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

"The present invention is about a system and process for improving the alignment and stability of implants in joint replacement surgeries. It uses position and orientation tracking sensors to track the position and orientation of body parts, surgery-related items, and virtual constructs or references. The system can display and output useful data relating to the position and orientation of these objects in real-time, allowing the surgeon to properly position and assess the performance of the implants. It can also use the position tracking information to produce numerical data that can be used for various tasks such as assessing the performance of trial prostheses and actual prosthetic components. The system can also generate data based on the position tracking and provide cues on screen or aurally to assist in the surgery. Overall, the system improves the accuracy and efficiency of joint replacement surgeries and reduces the risk of complications."

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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