Osteotomy and gradual distraction of the distal radius was performed on 12 sheep. After 3-6 weeks of daily distraction by external fixation, lengthening of 0.5-1.8 cm was achieved. Three weeks after distraction was begun, striae of new bone, organized in the direction of the distraction, were noted radiologically. The bony consolidation developed from the osteotomized bone ends to the center of the distraction area. Medullary structures also contributed to bone formation in the distraction area. Collagen bundles, organized in the direction of distraction, formed a template for the developing bone. The medullary canal remodeled 16 weeks after the operation. Solid bone formed after the distraction procedure with no additional bone transplantation.
Animals Bone Lengthening