Abstract: The present invention concerns a device for fixing osteosynthesis rods to pedicular screws (1), the device being of the type including a diapason-shaped head (4) defining two branches (4a, 4b) collectively receiving a rod (6) to be fixed, the head being locked in its housing (5) by a locking screw (7), wherein it further includes, threaded on the rod (6) and inserted between the locking screw (7) and the bottom of the housing (5), a split ring (9) whose opposing external faces (10) directed towards the locking screw (7) and said bottom are convex and received in complementary concave surfaces (11, 12) provided on the extremity of the locking screw (7) and the bottom of the receiving housing (5) of the rod (6), the ring (9), prior to locking of the screw (7), allowing for a certain angular clearance of the rod (6) with respect to the axis of the screw (1).

Abstract: A device for supporting a spinal column includes a screw having a U-shaped head, a joining element received within the head, a threaded bolt received within and threadedly engaging the head, and a cap covering an upper portion of the head. The head is internally threaded. The threaded bolt engages the joining element to block relative movement between the joining element and the screw. The cap avoids spreading of the head upon tightening of the bolt in the head.