SHAPER FOR VERTEBRAL FIXATION RODS

• US 20170360493A1
• Filed: 12/04/2015
• Published: 12/21/2017
• Est. Priority Date: 12/04/2014
• Status: Active Grant

• Current Assignee: Mazor Robotics LTC
• Original Assignee: Mazor Robotics, Ltd (Medtronic Plc)
• Inventors: ZUCKER, Edo, Shoham, Moshe
• Granted Patent: US 10,631,907 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/7002 Longitudinal elements, e.g. rods
• CPC Class Codes: A61B 17/8863 Apparatus for shaping or cutting osteosynthesis equipment by medical personnel
• CPC Class Codes: A61B 2017/00526 Methods of manufacturing
• CPC Class Codes: A61B 2034/108 Computer aided selection or customisation of medical implants or cutting guides
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 5/0036 including treatment, e.g., using an implantable medical device, ablating, ventilating
• CPC Class Codes: A61B 5/107 Measuring physical dimensions, e.g. size of the entire body or parts thereof
• CPC Class Codes: B21D 7/12 with programme control
• CPC Class Codes: B21D 7/14 combined with measuring of bends or lengths

Abstract

A system for rod bending for use in robotic spinal surgery, enabling the correct bending of a fusion rod to match the shape required to accurately pass through the heads of the pedicle screws. The system uses data generated by information provided to the robot by the surgeon'"'"'s preoperative plan, optionally augmented by feedback from the robot control system of deviations encountered intraoperatively. Such deviations could occur, for example, when the surgeon decides intraoperatively on a different trajectory or even to skip screws on one vertebra, in which case, the robot will be commanded to perform the alternative procedure, with commensurate instructions relayed to the control system of the rod-bending machine. The system is also able to thin down the rod at predetermined locations along its length, adapted to be at selected intervertebral locations, for maintaining limited flexibility between vertebrae, instead of fixating them.

Claims

1. A method for shaping an intervertebral connection rod for use in a computer assisted spinal stabilization procedure, comprising:

providing a surgical plan based on preoperative images of a patient'"'"'s spine, said plan defining the position and orientation of pedicle screws whose insertion into the patient'"'"'s vertebrae is to performed with the assistance of either a robotic system or a navigation system;

generating from said robotic or navigation system, positional data incorporating the co-ordinates of the points at which said rod sits correctly in each desired pedicle screw head;

inputting said positional data to the control system of a rod shaping system, said system adapted to use said positional data to bend a rod inserted therein, such that it adopts a shape that will sit correctly in said desired pedicle screw heads; and

actuating said system to generate a correctly shaped rod for use in said spinal stabilization procedure.

2. A method according to claim 1, wherein said robotic system is adapted to insert said pedicle screws, said method further comprising the step of adjusting said positional data according to any deviation from said preoperative surgical plan of the final position of said pedicle screw insertion, as determined by said robot system.

3. A method according to claim 1, wherein said navigation system is used to define the position of said pedicle screw heads by means of a touch probe.

4. A method according to claim 1, wherein said navigation system is used to define the position of said pedicle screw heads by means of reference markers either on said pedicle screw heads, or on a surgical tool adapted to drill a vertebral hole.

5. A method according to claim 1, wherein said rod-shaping system comprises a plurality of plunger pistons disposed laterally to a cavity in which said rod is clamped, and wherein said positional data is used to move said plunger pistons such that they bend said rod to a shape in accordance with said positional data.

6. A method according to claim 5, wherein said rod can be rotated, such that said plurality of plunger pistons can shape said rod in three dimensions.

7. A method according to claim 5, wherein said plurality of pistons are arranged in more than one plane such that said rod can be shaped in three dimensions without being rotated in said cavity.

8. A method according to claim 1, wherein said rod shaping system further comprises a rod thinning module, adapted to reduce the cross-sectional area of said rod at predetermined locations, such that the rod has increased flexibility at said predetermined locations.

9. A method according to claim 8, wherein the rod thinning module is able to adapt the cross sectional dimension of the rod in different planes according to clinical need.

10. A method according to claim 8, wherein said rod thinning module reduces the cross sectional dimension of said rod by means of indentations generated in the rod at said predetermined locations.

11. A method according to claim 10, wherein said indentations are generated by appropriately shaped plunger pistons.

12. A method according to claim 8, wherein said rod thinning module reduces the diameter of said rod by means of mechanical removal of material from said rod at said predetermined locations.

13. A method according to claim 12, where said mechanical removal of material is performed by a controlled milling action.

14. A method for generating an intervertebral connection rod for use in a dynamic spinal stabilization procedure in a subject, comprising:

providing a surgical plan of a patient'"'"'s spine, said plan defining the desired shape of said intervertebral connection rod in three dimensions, and defining vertebrae between which dynamic mutual motion is to be maintained;

using a rod shaping system to generate said intervertebral connection rod having said desired shape defined by said surgical plan; and

using said rod-shaping system to reduce the cross-sectional area of said rod at rod locations corresponding to regions falling between said vertebrae when said rod is attached to said subject, such that said rod has increased flexibility at said regions.

15. A method according to claim 14, wherein said surgical plan is based on preoperative images of said subject.

16. A system for generating an intervertebral connection rod for use in a dynamic spinal stabilization procedure in a subject, said system comprising:

clamps for holding said rod in said system;

a bending mechanism for applying predetermined bends to said rod at preselected longitudinal and azimuthal positions such that said rod is shaped in accordance with a surgical plan; and

at least one rod thinning element disposed such that the cross section of said rod can be reduced at predetermined locations along the length of said rod.

17. A system according to claim 16, wherein said bending mechanism comprises a set of adjustable rod-bending elements, disposed in positions that enable said elements to apply predetermined bends to said rod at preselected longitudinal and azimuthal positions such that said rod is shaped in accordance with a surgical plan.

18. A system according to claim 16, wherein said bending mechanism comprises a rotatable chuck for gripping said rod, and a controlled bending mandrel adapted to apply a lateral force on said rod at a point distanced from said chuck.

19. A system according to any claim 16, wherein said surgical plan is based on preoperative images of said subject.