BIOMECHANICAL PROPERTIES OF CANINE CORTICOCANCELLOUS BONE FROZEN IN NORMAL SALINE SOLUTION

Eleven pairs of canine metacarpal bones, 10 pairs of metatarsal bones, and 7 pairs of ribs were harvested cleanly and prepared for banking a t -20 C for 1 year. One bone of each pair was randomly assigned to 1 t ype of storage: plastic pack vs immersion in a normal solution of sodi um chloride. The contralateral bone was assigned to the opposite treat ment. Six pairs of metacarpal bones and 5 pairs of metatarsal bones we re tested in torsion to failure. No significant difference was found w ithin pairs. All ribs, 5 pairs of metacarpal bones, and 5 pairs of met atarsal bones were loaded in 4-point bending to failure. The energy ab sorbed at failure and the ultimate displacement of ribs and metacarpal and metatarsal bones were increased by 25 to 30% and 18 to 24%, respe ctively, when the bones were frozen in isotonic saline solution. Corti cocancellous grafts frozen in normal saline solution are biomechanical ly less fragile and brittle than grafts stored in plastic without sali ne solution.