Sonoelastographıc assessment of the age-related changes of the Achilles tendon

Abstract

Aims: Tendons are crucial for optimal muscle force transfer and subject to changes with aging which may impair functional ability of elderly individuals. Achilles is the largest and the strongest tendon in the body; therefore it is an excellent site for the radiologic investigation of aging of tendons. Sonoelastography (SE) is a new ultrasound-based imaging technique that provides information on elastic properties and stiffness of tissues. The aim of our study was to investigate the age-related alterations in Achilles tendons using SE. Material and methods: Forty five geriatric (age≥ 65 years) and 42 young (age 18-40 years) healthy consecutive subjects were enrolled. Subjects with known history of metabolic or endocrine diseases, sports or traumatic injuries, peripheral vascular disorders were excluded. Both Achilles tendons were scanned with a real-time SE probe at a frequency of 6-15 MHz. Strains of Achilles tendons' proximal, middle and distal parts were assessed semi-quantitatively with comparing a reference tissue. Results: Both SE methods -color coded evaluation and strain measurement-showed a remarkably stiffer tendon in the elderly subjects compared to young subjects in all thirds of Achilles tendons. In young subjects 84.9 % tendon thirds were blue, and 15.1% were green whereas, in elders 93.7% were blue and 6.3% were green (p=0.024). There was a significant correlation between age and stiffness of tendons assessed with strain indices. Conclusion: Our result showed increased tendon stiffness in elderly subjects which might be responsible for the high prevalence of Achilles tendinopathies observed in elderly subjects.

Real-time sonoelastography of the patellar and quadriceps tendons: pattern description in profesional athletes and healthy volunteers.

“…As our study, Drakonaki et al did not find any difference with age or sex [12]. On the other hand, Turan et al found that the Achilles tendon was remarkably stiffer in elderly subjects compared to young subjects in all parts of the tendon examination [24]. Despite biomechanical studies demonstrating different viscoelastic properties with physical activity, we could not quantify the difference with sonoelastography.…”

Quantitative ultrasound mapping of regional variations in shear wave speeds of the aging Achilles tendon

“…Notably, both animal and human studies have shown evidence that aged tendon exhibits increased stiffness of the inter-fascicular matrix [2], an increase in collagen cross-linking [3, 4], and a reduction in collagen fibril crimp angle [34]. Although tendon elasticity measures in humans have produced conflicting evidence regarding an age-related decrease in tendon compliance [6–10, 35], the ambiguity may arise in part from methodological factors or from spatial definitions of the tendon, which may span regions of free tendon and aponeurosis. For example, one traditional ultrasound approach for measuring tendon elasticity involves tracking anatomical landmarks (e.g.…”

“…Thus, the age-related increase in free tendon shear wave speed would seem to reflect the material properties of the unloaded tissue, which could arise from increased stiffness of the interfascicular matrix [2]. Likewise, a recent study using a sonoelastography technique observed that older adult Achilles tendons exhibit less deformation with manual palpation [35], possibly reflecting greater transverse stiffness.…”

Real-time sonoelastography: principles and clinical applications in tendon disorders.

“…Subsequently, Arda et al 13 reported on elasticity values of Achilles tendons using a numeric scale in healthy volunteers, with a mean of 51.5 ± 25.1 kPa as Young modulus. During aging, Achilles tendon exhibited an increased stiffness when compared to young adults 14,15 ; however, other Authors did not find any correlation 16 . A positive correlation was found between tendon stiffness and BMI 17 ; results in smokers are controversial 17,18 .…”

“…On the opposite side, diabetic patients with foot ulcers had thicker but softer tendons than healthy controls and diabetic patients without foot ulcers 41. In patients affected by ankylosing spondylitis, tendon pain was higher in patients with areas of softening. In particular, the distal third was the most commonly affected site and it was commonly associated with both bone erosion and enthesis enlargement 15,42 . Onal et al reported that patients with acromegaly had thicker tendon than healthy subjects, especially in active phase of disease.…”