Biomedical Engineering, Pennsylvania State University, University Park, PA, USA.
Graduate Program in Acoustics, Pennsylvania State University, University Park, PA, USA.
J Biomech. 2022 Feb;132:110934. doi: 10.1016/j.jbiomech.2021.110934. Epub 2021 Dec 22.
Tendon injuries are extremely common, resulting in mechanically weaker tendons that could lead to tendon rupture. Dry needling (DN) is widely used to manage pain and function after injury. However, DN is invasive and high inter-practitioner variability has led to mixed success rates. Focused ultrasound (fUS) is a non-invasive medical technology that directs ultrasound energy into a well-defined focal volume. fUS can induce thermal ablation or mechanical fractionation, with bioeffect type controlled through ultrasound parameters. Tendons must withstand high physiological loads, thus treatments maintaining tendon mechanical properties while promoting healing are needed. Our objective was to evaluate mechanical effects of DN and 3 fUS parameter sets, chosen to prioritize mechanical fractionation, on Achilles and supraspinatus tendons. Ex vivo rat Achilles and supraspinatus tendons (50 each) were divided into sham, DN, fUS-1, fUS-2, and fUS-3 (n = 10/group). Following treatment, tendons were mechanically tested. Elastic modulus of supraspinatus tendons treated with DN (126.64 ± 28.1 MPa) was lower than sham (153.02 ± 29.3 MPa; p = 0.0280). Stiffness and percent relaxation of tendons treated with DN (Achilles: 114.40 ± 31.6 N/mm; 49.10 ± 6.1%; supraspinatus: 109.53 ± 30.8 N/mm; 50.17 ± 7.6%) were lower (all p < 0.0334) than sham (Achilles: 141.34 ± 20.9 N/mm; 60.30 ± 7.7%; supraspinatus: 135.14 ± 30.2 N/mm; 60.85 ± 15.4%). Modulus of Achilles and supraspinatus tendons treated with fUS-1 (159.88 ± 25.7 MPa; 150.12 ± 22.0 MPa, respectively) were similar to sham (156.35 ± 23.0 MPa; 153.02 ± 29.3 MPa, respectively). These results suggest that fUS preserves mechanical properties better than DN, with fUS-1 performing better than fUS-2 and fUS-3. fUS should be studied further to fully understand its mechanical and healing effects to help evaluate fUS as an alternative, non-invasive treatment for tendon injuries.
肌腱损伤极为常见，导致机械强度降低，从而可能导致肌腱断裂。干针（DN）广泛用于管理损伤后的疼痛和功能。然而，DN 是侵入性的，并且由于从业者之间的高度可变性，导致成功率参差不齐。聚焦超声（fUS）是一种非侵入性的医疗技术，可将超声能量引导到一个明确的焦点容积中。fUS 可以诱导热消融或机械分割，通过超声参数控制生物效应类型。肌腱必须承受高生理负荷，因此需要保持肌腱机械性能同时促进愈合的治疗方法。我们的目的是评估 DN 和 3 种 fUS 参数设置对跟腱和冈上肌腱的机械影响，这些参数设置优先考虑机械分割。离体大鼠跟腱和冈上肌腱（每组 50 个）分为假手术、DN、fUS-1、fUS-2 和 fUS-3（每组 n = 10）。治疗后，对肌腱进行机械测试。接受 DN 治疗的冈上肌腱的弹性模量（126.64 ± 28.1 MPa）低于假手术组（153.02 ± 29.3 MPa；p = 0.0280）。接受 DN 治疗的肌腱的刚度和松弛百分比（跟腱：114.40 ± 31.6 N/mm；49.10 ± 6.1%；冈上肌腱：109.53 ± 30.8 N/mm；50.17 ± 7.6%）较低（所有 p < 0.0334）假手术组（跟腱：141.34 ± 20.9 N/mm；60.30 ± 7.7%；冈上肌腱：135.14 ± 30.2 N/mm；60.85 ± 15.4%）。接受 fUS-1 治疗的跟腱和冈上肌腱的模量（159.88 ± 25.7 MPa；150.12 ± 22.0 MPa）与假手术组相似（156.35 ± 23.0 MPa；153.02 ± 29.3 MPa）。这些结果表明，fUS 比 DN 更好地保持机械性能，fUS-1 比 fUS-2 和 fUS-3 更好。应该进一步研究 fUS，以充分了解其机械和愈合效果，从而帮助评估 fUS 作为治疗肌腱损伤的替代非侵入性治疗方法。
