Semi-rigid linking piece for stabilizing the spine

A vertebral stabilization system for fastening together at least two vertebrae each having a median plane substantially perpendicular to the axis of the spine of which they are part and a posterior wall defining a posterior median plane of said spine, said system comprising:

• at least two anchor members each adapted to be fixed into the posterior wall of a vertebra so that a line which intersects said two anchor members is substantially parallel to said axis of the spine, each anchor member comprising a shank and a rod receiving head configured to secure a spinal stabilization rod;
• a connecting member connected between the at least two anchor members, the connecting member further comprising:
• a flexible part comprising a first branch and a second branch defining a median plane substantially parallel to said posterior median plane of the spine, wherein the first branch and second branch are symmetrically spaced about a longitudinal axis of said connecting member, wherein a first end of the first branch and a first end of the second branch are interconnected to form a first end of the flexible part, and wherein a second end of the first branch and a second end of the second branch are interconnected to form a second end of the flexible part;
• and
• a first rigid rod forming part and a second rigid rod forming part, wherein the first rigid rod forming part extends from the first end of the flexible part and the second rigid rod forming part extends from the second end of the flexible part, wherein the first rigid rod forming part and second rigid rod forming part extend in opposite directions along the longitudinal axis and wherein the first rigid rod forming part and second rigid rod forming part each have a portion adapted to be secured in a rod receiving head portion of an anchor member;
• wherein said first and second branches of said flexible part have portions parallel to each other and to said longitudinal axis of said connecting member, a distance between said parallel portions being at least equal to a length of said parallel portions;
• wherein the cross-section of each of said first and second branches is less than the cross-section of each of said first and second rigid rod-forming parts so that said connecting member is able to bend elastically about an axis that is perpendicular to the longitudinal axis, whereby said vertebrae, which are interconnected in their posterior portions, are relatively movable along said axis of said spine.