The supraspinatus tendon is composed of 5 different layers consisting of intertwining bundles. On a front portion of the tendon, the layers become coated bundles which insert on the trochanter. At the insertion, the superficial or bursal surface of the tendon corresponding to the tendon fibers in contact with the subacromial bursa can be distinguished from the deep surface corresponding to the fibers in contact with the glenohumeral joint. A tendon tear may involve partial or total disruption of the tendon fibers and is called full-thickness tear if it affects the entire tendon, and partial-thickness tear if it involves only part of the tendon. Partial-thickness tears of the supraspinatus tendon include lesions of the superficial, deep and central surface or tendon delamination.A contrast enhanced examination requires injection of contrast agent into the joint (arthrography followed by computed tomography (CT) or magnetic resonance imaging (MRI)) to study the deep surface, and injection into the subacromial bursa (bursography followed by CT) to study the superficial surface. MRI and ultrasound (US) examination allow the study of these different tendon layers without the use of contrast agent (which is not possible at CT). PMID:23396264
Guerini, H; Fermand, M; Godefroy, D; Feydy, A; Chevrot, A; Morvan, G; Gault, N; Drapé, J L
The supraspinatus tendon is composed of 5 different layers consisting of intertwining bundles. On a front portion of the tendon, the layers become coated bundles which insert on the trochanter. At the insertion, the superficial or bursal surface of the tendon corresponding to the tendon fibers in contact with the subacromial bursa can be distinguished from the deep surface corresponding to the fibers in contact with the glenohumeral joint. A tendon tear may involve partial or total disruption of the tendon fibers and is called full-thickness tear if it affects the entire tendon, and partial-thickness tear if it involves only part of the tendon. Partial-thickness tears of the supraspinatus tendon include lesions of the superficial, deep and central surface or tendon delamination. A contrast enhanced examination requires injection of contrast agent into the joint (arthrography followed by computed tomography (CT) or magnetic resonance imaging (MRI)) to study the deep surface, and injection into the subacromial bursa (bursography followed by CT) to study the superficial surface. MRI and ultrasound (US) examination allow the study of these different tendon layers without the use of contrast agent (which is not possible at CT).
Guerini, H.; Fermand, M.; Godefroy, D.; Feydy, A.; Chevrot, A.; Morvan, G.; Gault, N.; Drape, J.L.
Rotator cuff injury comprises a continual spectrum of lesions ranging from tendinopathy, which may progress to partial- or full-thickness tear. This progression may be influenced by the interplay of extrinsic and intrinsic factors. We describe the case of a 29-year-man who presented with right shoulder pain for one year. His initial magnetic resonance (MR) arthrogram showed supraspinatus tendinopathy. Subsequent MR arthrogram, obtained after a road traffic accident, showed a bursal-sided partial-thickness tear of the supraspinatus tendon. In view of his worsening clinical symptoms, surgery was performed ten months later, revealing a full-thickness rotator cuff tear near the tendon insertion, with a tight subacromial space and bony protuberance of the humeral head. The pathogenesis of rotator cuff injuries, the roles of different imaging modalities in the diagnosis of rotator cuff injuries, as well as the advantages and limitations of various radiological modalities, are discussed. PMID:24068062
Bhagwani, S G; Peh, W C
Purpose The purpose of this study was to retrospectively evaluate sensitivity and specificity of a single magnetic resonance (MR)\\u000a arthrography series in abduction external rotation (ABER) position compared with conventional MR arthrography for detection\\u000a of supraspinatus tendon tears, with arthroscopy as gold standard, and to assess interobserver variability.\\u000a \\u000a \\u000a \\u000a Materials and methods Institutional review board approval was obtained; informed consent was waived. MR
Saskia A. Schreinemachers; Victor P. M. van der Hulst; W. Jaap Willems; Shandra Bipat; Henk-Jan van der Woude
Partial-thickness articular tears of the supraspinatus represent a not uncommon event in shoulder pathology, but their treatment remains controversial. We believe that these lesions must be treated with surgical repair: we hereby describe our technique of transtendon arthroscopic repair. We have treated 33 patients with an average age of 53.3 years (range 34-69). The average follow-up was 33 months (range 26-45). The post-operative Constant score values have shown a total increase of 48.2 points (from preoperative 44.4 points to post-operative 91.6 points). In the MRI follow-up assessment no cases of retears have occurred. The use of this technique enables the reconstitution of the tendon with complete reconstruction of its footprint without damaging its intact part. We believe that this can allow a better recovery. PMID:19711170
Castricini, R; Panfoli, N; Nittoli, R; Spurio, S; Pirani, O
Background: There are few biomechanical studies regarding partial-thickness rotator cuff tears and subsequent repair.Hypothesis: Partial-thickness intra-articular supraspinatus tendon tears increase articular-sided tendon strain as they increase in size. Repair of these tears will return strain to the intact state.Study Design: Controlled laboratory study.Methods: Twenty fresh-frozen human cadaveric shoulders were prepared by dissecting to the supraspinatus tendon and leaving the native
Augustus D. Mazzocca; Lina M. Rincon; Robert W. OConnor; Elifho Obopilwe; Matthew Andersen; Lauren Geaney; Robert A. Arciero
Background: To date, no studies document the effect of anabolic steroids on rotator cuff tendons.Study Design: Controlled laboratory study.Hypothesis: Anabolic steroids enhance remodeling and improve the biomechanical properties of bioartificially engineered human supraspinatus tendons.Methods: Bioartificial tendons were treated with either nandrolone decanoate (nonload, steroid, n = 18), loading (load, nonsteroid, n = 18), or both (load, steroid, n = 18).
Ioannis K. Triantafillopoulos; Albert J. Banes; Karl F. Bowman; Melissa Maloney; William E. Garrett; Spero G. Karas
MR imaging has been shown to be accurate in the diagnosis of rotator cuff disruption and tear. Uncertainty remains about the significance of Increased signal intensity in the critical zone of the supraspinatus tendon without visible disruption of tendon fibers and about the significance of other secondary findings commonly encountered with rotator cuff abnormalities, such as musculotendinous retraction or obliteration
Christian H. Neumann; R. Gary Holt; Lynne S. Steinbach; Anon H. Jahnke; Steve A. Petersen
PURPOSE: To characterize the supraspinatus tendon thickness, subacromial space, and the relationship between tendon thickness and subacromial space to further elucidate the mechanisms of subacromial impingement syndrome. METHODS: In a single-blind cross-sectional study, subjects were recruited with subacromial impingement syndrome (n = 20) and asymptomatic controls (n = 20) matched for age, gender, and hand dominance. Ultrasound images were collected using a 4-12-MHz linear transducer in B-mode of the supraspinatus tendon in the transverse (short axis) and the anterior aspect of the subacromial space outlet. Using image callipers, measurements of tendon thickness were taken at 3 points along the tendon and averaged for a single thickness measure. The subacromial space outlet was measured via the acromiohumeral distance (AHD) defined by the inferior acromion and superior humeral head. The occupation ratio was calculated as the tendon thickness as a percentage of AHD. RESULTS: The subacromial impingement syndrome group had a significantly thicker tendon (mean difference = 0.6 mm, p = 0.048) and a greater tendon occupation ratio (mean difference = 7.5 %, p = 0.014) compared to matched controls. There were no AHD group differences. CONCLUSIONS: The supraspinatus tendon was thicker and occupied a greater percentage of AHD, supporting an intrinsic mechanism. An extrinsic mechanism of tendon compression is theoretically supported, but future imaging studies need to confirm direct compression with elevation. Treatment to reduce tendon thickness may reduce symptoms, and surgical intervention to increase subacromial space may be considered if tendon compression can be verified. PMID:23736252
Michener, Lori A; Subasi Yesilyaprak, Sevgi S; Seitz, Amee L; Timmons, Mark K; Walsworth, Matthew K
Background: Good functional results have been reported for arthroscopic repair of rotator cuff tears, but the rate of tendon-to-bone healing is still unknown. Our hypothesis was that arthroscopic repair of full-thickness supraspinatus tears achieves a rate of complete tendon healing equivalent to those reported in the literature with open or mini-open techniques. Methods: Sixty-five consecutive shoulders with a chronic full-thickness
PASCAL BOILEAU; NICOLAS BRASSART; DUNCAN J. WATKINSON; MICHEL CARLES; ARMODIOS M. HATZIDAKIS; SUMANT G. KRISHNAN
Structural constitutive modeling approaches are often based on the assumption of affine fiber kinematics, even though this\\u000a assumption has rarely been evaluated experimentally. We are interested in applying mathematical models to understand the mechanisms\\u000a responsible for the inhomogeneous, anisotropic, and non-linear properties of human supraspinatus tendon (SST); however, the\\u000a relationship between macroscopic and fiber-level deformation in this tendon remains unknown
Spencer P. Lake; Daniel H. Cortes; Jennifer A. Kadlowec; Louis J. Soslowsky; Dawn M. Elliott
Purpose Peritendinous adhesions are an important complication of flexor tendon injury. Three hyaluronan (HA)-derived biomaterials were evaluated for the reduction of peritendinous adhesions following partial-thickness tendon injury in rabbits. Methods Rabbits (n = 24) were divided into three groups (n = 8 per group), which were used for gross evaluation, histologic assessment, or biomechanical testing. The fourth and third toes from both hindpaws of each rabbit were randomly assigned to one of four treatments: (i) untreated control, (ii) Seprafilm®, (iii) Carbylan™-SX in situ-crosslinked hydrogel, and (iv) pre-formed Carbylan™-SX film. Results Rabbits were sacrificed at three weeks post-surgery and evaluated anatomically, histologically, and mechanically. All materials used reduced adhesions relative to untreated controls for all three evaluations. Both the gross anatomic and histologic results revealed that Carbylan™-SX film was statistically superior to Seprafilm® and Carbylan™-SX gel in preventing tendon adhesion formation. In biomechanical tests, the Carbylan™-SX film-treated hindpaws required the least force to pull the tendon from the sheath. This force was statistically indistinguishable from that required to extrude an unoperated tendon (n = 8). Carbylan™-SX gel was less effective than Carbylan™-SX film but superior to Seprafilm® for all evaluations. Conclusions A crosslinked HA-derived film promoted healing of a flexor tendon injury without the formation of fibrosis at 3 weeks post-operatively.
Liu, Yanchun; Skardal, Aleksander; Shu, Xiao Zheng
Objectives To examine the dose–response relationship between cumulative duration of work with highly elevated arms (work above shoulder\\u000a level) as well as of manual material handling and ruptures of the supraspinatus tendon in a population-based case–control\\u000a study.\\u000a \\u000a \\u000a \\u000a \\u000a Methods In 14 radiologic practices, we recruited 483 male patients aged 25–65 with radiographically confirmed partial (n = 385) or total (n = 98) supraspinatus tears associated with shoulder
Andreas Seidler; Ulrich Bolm-Audorff; Gabriela Petereit-Haack; Elke Ball; Magdalena Klupp; Noëlle Krauss; Gine Elsner
Transosseous repair of a supraspinatus tendon (SSP) defect (Patte size II) can be difficult if the tendon is retracted and\\u000a the muscle atrophied. In this situation alternatives are margin convergence techniques, local tendon transfers or distant\\u000a tendon transfers in massive tears. The object of this study was to compare two local tendon transfers in terms of the feasibility\\u000a of the
Philip Kasten; Markus Loew; Markus Rickert
Objectives: To evaluate microvasculature in the borders of the supraspinatus tendon in rotator cuff lesions in order to determine the need to debrid the borders when surgical repair is performed. Methods: From June to December 224, samples were evaluated from 31 patients with full lesion of the supraspinatus tendon that had been submitted to arthroscopic rotator cuff lesion treatment. They
Ikemoto RY; Murachovsky J; Nascimento LGP; Bueno RS; Ueno FH; Akita Júnior J; ROBERTO YUKIO IKEMOTO; LUIS GUSTAVO; PRATA NASCIMENTO; ROGÉRIO SERPONE BUENO; FABRÍCIO HIDETOSHI UENO; JORGE AKITA JÚNIOR
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
Bank, R.; TeKoppele, J.; Oostingh, G.; Hazleman, B.; Riley, G.
FT-Raman spectroscopy was employed to access the biochemical alterations occurring on the degenerative process of the rotator cuff supraspinatus tendons. The spectral characteristic variations in the 351 spectra of samples of 39 patients were identified with the help of Principal Components Analysis. The main variations occurred in the 840-911; 1022- 1218; 1257; 1270; 1300; 1452; 1663; and 1751 cm-1 regions corresponding to the vibrational bands of proline, hydroxiproline, lipids, nucleic acids, carbohydrates, collagen, and elastin. These alterations are compatible with the pathology alterations reported on the literature. Scattering plots of PC 4 vs PC 2 and PC 3 vs PC 2 contrasted with histopathological analysis has enabled the spectral classification of the data into normal and degenerated groups of tendons. By depicting empiric lines the estimated sensibility and specificity were 39,6 % and 97,8 %, respectively for PC 4 vs PC 2 and 36,0 % and 100 %, respectively for PC 3 vs PC 2. These results indicate that Raman spectroscopy can be used to probe the general tendon quality and could be applied as co adjuvant element in the usual arthroscopy surgery apparatus to guide the procedure and possibly infer about the probability of rerupture.
Palma Fogazza, Bianca; da Silva Carvalho, Carolina; Godoy Penteado, Sergio; Meneses, Cláudio S.; Abrahão Martin, Airton; da Silva Martinho, Herculano
Background Collagen fiber re-alignment and uncrimping are two postulated mechanisms of tendon structural response to load. Recent studies have examined structural changes in response to mechanical testing in a postnatal development mouse supraspinatus tendon model (SST), however, those changes in the mature mouse have not been characterized. The objective of this study was to characterize collagen fiber realignment and crimp behavior throughout mechanical testing in a mature mouse SST. Method of Approach A tensile mechanical testing set-up integrated with a polarized light system was utilized for alignment and mechanical analysis. Local collagen fiber crimp frequency was quantified immediately following the designated loading protocol using a traditional tensile set up and a flash-freezing method. The effect of number of preconditioning cycles on collagen fiber re-alignment, crimp frequency and mechanical properties in midsubstance and insertion site locations were examined. Results Decreases in collagen fiber crimp frequency were identified at the toe-region of the mechanical test at both locations. The insertion site re-aligned throughout the entire test, while the midsubstance re-aligned during preconditioning and the test’s linear-region. The insertion site demonstrated a more disorganized collagen fiber distribution, lower mechanical properties and a higher cross-sectional area compared to the midsubstance location. Conclusions Local collagen fiber re-alignment, crimp behavior and mechanical properties were characterized in a mature mouse SST model. The insertion site and midsubstance respond differently to mechanical load and have different mechanisms of structural response. Additionally, results support that collagen fiber crimp is a physiologic phenomenon that may explain the mechanical test toe-region.
Miller, Kristin S.; Connizzo, Brianne K.; Feeney, Elizabeth; Soslowsky, Louis J.
Rotator cuff pathology causes substantial pain/disability and health care costs. Cell-based tissue engineering offers promise for improved outcomes in tendon to bone healing. Cells from the tendon-bone interface were used here to amplify surgical defect healing in a rat model. Cells from tendon-to-bone interface of the rotator cuff were seeded in sponges and implanted into critical rotator cuff defects: Group I, control; II, surgical defect only; III, suture-repaired defect; IV, surgical defect, repair with sponge only; V, surgical defect, repair with sponge with cells. Three, 6-, and 12-week results were assessed for histologic features. At 3 weeks, histologic indices in Group V were significantly increased versus other treatment groups. Group V (12 weeks) showed significantly improved collagen organization versus other treatment groups; there was no difference in collagen organization in Group I versus V. In summary, increased cellularity, inflammation, vascularity, and collagen organization were present at 3 weeks; increased collagen organization at 12 weeks in Group V provides evidence for improved healing with cells. Data further support the utility of tendon-bone interface cells in rotator cuff healing. PMID:23070709
Loeffler, Bryan J; Scannell, Brian P; Peindl, Richard D; Connor, Patrick; Davis, Daniel E; Hoelscher, Gretchen L; Norton, H James; Hanley, Edward N; Gruber, Helen E
Purpose. The purpose of this study was to investigate supraspinatus tendon sonographic morphology in a population of young overhead\\u000a athletes in correlation with main pathologic models of secondary shoulder impingement syndrome.\\u000a \\u000a \\u000a \\u000a Subjects and methods. Between April and May 2004, 20 subjects (ten professional basketball players and ten non-athlete controls of the same age,\\u000a weight and height ranges) underwent bilateral, standardised, sonographic sholulder
R. Girometti; A. De Candia; M. Sbuelz; F. Toso; C. Zuiani; M. Bazzocchi
Although the incidence of partial-thickness rotator cuff tears (PTRCTs) was reported to be from 13% to 32% in cadaveric studies, the actual incidence is not yet known. The causes of PTRCTs can be explained by either extrinsic or intrinsic theories. Studies suggest that intrinsic degeneration within the rotator cuff is the principal factor in the pathogenesis of rotator cuff tears. Extrinsic causes include subacromial impingement, acute traumatic events, and repetitive microtrauma. However, acromially initiated rotator cuff pathology does not occur and extrinsic impingement does not cause pathology on the articular side of the tendon. An arthroscopic classification system has been developed based on the location and depth of the tear. These include the articular, bursal, and intratendinous areas. Both ultrasound and magnetic resonance image are reported with a high accuracy of 87%. Conservative treatment, such as subacromial or intra-articular injections and suprascapular nerve block with or without block of the articular branches of the circumflex nerve, should be considered prior to operative treatment for PTRCTs.
Background: Rotator cuffs heal through a scar tissue interface after repair, which makes them prone to failure. Membrane type 1 matrix metalloproteinase (MT1-MMP) is upregulated during embryogenesis in areas that develop into tendon-bone insertion sites.Hypothesis: Bone marrow-derived stem cells in the presence of the developmental signal from MT1-MMP will drive the healing process toward regeneration and away from scar formation.Study
Lawrence V. Gulotta; David Kovacevic; Scott Montgomery; John R. Ehteshami; Jonathon D. Packer; Scott A. Rodeo
Tendinopathy and small partial-thickness tears of the rotator cuff tendon are common presentations in sports medicine. No promising treatment has yet been established. Corticosteroid injections may improve symptoms in the short term but do not primarily treat the tendon pathology. Ultrasound-guided autologous tenocyte implantation (ATI) is a novel bioengineered treatment approach for treating tendinopathy. We report the first clinical case of ATI in a 20-year-old elite gymnast with a rotator cuff tendon injury. The patient presented with 12 months of increasing pain during gymnastics being unable to perform most skills. At 1 year after ATI the patient reported substantial improvement of clinical symptoms. Pretreatment and follow-up MRIs were reported and scored independently by two experienced musculoskeletal radiologists. Tendinopathy was improved and the partial-thickness tear healed on 3 T MRI. The patient was able to return to national-level competition. PMID:23314880
Wang, Allan W; Bauer, Stefan; Goonatillake, Matthew; Breidahl, William; Zheng, Ming-Hao
A rotator cuff tear causes morphologic changes in rotator cuff muscles and tendons and reduced shoulder strength. The mechanisms by which these changes affect joint strength are not understood. This study’s purpose was to empirically determine rotation moment arms for subregions of supraspinatus, infraspinatus, and for teres minor, and to test the hypothesis that subregions of the cuff tendons increase their effective moment arms through connections to other subregions. Tendon excursions were measured for full ranges of rotation on 10 independent glenohumeral specimens with the humerus abducted in the scapular plane at 10 and 60°. Supraspinatus and infraspinatus tendons were divided into equal width subregions. Two conditions were tested: tendon divided to the musculotendinous junction, and tendon divided to the insertion on the humerus. Moment arms were determined from tendon excursion via the principle of virtual work. Moment arms for the infraspinatus (p < 0.001) and supraspinatus (p < 0.001) were significantly greater when the tendon was only divided to the musculotendinous junction versus division to the humeral head. Moment arms across subregions of infraspinatus (p < 0.001) and supraspinatus (p < 0.001) were significantly different. A difference in teres minor moment arm was not found for the two cuff tendon conditions. Moment arm differences between muscle subregions and for tendon division conditions have clinical implications. Interaction between cuff regions could explain why some subjects retain strength after a small cuff tear. This finding helps explain why a partial cuff repair may be beneficial when a complete repair is not possible. Data presented here can help differentiate between cuff tear cases that would benefit from cuff repair and cases for which cuff repair might not be as favorable.
Langenderfer, Joseph E.; Patthanacharoenphon, Cameron; Carpenter, James E.; Hughes, Richard E.
Several theories have been proposed to explain the mechanism of non-traumatic supraspinatus tendinopathy, which causes rotator cuff tendinitis and rotator cuff ruptures. However, these theories have not addressed all potential causes of rotator cuff tendinopathy. We propose that the microanatomy of the supraspinatus muscle and its response to gravity is the mechanism that responsible for non-traumatic supraspinatus tendinopathy and rotator cuff tears. Gravity causes chronic traction to the supraspinatus muscle, which results in elongation in the sarcomere length. Elongated sarcomere length causes compression on the micro vessels in the muscle which compromises internal microcirculation of the muscle and tendon. Poor microcirculation triggers ischemia and ischemia triggers inflammation process in the muscle and the tendon. This results in a higher incidence of tendinopathy. We also propose a new physiotherapeutic approach that may provide improved healing for rotator cuff tendinopathy. PMID:22633745
F?rat, Tüzün; Türker, Tolga
Purpose. The purpose of this study was to compare the accuracy of the conventional method for determining the percentage of partial thickness rotator cuff tears to a method using an intra-articular depth guide. The clinical utility of the intra-articular depth guide was also examined. Methods. Partial rotator cuff tears were created in cadaveric shoulders. Exposed footprint, total tendon thickness, and percentage of tendon thickness torn were determined using both techniques. The results from the conventional and intra-articular depth guide methods were correlated with the true anatomic measurements. Thirty-two patients were evaluated in the clinical study. Results. Estimates of total tendon thickness (r = 0.41, P = 0.31) or percentage of thickness tears (r = 0.67, P = 0.07) using the conventional method did not correlate well with true tendon thickness. Using the intra-articular depth guide, estimates of exposed footprint (r = 0.92, P = 0.001), total tendon thickness (r = 0.96, P = 0.0001), and percentage of tendon thickness torn (r = 0.88, P = 0.004) correlated with true anatomic measurements. Seven of 32 patients had their treatment plan altered based on the measurements made by the intra-articular depth guide. Conclusions. The intra-articular depth guide appeared to better correlate with true anatomic measurements. It may be useful during the evaluation and development of treatment plans for partial thickness articular surface rotator cuff tears.
Carroll, Michael J.; More, Kristie D.; Sohmer, Stephen; Nelson, Atiba A.; Sciore, Paul; Boorman, Richard; Hollinshead, Robert; Lo, Ian K. Y.
OBJECTIVES--To analyse the glycosaminoglycans of the adult human rotator cuff tendon matrix, to characterise changes in the glycosaminoglycan composition with age and in chronic rotator cuff tendinitis. METHODS--Rotator cuff (supraspinatus) tendons (n = 84) and common biceps tendons (n = 26) were obtained from cadavers with no history of tendon pathology (age range 11-95 years). Biopsies of rotator cuff tendons
G P Riley; R L Harrall; C R Constant; M D Chard; T E Cawston; B L Hazleman
The human supraspinatus muscle is clinically important as it is frequently injured in older adults and the elderly. We have previously shown that the supraspinatus has a complex architecture with two distinct regions each consisting of three parts. Further we have found dynamic changes in architectural parameters such as fiber bundle length markedly vary between these regions. Fiber types of the supraspinatus have not been thoroughly investigated throughout its volume and are of interest to clinicians treating supraspinatus pathologies. In this study we investigated the distribution of fiber types within the distinct regions and parts of supraspinatus. Samples of supraspinatus were excised from six distinct parts of each muscle from five formalin embalmed specimens (one male, four female; mean age 77±11.1 years) free of tendon pathology. Samples were frozen in liquid nitrogen and then cryosectioned. Serial sections were labeled using immunohistochemical techniques and antibodies against fast or slow myosin heavy chain isoforms. The mean percentage of Type I (slow) fibers ranged from 56.73% to 63.97%. Results demonstrated significant variations in fiber type distribution. The middle part of the anterior region has a significantly greater percentage of Type I fibers compared to that of the posterior. The superficial part of the anterior region has a greater percentage of Type II (fast) fibers compared to the middle and deep parts. Findings aid in highlighting the distinct functions of the anterior and posterior regions, and prompt the need to re-evaluate assessment and treatment techniques established on a limited understanding of the fiber type distribution. PMID:23463598
Kim, S Y; Lunn, D D; Dyck, R J; Kirkpatrick, L J; Rosser, B W C
The purpose of this anatomic study was to assess the risk to the suprascapular nerve by measuring the tension on the nerve and the angle between the nerve and its motor branch at the scapular notch with medial supraspinatus tendon retraction. Twelve shoulders in six cadavers were dissected to evaluate the branching point of the first motor branch of the
Mark J Albritton; Robert D Graham; Richard S Richards; Carl J Basamania
Reference/Citation: Wiechula R. The use of moist wound-healing dressings in the management of split-thickness skin graft donor sites: a systematic review. Int J Nurs Pract. 2003; 9:S9–S17. Clinical Question: Do rates of healing, infection, and pain differ depending on whether nonmoist or moist dressings are used to manage superficial to partial-thickness wounds? Data Sources: Investigations were identified by CINAHL, MEDLINE, Pre-MEDLINE, Cochrane Library, Current Contents, Health STAR, EMBASE, Expanded Academic Index, and Dissertation Abstracts International searches. The search terms included skin, graft, and donor. Additional searches were performed with reference lists and bibliographies of retrieved studies. Study Selection: To be included in the review, each study had to fulfill the following criteria: it had to be an intraindividual or prospective randomized controlled trial of human subjects; it had to include patients with postharvest split-thickness skin graft donor sites; it had to evaluate the effectiveness of primary and secondary wound dressings; and it had to have outcome measures that included healing (objective), infection (subjective), and pain (objective). Data Extraction: Data extraction and study quality assessment procedures were developed specifically for this review based on Cochrane Collaboration, Centre for Reviews and Dissemination, and Joanna Briggs Institute protocols and were performed independently by the author. Details of the procedures were not fully explained. The principal outcome measures were healing (proportion of sites healed within the study period or time to complete healing), rate of infection, and pain scores. The studies were grouped according to broad dressing type (nonmoist and moist) and specific types of moist dressings (hydrocolloids and polyurethane semipermeable transparent films). When comparable, study results were pooled and analyzed with a fixed-effects model. Data within broader dressing categories (nonmoist and moist) were analyzed with a random-effects model. ? 2 analysis was used to determine heterogeneity among the studies. RevMan software (version 4.04; Cochrane Centre, Oxford, UK) was used for statistical analysis. Main Results: The searches identified 111 studies and 1 integrative review, of which 58 studies met the inclusion and exclusion criteria. Inconsistency and variation in outcome measures and incomplete reporting of results prevented analysis of many studies. Wound healing was measured by days to complete healing (when dressings could be removed without trauma and pain) and wounds healed by day X (removal of dressings at regular intervals). Wound infection was subjectively measured based on clinical signs of infection (edema, heat, pain, or smell). Visual analog scales were used to measure pain levels. Among the broad categories of nonmoist (sterile gauze, fine mesh gauze, Xerofoam [Tyco Healthcare Group LP, Mansfield, MA]) and moist (DuoDERM hydrocolloid [ConvaTec, Princeton, NJ], Tegaderm transparent film [3M Health Care, St Paul, MN], Opsite transparent film [Smith & Nephew, London, UK]) dressings, the outcomes of healing, infection, and pain were analyzed. In 6 studies, the findings significantly favored moist dressings, compared with nonmoist dressings, for days to complete healing (weighted mean difference [WMD] = ?3.97, 95% confidence interval [CI] = ?5.91, ?2.02). In 9 studies, wounds healed by day X (day 7, 8, 9, 10, or 12) were analyzed. The results were varied and inconclusive because of a small number of trials and subjects. Among 10 studies, no significant difference was noted in infection rates between nonmoist and moist dressings (odds ratio [OR] = 0.41, 95% CI = 0.14, 1.18). Three studies using visual analog scales for the outcome of pain were converted into a uniform scale of 1 to 10 (10 representing most painful). The findings significantly favored moist dressings over nonmoist dressings (WMD = ?1.75, 95% CI = ?2.94, ?0.56). Among nonmoist and specific types of moist dressings,
Beam, Joel W
OBJECTIVES--To analyse the glycosaminoglycans of the adult human rotator cuff tendon matrix, to characterise changes in the glycosaminoglycan composition with age and in chronic rotator cuff tendinitis. METHODS--Rotator cuff (supraspinatus) tendons (n = 84) and common biceps tendons (n = 26) were obtained from cadavers with no history of tendon pathology (age range 11-95 years). Biopsies of rotator cuff tendons (supraspinatus and subscapularis tendons, n = 53) were obtained during open shoulder surgery to repair shoulder lesions (age range 38-80 years). Glycosaminoglycans were extracted by papain digestion and analysed by cellulose acetate electrophoresis, the carbazole assay for uronic acid and the dimethylmethylene blue dye-binding assay for sulphated glycosaminoglycans. Some digests were analysed for keratan sulphate by 5D4 monoclonal antibody ELISA. Soluble proteoglycans were extracted in 4M guanidine hydrochloride and analysed by 4-15% SDS PAGE. RESULTS--The mean (SD) sulphated glycosaminoglycan (GAG) content of the normal cadaver supraspinatus tendon was 12.3 (4.3) micrograms/mg dry weight, between three and ten times greater than in the common biceps tendon [1.2 (0.6) micrograms/mg dry weight]. The major GAG was chondroitin sulphate [6.9 (2.6) micrograms/mg dry weight], with a smaller proportion of dermatan sulphate [2.5 (1.2) micrograms/mg dry weight]. In contrast, the common biceps tendon contained predominantly dermatan sulphate [0.8 (0.2) microgram/mg dry weight] with less chondroitin sulphate [0.2 (0.2) microgram/mg dry weight]. There was no difference in the concentration of hyaluronan in these tendons [9.3 (2.8) micrograms/mg dry weight and 10.8 (4.3) micrograms/mg dry weight respectively] and there was no significant change of hyaluronan with age. Keratan sulphate was a small but significant component of the supraspinatus tendon [0.43 (0.33) microgram/mg dry weight, n = 25], whereas there was little or none in the common biceps tendon [0.04 (0.05) microgram/mg dry weight, n = 8] and there was no significant change across the age range. In the supraspinatus tendon, there was a significant decrease in total glycosaminoglycan, chondroitin sulphate and dermatan sulphate with age (p < 0.001), whether expressed relative to the tendon dry weight or total collagen content, and no change in the relative proportion of the different GAG types. There was, however, a large degree of variation within the samples. Supraspinatus tendons from patients with chronic tendinitis had a significantly increased concentration of hyaluronan [30.4 (10.1) micrograms/mg dry weight, p < 0.001], chondroitin sulphate [8.4 (1.8) micrograms/mg dry weight, p < 0.05] and dermatan sulphate [3.8 (1.1) micrograms/mg dry weight, p < 0.001] compared with normal cadaver supraspinatus tendons, although the keratan sulphate content was not significantly different [0.18 (0.05) microgram/mg dry weight]. CONCLUSIONS--The normal supraspinatus tendon has the proteoglycan/glycosaminoglycan of tendon fibrocartilage, which it is suggested is an adaptation to mechanical forces (tension, compression and shear) which act on the rotator cuff tendons in the shoulder, although other factors such as reduced vascularity, low oxygen tension and the influence of local growth factors may also be important. This functional adaptation may have important consequences for the structural strength of the supraspinatus tendon and to influence the ability of the tendon to repair after injury. The glycosaminoglycan composition of tendon specimens from patients with chronic tendinitis is consistent with acute inflammation and new matrix proteoglycan synthesis, even in relatively old tendon specimens and after at least one injection of corticosteroid. Images
Riley, G P; Harrall, R L; Constant, C R; Chard, M D; Cawston, T E; Hazleman, B L
Purpose: To describe and evaluate a simple perioperative test (the derotation sign) that differentiates significant (grade 3) partial-thickness and small full-thickness rotator cuff tears from insignificant (grades 1 and 2) partial-thickness rotator cuff tears and intact rotator cuffs. Type of Study: Sensitivity and specificity study. Methods: A study was conducted of 123 patients who underwent shoulder arthroscopy for chronic symptomatic
David E. Attarian
The influence of joint mobilization on tendinopathy of the biceps brachii and supraspinatus muscles A influência da mobilização articular nas tendinopatias dos músculos bíceps braquial e supra-espinal
The most common causes of shoulder pain are related to degeneration of the tendons of the rotator cuff muscles. Objective: To investigate the influence of joint mobilization by means of accessory movements of the shoulder during the early rehabilitation of 14 patients with chronic tendinopathy of the supraspinatus and\\/or biceps brachii muscles. Methods: Two treatment protocols were compared: application of
Barbosa RI; Goes R; Mazzer N; Fonseca MCR
Conflicting recommendations and clinical applications have been given concerning best practices for the management of burn blisters associated with partial-thickness burns. Arguments for the preservation of intact blisters center on the idea of naturally occurring biologic protection whereas the débridment of blisters has been advocated because of the perceived decreases in wound infection and complications. Recurring themes in burn wound management that are considered in this debate include infection, healing, functional and aesthetic outcome, patient comfort, ease of dressing care, and cost efficiency. The management of burn blisters should be supported by evidence across these six categories, should match the expertise of the provider, and should use the available resources in the practice setting. The purpose of this review is combine the findings of a comprehensive review of the published literature with respect to the management of blisters in the partial-thickness burn into a clinical guideline for best practice based on available evidence. PMID:16566539
Sargent, Rachael L
Elite overhead throwing athletes with rotator cuff tears represent a unique group of patients with an ultimate goal of returning to their previous level of competition. We hypothesized débridement of small partial-thickness rotator cuff tears would return the majority of elite overhead throwing athletes to their previous level of competition. Preoperative and intraoperative findings on 82 professional pitchers who had undergone débridement of partial-thickness rotator cuff tears were evaluated using our database. We obtained return to play data on 67 of the 82 players (82%); 51 (76%) were able to return to competitive pitching at the professional level and 37 (55%) were able to return to the same or higher level of competition. Of the 67 patients, 34 pitchers returned a questionnaire with a minimum followup of 18 months (mean 38 months; range 18 to 59 months). SF-12 scores were above average with a mean PSF-12 and MSF-12 of 55.04 and 56.49 respectively. An Athletic Shoulder Outcome Rating Scale score of greater than 60 was found in 76.5% of pitchers. Débridement of small partial-thickness rotator cuff tears allowed a majority of elite overhead throwing athletes to return to competitive pitching, however, returning to their previous level of competition remains a challenge for many of these players. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18264849
Reynolds, Scott B; Dugas, Jeffrey R; Cain, E Lyle; McMichael, Christopher S; Andrews, James R
Aquacel Hydrofiber is a moisture retentive topical dressing that has been demonstrated to be safe and efficacious for the management of partial-thickness burns, showing parity for most dressing related aspects to cadaver skin for this indication. Recently, 1.2% w/w silver has been added to the Aquacel Hydrofiber, to create Aquacel Ag. This new material releases silver within the dressing for up to two weeks, and it is this duration that differentiates it from other sustained release silver delivery products indicated for burn management. The dressing was tested in a phase II noncomparative trial in superficial, mid dermal, and mixed partial-thickness burns. Percentage and speed of reepithelialization were satisfactory and appear to be similar at least to results noted with silver sulfadiazine, although, no direct comparisons were performed in this study. Pain reduction between baseline and postburn day number three and five was statistically significant. Conformability, general ease of use and other functional dressing properties were rated very positively. Overall, Aquacel Ag combines several properties known to be beneficial for the management of partial-thickness burns and is a very good choice for superficial and mid-thickness burn injuries. PMID:14726745
Caruso, Daniel M; Foster, Kevin N; Hermans, Michel H E; Rick, Christina
A newly developed, carboxymethylcellulose based hydrofibre dressing, Aquacel, was tested for the treatment of partial thickness burns. In this study 84 patients with mainly partial thickness burns were included, 76 patients received 1 or 2 days pre-treatment with a topical antimicrobial agent. Clinical behaviour showed a strong resemblance with cadaver skin treatment with respect to adherence to the wound. Adverse reactions, incidence of clinical wound infection, healing time and the need for wound excision and grafting were analysed, as was the final outcome using the 'Vancouver Scar Scale'. The mean size of the wounds treated with the hydrofibre dressing was 6.0% body surface area (min: 1%, max: 18%). Two patients clinically showed signs of a wound infection during treatment, but in general wound cultures were low or negative. In 42 patients (50%) the wounds healed completely within 10 days, in six patients (7%) small defects remained that healed by further treatment with a topical antimicrobial cream. In 36 patients (43%) excision and grafting of the remaining deeper parts of the wounds was performed as this is the standard therapy in the centre for all burned areas that have not healed within 2-3 weeks post-injury. The extent of the surgical procedures was limited since 66.1% of the wound area had healed already at the end of the hydrofibre treatment. In 54 patients the outcome of the treatment after 2-3 months was analysed by means of the Vancouver Scar Scale, which showed favourable results in general, and especially for patients who did not require surgery. Compared to earlier experience with allograft skin it was concluded that hydrofibre dressing is a safe, suitable and easy to use material for treatment of partial thickness burns. PMID:11226656
Vloemans, A F; Soesman, A M; Kreis, R W; Middelkoop, E
Summary The structure of a tendon is an important example of complexity of ECM three-dimensional organization. The extracellular matrix (ECM) is a macromolecular network with both structural and regulatory functions. ECM components belong to four major types of macromolecules: the collagens, elastin, proteoglycans, and noncollagenous glycoproteins. Tendons are made by a fibrous, compact connective tissue that connect muscle to bone designed to transmit forces and withstand tension during muscle contraction. Here we show the ultrastructural features of tendon’s components.
Tresoldi, Ilaria; Oliva, Francesco; Benvenuto, Monica; Fantini, Massimo; Masuelli, Laura; Bei, Roberto; Modesti, Andrea
Acute compartment syndrome occurs when pressure within a confined fascial space rises to a level impairing microvascular perfusion to surrounding tissues. The majority of the reported literature is based on lower extremity compartment syndrome, but any muscle group within an osteofascial compartment has the potential to develop compartment syndrome. We report a case of a 64-year-old male who developed an acute compartment syndrome of both the supraspinatus and infraspinatus after sustaining a severely comminuted scapula fracture. Diagnosis of compartment syndrome was made after intracompartmental pressure measurements of the supraspinatus and infraspinatus revealed pressures within 30 mmHg of the diastolic blood pressure, prompting emergency decompressive fasciotomy. At final follow-up, the examination revealed full shoulder strength with near-full range of motion. There were no signs of sequelae from compartment syndrome at any point. Few case reports describe compartment syndrome of the periscapular fascial compartments. However, these cases were either retrospectively diagnosed or diagnosed via magnetic resonance imaging (MRI) findings and lab values. Surgical management of acute compartment syndrome of the supraspinatus has been reported in only one other case. To our knowledge, we report the only case of a patient with acute compartment syndrome of both the supraspinatus and infraspinatus compartments treated with emergent decompressive fasciotomy. Due to the devastating complications and functional loss of a missed diagnosis of compartment syndrome, a high index of clinical suspicion for developing compartment syndrome must be maintained in every fracture setting, regardless of anatomic location or rarity of reported cases.
Kenny, Ryan M.; Beiser, Christopher W.; Patel, Arun
Infection is of primary concern to those practitioners treating burns patients, as it is one of the primary complications associated with acute wounds and particularly with superficial partial-thickness burns. In the fight to reduce the risks, many practitioners deploy common antimicrobials agents prophylactically to help reduce risks, e.g. povidone-iodine. This review will examine the evidence to support this practice. The deployment of povidone-iodine in wound care is highly controversial, with questions being raised concerning not only the effectiveness of the product but also its safety and effect on wound healing. The use of povidone-iodine has been investigated both in vitro and in vivo, resulting in conflicting and often contradictory results. Of the work completed to date, researchers have failed to identify or control for extraneous variables which makes it difficult to compare and interpret research findings. The potential benefits or harm that the use of povidone-iodine may elicit in acute wounds is yet to be established. PMID:12682580
Improved healing of full- and partial-thickness cutaneous wounds in wet and moist environments is due primarily to retention of biological fluids over the wound preventing desiccation of denuded dermis or deeper tissues. This also allows faster and unimpeded migration of keratinocytes over the wound surface and enables the naturally occurring cytokines and growth factors to exert their beneficial effect on
B. S. Atiyeh; C. A. Al-Amm; K. A. El-Musa; A. Sawwaf; R. Dham
Deep dermal partial-thickness scalds remain one of the most common types of injuries in childhood. Local treatment of those wounds, alternatively described as IIb degree, is still very controversial. Some authors advise conservative treatment of such wounds, pointing to their ability to self-reepithelialise, which is possible but significantly prolonged. Other investigators postulate operative treatment, i.e., tangential necrectomy and split-thickness autologous skin grafting, which may shorten the time of wound healing. Arguments call for contra-arguments, and the problem still seems to be unresolved. There is indeed a lack of acceptable standardisation of the local treatment for deep dermal partial-thickness scalds in the paediatric population. The results of both conservative and operative treatment of 114 children aged between 3 months and 17 years, treated for deep dermal partial-thickness scalds from 1997 to 2004 are presented. The treatment of five groups of patients, divided into groups based on the extent of their burn wounds, is evaluated. The patients were treated by tangential necrectomy and skin grafting, mechanical dermabrasion, Granuflex(R) (Convatec) hydrocolloid dressings, Iruxol Mono(R) (Knoll) enzymatic dressings, or Aquacel Ag(R) (Convatec) hydrofibre dressings with silver ions. A number of parameters of wound healing were analysed. The results of this paper encouraged us to present and discuss a proposition for the standardisation of local treatment of deep dermal partial-thickness burn wounds in the paediatric population, according to the extent of injury. PMID:17968794
Ka?mierski, M; Ma?kowski, P; Jankowski, A; Harasymczuk, J
Oxidized linoleic acid metabolites (OLAMs) are a class of endogenous transient receptor potential vanilloid 1 (TRPV1) channel agonists released on exposure of tissue to transient noxious temperatures. These lipid compounds also contribute to inflammatory and heat allodynia. Because persistent pain after a burn injury represents a significant clinical challenge for treatment, we developed an in vivo rat model of partial-thickness cutaneous thermal injury and examined whether TRPV1 and specific OLAM metabolites play a role in mediating postburn pain injury. This peripheral model of burn injury had marked thermal allodynia peaking at 24h after thermal injury, with allodynia being maintained for up to 7d. Immunohistochemical characterization of tissue taken from injury sites revealed an increase in leukocyte/macrophage infiltration that was colocalized with TRPV1-positive fibers. Using this peripheral thermal injury model, we found that pharmacological blockade of peripheral TRPV1 receptors reduced thermal allodynia by about 98%. Moreover, there was a significant increase in OLAM levels compared to naive controls in hind paw skin biopsies. Additional studies of the metabolism of [C(14)]-linoleic acid in skin biopsies revealed the role of the cytochrome P450 (CYP) system in mediating the metabolism of linoleic acid after thermal injury. Finally, we demonstrated that direct inhibition of OLAMs using OLAM antibodies and indirect inhibition using the CYP inhibitor ketoconazole significantly reduced postburn thermal allodynia. Collectively, these findings point to a novel role of the OLAMs and CYP-related enzymes in generating postburn allodynia via activation of peripheral TRPV1. PMID:23891895
Green, Dustin P; Ruparel, Shivani; Roman, Linda; Henry, Michael A; Hargreaves, Kenneth M
We sought to determine if tendon inflammatory and histopathological responses increase in aged rats compared to young rats performing a voluntary upper extremity repetitive task, and if these changes are associated with motor declines. Ninety-six female Sprague-Dawley rats were used in the rat model of upper extremity overuse: 67 aged and 29 young adult rats. After a training period of 4 weeks, task rats performed a voluntary high repetition low force (HRLF) handle-pulling task for 2 hrs/day, 3 days/wk for up to 12 weeks. Upper extremity motor function was assessed, as were inflammatory and histomorphological changes in flexor digitorum and supraspinatus tendons. The percentage of successful reaches improved in young adult HRLF rats, but not in aged HRLF rats. Forelimb agility decreased transiently in young adult HRLF rats, but persistently in aged HRLF rats. HRLF task performance for 12 weeks lead to increased IL-1beta and IL-6 in flexor digitorum tendons of aged HRLF rats, compared to aged normal control (NC) as well as young adult HRLF rats. In contrast, TNF-alpha increased more in flexor digitorum tendons of young adult 12-week HRLF rats than in aged HRLF rats. Vascularity and collagen fibril organization were not affected by task performance in flexor digitorum tendons of either age group, although cellularity increased in both. By week 12 of HRLF task performance, vascularity and cellularity increased in the supraspinatus tendons of only aged rats. The increased cellularity was due to increased macrophages and connective tissue growth factor (CTGF)-immunoreactive fibroblasts in the peritendon. In conclusion, aged rat tendons were overall more affected by the HRLF task than young adult tendons, particularly supraspinatus tendons. Greater inflammatory changes in aged HRLF rat tendons were observed, increases associated temporally with decreased forelimb agility and lack of improvement in task success.
Kietrys, David M.; Barr-Gillespie, Ann E.; Amin, Mamta; Wade, Christine K.; Popoff, Steve N.; Barbe, Mary F.
OBJECTIVE:: A high prevalence of neovascularity in lower extremity tendinopathies has been reported. Neovascularity in those with rotator cuff tendinopathy exclusively has not been examined. The objective was to determine the prevalence of neovascularization in patients with rotator cuff tendinopathy compared with asymptomatic controls. DESIGN:: Single-blind cross-sectional study. SETTING:: Research laboratory. PARTICIPANTS:: Participants (n = 40; age = 44.9 years, 23-62 years; 20 females) with rotator cuff tendinopathy (n = 20) but without full-thickness rotator cuff tears, and asymptomatic controls that were age, gender, and hand dominance matched (n = 20) to the patients. INTERVENTIONS:: The participants laying in supine had their shoulder positioned in internal rotation and extension. Ultrasound images were collected of the supraspinatus tendon and subacromial bursae in the transverse and longitudinal planes using a linear transducer in color Doppler mode. MAIN OUTCOME MEASURES:: Images were assessed for neovascularization by 2 trained raters who were blinded to group (rotator cuff tendinopathy or asymptomatic group). RESULTS:: No statistically significant difference in neovascularization was identified between participants with and without rotator cuff tendinopathy (? = 0.13, df = 1, P = 0.72). Neovascularization was identified in 6 of 20 patients with rotator cuff tendinopathy (30%) and 5 of 20 asymptomatic control participants (25%). CONCLUSIONS:: The authors found no differences in neovascularization rate in patients with rotator cuff tendinopathy (30%) and asymptomatic controls (25%). The study indicates that neovascularization is not related to presence of symptomatic tendinopathy in those with rotator cuff tendinopathy. Neovascularization may not be a relevant sonographic finding to aid the clinical assessment of those with rotator cuff tendinopathy. PMID:23732364
Kardouni, Joseph R; Seitz, Amee L; Walsworth, Matthew K; Michener, Lori A
The reduced outflow rate caused by the increased resistance through trabecular meshwork (TM) has been thought to be the main reason for elevated intraocular pressure (IOP). It has been demonstrated that femtosecond laser pulses tuned to 1.7 µm wavelength can create the partial thickness channel in the sclera in ex vivo human eyes  and aqueous outflow can be increased by these channels in porcine eyes . It was also shown that the outflow rate is reduced over time in ex vivo human eyes . Therefore, the control experiment without laser treatment at the same condition was conducted and showed that outflow was reduced by 1.5 +/- 0.8 µl/min at 15mmHg and 1.8 +/- 1.0 µl/min at 25mmHg. However, the outflow rate increased by 0.26 µl/min at 15mmHg and 0.15 µl/min at 25mmHg after the partial thickness channel was created, meaning the amount of increased outflow rate might be more than measured considering the outflow reduction in control experiment. We suggest that the femtosecond laser created partial thickness channel can increase the outflow rate and delay the progression of glaucoma.
Chai, Dongyul; Chaudhary, Gautam; Kurtz, Ron; Juhasz, Tibor
Objective: To determine if the experimental (keratin-based) dressing accelerates epithelialization rates during healing of partial-thickness wounds, relative to a Standard Care dressing. Method: A randomized control trial was conducted using a Standard Care dressing side by side with the experimental dressing on a sample (n=26) of partial-thickness donor site wounds. The proximal/distal placement of the control and treatment was randomized. Percentage epithelialization after approximately 7 days was estimated from which time to fully epithelialize can be inferred. Patients were grouped into “young” (?50 y/o) and “old” (>50 y/o). Results: For the “old” patients (n=15), the median epithelialization percentage at 7 days is 5% and was significantly (P=.023) greater for the experimental dressing. For the “young” patients (n=11), the median epithelialization percentage at 7 days was 80% and there is no significant difference between the experimental and Standard Care control dressings. Conclusions: The experimental dressing significantly increases the rate of epithelialization of acute, traumatic partial-thickness wounds in older patients. We suggest that the dressing may be clinically useful in similar situations where epithelialization may be delayed because of patient or wound characteristics.
Davidson, Andrew; Jina, N. Hamesh; Marsh, Clive; Than, Martin; Simcock, Jeremy W.
Silver sulfadiazine has been used as a topical burn wound treatment for many years. Pain associated with dressing changes is a common problem in burn wounds. Aquacel Ag, a hydrofiber dressing coated with ionic silver has been reported to reduce burn wound infection and promote antimicrobial activity. The purpose of this study was to show the benefits of Aquacel Ag for the treatment of partial thickness burns. This prospective randomized study was conducted in 70 patients who had partial thickness burns less than 15% of total body surface area and were treated at Siriraj outpatient burn clinic during December 2006-February 2008. Patients were divided into two groups: Aquacel Ag-treated group with dressing changes every 3 days (35 patients) and 1% silver sulfadiazine-treated group, with daily dressing changes (35 patients). There was no difference in demographic data including age, gender, burn percentage between groups. Time-to-wound healing pain score during dressing change and cost of treatment were compared between both groups. Time-to-wound closure was significantly shorter in the Aquacel Ag-treated group (10 +/- 3 versus 13.7 +/- 4 days, P < 0.02) as well as pain scores at days 1, 3 and 7 (4.1 +/- 2.1, 2.1 +/- 1.8, 0.9 +/- 1.4 versus 6.1 +/- 2.3, 5.2 +/- 2.1, 3.3 +/- 1.9, respectively, P < 0.02). Total cost of treatment was 52 +/- 29 US dollars for the Aquacel Ag-treated group versus 93 +/- 36 US dollars for the silver sulfadiazine-treated group. This study showed that Aquacel Ag increased time to healing, decreased pain symptoms and increased patient convenience because of limiting the frequency of replacement of the dressing at lower total cost. This study confirms the efficacy of Aquacel Ag for the treatment of partial thickness burns at an outpatient clinic. PMID:20528992
Muangman, Pornprom; Pundee, Chanin; Opasanon, Supaporn; Muangman, Saipin
This prospective, randomized study compared protocols of care using either AQUACEL Ag Hydrofiber (ConvaTec, a Bristol-Myers Squibb company, Skillman, NJ) dressing with silver (n = 42) or silver sulfadiazine (n = 42) for up to 21 days in the management of partial-thickness burns covering 5% to 40% body surface area (BSA). AQUACEL Ag dressing was associated with less pain and anxiety during dressing changes, less burning and stinging during wear, fewer dressing changes, less nursing time, and fewer procedural medications. Silver sulfadiazine was associated with greater flexibility and ease of movement. Adverse events, including infection, were comparable between treatment groups. The AQUACEL Ag dressing protocol tended to have lower total treatment costs (Dollars 1040 vs. Dollars 1180) and a greater rate of re-epithelialization (73.8% vs 60.0%), resulting in cost-effectiveness per burn healed of Dollars 1,409.06 for AQUACEL Ag dressing and Dollars 1,967.95 for silver sulfadiazine. A protocol of care with AQUACEL(R) Ag provided clinical and economic benefits compared with silver sulfadiazine in patients with partial-thickness burns. PMID:16679897
Caruso, Daniel M; Foster, Kevin N; Blome-Eberwein, Sigri A; Twomey, John A; Herndon, David N; Luterman, Arnold; Silverstein, Paul; Antimarino, Jeffrey R; Bauer, Gregory J
Summary Both hyperlipidemia and metabolic syndrome have adverse effect on tendon structure. Atorvastatin is most widely used antihyperlipidemic drug. Statins have adverse effects on the tendon. Many studies have analyzed the relationship between atorvastatin and skeletal muscles. Atorvastatin administered after the surgical repair of a ruptured tendon appears to affect revascularization, collagenization, inflammatory cell infiltration, and collagen construction. Therefore, further investigations on the effects of atorvastatin on tendon healing are needed.
Esenkaya, Irfan; Unay, Koray
Latissimus dorsi transfer is a well-established method for the treatment of posterosuperior massive irreparable rotator cuff tears. We propose using an arthroscopically assisted technique that avoids insult to the deltoid. With the patient in the lateral decubitus position, an L-shaped incision is made along the anterior belly of the latissimus muscle and then along the posterior axillary line. The latissimus and teres major are identified and separated. The tendon insertion of the latissimus is isolated, and a FiberWire traction suture (Arthrex, Naples, FL) is placed, facilitating dissection of the muscle to the thoracodorsal neurovascular pedicle and subsequent mobilization. The interval deep to the deltoid and superficial to the teres minor is developed into a subdeltoid tunnel for arthroscopic tendon transfer. The latissimus tendon is then transferred and stabilized arthroscopically to the lateral aspect of the infraspinatus and supraspinatus footprints by multiple suture anchors.
Villacis, Diego; Merriman, Jarrad; Wong, Karlton; Rick Hatch, George F.
Internal snapping hip syndrome, or psoas tendonitis, is a recognised cause of nonarthritic hip pain. The majority of patients are treated conservatively; however, occasionally patients require surgical intervention. The two surgical options for iliopsoas tendinopathy are step lengthening of the iliopsoas tendon or releasing the tendon at the lesser trochanter. Although unusual, refractory snapping usually occurs soon after tenotomy. We report a case of a 47-year-old active female with internal snapping and pain following an open psoas tenotomy. Postoperatively she was symptom free for 13 years. An MRI arthrogram revealed reformation of a pseudo iliopsoas tendon reinserting into the lesser trochanter. The pain and snapping resolved after repeat iliopsoas tendon release. Reformation of tendons is an uncommon sequela of tenotomies. However the lack of long-term studies makes it difficult to calculate prevalence rates. Tendon reformation should be included in the differential diagnosis of failed tenotomy procedures after a period of symptom relief.
Garala, K.; Power, R. A.
Tendon adhesion is one of the most common causes of disability following tendon surgery. A case of extensive peritendinous adhesions of the Achilles tendon and tibialis posterior tendon after compound rupture of the tendons was reported. This was managed by endoscopic adhesiolysis of both tendons. The endoscopic approach allows early postoperative mobilisation which can relieve the tendon adhesion. PMID:24045762
Lui, Tun Hing
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.
Troy, Jared; Karlnoski, Rachel; Downes, Katheryne; Brown, Kimberly S.; Cruse, C. Wayne; Smith, David J.; Payne, Wyatt G.
Recent reports have suggested that human epidermal growth factor will accelerate the healing of corneal wounds and donor sites of burned patients undergoing split-thickness skin grafts. In one report using human epidermal growth factor in a silver sulfadiazine cream, these data were gathered from patients of various ages who had various depths of donor sites and degrees of burn. Therefore, despite the fact that these data were prospective, randomized, and double-blinded, we questioned the validity of the study. To test the hypothesis that topical application of human epidermal growth factor will enhance the healing of partial-thickness wounds, we utilized healthy volunteers (n = 17) and created bilateral split-thickness skin wounds (4 cm2) of the same depth (0.014 in) on each flank and then studied time until total epithelialization occurred. One side was treated with silver sulfadiazine as a control and the opposite side with silver sulfadiazine and human epidermal growth factor. There was no significant difference in the healing times between the human epidermal growth factor-treated sites and the silver sulfadiazine cream controls. PMID:7624397
Cohen, I K; Crossland, M C; Garrett, A; Diegelmann, R F
Introduction Tendons establish specific connections between muscles and the skeleton by transferring contraction forces from skeletal muscle to bone thereby allowing body movement. Tendon physiology and pathology are heavily dependent on mechanical stimuli. Tendon injuries clinically represent a serious and still unresolved problem since damaged tendon tissues heal very slowly and no surgical treatment can restore a damaged tendon to its normal structural integrity and mechanical strength. Understanding how mechanical stimuli regulate tendon tissue homeostasis and regeneration will improve the treatment of adult tendon injuries that still pose a great challenge in today's medicine. Source of data This review summarizes the current status of tendon treatment and discusses new directions from the point of view of cell-based therapy and regenerative medicine approach. We searched the available literature using PubMed for relevant original articles and reviews. Growing points Identification of tendon cell markers has enabled us to study precisely tendon healing and homeostasis. Clinically, tissue engineering for tendon injuries is an emerging technology comprising elements from the fields of cellular source, scaffold materials, growth factors/cytokines and gene delivering systems. Areas timely for developing research The clinical settings to establish appropriate microenvironment for injured tendons with the combination of these novel cellular- and molecular-based scaffolds will be critical for the treatment.
Sakabe, Tomoya; Sakai, Takao
Summary Tendon and tendon-bone junction injuries, while heal, have high re-tear rates. Mesenchymal stem cells (MSCs) have great appeal for the promotion of tendon and tendon-bone junction healing because of their high proliferation rate, multi-potency and relative ease of isolation from various tissues. Tendon stem cells have been identified recently and could be an alternative new cell source for tendon and tendon-bone junction repair. In this review, we summarized the in vitro characteristics of tendon stem cells. The evidence supporting the potential use of these cells for tendon and tendon-bone junction repair was presented. In order to therapeutically apply tendon stem cells in the clinical settings, standardization of tendon stem cell culture is essential. Issues relating to the sources, purity, efficacy, safety and delivery of tendon stem cells for tendon and tendon-bone junction repair were summarized and discussed. The direction for future research was suggested.
Lui, Pauline Po Yee; Wong, On Tik
Tendon and tendon-bone junction injuries, while heal, have high re-tear rates. Mesenchymal stem cells (MSCs) have great appeal for the promotion of tendon and tendon-bone junction healing because of their high proliferation rate, multi-potency and relative ease of isolation from various tissues. Tendon stem cells have been identified recently and could be an alternative new cell source for tendon and tendon-bone junction repair. In this review, we summarized the in vitro characteristics of tendon stem cells. The evidence supporting the potential use of these cells for tendon and tendon-bone junction repair was presented. In order to therapeutically apply tendon stem cells in the clinical settings, standardization of tendon stem cell culture is essential. Issues relating to the sources, purity, efficacy, safety and delivery of tendon stem cells for tendon and tendon-bone junction repair were summarized and discussed. The direction for future research was suggested. PMID:23738293
Lui, Pauline Po Yee; Wong, On Tik
Strength and function of autogenic and xenogenic reconstruction of digital extensor tendons was examined in an ovine model. In this study, tendon-graft junctions were formed by either suture augmented with a woven polyester tube (A), or augmented and shielded from surrounding tissues by chemically-treated bovine pericardium (S). By 12 wk, both A and S sheep had returned to full range
G. J. Rogers; B. K. Milthorpe; K. Schindhelm; C. R. Howlett; S. Roe
The nitrate form of the Group III transitional element gallium (GN) increases expression of specific structural components of the provisional wound matrix (i.e., collagen type I, fibronectin) in human dermal fibroblasts. To evaluate the potential of GN as a therapeutic option in management of cutaneous trauma, GN-treated partial thickness porcine wounds and experimentally "injured" human keratinocyte (NHK) monolayer cultures were compared with mirror image control (i.e., saline-treated) sites. GN suppressed cell proliferation in both models, as determined by reduced Ki-67 reactivity and significant lengthening of keratinocyte cell cycle transit times, while effectively promoting reepithelialization. The primary effect of GN was apparently to promote cell migration, as neither epidermal thickness nor epidermal differentiation was altered as a result of GN exposure in vivo or in vitro. Significantly enhanced epidermal reepithelialization was associated with alterations in expression of several keratinocyte integrin subunits. GN induced a significant increase in alpha5 expression. alpha5beta1 switching is a characteristic of the motile phenotype in the setting of cutaneous injury. Concomitantly, GN treatment also induced a dramatic (70%) decrease in the expression of the alpha3 subunit; alpha3beta1 binds laminin 5 and is associated with hemidesmosome formation and reestablishment of a nonmotile phenotype. Taken together, the GN-induced changes in integrin expression favor acellular migration. While the molecular mechanism of GN action on resident cells of the skin remains to be defined, these data suggest that GN administration which represses MMP activity in the wound and increases matrix synthesis also accelerates NHK motility and, thereby, may be a useful therapeutic agent for wound repair. PMID:11922726
Goncalves, John; Wasif, Nabil; Esposito, Darren; Coico, Jonathan M; Schwartz, Brian; Higgins, Paul J; Bockman, Richard S; Staiano-Coico, Lisa
????????????????Numerous physical modalities have been used in attempts to augment the healing process, including ultrasound, low- energy light therapy, and electrical stimulation (ES). ES has been shown to benefit tissue repair in a variety of wound types, but variations in study designs, administration, and parameters render its application in clinical practice somewhat unconventional. A dressing was designed to generate an electric potential of 0.6 V to 0.7 V in the presence of moisture, thereby delivering a sustained micro-current without the need for an external power source. The purpose of this study was to examine the effects of this bio-electric dressing (BED) on deep, partial-thickness wounds using six female specific pathogen-free animals and a well established porcine model for wound healing. Wounds (10 mm x 7 mm x 0.5 mm) were created in paravertebral and thoracic areas of these animals using a specialized electrokeratome and covered with the active polyester BED and a polyurethane film dressing (n = 30) (treatment) or an inactive polyester and film dressing (n = 30). Using an epidermal migration assay, wounds were assessed daily from day 4 through day 8 post-wounding. Differences in the proportion of wounds healed were statistically significant (P <0.001) on days 5 and 6 post-wounding. These results show BED is more effective than a control dressing treatment with moisture-retentive dressings in this animal model. Controlled clinical studies are warranted to elucidate the potential clinical implications of this treatment modality. PMID:22933701
Harding, Andrew C; Gil, Joel; Valdes, Jose; Solis, Michael; Davis, Stephen C
We conducted this Institutional Review Board-approved retrospective study to compare Aquacel Ag Hydrofiber dressing (Aquacel Ag) to a standard dressing for the treatment of partial thickness burns in children. We used the St. Christopher's Hospital burn center registry to identify 20 pediatric patients who had sustained partial thickness burns over a 10-month period. Ten of these patients had been treated with Aquacel Ag Hydrofiber dressing and 10 were treated with conventional Xeroflo gauze with Bacitracin Zinc ointment, the institutional standard of care for nonoperative partial-thickness burn wounds. Inclusion criteria included anyone with partial-thickness burns below the age of 18 years and in excellent baseline health. Exclusion criteria included inhalation injury, presence of full-thickness burns necessitating surgical debridement, cellulitic, or infected wounds, and percentage total body surface area involvement greater than 40%. Outcomes measured for the Aquacel Ag versus the Xeroflo gauze with Bacitracin Zinc ointment group included hospital length of stay (2.4 vs. 9.6 days), total number of in-house dressing changes (2.7 vs. 17.1), pain on a 10-point scale associated with dressing changes (6.4 vs. 8.2), total number of intravenous narcotic administrations (2.3 vs. 14.4), nursing time adjusted for percentage total body surface area (1.9 vs. 3.5 min), time to wound reepithelialization (10.3 vs. 16.3 days), and patient primary caregiver satisfaction score using a 4-point scale--with four delineating maximum satisfaction (3.8 vs. 1.8). Aquacel Ag proved to be a safe and effective means of treating partial thickness burns with a significant reduction in nursing time and patient pain involved with dressing changes. PMID:19349897
Saba, Salim Charles; Tsai, Roger; Glat, Paul
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.
The term "biceps brachii" is a Latin phrase meaning "two-headed (muscle) of the arm." As its name suggests, this muscle has two separate origins. The short head of biceps is extraarticular in location, originates from the coracoid process of the scapula, having a common tendon with the coracobrachialis muscle. The long head of biceps tendon (LBT) has a much more complex course, having an intracapsular and an extracapsular portion. The LBT originates from the supraglenoid tubercle, and in part, from the glenoid labrum; the main labral attachments vary arising from the posterior, the anterior of both aspects of the superior labrum (Bletran et al. in Top Magn Reson Imaging 14:35-49, 2003; Vangsness et al. in J Bone Joint Surg Br 76:951-954, 1994). Before entering the bicipital groove (extracapsular portion), the LBT passes across the "rotator cuff interval" (intracapsular portion). Lesions of the pulley system, the LBT, and the supraspinatus tendon, as well as the subscapularis, are commonly associated (Valadie et al. in J Should Elbow Surg 9:36-46, 2000). The pulley lesion can be caused by trauma or degenerative changes (LeHuec et al. in J Should Elbow Surg 5:41-46, 1996). MR arthrography appears to be a promising imaging modality for evaluation of the biceps pulley, through the distention of the capsule of the rotator interval space and depiction of the associated ligaments. PMID:23949931
Zappia, M; Reginelli, A; Russo, A; D'Agosto, G F; Di Pietto, F; Genovese, E A; Coppolino, F; Brunese, L
Tendon connects muscle to bone and functions to transmit muscular forces across joints to stabilize or move those joints. Tendons in the foot and ankle are subject to enormous loads and consequently make up a substantial portion of the body's tendon injuries. Understanding the mechanisms of these injuries requires an understanding of the relative rates of muscle, tendon, osteotendinous junction, and myotendinous junction adaptation. This article provides the practitioner with an overview of tendon anatomy, physiology, healing, and repair and correlates didactic and clinical aspects so that practitioners can better treat patients and get them back to normal functioning as quickly and as close to anatomic and physiologic capabilities as possible. PMID:16213379
Platt, Marc A
Damage to the biceps tendon is often seen in conjunction with rotator cuff tears. However, controversy exists regarding its role in the shoulder and its optimal treatment. A previous study determined that biceps tendons were detrimentally affected in the presence of rotator cuff tears in the rat model and this damage worsened over time. However, whether this damage progresses at later time points to provide a chronic model is unknown. The objective of this study was to determine the changes in the biceps tendon in the presence of a cuff tear over time. Our hypothesis was that histological, compositional, organizational and mechanical properties would worsen with time. We detached the supraspinatus and infraspinatus tendons of 48 rats and evaluated these properties at 1, 4, 8 and 16 weeks post detachment. Properties worsened through 8 weeks, but improved between 8 and 16 weeks. We therefore conclude that biceps tendon changes in this model are not truly chronic. Additionally, it has been shown that infraspinatus properties in this model return to normal by 16 weeks, when biceps properties improve, indicating that earlier repair of one or more of the rotator cuff tendons may lead to resolved pathology of the long head of the biceps tendon.
Peltz, Cathryn D.; Hsu, Jason E.; Zgonis, Miltiadis H.; Trasolini, Nicholas A.; Glaser, David L.; Soslowsky, Louis J.
Reepithelialization of deep burns requires spontaneous or active removal or debridement of the necrotic eschar, as recently defined by the American Burn Association. Debrase is a bromelain-derived enzymatic preparation that has been shown to result in rapid and selective debridement of human and animal burns. The authors hypothesized that rapid debridement of deep dermal burns with Debrase would result in earlier reepithelialization of the remaining dermis in a porcine model. Eighty deep dermal contact burns measuring 10 by 20 mm were created on the back and flanks of anesthetized domestic pigs (25 kg) using a brass template preheated in boiling water (100 degrees C) that was applied to the skin for a period of 30 seconds. The template was applied using a spring-loaded device designed to control the amount of pressure applied to the skin by the template. Burns were randomized to a 4-hour topical application of Debrase (lyophilized dry enzyme dissolved and activated in a hydrating vehicle) (n = 40) or its hydrating vehicle (n = 40) followed by daily application of a petrolatum-based antibiotic ointment. Wounds were visually assessed and photographed daily. Four-millimeter full-thickness punch biopsies were obtained for histological analysis using hematoxylin and eosin staining by a board-certified dermatopathologist masked to burn therapy at 7, 11, 13, and 15 days after injury. The primary outcome was the percentage of the burns that were completely reepithelialized at each time point. Secondary outcomes were time to complete reepithelialization and the mean percentage of reepithelialization on microscopic analysis. A sample of 40 burns in each group had 80% power to detect a 20% difference in the percentage of completely reepithelialized burns (two tailed, P < .05). The percentage of completely reepithelialized burns was higher for Debrase than control burns at days 11 (40.9% vs 3.1%; P = .002), 13 (87.5% vs 50%; P = .007), and 15 (97.5% vs 77.5%, P = .018). The mean (SD) percentage reepithelialization of Debrase-treated burns at 7 days was higher than of control burns (47.6% [3.2] vs 0% ; P < .001). A larger number of cells in the epidermis and dermis of debrided burns stained positive for the proliferation antigen Ki-67. There was no evidence of any adverse events in the normal skin adjacent to the Debrase-treated burns. Rapid enzymatic debridement of deep partial-thickness burns with Debrase results in earlier reepithelialization and cellular proliferation in swine, when compared with carrier and topical antibiotic dressings alone. PMID:20661148
Singer, Adam J; Taira, Breena R; Anderson, Ryon; McClain, Steve A; Rosenberg, Lior
Supraspinatus muscle atrophy and fatty infiltration are two distinct muscle abnormalities which can be seen after a chronic massive tear or suprascapular neuropathy. Isolated supraspinatus muscle denervation due to suprascapular nerve injury after shoulder dislocation is extremely rare. We report on a patient who developed isolated supraspinatus muscle atrophy and fatty infiltration after traumatic anterior shoulder instability. Possible explanations and etiologies of this rare condition are discussed in this report.
Alomar, Abdulaziz Z.; Powell, Tom; Burman, Mark L.
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.
Mathangi Ramakrishnan, K.; Babu, M.; Mathivanan; Jayaraman, V.; Shankar, J.
Background: Magnetic resonance (MR) arthrography is generally regarded as the gold standard for shoulder imaging. As an alternative to direct MR arthrography, the less invasive indirect MR arthrography technique was proposed, offering logistic advantages because fluoroscopic or ultrasonographic guidance for joint injection is not required. Purpose: To assess the diagnostic performance of indirect MR arthrography in the diagnosis of full-
P. Van Dyck; J. L. Gielen; J. Veryser; J. Weyler; F. M. Vanhoenacker; F. Van Glabbeek; W. De Weerdt; M. Maas; Woude van der H. J; P. M. Parizel
This patent describes a riser and tendon management system. It comprises means to set nominal conditions for the risers and tendons; means to measure actual riser and tendon conditions; means to compare the actual and nominal conditions of the risers and tendons; and means responsive to a differential between the actual and nominal riser and tendon conditions, which difference exceeds specified limits, and recommending corrective action to bring the risers and tendons back to within nominal conditions.
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.
Hodgson, R J; O'Connor, P J; Grainger, A J
Distal biceps tendon ruptures continue to be an important injury seen and treated by upper extremity surgeons. Since the mid-1980s, the emphasis has been placed on techniques that limit complications or improve initial tendon-to-bone fixation strength. Recently, basic science research has expanded the knowledge base regarding the biceps tendon structure, footprint anatomy, and biomechanics. Clinical data have further delineated the results of conservative and surgical management of both partial and complete tears in acute or chronic states. The current literature on the distal biceps tendon is described in detail. PMID:23474326
Schmidt, Christopher C; Jarrett, Claudius D; Brown, Brandon T
The tibialis posterior tendon is the largest and anteriormost tendon in the medial ankle. It produces plantar flexion and supination of the ankle and stabilizes the plantar vault. Sonographic assessment of this tendon is done with high-frequency, linear-array transducers; an optimal examination requires transverse retromalleolar, longitudinal retromalleolar, and distal longitudinal scans, as well as dynamic studies. Disorders of the posterior tibial tendon include chronic tendinopathy with progressive rupture, tenosynovitis, acute rupture, dislocation and instability, enthesopathies. The most common lesion is a progressive “chewing gum” lesion that develops in a setting of chronic tendinopathy; it is usually seen in overweight women over 50 years of age with valgus flat feet. Medial ankle pain must also be carefully investigated, and the presence of instability assessed with dynamic maneuvers (forced inversion, or dorsiflexion) of the foot. Sonography plays an important role in the investigation of disorders involving the posterior tibial tendon.
Flexor tendon injuries continue to pose a significant challenge to the hand surgeon. In particular, chronic tendon ruptures with adhesions of the tendons and sheath, damage or loss of the intrasynovial flexor tendons in zone II, and combined soft tissue and bone injuries present especially difficult problems for restoring satisfactory digital function. This challenge in flexor tendon reconstruction has motivated hand surgeons to explore and develop novel solutions for nearly a century. Recent advances and techniques in processing and decellularizing allograft human flexor tendon constructs may prove to be a new horizon for tendon reconstruction. PMID:23707595
Drake, David B; Tilt, Alexandra C; Degeorge, Brent R
Transplanted cells may have difficulty attaching to the surface of partial-thickness chondral lesions because of the anti-adhesive properties of the proteoglycan rich matrix. Therefore, the current study attempts to evaluate the effect of chondroitinase ABC (chABC) on the adhesion and behavior of transplanted synovial membrane-derived mesenchymal stem cells (SDSCs) in rabbit partial-thickness chondral defects. In ex vivo adhesion experiments, chABC treatment (0.1?U/ml) was increased in SDSC attachment to the cartilage explants, and significantly diminished by pretreatment with neutralizing antibody against fibronectin. In the in vivo experiments, 1 day and 4 weeks after the chABC treatment (0.1 and 1?U/ml), the immunoreactivity (IR) against CS-56 (intact chondroitin sulfate antibody) was markedly decreased; however, the IR of 2B6 (stub of the chondroitin 4-sulfate chain), 3B3 (stub of the chondroitin 6-sulfate chain), and fibronectin was increased. At 12 weeks, this IR returned to normal except in the high-dose chABC-treated group (1?U/ml). Furthermore, the attachment of SDSCs to the chondral defects after chABC treatment was increased at 7 days compared with that in the chondral defects pretreated with saline. However, the tissue repaired by SDSCs was negatively stained for type II collagen at 12 weeks. In conclusion, these results showed that the exposure to fibronectin by chABC treatment enhances the attachment of SDSCs to partial-thickness chondral defects. However, the tissue regenerated by SDSCs showed lack of hyaline cartilage regeneration. Thus, to understand the fate of transplanted MSCs in cartilage defect is very important for successful cell therapies. PMID:23629810
Lee, Jae-Chul; Min, Hyun Jin; Lee, Sahnghoon; Seong, Sang Cheol; Lee, Myung Chul
Tendon-to-bone integration is a great challenge for tendon or ligament reconstruction regardless of use of autograft or allograft tendons. We mineralized the tendon, thus transforming the tendon-to-bone into a "bone-to-bone" interface for healing. Sixty dog flexor digitorum profundus (FDP) tendons were divided randomly into five groups: (1) normal FDP tendon, (2) CaP (non-extraction and mineralization without fetuin), (3) CaPEXT (Extraction by Na2 HPO4 and mineralization without fetuin), (4) CaPFetuin (non-extraction and mineralization with fetuin), and (5) CaPEXTFetuin (extraction and mineralization with fetuin). The calcium and phosphate content significantly increased in tendons treated with combination of extraction and fetuin compared to the other treatments. Histology also revealed a dense mineral deposition throughout the tendon outer layers and penetrated into the tendon to a depth of 200?µm in a graded manner. Compressive moduli were significantly lower in the four mineralized groups compared with normal control group. No significant differences in maximum failure strength or stiffness were found in the suture pull-out test among all groups. Mineralization of tendon alters the interface from tendon to bone into mineralized tendon to bone, which may facilitate tendon-to-bone junction healing following tendon or ligament reconstruction. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1713-1719, 2013. PMID:23939935
Qu, Jin; Thoreson, Andrew R; Chen, Qingshan; An, Kai-Nan; Amadio, Peter C; Zhao, Chunfeng
Purpose: The objective of this study is to report on the complete arthroscopic repair of full-thickness tears of the supraspinatus. Type of Study: Prospective cohort study. Methods: Between 1995 and 1999, 139 full arthroscopic rotator cuff repairs were performed; 37 were repairs of full-thickness supraspinatus tears. Between 1997 and 1999, there were 24 patients who had a complete arthroscopic repair
William F. Bennett
Although the use of an occlusive wound covering accelerates the reepithelialization of a partial-thickness wound, it has the disadvantage of leading to wound exudate accumulation. The effect of an experimental polyetherurethane (PEU) wound covering with a high vapor permeability was compared with an occlusive wound covering (OpSite covering) and air exposure with respect to the rate of reepithelialization, eventual epidermal thickness, and scab thickness in 122 partial-thickness wounds in guinea pigs. The percentage of reepithelialization on day 2 was 85% in wounds covered with the permeable PEU membrane, whereas it was 66% and 35%, respectively, in wounds covered with the occlusive covering or exposed to air. The epidermal thickness did not differ among the three types of treatment. The scab thickness, however, was maximal in the uncovered air-exposed wounds. We conclude that epidermal wound healing is accelerated when the PEU wound covering is used. This wound-healing-promotion effect is apparently due to the high water vapor permeability of PEU, which induces clotting of the wound exudate, and subsequent jellifying of the clot layer. PMID:3413682
Jonkman, M F; Bruin, P; Hoeksma, E A; Nieuwenhuis, P; Klasen, H J; Pennings, A J; Molenaar, I
The effects of a new high vapour permeable poly-(ether urethane) (PEU) wound covering on evaporative water loss (EWL) and epidermis regeneration in partial-thickness wounds in guinea pigs were investigated and compared with an occlusive wound covering (OpSite) and air-exposed controls. It was also assessed whether the EWL reflected the phases of epidermis regeneration. In PEU-covered wounds, the initially raised EWL of 100 gm-2h-1 decreased in four days to 30 gm-2h-1, the same level as in occluded wounds. In control wounds this level was only reached after seven days, reflecting slower epidermis regeneration. The results showed that triphasic EWL behaviour corresponded to the sequence of wound healing. There was (1) a constant raised EWL until epidermal resurfacing is complete, (2) a fast EWL decrease during parakeratotic keratinization, and (3) a gradual normalization of the EWL during maturation of the stratum corneum. In wounds covered with OpSite this phasic EWL behaviour did not occur, owing to forced reduction because of the relatively impermeable covering. It was concluded that the PEU wound covering has an ideal water vapour permeance of 22.2 gm-2h-1 kPa-1, as can be seen in the accelerated epidermis regeneration and fast EWL reduction in partial thickness wounds in guinea pigs. PMID:2740844
Jonkman, M F; Molenaar, I; Nieuwenhuis, P; Klasen, H J
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.
Campagna, R.; Guerini, H.
The mechanical environment plays an important role in musculoskeletal tissue development. The present study characterized changes in supraspinatus muscle due to removal of mechanical cues during postnatal development. An intramuscular injection of botulinum toxin type A (BTX) was used to induce and maintain paralysis in the left shoulders of mice since birth while the right shoulders received saline and served as contralateral controls. A separate group of animals was allowed to develop normally without any injections. Muscles were examined postnatally at various time points. The maximum isometric tetanic force generated by the muscle was significantly reduced in the BTX group compared to saline and normal groups. The paralyzed muscles were smaller and showed significant muscle atrophy and fat accumulation on histologic evaluation. Myogenic genes myogenin, myoD1, myf5, myf6 and fast type II myosin heavy chain (MHC) isoform were significantly upregulated while slow type I MHC isoform was significantly downregulated in the BTX group. Adipogenic genes C/EBP?, PPAR?2, leptin and lipoprotein lipase were significantly upregulated in the BTX group. Results indicate that reduced muscle loading secondary to BTX-induced paralysis leads to fat accumulation and muscle degeneration in the developing muscle. Understanding the molecular and compositional changes in developing supraspinatus muscles may be useful for identifying and addressing the pathological changes that occur in shoulder injuries such as neonatal brachial plexus palsy.
Rosalina, Das; Jason, Rich; Mike, Kim H.; Audrey, McAlinden; Stavros, Thomopoulos
This article describes tendon disorders in cattle and treatments for such disorders. Tendon injuries causing loss of a production animal or a decreased level of production result in significant economic loss to the cattle producer. Tendon disorders may be congenital or acquired. Congenital abnormalities may include tendon laxity, contracted tendons, or tendon displacement. Acquired tendon disorders may include tendon laxity, contracture, luxation, tendinitis, laceration, avulsion, rupture, and tenosynovitis. PMID:18929961
Anderson, David E; Desrochers, André; St Jean, Guy
Background: Physical examination of patients with shoulder injury not involving actual rotator cuff tears frequently demonstrates decreased rotator cuff strength on manual muscle testing. This decrease has been attributed to supraspinatus muscle weakness, but it may be owing to alterations in scapular position.Hypothesis: The position of stabilized scapular retraction, by minimizing proximal kinetic chain factors and providing a stable base
W. Ben Kibler; Aaron Sciascia; David Dome
We have conducted a prospective double blind randomized and placebo controlled clinical study in 20 patients with shoulder pain syndrome caused by supraspinatus tendinitis to determine whether transdermal nitroglycerin (NTG) has analgesic action in this condition. In a randomized manner we used a 5-mg NTG (Nitroplast®) patch per day over 3 days or similar placebo patches applied in the most
José Ramón Berrazueta; Alfredo Losada; José Poveda; Alberto Ochoteco; Alberto Riestra; Eduardo Salas; José Antonio Amado
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
Thermann, H; Hüfner, T; Tscherne, H
A porcine deep partial-thickness wound model was used to evaluate the effects of a newly developed topical aqueous oxygen emulsion (TOE) on wound repair. The wounds were treated with TOE, which contains super-saturated oxygen or vehicle control. Semiquantitative immunofluorescent staining was performed to examine protein production for type I and type III collagen and vascular endothelial growth factor (VEGF). Immunofluorescent staining revealed higher protein levels of type I and type III collagen and VEGF in the TOE treatment group. Histological analysis also revealed improved angiogenesis and granulation tissue formation with topical TOE treatment and was consistent with the protein expression. In addition, the histology examination demonstrated faster epithelialization in wounds treated with TOE. The study suggests that sustained high levels of oxygen released by TOE may promote the process of wound repair through increasing collagen deposition and angiogenesis as well as stimulating epithelialization. PMID:24079742
Li, Jie; Ollague Sierra, Jose; Zhu, Linjian; Tang, Ling; Rahill, Kirah; El-Sabawi, Bassim; Liu-Mares, Wen; Mertz, Patricia M; Davis, Stephen C
The regulation of tendon homoeostasis, including adaptation to loading, is still not fully understood. Accumulating data, however, demonstrates that in addition to afferent (sensory) functions, the nervous system, via efferent pathways which are associated with through specific neuronal mediators plays an active role in regulating pain, inflammation and tendon homeostasis. This neuronal regulation of intact-, healing- and tendinopathic tendons has been shown to be mediated by three major groups of molecules including opioid, autonomic and excitatory glutamatergic neuroregulators. In intact healthy tendons the neuromediators are found in the surrounding structures: paratenon, endotenon and epitenon, whereas the proper tendon itself is practically devoid of neurovascular supply. This neuroanatomy reflects that normal tendon homoeostasis is regulated from the tendon surroundings. After injury and during tendon repair, however, there is extensive nerve ingrowth into the tendon proper, followed by a time-dependent emergence of sensory, autonomic and glutamatergic mediators, which amplify and fine-tune inflammation and regulate tendon regeneration. In tendinopathic condition, excessive and protracted presence of sensory and glutamatergic neuromediators has been identified, suggesting involvement in inflammatory, nociceptive and hypertrophic (degenerative) tissue responses. Under experimental and clinical conditions of impaired (e.g. diabetes) as well as excessive (e.g. tendinopathy) neuromediator release, dysfunctional tendon homoeostasis develops resulting in chronic pain and gradual degeneration. Thus there is a prospect that in the future pharmacotherapy and tissue engineering approaches targeting neuronal mediators and their receptors may prove to be effective therapies for painful, degenerative and traumatic tendon disorders. PMID:23718724
Ackermann, Paul W
Professional ballet dancers require an extraordinary anatomic, physiologic, and psychologic makeup to achieve and sustain their level of ability and activity. They are subject to a myriad of injuries as a result of the extreme demands of this profession. Tendon injuries are common and often coexist with other pathologies of the bone, ligaments, and psyche. It is critical that the dance doctor not examine the tendon injury in isolation, but rather the cause of the injury, either intrinsic from anatomic malalignment or from external sources, including poor form. PMID:18346542
Hodgkins, Christopher W; Kennedy, John G; O'Loughlin, Padhraigh F
Tendons and ligaments are unique forms of connective tissue that are considered an integral part of the musculoskeletal system. The ultimate function of tendon is to connect muscles to bones and to conduct the forces generated by muscle contraction into movements of the joints, whereas ligaments connect bone to bone and provide joint stabilization. Unfortunately, the almost acellular and collagen I–rich structure of tendons and ligaments makes them very poorly regenerating tissues. Injured tendons and ligaments are considered a major clinical challenge in orthopedic and sports medicine. This Review discusses the several factors that might serve as molecular targets that upon activation can enhance or lead to tendon neoformation.
Aslan, Hadi; Kimelman-Bleich, Nadav; Pelled, Gadi; Gazit, Dan
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
Strickland, J W
We previously developed chitosan cryogels from chitosan-gluconic acid conjugate without using toxic additives for wound care. In this study, we improved physiological characteristics of the previous cryogels by incorporating poly(vinyl alcohol) that also form cryogels. Mechanical strength of the cryogels was more than two times higher than that of the previous cryogels. Furthermore, the incorporation of poly(vinyl alcohol) enhanced water retention and resistance to degradation of the gels by lysozyme. The cryogels retained the favorable biological properties of the previous cryogels that they accelerate infiltration of inflammatory cells into wound sites. Time period for repairing 50 % of initial area of partial-thickness skin wound treated with the cryogels (4.0 ± 1.1 days) was shorter than those with gauze (6.5 ± 0.3 days) or a commercial hydrogel dressing (5.7 ± 0.3 days). Finally, we confirmed that incorporation of basic fibroblast growth factor into the cryogels was effective to further accelerate wound healing (2.7 ± 1.0 days). These results demonstrate that the cryogels in this study are promising for wound care. PMID:23801501
Takei, Takayuki; Nakahara, Hideki; Tanaka, Sadao; Nishimata, Hiroto; Yoshida, Masahiro; Kawakami, Koei
A disturbance in scapulohumeral rhythm may cause negative biomechanic effects on rotator cuff (RC). Alteration in scapular\\u000a motion and shoulder pain can influence RC strength. Purpose of this study was to assess supraspinatus and infraspinatus strength\\u000a in 29 overhead athletes with scapular dyskinesis, before and after 3 and 6 months of rehabilitation aimed to restore scapular\\u000a musculature balance. A passive posterior
Giovanni Merolla; Elisa De Santis; Fabrizio Campi; Paolo Paladini; Giuseppe Porcellini
Despite advances in surgical technique, rotator cuff repairs are plagued by a high rate of failure. This failure rate is in part due to poor tendon-to-bone healing; rather than regeneration of a fibrocartilaginous attachment, the repair is filled with disorganized fibrovascular (scar) tissue. Transforming growth factor beta 3 (TGF-?3) has been implicated in fetal development and scarless fetal healing and, thus, exogenous addition of TGF-?3 may enhance tendon-to-bone healing. We hypothesized that: TGF-?3 could be released in a controlled manner using a heparin/fibrin-based delivery system (HBDS); and delivery of TGF-?3 at the healing tendon-to-bone insertion would lead to improvements in biomechanical properties compared to untreated controls. After demonstrating that the release kinetics of TGF-?3 could be controlled using a HBDS in vitro, matrices were incorporated at the repaired supraspinatus tendon-to-bone insertions of rats. Animals were sacrificed at 14-56 days. Repaired insertions were assessed using histology (for inflammation, vascularity, and cell proliferation) and biomechanics (for structural and mechanical properties). TGF-?3 treatment in vivo accelerated the healing process, with increases in inflammation, cellularity, vascularity, and cell proliferation at the early timepoints. Moreover, sustained delivery of TGF-?3 to the healing tendon-to-bone insertion led to significant improvements in structural properties at 28 days and in material properties at 56 days compared to controls. We concluded that TGF-?3 delivered at a sustained rate using a HBDS enhanced tendon-to-bone healing in a rat model. PMID:21246611
Manning, Cionne N; Kim, H Mike; Sakiyama-Elbert, Shelly; Galatz, Leesa M; Havlioglu, Necat; Thomopoulos, Stavros
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.
Longo, Umile Giuseppe; Lamberti, Alfredo; Petrillo, Stefano; Maffulli, Nicola; Denaro, Vincenzo
Introduction: Conventional management of partial thickness facial burn wounds includes the use of silver sulphadiazine dressing s. Silver sulphadiazine forms an overlying slough that makes wound healing assessment difficult. Moist exposed burn ointment (MEBO) has b een proposed as the ideal burn wound dressing both for burns of the face and other sites. Proponents of MEBO claim that it accelera
E S W Ang; S T Lee; C S G Gan; L H Ng; D Machin
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
Gupta, Asheesh; Dai, Tianhong; Hamblin, Michael R
Purpose/Background: Several examination tests are currently used for diagnosing a supraspinatus lesion. The empty can (EC) test is currently considered the gold standard for testing, but full can (FC) testing is also utilized. Both of these tests do not fully eliminate the deltoid synergistic when resistance is applied. A new diagonal horizontal adduction (DHA) technique has been developed for evaluation of the supraspinatus that has not yet been compared with the existing techniques (EC/FC). Cross?sectional analysis (CSA) change during contraction as an ultrasonographic means of visualizing and measuring contraction of the supraspinatus has been reported previously. Objective: The purpose of this study was to use diagnostic musculoskeletal ultrasound (MSK) to compare CSA of the supraspinatus during the FC, EC, and the DHA tests. Methods: The supraspinatus muscle of 37 healthy, uninjured volunteers (21 males and 16 females, mean age of 26.9) were visualized and CSA was captured during 4 randomly assigned test positions (including control) using MSK. Results: A one?way Analysis of Variance with repeated measures of the mean CSA obtained in the testing positions was performed followed by least significant difference (LSD) for post?hoc analysis. Significant differences (p < 0.05) were found between the mean CSA of the controls and the CSA of each of the three testing procedures analyzed using the MSK. There were no significant differences (p < 0.05) in CSA between any of the three testing procedures. Conclusions: In this study, MSK visualized and objectified activity of the supraspinatus muscle as evidenced through increased mean CSA when resisted. All the testing positions (FC, EC, and DHA) demonstrated significantly increased mean CSA of the muscle when isometrically contracted when compared to the resting control. The DHA procedure also elicited significant increase in CSA of the supraspinatus. However, no significant difference was found between the CSA of the DHA when compared to the FC and EC tests. Level of Evidence: Level 2
White, Douglas M.; Smith, Wayne
BackgroundTendon is frequently injured structure in sports activities. Stretching before activities has been recommended to prevent athletes from injuries. Clinical studies reported that stretching had effects to reduce passive muscle stiffness and leads to an increased range of motion. Recent biomechanical studies suggested that stretching might also temporary affect tensile property of tendon. However, the detailed information regarding optimizing this
Atsushi Teramoto; Zong-Ping Luo
In 50 knees the length of the anterior cruciate ligament (ACL), the patellar tendon, and the distance between the tibial tuberosity and the femoral origin of the ACL were evaluated by means of three-dimensional magnetic resonance imaging (MRI), which permits subsequent reconstruction of any sectional view. The measurements showed that the patellar tendon was always markedly longer than the ACL
S. Högerle; R. Letsch; K. W. Sievers
The study was designed to examine the effects of partial fatigue on specific mechanical parameters which characterise human tendons in vitro. Specimens prepared from 12 intact Extensor digitorum longus tendons of the foot were subjected to partial fatigue, equivalent to 25% of the median fatigue life, by a cyclic square tension–tension stress waveform at the physiological frequency of 4Hz. The
H. Schechtman; D. L. Bader
The operative management of acute Achilles tendon rupture marks the beginning of a comprehensive rehabilitation program. The goals of the rehabilitation program start with the reduction of pain and swelling and the recovery of ankle motion and power. They conclude with the restoration of coordinated activity and safe return to athletic activity. The rehabilitation protocol is directed by the injury and the quality of the repair, along with the patient's age, medical and social history, and athletic inclination. The protocol is dynamic and responsive to changing clinical findings. PMID:19857848
Strom, Adam C; Casillas, Mark M
This series of case suggests that the entity of tenosynovitis of the popliteus tendon is more common than once recognized. A high index of sucpicion and accurate palpation of the lateral aspect of the knee lead one to the diagnosis. Knowledge of this entity may prevent future misdiagnosis of tear of the lateral meniscus and unnecessary meniscectomy as experienced by Helfet, Holden, and myself. There is a definite correlation with activities requiring downhill walking or running. The runners invariably complained of the oneset of symptoms during downhill running rather than uphill running. Back packing enthusiastscomplained of no symptoms for several days after ascending into the mountains, only to experience the symptoms at the end of a long, rapid descent out of the mountains. The pathomechanics of this inflammation of the popliteus tendon is not fully understood. Preliminary analysis of gait movies suggests that in downhill running there is an increased vector to displace the weight-bearing femur forward on the relatively fixed tibia as the knee is increasingly flexed (Fig. 5). Previously mentioned EMG functional studies indicate that the popliteus muscle is active during this weight-bearing phase of gait and may act to retard the femur from forward displacement on the tibia in conjunction with the quadriceps. More specifically, it may help to retard the lateral femoral condyle from rotating forward off the lateral tibial plateau. Downhill running or walking therefore may cause increased stress on the popliteus muscle-tendon unit in an effort to decelerate the body weight against the altered angle of gravitational pull, with resultant tenosynovitis and symptoms. In this series there were no top flight competitive runners. The typical patient was a 31-year-old physician who was jogging 1 to 5 miles and decided to increase his pace and distance, particularly while jogging downhill. The average age of this series of patients (31 years) at the time of onset, coupled with the fact many of these persons were relatively sedentary until stressing the knee by increased activity, suggests that there will be an increasing number of these patients in the future as jogging and running are prescribed for cardiovascular system conditioning. PMID:848633
Mayfield, G W
Tendon ruptures are common findings in foot and ankle practice. The etiology of tendon ruptures tends to be multifactorial-usually due to a combination of trauma, effects of systemic diseases, adverse effects of medications, and obesity. We present an unusual case of right Achilles tendinitis, left Achilles tendon rupture, bilateral peroneus longus tendon rupture, and left peroneus brevis tendon rupture of unknown etiology. This case report highlights the need for research for other possible, lesser known etiologies of tendon pathology. Level of Evidence: Therapeutic, Level IV, Case Study. PMID:23966259
Axibal, Derek P; Anderson, John G
We sought to determine the accuracy of ultrasound for the preoperative evaluation of shoulder impingement syndrome, rotator cuff tear, and abnormalities of the long head of the biceps tendon. The findings in 42 consecutive surgical cases were compared with the preoperative sonographic readings. Ultrasound detected all of the 10 full-thickness cuff tears identified at surgery (sensitivity 1.0, specificity 0.97) but detected only 6 of 13 partial-thickness cuff tears (sensitivity 0.46, specificity 0.97). A full-thickness tear was falsely diagnosed in one case of severe cuff abrasion. Dynamic scan criteria correctly diagnosed impingement in 27 of 34 cases (sensitivity 0.79, positive predictive value 0.96). Abnormalities of the long head of the biceps were accurately diagnosed with the exception of low-grade tendinitis and the superior labral tear, anterior to posterior, lesion. We concluded that ultrasound is a sensitive and accurate method of identifying patients with full-thickness tears of the rotator cuff, extracapsular biceps tendon pathology, or both. Dynamic ultrasound can help confirm, but not exclude, a clinical diagnosis of impingement. PMID:9658352
Read, J W; Perko, M
This study assessed medial patellofemoral ligament reconstruction using a partial-thickness quadriceps tendon graft in 14 knees in 13 patients. Nine patients were available for follow-up after a minimum of 24 months. Final patient evaluation was performed an average of 42 months postoperatively (range, 28-65 months). Primary outcome measure was occurrence of patellar dislocation postoperatively, and outcomes were quantified using the Kujala questionnaire and Crosby and Insall criteria. Postoperatively, no patient reported patellar dislocation. Using Crosby and Insall criteria, good or excellent results were achieved in 100% of patients. Mean Kujala score was 91.9. Postoperatively, all patients reported their knee was improved. These findings indicate medial patellofemoral ligament reconstruction with a quadriceps tendon graft is effective in preventing patellar dislocation and improving quality of life. However, patients should be counseled this procedure is indicated primarily for the treatment of recurrent instability, and postoperative relief of anterior knee pain is inconsistent. Level of Evidence: Level IV, Case Series. PMID:19292257
Dopirak, Ryan; Adamany, Damon; Bickel, Brent; Steensen, Robert
Although the Achilles tendon is the strongest in the body, it also is the most often ruptured. Achilles tendon rupture most often occurs during sports activities in middle-aged men. Operative repair of a ruptured Achilles tendon can be accomplished with a variety of techniques, ranging from open repair, to minimally invasive technique, to endoscopic-assisted repair. This article focuses on open repair of acute Achilles tendon rupture. Surgical techniques, rehabilitation protocol, and the authors' preferred method are described. PMID:19857843
Rosenzweig, Seth; Azar, Frederick M
A case history is presented of the repair of a neglected traumatic tendon laceration by the use of a permanent Silastic tendon implant, originally manufactured for hand surgery by a staged procedure. Stage I consists of implantation of the Silastic implant and allowance of a 2- to 3-month period for the production of a pseudosheath. Stage II consists of removal of the implant after using it to guide an auto- or allograft, through the newly formed pseudosheath for attachment to the anastomotic sites. PMID:2258563
LaBarbiera, A P; Solitto, R J
Thirteen injured digits in 10 patients (10 hands) with 20 potentially injured flexor tendons were preoperatively evaluated using real-time ultrasonography. The time interval between injury and ultrasonographic evaluation averaged 22 days. If a complete tendon laceration was found, the location of the proximal tendon stump was determined. Surgery was performed an average of 4 days after the ultrasonographic evaluation to
Donald H. Lee; Michelle L. Robbin; Robert Galliott; Veronica A. Graveman
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.
Triceps tendon avulsion injuries are rare. We report four weight lifters with triceps tendon raptures, two of whom had received local steroid injections for pain in the triceps. All four patients had taken oral anabolic steroids before injury. All patients had closed avulsion of the triceps tendon from its insertion into the olecranon. Three patients were injured while bench pressing
Jonathan L Sollender; Ghazi M Rayan; Glen A Barden
A finger exoskeleton has been developed to aid treatment of tendon injuries. The exoskeleton is designed to assist flexion\\/extension motions of a finger within its full range, in a natural and coordinated manner, \\u000awhile keeping the tendon tension within acceptable limits to avoid gap formation or rupture of the suture. In addition to offering robot assisted operation modes for tendon
Ismail Hakan Ertas; Elif Hocaoglu; Duygun Erol Barkana; Volkan Patoglu
Ruptures of the tibialis anterior tendon are rare. We present the clinical histories and MRI findings of three recent male patients with tibialis anterior tendon rupture aged 58–67 years, all of whom presented with pain over the dorsum of the ankle. Two of the three patients presented with complete rupture showing discontinuity of the tendon, thickening of the retracted portion of
Robert A. Gallo; Brett H. Kolman; Richard H. Daffner; Robert L. Sciulli; Catherine C. Roberts; Patrick J. DeMeo
The examination of Achilles tendon reflex is widely used as a simple, noninvasive clinical test in diagnosis and pharmacological therapy monitoring in such diseases as: hypothyroidism, hyperthyroidism, diabetic neuropathy, the lower limbs obstructive angiopathies and intermittent claudication. Presented Achilles tendon reflect measuring system is based on the piezoresistive sensor connected with the cylinder-piston system. To determinate the moment of Achilles tendon stimulation a detecting circuit was used. The outputs of the measuring system are connected to the PC-based data acquisition board. Experimental results showed that the measurement accuracy and repeatability is good enough for diagnostics and therapy monitoring purposes. A user friendly, easy-to-operate measurement system fulfills all the requirements related to recording, presentation and storing of the patients' reflexograms.
Szebeszczyk, Janina; Straszecka, Joanna
Abstract Reference: Hegedus EJ, Goode A, Campbell S, et al. Physical examination tests of the shoulder: a systematic review with meta-analysis of individual tests. Br J Sports Med. 2008;42(2):80–92. Clinical Question: The systematic review focused on various index tests for the shoulder. We concentrated on the subscapularis tendon results to determine the accuracy of reported index tests for clinically diagnosing subscapularis integrity. Data Sources: Studies were identified by an OVID search using MEDLINE, SPORTDiscus, and CINHAL databases (1966–2006) and a hand search by 2 authors (E.J.H. and S.C.). Primary search terms were shoulder, examination, and diagnosis. In addition to the database searches, personal files were hand searched by one of the authors (E.J.H.) for publications, posters, and abstracts. The reference lists in review articles were cross-checked, and all individual names of each special test were queried using MEDLINE and PubMed. Study Selection: The search was limited to English-language journals. Studies were eligible for inclusion if the criterion standard was surgery, magnetic resonance imaging, or injection (subacromial or acromioclavicular joint); at least 1 physical examination test or special test was studied; and one of the paired statistics of sensitivity and specificity was reported or could be determined. Excluded were studies in which the index test was performed under anesthesia or in cadavers, studies in which the index test was assigned the status of composite physical examination, and review articles. Studies were grouped according to the subscapularis index test assessed: lift off, internal-rotation lag sign, Napoleon sign, bear hug, belly off, and belly press. Data Extraction: Studies were selected in a 2-stage process. First, all abstracts and articles found through the search process were independently reviewed by 2 authors (E.J.H. and S.C.). Disagreement on inclusion of an article was resolved by consensus. Second, each selected study was assessed by each reviewer independently. A third reviewer made the final decision on any disagreements for the selected studies. The primary outcome measures were sensitivity and specificity and positive and negative likelihood ratios. The quality of a study was determined by assessing its internal and external validity. Validity was determined by the primary author (E.J.H.) using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) statement. Our work required data extraction from the original articles, which we used to generate 2 × 2 contingency tables for each index test. Pooled indices of clinical usefulness were then determined for each index test. Main Results: The specific search criteria identified 922 articles for review. Of these, 4 met the inclusion and exclusion criteria for subscapularis tendon tears, resulting in the number of studies assessing each index test as follows: 4 for lift off, 2 for internal-rotation lag sign, 2 for Napoleon sign, 1 for bear hug, 1 for belly off, and 1 for belly press. Subscapularis tears were identified by the criterion standard of surgery to visually assess the torn fibers. Across all 4 studies, a total of 304 shoulders were examined, 95 of which had a subscapularis tear (45 full thickness, 50 partial thickness), and 106 were injury free. Indices of clinical usefulness for full-thickness and partial-thickness subscapularis tears are reported in Tables 1 and 2, respectively.
Rigsby, Ruel; Sitler, Michael; Kelly, John D.
Tendon formation and repair rely on specific combinations of transcription factors, growth factors, and mechanical parameters that regulate the production and spatial organization of type I collagen. Here, we investigated the function of the zinc finger transcription factor EGR1 in tendon formation, healing, and repair using rodent animal models and mesenchymal stem cells (MSCs). Adult tendons of Egr1-/- mice displayed a deficiency in the expression of tendon genes, including Scx, Col1a1, and Col1a2, and were mechanically weaker compared with their WT littermates. EGR1 was recruited to the Col1a1 and Col2a1 promoters in postnatal mouse tendons in vivo. Egr1 was required for the normal gene response following tendon injury in a mouse model of Achilles tendon healing. Forced Egr1 expression programmed MSCs toward the tendon lineage and promoted the formation of in vitro-engineered tendons from MSCs. The application of EGR1-producing MSCs increased the formation of tendon-like tissues in a rat model of Achilles tendon injury. We provide evidence that the ability of EGR1 to promote tendon differentiation is partially mediated by TGF-?2. This study demonstrates EGR1 involvement in adult tendon formation, healing, and repair and identifies Egr1 as a putative target in tendon repair strategies. PMID:23863709
Guerquin, Marie-Justine; Charvet, Benjamin; Nourissat, Geoffroy; Havis, Emmanuelle; Ronsin, Olivier; Bonnin, Marie-Ange; Ruggiu, Mathilde; Olivera-Martinez, Isabel; Robert, Nicolas; Lu, Yinhui; Kadler, Karl E; Baumberger, Tristan; Doursounian, Levon; Berenbaum, Francis; Duprez, Delphine
Tissue engineering aims to induce tissue self-regeneration in vivo or to produce a functional tissue replacement in vitro to be then implanted in the body. To produce a viable and functional tendon, a uniaxially orientated collagen type I matrix has to be generated. Biochemical and physical factors can potentially alter both the production and the organisation of this matrix, and
Pierre-Olivier Bagnaninchi; Ying Yang; Alicia J El Haj; Nicola Maffulli; U Bosch
There is still no agreement on the nature of tissues' viscoelasticity and on its reliable modeling. We speculate that disagreements between previous observations stem from difficulties of separating between viscoelastic and preconditioning effects, since both are manifested by similar response features. Here, this and related issues were studied in the tendon as a prototype for other soft tissues. Sheep digital tendons were preconditioned under strain that was higher by 1% than the one used in subsequent testing. Each specimen was then subjected to stress relaxation, and quick release or creep. A stochastic microstructural viscoelastic theory was developed based on the collagen fibers' properties and on their gradual recruitment with stretch. Model parameters were estimated from stress relaxation data and predictions were compared with the creep data. Following its validation, the new recruitment viscoelasticity (RVE) model was compared, both theoretically and experimentally, with the quasilinear viscoelastic (QLV) theory. The applied preconditioning protocol produced subsequent pure viscoelastic response. The proposed RVE model provided excellent fit to both stress relaxation and creep data. Both analytical and numerical comparisons showed that the new RVE theory and the popular QLV one are equivalent under deformation schemes at which no fibers buckle. Otherwise, the equivalence breaks down; QLV may predict negative stress, in contrast to data of the quick release tests, while RVE predicts no such negative stress. The results are consistent with the following conclusions: (1) fully preconditioned tendon exhibits pure viscoelastic response, (2) nonlinearity of the tendon viscoelasticity is induced by gradual recruitment of its fibers, (3) a new structure-based RVE theory is a reliable representation of the tendon viscoelastic properties under both stress relaxation and creep tests, and (4) the QLV theory is equivalent to the RVE one (and valid) only under deformations in which no fibers buckle. The results also suggest that the collagen fibers themselves are linear viscoelastic. PMID:20353259
Einat, Raz; Yoram, Lanir
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.
Magnusson, S Peter; Narici, Marco V; Maganaris, Constantinos N; Kjaer, Michael
Pathologic processes intrinsic and extrinsic to the tendons have been proposed as the underlying cause of rotator cuff disease, but the precise etiology is not known. Tear formation is, in part, attributable to the accumulation of subrupture tendon fatigue damage. We review the molecular, mechanical, and structural changes induced in tendons subjected to controlled amounts of fatigue loading in an animal model of early tendinopathy. The distinct tendon responses to low and moderate levels of loading, as opposed to high levels, provide insight into the potential mechanisms for the therapeutic benefits of exercise in the treatment of rotator cuff tendinopathy. The progression of damage accumulation leading to fiber rupture and eventual tendon tearing seen with higher loading illustrates the progression from tendinopathy to full-thickness tearing. We hope that this more realistic animal model of tendon fatigue damage will allow better assessment of biologic, mechanical, tissue-engineering, and rehabilitation strategies to improve repair success. PMID:22244058
Neviaser, Andrew; Andarawis-Puri, Nelly; Flatow, Evan
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.
Ultrasound is a therapeutic agent commonly used to treat sports-related musculoskeletal conditions, including tendon injuries or tendinopathy. Despite the widespread popularity of therapeutic ultrasound, few clinical studies have proved its efficacy. Several animal studies have been conducted to explore its effectiveness. In addition, a number of in vitro studies investigating the mechanisms underlying the ability of this physical modality to enhance tendon healing or to treat tendinopathy are in progress. There is strong supporting evidence from animal studies about the positive effects of ultrasound on tendon healing. In vitro studies have also demonstrated that ultrasound can stimulate cell migration, proliferation, and collagen synthesis of tendon cells that may benefit tendon healing. These positive effects of therapeutic ultrasound on tendon healing revealed by in vivo and in vitro studies help explain the physiologic responses to this physical modality and could serve as the foundation for clinical practice. PMID:21552108
Tsai, Wen-Chung; Tang, Sf-T; Liang, Fang-Chen
Mineralisation of the tendon tissue has been described in various models of injury, ageing and disease. Often resulting in painful and debilitating conditions, the processes underlying this mechanism are poorly understood. To elucidate the progression from healthy tendon to mineralised tendon, an appropriate model is required. In this study, we describe the spontaneous and non-pathological ossification and calcification of tendons of the hindlimb of the domestic chicken (Gallus gallus domesticus). The appearance of the ossified avian tendon has been described previously, although there have been no studies investigating the developmental processes and underlying mechanisms leading to the ossified avian tendon. The tissue and cells from three tendons - the ossifying extensor and flexor digitorum longus tendons and the non-ossifying Achilles tendon - were analysed for markers of ageing and mineralisation using histology, immunohistochemistry, cytochemistry and molecular analysis. Histologically, the adult tissue showed a loss of healthy tendon crimp morphology as well as markers of calcium deposits and mineralisation. The tissue showed a lowered expression of collagens inherent to the tendon extracellular matrix and presented proteins expressed by bone. The cells from the ossified tendons showed a chondrogenic and osteogenic phenotype as well as tenogenic phenotype and expressed the same markers of ossification and calcification as the tissue. A molecular analysis of the gene expression of the cells confirmed these results. Tendon ossification within the ossified avian tendon seems to be the result of an endochondral process driven by its cells, although the roles of the different cell populations have yet to be elucidated. Understanding the role of the tenocyte within this tissue and the process behind tendon ossification may help us prevent or treat ossification that occurs in injured, ageing or diseased tendon. PMID:23826786
Agabalyan, Natacha A; Evans, Darrell J R; Stanley, Rachael L
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.
Krochmal, Daniel J.; Kuzon, William M.; Urbanchek, Melanie G.
A 17-year-old male presented to us following a hyperflexion injury to his right knee sustained while playing soccer. Immediately after the traumatic event, he developed a large, tense knee effusion. Physical examination revealed limited range of motion. MRI revealed a lobulated mass in the posteromedial aspect of the knee joint. The mass was excised and sections submitted to pathology. A pathologic, microscopic, and immunohistochemical characteristics revealed the final diagnosis of fibroma of tendon sheath in the knee. At 12 months followup, the patient reported no subjective symptoms, such as pain or limitation of athletic activities and has full range of motion. Additionally, he has demonstrated no signs of recurrence. We report a case of fibroma of the tendon sheath originating from the synovial membrane of the joint capsule of the knee.
Griesser, Michael J; Wakely, Paul E; Mayerson, Joel
\\u000a Achilles tendon lengthening is a delicate procedure whereby the risk of over lengthening (creating calcaneus), rupture, and\\u000a weakening of the gastrocnemius-soleus muscle is devastating. The Silfverskiöld test is clinically performed to differentiate\\u000a gastrocnemius equinus from gastrocnemius-soleus equinus. Many surgical techniques have been developed to treat negative results\\u000a of the Silfverskiöld test. The authors prefer a gastrocnemius-soleus recession in order to
Bradley M. Lamm; Dror Paley
The caudal tendons in tunas and other scombrid fish link myotomal muscle directly to the caudal fin rays, and thus serve to transfer muscle power to the hydrofoil-like tail during swimming. These robust collagenous tendons have structural and mechanical similarity to tendons found in other vertebrates, notably the leg tendons of terrestrial mammals. Biochemical studies indicate that tuna tendon collagen is composed of the (alpha1)(2),alpha2 heterotrimer that is typical of vertebrate Type I collagen, while tuna skin collagen has the unusual alpha1,alpha2,alpha3 trimer previously described in the skin of some other teleost species. Tuna collagen, like that of other fish, has high solubility due to the presence of an acid-labile intermolecular cross-link. Unlike collagen in mammalian tendons, no differences related to cross-link maturation were detected among tendons in tuna ranging from 0.05 to 72 kg (approx. 0.25-6 years). Tendons excised post-mortem were subjected to load cycling to determine the modulus of elasticity and resilience (mean of 1.3 GPa and 90%, respectively). These material properties compare closely to those of leg tendons from adult mammals that can function as effective biological springs in terrestrial locomotion, but the breaking strength is substantially lower. Peak tendon forces recorded during steady swimming appear to impose strains of much less than 1% of tendon length, and no more than 1.5% during bursts. Thus, the caudal tendons in tunas do not appear to function as elastic storage elements, even at maximal swimming effort. PMID:12485695
Shadwick, Robert E; Rapoport, H Scott; Fenger, Joelle M
Forearm lacerations involving muscle bellies are usually treated by repairing muscle fascia. Repair of tendons themselves is stronger and restores normal muscle anatomy better. Tendon repair requires good knowledge of forearm muscle and tendon anatomy. We have made cadaver measurements to produce graphical maps of locations of individual muscles tendons of origin and insertion, some practical guides for finding tendon ends and a simple grasping stitch for intramuscular tendons. PMID:21606787
Burnham, Jeremy M; Hollister, Anne M; Rush, David A; Avallone, Thomas J; Shi, Runhua; Jordan, Jenee' C
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
Józsa, L; Kannus, P
Pectoralis major tendon rupture is a rare shoulder injury, most commonly seen in weight lifters. This injury is being seen more regularly due to the increased emphasis on healthy lifestyles. Surgical repair of the pectoralis major tendon rupture has been shown to provide superior outcomes regarding strength return. Thus it appears that surgical repair is the treatment of choice for those wishing to return to competitive or recreational athletic activity. This article describes the history and physical examination process for the athlete with pectoralis tendon major rupture. Surgical vs conservative treatment will be discussed. This manuscript provides post surgical treatment guidelines that can be followed after surgical repair of the pectoralis tendon rupture.
Triceps tendon avulsion injuries are rare. We report four weight lifters with triceps tendon raptures, two of whom had received local steroid injections for pain in the triceps. All four patients had taken oral anabolic steroids before injury. All patients had closed avulsion of the triceps tendon from its insertion into the olecranon. Three patients were injured while bench pressing heavy weights, and one patient was injured while swinging a baseball bat. Satisfactory results were achieved after surgical reinsertion of the tendon. PMID:9593095
Sollender, J L; Rayan, G M; Barden, G A
The use of stems cells in tendon repair is of particular interest given the frequency of tendon injuries worldwide together with the technical difficulty often encountered when repairing or augmenting tendons. Stems cells have the capability to differentiate into a variety of different cell types including osteocytes and tenocytes, and if normal architecture of damaged tendon (either macroscopic or microscopic) could be restored, this would significantly improve the management of patients with these injuries. There is already encouraging research on the use of stems cells clinically although considerable further work is required to improve knowledge and clinical applications of stem cells in tissue engineering.
MacLean, S.; Khan, W. S.; Malik, A. A.; Snow, M.; Anand, S.
Heterotopic mineralization may result in tendon weakness, but effects on other biomechanical responses have not been reported. We used a needle injury, which accelerates spontaneous mineralization of murine Achilles tendons, to test two hypotheses: that injured tendons would demonstrate altered biomechanical responses; and that unilateral injury would accelerate mineralization bilaterally. Mice underwent left hind (LH) injury (I; n?=?11) and were euthanized after 20 weeks along with non-injured controls (C; n?=?9). All hind limbs were examined by micro computed tomography followed by biomechanical testing (I?=?7 and C?=?6). No differences were found in the biomechanical responses of injured tendons compared with controls. However, the right hind (RH) tendons contralateral to the LH injury exhibited greater static creep strain and total creep strain compared with those LH tendons (p???0.045) and RH tendons from controls (p???0.043). RH limb lesions of injured mice were three times larger compared with controls (p?=?0.030). Therefore, despite extensive mineralization, changes to the responses we measured were limited or absent 20 weeks postinjury. These results also suggest that bilateral occurrence should be considered where tendon mineralization is identified clinically. This experimental system may be useful to study the mechanisms of bilateral new bone formation in tendinopathy and other conditions. PMID:23754538
O'Brien, Etienne John Ogilvy; Shrive, Nigel G; Rosvold, Joshua M; Thornton, Gail M; Frank, Cyril B; Hart, David A
Calcific tendinosis (tendonosis/tendonitis) is a condition which results from the deposition of calcium hydroxyapatite crystals in any tendon of the body. Calcific tendonitis usually presents with pain, which can be exacerbated by prolonged use of the affected tendon. We report a case of calcific tendinosis in the posterior tibialis tendon at the navicular insertion. The pathology is rare in the foot, and extremely rare in the tibialis posterior tendon, indeed there are only 2 reported in the published literature. This case report highlights the need to consider calcific tendinosis in the foot despite its rarity. If this diagnosis is considered early, appropriate investigations can then be requested and unnecessary biopsies, use of antibiotics and surgery can be avoided. We also discuss possible causes of calcific tendinosis in the tibialis posterior tendon, the role of imaging modalities and review treatment methods.
Harries, Luke; Kempson, Susan; Watura, Roland
We present our findings in six athletic patients with a ruptured or partially ruptured posterior tibial tendon. Pain in the midarch region, difficulty pushing off while running, and a pronated flattened longitudinal arch are the usual symptoms and physical findings of this injury. Surgical treatment, including reattachment of the rup tured posterior tibial tendon, is effective in restoring some but
Lee Woods; Robert E. Leach
Retropharyngeal calcific tendonitis is an inflammatory process of the superior oblique tendons of the longus colli muscle, a neck flexor in the upper cervical spine, caused by deposition of calcium hydroxy- apatite crystals; the definitive diagnostic test is computed tomography (CT). Presented in this article are two cases seen at our institution. Patients typically present with acute onset of neck
Rhea Victoria; B. Razon; Asad Nasir; George S. Wu; Manal Soliman; Jeffrey Trilling
This report discusses the friction factor and ultimate tensile strength achieved by multi-strand tendons stressed around short radius curves. It was found that a pre-fabricated tendon of as many as 33 one-half-inch diameter strands, stressed through 1.7 r...
T. J. Bezouska
Injuries to the tendon (e.g., wrist tendonitis, epicondyltis) due to overuse are common in sports activities and the workplace. Most are associated with repetitive, high force hand activities. The mechanisms of cellular and structural damage due to cyclical loading are not well known. The purpose of this video is to present a new system that can simultaneously load four tendons in tissue culture. The video describes the methods of sterile tissue harvest and how the tendons are loaded onto a clamping system that is subsequently immersed into media and maintained at 37°C. One clamp is fixed while the other one is moved with a linear actuator. Tendon tensile force is monitored with a load cell in series with the mobile clamp. The actuators are controlled with a LabView program. The four tendons can be repetitively loaded with different patterns of loading, repetition rate, rate of loading, and duration. Loading can continue for a few minutes to 48 hours. At the end of loading, the tendons are removed and the mid-substance extracted for biochemical analyses. This system allows for the investigation of the effects of loading patterns on gene expression and structural changes in tendon. Ultimately, mechanisms of injury due to overuse can be studies with the findings applied to treatment and prevention.
Asundi, Krishna; Rempel, David
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. Moisture may seep into the grout around the tendons and cause corro...
G. Thomas A. Brown
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.
Frisch, Catherine Kayt Vincent
Tendon transfer is one treatment option for patients with massive irreparable rotator cuff tears. Although surgical indications are not clearly defined, the traditional thought is that the ideal candidate is young and lacks significant glenohumeral arthritis. The proposed benefits of tendon transfers are pain relief and potential increase in strength. The biomechanical rationale for the procedure is to restore the glenohumeral joint force couple and possibly to restore normal shoulder kinematics. The selection of donor tendon depends on the location of the rotator cuff deficiency. Transfers of latissimus dorsi and pectoralis major tendons have been shown to consistently improve pain; however, functional benefits are unpredictable. Trapezius tendon transfer may be an alternative in patients with massive posterosuperior rotator cuff tears, although longer-term follow-up is required. PMID:23908255
Omid, Reza; Lee, Brian
This paper reports on the design of an artificial tendon intended for use in a powered, lower limb prosthesis. To specify performance requirements, the properties of mammalian weight bearing tendons are drawn from the literature and compared with a number of existing tendon models. Based on the data, a mathematical model of an energy storing tendon is proposed and used
Glenn K. Klute; Joseph M. Czerniecki; Blake Hannaford
This is a case report of two children with congenital dislocation of the knee. They have been treated surgically with Z-lengthening of the quadriceps tendon and additional reconstruction of the quadriceps tendon with Achilles tendon allograft to fill in the remaining average 6 cm gap of the tendon. The patients were two girls, 6 and 9 years old. One of them had
Yetkin Söyüncü; Ercan M?hç?; Haluk Özcanl?; Merter Özenci; Feyyaz Aky?ld?z; A. Turan Ayd?n
A histologically normal insertion site does not regenerate following rotator cuff tendon-to-bone repair, which is likely due to abnormal or insufficient gene expression and/or cell differentiation at the repair site. Techniques to manipulate the biologic events following tendon repair may improve healing. We used a sheep infraspinatus repair model to evaluate the effect of osteoinductive growth factors and BMP-12 on tendon-to-bone healing. Magnetic resonance imaging and histology showed increased formation of new bone and fibrocartilage at the healing tendon attachment site in the treated animals, and biomechanical testing showed improved load-to-failure. Other techniques with potential to augment repair site biology include use of platelets isolated from autologous blood to deliver growth factors to a tendon repair site. Modalities that improve local vascularity, such as pulsed ultrasound, have the potential to augment rotator cuff healing. Important information about the biology of tendon healing can also be gained from studies of substances that inhibit healing, such as nicotine and antiinflammatory medications. Future approaches may include the use of stem cells and transcription factors to induce formation of the native tendon-bone insertion site after rotator cuff repair surgery.
Patellar tendonitis or "jumper's knee" is an important cause of anterior knee pain. The natural history, classification of the lesion, and treatment methods, however, remain controversial. This article presents a retrospective review of 40 patients (50 knees) with various stages of patellar tendonitis and examines the etiology, presentation, clinical picture, investigation, and results of conservative treatment. Twenty-nine men and 11 women ranging in age from 17-48 years comprised the study population. Ten patients had bilateral involvement. The overall evaluation of patients' treatment was 70% with normal or nearly normal results and 30% with abnormal or very abnormal results; most required surgical treatment in the form of arthroscopy, anterior compartment decompression, and patellar tendon exploration. Thirty-seven percent of the patients had a previous history of anterior knee pain (25% had Osgood-Schlatter disease and 12.5% had anterior knee pain). Patellar tendon involvement is appraised according to a new concept. Since patellar tendonitis is part of the wider picture of anterior knee pain, patellar tendonitis is classified as primary or secondary according to presentation, magnetic resonance imaging in general, and the pathology of the patellar tendon in particular. Treatment is planned accordingly. PMID:10323501
Duri, Z A; Aichroth, P M; Wilkins, R; Jones, J
In the present experiment we obtained the tensile properties of the human gastrocnemius tendon, a high-stressed tendon suitable for spring-like action during locomotion. Measurements were taken in vivo in six men. The gastrocnemius tendon elongation during tendon loading?unloading induced by muscle contraction?relaxation was measured using real-time ultrasonography. Tendon forces were calculated from the moment generated during isometric plantarflexion contraction, using
Constantinos N Maganaris; John P Paul
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
Frigg, Arno Martin; Valderrabano, Victor; Kundert, Hans-Peter; Hintermann, Beat
This paper aims to highlight the need for a refined tendon model to reproduce the main mechanical features of the integrated\\u000a muscle–tendon unit (MTU). Elastic nonlinearities of the tendon, both at the nano and microscale, are modeled by a multiscale\\u000a approach, accounting for the hierarchical arrangement (from molecules up to the fibers) of the collagen structures within\\u000a the tissue. This
Franco Maceri; Michele Marino; Giuseppe Vairo
Gross and histologic examinations of 15 normal cadaver and 15 surgical posterior tibial tendons from patients with posterior tibial tendon insufficiency were performed. All surgical specimens were abnormal with enlargement distal to the medial malleolus and a dull white appearance. At histologic examination, 12 of 15 cadaver tendons displayed normal tendon structure characterized by linear orientation of collagen bundles, normal fibroblast cellularity, low vascular density, and insertional chondroid metaplasia. The surgical specimens displayed a degenerative tendinosis characterized by increased mucin content, fibroblast hypercellularity, chondroid metaplasia, and neovascularization. This resulted in marked disruption of the linear orientation of the collagen bundles. PMID:9728698
Mosier, S M; Lucas, D R; Pomeroy, G; Manoli, A
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.
Sasaki, Jun; Itsubo, Toshiro; Nakamura, Koichi; Hayashi, Masanori; Uchiyama, Shigeharu; Kato, Hiroyuki
Patellar tendon width and length are commonly used for preoperative planning for anterior cruciate ligament reconstruction (ACLR). In the study reported here, we assessed the accuracy of preoperative measurements made by palpation through the skin, and correlated these measurements with the actual dimensions of the tendons at surgery. Before making incisions in 53 patients undergoing ACLR with patellar tendon autograft, we measured patellar tendon length with the knee in full extension and in 90° of flexion, and tendon width with the knee in 90° of flexion. The tendon was then exposed, and its width was measured with the knee in 90° of flexion. The length of the central third of the tendon was measured after the graft was prepared. Mean patellar tendon length and width with the knee in 90° of flexion were 39 mm and 32 mm, respectively. No clinical difference was found between the estimated pre-incision and surgical widths. However, the estimated pre-incision length with the knee in full extension and in 90° of flexion was significantly shorter than the surgical length. Skin measurements can be used to accurately determine patellar tendon width before surgery, but measurements of length are not as reliable. PMID:24078943
Zooker, Chad; Pandarinath, Rajeev; Kraeutler, Matthew J; Ciccotti, Michael G; Cohen, Steven B; Deluca, Peter F
A parametric study is being undertaken of the effects of extra low frequency (ELF) conductive electric fields on chicken tendon explant fibroplasia, collagen synthesis and oriented migration. Independent variables are: pulse repetition rate, pulse duratio...
S. F. Cleary L. M. Liu R. Diegelmann
A histologically normal insertion site does not regenerate following rotator cuff tendon-to-bone repair, which is likely due\\u000a to abnormal or insufficient gene expression and\\/or cell differentiation at the repair site. Techniques to manipulate the biologic\\u000a events following tendon repair may improve healing. We used a sheep infraspinatus repair model to evaluate the effect of osteoinductive\\u000a growth factors and BMP-12 on
David Kovacevic; Scott A. Rodeo
Three unusual cases of rupture of finger extensor tendons by attrition are reported. In one instance it was associated with long-standing nonunion of a scaphoid fracture, with a posttraumatic dorsal subluxation of the lower end of the ulna in another, and with a Madelung's deformity in the third. Extensor tendon rupture has not been previously recorded in the English-language literature after the first two conditions. PMID:2584656
Harvey, F J; Harvey, P M
Tendons are strong hierarchical structures, but how tensile forces are transmitted between different levels remains incompletely understood. Collagen fibrils are thought to be primary determinants of whole tendon properties, and therefore we hypothesized that the whole human patellar tendon and its distinct collagen fibrils would display similar mechanical properties. Human patellar tendons (n = 5) were mechanically tested in vivo by ultrasonography. Biopsies were obtained from each tendon, and individual collagen fibrils were dissected and tested mechanically by atomic force microscopy. The Young's modulus was 2.0 ± 0.5 GPa, and the toe region reached 3.3 ± 1.9% strain in whole patellar tendons. Based on dry cross-sectional area, the Young's modulus of isolated collagen fibrils was 2.8 ± 0.3 GPa, and the toe region reached 0.86 ± 0.08% strain. The measured fibril modulus was insufficient to account for the modulus of the tendon in vivo when fibril content in the tendon was accounted for. Thus, our original hypothesis was not supported, although the in vitro fibril modulus corresponded well with reported in vitro tendon values. This correspondence together with the fibril modulus not being greater than that of tendon supports that fibrillar rather than interfibrillar properties govern the subfailure tendon response, making the fibrillar level a meaningful target of intervention. The lower modulus found in vitro suggests a possible adverse effect of removing the tissue from its natural environment. In addition to the primary work comparing the two hierarchical levels, we also verified the existence of viscoelastic behavior in isolated human collagen fibrils. PMID:22114175
Svensson, René B; Hansen, Philip; Hassenkam, Tue; Haraldsson, Bjarki T; Aagaard, Per; Kovanen, Vuokko; Krogsgaard, Michael; Kjaer, Michael; Magnusson, S Peter
Background Treatment of ruptured Achilles tendons currently constitutes of conservative early functional treatment or surgical treatment either by open or minimal invasive techniques. We hypothesize that an experimental Achilles tendon suture in an animal model significantly deteriorates Achilles tendon microcirculation immediately following suturing. Methods Fifteen Achilles tendons of eight male Wistar rats (275–325 g) were included. After preparation of the Achilles tendon with a medial paratendinous approach, Achilles tendon microcirculation was assessed using combined Laser-Doppler and spectrophotometry (Oxygen-to-see) regarding: - tendinous capillary blood flow [arbitrary units AU] - tendinous tissue oxygen saturation [%] - tendinous venous filling pressure [rAU] The main body of the Achilles tendon was measured in the center of the suture with 50 Hz. 10 minutes after Achilles tendon suture (6-0 Prolene), a second assessment of microcirculatory parameters was performed. Results Achilles tendon capillary blood flow decreased by 57% following the suture (70 ± 30 AU vs. 31 ± 16 AU; p < 0.001). Tendinous tissue oxygen saturation remained at the same level before and after suture (78 ± 17% vs. 77 ± 22%; p = 0.904). Tendinous venous filling pressure increased by 33% (54 ± 16 AU vs. 72 ± 20 AU; p = 0.019) after suture. Conclusion Achilles tendon suture in anaesthetised rats causes an acute loss of capillary perfusion and increases postcapillary venous filling pressures indicating venous stasis. The primary hypothesis of this study was confirmed. In contrast, tendinous tissue oxygen saturation remains unchanged excluding acute intratendinous hypoxia within the first 10 minutes after suture. Further changes of oxygen saturation remain unclear. Furthermore, it remains to be determined to what extent reduced capillary blood flow as well as increased postcapillary stasis might influence tendon healing from a microcirculatory point of view in this animal setting.
Kraemer, Robert; Lorenzen, Johan; Rotter, Robert; Vogt, Peter M; Knobloch, Karsten
The Achilles tendon is believed to have first developed two million years ago enabling humans to run twice as fast. However if the Achilles tendon is so important in terms of evolution, then why is this tendon so prone to injury - especially for those more active like athletes. The Achilles tendon had an integral role in evolving apes from a herbivorous diet to early humans who started hunting for food over longer distances, resulting in bipedal locomotion. Evolutionary advantages of the Achilles tendon includes it being the strongest tendon in the body, having an energy-saving mechanism for fast locomotion, allows humans to jump and run, and additionally is a spring and shock absorber during gait. Considering these benefits it is therefore not surprising that studies have shown athletes have thicker Achilles tendons than subjects who are less active. However, contradictory to these findings that show the importance of the Achilles tendon for athletes, it is well known that obtaining an Achilles tendon injury for an athlete can be career-altering. A disadvantage of the Achilles tendon is that the aetiology of its pathology is complicated. Achilles tendon ruptures are believed to be caused by overloading the tensed tendon, like during sports. However studies have also shown athlete Achilles tendon ruptures to have degenerative changes in the tendon. Other flaws of the Achilles tendon are its non-uniform vascularity and incomplete repair system which may suggest the Achilles tendon is on the edge of evolution. Research has shown that there is a genetic influence on the predisposition a person has towards Achilles tendon injuries. So if this tendon is here to stay in our anatomy, and it probably is due to the slow rate of evolution in humans, research in genetic modification could be used to decrease athletes' predisposition to Achilles tendinopathy. PMID:21900004
Malvankar, S; Khan, W S
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° in stretched tendons vs. 148° 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.
Franchi, Marco; Fini, Milena; Quaranta, Marilisa; De Pasquale, Viviana; Raspanti, Mario; Giavaresi, Gianluca; Ottani, Vittoria; Ruggeri, Alessandro
Axial speed of sound (SOS) measurements have been successfully applied to noninvasively evaluate tendon load, while preliminary studies showed that this technique also has a potential clinical interest in the follow up of tendon injuries. The ultrasound propagation theory predicts that the SOS is determined by the effective stiffness, mass density and Poisson's ratio of the propagating medium. Tendon stiffness characterizes the tissue's mechanical quality, but it is often measured in quasi-static condition and for entire tendon segments, so it might not be the same as the effective stiffness which determines the SOS. The objectives of the present study were to investigate the relationship between axial SOS and tendon's nonlinear elasticity, measured in standard laboratory conditions, and to evaluate if tendon's mass density and cross-sectional area (CSA) affect the SOS level. Axial SOS was measured during in vitro cycling of 9 equine superficial digital tendons. Each tendon's stiffness was characterized with a tangent modulus (the continuous derivative of the true stress/true strain curve) and an elastic modulus (the slope of this curve's linear region). Tendon's SOS was found to linearly vary with the square root of the tangent modulus during loading; tendon's SOS level was found correlated to the elastic modulus's square root and inversely correlated to the tendon's CSA, but it was not affected by tendon's mass density. These results confirm that tendon's tangent and elastic moduli, measured in laboratory conditions, are related to axial SOS and they represent one of its primary determinants. PMID:22078274
Vergari, Claudio; Ravary-Plumioën, Bérangère; Evrard, Delphine; Laugier, Pascal; Mitton, David; Pourcelot, Philippe; Crevier-Denoix, Nathalie
Two methods are used to route the tibialis posterior tendon anteriorly to achieve dorsiflexion: (1) around the medial side of the tibia, or the subcutaneous route; and (2) through the interosseous membrane, or the interosseous route. This study determined the effect of site of tendon insertion on ankle and foot motions and compared the efficacy of both routes. Eleven fresh normal cadaveric legs were used. The detached tibialis posterior tendon was transferred anteriorly through the interosseous membrane and anchored to the first cuneiform along the first metatarsal axis by a barbed staple. The specimen was mounted on a mechanical testing machine. Tension was applied to the tendon and ankle and foot motions were measured. The experimental procedure was repeated with tendon insertion along the second metatarsal axis and serially through to the fifth metatarsal axis. The entire experiment was repeated using the subcutaneous route. The interosseous route was more effective in achieving maximum dorsiflexion with minimal pronation. Shifting the insertion medially caused supination, whereas a more lateral insertion caused pronation. PMID:7554643
Goh, J C; Lee, P Y; Lee, E H; Bose, K
Various studies have shown that the operative treatment of a freshly ruptured Achilles tendon is generally considered to be more appropriate than a nonoperative regimen. However, complications in open reconstructions are reported to occur in 11-29%. The method used in this study reduced the risk of complications arising from operation, but simultaneously allowed early postoperative mobilization and functional treatment. It was a percutaneous repair of the Achilles tendon, using two Lengemann extension wires for coadaptation of the ruptured tendon. To fix the rupture site, the authors used a fibrin sealant. The spikes of the wire were hooked in at the fascia of the soleus muscle. Via a big, curved needle, the wire was placed in the distal stumps of the ruptured tendon and guided out laterally and medially above the calcaneus. After blocking the wires distally, the fibrin sealant was applied at the rupture site. The current report describes this method of treatment in 66 patients. The postoperative observation period was 1 year. Sixty-four patients were male and two were female. Their average age was 42 years. The Achilles tendon ruptures occurred during sporting activities and were treated by operation within 22 hours on average. The outcome was very good in 98%. One patient (2%) suffered a rerupture due to trauma. There were no other complications. PMID:15132929
Gorschewsky, Ottmar; Pitzl, Martin; Pütz, Andrej; Klakow, Andreas; Neumann, Wolfram
We present the case of a patient with long-standing rheumatoid arthritis and an acute onset of total dysfunction of the posterior tibial tendon. On MRI, a rupture of the tendon was apparent. Intraoperatively, however, massive tenosynovitis with stricture of the tendon was identified as the cause of posterior tibial tendon dysfunction. This case illustrates a pitfall in MRI imaging with potential diagnostic and therapeutic consequences. PMID:12120910
Hasler, Paul; Hintermann, Beat; Meier, Monika
This study investigated whether gene transfer to the tendon-bone insertion site is possible during early tendon-transplant healing using viral vectors. In addition, we evaluated the optimal gene delivery technique for an in vivo adenoviral gene transfer to a tendon-bone insertion site in a bone tunnel. Twenty-six rabbits underwent a bilateral transfer of the flexor digitorum longus tendon into a bone
Christian Lattermann; Boris A. Zelle; Janey D. Whalen; Axel W. A. Baltzer; Paul D. Robbins; Christopher Niyibizi; Christopher H. Evans; Freddie H. Fu
PURPOSE: The present study evaluated the presence of stem cells in hamstring tendons from adult subjects of different ages. The aim was to isolate, characterize and expand these cells in vitro, and to evaluate whether cell activities are influenced by age. METHODS: Tendon stem cells (TSCs) were isolated through magnetic sorting from the hamstring tendons of six patients. TSC percentage, morphology and clonogenic potential were evaluated, as well as the expression of specific surface markers. TSC multi-potency was also investigated as a function of age, and quantitative polimerase chain reaction was used to evaluate gene expression of TSCs cultured in suitable differentiating media. RESULTS: The presence of easily harvestable stem cell population within adult human hamstring tendons was demonstrated. These cells exhibit features such as clonogenicity, multi-potency and mesenchymal stem cells markers expression. The age-related variations in human TSCs affect the number of isolated cells and their self-renewal potential, while multi-potency assays are not influenced by tendon ageing, even though cells from younger individuals expressed higher levels of osteogenic and adipogenic genes, while chondrogenic genes were highly expressed in cells from older individuals. CONCLUSIONS: These results may open new opportunities to study TSCs to better understand tendon physiology, healing and pathological processes such as tendinopathy and degenerative age-related changes opening new frontiers in the management of tendinopathy and tendon ruptures. PMID:23503946
Ruzzini, Laura; Abbruzzese, Franca; Rainer, Alberto; Longo, Umile Giuseppe; Trombetta, Marcella; Maffulli, Nicola; Denaro, Vincenzo
The purpose of this study was to compare the tensile strength of the central one third patellar tendon--as used for reconstruction of the anterior cruciate ligament--to that of the residual patellar tendon. Ten matched pairs of human cadaveric knees were used for this study, each specimen consisting of an intact patella-patellar tendon-proximal tibial unit. One knee from each pair was randomly selected for removal of both the medial and lateral one third of the patellar tendon, leaving the central one third intact. The contralateral knee of each pair underwent removal of the central one third of the patellar tendon, leaving the residual two thirds intact. Each specimen was then mounted in a materials testing machine and tensile tested to failure at a strain rate of 100%.s-1. The most important result to emerge from these experiments was that there was no significant difference in maximum force to failure for the residual patellar tendon compared to the central one third. Thus any thought that removal of the central one third as a graft still leaves a tendon twice as wide and therefore twice as strong as a graft is dispelled by these experiments. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5
Matava, M J; Hutton, W C
After flexor tendon repair there is often increased resistance to tendon gliding at the repair site, which is greater for techniques using increased suture strands or suture material. This increased “friction” may be measured as the “work of flexion” in the laboratory setting. Tendon repairs performed in zone 2 in human cadaver hands using the two strand Kessler, the lateral
M. Aoki; P. R. Manske; D. L. Pruitt; B. J. Larson
Giant cell tumour of the tendon sheath is a benign, solitary lesion, which is less common in foot than in hand. Recurrence is the most common complication after excision. We report a case of GCT-TS in the flexor tendon of the right big toe in 28 years old lady. The mass was excised widely with preservation of the flexor tendon.
Mohie Eldin Fadel; Axel Schulz; Ralph Linker; Jörg Jerosch
Tendinopathy is of distinct interest as it describes a painful tendon disease with local tenderness, swelling and pain associated with sonographic features such as hypoechogenic texture and diameter enlargement. Recent research elucidated microcirculatory changes in tendinopathy using laser Doppler flowmetry and spectrophotometry such as at the Achilles tendon, the patellar tendon as well as at the elbow and the wrist
The central third of the patellar tendon of the right knee was removed in 40 adult New Zealand White (NZW) rabbits. The animals were divided into two groups of 20 animals each. In group 1 the tendon defect was left open and in group 2 the tendon defect was closed. The peritenon was closed in all cases. The animals were
Giuseppe Milano; Antonio Gigante; Alfredo Schiavone Panni; Pier Damiano Mulas; Carlo Fabbriciani
Injuries of the peroneus tendons are common and both the athlete and the older population are at risk. MR imaging is a useful technique for revealing injuries of the peroneus tendons as well as showing anatomic factors associated with these lesions. This article reviews clinical factors and MR imaging characteristics of injuries of the peroneus tendons. PMID:11402870
Rademaker, J; Teichgräber, U K; Schröder, R J; Oestmann, J W; Felix, R
The authors present a new non-intrusive experimental procedure based on laser techniques for the measurement of mechanical properties of tendons. The procedure is based on the measurement of the first resonance frequency of the tendon by laser Doppler vibrometry during in vitro tensile experiments, with the final aim of establishing a measurement procedure to perform the mechanical characterization of tendons
Gian Marco Revel; Alessandro Scalise; Lorenzo Scalise
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
Schumacher, Hagen H A; James, Nick K
Posteromedial ankle complaints are most often caused by a disorder of the posterior tibial tendon. Two predominant groups of patients can be distinguished: the first involves younger patients who have some form of systemic inflammatory disease; the second involves older patients whose dysfunction is caused by chronic overuse. This article illustrates endoscopy of the posterior tibial tendon in a group of patients who had diverse pathology. None of the patients showed postoperative complications. All showed a quick recovery, early mobilization, none or mild postoperative pain, and nice wound healing. Although not all patients were free of complaints, all were satisfied with the intervention itself. Tendoscopy of the poterior tibial tendon offers the advantage of less morbidity, reduction of the postoperative pain, early mobilization, no wound healing problems and outpatient treatment. PMID:16798520
Bulstra, Gythe H; Olsthoorn, Paul G M; Niek van Dijk, C
Traditionally, tendons are considered to only contain tenocytes that are responsible for the maintenance, repair and remodeling\\u000a of tendons. Stem cells, which are termed tendon-derived stem cells (TDSCs), have recently been identified in tendons. This\\u000a review aims to summarize the current information about the in vitro characteristics of TDSCs, including issues related to TDSC isolation and culture, their cell morphology,
Pauline Po Yee Lui; Kai Ming Chan
Simultaneous rupture of quadriceps tendon with contralateral patellar tendon is very rare. There are only two case reports\\u000a in English literature. We report the case of a healthy 41-year-old female with simultaneous rupture of her left quadriceps\\u000a tendon and right patellar tendon. There were no known precipitating factors for this injury. Surgical repair and early rehabilitation\\u000a achieved satisfactory outcome.
A. Jalgaonkar; A. Rafee; O. Haddo; S. Sarkar
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
Yeh, Peter C; Shin, Steven S
Rupture of the Achilles tendon is a considerable cause of morbidity with reduced function following injury. Recent studies have shown little difference in outcome between the techniques of open and non-operative treatment using an early active rehabilitation programme. Meta-analyses have shown that non-operative management has increased risk of re-rupture whereas surgical intervention has risks of complications related to the wound and iatrogenic nerve injury. Minimally invasive surgery has been adopted as a way of reducing infections rates and wound breakdown however avoiding iatrogenic nerve injury must be considered. We discuss the techniques and outcomes of percutaneous and minimally invasive repairs of the Achilles tendon.
Achilles tendon rupture is a serious injury for which the best treatment is still controversial. Its primary goal should be to restore normal length and tension, thus obtaining an optimal function. Tendon elongation correlates significantly with clinical outcome; lengthening is an important cause of morbidity and may produce permanent functional impairment. In this article, we review all factors that may influence the repair, including the type of surgical technique, suture material, and rehabilitation program, among many others.
This study provides a model of the complex deltoid origin and end tendons, as a basis for further anatomical, biomechanical and clinical research. Although the deltoid is used in transpositions with upper limb paralysis, its detailed morphology and segmentation has not been object of much study. Morphologically, the deltoid faces two distinct challenges. It closely envelops a ball joint, and it reduces its width over a short distance from a very wide origin along clavicle, acromion and spina scapula, to an insertion as narrow as the humerus. These challenges necessitate specific morphological tendon adaptations. A qualitative model for these tendons is developed by the stepwise transformation of a unipennate muscle model into a functional deltoid muscle. Each step is the solution to one of the mentioned morphological challenges. The final model is of an end tendon consisting of a continuous succession of bipennate end tendon blades centrally interspaced by unipennate tendon parts. The origin tendon consists of lamellae that interdigitate with the end tendon blades, creating a natural segmentation. The model is illustrated by qualitative dissection results. In addition, in view of a proliferation of terms found in the literature to describe deltoid tendons, tendon concepts are reviewed and the systematic use of the unique and simple terminology of ‘origin and end tendons’ is proposed.
Leijnse, J N A L; Han, S-H; Kwon, Y H
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.
Birch, Helen L
Conflicts, snapping and instability of the tendons are common, and ultrasound (US) is the method of choice for evidencing these conditions thanks to the possibility to perform dynamic maneuvers during imaging studies. A conflict can occur between a tendon and a bone structure, other tendons, the retinacula or pulleys. Snapping can occur due to instability caused by rupture of the retinaculum, conflict between a thickened retinaculum and a bone prominence or due to an abnormal position of the tendon. Instability can occur due to insufficient ability of the retinaculum to keep the tendons in the bone groove or its failure to hold the tendons applied to the bone. The technique for evidencing conflicts, snapping and instability of the tendons is very demanding because it requires a thorough knowledge of the US appearance and dynamic maneuvers. However, at the present time US examination completed with dynamic maneuvers is the investigation of choice for evidencing these disorders and providing the clinicians with the necessary information.
Fantino, Olivier; Borne, J.; Bordet, Bertrand
The posterior tibial tendon transfer through the interosseous membrane, as popularized by Watkins in 1954, is a procedure for treating reducible eversion and dorsiflexory paresis used by lower extremity foot and ankle surgeons. The posterior tibial tendon has been transferred to various locations on the midfoot for equinus and equinovarus deformities. Dorsiflexory paresis is a common symptom in equinovarus deformity, clubfoot deformity, Charcot-Marie-Tooth disease, leprosy, mononeuropathy, trauma to the common peroneal nerve, cerebrovascular accident, and Duchenne's muscular dystrophy. The main difficulty with this procedure, often discussed by surgeons, is inadequate tendon length, making anchoring to the cuneiforms or cuboid difficult. The goal of our cadaveric study was threefold. First, we sought to determine whether the tendon length is sufficient when transferring the posterior tibial tendon to the dorsum of the foot through the interosseous membrane for a dynamic or a static transfer. Second, we wished to describe the surgical technique designed to obtain the maximal length. Finally, we sought to discuss the strategies used when the tendon length for transfer is insufficient. PMID:23369302
Pappas, Alexander J; Haffner, Kyle E; Mendicino, Samuel S
We report on 7 cases of partial rupture of the distal biceps tendon. The mean patient age was 52 years (range, 38-58 years). There were 5 men and 2 women. The dominant arm was affected in all 7 patients. Pain was the chief complaint in all patients. Immobilization and physiotherapy were attempted in all patients, and 4 had at least
Dimitris G. Vardakas; Douglas S. Musgrave; Sokratis E. Varitimidis; Felix Goebel; Dean G. Sotereanos
The treatment of pectoralis major tendon ruptures has been the subject of much debate. The classical history of the injury is forced abduction and external rotation. The cases of two patients (an amateur rugby union player and a recreational snowboarder) are reported. The diagnosis was made by clinical examination in both patients, and both were operated on more than two
J F Quinlan; M Molloy; B J Hurson
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.
Thaker, Hatim; Sharma, Arun K.
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
Traumatic dislocation of the peroneal tendons is an often unrecognized injury which has been reported to occur most commonly during snow skiing. The strength of the peroneal retinaculum is exceeded during resist ance to violent passive dorsiflexion or to inversion stress. Pain, swelling, and ecchymosis may hinder early diagnosis; however, intense retromalleolar pain on ac tive eversion is a specific,
Scott R. Arrowsmith; Lamar L. Fleming; Fred L. Allman
To decelerate the body and limbs, muscles lengthen actively to dissipate energy. During rapid energy-dissipating events, tendons buffer the work done on muscle by storing elastic energy temporarily, then releasing this energy to do work on the muscle. This elastic mechanism may reduce the risk of muscle damage by reducing peak forces and lengthening rates of active muscle. PMID:23873133
Roberts, Thomas J; Konow, Nicolai
The tail tendons from wallabies ( Macropus rufogriseus) suffer creep rupture at stresses of 10 MPa or above, whereas their yield stress in a dynamic test is about 144 MPa. At stresses between 20 and 80 MPa, the time-to- rupture decreases exponentially with stress, but at 10 MPa, the lifetime is well above this exponential. For comparison, the stress on
XIAO TONG WANG; ROBERT F. KER
Background Tendons function to transmit loads from muscle to move and stabilize joints and absorb impacts. Functionality of lacerated tendons is diminished, however clinical practice often considers surgical repair only after 50% or more of the tendon is lacerated, the “50% rule.” Few studies provide mechanical insight into the “50% rule.” Method of Approach In this study cyclic and static stress relaxation tests were performed on porcine flexor tendons before and after a 0.5, 1.0, 2.0, or 2.75mm deep transverse, mid-substance laceration. Elastic and viscoelastic properties, such as maximum stress, change in stress throughout each test, and stiffness, were measured and compared pre- and post-laceration. Results Nominal stress and stiffness parameters decreased, albeit disproportionately in magnitude, with increasing percent loss of cross-sectional area. Conversely, mean stress at the residual area (determined using remaining intact area at the laceration cross-section) exhibited a marked increase in stress concentration beginning at 47.2% laceration using both specified load and constant strain analyses. Conclusions The marked increase in stress concentration beginning near 50% laceration provides mechanical insight into the “50% rule.” Additionally, a drastic decrease in viscoelastic stress parameters after only an 8.2% laceration suggests that time-dependent mechanisms protecting tissues during impact loadings are highly compromised regardless of laceration size.
Kondratko, Jaclyn; Duenwald-Kuehl, Sarah; Lakes, Roderic; Vanderby, Ray
The flexor hallucis longus is the most common site of lower extremity tendon disorders in ballet dancers. Reduced vascularity is an important factor contributing to tendon degeneration and rupture under strain. A study was conducted on the vascular pattern of the human flexor hallucis longus tendon with injection techniques and immunohistochemically by using antibodies against laminin. Blood supply arose from the posterior tibial and the medial plantar artery. Peritendinous blood vessels penetrated the tendon and anastomosed with a longitudinally oriented intratendinous network. Injection specimens and immunohistochemistry revealed one avascular zone in which the tendon passed behind the talus and a second in which the tendon wrapped around the first metatarsal head. These are the most typical areas for tendon degeneration and rupture. PMID:12956563
Petersen, Wolf; Pufe, Thomas; Zantop, Thore; Paulsen, Friedrich
The profundus tendons of young adult chickens have been used to study flexor tendon healing within the digital sheath. Histological observation has shown that the preserved digital sheath prevented the tendon healing with adhesions and that the epitendon played a leading role in the process of tendon repair. Muscle tension must be removed from the sutured site for tendon repair
Yukuo Tokita; Akio Yamaya; Yoshiyasu Ito; Toshiyuki Fukuoka; Kenichiro Uchinishi; Yutaka Yabe
The molecules involved in vertebrate tendon formation during development remain largely unknown. To date, only two DNA-binding proteins have been identified as being involved in vertebrate tendon formation, the basic helix-loop-helix transcription factor Scleraxis and, recently, the Mohawk homeobox gene. We investigated the involvement of the early growth response transcription factors Egr1 and Egr2 in vertebrate tendon formation. We established that Egr1 and Egr2 expression in tendon cells was correlated with the increase of collagen expression during tendon cell differentiation in embryonic limbs. Vertebrate tendon differentiation relies on a muscle-derived FGF (fibroblast growth factor) signal. FGF4 was able to activate the expression of Egr genes and that of the tendon-associated collagens in chick limbs. Egr gene misexpression experiments using the chick model allowed us to establish that either Egr gene has the ability to induce de novo expression of the reference tendon marker scleraxis, the main tendon collagen Col1a1, and other tendon-associated collagens Col3a1, Col5a1, Col12a1, and Col14a1. Mouse mutants for Egr1 or Egr2 displayed reduced amounts of Col1a1 transcripts and a decrease in the number of collagen fibrils in embryonic tendons. Moreover, EGR1 and EGR2 trans-activated the mouse Col1a1 proximal promoter and were recruited to the tendon regulatory regions of this promoter. These results identify EGRs as novel DNA-binding proteins involved in vertebrate tendon differentiation by regulating type I collagen production.
Lejard, Veronique; Blais, Frederic; Guerquin, Marie-Justine; Bonnet, Aline; Bonnin, Marie-Ange; Havis, Emmanuelle; Malbouyres, Maryline; Bidaud, Christelle Bonod; Maro, Geraldine; Gilardi-Hebenstreit, Pascale; Rossert, Jerome; Ruggiero, Florence; Duprez, Delphine
The molecules involved in vertebrate tendon formation during development remain largely unknown. To date, only two DNA-binding proteins have been identified as being involved in vertebrate tendon formation, the basic helix-loop-helix transcription factor Scleraxis and, recently, the Mohawk homeobox gene. We investigated the involvement of the early growth response transcription factors Egr1 and Egr2 in vertebrate tendon formation. We established that Egr1 and Egr2 expression in tendon cells was correlated with the increase of collagen expression during tendon cell differentiation in embryonic limbs. Vertebrate tendon differentiation relies on a muscle-derived FGF (fibroblast growth factor) signal. FGF4 was able to activate the expression of Egr genes and that of the tendon-associated collagens in chick limbs. Egr gene misexpression experiments using the chick model allowed us to establish that either Egr gene has the ability to induce de novo expression of the reference tendon marker scleraxis, the main tendon collagen Col1a1, and other tendon-associated collagens Col3a1, Col5a1, Col12a1, and Col14a1. Mouse mutants for Egr1 or Egr2 displayed reduced amounts of Col1a1 transcripts and a decrease in the number of collagen fibrils in embryonic tendons. Moreover, EGR1 and EGR2 trans-activated the mouse Col1a1 proximal promoter and were recruited to the tendon regulatory regions of this promoter. These results identify EGRs as novel DNA-binding proteins involved in vertebrate tendon differentiation by regulating type I collagen production. PMID:21173153
Lejard, Véronique; Blais, Frédéric; Guerquin, Marie-Justine; Bonnet, Aline; Bonnin, Marie-Ange; Havis, Emmanuelle; Malbouyres, Maryline; Bidaud, Christelle Bonod; Maro, Géraldine; Gilardi-Hebenstreit, Pascale; Rossert, Jérome; Ruggiero, Florence; Duprez, Delphine
The aim of this study was to investigate the association between foot type and the morphometry of selected muscles and tendons of the lower limb. Sixty-one healthy participants (31 male, 30 female; aged 27.1?±?8.8 years) underwent gray-scale musculoskeletal ultrasound examination to determine the anterior-posterior (AP) thickness of tibialis anterior, tibialis posterior, and peroneus longus muscles and tendons as well as the Achilles tendon. Foot type was classified based on arch height and footprint measurements. Potentially confounding variables (height, weight, hip and waist circumference, rearfoot and ankle joint range of motion, and levels of physical activity) were also measured. Multiple linear regression models were used to determine the association between foot type with muscle and tendon morphometry accounting for potentially confounding variables. Foot type was significantly and independently associated with AP thickness of the tibialis anterior tendon, peroneus longus muscle, and Achilles tendon, accounting for approximately 7% to 16% of the variation. Flat-arched feet were associated with a thicker tibialis anterior tendon, a thicker peroneus longus muscle, and a thinner Achilles tendon. Foot type is associated with morphometry of tendons that control sagittal plane motion of the rearfoot; and the peroneus longus muscle that controls frontal plane motion of the rearfoot. These findings may be related to differences in tendon loading during gait. PMID:23301865
Murley, G S; Tan, J M; Edwards, R M; De Luca, J; Munteanu, S E; Cook, J L
Background: Donor muscles are often highly stretched in tendon transfer surgery. Despite literature reports that showed adaptation of the serial sarcomere number to moderate stretch, little is known regarding adaptation to stretch outside of the physiological range (commonly seen in clinical tendon transfer). This study was performed to evaluate muscle-tendon-unit adaptation to tendon transfer surgery in an animal model. Methods: Thirty-seven male New Zealand White rabbits were used for muscle analysis, and twenty-five of those rabbits were also used for biological analysis of the tendons after the experiment. The extensor digitorum muscle of the second toe was transferred at a specific sarcomere length of 3.7 ?m, chosen to be near the end of the descending limb of the rabbit sarcomere length-tension curve. Animals were killed at five time points, at which complete muscle architectural analysis as well as measurements of tendon dimension, tendon water content, and tendon cytokine transcript levels were performed. Results: As expected, a rapid increase in the serial sarcomere number (mean and standard error of the mean, 4658 ± 154 in the transferred muscle compared with 3609 ± 80 in the control muscle) was found one week after the surgery. From this time point until eight weeks, this increased serial sarcomere number paradoxically decreased, while the sarcomere length remained constant. Eventually, at eight weeks, it reached the same value (3749 ± 83) as that in the control muscle (3767 ± 61). Tendon adaptation was delayed relative to muscle adaptation, but it was no less dramatic. Tendon length increased by 1.43 ± 0.74 mm over the eight-week time period, corresponding to a strain of 15.55% ± 4.08%. Conclusions: To our knowledge, this is the first report of biphasic adaptation of the serial sarcomere number followed by tendon adaptation, and it indicates that muscle adapts more quickly than tendon does. Taken together, these results illustrate a complex and unique interaction between muscles and tendons that occurs during adaptation to stretching during tendon transfer. Clinical Relevance: Understanding the time course of muscle-tendon-unit adaptation can provide surgeons with information to guide postoperative care following tendon transfers as well as guidelines for tensioning muscles during tendon transfer.
Takahashi, Mitsuhiko; Ward, Samuel R.; Marchuk, Linda L.; Frank, Cyril B.; Lieber, Richard L.
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.
Extensor mechanism injuries constitute a major cause of anterior knee pain in the elite athlete. Sonography and magnetic resonance imaging (MRI) are the imaging methods of choice when assessing the infrapatellar tendon. A comprehensive imaging review of infrapatellar tendon normal anatomy, tendinopathy, and partial/full-thickness tendon tears is provided. The value of imaging the infrapatellar tendon in clinical practice, including whether sonography can predict symptoms in asymptomatic athletes, is discussed. Acute avulsion fractures, including periosteal sleeve avulsion, and chronic avulsion injuries, including Sinding-Larsen-Johansson and Osgood-Schlatter syndromes, are shown. Mimics of infrapatellar tendon pathology, including infrapatellar plica injury, patellar tendon-lateral femoral condyle friction syndrome, and Hoffa's syndrome, are illustrated. PMID:16784942
Peace, K A L; Lee, J C; Healy, J
Certain similarities can clearly be appreciated between Achilles and patellar tendon ruptures. Both are strong tendons that transmit force bridging at least one joint of the lower limb. When healthy, both require massive forces to be disrupted, and both can be weakened through certain systemic disease processes, steroids, and fluoroquinones. Both allow for a variety of innovative management possibilities that ultimately lend themselves to individual surgical preference. We feel that, although surgical management plays an important role in restoring continuity in knee extension and in plantar flexion, functional outcome inevitably relies on patient motivation and a well-established physiotherapy regime. Sports physicians should be able to identify both conditions early in their presentation, but still hold a high index of suspicion for these problems in athletes who have an acute exacerbation of ongoing tendinopathy. PMID:14560546
Maffulli, Nicola; Wong, Jason
During the period 1987-91, 153 cases of total Achilles tendon rupture were diagnosed in the city of Malmo (population 230,000). Almost two thirds were caused by sporting activities, notably badminton. Ruptures caused by nonsports injuries were found in older subjects. Compared to the age-specific incidence in 1950-73, a marked increase in both sports and nonsports injuries was found and patients in the latter group were older than in the former period. Patients with Achilles tendon ruptures can be classified into two subgroups with partly different etiologies: young or middle-aged athletes and older non-athletic persons. The increase in the former group is mostly explained by increased participation in recreational sports; the cause of increase in the latter group is unknown. PMID:8948254
Möller, A; Astron, M; Westlin, N
...of Prestressed Concrete Containment Structures With Grouted Tendons AGENCY: Nuclear...of Prestressed Concrete Containment Structures with Grouted Tendons.'' This guide...for prestressed concrete containment structures with grouted tendons. ADDRESSES:...
Recurrent dynamic and structural deformities following clubfoot surgery are commonly due to residual muscle imbalance from\\u000a a strong tibialis anterior muscle and weak antagonists. We asked whether subcutaneous tibialis anterior tendon transfer effectively\\u000a treated recurrent deformities following clubfoot surgery and whether the presence of structural deformities influenced the\\u000a outcome. The patients were divided into two groups: Group I, dynamic supination
George H. Thompson; Harry A. Hoyen; Tracey Barthel
Wallaby tail tendons fail after repeated application of stresses much lower than would be needed to break them in a single pull. We show that this a fatigue phenomenon, distinct from the creep rupture that occurs after prolonged application of a constant stress. The two phenomena are disctinguished by experiments in which tensile stress is cycled at different frequencies, ranging from 1 to 50 Hz. PMID:9244805
Wang, X T; Ker, R F; Alexander, R M
The surface of soft tendon tissue has been modified using calcium phosphate in order for the tendon to directly connect with hard bone and reconstruct an injured ligament. Calcium phosphate was coated onto the tendon in a soaking process using alternating a CaCl2 (200 mM) and a Na2HPO4 (120 mM) solution. According to SEM\\/EDX observations, calcium phosphate was formed, not
I. Yamaguchi; T. Kogure; M. Sakane; S. Tanaka; A. Osaka; J. Tanaka
De Zee, M., F. Bojsen-Møller, and M. Voigt. Dynamic viscoelastic behavior of lower extremity tendons during sim- ulated running. J Appl Physiol 89: 1352-1359, 2000.—The aim of this project was to see whether the tendon would show creep during long-term dynamic loading (here referred to as dynamic creep). Pig tendons were loaded by a material- testing machine with a human
M. DE ZEE; F. BOJSEN-MØLLER; M. VOIGT
Tendons are composed of longitudinally aligned collagen fibrils arranged in bundles with an undulating pattern, called crimp.\\u000a The crimp structure is established during embryonic development and plays a vital role in the mechanical behaviour of tendon,\\u000a acting as a shock-absorber during loading. However, the mechanism of crimp formation is unknown, partly because of the difficulties\\u000a of studying tendon development in
Andreas Herchenhan; Nicholas S. Kalson; David F. Holmes; Patrick Hill; Karl E. Kadler; Lee Margetts
. The purpose of this study was to investigate the differences in the viscoelastic properties of human tendon structures (tendon\\u000a and aponeurosis) in the medial gastrocnemius muscle between men (n=16) and women (n=13). The elongation of the tendon and aponeurosis of the medial gastrocnemius muscle was measured directly by ultrasonography,\\u000a while the subjects performed ramp isometric plantar flexion up to
Keitaro Kubo; Hiroaki Kanehisa; Tetsuo Fukunaga
Moment arm, muscle architecture, and tendon compliance in cadaveric human forearms were determined and used to model the wrist torque-joint angle relation (i.e. wrist torque profile). Instantaneous moment arms were calculated by differentiating tendon excursion with respect to joint rotation. Maximum isometric tension of each wrist muscle-tendon unit was predicted based on muscle physiological cross-sectional area. Muscle forces were subsequently
G. J. Loren; S. D. Shoemaker; T. J. Burkholder; M. D. Jacobson; J. Fridén; R. L. Lieber
Spontaneous bilateral rupture of Achilles tendon is rare. Rupture of the Achilles tendon has been described in patients on oral corticosteroid therapy. The sudden dorsiflexion of the plantar-flexed foot is the usual mechanism of injury. Spontaneous bilateral rupture is common in the degenerated tendon, which is often seen in patients with long-term corticosteroid therapy. This case is unusual because the patient has never taken steroids. We discuss the mechanism of injury and other probable causes. PMID:16131683
Rao, S K; Navadgi, B C; Vasdev, A
Background: The 1-incision and 2-incision techniques are commonly used methods to repair a distal biceps rupture, and they differ in the location of reinsertion of tendon into bone.Hypothesis: The native distal biceps brachii tendon inserts on the posterior-ulnar aspect of the bicipital tuberosity, which functions as a cam, increasing the tendon's moment arm during its principal action of forearm supination.
Jon Henry; Jeff Feinblatt; Christopher C. Kaeding; James Latshaw; Alan Litsky; Roman Sibel; Julie A. Stephens; Grant L. Jones
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.
Melvin, Alan; Litsky, Alan; Mayerson, Joel; Witte, David; Melvin, David; Juncosa-Melvin, Natalia
Retropharyngeal calcific tendonitis (RCT) is an uncommon, self-limiting condition that is often omitted in the differential diagnosis of a retropharyngeal fluid collection. This condition mimics a retropharyngeal abscess and should be considered when evaluating a fluid collection in the retropharyngeal space. Although calcific tendonitis at other sites has been well described in the medical literature, it appears that this entity has been underreported in the otolaryngology literature where only a few case reports have been identified. Presumably, the actual incidence is higher than the reported incidence, due to lack of familiarity with this disorder. As an otolaryngologist's scope of practice includes the managements of retropharyngeal lesions, it is important for the otolaryngologist to recognize the presentation of acute RCT and be familiar with appropriate treatment strategies. Retropharyngeal calcific tendonitis presents with neck pain, limitation of neck range of motion and includes inflammation, calcifications, and a sterile effusion within the longus colli muscle. Treatment is medical with nonsteroidal anti-inflammatory medications. RCT does not require surgical treatment, and an accurate diagnosis can prevent unnecessary attempts at operative drainage. In this study, we discuss two cases of RCT, summarize the salient features in diagnosis, including key radiologic features, discuss treatment options, and review the literature.
Surgical repair is the most reliable method of restoring flexion and supination strength of the elbow and forearm after acute rupture of the distal biceps tendon. Although there may be small measurable deficits in power, endurance, and terminal forearm rotation when carefully evaluated, most of the patients regain near normal upper extremity motion and function and can return to preinjury activities. There are currently 2 basic surgical approaches for distal biceps tendon repair, using 1 anterior incision or using 1 anterior and 1 lateral incision. Anterior repair alone has the advantage of a minimal risk of heterotopic bone formation, but carries a greater chance of injury to the posterior interosseous nerve. In turn, the 2-incision technique markedly diminishes the risk of radial nerve palsy, but is associated with a greater likelihood of heterotopic bone formation limiting forearm rotation. Rerupture of the distal biceps tendon after repair is uncommon with either technique, and the risk of all complications seems to increase with a delay in surgical intervention after rupture. When motion limiting heterotopic ossification does occur, surgical resection can proceed when the process becomes mature as defined by plain radiographs. Fortunately, functional forearm motion can be commonly restored in these cases with careful attention to surgical details and postoperative rehabilitation. PMID:18703974
Cohen, Mark S
This study aims to verify the effects of AsGa Laser in the scarring of tendon lesion in rats with low nourishment condition and to analyze the ideal light density by means of histopathologic findings highlighted by light microscopy. After the proposed nutritional condition was verified the animals were divided into 3 groups denominated as follows: GI control group, GII laser 1 J/sq.cm. and GIII laser 4 J/sq.cm. The lesions were induced by means of routine surgical process for tendon exposure: There was a crushing process with Allis pincers followed by saturated incision. The data obtained in relation to the amount of macrophage, leukocyte, fibroblast, vessel neoformation, fibrosis and collagen were submitted to parametric statistic procedures of variance analysis and "Tukey" Test and the result obtained was p < 0,05. According to the obtained results it can be concluded that low power laser therapy proved to be efficient in tendon repairing even though the animals suffered from malnutrition as well as the 1 J energy density proved to be more efficient in this case.
Carvalho, P. T. C.; Batista, Cheila O. C.; Fabíola, C.
The tail tendons from wallabies (Macropus rufogriseus) suffer creep rupture at stresses of 10 MPa or above, whereas their yield stress in a dynamic test is about 144 MPa. At stresses between 20 and 80 MPa, the time-to-rupture decreases exponentially with stress, but at 10 MPa, the lifetime is well above this exponential. For comparison, the stress on a wallaby tail tendon, when its muscle contracts isometrically, is about 13.5 MPa. Creep lifetime depends sharply on temperature and on specimen length, in contrast to strength and stiffness as observed in dynamic tests. The creep curve (strain versus time) can be considered as a combination of primary creep (decelerating strain) and tertiary creep (accelerating strain). Primary creep is non-damaging, but tertiary creep is accompanied by accumulating damage, with loss of stiffness and strength. 'Damage' is quantitatively defined as the fractional loss of stiffness. A creep theory is developed in which the whole of tertiary creep and, in particular, the creep lifetime are predicted from measurements made at the onset of creep, when the tendon is undamaged. This theory is based on a 'damage hypothesis', which can be stated as: damaged material no longer contributes to stiffness and strength, whereas intact material makes its full contribution to both. PMID:9244804
Wang, X T; Ker, R F
Several techniques are available for the correction of hallux abducto valgus, but none of them provide a direct and mechanically sound attachment to the lateral aspect of the first metatarsal head. The author describes adductor hallucis tendon ligamentation, a technique that produces direct stability between the first and second metatarsals. This stability is achieved by transferring the adductor hallucis tendon. The tendon is attached to the distal aspects of the first and second metatarsals. Adductor hallucis tendon ligamentation is a dependable option in the correction of hallux abducto valgus, providing an excellent outcome with good long-term results. PMID:12381801
Shrum, Dale G
Abstract Ultrasound imaging was used to measure the length of muscle fascicles in human gastrocnemius muscles while the muscle was passively lengthened and shortened by moving the ankle. In some subjects the muscle belly ‘buckled’ at short lengths. When the gastrocnemius muscle–tendon unit was passively lengthened from its shortest in vivo length by dorsiflexing the ankle, increases in muscle–tendon length were not initially accompanied by increases in muscle fascicle lengths (fascicle length remained constant), indicating muscle fascicles were slack at short muscle–tendon lengths. The muscle–tendon length at which slack is taken up differs among fascicles: some fascicles begin to lengthen at very short muscle–tendon lengths whereas other fascicles remain slack over a large range of muscle–tendon lengths. This suggests muscle fascicles are progressively ‘recruited’ and contribute sequentially to muscle–tendon stiffness during passive lengthening of the muscle–tendon unit. Even above their slack lengths muscle fascicles contribute only a small part (30%) of the total change in muscle–tendon length. The contribution of muscle fascicles to muscle–tendon length increases with muscle length. The novelty of this work is that it reveals a previously unrecognised phenomenon (buckling at short lengths), posits a new mechanism of passive mechanical properties of muscle (recruitment of muscle fascicles), and confirms with high-resolution measurements that the passive compliance of human gastrocnemius muscle–tendon units is due largely to the tendon. It would be interesting to investigate if adaptations of passive properties of muscles are associated with changes in the distribution of muscle lengths at which fascicles fall slack.
Herbert, Robert D; Clarke, Jillian; Kwah, Li Khim; Diong, Joanna; Martin, Josh; Clarke, Elizabeth C; Bilston, Lynne E; Gandevia, Simon C
The formation of the musculoskeletal system represents an intricate process of tissue assembly involving heterotypic inductive interactions between tendons, muscles and cartilage. An essential component of all musculoskeletal systems is the anchoring of the force-generating muscles to the solid support of the organism: the skeleton in vertebrates and the exoskeleton in invertebrates. Here, we discuss recent findings that illuminate musculoskeletal assembly in the vertebrate embryo, findings that emphasize the reciprocal interactions between the forming tendons, muscle and cartilage tissues. We also compare these events with those of the corresponding system in the Drosophila embryo, highlighting distinct and common pathways that promote efficient locomotion while preserving the form of the organism.
Schweitzer, Ronen; Zelzer, Elazar; Volk, Talila
In the surgical repair of Achilles tendon ruptures, suturing is standard, although fibrin glue also has been used for repair since the 1980s. Augmentation with the plantaris longus tendon is also a popular technique; however, no study has yet compared the outcome of augmented versus only glued repair of ruptured Achilles tendons. This study compares the long-term results of surgical repair of Achilles tendon rupture with fibrin glue versus fibrin glue augmented with the plantaris longus tendon. Forty patients who had undergone Achilles tendon repair with fibrin glue took part in a follow-up examination after an average of 11.5 years. The fibrin group consisted of 16 patients and the fibrin glue augmented with plantaris longus tendon group consisted of 15 patients. The modified Thermann score (adapted from Weber) and results of an isokinetic force measurement were the same in both groups, whereas complications in the 2 groups also did not differ. We conclude that augmentation with the plantaris longus tendon is not necessary when operatively treating acute ruptured Achilles tendons with fibrin glue. Level of Clinical Evidence: 2. PMID:19577719
Hohendorff, Bernd; Siepen, Wolf; Staub, Lukas
The authors present a new non-intrusive experimental procedure based on laser techniques for the measurement of mechanical properties of tendons. The procedure is based on the measurement of the first resonance frequency of the tendon by laser Doppler vibrometry during in vitro tensile experiments, with the final aim of establishing a measurement procedure to perform the mechanical characterization of tendons by extracting parameters such as the resonance frequency, also achievable during in vivo investigation. The experimental procedure is reported, taking into account the need to simulate the physiological conditions of the Achilles tendon, and the measurement technique used for the non-invasive determination of tendon cross-sectional area during tensile vibration tests at different load levels is described. The test procedure is based on a tensile machine, which measures longitudinal tendons undergoing controlled load conditions. Cross-sectional area is measured using a new non-contact procedure for the measurement of tendon perimeter (repeatability of 99% and accuracy of 2%). For each loading condition, vibration resonance frequency and damping, cross-sectional area and tensile force are measured, allowing thus a mechanical characterization of the tendon. Tendon stress-strain curves are reported. Stress-strain curves have been correlated to the first vibration resonance frequency and damping of the tendon measured using a single-point laser Doppler vibrometer. Moreover, experimental results have been compared with a theoretical model of a vibrating cord showing discrepancies. In vitro tests are reported, demonstrating the validity of the method for the comparison of different aged rabbit tendons.
Revel, Gian Marco; Scalise, Alessandro; Scalise, Lorenzo
Zones of hypovascularity are thought to exist in several tendons of the shoulder, contributing to localized tendon weakness and subsequent rupture in clinical practice. Although these zones have been demonstrated in many frequently ruptured tendons, the existence of a similar area in the often ruptured long head of biceps (LHB) tendon is largely unknown. Twenty cadaveric upper limb specimens were dissected after injection with either a radio-opaque lead oxide/milk mixture or India ink, followed by histological sectioning of the tendons. The LHB tendon was consistently supplied via its osteotendinous and musculotendinous junctions by branches of the thoracoacromial and brachial arteries respectively. In two specimens, additional branches from the anterior circumflex humeral artery travelling in a mesotenon vascularized the midsection of tendon. These source arteries divided the LHB tendon into either two or three vascular territories, depending upon the presence of the mesotenon-derived vascular supply. A zone of hypovascularity was consistently found in the region of the LHB tendon most frequently prone to rupture. This zone covered an area 1.2-3 cm from the tendon origin, extending from midway through the glenohumeral joint to the proximal inter-tubercular groove. This hypovascular region occurred on the border of two adjacent vascular territories, where reduced caliber choke vessels provide limited arterial supply. While it is probable that the limited arterial supply contributes to the susceptibility of this area to rupture, similar to other tendons the true pathogenesis is likely to be a combination of both vascular and mechanical factors. PMID:20821403
Cheng, Nicholas Mauwei; Pan, Wei-Ren; Vally, Fatima; Le Roux, Cara Michelle; Richardson, Martin Donald
A case of post-traumatic rupture of the common extensor tendon without associated fracture is reported. The extensor digitorum communis tendon to the middle finger was frayed by the distal edge of the extensor retinaculum at the fourth dorsal compartment.
H. TAKAMI; S. TAKAHASHI; H. INANAMI
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.
Konow, Nicolai; Azizi, Emanuel; Roberts, Thomas J.
The hamstring tendon autograft is one of the most commonly used graft choices in Anterior cruciate ligament (ACL) reconstruction. There are conflicting results regarding postoperative hamstring strength deficits in patients who have had a hamstring graft. The semitendinosus tendon has been shown to regenerate after harvesting for ACL autograft, suggesting that the muscle has the potential to regain normal function. However, no studies have been performed to define the microstructural changes that occur in the semitendinosus muscle after tendon resection. In this study, we hypothesized that fatty infiltration of the semitendinosus muscle after tendon harvest in New Zealand White rabbits increases postoperatively and remains constant or increases during the first year of repair. The semitendinosus tendon was unilaterally detached and harvested from 15 rabbits. Five rabbits were sacrificed at 3-, 6-, and 12-month intervals, and the semitendinosus muscle-tendon units were analyzed. The contralateral unoperated limb served as the control. The gross tendon and muscle dimensions and histologic percentage of fatty infiltration were measured. We found no significant difference in fatty infiltration at any time point between the control muscle and test specimens and that there was no progression of fatty infiltration over time. If these results hold true in humans, natural repair of the hamstring muscle following tendon harvest during ACL autograft reconstruction is not inhibited by fatty infiltration. PMID:23625808
Vourazeris, Jason D; Lawless, Matthew W; Markert, Ronald J; Stills, Harold F; Boivin, Gregory P
We report on a 13-year-old boy who was found to have a fibroma of the tendon sheath associated with the patellar tendon and\\u000a within Hoffa’s fat pad of the knee. This benign tumor has never been described in this location previously. The MRI characteristics\\u000a are correlated with the histologic findings.
John Hur; Timothy A. Damron; Andrei I. Vermont; Sharad C. Mathur
BackgroundDifferences in mechanical loading of the patellar tendon have been suggested as a reason for varying effects in rehabilitation of patellar tendinopathy using different eccentric squat exercises and devices. The aim was to characterize the magnitude and pattern of mechanical load at the knee and on the patellar tendon during four types of eccentric squat.
A. Frohm; K. Halvorsen; A. Thorstensson
We report on a rare case of fibroma of tendon sheath causing triggering of the right middle finger in an 86-year-old woman. Magnetic resonance imaging revealed a lesion attached to the flexor tendon sheath. Surgical excision was curative.
Akiko Nakagawa; Tetsuji Yamamoto; Toshihiro Akisue; Takashi Marui; Toshiaki Hitora
In this study, a numerical model based on the finite element method incorporating an arc-length solution algorithm for materially and geometrically nonlinear analysis of concrete beams prestressed with external tendons is established. The second-order effects are taken into account. The effects of external tendons are expressed by equivalent nodal loads of the beam element and therefore analysis of externally prestressed
Tie-jiong Lou; Yi-qiang Xiang
Changes in the macromolecular orientation and metachromasy of glycosaminoglycans (GAG) in newly synthesized and assembled collagen fibers in rat Achilles tendon after tendon excision were investigated in toluidine blue (TB)-stained preparations, based in the selective absorption of polarized light (= linear dichroism, LD) and of absorption of unpolarized light in situ. Extrinsic LD was observed microspectrophotometrically from the early phases of tendon repair onwards, although the absorption peaks in both parallel and perpendicular directions with respect to the plane of polarized light and the long axis of the collagen fibers occurred at the same wavelength, and thus differed from the pattern situation in normal adult controls. Compared to normal adult tendons, the pattern of LD in newly synthesized and assembled fibers was still not fully attained 110 days after surgical tendon removal. This incomplete recovery possibly reflected the influence of aging during the repair process. There was no correlation between LD and metachromasy. The highest absorption values for metachromatic staining occurred on the 7th day after tendon removal, at a time when LD was not intense. Treatment with hyaluronidase showed that the LD in the early stages of tendon repair was mostly due to hyaluronate whereas the LD in the later stages was due to chondroitin sulfates. The changes in LD during Achilles tendon repair were attributed to gradual modifications in the composition and macromolecular orientation of GAGs relative to the long axis of the collagen fibers. PMID:12899449
Mello, M L S; de Campos Vidal, B
Biomechanical properties of human wrist tendons were measured under loads predicted to be experienced by those tendons under physiological conditions. This was accomplished by measuring the architectural properties of the five prime wrist movers—extensors carpi radialis brevis (ECRB), extensor carpi radialis longus (ECRL), extensor carpi ulnaris (ECU), flexor carpi radials (FCR), flexor carpi ulnaris (FCU)- and predicting their maximum tension
Gregory J. Loren; Richard L. Lieber
The moment arm of the knee-extensor mechanism is described by the moment arm of the patellar tendon calculated with respect to the screw axis of the tibia relative to the femur. The moment arm may be found once the line of action of the patellar tendon and the position and orientation of the screw axis are known. In this study,
Janet L. Krevolin; Marcus G. Pandy; John C. Pearce
Simultaneous bilateral quadriceps tendon rupture is an uncommon injury in healthy people and only a few cases have been reported in athletes. This is the first report of a patient with simultaneous bilateral quadriceps tendon rupture incurred while playing basketball. The injury was surgically repaired and the patient had a good functional outcome.
M Shah; N Jooma
Simple axisymmetric modeling of a nuclear containment building has been often employed in practice to estimate structural behavior for the axisymmetric loadings such as internal pressure. In this case, the prestressing tendons placed in the containment dome should be axisymmetrically approximated, since most dome tendons are not arranged in an axisymmetric manner. Some procedures are proposed that can realistically implement
Se-Jin Jeon; Chul-Hun Chung
Previous descriptions of the pattern of communication between the digital flexor tendon sheaths have been largely based on imaging studies. An anatomic study on 12 cadaveric hands was conducted using water soluble dye and directly observed patterns of communication between the digital flexor tendon sheaths and the radial and ulnar bursae. Four out of twelve specimens (33%) demonstrated a communication
J. M. FUSSEY; K. F. CHIN; N. GOGI; S. GELLA; S. C. DESHMUKH
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.
Zhao, Heng; Ren, Yupeng; Wu, Yi-Ning; Liu, Shu Q.; Zhang, Li-Qun
Tendons are composed of fibroblasts and collagen fibrils. The fibrils are organized uniaxially and grouped together into fibers. Collagen VI is a non-fibrillar collagen expressed in developing and adult tendons. Human collagen VI mutations result in muscular dystrophy, joint hyperlaxity and contractures. The purpose of this study is to determine the functional roles of collagen VI in tendon matrix assembly. During tendon development, collagen VI was expressed throughout the extracellular matrix, but enriched around fibroblasts and their processes. To analyze the functional roles of collagen VI a mouse model with a targeted inactivation of Col6a1 gene was utilized. Ultrastructural analysis of Col6a1-/- versus wild type tendons demonstrated disorganized extracellular micro-domains and associated collagen fibers in the Col6a1-/- tendon. In Col6a1-/- tendons, fibril structure and diameter distribution were abnormal compared to wild type controls. The diameter distributions were shifted significantly toward the smaller diameters in Col6a1-/- tendons compared to controls. An analysis of fibril density (number/?m(2)) demonstrated a ~2.5 fold increase in the Col6a1-/- versus wild type tendons. In addition, the fibril arrangement and structure were aberrant in the peri-cellular regions of Col6a1-/- tendons with frequent very large fibrils and twisted fibrils observed restricted to this region. The biomechanical properties were analyzed in mature tendons. A significant decrease in cross-sectional area was observed. The percent relaxation, maximum load, maximum stress, stiffness and modulus were analyzed and Col6a1-/- tendons demonstrated a significant reduction in maximum load and stiffness compared to wild type tendons. An increase in matrix metalloproteinase activity was suggested in the absence of collagen VI. This suggests alterations in tenocyte expression due to disruption of cell-matrix interactions. The changes in expression may result in alterations in the peri-cellular environment. In addition, the absence of collagen VI may alter the sequestering of regulatory molecules such as leucine rich proteoglycans. These changes would result in dysfunctional regulation of tendon fibrillogenesis indirectly mediated by collagen VI. PMID:20951202
Izu, Yayoi; Ansorge, Heather L; Zhang, Guiyun; Soslowsky, Louis J; Bonaldo, Paolo; Chu, Mon-Li; Birk, David E
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.
Birch, Helen L.; Thorpe, Chavaunne T.; Rumian, Adam P.
Chronic tendon pathology is a common and often disabling condition, the causes of which remain poorly understood. The continuum model of tendon pathology was proposed to provide a model for the staging of tendon pathology and to assist clinicians in managing this often complex condition (Br. J. Sports Med., 43, 2009, 409). The model presents clinical, histological and imaging evidence for the progression of tendon pathology as a three-stage continuum: reactive tendinopathy, tendon disrepair and degenerative tendinopathy. It also provides clinical information to assist in identifying the stage of pathology, in addition to proposed treatment approaches for each stage. The usefulness of such a model is determined by its ability to incorporate and inform new and emerging research. This review examines the degree to which recent research supports or refutes the continuum model and proposes future directions for clinical and research application of the model. PMID:23837792
McCreesh, Karen; Lewis, Jeremy
Flexor tendon injuries in the hand present a real challenge in treatment. Poorly chosen or poorly executed treatment may lead to a functionless finger at best, impairing total hand function. A variety of approaches to treatment of flexor tendon injuries is available to the specially trained surgeon and a particular method is selected based on the merits of the case in question. Primary tendon repair is a viable choice under the proper conditions, while delayed primary repair allows a somewhat broader application of this technique. Flexor tendon grafting remains a very useful operation for the surgeon caring for tendon injuries of the hand. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7
Rankin, Edward A.
Bilateral simultaneous rupture of the quadriceps tendons is very rare and occurred in an 82-year-old man. This may be the fifth case to have been reported in the English literature. Only minor stress on extensor mechanisms preceded the ruptures. Interrupted mattress sutures restored muscle continuity and function. A "pull-out" wire system was not used for protection of healing muscles because adequate amount of tissue mass was available for approximation. Excellent results require intensive postoperative physical therapy. Old age of the patient should not be a deterrent to surgical treatment in carefully selected individuals. PMID:657630
Siwek, K W; Rao, J P
Heart valve repair is a biomaterial-dependent procedure, yet autogenous tissue for valvular reconstruction has to date been obtained mostly from the pericardium and fascia lata. Most clinical studies recommend valve repair as an alternative to replacement. We now put forward a hypothesis, extrapolated from hand surgery, for use of the plantaris tendon in heart valve repair. This proposal, if implemented, would increase the supply of autogenous donor tissue for valve repair, thereby enhancing the surgeon's armamentarium. The report describes a novel technique that in our judgment warrants future clinical development. (Tex Heart Inst J 2003;30:42–4)
Shuhaiber, Jeffrey H.; Shuhaiber, Hans H.
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.
Merolla, Giovanni; Paladini, Paolo; Campi, Fabrizio; Porcellini, Giuseppe
The terminology used to describe most common tendon disorders in the hand and wrist suggests that they are inflammatory in nature, although current evidence indicates that mechanical and degenerative factors are more important. Corticosteroid injections provide relief in 60% or more of cases; however, the duration of their effectiveness remains uncertain. Surgical release of the stenotic pulley or sheath is curative in well over 90% of cases; complications of surgery are rare, and relief is long-lasting. Enlightened management of these common problems demands evidence-based guidelines defining indications for surgery that will maximize outcomes and minimize costs. PMID:20438999
McAuliffe, John A
The mechanical model of a single tendon three phalanxes finger is presented. By means of the model both kinematic and dynamical behavior of the finger itself can be studied. This finger is a part of a more complex mechanical system that consists in a four finger grasping device for robots or in a five finger human hand prosthesis. A first prototype has been realized in our department in order to verify the real behavior of the model. Some results of both kinematic and dynamical behavior are presented.
Rossi, Cesare; Savino, Sergio
Complex hand injuries are those that involve significant soft-tissue loss with variable exposure of bones and/or joints, lacerated tendons, and neurovascular structures. Management of these injuries is optimally accomplished through the restoration of thin, pliable, ideally sensate tissue with reliable vascularity and a gliding surface to facilitate restoration of motion after repair. Unfortunately, optimal restoration may require complex surgical reconstruction and/or staged surgical procedures. This article presents an overview of some of the more commonly used options available to the reconstructive surgeon willing to tackle these difficult clinical cases. PMID:23660064
Carty, Matthew J; Blazar, Philip E
Tendons have uniquely high tensile strength, critical to their function to transfer force from muscle to bone. When injured, their innate healing response results in aberrant matrix organization and functional properties. Efforts to regenerate tendon are challenged by limited understanding of its normal development. Consequently, there are few known markers to assess tendon formation and parameters to design tissue engineering scaffolds. We profiled mechanical and biological properties of embryonic tendon and demonstrated functional properties of developing tendon are not wholly reflected by protein expression and tissue morphology. Using force volume-atomic force microscopy, we found that nano- and microscale tendon elastic moduli increase nonlinearly and become increasingly spatially heterogeneous during embryonic development. When we analyzed potential biochemical contributors to modulus, we found statistically significant but weak correlation between elastic modulus and collagen content, and no correlation with DNA or glycosaminoglycan content, indicating there are additional contributors to mechanical properties. To investigate collagen cross-linking as a potential contributor, we inhibited lysyl oxidase-mediated collagen cross-linking, which significantly reduced tendon elastic modulus without affecting collagen morphology or DNA, glycosaminoglycan, and collagen content. This suggests that lysyl oxidase-mediated cross-linking plays a significant role in the development of embryonic tendon functional properties and demonstrates that changes in cross-links alter mechanical properties without affecting matrix content and organization. Taken together, these data demonstrate the importance of functional markers to assess tendon development and provide a profile of tenogenic mechanical properties that may be implemented in tissue engineering scaffold design to mechanoregulate new tendon regeneration. PMID:23576745
Marturano, Joseph E; Arena, Jeffrey D; Schiller, Zachary A; Georgakoudi, Irene; Kuo, Catherine K
A tension leg platform (TLP) tendon system experiences oscillatory tensile stresses, and therefore is vulnerable to fatigue and fracture. Because design factors have significant uncertainty, a reliability analysis to quantify structural performance is appropriate. A maintenance program of periodic inspection and repair shows promise for improving system reliability and enhancing structural integrity. The performance of a TLP tendon system was
C. J. Kung; P. H. Wirsching
This is a case report of two children with congenital dislocation of the knee. They have been treated surgically with Z-lengthening of the quadriceps tendon and additional reconstruction of the quadriceps tendon with Achilles tendon allograft to fill in the remaining average 6 cm gap of the tendon. The patients were two girls, 6 and 9 years old. One of them had an operative treatment previously with a tendon lengthening procedure and it was failed and the other patient was untreated before. Preoperatively, untreated case was unable to walk. The other patient was limping. None of them was able to flex their knees beyond the neutral extension position. Postoperatively, both patients were able to walk and the knees were reduced to a range of motion of 0 degrees -95 degrees of flexion. The mean follow-up time was 20 months. PMID:16758235
Söyüncü, Yetkin; Mihçi, Ercan; Ozcanli, Haluk; Ozenci, Merter; Akyildiz, Feyyaz; Aydin, A Turan
We studied the range of appearance of asymptomatic patellar tendons and evaluated the effect of age, weight, joint effusions, and anterior cruciate ligament (ACL) tears on this tendon. One hundred and seventy-three patellar tendons in asymptomatic patients were studied at 1.5 tesla. Sagittal short and long TE images were evaluated in regard to tendon thickness, ratio of thickness of patellar
Mark E. Schweitzer; Donald G. Mitchell; Saundra M. Ehrlich
Summary An anatomical study on the blood sources and vascularity of the flexor digital tendon was conducted in the upper extremities of fresh cadavers by means of arterial injection and meticulous dissection of the transparent tendon under the microscope. According to whether or not synovial membrane surrounded the tendon, the flexor digital tendon can be divided into 2 regions: non-synovial
Z-Z Zhang; S-Z Zhong; B Sun; G-T Ho
Small tears in tendons are a common occurrence in athletes and others involved in strenuous physical activity. Natural healing in damaged tendons can result in disordered regrowth of the underlying collagen matrix of the tendon. These disordered regions are weaker than surrounding ordered regions of normal tendon and are prone to re-injury. Multiple cycles of injury and repair can lead
Robert Muratore; Tal Akabas; Isabella B. Muratore
The force and excursion within the canine digital flexor tendons were measured during passive joint manipulations that simulate those used during rehabilitation after flexor tendon repair and during active muscle contraction, simulating the active rehabilitation protocol. Tendon force was measured using a small buckle placed upon the tendon while excursion was measured using a suture marker and video analysis method.
R. L. Lieber; M. J. Silva; D. Amiel; R. H. Gelberman
Background We developed a novel technique to improve tendon-bone attachment by hybridizing calcium phosphate (CaP) with a tendon graft using an alternate soaking process. However, the long-term result with regard to the interface between the tendon graft and the bone is unclear. Methods We analyzed bone tunnel enlargement by computed tomography and histological observation of the interface and the tendon graft with and without the CaP hybridization 2 years after anterior cruciate ligament (ACL) reconstruction in goats using EndoButton and the postscrew technique (CaP, n = 4; control, n = 4). Results The tibial bone tunnel enlargement rates in the CaP group were lower than those in the control group (p < 0.05). In the CaP group, in the femoral and tibial bone tunnels at the anterior and posterior of the joint aperture site, direct insertion-like formation that contained a cartilage layer without tidemarks was more observed at the tendon-bone interface than in the control group (p < 0.05). Moreover, the gap area between the tendon graft and the bone was more observed at the femoral bone tunnel of the joint aperture site in the control group than in the CaP group (p < 0.05). The maturation of the tendon grafts determined using the ligament tissue maturation index was similar in both groups. Conclusions The CaP-hybridized tendon graft enhanced the tendon-bone healing 2 years after ACL reconstruction in goats. The use of CaP-hybridized tendon grafts can reduce the bone tunnel enlargement and gap area associated with the direct insertion-like formation in the interface near the joint.
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
Fahlström, M; Björnstig, U; Lorentzon, R
Application of a high-level decontamination or sterilisation procedure and cell removal technique to tendon allograft can reduce the concerns of disease transmission, immune reaction, and may improve remodelling of the graft after implantation. The decellularised matrix can also be used as a matrix for tendon tissue engineering. One such sterilisation factor, Peracetic acid (PAA) has the advantage of not producing harmful reaction residues. The aim of this study was to evaluate the effects of PAA treatment and a cell removal procedure on the production of tendon matrix. Human patellar tendons, thawed from frozen were treated respectively as: Group 1, control with no treatment; Group 2, sterilised with PAA (0.1 % (w/v) PAA for 3 h) Group 3, decellularised (incubation successively in hypotonic buffer, 0.1 % (w/v) sodium dodecyl sulphate, and a nuclease solution); Group 4, decellularised and PAA sterilised. Histological analysis showed that no cells were visible after the decellularisation treatment. The integrity of tendon structure was maintained after decellularisation and PAA sterilisation, however, the collagen waveform was slightly loosened. No contact cytotoxicity was found in any of the groups. Determination of de-natured collagen showed no significant increase when compared with the control. This suggested that the decellularisation and sterilisation processing procedures did not compromise the major properties of the tendon. The sterilised, decellularised tendon could be suitable for clinical use. PMID:23443409
Huang, Q; Ingham, E; Rooney, P; Kearney, J N
Flexor digitorum longus (FDL) is the primary flexor of the lateral four toes. It is a reliable source of tendon for transfer surgery. We present a case whereby a patient who required a reconstruction for adult acquired flatfoot deformity using FDL as a dynamic structure for transfer was found to have an absent FDL tendon at the time of operation, necessitating the use of flexor hallucis longus (FHL) instead. This unusual finding prompted us to investigate the frequency of absence of the FDL tendon. We reviewed our hospital MRI database of foot and ankle images specifically looking for patients with absence of this tendon. After randomization, 756 images were reviewed independently by two surgeons and a consultant musculoskeletal radiologist. No instances of an absent FDL tendon were identified. In conclusion, the frequency of absence of the FDL tendon is less than 1 in 750. Surgeons who require FDL for tendon transfer surgery need not image the foot preoperatively to anticipate the need for the use of FHL as an alternative. PMID:22334461
Magra, Merzesh; Taqvi, Syed; Cooper, Robert; Blundell, Chris M; Davies, Mark B
Debate continues over whether skeletal muscle performance and injury risk vary over the course of the menstrual cycle. Alterations in tendon properties may play a role in the potential fluctuations of both of these variables. The aim of the current study was to determine any association between menstrual cycle phase and corresponding levels of female sex hormones and tendon properties. Fifteen normally menstruating (28-32-day cycles) healthy females (age 23 +/- 1 years, mass 63.1 +/- 2.6 kg, height 1.66 +/- 0.02 m) not taking any form of hormonal contraceptive took part in this study. In vivo patellar tendon properties and associated circulating hormonal levels were assessed on 3 occasions including days 3 +/- 0.4, 13 +/- 0.2, and 21 +/- 0.3. Dynamometry, ultrasonography, electromyography, and biochemical assessment of circulating levels of estradiol and progesterone were utilized. No significant differences were seen in tendon mechanical properties among the 3 phases of the menstrual cycle (p > 0.05). Regressions were carried out and revealed that estrogen and maximal voluntary tendon force explained 17.8% (p = 0.043) of the variance in young's modulus. Our findings link estrogen to a chronic, rather than an acute, impact on tendon behavior. These findings are relevant to clinical outcomes, exercise performance, and injury risk. In terms of tendon properties, menstrual cycle phase does not necessarily need to be considered when organizing training and competition schedules. PMID:19918195
Burgess, Katherine E; Pearson, Stephen J; Onambélé, Gladys L
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?
Peroneal tendon injuries are recognized with increasing frequency to be the cause of persistent lateral ankle symptoms. The lesions are frequently found in patients with concomitant anatomical or biomechanical abnormalities, such as chronic lateral instability or cavovarus deformity. The most common mechanism involves a sudden inversion injury or repetitive activities. Three categories of injuries can be distinguished: (1) tendinitis and tenosynovitis, (2) tendon subluxation and dislocation and (3) tendon tears and ruptures. Many of these conditions respond to conservative therapy. However, when left untreated, the disorders can lead to persistent lateral ankle pain and substantial functional deficits. This is particularly true in patients with an underlying anatomical predisposition to lesions. PMID:21061115
Knupp, M; Hintermann, B
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.
Ikeda, Jun; Zhao, Chunfeng; Chen, Qingshan; Thoreson, Andrew R.; An, Kai-Nan; Amadio, Peter C.
In a previous study we found that the strength of a Kessler core suture in the flexor tendon was greater in flexor zone 2 than in zone 3. To further investigate the material properties of the flexor tendon without the influence of a locking suture configuration, we measured the ultimate strength of a simple loop suture in the flexor digitorum profundus tendon in zones 1, 2, and 3. Eight cadaver flexor digitorum profundus tendons were tested in 10 mm increments with a 3-0 polyester suture loop pull-out test in the mid-substance of the tendon. The mean strength in zones 1 and 2 (26.7 N, SD 5.6) was significantly higher than the mean strength in zone 3 (17.7 N, SD 5.4). We conclude that the difference is owing to variations of the structure of the flexor tendon in different sections of the tendon, as the suture configuration was a simple loop without a locking or grasping component. PMID:23315625
Havulinna, J; Leppänen, O V; Göransson, H
This report documents the anatomy of the lateral canthus using gross dissection, histologic examination, computed tomography, magnetic resonance imaging, and clinical measurement. Lateral canthal dissections of 16 cadaver orbits demonstrated a well-defined attachment of the tarsal plates to the orbital rim, averaging 10.6 mm in length and 10.2 mm in width at their insertion on Whitnall's tubercle, 1.5 mm behind the orbital rim and 9.7 mm inferior to the frontozygomatic suture. Histologic examination showed a band of dense fibrous tissue attached to the tarsal plates, with intermingled muscle fibers from the pretarsal orbicularis oculi muscle. A small pocket of fat was identified posterior to the orbital septum and anterior to the lateral canthal tendon. Clinical measurements of normal adults revealed 2 mm of lateral movement of the canthal angle during abduction, apparently caused by posterior fibrous attachments to the check ligament of the lateral rectus muscle. PMID:3566607
Gioia, V M; Linberg, J V; McCormick, S A
Adult acquired flatfoot deformity progresses through well defined stages as set out by Johnson and Strom. Myerson modified this classification system with the addition of a fourth, more advanced stage of the disease. This stage describes the involvement of the tibiotalar joint in addition to the hindfoot malalignment seen in stages II and III. This most advanced stage is comprised of a hindfoot valgus deformity, resulting from degeneration of the posterior tibial tendon, with associated valgus tilting of the talus within the mortise. The deformity at the tibiotalar joint may or may not be rigid. Although rigid deformities are still best treated with fusions of the ankle and hindfoot, supple tibiotalar deformity may be treated with joint sparing procedures involving reconstructive procedures of the foot and deltoid ligaments. PMID:17561206
Bluman, Eric M; Myerson, Mark S
Mechanical stimulation has been implicated as an important regulatory factor in tendon homeostasis. In this study, a custom-designed tensile loading system was used to apply controlled mechanical stimulation to isolated tendon fascicles, in order to examine the effects of 5% cyclic tensile strain at 1 Hz on cell proliferation and matrix synthesis. Sample viability and gross structural composition were maintained over a 24 h loading period. Data demonstrated no statistically significant differences in cell proliferation or glycosaminoglycan production, however, collagen synthesis was upregulated with the application of cyclic tensile strain over the 24 h period. Moreover, a greater proportion of the newly synthesised matrix was retained within the sample after loading. These data provide evidence of altered anabolic activity within tendon in response to mechanical stimuli, and suggest the importance of cyclic tensile loading for the maintenance of the collagen hierarchy within tendon.
Screen, Hazel R.C. [Medical Engineering Division and IRC in Biomedical Materials, Department of Engineering, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)]. E-mail: H.R.C.Screen@qmul.ac.uk; Shelton, Julia C. [Medical Engineering Division and IRC in Biomedical Materials, Department of Engineering, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Bader, Dan L. [Medical Engineering Division and IRC in Biomedical Materials, Department of Engineering, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Lee, David A. [Medical Engineering Division and IRC in Biomedical Materials, Department of Engineering, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)
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
Eckel, Tobin T; Nunley, James A
Objectives. (1) To develop a methodology to determine the trajectories of the digital flexor tendons using MRI. (2) To examine changes in tendon trajectories due to wrist posture, with and without pinch force. (3) To calculate the radius of curvature of the flexor tendons and note implications for contact forces on the median nerve. (4) To assess the use of
Peter J. Keir; Richard P. Wells
As the development of light-weight, small volume, and versatile manipulators has grown in the field of robotics, the need for more efficient and relevant power transmission systems in the manipulators has become increasingly apparent. It is clear that the advent of efficient, low friction, and backlash-free actuation systems promises to provide significant gains in manipulator performance. Tendon transmission has been widely used to actuate small volume and light-weight articulated manipulators, such as dextrous mechanical hands, for it permits actuators to be installed remotely from the end-effector, thus reducing the bulk and inertia of the manipulator system. Current research on such actuation systems is accomplished on the basis of specialized designs. The lack of systematic approaches has limited our scope in realizing performance of such transmission systems. Therefore, when associated with systematic methodologies, the study of tendon-driven manipulators promises to be of major importance in the field of robotics. This dissertation is concerned with four issues to enhance our use and understanding of tendon-driven manipulators. First, a systematic approach for the kinematics analysis of tendon-driven manipulators is established. A graph is used to represent the kinematic structure of tendon-driven manipulators. It is shown that the kinematic structure of tendon-driven manipulators is in every way similar to that of epicyclic gear trains. The fundamental circuit equation developed for the kinematic analysis of epicyclic gear trains can thus be applied to this type of mechanism. The displacement equation governing joint angle space and tendon space can easily be obtained. Secondly, the concept of structural isomorphism and the structural characteristics of tendon-driven manipulators are investigated. Based on the explored properties, a methodology for the enumeration of tendon-driven manipulators is developed. By applying the methodology, a class of kinematic structures having pseudo-triangular structure matrix is enumerated. Thirdly, a method for assessing the kinematic/static performance of tendon-driven manipulators is developed. Transmission ellipsoids of the manipulators are investigated. A criterion for differentiating force transmission characteristics and a procedure for identifying least maximum-tendon-force are established.
We evaluated the mechanical properties of six different circumferential tendon sutures with a variable number of suture strands. Seventy-two human cadaver flexor profundus tendons were cut and repaired using only a 6\\/0 polypropylene circumferential suture. The six running suture techniques were: Simple; Simple-locking; Lembert; Halsted; Cross-stitch; Lin-locking; using 10, 14 and 18 suture passes. The increased suture passes increased both
H. Kubota; M. Aoki; D. L. Pruitt; P. R. Manske
Objective. This study was undertaken to demonstrate a shift in tendon alignment at the first metatarsophalangeal joint in patients with\\u000a hallux valgus by means of magnetic resonance imaging. Design. Ten normal feet and 20 feet with the hallux valgus deformity conforming to conventional clinical and radiographic criteria\\u000a were prospectively studied using magnetic resonance imaging. Correlation was made between tendon position
S. Eustace; Daniel Williamson; Michael Wilson; J. O’Byrne; Lisa Bussolari; Mark Thomas; Michael Stephens; John Stack; Barbara Weissman
To determine whether the echo time of magnetic resonance gradient-echo and spin-echo imaging sequences may be important for the occurrence of high signal strength from tendon with pathological alterations, imaging sequences with sufficient spatial resolution and very short echo times were developed for whole-body imagers with standard gradient system. The sequences were applied on the Achilles tendons of five healthy
Fritz Schick; Florian Dammann; Otto Lutz; Claus D. Claussen
Ultrasound can be used to study tendon and muscle movement. However, quantization is mostly based on manual tracking of anatomical landmarks such as the musculotendinous junction, limiting the applicability to a small number of muscle-tendon units. The aim of this study is to quantify tendon displacement without employing anatomical landmarks, using dedicated speckle tracking in long B-mode image sequences. We devised a dedicated two-dimensional multikernel block-matching scheme with subpixel accuracy to handle large displacements over long sequences. Images were acquired with a Philips iE33 with a 7 MHz linear array and a VisualSonics Vevo 770 using a 40 MHz mechanical probe. We displaced the flexor digitorum superficialis of two pig cadaver forelegs with three different velocities (4,10 and 16 mm/s) over 3 distances (5, 10, 15 mm). As a reference, we manually determined the total displacement of an injected hyperechogenic bullet in the tendons. We automatically tracked tendon parts with and without markers and compared results to the true displacement. Using the iE33, mean tissue displacement underestimations for the three different velocities were 2.5 +/- 1.0%, 1.7 +/- 1.1% and 0.7 +/- 0.4%. Using the Vevo770, mean tissue displacement underestimations were 0.8 +/- 1.3%, 0.6 +/- 0.3% and 0.6 +/- 0.3%. Marker tracking displacement underestimations were only slightly smaller, showing limited tracking drift for non-marker tendon tissue as well as for markers. This study showed that our dedicated speckle tracking can quantify extensive tendon displacement with physiological velocities without anatomical landmarks with good accuracy for different types of ultrasound configurations. This technique allows tracking of a much larger range of muscle-tendon units than by using anatomical landmarks.
Korstanje, Jan-Wiebe H.; Selles, Ruud W.; Stam, Henk J.; Hovius, Steven E. R.; Bosch, Johan G.
Tendon injuries are common in human athletes [1-4]. Furthermore, such injuries are also\\u000aprevalent in the ageing sedentary population [5-7]. In recent decades, the incidence of tendon\\u000ainjuries has risen due to both an increase in an elderly population and a rise in participation in\\u000arecreational and competitive sporting activities. In the general population the lifetime cumulative\\u000aincidence of Achilles
Marieke de Mos
The authors describe one case of post-traumatic dislocation of the extensor carpi ulnaris tendon. They found eleven other cases reported in the literature. The type of lesion should be looked for in cases of trauma to the wrist without a bony lesion. The treatment should be surgical when function is impaired, either shortly after the initial trauma or if the dislocation becomes habitual. The aim is to reconstruct a tendon sheath. The results were generally satisfactory. PMID:3749557
Loty, B; Meunier, B; Mazas, F
In general, there is a higher incidence of musculoskeletal injuries during physical activity in women than in men. We hypothesized that in women rates of tendon collagen synthesis would be lower than in men at rest and after exercise, especially in the later luteal phase when estrogen and progesterone concentrations are higher than the early follicular phase. We studied tendon collagen fractional synthesis rate (FSR) in 15 young, healthy female subjects in either the early follicular (n = 8) or the late luteal phase (n = 7) 72 h after an acute bout of one-legged exercise (60 min kicking at 67% workload maximum) (72 h) and compared the results with those previously obtained for men. Samples were taken from the patellar tendon in both the exercised and rested legs to determine collagen FSR by the incorporation of [15N]proline into tendon collagen hydroxyproline. There was no effect of menstrual phase on tendon collagen synthesis either at rest or after exercise. However, there was a significant difference between women and men at rest (women = 0.025 +/- 0.002%/h, men = 0.045 +/- 0.008%/h; P < 0.05) and 72 h after exercise (women = 0.027 +/- 0.005%/h; men = 0.058 +/- 0.008%/h). Furthermore, rest and 72-h tendon collagen synthesis were not different in women, whereas in men tendon collagen synthesis remained significantly elevated 72 h after exercise. It is concluded that both in the resting state and after exercise, tendon collagen FSR is lower in women than in men, which may contribute to a lower rate of tissue repair after exercise. PMID:16990502
Miller, Benjamin F; Hansen, Mette; Olesen, Jens L; Schwarz, Peter; Babraj, John A; Smith, Kenneth; Rennie, Michael J; Kjaer, Michael
Acute and chronic tendon injuries are very common among athletes and in sedentary population. Most physicians prescribe anti-inflammatory managements to relieve the worst symptoms of swelling and pain, including non-steroidal anti-inflammatory drugs, corticosteroids and physical therapies. However, experimental research shows that pro-inflammatory mediators such as prostaglandins may play important regulatory roles in tendon healing. Noticeably nearly all cases of chronic
Kai-Ming Chan; Sai-Chuen Fu
For vertebrates to achieve locomotion and to hurl objects efficiently, they must be able to develop muscular forces, store\\u000a elastic energy in tendon, and then transfer this energy to the attached joints. After joint movement has been achieved, excess\\u000a energy dissipates by reverse transmission from the joint to the muscle-tendon unit, where it is dissipated in the muscle.\\u000a Locomotion and
Frederick H. Silver; Joseph W. Freeman; Gino Bradica
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
Crowley, Timothy P
This report describes two cases of traumatic closed index extensor tendon rupture at the musclotendinous junction. Both patients were injured when their work gloves were caught in the revolving parts of machines, and both were treated surgically. One of the patients completely ruptured the index extensor digitorum communis (EDC) and the extensor indicis proprius (EIP) tendons at the musclotendinous junction of dorsal forearm. In this patient, the distal stump of the index EDC tendon was sutured to the middle EDC tendon in an end-to-side juncture. The other patient completely ruptured the EIP tendon and partially ruptured the index EDC tendon at the musclotendinous junction. In this patient, tendon transfer of the extensor digiti minimi (EDM) to the EIP tendon and plication of the index EDC tendon were performed. In both cases, surgical intervention enabled the patients to extend their index fingers almost normally; however, the former complained of inability to extend his index finger independently. Tendon transfer of the EDM in cases of index extensor tendon rupture at the musclotendinous junction is a good method to restore ability to independently extend the index finger. However, consideration should be given to anatomical variation in the little finger. The EDC tendon is sometimes absent leaving the EDM tendon as the only extensor tendon to the little finger. PMID:22379446
Komura, Shingo; Yokoi, Tatsuo; Nonomura, Hidehiko
Fibres, aponeuroses, and tendons are often considered mechanically "in series" in skeletal muscles. This notion has led to oversimplified calculations of fibre forces from tendon forces, to incorrect derivations of constitutive laws for aponeuroses, and to misinterpretations of the recovery of elastic energy in stretch-shortening cycles of muscles. Here, we demonstrate theoretically, using examples of increasing complexity, that tendon and aponeurosis are not in series in a muscle fibre-aponeurosis-tendon complex. We then demonstrate that assuming the tendon and aponeurosis to be in series can lead to the appearance of mechanical work creation in these passive viscoelastic structures, a result that is mechanically impossible. Finally, we explain the mechanical role of the incompressible muscle matrix in force transmission from fibres to aponeuroses and tendon, and emphasize that incompressibility necessitates the introduction of extra forces necessary to maintain this constraint. Unfortunately, this requirement eliminates, for all but the simplest cases, a theoretical approach of muscle modeling based on intuitive free-body diagrams. PMID:16085074
Epstein, Marcelo; Wong, Max; Herzog, Walter
Recurrent volar displacement of the extensor digitorum communis tendon (EDC) at the metacarpophalangeal joint (MCPJ) more commonly occurs post-trauma or in the rheumatoid hand. This disabling condition of the hand results in painful swelling of the MCPJ, associated with "locking" of the extensor tendon. We report a simple surgical technique used to successfully 'secure' the EDC from recurrent displacement. This was performed for a 59-year-old man who developed the condition in his ring finger, following Vth ray amputation for severe Dupuytren's disease. First, the EDC over the IIIrd and IVth MCPJ are exposed using a longitudinal incision. The junctura tendinum between the EDC tendons was next extended proximally by 2 cm on the radial side of the IVth EDC and then divided to create a distally based junctura slip. Next, a 'lasso' was created by passing the slip beneath the IVth EDC tendon and then securing it onto itself with a 5/0 Ethibond suture (Ethicon Inc.). This reconstruction was then tested in all ranges of MCPJ flexion, successfully preventing volar displacement of the extensor tendon. The 'junctura lasso' provided a satisfactory solution for the patient, who, over the next four years; for the duration of his follow-up, suffered no further displacement of the extensor tendon. PMID:23422060
Yong, Chin Chean; Connolly, Cara M; Erdmann, Matt
Rotator cuff tears represent the most common shoulder injuries in the United States. The debilitating effect of this degenerative condition coupled with the high incidence of failure associated with existing graft choices underscore the clinical need for alternative grafting solutions. The two critical design criteria for the ideal tendon graft would require the graft to not only exhibit physiologically relevant mechanical properties but also be able to facilitate functional graft integration by promoting the regeneration of the native tendon-to-bone interface. Centered on these design goals, this review will highlight current approaches to functional and integrative tendon repair. In particular, the application of biomimetic design principles through the use of nanofiber- and nanocomposite-based scaffolds for tendon tissue engineering will be discussed. This review will begin with nanofiber-based approaches to functional tendon repair, followed by a section highlighting the exciting research on tendon-to-bone interface regeneration, with an emphasis on implementation of strategic biomimicry in nanofiber scaffold design and the concomitant formation of graded multi-tissue systems for integrative soft tissue repair. This review will conclude with a summary and future directions section.
Zhang, Xinzhi; Bogdanowicz, Danielle; Erisken, Cevat; Lee, Nancy M.; Lu, Helen H.
Rotator cuff tears represent the most common shoulder injuries in the United States. The debilitating effect of this degenerative condition coupled with the high incidence of failure associated with existing graft choices underscores the clinical need for alternative grafting solutions. The 2 critical design criteria for the ideal tendon graft would require the graft to not only exhibit physiologically relevant mechanical properties but also be able to facilitate functional graft integration by promoting the regeneration of the native tendon-to-bone interface. Centered on these design goals, this review will highlight current approaches to functional and integrative tendon repair. In particular, the application of biomimetic design principles through the use of nanofiber- and nanocomposite-based scaffolds for tendon tissue engineering will be discussed. This review will begin with nanofiber-based approaches to functional tendon repair, followed by a section highlighting the exciting research on tendon-to-bone interface regeneration, with an emphasis on implementation of strategic biomimicry in nanofiber scaffold design and the concomitant formation of graded multi-tissue systems for integrative soft-tissue repair. This review will conclude with a summary and discussion of future directions. PMID:22244070
Zhang, Xinzhi; Bogdanowicz, Danielle; Erisken, Cevat; Lee, Nancy M; Lu, Helen H
The authors devised an alternative arthroscopic double bundle ACL reconstruction technique using a bone patellar tendon bone\\u000a (BPTB)–gracilis tendon composite autograft. One tibial and two femoral tunnels were used to reconstruct two bundles of anterior\\u000a cruciate ligaments (ACL) [an anteromedial bundle (AM) and a post-erolateral bundle (PL)]. BTBB was fixed in the tunnels produced\\u000a on the isometric points of the
Kwang Am Jung; Su Chan Lee; Moon Bok Song; Choon Key Lee
Harvested hamstring tendons were recently shown to possess the ability to regrow and regain their function in flexing the knee joint. In this study, we report a case of failed regrowth of previously harvested semitendinosus tendon to its original insertion site in a 24-year-old professional soccer player. The disturbance resulted in the formation of a clearly visible Popeye-type muscular prominence
Teppo L. N. Järvinen; Tero A. H. Järvinen; Tero Penttilä; Arsi Harilainen; Jerker Sandelin; Timo Paakkala
The biceps brachii is a unique muscle with 2 proximal tendons and a single distal tendon. Although these tendons are part of the same muscle, they have significantly different functions. It is hypothesized that the long head of the biceps acts as a pain generator in the shoulder, though the biomechanical function is still under debate. Conversely, the distal biceps tendon is the major supinator of the forearm and serves a secondary flexor. As such, injuries to these tendons must be evaluated independently. Biceps brachii ruptures most often occur in middle-aged men following a traumatic event. Injuries to the long head of the biceps are primarily treated nonoperatively with adequate results. Injuries of distal tendon occur less often, but are receiving significant attention in the literature in regard to treatment options. Surgical repair of distal biceps ruptures is indicated in patients who want to restore supination strength and endurance. It is unclear which operative technique is superior, although the most recent data suggest increased strength of the cortical button repair. This article provides a comprehensive review of both proximal and distal biceps brachii ruptures in addition to our treatment algorithm. PMID:20631471
Geaney, Lauren E; Mazzocca, Augustus D
A tension leg platform (TLP) tendon system experiences oscillatory tensile stresses, and therefore is vulnerable to fatigue and fracture. Because design factors have significant uncertainty, a reliability analysis to quantify structural performance is appropriate. A maintenance program of periodic inspection and repair shows promise for improving system reliability and enhancing structural integrity. The performance of a TLP tendon system was simulated in order to study the relationship of design factors to system reliability. Effects on system reliability and maintenance performance (repair and replacement rates) can be studied as a function of (a) number of joints, J; (b) number of members, M; (c) inspection frequency; (d) inspection sensitivity as defined by the POD (probability of detection) curve; (e) ultimate strength; (f) repair policy; etc. The performance of an initially damaged or flawed tendon system is investigated. The reliability of a system that uses pressurized tendons to detect through-thickness cracks is studied, as is the vulnerability of the tendon system before replacement of broken tendons.
Kung, C.J. (American Bureau of Shipping, New York, NY (United States)); Wirsching, P.H. (Univ. of Arizona, Tucson, AZ (United States). Dept. of Aerospace and Mechanical Engineering)
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.
BENJAMIN, M.; RALPHS, J. R.
Tendons can function as springs and thereby preserve energy during cyclic loading. They might also have damping properties, which, hypothetically, could reduce risk of microinjuries due to fatigue at sites of local stress concentration within the tendon. At mechanical testing, damping will appear as hysteresis. How is damping influenced by training or disuse? Does training decrease hysteresis, thereby making the tendon a better spring, or increase hysteresis and thus improve damping? Seventy-eight female 10-wk-old Sprague-Dawley rats were randomized to three groups. Two groups had botulinum toxin injected into the calf muscles to unload the left Achilles tendon through muscle paralysis. One of these groups was given doxycycline, as a systemic matrix metalloproteinase inhibitor. The third group served as loaded controls. The Achilles tendons were harvested after 1 or 6 wk for biomechanical testing. An increase with time was seen in tendon dry weight, wet weight, water content, transverse area, length, stiffness, force at failure, and energy uptake in all three groups (P < 0.001 for each parameter). Disuse had no effect on these parameters. Creep was decreased with time in all groups. The only significant effect of disuse was on hysteresis (P = 0.004) and creep (P = 0.007), which both decreased with disuse compared with control, and on modulus, which was increased (P = 0.008). Normalized glycosaminoglycan content was unaffected by time and disuse. No effect of doxycycline was observed. The results suggest that in growing animals, the tendons continue to grow regardless of mechanical loading history, whereas maintenance of damping properties requires mechanical stimulation. PMID:17412787
Eliasson, Pernilla; Fahlgren, Anna; Pasternak, Björn; Aspenberg, Per
Quantitative ultrasound (QUS) techniques have recently been widely applied for the characterization of tissues. For example, they can be used for the quantification of Achilles tendon properties based on the broadband ultrasound attenuation (BUA) and the speed of sound (SOS) when the ultrasound wave passes through the tissues. This study is to develop an integrated system to investigate the properties of Achilles tendons using QUS images from UBIS 5000 (DMS, Montpellier, France) and B-mode ultrasound images from HDI 5000 (ATL, Ultramark, USA). Subjects including young (32 females and 17 males; mean age: 23.7 ± 2.0) and middle-aged groups (8 female and 8 males; mean age: 47.3 ± 8.5 s) were recruited and tested for this study. Only subjects who did not exercise regularly and had no record of tendon injury were studied. The results show that the BUA is significantly higher for the young group (45.2 ± 1.6 dB MHz-1) than the middle-age group (40.5 ± 1.9 dB MHz-1), while the SOS is significantly lower for the young (1601.9 ± 11.2 ms-1) compared to the middle-aged (1624.1 ± 8.7 m s-1). On the other hand, the thicknesses of Achilles tendons for both groups (young: 4.31 ± 0.23 mm; middle age: 4.24 ± 0.23 mm) are very similar. For one patient who had an Achilles tendon lengthening (ATL) surgery, the thickness of the Achilles tendon increased from 4 mm to 4.33 mm after the surgery. In addition, the BUA increased by about 7.2% while the SOS decreased by about 0.6%. In conclusion, noninvasive ultrasonic assessment of Achilles tendons is useful for assisting clinical diagnosis and for the evaluation of a therapeutic regimen.
Du, Yi-Chun; Chen, Yung-Fu; Chen, Pei-Jarn; Lin, Yu-Ching; Chen, Tainsong; Lin, Chii-Jeng
A case of closed rupture of the extensor digitorum communis tendon following a fracture of the lower end of the radius with anterior displacement, is described. This rare complication was treated successfully by abductor pollicis longus tendon transfer.
IAIN MACKAY; ROBERT G. SIMPSON
The study is concerned with the possibility of utilizing fiber reinforced plastic rods as prestressing tendons, in place of traditional steel tendons, in elements of prestressed concrete bridges exposed to corrosive environments. A survey was made of avai...
A. H. Mattock K. Babaei
BackgroundThe purpose of this study was to compare the initial strength of acromioclavicular joint reconstructions using coracoclavicular (CC) tendon grafts utilizing interference screws, a tendon square knot or side-to-side suturing for graft fixation.
Robert Z. Tashjian; Jodi D. Southam; Todd Clevenger; Kent N. Bachus
We assessed the applicability of a partially biodegradable synthetic material composed of polyglycolic acid (PGA) and dacron to repair or replace severely injured tendons. Adult rabbits underwent complete laceration and repair of one Achilles tendon. Grou...
W. G. Rodkey H. E. Cabaud J. A. Feagin P. C. Perlik
Anatomic variations of the extensor tendons of the forearm are frequent and its knowledge is important to assess the diseased and traumatized hand. During routine cadaveric dissection in the Department of Anatomy, Kasturba Medical College, Mangalore, India, we came across unusual variations in the left upper limb of a 51-years-old male cadaver. The variants are, the complete absence of the extensor pollicis brevis (EPB), the abductor pollicis longus (APL) having six slips of insertion with additional muscle slip from the brachio-radialis (BR). The extensor digitorum communis (EDC) had five tendon slips, the extra tendon splits close to the metacarpo-phalangeal (MP) joint and contribute to the tendons of the ring and little fingers. The number of accessory tendons of APL has functional significance in the development of de Quervain's stenosing tendovaginitis. The present case is unique in the sense that, all the three variations are present in the ipsilateral upper limb. The occurrence of these anomalies and its clinical and embryological significance are discussed. PMID:18273511
Nayak, S R; Krishnamurthy, A; Pai, Mangala M; Prabhu, Latha V; Ramanathan, Lakshmi A; Ganesh Kumar, C; Thomas, Merin M
Biological fixation of soft tissue-based grafts for anterior cruciate ligament (ACL) reconstruction poses a major clinical challenge. The ACL integrates with subchondral bone through a fibrocartilage enthesis, which serves to minimize stress concentrations and enables load transfer between two distinct tissue types. Functional integration thus requires the reestablishment of this fibrocartilage interface on reconstructed ACL grafts. We designed and characterized a novel mechanoactive scaffold based on a composite of poly-?-hydroxyester nanofibers and sintered microspheres; we then used the scaffold to test the hypothesis that scaffold-induced compression of tendon grafts would result in matrix remodeling and the expression of fibrocartilage interface-related markers. Histology coupled with confocal microscopy and biochemical assays were used to evaluate the effects of scaffold-induced compression on tendon matrix collagen distribution, cellularity, proteoglycan content, and gene expression over a 2-week period. Scaffold contraction resulted in over 15% compression of the patellar tendon graft and upregulated the expression of fibrocartilage-related markers such as Type II collagen, aggrecan, and transforming growth factor-?3 (TGF-?3). Additionally, proteoglycan content was higher in the compressed tendon group after 1 day. The data suggest the potential of a mechanoactive scaffold to promote the formation of an anatomic fibrocartilage enthesis on tendon-based ACL reconstruction grafts.
Spalazzi, Jeffrey P.; Vyner, Moira C.; Jacobs, Matthew T.; Moffat, Kristen L.
During some of the inspections at nuclear power plants with prestressed concrete containments, it was observed that the containments has experienced leakage of the tendon sheathing filler (i.e., streaks). The objective of this activity was to provide an indication of the extent of tendon sheathing filler leakage into the concrete and its affects on concrete properties. Literature was reviewed and concrete core samples were obtained from the Trojan Nuclear Plant and tested. The literature primarily addressed effects of crude or lubricating oils that are known to cause concrete damage. However, these materials have significantly different characteristics relative to the materials used as tendon sheathing fillers. Examination and testing of the concrete cores indicated that the appearance of tendon sheathing filler on the concrete surface was due to leakage from the conduits and its subsequent migration through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks and there was no perceptible movement into the concrete. Results of compressive strength testing indicated that the concrete quality was consistent in the containment and that the strength had increased over 40% in 25.4 years relative to the average compressive strength at 28-days age.
Naus, D.J.; Oland, C.B. [Oak Ridge National Lab., TN (United States)
Patellar tendon-related pain is common in the athletic patient. When it occurs in skeletally mature patients participating in running, jumping, or kicking sports, the diagnosis of jumper’s knee patellar tendonitis is usually made. If patellar tendon pain is associated with a mass, the differential diagnosis should be broadened to include crystalline arthropathy. This article presents a case of a highly athletic 45-year-old man with a history of gout, anterior knee pain, and an enlarging mass in the region of the patellar tendon. Conservative management failed, and an excisional biopsy found it to be an intra-tendinous gouty tophus. To our knowledge, only 1 report exists documenting a patellar tendon mass secondary to gout, and no case report exists documenting this problem in an athlete. The interplay between athletics and gout has not been well described. Despite the long-term protective nature of fitness, transient elevations in uric acid associated with athletic endeavors may contribute acutely to manifestations of gout in some athletes. Resultant intra- or extra-articular pathology may present as, and easily be mistaken for, a sports-related injury. Without appropriate medical management, tophaceous deposition may continue to occur and treatment of the resultant mass may require surgical intervention.
Gililland, Jeremy M.; Webber, Nicholas P.; Jones, Kevin B.; Randall, R. Lor; Aoki, Stephen K.
The mechanical behavior of tendons has been well studied in vitro. A noninvasive method to acquire mechanical data would be highly beneficial. Elastography has been a promising method of gathering in vivo tissue mechanical behavior, but it has inherent limitations. This study presents acoustoelasticity as an alternative ultrasound-based method of measuring tendon stress and strain by reporting a relationship between ultrasonic echo intensity (B mode ultrasound image brightness) and mechanical behavior of tendon in vitro. Porcine digital flexor tendons were cyclically loaded in a mechanical testing system while ultrasonic echo response was recorded. We report that echo intensity closely follows the applied cyclic strain pattern in time with higher strain protocols resulting in larger echo intensity changes. We also report that echo intensity is related nonlinearly to stress and nearly linearly to strain. This indicates that ultrasonic echo intensity is related to the mechanical behavior in a loaded tissue by an acoustoelastic response, as previously described in homogeneous, nearly incompressible materials. Acoustoelasticity is therefore able to relate strain-dependent stiffness and stress to the reflected echo, even in the processed B-mode signals reflected from viscoelastic, inhomogeneous material such as tendon, and is a promising metric to acquire in vivo mechanical data noninvasively.
Duenwald, Sarah; Kobayashi, Hirohito; Frisch, Kayt; Lakes, Roderic; Vanderby, Ray
Injuries to ligaments and tendons heal by formation of inferior repair tissue. This may result in severe joint dysfunction. Because of an increased occurrence of sports-related injuries, musculoskeletal disorders may become one of the major burden of health care. Tissue engineering offers the potential to improve the quality of ligament and tendon tissues during the healing process and may provide a more effective approach to the treatment of injuries to ligaments and tendons than traditional methods. Application of growth factors, gene transfer techniques, cell therapy and cell-matrix composites have shown to affect the process of ligament and tendon healing. The benefits of using mesenchymal stem cells on a three dimensional biological matrix have been shown recently. Tissue engineering will also include mechanical manipulation of tissue environments to accelerate cell differentiation and to improve matrix formation. Fibroblast-seeded polymer scaffolds could be useful in ligament and tendon replacement in which autogenous fibroblasts would be obtained through biopsy, cultured and seeded onto a scaffold. PMID:11968548
Bosch, U; Krettek, C
We present a rare case of spontaneous tendon rupture of the extensor digitorum communis (EDC) in a patient with systemic lupus erythematosus (SLE). Inflammation in SLE presents as periarthritis, which may develop into Jaccoud's arthropathy. We bridged the ruptured tendon of the EDC (III) at the metacarpophalangeal (MP) joint of this patient with a tendon graft. This case demonstrates that this portion of the MP joint can be a site of tendon rupture of fingers in SLE patients. PMID:22782531
Oishi, Hisao; Oda, Ryo; Morisaki, Shinsuke; Fujiwara, Hiroyoshi; Tokunaga, Daisaku; Kubo, Toshikazu
Several studies report that tendons can regenerate after harvesting. These studies have been performed especially in patellar\\u000a and hamstring tendons. At our institution, 10 cm length of full thickness peroneus longus tendon has been harvested to reconstruct\\u000a torn anterior cruciate ligament since 1997 as a different graft source. The aim of this study was to investigate whether the\\u000a peroneus longus tendon
Servet Kerimo?lu; Polat Ko?ucu; Murat Livao?lu; Ismail Yükünç; Ahmet U?ur Turhan
Objective:To examine the relative prevalence of histological changes that have been found to be associated with the process of tendinopathy in lesions of the tendon of the long head of the biceps brachii and to evaluate the reliability of histopathological evaluation of tendon tissue in lesions of the tendon of the long head of the biceps.Design:Tendon samples were taken from
U G Longo; F Franceschi; L Ruzzini; C Rabitti; S Morini; N Maffulli; V Denaro
Chronic patellar tendon rupture is a rare disabling injury that is technically difficult to repair. Many different surgical\\u000a methods have been reported for the reconstruction of chronic patellar tendon ruptures. We are reporting the use of contralateral\\u000a bone-tendon-bone (BTB) autograft for chronic patellar tendon rupture reconstruction followed by double-wire loop reinforcement\\u000a and without postoperative immobilization. One year after the operation,
Miroslav Z. Milankov; Natasa Miljkovic; Milan Stankovic
Tissue engineering may play a major role in the treatment of rotator cuff tendon lesions through replacement of an injured\\u000a tendon segment. Tendons have very poor spontaneous regenerative capabilities, and despite intensive remodelling, complete\\u000a regeneration is never achieved and the strength of tendon and ligaments remains as much as 30% lower than normal even months\\u000a or years following an acute
Roberto Rotini; Milena Fini; Gianluca Giavaresi; Alessandro Marinelli; Enrico Guerra; Diego Antonioli; Alessandro Castagna; Roberto Giardino
Background: Anterior cruciate ligament reconstruction is commonly performed with autogenous hamstring tendon grafts.Purpose: To ascertain the effects of braiding on ultimate tensile strength and stiffness of hamstring tendon graft.Study Design: Controlled laboratory study.Methods: Sixteen fresh-frozen semitendinosus and gracilis tendons were harvested from eight matched (right and left) human cadaveric specimens. Both sets of hamstring tendons from each matched pair were
Peter J. Millett; Bruce S. Miller; Matthew Close; William I. Sterett; William Walsh; Richard J. Hawkins
\\u000a The deep tendon reflex responses are judged by clinicians through visual observation with great variations between different\\u000a examiners leading to high possibilities of errors. This study proposed an alternative approach to quantify the deep tendon\\u000a reflex responses. In the preliminary stage, the motion analysis system was used to collect quantitative data for patellar\\u000a tendon reflex, one of the deep tendon
L. K. Tham; N. A. Abu Osman; K. S. Lim; B. Pingguan-Murphy; W. A. B. Wan Abas
A novel technique to estimate the contribution of finger extensor tendons to joint moment generation was proposed. Effective static moment arms (ESMAs), which represent the net effects of the tendon force on joint moments in static finger postures, were estimated for the 4 degrees of freedom (DOFs) in the index finger. Specifically, the ESMAs for the five tendons contributing to
Sang Wook Lee; Hua Chen; Joseph D. Towles; Derek G. Kamper
Background. The objective of this study was to investigate the use of amniotic membrane as a long-term bioprosthesis in hand surgery.The role of the amniotic membrane was investigated in chickens with regard to the prevention of adhesion formation following tendon repair in zone II. Methods. In the control group, the flexor tendon sheath was excised and the tendon repaired. In
Fahir Demirkan; Nagehan Colakoglu; Ozkan Herek; Gürkan Erkula
Multiple grooved substrata with groove depth 5 µm were found to facilitate the healing of completely divided rat flexor tendons in vitro. Sections of tendons cultured on plain substrata showed only partial healing with incompletely sealed epitenon layers and immature thin collagen fibres. Tendons cultured on patterned substrata healed with complete restoration of the epitenon layer and reconstitution of the
B. Wòjciak; J. Crossan; A. S. G. Curtis; C. D. W. Wilkinson
Tendon elasticity is important for economical locomotion; however it is unknown whether tendon stiffness is appropriate to achieve an optimal efficiency in various muscles. Here we test the hypothesis that the Achilles tendon is of an appropriate stiffness to maximise medial gastrocnemius muscle efficiency during locomotion with different power requirements. To test this hypothesis we used a three element Hill
G. A. Lichtwark; A. M. Wilson
Various sonography studies have evaluated the normal flexor tendons of the fingers by reporting the echogenicity of these structures. Due to the descriptive nature of these studies, little information is available concerning the reproducibility of sonographic measures of the finger flexor tendons. The aim of this study was to determine whether sonography measurement of finger flexor tendons can provide reproducible
Hala Reaiche; Marie Williams; Maureen McEvoy
This report compares the morphology and the concentrations of glycosaminoglycans (GAGs) in an injured superficial digital flexor tendon (SDFT) of a horse with those of a normal tendon. An injured 6-year-old male Thoroughbred exhibited heat and swelling around the SDFT of the right forelimb. On histopathological examination, exuberant granulation was observed in the affected tendon, with activated tenocytes, angiogenesis, haemorrhage,
A. Kobayashi; M. Sugisaka; K. Takehana; M. Yamaguchi; Eerdunchaolu K. Iwasa; M. Abe
An inflammatory process was induced by intratendinous injection of bacterial collagenase into the superficial digital flexor tendon (SDFT) of the left thoracic limb of 10 horses. One week later, the tendons in five of the horses (group 1) were treated with glycosaminoglycan polysulphate (GAGPS), and the tendons of the other five (group 2) were treated with saline solution. The horses
J. R. E. Moraes; G. G. Facco; F. R. Moraes; J. R. Engracia Filho; L. G. Miyazato; D. C. Beretta
This study examines the hypothesis that recombinant human bone morphogenetic protein-2 can enhance bone ingrowth into a tendon graft placed into a bone tunnel. We transplanted the long digital extensor tendon into a drill hole in the proximal tibia in 65 adult mongrel dogs. We applied two different doses of the bone morphogenetic protein to the tendon-bone interface in one
Scott A. Rodeo; Katsunori Suzuki; Xiang-hua Deng; John Wozney; Russell F. Warren
This study investigated the strain pattern in human patellar tendon in an area of the tendon where changes commonly associated with patellar tendinitis are found. Eight fresh frozen human knees were instrumented with strain gauges on both the anterior and posterior side of the proximal patellar tendon. Both static and dynamic measurements were carried out in a range from 0°
Louis C. Almekinders; Jurrien H. Vellema; Paul S. Weinhold
Tendon injuries at the epicondyle can occur in athletes and workers whose job functions involve repetitive, high force hand activities, but the early pathophysiologic changes of tendon are not well known. The purpose of this study was to evaluate early tendon structural changes, specifically the formation of microtears, caused by cyclical loading. The Flexor Digitorum Profundus (FDP) muscle of nine
Leena H. Nakama; Karen B. King; Sven Abrahamsson; David M. Rempel
This paper describes the assessment of neutron doses to the concrete pressure vessels and stressing tendons above the cores of the Wylfa nuclear power plant. Following the observation of unexpected levels of activation in a routinely removed tendon from the top cap gallery, it was thought prudent to assess neutron doses to the vessel and its tendons and to consider
D. A. Allen; D. A. Thornton; G. A. Wright; A. J. Bird; S. Rycroft
We evaluated the biomechanical properties of patellar tendon allografts from donors aged 18 to 55 years. Bone-patellar tendon-bone complexes were harvested from acceptable donors and processed. Fat and soft tissue were removed, and the tendons were sectioned lengthwise leaving the central third. Area measure ments were taken, and mechanical testing was per formed. Specimens were pulled to failure at a
Charlene M. Flahiff; Andrew T. Brooks; J. Marcus Hollis; Jack L. Vander Schilden; Richard W. Nicholas
In rare incidences of combined ruptures of the ACL and patellar tendon, either the patellar tendon ruptures or the associated ACL tear is often initially missed. Even when recognized, there is no established treatment regimen. We report a case of an intercollegiate football player with a combined rupture of the ACL and patellar tendon that was successfully treated by primary
Lydia A. Futch; William P. Garth; Greg J. Folsom; William K. Ogard
In the last few years, the effectiveness of cement grout in galvanized or polyethylene ducts, the most widely used corrosion protection system for multistrand bonded post-tensioned concrete tendons, has been under debate, due to significant tendon corrosion damage, several reported failures of individual tendons as well as a few collapses of non-typical structures. While experience in the USA has been
Ruben Mario Salas Pereira
Background: The triceps tendon has been described as a single unit with contribution from each of the 3 heads of the muscle. An observation at the time of surgical repair of a triceps tendon injury led to an anatomical study to further define the anatomy of this tendon as it inserts on the olecranon.Hypothesis: The medial head of the triceps
Michael Madsen; Robert G. Marx; Peter J. Millett; Scott A. Rodeo; John W. Sperling; Russell F. Warren
Extensor tendon subluxation can result from a disruption to the extensor retinacular system and/or the sagittal band at the metacarpophalangeal joint. When conservative treatment is insufficient to correct the subluxation, surgical treatment is necessary and various surgical techniques exist. We present a novel stabilization technique to centralize the extensor tendon using a junctura tendinum to lengthen an extensor digitorum communis tendon graft. This technique is simple and effective, creating a strong repair without associated stiffness. To achieve a less morbid, stable repair, we mimicked normal anatomy with minimal disruption to local soft tissue structures. This technique seems to offer biomechanical advantages over previously described techniques and shows successful treatment in the illustrated patient. PMID:23391359
ElMaraghy, Amr W; Pennings, Amanda
Generally, outcome after surgical repair of complete Achilles tendon rupture is good. However, some patients have ongoing problems with dorsiflexion of the ankle joint. We report on eight patients, who did not achieve heel contact because of reduced ankle dorsiflexion 5 months after surgical repair of complete Achilles tendon rupture. All patients received at least three cycles of injections with 200-300 units of Botulinum toxin A (BOTOX) into the gastrocnemius and soleus muscle. Weakening of the triceps surae by Botulinum toxin allowed patients to perform the required exercises and to tolerate casting at night. Thus, all patients were able to tolerate plantigrade foot position 9 months after beginning of Botulinum toxin treatment. At final follow-up after 2 years, pain had significantly improved, and a mean dorsiflexion of 21 degrees was reached. In conclusion, treatment of the calf muscles with BOTOX is a safe and effective method to improve restricted dorsiflexion in patients after Achilles tendon repair. PMID:19826783
Reuter, Iris; Lorbach, Olaf; Mehnert, Sabine; Kaps, Manfred; Engelhardt, Martin
Giant cell tumours of the tendon sheath (GCTTS) and pigmented villonodular synovitis (PVNS) are part of a spectrum of benign proliferative lesions of synovial origin that may affect the joints, bursae and tendon sheaths. This review article describes the clinicopathological features and imaging findings in patients with GCTTS. GCTTS usually presents as a soft tissue mass with pressure erosion of the underlying bone. Magnetic resonance (MR) imaging of GCTTS typically shows low to intermediate signal on T1- and T2-weighted spin-echo sequences due to the presence of haemosiderin, which exerts a paramagnetic effect. On gradient-echo sequences, the paramagnetic effect of haemosiderin is further exaggerated, resulting in areas of very low signal due to the blooming artefact. Ultrasonography shows a soft mass related to the tendon sheath that is hypervascular on colour or power Doppler imaging. PMID:20077044
Wan, J M C; Magarelli, N; Peh, W C G; Guglielmi, G; Shek, T W H
Stem cells are one of the most fascinating areas in regenerative medicine today. They play a crucial role in development and regeneration and are defined as cells that continuously reproduce themselves while maintaining the ability to differentiate into various cell types. Stem cells are found at all developmental stages, from embryonic stem cells (ESCs) which differentiate into all cell types, to adult stem cells (ASCs) which are responsible for tissue regeneration. Studies using animal models have shown promising results following cell therapy for induced injury in musculoskeletal system, including tendon healing, but the results can be variable. Alternative sources for cell therapy in tendon pathology may include ESCs, ASCs (bone marrow, adipose tissue or tendon derived stem cells) or induced pluripotent stem cells (iPSCs). While ethical and safety concerns currently forbid clinical application of ESCs and iPSCs, initial clinical trials with ASCs are promising. PMID:23738298
Filomeno, Paola; Dayan, Victor; Touriño, Cristina
Abstract The purpose of the study was to identify factors influencing the outcome and prognosis of rupture of the tendon of the peroneus tertius muscle in 27 horses. Information on history, physical examination findings, diagnosis, treatment, and final outcome was summarized from medical records. Long-term follow-up information on horses was obtained by telephone survey. A stepwise logistic regression model was used to analyze factors influencing the outcome. Rupture occurred in the midbody of the tendon in 11 horses, at the insertion site in 11 horses, and at the origin in 2 horses. Overall, 18/23 (78.3%) horses returned to their previous level of exercise, 5/23 (21.7%) horses were euthanized due to persistent lameness. If the horse was racing at the time of injury or had an additional structure injured besides the peroneus tertius tendon, it was less likely to return to its intended use.
During inspections performed at US nuclear power plants several years ago, some of the prestressed concrete containment had experienced leakage of the tendon sheathing filler. A study was conducted to indicate the extent of the leakage into the concrete and its potential effects on concrete properties. Concrete core samples were obtained from the Trojan Nuclear Plant. Examination and testing of the core samples indicated that the appearance of tendon sheathing filler on the surface was due to leakage of the filler from the conduits and its subsequent migration to the concrete surface through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks with no perceptible movement into the concrete. Results of compressive strength tests indicated that the concrete quality was consistent in the containment and that the strength had increased relative to the strength at 28 days age.
Costello, J.F.; Naus, D.J.; Oland, C.B.
Introduction Weight lifting is commonly associated with an increase in knee injury risk. Local steroid injection is thought to be associated\\u000a with increased risk of spontaneous tendon rupture. The purpose of this report is to describe incidence of rupture of the patellar\\u000a tendon after receiving multiple local steroid injections in weight lifters.\\u000a \\u000a \\u000a \\u000a Materials and methods Seven weight lifters presented at the hospital
Shen-Kai Chen; Cheng-Chang Lu; Pei-His Chou; Lan-Yuen Guo; Wen-Lan Wu
A case of a young body-builder who had ingested megadoses of anabolic-androgenic steroids (AAS) for 6 yr and who sustained bilateral avulsions of the distal biceps tendon is presented. Explosive behavior, painful gynecomastia, and a slight hypertrophy of both the left and right ventricular walls of the heart were other possible adverse effects of AAS in this patient. Reinsertion of both distal biceps tendons to the radial tuberosity was performed according to the Boyd-Anderson technique and a good result was achieved. PMID:7968426
Visuri, T; Lindholm, H
Introduction A prospective study of modified percutaneous Achilles tendon repair performed between 1999 and 2005 under local infiltration\\u000a anesthesia is presented; the study evaluated the results of percutaneous repair technique by visualization of the synovia\\u000a under endoscopic control, followed by early functional postoperative treatment for surgical intervention of acute Achilles\\u000a tendon ruptures.\\u000a \\u000a \\u000a \\u000a Patients Sixty-two patients (58 males, 4 females, mean age 32)
Mahmut Nedim Doral; Murat Bozkurt; Egemen Turhan; Mehmet Ayvaz; Özgür Ahmet Atay; Ak?n Üzümcügil; Gürsel Leblebicio?lu; Defne Kaya; Tolga Aydo?
The material properties of a tendon affect its ability to store and return elastic energy, resist damage, provide mechanical feedback and amplify or attenuate muscle power. While the structural properties of a tendon are known to respond to a variety of stimuli, the extent to which material properties vary among individual muscles remains unclear. We studied the tendons of six different muscles in the hindlimb of Eastern wild turkeys to determine whether there was variation in elastic modulus, ultimate tensile strength and resilience. A hydraulic testing machine was used to measure tendon force during quasi-static lengthening, and a stress-strain curve was constructed. There was substantial variation in tendon material properties among different muscles. Average elastic modulus differed significantly between some tendons, and values for the six different tendons varied nearly twofold, from 829±140 to 1479±106 MPa. Tendons were stretched to failure, and the stress at failure, or ultimate tensile stress, was taken as a lower-limit estimate of tendon strength. Breaking tests for four of the tendons revealed significant variation in ultimate tensile stress, ranging from 66.83±14.34 to 112.37±9.39 MPa. Resilience, or the fraction of energy returned in cyclic length changes was generally high, and one of the four tendons tested was significantly different in resilience from the other tendons (range: 90.65±0.83 to 94.02±0.71%). An analysis of correlation between material properties revealed a positive relationship between ultimate tensile strength and elastic modulus (r(2)=0.79). Specifically, stiffer tendons were stronger, and we suggest that this correlation results from a constrained value of breaking strain, which did not vary significantly among tendons. This finding suggests an interdependence of material properties that may have a structural basis and may explain some adaptive responses observed in studies of tendon plasticity. PMID:22771746
Matson, Andrew; Konow, Nicolai; Miller, Samuel; Konow, Pernille P; Roberts, Thomas J
Spontaneous ruptures of the extensor mechanism of the knee are very rare. They tend to increase considerably in patients with metabolic diseases such as chronic renal failure, hyperparathyroidism, diabetes, gout, and systemic lupus erythematosus. The reported case regards a 48-year-old man with chronic, spontaneous and simultaneous quadriceps, and contra-lateral patellar tendon rupture. The patient suffered from chronic renal failure and for the past year from tertiary hyperparathyroidism. Ruptured tendons were repaired and both knee were evaluated monthly for the next 12 months. Good functional recovery was achieved on both knees without relapse. This case emphasizes the importance of long-term high parathyroid hormone level in the etiology of tendons ruptures.
Grecomoro, Giuseppe; Martorana, Umberto
Spontaneous ruptures of the extensor mechanism of the knee are very rare. They tend to increase considerably in patients with metabolic diseases such as chronic renal failure, hyperparathyroidism, diabetes, gout, and systemic lupus erythematosus. The reported case regards a 48-year-old man with chronic, spontaneous and simultaneous quadriceps, and contra-lateral patellar tendon rupture. The patient suffered from chronic renal failure and for the past year from tertiary hyperparathyroidism. Ruptured tendons were repaired and both knee were evaluated monthly for the next 12 months. Good functional recovery was achieved on both knees without relapse. This case emphasizes the importance of long-term high parathyroid hormone level in the etiology of tendons ruptures. PMID:19384613
Grecomoro, Giuseppe; Camarda, Lawrence; Martorana, Umberto
We tested four types of surgical repair for load to failure and distraction in a bovine model of Achilles tendon repair. A total of 20 fresh bovine Achilles tendons were divided transversely 4 cm proximal to the calcaneal insertion and randomly repaired using the Dresden technique, a Krackow suture, a triple-strand Dresden technique or a modified oblique Dresden technique, all using a Fiberwire suture. Each tendon was loaded to failure. The force applied when a 5 mm gap was formed, peak load to failure, and mechanism of failure were recorded. The resistance to distraction was significantly greater for the triple technique (mean 246.1 N (205 to 309) to initial gapping) than for the Dresden (mean 180 N (152 to 208); p = 0.012) and the Krackow repairs (mean 101 N (78 to 112; p < 0.001). Peak load to failure was significantly greater for the triple-strand repair (mean 675 N (453 to 749)) than for the Dresden (mean 327.8 N (238 to 406); p < 0.001), Krackow (mean 223.6 N (210 to 252); p < 0.001) and oblique repairs (mean 437.2 N (372 to 526); p < 0.001). Failure of the tendon was the mechanism of failure for all specimens except for the tendons sutured using the Krackow technique, where the failure occurred at the knot. The triple-strand technique significantly increased the tensile strength (p = 0.0001) and gap resistance (p = 0.01) of bovine tendon repairs, and might have advantages in human application for accelerated post-operative rehabilitation. PMID:22529088
Ortiz, C; Wagner, E; Mocoçain, P; Labarca, G; Keller, A; Del Buono, A; Maffulli, N
The ability of tendons to glide smoothly during muscle contraction is impaired after injury by fibrous adhesions that form between the damaged tendon surface and surrounding tissues. To understand how adhesions form we incubated excised tendons in fibrin gels (to mimic the homeostatic environment at the injury site) and assessed cell migration. We noticed cells exiting the tendon from only
Susan H. Taylor; Sarah Al-Youha; Tom van Agtmael; Yinhui Lu; Jason Wong; Duncan A. McGrouther; Karl E. Kadler; Sudha Agarwal
Ordered tissue like tendon is known to exhibit the magic-angle phenomenon in magnetic resonance investigations. Due to the anisotropic structure the transverse relaxation time T2 depends on the orientation of the tendon in the magnetic field. In medical imaging, relaxation measurements of tendon orientation are restricted by the size of the object and the space available in the magnet. For humans, tendon orientation can only be varied within small limits. As a consequence, the magic-angle phenomenon may lead to a misjudgement of tendon condition. It is demonstrated that the NMR-MOUSE (mobile universal surface explorer), a hand-held NMR sensor, can be employed to investigate the anisotropy of T2 in Achilles tendon in vivo. The NMR-MOUSE provides a convenient tool for analyzing the correlation of T2 and the physical condition of tendon.
Haken, R.; Blümich, B.
The aim of this study was to quantify the amount of tendon excursion and load experienced during simulated active and passive rehabilitation exercises. Six cadaver specimens were utilized to examine tendon excursion and load. Lateral fluoroscopic images were used to measure the excursions of metal markers placed in the flexor digitorum superficialis and profundus tendons of the index, middle, and ring fingers. Measurements were performed during ten different passive and active simulated motions. Mean tendon forces were higher in all active versus passive movements. Blocking movements placed the highest loads on the flexor tendons. Active motion resulted in higher tendon excursion than did passive motion. Simulated hook position resulted in the highest total tendon excursion and the highest inter-tendinous excursion. This knowledge may help optimize the management of the post-operative exercise therapy regimen. PMID:23221181
Sapienza, A; Yoon, H K; Karia, R; Lee, S K
Loss of Achilles tendon combined with overlying soft tissue loss is a challenging problem. Multiple techniques like tendon graft with coverage by soft tissue flap or composite flaps have been used. All these options are technically demanding. Reports do exist whereby muscle flaps bridging the defect used as cover in course of time could transmit the tendon force across the defect. We are presenting a case where a free gracilis muscle flap used to cover the soft tissue defect at the Achilles tendon at 2 years follow up provided stable cover and produced active function of the Achilles tendon allowing the patient to stand tip toe. Mechanism of its action has been analysed by MRI and M-mode ultrasound. While in primary Achilles tendon injury reconstruction is still the recommended option, in complex situations mere filling of the gap with the flap without formal reconstruction of the tendon could give good functional outcome. This technique can be used in demanding situations.
Sabapathy, S. Raja; Venkataramani, Hari; Latheef, Latheesh; Bhardwaj, Praveen
Ankle injuries are a frequent cause of patient visits to the emergency department and orthopaedic and primary care offices. Although lateral ligament sprains are the most common pathologic conditions, peroneal tendon subluxations occur with a similar inversion mechanism. Multiple grades of subluxation have been described with a recent addition of intrasheath subluxation. Magnetic resonance imaging is the best imaging modality
Jennifer A Roth; Walter C Taylor; Joseph Whalen
The cause of carpal tunnel syndrome in a 51 year-old female patient was the attachement of the flexor digitorum superficialis tendon to the palmar aponeurosis. Variations of the musculature in the hand are not only of anatomic interest, but are also of clinical significance in so far as they may present a source of diagnostic and therapeutic errors. PMID:3699592
In patients with tennis elbow, the common extensor tendon showed a pronounced reactive change consisting of mesenchymal cell proliferation along with aggregates of newly formed vascular channels. When studied ultrastructurally, many of the mesenchymal cells adjacent to the vascular channels were surrounded by a basal lamina, which is not normally seen around tenocytes. The cytoplasm of these cells showed features
Kiriti Sarkar; Hans K. Uhthoff
The repeated use of local steroid injections in the treatment of tenosynovitis in the active athlete is to be abandoned, not only because it masks the symptoms of tenosynovitis, giving the patient a false sense of security, but also because local injection of steroid decreases the tensile strength of tendon and predisposes it to complete rupture.
Louis J. Unverferth; Melvin L. Olix
This paper describes a novel bow spring and tendon actuator design for a haptic interface that provides high- bandwidth force transmission to the ìngers, with a large range of motion. This is combined with a low-cost step- per motor and a low-cost optical encoder, along with self- calibration and control compensation to produce a smooth force source with excellent hard
Dale A. Lawrence; Lucy Y. Pao; Sutha Aphanuphong
The paper describes tests on two concrete beams, prestressed with parallel-lay aramid ropes (Parafil). One beam had a length of 5m, with an I-beam section, and was stressed with a single, straight, unbonded tendon in a duct on the centerline. The other be...
C. J. Burgoyne G. B. Guimaraes J. J. Chambers
Two cats presented with bilateral flexor tendon contracture following onychectomy. This previously unreported complication proved to be painful and debilitating. Deep digital flexor tenectomy successfully resolved the problem. Twelve months after surgery, the first cat remains free of complications. The second cat recovered full limb function, but died of unrelated causes. PMID:15884646
Cooper, Maureen A; Laverty, Peter H; Soiderer, Emily E
Deep venous thrombosis (DVT) is a significant source of morbidity and mortality and is associated with many orthopedic procedures. Previous studies have reported highly variable DVT rates in patients with Achilles tendon rupture undergoing operative and nonoperative treatment. We performed a retrospective chart review for all patients who underwent Achilles tendon repair at our institution from January 2006 to February 2012. Patient data were collected from the electronic medical record system. A total of 115 patients were eligible for the present study. Of these patients, 27 (23.47%) with a surgically treated Achilles tendon rupture developed a symptomatic DVT either while waiting for, or after, surgical intervention, with approximately one third of these diagnosed before surgical intervention. Of the 27 patients with DVT, 3 had a proximal DVT and 24 had a distal DVT. One patient developed a pulmonary embolism. The DVT incidence was greater in the 2 older age groups (40 to 59 and 60 to 79 years) compared individually with the younger age group (20 to 39 years; p < .0026 and p < .0014, respectively). We have shown a high incidence of DVT after Achilles tendon rupture. We recommend a high level of suspicion for the signs and symptoms of DVT during the follow-up period. In addition, patient education and early mobilization should be advocated, especially for patients older than 40 years. Additional randomized controlled trials investigating any benefits to pharmaceutical DVT prophylaxis in this population are needed to establish evidence-based recommendations. PMID:23623625
Makhdom, Asim M; Cota, Adam; Saran, Neil; Chaytor, Ruth
The authors report on a rare case of multicentric giant cell tumor of the tendon sheath in the right index finger of a 76-year-old woman. In the present case, three lesions simultaneously arose at different sites in the same finger. Magnetic resonance imaging and intraoperative findings revealed no contiguity among the three lesions. A multicentric origin of the tumor is
Toshihiro Akisue; Tetsuji Yamamoto; Teruya Kawamoto; Toshiaki Hitora
Dislocation of the flexor hallucis longus tendon is an exceptional occurrence. To our knowledge, this is the first case ever reported of an intermittent dislocation in a 17-year-old woman; she was a synchronised swimmer. She consulted for a right internal retro-malleolar syndrome. Voluntary \\
M. Renard; J. Simonet; P. Bencteux; P. Raynaud; N. Biga; J. Thiébot
Many robotic hands or prosthetic hands have been developed in the last several decades, and many use tendon-driven mechanisms for their transmissions. Robotic hands are now built with underactuated mechanisms, which have fewer actuators than degrees of freedom, to reduce mechanical complexity or to realize a biomimetic motion such as flexion of an index finger. The design is heuristic and
Ryuta Ozawa; Kazunori Hashirii; Hiroaki Kobayashi
Abstract Two cats presented with bilateral flexor tendon contracture following onychectomy. This previously unreported complication proved to be painful and debilitating. Deep digital flexor tenectomy successfully resolved the problem. Twelve months after surgery, the first cat remains free of complications. The second cat recovered full limb function, but died of unrelated causes.
Ten athletes with distal biceps tendon ruptures that had been anatomically repaired with a double-incision technique were reviewed to determine their functional recovery. All of the patients were men, with an average age of 40 years (range, 25 to 49). Eight of the 10 patients were weight lifters or body builders, and 7 had participated on a competitive level at
Donald F. DAlessandro; Clarence L. Shields; James E. Tibone; Robert W. Chandler
Eccentric contractions, where the active muscle is stretched, can lead to muscle damage. One of the signs of damage is a rise in the whole-muscle passive tension. Here we have asked, how many eccentric contractions are necessary to produce a measurable rise in passive tension and can this be detected by the muscle's tension sensors, the tendon organs? Responses of
J. E. Gregory; D. L. Morgan; U. Proske
Tendon pathology is frequently sub-clinical prior to frank rupture, denoting the need for non-destructive methods of assessing disease presence and progression. Despite the lack of clinical presentation, previous studies have observed that distinct changes to the tendon microstructure are present, and that such qualitative changes have a dose-response relationship with the level of damage accumulated. These initial findings suggest that there is value in investigating the physical nature of damage within tendon, not only to better understand the pathological process, but to gain insight into reparative processes and develop treatments. However, a necessary first step towards carrying out these avenues of research is to develop diagnostic tools for quantitatively assessing the level of damage present. In this study, we established a dose-response relationship between a quantitative measure of structural damage and the level of global damage induced. Furthermore, we developed and validated an automated technique for quantifying matrix disorganization (damage), which correlates and co-localizes strongly with manual quantification. In combination, these findings allow us to measure the amount of damage accumulation of a region of tendon on a clinical scale, rapidly and accurately.
Sereysky, Jedd B.; Andarawis-Puri, Nelly; Ros, Stephen J.; Jepsen, Karl J.; Flatow, Evan L.
Three types of tendons were developed for tension leg platforms. Each type is a 500 mm diameter, 25 mm wall, 10 m long steel pipe that has forged connectors girth-welded at both ends, and has a yield strength of approximately 56 kgf/sq mm. The three-piece...
Y. Takeshi Y. Shiomi S. Yano N. Noudo H. Mimura
We describe the imaging and pathologic features of a case of intratendinous patellar gouty tophus incidentally discovered in a patient with knee pain. The possibility of intratendinous gouty tophus must be kept in mind by sports physicians, especially in the management of patellar tendinopathy in athletes. It may be associated with other injuries, such as enthesopathies or partial tendon tears. PMID:22457228
Rodas, Gil; Pedret, Carles; Català, Jordi; Soler, Robert; Orozco, Lluís; Cusi, Manuel
Tendon properties have an important effect on the mechanical behaviour of muscles, with compliant tendons allowing near-isometric muscle contraction and facilitating elastic energy storage and recoil. Stiff tendons, in contrast, facilitate rapid force transfer and precise positional control. In humans, the long Achilles tendon contributes to the mechanical efficiency of running via elastic energy storage and recovery, and its presence has been linked to the evolution of habitual bipedalism. Gibbons also possess relatively long hind limb tendons; however, their role is as yet unknown. Based on their large dimensions, and inferring from the situation in humans, we hypothesize that the tendons in the gibbon hind limb will facilitate elastic energy storage and recoil during hind-limb-powered locomotion. To investigate this, we determined the material properties of the gibbon Achilles and patellar tendon in vitro and linked this with available kinematic and kinetic data to evaluate their role in leaping and bipedalism. Tensile tests were conducted on tendon samples using a material testing machine and the load-displacement data were used to calculate stiffness, Young's modulus and hysteresis. In addition, the average stress-in-life and energy absorption capacity of both tendons were estimated. We found a functional difference between the gibbon Achilles and patellar tendon, with the Achilles tendon being more suitable for elastic energy storage and release. The patellar tendon, in contrast, has a relatively high hysteresis, making it less suitable to act as elastic spring. This suggests that the gibbon Achilles tendon might fulfil a similar function as in humans, contributing to reducing the locomotor cost of bipedalism by acting as elastic spring, while the high stiffness of the patellar tendon might favour fast force transfer upon recoil and, possibly, enhance leaping performance. PMID:23868842
Vereecke, Evie E; Channon, Anthony J
Tendon pain after repair of an acute Achilles tendon rupture can result from suture granuloma formation, modification of the threshold of the pain receptors inside the tendon by scar tissue, expansion of the paratenon by tendon enlargement with secondary stimulation of mechanoreceptors, or underlying tendon degeneration. In the present technique report, an endoscopic technique of Achilles tenolysis for denervation and debulking is described that might be applicable in cases in which conservative treatment fails to alleviate the pain. PMID:23085384
Lui, Tun Hing
Background: Postfixation loosening within the Krackow stitch—tendon construct may be associated with gap formation in patellar tendon repair.Hypothesis: Pretensioning the Krackow stitch—tendon construct decreases postfixation gap formation in transpatellar patellar tendon repair.Study Design: Controlled laboratory study.Methods: Patellar tendon rupture was simulated in 8 pairs of cadaveric knees. Standard manual traction was used in all specimens to remove Krackow stitch slack.
Erik M. Krushinski; Brent G. Parks; Richard Y. Hinton
The function of the posterior tibial (PT) tendon is to stabilize the hindfoot against valgus and eversion forces. It functions as the primary invertor of the foot and assists the Achilles tendon in plantar flexion. The PT tendon is a stance phase muscle, firing from heel strike to shortly after heel lift-off. It decelerates subtalar joint pronation after heel contact. It functions as a powerful subtalar joint supinator and as a support of the medial longitudinal arch. The action of the tendon travels to the transverse tarsal joints, locking them and allowing the gastrocnemius to support heel rise. Acute injuries of the PT tendon are rare and mostly affect the active middle-aged patient or they are the result of complex injuries to the ankle joint complex. Dysfunction of the PT tendon following degeneration and rupture, in contrast, has shown an increasing incidence in recent years. To which extent changed lifestyle, advancing age, comorbidities, and obesity play a role has not yet been clarified in detail. Dysfunction of the PT tendon results in progressive destabilization of the hind- and midfoot. Clinically, the ongoing deformation of the foot can be classified into four stages: in stage 1, the deformity is distinct and fully correctable; in stage II, the deformity is obvious, but still correctable; in stage III, the deformity has become stiff; and in stage IV, the ankle joint is also involved in the deformity. Treatment modalities depend on stage: while conservative measures may work in stage I, surgical treatment is mandatory for the later stages. Reconstructive surgery is advised in stage II, whereas in stage III and IV correcting and stabilizing arthrodeses are advised. A promising treatment option for stage IV may be adding an ankle prosthesis to a triple arthrodesis, as long as the remaining competence of the deltoid ligament is sufficient. An appropriate treatment is mandatory to avoid further destabilization and deformation of the foot. Failures of treatment result mostly from underestimation of the problem or insufficient treatment of existing instability and deformity. PMID:21088955
Hintermann, B; Knupp, M
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.
O'Brien, Thomas D; Reeves, Neil D; Baltzopoulos, Vasilios; Jones, David A; Maganaris, Constantinos N
Corticosteroid injection is commonly used to treat tendon injuries but is often associated with tendon rupture and impaired tendon healing. The effects of dexamethasone on tenocytes have been studied in vitro but only using high concentrations of dexamethasone in monolayer cultures of tenocytes over short periods of time. We have therefore investigated the effects of physiological and pharmacological concentrations of dexamethasone on monolayer cultures of tenocytes over extended time periods. We have also used fibroblastic-colony forming unit cultures to examine the effects of dexamethasone on a progenitor cell population located in tendons. Culturing tenocytes in the presence of dexamethasone for a period of 24 days resulted in a concentration-related decrease in cell number and collagen synthesis as compared to control cultures. This effect was time dependent with cell number in both dexamethasone-treated and control cultures leveling off after 14 days with the control cultures reaching higher cell densities. In contrast in control cultures, collagen accumulation continued to increase until week 4, whereas in the presence of dexamethasone, this tended to level off after 14 days. To study the role of progenitor cell recruitment, the effects of dexamethasone were investigated using the fibroblastic-colony forming unit assay. Treatment with dexamethasone at concentrations of 0.1 nM to 10 microM leads to a progressive reduction in mean colony size as compared to control cultures. Colony number remained constant at concentrations below 10 nM but fell progressively at concentrations above this. In conclusion, dexamethasone reduces both cell number and collagen synthesis in tenocyte cultures in a concentration-dependent manner by both direct effects on tenocyte proliferation and collagen accumulation, and also by modulating the recruitment of tendon progenitor cells. PMID:16435354
Scutt, Nanette; Rolf, Christer G; Scutt, Andrew
Passive elastic behavior of tendon tissue from rats subjected to different dietary treatments was characterized. For that purpose, twenty-four weanling Wistar rats (41.02 ± 0.16 g) were randomly distributed into four groups. During 88 days each group was fed on different diets: control diet and diets containing advanced glycation end products (AGEs) from glucose-lysine model system, from bread crust and bread dough, respectively. After the trial animals were sacrificed and tendon samples were extracted and tested mechanically to fracture in a uniaxial tensile test machine. A transversely-hyperelastic model was formulated based on stress-strain relationships and its parameters were fit to the experimental data using the Levenberg-Marquardt optimization algorithm. Material parameters were incorporated in a finite element model to study different stress-strain distributions in a muscle-tendon unit. Results show higher strains and stresses in the muscle belly when properties of a stiffer tendon associated with a diet rich in AGEs are included in the model. A real increase in this mechanical response of the tissue could imply possible pain in joint mobility. PMID:23064866
Grasa, J; Calvo, B; Delgado-Andrade, C; Navarro, M P
Tendons play a significant role in the modulation of forces transmitted between bones and skeletal muscles and consequently protect muscle fibers from contraction-induced, or high-strain, injuries. Myostatin (GDF-8) is a negative regulator of muscle mass. Inhibition of myostatin not only increases the mass and maximum isometric force of muscles, but also increases the susceptibility of muscle fibers to contraction-induced injury. We hypothesized that myostatin would regulate the morphology and mechanical properties of tendons. The expression of myostatin and the myostatin receptors ACVR2B and ACVRB was detectable in tendons. Surprisingly, compared with wild type (MSTN+/+) mice, the tendons of myostatin-null mice (MSTN?/?) were smaller and had a decrease in fibroblast density and a decrease in the expression of type I collagen. Tendons of MSTN?/? mice also had a decrease in the expression of two genes that promote tendon fibroblast proliferation: scleraxis and tenomodulin. Treatment of tendon fibroblasts with myostatin activated the p38 MAPK and Smad2/3 signaling cascades, increased cell proliferation, and increased the expression of type I collagen, scleraxis, and tenomodulin. Compared with the tendons of MSTN+/+ mice, the mechanical properties of tibialis anterior tendons from MSTN?/? mice had a greater peak stress, a lower peak strain, and increased stiffness. We conclude that, in addition to the regulation of muscle mass and force, myostatin regulates the structure and function of tendon tissues.
Mendias, Christopher L.; Bakhurin, Konstantin I.; Faulkner, John A.
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.
Heinemeier, Katja Maria; Schjerling, Peter; Heinemeier, Jan; Magnusson, Stig Peter; Kjaer, Michael
The musculoskeletal system (muscle-tendon-bone) demonstrates numerous age-related changes, with modifications in tendons the least well studied, although increased predisposition to tendinopathy and rupture have been reported. In order to gain insights into the basis of age-associated increase in tendon injuries, we compared Achilles and tibialis anterior tendons and myotendinous junctions (MTJs) from 3- to 5- and 22- to 25-month-old rats for underlying structure and composition. Significant decreases were observed by qRT-PCR for collagen I, III, and V mRNA expression in tendons of old rats, but immunostaining detected no apparent differences in collagen I and V expression on the protein level. Tendons of old compared with young rats had decreased mRNA expression levels of proteoglycan 4 (PRG4) and elastin (Eln), but no differences in the mRNA expression of connective tissue growth factor, TGF-beta 1, or stromal cell-derived factor 1. For PRG4, immunostaining showed good correlation with qRT-PCR results. This is the first study to show reductions in PRG4 in tendons and MTJs of old rats. Decreased PRG4 expression in tendons could result in increased tendon stiffness and may be associated with decreased activity in the elderly. The diminished collagen mRNA expression in combination with decreased PRG4 and Eln mRNA expression may be associated with increased risk of tendon injury with aging. PMID:23354684
Kostrominova, Tatiana Y; Brooks, Susan V
We investigated the hypothesis that exogenous collagen cross-linking can augment intact regions of tendon to mitigate mechanical propagation of partial tears. We first screened the low toxicity collagen cross-linkers genipin, methylglyoxal and ultra-violet (UV) light for their ability to augment tendon stiffness and failure load in rat tail tendon fascicles (RTTF). We then investigated cross-linking effects in load bearing equine superficial digital flexor tendons (SDFT). Data indicated that all three cross-linking agents augmented RTTF mechanical properties but reduced native viscoelasticity. In contrast to effects observed in fascicles, methylglyoxal treatment of SDFT detrimentally affected tendon mechanical integrity, and in the case of UV did not alter tendon mechanics. As in the RTTF experiments, genipin cross-linking of SDFT resulted in increased stiffness, higher failure loads and reduced viscoelasticity. Based on this result we assessed the efficacy of genipin in arresting tendon tear propagation in cyclic loading to failure. Genipin cross-linking secondary to a mid-substance biopsy-punch significantly reduced tissue strains, increased elastic modulus and increased resistance to fatigue failure. We conclude that genipin cross-linking of injured tendons holds potential for arresting tendon tear progression, and that implications of the treatment on matrix remodeling in living tendons should now be investigated. PMID:22102295
Fessel, Gion; Wernli, Jeremy; Li, Yufei; Gerber, Christian; Snedeker, Jess G
Background The purpose of the current study was to investigate the effects of aging on tendon response to repetitive exposures of stretch-shortening cycles (SSC's). Methods The left hind limb from young (3 mo, N = 4) and old (30 mo, N = 9) male Fisher 344 × Brown Norway rats were exposed to 80 maximal SSCs (60 deg/s, 50 deg range of motion) 3x/week for 4.5 weeks in vivo. After the last exposure, tendons from the tibialis anterior muscle were isolated, stored at -80°C, and then tested using a micro-mechanical testing machine. Deformation of each tendon was evaluated using both relative grip-to-grip displacements and reference marks via a video system. Results At failure, the young control tendons had higher strain magnitude than the young exposed (p < 0.01) and the old control tendons (p < .0001). Total load at inflection was affected by age only (p < 0.01). Old exposed and control tendons exhibited significantly higher loads at the inflection point than their young counterparts (p < 0.05 for both comparisons). At failure, the old exposed tendons carried higher loads than the young exposed tendons (p < 0.05). Stiffness was affected by age only at failure where the old tendons exhibited higher stiffness in both exposed and control tendons than their young counterparts (p < 0.05 and p < 0.01, respectively). Conclusion The chronic protocol enhanced the elastic stiffness of young tendon and the loads in both the young and old tendons. The old exposed tendons were found to exhibit higher load capacity than their younger counterparts, which differed from our initial hypothesis.
Ensey, James S; Hollander, Melinda S; Wu, John Z; Kashon, Michael L; Baker, Brent B; Cutlip, Robert G
Purpose: The purpose of this study was to compare intraosseous graft healing between the doubled flexor tendon (FT) graft and the bone–patellar tendon–bone (BPTB) graft in anterior cruciate ligament (ACL) reconstruction. Type of Study: Randomized trial. Methods: A biomechanical and histologic study was conducted with 24 adult beagle dogs. Bilateral ACL reconstructions were performed in each animal. Autogenous doubled FT
Fumihisa Tomita; Kazunori Yasuda; Susumu Mikami; Toshihiko Sakai; Shuji Yamazaki; Harukazu Tohyama
Latissimus dorsi tendon transfer (LDTT) is technically challenging. In order to clarify the local structural anatomy, we undertook a morphometric study using six complete cadavers (12 shoulders). Measurements were made from the tendon to the nearby neurovascular structures with the arm in two positions: flexed and internally rotated, and adducted in neutral rotation. The tendon was then transferred and measurements were taken from the edge of the tendon to a reference point on the humeral head in order to assess the effect of a novel two-stage release on the excursion of the tendon. With the shoulder flexed and internally rotated, the mean distances between the superior tendon edge and the radial nerve, brachial artery, axillary nerve and posterior circumflex artery were 30 mm (26 to 34), 28 mm (17 to 39), 21 mm (12 to 28) and 15 mm (10 to 21), respectively. The mean distance between the inferior tendon edge and the radial nerve, brachial artery and profunda brachii artery was 18 mm (8 to 27), 22 mm (15 to 32) and 14 mm (7 to 21), respectively. Moving the arm to a neutral position reduced these distances. A mean of 15 mm (8 to 21) was gained from a standard soft-tissue release, and 32 mm (20 to 45) from an extensile release. These figures help to define further the structural anatomy of this region and the potential for transfer of the latissimus dorsi tendon. PMID:23539704
Henry, P D G; Dwyer, T; McKee, M D; Schemitsch, E H
We compared the outcome of anterior cruciate ligament reconstruction using hamstring tendon autograft with outcome using patellar tendon autograft at 2 years after surgery. Patients had an isolated anterior cruciate ligament injury and, apart from the grafts, the arthroscopic surgical technique was identical. Prospective assessment was performed on 90 patients with isolated anterior cruciate ligament injury undergoing reconstruction with a
Ian S. Corry; Jonathan M. Webb; Amanda J. Clingeleffer; Leo A. Pinczewski
Tendons consist of parallel longitudinal rows of cells separated by collagen fibres. The cells are in intimate contact longitudinally within rows, and laterally via sheet-like lateral cell processes between rows. At points of contact, they are linked by gap junctions. Since tendons stretch under load, such cell contacts require protection. Here we describe the organisation of the actin cytoskeleton and
J. R Ralphs; A. D Waggett; M Benjamin
Background There is a paucity of data regarding molecular markers that identify the phenotype of the tendon cell. This study aims to quantify gene expression markers that distinguish between tendon fibroblasts and other mesenchymal cells which may be used to investigate tenogenesis. Methods Expression levels for 12 genes representative of musculoskeletal tissues, including the proposed tendon progenitor marker scleraxis, relative to validated reference genes, were evaluated in matched samples of equine tendon (harvested from the superficial digital flexor tendon), cartilage and bone using quantitative PCR (qPCR). Expression levels of genes associated with tendon phenotype were then evaluated in healthy, including developmental, and diseased equine tendon tissue and in tendon fibroblasts maintained in both monolayer culture and in three dimensional (3D) collagen gels. Results Significantly increased expression of scleraxis was found in tendon compared with bone (P = 0.002) but not compared to cartilage. High levels of COL1A2 and scleraxis and low levels of tenascin-C were found to be most representative of adult tensional tendon phenotype. While, relative expression of scleraxis in developing mid-gestational tendon or in acute or chronically diseased tendon did not differ significantly from normal adult tendon, tenascin-C message was significantly upregulated in acutely injured equine tendon (P = 0.001). Relative scleraxis gene expression levels in tendon cell monolayer and 3D cultures were significantly lower than in normal adult tendon (P = 0.002, P = 0.02 respectively). Conclusion The findings of this study indicate that high expression of both COL1A2 and scleraxis, and low expression of tenascin-C is representative of a tensional tendon phenotype. The in vitro culture methods used in these experiments however, may not recapitulate the phenotype of normal tensional tendon fibroblasts in tissues as evidenced by gene expression.
Taylor, Sarah E; Vaughan-Thomas, Anne; Clements, Dylan N; Pinchbeck, Gina; Macrory, Lisa C; Smith, Roger KW; Clegg, Peter D
Summary Aging is a major risk factor for tendon injury and impaired tendon healing, but the basis for these relationships remains poorly understood. Here we show that rat tendon-derived stem/progenitor cells (TSPCs) differ in both self-renewal and differentiation capability with age. The frequency of TSPCs in tendon tissues of aged animals is markedly reduced based on colony formation assays. Proliferation rate is decreased, cell cycle progression is delayed and cell fate patterns are also altered in aged TSPCs. In particular, expression of tendon lineage marker genes decreased while adipocytic differentiation increased. Cited2, a multi-stimuli responsive transactivator involved in cell growth and senescence, was also downregulated in aged TSPCs while CD44, a matrix assembling and organizing protein implicated in tendon healing, was upregulated, suggesting that these genes participate in the control of TSPC function.
Zhou, Zuping; Akinbiyi, Takintope; Xu, Lili; Ramcharan, Melissa; Leong, Daniel J.; Ros, Stephen J.; Colvin, Alexis C.; Schaffler, Mitchell B.; Majeska, Robert J.; Flatow, Evan L.; Sun, Hui B.
The effect of varying degrees of flexor sheath integrity (sheath excised, incised, or incised and repaired) on the uptake of /sub 2/H-proline by chicken flexor tendons in Zone II was studied. The tendons were either: normal and uninjured, lacerated and repaired, or uninjured except for vinculum longum ligation. Different degrees of sheath integrity did not influence the uptake of /sub 2/H-proline by the tendons. The tendon does not appear to be dependent on a synovial environment for nutrients and is capable of obtaining these nutrients by diffusion from the surrounding extracellular tissue fluid. Diffusion is the primary nutrient pathway to the flexor tendon in this area, because removing its major vascular attachment (i.e., the vinculum longum) did not effect proline uptake. Careful closure of the sheath with restoration of a synovial environment does not appear to be necessary for tendon nutrition.
Peterson, W.W.; Manske, P.R.; Lesker, P.A.
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
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.
Karimpoor, Mahta; Screen, Hazel; Morrissey, Dylan
A 33-year-old man sustained an acute Achilles tendon rupture which was surgically repaired. Early nonweight-bearing range of motion and strengthening of the ankle and the repaired muscle unit was allowed at 4 weeks postoperatively, and closed-chain dorsiflexion was allowed at 6 weeks. Casts and/or ankle-foot orthoses were used to continue protection of the Achilles from reinjury and full body forces as the repaired muscle continued to heal. In this case, range-of-motion and strengthening exercises were initiated at an earlier stage in the treatment program without compromising the result. When indicated, this treatment will provide excellent posttraumatic function of the surgically repaired Achilles tendon in the motivated and compliant patient.
Dugan, Dirk H.; Hobler, Christopher K.
The acute Achilles tendon rupture is a typical sports injury, which most commonly occurs in men. The diagnosis is easy to make but there is no consensus on best treatment: surgical or conservative treatment? In the case of surgical repair, the risk of a re-rupture is considerably smaller compared to conservative treatment by cast immobilisation. The results of conservative treatment using a functional brace are not good enough to serve as a good alternative for surgery. If surgical treatment is chosen, minimally invasive surgery should be performed. The risk of re-rupture is the same as in open reconstruction but the risk of, a possibly severe, wound infection is smaller. Independent of the suture technique chosen, the postoperative rehabilitation should be functional as opposed to full immobilisation. Too little is currently known about the treatment of acute Achilles tendon rupture for a broadly supported treatment guideline to be realised. PMID:19785867
Kolfschoten, Nicky; Metz, Roderik; Verleisdonk, Egbert-Jan M M
There are very few reports in the literature on the results of surgery for ganglia of the flexor tendon sheaths of the digits. We reviewed 24 patients operated for flexor tendon sheath ganglia 8 (3–11) years previously. Two operations were for recurrences and one of these recurred again. There was one permanent digital nerve injury and one patient complained of cold sensibility. VAS (0=best; 100=worst) for mean general complaints from the hand was remembered as 51 before surgery and was 5 at review. Mean pain at review was reported as VAS 4 and general satisfaction with the operation as VAS 3. All stated that they would have consented to surgery if they had known the outcome in advance. We conclude that the results of surgery are good, although complications do occur.
Finsen, Vilhjalmur; Haberg, ?yvind; Borchgrevink, Grethe Elisabeth
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.
Kuo, Chung-Hsien; Chiou, Kuo-Wei
The hierarchical architecture and complex biologic functions of native sheath make its biomimetic substitute a daunting challenge. In this study, a biomimetic bilayer sheath membrane consisting of hyaluronic acid-loaded poly(?-caprolactone) (HA/PCL) fibrous membrane as the inner layer and PCL fibrous membrane as the outer layer was fabricated by a combination of sequential and microgel electrospinning technologies. This material was characterized by mechanical testing and analysis of morphology, surface wettability, and drug release. Results of an in vitro drug release study showed sustained release. The outer layer had fewer cells proliferating on its surface compared to tissue culture plates or the inner layer. In a chicken model, peritendinous adhesions were reduced and tendon gliding were improved by the application of this sheath membrane. Taken together, our results demonstrate that such a biomimetic bilayer sheath can release HA sustainably as well as promoting tendon gliding and preventing adhesion. PMID:23025492
Liu, Shen; Zhao, Jingwen; Ruan, Hongjiang; Tang, Tingting; Liu, Guangwang; Yu, Degang; Cui, Wenguo; Fan, Cunyi
The epidemiology of Achilles tendon ruptures was examined during the 13-year period 1984-1996 in a Danish county. Five hospitals, serving a population of 220,000 cooperated. There were 718 ruptures, 544 men (75.8%) and 174 women (24.2%). The male to female ratio was 3:1. The average age was 42.1 years (3-82) and 62% were between 30-49 years. 74.2% of the ruptures were sport-related and 89% of these occurred in ball and racket games. The annual incidence of achilles tendon ruptures increased from 18.2/10(5) inhabitants in 1984 to 37.3/10(5) in 1996. The peak incidence in sport-related ruptures occurred in the age group 30-49 years, but ruptures not related to sport occurred in older patients with a peak incidence in those 50-59 years. PMID:10211195
Houshian, S; Tscherning, T; Riegels-Nielsen, P
PURPOSE OF THE STUDY To present the results of surgical repair of ruptures of the distal tendon of the biceps brachii muscle and thus show the adequacy of this treatment. MATERIAL Between 1987 and 2006, 19 patients had surgery for distal biceps tendon rupture. Only one side was affected in each patient. All patients were men between 28 and 69 years (average age, 47.5 years) at the time of injury (surgery). When the patients were evaluated at the end of 2007, 18 patients were included, because one died a year after surgery. METHODS The surgical repair always included a single-incision anatomical reattachment into the radial tuberosity. In 11 patients, a modified Mac Reynolds method with screw and washer fixation was used; in seven patients the insertion was fixed with Mitek anchors and, in one, it was sutured to the adjacent soft tissues. The average follow-up was 7 years (range, 1 to 20.5 years). The patients were evaluated for the cause of injury, their physical activity, age, dominance of the injured arm, surgical procedure and complications. RESULTS In 18 patients surgical repair was done early and, in one, at 16 days after injury. In all of them the tendon was detached from its site of insertion, but never torn. The intra-operative complications included, in one patient, bleeding owing to iatrogenic damage to a branch of the brachial artery, and difficult separation of the tendon due to its previous healed injury in another patient. Early post-operative complications included superficial skin necrosis in one patient and transient neurological deficit of the dorsal brand of the radial nerve and of the lateral cutaneous nerve of the forearm in two and one patient, respectively. The late complications were heterotropic ossification in three patients and screw migration in the one treated by the Mac Reynolds method. Excellent results were recorded in 11 patients (61 %), and good outcomes with a slight restriction of motion or muscle strength not limiting the patient's physical activities were in six (33.5 %) patients; only one patient (5.5 %) experienced pain on moderate exercise and had recurrent heterotropic ossification. Apart from this condition, there was no difference in the frequency of complications associated with the method used. DISCUSSION Only sparse information on distal biceps tendon ruptures has been available in the relevant Czech literature and, if so, only small groups with short follow-ups have been involved. Conservative treatment or the methods of non-anatomical reattachment have poor functional outcomes. Much better results are achieved by anatomical reattachment. Based on our experience with the Mac Reynolds technique, an anterior single-incision approach using fixation with Mitek anchors can be recommended. CONCLUSIONS Early surgical repair involving anatomical reattachment from the anterior singleincision approach with two Mitek anchors is recommended when a rupture of the distal tendon insertion of the biceps brachii is diagnosed. Key words: biceps radii muscle, biceps tendon injury, tendon fixation, bone screw and washer use. PMID:19268049
Behounek, J; Hrubina, M; Skoták, M; Krumpl, O; Zahálka, M; Dvorák, J; Fucík, M
Background. Repetitive motion of the hand has been suggested as a major factor of pathogenesis of cumulative trauma disorders (e.g., carpal tunnel syndrome). The purpose of this study was to investigate the 3D displacement of the median nerve and extrinsic finger flexor tendons (flexor digitorum superficialis; flexor digitorum profundus) as a function of flexion\\/extension of metacarpophalangeal joints of the index
U. Chris Ugbolue; Wei-Hsiu Hsu; Robert J. Goitz; Zong-Ming Li
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
Maclellan, G. E.; Vyvyan, Barbara
Actuators and gear trains of most biped humanoid robots are divergently allocated on the links of two legs. Disadvantages\\u000a of such a mechanical design are complicated wiring of power cord and sensing\\/ control signal bundles and imprecise kinetics\\u000a models of mixed link-and-actuator structures. Based on these drawbacks, this paper proposes a tendon-driven mechanism to develop\\u000a a lower body structure of
Chung-Hsien Kuo; Kuo-Wei Chiou
Abstract A novel technique,to estimate the contribution of finger extensor tendons,to joint moment,generation,was proposed. Effective static moment arms (ESMAs), which represent the net effects of the tendon force on joint moments in static finger postures, were estimated for the 4 degrees of freedom (DOFs) in the index finger. Specifically, the ESMAs for the five tendons contributing to the finger extensor
Sang Wook Lee; Hua Chen; Joseph D. Towles; Derek G. Kamper
Purpose Extensor tendon rupture on the dorsum of the wrist is commonly seen in patients with rheumatoid arthritis (RA). The diagnosis\\u000a of tendon rupture is usually straightforward, but it is sometimes difficult in the hand with complex deformity. The purposes\\u000a of this study were to investigate the reliability of three-dimensional computed tomography (3DCT) imaging of extensor tendons\\u000a in the rheumatoid wrist
Asami Abe; Hajime Ishikawa; Akira Murasawa; Kiyoshi Nakazono
Platelet-rich plasma (PRP) containing hepatocyte growth factor (HGF) and other growth factors are widely used in orthopaedic/sports medicine to repair injured tendons. While PRP treatment is reported to decrease pain in patients with tendon injury, the mechanism of this effect is not clear. Tendon pain is often associated with tendon inflammation, and HGF is known to protect tissues from inflammatory damages. Therefore, we hypothesized that HGF in PRP causes the anti-inflammatory effects. To test this hypothesis, we performed in vitro experiments on rabbit tendon cells and in vivo experiments on a mouse Achilles tendon injury model. We found that addition of PRP or HGF decreased gene expression of COX-1, COX-2, and mPGES-1, induced by the treatment of tendon cells in vitro with IL-1?. Further, the treatment of tendon cell cultures with HGF antibodies reduced the suppressive effects of PRP or HGF on IL-1?-induced COX-1, COX-2, and mPGES-1 gene expressions. Treatment with PRP or HGF almost completely blocked the cellular production of PGE2 and the expression of COX proteins. Finally, injection of PRP or HGF into wounded mouse Achilles tendons in vivo decreased PGE2 production in the tendinous tissues. Injection of platelet-poor plasma (PPP) however, did not reduce PGE2 levels in the wounded tendons, but the injection of HGF antibody inhibited the effects of PRP and HGF. Further, injection of PRP or HGF also decreased COX-1 and COX-2 proteins. These results indicate that PRP exerts anti-inflammatory effects on injured tendons through HGF. This study provides basic scientific evidence to support the use of PRP to treat injured tendons because PRP can reduce inflammation and thereby reduce the associated pain caused by high levels of PGE2.
Zhang, Jianying; Middleton, Kellie K.; Fu, Freddie H.; Im, Hee-Jeong; Wang, James H-C.
Irradiation sterilization is in wide use among tissue banks, for both hard and soft tissue grafts. Irradiation of tendon can impair its mechanical properties. Following implantation of a tendon graft, re-vascularization and resorption processes reduce its mechanical performance. Tendon with severely impaired properties may not be suitable for use as a load-bearing graft, e.g. as anterior cruciate ligament replacement. An
C. W. Smith; J. N. Kearney
Achilles tendon surgery is quite common, typical indications being acute tendon rupture and chronic tendinitis. Post-operative wound infection or skin necrosis occurs in 2.4–5% of these operations. Soft tissue reconstruction of the Achilles tendon region presents a challenge due to the limited amount of local tissue available. We interviewed 25 consecutive patients with a post-operative skin defect, caused by infection
Antti Koski; Erkki Tukiainen; Sinikka Suominen; Sirpa Asko-Seljavaara
Platelet-rich plasma (PRP) containing hepatocyte growth factor (HGF) and other growth factors are widely used in orthopaedic/sports medicine to repair injured tendons. While PRP treatment is reported to decrease pain in patients with tendon injury, the mechanism of this effect is not clear. Tendon pain is often associated with tendon inflammation, and HGF is known to protect tissues from inflammatory damages. Therefore, we hypothesized that HGF in PRP causes the anti-inflammatory effects. To test this hypothesis, we performed in vitro experiments on rabbit tendon cells and in vivo experiments on a mouse Achilles tendon injury model. We found that addition of PRP or HGF decreased gene expression of COX-1, COX-2, and mPGES-1, induced by the treatment of tendon cells in vitro with IL-1?. Further, the treatment of tendon cell cultures with HGF antibodies reduced the suppressive effects of PRP or HGF on IL-1?-induced COX-1, COX-2, and mPGES-1 gene expressions. Treatment with PRP or HGF almost completely blocked the cellular production of PGE2 and the expression of COX proteins. Finally, injection of PRP or HGF into wounded mouse Achilles tendons in vivo decreased PGE2 production in the tendinous tissues. Injection of platelet-poor plasma (PPP) however, did not reduce PGE2 levels in the wounded tendons, but the injection of HGF antibody inhibited the effects of PRP and HGF. Further, injection of PRP or HGF also decreased COX-1 and COX-2 proteins. These results indicate that PRP exerts anti-inflammatory effects on injured tendons through HGF. This study provides basic scientific evidence to support the use of PRP to treat injured tendons because PRP can reduce inflammation and thereby reduce the associated pain caused by high levels of PGE2. PMID:23840657
Zhang, Jianying; Middleton, Kellie K; Fu, Freddie H; Im, Hee-Jeong; Wang, James H-C
Recently, Baratta and Solomonow J. Biomechanics24, 109–116 (1991) studied the effect of tendon on muscle-tendon complex behavior in cat tibialis anterior (TA) muscle. This was done by determining the relation between neural stimulation and muscle force in a dynamic isometric experiment, both before and after the removal of the distal tendon. From their results, Baratta and Solomonow concluded that in
Arthur J. van Soest; Peter A. Huijing; Moshe Solomonow
Achilles tendon injuries are common in runners. The aim of the present study was to analyse the training programme, any Achilles tendon problems, muscle eightness and range of motion of the ankle joint, and concentric and eccentric musle torques of the calf muscles in middle-distance runners with and without Achilles tendon problems. Eighty-three middle-distance runners answered a questionnaire on their
Y. Haglund-Åkerlind; E. Eriksson
Background: The changes associated with Achilles insertional tendinopathy (AIT) are seen in the anterior portion of the Achilles tendon near its calcaneal insertion. Strain behavior of this portion of the tendon was evaluated.Hypothesis: The highest strains are in the anterior portion of the tendon.Study Design: Controlled laboratory study.Methods: Six cadaveric legs were tested. While moving through a functional range of
Jeffrey Lyman; Paul S. Weinhold; Louis C. Almekinders
Background: The results of revision anterior cruciate ligament reconstruction are limited in the current literature, and no studies have previously documented the outcome of revision anterior cruciate ligament reconstruction using solely hamstring tendon grafts.Hypothesis: Revision anterior cruciate ligament reconstruction with 4-strand hamstring tendon graft affords acceptable results and is comparable to reported outcomes with the bone–patellar tendon–bone graft.Study Design: Case
Lucy J. Salmon; Leo A. Pinczewski; Vivianne J. Russell; Kathryn Refshauge
A tendon-driven multijoint robot is a humanlike robot which is driven by a tendon-driven actuator. One of the problems is that the complexity of the tendon-driven multijoint robot body structure. The complexity makes it difficult to control body by commonly used methods which are based on a dynamics computation of a physical robot model. We proposed a appropriate control method
Takuma Shirai; Junichi Urata; Yuto Nakanishi; Kei Okada; Masayuki Inaba
By means of scanning and transmissive electron microscopy, the construction of the fibrous framework of the human skeletal muscles, fasciae and tendons has been investigated and its morphofunctional analysis has been performed. The fibrous framework of the endomysium is presented as a complexly organized system of anastomosing fibers of the connective tissue, forming a net-like construction. The fibrous structures of the framework are united into a whole construction by connecting fibers and fibrils. Different types of structural interconnection of collagenous fibers with sarcolemma are revealed. The structure of the fibrous framework both in different muscles and within one muscle has certain peculiarities. The main constructive element of the fascial fibrous framework make large anastomosing collagenous fibers, their architectonics is stabilized by connective fibers and fibrils. The construction of the tendinous fibrous framework is characterized by a pronounced anisotropia of the largest collagenous fibers and a developed network of connective structures both on the surface and inside the collagenous fibers. Structural mechanisms, interconnecting muscles and tendons, are demonstrated. Presence of anastomoses between the fibrils in the composition of the collagenous fibers in the fascia and Achilles tendon are stated. Together with the peculiarities existing, the general principle of the structural organization of the fibrous framework of the muscle system is the net-like constructure dependent on presence of anastomoses and elements of the connective system between the fibrous structures. Depending on the organ's function, the construction of the network acquires certain specific morphological forms. PMID:2936318
Khoroshkov, Iu A; Odintsova, N A
Purpose To investigate the degree of reunion in rabbit eyes of the superior oblique tendon after several surgical weakening procedures. Methods A total of 32 rabbits (64 eyes) were used in this study. The rabbits were randomly assigned to four groups, eight rabbits (16 eyes) in the tenotomy group, eight rabbits (16 eyes) in the tenectomy group, eight rabbits (16 eyes) in the disinsertion group and eight rabbits (16 eyes) in the recession group. The degree of reunion or reattachment of the superior oblique tendon on the globe were examined on four eyes in each group at postoperative weeks two, four, six and eight. Results At eight weeks, the newly created insertion site remained at the same site in all eyes in the recession group, and the distal end of the superior oblique tendon was reattached at the medial border of the superior rectus muscle in all four eyes in the tenotomy and disinsertion groups, and in three of four eyes in the tenectomy group. Conclusions From this experimental study, it was speculated that superior oblique recession is more effective than other superior oblique weakening procedures. This result could be helpful in the prediction of time of recurrence for superior oblique overaction after superior oblique weakening procedures.
Kang, Dae Wook; Oh, Ji Hye; Chun, Bo Young
The best treatment of acute Achilles tendon rupture remains debated. Patient-reported outcome measures have become cornerstones in treatment evaluations. The Achilles tendon total rupture score (ATRS) has been developed for this purpose but requires additional validation. The purpose of the present study was to validate a Danish translation of the ATRS. The ATRS was translated into Danish according to internationally adopted standards. Of 142 patients, 90 with previous rupture of the Achilles tendon participated in the validity study and 52 in the reliability study. The ATRS showed moderately strong correlations with the physical subscores of the Medical Outcomes Study 36-item Short-Form Health Survey (r = .70 to .75; p < .0001) and Victorian Institute of Sports Assessment-Achilles questionnaire (r = .71; p < .0001). Test-retest of the ATRS showed no significant difference in the mean (2.41; p = .07). The limits of agreement were ±18.53. A strong correlation was found between test and retest (intercorrelation coefficient .908); the standard error of measurement was 6.7, and the minimal detectable change was 18.5. The Danish version of the ATRS showed moderately strong criterion validity. For study and follow-up purposes, the ATRS seems reliable for comparisons of groups of patients. Its usability is limited for repeated assessment of individual patients. The development of analysis guidelines would be desirable. PMID:23965178
Ganestam, Ann; Barfod, Kristoffer; Klit, Jakob; Troelsen, Anders
Originally described by Brock and Teare, today hypertrophic cardiomyopathy is clinically defined as left (or right) ventricular hypertrophy without a known cardiac or systemic cause, such as systemic hypertension, Fabry's disease or aortic stenosis.Also appreciated today is the enormous genotypic and phenotypic heterogeneity of this disease with more than 300 mutations over more than 24 genes, encoding various sarcomeric, mitochondrial and calcium-handling proteins, all as genetic causes for hypertrophic cardiomyopathy.Phenotypically, the disease can vary from negligible to extreme hypertrophy, affecting either the left and/or right ventricle in an apical, midventricular or subaortic location.Left ventricular false tendons are thin, fibrous or fibromuscular structures that traverse the left ventricular cavity. Recently, a case report was presented where it was shown that such a false tendon, originating from a subaortic location, was responsible for striking ST-segment elevation on the surface electrocardiogram.In this case report, a case is presented where such a subaortic tendon led to the classic echocardiographic appearance of hypertrophic cardiomyopathy, thus in the assessment of hypertrophic cardiomyopathy, this entity needs to be excluded in order to prevent a false positive diagnosis of hypertrophic cardiomyopathy. PMID:19573250
Despite the controversy regarding the best treatment for an acute Achilles tendon rupture, percutaneous and minimally invasive techniques seem to offer good results in terms of low risks of rerupture and complications with satisfactory clinical and functional outcomes. A comparison between a percutaneous surgical technique and a minimally invasive one has not been reported in the literature. We consecutively evaluated 12 patients who had a modified Ma and Griffith percutaneous Achilles tendon repair and 12 patients who had a minimally invasive technique. The same semifunctional rehabilitation protocol was used after surgery in both groups. At a minimum followup of 24 months (mean, 33 months; range, 24-42 months), we observed no reruptures or major complications in either group. Both groups had similarly high values for the American Orthopaedic Foot and Ankle Society score. The two techniques allowed equivalent time for return to work and sports. In the group of patients treated with the modified Ma and Griffith suture only, the mean loss of calf circumference in the injured leg was greater, compared with the contralateral leg. The two groups were isokinetically similar. In this study, the percutaneous and minimally invasive techniques of repair of the Achilles tendon yielded essentially identical clinical and functional outcomes. PMID:17290155
Ceccarelli, Francesco; Berti, Lisa; Giuriati, Laura; Romagnoli, Matteo; Giannini, Sandro
Assembling artificial collagenous tissues with structural, functional, and mechanical properties which mimic natural tissues is of vital importance for many tissue engineering applications. While the electro-mechanical properties of collagen are thought to play a role in, for example, bone formation and remodeling, this functional property has not been adequately addressed in engineered tissues. Here the electro-mechanical properties of rat tail tendon are compared with those of dried isoelectrically focused collagen hydrogels using piezoresponse force microscopy under ambient conditions. In both the natural tissue and the engineered hydrogel D-periodic type I collagen fibrils are observed, which exhibit shear piezoelectricity. While both tissues also exhibit fibrils with parallel orientations, Fourier transform analysis has revealed that the degree of parallel alignment of the fibrils in the tendon is three times that of the dried hydrogel. The results obtained demonstrate that isoelectrically focused collagen has similar structural and electro-mechanical properties to that of tendon, which is relevant for tissue engineering applications. PMID:22522132
Denning, D; Abu-Rub, M T; Zeugolis, D I; Habelitz, S; Pandit, A; Fertala, A; Rodriguez, B J
Forty consecutive tendon suspension sling arthroplasties for relief of pantrapezial osteoarthritis in 38 patients were reviewed. The procedure consists of excision of the trapezium and reconstitution of the tethering action of the first intermetacarpal and the palmar oblique carpometacarpal ligaments; 50% of the distally based flexor carpi radialis tendon is used. A double figure-eight sling suspends the first metacarpal securely, followed by distal advancement of the abductor pollicis longus to tighten the sling and palmarly abduct the thumb ray. The technique resulted in relief of pain, preservation of strength, maintenance of a normally contoured first web space, and functional carpometacarpal range of motion. Procedures were performed over a 4-year period (1986 to 1990), with an average follow-up of 21 months. At final follow-up, 85% of the patients had minimal symptoms; key pinch and grip strengths measured 76% and 81% of the contralateral uninvolved side, respectively. The logic of the mechanical design of the procedure and encouraging subjective and objective follow-up at 4 years make the technique of tendon suspension sling arthroplasty an attractive alternative to existing procedures for the surgical management of recalcitrant and disabling osteoarthritis of the basilar thumb joint. PMID:1748769
Kleinman, W B; Eckenrode, J F
Extracellular matrix (ECM) materials are currently utilized for soft tissue repair applications such as vascular grafts, tendon reconstruction, and hernia repair. These materials are derived from tissues such as human dermis and porcine small intestine submucosa, which must be rendered acellular to prevent disease transmission and decrease the risk of an immune response. The ideal decellularization technique removes cells and cellular remnants, but leaves the original collagen architecture intact. The tissue utilized in this study was the central tendon of the porcine diaphragm, which had not been previously investigated for soft tissue repair. Several treatments were investigated during this study including peracetic acid, TritonX-100, sodium dodecyl sulfate, and tri(n-butyl) phosphate (TnBP). Of the decellularization treatments investigated, only 1% TnBP was effective in removing cell nuclei while leaving the structure and composition of the tissue intact. Overall, the resulting acellular tissue scaffold retained the ECM composition, strength, resistance to enzymatic degradation, and biocompatibility of the original tissue, making 1% TnBP an acceptable decellularization treatment for porcine diaphragm tendon. PMID:21210498
Deeken, C R; White, A K; Bachman, S L; Ramshaw, B J; Cleveland, D S; Loy, T S; Grant, S A
The proximal region of the superficial digital flexor tendon of pigs passes under the tibiotarsal joint, where it is subjected to compressional and tensional forces. This region was divided into a surface portion (sp), which is in direct contact with the bone and into a deep portion (dp), which is the layer opposite the articulating surface. The purpose of this work was to analyse the distribution and organisation of the collagen bundles and proteoglycans in the extracellular matrix in sp and dp. Toluidine-blue-stained sections were analysed under a polarising microscope. Strong basophilia and metachromasia were observed in sp, demonstrating accumulation of proteoglycan in a region bearing compression, but the intensity was reduced the further layers were from the bone. Linear dichroism confirmed that the glycosaminoglycan molecules were disposed predominantly parallel to the longest axis of the collagen fibrils. Birefringence analysis showed a higher molecular order and aggregation of the collagen bundles in areas where the tension was more prominent. The crimp pattern was more regular in dp than in sp, probably as a requirement for tendon stretching. The optical anisotropy exhibited by the collagen bundles also confirmed the helical organisation of the collagen bundles in the tendon. Hyaluronidase digestion caused a decrease in the basophilia, but this was not eliminated, supporting the idea that in the matrix, proteoglycans are not completely available to the enzyme action.
Feitosa, Vera Lucia C; Vidal, Benedicto C; Pimentel, Edson R
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
Delgado-Brambila, H A; Cristiani, D G; Tinajero, E C; Burgos-Elías, V
Rupture of the triceps mechanism is an uncommon injury that has been recognized with increasing frequency in recent years. It has been proposed that such injuries commonly accompany fractures of the radial head and must be actively evaluated in the presence of such a fracture. We present a unique case of isolated rupture of the triceps tendon in an athlete who was lifting weights. This case was complicated by a history of olecranon bursitis that had been treated with numerous local steroid injections, as well as a history of anabolic steroid abuse. Both systemic steroids and local injections may predispose tendons to rupture. Triceps tendon ruptures may result in uniformly good to excellent results if recognized and treated surgically. This case also serves as a reminder of the risks of treating inflamed tissues with local steroid injections, especially in strength athletes who place high demands on their musculoskeletal structures. Finally, this case documents a second case of triceps mechanism rupture in an athlete who has abused anabolic steroids. A study by Hunter et al. suggests that oral steroid abuse may be associated with detrimental effects on the mechanical properties of connective tissue, demonstrating another negative effect of anabolic steroid use in athletes. PMID:8346768
Stannard, J P; Bucknell, A L
Background: Traditionally the repaired extensor tendons have been treated postoperatively in static splints for several weeks, leading to formation of adhesions and prolonged rehabilitation. Early mobilization using dynamic splints is common, but associated with many shortcomings. We attempted to study the results of early active mobilization, using a simple static splint, and easy-to-follow rehabilitation plan. Materials and Methods: In a prospective study 26 cases of cut extensor tendons in Zone V to VIII were treated with primary or delayed primary repair. Following this, early active mobilization was undertaken, using an easy-to-follow rehabilitation plan. The results were assessed according to the criteria of Dargan at six weeks and one year. Results: All the 26 patients were followed up for one year. 20 out of 26 patients were below 30 years of age, involving the dominant hand more commonly (16 patients, 62%). Agriculture instruments were the most common mode of injury (13 patients, 50%). The common site for injury was extensor zone VI (42%, n = 11). Conclusion: Rehabilitation done for repaired extensor tendon injuries by active mobilization plan using a simple static splint has shown good results.
Saini, Narender; Sharma, Mohan; Sharma, VD; Patni, Purnima
The authors reviewed data from 40 peroneal tendon surgeries performed on 39 patients (25 males and 14 females) between 1991 and 1999. Patients underwent tendon repair, subluxation repair, and/or accessory ossicle and muscle excisions. Some patients underwent more than one procedure, including eight undergoing ankle stabilizations. Preoperatively and postoperatively, the American Orthopaedic Foot and Ankle Society ankle-hindfoot score was assessed. Average preoperative and postoperative ankle-hindfoot scores were 61.6 (range, 19 to 72) and 91.4 (range, 63 to 100), respectively. Mean group return-to-activity time, defined as initiation of regular activity, including sports, was 3.2 months (range, 1 to 6 months). There were 17 athletes and 22 active patients; no patients were sedentary. Magnetic resonance imaging was used to evaluate peroneal tendon pathology in 29 patients. Sensitivity was 82.7%; specificity, 50%; and positive predictive value, 100%. Overall results were excellent in 25 cases, good in 12, fair in 1, and poor in 2. A paired t-test showed that patients with previous steroid injections had statistically poorer results. Patients with symptoms for more than 12 months also had poorer outcomes. PMID:12869596
Saxena, Amol; Wolf, Steven K
Heterotopic tendon mineralization (ossification or calcification), which may be a feature of tendinopathy or which may develop following surgical trauma (repair or graft harvest), has not received much attention. The purpose of this article is to review the prevalence, mechanisms and consequences of heterotopic tendon mineralization and to identify the gaps in our current understanding. We focus on endochondral heterotopic ossification and draw on knowledge of the mechanisms of this process in other tissues and conditions. Finally, we introduce a novel murine Achilles tendon needle injury model, which will enable us to further study the mechanisms and biomechanical consequences of tendon mineralization.
O'Brien, Etienne J O; Frank, Cyril B; Shrive, Nigel G; Hallgrimsson, Benedikt; Hart, David A
This study's purpose was to assess the in vivo effect of auto-crosslinked hyaluronic acid (HA) gel, a natural HA derivative with increased viscosity and tissue residence time, on adhesions and healing of injured and surgically repaired rabbit digital flexor tendons. The second and third right deep digital flexor tendons from 48 rabbits (n = 96 tendons) were cut and repaired with a modified Kessler and running peripheral suture. Animals were randomized to two groups, receiving either HA gel or saline injected around both freshly repaired tendons. After 2, 3, 6, and 12 weeks, six rabbits in each group were euthanized. Tendon pull-out force and breaking strength were measured as a value for adhesion formation and tendon healing, respectively. A histological assessment of adhesions and healing was related to the mechanical results. A significantly faster increase in breaking strength was found in HA gel-treated compared to saline-treated tendons; this coincided with a significantly accelerated tissue repair response after injury. No significant difference in adhesion formation was found between the two groups at any time. Our results indicate a significant acceleration of in vivo healing of tendons treated with HA gel. Adhesion formation was unaffected. These results could have important clinical value in promoting rehabilitation after tendon injury. PMID:18756508
de Wit, Thijs; de Putter, Dennis; Tra, Wendy M W; Rakhorst, Hinne A; van Osch, Gerjo J V M; Hovius, Steven E R; van Neck, Johan W
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 (14)C bomb-pulse method. This method takes advantage of the dramatic increase in atmospheric levels of (14)C, produced by nuclear bomb tests in 1955-1963, which is reflected in all living organisms. Levels of (14)C 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 (14)C corresponding to atmospheric levels several decades before tissue sampling, demonstrating a very limited tissue turnover. The tendon concentrations of (14)C 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, (14)C 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. PMID:23401563
Heinemeier, Katja Maria; Schjerling, Peter; Heinemeier, Jan; Magnusson, Stig Peter; Kjaer, Michael
Ultrasound can be used to study tendon movement. However, measurement of tendon movement is mostly based on manual tracking of anatomical landmarks such as the musculo-tendinous junction, limiting the applicability to a small number of muscle-tendon units. The aim of this study was to quantify tendon displacement without anatomical landmarks using a speckle tracking algorithm optimized for tendons in long B-mode image sequences. A dedicated two-dimensional multi-kernel block-matching scheme with subpixel motion estimation was devised to handle large displacements over long sequences. The accuracy of the tracking on porcine tendons was evaluated during different displacements and velocities. Subsequently, the accuracy of tracking the flexor digitorum superficialis (FDS) of a human cadaver hand was evaluated. Finally, the in-vivo accuracy of the tendon tracking was determined by measuring the movement of the FDS at the wrist level. For the porcine experiment and the human cadaver arm experiment tracking errors were, on average, 0.08 and 0.05mm, respectively (1.3% and 1.0%). For the in-vivo experiment the tracking error was, on average, 0.3mm (1.6%). This study demonstrated that our dedicated speckle tracking can quantify tendon displacement at different physiological velocities without anatomical landmarks with high accuracy. The technique allows tracking over large displacements and in a wider range of tendons than by using anatomical landmarks. PMID:20152983
Korstanje, Jan-Wiebe H; Selles, Ruud W; Stam, Henk J; Hovius, Steven E R; Bosch, Johan G
Studies were performed evaluating the role of Smad3, a transcription factor mediating canonical TGF-? signaling, on scarring and adhesion formation using an established flexor digitorum longus (FDL) tendon repair model. In unoperated animals the metatarsophalangeal (MTP) range of motion (ROM) was similar in Smad3?/? and wild type (WT) mice while the basal tensile strength of Smad3?/? tendons was significantly (39%) lower than in WT controls. At 14 and 21 days following repair Smad3?/? MTP ROM reached approximately 50% of the level of the basal level and was twice that observed in WT tendon repairs, consistent with reduced adhesion formation. Smad3?/? and WT maximal tensile repair strength on post-operative day 14 was similar. However, Smad3?/? tendon repairs maximal tensile strength on day 21 was 42% lower than observed in matched WT mice, mimicking the relative decrease in strength observed in Smad3?/? FDL tendons under basal conditions. Histology showed reduced "healing callus" in Smad3?/? tendons while quantitative PCR, in situ hybridization, and immunohistochemistry showed decreased col3a1 and col1a1 and increased MMP9 gene and protein expression in repaired Smad3?/? tendons. Thus, Smad3?/? mice have reduced collagen and increased MMP9 gene and protein expression and decreased scarring following tendon FDL tendon repair.
Katzel, Evan B.; Wolenski, Matthew; Loiselle, Alayna E.; Basile, Patrick; Flick, Lisa M.; Langstein, Howard N.; Hilton, Matthew J.; Awad, Hani A.; Hammert, Warren C.; O'Keefe, Regis J.
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. PMID:23224178
Yang, Ying; Rupani, Asha; Bagnaninchi, Pierre; Wimpenny, Ian; Weightman, Alan
Objective Patellar tendon injury, defined by tendon abnormality (TA) on imaging and by pain, is common among volleyball players, but little is known about change in this injury over a volleyball season. Increased activity in the season compared with the off season may result in the development of TA and/or pain. This study investigated the behaviour of TA and pain over a competitive volleyball season. Methods Tendon abnormality and pain were measured in 101 volleyball players at the beginning and end of a season. Pain was measured with the single leg decline squat test, which loads the patellar tendon, and TA was detected with ultrasound imaging. Hours of weekly activity were measured and compared during the season and the off season. The proportion of tendons that underwent development and resolution in TA and/or pain over the season was investigated. Results Hours of weekly activity was greater during the season than in the off season. Most of the tendons investigated (66.3%) did not undergo a change in TA or pain over the season. Tendon abnormality and/or pain developed in 16.6% of tendons and resolved in 11.2%. Conclusions The tendons of volleyball players respond variably to the increased load over the season. Change in TA and pain does not appear to be entirely dependent upon load.
Malliaras, P; Cook, J; Ptasznik, R; Thomas, S
IntroductionRuptures of the Achilles tendon are common however simultaneous ruptures occur less frequently. Eccentric loading exercise programmes have been used to successfully treat Achilles tendinopathy.
Michael R. Carmont; Adrian M. Highland; Christopher M. Blundell; Mark B. Davies
Flexor tendon injuries are seen commonly yet the management protocols are still widely debated. The advances in suture techniques, better understanding of the tendon morphology and its biomechanics have resulted in better outcomes. There has been a trend toward the active mobilization protocols with development of multistrand core suture techniques. Zone 2 injuries remain an enigma for the hand surgeons even today but the outcome results have definitely improved. Biomolecular modulation of tendon repair and tissue engineering are now the upcoming fields for future research. This review article focuses on the current concepts in the management of flexor tendon injuries in zone 2.
Kotwal, Prakash P; Ansari, Mohammed Tahir
A twenty-year-old male visited our clinic with wrist and long finger metacarpophalangeal (MP) joint pain. Dynamic ultrasonography revealed sagittal band (SB) ulnar subluxation and extensor carpi ulnaris (ECU) volar subluxation. Magnetic resonance imaging showed longitudinal splitting and dislocation of the volar half slip of the ECU tendon. The redundant radial SB was augmented and ECU sheath was advanced to the periosteum using suture anchors. He was able to perform his previous activities at the last follow-up. We encountered a case of "simulateous" ECU dislocation with extensor tendon subluxation of the long finger at the MP joint. Therefore, we report this case with a review of the relevant literature. PMID:23467477
Kim, Byung-Sung; Yoon, Hong-Gi; Kim, Hyung-Tae; Park, Kang-Hee; Kim, Chang-Geun; Song, Hyun-Seok
Harvested hamstring tendons were recently shown to possess the ability to regrow and regain their function in flexing the knee joint. In this study, we report a case of failed regrowth of previously harvested semitendinosus tendon to its original insertion site in a 24-year-old professional soccer player. The disturbance resulted in the formation of a clearly visible Popeye-type muscular prominence in the proximal thigh and a notable gap in the midthigh distal to the muscular prominence in knee flexion. Furthermore, 6 months after surgery, in the second full-speed soccer practice, the patient experienced a sudden sharp pain in his hamstring muscles, which was later diagnosed as being from a strain of the semitendinosus muscle. PMID:12671606
Järvinen, Teppo L N; Järvinen, Tero A H; Penttilä, Tero; Harilainen, Arsi; Sandelin, Jerker; Paakkala, Timo
Background—After Achilles tendon repair, immediate weightbearing and immobilisation closer to neutral plantarflexion are thought to limit atrophy and stiffness, but may place deleterious stress on the repair. Objectives—To estimate the relative stress on the Achilles tendon during weightbearing with immobilisation in varying degrees of plantarflexion. Methods—Electromyographic (EMG) activity from the plantarflexors was recorded during walking in 10 subjects (six men, four women) without ankle pathology. Four walking conditions were examined: (a) normal walking; (b) immobilised (cam-walker) in neutral plantarflexion; (c) immobilised with a 0.5 inch heel lift; (d) immobilised with a 1 inch heel lift. EMG activity relative to plantarflexor torque was determined for each subject during isometric contractions at 25%, 50%, 75%, and 100% of maximal voluntary contraction (MVC). EMG activity during walking was calculated as a percentage of MVC based on the EMG-torque relation during graded isometric contractions. Results—During normal walking, the plantarflexor torque was estimated to be 30 (12)% (mean (SD)) of MVC, compared with 21 (15)% MVC for immobilisation in neutral (p<0.05), 17 (15)% MVC with the addition of a 0.5 inch heel lift (p<0.01), and 12 (12)% MVC with the addition of a 1 inch heel lift (p<0.01). The 1 inch heel lift resulted in less than 10° plantarflexion in all subjects. Conclusions—When the ankle is immobilised, stress on the Achilles tendon is determined by the degree of plantarflexion and the contractile activity of the plantarflexors. In the immobilised ankle, the addition of a 1 inch heel lift was sufficient to minimise plantarflexor activity during walking. Key Words: Achilles tendon; EMG; heel lifts; soleus; gastrocnemius
Akizuki, K; Gartman, E; Nisonson, B; Ben-Avi, S; McHugh, M