CAS Knee Surgery Guide Using Intermediary Pin Mounting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current total knee replacement (TKR) surgeries require invasive procedures involving multiple drilled holes and pins in the distal femur, increasing surgical invasiveness and complexity.
Innovation Solution
A method and system for orthopedic knee surgery using a computer-assisted surgery (CAS) system that involves positioning a drill guide to determine pin locations outside the resection region, installing locating pins, and using a bone reference with a trackable member to digitize landmarks, allowing for the mounting of a cutting guide without direct pinning, thereby reducing the need for invasive procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If multiple drilled holes and pins are used to secure the cutting guide block to the distal femur, then the cutting guide can be firmly fixed in place, but the surgical invasiveness and complexity increase
Solution Approach 1:
A positioning block is introduced as an intermediary device that temporarily secures the cutting guide block to the femur using only two pins instead of multiple pins. The positioning block acts as a mediator that provides sufficient stabilization during the cutting process while minimizing invasive pin placements in the distal femur.
Solution Approach 2:
The function of securing the cutting guide block is extracted from direct multiple-pin fixation to a simplified two-pin system using the positioning block. This reduces the number of invasive pin placements while maintaining adequate fixation stability during the surgical procedure.
2Reliability
If a distal cutting block is pinned directly in place on the bone, then the cutting guide is securely positioned, but additional pins and drilling are required increasing procedural complexity
Solution Approach 1:
The positioning block and cutting guide block are merged into an integrated assembly where the positioning block forms part of the cutting guide structure. This combination allows the cutting guide to be secured with fewer pins while maintaining positioning accuracy, thereby reducing procedural complexity.
Solution Approach 2:
The positioning block serves multiple functions: it provides structural support for the cutting guide block, enables secure positioning with minimal pins, and facilitates accurate guide placement. This multi-functionality reduces the need for separate fixation components and procedures.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach minimizes the number of drilled holes and pins required, reducing surgical invasiveness, improving surgical efficiency, and enhancing the accuracy of bone resections during TKR procedures.
Implementation Method 1
Known optical, radio frequency and magnetic based CAS systems employ passive and active trackable elements affixed to objects, such as surgical tools and patient bone references, in order to permit the determination of position and orientation of the objects in three-dimensional space
Implementation Method 2
intra operative landmark digitization are some of the methods used to provide accurate patient anatomical information to the CAS system, such that the real-time position of the same anatomical elements can be registered or calibrated and thus tracked by the CAS system
Data Source
AI summary
A method and system (10) for the installation of a cutting guide (60) on a bone element (33) in orthopedic computer assisted surgery is provided. The method includes positioning a drill guide (30) against a distal end of the bone element (33), determining at least two pin locations on one of a medial (31) and a lateral side of the bone element (33), fastening locating pins (42) to the bone element (33) at the determined pin locations, removing the drill guide (30) and installing a CAS bone reference (20) in its place on the same locating pins (42), and subsequently mounting the cutting guide (60) to the same locating pins (42).