Implant for osteosynthesis device in particular of the backbone

An implant for an osteosynthesis device, in particular for the spine, the implant comprising:

• a first assembly comprising:
• a fixing body for a bracing rod, said body being arranged to present a reception housing for receiving an anchor screw head, thereby defining a ball joint between the anchor screw and the fixing body;
• a positioning ring for interposing between the anchor screw head and the bracing rod;
• and a second assembly comprising a nut type system for fastening the bracing rod to the fixing body,
• wherein
• the first assembly has a positioning ring mounted in the fixing body with freedom to move in limited linear displacement and allowing the body and the anchor screw to rotate freely relative to each other in the absence of the bracing rod;
• and
• the second assembly has a nut type system adapted on being screwed onto the body to bear against the bracing rod and move the positioning ring in linear manner so that on being tightened it clamps the bracing rod between said system and the positioning ring, and also clamps the anchor screw between the positioning ring and the fixing body;
• wherein the positioning ring is guided to move with limited linear displacement relative to the fixing body by means of a guide peg co-operating with a complementary bore.