COMPARISON OF THE FIXATION OF SUBCAPITAL FEMORAL-NECK OSTEOTOMIES WITH ABSORBABLE SELF-REINFORCED POLY-L-LACTIDE LAG-SCREWS OR METALLIC SCREWS IN SHEEP

Seven subcapital femoral osteotomies of adult sheep were each fixed wi th two absorbable self-reinforced poly-L-lactide lag-screws, and seven other osteotomies were each fixed with two metallic cancellous bone s crews. At 3 and 12 weeks, radiographs were taken and callus formation, displacement, and union were evaluated. At 12 weeks, the animals were killed and strength measurements were carried out. According to the r adiographs, union was achieved in six of seven osteotomies in both gro ups, while after 3 weeks one fixation in both the group treated with a bsorbable screws and the group treated with metallic screws had failed . There were no statistical differences between the groups with respec t to callus formation or displacement. Regarding the strength of the o steotomized bones, at 12 weeks there were no statistically significant differences in the load-carrying capacity between the bones fixed wit h self-reinforced poly-L-lactide screws and those fixed with metallic screws. These results showed that self-reinforced poly-L-lactide screw s, which have been used successfully in fractures and osteotomies in c ancellous bone, are strong enough to support this more demanding fixat ion of weight-bearing bones.