Computer assisted intramedullary rod surgery system with enhanced features

Abstract

A computer assisted surgery system for positioning a surgical implant within a patient's body that includes a localizing device configured to measure a pose of the surgical implant, an imaging device adapted for acquiring images of the surgical implant, and a computer adapted for calculating an adjusted pose for the surgical implant based on information developed from the images so as to compensate for deformation of the surgical implant or inaccuracies in localization.

Description

RELATED APPLICATIONS [0001] This application is a continuation of U.S. application Ser. No. 10 / 756,020, entitled “Computer Assisted Intramedullary Rod Surgery System With Enhanced Features,” which was filed Jan. 12, 2004 (the “'020 application”), which is in turn a continuation of U.S. application Ser. No. 09 / 683,107, entitled “Computer Assisted Intramedullary Rod Surgery System With Enhanced Features,” which was filed Nov. 19, 2001, now U.S. Pat. No. 6,718,194 (the “'194 patent”), which claims the benefit of U.S. Provisional Application No. 60 / 249,697, which was filed Nov. 17, 2000 (the “'697 application”). The '020 application, the '194 patent, and the '697 application are hereby incorporated by reference in their entireties.BACKGROUND OF THE INVENTION [0002] This invention relates to a computer assisted surgery system for use in inserting interlocking screws in an intramedullary rod. [0003] A current surgical treatment for fractures of the shaft of long bones (e.g., femur and tib...

AI Technical Summary

Benefits of technology

[0009] Accordingly, one objective of the present invention is to provide a computer assisted surgery system for positioning an instrument relative to a portion of a surgical implant. More specifically, it assists a surgeon in drilling a hole through a long bone and through transversely oriented holes in an intramedullary rod (IM rod) during a fracture fixation procedure regardless of deformation of the IM rod.

[0010] Another objective of the invention is to provide a technique and apparatus for accurately displaying the trajectory of the drill relative to the holes of the IM rod.

[0011] Still another objective of the invention is to provide a technique and apparatus for using x-ray images of the IM rod to accurately determine the locations of the holes.

[0012] These and other objects of the present invention are achieved by the use of a computer assisted surgery system, including a computer, a localizing device and a display monitor. The system also includes a tracked adapter attached to the IM rod and a drill guide, both of which have their poses determined by the localizer. With the IM rod inserted in a long bone, and the tracked adapter attached to the exposed end of the IM rod the pose of the adapter and the IM rod are measured by the localizing device. Two approximately orthogonal x-ray images are then obtained of the IM rod in the vicinity of the holes. Image processing techniques are used to accurately determine the location of the IM rod from the x-ray images and an adjusted pose is calculated for the IM rod. A graphic representation of the drill trajectory is displayed superimposed over the images of the IM rod and over a graphic representation of the IM rod, in order to assist the surgeon in placing the drill in the proper position relative to the IM rod holes.

Problems solved by technology

The insertion of the screws farthest from the IM rod insertion hole is currently a difficult and time consuming procedure requiring numerous x-ray images.

External jigs have been tried with little success because inaccuracies in the jig, inaccuracy of the mounting between jig and IM rod, and deformation of the IM rod accumulate to cause the final jig hole positions to be unreliably aligned with the IM rod holes.

Another difficulty with existing image guided systems is that the surgeon must align the drill guide while viewing an “end on” representation of the drill guide, which can be quite challenging.

These devices, however, require equipment dedicated to this one surgical task, require the extra step of inserting an emitter to the level of the hole, and typically provide only rudimentary “end on” representations of the drill trajectory.

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