was much greater in more experienced radiologists than in those with less experience. PMID:17289860

  12. Efficiency of microbial cellulose dressing in partial-thickness burn wounds.

    PubMed

    Muangman, Pornprom; Opasanon, Supaporn; Suwanchot, Supaparn; Thangthed, Orapin

    2011-03-01

    Microbial cellulose is a natural polymer that can hold a quantity of water without any disconformities. Therefore, it is proposed for use as wound dressing material. We report a case of 28% total body surface area partial-thickness flame burn: approximately 4.5% superficial partial-thickness burns on anterior face and 23.5% combined superficial and deep partial-thickness burns on both upper arms and anterior trunk. A microbial cellulose dressing, Nanocell (Thai Nano Cellulose Co Ltd, Bangkok, Thailand), was applied to the face wound only once, without any further dressing change. Progress of healing, until full epithelialization on the face, was observed for 2 weeks. During the treatment period, the patient did not show any irritation or allergic reaction to this new dressing, and wound swab culture showed no evidence of bacteria presence. This innovative material can be an alternative dressing for superficial partial-thickness burn wounds. PMID:24527162

  13. Apoptotic cells are present in ischemic zones of deep partial-thickness burns.

    PubMed

    Gravante, Gianpiero; Palmieri, Maria Beatrice; Esposito, Gaetano; Delogu, Daniela; Santeusanio, Giuseppe; Filingeri, Vincenzino; Montone, Antonio

    2006-01-01

    Deep partial-thickness burns exhibit ambiguous behavior, either spontaneously healing or evolving into full-thickness burns. The aim of this study was to investigate these lesions for the presence of apoptotic cells and to compare their rate with that of superficial and full-thickness burns. We used colocalization of DNA fragments (ie, terminal deoxynucleotidyl transferase Biotin-dUTP nick end labeling) and Fas ligand CD95 antibodies to calculate the apoptotic rate of superficial, deep partial-thickness and full-thickness burns in 45 patients after the thermal injury. Biopsies were collected mainly during the acute postburn phase (first week of hospitalization). Deep partial-thickness burns presented apoptotic cells, both in the dermis and in cutaneous adnexa, and showed a higher apoptotic rate than superficial and full-thickness burns (44.5% in deep partial thickness, interquartile range 6.3-90.5%; 5.6% in superficial partial thickness, interquartile range: 0-13%; 0% for full-thickness burn; P = .000243). A significant greater apoptotic rate was present in cells of deep partial-thickness burns when compared with superficial and full thickness. These data would suggest that deep burns sustain an ischemic damage that forces cells to undergo apoptosis and could represent the biologic basis for their clinical evolution into full-thickness burns. Further correlation studies are now required to confirm this hypothesis. PMID:16998402

  14. Tendonitis (image)

    MedlinePLUS

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

  15. Preservation methods of allografts and their (lack of) influence on clinical results in partial thickness burns.

    PubMed

    Hermans, Michel H E

    2011-08-01

    Allografts, cadaver skin and amnion membrane are considered the golden standard in the management of partial thickness burns. However, debate on whether the tissue needs to be viable is on-going, since many believe that viable grafts result in better healing. The objective of this literature survey was to analyse the evidence on the method of preservation of allografts (cadaver skin or amnion membrane, glycerol, cryopreservation, lyophilisation) having a clinical impact on the healing of partial thickness burns. The survey focussed on preservation techniques and clinical outcomes (reepithelialisation) in partial thickness burns, as well as on differences in viability, immunogenicity and antimicrobial properties of the preservation methods. Most studies on allograft treatment of partial thickness burns are observational, with only one study of a (historical) comparative nature. A true meta-analysis was not performed and the results of this survey are observational in nature as well: they indicate that there is no evidence that viability of the graft influences healing outcomes. Thus, instead of viability, other aspects, such as intrinsic antimicrobial safety of the preservation method and cost should be the primary criteria for the choice of preservation method to be used for allografts. PMID:21353745

  16. 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.

  17. Biosynthetic skin substitute vs. 1% silver sulfadiazine for treatment of inpatient partial-thickness thermal burns.

    PubMed

    Gerding, R L; Imbembo, A L; Fratianne, R B

    1988-08-01

    When used appropriately on superficial or moderate-depth partial-thickness burns, Biobrane significantly decreased total healing time to complete reepithelialization, reduced pain, and was associated with decreased nursing time and costs when compared to 1% silver sulfadiazine cream. Care must be used in selecting wounds for Biobrane therapy. They must be fresh, noninfected, and free of eschar and debris with a moist, sensate surface that demonstrates capillary blanching and refill. Wounds must be inspected regularly for nonadherence and signs of infection. Early fluid accumulation requires prompt aspiration. Biobrane should be removed if fluid reaccumulates or the Biobrane becomes nonadherent at any time after 48 hours. When used appropriately, Biobrane offers significant advantages over conventional therapy of acute partial-thickness burns. PMID:3411648

  18. Optimal treatment of partial thickness burns in children: a systematic review.

    PubMed

    Vloemans, A F P M; Hermans, M H E; van der Wal, M B A; Liebregts, J; Middelkoop, E

    2014-03-01

    A large part of the patient population of a burn centre consists of children, most of whom are younger than four years. The majority of these young children suffer from superficial and deep partial thickness scald burns that may easily deepen to full thickness burns. A proper wound therapy, that prevents infection and ensures a moist wound condition, might prevent the deterioration of the wound. Therefore, we performed a systematic review of wound management and dressing materials to select the best treatment option for children with burns. A search in Medline and Embase revealed 51 articles for a critical appraisal. The articles were divided into randomized controlled trials, cohort studies and a group of case-reports. Total appraisal did not differ much amongst the groups; the level of evidence was highest in the randomized controlled trials and lowest in the case-reports. In 16 out of 34 comparative studies, silver sulfadiazine or a silver sulfadiazine/chlorhexidine-gluconate combination was the standard of wound care treatment. The competitor dressing was Biobrane(®) in six studies and amnion membrane in three. Tulle gauze, or tulle gauze impregnated with an antibacterial addition were the standard of care treatment in seven studies. In general, membranous dressings like Biobrane(®) and amnion membrane performed better than the standard of care on epithelialization rate, length of hospital stay and pain for treatment of partial thickness burns in children. However, hardly any of the studies investigated long-term results like scar formation. PMID:24290852

  19. Estimating the time and temperature relationship for causation of deep-partial thickness skin burns.

    PubMed

    Abraham, John P; Plourde, Brian; Vallez, Lauren; Stark, John; Diller, Kenneth R

    2015-12-01

    The objective of this study is to develop and present a simple procedure for evaluating the temperature and exposure-time conditions that lead to causation of a deep-partial thickness burn and the effect that the immediate post-burn thermal environment can have on the process. A computational model has been designed and applied to predict the time required for skin burns to reach a deep-partial thickness level of injury. The model includes multiple tissue layers including the epidermis, dermis, hypodermis, and subcutaneous tissue. Simulated exposure temperatures ranged from 62.8 to 87.8°C (145-190°F). Two scenarios were investigated. The first and worst case scenario was a direct exposure to water (characterized by a large convection coefficient) with the clothing left on the skin following the exposure. A second case consisted of a scald insult followed immediately by the skin being washed with cool water (20°C). For both cases, an Arrhenius injury model was applied whereby the extent and depth of injury were calculated and compared for the different post-burn treatments. In addition, injury values were compared with experiment data from the literature to assess verification of the numerical methodology. It was found that the clinical observations of injury extent agreed with the calculated values. Furthermore, inundation with cool water decreased skin temperatures more quickly than the clothing insulating case and led to a modest decrease in the burn extent. PMID:26188899

  20. Bifurcated intraarticular long head of biceps tendon

    PubMed Central

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

    2014-01-01

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

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

    SciTech Connect

    Satoh, Yasushi Saitoh, Daizoh; Takeuchi, Atsuya; Ojima, Kenichiro; Kouzu, Keita; Kawakami, Saki; Ito, Masataka; Ishihara, Masayuki; Sato, Shunichi; Takishima, Kunio

    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.

  2. Healing of partial thickness porcine skin wounds in a liquid environment.

    PubMed

    Breuing, K; Eriksson, E; Liu, P; Miller, D R

    1992-01-01

    This study employs a liquid-tight vinyl chamber for the topical fluid-phase treatment of experimental wounds in pigs. Continuous treatment with normal saline significantly reduced the early progression of tissue destruction in partial thickness burns. Uncovered burns formed a deep layer of necrosis (0.49 +/- 0.004 mm, mean +/- SD) although burn wounds covered with empty chambers demonstrated less necrosis (0.14 +/- 0.01 mm), fluid-treated wounds formed no eschar, and little tissue necrosis could be detected (less than 0.005 mm). Topical treatment with hypertonic dextran increased water flux across burn wounds by 0.24 ml/cm2/24 hr (mean, n = 95) over saline-treated wounds during the first 5 days after wounding. When partial thickness burn and excisional wounds were immersed in isotonic saline until healed, the daily efflux of water, protein, electrolytes, and glucose across the wound surface declined during healing to baseline values found in controls (saline-covered unwounded skin). The declining protein permeability was used as a reproducible, noninvasive, endogenous marker for the return of epithelial barrier function. Saline-treated excisional wounds healed within 8.6 +/- 0.6 days (mean +/- SD, n = 27) and burn wounds within 12.1 +/- 1.4 days (mean +/- SD, n = 15). Healing of fluid-treated wounds occurred without tissue maceration and showed less inflammation and less scar formation than healing of air exposed wounds (no attempt was made to compare rates of healing between air- and fluid-exposed wounds). We consider the fluid-filled chamber a potentially very useful diagnostic, monitoring, and delivery system for wound-healing research and for human wound therapy. PMID:1548868

  3. Effects of isotretinoin treatment on cartilage and tendon thicknesses: an ultrasonographic study.

    PubMed

    Y?ld?zgören, Mustafa Turgut; Karata? To?ral, Arzu; Baki, Ali Erdem; Ekiz, Timur

    2015-07-01

    Effects of retinoic acid on collagen synthesis and cartilage have previously been shown. However, its effects on cartilage and tendons in humans have not been studied yet. Therefore, in order to provide a morphologic insight, the aim of this study was to measure femoral cartilage, Achilles and supraspinatus tendon thicknesses in patients under systemic isotretinoin treatment by using ultrasound. Fifteen patients (nine F, six M) who used isotretinoin for their acnes were included. All patients were treated with isotretinoin 0.5 mg/kg/day for the first month, and the dosage was escalated up to 1 mg/kg/day thereafter. Distal femoral cartilage, supraspinatus, and Achilles tendons thicknesses have been evaluated both before the treatment and at the end of the third month. Femoral cartilage thicknesses were assessed from three midpoints bilaterally; medial condyle, lateral condyle, and intercondylar area. Short/long-axis diameters and cross-sectional area of the Achilles tendons and axial tendon thicknesses of supraspinatus tendon were evaluated from the nondominant side. The mean age of the patients was 20.1?±?4.9 years, and body mass index was 21.7?±?2.5 kg/m(2). Although posttreatment cartilage measurements of 30 knees were lower for the three midpoints, it reached significance only for lateral condyle (p?=?0.05). In addition, posttreatment tendon measurements were not statistically significant compared with pretreatment values (all p?>?0.05). Systemic isotretinoin treatment seems to make cartilage thinner. Further studies considering histological and molecular evaluations with more sample sizes are awaited. PMID:24985041

  4. Achilles Tendonitis

    MedlinePLUS

    ... Plan Hot Topics Meningitis Choosing Your Mood Prescription Drug Abuse Healthy School Lunch Planner How Can I Help ... or intense strain on the tendon. But non-athletes also can get it if they put a ...

  5. Tendon repair

    MedlinePLUS

    Tendon repair can be performed using: Local anesthesia (the immediate area of the surgery is pain-free) Regional anesthesia (the local and surrounding areas are pain-free) General anesthesia (the patient ...

  6. Acute discrimination between superficial-partial and deep-partial thickness burns in a preclinical model with laser speckle imaging.

    PubMed

    Crouzet, Christian; Nguyen, John Quan; Ponticorvo, Adrien; Bernal, Nicole P; Durkin, Anthony J; Choi, Bernard

    2015-08-01

    A critical need exists for a robust method that enables early discrimination between superficial-partial and deep-partial thickness burn wounds. In this study, we report on the use of laser speckle imaging (LSI), a simple, non-invasive, optical imaging modality, to measure acute blood flow dynamics in a preclinical burn model. We used a heated brass comb to induce burns of varying severity to nine rats and collected raw speckle reflectance images over the course of three hours after burn. We induced a total of 12 superficial-partial and 18 deep-partial thickness burn wounds. At 3h after burn we observed a 28% and 44% decrease in measured blood flow for superficial-partial and deep-partial thickness burns, respectively, and that these reductions were significantly different (p=0.00007). This preliminary data suggests the potential role of LSI in the clinical management of burn wounds. PMID:25814299

  7. Lanolin and epidermal growth factor in healing of partial-thickness pig wounds.

    PubMed

    Chvapil, M; Gaines, J A; Gilman, T

    1988-01-01

    A total of 80 partial-thickness wounds (4.4 cm2 size, 400 micron deep) was inflicted by electrokeratome in the dermal skin layer of four piglets, 15 kg body weight. The wounds were treated with gauze (control), lanolin cream (Lanolor or Lanolin with emulsifiers, Squibb) or with human epidermal growth factor (EGF) delivered in lanolin cream (10 micrograms EGF/mL cream). The treatment was applied every 12 hours for 12 to 120 hours after wounding. The reepithelization rate of the wound was determined by standardized morphometric method. In addition, we measured the thickness of the dermis and cell counts in the dermis. We found that most of the statistically significant enhancement of the epithelization rate, thickness of the dermis, and higher cell count in the dermis were attributed to the effect of lanolin cream alone. The additional significant enhancement of healing by EGF over that of lanolin alone was documented in one of our experiments, but was only marginal. In another experiment using another commercial formulation of lanolin, we found no difference between the effect of EGF and lanolin. Several hypotheses were suggested to explain the effect of the two tested lanolin cream formulations, which induced strong inflammatory reaction in the wound. PMID:3262107

  8. 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

  9. Comparison between cryopreserved and glycerol-preserved allografts in a partial-thickness porcine wound model.

    PubMed

    Yoon, Cheonjae; Lim, Kihwan; Lee, Sungjun; Choi, Yanghwan; Choi, Youngwhan; Lee, Jungsuk

    2016-03-01

    Human skin allografts are one of the best temporary biological coverings for severely burned patients. Cryopreserved (CPA) and glycerol-preserved (GPA) allografts are the most widely used types. This study compared the allograft efficiency of both preservation methods under the same conditions. To simulate actual clinical conditions, we used a porcine wound model. In addition, we evaluated the macroscopic and microscopic scoring of graft performance for each method. Porcine cadaver skin 1 mm thick was obtained from one pig. Cryopreserved skin cell viability was 20.8 %, glycerol-preserved skin was 9.08 %, and fresh skin was 58.6 %. We made ten partial-thickness wounds each in two pigs. The take rates on day 2 were 96.23 and 82.65 % in the GPA and CPA group (both n = 9), respectively. After 1 week, the take rates of both groups were nearly equal. The removal rate at week 5 was 98.87 and 94.41 % in the GPA and CPA group, respectively. On microscopic findings at week 2, inflammation was greater in the CPA group. Other findings such as fibroblast hyperplasia and neovascularization were not significantly different between both groups. At week 5, the score of collagen fiber synthesis was 2.67 ± 0.47 and 2.33 ± 0.47 in the GPA and CPA group, respectively. The epidermal-dermal junction was 2.22 ± 0.79 and 2.00 ± 0.47 in the GPA and CPA group, respectively. These findings suggest that wound healing takes longer in the CPA group. The preservation method of allografts is not a absolute factor in the wound healing process in this wound model. PMID:26150190

  10. ATP hydrolysis reduces neutrophil infiltration and necrosis in partial-thickness scald burns in mice

    PubMed Central

    Bayliss, Jill; DeLaRosa, Sara; Wu, Jianfeng; Peterson, Jonathan R; Eboda, Oluwatobi N.; Su, Grace L; Hemmila, Mark; Krebsbach, Paul H.; Cederna, Paul S.; Wang, Stewart C; Xi, Chuanwu; Levi, Benjamin

    2014-01-01

    Objective Extracellular ATP, present in thermally-injured tissue, modulates the inflammatory response and causes significant tissue damage. We hypothesize that neutrophil infiltration and ensuing tissue necrosis would be mitigated by removing ATP-dependent signaling at the burn site. Methods Mice were subjected to 30% total-body- surface-area partial-thickness scald burn by dorsal skin immersion in a water bath at 60°C or 20°C (non-burn controls). In the treatment arm, an ATP hydrolyzing enzyme, apyrase, was applied directly to the site immediately after injury. Skin was harvested after 24 hours and 5 days for hematoxylin and eosin stain (H&E), elastase, and Ki-67 staining. TNF-α and IFN-β expression were measured through qRT-PCR. Results At 24 hours, the amount of neutrophil infiltration was different between the burn and burn + apyrase groups (p<0.001). Necrosis was less extensive in the apyrase group when compared to the burn group at 24 hours and 5 days. TNF-α and IFN-β expression at 24 hours in the apyrase group was lower than in the burn group (p <0.05). However, Ki-67 signaling was not significantly different among the groups. Conclusions Our results support the role of extracellular ATP in neutrophil activity. We demonstrate that ATP hydrolysis at the burn site allays the neutrophil response to thermal injury and reduces tissue necrosis. This decrease in inflammation and tissue necrosis is at least partially due to TNF-α and IFN-β signaling. Apyrase could be used as topical inflammatory regulators to quell the injury caused by inflammation. PMID:23877144

  11. 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

  12. 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

  13. Cost-effectiveness comparison between topical silver sulfadiazine and enclosed silver dressing for partial-thickness burn treatment.

    PubMed

    Sheckter, Clifford C; Van Vliet, Michael M; Krishnan, Naveen M; Garner, Warren L

    2014-01-01

    The standard treatment of partial-thickness burns includes topical silver products such as silver sulfadiazine (SSD) cream and enclosed dressings including silver-impregnated foam (Mepilex Ag; Molnlycke Health Care, Gothenburg, Sweden) and silver-laden sheets (Aquacel Ag; ConvaTec, Skillman, NJ). The current state of health care is limited by resources, with an emphasis on evidence-based outcomes and cost-effective treatments. This study includes a decision analysis with an incremental cost-utility ratio comparing enclosed silver dressings with SSD in partial-thickness burn patients with TBSA less than 20%. A comprehensive literature review was conducted to identify clinically relevant health states in partial-thickness burn patients. These health states include successful healing, infection, and noninfected delayed healing requiring either surgery or conservative management. The probabilities of these health states were combined with Medicare CPT reimbursement codes (cost) and patient-derived utilities to fit into the decision model. Utilities were obtained using a visual analog scale during patient interviews. Expected cost and quality-adjusted life years (QALYs) were calculated using the roll-back method. The incremental cost-utility ratio for enclosed silver dressing relative to SSD was $40,167.99/QALY. One-way sensitivity analysis of complication rates confirmed robustness of the model. Assuming a maximum willingness to pay $50,000/QALY, the complication rate for SSD must be 22% or higher for enclosed silver dressing to be cost effective. By varying complication rates for SSD and enclosed silver dressings, the two-way sensitivity analysis demonstrated the cost effectiveness of using enclosed silver dressing at the majority of complication rates for both treatment modalities. Enclosed silver dressings are a cost-effective means of treating partial thickness burns. PMID:24121806

  14. 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

  15. Arthroscopic biceps tendon tenodesis: the anchorage technical note.

    PubMed

    Castagna, A; Conti, M; Mouhsine, E; Bungaro, P; Garofalo, R

    2006-06-01

    Treatment of long head biceps (LHB) tendon pathology has become an area of renewed interest and debate among orthopaedic surgeons in recent years. The background of this manuscript is a description of biceps tenodesis which ensure continual dynamic action of the tendon which depresses the head and impedes lateral translation. A new technique has been developed in order to treat LHB tendon irreversible structural abnormalities associated with cuff rotator lesions. This technique entails the construction of a biological anchor between the LHB and supraspinatus and/or infraspinatus tendons according to arthroscopic findings. The rationale, although not supported by biomechanical studies is to obtain a triple, biomechanical effect. The first of these biomechanical effects which we try to promote through the procedure of transposition is the elimination of the deviation and oblique angle which occurs as the LHB completes its intra-articular course prior to reaching the bicipital groove. Furthermore, we have found this technique extremely useful in the presence of large ruptures of the rotator cuff with muscle retraction. The most common complication associated to this particular method, observed in less than 3%, is failed biological fixation which manifests as subsidence of the tenodesis and consequent descent of the tendon with evident aesthetic deformity. PMID:16374589

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

    PubMed Central

    Schwartz, AG; Lipner, JH; Pasteris, JD; Genin, GM; Thomopoulos, S

    2013-01-01

    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 significantly reduced by BtxA-unloading, suggesting that the reduction of mechanical function resulted in part from geometric changes. However, strength, modulus, and toughness were also 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

  17. Treatment of supraspinatus tendinopathy with ultrasound guided dry needling

    PubMed Central

    Settergren, Roy

    2013-01-01

    Objective The purpose of this case study is to describe the treatment of a patient with tendinopathy using sonographically guided dry needling. Tendinopathies are a highly prevalent problem in musculoskeletal medicine, and no one form of treatment has gained universal acceptance as being superior to another. Clinical Features A 30-year-old woman with a 4-month history of anterolateral right shoulder pain was diagnosed with supraspinatus tendinopathy upon physical examination, which was confirmed with diagnostic sonography. Intervention and Outcome Sonography was used to guide an acupuncture needle into the pathologic tissue to induce a humoral healing response. Therapeutic exercise was also prescribed. At 10-day follow-up, increased echogenicity was found in the previously heterogenous hypoechoic areas. The patient also experienced a subjective resolution of her shoulder pain, which did not return with increased physical activity. Conclusions Sonographically guided dry needling was shown to be beneficial for this patient as evident by sonographic changes pre- and postprocedure. PMID:23997721

  18. Endoscopic Management of Gluteus Medius Tendon Tears.

    PubMed

    Thaunat, Mathieu; Noël, Eric; Nové-Josserand, Laurent; Murphy, Colin G; Sbiyaa, Mouhcine; Sonnery-Cottet, Bertrand

    2016-03-01

    Tears in the gluteus medius and minimus tendons have been recognized as an important cause of recalcitrant greater trochanteric pain syndrome. Because of the frequency of partial-thickness undersurface tears, this relatively unknown pathology is often misdiagnosed and left untreated. Surgery is indicated in case of 4 associated conditions: (i) Failure of conservative treatment with duration of symptoms >6 months; (ii) magnetic resonance imaging showing a tendon tear; (iii) positive ultrasound-guided infiltration test; and (iv) the absence of an evolved fatty degeneration or atrophy of the gluteus medius and minimus muscle. Endoscopic repair of partial or full-thickness tears, with systematic resection of the bony structures implicated in the impingement, and a complete bursectomy appear to give satisfactory results, although these results remain to be confirmed by clinical studies with longer follow-up. The degree of tendon degeneration may compromise the tissue left for reattachment, raising concerns over its healing capacity, durability, and ultimate strength of the repair. PMID:26752773

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

    PubMed

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

    2014-01-01

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

  20. ARTHROSCOPY FOR TREATMENT OF REFRACTORY CALCIFIC TENDONITIS OF THE SHOULDER

    PubMed Central

    Fernandes, Marcos Rassi; Fernandes, Rui José

    2015-01-01

    Objective: To evaluate the results from arthroscopic treatment in patients with calcific tendonitis of the shoulder. Methods: Between September 2001 and June 2006, 55 patients with calcific tendonitis of the shoulder that was resistant to conservative treatment were evaluated, with follow-up of 12 to 70 months. The mean age was 42 years, ranging from 30 to 64 years; 44 patients were female (80%). There were 37 right shoulders, and 63.63% of the cases were on the dominant side. Pain was the main symptom, and the mean time between onset of symptoms and arthroscopy was 38 months (range: five to 120 months). The tendon affected was the supraspinatus in 42 cases, the infraspinatus in 11 cases and an association between these in two cases. Acromioplasty was carried out in 12 patients (21.82%) and subacromial bursectomy was performed in all cases. Results: According to the UCLA criteria, 46 cases were excellent and six were good, making a total of 52 satisfactory results (94.54%). Conclusion: Arthroscopic treatment of calcific tendonitis of the shoulder appears to be an effective method, with high rates of satisfactory results. Associated acromioplasty is not necessary.

  1. 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

  2. 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

  3. Transverse Compression of Tendons.

    PubMed

    Samuel Salisbury, S T; Paul Buckley, C; Zavatsky, Amy B

    2016-04-01

    A study was made of the deformation of tendons when compressed transverse to the fiber-aligned axis. Bovine digital extensor tendons were compression tested between flat rigid plates. The methods included: in situ image-based measurement of tendon cross-sectional shapes, after preconditioning but immediately prior to testing; multiple constant-load creep/recovery tests applied to each tendon at increasing loads; and measurements of the resulting tendon displacements in both transverse directions. In these tests, friction resisted axial stretch of the tendon during compression, giving approximately plane-strain conditions. This, together with the assumption of a form of anisotropic hyperelastic constitutive model proposed previously for tendon, justified modeling the isochronal response of tendon as that of an isotropic, slightly compressible, neo-Hookean solid. Inverse analysis, using finite-element (FE) simulations of the experiments and 10?s isochronal creep displacement data, gave values for Young's modulus and Poisson's ratio of this solid of 0.31?MPa and 0.49, respectively, for an idealized tendon shape and averaged data for all the tendons and E?=?0.14 and 0.10?MPa for two specific tendons using their actual measured geometry. The compression load versus displacement curves, as measured and as simulated, showed varying degrees of stiffening with increasing load. This can be attributed mostly to geometrical changes in tendon cross section under load, varying according to the initial 3D shape of the tendon. PMID:26833218

  4. Tendon development and diseases.

    PubMed

    Gaut, Ludovic; Duprez, Delphine

    2016-01-01

    Tendon is a uniaxial connective tissue component of the musculoskeletal system. Tendon is involved in force transmission between muscle and bone. Tendon injury is very common and debilitating but tendon repair remains a clinical challenge for orthopedic medicine. In vertebrates, tendon is mainly composed of type I collagen fibrils, displaying a parallel organization along the tendon axis. The tendon-specific spatial organization of type I collagen provides the mechanical properties for tendon function. In contrast to other components of the musculoskeletal system, tendon biology is poorly understood. An important goal in tendon biology is to understand the mechanisms involved in the production and assembly of type I collagen fibrils during development, postnatal formation, and healing processes in order to design new therapies for tendon repair. In this review we highlight the current understanding of the molecular and mechanical signals known to be involved in tenogenesis during development, and how development provides insights into tendon healing processes. WIREs Dev Biol 2016, 5:5-23. doi: 10.1002/wdev.201 For further resources related to this article, please visit the WIREs website. PMID:26256998

  5. Achilles tendon rupture - aftercare

    MedlinePLUS

    ... MRI scan to see what type of Achilles tendon tear you have. An MRI is a type of ... partial tear means at least some of the tendon is still OK. A full tear means your tendon is torn completely and the ...

  6. 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

  7. A historical appraisal of the use of cryopreserved and glycerol-preserved allograft skin in the treatment of partial thickness burns.

    PubMed

    Vloemans, A F P M; Middelkoop, E; Kreis, R W

    2002-10-01

    Two studies into the use of allograft skin in the treatment of partial thickness burn injuries in this burn centre have provided the opportunity to discuss changes and similarities over a 20 year period. The first study described results obtained with cryopreserved allografts in partial thickness burns in the period 1979-1981. The second study concerned patients with partial thickness injuries treated with glycerol-preserved allografts in the period 1998-2000. A reduction was noted concerning the need for secondary autografting in the group treated with glycerolized allografts. The probability that this difference has occurred by chance is small (P=0.089). Various other factors that might account for the differences in outcome, include general improvements in health and social welfare, differences in treatment protocols, and differences in allograft properties. A prospective comparative trial is indicated to study direct differences between the two types of allograft. PMID:12237059

  8. The effects of exercise using PNF in patients with a supraspinatus muscle tear

    PubMed Central

    Kim, Jwa-jun; Lee, Sang-yeol; Ha, Kyungjin

    2015-01-01

    [Purpose] The aim of this study was to examine the effects of proprioceptive neuromuscular facilitation techniques and simple exercise on subjective pain reduction and blood flow velocity in supraspinatus tear patients and to evaluate muscle recovery. [Subjects and Methods] The 20 subjects of this study were diagnosed with supraspinatus tears by MRI. The subjects have performed PNF techniques and Simple exercise for 12 weeks. [Results] After 12 weeks of proprioceptive neuromuscular facilitation techniques and simple exercise, the blood flow velocity, Visual Analogue Scale, and disabilities of the arm, shoulder, and hand score showed statistically significant difference. Also, the difference between the proprioceptive neuromuscular facilitation techniques and simple exercise was statistically significant. [Conclusion] In conclusion, 12 weeks of proprioceptive neuromuscular facilitation treatment and simple exercise therapy had no effect on pain reduction in patients with supraspinatus tear, but in terms of functionality, the proprioceptive neuromuscular facilitation treatment was effective. PMID:26356542

  9. 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

  10. Biomaterials modulate interleukin-8 and other inflammatory proteins during reepithelialization in cutaneous partial-thickness wounds in pigs.

    PubMed

    Kleinbeck, Kyle R; Faucher, Lee D; Kao, Weiyuan J

    2010-01-01

    Acute and chronic cutaneous wounds remain a clinical challenge that require a mechanistic understanding to advance treatment options. For example, the role of inflammatory mediators during wound healing is not completely understood. Biomimetic materials, such as an in situ photopolymerizable semi-interpenetrating network (sIPN) derived from extracellular matrix components, show great potential in improving healing through the delivery of therapeutic agents and the function as a temporary tissue scaffold. In this study, we characterized the temporal profile of porcine cutaneous partial-thickness wound healing in response to Xeroform and sIPN treatment via histological and inflammatory protein analyses in epidermal, remodeling dermal, and dermal regions. Generally, interleukin (IL)-1?, IL-2, IL-4, IL-6, IL-10, IL-12p70, interferon-?, and tumor necrosis factor-?, but not IL-8, were expressed in the epidermis and remodeling dermis in a time course that followed the progression of epidermal maturation in response to both treatments. Differences in cellularity and protein expression were observed between treatments in a time- and region-dependent manner. In particular, the healing response to sIPN exemplified a potentially key relationship between IL-8 expression and reepithelialization. These results provide insights into the expression of inflammatory mediators and the time course of cutaneous healing and the capacity for biomaterials to further modulate this relationship. PMID:20731797

  11. The Use of EZ Derm® in Partial-Thickness Burns: An Institutional Review of 157 Patients

    PubMed Central

    Troy, Jared; Karlnoski, Rachel; Downes, Katheryne; Brown, Kimberly S.; Cruse, C. Wayne; Smith, David J.; Payne, Wyatt G.

    2013-01-01

    Objectives: To evaluate the use of EZ Derm® (Molnlycke Health Care, US, LLC, Norcross, GA) on partial-thickness burns. Methods: A retrospective review of medical records from patients presenting to the Tampa General Regional Burn Center from January 1, 2008, through January 1, 2012, was conducted. A hospitalwide list of patients was generated on the basis of the presence of charge codes for EZ Derm®. All encounters that did not pass through the Burn Unit were excluded. Applicable charts were reviewed for basic patient characteristics, burn characteristics, outcomes, and complications. Complications were defined as premature separation of EZ Derm®, deviation from a flat fully epithelized wound at the time of final EZ Derm® separation and hypertrophic/keloid scaring. Results: A total of 157 patients were identified and met the study criteria. Eighteen complications were reported from 16 of the 157 patients. Complications were attributed to positioning (2/133 = 1.5%), infection (4/133 = 3.0%), incomplete epithelialization at time of separation (3/133 = 2.2%), need for additional excision and grafting (6/133 = 4.5%), hypertrophic scaring (2/60 = 3.3), and cryptogenic (1/133 = 0.75). Conclusions: EZ Derm® has proven to be a robust wound dressing that provides cost-effective, consistent durable wound coverage with minimal complications that resolve without long-term sequela. PMID:23573334

  12. Tendon functional extracellular matrix.

    PubMed

    Screen, Hazel R C; Berk, David E; Kadler, Karl E; Ramirez, Francesco; Young, Marian F

    2015-06-01

    This article is one of a series, summarizing views expressed at the Orthopaedic Research Society New Frontiers in Tendon Research Conference. This particular article reviews the three workshops held under the "Functional Extracellular Matrix" stream. The workshops focused on the roles of the tendon extracellular matrix, such as performing the mechanical functions of tendon, creating the local cell environment, and providing cellular cues. Tendon is a complex network of matrix and cells, and its biological functions are influenced by widely varying extrinsic and intrinsic factors such as age, nutrition, exercise levels, and biomechanics. Consequently, tendon adapts dynamically during development, aging, and injury. The workshop discussions identified research directions associated with understanding cell-matrix interactions to be of prime importance for developing novel strategies to target tendon healing or repair. PMID:25640030

  13. Atrophy, inducible satellite cell activation, and possible denervation of supraspinatus muscle in injured human rotator-cuff muscle.

    PubMed

    Gigliotti, Deanna; Leiter, Jeff R S; Macek, Bryce; Davidson, Michael J; MacDonald, Peter B; Anderson, Judy E

    2015-09-15

    The high frequency of poor outcome and chronic pain after surgical repair of shoulder rotator-cuff injury (RCI) prompted this study to explore the potential to amplify muscle regeneration using nitric oxide (NO)-based treatment. After preoperative magnetic resonance imaging (MRI), biopsies of supraspinatus and ipsilateral deltoid (as a control) were collected during reparative surgery for RCI. Muscle fiber diameter, the pattern of neuromuscular junctions observed with alpha-bungarotoxin staining, and the ?:? subunit ratio of acetylcholine receptors in Western blots were examined in tandem with experiments to determine the in vitro responsiveness of muscle satellite cells to activation (indicated by uptake of bromodeoxyuridine, BrdU) by the NO-donor drug, isosorbide dinitrate (ISDN). Consistent with MRI findings of supraspinatus atrophy (reduced occupation ratio and tangent sign), fiber diameter was lower in supraspinatus than in deltoid. ISDN induced a significant increase over baseline (up to 1.8-fold), in the proportion of BrdU+ (activated) Pax7+ satellite cells in supraspinatus, but not in deltoid, after 40 h in culture. The novel application of denervation indices revealed a trend for supraspinatus muscle to have a higher ?:? subunit ratio than deltoid (P = 0.13); this ratio inversely with both occupancy ratio (P < 0.05) and the proportion of clusters at neuromuscular junctions (P = 0.05). Results implicate possible supraspinatus denervation in RCI and suggest NO-donor treatment has potential to promote growth in atrophic supraspinatus muscle after RCI and improve functional outcome. PMID:26135801

  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. 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

  16. 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 ...

  17. Advantages of collagen based biological dressings in the management of superficial and superficial partial thickness burns in children

    PubMed Central

    Mathangi Ramakrishnan, K.; Babu, M.; Mathivanan; Jayaraman, V.; Shankar, J.

    2013-01-01

    Summary Collagen based dressings for acute burn wound management have been extensively used in India, particularly in the city of Chennai. Due to the high levels of humidity in our city, closed dressings become infected and treatment with topical antimicrobials, like Silver Sulfadiazine cream, quickly become desiccated. Collagen membrane dressings were manufactured by the biomaterial laboratory of the Central Leather Research Institute (CLRI), Government of India in Chennai, and then the process was patented. Collagen was extracted from bovine skin and Achilles tendons, and then reconstituted. This was used on burn wounds as dressings after clearance from the Institutional Review Board and Ethics Committees of the Hospital and CLRI. Continued research in this field to enable resulted in the design of silver sulphadiazine loaded alginate microspheres which were embedded in the reconstituted collagen. Controlled delivery of silver sulphadiazine. This collagen membrane was used in chronic infected burns. Low molecular weight heparin was given subcutaneously to improve wound healing in burn injuries and collagen membrane dressings were also applied. After several trials the process technology was patented. The advantages and disadvantages of the collagen membrane cover is elaborated in a group of 487 pediatric burn patients. The trial was conducted at the burn unit of Kanchi Kamakoti Childs Trust Hospital (KKCTH) in Chennai, India. PMID:24133405

  18. In vitro effects of glutamate and N-methyl-D-aspartate receptor (NMDAR) antagonism on human tendon derived cells.

    PubMed

    Dean, Benjamin John Floyd; Snelling, Sarah J B; Dakin, Stephanie Georgina; Javaid, Muhammad Kassim; Carr, Andrew Jonathan

    2015-10-01

    It is known that extracellular glutamate concentrations are increased in tendinopathy but the effects of glutamate upon human tendon derived cells are unknown. The primary purpose was to investigate the effect of glutamate exposure on human tendon-derived cells in terms of viability, protein, and gene expression. The second purpose was to assess whether NMDAR antagonism would affect the response of tendon-derived cells to glutamate exposure. Human tendon-derived cells were obtained from supraspinatus tendon tissue obtained during rotator cuff repair (tendon tear derived cells) and from healthy hamstring tendon tissue (control cells). The in vitro impact of glutamate exposure and NMDAR antagonism (MK-801) was measured using the Alamar blue cell viability assay, immunocytochemistry, and quantitative real-time PCR. Glutamate reduced cell viability at 24 h in tendon tear derived cells but not in control cells at concentrations of 7.5 mM and above. Cell viability was significantly reduced after 72 h of 1.875 mM glutamate in both cell groups; this deleterious effect was attenuated by NMDAR antagonism with 10 µM MK-801. Both 24 and 72 h of 1.875 mM glutamate exposure reduced Type 1 alpha 1 collagen (COL1A1) and Type 3 alpha 1 collagen (COL3A1) gene expression, but increased Aggrecan gene expression. We propose that these effects of glutamate on tendon derived cells including reduced cell viability and altered matrix gene expression contribute to the pathogenesis of tendinopathy. PMID:26041147

  19. Sustainable antimicrobial effect of silver sulfadiazine-loaded nanosheets on infection in a mouse model of partial-thickness burn injury.

    PubMed

    Ito, Keisuke; Saito, Akihiro; Fujie, Toshinori; Nishiwaki, Keisuke; Miyazaki, Hiromi; Kinoshita, Manabu; Saitoh, Daizoh; Ohtsubo, Shinya; Takeoka, Shinji

    2015-09-01

    Partial-thickness burn injury has the potential for reepithelialization and heals within 3weeks. If the wound is infected by bacteria before reepithelization, however, the depth of disruption increases and the lesion easily progresses to the full-thickness dermal layers. In the treatment of partial-thickness burn injury, it is important to prevent the wound area from bacterial infection with an antimicrobial dressing. Here, we have tested the antimicrobial properties of polymeric ultra-thin films composed of poly(lactic acid) (termed "PLA nanosheets"), which have high flexibility, adhesive strength and transparency, and silver sulfadiazine (AgSD), which exhibits antimicrobial efficacy. The AgSD-loaded nanosheet released Ag(+) for more than 3days, and exerted antimicrobial efficacy against methicillin-resistant Staphylococcus aureus (MRSA) in an in vitro Kirby-Bauer test. By contrast, a cell viability assay indicated that the dose of AgSD used in the PLA nanosheets did not show significant cytotoxicity toward fibroblasts. In vivo evaluation using a mouse model of infection in a partial-thickness burn wound demonstrated that the nanosheet significantly reduced the number of MRSA bacteria on the lesion (more than 10(5)-fold) and suppressed the inflammatory reaction, thereby preventing a protracted wound healing process. PMID:26079191

  20. 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

  1. A method to test contractility of the supraspinatus muscle in mouse, rat, and rabbit.

    PubMed

    Valencia, Ana P; Iyer, Shama R; Pratt, Stephen J P; Gilotra, Mohit N; Lovering, Richard M

    2016-02-01

    The rotator cuff (RTC) muscles not only generate movement but also provide important shoulder joint stability. RTC tears, particularly in the supraspinatus muscle, are a common clinical problem. Despite some biological healing after RTC repair, persistent problems include poor functional outcomes with high retear rates after surgical repair. Animal models allow further exploration of the sequela of RTC injury such as fibrosis, inflammation, and fatty infiltration, but there are few options regarding contractility for mouse, rat, and rabbit. Histological findings can provide a "direct measure" of damage, but the most comprehensive measure of the overall health of the muscle is contractile force. However, information regarding normal supraspinatus size and contractile function is scarce. Animal models provide the means to compare muscle histology, imaging, and contractility within individual muscles in various models of injury and disease, but to date, most testing of animal contractile force has been limited primarily to hindlimb muscles. Here, we describe an in vivo method to assess contractility of the supraspinatus muscle and describe differences in methods and representative outcomes for mouse, rat, and rabbit. PMID:26586911

  2. Posterior Tibial Tendon Dysfunction

    MedlinePLUS

    ... helpful. This patient is able to perform a single limb heel rise on the right leg. Magnetic resonance imaging (MRI). These studies can create images of so tissues like the tendons and muscles. ...

  3. Inflamed shoulder tendons (image)

    MedlinePLUS

    Tearing and inflammation of the tendons of the shoulder muscles can occur in sports which require the ... pitching, swimming, and lifting weights. Most often the shoulder will heal if a break is taken from ...

  4. Proximal Biceps Tendonitis

    MedlinePLUS

    ... teens, biceps tendonitis is usually an overuse injury. Baseball pitchers, swimmers, tennis players, and people who have ... But if you swim or play tennis or baseball, that might not be an option! If your ...

  5. 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

  6. Achilles Tendon Disorders.

    PubMed

    Saini, Sundeep S; Reb, Christopher W; Chapter, Megan; Daniel, Joseph N

    2015-11-01

    Disorders of the Achilles tendon, the largest tendon in the human body, are common and occur in both active and sedentary persons. A thorough history and physical examination allow primary care physicians to make an accurate diagnosis and to initiate appropriate management. Mismanaged or neglected injuries markedly decrease a patient's quality of life. A growing body of related literature is the basis for current therapeutic regimens, which use a multimodal conservative approach, including osteopathic manipulative treatment. Although primary care physicians can manage most cases of Achilles tendon disorders, specialty care may be needed in certain instances. Procedural intervention should consider any comorbid conditions in addition to patients' lifestyle to help guide decision making. When appropriately managed, Achilles tendon disorders generally carry a favorable prognosis. PMID:26501760

  7. Subrupture Tendon Fatigue Damage

    PubMed Central

    Laudier, Damien M.; Shine, Jean H.; Basta-Pljakic, Jelena; Jepsen, Karl J.; Schaffler, Mitchell B.; Flatow, Evan L.

    2016-01-01

    The mechanical and microstructural bases of tendon fatigue, by which damage accumulates and contributes to degradation, are poorly understood. To investigate the tendon fatigue process, rat flexor digitorum longus tendons were cyclically loaded (1–16 N) until reaching one of three levels of fatigue damage, defined as peak clamp-to-clamp strain magnitudes representing key intervals in the fatigue life: i) Low (6.0%–7.0%); ii) Moderate (8.5%–9.5%); and iii) High (11.0%–12.0%). Stiffness, hysteresis, and clamp-to-clamp strain were assessed diagnostically (by cyclic loading at 1–8 N) before and after fatigue loading and following an unloaded recovery period to identify mechanical parameters as measures of damage. Results showed that tendon clamp-to-clamp strain increased from pre- to post-fatigue loading significantly and progressively with the fatigue damage level (p≤0.010). In contrast, changes in both stiffness and hysteresis were significant only at the High fatigue level (p≤0.043). Correlative microstructural analyses showed that Low level of fatigue was characterized by isolated, transverse patterns of kinked fiber deformations. At higher fatigue levels, tendons exhibited fiber dissociation and localized ruptures of the fibers. Histomorphometric analysis showed that damage area fraction increased significantly with fatigue level (p≤0.048). The current findings characterized the sequential, microstructural events that underlie the tendon fatigue process and indicate that tendon deformation can be used to accurately assess the progression of damage accumulation in tendons. PMID:18683881

  8. Tendon of the long head of the biceps originating from the rotator cuff – An uncommon anatomical variation: case report☆

    PubMed Central

    Andreoli, Carlos Vicente; Esteves, Leonardo Roure; Figueiredo, Eduardo; Belangero, Paulo Santoro; de Castro Pochini, Alberto; Ejnisman, Benno

    2015-01-01

    Anatomical variations at the origin of the biceps tendon have been described by several authors, but occurrences of an origin in the supraspinatus are rare. It is unclear whether this variation might contribute toward pathological conditions of the shoulder. Our objective here was to describe a case of an anatomical variation in the origin of the tendon of the long head of the biceps. The clinical information, preoperative images and arthroscopic images relating to a patient with an aberrant origin of the long head of the biceps, which was observed during shoulder arthroscopy, were reviewed. In this case study, the origin of the biceps was found in the rotator cuff, without any origin from the supraglenoid tubercle or upper labrum. This variant did not seem to contribute toward the pathological condition of the shoulder, and standard treatment for the concomitant condition was sufficient for treating it. PMID:26962493

  9. [Achilles tendon rupture].

    PubMed

    Thermann, H; Hüfner, T; Tscherne, H

    2000-03-01

    The treatment of acute of Achilles tendon rupture experienced a dynamic development in the last ten years. Decisive for this development was the application of MRI and above all the ultrasonography in the diagnostics of the pathological changes and injuries of tendons. The question of rupture morphology as well as different courses of healing could be now evaluated objectively. These advances led consequently to new modalities in treatment concepts and rehabilitation protocols. The decisive input for improvements of the outcome results and particularly the shortening of the rehabilitation period came with introduction of the early functional treatment in contrast to immobilizing plaster treatment. In a prospective randomized study (1987-1989) at the Trauma Dept. of the Hannover Medical School could show no statistical differences comparing functional non-operative with functional operative therapy with a special therapy boot (Variostabil/Adidas). The crucial criteria for therapy selection results from the sonographically measured position of the tendon stumps in plantar flexion (20 degrees). With complete adaptation of the tendons' ends surgical treatment does not achieve better results than non-operative functional treatment in term of tendon healing and functional outcome. Regarding the current therapeutic standards each method has is advantages and disadvantages. Both, the operative and non-operative functional treatment enable a stable tendon healing with a low risk of re-rupture (1-2%). Meanwhile there is consensus for early functional after-treatment of the operated Achilles' tendons. There seems to be a trend towards non-operative functional treatment in cases of adequate sonographical findings, or to minimal invasive surgical techniques. PMID:10798233

  10. Tendon Driven Finger Actuation System

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  11. Nonsilver treatment vs. silver sulfadiazine in treatment of partial-thickness burn wounds in children: a systematic review and meta-analysis.

    PubMed

    Rashaan, Zjir M; Krijnen, Pieta; Klamer, Rachel R M; Schipper, Inger B; Dekkers, Olaf M; Breederveld, Roelf S

    2014-01-01

    The evidence for application of silver-containing dressings and topicals in the treatment of partial-thickness burns in pediatric patients is largely based on clinical trials involving adult patients despite the important differences between the skin of children and adults. A systematic review and meta-analysis was performed of all randomized controlled trials comparing nonsilver treatment with silver-containing dressings and silver topical agents in children with partial-thickness burns in the acute stage. Endpoints were wound healing, grafting, infection, pain, number of dressing changes, length of hospital stay, and scarring. Seven randomized controlled trials were included involving 473 participants. All trials used silver sulfadiazine as control in comparison with five different nonsilver treatments. Most trials were of moderate quality with high risk of bias. Use of nonsilver treatment led to shorter wound healing time (weighted mean difference: -3.43 days, 95% confidence interval: -4.78, -2.07), less dressing changes (weighted mean difference: -19.89 dressing changes, 95% confidence interval: -38.12, -1.66), and shorter length of hospital stay (weighted mean difference: -2.07 days, 95% confidence interval: -2.63, -1.50) compared with silver sulfadiazine treatment, but no difference in the incidence of wound infection or grafting was found. In conclusion, nonsilver treatment may be preferred over silver sulfadiazine, but high-quality randomized controlled trials are needed to validly confirm the effectiveness of silver containing preparations, in particular silver-containing dressings, above nonsilver treatments. PMID:24899251

  12. 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

  13. Platelet-Rich Plasma Treatment With Physical Therapy in Chronic Partial Supraspinatus Tears

    PubMed Central

    Ilhanli, Ilker; Guder, Necip; Gul, Murat

    2015-01-01

    Background: Despite the insufficient evidence, due to potential contribution to the improvement, platelet-rich plasma (PRP) is emerging as a promising method. Objectives: The aim of this study was to assess the effectiveness of PRP injection in partial supraspinatus tears by comparing with physical therapy (PT). Patients and Methods: Seventy patients with chronic partial supraspinatus tears in magnetic resonance imaging were randomized into two groups; PRP (n = 35) and PT (n = 35). Before the treatment, at the end of the treatment and at the 12th month after the end of the treatment, range of motion (ROM), visual analog scale (VAS) for pain, Disabilities of Arm, Shoulder and Hand questionnaire (DASH), Neer’s, Hawkins’ and drop arm tests and Beck Depression Inventory were investigated. Results: Statistical analysis was made for 62 subjects (PRP group, n = 30; PT group, n = 32). There were no differences between the groups according to demographic data. At the 12th month after the end of the treatment, significant improvement in ROM was detected in both groups, pain was reduced significantly in both groups and improvement of the DASH score was observed in both groups. At all the evaluation steps, increases in ROM degrees were significantly higher in the PT group than the PRP group. For VAS in activity and in rest, after the treatment, improvement was higher in the PT group than the PRP group. However, improvement of the DASH score of the PRP group was significantly better than the PT group. Conclusions: When we compared with PT, PRP seemed to be a well-tolerated application which showed promising results in patients with chronic partial supraspinatus tears. PMID:26473076

  14. Tibialis Anterior Tendon Transfer.

    PubMed

    Mulhern, Jennifer L; Protzman, Nicole M; Brigido, Stephen A

    2016-01-01

    Tendon transfer procedures are used commonly for the correction of soft tissue imbalances and instabilities. The complete transfer and the split transfer of the tibialis anterior tendon are well-accepted methods for the treatment of idiopathic equinovarus deformity in children and adults. Throughout the literature, complete and split transfer have been shown to yield significant improvements in ankle and foot range of motion and muscle function. At present, there is insufficient evidence to recommend one procedure over the other, although the split procedure has been advocated for consistently achieving inversion to eversion muscle balance without overcorrection. PMID:26590723

  15. Posterior Tibial Tendon Transfer.

    PubMed

    Shane, Amber M; Reeves, Christopher L; Cameron, Jordan D; Vazales, Ryan

    2016-01-01

    When performed correctly with the right patient population, a tibialis posterior muscle/tendon transfer is an effective procedure. Many different methods have been established for fixating the tendon, each of which has its' own indications. Passing through the interosseous membrane is the preferred and recommended method and should be used unless this is not possible. Good surgical planning based on patient needs and expectations, along with excellent postoperative care including early range of motion and physical therapy minimizes risk of complications and allows for the optimal outcome to be achieved. PMID:26590722

  16. Jones Tendon Transfer.

    PubMed

    Derner, Richard; Holmes, Jeffrey

    2016-01-01

    Hallux malleus is a deformity of the great toe. There is a dorsiflexion contracture at the metatarsophalangeal joint and plantar flexion of the interphalangeal joint. The deformity is commonly attributed to muscular imbalances of the various structures acting on the great toe. Jones tendon transfer is a procedure used to remove the deforming force to the clawed hallux. It is most often performed in conjunction with a hallux interphalangeal joint fusion. Typically there is a neurologic component causing a deformity to the entire foot, necessitating adjunct procedures. The Jones tendon transfer has shown to have reproducible results. PMID:26590724

  17. Repair of large animal partial-thickness cartilage defects through intraarticular injection of matrix-rejuvenated synovium-derived stem cells.

    PubMed

    Pei, Ming; He, Fan; Li, Jingting; Tidwell, John E; Jones, Alvin C; McDonough, E Barry

    2013-05-01

    Cartilage defects have a limited ability to self-heal. Stem cell treatment is a promising approach; however, replicative senescence is a challenge to acquiring large-quantity and high-quality stem cells for cartilage regeneration. Synovium-derived stem cells (SDSCs) are a tissue-specific stem cell for cartilage regeneration. Our recent findings suggest that decellularized stem cell matrix (DSCM) can rejuvenate expanded SDSCs in cell proliferation and chondrogenic potential. In this study, we were investigating (1) whether transforming growth factor (TGF)-?1 and TGF-?3 played a similar role in chondrogenic induction of SDSCs after expansion on either DSCM or plastic flasks (plastic), and (2) whether DSCM-expanded SDSCs had an enhanced capacity in repairing partial-thickness cartilage defects in a minipig model. SDSCs were isolated from synovium in two 3-month-old pigs and DSCM was prepared using SDSCs. Passage 2 SDSCs were expanded on either DSCM or plastic for one passage. The expanded cells were evaluated for cell morphology, chondrogenic capacity, and related mechanisms. TGF-?1 and TGF-?3 were compared for their role in chondrogenesis of SDSCs after expansion on either DSCM or plastic. The chondrogenic induction medium without TGF-? served as a control. In 13 minipigs, we intraarticularly injected DSCM- or plastic-expanded SDSCs or saline into knee partial-thickness cartilage defects and assessed their repair using histology and immunohistochemistry. We found DSCM-expanded SDSCs were small, had a fibroblast-like shape, and grew quickly in a three-dimensional format with concomitant up-regulation of phosphocyclin D1 and TGF-? receptor II. Plastic-expanded SDSCs exhibited higher mRNA levels of chondrogenic markers when incubated with TGF-?3, while DSCM-expanded SDSCs displayed comparable chondrogenic potential when treated with either TGF-? isotype. In the minipig model, DSCM-expanded SDSCs were better than plastic-expanded SDSCs in enhancing collagen II and sulfated glycosaminoglycan expression in repair of partial-thickness cartilage defects, but both groups were superior to the saline control group. Our observations suggested that DSCM is a promising cell expansion system that can promote cell proliferation and enhance expanded cell chondrogenic potential in vitro and in vivo. Our approach could lead to a tissue-specific cell expansion system providing large-quantity and high-quality stem cells for the treatment of cartilage defects. PMID:23216161

  18. Proximal Biceps Tendonitis

    MedlinePLUS

    ... of biceps tendonitis, make sure you know the right way to play. Playing in the wrong way can put your arm in weird positions ... consult your doctor. © 1995- The Nemours Foundation. All rights ... Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart. ...

  19. Flexor tendon surgery. Part 2: Free tendon grafts and tenolysis.

    PubMed

    Strickland, J W

    1989-11-01

    We have attempted to review the development and current status of flexor tendon surgery. The methods of acute flexor tendon repair, conventional free tendon grafting, staged flexor tendon reconstruction, tenolysis and pulley restoration have been discussed, with the published results included for each procedure. The role of rehabilitation has also been reviewed and the ongoing quest for an active flexor tendon prosthetic implant has been briefly mentioned. It may be seen that flexor tendon surgery is a complex and difficult art which requires a thorough appreciation of the normal flexor tendon system, the exact status of that system following injury and surgery and a strong understanding of the techniques which may be best utilised to restore tendon gliding and digital joint motion. The procedures described require both technical skill and experience and the post-operative therapy programmes must be carefully chosen for each patient. With the important laboratory and clinical advancements occurring in many areas of flexor tendon surgery, it is realistic to believe that in the future the techniques described here will be substantially altered and modified and to hope that results will continue to improve until the patient and surgeon can expect to restore most digits to nearly full function after flexor tendon interruption. PMID:2695588

  20. Arthroscopic Marginal Resection of a Lipoma of the Supraspinatus Muscle in the Subacromial Space

    PubMed Central

    Pagán Conesa, Alejandro; Aznar, Carlos Verdú; Herrera, Manuel Ruiz; Lopez-Prats, Fernando Anacleto

    2015-01-01

    Subacromial impingement syndrome is a common cause of shoulder pain in young adults and seniors at present. The etiology of this syndrome is associated with several shoulder disorders, most related to aging, overhead activities, and overuse. The subacromial space is well circumscribed and limited in size, and soft-tissue growing lesions, such as tumors, can endanger the normal function of the shoulder girdle. We present a case of shoulder impingement syndrome caused by an intramuscular lipoma of the supraspinatus muscle in the subacromial space in a 50-year-old male bank manager. Radiographs, magnetic resonance imaging, and a computed tomography scan showed a well-circumscribed soft-tissue tumor at the supraspinatus-musculotendinous junction. It was arthroscopically inspected and dissected and complete marginal excision was performed through a conventional augmented anterolateral portal, avoiding the need to open the trapezius fascia or perform an acromial osteotomy. Microscopic study showed a benign lipoma, and the shoulder function of the patient was fully recovered after a rehabilitation period of 4 months. This less invasive technique shows similar results to conventional open surgery. PMID:26759779

  1. Arthroscopic Marginal Resection of a Lipoma of the Supraspinatus Muscle in the Subacromial Space.

    PubMed

    Pagán Conesa, Alejandro; Aznar, Carlos Verdú; Herrera, Manuel Ruiz; Lopez-Prats, Fernando Anacleto

    2015-08-01

    Subacromial impingement syndrome is a common cause of shoulder pain in young adults and seniors at present. The etiology of this syndrome is associated with several shoulder disorders, most related to aging, overhead activities, and overuse. The subacromial space is well circumscribed and limited in size, and soft-tissue growing lesions, such as tumors, can endanger the normal function of the shoulder girdle. We present a case of shoulder impingement syndrome caused by an intramuscular lipoma of the supraspinatus muscle in the subacromial space in a 50-year-old male bank manager. Radiographs, magnetic resonance imaging, and a computed tomography scan showed a well-circumscribed soft-tissue tumor at the supraspinatus-musculotendinous junction. It was arthroscopically inspected and dissected and complete marginal excision was performed through a conventional augmented anterolateral portal, avoiding the need to open the trapezius fascia or perform an acromial osteotomy. Microscopic study showed a benign lipoma, and the shoulder function of the patient was fully recovered after a rehabilitation period of 4 months. This less invasive technique shows similar results to conventional open surgery. PMID:26759779

  2. Is the Supraspinatus Muscle Atrophy Truly Irreversible after Surgical Repair of Rotator Cuff Tears?

    PubMed Central

    Chung, Seok Won; Kim, Sae Hoon; Tae, Suk-Kee; Yoon, Jong Pil; Choi, Jung-Ah

    2013-01-01

    Background Atrophy of rotator cuff muscles has been considered an irreversible phenomenon. The purpose of this study is to evaluate whether atrophy is truly irreversible after rotator cuff repair. Methods We measured supraspinatus muscle atrophy of 191 patients with full-thickness rotator cuff tears on preoperative magnetic resonance imaging and postoperative multidetector computed tomography images, taken at least 1 year after operation. The occupation ratio was calculated using Photoshop CS3 software. We compared the change between pre- and postoperative occupation ratios after modifying the preoperative occupation ratio. In addition, possible relationship between various clinical factors and the change of atrophy, and between the change of atrophy and cuff integrity after surgical repair were evaluated. Results The mean occupation ratio was significantly increased postoperatively from 0.44 ± 0.17 to 0.52 ± 0.17 (p < 0.001). Among 191 patients, 81 (42.4%) showed improvement of atrophy (more than a 10% increase in occupation ratio) and 33 (17.3%) worsening (more than a 10% decrease). Various clinical factors such as age tear size, or initial degree of atrophy did not affect the change of atrophy. However, the change of atrophy was related to repair integrity: cuff healing failure rate of 48.5% (16 of 33) in worsened atrophy; and 22.2% (18 of 81) in improved atrophy (p = 0.007). Conclusions The supraspinatus muscle atrophy as measured by occupation ratio could be improved postoperatively in case of successful cuff repair. PMID:23467404

  3. Miscellaneous conditions of tendons, tendon sheaths, and ligaments.

    PubMed

    Dyson, S J; Dik, K J

    1995-08-01

    The use of diagnostic ultrasonography has greatly enhances our ability to diagnose injuries of tendons and tendon sheaths that were previously either unrecognized or poorly understood. For may of these injuries, there is currently only a small amount of follow-up data. This article considers injuries of the deep digital flexor tendon and its accessory ligament, the carpal tunnel syndrome soft tissue swellings on the dorsal aspect of the carpus, intertubercular (bicipital) bursitis and bicipital tendinitis, injuries of the gastrocnemius tendon, common calcaneal tendinitis, rupture of peroneus (fibularis tertius) and ligaments injuries of the back. PMID:7584739

  4. 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

  5. Traumatic flexor tendon injuries.

    PubMed

    Lapegue, F; Andre, A; Brun, C; Bakouche, S; Chiavassa, H; Sans, N; Faruch, M

    2015-12-01

    The flexor system of the fingers consisting of flexor tendons and finger pulleys is a key anatomic structure for the grasping function. Athletes and manual workers are particularly at risk for closed injuries of the flexor system: ruptured pulleys, ruptures of the flexor digitorum profundus from its distal attachment ("jersey finger"), and less frequently, ruptures of the flexor digitorum superficialis and of the lumbrical muscles. Open injuries vary more and their imaging features are more complex since tendons may be torn in several locations, the locations may be unusual, the injuries may be associated with nerve and vascular injuries, fibrosis… Sonography is the best imaging modality to associate with the clinical exam for it allows an experienced physician to make an accurate and early diagnosis, crucial to appropriate early treatment planning. PMID:26564614

  6. Distal biceps tendon injuries.

    PubMed

    Miyamoto, Ryan G; Elser, Florian; Millett, Peter J

    2010-09-01

    Distal biceps tendon ruptures present with an initial tearing sensation accompanied by acute pain; weakness may follow. The hook test is very reliable for diagnosing ruptures, and magnetic resonance imaging can provide information about the integrity and any intrasubstance degeneration of the tendon. There are subtle differences between the outcomes of single and modified two-incision operative repairs. With regard to complications, there is a higher prevalence of nerve injuries in association with single-incision techniques and a higher prevalence of heterotopic ossification in association with two-incision techniques. Fixation techniques include the use of bone tunnels, suture anchors, interference screws, and cortical fixation buttons. There is no clinical evidence supporting the use of one fixation method over another, although cortical button fixation has been shown to provide the highest load tolerance and stiffness. Postoperative rehabilitation has become more aggressive as fixation methods have improved. PMID:20810864

  7. Wide-Awake Primary Flexor Tendon Repair, Tenolysis, and Tendon Transfer

    PubMed Central

    2015-01-01

    Tendon surgery is unique because it should ensure tendon gliding after surgery. Tendon surgery now can be performed under local anesthesia without tourniquet, by injecting epinephrine mixed with lidocaine, to achieve vasoconstriction in the area of surgery. This method allows the tendon to move actively during surgery to test tendon function intraoperatively and to ensure the tendon is properly repaired before leaving the operating table. I applied this method to primary flexor tendon repair in zone 1 or 2, tenolysis, and tendon transfer, and found this approach makes tendon surgery easier and more reliable. This article describes the method that I have used for tendon surgery. PMID:26330947

  8. Inhibition of 5-LOX, COX-1, and COX-2 Increases Tendon Healing and Reduces Muscle Fibrosis and Lipid Accumulation After Rotator Cuff Repair

    PubMed Central

    Oak, Nikhil R.; Gumucio, Jonathan P.; Flood, Michael D.; Saripalli, Anjali L.; Davis, Max E.; Harning, Julie A.; Lynch, Evan B.; Roche, Stuart M.; Bedi, Asheesh; Mendias, Christopher L.

    2014-01-01

    Background The repair and restoration of function after chronic rotator cuff tears are often complicated by muscle atrophy, fibrosis, and fatty degeneration of the diseased muscle. The inflammatory response has been implicated in the development of fatty degeneration after cuff injuries. Licofelone is a novel anti-inflammatory drug that inhibits 5-lipoxygenase (5-LOX), as well as cyclooxygenase (COX)-1 and COX-2 enzymes, which play important roles in inducing inflammation after injuries. While previous studies have demonstrated that nonsteroidal anti-inflammatory drugs and selective inhibitors of COX-2 (coxibs) may prevent the proper healing of muscles and tendons, studies about bone and cartilage have demonstrated that drugs that inhibit 5-LOX concurrently with COX-1 and COX-2 may enhance tissue regeneration. Hypothesis After the repair of a chronic rotator cuff tear in rats, licofelone would increase the load to failure of repaired tendons and increase the force production of muscle fibers. Study Design Controlled laboratory study. Methods Rats underwent supraspinatus release followed by repair 28 days later. After repair, rats began a treatment regimen of either licofelone or a vehicle for 14 days, at which time animals were euthanized. Supraspinatus muscles and tendons were then subjected to contractile, mechanical, histological, and biochemical analyses. Results Compared with controls, licofelone-treated rats had a grossly apparent decrease in inflammation and increased fibro-cartilage formation at the enthesis, along with a 62% increase in the maximum load to failure and a 51 % increase in peak stress to failure. Licofelone resulted in a marked reduction in fibrosis and lipid content in supraspinatus muscles as well as reduced expression of several genes involved in fatty infiltration. Despite the decline in fibrosis and fat accumulation, muscle fiber specific force production was reduced by 23%. Conclusion The postoperative treatment of cuff repair with licofelone may reduce fatty degeneration and enhance the development of a stable bone-tendon interface, although decreases in muscle fiber specific force production were observed, and force production in fact declined. Clinical Relevance This study demonstrates that the inhibition of 5-LOX, COX-1, and COX-2 modulates the healing process of repaired rotator cuff tendons. Although further studies are necessary, the treatment of patients with licofelone after cuff repair may improve the development of a stable enthesis and enhance postoperative outcomes. PMID:25245131

  9. 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

  10. 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

  11. 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

  12. The role of stretching in tendon injuries.

    PubMed

    Witvrouw, E; Mahieu, N; Roosen, P; McNair, P

    2007-04-01

    The function of tendons can be classified into two categories: tensile force transmission, and storage and release of elastic energy during locomotion. The action of tendons in storing and releasing energy is mainly seen in sports activities with stretch-shortening cycles (SSCs). The more intense the SSC movements are (jumping-like activities), the more frequently tendon problems are observed. High SSC movements impose high loads on tendons. Consequently, tendons that frequently deal with high SSC motion require a high energy-absorbing capacity to store and release this large amount of elastic energy. As the elasticity of tendon structures is a leading factor in the amount of stored energy, prevention and rehabilitation programmes for tendon injuries should focus on increasing this tendon elasticity in athletes performing high SSC movements. Recently, it has been shown that ballistic stretching can significantly increase tendon elasticity. These findings have important clinical implications for treatment and prevention of tendon injuries. PMID:17261561

  13. 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

  14. 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

  15. Effect of highly purified capsaicin on articular cartilage and rotator cuff tendon healing: An in vivo rabbit study.

    PubMed

    Friel, Nicole A; McNickle, Allison G; DeFranco, Michael J; Wang, FanChia; Shewman, Elizabeth F; Verma, Nikhil N; Cole, Brian J; Bach, Bernard R; Chubinskaya, Susan; Kramer, Susan M; Wang, Vincent M

    2015-12-01

    Highly purified capsaicin has emerged as a promising injectable compound capable of providing sustained pain relief following a single localized treatment during orthopedic surgical procedures. To further assess its reliability for clinical use, the potential effect of highly purified capsaicin on articular cartilage metabolism as well as tendon structure and function warrants clarification. In the current study, rabbits received unilateral supraspinatus transection and repair with a single 1?ml injection of capsaicin (R+C), PEG-only placebo (R+P), or saline (R+S) into the glenohumeral joint (GHJ). An additional group received 1?ml capsaicin onto an intact rotator cuff (I+C). At 18 weeks post-op, cartilage proteoglycan (PG) synthesis and content as well as cell viability were similar (p>0.05) across treatment groups. Biomechanical testing revealed no differences (p>0.05) among tendon repair treatment groups. Similarly, histologic features of both cartilage and repaired tendons showed minimal differences across groups. Hence, in this rabbit model, a single injection of highly purified capsaicin into the GHJ does not induce a deleterious response with regard to cartilage matrix metabolism and cell viability, or rotator cuff healing. These data provide further evidence supporting the use of injectable, highly purified capsaicin as a safe alternative for management of postoperative pain following GHJ surgery. PMID:26135547

  16. [Pathophysiology of overuse tendon injury].

    PubMed

    Kannus, P; Paavola, M; Paakkala, T; Parkkari, J; Järvinen, T; Järvinen, M

    2002-10-01

    Overuse tendon injury is one of the most common injuries in sports. The etiology as well as the pathophysiological mechanisms leading to tendinopathy are of crucial medical importance. At the moment intrinsic and extrinsic factors are assumed as mechanisms of overuse tendon injury. Except for the acute, extrinsic trauma, the chronic overuse tendon injury is a multifactorial process. There are many other factors, such as local hypoxia, less of nutrition, impaired metabolism and local inflammatory that may also contribute to the development of tissue damage. The exact interaction of these factors cannot be explained entirely at the moment. Further studies will be necessary in order to get more information. PMID:12402104

  17. Rectus Femoris Tendon Calcification

    PubMed Central

    Zini, Raul; Panascì, Manlio; Papalia, Rocco; Franceschi, Francesco; Vasta, Sebastiano; Denaro, Vincenzo

    2014-01-01

    Background: Since it was developed, hip arthroscopy has become the favored treatment for femoroacetabular impingement. Due to recent considerable improvements, the indications for this technique have been widely extended. Injuries of the rectus femoris tendon origin, after an acute phase, could result in a chronic tendinopathy with calcium hydroxyapatite crystal deposition, leading to pain and loss of function. Traditionally, this condition is addressed by local injection of anesthetic and corticosteroids or, when conservative measures fail, by open excision of the calcific lesion by an anterior approach. Purpose: To assess whether arthroscopic excision of calcification of the proximal rectus is a safe and effective treatment. Study Design: Case series; Level of evidence, 4. Methods: Outcomes were studied from 6 top amateur athletes (age range, 30-43 years; mean, 32.6 years) affected by calcification of the proximal rectus who underwent arthroscopic excision of the calcification. Patients were preoperatively assessed radiographically, and diagnosis was confirmed by a 3-dimensional computed tomography scan. To evaluate the outcome, standardized hip rating scores were used pre- and postoperatively (at 6 and 12 months): the Hip disability and Osteoarthritis Outcome Score, Oxford Hip Score, and Modified Harris Hip Score. Moreover, visual analog scales (VAS) for pain, sport activity level (SAL), and activities of daily living (ADL) were also used. Results: One year after surgery, all patients reported satisfactory outcomes, with 3 of 6 rating their return-to-sport level as high as preinjury level, and the remaining 3 with a percentage higher than 80%. Five patients ranked their ability to carry on daily activities at 100%. Statistical analysis showed significant improvement of the Oxford Hip Score, the Modified Harris Hip Score, and all 3 VAS subscales (pain, SAL, and ADL) from pre- to latest postoperative assessment (P < .05). Conclusion: Arthroscopic excision of rectus femoris tendon calcification yields satisfying results with few risks to the patient as well as rapid recovery. Clinical Relevance: The recent improvements in hip arthroscopy give the opportunity to address an increasing number of hip conditions effectively and safely, with rapid recovery for the patient. Arthroscopic excision of rectus femoris tendon calcification can be considered a feasible option, with few risks to the patient, rapid recovery, and satisfying outcomes. PMID:26535288

  18. Tendon, tendon sheath, and ligament injuries in the pastern.

    PubMed

    Dyson, S J; Denoix, J M

    1995-08-01

    The palmar (plantar) aspect of the pastern is an anatomically complex area and an understanding of this is a prerequisite for accurate diagnosis of injuries in this area. The gross and normal ultrasonographic anatomy are described, and injuries of the superficial and deep digital flexor tendons and the digital flexor tendon sheath, the distal sesamoidean ligaments, and the palmar ligaments of the proximal interphalangeal joint are discussed. PMID:7584735

  19. [Achilles tendon ruptures and tibialis anterior tendon ruptures].

    PubMed

    Pagenstert, G; Leumann, A; Frigg, A; Valderrabano, V

    2010-12-01

    Achilles tendon ruptures (ATR) are becoming the most frequent tendon rupture of the lower extremity, whereas less than 100 cases of tibialis anterior tendon ruptures (TATR) have been reported. Common in both tendons are the degenerative causes of ruptures in a susceptible tendon segment, whereas traumatic transections occur at each level. Triceps surae and tibialis anterior muscles are responsible for the main sagittal ankle range of motion and ruptures lead to a distinctive functional deficit. However, diagnosis is delayed in up to 25% of ATR and even more frequently in TATR. Early primary repair provides the best functional results. With progressive retraction and muscle atrophy delayed tendon reconstruction has less favourable functional results. But not all patients need full capacity, power and endurance of these muscles and non-surgical treatment should not be forgotten. Inactive patients with significant comorbidities and little disability should be informed that surgical treatment of TATR is complicated by high rates of rerupture and surgical treatment of ATR can result in wound healing problems rarely necessitating some kind of transplantation. PMID:21110002

  20. A randomised clinical trial comparing a hydrocolloid-derived dressing and glycerol preserved allograft skin in the management of partial thickness burns.

    PubMed

    Vloemans, A F P M; Soesman, A M; Suijker, M; Kreis, R W; Middelkoop, E

    2003-11-01

    Membranous dressings for the treatment of partial and mixed thickness burns are among the most innovative and promising new developments of the last years. In this study, we present data of a randomised prospective comparative study on a carboxymethylcellulose based dressing, Hydrofibre((R)) and glycerolized human allograft skin. In a 2 year period, 80 patients (40 for each material) were enrolled in the trial. Study wounds (<10% TBSA) that had not re-epithelialised after 14+/-3 days were debrided and grafted or, if small enough, managed with a topical antimicrobial agent. Mean total TBSA was 8.3+/-5.2%, study burn 3.7+/-2.0% for the Hydrofibre((R)) group and 7.3+/-4.3% total, 3.4+/-2.1% study burn for the allograft skin group (n.s. Wilcoxon rank sum test). No significant differences between groups were established in number of patients with superficial/deep burns. In both groups about 2/3 of the patients healed completely with the dressings applied (24/40 versus 27/40 for Hydrofibre((R)) versus allograft skin, respectively). However, a higher incidence of post-study excision and grafting was found in the Hydrofibre((R)) group (45% versus 15% in the allograft skin group, P=0.004, Mann-Whitney). At 10 weeks follow-up no significant differences were seen in scar colour, pigmentation, pliability, height or itching (Vancouver Scar Scale). Skin elasticity, measured by the Cutometer((R)), was significantly better for the allograft group (P=0.010, Wilcoxon). These differences were no longer found at 6 months and 1 year follow-up. Incidence of hypertrophy after 6 months was higher, but not significantly, in the Hydrofibre((R)) compared to the allograft skin group (52.5% versus 30%, P=0.09, chi-square). In view of the results from our comparative study on Hydrofibre((R)) versus allograft skin, we prefer the use of allograft skin for the category of larger burns of mixed depth, usually presented to burn centres. However, for partial thickness and small burns Hydrofibre((R)) can be the first choice in treatment. PMID:14556729

  1. Hyaluronic acid and tendon lesions

    PubMed Central

    Kaux, Jean-François; Samson, Antoine; Crielaard, Jean-Michel

    2015-01-01

    Summary Introduction recently, the viscoelastic properties of hyaluronic acid (HA) on liquid connective tissue have been proposed for the treatment of tendinopathies. Some fundamental studies show encouraging results on hyaluronic acid’s ability to promote tendon gliding and reduce adhesion as well as to improve tendon architectural organisation. Some observations also support its use in a clinical setting to improve pain and function. This literature review analyses studies relating to the use of hyaluronic acid in the treatment of tendinopathies. Methods this review was constructed using the Medline database via Pubmed, Scopus and Google Scholar. The key words hyaluronic acid, tendon and tendinopathy were used for the research. Results in total, 28 articles (in English and French) on the application of hyaluronic acid to tendons were selected for their relevance and scientific quality, including 13 for the in vitro part, 7 for the in vivo animal part and 8 for the human section. Conclusions preclinical studies demonstrate encouraging results: HA permits tendon gliding, reduces adhesions, creates better tendon architectural organisation and limits inflammation. These laboratory observations appear to be supported by limited but encouraging short-term clinical results on pain and function. However, controlled randomised studies are still needed. PMID:26958533

  2. Histopathological findings in chronic tendon disorders.

    PubMed

    Järvinen, M; Józsa, L; Kannus, P; Järvinen, T L; Kvist, M; Leadbetter, W

    1997-04-01

    Tendon injuries and other tendon disorders represent a common diagnostic and therapeutic challenge in sports medicine, resulting in chronic and long-lasting problems. Tissue degeneration is a common finding in many sports-related tendon complaints. In the great majority of spontaneous tendon ruptures, chronic degenerative changes are seen at the rupture site of the tendon (1). Systemic diseases and diseases specifically deteriorating the normal structure of the tendon (i.e. foreign bodies, and metabolic, inherited and infectious tendon diseases) are only rarely the cause of tendon pathology. Inherited diseases, such as various hereditary diseases with disturbed collagen metabolism and characteristic pathological structural alterations (Ehlers-Danlos syndrome, Marfani syndrome, homocystinuria (ochronosis)), represent approximately 1% of the causes of chronic tendon complaints (2), whereas foreign bodies are somewhat more common and are found in less than 10% of all chronic tendon problems (1). Rheumatoid arthritis and sarcoidosis are typical systemic diseases that cause chronic inflammation in tendon and peritendinous tissues. Altogether, these 'specific' disorders represented less than 2% of the pathological alterations found in the histological analysis of more than 1000 spontaneously ruptured tendons (1, 3, 4). In this material, degenerative changes were seen in a great majority of the tendons, indicating that a spontaneous tendon rupture is a typical clinical end-state manifestation of a degenerative process in the tendon tissue. The role of overuse in the pathogenesis of chronic tendon injuries and disorders is not completely understood. It has been speculated that when tendon is overused it becomes fatigued and loses its basal reparative ability, the repetitive microtraumatic processes thus overwhelming the ability of the tendon cells to repair the fiber damage. The intensive repetitive activity, which often is eccentric by nature, may lead to cumulative microtrauma which further weakens the collagen cross-linking, non-collagenous matrix, and vascular elements of the tendon. Overuse has also been speculated to cause chronic tendon problems, by disturbing the micro- and macrovasculature of the tendon and resulting in insufficiency in the local blood circulation. Decreased blood flow simultaneous with an increased activity may result in local tissue hypoxia, impaired nutrition and energy metabolism, and together these factors are likely to play an important role in the sequence of events leading to tendon degeneration (4). A sedentary lifestyle has been proposed as a main reason for poor basal circulation of the tendon, and presumably is at least partly responsible for the high number of tendon problems in people with a sedentary lifestyle who occasionally take part in high physical activity sports events. PMID:9211609

  3. Partial rupture of the distal biceps tendon.

    PubMed

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

    2000-05-01

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

  4. 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

  5. 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.

  6. Tibialis Anterior Tendon Transfer for Posterior Tibial Tendon Insufficiency.

    PubMed

    Ramanujam, Crystal L; Stapleton, John J; Zgonis, Thomas

    2016-01-01

    The Cobb procedure is useful for addressing stage 2 posterior tibial tendon dysfunction and is often accompanied by a medial displacement calcaneal osteotomy and/or lateral column lengthening. The Cobb procedure can also be combined with selected medial column arthrodesis and realignment osteotomies along with equinus correction when indicated. PMID:26590721

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

    PubMed

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

    2009-06-01

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

  8. 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

  9. Minimally invasive quadriceps tendon harvest.

    PubMed

    Almazán Díaz, Arturo; Cruz López, Francisco; Pérez Jiménez, Francisco-Xavier; Ibarra Ponce de León, José-Clemente

    2006-06-01

    Quadriceps tendon (QT) is becoming a popular graft for primary and revision ligament surgery. A subcutaneous technique for graft harvesting a QT is presented. Special closed tendon strippers were designed; these devices have 10- and 11-mm inner diameters and are stronger and sharper than regular hamstrings strippers. In the mid-line of the patellar upper pole, a 2-cm longitudinal incision is made, a 20- x 10-mm bone plug is created with an oscillating saw, and the tendon stripper is positioned and advanced into the thigh, dissecting the QT until the desired length, usually 10 cm, is obtained. The graft can be released by making a stab incision at the device's tip or by ventrally pointing and turning the tendon stripper to amputate the graft's end. The QT graft can be prepared in several fashions for 1- or 2-bundle ligament reconstructions. The technique was tested and refined in 3 cadaver specimens and has been used at our institution since 2003 in 18 primary posterior cruciate ligament reconstructions with no problems. This minimally invasive technique is safe, provides a consistently good-quality graft with excellent cosmetic results, and is simple and easily reproducible. PMID:16762711

  10. 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. ...

  11. Synergy of tendon stem cells and platelet-rich plasma in tendon healing.

    PubMed

    Chen, Lei; Dong, Shi-Wu; Liu, Jun-Peng; Tao, Xu; Tang, Kang-Lai; Xu, Jian-Zhong

    2012-06-01

    Injured rat Achilles tendons were treated with botulism toxin to create a mechanically unloaded condition (unloaded) or left untreated (loaded), and then treated with phosphate-buffered saline (PBS), platelet-rich plasma (PRP), tendon stem cells (TSCs), or a combination (TSCs + PRP). mRNA and protein expression of collagen I, collagen III, tenascin C, and Smad 8 were determined by real time PCR and immunostaining, respectively. Loaded tendons treated with PBS, PRP, or TSCs for 3 or 14 days had higher collagen I mRNA expression than unloaded tendons. Loaded tendons treated with PBS for 3 or 14 days or with PRP for 3 days had higher collagen I protein levels than unloaded tendons. Loaded tendons treated for 3 days with PBS, for 14 days with PRP or TSCs or TSCs + PRP for 3 or 14 days had higher collagen III protein levels than unloaded tendons. Collagen I mRNA levels were higher in TSCs + PRP-treated loaded tendons compared to PBS-treated loaded tendons on day 3 of treatment. Based on changes in the expression of tendon-healing genes, our data suggest that the combination of TSCs and PRP has synergistic effects on tendon healing under both loaded and unloaded conditions, and loaded conditions improve tendon healing. PMID:22161871

  12. Informing tendon tissue engineering with embryonic development

    PubMed Central

    Glass, Zachary A.; Schiele, Nathan R.; Kuo, Catherine K.

    2014-01-01

    Tendon is a strong connective tissue that transduces muscle-generated forces into skeletal motion. In fulfilling this role, tendons are subjected to repeated mechanical loading and high stress, which may result in injury. Tissue engineering with stem cells offers the potential to replace injured/damaged tissue with healthy, new living tissue. Critical to tendon tissue engineering is the induction and guidance of stem cells towards the tendon phenotype. Typical strategies have relied on adult tissue homeostatic and healing factors to influence stem cell differentiation, but have yet to achieve tissue regeneration. A novel paradigm is to use embryonic developmental factors as cues to promote tendon regeneration. Embryonic tendon progenitor cell differentiation in vivo is regulated by a combination of mechanical and chemical factors. We propose that these cues will guide stem cells to recapitulate critical aspects of tenogenesis and effectively direct the cells to differentiate and regenerate new tendon. Here, we review recent efforts to identify mechanical and chemical factors of embryonic tendon development to guide stem/progenitor cell differentiation toward new tendon formation, and discuss the role this work may have in the future of tendon tissue engineering. PMID:24484642

  13. Human tendon behaviour and adaptation, in vivo

    PubMed Central

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

    2008-01-01

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

  14. Periosteal augmentation of a tendon graft improves tendon healing in the bone tunnel.

    PubMed

    Youn, Inchan; Jones, Deryk G; Andrews, Pamela J; Cook, Marcus P; Suh, J-K Francis

    2004-02-01

    Secure fixation of tendon or ligament to bone has been a challenging problem. The periosteum is an osteogenic organ that regulates bone growth and remodeling at the outer surface of cortical bone and also is known to play an important role in forming a tendon insertion site to bone. Therefore, we hypothesized that a freshly harvested periosteum can be used as a stimulative scaffold to biologically reinforce the attachment of tendon graft to bone. Using a rabbit hallucis longus tendon and calcaneus process model, we found that a periosteal augmentation of a tendon graft could enhance the structural integrity of the tendon-bone interface, when the periosteum is placed between the tendon and bone interface with the cambium layer facing toward the bone. Clinically, the use of an autogenous periosteum patch would be an optimal choice for biologic augmentation of the tendon graft in the bone tunnel, because the tissue is readily available for harvest from the patient's body. PMID:15021159

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

    PubMed Central

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

    2012-01-01

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

  16. 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

  17. 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

  18. Nutrient pathways of flexor tendons in primates

    SciTech Connect

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

    1982-09-01

    The perfusion and diffusion pathways to the flexor profundus tendons of 40 monkeys were investigated by measuring the uptake of tritiated proline by various tendon segments. In the absence of all vascular connections, the process of diffusion provides nutrients to all areas of flexor tendon and in this study the process of diffusion was greater. The distal segment of tendon was observed to be profused most rapidly. The proximal tendon segment is perfused from both the muscular-tendinous junction and the vinculum longus; vincular segment perfusion is via the vinculum longus vessels alone; central segment perfusion is shared by the vinculum longus and vinculum brevis vasculature. The distal segment uptake is by both the process of diffusion or vinculum brevis perfusion. The osseous attachment at the distal phalanx contributes little to tendon nutrition.

  19. On the mechanical function of tendon.

    PubMed

    Kafka, V; Jírová, J; Smetana, V

    1995-01-01

    A mesoscopic approach is followed for mathematical modelling of the specific deformation properties of tendon. The approach starts from our general concept of modelling mechanical behaviour of heterogeneous media and assumes that the structure of tendon is optimized in such a way that it enables its adjacent muscle to work with a constant performance in the course of increasing loading (acting like a gearbox in a car). The model based on this assumption gives results that are in a very good accordance with observed properties of tendons. Clinical experience reveals that if this function of tendon is violated pathological changes appear in the respective muscle. RELEVANCE: Clarification and mathematical modelling of the mechanical function of tendon is of intellectual interest in its own right, but it is important also for cautioning surgeons against unnecessary violation of this function, and for tissue engineering aspects if tendon must be replaced. PMID:11415531

  20. Muscle Force and Power Following Tendon Repair at Altered Tendon Length

    PubMed Central

    Krochmal, Daniel J.; Kuzon, William M.; Urbanchek, Melanie G.

    2008-01-01

    Background While a great deal is known regarding the performance of muscle with intact tendon, little is known about muscle performance when tendon is surgically lengthened or shortened. This knowledge may allow surgeons to more accurately predict functional outcome following tendon repair when correcting a simple tendon laceration or performing a more complex vascularized neuromuscular transfer. Materials and Methods We studied muscle performance 12 weeks following extensor tendon repairs producing altered tendon lengths. Forty male Fischer 344 rats underwent division of the proximal and distal tendons of the extensor digitorum longus muscle. Tendons were immediately repaired producing tendons with increased length, decreased length, or pre-surgical length (control). Observation confirmed that altered tendon length produced inverse changes in initial resting muscle tension. Results Muscle in the Decreased Tendon Length group demonstrated a 15.2% greater muscle mass, 4.9% greater muscle length, 9.6% greater physiologic cross-sectional area, 12.6% greater maximum isometric force, and 31.9% greater maximum power relative to the Control Tendon Length group (p < 0.05). The Increased Tendon Length group did not differ significantly from the Control Tendon Length group for any measurement. Histologically, muscles set with a decreased tendon length demonstrated normal appearing hypertrophied fibers, without evidence of detrimental histological effects such as fibrosis, denervation, necrosis, inflammation, fiber type changes, or fiber splitting. Conclusion These data support the clinical practice of setting muscles with increased passive tension when performing tendon transfer surgeries. Conversely, setting muscles with decreased tension does not necessarily result in a force or power deficit. PMID:17961595

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

    PubMed

    Mabe, Isaac; Hunter, Shawn

    2014-12-01

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

  2. Achilles tendon rupture in badminton.

    PubMed Central

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

    1989-01-01

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

  3. Metastatic pleomorphic adenoma to the supraspinatus muscle: a case report and review of a rare aggressive clinical entity

    PubMed Central

    McGarry, James G; Redmond, Maeve; Tuffy, John B; Wilson, Lorraine; Looby, Seamus

    2015-01-01

    We report a case of a 65-year-old female with a recurrent right parotid pleomorphic adenoma (PA) 24 years after initial surgical excision. Positron-emission tomography (PET) and computed tomography (CT) demonstrated an unusual suspicious FDG-avid erosive rim enhancing mass centered in the right supraspinatus muscle. Cytology from CT-guided aspiration of the mass was consistent with a histologically benign PA, and the patient was diagnosed with metastatic pleomorphic adenoma (MPA). The patient later developed diffuse pulmonary metastases and died within 3 months. MPA, although rare, is recognised as a potentially lethal malignant complication of recurrent or longstanding benign PA. As no biochemical or genetic parameters are predictive of malignant change, patients presenting with recurrent PA should be considered for screening for metastatic disease. PMID:26629288

  4. Fracture of an ossified tibialis anterior tendon.

    PubMed

    Lee, Woo-Chun; Moon, Jeong-Seok; Kim, Ji-Yeong; Ko, Hyeong-Tak

    2009-02-01

    Fractures of ossified tibialis anterior tendon have been successfully managed by the excision of the ossified tendon and transfer of the extensor hallucis longus tendon. A 64-year-old man sustained an injury during mountain hiking 2 weeks prior to presentation, falling down on his heels with his ankle fully plantarflexed. Two tender and bony hard masses were palpable along the course of the tibialis anterior tendon, one at the anteromedial aspect of the ankle and another at the dorsum of the talonavicular joint. Radiographs of the ankle demonstrated an approximately 2x1-cm ovoid-shaped bony mass at the anterior aspect of the ankle joint and another bony mass of similar size and shape at the dorsal aspect of the talonavicular joint. He underwent operative exploration, and complete rupture of the tendon through a bony mass was observed. The gap between the torn ends of the tendon after excision of the mass was too long to be repaired directly. Extensor hallucis longus tendon was retrieved 1 cm proximal to the metatarsophalangeal joint and was passed through the insertion of the anterior tibial tendon and pulled proximally and sutured to itself with the ankle in neutral. At 1 year after surgery, plain radiographs and ultrasonography showed no recurrence of calcification or ossification in the tendon and good mobility of the tibialis anterior muscle was observed. PMID:19301787

  5. Histopathological findings in spontaneous tendon ruptures.

    PubMed

    Józsa, L; Kannus, P

    1997-04-01

    A spontaneous rupture of a tendon may be defined as a rupture that occurs during movement and activity, that should not and usually does not damage the involved musculotendinous units (1). Spontaneous tendon ruptures were uncommon before the 1950s. Böhler found only 25 Achilles tendon ruptures in Wien between 1925 and 1948 (2). Mösender & Klatnek treated 20 Achilles tendon ruptures between 1953 and 1956, but 105 ruptures between 1964 and 1967 (3). Lawrence et al. found only 31 Achilles tendon ruptures in Boston during a period of 55 years (1900-1954) (4). During the recent decades tendon ruptures have, however, become relatively common in developed countries, especially in Europe and North America. A high incidence of tendon ruptures has been reported in Austria, Denmark, Finland, Germany. Hungary, Sweden, Switzerland and the USA; somewhat lower incidences have been reported in Canada, France, Great Britain and Spain. On the other hand, Greece, Japan, the Netherlands and Portugal have reported a clearly lower incidence. Interestingly, Achilles tendon ruptures are a rarity in developing countries, especially in Africa and East-Asia (5). In many developed countries, the increases in the rupture incidence have been dramatic. In the National Institute of Traumatology in Budapest, Hungary, the number of patients with an Achilles tendon rupture increased 285% in men and 500% in women between two successive 7-year periods, 1972-1978 and 1979-1985 (5). PMID:9211612

  6. Tendon sheath fibroma in the thigh.

    PubMed

    Moretti, Vincent M; Ashana, Adedayo O; de la Cruz, Michael; Lackman, Richard D

    2012-04-01

    Tendon sheath fibromas are rare, benign soft tissue tumors that are predominantly found in the fingers, hands, and wrists of young adult men. This article describes a tendon sheath fibroma that developed in the thigh of a 70-year-old man, the only known tendon sheath fibroma to form in this location. Similar to tendon sheath fibromas that develop elsewhere, our patient's lesion presented as a painless, slow-growing soft tissue nodule. Physical examination revealed a firm, nontender mass with no other associated signs or symptoms. Although the imaging appearance of tendon sheath fibromas varies, our patient's lesion appeared dark on T1- and bright on T2-weighted magnetic resonance imaging. It was well marginated and enhanced with contrast.Histologically, tendon sheath fibromas are composed of dense fibrocollagenous stromas with scattered spindle-shaped fibroblasts and narrow slit-like vascular spaces. Most tendon sheath fibromas can be successfully removed by marginal excision, although 24% of lesions recur. No lesions have metastasized. Our patient's tendon sheath fibroma was removed by marginal excision, and the patient remained disease free 35 months postoperatively. Despite its rarity, tendon sheath fibroma should be included in the differential diagnosis of a thigh mass on physical examination or imaging, especially if it is painless, nontender, benign appearing, and present in men. PMID:22495871

  7. Endoscopic Resection of Gouty Tophus of the Patellar Tendon

    PubMed Central

    Lui, Tun Hing

    2015-01-01

    Tophaceous deposition of tendon can result in spontaneous patellar tendon rupture. Surgical therapy may be needed to control symptoms and prevent tendon rupture. Open debridement of the lesion requires a lengthy incision over the lesion; this may result in symptomatic scar adhesion of the patellar tendon or an unhealed wound with persistent tophaceous discharge. Moreover, the other part of the patellar tendon cannot be examined through the incision. We describe a technique for endoscopic resection of a gouty tophus of the patellar tendon. It has the advantage of small incisions away from the lesion and tendon and minimizes wound problems. The whole patellar tendon can be examined endoscopically. PMID:26759781

  8. Characterization of deposits in patients with calcific tendinopathy of the supraspinatus. Role of phytate and osteopontin.

    PubMed

    Grases, Felix; Muntaner-Gimbernat, Lorenzo; Vilchez-Mira, Mar; Costa-Bauzá, Antonia; Tur, Fernando; Prieto, Rafel Maria; Torrens-Mas, Margalida; Vega, Fabiana Gisela

    2015-04-01

    Calcific tendinopathy of the tendons of the rotator cuff is common in adults. These calcifications tend to be reabsorbed after a period of acute pain. This study evaluated the morphologic characteristics of calcific deposits and the participation of phytate and osteopontin (OPN) in their development. Calcific deposits were removed from 21 patients with calcific tendinopathy by ultrasound-guided needle puncture under local anesthesia. The removed deposits were evaluated by scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The amounts of calcium and phosphorus in the deposits were semi-quantitatively determined by energy dispersive X-ray analysis. Phytate was determined in 2?h urine samples, and OPN was extracted from a pool of deposits. The calcific deposits consisted of amorphous and poorly crystalline carbonated hydroxyapatite containing molecular water and organic matter. OPN was associated with the hydroxyapatite deposits. Phytate concentrations were significantly lower in the urine of patients with calcific tendinopathy than in healthy controls. The deficit in crystallization inhibitors such as phytate, and the presence of regulators such as OPN, may play important roles in the development of calcific tendinopathy. PMID:25490945

  9. The mechanical strength of side-to-side tendon repair with mismatched tendon size and shape.

    PubMed

    Fridén, J; Tirrell, T F; Bhola, S; Lieber, R L

    2015-03-01

    Tendon transfers frequently require coaptation of two mismatched tendons. In this cadaver study, ultimate load, stiffness, and Young's modulus were measured in tendon-to-tendon attachments with mismatched donor and recipient tendons, using pronator teres (PT) to extensor carpi radialis brevis (ECRB) and flexor carpi ulnaris (FCU) to extensor digitorum communis (EDC). FCU-to-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 transferred muscles, with safety factors of four-fold for the FCU-to-EDC and two-fold for the PT-to-ECRB transfers. This implies that size and shape mismatches should not be contraindications to tendon attachment in transfers. The strength safety factors suggest that postoperative immobilization of these transfers is unnecessary. PMID:24413573

  10. Augmentation of tendon-to-bone healing.

    PubMed

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

    2014-03-19

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

  11. The pathology of flexor tendon repair.

    PubMed

    Matthews, P

    1979-10-01

    This paper discusses the problems of failure after tendon repair. For a long time the subject has been dominated by the problem of adhesion formation. Recent work has shown that this is not inevitable, and consideration of other factors, particularly the nutrition of tendon tissue is leading to the possibilities of other methods of treatment. PMID:520866

  12. Structure-mechanics relationships in mineralized tendons.

    PubMed

    Spiesz, Ewa M; Zysset, Philippe K

    2015-12-01

    In this paper, we review the hierarchical structure and the resulting elastic properties of mineralized tendons as obtained by various multiscale experimental and computational methods spanning from nano- to macroscale. The mechanical properties of mineralized collagen fibres are important to understand the mechanics of hard tissues constituted by complex arrangements of these fibres, like in human lamellar bone. The uniaxial mineralized collagen fibre array naturally occurring in avian tendons is a well studied model tissue for investigating various stages of tissue mineralization and the corresponding elastic properties. Some avian tendons mineralize with maturation, which results in a graded structure containing two zones of distinct morphology, circumferential and interstitial. These zones exhibit different amounts of mineral, collagen, pores and a different mineral distribution between collagen fibrillar and extrafibrillar space that lead to distinct elastic properties. Mineralized tendon cells have two phenotypes: elongated tenocytes placed between fibres in the circumferential zone and cuboidal cells with lower aspect ratios in the interstitial zone. Interestingly some regions of avian tendons seem to be predestined to mineralization, which is exhibited as specific collagen cross-linking patterns as well as distribution of minor tendon constituents (like proteoglycans) and loss of collagen crimp. Results of investigations in naturally mineralizing avian tendons may be useful in understanding the pathological mineralization occurring in some human tendons. PMID:25922092

  13. 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.

  14. Growth factors in porcine full and partial thickness burn repair. Differing targets and effects of keratinocyte growth factor, platelet-derived growth factor-BB, epidermal growth factor, and neu differentiation factor.

    PubMed Central

    Danilenko, D. M.; Ring, B. D.; Tarpley, J. E.; Morris, B.; Van, G. Y.; Morawiecki, A.; Callahan, W.; Goldenberg, M.; Hershenson, S.; Pierce, G. F.

    1995-01-01

    The topical application of recombinant growth factors such as epidermal growth factor, platelet-derived growth factor-BB homodimer (rPDGF-BB), keratinocyte growth factor (rKGF), and neu differentiation factor has resulted in significant acceleration of healing in several animal models of wound repair. In this study, we established highly reproducible and quantifiable full and deep partial thickness porcine burn models in which burns were escharectomized 4 or 5 days postburn and covered with an occlusive dressing to replicate the standard treatment in human burn patients. We then applied these growth factors to assess their efficacy on several parameters of wound repair: extracellular matrix and granulation tissue production, percent reepithelialization, and new epithelial area. In full thickness burns, only rPDGF-BB and the combination of rPDGF-BB and rKGF induced significant changes in burn repair. rPDGF-BB induced marked extracellular matrix and granulation tissue production (P = 0.013) such that the burn defect was filled within several days of escharectomy, but had no effect on new epithelial area or reepithelialization. The combination of rPDGF-BB and rKGF in full thickness burns resulted in a highly significant increase in extracellular matrix and granulation tissue area (P = 0.0009) and a significant increase in new epithelial area (P = 0.007), but had no effect on reepithelialization. In deep partial thickness burns, rKGF induced the most consistent changes. Daily application of rKGF induced a highly significant increase in new epithelial area (P < 0.0001) but induced only a modest increase in reepithelialization (83.7% rKGF-treated versus 70.2% control; P = 0.016) 12 days postburn. rKGF also doubled the number of fully reepithelialized burns (P = 0.02) at 13 days postburn, at least partially because of marked stimulation of both epidermal and follicular proliferation as assessed by proliferating cell nuclear antigen expression. In situ hybridization for KGFR in porcine burns revealed strong expression of KGFR on hair follicles and basal epidermis, confirming direct rKGF action on follicular as well as epidermal keratinocytes. Although the epithelial proliferation induced by rKGF resulted in marked neoepidermal psoriasiform hyperplasia with exaggerated rete ridges and neoepidermal and follicular maturation as assessed by expression of cytokeratin 10, a marker of keratinocyte terminal differentiation was not delayed and appeared to be accelerated in some rKGF-treated burns. Recombinant epidermal growth factor induced a trend toward increased new epithelial area in deep partial thickness burns, but had no effect on reepithelialization. The recombinant neu differentiation factor-alpha 2 isoform had no significant biological effects in either full or deep partial thickness burns.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 Figure 2 Figure 4 Figure 7 Figure 8 PMID:7485390

  15. Tendon Vasculature in Health and Disease

    PubMed Central

    Tempfer, Herbert; Traweger, Andreas

    2015-01-01

    Tendons represent a bradytrophic tissue which is poorly vascularized and, compared to bone or skin, heal poorly. Usually, a vascularized connective scar tissue with inferior functional properties forms at the injury site. Whether the increased vascularization is the root cause of tissue impairments such as loss of collagen fiber orientation, ectopic formation of bone, fat or cartilage, or is a consequence of these pathological changes remains unclear. This review provides an overview of the role of tendon vasculature in healthy and chronically diseased tendon tissue as well as its relevance for tendon repair. Further, the nature and the role of perivascular tendon stem/progenitor cells residing in the vascular niche will be discussed and compared to multipotent stromal cells in other tissues. PMID:26635616

  16. 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.

  17. Examination of the Biceps Tendon.

    PubMed

    McFarland, Edward G; Borade, Amrut

    2016-01-01

    The examination of the shoulder for conditions involving the biceps tendon continues to be challenging. Numerous examination tests for biceps and superior labrum anterior and posterior (SLAP) lesions have been scientifically evaluated. This section reports on how to perform these tests and summarizes the clinical utility of the tests. Many of the tests for the examination of the biceps and for SLAP lesions do not have high sensitivity and specificity, which limits their usefulness. Although the dynamic shear test has promise for making the diagnosis of SLAP lesions, the studies reporting its clinical utility are disparate. PMID:26614467

  18. The Role of Detraining in Tendon Mechanobiology

    PubMed Central

    Frizziero, Antonio; Salamanna, Francesca; Della Bella, Elena; Vittadini, Filippo; Gasparre, Giuseppe; Nicoli Aldini, Nicolò; Masiero, Stefano; Fini, Milena

    2016-01-01

    Introduction: Several conditions such as training, aging, estrogen deficiency and drugs could affect the biological and anatomo-physiological characteristics of the tendon. Additionally, recent preclinical and clinical studies examined the effect of detraining on tendon, showing alterations in its structure and morphology and in tenocyte mechanobiology. However, few data evaluated the importance that cessation of training might have on tendon. Basically, we do not fully understand how tendons react to a phase of training followed by sudden detraining. Therefore, within this review, we summarize the studies where tendon detraining was examined. Materials and Methods: A descriptive systematic literature review was carried out by searching three databases (PubMed, Scopus and Web of Knowledge) on tendon detraining. Original articles in English from 2000 to 2015 were included. In addition, the search was extended to the reference lists of the selected articles. A public reference manager (www.mendeley.com) was adopted to remove duplicate articles. Results: An initial literature search yielded 134 references (www.pubmed.org: 53; www.scopus.com: 11; www.webofknowledge.com: 70). Fifteen publications were extracted based on the title for further analysis by two independent reviewers. Abstracts and complete articles were after that reviewed to evaluate if they met inclusion criteria. Conclusions: The revised literature comprised four clinical studies and an in vitro and three in vivo reports. Overall, the results showed that tendon structure and properties after detraining are compromised, with an alteration in the tissue structural organization and mechanical properties. Clinical studies usually showed a lesser extent of tendon alterations, probably because preclinical studies permit an in-depth evaluation of tendon modifications, which is hard to perform in human subjects. In conclusion, after a period of sudden detraining (e.g., after an injury), physical activity should be taken with caution, following a targeted rehabilitation program. However, further research should be performed to fully understand the effect of sudden detraining on tendons. PMID:26973517

  19. Functional Tissue Engineering of Tendon: Establishing Biological Success Criteria for Improving Tendon Repair

    PubMed Central

    Breidenbach, Andrew P; Gilday, Steven D; Lalley, Andrea L; Dyment, Nathaniel A; Gooch, Cynthia; Shearn, Jason T; Butler, David L

    2013-01-01

    Improving tendon repair using Functional Tissue Engineering (FTE) principles has been the focus of our laboratory over the last decade. Although our primary goals were initially focused only on mechanical outcomes, we are now carefully assessing the biological properties of our tissue-engineered tendon repairs so as to link biological influences with mechanics. However, given the complexities of tendon development and healing, it remains challenging to determine which aspects of tendon biology are the most important to focus on in the context of tissue engineering. To address this problem, we have formalized a strategy to identify, prioritize, and evaluate potential biological success criteria for tendon repair. We have defined numerous biological properties of normal tendon relative to cellular phenotype, extracellular matrix and tissue ultra-structure that we would like to reproduce in our tissue-engineered repairs and prioritized these biological criteria by examining their relative importance during both normal development and natural tendon healing. Here, we propose three specific biological criteria which we believe are essential for normal tendon function: 1) scleraxis-expressing cells; 2) well-organized and axially-aligned collagen fibrils having bimodal diameter distribution; and 3) a specialized tendon-to-bone insertion site. Moving forward, these biological success criteria will be used in conjunction with our already established mechanical success criteria to evaluate the effectiveness of our tissue-engineered tendon repairs. PMID:24200342

  20. Is higher serum cholesterol associated with altered tendon structure or tendon pain? A systematic review

    PubMed Central

    Tilley, Benjamin J; Cook, Jill L; Docking, Sean I; Gaida, James E

    2015-01-01

    Background Tendon pain occurs in individuals with extreme cholesterol levels (familial hypercholesterolaemia). It is unclear whether the association with tendon pain is strong with less extreme elevations of cholesterol. Objective To determine whether lipid levels are associated with abnormal tendon structure or the presence of tendon pain. Methods We conducted a systematic review and meta-analysis. Relevant articles were found through an electronic search of 6 medical databases—MEDLINE, Cochrane, AMED, EMBASE, Web of Science and Scopus. We included all case–control or cross-sectional studies with data describing (1) lipid levels or use of lipid-lowering drugs and (2) tendon structure or tendon pain. Results 17 studies (2612 participants) were eligible for inclusion in the review. People with altered tendon structure or tendon pain had significantly higher total cholesterol, low-density lipoprotein cholesterol and triglycerides, as well as lower high-density lipoprotein cholesterol; with mean difference values of 0.66, 1.00, 0.33, and ?0.19 mmol/L, respectively. Conclusions The results of this review indicate that a relationship exists between an individual’s lipid profile and tendon health. However, further longitudinal studies are required to determine whether a cause and effect relationship exists between tendon structure and lipid levels. This could lead to advancement in the understanding of the pathoaetiology and thus treatment of tendinopathy. PMID:26474596

  1. Anterior cruciate ligament reconstruction: clinical outcomes of patella tendon and hamstring tendon grafts.

    PubMed

    Gulick, Dawn T; Yoder, Heather N

    2002-09-01

    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

  2. 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

  3. 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

  4. Combined anterior tibial tendon rupture and posterior tibial tendon dysfunction in advanced flatfoot.

    PubMed

    Frigg, Arno Martin; Valderrabano, Victor; Kundert, Hans-Peter; Hintermann, Beat

    2006-01-01

    The combination of spontaneous anterior tibial tendon rupture and posterior tibial tendon dysfunction has rarely been reported in the literature. This is a case report of a 78-year-old patient presenting with a history of longstanding, progressive flatfoot deformity, clinically grade III posterior tibial tendon dysfunction, and dropfoot gait. Radiographic films revealed severe flatfoot, and the clinical examination was consistent with a complete rupture of the anterior tibial tendon and severe posterior tibial tendon degeneration as well as rupture of the spring and deltoid ligaments. Treatment by triple arthrodesis and repair of the anterior tibial tendon affected pain relief and clinical as well as radiographic correction at the 4-month postoperative assessment. PMID:17145469

  5. Late flexor digitorum longus tendon rupture after transfer for posterior tibial tendon insufficiency: a case report.

    PubMed

    Ouzounian, T J

    1995-08-01

    A 64-year-old woman was treated for an idiopathic complete rupture of the posterior tibial tendon with transfer of the flexor digitorum longus tendon to the navicular. After an initial excellent result, she returned 41 months later after experiencing a sudden pop in the medial retromalleolar area, followed by progressive medial ankle pain. At reoperation, a complete rupture of the flexor digitorum longus tendon was noted at its insertion into the navicular. Reconstruction was performed utilizing a sliding lengthening of the flexor digitorum longus tendon and reattachment to the navicular with a suture anchor. Clinical improvement was noted at the 12-month follow-up evaluation. This case presentation is of clinical interest, as late acute failure of a flexor digitorum longus tendon transfer for posterior tibial tendon rupture has not been reported previously. PMID:8520667

  6. Catastrophic Failure of an Infected Achilles Tendon Rupture Repair Managed with Combined Flexor Hallucis Longus and Peroneus Brevis Tendon Transfer.

    PubMed

    Simonson, Devin C; Elliott, Andrew D; Roukis, Thomas S

    2016-01-01

    Deep infection is one of the most devastating complications following repair of an Achilles tendon rupture. Treatment requires not only culture-driven antibiotic therapy, but more importantly, appropriate débridement of some or even all of the Achilles tendon. This may necessitate delayed reconstruction of the Achilles tendon. The authors present a successful case of reconstruction of a chronically infected Achilles tendon in an otherwise healthy 43-year-old man via a multistaged approach using the flexor hallucis longus and peroneus brevis tendons. We also provide a brief review of the literature regarding local tendon transfer used in the reconstruction of Achilles tendon rupture. PMID:26590732

  7. Principles and Biomechanical Considerations of Tendon Transfers.

    PubMed

    Walton, Laura; Villani, Matthew F

    2016-01-01

    Whether performed as a primary procedure or used to augment and support osseous reconstruction, tendon transfers are a key skill for the foot and ankle surgeon. Understanding the biomechanics preoperative and postoperatively is essential in performing appropriate procedures and in supporting patients through the rehabilitation process. Often the complexity of tendon transfer surgery is lost because it is deemed a soft tissue procedure and in theory should be less complex than osseous procedures. However, the dynamic nature of musculature and tendons require a deeper understanding of surgical and biomechanical concepts. PMID:26590719

  8. Proximal Biceps Tendon and Rotator Cuff Tears.

    PubMed

    Virk, Mandeep S; Cole, Brian J

    2016-01-01

    The long head of biceps tendon (LHBT) is frequently involved in rotator cuff tears and can cause anterior shoulder pain. Tendon hypertrophy, hourglass contracture, delamination, tears, and tendon instability in the bicipital groove are common macroscopic pathologic findings affecting the LHBT in the presence of rotator cuff tears. Failure to address LHBT disorders in the setting of rotator cuff tear can result in persistent shoulder pain and poor satisfaction after rotator cuff repair. Tenotomy or tenodesis of the LHBT are effective options for relieving pain arising from the LHBT in the setting of reparable and selected irreparable rotator cuff tears. PMID:26614474

  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. Les plaies du tendon patellaire

    PubMed Central

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

    2014-01-01

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

  11. 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

  12. Multi-Layer Electrospun Membrane Mimicking Tendon Sheath for Prevention of Tendon Adhesions

    PubMed Central

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

    2015-01-01

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

  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. Assessment of Postoperative Tendon Quality in Patients With Achilles Tendon Rupture Using Diffusion Tensor Imaging and Tendon Fiber Tracking.

    PubMed

    Sarman, Hakan; Atmaca, Halil; Cakir, Ozgur; Muezzinoglu, Umit Sefa; Anik, Yonca; Memisoglu, Kaya; Baran, Tuncay; Isik, Cengiz

    2015-01-01

    Although pre- and postoperative imaging of Achilles tendon rupture (ATR) has been well documented, radiographic evaluations of postoperative intratendinous healing and microstructure are still lacking. Diffusion tensor imaging (DTI) is an innovative technique that offers a noninvasive method for describing the microstructure characteristics and organization of tissues. DTI was used in the present study for quantitative assessment of fiber continuity postoperatively in patients with acute ATR. The data from 16 patients with ATR from 2005 to 2012 were retrospectively analyzed. The microstructure of ART was evaluated using tendon fiber tracking, tendon continuity, fractional anisotropy, and apparent diffusion coefficient values by way of DTI. The distal and proximal portions were measured separately in both the ruptured and the healthy extremities of each patient. The mean patient age was 41.56 ± 8.49 (range 26 to 56) years. The median duration of follow-up was 21 (range 6 to 80) months. The tendon fractional anisotropy values of the ruptured Achilles tendon were significantly lower statistically than those of the normal side (p = .001). However, none of the differences between the 2 groups with respect to the distal and proximal apparent diffusion coefficient were statistically significant (p = .358 and p = .899, respectively). In addition, the fractional anisotropy and apparent diffusion coefficient measurements were not significantly different in the proximal and distal regions of the ruptured tendons compared with the healthy tendons. The present study used DTI and fiber tracking to demonstrate the radiologic properties of postoperative Achilles tendons with respect to trajectory and tendinous fiber continuity. Quantifying DTI and fiber tractography offers an innovative and effective tool that might be able to detect microstructural abnormalities not appreciable using conventional radiologic techniques. PMID:25736446

  15. Primary hydatid cyst of the supraspinatus muscle: complete removal of the germinal layer and cytodiagnosis by fine-needle aspiration.

    PubMed

    Das, Dilip K; El-Sharawy, Maha; Ayyash, Emad H; Al-Enezi, Nadia A; Iqbal, Jamshed R; Madda, John P

    2014-03-01

    Primary hydatid disease of the skeletal muscle without systemic involvement is rare. The purpose of this report is to document the novel clinical presentation and the interesting facets of fine-needle aspiration in a case of hydatid disease. It was a case of primary hydatid cyst of the left supraspinatus muscle in an Indian woman living in Kuwait, which was clinically diagnosed as a lipoma. Fine-needle aspiration (FNA) yielded 2 ml of clear fluid with white particulate material. The cytocentrifuged smears prepared from the aspirated fluid showed many scolices, occasional laminated cyst wall fragments and numerous hooklets. The laminated cyst wall and scolices were PAS positive. Trichrome staining imparted a demon-head-like appearance to the scolices. The cytodiagnosis of hydatid cyst was corroborated by histopathological examination of an excised whitish membrane and an irregular cystic fragment, which showed parallel laminations without germinal layer, and skeletal muscle with granulomas and a dense eosinophilic infiltration, respectively. Quantitative serological (indirect hemagglutination) test on blood sample collected 9 days after the excision of the cyst showed insignificant antibody titer to Echinococcus sp. and after 6 weeks the antibodies were completely absent. CT scan of the chest and abdomen performed 7 weeks after removal of cyst showed no evidence of visceral hydatid cyst. PMID:23008130

  16. 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

  17. Common Disorders of the Achilles Tendon

    MedlinePLUS

    ... after periods of rest, then improves somewhat with motion but later worsens with increased activity. Tenderness, or ... foot and ankle and evaluate the range of motion and condition of the tendon. The extent of ...

  18. 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

  19. A posterior tibial tendon skipping rope.

    PubMed

    van Sterkenburg, M N; Haverkamp, D; van Dijk, C N; Kerkhoffs, G M M J

    2010-12-01

    This report presents an athletic patient with swelling and progressive pain on the posteromedial side of his right ankle on weight bearing. MRI demonstrated tenosynovitis and suspicion of a length rupture. On posterior tibial tendoscopy, there was no rupture, but medial from the tendon a tissue cord came into view, causing impingement on the tendon at the level of maximum pain. The cord was released and 2 weeks and 1 year after the procedure the patient reported no complaints. PMID:20556356

  20. [Primary repair of extensor tendon injuries of the hand].

    PubMed

    Mascharka, Z

    2007-06-01

    Knowledge of the functional anatomy of the extensor tendons with the sliding mechanism is essential for better understanding the surgical therapy and the postoperative care in the different trauma zones of the extensor tendon. In addition the localization of the injury is very important for the clinical findings, therapy, after-care and long term prognosis. Anatomical facts, injury mechanisms and associated injuries have to be considered in the therapy concept. Several therapy possibilities are known: immobilizing with splint for the closed rupture in zone I, reinsertion in zone III (with a temporary Kirschner-wire-pinning), tendon suture, tendon transplantation or transposition. Controlled mobilization after suture should be aspired (similar to the one of the flexor tendon) especially after squeezing, multi tendon injuries, tendon transplantations or injuries in zone VII. Pathological and iatrogenic tendon lesions are special forms of tendon injuries. PMID:17559022

  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. Acute Patellar Tendon Rupture after Total Knee Arthroplasty Revision

    PubMed Central

    Rhee, Seung Joon; Pham, The Hien

    2015-01-01

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

  3. Laminar Tendon Composites with Enhanced Mechanical Properties

    PubMed Central

    Alberti, Kyle A.; Sun, Jeong-Yun; Illeperuma, Widusha R.; Suo, Zhigang; Xu, Qiaobing

    2015-01-01

    Purpose A strong isotropic material that is both biocompatible and biodegradable is desired for many biomedical applications, including rotator cuff repair, tendon and ligament repair, vascular grafting, among others. Recently, we developed a technique, called “bioskiving” to create novel 2D and 3D constructs from decellularized tendon, using a combination of mechanical sectioning, and layered stacking and rolling. The unidirectionally aligned collagen nanofibers (derived from sections of decellularized tendon) offer good mechanical properties to the constructs compared with those fabricated from reconstituted collagen. Methods In this paper, we studied the effect that several variables have on the mechanical properties of structures fabricated from tendon slices, including crosslinking density and the orientation in which the fibers are stacked. Results We observed that following stacking and crosslinking, the strength of the constructs is significantly improved, with crosslinked sections having an ultimate tens ile strength over 20 times greater than non-crosslinked samples, and a modulus nearly 50 times higher. The mechanism of the mechanical failure mode of the tendon constructs with or without crosslinking was also investigated. Conclusions The strength and fiber organization, combined with the ability to introduce transversely isotropic mechanical properties makes the laminar tendon composites a biocompatiable material that may find future use in a number of biomedical and tissue engineering applications. PMID:25691802

  4. The cell biology of suturing tendons

    PubMed Central

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

    2010-01-01

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

  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. Ultrasound-Based Tendon Micromorphology Predicts Mechanical Characteristics of Degenerated Tendons.

    PubMed

    Kulig, Kornelia; Chang, Yu-Jen; Winiarski, Slawomir; Bashford, Gregory R

    2016-03-01

    The purpose of this study was to explore the relationship between tendon micro-morphology quantified from a sonogram and tendon mechanical characteristics measured in vivo. Nineteen adults (nine with unilateral Achilles tendinosis) participated. A commercial ultrasound scanner was used to capture longitudinal B-mode ultrasound images from the mid-portion of bilateral Achilles tendons and a custom image analysis program was used to analyze the spatial frequency content of manually defined regions of interest; in particular, the average peak spatial frequency of the regions of interest was acquired. In addition, a dynamometer and a motion analysis system indirectly measured the tendon mechanical (stiffness) and material (elastic modulus) properties. The peak spatial frequency correlated with tendon stiffness (r = 0.74, p = 0.02) and elastic modulus (r = 0.65, p = 0.05) in degenerated tendons, but not healthy tendons. This is the first study relating the mechanical characteristics of degenerated human Achilles tendon using a non-invasive micro-morphology analysis approach. PMID:26718836

  7. Endoscopic Flexor Hallucis Longus Tendon Transfer for Chronic Achilles Tendon Rupture.

    PubMed

    Lui, Tun Hing; Chan, Wai Chung; Maffulli, Nicola

    2016-03-01

    Chronic Achilles tendon rupture posed significant disability to the patients. Flexor hallucis longus (FHL) transfer can be used to restore the plantarflexion power of the ankle. Traditionally, a long medial incision with extensive soft tissue dissection is needed for FHL transfer. With the advance in flexor hallucis tendoscopy, endoscopic FHL tendon transfer can be performed without extensive soft tissue dissection. PMID:26752778

  8. Patellar tendon and tibial tubercle reconstruction using quadriceps tendon with patellar bone plug autograft.

    PubMed

    Edwards, T B; Lewis, J E; Guanche, C A

    1997-05-01

    This report describes a technique for the reconstruction of a patellar tendon-tibial tubercle deficiency. This technique uses an easy-to-harvest, low-morbidity graft (autogenous quadriceps tendon), while allowing aggressive rehabilitation as a result of the strength of the graft. PMID:9258831

  9. Shear Load Transfer in High and Low Stress Tendons

    PubMed Central

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

    2016-01-01

    Background Tendon is an integral part of joint movement and stability, as it functions to transmit load from muscle to bone. It has an anisotropic, fibrous hierarchical structure that is generally loaded in the direction of its fibers/fascicles. Internal load distributions are altered when joint motion rotates an insertion site or when local damage disrupts fibers/fascicles, potentially causing inter-fiber (or inter-fascicular) shear. Tendons with different microstructure (helical versus linear) may redistribute loads differently. Method of Approach This study explored how shear redistributes axial loads in rat tail tendon (low stress tendons with linear microstructure) and porcine flexor tendon (high stress with helical microstructure) by creating lacerations on opposite sides of the tendon, ranging from about 20-60% of the tendon width, to create various magnitudes of shear. Differences in fascicular orientation were quantified using polarized light microscopy. Results and Conclusions Unexpectedly, both tendon types maintained about 20% of pre-laceration stress values after overlapping cuts of 60% of tendon width (no intact fibers end to end) suggesting that shear stress transfer can contribute more to overall tendon strength and stiffness than previously reported. All structural parameters for both tendon types decreased linearly with increasing laceration depth. The tail tendon had a more rapid decline in post-laceration elastic stress and modulus parameters as well as a more linear and less tightly packed fascicular structure, suggesting that positional tendons may be less well suited to redistribute loads via a shear mechanism. PMID:25700261

  10. 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.

  11. Modelling approaches for evaluating multiscale tendon mechanics.

    PubMed

    Fang, Fei; Lake, Spencer P

    2016-02-01

    Tendon exhibits anisotropic, inhomogeneous and viscoelastic mechanical properties that are determined by its complicated hierarchical structure and varying amounts/organization of different tissue constituents. Although extensive research has been conducted to use modelling approaches to interpret tendon structure-function relationships in combination with experimental data, many issues remain unclear (i.e. the role of minor components such as decorin, aggrecan and elastin), and the integration of mechanical analysis across different length scales has not been well applied to explore stress or strain transfer from macro- to microscale. This review outlines mathematical and computational models that have been used to understand tendon mechanics at different scales of the hierarchical organization. Model representations at the molecular, fibril and tissue levels are discussed, including formulations that follow phenomenological and microstructural approaches (which include evaluations of crimp, helical structure and the interaction between collagen fibrils and proteoglycans). Multiscale modelling approaches incorporating tendon features are suggested to be an advantageous methodology to understand further the physiological mechanical response of tendon and corresponding adaptation of properties owing to unique in vivo loading environments. PMID:26855747

  12. Structure-function relationships in tendons: a review.

    PubMed

    Benjamin, M; Kaiser, E; Milz, S

    2008-03-01

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

  13. Structure-function relationships in tendons: a review

    PubMed Central

    Benjamin, M; Kaiser, E; Milz, S

    2008-01-01

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

  14. 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

  15. Tendon neuroplastic training: changing the way we think about tendon rehabilitation: a narrative review.

    PubMed

    Rio, Ebonie; Kidgell, Dawson; Moseley, G Lorimer; Gaida, Jamie; Docking, Sean; Purdam, Craig; Cook, Jill

    2016-02-01

    Tendinopathy can be resistant to treatment and often recurs, implying that current treatment approaches are suboptimal. Rehabilitation programmes that have been successful in terms of pain reduction and return to sport outcomes usually include strength training. Muscle activation can induce analgesia, improving self-efficacy associated with reducing one's own pain. Furthermore, strength training is beneficial for tendon matrix structure, muscle properties and limb biomechanics. However, current tendon rehabilitation may not adequately address the corticospinal control of the muscle, which may result in altered control of muscle recruitment and the consequent tendon load, and this may contribute to recalcitrance or symptom recurrence. Outcomes of interest include the effect of strength training on tendon pain, corticospinal excitability and short interval cortical inhibition. The aims of this concept paper are to: (1) review what is known about changes to the primary motor cortex and motor control in tendinopathy, (2) identify the parameters shown to induce neuroplasticity in strength training and (3) align these principles with tendon rehabilitation loading protocols to introduce a combination approach termed as tendon neuroplastic training. Strength training is a powerful modulator of the central nervous system. In particular, corticospinal inputs are essential for motor unit recruitment and activation; however, specific strength training parameters are important for neuroplasticity. Strength training that is externally paced and akin to a skilled movement task has been shown to not only reduce tendon pain, but modulate excitatory and inhibitory control of the muscle and therefore, potentially tendon load. An improved understanding of the methods that maximise the opportunity for neuroplasticity may be an important progression in how we prescribe exercise-based rehabilitation in tendinopathy for pain modulation and potentially restoration of the corticospinal control of the muscle-tendon complex. PMID:26407586

  16. Tendon neuroplastic training: changing the way we think about tendon rehabilitation: a narrative review

    PubMed Central

    Rio, Ebonie; Kidgell, Dawson; Moseley, G Lorimer; Docking, Sean; Purdam, Craig; Cook, Jill

    2016-01-01

    Tendinopathy can be resistant to treatment and often recurs, implying that current treatment approaches are suboptimal. Rehabilitation programmes that have been successful in terms of pain reduction and return to sport outcomes usually include strength training. Muscle activation can induce analgesia, improving self-efficacy associated with reducing one's own pain. Furthermore, strength training is beneficial for tendon matrix structure, muscle properties and limb biomechanics. However, current tendon rehabilitation may not adequately address the corticospinal control of the muscle, which may result in altered control of muscle recruitment and the consequent tendon load, and this may contribute to recalcitrance or symptom recurrence. Outcomes of interest include the effect of strength training on tendon pain, corticospinal excitability and short interval cortical inhibition. The aims of this concept paper are to: (1) review what is known about changes to the primary motor cortex and motor control in tendinopathy, (2) identify the parameters shown to induce neuroplasticity in strength training and (3) align these principles with tendon rehabilitation loading protocols to introduce a combination approach termed as tendon neuroplastic training. Strength training is a powerful modulator of the central nervous system. In particular, corticospinal inputs are essential for motor unit recruitment and activation; however, specific strength training parameters are important for neuroplasticity. Strength training that is externally paced and akin to a skilled movement task has been shown to not only reduce tendon pain, but modulate excitatory and inhibitory control of the muscle and therefore, potentially tendon load. An improved understanding of the methods that maximise the opportunity for neuroplasticity may be an important progression in how we prescribe exercise-based rehabilitation in tendinopathy for pain modulation and potentially restoration of the corticospinal control of the muscle-tendon complex. PMID:26407586

  17. Effect of pulley excision on flexor tendon biomechanics.

    PubMed

    Peterson, W W; Manske, P R; Bollinger, B A; Lesker, P A; McCarthy, J A

    1986-01-01

    Flexor tendon function following excision of various portions of the fibro-osseous pulley system was measured biomechanically using a tensile testing machine. The biomechanical parameters measured were tendon excursion (the excursion of the tendon required to fully flex the digit) and work of flexion (the area under the force-excursion curve, representing all the forces that resist tendon flexion). In this experiment, work of flexion included the forces necessary to accomplish full digital flexion against a 15-g counter-weight, as well as the frictional forces that resist tendon gliding. The results indicate that the work of flexion was affected to a greater degree by pulley loss than was tendon excursion, suggesting that it is a more sensitive measurement of tendon function. A2 was found to be the single most important pulley for flexor tendon function, followed by A4. However, both A2 and A4 had to be present if near-normal hand function was to be achieved; sacrificing the A1 pulley was not associated with a significant loss of flexion. The "pulley effect" of the skin and soft tissue as a supplement to the fibro-osseous pulleys in reducing tendon bow-stringing was also noted. Although the parameters of tendon excursion and work of flexion were used in this study to determine the effect of pulley loss on tendon function, they can also be used to evaluate other flexor tendon studies, such as pulley reconstruction. PMID:3950813

  18. An Overview of the Management of Flexor Tendon Injuries

    PubMed Central

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

    2012-01-01

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

  19. Achilles tendon rupture in atypical patient populations.

    PubMed

    Kingsley, Peter

    2016-03-01

    Rupture of the Achilles tendon is a significant injury, and the likelihood of a good recovery is directly associated with early diagnosis and appropriate referral. Such injuries are commonly assessed and identified by practitioners working in 'minors' areas of emergency departments or urgent care settings. The literature frequently describes rupture of the Achilles tendon as 'typically sport-related' affecting 'middle-aged weekend warriors', but this aetiology accounts for only about 70% of such injuries. Factors such as the natural ageing process, obesity and use of some commonly prescribed medications, can increase the risk of developing a tendinopathy and subsequent rupture, often from a seemingly insignificant incident. However, research suggests that injuries in this patient population are more likely be missed on first examination. This article describes risk factors that should alert clinicians to the possibility of Achilles tendon rupture in 'atypical' patient populations. PMID:26948227

  20. Distal biceps tendon reconstruction in chronic ruptures.

    PubMed

    Darlis, Nickolaos A; Sotereanos, Dean G

    2006-01-01

    The purpose of this retrospective study was to evaluate the results of anatomic reattachment with reconstruction of the distal biceps tendon using an Achilles tendon allograft in 7 male patients with chronic distal biceps ruptures. Through a 1-incision anterior approach, the tendon allograft was attached to the bicipital tuberosity by using suture anchors and then secured to the biceps remnant. Follow-up averaged 29 months. Mean elbow flexion was 145 degrees, an extension deficit of 20 degrees was observed in 1 patient, and mean pronosupination was 170 degrees. All patients had 5/5 strength in flexion and supination on manual testing, and all returned to their employment. Mean supination strength was 87% of the contralateral healthy extremity. Six achieved an excellent and 1 a good rating in the Mayo elbow performance score. No complications were encountered. This technique is an excellent alternative to nonanatomic reattachment to the brachialis muscle for patients with high functional demands in pronosupination. PMID:16979059

  1. Flucloxacillin reduces stiffness following flexor tendon repair.

    PubMed

    Schumacher, Hagen H A; James, Nick K

    2008-12-01

    To determine the benefit of antibiotic prophylaxis on postoperative mobility in flexor tendon repairs, case notes of 72 flexor tendon injuries in twenty four patients were analyzed retrospectively (2001-2003). Only patients with non-contaminated injuries from sharp instruments in flexor zone 2 were included in the study; 57% were male, average age was 31 years, and 24% were smokers. The majority of injuries were caused by metal blades (45%). Most tendons were repaired with modified Kessler technique (69%). Twenty-five percent received intravenous flucloxacillin or co-amoxiclav perioperatively. Reduced total active motion (TAM, found in 25% of patients more than 7 weeks after surgical repair) significantly complicated patients without perioperative intravenous flucloxacillin cover. The use of intravenous perioperative flucloxacillin is a plausible adjunct in surgery to prevent postoperatively reduced mobility. PMID:18780024

  2. Tissue engineering and rotator cuff tendon healing.

    PubMed

    Dines, Joshua S; Grande, Daniel A; Dines, David M

    2007-01-01

    Rotator cuff tears are common soft-tissue injuries that often require surgical treatment. Initial efforts to better tendon healing centered on improving the strength of the repair. More recent studies have focused on biologic enhancement of the healing process. Tissue engineering is a multidisciplinary field that involves the application of scientific principles toward creating living tissue to replace, repair, or augment diseased tissue. Gene therapy involves the transfer of a certain gene into a cell so that the cell translates the gene into a specific protein. The advantage of using a gene-therapy, tissue-engineered approach to effect healing rests in the ability of the physician to select growth factors with documented roles in the tendon-healing cascade. Ideally, an improvement to the current repair technique would yield improved tendon healing leading to improved clinical results. PMID:17524676

  3. 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

  4. Structural properties of the subscapularis tendon.

    PubMed

    Halder, A; Zobitz, M E; Schultz, E; An, K N

    2000-09-01

    The subscapularis muscle is an important mover and stabilizer of the glenohumeral joint. The purpose of this study was to measure regional variations in the structural properties of the subscapularis tendon in two joint positions. Subscapularis tendons from cadaveric shoulders were divided into four sections superiorly to inferiorly and tested to failure at 0 or 60 degrees of glenohumeral abduction. Arm position had a significant influence on stiffness in the inferior and superior portions (p < 0.05). The inferior region showed a higher stiffness in the hanging-arm position (0 degrees) than at 60 degrees of abduction (27.4+/-17.7 compared with 9.5+/-5.9 N/mm). Meanwhile, stiffness of the superior portion was higher at 60 degrees of abduction than in the hanging-arm position (208.7+/-60.9 compared with 147.2+/-32.3 N/mm). In the hanging-arm position (0 degrees) and at 60 degrees of abduction, the superior and midsuperior portions failed at significantly higher loads (superior: 623.2+/-198.6 and 478.2+/-206.6 N at 0 and 60 degrees of abduction, respectively; midsuperior: 706.2+/-164.6 and 598.4+/-268.4 N, respectively) than did the inferior portion (75.1+/-54.2 and 30.3+/-13.0 N, respectively). Likewise, stiffness of the superior and midsuperior portions was significantly higher than that of the inferior region in both positions. Higher stiffness and ultimate load in the superior tendon region may explain the infrequent extension of rotator cuff tears into the subscapularis tendon. Conversely, the significantly lower ultimate load and stiffness in the inferior tendon region could facilitate anterior dislocation of the humeral head when this portion stabilizes the joint in a dislocated position. Therefore, repair of torn inferior portions of the subscapularis tendon should be considered in surgery for glenohumeral instability. PMID:11117307

  5. Tendon ruptures: mallet, flexor digitorum profundus.

    PubMed

    Yeh, Peter C; Shin, Steven S

    2012-08-01

    Mallet injuries are the most common closed tendon injury in the athlete. Flexor digitorum profundus ruptures are rare in baseball, but are common injuries in contact sports. The diagnosis for each condition is based on clinical examination, although radiographs should be evaluated for a possible bony component. Treatment for mallet injury depends on the athlete's goals of competition and understanding of the consequences of any treatment chosen. Gripping, throwing, and catching would be restricted or impossible with the injured finger immobilized. Treatment of FDP ruptures is almost always surgical and requires reattachment of the torn tendon to the distal phalanx. PMID:22883898

  6. Spontaneous Achilles tendon rupture in alkaptonuria.

    PubMed

    Alajoulin, Omar A; Alsbou, Mohammed S; Ja'afreh, Somayya O; Kalbouneh, Heba M

    2015-12-01

    Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations. PMID:26620992

  7. Spontaneous Achilles tendon rupture in alkaptonuria

    PubMed Central

    Alajoulin, Omar A.; Alsbou, Mohammed S.; Ja’afreh, Somayya O.; Kalbouneh, Heba M.

    2015-01-01

    Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations. PMID:26620992

  8. The role of animal models in tendon research.

    PubMed

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

    2014-06-01

    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

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

    PubMed

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

    2004-01-01

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

  10. [Primary treatment of complicated flexor tendon injuries of the hand].

    PubMed

    Lotter, O; Vogel, D; Stahl, S; Pfau, M; Schaller, H-E

    2011-06-01

    Complicated flexor tendon injuries are classified into lacerations, avulsions, ruptures, and defects. They are often a challenge for hand surgeons and frequently they present unsatisfactory functional results postoperatively. Lacerations and avulsions are usually treated by pull-out sutures and suture anchors. In ruptures, the causality should be sought. Tendon-linking, transposition and tenodesis/arthrodesis are the domain of rheumatoid arthritis. The primary transplantation of tendons is rarely indicated, ideally in non-contaminated flexor tendon defects in zones III-V with an uninjured surrounding soft tissue situation. Postoperative rehabilitation programs are very the same as in normal flexor tendon injuries. PMID:21660511

  11. 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

  12. Combined Tendon and Bone Allograft Transplantation for Chronic Achilles Tendon Ruptures.

    PubMed

    Catanzariti, Alan R; Hentges, Matthew

    2016-01-01

    Combined flexor hallucis longus tendon transfer and bone-tendon allograft transplantation is a reasonable option for advanced distal-segment Achilles tendinopathy. This procedure provides anatomic restoration and improved function of the posterior muscle group without sacrificing the regional anatomy. Allograft transplantation is safe and does not require immunosuppressive therapy. The soft tissue envelope should be healthy because wound complications can be an issue. This procedure is especially helpful in patients with significant disability. PMID:26590730

  13. 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

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

    PubMed

    Birch, Helen L

    2007-08-01

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

  15. Anatomical heterogeneity of tendon: Fascicular and interfascicular tendon compartments have distinct proteomic composition.

    PubMed

    Thorpe, Chavaunne T; Peffers, Mandy J; Simpson, Deborah; Halliwell, Elizabeth; Screen, Hazel R C; Clegg, Peter D

    2016-01-01

    Tendon is a simple aligned fibre composite, consisting of collagen-rich fascicles surrounded by a softer interfascicular matrix (IFM). The composition and interactions between these material phases are fundamental in ensuring tissue mechanics meet functional requirements. However the IFM is poorly defined, therefore tendon structure-function relationships are incompletely understood. We hypothesised that the IFM has a more complex proteome, with faster turnover than the fascicular matrix (FM). Using laser-capture microdissection and mass spectrometry, we demonstrate that the IFM contains more proteins, and that many proteins show differential abundance between matrix phases. The IFM contained more protein fragments (neopeptides), indicating greater matrix degradation in this compartment, which may act to maintain healthy tendon structure. Protein abundance did not alter with ageing, but neopeptide numbers decreased in the aged IFM, indicating decreased turnover which may contribute to age-related tendon injury. These data provide important insights into how differences in tendon composition and turnover contribute to tendon structure-function relationships and the effects of ageing. PMID:26842662

  16. Anatomical heterogeneity of tendon: Fascicular and interfascicular tendon compartments have distinct proteomic composition

    PubMed Central

    Thorpe, Chavaunne T.; Peffers, Mandy J.; Simpson, Deborah; Halliwell, Elizabeth; Screen, Hazel R. C.; Clegg, Peter D.

    2016-01-01

    Tendon is a simple aligned fibre composite, consisting of collagen-rich fascicles surrounded by a softer interfascicular matrix (IFM). The composition and interactions between these material phases are fundamental in ensuring tissue mechanics meet functional requirements. However the IFM is poorly defined, therefore tendon structure-function relationships are incompletely understood. We hypothesised that the IFM has a more complex proteome, with faster turnover than the fascicular matrix (FM). Using laser-capture microdissection and mass spectrometry, we demonstrate that the IFM contains more proteins, and that many proteins show differential abundance between matrix phases. The IFM contained more protein fragments (neopeptides), indicating greater matrix degradation in this compartment, which may act to maintain healthy tendon structure. Protein abundance did not alter with ageing, but neopeptide numbers decreased in the aged IFM, indicating decreased turnover which may contribute to age-related tendon injury. These data provide important insights into how differences in tendon composition and turnover contribute to tendon structure-function relationships and the effects of ageing. PMID:26842662

  17. Spondylodiscitis and Achilles tendonitis due to gout.

    PubMed

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

    2014-11-01

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

  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. Tendon fatigue in response to mechanical loading.

    PubMed

    Andarawis-Puri, N; Flatow, E L

    2011-06-01

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

  20. On muscle, tendon and high heels.

    PubMed

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

    2010-08-01

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

  1. Engaging Stem Cells for Customized Tendon Regeneration

    PubMed Central

    Thaker, Hatim; Sharma, Arun K.

    2012-01-01

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

  2. Minimally Invasive Approach to Achilles Tendon Pathology.

    PubMed

    Hegewald, Kenneth W; Doyle, Matthew D; Todd, Nicholas W; Rush, Shannon M

    2016-01-01

    Many surgical procedures have been described for Achilles tendon pathology; however, no overwhelming consensus has been reached for surgical treatment. Open repair using a central or paramedian incision allows excellent visualization for end-to-end anastomosis in the case of a complete rupture and detachment and reattachment for insertional pathologies. Postoperative wound dehiscence and infection in the Achilles tendon have considerable deleterious effects on overall functional recovery and outcome and sometimes require plastic surgery techniques to achieve coverage. With the aim of avoiding such complications, foot and ankle surgeons have studied less invasive techniques for repair. We describe a percutaneous approach to Achilles tendinopathy using a modification of the Bunnell suture weave technique combined with the use of interference screws. No direct end-to-end repair of the tendon is performed, rather, the proximal stump is brought in direct proximity of the distal stump, preventing overlengthening and proximal stump retraction. This technique also reduces the suture creep often seen with end-to-end tendon repair by providing a direct, rigid suture to bone interface. We have used the new technique to minimize dissection and exposure while restoring function and accelerating recovery postoperatively. PMID:26385574

  3. Avoiding Anomalous Tendon Harvest at the Pes Anserinus Insertion.

    PubMed

    Cidambi, Krishna R; Pennock, Andrew T; Dwek, Jerry R; Edmonds, Eric W

    2016-01-01

    The purpose of this study was to identify the frequency and characteristics of anomalous pes anserinus tendon morphology in an adolescent population undergoing knee anterior cruciate ligament (ACL) reconstruction surgery. The records of all children who underwent ACL reconstruction surgery at our tertiary care children's hospital from June 2008 through February 2012 were reviewed. Operative reports were reviewed for any indication that an anomaly existed in the pes anserinus or that there was difficulty harvesting the required tendons. Magnetic resonance imaging (MRI) studies were then reviewed for these patients looking for evidence of any anomaly within the pes anserinus structures. Retrospective review was performed on 123 children (mean age, 16.1 years). Three girls (mean age, 16.2 years) were identified as having a low-lying muscle belly and accessory tendon when attempting to harvest the gracilis tendon. Proximal exploration of this short tendon conjoining the gracilis insertion revealed a muscle belly approximately 5 cm from its insertion in the pes anserinus. This anomaly was present in 2.4% of the cases. Based on previous literature, the anomalous muscle present in our cohort could be sartorius or semimembranosus. MRI analysis suggests that the accessory muscle and tendon could be an aberrant strip of the semimembranosus tendon, an anomalous tendon and muscle belly of the gracilis, or a thickening and separation of the sartorius tendon. Anomalous pes anserinus tendons were found to exist in 2.4% of our adolescent study population. At the time of surgery, if a tendon is harvested with a very low-lying muscle belly (with less than 6 cm of tendon), then the presence of an aberrant tendon should be considered. Preoperative MRI may provide evidence of an anomalous tendon if that information is sought. PMID:25556897

  4. Decellularized and Engineered Tendons as Biological Substitutes: A Critical Review

    PubMed Central

    Lovati, Arianna B.; Bottagisio, Marta; Moretti, Matteo

    2016-01-01

    Tendon ruptures are a great burden in clinics. Finding a proper graft material as a substitute for tendon repair is one of the main challenges in orthopaedics, for which the requirement of a biological scaffold would be different for each clinical application. Among biological scaffolds, the use of decellularized tendon-derived matrix increasingly represents an interesting approach to treat tendon ruptures. We analyzed in vitro and in vivo studies focused on the development of efficient protocols for the decellularization and for the cell reseeding of the tendon matrix to obtain medical devices for tendon substitution. Our review considered also the proper tendon source and preclinical animal models with the aim of entering into clinical trials. The results highlight a wide panorama in terms of allogenic or xenogeneic tendon sources, specimen dimensions, physical or chemical decellularization techniques, and the cell type variety for reseeding from terminally differentiated to undifferentiated mesenchymal stem cells and their static or dynamic culture employed to generate implantable constructs tested in different animal models. We try to identify the most efficient approach to achieve an optimal biological scaffold for biomechanics and intrinsic properties, resembling the native tendon and being applicable in clinics in the near future, with particular attention to the Achilles tendon substitution. PMID:26880985

  5. The Cellular Biology of Flexor Tendon Adhesion Formation

    PubMed Central

    Wong, Jason K.F.; Lui, Yin H.; Kapacee, Zoher; Kadler, Karl E.; Ferguson, Mark W. J.; McGrouther, Duncan A.

    2009-01-01

    Intrasynovial flexor tendon injuries of the hand can frequently be complicated by tendon adhesions to the surrounding sheath, limiting finger function. We have developed a new tendon injury model in the mouse to investigate the three-dimensional cellular biology of intrasynovial flexor tendon healing and adhesion formation. We investigated the cell biology using markers for inflammation, proliferation, collagen synthesis, apoptosis, and vascularization/myofibroblasts. Quantitative immunohistochemical image analysis and three-dimensional reconstruction with cell mapping was performed on labeled serial sections. Flexor tendon adhesions were also assessed 21 days after wounding using transmission electron microscopy to examine the cell phenotypes in the wound. When the tendon has been immobilized, the mouse can form tendon adhesions in the flexor tendon sheath. The cell biology of tendon healing follows the classic wound healing response of inflammation, proliferation, synthesis, and apoptosis, but the greater activity occurs in the surrounding tissue. Cells that have multiple “fibripositors” and cells with cytoplasmic protrusions that contain multiple large and small diameter fibrils can be found in the wound during collagen synthesis. In conclusion, adhesion formation occurs due to scarring between two damaged surfaces. The mouse model for flexor tendon injury represents a new platform to study adhesion formation that is genetically tractable. PMID:19834058

  6. Cryotherapy suppresses tendon inflammation in an animal model

    PubMed Central

    Zhang, Jianying; Pan, Tiffany; Wang, James H.-C.

    2015-01-01

    Summary Cryotherapy (or cold treatment) has been a popular treatment to relieve pain caused by injuries to tissues such as tendons. However, the exact mechanisms behind the beneficial effects of cryotherapy in tendons remain largely unclear. As prostaglandin E2 (PGE2) is known to be a major mediator of acute inflammation in tissues, which is related to tissue pain, we hypothesized that the beneficial effects of cryotherapy in tendons are mediated by downregulation of PGE2 levels. To test this hypothesis, we applied cold treatment to mouse patellar and Achilles tendons using two animal models: exhaustive mouse treadmill running and acute mouse tendon injury by needle penetration. We then measured the levels of PGE2 and protein expression levels of COX-2, an enzyme responsible for PGE2 production in tissues, under both experimental conditions. We found that treadmill running increased PGE2 levels in both patellar and Achilles tendons compared to control mice without running. Cold treatment for 30 min after treadmill running was sufficient to reduce PGE2 levels to near baseline control levels in both tendons. An extension of cold treatment to 60 min resulted only in a marginal decrease in patellar tendons, but a marked decrease in Achilles tendons. Moreover, COX-2 protein levels in both tendons were also lowered by cold treatment, suggesting that the reduction of PGE2 levels in tendons by cold treatment is at least in part due to the decreased COX-2 expression. Similarly, in the acutely injured tendons, 30 min of cold treatment after needle penetration reduced PGE2 levels when compared to the controls at room temperature (22°C). This decrease was sustained up to at least 3 h after the administration of cryotherapy. Given that PGE2 is a known pain sensitiser, the results of this study suggest that the ability of cold treatment to reduce pain may be attributable to its ability to decrease PGE2 production in tendons. PMID:26594634

  7. Grasp Assist Device with Shared Tendon Actuator Assembly

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Bergelin, Bryan J. (Inventor); Bridgwater, Lyndon (Inventor)

    2015-01-01

    A grasp assist device includes a glove with first and second tendon-driven fingers, a tendon, and a sleeve with a shared tendon actuator assembly. Tendon ends are connected to the respective first and second fingers. The actuator assembly includes a drive assembly having a drive axis and a tendon hook. The tendon hook, which defines an arcuate surface slot, is linearly translatable along the drive axis via the drive assembly, e.g., a servo motor thereof. The flexible tendon is routed through the surface slot such that the surface slot divides the flexible tendon into two portions each terminating in a respective one of the first and second ends. The drive assembly may include a ball screw and nut. An end cap of the actuator assembly may define two channels through which the respective tendon portions pass. The servo motor may be positioned off-axis with respect to the drive axis. XXXX addresses some of the limitations present in the prior art approaches noted above. The grasp assist device includes a glove and a sleeve, which may be worn on a respective hand and forearm of an operator. Linear actuators supported within the sleeve provide tension to flexible tendons, which in turn are connected to the fingers and/or thumb of a glove. The selective tensioning of the tendons improves the operator's grasp strength, and may also facilitate rehabilitation from an injury. It is recognized herein that existing tendon-driven grasp assist devices have certain performance limitations. For example, some designs may require actuator over sizing in order to provide a sufficient amount of actuator travel for applying necessary amounts of tension to a given tendon, e.g., to fully close a finger of a hand wearing the glove into a desired grasp pose. Substantial increases in both size and

  8. 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

  9. Impingement of the deep surface of the subscapularis tendon and the reflection pulley on the anterosuperior glenoid rim: a preliminary report.

    PubMed

    Gerber, C; Sebesta, A

    2000-01-01

    Sixteen patients underwent detailed arthroscopic evaluation; all had moderate to severe, primarily unexplained shoulder pain provoked by anterior elevation and internal rotation, and all were nonresponsive to subacromial injection of local anesthetic. None of the patients had any symptoms or signs of instability. Partial subscapularis lesions were documented in 10 of 13 patients who had undergone preoperative arthro-magnetic resonance imaging. At arthroscopy, an isolated lesion of the common humeral insertion of the superior glenohumeral and coracohumeral ligaments (a so-called pulley lesion) was found in 3 cases, a lesion associating a pulley and an articular side partial subscapularis lesion in 10 cases, and an isolated articular side partial subscapularis tear in 3 cases. The most painful movement, which consisted of flexion and internal rotation, caused impingement of the involved ligamentous and/or capsular insertions in all patients. If the arm was elevated above 90 degrees, the zone of mechanical contact was between the long head of the biceps and the pulley region and superiormost aspect of the labrum; if elevation was decreased, impingement occurred between the tendinous insertion of the subscapularis and the anterior glenoid labrum and rim. This study suggests that in addition to the posterosuperior impingement of the supraspinatus tendon originally described by Walch, anterosuperior impingement of the deep surface of the subscapularis is a form of intraarticular impingement responsible for painful structural disease of the shoulder. PMID:11155300

  10. Increased unilateral tendon stiffness and its effect on gait 2-6 years after Achilles tendon rupture.

    PubMed

    Agres, A N; Duda, G N; Gehlen, T J; Arampatzis, A; Taylor, W R; Manegold, S

    2015-12-01

    Achilles tendon rupture (ATR) alters tissue composition, which may affect long-term tendon mechanics and ankle function during movement. However, a relationship between Achilles tendon (AT) properties and ankle joint function during gait remains unclear. The primary hypotheses were that (a) post-ATR tendon stiffness and length differ from the noninjured contralateral side and that (b) intra-patient asymmetries in AT properties correlate to ankle function asymmetries during gait, determined by ankle angles and moments. Ultrasonography and dynamometry were used to assess AT tendon stiffness, strain, elongation, and rest length in both limbs of 20 ATR patients 2-6 years after repair. Three-dimensional ankle angles and moments were determined using gait analysis. Injured tendons exhibited increased stiffness, rest length, and altered kinematics, with higher dorsiflexion and eversion, and lower plantarflexion and inversion. Intra-patient tendon stiffness and tendon length ratios were negatively correlated to intra-patient ratios of the maximum plantarflexion moment and maximum dorsiflexion angle, respectively. These results suggest that after surgical ATR repair, higher AT stiffness, but not a longer AT, may contribute to deficits in plantarflexion moment generation. These data further support the claim that post-ATR tendon regeneration results in the production of a tissue that is functionally different than noninjured tendon. PMID:25902929

  11. Fibrocartilage associated with human tendons and their pulleys.

    PubMed Central

    Benjamin, M; Qin, S; Ralphs, J R

    1995-01-01

    The presence of fibrocartilage in tendons that wrap around bony or fibrous pulleys is well known. It is an adaptation to resisting compression or shear, but the extent to which the structure of most human tendons is modified where they contact pulleys is less clear, for there has been no single comprehensive survey of a large number of sites. Less is known of the structure of the corresponding pulleys. In the present study, 38 regions of tendons that wrap around bony pulleys or pass beneath fibrous retinacula have been studied in routine histology sections taken from each of 2 or 3 elderly dissecting room cadavers. Most of the corresponding pulleys have also been examined. Fibrocartilage was present in 22 of the 38 tendon sites and it was most conspicuous where the tendons pressed predominantly against bone rather than retinacula and where they showed a large change in direction. Fibrocartilage was more characteristic of tendons at the ankle than the wrist, probably because the long axis of the foot is at right angles to that of the leg. There was considerable variation in the structure of tendon fibrocartilage. The most fibrocartilaginous tendons had oval or round cells embedded in a highly metachromatic matrix with interwoven or spiralling collagen fibres. At other sites, fibrocartilage cells were arranged in rows between parallel collagen fibres. The differences probably relate to differences in development. A single tendon could be modified at successive points along its length and fibrocartilage could be present in the endotenon and epitenon as well as in the tendon itself. Pathological changes seen in 'wrap around' tendons were fragmentation and partial delamination of the compressed surface, chondrocyte clustering, fatty infiltration and bone formation. Three types of pulleys were described for tendons--bony prominences and grooves, fibrous retinacula and synovial joints. The extent of cartilaginous differentiation on the periosteum of bony pulleys frequently mirrored that in the corresponding tendon. The cartilage or fibrocartilage prevents the tendon from 'sawing' through the bone. Some of the best known retinacula were largely fibrous, though the inferior peroneal retinaculum and the trochlea for the superior oblique were cartilaginous. The results underline the considerable regional heterogeneity in different tendons and their pulleys. They show that one tendon is not like another and that tendons may need to be carefully selected for particular surgical transfers or joint reconstructions. Images Fig. 1 Figs 2-3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 PMID:8586561

  12. A Tendon Cell Specific RNAi Screen Reveals Novel Candidates Essential for Muscle Tendon Interaction

    PubMed Central

    Tiwari, Prabhat; Malhotra, Vivek; VijayRaghavan, K.

    2015-01-01

    Tendons are fibrous connective tissue which connect muscles to the skeletal elements thus acting as passive transmitters of force during locomotion and provide appropriate body posture. Tendon-derived cues, albeit poorly understood, are necessary for proper muscle guidance and attachment during development. In the present study, we used dorsal longitudinal muscles of Drosophila and their tendon attachment sites to unravel the molecular nature of interactions between muscles and tendons. We performed a genetic screen using RNAi-mediated knockdown in tendon cells to find out molecular players involved in the formation and maintenance of myotendinous junction and found 21 candidates out of 2507 RNAi lines screened. Of these, 19 were novel molecules in context of myotendinous system. Integrin-βPS and Talin, picked as candidates in this screen, are known to play important role in the cell-cell interaction and myotendinous junction formation validating our screen. We have found candidates with enzymatic function, transcription activity, cell adhesion, protein folding and intracellular transport function. Tango1, an ER exit protein involved in collagen secretion was identified as a candidate molecule involved in the formation of myotendinous junction. Tango1 knockdown was found to affect development of muscle attachment sites and formation of myotendinous junction. Tango1 was also found to be involved in secretion of Viking (Collagen type IV) and BM-40 from hemocytes and fat cells. PMID:26488612

  13. A ganglion of the patellar tendon in patellar tendon-lateral femoral condyle friction syndrome.

    PubMed

    Touraine, Sébastien; Lagadec, Matthieu; Petrover, David; Genah, Idan; Parlier-Cuau, Caroline; Bousson, Valérie; Laredo, Jean-Denis

    2013-09-01

    Intratendinous ganglia are rare. We report the case of a sedentary woman with chronic mechanical anterolateral pain of the knee and an extensive ganglion of the patellar tendon as indicated on magnetic resonance (MR) and ultrasound (US) examinations. There was evidence of a high-riding patella, patellar malalignment and patellar tendon-lateral femoral condyle friction syndrome with significantly close contact between the patellar tendon and the lateral facet of the femoral trochlea. The ultrasound-guided aspiration of the ganglion enabled a localized injection of an anti-inflammatory drug (cortivazol) and the cytopathological examination of the fluid, which confirmed the diagnosis. Clinical improvement was maintained with knee rehabilitation and was satisfactory at follow-up after 1 year. To our knowledge, we report the first case of a ganglion of the patellar tendon subsequent to patellar tendon-lateral femoral condyle friction syndrome. We found that this case was illustrative of mucoid degeneration in connective tissue due to chronic repetitive microtraumas. Additionally, this case provided the opportunity to discuss the management of this condition in a sedentary individual with a high-riding patella and patellar malalignment. PMID:23657611

  14. Patellar tendon ossification after anterior cruciate ligament reconstruction using bone – patellar tendon – bone autograft

    PubMed Central

    2013-01-01

    Background Among the various complications described in literature, the patellar tendon ossification is an uncommon occurrence in anterior cruciate ligament (ACL) reconstruction using bone – patellar tendon – bone graft (BPTB). The heterotopic ossification is linked to knee traumatism, intramedullary nailing of the tibia and after partial patellectomy, but only two cases of this event linked to ACL surgery have been reported in literature. Case presentation We present a case of a 42-year-old Caucasian man affected by symptomatic extended heterotopic ossification of patellar tendon after 20 months from ACL reconstruction using BPTB. The clinical diagnosis was confirmed by Ultrasound, X-Ray and Computed Tomography studies, blood tests were performed to exclude metabolic diseases then the surgical removal of the lesion was performed. After three years from surgery, the patient did not report femoro-patellar pain, there was not range of motion limitation and the clinical-radiological examinations resulted negative. Conclusion The surgical removal of the ossifications followed by anti-inflammatory therapy, seems to be useful in order to relieve pain and to prevent relapses. Moreover, a thorough cleaning of the patellar tendon may reveal useful, in order to prevent bone fragments remain inside it and to reduce patellar tendon heterotopic ossification risk. PMID:23663528

  15. [Animal experiment study of healing of the sutured flexor tendon].

    PubMed

    Martini, A K; Blimke, B

    1992-01-01

    The purpose of the present study was to determine whether tendons contain intrinsic cells capable of repair. To accomplish this, rabbit flexor tendons were exposed microsurgically, cut through, resutured and transferred as free transplant into the knee-joint. Immobilisation of the knee-joint will cause progressive formation of adhesions permitting neovascularisation of the transplant. Both is not observed when sutured flexor tendons were put in a knee articulation with full range of joint motion. Transmission electron micrography revealed up to 8 weeks after implantation vital cells and incidences of collagen neosynthesis independently whether adhesions existed or not. Histologically intrinsic repair was confirmed in mobile transplants and mainly initiated by cells of the visceral synovial sheet which form an anatomic-surgical unity with the tendon. In conclusion the importance of the synovial fluid for the tendon nutrition is underlined by the fact that an intrinsic healing of flexor tendon is possible without formation of adhesions. PMID:1582849

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

    PubMed Central

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

    2014-01-01

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

  17. 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

  18. An efficient robotic tendon for gait assistance.

    PubMed

    Hollander, Kevin W; Ilg, Robert; Sugar, Thomas G; Herring, Donald

    2006-10-01

    A robotic tendon is a spring based, linear actuator in which the stiffness of the spring is crucial for its successful use in a lightweight, energy efficient, powered ankle orthosis. Like its human analog, the robotic tendon uses its inherent elastic nature to reduce both peak power and energy requirements for its motor. In the ideal example, peak power required of the motor for ankle gait is reduced from 250 W to just 77 W. In addition, ideal energy requirements are reduced from nearly 36 J to just 21 J. Using this approach, an initial prototype has provided 100% of the power and energy necessary for ankle gait in a compact 0.95 kg package, seven times less than an equivalent motor/gearbox system. PMID:16995768

  19. 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

  20. Arthroscopically assisted Z-lengthening of extensor hallucis longus tendon.

    PubMed

    Lui, T H

    2007-11-01

    Extensor hallucis longus tendon contracture can lead to hyperextension deformity of the big toe. We describe an endoscopic approach of Z-lengthening of the tendon. Extensor hallucis longus tendoscopy is performed with a distal portal at the level of the metatarsal neck and a proximal portal at the level of the navicular. At the distal portal, the medial half of the extensor hallucis longus tendon is cut and a stay stitch of No. 2 ethibond is applied. It is then stripped proximally with a tendon stripper to the proximal portal. A stay stitch of No. 2 ethibond is applied to the lateral half of the tendon at the proximal portal and it is cut proximal to the stitch. With the ankle plantarflexed and the big toe kept in the similar position as the lesser toes, the tendon segments are kept in tension through the stay stitches via the proximal and distal portals. The stay stitches of distal tendon segment are sutured to the proximal segment at the same level of the cut end of the distal fragment with the aid of an eyed needle under arthroscopic visualization through the distal portal. The needle is passed through the tendon and then the skin. The suture is also passed through the skin and then retrieved to the proximal portal by a hemostat. It is then sutured to the proximal tendon segment at the proximal portal. Similarly, the proximal tendon end is sutured to the distal tendon segment at the corresponding level and the endoscopic Z-lengthening of the extensor hallucis longus tendon is then completed. PMID:17576583

  1. A 3-Dimensional Anatomic Study of the Distal Biceps Tendon

    PubMed Central

    Walton, Christine; Li, Zhi; Pennings, Amanda; Agur, Anne; Elmaraghy, Amr

    2015-01-01

    Background Complete rupture of the distal biceps tendon from its osseous attachment is most often treated with operative intervention. Knowledge of the overall tendon morphology as well as the orientation of the collagenous fibers throughout the musculotendinous junction are key to intraoperative decision making and surgical technique in both the acute and chronic setting. Unfortunately, there is little information available in the literature. Purpose To comprehensively describe the morphology of the distal biceps tendon. Study Design Descriptive laboratory study. Methods The distal biceps terminal musculature, musculotendinous junction, and tendon were digitized in 10 cadaveric specimens and data reconstructed using 3-dimensional modeling. Results The average length, width, and thickness of the external distal biceps tendon were found to be 63.0, 6.0, and 3.0 mm, respectively. A unique expansion of the tendon fibers within the distal muscle was characterized, creating a thick collagenous network along the central component between the long and short heads. Conclusion This study documents the morphologic parameters of the native distal biceps tendon. Reconstruction may be necessary, especially in chronic distal biceps tendon ruptures, if the remaining tendon morphology is significantly compromised compared with the native distal biceps tendon. Knowledge of normal anatomical distal biceps tendon parameters may also guide the selection of a substitute graft with similar morphological characteristics. Clinical Relevance A thorough description of distal biceps tendon morphology is important to guide intraoperative decision making between primary repair and reconstruction and to better select the most appropriate graft. The detailed description of the tendinous expansion into the muscle may provide insight into better graft-weaving and suture-grasping techniques to maximize proximal graft incorporation. PMID:26665092

  2. 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.

  3. 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

  4. Biological Augmentation of Flexor Tendon Repair: A Challenging Cellular Landscape.

    PubMed

    Loiselle, Alayna E; Kelly, Meghan; Hammert, Warren C

    2016-01-01

    Advances in surgical technique and rehabilitation have transformed zone II flexor tendon injuries from an inoperable no-man's land to a standard surgical procedure. Despite these advances, many patients develop substantial range of motion-limiting adhesions after primary flexor tendon repair. These suboptimal outcomes may benefit from biologic augmentation or intervention during the flexor tendon healing process. However, there is no consensus biological approach to promote satisfactory flexor tendon healing; we propose that insufficient understanding of the complex cellular milieu in the healing tendon has hindered the development of successful therapies. This article reviews recent advances in our understanding of the cellular components of flexor tendon healing and adhesion formation, including resident tendon cells, synovial sheath, macrophages, and bone marrow-derived cells. In addition, it examines molecular approaches that have been used in translational animal models to improve flexor tendon healing and gliding function, with a specific focus on progress made using murine models of healing. This information highlights the importance of understanding and potentially exploiting the heterogeneity of the cellular environment during flexor tendon healing, to define rational therapeutic approaches to improve healing outcomes. PMID:26652792

  5. 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

  6. Engineering Tendon: Scaffolds, Bioreactors, and Models of Regeneration.

    PubMed

    Youngstrom, Daniel W; Barrett, Jennifer G

    2016-01-01

    Tendons bridge muscle and bone, translating forces to the skeleton and increasing the safety and efficiency of locomotion. When tendons fail or degenerate, there are no effective pharmacological interventions. The lack of available options to treat damaged tendons has created a need to better understand and improve the repair process, particularly when suitable autologous donor tissue is unavailable for transplantation. Cells within tendon dynamically react to loading conditions and undergo phenotypic changes in response to mechanobiological stimuli. Tenocytes respond to ultrastructural topography and mechanical deformation via a complex set of behaviors involving force-sensitive membrane receptor activity, changes in cytoskeletal contractility, and transcriptional regulation. Effective ex vivo model systems are needed to emulate the native environment of a tissue and to translate cell-matrix forces with high fidelity. While early bioreactor designs have greatly expanded our knowledge of mechanotransduction, traditional scaffolds do not fully model the topography, composition, and mechanical properties of native tendon. Decellularized tendon is an ideal scaffold for cultivating replacement tissue and modeling tendon regeneration. Decellularized tendon scaffolds (DTS) possess high clinical relevance, faithfully translate forces to the cellular scale, and have bulk material properties that match natural tissue. This review summarizes progress in tendon tissue engineering, with a focus on DTS and bioreactor systems. PMID:26839559

  7. A conceptual framework for computational models of Achilles tendon homeostasis.

    PubMed

    Smith, David W; Rubenson, Jonas; Lloyd, David; Zheng, Minghao; Fernandez, Justin; Besier, Thor; Xu, Jiake; Gardiner, Bruce S

    2013-01-01

    Computational modeling of tendon lags the development of computational models for other tissues. A major bottleneck in the development of realistic computational models for Achilles tendon is the absence of detailed conceptual and theoretical models as to how the tissue actually functions. Without the conceptual models to provide a theoretical framework to guide the development and integration of multiscale computational models, modeling of the Achilles tendon to date has tended to be piecemeal and focused on specific mechanical or biochemical issues. In this paper, we present a new conceptual model of Achilles tendon tissue homeostasis, and discuss this model in terms of existing computational models of tendon. This approach has the benefits of structuring the research on relevant computational modeling to date, while allowing us to identify new computational models requiring development. The critically important functional issue for tendon is that it is continually damaged during use and so has to be repaired. From this follows the centrally important issue of homeostasis of the load carrying collagen fibrils within the collagen fibers of the Achilles tendon. Collagen fibrils may be damaged mechanically-by loading, or damaged biochemically-by proteases. Upon reviewing existing computational models within this conceptual framework of the Achilles tendon structure and function, we demonstrate that a great deal of theoretical and experimental research remains to be done before there are reliably predictive multiscale computational model of Achilles tendon in health and disease. PMID:23757159

  8. Arthroscopic reconstruction of a ruptured patellar tendon: a technical note.

    PubMed

    Gokce, Alper; Ekici, Huseyin; Erdogan, Fahri

    2008-06-01

    A traumatic patellar tendon rupture of a 35-year-old, otherwise healthy male was reconstructed with semi-tendinosus and gracillis tendons. Tendon grafts were harvested with an open-ended tendon stripper without dissecting them free from their tibial insertion. A transpatellar tunnel was drilled appropriate to the tendon size and a passing pin was used across the length of the patella. Graft bundles were passed in a standard fashion, traversing through the midst of the distal part of the patellar tendon via a beath pin with a loaded looped suture. The endo-button device was then flipped and fixed as an anchor. The patella was positioned at the original placement under arthroscopic visualization and the free ends of the hamstring tendons were attached to a post-fixation screw through the Krackow sutures. Tendon grafts were gathered on the tuberositas tibia and fixed with two additional staples. The patient could flex his knee up to 130 deg at the 3-month follow-up. It was demonstrated that arthroscopic reconstruction of a ruptured patellar tendon may be the optimal surgical choice to minimize trauma and begin early rehabilitation. PMID:18322673

  9. Complications of Tendon Surgery in the Foot and Ankle.

    PubMed

    Barp, Eric A; Erickson, John G

    2016-01-01

    This article discusses four subsets of patients that have an increased risk of complications from tendon surgery in the foot and ankle: smokers, diabetics, and patients with peroneal or Achilles tendon pathology. Very little has been published on the complications of other tendon surgeries in the foot and ankle other than Achilles tendon repair. Data can be extrapolated from the general orthopedic literature and animal studies to help guide therapy and treatment options. The foot and ankle surgeon must take into account the entirety of the history and physical examination to develop a treatment plan that optimizes each patient's chance for a complication-free recovery. PMID:26590733

  10. Compression therapy promotes proliferative repair during rat Achilles tendon immobilization.

    PubMed

    Schizas, Nikos; Li, Jian; Andersson, Therese; Fahlgren, Anna; Aspenberg, Per; Ahmed, Mahmood; Ackermann, Paul W

    2010-07-01

    Achilles tendon ruptures are treated with an initial period of immobilization, which obstructs the healing process partly by a reduction of blood circulation. Intermittent pneumatic compression (IPC) has been proposed to enhance tendon repair by stimulation of blood flow. We hypothesized that daily IPC treatment can counteract the deficits caused by 2 weeks of immobilization post tendon rupture. Forty-eight Sprague-Dawley SD) rats, all subjected to blunt Achilles tendon transection, were divided in three equal groups. Group A was allowed free cage activity, whereas groups B-C were immobilized at the operated hindleg. Group C received daily IPC treatment. Two weeks postrupture the rats were euthanatized and the tendons analyzed with tensile testing and histological assessments of collagen organization and collagen III-LI occurrence. Immobilization significantly reduced maximum force, energy uptake, stiffness, tendon length, transverse area, stress, organized collagen diameter and collagen III-LI occurrence by respectively 80, 75, 77, 22, 47, 65, 49, and 83% compared to free mobilization. IPC treatment improved maximum force 65%, energy 168%, organized collagen diameter 50%, tendon length 25%, and collagen III-LI occurrence 150% compared to immobilization only. The results confirm that immobilization impairs healing after tendon rupture and furthermore demonstrate that IPC-treatment can enhance proliferative tendon repair by counteracting biomechanical and morphological deficits caused by immobilization. PMID:20058263

  11. Ossification of the bilateral Achilles tendon: a rare entity

    PubMed Central

    Arora, Abhishek J

    2015-01-01

    Ossification of the Achilles tendon is a rare clinical entity comprising of one or more segments of variable sized ossified masses in the fibrocartilaginous substance of the tendon. The etiology of ossification of the Achilles tendon is multifactorial with recurrent trauma and surgery comprising major predisposing factors, with others being metabolic, systemic, and infectious diseases. The possibility of a genetic predisposition towards this entity has also been raised, but has not yet been proven. We present a rare case of ossification of the bilateral Achilles tendons without any history of trauma or surgery in a 48-year-old female patient. PMID:26413314

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

    PubMed

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

    2014-08-01

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

  13. An alternative cruciate reconstruction graft: the central quadriceps tendon.

    PubMed

    Fulkerson, J P; Langeland, R

    1995-04-01

    The central quadriceps tendon, above the patella, is thicker and wider than the patella tendon. Using precise technique, one can obtain a tendon graft for cruciate reconstruction with 50% greater mass than a patellar tendon bone-tendon-bone graft of similar width. The central quadriceps tendon graft may be harvested by a second surgeon while the first surgeon is simultaneously accomplishing notch-plasty and tunnel placement for cruciate ligament reconstruction. Consequently, this cruciate ligament reconstruction graft offers time savings as well as greater tendon volume. The central quadriceps tendon graft is difficult to harvest, with significant risk of entering the suprapatellar pouch and losing knee distension during ACL reconstruction. By careful adherence to the technique described in this article, the surgeon can obtain this reconstruction graft safely. It is important to recognize the anatomic subtleties of the proximal patella, which include a curved proximal surface, dense cortical bone, and closely adherent suprapatellar pouch. Proper technique is of utmost importance in obtaining this tendon graft safely and efficiently. PMID:7794444

  14. Engineering Tendon: Scaffolds, Bioreactors, and Models of Regeneration

    PubMed Central

    Youngstrom, Daniel W.; Barrett, Jennifer G.

    2016-01-01

    Tendons bridge muscle and bone, translating forces to the skeleton and increasing the safety and efficiency of locomotion. When tendons fail or degenerate, there are no effective pharmacological interventions. The lack of available options to treat damaged tendons has created a need to better understand and improve the repair process, particularly when suitable autologous donor tissue is unavailable for transplantation. Cells within tendon dynamically react to loading conditions and undergo phenotypic changes in response to mechanobiological stimuli. Tenocytes respond to ultrastructural topography and mechanical deformation via a complex set of behaviors involving force-sensitive membrane receptor activity, changes in cytoskeletal contractility, and transcriptional regulation. Effective ex vivo model systems are needed to emulate the native environment of a tissue and to translate cell-matrix forces with high fidelity. While early bioreactor designs have greatly expanded our knowledge of mechanotransduction, traditional scaffolds do not fully model the topography, composition, and mechanical properties of native tendon. Decellularized tendon is an ideal scaffold for cultivating replacement tissue and modeling tendon regeneration. Decellularized tendon scaffolds (DTS) possess high clinical relevance, faithfully translate forces to the cellular scale, and have bulk material properties that match natural tissue. This review summarizes progress in tendon tissue engineering, with a focus on DTS and bioreactor systems. PMID:26839559

  15. Prevention of Tendon Adhesions by ERK2 Small Interfering RNAs

    PubMed Central

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

    2013-01-01

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

  16. 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

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

    PubMed

    Song, S J; Deland, J T

    2001-04-01

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

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

    PubMed

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

    2014-10-01

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

  19. Tendon Progenitor Cells in Injured Tendons Have Strong Chondrogenic Potential: The CD105-Negative Subpopulation Induces Chondrogenic Degeneration

    PubMed Central

    Asai, Shuji; Otsuru, Satoru; Candela, Maria Elena; Cantley, Leslie; Uchibe, Kenta; Hofmann, Ted J.; Zhang, Kairui; Wapner, Keith L.; Soslowsky, Louis J; Horwitz, Edwin M.; Enomoto-Iwamoto, Motomi

    2014-01-01

    To study the cellular mechanism of the tendon repair process, we used a mouse Achilles tendon injury model to focus on the cells recruited to the injured site. The cells isolated from injured tendon 1 week after the surgery and uninjured tendons contained the connective tissue progenitor populations as determined by colony-forming capacity, cell surface markers and multipotency. When the injured tendon-derived progenitor cells (inTPCs) were transplanted into injured Achilles tendons, they were not only integrated in the regenerating area expressing tenogenic phenotype but also trans-differentiated into chondrogenic cells in the degenerative lesion that underwent ectopic endochondral ossification. Surprisingly, the micromass culture of the inTPCs rapidly underwent chondrogenic differentiation even in the absence of exogenous BMPs or TGF?s. The cells isolated from human ruptured tendon tissues also showed connective tissue progenitor properties and exhibited stronger chondrogenic ability than bone marrow stromal cells. The mouse inTPCs contained two subpopulations one positive and one negative for CD105, a co-receptor of the TGF? superfamily. The CD105-negative cells showed superior chondrogenic potential in vitro and induced larger chondroid degenerative lesions in mice as compared to the CD105-positive cells. These findings indicate that tendon progenitor cells are recruited to the injured site of tendons and have a strong chondrogenic potential and that the CD105-negative population of these cells would be the cause for chondroid degeneration in injured tendons. The newly identified cells recruited to the injured tendon may provide novel targets to develop therapeutic strategies to facilitate tendon repair. PMID:25220576

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

    PubMed

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

    2011-03-01

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

  1. 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

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

    PubMed Central

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

    2015-01-01

    Adhesion of the tendon is a major challenge for the orthopedic surgeon during tendon repair. Manipulation of biological environment is one of the concepts to prevent adhesion. Lots of biochemicals have been studied for this purpose. We aimed to determine the effect of phospholipids on adhesion and biomechanical properties of tendon in an animal tendon repair model. Seventy-two Wistar rats were divided into 4 groups. Achilles tendons of rats were cut and repaired. Phospholipids were applied at two different dosages. Tendon adhesion was determined histopathologically and biomechanical test was performed. At macroscopic evaluation of adhesion, there are statistically significant differences between multiple-dose phospholipid injection group and Control group and also hyaluronic acid group and Control group (p < 0.008). At microscopic evaluation of adhesion, there was no statistically significant difference (p > 0.008). Ultimate strength was highest at hyaluronic acid injection group and lowest at multiple-dose phospholipid injection group. Single-dose phospholipids (surfactant) application may have a beneficial effect on the tendon adhesion. Although multiple applications of phospholipids seem the most effective regime to reduce the tendon adhesion among groups, it deteriorated the biomechanical properties of tendon. PMID:26101776

  3. The interfascicular matrix enables fascicle sliding and recovery in tendon, and behaves more elastically in energy storing tendons

    PubMed Central

    Thorpe, Chavaunne T.; Godinho, Marta S.C.; Riley, Graham P.; Birch, Helen L.; Clegg, Peter D.; Screen, Hazel R.C.

    2015-01-01

    While the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the cost of locomotion. Energy storing tendons experience extremely high strains and need to be able to recoil efficiently for maximum energy storage and return. In the equine forelimb, the energy storing superficial digital flexor tendon (SDFT) has much higher failure strains than the positional common digital extensor tendon (CDET). However, we have previously shown that this is not due to differences in the properties of the SDFT and CDET fascicles (the largest tendon subunits). Instead, there is a greater capacity for interfascicular sliding in the SDFT which facilitates the greater extensions in this particular tendon (Thorpe et al., 2012). In the current study, we exposed fascicles and interfascicular matrix (IFM) from the SDFT and CDET to cyclic loading followed by a test to failure. The results show that IFM mechanical behaviour is not a result of irreversible deformation, but the IFM is able to withstand cyclic loading, and is more elastic in the SDFT than in the CDET. We also assessed the effect of ageing on IFM properties, demonstrating that the IFM is less able to resist repetitive loading as it ages, becoming stiffer with increasing age in the SDFT. These results provide further indications that the IFM is important for efficient function in energy storing tendons, and age-related alterations to the IFM may compromise function and predispose older tendons to injury. PMID:25958330

  4. Muscle power attenuation by tendon during energy dissipation

    PubMed Central

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

    2012-01-01

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

  5. Ultrasonic evaluations of Achilles tendon mechanical properties poststroke

    PubMed Central

    Zhao, Heng; Ren, Yupeng; Wu, Yi-Ning; Liu, Shu Q.; Zhang, Li-Qun

    2009-01-01

    Spasticity, contracture, and muscle weakness are commonly observed poststroke in muscles crossing the ankle. However, it is not clear how biomechanical properties of the Achilles tendon change poststroke, which may affect functions of the impaired muscles directly. Biomechanical properties of the Achilles tendon, including the length and cross-sectional area, in the impaired and unimpaired sides of 10 hemiparetic stroke survivors were evaluated using ultrasonography. Elongation of the Achilles tendon during controlled isometric ramp-and-hold and ramping up then down contractions was determined using a block-matching method. Biomechanical changes in stiffness, Young's modulus, and hysteresis of the Achilles tendon poststroke were investigated by comparing the impaired and unimpaired sides of the 10 patients. The impaired side showed increased tendon length (6%; P = 0.04), decreased stiffness (43%; P < 0.001), decreased Young's modulus (38%; P = 0.005), and increased mechanical hysteresis (1.9 times higher; P < 0.001) compared with the unimpaired side, suggesting Achilles tendon adaptations to muscle spasticity, contracture, and/or disuse poststroke. In vivo quantitative characterizations of the tendon biomechanical properties may help us better understand changes of the calf muscle-tendon unit as a whole and facilitate development of more effective treatments. PMID:19118156

  6. Harnessing endogenous stem/progenitor cells for tendon regeneration

    PubMed Central

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

    2015-01-01

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

  7. Estimation of musculotendon kinematics under controlled tendon indentation.

    PubMed

    Chardon, Matthieu K; Dhaher, Yasin Y; Suresh, Nina I; Jaramillo, Giselle; Rymer, W Zev

    2015-10-15

    The effects of tendon indentation on musculotendon unit mechanics have been left largely unexplored. Tendon indentation is however routinely used in the tendon reflex exam to diagnose the state of reflex pathways. Because muscle mechanoreceptors are sensitive to mechanical changes of the musculotendon unit, this gap in knowledge could potentially impact our understanding of these neurological exams. Accordingly, we have used ultrasound (US) imaging to compare the effects of tendon indentation with the effects angular rotation of the elbow in six neurologically intact individuals. We used sagittal ultrasound movies of the biceps brachii to compare length changes induced by each of these perturbations. Length changes were quantified using a pixel-tracking protocol. Our results show that a 20mm indentation of the distal tendon is broadly equivalent to a 15° elbow rotation. We also show that within the imaging window the strain differences between the two stretching protocols are statistically insignificant. Finally, we show that there exists a significant linear relationship between the two stretching techniques and that this relationship spans a large rotational angle to indentation depth. We have used a novel tendon probe to administer controlled tendon indentations as a way to characterize musculotendon kinematics. Using this probe, we confirm that tendon indentation can be physiologically equated with joint rotation, and can thus be used as an input for muscle stretching protocols. Furthermore, this is potentially a simpler and more practical alternative to externally imposed angular joint motion. PMID:26321363

  8. Arthroscopic treatment of popliteus tendon dysfunction following total knee arthroplasty.

    PubMed

    Allardyce, T J; Scuderi, G R; Insall, J N

    1997-04-01

    Following total knee arthoplasty, the popliteus tendon may cause a "snap" when it rolls over a retained lateral femoral condylar osteophyte or when it subluxates over the posterior condyle of the femoral component. When this condition is painful and fails to respond to conservative treatment, arthroscopic release of the popliteus tendon has been beneficial. PMID:9113555

  9. Suitability of Thiel embalmed tendons for biomechanical investigation.

    PubMed

    Fessel, Gion; Frey, Kevin; Schweizer, Andreas; Calcagni, Maurizio; Ullrich, Oliver; Snedeker, Jess G

    2011-05-01

    The standard post-mortem storage method for biomechanical testing is freezing. Freezing minimally alters the biomechanical characteristics of tendons but only suspends the process of decay. Chemical fixation arrests decay and overcomes risk of infection, but alters the biomechanical properties of tendons. On the other hand, Thiel preservation has been reported to maintain soft tissue consistency similar to that of living tissue. The current study investigates the effects of Thiel embalming on human digitorum profundus tendons (FDP) from fresh-frozen and Thiel embalmed cadavers. Cross-sectional area was measured at pre-load, samples were preconditioned and then ramped at a constant strain-rate to failure. Thiel preserved tendons had statistically lower failure stress with median of 38MPa compared to fresh frozen samples with median of 60MPa (p-value=0.048) and trended to a decreased tangential modulus. To overcome limited donor number and masking factors of age, gender, and time embalmed, we also performed experiments in rat tail tendon fascicle. Similar quasi-static ramp to failure tests were performed with control and Thiel treated sample pairs. Similar differences were observed to those found as in human FDP, however these trends were statistically significant. In both tendons, Thiel preserved samples demonstrated altered failure characteristics, indicating a different collagen fiber/collagen network failure mechanism most likely due to partial denaturing by boric acid in Thiel solution. In conclusion, Thiel embalmed tendons did not faithfully represent the biomechanical characteristics of fresh frozen tendons. PMID:21511447

  10. 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

  11. A rare knee extensor mechanism injury: Vastus intermedius tendon rupture

    PubMed Central

    Cetinkaya, Engin; Aydin, Canan Gonen; Akman, Yunus Emre; Gul, Murat; Arikan, Yavuz; Aycan, Osman Emre; Kabukcuoglu, Yavuz Selim

    2015-01-01

    Introduction Quadriceps tendon injuries are rare. There is a limited number of studies in the literature, reporting partial quadriceps tendon ruptures. We did not find any study reporting an isolated vastus intermedius tendon injury in the literature. Presentation of case A 22 years old professional rugby player with the complaints of pain in the right lower limb, decreased range of motion in right knee and a mass in the mid-anterior of the right thigh applied following an overloading on his hyperflexed knee during a rugby match. T2 sequence magnetic resonance images revealed discontinuity in the vastus intermedius tendon and intramuscular hematoma. The patient has been conservatively treated. Discussion Quadriceps tendon ruptures generally occur after the 4th decade in the presence of degenerative changes. Our case is a young professional rugby player. Isolated vastus intermedius tendon rupture is unusual. Conservative treatment is performed as the intermedius tendon is in the deepest layer of the quadriceps muscle. Conclusion We report the first case of isolated rupture of the vastus intermedius tendon in the literature and we claim that disorder may be succesfully treated with conservative treatment and adequate physiotheraphy. PMID:26298093

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

    PubMed

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

    2015-07-01

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

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

    PubMed Central

    Nesselroade, Ryan D.; Nickels, Leslie Connor

    2010-01-01

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

  14. Granuloma formation secondary to Achilles tendon repair with nonabsorbable suture

    PubMed Central

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

    2014-01-01

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

  15. Achilles Tendon Open Repair Augmented with Volar Turndown Tendon Flap and Deep Posterior Crural Fasciotomy

    PubMed Central

    Özer, Hamza; Selek, Hakan; Harput, Gülcan; Öznur, Ali; Baltac?, Gül

    2014-01-01

    Objectives: The aim of the study was to investigate the outcomes after open repair of Achilles tendon rupture with augmented volar turndown gastrocnemius flap and deep posterior crural fasciotomy. Methods: Twenty-three (22male/1female) patients with acute Achilles tendon injury were operated. Open end to end repair and augmentation with a volar turndown gastrocnemius flap and fasciotomy of the deep posterior compartment was performed in each patient. Home physiotherapy program was instructed for each patient. Muscle strength, balance and jump performance were assessed. Results: All patients returned to their preinjury activity level and repairs healed without any major complication. One patient had serous drainage who did not require surgical intervention (4,3%). There was no significant difference between involved and uninvolved leg in terms of concentric and eccentric muscle strength (p=0.82 and p=0.53, respectively). In Y balance test, there was no significant difference between involved and uninvolved legs in anterior (p=0.06), posteromedial (p=0.97) and posterolateral (p=1.00). In addition, there were no significant differences between leg in vertical jump (p=0.16) and one leg hop (p=0.15) tests. AOFAS Hindfoot score was 98.6±2.3 (93-100). Conclusion: Open end to end repair of the Achilles tendon rupture with augmentation and fasciotomy of the deep posterior compartment healed without any major complication. Fasciotomy of the deep posterior compartment decreased the tension at the skin repair site while decompressing the supeficial compartment anteriorly. Additionally, the augmented bulky repair construct of the Achilles tendon cambered volarly through the deep posterior compartment and decreased irritation sense during and after tendon healing.

  16. System and Method for Tensioning a Robotically Actuated Tendon

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  17. Force Model for Control of Tendon Driven Hands

    NASA Technical Reports Server (NTRS)

    Pena, Edward; Thompson, David E.

    1997-01-01

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

  18. A New Clinical Test in Diagnosing Quadriceps Tendon Rupture

    PubMed Central

    Jolles, BM; Garofalo, R; Gillain, L; Schizas, C

    2007-01-01

    INTRODUCTION Extensor mechanism ruptures might be easily overlooked and misdiagnosed, and delayed diagnosis of quadriceps tendon rupture is frequent. However, the literature recommends early surgical repair within 72 h. PATIENTS AND METHODS This paper describes a new simple clinical diagnostic test that directly evaluates the integrity of the distal 5 cm of the quadriceps tendon itself. It consists of inserting a needle in the tendon, proximal to the suspected rupture and mobilising the knee joint. RESULTS The suspected ruptured quadriceps tendons with a positive ‘needle’ diagnostic test were confirmed intra-operatively. CONCLUSIONS This minimally invasive and easily available technique should be considered in the diagnostic work-up and treatment planning of patients with suspected tears of the quadriceps tendon. PMID:17394710

  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. 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.

  1. 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

  2. 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.

  3. [Distal biceps tendon tear. A case report].

    PubMed

    Alanis Blancas, Luis Manuel; Zamora Muñoz, Paola Maritza; Cruz Miranda, Angel

    2009-01-01

    Distal tears of the biceps tendon are rare lesions and account for 3-5% of all biceps lesions. Surgical treatment produces better outcomes than conservative treatment from the perspective of forearm flexion and supination. Different implants and approaches are currently available to improve the course of patients and reduce the postoperative complications. The case of a patient who underwent surgical treatment with anatomical reattachment with anchors is presented herein as well as his two-year follow-up. This is considered as an excellent outcome given that the patient remained asymptomatic and returned to his previous athletic activity without complications. PMID:19960662

  4. Pectoralis major tendon rupture. Surgical procedures review.

    PubMed Central

    Merolla, Giovanni; Paladini, Paolo; Campi, Fabrizio; Porcellini, Giuseppe

    2012-01-01

    Summary Pectoralis major (PM) muscle is the powerful dynamic stabiliser of the shoulder that acts as a flexor, adductor and internal rotator. The rupture of the PM tendon is a relatively rare injury that was firstly described in a French boy by Patissier in 1822 and later, in 1861, by Letenneur who reported another similiar case. To date, over 200 cases have been published. In this article we describe the clinical anatomy and the mechanism of injuries of PM and we review the surgical procedures for acute and chronic ruptures. PMID:23738281

  5. The anisotropic compressive mechanical properties of the rabbit patellar tendon.

    PubMed

    Williams, Lakiesha N; Elder, Steven H; Bouvard, J L; Horstemeyer, M F

    2008-01-01

    In this study, we examine the transverse and longitudinal compressive mechanical behavior of the rabbit patellar tendon. The anisotropic compressive properties are of interest, because compression occurs where the tendon attaches to bone and where the tendon wraps around bone leading to the development of fibro-cartilaginous matrices. We quantified the time dependent viscoelastic and anisotropic behavior of the tendon under compression. For both orientations, sections of patellar tendon were drawn from mature male white New Zealand rabbits in preparation for testing. The tendons were sequentially compressed to 40% strain at strain rates of 0.1, 1 and 10% strain(s) using a computer-controlled stepper motor driven device under physiological conditions. Following monotonic loading, the tendons were subjected to stress relaxation. The tendon equilibrium compressive modulus was quantified to be 19.49+/-11.46 kPa for the transverse direction and 1.11+/-0.57 kPa for the longitudinal direction. The compressive modulus at applied strain rates of 0.1, 1 and 10% strain(s) in the transverse orientation were 13.48+/-2.31, 18.24+/-4.58 and 20.90+/-8.60 kPa, respectively. The compressive modulus at applied strain rates of 0.1, 1 and 10% strain/s in the longitudinal orientation were 0.19+/-0.11, 1.27+/-1.38 and 3.26+/-3.49 kPa, respectively. The modulus values were almost significantly different for the examination of the effect of orientation on the equilibrium modulus (p=0.054). Monotonic loading of the tendon showed visual differences of the strain rate dependency; however, no significant difference was shown in the statistical analysis of the effect of strain rate on compressive modulus. The statistical analysis of the effect of orientation on compressive modulus showed a significant difference. The difference shown in the orientation analysis validated the anisotropic nature of the tendon. PMID:19065006

  6. Cell phenotypic variation in normal and damaged tendons

    PubMed Central

    Clegg, Peter D; Strassburg, Sandra; Smith, Roger K

    2007-01-01

    Injuries to tendons are common in both human athletes as well as in animals, such as the horse, which are used for competitive purposes. Furthermore, such injuries are also increasing in prevalence in the ageing, sedentary population. Tendon diseases often respond poorly to treatment and require lengthy periods of rehabilitation. The tendon has a unique extracellular matrix, which has developed to withstand the mechanical demands of such tensile-load bearing structures. Following injury, any repair process is inadequate and results in tissue that is distinct from original tendon tissue. There is growing evidence for the key role of the tendon cell (tenocyte) in both the normal physiological homeostasis and regulation of the tendon matrix and the pathological derangements that occur in disease. In particular, the tenocyte is considered to have a major role in effecting the subclinical matrix degeneration that is thought to occur prior to clinical disease, as well as in the severe degradative events that occur in the tendon at the onset of clinical disease. Furthermore, the tenocyte is likely to have a central role in the production of the biologically inadequate fibrocartilaginous repair tissue that develops subsequent to tendinopathy. Understanding the biology of the tenocyte is central to the development of appropriate interventions and drug therapies that will either prevent the onset of disease, or lead to more rapid and appropriate repair of injured tendon. Central to this is a full understanding of the proteolytic response in the tendon in disease by such enzymes as metalloproteinases, as well as the control of the inappropriate fibrocartilaginous differentiation. Finally, it is important that we understand the role of both intrinsic and extrinsic cellular elements in the repair process in the tendon subsequent to injury. PMID:17696903

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

    PubMed

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

    2009-05-11

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

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

    PubMed Central

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

    2014-01-01

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

  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. COMPLICATIONS OF JOINT, TENDON, AND MUSCLE INJECTIONS.

    PubMed

    Cheng, Jianguo; Abdi, Salahadin

    2007-07-01

    Prevention of complications is one of the most important aspects of patient care in pain management. The objective of this study is to review documented complications in medical literature that are associated with interventional pain management, specifically those associated with joint, tendon, and muscle injections. We conducted Medline research from 1966 to November 2006 using keywords complication, injection, radiofrequency, closed claim, facet, zygophyseal joint, sacroiliac joint, shoulder, hip, knee, carpel tunnel, bursa, and trigger point. We found over 35 relevant papers in forms of original articles, case reports, and reviews. The most common complications appear to be infections that have been associated with virtually all of these injections. These infections include spondylodiscitis, septic arthritis, epidural abscess, necrotizing fasciitis, osteomyelitis, gas gangrene, and albicans arthritis. Other complications include spinal cord injury and peripheral nerve injuries, pneumothorax, air embolism, pain or swelling at the site of injection, chemical meningism, granulomatous inflammation of the synovium, aseptic acute arthritis, embolia cutis medicamentosa, skeletal muscle toxicity, and tendon and fascial ruptures. We suggest that many of the infectious complications may be preventable by strict adherence to aseptic techniques and that some of the other complications may be minimized by refining the procedural techniques with a clear understanding of the relevant anatomies. PMID:18591992

  11. Acute Achilles tendon rupture in badminton players.

    PubMed

    Fahlström, M; Björnstig, U; Lorentzon, R

    1998-01-01

    All patients with badminton-related acute Achilles tendon ruptures registered during 1990 to 1994 at the University Hospital of Umeå were retrospectively followed up using a questionnaire. Thirty-one patients (mean age, 36.0 years), 27 men and 4 women, were included. Thirty patients (97%) described themselves as recreational players or beginners. The majority of the injuries (29 of 31, 94%) happened at the middle or end of the planned game. Previous local symptoms had been noticed by five patients (16%). Long-term results showed that patients treated with surgery had a significantly shorter sick leave absence than patients treated without surgery (50 versus 75 days). There was no obvious selection favoring any treatment modality. None of the surgically treated patients had reruptures, but two reruptures occurred in the nonsurgically treated group. There seemed to be fewer remaining symptoms and a higher sports activity level after the injury in the surgically treated group. Our results indicate that local muscle fatigue may interfere with strength and coordination. Preventive measures such as specific treatment of minor injuries and adequate training of strength, endurance, and coordination are important. Our findings also indicate that surgical treatment and careful postoperative rehabilitation is of great importance among badminton players of any age or sports level with Achilles tendon rupture. PMID:9617415

  12. Current Concepts in Examination and Treatment of Elbow Tendon Injury

    PubMed Central

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

    2013-01-01

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

  13. Quantification of regional blood flow to canine flexor tendons

    SciTech Connect

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

    1984-01-01

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

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

    PubMed

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

    2015-01-01

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

  15. Development of a tendon driven system using a pneumatic balloon

    NASA Astrophysics Data System (ADS)

    Sato, Rika; Nagase, Jun-ya; Saga, Norihiko; Chonan, Seiji

    2007-01-01

    This paper is a study on a new type of a tendon system driven by a pneumatic balloon. It consists of a tendon and a silicon tube. Both ends of the silicon tube are closed and the tube expands like a balloon with the supply of air, which distends the silicon tube and pulls the tendon. Two types of actuation systems are considered. One is a high power system while the other a long stroke type. These two actuation systems have a difference in the mechanism of driving the tendon. In the high power system, the tendon is wound around the balloon. On the other hand, for the long stroke type, one end of the tendon is clamped near the balloon. The states of expansion are examined for both the high power type and the long stroke type. A cover is introduced to prevent the excessive expansion of the inflated balloon. The basic characteristics of the two tendon systems are discussed. A comparison with a human muscle is also presented.

  16. Production of a sterilised decellularised tendon allograft for clinical use.

    PubMed

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

    2013-12-01

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

  17. 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

  18. Quantification of regional blood flow to canine flexor tendons.

    PubMed

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

    1984-01-01

    Although the blood supply and the microcirculation of flexor tendons have been studied and defined extensively using qualitative methods, the quantitative assessment of blood flow has been lacking because of the limitations of the available experimental techniques. We studied the regional blood supply to the flexor tendons of dogs by the technique of radionuclide-labeled microspheres. Seven adult mongrel dogs were used. Microsphere injection and tissue-counting techniques previously used for other tissues were applied. Samples of proximal, isthmus, and distal portions of the profundus and superficialis flexor tendons were harvested from each digital unit of available limbs from each dog. Mean (+/- SE) flows (ml/100 g dry tissue/min) were proximal profundus 1.78 +/- 0.60 and superficialis 7.10 +/- 1.50. The differences were significant (p less than 0.01). The study suggests that regional variation in blood flow to canine digital flexor tendons exists, so that a single value for blood flow to these tendons is not relevant. Furthermore, the study supports the concept of dual (vascular and synovial) nutrition to the digital flexor tendons in dogs. These observations may have implications regarding tendon repair techniques. PMID:6491815

  19. Tenocyte contraction induces crimp formation in tendon-like tissue

    PubMed Central

    Holmes, David F.; Hill, Patrick; Kadler, Karl E.; Margetts, Lee

    2013-01-01

    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 synthesize a tendon-like construct comprised of collagen fibrils arranged in parallel bundles. Investigations using polarized 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 ECM. 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

  20. 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

  1. Imaging horse tendons using multimodal 2-photon microscopy.

    PubMed

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

    2014-03-15

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

  2. Tendon bottom connector for a tension leg platform

    SciTech Connect

    Kipp, R.M.

    1991-04-02

    This patent describes a floating tension-leg platform having anchoring tendons extending from the platform with the lower ends of the tendons being connected in tension to anchor means fixedly secured to the ocean floor in deep water, the connection being made by underwater-actuatable and remotely-connectable and releasable tendon connector means. It includes first and second connector portions a first inwardly-directed camming surface; a circumferential latching groove; a latching shoulder; a second camming surface; a latching sleeve; collet spring fingers; and outwardly-extending latches.

  3. Resection of the common digital extensor tendon in a gelding.

    PubMed

    Booth, T M; Clegg, P D; Singer, E R; Cheeseman, M T

    2000-03-25

    A four-year-old gelding was lame owing to a chronic septic common digital extensor tendon and sheath. The horse had been treated by open surgical lavage but the sepsis had recurred after three months. Physical, ultrasonographic, cytological and histological examinations confirmed chronic septic tenosynovitis and tendonitis. The entire intrathecal component of the common digital extensor tendon was resected under general anaesthesia and the synovial lining of the sheath was ablated. Postoperatively the horse regained good limb function and became sound. PMID:10803983

  4. Triceps tendon tear in a middle-aged weightlifter.

    PubMed

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

    2013-11-01

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

  5. 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

  6. Tenascin-C Expression in Equine Tendon-derived Cells During Proliferation and Migration.

    PubMed

    Nemoto, Manabu; Kizaki, Keiichiro; Yamamoto, Yoshio; Oonuma, Toshina; Hashizume, Kazuyoshi

    2013-01-01

    In vitro cell studies might be a useful tool for studying tendon pathology, but no suitable in vitro models exist for tendon disorders. The purpose of this study was to confirm whether cell scratch culture using tendon-derived fibroblasts can provide a suitable in vitro tendon disorder model. Extracellular matrix components were examined immunohistochemically in tendon tissue, and then their related gene expression levels were analyzed by conventional reverse transcription polymerase chain reaction (RT-PCR) and/or quantitative real-time RT-PCR in tissues and cells. Collagen type I (Col I), collagen type III (Col III), tenascin-C (TN-C) and cartilage oligomeric matrix protein (COMP) were detected in tendon tissue sections, and RT-PCR confirmed their expression in tendon tissue and cells. Cells that had been cultured from explanted tendon tissue maintained the characteristics of in vivo tendon cells. The combination of TN-C and COMP might be a useful marker of tendon cells because they display more tendon-specific expression than Col I and III. In particular, the significant increase of TN-C mRNA expression in the scratch wound assay, at 12 hr after scratching, concomitant with the regeneration of the cell sheet, indicates its crucial role in tendon cell proliferation and migration. Thus, TN-C appears to be a key factor in tendon wound healing. In vitro cell scratch assays using tendon cells appear to mimic the repair of tendon tissue after injury. PMID:24833997

  7. Compressive properties of cd-HA-gelatin modified intrasynovial tendon allograft in canine model in vivo

    PubMed Central

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

    2013-01-01

    Although we sometimes use the intrasynovial tendon allograft as a donor, the gliding ability of allograft prepared by lyophilization is significantly decreased. The gliding ability of the grafted tendon after tendon reconstruction is very important because the high gliding resistance causes more adhesion and leads to poor clinical results. We recently revealed that tendon surface treatment with a carbodiimide derivatized HA (cd-HA)-gelatin mixture for intrasynovial tendon allograft significantly improved its gliding ability. The purpose of this study was to investigate whether this cd-HA-gelatin treatment affects the tendon mechanical property or not. A total of 40 flexor digitorum profundus (FDP) tendons from canines were evaluated for compressive property by using indentation test. Indentation stiffness was measured for normal tendon, rehydrated tendon after lyophilization, rehydrated tendon after lyophilization that was implanted 6 weeks in vivo, and cd-HA treated rehydrated tendon after lyophilization that was implanted 6 weeks in vivo. The results for all groups showed no significant difference in the tendon compressive properties. The findings of these results demonstrate that cd-HA treatment for intrasynovial tendon allograft is an excellent method to improve the tendon gliding ability after lyophilization without changing the compressive property of donor tendon. PMID:21549380

  8. Tension Stiffened and Tendon Actuated Manipulator

    NASA Technical Reports Server (NTRS)

    Doggett, William R. (Inventor); Dorsey, John T. (Inventor); Ganoe, George G. (Inventor); King, Bruce D. (Inventor); Jones, Thomas C. (Inventor); Mercer, Charles D. (Inventor); Corbin, Cole K. (Inventor)

    2015-01-01

    A tension stiffened and tendon actuated manipulator is provided performing robotic-like movements when acquiring a payload. The manipulator design can be adapted for use in-space, lunar or other planetary installations as it is readily configurable for acquiring and precisely manipulating a payload in both a zero-g environment and in an environment with a gravity field. The manipulator includes a plurality of link arms, a hinge connecting adjacent link arms together to allow the adjacent link arms to rotate relative to each other and a cable actuation and tensioning system provided between adjacent link arms. The cable actuation and tensioning system includes a spreader arm and a plurality of driven and non-driven elements attached to the link arms and the spreader arm. At least one cable is routed around the driven and non-driven elements for actuating the hinge.

  9. Rehabilitating Psoas Tendonitis: A Case Report

    PubMed Central

    2008-01-01

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

  10. Late quadriceps tendon rupture at the donor site following cruciate ligament reconstruction using central quadriceps tendon graft.

    PubMed

    Pandey, Vivek; Madi, Sandesh; Joseph, Amy; Acharya, Kiran

    2015-01-01

    Central quadriceps tendon (CQT) graft has been successfully used as a viable autograft option in cruciate ligament reconstruction of the knee. The prime emphasis in the majority of the literature is given to surgical details of quadriceps graft harvesting and outcome of cruciate ligament reconstruction. There is less discussion about donor site morbidity in CQT graft, and it is less frequent as compared to that in bone patellar tendon bone graft. We report an extremely unusual case of late quadriceps tendon rupture at the donor site following anterior cruciate ligament reconstruction using CQT graft. PMID:26475883

  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. Exploring the role of hypercholesterolemia in tendon health and repair.

    PubMed

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

    2014-07-01

    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

  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. Suture techniques for tendon repair; a comparative review

    PubMed Central

    Rawson, Shelley; Cartmell, Sarah; Wong, Jason

    2013-01-01

    Summary Over the past five decades we have seen numerous iterations of suture repair methods for tendon. The pursuit of the ultimate repair has led to many repair methods being described. This comprehensive compilation of the suture repair techniques will describe the factors that affect repair success, including repair strength, gapping resistance, glide and rehabilitation. Different approaches to rejoining severed tendons will be critiqued on their biomechanical ability to improve tendon repair strength, maintaining glide, reducing tendon damage, and minimising adhesion formation. It is important to highlight how the suture repairs have evolved and improved but also review how they may contribute to their own trauma. The apparent paradox between providing mechanical strength and minimising adhesions require refinements in the field to improve on functional outcomes. PMID:24367784

  15. Nonlinear optical imaging characteristics in rat tail tendon

    NASA Astrophysics Data System (ADS)

    Liu, N. R.; Zhang, X. Z.; Qiu, Y. S.; Chen, R.

    2013-04-01

    The aim of this study was to examine the characteristics of skeletal muscle fibers in tail tendons, explore the content of intrinsic components at different depths and ascertain the optimum excitation wavelength, which will help to establish a relationship between diagnosis and therapy and the tendon injury. A multiphoton microscopic imaging system was used to achieve the images and spectra via an imaging mode and a Lambda mode, respectively. This work demonstrates that the skeletal muscle fibers of the tail tendon are in good order. Second harmonic generation (SHG) and two-photon excited fluorescence (TPEF) signals originating from certain intrinsic components are varied with depth, and the SHG/TPEF intensity ratios are varied at different excitation wavelengths. Below 800 nm is the optimum for cell TPEF, while above 800 nm is the optimum for SHG. With the development of imaging techniques, a nonlinear optical imaging system will be helpful to represent the functional behaviors of tissue related to tendon injury.

  16. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  17. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  18. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  19. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  20. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  1. Botox as an adjuvant to tendon transfer for foot drop.

    PubMed

    Eckel, Tobin T; Nunley, James A

    2013-01-01

    The authors' hypothesis was that weakening the gastrocnemius muscle at the time of tendon transfer will reduce the risk of rupture and facilitate faster rehabilitation with increased active dorsiflexion and improved overall outcome, because the transferred tendon is spared the antagonistic effect of the gastrocnemius during the early recovery period. A retrospective chart review identified 12 patients who underwent a tibialis posterior tendon (PTT) transfer with gastrocnemius Botox injection for foot drop. All statistical analyses were conducted using SAS version 9.2 (SAS Institute, Inc., Cary, North Carolina). There were no failures or tendon ruptures. All patients had zero dorsiflexion (DF) strength preoperatively, and those with DF strength documented postoperatively had a mean DF strength at final clinical evaluation of 3.9 (p < .001) with a mean active DF of 4°. It was concluded that gastrocnemius chemodenervation with Botox at the time of PTT transfer is a safe and effective means of restoring active dorsiflexion. PMID:24063800

  2. Repair of patellar tendon rupture using suture anchors.

    PubMed

    Bushnell, Brandon D; Tennant, Joshua N; Rubright, James H; Creighton, R Alexander

    2008-04-01

    Acute isolated rupture of the patellar tendon traditionally has been repaired via transpatellar suture tunnels. This retrospective study evaluated the demographics and epidemiology of this injury as well as the effectiveness and complication rates of our suture anchor technique. Between 1993 and 2005, a total of 82 cases of patellar tendon disruption in 71 patients were repaired. Fourteen cases involved basic primary repair with suture anchors of an acute isolated rupture of the patellar tendon and had an average follow-up of 29 months (range: 3-112 months). There were 3 (21%) failures of repair. The remaining 11 patients had excellent range of motion and strength and returned to their preoperative level of function. These results are comparable with other reports in the literature. The suture anchor technique thus represents a viable option for repair of patellar tendon ruptures and should be investigated further with a randomized, controlled trial. PMID:18500063

  3. Mechanical properties of the patellar tendon in adults and children.

    PubMed

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

    2010-04-19

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

  4. The re-attachment of tendon and ligament avulsions.

    PubMed

    Grant, I; Pandya, A; Mahaffey, P J

    2002-08-01

    This paper presents our experience of a new technique for the reattachment of tendons in the hand. A percutaneous Kirschner wire is fashioned into a hoop to support an intratendinous suture. This mechanism maintains continuous traction upon the avulsed tendon. The technique avoids extensive dissection of the fingertip and the direct application of pressure on the dorsal surface of the digit, which might cause skin breakdown. PMID:12162972

  5. Surgical management of isolated popliteus tendon injuries in paediatric patients.

    PubMed

    Liu, Joseph N; Rebolledo, Brian J; Warren, Russell F; Green, Daniel W

    2016-03-01

    Isolated popliteus avulsion injuries are a rare occurrence, especially in the skeletally immature population. Two cases of isolated popliteus tendon avulsion injuries in paediatric patients were identified and successfully managed with suture anchor reattachment of the avulsed fragment in the anatomic position. The objective of this case report is to raise awareness of orthopaedic surgeons to the rarely encountered isolated popliteus tendon injury that can occur in paediatric patients. Level of evidence Expert opinion, Level V. PMID:26856317

  6. Traumatic rupture of both peroneal longus and brevis tendons.

    PubMed

    Pelet, Stéphane; Saglini, Marco; Garofalo, Raffaele; Wettstein, Michael; Mouhsine, Elyazid

    2003-09-01

    Injuries of peroneal tendons are rare. Diagnosis of traumatic rupture is often late and presents as chronic ankle instability. A case of a complete traumatic rupture of both peroneal longus and brevis tendons with acute clinical and radiological diagnosis is presented. Surgical repair was performed by direct end-to-end suture on the 4th day after trauma, with excellent functional outcome at 1-year follow-up. PMID:14524524

  7. 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

  8. The flexor tendon pulley system and rock climbing.

    PubMed

    Crowley, Timothy P

    2012-06-01

    Rock climbing has increased in popularity over the past two decades. Closed traumatic rupture of the finger flexor tendon pulleys is rare among the general population but is seen much more commonly in rock climbers. This article reviews the anatomy and biomechanics of the finger flexor tendon pulleys, how they may be injured in rock climbing and how these injuries are best diagnosed and managed. PMID:23730085

  9. Substantial creep in healing human Achilles tendons. A pilot study

    PubMed Central

    Aspenberg, Per; Schepull, Thorsten

    2015-01-01

    Summary Background healing after rupture of the Achilles tendon can be described in terms of mechanical properties of the new-formed tissue, constituting the tendon callus. In previous human studies, the elastic modulus and the density remained almost constant during 3 months after mobilization started, and then improved up to one year. So far, time-dependent deformation of the healing human tendon has not been reported. Methods in a series of 16 patients, operated with Achilles tendon suture, we implanted tantalum beads into the tendon and measured the distance between them repeatedly during 3 min of constant loading, using an ordinary image intensifier. The patients unloaded their leg for 30 min before the test. To avoid bias, all images were investigated in a randomized and blinded order. Results total strain during 3 min of constant loading at 7 weeks post injury amounted to 5%, and at 19 weeks to 3%. About half of the strain, after the loading was applied, occurred during the second and third min. Considerable strain also occurred just before loading, when the patient was told that a load would be applied, but before this was actually done. Conclusion the measurements were crude, and this study should be seen as a pilot. Still, visco-elastic properties seem to dominate the mechanical behavior the healing Achilles tendon from start of mobilization to 19 weeks, at least when tested after 30 min rest. This deserves further studies with more precise methods. PMID:26605187

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

    PubMed

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

    2011-06-01

    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

  11. Posterior Tibialis Tendon Dysfunction: Overview of Evaluation and Management.

    PubMed

    Yao, Kaihan; Yang, Timothy Xianyi; Yew, Wei Ping

    2015-06-01

    EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Recognize posterior tibialis tendon dysfunction and begin to include it in differential diagnoses. 2. Recall the basic anatomy and pathology of the posterior tibialis tendon. 3. Assess a patient for posterior tibialis tendon dysfunction with the appropriate investigations and stratify the severity of the condition. 4. Develop and formulate a treatment plan for a patient with posterior tibialis tendon dysfunction. The posterior tibialis is a muscle in the deep posterior compartment of the calf that plays several key roles in the ankle and foot. Posterior tibialis tendon dysfunction is a complex but common and debilitating condition. Degenerative, inflammatory, functional, and traumatic etiologies have all been proposed. Despite being the leading cause of acquired flatfoot, it is often not recognized early enough. Knowledge of the anatomical considerations and etiology of posterior tibialis tendon dysfunction, as well as key concepts in its evaluation and management, will allow health care professionals to develop appropriate intervention strategies to prevent further development of flatfoot deformities. PMID:26091214

  12. Chondrogenic differentiation and lubricin expression of caprine infraspinatus tendon cells.

    PubMed

    Funakoshi, Tadanao; Spector, Myron

    2010-06-01

    Reparative strategies for the treatment of injuries to tendons, including those of the rotator cuff of the shoulder, need to address the formation of the cartilage which serves as the attachment apparatus to bone and which forms at regions undergoing compressive loading. Moreover, recent work indicates that cells employed for rotator cuff repair may need to synthesize a lubricating glycoprotein, lubricin, which has recently been found to play a role in tendon tribology. The objective of the present study was to investigate the chondrogenic differentiation and lubricin expression of caprine infraspinatus tendon cells in monolayer and three-dimensional culture, and to compare the behavior with bone marrow-derived mesenchymal stem cells (MSCs). The results demonstrated that while tendon cells in various media, including chondrogenic medium, expressed lubricin, virtually none of the MSCs synthesized this important lubricating molecule. Also of interest was that the cartilage formation capacity of the tendon cells grown in pellet culture in chondrogenic medium was comparable with MSCs. These data inform the use of tendon cells for rotator cuff repair, including for fibrocartilaginous zones. PMID:20058273

  13. 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

  14. Biomimetic scaffold design for functional and integrative tendon repair.

    PubMed

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

    2012-02-01

    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 underscores the clinical need for alternative grafting solutions. The 2 critical design criteria for the ideal tendon graft would require the graft to not only exhibit physiologically relevant mechanical properties but also be able to facilitate functional graft integration by promoting the regeneration of the native tendon-to-bone interface. Centered on these design goals, this review will highlight current approaches to functional and integrative tendon repair. In particular, the application of biomimetic design principles through the use of nanofiber- and nanocomposite-based scaffolds for tendon tissue engineering will be discussed. This review will begin with nanofiber-based approaches to functional tendon repair, followed by a section highlighting the exciting research on tendon-to-bone interface regeneration, with an emphasis on implementation of strategic biomimicry in nanofiber scaffold design and the concomitant formation of graded multi-tissue systems for integrative soft-tissue repair. This review will conclude with a summary and discussion of future directions. PMID:22244070

  15. Human Achilles tendon glycation and function in diabetes.

    PubMed

    Couppé, Christian; Svensson, Rene Brüggebusch; Kongsgaard, Mads; Kovanen, Vuokko; Grosset, Jean-Francois; Snorgaard, Ole; Bencke, Jesper; Larsen, Jytte Overgaard; Bandholm, Thomas; Christensen, Tomas Møller; Boesen, Anders; Helmark, Ida Carøe; Aagaard, Per; Kjaer, Michael; Magnusson, Stig Peter

    2016-01-15

    Diabetic patients have an increased risk of foot ulcers, and glycation of collagen may increase tissue stiffness. We hypothesized that the level of glycemic control (glycation) may affect Achilles tendon stiffness, which can influence gait pattern. We therefore investigated the relationship between collagen glycation, Achilles tendon stiffness parameters, and plantar pressure in poorly (n = 22) and well (n = 22) controlled diabetic patients, including healthy age-matched (45-70 yr) controls (n = 11). There were no differences in any of the outcome parameters (collagen cross-linking or tendon stiffness) between patients with well-controlled and poorly controlled diabetes. The overall effect of diabetes was explored by collapsing the diabetes groups (DB) compared with the controls. Skin collagen cross-linking lysylpyridinoline, hydroxylysylpyridinoline (136%, 80%, P < 0.01) and pentosidine concentrations (55%, P < 0.05) were markedly greater in DB. Furthermore, Achilles tendon material stiffness was higher in DB (54%, P < 0.01). Notably, DB also demonstrated higher forefoot/rearfoot peak-plantar-pressure ratio (33%, P < 0.01). Overall, Achilles tendon material stiffness and skin connective tissue cross-linking were greater in diabetic patients compared with controls. The higher foot pressure indicates that material stiffness of tendon and other tissue (e.g., skin and joint capsule) may influence foot gait. The difference in foot pressure distribution may contribute to the development of foot ulcers in diabetic patients. PMID:26542519

  16. [Arthroscopic repair of partial subcapularis tendon lesions. Simplified approach].

    PubMed

    Pagán Conesa, Alejandro; Sánchez Martin, Alfredo; Aznar, Carlos Verdú

    2008-01-01

    We present a technical variation for arthroscopic subscapularis tendon repair. Sutures of isolated partial subscapularis tendon avulsions can be passed and fixed securely through an isolated anterolateral portal just over the rotator interval (mono-tunnel technique). Primarily a shoulder free of fixation devices is needed. Patient on a beach chair position or lateral decubitus without traction is advised. The best view can be obtained from a posterior portal with the shoulder on 75 degrees forward elevation and 90 degrees medial rotation. In a shoulder 30 degrees adducted at a good view can be also obtained from the antero-lateral portal. This working portal alone allows joint and tendon inspection, introduction of round burrs and devices needed for working on bone bed receptor. A titanium anchor of 5 mm with doubled non-absorbable suture is used, it can be passed through tendon with the Artropierce and an all-inside arthroscopic knot tying is done by just one tunnel thus minimizing the potential of injury of the coracohumeral ligament complex. This technique allows the surgeon to perform subscapularis tendon repair easily with reproducible good results in 7 cases of isolated partial tendon avulsions in this serie. We also recommend it in combination with other rotator cuff repairing techniques. PMID:18979983

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

    PubMed Central

    BENJAMIN, M.; RALPHS, J. R.

    1998-01-01

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

  18. Patellar Tendon–Trochlear Groove Angle Measurement

    PubMed Central

    Hinckel, Betina B.; Gobbi, Riccardo G.; Kihara Filho, Eduardo N.; Demange, Marco K.; Pécora, José Ricardo; Camanho, Gilberto Luis

    2015-01-01

    Background: The tibial tubercle–trochlear groove (TT-TG) is used as the gold standard for patellofemoral malalignment. Purpose: To assess 3 patellar tendon–trochlear groove (PT-TG) angle measurement techniques and the PT-TG distance measurement (tendinous cartilaginous TT-TG) as predictors of patellar instability. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Three PT-TG angle measurements and the PT-TG distance were measured in 82 participants with patellar instability and 100 controls using magnetic resonance imaging (MRI). Measurement landmarks were the line tangent to the posterior femoral condyles, the deepest point of the trochlea, the transepicondylar line, and the patellar tendon center. All measurements were recorded once by 1 examiner, and the measurements were recorded twice by 2 examiners in a random group of 100 knees. Mean values and standard deviations (SDs) were obtained. Normality cutoff values were defined as 2 and 3 SDs above the mean in the control group. The sensitivity, specificity, and positive likelihood ratio (LR+) were calculated. Inter- and intrarater reliability were assessed based on the intraclass correlation coefficient (ICC). Results: The measurements from the patellar instability and control groups, respectively, for angle 1 (16.4° and 8.4°), angle 2 (31° and 15.6°), angle 3 (30.8° and 15.7°), PT-TG distance (14.5 and 8.4 mm), and patellar tilt (21.1° and 7.5°) were significantly different (P < .05). The angle measurements showed greater sensitivity, specificity, and LR+ than the PT-TG distance. Inter- and intrarater ICC values were >0.95 for all measurements. Conclusion: The PT-TG angle and the PT-TG distance are reliable and are different between the patellar instability and control groups. PT-TG angles are more closely associated with patellar instability than PT-TG distance. Clinical Relevance: PT-TG angle measurements show high reliability and association with patellar instability and can aid in the assessment of extensor mechanism malalignment. A more sensitive and specific evaluation of extensor mechanism malalignment can improve patient care by preventing both redislocation and abnormal tracking of overlooked malalignment and complications of unnecessary tibial tuberosity medialization. PMID:26535396

  19. Effects of celecoxib on proliferation and tenocytic differentiation of tendon-derived stem cells

    SciTech Connect

    Zhang, Kairui; Zhang, Sheng; Li, Qianqian; Yang, Jun; Dong, Weiqiang; Wang, Shengnan; Cheng, Yirong; Al-Qwbani, Mohammed; Wang, Qiang; Yu, Bin

    2014-07-18

    Highlights: • Celecoxib has no effects on TDSCs cell proliferation in various concentrations. • Celecoxib reduced mRNAs levels of tendon associated transcription factor. • Celecoxib reduced mRNAs levels of main tendon associated collagen. • Celecoxib reduced mRNAs levels of tendon associated molecules. - Abstract: NSAIDs are often ingested to reduce the pain and improve regeneration of tendon after tendon injury. Although the effects of NSAIDs in tendon healing have been reported, the data and conclusions are not consistent. Recently, tendon-derived stem cells (TDSCs) have been isolated from tendon tissues and has been suggested involved in tendon repair. Our study aims to determine the effects of COX-2 inhibitor (celecoxib) on the proliferation and tenocytic differentiation of TDSCs. TDSCs were isolated from mice Achilles tendon and exposed to celecoxib. Cell proliferation rate was investigated at various concentrations (0.1, 1, 10 and 100 μg/ml) of celecoxib by using hemocytometer. The mRNA expression of tendon associated transcription factors, tendon associated collagens and tendon associated molecules were determined by reverse transcription-polymerase chain reaction. The protein expression of Collagen I, Collagen III, Scleraxis and Tenomodulin were determined by Western blotting. The results showed that celecoxib has no effects on TDSCs cell proliferation in various concentrations (p > 0.05). The levels of most tendon associated transcription factors, tendon associated collagens and tendon associated molecules genes expression were significantly decreased in celecoxib (10 μg/ml) treated group (p < 0.05). Collagen I, Collagen III, Scleraxis and Tenomodulin protein expression were also significantly decreased in celecoxib (10 μg/ml) treated group (p < 0.05). In conclusion, celecoxib inhibits tenocytic differentiation of tendon-derived stem cells but has no effects on cell proliferation.

  20. Development of the shields for tendon injury repair using polyvinyl alcohol--hydrogel ( PVA-H).

    PubMed

    Kobayashi, M; Toguchida, J; Oka, M

    2001-01-01

    In recent years, marked advances have been made in repair techniques for tendon injury, but the treatment of finger flexor tendon injury is still one of the most difficult and important problems in the orthopedic field. The main problem in tendon repair is adhesion between the tendon and surrounding tissue. To prevent this adhesion and achieve tendon union, we developed adhesion preventive shields for tendon repair using polyvinyl alcohol hydrogel ( PVA-H) with 90% water content, and carried out an implant experiment using the deep flexor tendon of the third toe of domestic fowl. Injured tendons shielded with PVA-H showed union at about 3 weeks after the operation without adhesion to the surrounding tissue and good function such as gliding and range of motion. Neither breakage of the PVA-H shield itself nor infection, nor degeneration in the surrounding tissue were observed. These results confirmed that the tendon itself has repair ability, and the tendon is regenerated by synovial nutrition through PVA-H. High water content PVA-H may have clinically potential and be applicable to adhesion-preventive shields for tendon repair. However, re-rupture was observed, probably due to accidental tendon injury at an early period after the operation. In some cases, tendon immobilization methods to prevent re-rupture might be necessary. PMID:11410891

  1. Contribution of biomechanics to management of ligament and tendon injuries.

    PubMed

    Woo, Savio L Y; Fisher, Matthew B; Feola, Andrew J

    2008-03-01

    The contribution of biomechanics to the advancement of management of ligament and tendon injuries has been significant. Thanks to Professor Y.C. Fung's writing and guidance, our field of research has done fundamental work on anatomy and biology of ligaments and tendons, developed methods to accurately determine mechanical properties, identified various experimental factors which could change the outcome measurements as well as examined biological factors that change tissue properties in-vivo. Professor Fung also gave us his quasi-linear viscoelastic theory for soft tissues so that the time and history dependent properties of ligaments and tendons could be properly described. We have further adopted Professor Fung's eight steps on methods of approach for biomechanical investigation to understand as well as enhance the treatment of ligament and tendon injuries during work or sports related activities. Examples on how to better treat the tears of the medial collateral ligament of the knee, as well as how to improve reconstruction procedures for the anterior cruciate ligament are presented in detail. Currently the use of functional tissue engineering for ligament and tendon healing is a topic of great interest. Here the use of biological scaffolds, such as porcine small intestinal submucosa, has shown promise. For the last 35 to 40 years, the field of biomechanics has made great strides in the treatment of ligament and tendon injuries, and many patients have benefited. The future is even brighter because of what has been done properly in the past. Exciting advances can be made in the field of tissue engineering through novel in-vitro culture and bioscaffold fabrication techniques. Recent technology can also allow the collection of in-vivo data so that ligament and tendon injuries can be better understood. Yet, solving new and more complex problems must still follow the stepwise methods of approach as taught by Professor Fung. PMID:18524246

  2. 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.

  3. 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

  4. Giant Cell Tumor of Tendon Sheath

    PubMed Central

    Briët, Jan Paul; Becker, Stéphanie JE; Oosterhoff, Thijs CH; Ring, David

    2015-01-01

    Background: Giant cell tumor of tendon sheath (GCTTS) is often thought of as a volar finger mass. We hypothesized that GCTTS are equally common on the dorsal and volar aspects of the hand. In addition, we hypothesized that there are no factors associated with the location (volar versus dorsal) and largest measured dimension of a GCTTS. Methods: A total of 126 patients with a pathological diagnosis of a GCTTS of the hand or finger were reviewed. Basic demographic and GCTTS specific information was obtained. Bivariable analyses were used to assess predicting factors for location (volar or dorsal side) and largest measured diameter of a GCTTS. Results: Seventy-two tumors (57%) were on the volar side of the hand, 47 (37%) were dorsal, 6 (4.8%) were both dorsal and volar, and one was midaxial (0.79%). The most common site of a GCTTS was the index finger (30%). There were no factors significantly associated with the location (volar or dorsal, n=119) of the GCTTS. There were also no factors significantly associated with a larger diameter of a GCTTS. Conclusions: A GCTTS was more frequently seen on the volar aspect of the hand. No significant factors associated with the location or an increased size of a GCTTS were found in this study. PMID:25692164

  5. Ultrasound elastography for imaging tendons and muscles

    PubMed Central

    2012-01-01

    Ultrasound elastography is a recently developed ultrasound-based method which allows the qualitative or quantitative evaluation of the mechanical properties of tissue. Strain (compression) ultrasound elastography is the commonest technique performed by applying mild compression with the hand-held transducer to create real-time strain distribution maps, which are color-coded and superimposed on the B-mode images. There is increasing evidence that ultrasound elastography can be used in the investigation of muscle, tendon and soft tissue disease in the clinical practice, as a supplementary tool to conventional ultrasound examination. Based on preliminary data, potential clinical applications include early diagnosis, staging, and guiding interventions musculotendinous and neuromuscular disease as well as monitoring disease during rehabilitation. Ultrasound elastography could also be used for research into the biomechanics and pathophysiology of musculotendinous disease. Despite the great interest in the technique, there is still limited evidence in the literature and there are several technical issues which limit the reproducibility of the method, including differences in quantification methods, artefacts, limitations and variation in the application of the technique by different users. This review presents the published evidence on musculoskeletal applications of strain elastography, discusses the technical issues and future perspectives of this method and emphasizes the need for standardization and further research.

  6. 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

  7. The vasculature and its role in the damaged and healing tendon.

    PubMed

    Fenwick, Steven A; Hazleman, Brian L; Riley, Graham P

    2002-01-01

    Tendon pathology has many manifestations, from spontaneous rupture to chronic tendinitis or tendinosis; the etiology and pathology of each are very different, and poorly understood. Tendon is a comparatively poorly vascularised tissue that relies heavily upon synovial fluid diffusion to provide nutrition. During tendon injury, as with damage to any tissue, there is a requirement for cell infiltration from the blood system to provide the necessary reparative factors for tissue healing. We describe in this review the response of the vasculature to tendon damage in a number of forms, and how and when the revascularisation or neovascularisation process occurs. We also include a section on the revascularisation of tendon during its use as a tendon graft in both ligament reconstruction and tendon-tendon grafting. PMID:12106496

  8. Diclofenac Patch for Treatment of Mild to Moderate Tendonitis or Bursitis

    ClinicalTrials.gov

    2008-08-05

    Rotator Cuff Tendonitis; Bicipital Tendonitis; Subdeltoid Bursitis of the Shoulder; Subacromial Bursitis of the Shoulder; Medial Epicondylitis of the Elbow; Lateral Epicondylitis of the Elbow; DeQuervain's Tenosynovitis of the Wrist

  9. Editorial Commentary: Quadriceps Tendon Autograft Use for Anterior Cruciate Ligament Reconstruction Predicted to Increase.

    PubMed

    Lubowitz, James H

    2016-01-01

    Quadriceps tendon autograft is the least utilized choice for anterior cruciate ligament reconstruction, but use is expected to increase. Harvest of the full thickness of the distal quadriceps tendon is of concern, but morbidity seems low. PMID:26743412

  10. Tendon Mechanobiology: Current Knowledge and Future Research Opportunities

    PubMed Central

    Lavagnino, Michael; Wall, Michelle E.; Little, Dianne; Banes, Albert J.; Guilak, Farshid; Arnoczky, Steven P.

    2015-01-01

    Tendons mainly function as load-bearing tissues in the muscloskeletal system, transmitting loads from muscle to bone. Tendons are dynamic structures that respond to the magnitude, direction, frequency, and duration of physiologic as well as pathologic mechanical loads via complex interactions between cellular pathways and the highly specialized extracellular matrix. This paper reviews the evolution and current knowledge of mechanobiology in tendon development, homeostasis, disease, and repair. In addition, we review several novel mechanotransduction pathways that have been identified recently in other tissues and cell types, providing potential research opportunities in the field of tendon mechanobiology. We also highlight current methods, models, and technologies being used in a wide variety of mechanobiology research that could be investigated in the context of their potential applicability for answering some of the fundamental unanswered questions in this field. The article concludes with a review of the major questions and future goals discussed during the recent ORS/ISMMS New Frontiers in Tendon Research Conference held September 10–11, 2014 in New York City. PMID:25763779

  11. Should we think about wrist extensor after flexor tendon repair?

    PubMed Central

    Ferreira, Aline M; Tanaka, Denise M; Barbosa, Rafael I; Marcolino, Alexandre M; Elui, Valeria MC; Mazzer, Nilton

    2013-01-01

    Objective: To evaluate the activity of wrist extensor muscle, correlating with wrist motion during gripping after flexor tendon repair. Design: Cross-sectional clinical measurement study. Setting: Laboratory for biomechanics and rehabilitation. Subjects: A total of 11 patients submitted to rehabilitation by early passive motion of the fingers with wrist flexion position were evaluated after 8 weeks of fingers flexor tendon repair and 11 healthy volunteers, all ranging from 20 to 37 years of age. Intervention: Volunteers performed an isometric standardized gripping task. Main measures: We used electrogoniometry to analyze wrist range of motion and surface electromyography, considering 100% maximum voluntary contraction to represent the amplitude of electromyographic activity of the extensor carpi radialis and flexor digitorum superficialis. Results: Patients with flexor tendon repair showed co-activation deficit between wrist extensor (extensor carpi radialis) and flexor finger muscles (flexor digitorum superficialis) during gripping in the intermediate phase of rehabilitation, despite some recovering mobility for wrist extension (p ? 0.05). A moderate correlation between range of motion and extensor carpi radialis was present only for injured group (r = 0.32). Total active motion score, which represents finger active excursion, was regular or poor in 65% of cases, all with nerve repair associated. Conclusion: Wrist extensors have an important synergist role at handgrip, although some imbalance can be present after flexor tendon repair. These preliminary findings suggest that emphasis could be directed to add synergistic wrist motion in rehabilitation protocols after flexor tendon repair. Future studies with early active rehabilitation are necessary. PMID:26770674

  12. An investigation of tendon sheathing filler migration into concrete

    SciTech Connect

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

    1998-03-01

    During some of the inspections at nuclear power plants with prestressed concrete containments, it was observed that the containments has experienced leakage of the tendon sheathing filler (i.e., streaks). The objective of this activity was to provide an indication of the extent of tendon sheathing filler leakage into the concrete and its affects on concrete properties. Literature was reviewed and concrete core samples were obtained from the Trojan Nuclear Plant and tested. The literature primarily addressed effects of crude or lubricating oils that are known to cause concrete damage. However, these materials have significantly different characteristics relative to the materials used as tendon sheathing fillers. Examination and testing of the concrete cores indicated that the appearance of tendon sheathing filler on the concrete surface was due to leakage from the conduits and its subsequent migration through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks and there was no perceptible movement into the concrete. Results of compressive strength testing indicated that the concrete quality was consistent in the containment and that the strength had increased over 40% in 25.4 years relative to the average compressive strength at 28-days age.

  13. Tendon-to-Bone Attachment: From Development to Maturity

    PubMed Central

    Zelzer, Elazar; Blitz, Einat; Killian, Megan L.; Thomopoulos, Stavros

    2014-01-01

    The attachment between tendon and bone occurs across a complex transitional tissue that minimizes stress concentrations and allows for load transfer between muscles and skeleton. This unique tissue cannot be reconstructed following injury, leading to high incidence of recurrent failure and stressing the need for new clinical approaches. This review describes the current understanding of the development and function of the attachment site between tendon and bone. The embryonic attachment unit, namely, the tip of the tendon and the bone eminence into which it is inserted, was recently shown to develop modularly from a unique population of Sox9- and Scx-positive cells, which are distinct from tendon fibroblasts and chondrocytes. The fate and differentiation of these cells is regulated by transforming growth factor beta and bone morphogenetic protein signaling, respectively. Muscle loads are then necessary for the tissue to mature and mineralize. Mineralization of the attachment unit, which occurs postnatally at most sites, is largely controlled by an Indian hedgehog/parathyroid hormone-related protein feedback loop. A number of fundamental questions regarding the development of this remarkable attachment system require further study. These relate to the signaling mechanism that facilitates the formation of an interface with a gradient of cellular and extracellular phenotypes, as well as to the interactions between tendon and bone at the point of attachment. PMID:24677726

  14. Cell therapies for tendons: old cell choice for modern innovation.

    PubMed

    Petrou, Ilias G; Grognuz, Anthony; Hirt-Burri, Nathalie; Raffoul, Wassim; Applegate, Lee Ann

    2014-01-01

    Although tissue engineering and cell therapies are becoming realistic approaches for medical therapeutics, it is likely that musculoskeletal applications will be among the first to benefit on a large scale. Cell sources for tissue engineering and cell therapies for tendon pathologies are reviewed with an emphasis on small defect tendon injuries as seen in the hand which could adapt well to injectable cell administration. Specifically, cell sources including tenocytes, tendon sheath fibroblasts, bone marrow or adipose-derived stem cells, amniotic cells, placenta cells and platelet-derivatives have been proposed to enhance tendon regeneration. The associated advantages and disadvantages for these different strategies will be discussed and evolving regulatory requirements for cellular therapies will also be addressed. Human progenitor tenocytes, along with their clinical cell banking potential, will be presented as an alternative cell source solution. Similar cell banking techniques have already been described with other progenitor cell types in the 1950's for vaccine production, and these "old" cell types incite potentially interesting therapeutic options that could be improved with modern innovation for tendon regeneration and repair. PMID:25102358

  15. Synthetic collagen fascicles for the regeneration of tendon tissue.

    PubMed

    Kew, S J; Gwynne, J H; Enea, D; Brookes, R; Rushton, N; Best, S M; Cameron, R E

    2012-10-01

    The structure of an ideal scaffold for tendon regeneration must be designed to provide a mechanical, structural and chemotactic microenvironment for native cellular activity to synthesize functional (i.e. load bearing) tissue. Collagen fibre scaffolds for this application have shown some promise to date, although the microstructural control required to mimic the native tendon environment has yet to be achieved allowing for minimal control of critical in vivo properties such as degradation rate and mass transport. In this report we describe the fabrication of a novel multi-fibre collagen fascicle structure, based on type-I collagen with failure stress of 25-49 MPa, approximating the strength and structure of native tendon tissue. We demonstrate a microscopic fabrication process based on the automated assembly of type-I collagen fibres with the ability to produce a controllable fascicle-like, structural motif allowing variable numbers of fibres per fascicle. We have confirmed that the resulting post-fabrication type-I collagen structure retains the essential phase behaviour, alignment and spectral characteristics of aligned native type-I collagen. We have also shown that both ovine tendon fibroblasts and human white blood cells in whole blood readily infiltrate the matrix on a macroscopic scale and that these cells adhere to the fibre surface after seven days in culture. The study has indicated that the synthetic collagen fascicle system may be a suitable biomaterial scaffold to provide a rationally designed implantable matrix material to mediate tendon repair and regeneration. PMID:22728568

  16. Characterization and differentiation of equine tendon-derived progenitor cells.

    PubMed

    Lovati, A B; Corradetti, B; Lange Consiglio, A; Recordati, C; Bonacina, E; Bizzaro, D; Cremonesi, F

    2011-01-01

    Mesenchymal stem cells have been recently investigated for their potential use in regenerative medicine. Population of adult stem cells were recently identified in human and lab animal tendons, but no detailed investigations have been made in the equine species. The aim of our study is to identify a progenitor cell population from tendon tissue (TSPCs) in the horse superficial digital flexor tendon that are able to be highly clonogenic, to grow fast and to differentiate in different induced cell lineages as well as bone marrow derived progenitor cells (BM-MSCs). The hypothesis that TSPCs possess a mesenchymal stem cell behavior opens a new prospective for tendon regenerative medicine approaches. TSPCs were expanded more rapidly and showed higher plating efficiency when compared with BM-MSCs. Both cell lines expressed identical stem cell markers in vitro and they were able to differentiate towards osteogenic and adipogenic lineages as demonstrated with cytochemical staining and mRNA gene expression. TSPCs showed a positive but limited chondrogenic differentiation compared with BM-MSCs as demonstrated by histological and biochemical analyses. According to our results, equine TSPCs have high clonogenic properties and proliferating potential, they express stem cell markers and have the capability to be multipotent as well as BM-MSCs. These findings suggest that TSPCs may represent a good model for stem cell biology and could be useful for future tendon regenerative medicine investigations. PMID:22051173

  17. Correlation of remaining patellar tendon width with quadriceps strength after autogenous bone-patellar tendon-bone anterior cruciate ligament reconstruction.

    PubMed

    Shelbourne, K D; Rubinstein, R A; VanMeter, C D; McCarroll, J R; Rettig, A C

    1994-01-01

    One hundred twenty-one patients were prospectively studied to determine whether the different remaining patellar tendon widths after central 10-mm bone-patellar tendon-bone graft harvest influenced the rate and level of quadriceps strength achieved during rehabilitation. Size of the patellar tendon width, measured at the same location in each patient, ranged from 24 to 35 mm. For this study, patients were grouped according to their remaining tendon size into small (14 to 17 mm; mean, 15.8), medium (18 to 20 mm; mean, 19.2), and large (21 to 25 mm; mean, 22.5) widths. Postoperatively, the patient's isokinetic quadriceps scores were determined at 6 weeks, 3 months, 6 months, and 1 year. At 6 weeks, the small- and medium-width tendon groups were significantly weaker than the large-width tendon group. At 3 months, only the small-width tendon group continued to be significantly weaker than the large-width tendon group. At and beyond 6 months, no statistically significant differences were seen between remaining patellar tendon width groups and their isokinetic quadriceps scores. A constant-sized autogenous patellar tendon graft may be harvested for anterior cruciate ligament reconstruction without compromising ultimate postoperative quadriceps strength recovery. PMID:7856801

  18. Effects of lubricant and autologous bone marrow stromal cell augmentation on immobilized flexor tendon repairs.

    PubMed

    Zhao, Chunfeng; Ozasa, Yasuhiro; Shimura, Haruhiko; Reisdorf, Ramona L; Thoreson, Andrew R; Jay, Gregory; Moran, Steven L; An, Kai-Nan; Amadio, Peter C

    2016-01-01

    The purpose of the study was to test a novel treatment that carbodiimide-derivatized-hyaluronic acid-lubricin (cd-HA-lubricin) combined cell-based therapy in an immobilized flexor tendon repair in a canine model. Seventy-eight flexor tendons from 39 dogs were transected. One tendon was treated with cd-HA-lubricin plus an interpositional graft of 8?×?10(5) BMSCs and GDF-5. The other tendon was repaired without treatment. After 21 day of immobilization, 19 dogs were sacrificed; the remaining 20 dogs underwent a 21-day rehabilitation protocol before euthanasia. The work of flexion, tendon gliding resistance, and adhesion score in treated tendons were significantly less than the untreated tendons (p?tendons was higher than the treated tendons at 21 and 42 days (p?tendons showed a smooth surface and viable transplanted cells 42 days after the repair, whereas untreated tendons showed severe adhesion formation around the repair site. The combination of lubricant and cell treatment resulted in significantly improved digit function, reduced adhesion formation. This novel treatment can address the unmet needs of patients who are unable to commence an early mobilization protocol after flexor tendon repair. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:154-160, 2016. PMID:26177854

  19. Proteomics-based identification of novel proteins in temporal tendons of patients with masticatory muscle tendon--aponeurosis hyperplasia.

    PubMed

    Nakamoto, A; Sato, T; Hirosawa, N; Nakamoto, N; Enoki, Y; Chida, D; Usui, M; Takeda, S; Nagai, T; Sasaki, A; Sakamoto, Y; Yoda, T

    2014-01-01

    Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a new disease associated with limited mouth opening that is often misdiagnosed as a temporomandibular disorder; subsequently, patients are mistakenly treated with irreversible operations. Due to the poor presentation and characterization of symptoms, the underlying pathological conditions remain unclear. We have previously conducted a proteomic analysis of tendons derived from one MMTAH subject and one facial deformity subject using two-dimensional fluorescence difference gel electrophoresis and liquid chromatography coupled with tandem mass spectrometry. However, the results were obtained for only one subject. The aim of the present study was to confirm the expression of specific molecules in tendon tissues from multiple subjects with MMTAH by applying two-dimensional polyacrylamide gel electrophoresis with matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Of the 19 proteins identified in tendons from both MMTAH and facial deformity patients, fibrinogen fragment D and beta-crystallin A4 were up-regulated, whereas myosin light chain 4 was down-regulated in MMTAH. We also found fibrinogen to be expressed robustly in tendon tissues of MMTAH patients. Our data provide the possibility that the distinctive expression of these novel proteins is associated with the pathology of MMTAH. PMID:23870541

  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. 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.

  3. 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.

  4. 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.

  5. An Investigation of Tendon Corrosion-Inhibitor Leakage into Concrete

    SciTech Connect

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

    1999-07-05

    During inspections performed at US nuclear power plants several years ago, some of the prestressed concrete containment had experienced leakage of the tendon sheathing filler. A study was conducted to indicate the extent of the leakage into the concrete and its potential effects on concrete properties. Concrete core samples were obtained from the Trojan Nuclear Plant. Examination and testing of the core samples indicated that the appearance of tendon sheathing filler on the surface was due to leakage of the filler from the conduits and its subsequent migration to the concrete surface through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks with no perceptible movement into the concrete. Results of compressive strength tests indicated that the concrete quality was consistent in the containment and that the strength had increased relative to the strength at 28 days age.

  6. 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.

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

    PubMed

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

    2013-04-01

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

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

    PubMed Central

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

    2013-01-01

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

  9. 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. PMID:25810985

  10. Irreducible Anteromedial Dislocation of Radial Head with Biceps Tendon Interposition.

    PubMed

    Climent-Peris, Vicente J; Sirera-Vercher, Josette; Sanz-Amaro, M Dolores

    2016-01-01

    The case presents an isolated irreducible anteromedial dislocation of radial head due to biceps tendon interposition on a 14-year-old female patient. After an unsuccessful closed reduction, a lateral approach of the left elbow was carried out through Kocher's interval. Given that no pathology was found on the radiohumeral joint, the approach was extended distally. This revealed that the biceps tendon was displaced laterally around the radial neck, preventing the reduction. Once the tendon was taken back to its anatomical position, the radial head reduction was performed successfully. The patient achieved a complete functional recovery. Possible injury mechanisms are discussed, as well as the importance of identifying such a rare injury. PMID:26925279

  11. Irreducible Anteromedial Dislocation of Radial Head with Biceps Tendon Interposition

    PubMed Central

    Climent-Peris, Vicente J.; Sirera-Vercher, Josette; Sanz-Amaro, M. Dolores

    2016-01-01

    The case presents an isolated irreducible anteromedial dislocation of radial head due to biceps tendon interposition on a 14-year-old female patient. After an unsuccessful closed reduction, a lateral approach of the left elbow was carried out through Kocher's interval. Given that no pathology was found on the radiohumeral joint, the approach was extended distally. This revealed that the biceps tendon was displaced laterally around the radial neck, preventing the reduction. Once the tendon was taken back to its anatomical position, the radial head reduction was performed successfully. The patient achieved a complete functional recovery. Possible injury mechanisms are discussed, as well as the importance of identifying such a rare injury. PMID:26925279

  12. Traumatic subluxation/dislocation of the peroneal tendons.

    PubMed

    Brage, M E; Hansen, S T

    1992-09-01

    Traumatic subluxation/dislocation of the peroneal tendons has been reported following a variety of sports-related activities. The peroneal musculature contracts reflexively during the injury and overcomes the restraining soft tissue. The tendons can then dislocate anteriorly from behind the distal fibula. Some patients have anatomical variations of the posterolateral ankle that predispose them to injury. If the physician is unaware of the injury, the diagnosis may be missed in the acute setting and can develop into a chronic, disabling condition. Treatment of the acute injury is controversial because advocates exist for both conservative and surgical therapies. The chronic, painful lesion should be treated operatively. A tremendous number of surgical procedures have been described for the treatment of chronic tendon dislocations. Choice of a surgical procedure depends upon the anatomy of the peroneal groove and the retinaculum, and the nature of the damage to the area. PMID:1427535

  13. Could Ossification of the Achilles Tendon Have a Hereditary Component?

    PubMed Central

    Cortbaoui, Chawki

    2013-01-01

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

  14. Partial-Thickness Grooves In A VBL Memory Device

    NASA Technical Reports Server (NTRS)

    Katti, Romney R.; Wu, Jiin-Chuan; Stadler, Henry L.

    1994-01-01

    Bias magnetic fields tailored to match those needed elsewhere in device. Grooves through part of thickness of magnetic garnet storage layer of vertical-Bloch-line (VBL) memory device used to confine magnetic bubble and stripe domains in desired storage areas. VBL-memory concept described in "Vertical-Bloch-Line Memory" (NPO-18467).

  15. PAPP-A affects tendon structure and mechanical properties.

    PubMed

    Yang, Tai-Hua; Thoreson, Andrew R; An, Kai-Nan; Zhao, Chunfeng; Conover, Cheryl A; Amadio, Peter C

    2015-10-01

    Pregnancy-associated plasma protein-A (PAPP-A) serves to increase local insulin-like growth factor (IGF) stimulation of proliferation and differentiation in many tissues through proteolysis of inhibitory IGF-binding proteins. The purpose of this study was to investigate the effects of PAPP-A on tendon structure and mechanical properties. A total of 30 tails from 6-month-old mice were tested with 10 tails in each of following groups: PAPP-A knockout (KO), skeletal-specific PAPP-A overexpressing transgenic (Tg) and wild type (WT). Morphologically, the total tail cross-sectional area (CSA), individual tissue CSAs of bone, muscle and tendon, and fascicle diameter were measured. A fascicle pullout test was performed to assess stiffness and strength of interfascicular structures. Fascicles were mechanically characterized through low and high displacement rate uniaxial tension tests providing modulus at each rate, hysteresis area and stress relaxation ratio. The KO mice had a smaller total tail CSA (p<0.05), fascicle diameter (p<0.05), absolute tendon CSA (p<0.05), fast and slow stiffness (p<0.05 for both) and larger hysteresis area (p<0.05) compared to WT and Tg mice. On the other hand, the Tg mice had a larger fascicle diameter (p<0.05), absolute tendon CSA (p<0.05), higher interfascicular strength and stiffness (p<0.05) and lower fascicular modulus at low displacement rates (p<0.05) compared to WT and KO mice. Tg mice also had larger total tail CSA area (p<0.05) and smaller hysteresis area (p<0.05) than KO mice, and larger normalized tendon CSA (p<0.05) than WT mice. Based on these data, we conclude that PAPP-A affects fascicle structure, thereby affecting tendon phenotype. PMID:26306763

  16. Prediction of the elastic strain limit of tendons.

    PubMed

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

    2014-02-01

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

  17. The Role of Bioreactors in Ligament and Tendon Tissue Engineering.

    PubMed

    Mace, James; Wheelton, Andy; Khan, Wasim S; Anand, Sanj

    2016-01-01

    Bioreactors are pivotal to the emerging field of tissue engineering. The formation of neotissue from pluripotent cell lineages potentially offers a source of tissue for clinical use without the significant donor site morbidity associated with many contemporary surgical reconstructive procedures. Modern bioreactor design is becoming increasingly complex to provide a both an expandable source of readily available pluripotent cells and to facilitate their controlled differentiation into a clinically applicable ligament or tendon like neotissue. This review presents the need for such a method, challenges in the processes to engineer neotissue and the current designs and results of modern bioreactors in the pursuit of engineered tendon and ligament. PMID:26337379

  18. Biomechanical risk factors and flexor tendon frictional work in the cadaveric carpal tunnel.

    PubMed

    Kociolek, Aaron M; Tat, Jimmy; Keir, Peter J

    2015-02-01

    Pathological changes in carpal tunnel syndrome patients include fibrosis and thickening of the subsynovial connective tissue (SSCT) adjacent to the flexor tendons in the carpal tunnel. These clinical findings suggest an etiology of excessive shear-strain force between the tendon and SSCT, underscoring the need to assess tendon gliding characteristics representative of repetitive and forceful work. A mechanical actuator moved the middle finger flexor digitorum superficialis tendon proximally and distally in eight fresh frozen cadaver arms. Eighteen experimental conditions tested the effects of three well-established biomechanical predictors of injury, including a combination of two wrist postures (0° and 30° flexion), three tendon velocities (50, 100, 150mm/sec), and three forces (10, 20, 40N). Tendon gliding resistance was determined with two light-weight load cells, and integrated over tendon displacement to represent tendon frictional work. During proximal tendon displacement, frictional work increased with tendon velocity (58.0% from 50-150mm/sec). There was a significant interaction between wrist posture and tendon force. In wrist flexion, frictional work increased 93.0% between tendon forces of 10 and 40N. In the neutral wrist posture, frictional work only increased 33.5% (from 10-40N). During distal tendon displacement, there was a similar multiplicative interaction on tendon frictional work. Concurrent exposure to multiple biomechanical work factors markedly increased tendon frictional work, thus providing a plausible link to the pathogenesis of work-related carpal tunnel syndrome. Additionally, our study provides the conceptual basis to evaluate injury risk, including the multiplicative repercussions of combined physical exposures. PMID:25553671

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

    PubMed

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

    2013-12-01

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

  20. [Repair of a triceps tendon rupture using autogenous semi-tendinous and gracilis tendons. A case report and retrospective chart review].

    PubMed

    Dos Remedios, C; Brosset, T; Chantelot, C; Fontaine, C

    2007-06-01

    The authors report the rare case of an athlete having a complete rupture of the distal triceps tendon associated with severe chronic degenerative pathology of the triceps tendon induced by forced weight-lifting exercises and repetitive corticosteroid injections. Reconstruction of the ruptured triceps was possible using autogenous semi-tendinous and gracilis tendons. The good functional outcome obtained with this technique and the analysis of the retrospective chart review suggest that when direct reattachment is impossible (tendon retraction or loss of tendon in post-traumatic or degenerative injury) or not sufficient (weakness after total elbow arthroplasty surgery), the use of an autogenous semi-tendinous and gracilis tendons permits a good functional outcome. PMID:17616417

  1. Experimental studies in chickens on the initial nutrition of tendon grafts.

    PubMed

    Manske, P R; Lesker, P A; Bridwell, K

    1979-11-01

    A study of nutrition of various tendon graft preparations in adult chickens (up to 2 weeks after grafting), using tritiated proline and a trichloracetic acid extraction technique which separated the free and metabolized amino acid fractions, suggests that diffusion of nutrients is an important process in the initial nutrition of tendon grafts, that tendon grafts are metabolically active and viable structures, that adhesions which are frequently associated with tendon grafts do not appear to be essential to the nutrition of grafts, and that tendon grafts within fibrous pseudosheaths are nourished as effectively as grafts within synovial sheaths. PMID:512314

  2. Missed Medial Malleolar Fracture Associated With Achilles Tendon Rupture: A Case Report and Literature Review.

    PubMed

    Nakajima, Koji; Taketomi, Shuji; Inui, Hiroshi; Nakamura, Kensuke; Sanada, Takaki; Tanaka, Sakae

    2016-01-01

    A 45-year-old man sustained an Achilles tendon rupture while playing futsal. A concomitant medial malleolar fracture was not diagnosed until the patient underwent an operation for Achilles tendon repair. A routine postoperative radiograph showed a minimally displaced medial malleolar fracture. Conservative treatment was chosen for the fracture. The function of the Achilles tendon recovered well, and the fracture was united. A medial malleolar fracture can be missed when an Achilles tendon rupture occurs simultaneously. Thus, surgeons should consider the possibility of medial malleolar fracture associated with an Achilles tendon rupture. PMID:25441273

  3. [Questions concerning two-stage reconstruction of injured flexor tendons. III. Ultrastructure of the tenosynovium in the pseudo-tendon sheath created by using a silicone rod].

    PubMed

    Salamon, A; Bíró, V; Vámhidy, L; Trombitás, K; Józsa, L

    1993-01-01

    Authors have investigated the ultrastructure of the pseudo tendon sheath, formed with silicon rod and man. They have observed a superficial structure, resembling the normal tendon sheath in scanning electron microscopic examination. With transmission electron microscopy phagocyte "A" type and secretion "B" type synovial cells were found. Authors state that the newly formed tenosynovium has an important role in the nutrition of the tendon graft and the prevention of adhesions. PMID:8136879

  4. Experimental flexor tendon healing without adhesion formation--a new concept of tendon nutrition and intrinsic healing mechanisms. A preliminary report.

    PubMed

    Lundborg, G

    1976-10-01

    An experimental model is presented enabling an analysis of the healing process of completely cut and re-sutured free segments of rabbit flexor tendons, kept avascular in a synovial milieu and completely isolated from adhesion formation. Under these conditions the cut tendons heal within a few weeks. It can be shown that this healing process is a result of intrinsic tendon cell activity only. PMID:976821

  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. Engineered tendon with decellularized xenotendon slices and bone marrow stromal cells: an in vivo animal study

    PubMed Central

    Omae, Hiromichi; Sun, Yu Long; An, Kai-Nan; Amadio, Peter C.; Zhao, Chunfeng

    2013-01-01

    The purpose of this study was to investigate an engineered composite of multilayer acellular tendon slices seeded with bone marrow stromal cells (BMSCs) as a possible solution for tendon reconstruction. BMSCs were harvested from 15 rabbits and infraspinatus tendons were harvested from 17 dogs. The decellularized tendons were sectioned in longitudinal slices with a thickness of 50 ?m. The BMSCs were seeded on the slices and then the slices were bundled into one composite. The composite was implanted into a rabbit patellar tendon defect. Tendon slices without BMSCs were implanted into the contralateral patellar tendon as a control. The composites were evaluated by histology and qRT–PCR. The viability of BMSCs was assessed using a fluorescent marker. Histology showed viable cells between the collagen fibres on the cell-seeded side. Analysis by qRT–PCR showed higher tenomodulin, collagen type III, MMP3 and MMP13 expressions and lower collagen type I expression in the cell-seeded composite than in the tendon slices without BMSCs. We conclude that BMSCs can survive in a multilayer composite, express a tendon phenotype and enhance the metabolism of tendon in vivo. This in vivo study suggests a potential utility of this composite in tendon reconstruction. PMID:21449044

  7. 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

  8. Ten weeks of treadmill running decreases stiffness and increases collagen turnover in tendons of old mice.

    PubMed

    Wood, Lauren K; Brooks, Susan V

    2016-02-01

    Increased tendon stiffness in response to mechanical loading is well established in young animals. Given that tendons stiffen with aging, we aimed to determine the effect of increased loading on tendons of old animals. We subjected 28-month-old mice to 10 weeks of uphill treadmill running; sedentary 8- and 28-month-old mice served as controls. Following training, plantaris tendon stiffness and modulus were reduced by approximately half, such that the values were not different from those of tendons from adult sedentary animals. The decrease in plantaris tendon stiffness was accompanied by a similar reduction in the levels of advanced glycation end-product protein adducts in tibialis anterior tendons of trained compared with sedentary old mice. In Achilles tendons, elevated mRNA levels for collagen type 1, matrix-metalloproteinase-8, and lysyl oxidase following training suggest that collagen turnover was likely also increased. The dramatic mechanical and structural changes induced by training occurred independent of changes in cell density or tendon morphology. Finally, Achilles tendon calcification was significantly reduced following exercise. These results demonstrate that, in response to exercise, tendons from old animals are capable of replacing damaged and dysfunctional components of extracellular matrix with tissue that is mechanically and structurally comparable to adult tissue. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:346-353, 2016. PMID:25640809

  9. Presence of a long accessory flexor tendon of the toes in surgical treatment for tendinopathy of the insertion of the calcaneal tendon: case report☆

    PubMed Central

    Gomes Júnior, Nelson Pelozo; Andreoli, Carlos Vicente; Pochini, Alberto de Castro; Raduan, Fernando Cipolini; Ejnisman, Benno; Cohen, Moisés

    2015-01-01

    The presence of accessory tendons in the foot and ankle needs to be recognized, given that depending on their location, they may cause disorders relating either to pain processes or to handling of the surgical findings. We describe the presence of an accessory flexor tendon of the toes, seen in surgical exposure for transferring the long flexor tendon of the hallux to the calcaneus, due to the presence of a disorder of tendinopathy of the insertion of the calcaneal tendon in association with Haglund's syndrome.

  10. Use of a Hunter Rod for Staged Reconstruction of Peroneal Tendons.

    PubMed

    Raikin, Steven M; Schick, Faith A; Karanjia, Homyar N

    2016-01-01

    Peroneal tendon pathology is a commonly reported cause of lateral ankle pain. The causes include cavovarus foot type, overuse, chronic tendinosis, peroneal subluxation or dislocation, acute traumatic split tears, and traumatic rupture. The purpose of the present report is to describe an alternative approach for surgical reconstruction of the peroneal tendons in patients when repair might no longer be effective. The use of a Hunter rod was originally described by Hunter in 1971 for 2-stage reconstruction of tendons in the hand. We present a 2-stage surgical technique with the use of a Hunter rod as a temporary implant to stimulate generation of a healthy peroneal tendon sheath to host a flexor hallucis longus tendon transfer. This has proved to be a successful treatment option for patients with severe peroneal tendon damage and scarring along the peroneal tendon sheath. We offer a sample case to illustrate a patient with such indications. PMID:26282362

  11. 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

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

    PubMed

    Caborn, David N M; Selby, Jeffrey B

    2002-01-01

    For a variety of reasons, bone-patellar tendon-bone and Achilles tendon allografts have been used more commonly in anterior cruciate ligament reconstruction. Soft-tissue allografts used mainly are the semitendinosus, gracilis, and occasionally the quadriceps tendons. The anterior tibialis tendon is a thick, strong tendon that can be prepared with one doubling of the graft, has a large cross-sectional area, and has been shown to be stronger than semitendinosus, gracilis, patellar tendon, and native anterior cruciate ligament. Use of allograft shortens surgical time, eliminates graft harvest-site morbidity, and allows for a large supply of grafts for repeat or multiple ligament procedures. This graft can be fixed to the femoral and tibial bone tunnels with bioabsorbable interference screws for a hardware-free, completely endoscopic procedure. Two- to 4-year results of allograft procedures are comparable to autograft procedures, and there have been no early failures with this described technique using anterior tibialis tendon. PMID:11774151

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

    TOXLINE Toxicology Bibliographic Information

    Caborn DN; Selby JB

    2002-01-01

    For a variety of reasons, bone-patellar tendon-bone and Achilles tendon allografts have been used more commonly in anterior cruciate ligament reconstruction. Soft-tissue allografts used mainly are the semitendinosus, gracilis, and occasionally the quadriceps tendons. The anterior tibialis tendon is a thick, strong tendon that can be prepared with one doubling of the graft, has a large cross-sectional area, and has been shown to be stronger than semitendinosus, gracilis, patellar tendon, and native anterior cruciate ligament. Use of allograft shortens surgical time, eliminates graft harvest-site morbidity, and allows for a large supply of grafts for repeat or multiple ligament procedures. This graft can be fixed to the femoral and tibial bone tunnels with bioabsorbable interference screws for a hardware-free, completely endoscopic procedure. Two- to 4-year results of allograft procedures are comparable to autograft procedures, and there have been no early failures with this described technique using anterior tibialis tendon.

  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. 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

  16. Changes in the Achilles tendon reflexes following Skylab missions

    NASA Technical Reports Server (NTRS)

    Baker, J. T.; Nicogossian, A. E.; Hoffler, G. W.; Johnson, R. L.; Hordinsky, J. R.

    1977-01-01

    Postflight measurements of Achilles tendon reflex duration on Skylab crewmen indicate a state of disequilibrium between the flexor and extensor muscle groups with an initial decrease in reflex duration. As the muscles regain strength and mass there occurs an overcompensation reflected by increased reflex duration. Finally, when a normal neuromuscular state is reached the reflex duration returns to baseline value.

  17. Fibrous Tendon Hypertrophy after Gastrocnemius Recession: A Case Report.

    PubMed

    Jastifer, James R; Coughlin, Michael J

    2016-01-01

    Surgical complications after gastrocnemius recession have been rare in published studies. We report a case of symptomatic fibrous tendon hypertrophy requiring revision surgery. Additionally, we have provided a review of the published data on the complications related to this procedure. PMID:25116231

  18. The use of Zylon fibers in ULDB tendons

    NASA Astrophysics Data System (ADS)

    Seely, Loren; Zimmerman, Mike; McLaughlin, Joe

    2004-01-01

    Early in the development of the ultra long duration balloon (ULDB), Zylon was selected as the tendon material due to its favorable stress-strain properties. It is a next generation fiber whose strength and modulus are almost double those of the Kevlar fibers. In addition there are two versions of the Zylon, as spun (AS) and high modulus (HM). Data will be presented on why HM was chosen. Early in the development process, it was learned that this material exhibited an unusual sensitivity to degradation by ambient light. This is in addition to the expected sensitivity to UV (Ultraviolet) radiation. The fiber manufacturer reported all of these properties in their literature. Due to the operating environment of the ULDB it is necessary to protect the tendons from both visible and UV radiation. Methods to protect the tendons will be discussed. In addition, information on the long term exposure of the braided tendon over a thirty-two month period in a controlled manufacturing plant will be provided. Special testing methods will be noted.

  19. Graft site morbidity with autogenous semitendinosus and gracilis tendons.

    PubMed

    Yasuda, K; Tsujino, J; Ohkoshi, Y; Tanabe, Y; Kaneda, K

    1995-01-01

    To distinguish between morbidity caused by harvesting semitendinosus and gracilis tendons and morbidity associated with anterior cruciate ligament reconstruction surgery, we performed a prospective randomized study using 65 patients who underwent anterior cruciate ligament reconstruction using these tendons. The patients underwent either contralateral (N = 34) or ipsilateral (N = 31) graft harvest. For the nonoperated knees in the ipsilateral harvest group, isometric and isokinetic strength of the quadriceps and hamstring muscles increased to approximately 120% of the preoperative value at 12 months after surgery. Compared with these knees, the tendon harvest did not affect quadriceps muscle strength at all. However, harvest did decrease hamstring muscles strength for 9 months after surgery. The graft harvest in the knees with anterior cruciate ligament reconstruction also did not significantly affect quadriceps muscle strength, but it did significantly decrease hamstring muscles strength only at 1 month. Activity-related soreness at the donor site was rarely restricting and resolved by 3 months. This study demonstrated that the semitendinosus and gracilis tendon graft is a reasonable choice to minimize the donor site morbidity in ligament reconstruction using autografts. PMID:8600739

  20. Investigation to predict patellar tendon reflex using motion analysis technique.

    PubMed

    Tham, L K; Osman, N A Abu; Lim, K S; Pingguan-Murphy, B; Abas, W A B Wan; Zain, N Mohd

    2011-05-01

    The investigation of patellar tendon reflex involves development of a reflex hammer holder, kinematic data collection and analysis of patellar reflex responses using motion analysis techniques. The main aim of this research is to explore alternative means of assessing reflexes as a part of routine clinical diagnosis. The motion analysis system was applied to provide quantitative data which is a more objective measure of the patellar tendon reflex. Kinematic data was collected from 28 males and 22 females whilst subjected to a knee jerk test. Further analysis of kinematic data was performed to predict relationships which might affect the patellar tendon reflex. All subjects were seated on a high stool with their legs hanging freely within the capture volume of the motion analysis system. Knee jerk tests were applied to all subjects, on both sides of the leg, by eliciting hypo, hyper, and normal reflexes. An additional reinforcement technique called the Jendrassik manoeuvre was also performed under the same conditions to elicit a normal patellar tendon reflex. The comparison of reflex response between genders showed that female subjects generally had a greater response compared to males. However, the difference in reflex response between the left leg and the right leg was not significant. Tapping strength to elicit a hyper-reflex produced greater knee-jerk compared to the normal clinical tapping strength. All results were in agreement with clinical findings and results found by some early researchers. PMID:21146440

  1. Age-related changes in mechanical properties of the Achilles tendon

    PubMed Central

    Waugh, C M; Blazevich, A J; Fath, F; Korff, T

    2012-01-01

    The stiffness of a tendon, which influences muscular force transfer to the skeleton and increases during childhood, is dependent on its material properties and dimensions, both of which are influenced by chronic loading. The aims of this study were to: (i) determine the independent contributions of body mass, force production capabilities and tendon dimensions to tendon stiffness during childhood; and (ii) descriptively document age-related changes in tendon mechanical properties and dimensions. Achilles tendon mechanical and material properties were determined in 52 children (5–12 years) and 19 adults. Tendon stiffness and Young's modulus (YM) were calculated as the slopes of the force–elongation and stress-strain curves, respectively. Relationships between stiffness vs. age, mass and force, and between YM vs. age, mass and stress were determined by means of polynomial fits and multiple regression analyses. Mass was found to be the best predictor of stiffness, whilst stress was best related to YM (< 75 and 51% explained variance, respectively). Combined, mass and force accounted for up to 78% of stiffness variation. Up to 61% of YM variability could be explained using a combination of mass, stress and age. These results demonstrate that age-related increases in tendon stiffness are largely attributable to increased tendon loading from weight-bearing tasks and increased plantarflexor force production, as well as tendon growth. Moreover, our results suggest that chronic increases in tendon loading during childhood result in microstructural changes which increase the tendon's YM. Regarding the second aim, peak stress increased from childhood to adulthood due to greater increases in strength than tendon cross-sectional area. Peak strain remained constant as a result of parallel increases in tendon length and peak elongation. The differences in Achilles tendon properties found between adults and children are likely to influence force production, and ultimately movement characteristics, which should be explicitly examined in future research. PMID:22150089

  2. Involvement of Na+/Ca2+ exchanger in migration and contraction of rat cultured tendon fibroblasts

    PubMed Central

    Sakamoto, Kazuho; Owada, Yuki; Shikama, Yayoi; Wada, Ikuo; Waguri, Satoshi; Iwamoto, Takahiro; Kimura, Junko

    2009-01-01

    In response to injury and inflammation of tendons, tendon fibroblasts are activated, migrate to the wound, and eventually induce contraction of the extracellular matrices to repair the tissue. Under such conditions, Ca2+ signalling is involved in motility and contractility of tendon fibroblasts. Using cultured tendon fibroblasts isolated from rat Achilles tendons, we investigated functional expression of Na+/Ca2+ exchangers (NCX). The fluorometric study showed that the intracellular Ca2+ concentration ([Ca2+]i) was increased by reducing extracellular Na+ concentration ([Na+]o) in tendon fibroblasts. Selective NCX inhibitors, KB-R7943 and SEA0400, both attenuated [Na+]o-dependent [Ca2+]i elevation and the resting [Ca2+]i in tendon fibroblasts. RT-PCR, Western blots and sequence analyses revealed that NCX1.3 and NCX1.7 were expressed in cultured tendon fibroblasts. NCX2 mRNA was undetected. NCX3 expression was negligibly low. Immunofluorescence microscopy indicated that NCX1 protein localized in the plasma membrane especially at the microspikes of tendon fibroblasts. In the wound-healing scratch assay, the cells migrated toward the space created by a scratch and almost completely filled the space within 48 h. This phenomenon was significantly suppressed by KB-R7943 and SEA0400. Furthermore, the NCX inhibitors abrogated the tendon fibroblast-mediated collagen-matrix contractions. Two types of siRNAs for NCX1 also suppressed the migration and contraction of tendon fibroblasts. We conclude that NCX is expressed and mediates Ca2+ influx in cultured tendon fibroblasts. Since the pharmacological inhibitors and siRNA for NCX1 suppressed motility and contractility of tendon fibroblasts, NCX may play an important role in the function of tendon fibroblasts in the wound healing. PMID:19770194

  3. The Dynamics of Collagen Uncrimping and Lateral Contraction in Tendon and the Effect of Ionic Concentration

    PubMed Central

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

    2013-01-01

    Under tensile loading, tendon undergoes a number of unique structural changes that govern its mechanical response. For example, stretching a tendon is known to induce both the progressive “uncrimping” of wavy collagen fibrils and extensive lateral contraction mediated by fluid flow out of the tissue. However, it is not known whether these processes are interdependent. Moreover, the rate-dependence of collagen uncrimping and its contribution to tendon’s viscoelastic mechanical properties are unknown. Therefore, the objective of this study was to a) develop a methodology allowing for simultaneous measurement of crimp, stress, axial strain and lateral contraction in tendon under dynamic loading; b) determine the interdependence of collagen uncrimping and lateral contraction by testing tendons in different swelling conditions; and c) assess how the process of collagen uncrimping depends on loading rate. Murine flexor carpi ulnaris (FCU) tendons in varying ionic environments were dynamically stretched to a set strain level and imaged through a plane polariscope with the polarizer and analyzer at a fixed angle. Analysis of the resulting images allowed for direct measurement of the crimp frequency and indirect measurement of the tendon thickness. Our findings demonstrate that collagen uncrimping and lateral contraction can occur independently and interstitial fluid impacts tendon mechanics directly. Furthermore, tensile stress, transverse contraction and degree of collagen uncrimping were all rate-dependent, suggesting that collagen uncrimping plays a role in tendon’s dynamic mechanical response. This study is the first to characterize the time-dependence of collagen uncrimping in tendon establishes structure-function relationships for healthy tendons that can be used to better understand and assess changes in tendon mechanics after disease or injury. PMID:23876711

  4. The role of vasculature and angiogenesis for the pathogenesis of degenerative tendons disease.

    PubMed

    Pufe, T; Petersen, W J; Mentlein, R; Tillmann, B N

    2005-08-01

    More than 100 years ago Wilhelm Roux (1895) introduced the term "functional adaptation to anatomy and physiology". Compared with other organ systems the functional adaptation processes are best identifiable in the locomotor system, like for example in the two types of tendons: traction and gliding tendons. Traction tendons are tendons where the direction of pull is in line with the direction of the muscle (e.g. Achilles tendon). Gliding tendons (e.g. tibialis posterior tendon) change direction by turning around a bony or fibrous hypomochlion. In this region the tendon is subjected to intermittent compressive and shear forces and the extracellular matrix consists of avascular fibrocartilage. Avascularity is considered to be a key factor for the etiology of degenerative tendon disease. The repair capability after repetitive microtrauma is strongly compromised in avascular tissue of gliding tendons. Reduced vascularity is not a specific feature of gliding tendons; several studies have shown that the number and size of blood vessels are largely shortened in the waist of the Achilles tendon. However, histological biopsies from degenerated Achilles tendons and Doppler flow examinations revealed a high blood vessel density in patients with degenerative tendon disease. Angiogenesis is mediated by angiogenic factors and recent studies have shown that the vascular endothelial growth factor (VEGF) is highly expressed in degenerative Achilles tendons, whereas VEGF expression is nearly completely downregulated in healthy tendons. Several factors are able to upregulate VEGF expression in tenocytes: hypoxia, inflammatory cytokines and mechanical load. Since VEGF has the potential to stimulate the expression of matrix metalloproteinases and inhibit the expression of tissue inhibitors of matrix metalloproteinases tissue inhibitor of metalloproteinases (TIMP) in various cell types (e.g. endothelial cells, fibroblasts, chondrocytes), this cytokine might play a significant role for the pathogenetic processes during degenerative tendon disease. An animal experiment in the rabbit has shown that local injection of VEGF reduced the material properties of the Achilles tendon. These experimental findings are in accordance with clinical results that a locally administered (in the area with neovascularization) sclerosing drug (Polidocanol) has a beneficial effect on chronic mid-portion Achilles tendinosis. In conclusion, decreased and increased vascularity might be involved in the pathogenesis of degenerative Achilles tendon disease. PMID:15998338

  5. 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

  6. Muscle–tendon structure and dimensions in adults and children

    PubMed Central

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

    2010-01-01

    Muscle performance is closely related to the architecture and dimensions of the muscle–tendon unit and the effect of maturation on these architectural characteristics in humans is currently unknown. This study determined whether there are differences in musculo-tendinous architecture between adults and children of both sexes. Fascicle length and pennation angle were measured from ultrasound images at three sites along the length of the vastus intermedius, vastus lateralis, vastis medialis and rectus femoris muscles. Muscle volume and muscle–tendon length were measured from magnetic resonance images. Muscle physiological cross-sectional area (PCSA) was calculated as the ratio of muscle volume to optimum fascicle length. Fascicle length was greater in the adult groups than in children (P < 0.05) but pennation angle did not differ between groups (P > 0.05). The ratios between fascicle and muscle length and between fascicle and tendon length were not different (P > 0.05) between adults and children for any quadriceps muscle. Quadriceps volume and PCSA of each muscle were greater in adults than children (P < 0.01) but the relative proportion of each head to the total quadriceps volume was similar in all groups. However, the difference in PCSA between adults and children (men ? 104% greater than boys, women ? 57% greater than girls) was greater (P < 0.05) than the difference in fascicle length (men ? 37% greater than boys, women ? 10% greater than girls). It is concluded that the fascicle, muscle and tendon lengthen proportionally during maturation, thus the muscle–tendon stiffness and excursion range are likely to be similar in children and adults but the relatively greater increase in PCSA than fascicle length indicates that adult muscles are better designed for force production than children’s muscles. PMID:20345856

  7. 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

  8. 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

  9. 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

  10. Lack of tissue renewal in human adult Achilles tendon is revealed by nuclear bomb 14C

    PubMed Central

    Heinemeier, Katja Maria; Schjerling, Peter; Heinemeier, Jan; Magnusson, Stig Peter; Kjaer, Michael

    2013-01-01

    Tendons are often injured and heal poorly. Whether this is caused by a slow tissue turnover is unknown, since existing data provide diverging estimates of tendon protein half-life that range from 2 mo to 200 yr. With the purpose of determining life-long turnover of human tendon tissue, we used the 14C bomb-pulse method. This method takes advantage of the dramatic increase in atmospheric levels of 14C, produced by nuclear bomb tests in 1955–1963, which is reflected in all living organisms. Levels of 14C were measured in 28 forensic samples of Achilles tendon core and 4 skeletal muscle samples (donor birth years 1945–1983) with accelerator mass spectrometry (AMS) and compared to known atmospheric levels to estimate tissue turnover. We found that Achilles tendon tissue retained levels of 14C corresponding to atmospheric levels several decades before tissue sampling, demonstrating a very limited tissue turnover. The tendon concentrations of 14C approximately reflected the atmospheric levels present during the first 17 yr of life, indicating that the tendon core is formed during height growth and is essentially not renewed thereafter. In contrast, 14C levels in muscle indicated continuous turnover. Our observation provides a fundamental premise for understanding tendon function and pathology, and likely explains the poor regenerative capacity of tendon tissue.—Heinemeier, K. M., Schjerling, P., Heinemeier, J., Magnusson, S. P., Kjaer, M. Lack of tissue renewal in human adult Achilles tendon is revealed by nuclear bomb 14C. PMID:23401563

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

    PubMed

    Kalisiak, O

    2012-01-01

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

  12. The cellular biology of flexor tendon adhesion formation: an old problem in a new paradigm.

    PubMed

    Wong, Jason K F; Lui, Yin H; Kapacee, Zoher; Kadler, Karl E; Ferguson, Mark W J; McGrouther, Duncan A

    2009-11-01

    Intrasynovial flexor tendon injuries of the hand can frequently be complicated by tendon adhesions to the surrounding sheath, limiting finger function. We have developed a new tendon injury model in the mouse to investigate the three-dimensional cellular biology of intrasynovial flexor tendon healing and adhesion formation. We investigated the cell biology using markers for inflammation, proliferation, collagen synthesis, apoptosis, and vascularization/myofibroblasts. Quantitative immunohistochemical image analysis and three-dimensional reconstruction with cell mapping was performed on labeled serial sections. Flexor tendon adhesions were also assessed 21 days after wounding using transmission electron microscopy to examine the cell phenotypes in the wound. When the tendon has been immobilized, the mouse can form tendon adhesions in the flexor tendon sheath. The cell biology of tendon healing follows the classic wound healing response of inflammation, proliferation, synthesis, and apoptosis, but the greater activity occurs in the surrounding tissue. Cells that have multiple "fibripositors" and cells with cytoplasmic protrusions that contain multiple large and small diameter fibrils can be found in the wound during collagen synthesis. In conclusion, adhesion formation occurs due to scarring between two damaged surfaces. The mouse model for flexor tendon injury represents a new platform to study adhesion formation that is genetically tractable. PMID:19834058

  13. 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

  14. Stretching Your Energetic Budget: How Tendon Compliance Affects the Metabolic Cost of Running

    PubMed Central

    Uchida, Thomas K.; Hicks, Jennifer L.; Dembia, Christopher L.; Delp, Scott L.

    2016-01-01

    Muscles attach to bones via tendons that stretch and recoil, affecting muscle force generation and metabolic energy consumption. In this study, we investigated the effect of tendon compliance on the metabolic cost of running using a full-body musculoskeletal model with a detailed model of muscle energetics. We performed muscle-driven simulations of running at 2–5 m/s with tendon force–strain curves that produced between 1 and 10% strain when the muscles were developing maximum isometric force. We computed the average metabolic power consumed by each muscle when running at each speed and with each tendon compliance. Average whole-body metabolic power consumption increased as running speed increased, regardless of tendon compliance, and was lowest at each speed when tendon strain reached 2–3% as muscles were developing maximum isometric force. When running at 2 m/s, the soleus muscle consumed less metabolic power at high tendon compliance because the strain of the tendon allowed the muscle fibers to operate nearly isometrically during stance. In contrast, the medial and lateral gastrocnemii consumed less metabolic power at low tendon compliance because less compliant tendons allowed the muscle fibers to operate closer to their optimal lengths during stance. The software and simulations used in this study are freely available at simtk.org and enable examination of muscle energetics with unprecedented detail. PMID:26930416

  15. Fetal Development of the Human Obturator Internus Muscle With Special Reference to the Tendon and Pulley.

    PubMed

    Naito, Michiko; Suzuki, Ryoji; Abe, Hiroshi; Rodriguez-Vazquez, Jose Francisco; Murakami, Gen; Aizawa, Shin

    2015-07-01

    To examine the development of the tendon pulley of the obturator internus muscle (OI), we observed paraffin sections of 26 human embryos and fetuses (?6-15 weeks of gestation). The OI was characterized by early maturation of the proximal tendon in contrast to the delayed development of the distal tendon. At 6 weeks, the ischium corresponded to a simple round mass similar to the tuberosity in adults. At 8 weeks, before development of the definite lesser notch of the ischium, initial muscle fibers of the OI, running along the antero-posterior axis, converged onto a thick and tight but short tendon running along the left-right axis. Thus, at the beginning of development, the OI muscle belly and tendon met almost at a right angle. At 10 weeks, the OI tendon extended inferiorly along the sciatic nerve, but the distal part remained thin and loose and it was embedded in the gluteus medius tendon. At 15 weeks, in association with the gemellus muscles, the distal OI tendon was established. The mechanically strong sciatic nerve was first likely to catch the OI muscle fibers to provide a temporary insertion. Next, the ischium developing upward seemed to push the tendon to make the turn more acute along the cartilaginous ridge. Finally, the gemellus muscle appeared to provide inferior traction to the OI tendon for separation from the gluteus medius to create the final, independent insertion. Without such guidance, the piriformis tendon first attached to the OI tendon and then merged with the gluteus medius tendon. PMID:25683268

  16. Equine Induced Pluripotent Stem Cells have a Reduced Tendon Differentiation Capacity Compared to Embryonic Stem Cells.

    PubMed

    Bavin, Emma P; Smith, Olivia; Baird, Arabella E G; Smith, Lawrence C; Guest, Deborah J

    2015-01-01

    Tendon injuries occur commonly in horses and their repair through scar tissue formation predisposes horses to a high rate of re-injury. Pluripotent stem cells may provide a cell replacement therapy to improve tendon tissue regeneration and lower the frequency of re-injury. We have previously demonstrated that equine embryonic stem cells (ESCs) differentiate into the tendon cell lineage upon injection into the damaged horse tendon and can differentiate into functional tendon cells in vitro to generate artificial tendons. Induced pluripotent stem cells (iPSCs) have now been derived from horses but, to date, there are no reports on their ability to differentiate into tendon cells. As iPSCs can be produced from adult cell types, they provide a more accessible source of cells than ESCs, which require the use of horse embryos. The aim of this study was to compare tendon differentiation by ESCs and iPSCs produced through two independent methods. In two-dimensional differentiation assays, the iPSCs expressed tendon-associated genes and proteins, which were enhanced by the presence of transforming growth factor-?3. However, in three-dimensional (3D) differentiation assays, the iPSCs failed to differentiate into functional tendon cells and generate artificial tendons. These results demonstrate the utility of the 3D in vitro tendon assay for measuring tendon differentiation and the need for more detailed studies to be performed on equine iPSCs to identify and understand their epigenetic differences from pluripotent ESCs prior to their clinical application. PMID:26664982

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

    PubMed Central

    Legerlotz, Kirsten; Demirci, Taylan; Klemt, Christian; Riley, Graham P; Screen, Hazel RC

    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

  18. Equine Induced Pluripotent Stem Cells have a Reduced Tendon Differentiation Capacity Compared to Embryonic Stem Cells

    PubMed Central

    Bavin, Emma P.; Smith, Olivia; Baird, Arabella E. G.; Smith, Lawrence C.; Guest, Deborah J.

    2015-01-01

    Tendon injuries occur commonly in horses and their repair through scar tissue formation predisposes horses to a high rate of re-injury. Pluripotent stem cells may provide a cell replacement therapy to improve tendon tissue regeneration and lower the frequency of re-injury. We have previously demonstrated that equine embryonic stem cells (ESCs) differentiate into the tendon cell lineage upon injection into the damaged horse tendon and can differentiate into functional tendon cells in vitro to generate artificial tendons. Induced pluripotent stem cells (iPSCs) have now been derived from horses but, to date, there are no reports on their ability to differentiate into tendon cells. As iPSCs can be produced from adult cell types, they provide a more accessible source of cells than ESCs, which require the use of horse embryos. The aim of this study was to compare tendon differentiation by ESCs and iPSCs produced through two independent methods. In two-dimensional differentiation assays, the iPSCs expressed tendon-associated genes and proteins, which were enhanced by the presence of transforming growth factor-β3. However, in three-dimensional (3D) differentiation assays, the iPSCs failed to differentiate into functional tendon cells and generate artificial tendons. These results demonstrate the utility of the 3D in vitro tendon assay for measuring tendon differentiation and the need for more detailed studies to be performed on equine iPSCs to identify and understand their epigenetic differences from pluripotent ESCs prior to their clinical application. PMID:26664982

  19. TGF-beta1 Suppresses Plasmin and MMP Activity in Flexor Tendon Cells via PAI-1: Implications for Scarless Flexor Tendon Repair

    PubMed Central

    Farhat, Youssef M.; Al-Maliki, Alaa A.; Easa, Anas; O’Keefe, Regis J.; Schwarz, Edward M.; Awad, Hani A.

    2014-01-01

    Flexor tendon injuries caused by deep lacerations to the hands are a challenging problem as they often result in debilitating adhesions that prevent the movement of the afflicted fingers. Evidence exists that tendon adhesions as well as scarring throughout the body are largely precipitated by the pleiotropic growth factor, TGF-?1, but the effects of TGF-?1 are poorly understood in tendon healing. Using an in vitro model of tendon healing, we previously found that TGF-?1 causes gene expression changes in tenocytes that are consistent with scar tissue and adhesion formation, including upregulation of the anti-fibrinolytic protein, PAI-1. Therefore, we hypothesized that TGF-?1 contributes to scarring and adhesions by reducing the activity of proteases responsible for ECM degradation and remodeling, such as plasmin and MMPs, via upregulation of PAI-1. To test our hypothesis, we examined the effects of TGF-?1 on the protease activity of tendon cells. We found that flexor tendon tenocytes treated with TGF-?1 had significantly reduced levels of active MMP-2 and plasmin. Interestingly, the effects of TGF-?1 on protease activity were completely abolished in tendon cells from homozygous PAI-1 KO mice, which are unable to express PAI-1. Our findings support the hypothesis that TGF-?1 induces PAI-1, which suppresses plasmin and plasmin-mediated MMP activity, and provide evidence that PAI-1 may be a novel therapeutic target for preventing adhesions and promoting a scarless, regenerative repair of flexor tendon injuries. PMID:24962629

  20. Adaptability of elderly human muscles and tendons to increased loading

    PubMed Central

    Narici, Marco V; Maganaris, Constantinos N

    2006-01-01

    Senile sarcopenia, the loss of muscle mass associated with aging, is one of the main causes of muscle weakness and reduced locomotor ability in old age. Although this condition is mainly driven by neuropathic processes, nutritional, hormonal and immunological factors, as well as a reduction in physical activity, contribute to this phenomenon. Sarcopenia alone, however, does not fully account for the observed muscle weakness, as the loss of force is greater than that accounted for by the decrease in muscle size. As a consequence, a reduction in the force per unit area, both at single fibre and at whole muscle level, is observed. We recently suggested that at whole muscle level, this reduction in intrinsic force is the result of the combined effect of changes in (1) muscle architecture, (2) tendon mechanical properties, (3) neural drive (reduced agonist and increased antagonist muscle activity) and (4) single fibre-specific tension. Whereas several studies support the role of the last two factors in the loss of intrinsic muscle force with aging, alterations in muscle architecture and in tendon mechanical properties have also been shown to contribute to the above phenomenon. Indeed, sarcopenia of the human plantarflexors, represented by a 25% reduction in muscle volume, was found to be associated with a 10% reduction in fibre fascicle length and 13% reduction in pennation angle. These architectural alterations were accompanied by a 10% decrease in tendon stiffness, attributable to alterations in tendon material properties, as suggested by a 14% decrease in Young's modulus. Most of these changes may be reversed by 14 weeks of resistive training; both fibre fascicle length and tendon stiffness were found to be increased by 10 and 64%, respectively. Surprisingly, however, training had no effect on the estimated relative length–tension properties of the muscle, indicating that the effects of greater tendon stiffness and increased fascicle length cancelled out each other. It seems that natural strategies may be in place to ensure that the relative operating range of muscle remains unaltered by changes in physical activity, in old age. PMID:16637869

  1. 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.

  2. Progression from calcifying tendinitis to rotator cuff tear.

    PubMed

    Gotoh, Masafumi; Higuchi, Fujio; Suzuki, Ritsu; Yamanaka, Kensuke

    2003-02-01

    This report documents the clinical, radiographic and histologic findings in a 46-year-old man with calcifying tendinitis in his left shoulder which progressed to rotator cuff tear. The patient had a 1-year history of repeated calcifying tendinitis before being referred to our hospital. On the initial visit, radiographs and magnetic resonance imaging (MRI) revealed calcium deposition localized in the supraspinatus tendon without apparent tear. Three months after the first visit, MRI revealed a partial-thickness rotator cuff tear at the site of calcium deposition. Surgical and histologic findings demonstrated that calcium deposition was the cause of cuff rupture. To our knowledge, based on a review of the English literature, this is the first case report in which the progression from calcifying tendinitis to rotator cuff tear has been serially observed. PMID:12589487

  3. 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.

  4. The Effect of Autologous Platelet Rich Plasma in the Treatment of Achilles Tendon Ruptures

    PubMed Central

    Şen, Baran; Güler, Serkan; Çeçen, Berivan; Kumtepe, Erdem; Bağrıyanık, Alper; Özkal, Sermin; Özcan, M. Ali; Özsan, Hayri; Şanlı, Namık; Tatari, Mehmet Hasan

    2014-01-01

    Objectives: The aim of this study was to determine the effect of autologous platelet rich plasma (PRP) in the treatment of Achilles tendon ruptures in rabbits. Methods: The study included 14 New Zealand albino rabbits that were divided randomly into 2 groups, A and B, each containing seven rabbits. On day zero, all 28 Achilles tendons were tenotomized and repaired. In group A, the tendons were injected with PRP post surgery whereas those in group B were left untreated. On day 28, the right tendons in both groups were examined histopathologically via both light and electron microscopy, and the left tendons were subjected to biomechanical testing. Results: The histological and biomechanical findings in group A were better than those in group B, but the difference was not significant. Conclusion: PRP had no effect on the healing process 28 days post Achilles tendon rupture.

  5. The effect of flexor sheath integrity on nutrient uptake by chicken flexor tendons.

    PubMed

    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 3H-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 3H-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. PMID:4064412

  6. Monitoring of sutured flexor tendons using spectral domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Tay, Chia-Meng B.; Chow, Tzu-Hao; Ng, Beng-Koon; He, Min; Gan, Wei-Tat A.; Chong, Khin-Sze A.

    2010-02-01

    The material behaviour of sutured tendons is important in healing models as mechanical trauma to the tendon during surgery can compromise the healing process. This work demonstrates the use of spectral domain optical coherence tomography (SD-OCT) for the monitoring of normal and injured, and subsequently repaired flexor tendons and their behaviour under load. Vertical crimp patterns in normal tendons were observed to be replaced by uniform scattering as the load increases, but the crimp periods in sutured tendons were constrained at the suture site, with gap separation at the suture joint tapering off at high loads. This information could be useful for surgeons who need to balance gap separation in healing tendons and sustainable load.

  7. The musculoskeletal loading profile of the thumb during pipetting based on tendon displacement.

    PubMed

    Wu, John Z; Sinsel, Erik W; Shroyer, Justin F; Welcome, Daniel E; Zhao, Kristin D; An, Kai-Nan; Buczek, Frank L

    2013-12-01

    Strong evidence indicates that highly repetitive manual work is associated with the development of upper extremity musculoskeletal disorders (MSDs). One of the occupational activities that involves highly repetitive and forceful hand work is manual pipetting in chemical or biological laboratories. In the current study, we quantified tendon displacement as a parameter to assess the cumulative loading exposure of the musculoskeletal system in the thumb during pipetting. The maximal tendon displacement was found in the flexor pollicis longus (FPL) tendon. Assuming that subjects' pipetting rates were maintained constant during a period of 1 h, the average accumulated tendon displacement in the FPL reached 29 m, which is in the lower range of those observed in other occupational activities, such as typing and nail gun operations. Our results showed that tendon displacement data contain relatively small standard deviations, despite high variances in thumb kinematics, suggesting that the tendon displacements may be useful in evaluating the musculoskeletal loading profile. PMID:24018066

  8. Spring or string: does tendon elastic action influence wing muscle mechanics in bat flight?

    PubMed

    Konow, Nicolai; Cheney, Jorn A; Roberts, Thomas J; Waldman, J Rhea S; Swartz, Sharon M

    2015-10-01

    Tendon springs influence locomotor movements in many terrestrial animals, but their roles in locomotion through fluids as well as in small-bodied mammals are less clear. We measured muscle, tendon and joint mechanics in an elbow extensor of a small fruit bat during ascending flight. At the end of downstroke, the tendon was stretched by elbow flexion as the wing was folded. At the end of upstroke, elastic energy was recovered via tendon recoil and extended the elbow, contributing to unfurling the wing for downstroke. Compared with a hypothetical 'string-like' system lacking series elastic compliance, the tendon spring conferred a 22.5% decrease in muscle fascicle strain magnitude. Our findings demonstrate tendon elastic action in a small flying mammal and expand our understanding of the occurrence and action of series elastic actuator mechanisms in fluid-based locomotion. PMID:26423848

  9. Tendon injuries in horses treated with carbon fibre implants.

    PubMed

    Vaughan, L C; Edwards, G B; Gerring, E L

    1985-01-01

    Implants of carbon fibre, made by plaiting a tow of 10,000 filaments of Grafil type HT-S, were used to treat strains and ruptures of digital flexor tendons in 46 horses. The relevant clinical data, the techniques employed and an analysis of the results are described. Apart from two horses in which the implant was extruded and had to be removed, there were minimal untoward consequences of the surgery. Of the 34 horses with acute or chronic tendinitis, 14 returned to racing, seven were used as hunters and seven as hacks. Among the former group, seven suffered a further strain while racing but the others performed well for some time. Twelve horses with severed tendons recovered well and only in one did infection occur. Overall the results in the latter were better than had previously been achieved using other repair materials. PMID:3979373

  10. [Long-term results of 2-stage flexor tendon grafting].

    PubMed

    Madee, W; Reill, P

    1983-12-01

    The authors report the results of 85 two-stage tendon grafts (with Silastic rod preparation and subsequent tendon grafting) in which the evaluation was based upon the classification of Buck-Gramcko. The time between the end of treatment and physical evaluation varied from three to six years. The interpretation of the results was based on the analysis of the preoperative state according to the nature of the lesion and the severity of the injury (Boyes/Hunter). No distinct correlation between the type of injury and the functional results was found. In contrast a clear relationship was found between the final results and the preoperative state--good, scar, joint, multiple, salvage (Boyes/Hunter)--especially when nerves were involved. The high number of bad results even in cases with an excellent preoperative state is important for a critical approach to the technique. Nevertheless, in appropriate cases the method is undoubtedly of value. PMID:6654198

  11. 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

  12. 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.

  13. Multiple giant cell tumours of tendon sheath: a rare occurrence.

    PubMed

    Pathade, Smita Charandas; Kurpad, Ramkumar; Tauheed, Mohammed

    2014-01-01

    Giant Cell Tumours Of Tendon Sheath (GCTTS) are the second most frequent soft tissue tumours affecting the hand with an overall incidence of 1 in 50,000 individuals. These tumours are usually localized and solitary, with multiple GCTTS occurring rarely. Multi-centric origin is considered unusual and very few cases of multiple GCTTS have been reported till date. Here, we report a rare case of a 26-year-old female who presented with multiple painless swellings on palmar aspect of little finger of right hand since six months. Clinical diagnosis of Dupuytren's contracture was given. Intraoperative examination revealed multiple separate nodules, firmly attached to the flexor tendon synovial sheath. Histopathology showed features of GCTTS. PMID:24596760

  14. Multiple Giant Cell Tumours of Tendon Sheath: A Rare Occurrence

    PubMed Central

    Pathade, Smita Charandas; Kurpad, Ramkumar; Tauheed, Mohammed

    2014-01-01

    Giant Cell Tumours Of Tendon Sheath (GCTTS) are the second most frequent soft tissue tumours affecting the hand with an overall incidence of 1 in 50,000 individuals. These tumours are usually localized and solitary, with multiple GCTTS occurring rarely. Multi-centric origin is considered unusual and very few cases of multiple GCTTS have been reported till date. Here, we report a rare case of a 26-year-old female who presented with multiple painless swellings on palmar aspect of little finger of right hand since six months. Clinical diagnosis of Dupuytren’s contracture was given. Intraoperative examination revealed multiple separate nodules, firmly attached to the flexor tendon synovial sheath. Histopathology showed features of GCTTS. PMID:24596760

  15. Dynamic tracking of tendon elongation in ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Karimpoor, Mahta; Screen, Hazel; Morrissey, Dylan

    2010-02-01

    The aim of this study was to evaluate the elongation of the Achilles tendon by looking at the changing position of Myo-Tendenious Junction (MTJ) using ultrasound during isometric contraction on an Isometric dynamometer. A sequence of ultrasound images in the form of movie, obtained from a unit operating at a frequency of 12MHz during isometric contraction, was analyzed offline using MATLAB to track the MTJ. This investigation has implemented important techniques for in vivo feature extraction of Achilles tendon. Prior to feature extraction, the images were filtered by anisotropic diffusion method and morphological enhancements. The cross correlation search algorithm with an adaptive mask was utilized to track MTJ by comparing adjacent segmented frames. The present method was studied on seventeen subjects, where it was able to measure the related movement accurately.

  16. [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.

  17. 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

  18. 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

  19. Diagnosing Achilles tendon injuries in the emergency department.

    PubMed

    Gibbons, Lynda

    2013-09-01

    Achilles tendon (AT) injury is an overuse injury often seen in professional and recreational athletes. It tends to affect men, particularly those in their thirties and forties, more than women, and is typically seen in people who are intermittently active. To ensure AT ruptures are identified and treated effectively, early intervention in emergency departments (EDs) is crucial. This article discusses how advanced nurse practitioners can use their comprehensive problem-solving, clinical decision-making and clinical judgement skills to manage patients who present with suspected AT injury. It also describes the anatomy of tendon rupture, the aetiology and mechanism of injuries, and the importance of assessment and diagnostic tools, therapeutic techniques and management strategies. Finally, it considers the psychological effect this injury can have on patients, while in the ED and after discharge. A case study is included as an example of ED management. PMID:24024724

  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. Flexor tendon injuries in children: Rehabilitative options and confounding factors.

    PubMed

    von der Heyde, Rebecca

    2015-01-01

    Research pertaining to the rehabilitation of children with flexor tendon injuries is less prevalent than that in the adult population, and most authors agree that immobilization protocols comprise a safe and efficacious choice. This article presents suggested protocols and correlated literature regarding the outcomes of immobilization, early passive motion, and early active motion in the pediatric population. Confounding factors which influence rehabilitative choices, both personal and environmental, are also presented. PMID:25840491

  2. Entrapment of the flexor hallucis longus tendon following ankle arthrodesis.

    PubMed

    Keith, Troy; Robinson, Andrew H N

    2016-03-01

    Impingement following arthroscopic ankle arthrodesis has not been reported in the literature previously. We present a case report of a 68-year-old male 9 months following an uncomplicated arthroscopic ankle fusion presenting with persistent posteromedial ankle pain. Flexor hallucis longus (FHL) tendon impingement resulting from a prominent os trigonum was identified. This was successfully treated utilising hindfoot endoscopy with excision of the os trigonum and FHL release. PMID:26855428

  3. Effect of Calendula officinalis cream on achilles tendon healing.

    PubMed

    Aro, A A; Perez, M O; Vieira, C P; Esquisatto, M A M; Rodrigues, R A F; Gomes, L; Pimentel, E R

    2015-02-01

    In recent years, the scientific community has undertaken research on plant extracts, searching for compounds with pharmacological activities that can be used in diverse fields of medicine. Calendula officinalis L. is known to have antioxidant, anti-inflammatory, antibacterial, and wound healing properties when used to treat skin burns. Therefore, the purpose of this study was to analyze the effects of C. officinalis on the initial phase of Achilles tendon healing. Wistar rats were separated in three groups: Calendula (Cal)-rats with a transected tendon were treated with topical applications of C. officinalis cream and then euthanized 7 days after injury; Control (C)-rats were treated with only vehicle after transection; and Normal (N)-rats without tenotomy. Higher concentrations of hydroxyproline (an indicator of total collagen) and non-collagenous proteins were observed in the Cal group in relation to the C group. Zymography showed no difference in the amount of the isoforms of metalloproteinase-2 and of metalloproteinase-9, between C and Cal groups. Polarization microscopy images analysis showed that the Cal group presented a slightly higher birefringence compared with the C group. In sections of tendons stained with toluidine blue, the transected groups presented higher metachromasy as compared with the N group. Immunocytochemistry analysis for chondroitin-6-sulfate showed no difference between the C and Cal groups. In conclusion, the topical application of C. officinalis after tendon transection increases the concentrations of collagen and non-collagenous proteins, as well as the collagen organization in the initial phase of healing. PMID:25266273

  4. 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

  5. [Management of zone 1 flexor digitorum profundus tendon injuries].

    PubMed

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

    2014-12-01

    Flexor tendons repair in zone 1 is classically considered providing good results with an overall satisfactory finger function. However, the objective functional results after surgical repair of flexor digitorum profundus are sometimes disappointing. The authors describe the different surgical repair techniques available to the operator from so-called "traditional" sutures to newer methods of internal fixation using miniaturized anchor sutures. The management of postoperative procedures, that of failures and old cases are reported. PMID:24837520

  6. Anatomic anterior cruciate ligament reconstruction with quadriceps tendon autograft.

    PubMed

    Rabuck, Stephen J; Musahl, Volker; Fu, Freddie H; West, Robin V

    2013-01-01

    A multitude of graft options exist including both allograft and autograft sources for reconstruction of the anterior cruciate ligament. With recent concerns regarding the early graft failure and cost-effectiveness of allograft sources, more attention has been directed toward autograft options. However, autograft harvest has been associated with specific morbidity that can result in suboptimal outcomes. The quadriceps tendon is an excellent biomechanical and biologic option. PMID:23177469

  7. Bilateral Congenital Agenesis of the Long Head of the Biceps Tendon: The Beginning

    PubMed Central

    Rego Costa, Francisco; Esteves, Cátia; Melão, Lina

    2016-01-01

    The biceps brachii muscle is prone to variants but absence of the long head of the biceps (LHB) tendon is an exceptionally rare anomaly. This report concerns the fourth case of bilateral congenital absence of the LHB tendon and presents the ultrasonography (US) and magnetic resonance (MR) findings. Our case has the peculiarity of being the first in which bilateral LHB tendon agenesis is not associated with rotator cuff or labral tears. PMID:26904345

  8. 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

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

    PubMed

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

    2013-01-01

    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

  10. 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

  11. Effects of Increased Loading on In Vivo Tendon Properties: A Systematic Review

    PubMed Central

    WIESINGER, HANS-PETER; KÖSTERS, ALEXANDER; MÜLLER, ERICH; SEYNNES, OLIVIER R.

    2015-01-01

    ABSTRACT Introduction In vivo measurements have been used in the past two decades to investigate the effects of increased loading on tendon properties, yet the current understanding of tendon macroscopic changes to training is rather fragmented, limited to reports of tendon stiffening, supported by changes in material properties and/or tendon hypertrophy. The main aim of this review was to analyze the existing literature to gain further insights into tendon adaptations by extracting patterns of dose-response and time-course. Methods PubMed/Medline, SPORTDiscus, and Google Scholar databases were searched for studies examining the effect of training on material, mechanical, and morphological properties via longitudinal or cross-sectional designs. Results Thirty-five of 6440 peer-reviewed articles met the inclusion criteria. The key findings were i) the confirmation of a nearly systematic adaptation of tendon tissue to training, ii) the important variability in the observed changes in tendon properties between and within studies, and iii) the absence of a consistent incremental pattern regarding the dose-response or the time-course relation of tendon adaptation within the first months of training. However, long-term (years) training was associated with a larger tendon cross-sectional area, without any evidence of differences in material properties. Our analysis also highlighted several gaps in the existing literature, which may be addressed in future research. Conclusions In line with some cross-species observations about tendon design, tendon cross-sectional area allegedly constitutes the ultimate adjusting parameter to increased loading. We propose here a theoretical model placing tendon hypertrophy and adjustments in material properties as parts of the same adaptive continuum. PMID:25563908

  12. Accuracy of MRI technique in measuring tendon cross-sectional area.

    PubMed

    Couppé, C; Svensson, R B; Sødring-Elbrønd, V; Hansen, P; Kjaer, M; Magnusson, S P

    2014-05-01

    Magnetic resonance imaging (MRI) has commonly been applied to determine tendon cross-sectional area (CSA) and length either to measure structural changes or to normalize mechanical measurements to stress and strain. The ability to reproduce CSA measurements on MRI images has been reported, but the accuracy in relation to actual tendon dimensions has never been investigated. The purpose of this study was to compare tendon CSA measured by MRI with that measured in vitro with the mould casting technique. The knee of a horse was MRI-scanned with 1.5 and 3 tesla, and two examiners measured the patellar tendon CSA. Thereafter, the patellar tendon of the horse was completely dissected and embedded in an alginate cast. The CSA of the embedded tendon was measured directly by optical imaging of the cast impression. 1.5 tesla grey tendon CSA and 3 tesla grey tendon CSA were 16.5% and 13.2% lower than the mould tendon CSA, respectively. Also, 3 tesla tendon CSA, based on the red-green border on the National Institute of Health (NIH) colour scale, was lower than the mould tendon CSA by 2.8%. The typical error between examiners was below 2% for all the measured CSA. The typical error between examiners was below 2% for all the measured CSA. These data show that measuring tendon CSA on the grey-scale MRI images is associated with an underestimation, but by optimizing the measurement using a 3 tesla MRI and the appropriate NIH colour scale, this underestimation could be reduced to 2.8% compared with the direct measurements on the mould. PMID:24119143

  13. Evidence of accumulated stress in Achilles and anterior knee tendons in elite badminton players.

    PubMed

    Boesen, Anders Ploug; Boesen, Morten Ilum; Koenig, Merete Juhl; Bliddal, Henning; Torp-Pedersen, Soren; Langberg, Henning

    2011-01-01

    Tendon-related injuries are a major problem, but the aetiology of tendinopathies is unknown. In tendinopathies as well as during unaccustomed loading, intra-tendinous flow can be detected indicating that extensive loading can provoke intra-tendinous flow. The aim of present study is to evaluate the vascular response as indicated by colour Doppler (CD) activity in both the Achilles and patella tendon after loading during high-level badminton matches. The Achilles tendon was subdivided into a mid-tendon, pre-insertional, and insertional region and the anterior knee tendons into a quadriceps-, patella- and tuberositas region. Intra-tendinous flow was measured using both a semi-quantitative grading system (CD grading) and a quantitative scoring system (CF) on colour Doppler. Intra-tendinous flow in the Achilles and anterior knee tendons was examined in fourteen single players before tournament and after 1st and 2nd match, respectively on both the dominant and non-dominant side. All players had abnormal intra-tendinous flow (Colour Doppler ? grade 2) in at least one tendon in at least one scan during the tournament. At baseline, only two of the 14 players had normal flow in all the tendons examined. After 1st match, tendencies to higher intra-tendinous flow were observed in both the dominant patella tendon and non-dominant quadriceps tendon (P-values n.s.). After 2nd match, intra-tendinous flow was significant increased in the dominant patella tendon (P = 0.009). In all other locations, there was a trend towards a stepwise increase in intra-tendinous flow. The preliminary results indicate that high amount of intra-tendinous flow was found in elite badminton players at baseline and was increased after repetitive loading, especially in the patella tendon (dominant leg). The colour Doppler measurement can be used to determine changes in intra-tendinous flow after repetitive loading. PMID:20652535

  14. Avulsion of the flexor digitorum tendon secondary to enchondroma of the distal phalanx

    PubMed Central

    Wong, Winnie; Cross, Karen; Mahoney, James

    2004-01-01

    Flexor digitorum profundus (FDP) tendon avulsion is a common injury in sports. This is secondary to forced extension against flexor digitorum profundus contraction. However, avulsion injury of the FDP tendon secondary to an enchondroma of the distal phalanx is extremely rare. There have only been three previous reports of such an occurrence. This report describes a fourth case of an avulsion injury of the FDP tendon secondary to enchondroma of the distal phalanx of the fourth digit. PMID:24115877

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

    PubMed Central

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

    2013-01-01

    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 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 (R2=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

  16. Is There Any Correlation Between Patient Height and Patellar Tendon Length?

    PubMed Central

    Navali, Amir M; Jafarabadi, Mohammad Asghari

    2015-01-01

    Background: A potential specific problem of patellar tendon graft in ACL reconstruction is the possibility of graft-tunnel mismatch which could be more problematic with anatomic ACL reconstruction where the femoral tunnel is placed low on the lateral wall of the lateral femoral condyle. The occasional occurrence of this mismatch raises the question that whether a correlation exists between patient height and patellar tendon length. The purpose of the present study was to measure patellar tendon length as an anthropometric finding and to evaluate whether a correlation exists between patient height and patellar tendon length. Methods: Intra-operative measurement of patellar tendon length was carried out in 267 consecutive patients during bone-patellar tendon-bone (BTB) graft ACL reconstruction. Patient age, gender, height were recorded. The patellar tendon measurements were done independently by two surgeons and the possible inter-observer errors were checked. The data were analyzed using the Pearson correlation. Results: The mean length of the patellar tendon was 46.4 ± 4.8 mm (Mean ± SD) with a range of 32–61 mm. The mean patient height was 177 ± 7 cm (Mean ± SD) with a range of 159–197 cm. A weak positive correlations were found between patient height and patellar tendon length (Pearson r = 0.24, P< 0.001). The linear regression equation for patellar tendon length (y, in millimeters) as a function of patient height (x, in centimeters) can be expressed as y=16.54 + 0.17x. Conclusions: Our study showed a weak correlation between patellar tendon length and patient height. This finding is in contrast to the usual measurements in human anthropometry in which taller individuals have normally longer tendons and ligaments. The graft-tunnel mismatch may be the result of this variation. PMID:26110175

  17. 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

  18. Management of achilles tendon injury: A current concepts systematic review

    PubMed Central

    Gulati, Vivek; Jaggard, Matthew; Al-Nammari, Shafic Said; Uzoigwe, Chika; Gulati, Pooja; Ismail, Nizar; Gibbons, Charles; Gupte, Chinmay

    2015-01-01

    Achilles tendon rupture has been on the rise over recent years due to a variety of reasons. It is a debilitating injury with a protracted and sometimes incomplete recovery. Management strategy is a controversial topic and evidence supporting a definite approach is limited. Opinion is divided between surgical repair and conservative immobilisation in conjunction with functional orthoses. A systematic search of the literature was performed. Pubmed, Medline and EmBase databases were searched for Achilles tendon and a variety of synonymous terms. A recent wealth of reporting suggests that conservative regimens with early weight bearing or mobilisation have equivalent or improved rates of re-rupture to operative regimes. The application of dynamic ultrasound assessment of tendon gap may prove crucial in minimising re-rupture and improving outcomes. Studies employing functional assessments have found equivalent function between operative and conservative treatments. However, no specific tests in peak power, push off strength or athletic performance have been reported and whether an advantage in operative treatment exists remains undetermined. PMID:25992315

  19. Preparation of rat tail tendons for biomechanical and mechanobiological studies.

    PubMed

    Bruneau, Amélie; Champagne, Nadia; Cousineau-Pelletier, Paule; Parent, Gabriel; Langelier, Eve

    2010-01-01

    Rat tail tendons (RTTs) are a common biological model used in experimental in vitro studies in the fields of tendon physiology and tendinopathy. Working with those tissues is challenging because they are very fragile, and until now there was no rigorously detailed protocol for their isolation. Faced with these challenges, we have developed methods and instruments to facilitate manipulation of RTTs and control tissue viability, sterility and integrity. This article describes the experimental procedures used to prepare RTTs for biomechanical and mechanobiological studies. Our work is divided into four main steps: extraction, cross-sectional area measurement, rinsing and loading into the bioreactor chamber. At each step, all procedures, materials and manipulations are presented in detail so that they can be easily reproduced. Moreover, the specific instruments developed are presented: a manipulation plate used to segregate RTTs, an optic micrometer to position the tissue during the cross-sectional area measurement and an anchoring system to attach the RTTs onto a bioreactor. Finally, we describe the results obtained after multiple tests to validate our methods. The viability, sterility and integrity evaluations demonstrate that our procedures are sufficiently rigorous for manipulations of fragile tissues such as rat tail tendons. PMID:20729800

  20. Radioprotection of Tendon Tissue via Crosslinking and Free Radical Scavenging

    PubMed Central

    Seto, Aaron; Gatt, Charles J.

    2008-01-01

    Ionizing radiation could supplement tissue bank screening to further reduce the probability of diseases transmitted by allografts if denaturation effects can be minimized. It is important, however, such sterilization procedures be nondetrimental to tissues. We compared crosslinking and free radical scavenging potential methods to accomplish this task in tendon tissue. In addition, two forms of ionizing irradiation, gamma and electron beam (e-beam), were also compared. Crosslinkers included 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and glucose, which were used to add exogenous crosslinks to collagen. Free radical scavengers included mannitol, ascorbate, and riboflavin. Radioprotective effects were assessed through tensile testing and collagenase resistance testing after irradiation at 25 kGy and 50 kGy. Gamma and e-beam irradiation produced similar degenerative effects. Crosslinkers had the highest strength at 50 kGy, EDC treated tendons had 54% and 49% higher strength than untreated, for gamma and e-beam irradiation respectively. Free radical scavengers showed protective effects up to 25 kGy, especially for ascorbate and riboflavin. Crosslinked samples had higher resistance to collagenase and over a wider dose range than scavenger-treated. Of the options studied, the data suggest EDC precrosslinking or glucose treatment provides the best maintenance of native tendon properties after exposure to ionizing irradiation. PMID:18512113

  1. Normal values of patellar and ankle tendon reflex latencies.

    PubMed

    Frijns, C J; Laman, D M; van Duijn, M A; van Duijn, H

    1997-02-01

    The clinical value of latency measurement of tendon reflexes in neurological patients has been reported by several authors. However, normal values are not readily comparable. In the present study, latencies and amplitudes of patellar (PTR) and ankle tendon reflexes (ATR) were measured at rest and after facilitation in 102 normal controls. A manually operated reflex hammer, tipped with electrically conductive rubber, ensured an immediate start of the sweep of the oscilloscope. Latencies showed a significant correlation with height (r = 0.70 for PTR and r = 0.72 for ATR, P < 0.0001) and to a lesser degree with age (r = 0.16 and r = 0.30, P < 0.0001). While amplitudes were highly variable, rendering them less useful for diagnostic purposes, latencies showed minimal intra-individual variability (CV 1.5 and 0.8%, respectively). Correlation of ATR-latency with the H-reflex latency of the soleus muscle was very high (r = 0.97, P < 0.0001). Comparison with three other hammer types yielded corresponding results with a hammer supplied with a piezo-electric element; however, significantly shorter latencies were found with a hammer with a microswitch, and with another hammer with a spring-contact, due to a delay from the tap on the tendon until the start of the sweep of the monitor. PMID:9107465

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

    PubMed

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

    2012-01-01

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

  3. Preparation of Rat Tail Tendons for Biomechanical and Mechanobiological Studies

    PubMed Central

    Bruneau, Amélie; Champagne, Nadia; Cousineau-Pelletier, Paule; Parent, Gabriel; Langelier, Eve

    2010-01-01

    Rat tail tendons (RTTs) are a common biological model used in experimental in vitro studies in the fields of tendon physiology and tendinopathy. Working with those tissues is challenging because they are very fragile, and until now there was no rigorously detailed protocol for their isolation. Faced with these challenges, we have developed methods and instruments to facilitate manipulation of RTTs and control tissue viability, sterility and integrity. This article describes the experimental procedures used to prepare RTTs for biomechanical and mechanobiological studies. Our work is divided into four main steps: extraction, cross-sectional area measurement, rinsing and loading into the bioreactor chamber. At each step, all procedures, materials and manipulations are presented in detail so that they can be easily reproduced. Moreover, the specific instruments developed are presented: a manipulation plate used to segregate RTTs, an optic micrometer to position the tissue during the cross-sectional area measurement and an anchoring system to attach the RTTs onto a bioreactor. Finally, we describe the results obtained after multiple tests to validate our methods. The viability, sterility and integrity evaluations demonstrate that our procedures are sufficiently rigorous for manipulations of fragile tissues such as rat tail tendons. PMID:20729800

  4. Biocompatibility and degradation of tendon-derived scaffolds

    PubMed Central

    Alberti, Kyle A.; Xu, Qiaobing

    2016-01-01

    Decellularized extracellular matrix has often been used as a biomaterial for tissue engineering applications. Its function, once implanted can be crucial to determining whether a tissue engineered construct will be successful, both in terms of how the material breaks down, and how the body reacts to the material’s presence in the first place. Collagen is one of the primary components of extracellular matrix and has been used for a number of biomedical applications. Scaffolds comprised of highly aligned collagen fibrils can be fabricated directly from decellularized tendon using a slicing, stacking, and rolling technique, to create two- and three-dimensional constructs. Here, the degradation characteristics of the material are evaluated in vitro, showing that chemical crosslinking can reduce degradation while maintaining fiber structure. In vivo, non-crosslinked and crosslinked samples are implanted, and their biological response and degradation evaluated through histological sectioning, trichrome staining, and immunohistochemical staining for macrophages. Non-crosslinked samples are rapidly degraded and lose fiber morphology while crosslinked samples retain both macroscopic structure as well as fiber orientation. The cellular response of both materials is also investigated. The in vivo response demonstrates that the decellularized tendon material is biocompatible, biodegradable and can be crosslinked to maintain surface features for extended periods of time in vivo. This study provides material characteristics for the use of decellularized tendon as biomaterial for tissue engineering. PMID:26816651

  5. How does static stretching influence the tendons mechanical response?

    PubMed Central

    Rossetto, Nathalia Polisello; Fabbro, Inácio Maria Dal; Piedade, Sérgio Rocha

    2013-01-01

    OBJECTIVE: Analyze in vitro the mechanical response of bovine calcaneus tendons subjected to static stretching in three different intervals (15, 30, 45 s). METHODS: Six groups of bovine calcaneus tendons (n=10) were formed according to the static stretching protocol: three different intervals (15, 30, 45 s) and initial stretching percentage (2.5% and 3.5%). The control group (n=10) did not perform prior stretching. At the end of the stretching tests, the specimens were subjected to stress rupture tests. RESULTS: The values for force relaxation presented stability after the 30th second (p<0.0001) at both levels of deformation. Greater force relaxation (p<0.0026) and the least tensile strength (p=0.0123) was observed in the group that was subjected to the highest stretch percentage (3.5%). No difference was observed between the rupture parameters of the stretch and control groups. The variables, stretch duration and percentage did not demonstrate interaction. CONCLUSION: In relation to force relaxation, the 30 second interval seems to be the most effective when stretching tendons. This fact should be considered when establishing new clinical stretching protocols. Laboratory investigation. PMID:24453678

  6. Influence of Age on Patellar Tendon Reflex Response

    PubMed Central

    Chandrasekhar, Annapoorna; Abu Osman, Noor Azuan; Tham, Lai Kuan; Lim, Kheng Seang; Wan Abas, Wan Abu Bakar

    2013-01-01

    Background A clinical parameter commonly used to assess the neurological status of an individual is the tendon reflex response. However, the clinical method of evaluation often leads to subjective conclusions that may differ between examiners. Moreover, attempts to quantify the reflex response, especially in older age groups, have produced inconsistent results. This study aims to examine the influence of age on the magnitude of the patellar tendon reflex response. Methodology/Principal Findings This study was conducted using the motion analysis technique with the reflex responses measured in terms of knee angles. Forty healthy subjects were selected and categorized into three different age groups. Patellar reflexes were elicited from both the left and right patellar tendons of each subject at three different tapping angles and using the Jendrassik maneuver. The findings suggested that age has a significant effect on the magnitude of the reflex response. An angle of 45° may be the ideal tapping angle at which the reflex can be elicited to detect age-related differences in reflex response. The reflex responses were also not influenced by gender and were observed to be fairly symmetrical. Conclusions/Significance Neurologically normal individuals will experience an age-dependent decline in patellar reflex response. PMID:24260483

  7. Non-Uniform Displacements within the Achilles Tendon observed during Passive and Eccentric Loading

    PubMed Central

    Slane, Laura Chernak; Thelen, Darryl G.

    2014-01-01

    The goal of this study was to investigate Achilles tendon tissue displacement patterns under passive and eccentric loading conditions. Nine healthy young adults were positioned prone on an examination table with their foot secured to a rotating footplate aligned with the ankle. Subjects cyclically rotated their ankle over a 25 deg range of motion at 0.5 Hz. An inertial load geared to the footplate induced eccentric plantarflexor contractions with dorsiflexion. Passive cyclic ankle motion was also performed over the same angular range of motion. An ultrasound transducer positioned over the distal Achilles tendon was used to collect radiofrequency (RF) images at 70 frames/sec. Two-dimensional ultrasound elastographic analysis of the RF data was used to track tendon tissue displacements throughout the cyclic motion. Non-uniform tissue displacement patterns were observed in all trials, with the deeper portions of the Achilles tendon consistently exhibiting larger displacements than the superficial tendon (average of 0.9–2.6 mm larger). Relative to the passive condition, eccentric loading consistently induced smaller tissue displacements in all tendon regions, except for the superficial tendon in a flexed knee posture. Significantly greater overall tissue displacement was observed in a more extended knee posture (30 deg) relative to a flexed knee posture (90 deg). These spatial- and posture-dependent displacement patterns suggest that the tendon undergoes nonuniform deformation under in vivo loading conditions. Such behavior could reflect relative sliding between the distinct tendon fascicles that arise from the gastrocnemius and soleus muscles. PMID:25150898

  8. IMPROVEMENT OF TENDON REPAIR USING MUSCLE GRAFTS TRANSDUCED WITH TGF-?1 cDNA

    PubMed Central

    Majewski, Martin; Porter, Ryan M.; Betz, Oliver B.; Betz, Volker M.; Clahsen, Harald; Flückiger, Rudolf; Evans, Christopher H.

    2015-01-01

    Tendon rupture is a common injury. Inadequate endogenous repair often leaves patients symptomatic, with tendons susceptible to re-rupture. Administration of certain growth factors improves tendon healing in animal models, but their delivery remains a challenge. Here we evaluated the delivery of TGF-?1 to tendon defects by the implantation of genetically modified muscle grafts. Rat muscle biopsies were transduced with recombinant adenovirus encoding TGF-?1 and grafted onto surgically transected Achilles tendons in recipient animals. Tissue regenerates were compared to those of controls by biomechanical testing as well as histochemical and immunohistochemical analyses. Healing was greatly accelerated when genetically modified grafts were implanted into tendon defects, with the resulting repair tissue gaining nearly normal histological appearance as early as 2 weeks postoperatively. This was associated with decreased deposition of type III collagen in favour of large fibre bundles indicative of type I collagen. These differences in tendon composition coincided with accelerated restoration of mechanical strength. Tendon thickness increased in gene-treated animals at weeks 1 and 2, but by week 8 became significantly lower than that of controls suggesting accelerated remodelling. Thus localised TGF-?1 delivery via adenovirus-modified muscle grafts improved tendon healing in this rat model and holds promise for clinical application. PMID:22354460

  9. Pentadecapeptide BPC 157 enhances the growth hormone receptor expression in tendon fibroblasts.

    PubMed

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

    2014-01-01

    BPC 157, a pentadecapeptide derived from human gastric juice, has been demonstrated to promote the healing of different tissues, including skin, muscle, bone, ligament and tendon in many animal studies. However, the underlying mechanism has not been fully clarified. The present study aimed to explore the effect of BPC 157 on tendon fibroblasts isolated from Achilles tendon of male Sprague-Dawley rat. From the result of cDNA microarray analysis, growth hormone receptor was revealed as one of the most abundantly up-regulated genes in tendon fibroblasts by BPC 157. BPC 157 dose- and time-dependently increased the expression of growth hormone receptor in tendon fibroblasts at both the mRNA and protein levels as measured by RT/real-time PCR and Western blot, respectively. The addition of growth hormone to BPC 157-treated tendon fibroblasts dose- and time-dependently increased the cell proliferation as determined by MTT assay and PCNA expression by RT/real-time PCR. Janus kinase 2, the downstream signal pathway of growth hormone receptor, was activated time-dependently by stimulating the BPC 157-treated tendon fibroblasts with growth hormone. In conclusion, the BPC 157-induced increase of growth hormone receptor in tendon fibroblasts may potentiate the proliferation-promoting effect of growth hormone and contribute to the healing of tendon. PMID:25415472

  10. Temporalis Muscle Tendon Unit Transfer for Smile Restoration After Facial Paralysis.

    PubMed

    Owusu Boahene, Kofi D

    2016-02-01

    Temporalis muscle tendon unit (MTU) transfer may be used as a single-stage procedure for dynamic reanimation of the paralyzed face. Principles and biomechanics of muscle function and tendon transposition are essential in optimizing outcome. Critical steps and pearls for success include minimizing scarring, maintaining glide plains, mobilizing adequate tendon length, insertion of MTU at ideal tension based on intraoperative dynamic tension-excursion relationship, and insertion of tendon as close to the lip margin as possible. Because muscles adapt to tension, load, and task changes by altering their sarcomere arrangement and muscle fiber composition, physiotherapy should be initiated to use the repurposed temporalis MTU for smile restoration. PMID:26611700

  11. Tensile properties of craniofacial tendons in the mature and aged zebrafish.

    PubMed

    Shah, Rishita R; Nerurkar, Nandan L; Wang, Calvin C; Galloway, Jenna L

    2015-06-01

    The zebrafish Danio rerio is a powerful model for the study of development, regenerative biology, and human disease. However, the analysis of load-bearing tissues such as tendons and ligaments has been limited in this system. This is largely due to technical limitations that preclude accurate measurement of their mechanical properties. Here, we present a custom tensile testing system that applies nano-Newton scale forces to zebrafish tendons as small as 1 mm in length. Tendon properties were remarkably similar to mammalian tendons, including stress-strain nonlinearity and a linear modulus (515 ± 152 MPa) that aligned closely with mammalian data. Additionally, a simple exponential constitutive law used to describe tendon mechanics was successfully fit to zebrafish tendons; the associated material constants agreed with literature values for mammalian tendons. Finally, mature and aged zebrafish comparisons revealed a significant decline in mechanical function with age. Based on the exponential constitutive model, age-related changes were primarily caused by a reduction in nonlinearity (e.g., changes in collagen crimp or fiber recruitment). These findings demonstrate the utility of zebrafish as a model to study tendon biomechanics in health and disease. Moreover, these findings suggest that tendon mechanical behavior is highly conserved across vertebrates. PMID:25665155

  12. 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

  13. Effect of Heparin on Post-Operative Adhesion in Flexor Tendon Surgery of the Hand.

    PubMed

    Akbari, Hossein; Rahimi, Amir Asadollah Khajeh; Ghavami, Yaser; Mousavi, Seyed Jaber; Fatemi, Mohammad Javad

    2015-12-01

    Flexor tendon laceration is a common hand injury. Timely and correct diagnosis of this defect is an important factor for restoring hand function. Post-operative adhesion is a frequent problem after tendon repair and its prevention is difficult in some types of tendon lacerations. There have been some controversial studies on the positive effect of some materials and substances on prevention of these adhesions. This study aims to evaluate effects of the Heparin in postoperative tendon adhesions. In this clinical trial, 100 patients with laceration of flexor tendons in zone II of the hand were enrolled. The patients were randomly divided into two groups. In the first group, 0.5 cc Heparin (5000 IU/cc) was injected into each tendon ends before tendon repair. In the control group, repair was carried out without any heparin injection. After 3 months the total active range of motion (TAROM), mean extension gap (MEG) and mean flexion gap (MFG) were measured and compared between these two groups. The TAROM and MEGs were not significantly different between two groups; but MFGs were significantly better in Heparin treated group (P < 0.02). However rupture rate was significantly higher in heparin treated group (P = 0.003). Heparin may improve the tendons function and reduce the postoperative adhesions in zone II of the hand; however there is a significant risk of tendon rupture. PMID:26578825

  14. 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.

  15. Spontaneous Rupture of the Extensor Pollicis Longus Tendon due to Unusual Etiology

    PubMed Central

    Ta?, Süleyman; Balta, Serkan; Benlier, Erol

    2014-01-01

    Background: The etiology of spontaneous rupture of the extensor pollicis longus tendon includes systemic or local steroid injections, wrist fracture, tenosynovitis, synovitis, rheumatoid arthritis, and repetitive wrist motions. Case Report: We encountered a case of extensor pollicis longus tendon rupture with an unusual etiology, cow milking. In this case, transfer of the extensor indicis proprius tendon was performed successfully. At 1 year after surgery, extension of the thumb was sufficient. Conclusion: It appears that patients with occupations involving repetitive motions are at a high risk of closed tendon ruptures. PMID:25207178

  16. 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

  17. 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

  18. Achilles tendon shape and echogenicity on ultrasound among active badminton players.

    PubMed

    Malliaras, P; Voss, C; Garau, G; Richards, P; Maffulli, N

    2012-04-01

    The relationship between Achilles tendon ultrasound abnormalities, including a spindle shape and heterogeneous echogenicity, is unclear. This study investigated the relationship between these abnormalities, tendon thickness, Doppler flow and pain. Sixty-one badminton players (122 tendons, 36 men, and 25 women) were recruited. Achilles tendon thickness, shape (spindle, parallel), echogenicity (heterogeneous, homogeneous) and Doppler flow (present or absent) were measured bilaterally with ultrasound. Achilles tendon pain (during or after activity over the last week) and pain and function [Victorian Institute of Sport Achilles Assessment (VISA-A)] were measured. Sixty-eight (56%) tendons were parallel with homogeneous echogenicity (normal), 22 (18%) were spindle shaped with homogeneous echogenicity, 16 (13%) were parallel with heterogeneous echogenicity and 16 (13%) were spindle shaped with heterogeneous echogenicity. Spindle shape was associated with self-reported pain (P<0.05). Heterogeneous echogenicity was associated with lower VISA-A scores than normal tendon (P<0.05). There was an ordinal relationship between normal tendon, parallel and heterogeneous and spindle shaped and heterogeneous tendons with regard to increasing thickness and likelihood of Doppler flow. Heterogeneous echogenicity with a parallel shape may be a physiological phase and may develop into heterogeneous echogenicity with a spindle shape that is more likely to be pathological. PMID:20561268

  19. 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. PMID:25611186

  20. Fibroma of the peroneus longus tendon sheath in a child: a case report.

    PubMed

    Nason, Gregory J; Baker, Joseph F; O'Toole, Patrick; Walsh, Anna; Lui, Darren F; O'Neill, Francis; O'Sullivan, Maureen; Kelly, Paula M

    2013-12-01

    Tendon sheath fibromas are rare, benign soft-tissue tumours and usually involve tendons of the upper extremities, particularly the fingers. The most common presentation is a painless, slow-growing swelling. Tendon sheath fibromas are composed of dense fibrocollagenous stromas with scattered, spindle-shaped fibroblasts and narrow, slit-like vascular spaces. Ultrasonography and magnetic resonance imaging are useful diagnostic tools. We report on an 11-year-old boy with a fibroma involving the right peroneus longus tendon sheath. PMID:24366807

  1. 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.

  2. Subject-specific finite element analysis to characterize the influence of geometry and material properties in Achilles tendon rupture.

    PubMed

    Shim, Vickie B; Fernandez, Justin W; Gamage, Prasad B; Regnery, Camille; Smith, David W; Gardiner, Bruce S; Lloyd, David G; Besier, Thor F

    2014-11-28

    Achilles tendon injuries including rupture are one of the most frequent musculoskeletal injuries, but the mechanisms for these injuries are still not fully understood. Previous in vivo and experimental studies suggest that tendon rupture mainly occurs in the tendon mid-section and predominantly more in men than women due to reasons yet to be identified. Therefore we aimed to investigate possible mechanisms for tendon rupture using finite element (FE) analysis. Specifically, we have developed a framework for generating subject-specific FE models of human Achilles tendon. A total of ten 3D FE models of human Achilles tendon were generated. Subject-specific geometries were obtained using ultrasound images and a mesh morphing technique called Free Form Deformation. Tendon material properties were obtained by performing material optimization that compared and minimized difference in uniaxial tension experimental results with model predictions. Our results showed that both tendon geometry and material properties are highly subject-specific. This subject-specificity was also evident in our rupture predictions as the locations and loads of tendon ruptures were different in all specimens tested. A parametric study was performed to characterize the influence of geometries and material properties on tendon rupture. Our results showed that tendon rupture locations were dependent largely on geometry while rupture loads were more influenced by tendon material properties. Future work will investigate the role of microstructural properties of the tissue on tendon rupture and degeneration by using advanced material descriptions. PMID:25458149

  3. Peroneal Tendon Reconstruction and Coverage for Treatment of Septic Peroneal Tenosynovitis: A Devastating Complication of Lateral Ankle Ligament Reconstruction With a Tendon Allograft.

    PubMed

    Schade, Valerie L; Harsha, Wayne; Rodman, Caitlin; Roukis, Thomas S

    2016-01-01

    Septic peroneal tenosynovitis is a rare and significant challenge. A search of peer-reviewed published studies revealed only 5 case reports to guide treatment, none of which resulted in significant loss of both peroneal tendons necessitating reconstruction. No clear guidance is available regarding how to provide reliable reconstruction of both peroneal tendons after a significant loss secondary to septic tenosynovitis. In the present report, we describe the case of a young, active-duty soldier who underwent lateral ankle ligament reconstruction with a tendon allograft whose postoperative course was complicated by septic peroneal tenosynovitis resulting in significant loss of both peroneal tendons. Reconstruction was achieved in a staged fashion with the use of silicone rods and external fixation to maintain physiologic tension and preserve peroneal tendon function, followed by reconstruction of both peroneal tendons and the superior peroneal retinaculum with a tensor fascia lata autograft. Soft tissue coverage was obtained with an anterolateral thigh free tissue transfer and a split-thickness skin graft. The patient returned to full activity as an active-duty soldier with minimal pain and no instability of the right lower extremity. The muscle strength of both peroneal tendons remained at 5 of 5, and no objective findings of ankle instability were seen at 3.5 years postoperatively. PMID:26002675

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

    PubMed Central

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

    2015-01-01

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

  5. In Vivo Finger Flexor Tendon Force while Tapping on a Keyswitch

    PubMed Central

    Dennerlein, Jack Tigh; Diao, Edward; Mote, C. D.; Rempel, David M.

    2009-01-01

    Summary Force may be a risk factor for musculoskeletal disorders of the upper extremity associated with typing and keying. However, the internal finger flexor tendon forces and their relationship to fingertip forces during rapid tapping on a keyswitch have not yet been measured in vivo. During the open carpal tunnel release surgery of five human subjects, a tendon-force transducer was inserted on the flexor digitorum super-ficialis of the long finger. During surgery, subjects tapped with the long finger on a computer keyswitch, instrumented with a keycap load cell. The average tendon maximum forces during a keystroke ranged from 8.3 to 16.6 N (mean = 12.9 N, SD = 3.3 N) for the subjects, four to seven times larger than the maximum forces observed at the fingertip. Tendon forces estimated from an isometric tendon-force model were only one to two times larger than tip force, significantly less than the observed tendon forces (p = 0.001). The force histories of the tendon during a keystroke were not proportional to fingertip force. First, the tendon-force histories did not contain the high-frequency fingertip force components observed as the tip impacts with the end of key travel. Instead, tendon tension during a keystroke continued to increase throughout the impact. Second, following the maximum keycap force, tendon tension during a keystroke decreased more slowly than fingertip force, remaining elevated approximately twice as long as the fingertip force. The prolonged elevation of tendon forces may be the result of residual eccentric muscle contraction or passive muscle forces, or both, which are additive to increasing extensor activity during the release phase of the keystroke. PMID:10221833

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

    PubMed

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

    2008-12-01

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

  7. 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

  8. Freeze-Dried Tendon Allografts as Tissue Engineering Scaffolds for Gdf5 Gene Delivery

    PubMed Central

    Basile, Patrick; Dadali, Tulin; Jacobson, Justin; Hasslund, Sys; Ulrich-Vinther, Michael; Søballe, Kjeld; Nishio, Yasuhiko; Drissi, M Hicham; Langstein, Howard N; Mitten, David J; O’Keefe, Regis J; Schwarz, Edward M; Awad, Hani A

    2009-01-01

    Tendon reconstruction using grafts often results in adhesions that limit joint flexion. These adhesions are precipitated by inflammation, fibrosis, and paucity of tendon differentiation signals during healing. To study this problem, we developed a mouse model in which the FDL tendon is reconstructed using a live autograft or a freeze-dried allograft and identified Gdf5 as a therapeutic target. Here we investigate the potential of rAAV-Gdf5 coated freeze-dried tendon allografts as “therapeutically-endowed” tissue engineering scaffolds to reduce adhesions. In reporter gene studies we demonstrate that rAAV-coated tendon allografts mediate efficient transduction of adjacent soft tissues, with expression peaking at 7-days. We also demonstrate that rAAV-Gdf5 vector significantly accelerates wound healing in an in vitro fibroblast scratch model, and when loaded onto freeze-dried FDL tendon allografts significantly improves the metatarsophalangeal joint flexion compared to rAAV-lacZ controls. Collectively, our data demonstrate the feasibility and efficacy of therapeutic tendon allograft processing as a novel paradigm in tissue engineering to address difficult clinical problems such as tendon adhesions. PMID:18180771

  9. The effect of dry needling and treadmill running on inducing pathological changes in rat Achilles tendon.

    PubMed

    Kim, Bom Soo; Joo, Young Chae; Choi, Byung Hyune; Kim, Kil Hwan; Kang, Joon Soon; Park, So Ra

    2015-11-01

    Achilles tendinopathy is a common degenerative condition without a definitive treatment. An adequate chronic animal model of Achilles tendinopathy has not yet been developed. The purpose of this study was to evaluate the individual and combined effects of dry needling and treadmill running on the Achilles tendon of rats. Percutaneous dry needling, designed to physically replicate microrupture of collagen fibers in overloaded tendons, was performed on the right Achilles tendon of 80 Sprague-Dawley rats. The rats were randomly divided into two groups: a treadmill group, which included rats that underwent daily uphill treadmill running (n?=?40), and a cage group, which included rats that could move freely within their cages (n?=?40). At the end of weeks 1 and 4, 20 rats from each group were sacrificed, and bilateral Achilles tendons were collected. The harvested tendons were subjected to mechanical testing and histological analysis. Dry needling induced histological and mechanical changes in the Achilles tendons at week 1, and the changes persisted at week 4. The needled Achilles tendons of the treadmill group tended to show more severe histological and mechanical changes than those of the cage group, although these differences were not statistically significant. Dry needling combined with free cage activity or treadmill running produced tendinopathy-like changes in rat Achilles tendons up to 4 weeks after injury. Dry needling is an easy procedure with a short induction period and a high success rate, suggesting it may have relevance in the design of an Achilles tendinopathy model. PMID:26076317

  10. Basic FGF or VEGF gene therapy corrects insufficiency in the intrinsic healing capacity of tendons

    PubMed Central

    Tang, Jin Bo; Wu, Ya Fang; Cao, Yi; Chen, Chuan Hao; Zhou, You Lang; Avanessian, Bella; Shimada, Masaru; Wang, Xiao Tian; Liu, Paul Y.

    2016-01-01

    Tendon injury during limb motion is common. Damaged tendons heal poorly and frequently undergo unpredictable ruptures or impaired motion due to insufficient innate healing capacity. By basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) gene therapy via adeno-associated viral type-2 (AAV2) vector to produce supernormal amount of bFGF or VEGF intrinsically in the tendon, we effectively corrected the insufficiency of the tendon healing capacity. This therapeutic approach (1) resulted in substantial amelioration of the low growth factor activity with significant increases in bFGF or VEGF from weeks 4 to 6 in the treated tendons (p < 0.05 or p < 0.01), (2) significantly promoted production of type I collagen and other extracellular molecules (p < 0.01) and accelerated cellular proliferation, and (3) significantly increased tendon strength by 68–91% from week 2 after AAV2-bFGF treatment and by 82–210% from week 3 after AAV2-VEGF compared with that of the controls (p < 0.05 or p < 0.01). Moreover, the transgene expression dissipated after healing was complete. These findings show that the gene transfers provide an optimistic solution to the insufficiencies of the intrinsic healing capacity of the tendon and offers an effective therapeutic possibility for patients with tendon disunion. PMID:26865366

  11. Ultrasound Stimulation of Type I Collagen and Type III Collagen Expression of Tendon Cells

    NASA Astrophysics Data System (ADS)

    Chen, Huang-Chung; Tsai, Wen-Chung; Tang, Chu-Wen; Pang, Jong-Hwei S.

    2005-03-01

    This study was designed to determine the effect of ultrasound on tendon cells intrinsic to rat Achilles tendon plated on collagen-coated dishes. Furthermore, the in vitro effect of ultrasound on type I collagen and type III collage expression of tendon cells was investigated. Cultured tendon cells were treated with ultrasound at a frequency of 1.0 MHz, either pulsed (duty factor: 20%) or continuous mode with the intensity of 1.0 W/cm2 for 5 minutes. The expression of type I collagen and type III collagen of tendon cells was evaluated by immunocytochemistry 24 hours after ultrasound treatment. The results revealed that tendon cells cultured on dishes without collagen coating would lyse and detach from the dish after ultrasound exposure. However, cells cultured on collagen-coated dishes proliferate actively. Immunocytochemical staining revealed that ultrasound treated tendon cells stained more strongly for type I collagen and type III collagen than control cells. In conclusion, a collagen-coated dish is essential to prevent cell lysis and detachment from the dish after ultrasound exposure. Furthermore, either continuous or pulsed ultrasound could stimulate the expression of type I collagen and type III collagen by tendon cells.

  12. 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

  13. The effects of bone marrow stromal cell transplants on tendon healing in vitro

    PubMed Central

    Zhao, Chunfeng; Chieh, Hsiao-Feng; Bakri, Karim; Ikeda, Jun; Sun, Yu-Long; Moran, Steven L.; An, Kai-Nan; Amadio, Peter C.

    2014-01-01

    The purpose of this study was to investigate the effect of bone marrow stromal cells (BMSCs) on tendon healing in a canine ex vivo model. Bone marrow was harvested and BMSCs were isolated and cultured according to established protocols. Cells were seeded into 0.5 mg/ml collagen gels and cultured for 24 h to allow gel contraction, and then implanted between the lacerated ends of repaired flexor digitorum profundus tendons. Tendons repaired with a gel patch alone and without a gel patch served as control groups. After 2 and 4 weeks in culture, the repaired tendons were evaluated for breaking strength and stiffness. Cell viability was assessed by labeling the cells with PKH26 red fluorescent cell linker. The maximal strength and stiffness of repaired tendons with the BMSC-seeded patch were significantly higher than the repaired tendons without a patch or with a patch without cells, at both 2 and 4 weeks (p < 0.05). Viable BMSC were present between the cut tendon ends at both 2 and 4 weeks. We conclude that BMSC-seeded gel patch transplantation has the potential to enhance flexor tendon healing, and we plan to investigate this effect in vivo. PMID:19736035

  14. Basic FGF or VEGF gene therapy corrects insufficiency in the intrinsic healing capacity of tendons.

    PubMed

    Tang, Jin Bo; Wu, Ya Fang; Cao, Yi; Chen, Chuan Hao; Zhou, You Lang; Avanessian, Bella; Shimada, Masaru; Wang, Xiao Tian; Liu, Paul Y

    2016-01-01

    Tendon injury during limb motion is common. Damaged tendons heal poorly and frequently undergo unpredictable ruptures or impaired motion due to insufficient innate healing capacity. By basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) gene therapy via adeno-associated viral type-2 (AAV2) vector to produce supernormal amount of bFGF or VEGF intrinsically in the tendon, we effectively corrected the insufficiency of the tendon healing capacity. This therapeutic approach (1) resulted in substantial amelioration of the low growth factor activity with significant increases in bFGF or VEGF from weeks 4 to 6 in the treated tendons (p?tendon strength by 68-91% from week 2 after AAV2-bFGF treatment and by 82-210% from week 3 after AAV2-VEGF compared with that of the controls (p?tendon and offers an effective therapeutic possibility for patients with tendon disunion. PMID:26865366

  15. Biomechanical responses of different rat tendons to nandrolone decanoate and load exercise.

    PubMed

    Marqueti, R C; Prestes, J; Wang, C C; Ramos, O H P; Perez, S E A; Nakagaki, W R; Carvalho, H F; Selistre-de-Araujo, H S

    2011-12-01

    Androgenic-anabolic steroids (AAS) have been associated with an increased incidence of tendon rupture. The aim of this study was to compare the biomechanical properties of the rat calcaneal tendon (CT), superficial flexor tendon (SFT), and deep flexor tendon (DFT), and to determine the effect of jump training in association with AAS. Animals were separated into four groups: sedentary, trained, AAS-treated sedentary rats (AAS), and AAS-treated and trained animals. Mechanical testing showed that the CT differed from the DFT and SFT, which showed similar mechanical properties. Jump caused the CT to exhibit an extended toe region, an increased resistance to tensional load, and a decreased elastic modulus, characteristics of an elastic tendon capable of storing energy. AAS caused the tendons to be less compliant, and the effects were reinforced by simultaneous training. The DFT was the most affected by training, AAS, and the interaction of both, likely because of its involvement in the toe-off step of jumping, which we suggest is related to the rapid transmission of force as opposed to energy storage. In conclusion, tendons are differently adapted to exercise, but responded equally to AAS, showing reduced flexibility, which is suggested to increase the risk of tendon rupture in AAS consumers. PMID:20673248

  16. Triceps tendon rupture: the knowledge acquired from the anatomy to the surgical repair.

    PubMed

    Celli, A

    2015-09-01

    Triceps injuries are relatively uncommon in most traumatic events, and the distal triceps tendon ruptures are rare. Recently, the knowledge of this tendon lesion has increased, and it seems to be related to more precise diagnostic and clinical assessments. The most common mechanism of injury remains a forceful eccentric contraction of the muscle, while several other risk factors have been studied as chronic renal failure, endocrine disorders, metabolic bone diseases as well as steroid use. Olecranon bursitis and local corticosteroid injections may also play a role. The commonest site of rupture is at the tendon's insertion into the olecranon and rarely at the myotendinous junction or intramuscularly. The surgical intervention is recommended in acute complete ruptures, and non-operative treatment is reserved for patients with major comorbidities, as well as for partial ruptures with little functional disability and in low demanding patients. Various techniques and approaches as the direct repair to bone, the tendon augmentation, the anconeus rotation flap and the Achilles tendon allograft have been proposed for the management of these challenging injuries. The goal of surgical management should be an anatomical repair of the injured tendon by selection of a procedure with a low complication rate and one that allows early mobilization. This manuscript focuses the triceps tendon ruptures starting from the anatomy to the diagnosis and entity of the triceps tendon injuries, as well as the indications and guidelines for the management. PMID:25957546

  17. 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

  18. Principles of Tendon Reconstruction Following Complex Trauma of the Upper Limb

    PubMed Central

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

    2015-01-01

    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

  19. Does the adolescent patellar tendon respond to 5 days of cumulative load during a volleyball tournament?

    PubMed

    van Ark, M; Docking, S I; van den Akker-Scheek, I; Rudavsky, A; Rio, E; Zwerver, J; Cook, J L

    2016-02-01

    Patellar tendinopathy (jumper's knee) has a high prevalence in jumping athletes. Excessive load on the patellar tendon through high volumes of training and competition is an important risk factor. Structural changes in the tendon are related to a higher risk of developing patellar tendinopathy. The critical tendon load that affects tendon structure is unknown. The aim of this study was to investigate patellar tendon structure on each day of a 5-day volleyball tournament in an adolescent population (16-18 years). The right patellar tendon of 41 players in the Australian Volleyball Schools Cup was scanned with ultrasound tissue characterization (UTC) on every day of the tournament (Monday to Friday). UTC can quantify structure of a tendon into four echo types based on the stability of the echo pattern. Generalized estimating equations (GEE) were used to test for change of echo type I and II over the tournament days. Participants played between eight and nine matches during the tournament. GEE analysis showed no significant change of echo type percentages of echo type I (Wald chi-square = 4.603, d.f. = 4, P = 0.331) and echo type II (Wald chi-square = 6.070, d.f. = 4, P = 0.194) over time. This study shows that patellar tendon structure of 16-18-year-old volleyball players is not affected during 5 days of cumulative loading during a volleyball tournament. PMID:25694241

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

    PubMed Central

    2014-01-01

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