Targeting an orthopaedic implant landmark

• US 9,585,722 B2
• Filed: 05/11/2015
• Issued: 03/07/2017
• Est. Priority Date: 04/27/2009
• Status: Active Grant

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: Ritchey, Nicholas S., Janna, Sied W., Wilhelm, Hoa La, Heotis, Charles C.
• Primary Examiner(s): Hammond, Ellen C
• Assistant Examiner(s): BRAY, STUART SAMUEL
• Application Number:
  US14/708,678
• Publication Number:
  US 20150238277A1
• Time in Patent Office: 666 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 17/1707 using electromagnetic effects, e.g. with magnet and external sensors
• CPC Class Codes: A61B 17/1725 for applying transverse screws or pins through intramedullary nails or pins
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/0813 Accessories designed for easy sterilising, i.e. re-usable
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 5/1127 using markers

Abstract

A system for targeting landmarks on devices such as surgical implants is disclosed. The system can include a field generator for generating one or more magnetic fields, an orthopedic implant located within the magnetic fields, the implant having at least one landmark, a removable probe with a first magnetic sensor, a landmark identifier and a processor. The landmark identifier can contain a second sensor, or, alternatively, the field generator. The processor can utilize sensor data and, if desirable, field generator and other information, to generate and display the position and orientation of the sensor(s) in preferably six degrees of freedom, and thereby, to generate and display the position and orientation of the landmark(s). The system allows for blind targeting of one or more landmarks. The landmark identifier, field generator and/or drill motor may be disposed in an autoclavable housing.

Claims

1. A system for targeting a landmark on an orthopaedic implant comprising:

an autoclavable device comprising;

an autoclavable housing comprising an outer covering; and

a field generator for generating an electromagnetic field, the field generator comprising a plurality of magnetic field generating elements disposed within the outer covering of the housing, wherein the autoclavable device is configured to be operable to generate the electromagnetic field for targeting the landmark after being subjected to autoclave sterilization;

an electromagnetic sensor for disposition at a set distance from the landmark, the electromagnetic sensor being configured to generate sensor data in response to the generated electromagnetic field, the generated sensor data indicating a relative position of the electromagnetic sensor with respect to the autoclavable device; and

a drill guide removably coupleable to the housing of the autoclavable device.

2. The system of claim 1, further comprising a removable probe that extends into the orthopaedic implant, the electromagnetic sensor being coupled to the removable probe.

3. The system of claim 2, further comprising an adjustable stop that is connectable to the orthopaedic implant, the adjustable stop comprising a slot through which removable probe extends, the adjustable stop comprising a clamping mechanism to hold the removable probe in a fixed position with respect to the adjustable stop.

4. The system of claim 3, wherein the removable probe comprises a plurality of spaced apart indicators, and the clamping mechanism is configured to be selectively set to hold the removable probe in a fixed position at an indicator or between two indicators.

5. The system of claim 1, wherein the autoclavable device comprises a removable second covering placed over the outer covering.

6. The system of claim 5, wherein the autoclavable device comprises an autoclavable internal mounting structure formed of a non-magnetic material, the autoclavable internal mounting structure being located within the outer covering, the plurality of magnetic field generating elements being mounted to the autoclavable internal mounting structure.

7. The system of claim 1, wherein the autoclavable device defines a central opening, and the drill guide is configured to couple to the autoclavable device around the central opening.

8. The system of claim 7, wherein the drill guide comprises a sleeve or tube having an opening aligned with the central opening of the autoclavable device when the drill guide is attached to the autoclavable device.

9. The system of claim 1, further comprising a processor configured to receive sensor data from the electromagnetic sensor and determine a position of the autoclavable device based on the sensor data.

10. The system of claim 9, further comprising a display, wherein the processor is configured to cause the display to indicate a position of an axis of the drill guide relative to the orthopaedic implant.

11. The system of claim 1, wherein the outer covering is formed of silicone.

12. The system of claim 1, wherein the plurality of magnetic field generating elements is encapsulated within the outer covering.

13. The system of claim 1, wherein the plurality of magnetic field generating elements comprises at least three induction coils.

14. The system of claim 1, wherein the drill guide has a serrated tip.

15. The system of claim 1, wherein the autoclavable device is configured to produce a sequence of multiple spatial magnetic field shapes.

16. The system of claim 1, wherein the electromagnetic sensor is an inductive sensor.

17. The system of claim 1, wherein the electromagnetic sensor is configured to provide data indicating a position of the electromagnetic sensor in six degrees of freedom.

18. The system of claim 1, wherein the autoclavable device defines a plurality of indentations spaced apart along an exterior of the autoclavable device.

19. The system of claim 1, wherein the autoclavable device is disk-shaped.

20. The system of claim 1, wherein the orthopaedic implant comprises one of an intramedullary nail, a bone plate, a hip prosthetic, a knee prosthetic, and a shoulder prosthetic.