Spinal instruments, particularly for a rod
AssigneeStryker France
InventorEric Petreto
Life of this patent
Estimating the term…
Abstract
The invention relates to a spinal instrument for essentially smooth adjustable connecting rods. The spinal instrument has a nut (5) that clamps receiving and locking assembly (8) to a multi-threaded bone anchor member (1). The receiving and locking assembly (8) has a compressible ring (24) disposed within a clamp (9) having a lower branch (10) and an upper branch (11) coupled between a connecting area (12). The connecting rod fits into the compressible ring (24). With the cavity-ring assembly forming a ball joint, the connecting rod may be clamped into the required angular position. Other features are disclosed.
Claims17
A spinal instrument for essentially smooth adjustable connecting rods, the spinal instrument comprising:
- a nut (5);
- a bone anchor member (1) having an anchor portion (2) separated from a projecting screwthreaded head (3) by an intermediate body (4) having a polygon section (19) with an upper portion, the upper portion of which forms an abutment (7), the projecting screwthreaded head (3) being associated with the nut (5);
- and
- a receiving and locking assembly (8), the assembly (8) having a clamp (9) and a compressible ring (24),
- the clamp (9) having a lower branch (10) and an upper branch (11) linked by a connecting area (12), the lower branch (10) and the upper branch (12) each being provided with an orifice (17) and orifice (18), respectfully, the lower branch orifice (17) aligned to the upper branch orifice (18) so that the projecting screwthreaded head (3) can be passed therethrough as far as the abutment (7), the connecting area (12) of the clamp (9) delimiting a cavity (20) between the lower branch (10) and the upper branch (11),
- the compressible ring (24) housed in the cavity (20), the compressible ring (24) having a central passage (25) to receive the connecting rod, the receiving and locking assembly (8) forming a ball joint so that the clamping of the lower branch (10) and the upper branch (11) by the nut (5) engaged on the screwthreaded head (3) locks the compressible ring (24) and the connecting rod in the required angular position.
Dependencies are inferred from the claim text.