Intraoperative Implant Cavity Adjustment via Force Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current orthopedic surgery techniques face challenges in accurately adjusting implant cavity dimensions intraoperatively due to limited pre-operative bone quality data, leading to potential misalignment and reduced implant longevity.
Innovation Solution
A method and system that utilize image data sets to generate surgical plans with expected cutting forces and temperatures, allowing for intraoperative adjustments of implant cavity dimensions based on real-time feedback from cutting instruments, ensuring improved implant fit and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pre-operative planning is performed using image data sets without additional bone quality data, then the surgical plan can be generated efficiently, but the accuracy of implant cavity dimensioning is reduced leading to potential misalignment
Solution Approach 1:
The system performs preliminary action by acquiring bone quality data (such as Hounsfield units from CT scans) before surgical planning, and uses this data to pre-adjust cavity dimensions. This allows the surgical plan to be generated with improved accuracy without delaying the overall surgical workflow, as the bone quality assessment is integrated into the pre-operative imaging phase.
Solution Approach 2:
The system replaces manual trial-and-error adjustment of cavity dimensions with an automated computational system that uses bone quality data (Hounsfield units) to calculate optimal cavity dimensions. This substitution of mechanical/manual adjustment with computational analysis improves both precision and efficiency simultaneously.
2Stability of the object's composition
If the implant cavity size is reduced to increase press-fit in poor bone quality, then initial implant stability is improved, but the risk of stress-shielding and bone resorption increases
Solution Approach 1:
The system applies local quality by analyzing bone quality data (Hounsfield units) at different locations around the implant site and adjusting cavity dimensions locally rather than uniformly. This allows optimal press-fit to be achieved in poor bone quality regions while maintaining appropriate cavity size in good bone quality regions, thereby improving initial stability without causing excessive stress-shielding.
Solution Approach 2:
The system changes the parameter of cavity dimension based on the parameter of bone quality (Hounsfield units). By dynamically adjusting cavity size according to measured bone density, the system optimizes the balance between press-fit (for stability) and bone preservation (to avoid stress-shielding), transforming a fixed-size approach into an adaptive size approach.
3Manufacturing precision
If additional bone quality data is acquired pre-operatively to improve implant cavity planning, then implant placement accuracy is improved, but radiation exposure and procedure complexity increase
Solution Approach 1:
The system applies universality by using the existing pre-operative CT scan data (acquired for other surgical planning purposes) for dual functionality: both for anatomical visualization and for bone quality assessment (Hounsfield unit analysis). This eliminates the need for additional dedicated bone quality imaging, thereby improving accuracy without increasing radiation exposure.
Solution Approach 2:
The system enables self-service by extracting bone quality information (Hounsfield units) from the standard pre-operative CT imaging data that is already acquired for surgical planning. The existing imaging data serves multiple purposes, and the system automatically processes this data to provide bone quality metrics without requiring separate imaging procedures.
4Adaptability or versatility
If manual adjustment of implant cavity dimensions is performed based on user experience, then adaptability to bone quality variations is improved, but measurement precision and consistency are reduced
Solution Approach 1:
The system implements feedback by using measured bone quality data (Hounsfield units) from the patient's actual bone to automatically adjust cavity dimensions. This objective feedback mechanism replaces subjective manual adjustment, providing both adaptability to individual bone quality variations and consistent, repeatable measurements across different patients and surgeons.
Solution Approach 2:
The system replaces manual visual inspection and经验-based adjustment with automated computational analysis of bone quality data. This substitution introduces precise, objective measurement of bone density and automatic calculation of optimal cavity dimensions, eliminating variability associated with manual assessment while maintaining adaptability to individual patient characteristics.
Data Source
AI summary
A method and system are provided to intraoperatively adjust the dimensions of a pre-operatively planned implant cavity to improve implant fit in a bone. The method includes obtaining a preoperative image data set of the bone. A surgical plan is generated using the image data set and/or a three-dimensional (3-D) bone model of the patient's bone generated from the image data set. Intraoperatively, the patient's bone is exposed and registered to the surgical plan and a computer assisted surgical system. The computer assisted surgical system having a cutting tip and a force sensor for sensing actual forces exerted on the cutting tip as an initial cut is created on the bone at a first bone region. Based on the difference between the actual cutting force and the expected cutting force in the plan, the dimensions of the cavity are adjusted accordingly.