Electrical stimulation of bone nonunion with the presence of a gap.

A total of 22 established nonunions was treated with a capacitively-coupled electrical signal. A gap of 0.5 cm or more between the fragments was present in all of these nonunions. After an average of 26 weeks of treatment with capacitive coupling, radiographic assessment showed solid bone union in 72.7% of the cases. The results were better when the fracture site was metaphyseal. When the site was diaphyseal, bone healing was mainly achieved by bone trabeculae invading the gap. When the site was metaphyseal, healing occurred by the formation of a peripheral callus. The results were not affected by the presence of infection. In 8 of the cases osteomyelitis occurred, but all healed.