BONE FIXING DEVICE FOR FIXING TO SACRUM DURING BACKBONE JOINTING OPERATION

PROBLEM TO BE SOLVED: To facilitate installation to a designated position by providing a link means formed by a member having a plate element with a hole and a screw part formed in the hole, and forming a support surface in a spherical surface. SOLUTION: This sacrum fixing device 1 comprises an upper eyelet 4, a sacrum plate (plate element) 5, and a rod 6, wherein there is provided a series of holes 7 penetrating the plate 5. The holes 7 are communicated with each other through a piercing slot. Each hole 7 is provided with a spherical cup part 7a in such a manner as to co-operate with the complementary type lower jaw part of the head part 21 of a bone fastening screw 2. The upper surface of the screw head part 21 is a flat spherical heat part, and a fastening tool receiving socket 21 is provided on the upper surface. A plug 3 screw-in female screw part 8 is provided on the hole 7 inner peripheral surface. A spherical cup-like housing is formed to be co-operated with the screw head part 21. By the plug 3, the screw 2 is fixed in an attitude with an angle determined by an operator.