Garcia Mason J, Caro Daniela, Lalli Alberto, Intermesoli Giovanni, Ramappa Arun J, DeAngelis Joseph P, Longo Umile Giuseppe, Nazarian Ara
Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Mechanical Engineering Department, Boston University, Boston, MA, USA.
JSES Int. 2025 Mar 12;9(4):1107-1113. doi: 10.1016/j.jseint.2025.02.007. eCollection 2025 Jul.
Rotator cuff (RC) tears are one of the most common tendinous injuries in the adult population, resulting in pain and loss of function. While many tears are often asymptomatic, many patients will experience tears progression and the development of symptoms. The objective of this study is to determine the location of RC tear initiation and the subsequent biomechanical changes as a function of tear size.
8 fresh-frozen (n = 8) human cadaveric supraspinatus tendons (mean age: 68.6 ± 14.2) were subjected to fatigue loading. Images were taken to capture the location of tear initiation and subsequent progression. Tendon stiffness and nominal strain were measured throughout the tendon's lifecycle to determine changes to the biomechanical properties as a function of tear size.
The location of tear initiation was 15.89 3.33 mm (range: 13.00-22.22 mm) from the anterior edge of the supraspinatus tendon. As tears progressed, tendon stiffness decreased (R = 0.68, < .001) and nominal strain increased (R = 0.71, < .001). Biomechanical changes to the supraspinatus tendon occurred between the following tear sizes: 0-100 mm and 100-200 mm ( = .001) and between 100-200 mm and 400 mm or larger ( < .001).
In a biomechanical model of RC tears induced by fatigue loading, tear initiation was observed approximately 16 mm posterior to the biceps tendon, positioning it further posterior than previously believed. Alterations to the biomechanical properties occur due to tear progression. However, these changes are most severe and significant when tears progress to >100 mm and further progress to >400 mm. These insights provide a potentially clinically relevant definition of tear progression based on biomechanical changes to the supraspinatus tendon.
肩袖（RC）撕裂是成年人群中最常见的肌腱损伤之一，会导致疼痛和功能丧失。虽然许多撕裂通常无症状，但许多患者会经历撕裂进展和症状发展。本研究的目的是确定肩袖撕裂起始的位置以及随后作为撕裂大小函数的生物力学变化。
对8条新鲜冷冻（n = 8）的人尸体冈上肌腱（平均年龄：68.6 ± 14.2）进行疲劳加载。拍摄图像以捕捉撕裂起始位置和随后的进展情况。在整个肌腱生命周期内测量肌腱刚度和名义应变，以确定作为撕裂大小函数的生物力学特性变化。
撕裂起始位置距离冈上肌腱前缘15.89 ± 3.33 mm（范围：13.00 - 22.22 mm）。随着撕裂进展，肌腱刚度降低（R = 0.68，P <.001），名义应变增加（R = 0.71，P <.001）。冈上肌腱的生物力学变化发生在以下撕裂大小之间：0 - 100 mm和100 - 200 mm（P =.001）以及100 - 200 mm和400 mm或更大（P <.001）。
在疲劳加载诱发肩袖撕裂的生物力学模型中，观察到撕裂起始于肱二头肌肌腱后方约16 mm处，其位置比先前认为的更靠后。由于撕裂进展，生物力学特性发生改变。然而，当撕裂进展到>100 mm并进一步进展到>400 mm时，这些变化最为严重和显著。这些见解基于冈上肌腱的生物力学变化提供了一个潜在的临床相关的撕裂进展定义。
