| 1. |
- Arndt, Anton, 1968-, et al.
(författare)
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Non-uniform displacement within the Achilles tendon durig passive ankle joint motion.
- 2012
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Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 20:9, s. 1868-74
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE:An initial step in the understanding of Achilles tendon dynamics is to investigate the effects of passive motion, thereby minimising muscle activation and reducing internal joint forces. Internal tendon dynamics during passive ankle joint motion have direct implications for clinical rehabilitation protocols after Achilles tendon surgery. The aim of this study was to test the hypothesis that tendon tissue displacement is different in different layers of the Achilles tendon during controlled passive ankle joint movements.METHODS:Ultrasound imaging was conducted on the right Achilles tendon of nine healthy recreationally active males. Standardised isokinetic passive dorsi-plantar-flexion movements were performed with a total range of motion of 35°. The tendon was divided into superficial, central and deep layers in the resulting B-mode ultrasound images viewed in the sagittal plane. A block-matching speckle tracking algorithm was applied post-process, with kernels for the measurement of displacement placed in each of the layers.RESULTS:The mean (SD) displacement of the Achilles tendon during passive dorsiflexion was 8.4 (1.9) mm in the superficial layer, 9.4 (1.9) mm in the central portion and 10.4 (2.1) mm in the deep layer, respectively. In all cases, the movement of the deep layer of the tendon was greater than that of the superficial one (P < 0.01).CONCLUSIONS:These results, achieved in vivo with ultrasonographic speckle tracking, indicated complex dynamic differences in different layers of the Achilles tendon, which could have implications for the understanding of healing processes of tendon pathologies and also of normal tendon function.
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| 2. |
- Bagge, Johan, 1984-
(författare)
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TNF-α and neurotrophins in Achilles tendinosis
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tenocytes are the principal cells of the human Achilles tendon. In tendinosis, changes in the metabolism and morphology of these cells occur. Neurotrophins are growth factors essential for the development of the nervous system. Tumour necrosis factor alpha (TNF-α) has been found to kill sarcomas but has destructive effects in several major diseases. The two systems have interaction effects and are associated with apoptosis, proliferation, and pain signalling in various diseases. Whether these systems are present in the Achilles tendon and in Achilles tendinosis is unknown. The hypothesis is that the tenocytes produce substances belonging to these systems. In Studies I–III, we show that the potent effects of these substances are also likely to occur in the Achilles tendon. We found tenocyte immunoreactions for the neurotrophins brain-derived neurotrophic factor (BDNF), the nerve growth factor (NGF), the neurotrophin receptor p75, and for TNF-α and both of its receptors, TNFR1 and TNFR2. This occurred in both subjects with painful mid-portion Achilles tendinosis, and in controls. Furthermore, we found mRNA expression for BDNF and TNF-α in tenocytes, which proves that these cells produce these substances. TNFR1 mRNA was also detected for the tenocytes, and TNFR1 immunoreactions were upregulated in tendinosis tendons. This might explain why tenocytes in tendinosis undergo apoptosis more often than in normal tendons. Total physical activity (TPA) level and blood concentration of both soluble TNFR1 and BDNF were measured in Study IV. The results showed that the blood concentration of both factors were similar in subjects with tendinosis and in controls. Nevertheless, the TPA level was related to the blood concentration of sTNFR1 in tendinosis, but not in controls. This relationship should be studied further. The findings of this doctoral thesis show that neurotrophin and TNF-α systems are expressed in the Achilles tendon. We believe that the functions include tissue remodelling, proliferation and apoptosis.
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| 3. |
- Bjur, Dennis, 1965-
(författare)
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The human Achilles tendon : innervation and intratendinous production of nerve signal substances - of importance in understanding the processes of Achilles tendinosis
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tendinopathies are painful tendon conditions of presumably multifactorial genesis. In tendinosis, as in Achilles tendinosis, there is apart from pain also morphological changes which are described as degenerative with no signs of inflammation. The exact mechanisms behind these conditions are still, to a large extent, unknown. Pain, being the foremost impairing symptom, leads us to the hypothesis that nerves are deeply involved in the symptoms and processes of Achilles tendinosis. Locally produced nerve signal substances may also be involved in the processes. Knowledge of the innervation patterns within the tendon and knowledge on a possible local nerve signal substance production are therefore of utmost importance. There is a lack of information on these aspects. The specific aims of this thesis were 1) to investigate the innervation patterns regarding general, sensory, cholinergic and sympathetic innervations, and 2) to examine for the possible occurrence of a production of nerve signal substances and a presence of receptors related to these in the tendon cells, the tenocytes. Painfree normal and tendinosis Achilles tendons were examined. Immunohistochemistry, using antibodies against the general nerve marker PGP9.5, the synthesizing enzymes for acetylcholine (choline acetyltransferase; ChAT), and catecholamines (tyrosine hydroxylase; TH), the vesicular acetylcholine transporter (VAChT), neuropeptide Y (NPY), substance P and calcitonin gene-related peptide, was applied. Immunohistochemistry was also used for the delineation of muscarinic (M2R), adrenergic (α1-AR) and NPY-ergic (Y1 and Y2) receptors. To detect mRNA for TH and ChAT, in situ hybridization was used. In normal Achilles tendons, as well as in the tendinosis tendons, there was a very scanty innervation within the tendon tissue proper, the main general, sensory and sympathetic innervations being found in the paratendinous loose connective tissue. Interestingly, the tenocytes showed immunoreactions for ChAT, VAChT, TH, M2R, α1-AR and Y1R. The reactions were clearly more observable in tendons of tendinosis patients than in those of controls. The tenocytes of tendinosis patients also displayed mRNA reactions for ChAT and TH. Nevertheless, all tenocytes in the tendinosis specimens did not show these reactions. Immunoreactions for α1-AR, M2R and Y1R were also seen for blood vessel walls. The present thesis shows that there is a very limited innervation within tendon tissue proper, whilst there is a substantial innervation in the paratendinous loose connective tissue. It also gives evidence for an occurrence of production of catecholamines and acetylcholine in tenocytes, especially for tendinosis tendons. Furthermore, that ACh, catecholamines and NPY can have effects on these, as well as on blood vessels, via the receptors observed. The observations suggest that Achilles tendon tissue, whilst containing a very scarce innervation, exhibits autocrine/paracrine cholinergic/catecholaminergic/NPY-ergic effects that are upregulated in tendinosis. These findings are of great importance as the results of such effects may mimic processes that are known to occur in tendinosis. That includes effects related to proliferation and angiogenesis, and blood vessel and collagen regulating effects. In conclusion, within the Achilles tendon there is a very scarce innervation, whilst there appears to be a marked local production of nerve signal substances in Achilles tendinosis, namely in the tenocytes, the cells also harbouring receptors for these substances. The observations give a new insight into how the tendon tissue of the Achilles tendon is influenced by signal substances and may give options for new treatments of Achilles tendinosis.
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| 4. |
- Farfaras, Stefanos, et al.
(författare)
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More histologic and ultrastructural degenerative signs in the subscapularis tendon and the joint capsule in male patients with shoulder impingement
- 2018
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Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 26:1, s. 79-87
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of the present study was to analyze biopsy samples from the subscapularis tendon and from the joint capsule from male patients with shoulder impingement syndrome (SAIS) and compare them with samples from male patients with post-traumatic recurrent shoulder instability. The hypothesis of the study was that patients with SAIS would have more histologic and ultrastructural degenerative changes in their subscapularis tendon and joint capsule than patients with post-traumatic recurrent shoulder instability. Methods: Male patients scheduled for surgery, with either subacromial decompression or Bankart reconstruction, were included. Four biopsies from each patient were obtained from the capsule and four from the subscapularis tendon during arthroscopic surgery. The histologic characteristics and the presence of glycosaminoglycans were assessed using the light microscope, and the ultrastructure was assessed using a transmission electron microscope. Results: Eight patients, median age 53 (45–74) years (p < 0.0001), were included in the impingement group, and 12 patients, median age 27 (22–48) years, were included in the instability group. The histologic assessment revealed significantly higher cellularity and total degeneration score in the capsule (p = 0.016 and p = 0.014 respectively) in patients with subacromial impingement compared with the instability patients. The corresponding finding was not made for the subscapularis tendon. The ultrastructural evaluation revealed that the instability patients had more fibrils with a large diameter (indicating less degeneration) in both the subscapularis tendon and the capsule compared with the impingement patients (p < 0.0001). Conclusion: Male patients with subacromial impingement have more histologic and ultrastructural degenerative changes in their shoulder compared with patients with post-traumatic recurrent shoulder instability. Clinical relevance: It appears that in patients with subacromial impingement, the whole shoulder joint is affected and not only the subacromial space. It is the opinion of the authors that intra-articular therapeutic injections could be tried more often in these patients. Level of evidence: III.
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| 5. |
- Fröberg, Åsa, et al.
(författare)
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Altered patterns of displacement within the Achilles tendon following surgical repair
- 2017
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Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 25:6, s. 1857-1865
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Tidskriftsartikel (refereegranskat)abstract
- Ultrasound speckle tracking was used to compare tendon deformation patterns between uninjured and surgically repaired Achilles tendons at 14-27-month follow-up. The hypothesis was that the non-homogenous displacement pattern previously described in uninjured tendons, where displacement within deep layers of the tendons exceeds that of superficial layers, is altered following tendon rupture and subsequent surgical repair. In the first part of this study, an in-house-developed block-matching speckle tracking algorithm was evaluated for assessment of displacement on porcine flexor digitorum tendons. Displacement data from speckle tracking were compared to displacement data from manual tracking. In the second part of the study, eleven patients with previous unilateral surgically treated Achilles tendon rupture were investigated using ultrasound speckle tracking. The difference in superficial and deep tendon displacement was assessed. Displacement patterns in the surgically repaired and uninjured tendons were compared during passive motion (Thompson's squeeze test) and during active ankle dorsiflexion. The difference in peak displacement between superficial and deep layers was significantly (p < 0.01) larger in the uninjured tendons as compared to the surgically repaired tendons both during Thompson's test (-0.7 +/- 0.2 mm compared to -0.1 +/- 0.1 mm) and active dorsiflexion (3.3 +/- 1.1 mm compared to 0.3 +/- 0.2 mm). The evaluation of the speckle tracking algorithm showed correlations of r ae 0.89 between displacement data acquired from speckle tracking and the reference displacement acquired from manual tracking. Speckle tracking systematically underestimated the magnitude of displacement with coefficients of variation of less than 11.7%. Uninjured Achilles tendons display a non-uniform displacement pattern thought to reflect gliding between fascicles. This pattern was altered after a mean duration of 19 +/- 4 months following surgical repair of the tendon indicating that fascicle sliding is impaired. This may affect modulation of the action between different components of the triceps surae, which in turn may affect force transmission and tendon elasticity resulting in impaired function and risk of re-rupture.
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| 6. |
- Gardin, Anna, et al.
(författare)
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Dynamic contrast enhanced magnetic resonance imaging in chronic Achilles tendinosis
- 2013
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Ingår i: BMC Medical Imaging. - : Springer Science and Business Media LLC. - 1471-2342. ; 13, s. 39-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic Achilles tendinosis is a common problem. When evaluating and comparing different therapies there is a need for reliable imaging methods. Our aim was to evaluate if chronic Achilles tendinosis affects the dynamic contrast-enhancement in the tendon and its surroundings and if short-term eccentric calf-muscle training normalizes the dynamic contrast-enhancement. Methods: 20 patients with chronic Achilles tendinopathy were included. Median duration of symptoms was 31 months (range 6 to 120 months). Both Achilles tendons were examined with dynamic contrast enhanced MRI before and after a 12-week exercise programme of eccentric calf-muscle training. The dynamic MRI was evaluated in tendon, vessel and in fat ventrally of tendon. Area under the curve (AUC), time to peak of signal, signal increase per second (SI/s) and increase in signal between start and peak as a percentage (SI%) was calculated. Pain and performance were evaluated using a questionnaire. Results: In the fat ventrally of the tendon, dynamic contrast enhancement was significantly higher in the symptomatic leg compared to the contralateral non-symptomatic leg before but not after treatment. Despite decreased pain and improved performance there was no significant change of dynamic contrast enhancement in symptomatic tendons after treatment. Conclusion: In Achilles tendinosis there is an increased contrast enhancement in the fat ventrally of the tendon. The lack of correlation with symptoms and the lack of significant changes in tendon contrast enhancement parameters do however indicate that dynamic enhanced MRI is currently not a useful method to evaluate chronic Achilles tendinosis.
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| 7. |
- Gärdin, Anna, et al.
(författare)
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The long-term clinical and MRI results following eccentric calf muscle training in chronic Achilles tendinosis
- 2010
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Ingår i: Skeletal Radiology. - : Springer Science and Business Media LLC. - 0364-2348 .- 1432-2161. ; 39:5, s. 435-442
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To evaluate the long-term results following eccentric calf-muscle training in patients with chronic Achilles tendinopathy.MATERIALS AND METHODS: A total of 24 patients with chronic Achilles tendinopathy were included in a study evaluating MRI findings and clinical symptoms before and after 3 months of daily eccentric calf-muscle strength training. Median duration of symptoms was 18 months (range 6-120). Four of the patients did not perform the prescribed treatment for different reasons and were followed for 14 months. The resulting 20 treated patients completed 4.2-year (range 29-58 months) follow up. Tendon volume was evaluated by using 3D seed growing technique and signal abnormalities were visually semi-quantitatively graded. Level of pain and performance was categorized using a questionnaire completed by the patient.RESULTS: In the symptomatic treated patients, median intensity level of pain decreased from moderate/severe at time of inclusion to mild at follow up (p < 0.05). Median level of performance increased from severe impairment at time of inclusion to normal at follow up (p < 0.05). 12 out of 20 patients had raised intratendinous signal at time of inclusion compared to 2 out of 20 patients at follow up (p < 0.001). Mean tendon-volume measured 6.7 cm(3) (SD 2.0) at time of inclusion and 6.4 cm(3) (SD 2.0) at follow up (p = 0.18). The four symptomatic non-treated tendons did not improve regarding pain, performance, intratendinous signal or tendon volume.CONCLUSION: We found decreased pain, improved performance and decreased intratendinous signal both compared to index examination and immediately after the 3 months training regimen in a 4.2-year clinical and MRI follow up, in a group of patients treated with heavy loaded eccentric calf-muscle training for chronic Achilles tendinopathy. The improvements were greater at 4.2-year follow up, despite no further active treatment, than immediately after the treatment. This may indicate a good long-term prognosis for Achilles tendinosis patients.
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| 8. |
- Hedlundh, Urban, et al.
(författare)
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Periprosthetic joint infection after total hip arthroplasty induces histological degeneration of the gluteus medius tendon.
- 2023
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Ingår i: Bone & Joint Open (BJO). - 2633-1462. ; 4:8, s. 628-635
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Tidskriftsartikel (refereegranskat)abstract
- A revision for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) has a major effect on the patient's quality of life, including walking capacity. The objective of this case control study was to investigate the histological and ultrastructural changes to the gluteus medius tendon (GMED) in patients revised due to a PJI, and to compare it with revision THAs without infection performed using the same lateral approach.A group of eight patients revised due to a PJI with a previous lateral approach was compared with a group of 21 revised THAs without infection, performed using the same approach. The primary variables of the study were the fibril diameter, as seen in transmission electron microscopy (TEM), and the total degeneration score (TDS), as seen under the light microscope. An analysis of bacteriology, classification of infection, and antibiotic treatment was also performed.Biopsy samples from the GMED from infected patients revealed a larger fibril diameter than control patients, as seen in the TEM (p < 0.001). Uninfected patients were slightly older and had their revisions performed significantly later than the infected patients. Histologically, samples from infected patients revealed significantly more vascularity (p < 0.001), the presence of glycosaminoglycans (p < 0.001), and a higher TDS (p = 0.003) than the control patients. The majority of patients had staphylococcal infections of various species.More histological degeneration in the GMED was found in patients undergoing THA revision surgery due to PJI than in patients undergoing THA revision surgery due to other reasons.
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| 9. |
- Movin, Tomas
(författare)
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Aspects of aetiology, pathoanatomy and diagnostic methods in chronic mid-portion achillodynia
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The objectives of this thesis are to study aetiology and pathoanatomy, and to evaluate diagnostic methods in patients with long-standing pain and tenderness localised to the mid portion of the Achilles tendon. Treatment had failed to relieve symptoms prior to referral to our clinic, where some of these patients underwent surgical treatment. Fifty eight patients, derived from 60 consecutive operations, were analysed regarding history, clinical assessment, ultrasound, histopathology and outcome of surgery. One third of the patients were not used to any form of vigorous physical activity. Ultrasonographic pathology was observed in 54 out of 59 examinations. Macroscopically diseased tendon tissue showed marked histopathological changes. At the follow-up to surgery, after in median 25 months (range 12-50), there was an overall satisfactory result in 75% of the patients. Topical applications of ketoprofen, a hydrophilic non-steroidal anti-inflammatory drug, in patients in surgery for chronic tendon disorders revealed high concentrations of ketoprofen in fat, paratenon and tendon, while plasma levels were found to below. The results indicated a direct penetration and that tissues act as a reservoir for ketoprofen. No attempt was made to study clinical effects. Tendon biopsies from 40 surgically treated patients revealed abnormal fibre structure and arrangement, focal variations in cellularity, rounded nuclei, decreased collagen stainability and increased non-collagenous matrix. Increased vascularity was seen in 26 out of the 40 subjects. Inflammatory cell infiltration was not found. A semi-quantitative grading, using a total tendon score, had a median of 21 (6-24) compared to 0 (0-13)in control biopsies (p<0.001). The volume-density estimation of glycosaminoglycan-rich areas had a median of 0.47 (0-0.86) in patients and 0 (0-0.07) in controls (p<0.001). A percutaneous core biopsy technique, guided by ultrasound and performed under local anaesthesia, turned out to be a reliable and valid tool, which can be used in clinical and experimental in vivo studies of Achilles tendon disorders. Gadolinium contrast enhancement improved the imaging of intra-tendinous signal abnormality on Tl-weighted magnetic resonance images. The increased amount of extracellular glycosaminoglycans, highly fixed negatively charged macromolecules with water retaining capacity, may contribute to explain this finding. Intra-tendinous alterations were imaged with contrast medium enhanced magnetic resonance and with ultrasound in 20 patients with achillodynia. Core biopsies were obtained from ultrasound hypoechoic and normoechoic regions. The increased signal abnormality in gadolinium contrast enhanced Tl-weighted images revealed a larger volume of the lesion compared with ultrasound. Hypoechoic areas showed a markedly abnormal tendon structure. However, moderate pathology was found also in the neighbouring normoechogenous areas within the same tendon, indicating a more generalised disorder than imaged by echogenic properties. In conclusion, the data and the new tools presented in this thesis encourage further studies including treatment on the Achilles and other tendon disorders.
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| 10. |
- Möller, Michael, 1957, et al.
(författare)
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The ultrasonographic appearance of the ruptured Achilles tendon during healing: a longitudinal evaluation of surgical and nonsurgical treatment, with comparisons to MRI appearance.
- 2002
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Ingår i: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA. - : Springer Science and Business Media LLC. - 0942-2056. ; 10:1, s. 49-56
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Tidskriftsartikel (refereegranskat)abstract
- This prospective, randomized trial compared healing characteristics of the Achilles tendon after surgical and nonsurgical treatment for complete rupture of the Achilles tendon. Fifty-eight patients were examined by ultrasonography after 6, 12, and 24 months and by magnetic resonance imaging after 12 months. A standardized protocol was used, and the outcome was correlated with clinical findings. Common findings 1 year after the injury were tendon thickening and moderate heterogeneity of the tendon. Peritendinous reactions, edema, and defects were present only in a minority of patients. There were no significant differences between the treatment groups in any of the evaluated parameters apart from the gliding function of the tendon, which was significantly less in the surgically treated group than in the nonsurgically treated group. No correlations were found between the radiological findings and the clinical parameters, such as muscle strength, endurance, and range of motion. We conclude that the roles of ultrasonography and magnetic resonance imaging during the healing process after Achilles tendon rupture are limited, due to a weak correlation with clinical findings.
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