An Implantable Magnetohydrodynamic Pump for Generating Fluid Flow During Bone Fracture Healing

Abstract Nonunion and delayed union, which occur in approximately 5–10% of major long bone fracture cases, significantly complicate treatment and negatively impact patients' quality of life. This necessitates the need for novel treatment strategies to enhance healing outcomes. Researchers have explored the role of fluid flow in stimulating bone cells and regulating bone regeneration; however, these studies are mostly conducted in silico or in vitro. This study introduces a magnetohydrodynamic (MHD) device integrated into a bone fixation plate for investigating the effects of fluid flow on bone regeneration in vivo. An implantable MHD device was designed and fabricated to induce fluid flow in vivo. To validate the device's biocompatibility, it was implanted in female Wistar rats upon the creation of a 2 mm unilateral segmental bone defect for four weeks. The results show complete device functionality throughout seven post-injury fluid flow treatments administered over 28 days. The device is designed to induce fluid flow of varying magnitudes at the fracture site, enabling investigation of its potential impact on bone healing. In addition, the device did not induce adverse effects such as fibrous encapsulation or tissue necrosis in vivo, supporting its potential for investigating fluid flow stimulation as a treatment approach for improving healing in delayed and nonunion fractures. The potential of a fluid flow treatment holds great significance for researchers, addressing a critical knowledge gap regarding the impact of fluid flow on healing calluses, while offering an alternative regimen for the elderly and those with multiple injuries.