Abstract: A method and apparatus whereby a direct current at an average amplitude of substantially 20 microamperes is caused to flow from the inserted end of a cathode electrode at one longitudinal side of a fractured or otherwise defective osteal zone, through said zone, and to an anode having electrically conductive circumferential contact with the skin on the other longitudinal side of the zone of the defect. The cathode electrode is a pin inserted through marrow and into internal contact with the cortex at said one longitudinal side. For greatest effectiveness, the direct current comprises a steady component which exceeds the maximum amplitude of a varying component, and both components are of the same polarity.