continuous shear wave elastography as a diagnostic marker for tendinopathy

描述（由申请人提供）：肌腱病是一种局部肌腱损伤，其特征是正常胶原结构丧失，糖胺聚糖增加，细胞增多，新生血管形成和神经向内生长。过度使用（过度负荷）被认为是主要的原因。跟腱是人体最强壮的肌腱，但仍然经常受伤。在成人人群中，跟腱病的发病率为2.5 / 1000。中部肌腱病变是跟腱最常见的病理状况，占跟腱过度使用损伤的55%至65%。肌腱病的首选治疗方法是治疗性运动，这被认为可以促进肌腱胶原结构的重塑。运动剂量对肌腱愈合有很大影响。运动剂量的两个极端（固定和过度使用）已被证明对肌腱愈合有害。这表明有一个最佳的运动剂量，以最大限度地提高功能和肌腱性能。然而，量化治疗（即运动）的效果是困难的，因为缺乏非侵入性的、经济有效的方法来量化肌腱的组成、结构和重塑。目前，通过临床、功能和患者报告的结果来评估治疗，这些结果评估足部的活动范围、下肢的力量和症状。然而，这些结果的局限性是缺乏对肌腱结构和力学性能的评估。为了克服这一限制，我们提出通过超声弹性成像对粘弹性特性进行非侵入性测量，作为对肌腱组成、结构和最终功能变化的等效测量。我们最近开发了一种名为连续横波弹性成像（cSWE）的超声技术来测量肌腱的局部粘弹性特性。这项新技术安全、无创、廉价，与商业上可用的方法相比，有两个主要优点：1)参数可以调整，以测量高刚度的组织，如跟腱；2)该技术可用于测量肌腱粘弹性的空间变化（即地图）。因此，该技术适用于评估局部病变

DESCRIPTION (provided by applicant): Tendinopathy is a localized tendon injury characterized by loss of normal collagen architecture, increased glycosaminoglycans, hypercellularity, neovascularization, and nerve ingrowth. Overuse (excessive loading) is considered the major causation factor. The Achilles tendon is the strongest tendon in the body but still often injured. In the adult population the incidence rate for Achilles tendinopathy is 2.5 per 1000. Mid-portion tendinopathy is the most common pathological condition in the Achilles tendon and represents between 55% and 65% of the Achilles tendon overuse injuries. The preferred treatment for tendinopathy is therapeutic exercise, which is believed to promote remodeling of the collagenous structure of the tendon. Tendon healing is highly affected by exercise dosage. The two extremes in exercise dosage (immobilization and overuse) have shown to be detrimental for tendon healing. This suggests there is an optimum exercise dosage to maximize function and tendon properties. However, quantifying the effect of treatment (i.e., exercise) is difficult due to the lack non-invasive cost-effective methods to quantify tendon composition, structure and remodeling. Currently, treatments are evaluated using clinical, functional and patient-reported outcomes which evaluate the range of motion of the foot, strength of the lower leg, and symptoms. However, a limitation of these outcomes is the lack of evaluation of tendon structure and mechanical properties. To overcome this limitation, we propose non- invasive measurements of viscoelastic properties, via ultrasound elastography, as an equivalent measurement of changes in composition, structure, and ultimately function of the tendon. We recently developed an ultrasound technique, named Continuous Shear Wave Elastography (cSWE), to measure local viscoelastic properties of tendons. This novel technique is safe, non-invasive, inexpensive, and offer two main advantages over commercially available methods: 1) the parameters can be tune to measure tissue with high stiffness such as the Achilles tendon, 2) the technique can be used to measure spatial variations (i.e. a map) of tendon viscoelastic properties. Therefore, this technique is suitable to evaluate localized lesions caused by tendinopathy, tears or ruptures. The objectives of the study are to quantify the effect of mid-portion tendinopathy on the viscoelastic properties of the Achilles tendon at the moment of diagnosis and during treatment and to explore possible correlations between viscoelastic properties and clinical/functional outcomes. This study will help establishing cSWE as a clinical technique that can potentially play an important role in optimizing a therapeutic exercise program and/or other treatments for tendinopathy to achieve faster return of function, preventing long-term deficits and re-injury, and minimizing the burden and cost to the health care system.