Bones are made up of living tissue and a fracture results in two broken ends; one of which has a positive charge and the other end which has a negative charge. The stimulator generates an electromagnetic field that helps attract the two oppositely charged ends of the bones to each other by promoting new bone growth and fusion, which leads to healing. There are four main stages of fracture healing: inflammation, soft callus formation, hard callus formation, and bone remodeling [2].

Inflammation occurs immediately after the bone is broken. It develops due to the disruption of the blood supply and bleeding from the fractured ends, which causes swelling and bruising at the fracture site. Soft callus formation refers to the formation of cartilage between the two fractured ends, and this begins a couple of days after the fracture has occurred. Hard callus formation begins around 2 to 3 weeks after the fracture and is the stage when the cartilage starts to transform into bone. This stage continues for 6 to 12 weeks. Bone remodeling begins after the fractured ends have fused together and refers to the formation of extra bone at the site. Unfortunately, in the case of nonunion fractures, this process does not take place as it normally would [1, 2].