高位脛骨骨切り術固定材料の力学的検討

抄録

Loss of correction due to lack of fixation rigidity of staples still remains a problem after high tibial osteotomy. Ogata has developed a new design of staple which is characterized by the blade-like inserting portion and the addition of one cortical screw at the distal portion. This study was carried out to compare the fixation rigidity of standard stepped staples with Ogata's staple. High tibial osteotomy was done for 30 saw bones which were divided into three groups fixed by one stepped staple, two stepped staples, and one Ogata's staple. The proximal part of the tibia was mounted and bending load was applied antero-posteriorly and latero-medially at 20cm distal point to the osteotomy site by using the mechanical test machine. Ultimate moment of three groups were compared statistically. In the antero-posterior loading test, mean moments of three groups were 5.1, 10.6, and 11.1Nm, respectively and in the latero-medial loading test, theywere 11.7, 17.4, and 22.1Nm, respectively. Ogata's staple showed the statistically equivalent fixation rigidity to two stepped staples, while use of only one stepped staple was singnificantly weak. Although the stepped staple was loosened and eventually taken off with loading, Ogata's staple remained stable. The conclusion of this study is that Ogata's staple has adequate fixation rigidity and prevent loosening of the staple.