Efficacy of Low-Intensity Pulsed Ultrasound (LIPUS) in the Treatment of Delayed Union and Non-Union: A Integrative Literature Review

Abstract

Introduction: Bone fracture is characterized by the discontinuity of the bone structure resulting from mechanical impacts, the severity of which varies according to soft tissue involvement and the geometry of the lesion line. Failures in the biological healing process can result in delayed union and non-union (pseudoarthrosis). Given the need for interventions that bypass secondary surgical procedures, Low-Intensity Pulsed Ultrasound (LIPUS) stands out as a non-invasive adjuvant therapeutic modality. Objective: To verify whether the action of LIPUS in the treatment stimulates healing in fractures with delayed union and pseudoarthrosis, as well as to evaluate clinical improvement. Method: An integrative literature review was conducted based on scientific articles, clinical trials, and orthopedic manuals published between 2019 and 2025. The search focused on indexed databases using terms associated with bone fractures and pulsed ultrasound therapy. Results: The data demonstrate that LIPUS acts positively on the healing of fractures with delayed union or pseudoarthrosis, converting mechanical stimuli into cellular responses with minimal thermal dissipation. The treatment significantly stimulates local angiogenesis and promotes the differentiation of mesenchymal stem cells into osteoblasts and chondroblasts, culminating in the accelerated formation and maturation of the bone callus. Conclusion: It was concluded that LIPUS is an effective treatment in healing delayed union and pseudoarthrosis, besides providing clinical improvement with pain relief.