Disclosed are embodiments of a dynamic stabilizer system for dynamically stabilizing the sacrum and at least lumbar vertebra L5. The dynamic stabilizer system may comprise two anchoring members that can be implanted at distinct locations in the sacrum, a mechanical fastener element having two ends and a flexible portion that can be securely fastened on the spinous process of a lumbar vertebra, and two distinct rods, each securing onto the anchoring members and the mechanical fastener element. In some embodiments, the dynamic stabilizer system may further comprise one or more spacers, each interposed between two spinous processes. The mechanical fastener element further comprises features for securing the one or more spacers.