Computer Assisted Knee Arthroplasty Instrumentation, Systems, and Processes

Abstract

Instrumentation, systems, and processes for tracking anatomy, instrumentation, trial implants, implants, and references, and rendering images and data related to them in connection with surgical operations, for example total knee arthroplasties (“TKA”). These instrumentation, systems, and processes are accomplished by using a computer to intraoperatively obtain images of body parts and to register, navigate, and track surgical instruments. Disclosed in this document are also alignment modules and other structures and processes which allow for coarse and fine alignment of instrumentation and other devices relative to bone for use in connection with the tracking systems of the present invention.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. patent application Ser. No. 10 / 229,372 filed on Aug. 27, 2002, which is continuation-in-part of U.S. patent application Ser. No. 10 / 084,012 filed on Feb. 27, 2002, which claims the benefit of U.S. Provisional Application No. 60 / 355,899 filed on Feb. 11, 2002 and Provisional Application No. 60 / 271,818 filed on Feb. 27, 2001. The disclosure of each prior application is incorporated by reference in its entirety.BACKGROUND OF THE INVENTION Field of the Invention [0002] The field of the invention includes instrumentation, systems, and processes for tracking anatomy, implements, instrumentation, trial implants, implant components and virtual constructs or references, and rendering images and data related to them in connection with orthopedic, surgical and other operations, for example Total Knee Arthroplasty (“TKA”). Anatomical structures and such items may be attached to or otherwise associated with f...

AI Technical Summary

Benefits of technology

[0006] As one example, images such as fluoroscopy images showing internal aspects of the femur and tibia can be displayed on the monitor in combination with actual or predicted shape, position and orientation of surgical implements, instrumentation components, trial implants, actual prosthetic components, and rotational axes in order to allow the surgeon to properly position and assess performance of various aspects of the joint being repaired, reconstructed or replaced. The surgeon may navigate tools, instrumentation, trial prostheses, actual prostheses and other items relative to bones and other body parts in order to perform TKA's more accurately, efficiently, and with better alignment and stability. Instrumentation, systems, and processes according to the present invention can also use the position tracking information and, if desired, data relating to shape and configuration of surgical related items and virtual constructs or references in order to produce numerical data which may be used with or without graphic imaging to perform tasks such as assessing performance of trial prosthetics statically and throughout a range of motion, appropriately modifying tissue such as ligaments to improve such performance and similarly assessing performance of actual prosthetic components which have been placed in the patient for alignment and stability. Instrumentation, systems, and processes according to the present invention can also generate data based on position tracking and, if desired, other information to provide cues on screen, aurally or as otherwise desired to assist in the surgery such as suggesting certain bone modification steps or measures which may be taken to release certain ligaments or portions of them based on performance of components as sensed by instrumentation, systems, and processes according to the present invention.

[0048]FIG. 23 is a screen face according to one embodiment of the present invention which presents graphic indicia which may be employed to help determine reference locations within bone structure.

Problems solved by technology

A leading cause of wear and revision in prosthetics such as knee implants, hip implants and shoulder implants is less than optimum implant alignment.

Additionally, surgeons often use visual landmarks or “rules of thumb” for alignment which can be misleading due to anatomical variability.

This intrusion increases the risk of fat embolism and unnecessary blood loss in the patient.

Another challenge for surgeons is soft tissue or ligament balancing after the bone resections have been made.

Releasing some of the soft tissue points can change the balance of the knee; however, the multiple options can be confusing for many surgeons.

In revision TKA, for example, many of the visual landmarks are no longer present, making alignment and restoration of the joint line difficult.

For instance, systems which use CT and MRI data generally require the placement of reference frames preoperatively which can lead to infection at the pin site.

Current registration methods are less accurate than the fluoroscopic system.

These imaging modalities are also more expensive.

This can be very time intensive resulting in longer operating room time.

This calculation is also time consuming at the system must find multiple points in different planes in order to find the center of rotation.

This is also problematic in patients with a pathologic condition.

Ligaments and soft tissues in the arthritic patient are not normal and thus will give a center of rotation that is not desirable for normal knees.

Robotic systems require expensive CT or MRI scans and also require pre-operative placement of reference frames, usually the day before surgery.

These systems are also much slower, almost doubling operating room time and expense.

Some systems provide variable alignment modules, but none of these systems allow gross placement of cutting instruments followed by fine adjustment of cutting instruments through computer assisted navigation technology.

Further, these systems can only be used with tibial instrumentation and cannot be used for femoral alignment and cutting.

None of these systems can effectively track femoral and / or tibial trials during a range of motion and calculate the relative positions of the articular surfaces, among other things.

Also, none of them currently make suggestions on ligament balancing, display ligament balancing techniques, or surgical techniques.

Additionally, none of these systems currently track the patella.

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