Focused ultrasound as an alternative to dry needling for the treatment of tendinopathies: A murine model.

Tendinopathies account for 30% of 102 million annual musculoskeletal injuries occurring annually in the United States. Current treatments, like dry needling, induce microdamage to promote healing but produce mixed success rates. Previously, we showed focused ultrasound can noninvasively create microdamage while preserving mechanical properties in ex vivo murine tendons.

Dual-frequency boiling histotripsy in an ex vivo bovine tendinopathy model.

Histotripsy fractionates most soft tissues; however, healthy tendons have shown resistance to histotripsy fractionation. Prior work has shown that pre-heating tendons increases susceptibility to histotripsy fractionation; combining multiple driving frequencies may also allow successful fractionation of tendons. Here, we evaluate single- and dual-frequency histotripsy in four healthy and eight tendinopathic ex vivo bovine tendons.

High intensity focused ultrasound atomization and erosion in healthy and tendinopathic tendons.

High-intensity focused ultrasound (HIFU) can induce thermal and mechanical mechanisms in a well-defined focal volume of tissues. Histotripsy is a form of mechanical HIFU that can initiate and interact with bubble(s) to cause shock scattering and perhaps atomization within the bubble(s) to fractionate most soft tissues. Ultrasonic atomization, or the ejection of fine droplets from an acoustically-excited liquid exposed to air, has been shown to erode planar soft tissue surfaces, which has led to theories that atomization is a mechanism in histotripsy.

Therapeutic Ultrasound and Shockwave Therapy for Tendinopathy: A Narrative Review.

Tendon injury is prevalent and costly in the United States, comprising 45% of the 66 million musculoskeletal injuries and costing $114 billion annually. Surgical and therapeutic methods, such as arthroscopic surgery, dry needling, and physical therapy, produce mixed success in reintroducing a healing response in tendinopathy due in part to inconsistent dosing and monitoring. Ultrasound is one therapeutic modality that has been shown to noninvasively induce bioeffects in tendon that may help promote healing.

Ultrasound-Responsive Hydrogels for On-Demand Protein Release.

The development of tunable, ultrasound-responsive hydrogels that can deliver protein payload on-demand when exposed to focused ultrasound is described in this study. Reversible Diels-Alder linkers, which undergo a retro reaction when stimulated with ultrasound, were used to cross-link chitosan hydrogels with entrapped FITC-BSA as a model protein therapeutic payload. Two Diels-Alder linkage compositions with large differences in the reverse reaction energy barriers were compared to explore the influence of linker composition on ultrasound response.

Automated Tissue Strain Calculations Using Harris Corner Detection.

The elastic modulus, or slope of the stress-strain curve, is an important metric for evaluating tissue functionality, particularly for load-bearing tissues such as tendon. The applied force can be tracked directly from a mechanical testing system and converted to stress using the tissue cross-sectional area; however, strain can only be calculated in post-processing by tracking tissue displacement from video collected during mechanical testing. Manual tracking of Verhoeff stain lines pre-marked on the tissue is time-consuming and highly dependent upon the user.

Effects of focused ultrasound and dry needling on tendon mechanical properties.

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.

Comparison between dry needling and focused ultrasound on the mechanical properties of the rat Achilles tendon: A pilot study.

In the U.S., approximately 14 million tendon and ligament injuries are reported each year.

Histotripsy in collagenous tendons.

Tendon injuries comprise 45% of the 66 million musculoskeletal injuries each year with annual costs of $114 billion. Conservative therapies to treat injured tendon produce mixed success rates. Histotripsy is a high intensity focused ultrasound modality that creates and oscillates bubbles to fractionate soft tissues in a well-defined focal volume; however, highly collagenous tissues like tendon have proven resistant to histotripsy.