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Eiji Itoi - One of the best experts on this subject based on the ideXlab platform.
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quantifying extensibility of rotator cuff muscle with tendon rupture using shear wave elastography a cadaveric study
Journal of Biomechanics, 2017Co-Authors: Taku Hatta, Yoshiaki Itoigawa, John W. Sperling, Scott P. Steinmann, Hugo Giambini, Alexander W Hooke, Eiji ItoiAbstract:Surgical repair for large rotator cuff tear remains challenging due to tear size, altered muscle mechanical properties, and poor musculotendinous extensibility. Insufficient extensibility might lead to an incomplete reconstruction; moreover, excessive stresses after repair may result in repair failure without healing. Therefore, estimates of extensibility of cuff muscles can help in pre-surgical planning to prevent unexpected scenarios during surgery. The purpose of this study was to determine if quantified mechanical properties of the Supraspinatus muscle using shear wave elastography (SWE) could be used to predict the extensibility of the musculotendinous unit on cadaveric specimens. Forty-five fresh-frozen cadaveric shoulders (25 intact and 20 with rotator cuff tear) were used for the study. Passive stiffness of 4 anatomical regions in the Supraspinatus muscle was first measured using SWE. After detaching the distal edge of Supraspinatus muscle from other cuff muscles, the detached muscle was axially pulled with the scapula fixed. The correlation between the SWE modulus and the extensibility of the muscle under 30 and 60N loads was assessed. There was a significant negative correlation between SWE measurements and the experimental extensibility. SWE modulus for the anterior-deep region in the Supraspinatus muscle showed the strongest correlation with extensibility under 30N (r=0.70, P<0.001) and 60N (r=0.68, P<0.001). Quantitative SWE assessment for the Supraspinatus muscle was highly correlated with extensibility of musculotendinous unit on cadaveric shoulders. This technique may be used to predict the extensibility for rotator cuff tears for pre-surgical planning.
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Feasibility assessment of shear wave elastography to rotator cuff muscle
Clinical Anatomy, 2014Co-Authors: Yoshiaki Itoigawa, Eiji Itoi, John W. Sperling, Scott P. Steinmann, Qingshan Chen, Pengfei Song, Shigao Chen, Taku HattaAbstract:Pre-surgical measurement of Supraspinatus muscle extensibility is important for rotator cuff repair. The purpose of the present study was to explore the potential feasibility of a shear wave ultrasound elastography (SWE)-based method, combined with B-mode ultrasound, to measure the in vivo stiffness of the Supraspinatus muscle non-invasively and thus obtain key information about Supraspinatus muscle extensibility. Our investigation comprised two steps. First, we determined the orientation of the Supraspinatus muscle fibers in cadaveric shoulders without rotator cuff tear in order to optimize the ultrasound probe positions for SWE imaging. Second, we investigated the feasibility of quantifying the stiffness of the normal Supraspinatus muscle by SWE in vivo. The Supraspinatus muscle was divided into four anatomical regions: anterior superficial (AS), posterior superficial (PS), anterior deep (AD), and posterior deep (PD). Each region was examined by SWE. The SWE stiffnesses of AD, AS, PD, and PS were 40.0 ± 12.4, 34.0 ± 9.9, 32.7 ± 12.7, 39.1 ± 15.7 kPa, respectively. SWE combined with B-Mode ultrasound imaging could be a feasible method for quantifying the local stiffness of the rotator cuff muscles. Clin. Anat. 28:213–218, 2015. © 2014 Wiley Periodicals, Inc.
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Ultrasound elastography-based assessment of the elasticity of the Supraspinatus muscle and tendon during muscle contraction
Journal of Shoulder and Elbow Surgery, 2014Co-Authors: Takayuki Muraki, Hiroaki Ishikawa, Shuhei Morise, Nobuyuki Yamamoto, Hirotaka Sano, Eiji Itoi, Shin-ichi IzumiAbstract:Background: Although elasticity of the Supraspinatus muscle and tendon is a useful parameter to represent the conditions of the Supraspinatus muscle and tendon, assessment of the elasticity in clinical settings has not been established. The purpose of this study was to determine the elasticity of the Supraspinatus muscle belly and tendon under different muscle contraction conditions using ultrasound real-time tissue elastography (RTE). Methods: Twenty-three healthy individuals participated in this study. Ultrasound RTE was used for elasticity measurements of the muscle belly and tendon of the Supraspinatus muscle. The elasticity was defined as the ratio of strain in the tissues to that in an acoustic coupler (reference). A greater ratio indicated that the tissue was softer. Measurements were performed with study subjects in the lateral decubitus position at 10 � of shoulder abduction under conditions of (1) no contraction, (2) isometric contraction without a weight, and (3) isometric contraction with a 1-kg weight. Results: The intraclass correlation coefficient (ICC1,3) of 3 measurements under each condition ranged from 0.931 to 0.998, showing high intraobserver reliability. Strain ratios for both the Supraspinatus muscle belly and tendon significantly decreased with increases in muscle contraction (P < .001). Conclusions: Ultrasound RTE with the acoustic coupler has the potential to noninvasively detect changes in the elasticity of the Supraspinatus muscle belly and tendon that accompany varying levels of muscle contraction in clinical practice. Level of evidence: Basic Science Study, Biomechanics, Imaging. 2015 Journal of Shoulder and Elbow Surgery Board of Trustees.
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Sarcomere length of torn rotator cuff muscle.
Journal of Shoulder and Elbow Surgery, 2009Co-Authors: Tatsuru Tomioka, Nobuyuki Yamamoto, Hiroshi Minagawa, Hiroaki Kijima, Hidekazu Abe, Matthieu Maesani, Kazuma Kikuchi, Hiroshi Abe, Yoichi Shimada, Eiji ItoiAbstract:Background Sarcomere length is one of the factors related to the contractile ability of muscle. There is no report about sarcomere length of torn rotator cuff muscles. The purpose of this study was to clarify sarcomere length of torn rotator cuff muscles. Materials and methods Twenty-eight embalmed cadaver shoulders (14 shoulders with intact rotator cuff and 14 shoulders with full-thickness rotator cuff tears: an isolated tear of the Supraspinatus in 3, a combined tear of the Supraspinatus and infraspinatus in 4, and a combined tear of the Supraspinatus, infraspinatus and subscapularis in 7) were used in this study. Muscle fiber length was measured using a digital caliper. Sarcomere length was measured by laser diffraction method. Results Muscle fiber lengths of the Supraspinatus and infraspinatus (33.0 ± 6.5 mm and 61.5 ± 14.0 mm, respectively) in the cuff tear group were significantly shorter than those in the intact cuff group (56.9 ± 10.1 mm and 74.2 ± 10.0 mm: P P = .010). The sarcomere lengths of these muscles were 3.00 ± 0.44 μm and 3.12 ± 0.45 μm in the intact cuff group and 2.90 ± 0.34 μm and 3.01 ± 0.34 μm in the cuff tear group. The sarcomere lengths showed no significant difference ( P = 0.46 and P = .37). Conclusion The sarcomere lengths of the Supraspinatus and infraspinatus with torn tendons were not significantly different from those with intact tendons, although the muscle fiber lengths were significantly shorter with torn tendons.
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elasticity of the Supraspinatus tendon muscle unit is preserved after acute tendon tearing in the rabbit
Tohoku Journal of Experimental Medicine, 2008Co-Authors: Mitsuyoshi Mineta, Hirotaka Sano, Ryogo Ichinose, Yoshifumi Saijo, Eiji ItoiAbstract:Supraspinatus tendon tearing is one of the most common causes of the shoulder pain and dysfunction, which often requires a surgical repair. In this situation, proximal tendon stump is usually retracted medially from its original insertion. For successful reduction of the retracted tendon stump to its original insertion, the elasticity of the tendon-muscle unit should be preserved by the time of surgery. The purpose of the present study was to clarify the chronological changes in the elasticity of the Supraspinatus tendon-muscle unit after acute tendon tearing to determine the optimal timing for the surgery. Right Supraspinatus tendon was detached (detached side) in 40 male Japanese white rabbits, with left shoulders served as controls (control side). Eight animals were euthanized at 3 days and 1, 2, 4, or 8 weeks after surgery. Tissue sound speed that closely correlates to its elasticity was measured with a scanning acoustic microscope. In the Supraspinatus tendon, tissue sound speed at 3 days after surgery was 1691.1 m/s, compared to 1714.3 m/s at the control side, but the difference was not statistically significant at any postoperative time period up to 8 weeks. In the Supraspinatus muscle, tissue sound speed was not affected at all by the detachment of the tendon. The present study indicated that the elasticity of the Supraspinatus tendon-muscle unit was well preserved for 8 weeks after the detachment. In the clinical practice, the retracted Supraspinatus tendon stump could be repaired without excessive tension by 8 weeks from the acute tendon tearing.
Christian Gerber - One of the best experts on this subject based on the ideXlab platform.
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Retraction of Supraspinatus Muscle and Tendon as Predictors of Success of Rotator Cuff Repair
American Journal of Sports Medicine, 2012Co-Authors: Dominik C. Meyer, Karl Wieser, Mazda Farshad, Christian GerberAbstract:Background:The structural failure rate of rotator cuff repair can exceed 50%. Important predictors for repair failure are preoperative fatty muscle infiltration and myotendinous retraction.Purpose:To quantitatively assess the prognostic value of preoperative retraction of both the Supraspinatus muscle and tendon for the outcome of Supraspinatus repair.Study Design:Cohort study; Level of evidence, 3.Methods:In 33 shoulders with complete Supraspinatus tendon ruptures subjected to arthroscopic repair, magnetic resonance imaging (MRI) scans taken preoperatively and after a mean follow-up of 24 months were studied. The exact position of the lateral extension of the Supraspinatus muscle and of the tendon end was evaluated and correlated with the preoperative stage of fatty infiltration (Goutallier) and the failure rate of tendon repair.Results:The mean lengthening of the muscle and tendon end was −3 mm and 4 mm in the failed repairs (n = 19) and 14 mm and 8 mm in the successful repairs (n = 14). If the supraspi...
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effect of selective experimental suprascapular nerve block on abduction and external rotation strength of the shoulder
Journal of Shoulder and Elbow Surgery, 2007Co-Authors: Christian Gerber, Stephan Blumenthal, Armin Curt, Clement M L WernerAbstract:The relative contribution to strength of the Supraspinatus and infraspinatus to abduction and external rotation is not precisely known. Optimal testing positions for clinical assessment of Supraspinatus and infraspinatus function are not precisely defined. We sequentially performed electromyographically controlled, complete nerve blocks of the suprascapular nerve, first at the spinoglenoid notch, to induce complete, isolated infraspinatus palsy. The suprascapular nerve was then blocked at the scapular notch, resulting in complete Supraspinatus and infraspinatus palsy in 11 volunteers. Strength of abduction in the scapular plane and of external rotation was measured at 0°, 30°, 60°, and 90° of abduction, by use of a validated, instrumented strength-measuring device. Complete isolated infraspinatus palsy was obtained in 11 volunteers and complete combined Supraspinatus and infraspinatus palsy in 9. Infraspinatus palsy alone led to a loss of approximately 70% of external rotation strength and approximately 45% of abduction strength. The degree of loss of strength was not dependent on the angle of abduction. Paralysis of the infraspinatus and the Supraspinatus led to a loss of external rotator strength of approximately 80% and a loss of abductor strength of approximately 75%. The loss was again independent of the angle of abduction at which the testing took place. Testing of Supraspinatus and infraspinatus strength can be performed at any angle between 30° and 90° without a change in specificity. The contribution of the infraspinatus to abduction strength is great. In the acute situation, the teres minor does not contribute more than 20% of external rotation strength at any degree of abduction.
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passive tension in the Supraspinatus musculotendinous unit after long standing rupture of its tendon a preliminary report
Journal of Shoulder and Elbow Surgery, 1998Co-Authors: Otmar Hersche, Christian GerberAbstract:Abstract Incomplete functional recovery after rotator cuff surgery can be caused by rerupture or incomplete restoration of the contractile properties of the muscle-tendon-bone unit. We measured the passive tension generated in the Supraspinatus musculotendinous unit at the time of repair of the Supraspinatus tendon performed for the treatment of long-standing rupture in four patients and compared our results with the values of an intact musculotendinous unit. In stepwise elongation from 10 to 20 mm, passive tension increased by a factor of 2.2 ± 0.4 in the study group. In the control case passive tension increased by a factor of only 1.3. Mean tension in 60° of abduction was 14.25 ± 3.4 N in the four long-standing ruptures and 10 N in the control case. If the arm was brought to the side, tension rose to 25 N in the control case, whereas mean tension increased to 59.25 ± 12.7 N in long-standing rupture of the Supraspinatus muscle. Our findings demonstrate that passive tension in the Supraspinatus is increased after long-standing rupture of its tendon. This result suggests that active force generation by this muscle will be compromised after surgery and that the high strain after repair may expose the musculotendinous unit to further damage. (J Shoulder Elbow Surg 1998;7:393-6.)
Yoshiaki Itoigawa - One of the best experts on this subject based on the ideXlab platform.
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Supraspinatus muscle and tendon stiffness changes after arthroscopic rotator cuff repair a shear wave elastography assessment
Journal of Orthopaedic Research, 2020Co-Authors: Yoshiaki Itoigawa, Tomoki Wada, Takayuki Kawasaki, Daichi Morikawa, Yuichiro Maruyama, Kazuo KanekoAbstract:Re-tearing after arthroscopic rotator cuff repair (ARCR) frequently occurs, and high stiffness of the rotator cuff may be one of the factors. We investigated changes in stiffness of the Supraspinatus muscle and tendon after ARCR as measured by shear wave elastography (SWE) with B-mode ultrasound, and compared the Supraspinatus muscle stiffness of patients with recurrent tears and patients with healed rotator cuffs. Sixty patients with Supraspinatus tears requiring ARCR underwent serial SWE of their Supraspinatus muscles and repaired tendons. SWE was performed before surgery (Pre-Op) and at 1 week, 1 month, 2 months, 3 months, 4 months, 5 months, and 6 months after surgery. Additionally, the repaired rotator cuffs were evaluated using magnetic resonance imaging at 6 months after surgery to classify patients into a healed rotator cuff group and a recurrent tear group. Differences in SWE values between the groups were assessed at each time point. The SWE value of the repaired tendon at 1 week after ARCR was significantly greater than at 3 and 6 months. The SWE value for the Supraspinatus muscle at 1 month after ARCR surgery in the healed group was lower than at Pre-Op and 4, 5, and 6 months after surgery, and it was also lower than that at 1 month after surgery in the re-tear group. There were no significant differences between time points in the SWE values of the Supraspinatus muscle in the re-tear group. The SWE value of the muscle in the re-tear group was greater than in the healed group at 1 month after surgery (p < 0.05). Increased SWE values at 1 month after ARCR may predict recurrent rotator cuff tears after surgery rather than evaluating the tendon. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:219-227, 2020.
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shear wave elastography can predict passive stiffness of Supraspinatus musculotendinous unit during arthroscopic rotator cuff repair for presurgical planning
Arthroscopy, 2018Co-Authors: Yoshiaki Itoigawa, Tomoki Wada, Takayuki Kawasaki, Yuichiro Maruyama, Keiichi Yoshida, Kazuo KanekoAbstract:Purpose To determine the feasibility of shear wave elastography (SWE) with B-mode ultrasound in predicting the stiffness of the rotator cuff muscle before arthroscopic rotator cuff repair to evaluate the difficulty of the surgical procedure, as well as to compare SWE with the Goutallier stage on magnetic resonance imaging (MRI). Methods Thirty-eight patients with a full-thickness Supraspinatus tear requiring arthroscopic rotator cuff repair participated. The Goutallier stage of fatty infiltration on MRI was measured before surgery, as was the SWE modulus of the anterior superficial, anterior deep, posterior superficial, and posterior deep (PD) regions of the Supraspinatus muscle. To measure the stiffness of the Supraspinatus musculotendinous unit during surgery, the Supraspinatus tendon was axially stretched until the anatomic insertion site was reached, and force per deformation was recorded. The correlation between stiffness of the Supraspinatus and SWE value in each region of the Supraspinatus muscle or Goutallier stage was determined. In addition, patients were divided into 2 groups: (1) In the complete footprint coverage group, greater than 50% of the footprint was covered during the stiffness measurement, and (2) in the incomplete footprint coverage group, less than 50% of the footprint was covered during the stiffness measurement. Differences in SWE value and Goutallier stage were measured between the 2 groups. Results The best correlation of stiffness with the SWE modulus of the PD muscle of the Supraspinatus was R = 0.69, and the correlation of stiffness with the Goutallier stage on MRI was R = 0.48. The SWE value of the PD region was greater in the incomplete footprint coverage group than in the complete footprint coverage group, although the Goutallier stage was not significantly different. Conclusions The highest correlation with stiffness of the Supraspinatus musculotendinous unit was with the SWE modulus of the PD muscle, as compared with SWE evaluation of the other regions or the Goutallier stage on MRI. Ultrasound SWE can predict the stiffness of the Supraspinatus musculotendinous unit best. Clinical Relevance Rotator cuff retraction adds difficulty to arthroscopic rotator cuff repair. Ultrasound SWE may be used for presurgical planning.
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quantifying extensibility of rotator cuff muscle with tendon rupture using shear wave elastography a cadaveric study
Journal of Biomechanics, 2017Co-Authors: Taku Hatta, Yoshiaki Itoigawa, John W. Sperling, Scott P. Steinmann, Hugo Giambini, Alexander W Hooke, Eiji ItoiAbstract:Surgical repair for large rotator cuff tear remains challenging due to tear size, altered muscle mechanical properties, and poor musculotendinous extensibility. Insufficient extensibility might lead to an incomplete reconstruction; moreover, excessive stresses after repair may result in repair failure without healing. Therefore, estimates of extensibility of cuff muscles can help in pre-surgical planning to prevent unexpected scenarios during surgery. The purpose of this study was to determine if quantified mechanical properties of the Supraspinatus muscle using shear wave elastography (SWE) could be used to predict the extensibility of the musculotendinous unit on cadaveric specimens. Forty-five fresh-frozen cadaveric shoulders (25 intact and 20 with rotator cuff tear) were used for the study. Passive stiffness of 4 anatomical regions in the Supraspinatus muscle was first measured using SWE. After detaching the distal edge of Supraspinatus muscle from other cuff muscles, the detached muscle was axially pulled with the scapula fixed. The correlation between the SWE modulus and the extensibility of the muscle under 30 and 60N loads was assessed. There was a significant negative correlation between SWE measurements and the experimental extensibility. SWE modulus for the anterior-deep region in the Supraspinatus muscle showed the strongest correlation with extensibility under 30N (r=0.70, P<0.001) and 60N (r=0.68, P<0.001). Quantitative SWE assessment for the Supraspinatus muscle was highly correlated with extensibility of musculotendinous unit on cadaveric shoulders. This technique may be used to predict the extensibility for rotator cuff tears for pre-surgical planning.
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Feasibility assessment of shear wave elastography to rotator cuff muscle
Clinical Anatomy, 2014Co-Authors: Yoshiaki Itoigawa, Eiji Itoi, John W. Sperling, Scott P. Steinmann, Qingshan Chen, Pengfei Song, Shigao Chen, Taku HattaAbstract:Pre-surgical measurement of Supraspinatus muscle extensibility is important for rotator cuff repair. The purpose of the present study was to explore the potential feasibility of a shear wave ultrasound elastography (SWE)-based method, combined with B-mode ultrasound, to measure the in vivo stiffness of the Supraspinatus muscle non-invasively and thus obtain key information about Supraspinatus muscle extensibility. Our investigation comprised two steps. First, we determined the orientation of the Supraspinatus muscle fibers in cadaveric shoulders without rotator cuff tear in order to optimize the ultrasound probe positions for SWE imaging. Second, we investigated the feasibility of quantifying the stiffness of the normal Supraspinatus muscle by SWE in vivo. The Supraspinatus muscle was divided into four anatomical regions: anterior superficial (AS), posterior superficial (PS), anterior deep (AD), and posterior deep (PD). Each region was examined by SWE. The SWE stiffnesses of AD, AS, PD, and PS were 40.0 ± 12.4, 34.0 ± 9.9, 32.7 ± 12.7, 39.1 ± 15.7 kPa, respectively. SWE combined with B-Mode ultrasound imaging could be a feasible method for quantifying the local stiffness of the rotator cuff muscles. Clin. Anat. 28:213–218, 2015. © 2014 Wiley Periodicals, Inc.
B L Hazleman - One of the best experts on this subject based on the ideXlab platform.
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matrix metalloproteinase activities and their relationship with collagen remodelling in tendon pathology
Matrix Biology, 2002Co-Authors: G P Riley, B L Hazleman, V A Curry, Jack Degroot, Nicole Verzijl, Ruud A BankAbstract:Our aim was to correlate the activity of matrix metalloproteinases (MMPs) with denaturation and the turnover of collagen in normal and pathological human tendons. MMPs were extracted from ruptured Supraspinatus tendons (n=10), macroscopically normal (‘control’) Supraspinatus tendons (n=29) and normal short head of biceps brachii tendons (n=24). Enzyme activity was measured using fluorogenic substrates selective for MMP-1, MMP-3 and enzymes with gelatinolytic activity (MMP-2, MMP-9 and MMP-13). Collagen denaturation was determined by α-chymotrypsin digestion. Protein turnover was determined by measuring the percentage of d-aspartic acid (% d-Asp). Zymography was conducted to identity specific gelatinases. MMP-1 activity was higher in ruptured Supraspinatus compared to control Supraspinatus and normal biceps brachii tendons (70.9, 26.4 and 11.5 fmol/mg tendon, respectively; P<0.001). Gelatinolytic and MMP-3 activities were lower in normal biceps brachii and ruptured Supraspinatus compared to control Supraspinatus (gelatinase: 0.18, 0.23 and 0.82 RFU/s/mg tendon respectively; P<0.001; MMP-3: 9.0, 8.6 and 55 fmol/mg tendon, respectively; P<0.001). Most gelatinase activity was shown to be MMP-2 by zymography. Denatured collagen was increased in ruptured Supraspinatus compared to control Supraspinatus (20.4% and 9.9%, respectively; P<0.001). The % d-Asp content increased linearly with age in normal biceps brachii but not in control Supraspinatus and was significantly lower in ruptured Supraspinatus compared to age-matched control tendons (0.33 and 1.09% d-Asp, respectively; P<0.01). We conclude that the short head of biceps brachii tendons show little protein turnover, whereas control Supraspinatus tendons show relatively high turnover mediated by the activity of MMP-2, MMP-3 and MMP-1. This activity is thought to represent a repair or maintenance function that may be associated with an underlying degenerative process caused by a history of repeated injury and/or mechanical strain. After tendon rupture, there was increased activity of MMP-1, reduced activity of MMP-2 and MMP-3, increased turnover and further deterioration in the quality of the collagen network. Tendon degeneration is shown to be an active, cell-mediated process that may result from a failure to regulate specific MMP activities in response to repeated injury or mechanical strain.
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glycosaminoglycans of human rotator cuff tendons changes with age and in chronic rotator cuff tendinitis
Annals of the Rheumatic Diseases, 1994Co-Authors: G P Riley, R L Harrall, C R Constant, M D Chard, Timothy E Cawston, B L HazlemanAbstract: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.
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tendon degeneration and chronic shoulder pain changes in the collagen composition of the human rotator cuff tendons in rotator cuff tendinitis
Annals of the Rheumatic Diseases, 1994Co-Authors: G P Riley, R L Harrall, C R Constant, M D Chard, Timothy E Cawston, B L HazlemanAbstract:OBJECTIVES--To analyse the collagen composition of normal adult human Supraspinatus tendon and to compare with: (1) a flexor tendon (the common biceps tendon) which is rarely involved in any degenerative pathology; (2) degenerate tendons from patients with chronic rotator cuff tendinitis. METHODS--Total collagen content, collagen solubility and collagen type were investigated by hydroxyproline analysis, acetic acid and pepsin digestion, cyanogen bromide peptide analysis, SDS-PAGE and Western blotting. RESULTS--The collagen content of the normal cadaver Supraspinatus tendons (n = 60) was 96.3 micrograms HYPRO/mg dry weight (range 79.3-113.3) and there was no significant change across the age range 11 to 95 years. There was no significant difference from the common biceps tendon [93.3 (13.5) micrograms HYPRO/mg dry weight, n = 24]. Although extremely insoluble in both acetic acid and pepsin, much of the collagen was soluble after cyanogen bromide digestion [mean 47.9% (29.8)]. Seventeen per cent (10/60) of the 9normal9 cadaver Supraspinatus tendon sample contained more than 5% type III collagen, although none of the common biceps tendons had significant amounts. Degenerate Supraspinatus and subscapularis tendons had a reduced collagen content [83.8 (13.9) micrograms/mg dry weight and 76.9 (16.8) micrograms/mg dry wt respectively) and were more soluble in acetic acid, pepsin and cyanogen bromide (p
George A. C. Murrell - One of the best experts on this subject based on the ideXlab platform.
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shoulder pain in elite swimmers primarily due to swim volume induced Supraspinatus tendinopathy
British Journal of Sports Medicine, 2010Co-Authors: Mya Lay Sein, Judie Walton, Brent Kirkbride, Donald Kuah, James Linklater, Richard Appleyard, George A. C. MurrellAbstract:Background/hypothesis: Shoulder pain in elite swimmers is common, and its pathogenesis is uncertain. Hypothesis/study design: The authors used a crosssectional study design to test Jobe’s hypothesis that repetitive forceful swimming leads to shoulder laxity, which in turn leads to impingement pain. Methods: Eighty young elite swimmers (13–25 years of age) completed questionnaires on their swimming training, pain and shoulder function. They were given a standardised clinical shoulder examination, and tested for glenohumeral joint laxity using a non-invasive electronic laxometer. 52/80 swimmers also attended for shoulder MRI. Results: 73/80 (91%) swimmers reported shoulder pain. Most (84%) had a positive impingement sign, and 69% of those examined with MRI had Supraspinatus tendinopathy. The impingement sign and MRIdetermined Supraspinatus tendinopathy correlated strongly (r s =0.49, p<0.00001). Increased tendon thickness correlated with Supraspinatus tendinopathy (r s =0.37, p<0.01). Laxity correlated weakly with impingement pain (r s =0.23, p<0.05) and was not associated with Supraspinatus tendinopathy (r s =0.14, p=0.32). The number of hours swum/week (r s =0.39, p<0.005) and weekly mileage (r s =0.34, p=0.01) both correlated signifi cantly with Supraspinatus tendinopathy. Swimming stroke preference did not. Conclusions: These data indicate: (1) Supraspinatus tendinopathy is the major cause of shoulder pain in elite swimmers; (2) this tendinopathy is induced by large amounts of swimming training; and (3) shoulder laxity per se has only a minimal association with shoulder impingement in elite swimmers. These fi ndings are consistent with animal and tissue culture fi ndings which support an alternate hypothesis: the intensity and duration of load to tendon fi bres and cells cause tendinopathy, impingement and shoulder pain.
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topical glyceryl trinitrate application in the treatment of chronic Supraspinatus tendinopathy a randomized double blinded placebo controlled clinical trial
American Journal of Sports Medicine, 2005Co-Authors: Justin A. Paoloni, Janis Nelson, Richard Appleyard, George A. C. MurrellAbstract:Background: Topical glyceryl trinitrate therapy has previously demonstrated short-term pain reduction in patients with Supraspinatus tendinopathy.Hypothesis: Topical glyceryl trinitrate improves outcome measures in patients with Supraspinatus tendinopathy.Study Design: Randomized controlled clinical trial; Level of evidence, 1.Methods: Fifty-three patients (57 shoulders) were recruited, and the authors completed a prospective, randomized, double-blinded, placebo-controlled clinical trial of continuous topical glyceryl trinitrate treatment (1.25 mg/24-h glyceryl trinitrate).Results: The glyceryl trinitrate group had significantly reduced shoulder pain with activity, at night, and at rest at week 24 (P = .03); reduced internal rotation impingement at week 24 (P = .02); increased range of motion in abduction and internal rotation at week 24 (P = .04); and increased force at weeks 12 and 24 with Supraspinatus muscle testing (P = .001), external rotation (P = .04), internal rotation (P = .01), adduction (P = ....
