Knee Implant Planning via Virtual Motion Capture and Impingement Analysis
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Solution Overview
Problem
Conventional patella tracking methods for knee implants provide low yield of information on relative movement and contact, leading to insufficient simulation of end conditions and suboptimal implant positioning, which can result in pain and unnatural strains during movement.
Innovation Solution
A computer-assisted planning method and device that captures spatial and surface contour data of the genicular anatomy, uses motion capturing to simulate the movement of individual parts, and virtually adjusts the implant position to minimize contact or impingement, allowing for optimal positioning and orientation of knee implants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If conventional point-by-point tracking or motion capturing for individual points on the patella is used, then the complexity of the measurement system is reduced, but the information yield on relative movement and contact of joint parts is insufficient
Solution Approach 1:
The patent divides the patella surface into multiple measurement points arranged in a grid pattern, rather than tracking a single point. This segmentation allows comprehensive capture of surface deformation and contact information across the entire patella, resolving the information deficiency while maintaining manageable system complexity through systematic point distribution.
Solution Approach 2:
The patent transitions from tracking individual isolated points to capturing the entire surface topology of the patella in three dimensions. By mapping the complete surface geometry and deformation field, the system gains dimensional information about contact areas and pressure distribution, significantly increasing information yield without proportionally increasing device complexity.
2Ease of operation
If basic patella tracking is performed to determine trajectory, then the ease of operation is improved, but the simulation of end conditions becomes insufficient for optimum planning
Solution Approach 1:
The patent performs pre-operative motion capture and surface scanning to establish the patient's natural joint kinematics and patella contact patterns before implantation. This preliminary data collection allows the simulation to accurately predict post-implantation conditions, improving reliability while keeping the actual surgical procedure simple and easy to perform.
Solution Approach 2:
The patent creates a digital replica or virtual model of the patient's actual knee joint anatomy and motion patterns. This copied model allows realistic simulation of various implant scenarios without requiring complex physical prototypes or trial implants, maintaining ease of operation while significantly improving the reliability of end condition simulation.
3Productivity
If implant positioning is planned without comprehensive contact data, then the productivity of the planning process is improved, but the implant positioning may cause pain and unnatural strains during movement
Solution Approach 1:
The patent replaces physical trial-and-error implant positioning with computer-based simulation and analysis. By using motion capture data and finite element analysis to predict contact patterns and stress distributions, the system identifies optimal implant positions that avoid harmful contact and strains, eliminating the need for multiple surgical adjustments while ensuring pain-free function.
Solution Approach 2:
The patent incorporates feedback loops where simulation results regarding contact patterns and stress distributions are used to iteratively optimize implant positioning. The system provides feedback on potential harmful contact areas, allowing planners to adjust positioning virtually before surgery, thereby preventing pain and unnatural strains while maintaining efficient single-stage surgical planning.
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 provides a more comprehensive simulation of knee joint mechanics, enabling precise identification and adjustment of implant positioning to prevent pain and unnatural strains, ensuring anatomically correct movement and reduced contact intensity between implant and surrounding anatomy.
Implementation Method 1
passive marker reflectors, which reflect infrared light, can be detected by two infrared light cameras, whereby spatial locations and/or spatial movements of the body can be determined by stereoscopic observation
Data Source
AI summary
A planning method and device for knee implants, wherein spatial data on the configuration of a patient's genicular anatomy, in particular of at least a part of the femur and/or the patella and/or the tibia, are captured in order to be inputted into a computer-assisted planning station; the movement of the parts of the genicular anatomy is recorded using a tracking and/or motion capturing method; the captured anatomical and movement data are made available to the computer-assisted planning station; a part of the patient's genicular anatomy is virtually replaced in the planning station by a sample implant and movements of the knee together with the sample implant are simulated; contact and impingement between the non-replaced parts of the genicular anatomy and the implant during the virtual movement is ascertained according to its magnitude; and wherein an adjustment of the positioning, shape or orientation of the implant or of a number of these parameters is determined until the contact and impingement become non-critical and the adjustment thus determined is defined as a suitable adjustment.