The Role of the Paratenon in Achilles Tendon Healing: A Study in Rats

2018 ◽  
Vol 46 (5) ◽  
pp. 1214-1219 ◽  
Author(s):  
Sebastian A. Müller ◽  
Christopher H. Evans ◽  
Patricia E. Heisterbach ◽  
Martin Majewski
Keyword(s):  
Achilles Tendon ◽  
Tendon Healing ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Sprague Dawley ◽  
Cross Sectional ◽  
Collagen Formation ◽  
Tendon Defect ◽  
Tear Resistance

Background: The role of the paratenon in tendon healing is unknown. The present study compares healing in the presence or absence of the paratenon in an Achilles tendon defect model in rats. Hypothesis: Resection of the paratenon impairs tendon healing. Study Design: Controlled laboratory study. Methods: Sixty skeletally mature Sprague Dawley rats were randomly assigned to either a resected paratenon (RP) group or an intact paratenon (IP) group. In all animals, a 4-mm portion of the Achilles tendon was resected in the midsubstance. In the RP group, the paratenon was resected completely. In the IP group, the paratenon was opened longitudinally and closed again after the tendon defect had been created. One, 2, and 4 weeks after surgery, 7 animals per group were tested biomechanically and 3 animals per group examined histologically. Results: The recovery of mechanical strength was much more rapid in IP tendons. Tear resistance was significantly increased for IP tendons (41.3 ± 8.8 N and 47.3 ± 14.1 N, respectively) compared with RP tendons (19.3 ± 9.1 N and 33.2 ± 6.4 N, respectively) after 1 and 2 weeks. The cross-sectional area was larger in the IP group after 1 and 2 weeks (8.2 ± 2.3 mm2 and 11.3 ± 3.1 mm2 vs 5.0 ± 2.4 mm2 and 5.9 ± 2.0 mm2, respectively) compared with the RP group. Tendon stiffness was greater in the IP group after 1 week (10.4 ± 1.9 N/mm vs 4.5 ± 1.6 N/mm, respectively) compared with the RP group. In comparison, normal contralateral tendons had a maximal tear resistance of 56.6 ± 7.2 N, a cross-sectional area of 3.6 ± 0.7 mm2, and stiffness of 17.3 ± 3.8 N/mm. Hematoxylin and eosin staining revealed slightly delayed healing of RP tendons. Early collagen formation was seen in the IP group already after 1 week, whereas in the RP group, this only occurred after 2 weeks. After 4 weeks, the IP tendons showed more collagen crimp formation than the RP tendons. Conclusion: An intact paratenon promotes healing of the Achilles tendon. Clinical Relevance: Although incision or resection of the paratenon has been advocated when repairing injured or degenerative tendons, our data suggest that the integrity of the paratenon should be preserved.

scholarly journals Patients with Achilles Tendon Rupture Have a Degenerated Contralateral Achilles Tendon: An Elastography Study

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Qianru Li ◽  
Qi Zhang ◽  
Yehua Cai ◽  
Yinghui Hua
Keyword(s):  
Achilles Tendon ◽  
Axial Strain ◽  
Achilles Tendon Rupture ◽  
Cross Sectional Area ◽  
Control Group ◽  
Computer Assisted ◽  
Study Group ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Mean

Purpose. To evaluate differences of Achilles tendon (AT) hardness and morphology between asymptomatic tendons in patients with acute AT ruptures on the contralateral side and asymptomatic tendons in healthy people by using computer-assisted quantification on axial-strain sonoelastography (ASE). Methods. The study consisted of 33 asymptomatic tendons in 33 patients (study group) and 34 tendons in 19 healthy volunteers (control group). All the tendons were examined by both ASE and conventional ultrasound. Computer-assisted quantification on ASE was applied to extract hardness variables, including the mean (Hmean), 20th percentile (H20), median (H50) and skewness (Hsk) of the hardness within tendon, and the ratio of the mean hardness within tendon to that outside tendon (Hratio) and three morphological variables: the thickness (THK), cross-sectional area, and eccentricity (ECC) of tendons. Results. The Hmean, Hsk, H20, H50, and Hratio in the proximal third of the tendon body in study group were significantly smaller than those in control group (Hmean: 0.43±0.09 vs 0.50±0.07, p=0.001; Hsk: -0.53±0.51 vs -1.09±0.51, p<0.001; H20: 0.31±0.10 vs 0.40±0.10, p=0.001; H50: 0.45±0.10 vs 0.53±0.08, p<0.001; Hratio: 1.01±0.25 vs 1.20±0.23, p=0.003). The THK and cross-sectional area of tendons in the study group were larger than those in the control group (p<0.05). Conclusions. As a quantitative objective method, the computer-assisted ASE reveals that the asymptomatic ATs contralateral to acute rupture are softer than those of healthy control group at the proximal third and the asymptomatic tendons in people with rupture history are thicker, larger, and rounder than those of normal volunteers especially at the middle and distal thirds of AT body.

scholarly journals Sex Differences in the Morphological and Mechanical Properties of the Achilles Tendon

2021 ◽  
Vol 18 (17) ◽  
pp. 8974
Author(s):  
Xini Zhang ◽  
Liqin Deng ◽  
Songlin Xiao ◽  
Lu Li ◽  
Weijie Fu
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Cross Sectional Area ◽  
Morphological Properties ◽  
Sectional Area ◽  
Cross Sectional ◽  
Force Peak ◽  
Strain Stress

Background: Patients with Achilles tendon (AT) injuries are often engaged in sedentary work because of decreasing tendon vascularisation. Furthermore, men are more likely to be exposed to AT tendinosis or ruptures. These conditions are related to the morphological and mechanical properties of AT, but the mechanism remains unclear. This study aimed to investigate the effects of sex on the morphological and mechanical properties of the AT in inactive individuals. Methods: In total, 30 inactive healthy participants (15 male participants and 15 female participants) were recruited. The AT morphological properties (cross-sectional area, thickness, and length) were captured by using an ultrasound device. The AT force–elongation characteristics were determined during isometric plantarflexion with the ultrasonic videos. The AT stiffness was determined at 50%–100% maximum voluntary contraction force. The AT strain, stress, and hysteresis were calculated. Results: Male participants had 15% longer AT length, 31% larger AT cross-sectional area and 21% thicker AT than female participants (p < 0.05). The plantarflexion torque, peak AT force, peak AT stress, and AT stiffness were significantly greater in male participants than in female participants (p < 0.05). However, no significant sex-specific differences were observed in peak AT strain and hysteresis (p > 0.05). Conclusions: In physically inactive adults, the morphological properties of AT were superior in men but were exposed to higher stress conditions. Moreover, no significant sex-specific differences were observed in peak AT strain and hysteresis, indicating that the AT of males did not store and return elastic energy more efficiently than that of females. Thus, the mechanical properties of the AT should be maintained and/or improved through physical exercise.

Role of diffusion tensor imaging in the evaluation of ulnar nerve involvement in leprosy

2021 ◽  
pp. 20210290
Author(s):  
Ankita Aggarwal ◽  
Chandan Jyoti Das ◽  
Neena Khanna ◽  
Raju Sharma ◽  
Deep Narayan Srivastava ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Peripheral Neuropathy ◽  
Ulnar Nerve ◽  
Diffusion Tensor ◽  
Cross Sectional Area ◽  
Ulnar Neuropathy ◽  
Control Group ◽  
Sectional Area ◽  
Cross Sectional

Objective: Early detection of peripheral neuropathy is extremely important as leprosy is one of the treatable causes of peripheral neuropathy. The study was undertaken to assess the role of diffusion tensor imaging (DTI) in ulnar neuropathy in leprosy patients. Methods: This was a case–control study including 38 patients (72 nerves) and 5 controls (10 nerves) done between January 2017 and June 2019. Skin biopsy proven cases of leprosy, having symptoms of ulnar neuropathy (proven on nerve conduction study) were included. MRI was performed on a 3 T MR system. Mean cross-sectional area, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of ulnar nerve at cubital tunnel were calculated. Additional ancillary findings and appearance of base sequences were evaluated. Results: Ulnar nerve showed thickening with altered T2W signal in all the affected nerves, having an average cross-sectional area of 0.26 cm2. Low FA with mean of 0.397 ± 0.19 and high ADC with mean of 1.28 ± 0.427 x 10 −3 mm2/s of ulnar nerve in retrocondylar groove was obtained. In the control group, mean cross-sectional area was 0.71cm2 with mean FA and ADC of 0.53 ± 0.088 and 1.03 ± 0.24 x 10 −3 mm2/s respectively. Statistically no significant difference was seen in diseased and control group. Cut-off to detect neuropathy for FA and ADC is 0.4835 and 1.1020 × 10 −3 mm2/s respectively. Conclusion: DTI though is challenging in peripheral nerves, however, is proving to be a powerful complementary tool for assessment of peripheral neuropathy. Our study validates its utility in infective neuropathies. Advances in knowledge: 1. DTI is a potential complementary tool for detection of peripheral neuropathies and can be incorporated in standard MR neurography protocol. 2. In leprosy-related ulnar neuropathy, altered signal intensity with thickening or abscess of the nerve is appreciated along with locoregional nodes and secondary denervation changes along with reduction of FA and rise in ADC value. 3. Best cut-offs obtained in our study for FA and ADC are 0.4835 and 1.1020 × 10 −3 mm2/s respectively.

Role of superoxide anion in regulating pressor and vascular hypertrophic response to angiotensin II

2002 ◽  
Vol 282 (5) ◽  
pp. H1697-H1702 ◽  
Author(s):  
Hui Di Wang ◽  
Douglas G. Johns ◽  
Shanqin Xu ◽  
Richard A. Cohen
Keyword(s):  
Superoxide Anion ◽  
Pressor Response ◽  
Cross Sectional Area ◽  
Ang Ii ◽  
Sectional Area ◽  
Wild Type ◽  
Cross Sectional ◽  
Hypertrophic Response

Our purpose was to address the role of NAPDH oxidase-derived superoxide anion in the vascular response to ANG II. Blood pressure, aortic superoxide anion, 3-nitrotyrosine, and medial cross-sectional area were compared in wild-type mice and in mice that overexpress human superoxide dismutase (hSOD). The pressor response to ANG II was significantly less in hSOD mice. Superoxide anion levels were increased twofold in ANG II-treated wild-type mice but not in hSOD mice. 3-Nitrotyrosine increased in aortic endothelium and adventitia in wild-type but not hSOD mice. In contrast, aortic medial cross-sectional area increased 50% with ANG II in hSOD mice, comparable to wild-type mice. The lower pressor response to ANG II in the mice expressing hSOD is consistent with a pressor role of superoxide anion in wild-type mice, most likely because it reacts with nitric oxide. Despite preventing the increase in superoxide anion and 3-nitrotyrosine, the aortic hypertrophic response to ANG II in vivo was unaffected by hSOD.

Combination of hormone replacement therapy and high physical activity is associated with differences in Achilles tendon size in monozygotic female twin pairs

2009 ◽  
Vol 106 (4) ◽  
pp. 1332-1337 ◽  
Author(s):  
T. Finni ◽  
V. Kovanen ◽  
P. H. A. Ronkainen ◽  
E. Pöllänen ◽  
G. R. Bashford ◽  
...  
Keyword(s):  
Physical Activity ◽  
Hormone Replacement Therapy ◽  
Achilles Tendon ◽  
Replacement Therapy ◽  
Hormone Replacement ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Physically Active ◽  
Tendon Thickness

Estrogen concentration has been suggested to play a role in tendon abnormalities and injury. In physically active postmenopausal women, hormone replacement therapy (HRT) has been suggested to decrease tendon diameter. We hypothesized that HRT use and physical activity are associated with Achilles tendon size and tissue structure. The study applied cotwin analysis of fourteen 54- to 62-yr-old identical female twin pairs with current discordance for HRT use for an average of 7 yr. Achilles tendon thickness and cross-sectional areas were determined by ultrasonography, and tendon structural organization was analyzed from the images using linear discriminant analysis (LDA). Maximal voluntary and twitch torques from plantar flexor muscles were measured. Serum levels of estradiol, estrone, testosterone, and sex hormone binding globulin were analyzed. Total daily metabolic equivalent score (MET-h/day) was calculated from physical activity questionnaires. Results showed that, in five physically active (MET > 4) pairs, the cotwins receiving HRT had greater estradiol level ( P = 0.043) and smaller tendon cross-sectional area than their sisters (63 vs. 71 mm2, P = 0.043). Among all pairs, Achilles tendon thickness and cross-sectional area did not significantly differ between HRT using and nonusing twin sisters. Intrapair correlation for Achilles tendon thickness was high, despite HRT use discordance ( r = 0.84, P < 0.001). LDA distinguished different tendon structure only from two of six examined twin pairs who had a similar level of physical activity. In conclusion, the effect of HRT on Achilles tendon characteristics independent of genetic confounding may be present only in the presence of sufficient physical activity. In physically active twin pairs, the higher level of estrogen seems to be associated with smaller tendon size.

CROSS-SECTIONAL AREA OF THE ACHILLES TENDON IN YOUNG AND ELDERLY WOMEN

2001 ◽  
Vol 33 (5) ◽  
pp. S126 ◽  
Author(s):  
N Beyer ◽  
H Abrahamsen ◽  
K Neergaard ◽  
M Kjaer ◽  
P Aagaard ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Elderly Women ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional
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