Patent ID: 11911076
Assignee: SOUTHERN CROSS PATENTS PTY LTD
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 11:
12. A method of assembling a modular pedicle screw assembly, said method comprising the operations:
selecting an inner collet from a plurality of inner collets including at least a uniaxial inner collet having a bearing surface, and a polyaxial inner collet frangibly connected to an insert;
loading the selected inner collet within a seat for retention within said seat;
pressing the selected inner collet and the associated seat over a common-shaped head of a bone screw selected from a plurality of bone screws of different shaft diameters and/or lengths, the common-shaped head for each of the plurality of bone screws being (a) ball-shaped with a truncated surface and (b) of substantially the same size and shape;
receiving the common-shaped head of the selected bone screw within the selected inner collet for uniaxial or polyaxial movement depending on whether the selected collet is the uniaxial inner collet or the polyaxial inner collet, said uniaxial movement being enabled by tilting of the said uniaxial inner collet about the head of the selected bone screw wherein the bearing surface of the uniaxial inner collet cooperates with the truncated surface of the head of said bone screw, and said polyaxial movement being mobilized by release of the insert connected to said polyaxial inner collet wherein said insert locates at the truncated surface of the head of the selected bone screw; and
activating the selected inner collet by movement of an inner collet actuator arranged to engage the seat whereby activation of said selected inner collet effects its clamping about the common-shaped head of the selected bone screw.