Individualized Kinematic Total Knee Replacement Planning System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current total knee replacement (TKR) alignment methods, such as mechanical and kinematic alignment, often result in unsatisfactory outcomes for patients, with up to 25% of mechanically aligned TKRs showing poor results due to complex resection requirements and surgeon errors, highlighting the need for more precise and individualized approaches.
Innovation Solution
A method and device for facilitating individualized kinematically aligned TKRs by determining specific anatomical and pathoanatomical data, including coronal mechanical lateral distal femoral angle and posterior condylar axis, to generate precise bone and cartilage resection data, which are used to create a recommended three-dimensional surgeon plan for optimal implant alignment, allowing for adjustments based on surgeon preferences and limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If kinematic alignment technique is used to recreate the three kinematic axes of the knee, then clinical outcome scores improve, but resection complexity increases and may result in resections outside preferred limits
Solution Approach 1:
The system performs preoperative planning and generates patient-specific cutting guides before surgery, calculating all necessary resection parameters (coronal alignment angles, sagittal slopes, resection depths) in advance. This preliminary computational action reduces intraoperative complexity by providing a complete surgical roadmap that guides the surgeon through each resection step with precise parameters, thereby maintaining improved clinical outcomes while reducing procedural complexity.
2Ease of operation
If mechanical alignment method is used to align TKRs at right angles to mechanical axes, then alignment simplicity is maintained, but patient satisfaction decreases with up to 25% showing poor results
Solution Approach 1:
The system transitions from universal mechanical alignment to individualized kinematic alignment by determining patient-specific anatomical parameters (coronal mechanical lateral distal femoral angle, posterior condylar axis, tibial plateau slope) and using these localized anatomical characteristics to customize the alignment plan for each patient. This localizes the alignment approach to match individual knee anatomy rather than applying a standardized mechanical axis method, thereby improving patient satisfaction while maintaining operational feasibility through computerized planning.
3Manufacturing precision
If individualized kinematic alignment is implemented, then alignment precision improves, but surgeon error risk increases due to complex resection requirements
Solution Approach 1:
The system introduces computerized planning software and patient-specific cutting guides as intermediary tools between the surgeon's intent and the actual bone resection. The software calculates precise resection parameters based on patient anatomy and generates customized guides that physically guide the resection process intraoperatively. This intermediary computational and physical guidance system reduces surgeon error risk by providing step-by-step instructions and physical constraints that ensure precise execution of the individualized kinematic alignment plan.
4Adaptability or versatility
If multiple variables are maintained to optimally align each knee, then alignment adaptability improves, but procedural complexity increases
Solution Approach 1:
The system creates a universal computational platform that handles multiple alignment variables (coronal angles, sagittal slopes, rotational parameters, resection depths) through integrated software that performs all calculations and generates comprehensive surgical plans. The patient-specific cutting guides serve as multi-functional tools that incorporate multiple alignment parameters into single physical devices that guide various resection steps. This universal system manages procedural complexity by consolidating multiple variables into an integrated planning and guidance workflow, thereby maintaining high alignment adaptability across diverse patient anatomies.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Methods, non-transitory computer readable media, and individualized kinematic total knee replacement (TKR) analysis computing devices that obtain prosthesis data for a prosthesis. Anatomical and pathoanatomical data for a patient is determined. The anatomical data comprises at least a coronal mechanical lateral distal femoral angle and a posterior condylar axis that is specific to the patient. Bone and cartilage resection data is determined based on the prosthesis data, the anatomical data, and the pathoanatomical data. In one example, a recommended three-dimensional total knee replacement surgeon plan for the patient is output via a graphical interface. The recommended three-dimensional total knee replacement surgeon plan comprises the bone and cartilage resection data for facilitating implantation of the prosthesis in the patient. In another example, one or more femoral and tibial guides are formed based on the three- dimensional total knee replacement surgeon plan, wherein the femoral and tibial guides are specific to the patient.