A vertebral connecting rod and a spinal osteosynthesis device are disclosed. The vertebral connecting rod 1, which is adapted to be rigidly supported with a pair of spinal implants 5, 5 anchored to vertebral bodies 3, 3 such as thoracic vertebrae or lumbar vertebrae etc., has a pin-shaped section 7 of which one distal end formed with a hook segment 11 for hanging an interconnecting member 9. A slip-out protective member 19 is engageable with the hook segment 11. In a preferred embodiment, the pin-shaped section has at its arbitrary position formed with an engagement convex segment 27 adapted to engage with a corresponding engagement concave recess formed in the spinal implant 5.
