Adaptive low-intensity pulsed ultrasound for accelerated fracture healing and chronic tendinopathic disorders: design and controlled clinical evaluation of a portable low-cost system

Although low-intensity pulsed ultrasound (LIPUS) has been widely investigated as a non-invasive regenerative therapy, optimization of stimulation parameters for different tissue conditions and fracture severities remains an active area of research. This study presents the design and translational clinical evaluation of a portable low-cost LIPUS platform incorporating adjustable stimulation intensity and duty-cycle modulation for personalized fracture and tendinopathy management. The developed system operated at 1.5 MHz with configurable acoustic intensities ranging from 40–60 mW/cm 2 and adaptable duty cycles (1:1–1:4), delivered for 30 min/session. Clinical evaluation included a retrospective controlled fracture cohort comprising 53 patients (31 treated with adjunctive LIPUS and 22 control group) together with an exploratory cohort of 27 patients with chronic tendinopathic disorders. The fracture cohort included recent fractures, delayed unions, and established non-unions. Additional exploratory applications included chronic lateral epicondylitis (n = 12) and Achilles tendinopathy (n = 15). Adjunctive LIPUS treatment was associated with significantly accelerated fracture healing, particularly in recent fractures (1.43 ± 0.59 vs 3.86 ± 2.82 months, p = 0.001). Delayed-union and non-union cases also demonstrated favorable healing outcomes despite increased biological complexity. Kaplan–Meier analysis revealed significantly faster union probability in the LIPUS cohort. In chronic tendinopathy, 92.6% of patients exceeded a predefined clinically meaningful improvement threshold of 75% despite prolonged symptom duration and previous conservative treatment failure. These findings support the feasibility and translational potential of an adjustable low-cost LIPUS platform for accelerating fracture healing and managing chronic tendinopathic disorders. The proposed system may provide an accessible and scalable therapeutic alternative for outpatient and resource-limited clinical environments.