Biodegradable guide for bone regeneration. Polyurethane membranes tested in rabbit radius defects.

Segmental, 1-cm osteoperiosteal defects were produced in both radii of 10 rabbits. One defect was covered with a biodegradable polyurethane membrane formed as a tube. The contralateral defect served as an untreated control. Healing was analyzed by radiographic and histologic studies after 5 weeks. Nine out of 10 control defects displayed nonunion, whereas membrane-treated defects consistently healed by forming callus external to the membrane fusing the bone fragments. Loose connective tissue was predominant in the bone gap underneath the membrane. Presumably, the membrane has served as a scaffold for regenerating periosteum.