Oxidized cellulose and collagen are two absorbable hemostatic scaffolding materials that are used widely in surgery. A histomorphological study was undertaken to determine the tissue response and extent of healing brought about by intraosseously implanting these two materials in the femur and tibia of sheep. There was no major difference in the rate of repair of the bone defects brought about by these two materials, with the bone defects being completely repaired by lamellar bone at 6-8 weeks. Therefore, our results suggest that, in most instances where collagen is presently used in surgical applications, it could be substituted by oxidized cellulose. (C) 2003 Kluwer Academic Publishers.