Targeting an orthopaedic implant landmark

• US 20100274121A1
• Filed: 04/12/2010
• Published: 10/28/2010
• 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: Wilhelm, Hoa, Janna, Sied W., Ritchey, Nicholas S., Heotis, Charles C.
• Granted Patent: US 9,031,637 B2
• Time in Patent Office: Days
• US Class Current: 600/424
• 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 orthopaedic 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 housing;

a field generator disposed within the housing for generating an electromagnetic field;

a first electromagnetic sensor for disposition at a set distance from the landmark that generates sensor data in response to the generated electromagnetic field; and

an element removably coupled to the housing, the element defining a longitudinal axis that represents one axis of the generated magnetic field, wherein the system is configured to use the one axis of the generated electromagnetic field to determine the position of the element relative to the landmark.

2. The system of claim 1, further comprising at least one of:

a first probe having a proximal portion and a distal portion, the first electromagnetic sensor disposed on the distal portion of the probe;

a retractable probe including the first electromagnetic sensor; and

a retractable probe including the first electromagnetic sensor and a housing containing at least a portion of the retractable probe.

3. The system of claim 2, further comprising a second electromagnetic sensor disposed on the proximal portion of the first probe.

4. The system of claim 2, further comprising a second probe having a proximal and a distal portion and a third electromagnetic sensor disposed on the distal end of the second probe, the second probe being longer than the first probe.

5. The system of claim 1, further comprising a processor for comparing the sensor data from the first electromagnetic sensor and the element and using the set distance to calculate the position of the element relative to the landmark.

6. The system of claim 2, further comprising an adjustable stop connectable to the orthopedic implant, the adjustable stop comprising a slot through which the first or second probe extends and comprising a clamping mechanism to hold the first or second probe in a fixed position.

7. The system of claim 6, wherein the first or second probe comprises a plurality of spaced apart indicators such that the clamping mechanism can be selectively set to hold the first or second probe in a fixed position at an indicator or between two indicators.

8. The system of claim 1, further comprising a handle removably coupled to the orthopedic implant.

9. The system of claim 1, wherein the autoclavable housing is disk-shaped.

10. The system of claim 1, wherein the element comprises one of a drill guide, a drill sleeve, a drill, a drill nose, a drill barrel, a drill chuck, and a fixation element.

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

12. The system of claim 2, wherein the first or second probe is coiled prior to placement into the orthopedic implant.

13. The system of claim 1, wherein the first electromagnetic sensor comprises a proximal and a distal end, the distal end of the first electromagnetic sensor is connected to a proximal end of the orthopedic implant such that the first electromagnetic sensor is spaced apart a set distance from at least one landmark disposed in a proximal region of the orthopedic implant.

14. The system of claim 1, wherein at least the housing and the element are reusable.

15. The system of claim 1, wherein the housing is made from one of ceramic, silicone, polypropylene (PP), polycarbonate (PC), polymethylpentene (PMP), PTFE resin, or polymethyl methacrylate (PMMA or acrylic).

16. An apparatus for targeting a landmark of an orthopaedic implant comprising:

an insertion handle removably attachable to the orthopaedic implant;

an adjustable stop comprising an actuator; and

a probe comprising a sensor and a plurality of markings to assist in placing the probe and sensor at a desired location with respect to the orthopaedic implant.

17. The apparatus of claim 16, wherein the adjustable stop comprises a mating portion such that when the stop is connected to the insertion handle, the stop is located or fixed within three degrees of freedom.

18. The apparatus of claim 16, wherein the insertion handle is attached to the orthopaedic implant through use of a cannulated bolt.

19. A kit for targeting a landmark of an orthopaedic implant, the kit comprising:

a proximal targeting probe comprising a tape body and a sensor included within or on the tape body at a predetermined distance from a reference point of the tape body, and comprising a first indicator that indicates that the proximal targeting probe is to be used for targeting proximal landmarks of an orthopaedic implant; and

a distal targeting probe comprising a tape body that is longer than the tape body of the proximal targeting probe and a sensor included within or on the tape body of the distal targeting probe at a second predetermined distance from a second reference point of the target body of the distal targeting probe, the distal targeting probe comprising a second indicator that indicates that the distal targeting probe is to be used for targeting distal landmarks of the orthopaedic implant.

20. The kit of claim 19, wherein the first indicator comprises a color-coded grip and the second indicator comprises a color-coded grip that is a different color than the first indicator.