Progressive approach osteosynthesis device and preassembly method
The present invention relates to an osteosynthesis device, particularly for spinal support or correction, enabling easier and compact implantation, that can be particularly used in the case of implantation via the anterior approach, and a preassembly method for such a device. Said device comprises implants screwed into two vertebrae and one plate characterized in that the plate is joined to at least one implant by attachment structure able to hold said plate without preventing the implant from rotating on its screwing axis, or without preventing a specified clearance of the plate with respect to the implant. In this way, said attachment structure make it possible to continue screwing the implant, or adjust the position of the plate after the plate has been on the implant.
1. An osteosynthesis device comprising:
a plate and
a plurality of implants, each of the implants comprising
a bone anchor having a longitudinal implant axis and a screw head,
a clamping support having a longitudinal clamping support axis and comprising
a support head,
a drive coupler configured for connection to a drive tool,
a plate support, and
a clamp,
a universal joint coupling the bone anchor and the clamping support and being configured for transmission of a rotation of the clamping support around its longitudinal clamping support axis imparted at the drive coupler to a rotation of the bone anchor around its longitudinal implant axis while an angle between the implant axis and the clamping support axis is non-zero, and
the clamping support being configured to permit said transmission while the plate is attached to the implant.
2. The osteosynthesis device of claim 1 , in which the bone anchor further comprises a threaded portion disposed along an external surface of the bone anchor and configured for screwing into a bone.
3. The osteosynthesis device of claim 2 , in which the bone anchor further comprises a threaded portion disposed along a hollow core that has a bone-fusion opening.
4. The osteosynthesis device of claim 1 , in which the plate comprises a cylindrical bar and the plate support comprises a partially cylindrical surface complementary to the surface of the bar.
5. The osteosynthesis device of claim 1 , in which the clamping support is elongated and has first and second distal ends along its clamping support axis, with the support head disposed at the first distal end and the drive coupler disposed at the second distal end.
6. The osteosynthesis device of claim 1 , in which the drive coupler comprises a hexagonal recess and the clamp comprises a nut.
7. The osteosynthesis device of claim 1 , in which the plate support comprises an opening configured for rotatable disposition of the plate support about the clamping support axis.
8. The osteosynthesis device of claim 1 , in which the plate support and the screw head have complementary surfaces configured for support of the plate support by the screw head.
9. The osteosynthesis device of claim 8 , in which the complementary surfaces are partially spherical.
10. The osteosynthesis device of claim 1 , in which the screw head comprises a housing in which the support head is disposed, and the screw head has a projection configured to cooperate with a concave portion of the support head to prevent rotation, relative to the bone anchor, of the clamping support around its clamping support axis.