Patella Cutting Assembly With Adjustable Resection Inclination
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Solution Overview
Problem
Existing knee replacement procedures face challenges in accurately resecting the patella to achieve optimal soft tissue tension and alignment with the femoral component, as existing tools lack the ability to adjust the inclination and depth of the cut relative to the patella's posterior surface.
Innovation Solution
A cutting assembly with a patella clamp that provides a reference surface and a support surface, featuring a connector arrangement allowing adjustable inclination and depth settings through interchangeable connector and spacer inserts, enabling precise resection of the patella to match the patella implant component.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed cutting guide is used for patella resection, then the surgical procedure is simple, but the ability to adjust inclination and depth of cut is limited
Solution Approach 1:
The cutting assembly incorporates adjustable components including the cutting block with movable positioning mechanisms, depth stop mechanisms with variable height settings, and inclination adjustment features that allow dynamic modification of cutting parameters during surgery, transforming a static guide into a dynamic, adaptable system
Solution Approach 2:
The cutting assembly is divided into modular segments including the cutting block, guide rails, depth stop mechanisms, and base structure, allowing independent adjustment of each component to achieve desired cutting inclination and depth while maintaining overall system functionality
2Manufacturing precision
If a simple clamp is used to hold the patella, then the device is easy to operate, but it cannot provide accurate reference surfaces for cutting
Solution Approach 1:
The clamp is integrated with the cutting block and reference surface structures, combining clamping function with positioning and cutting guidance functions into a single unified assembly, eliminating the need for separate positioning devices while maintaining ease of operation
Solution Approach 2:
The clamp incorporates self-aligning features and self-positioning mechanisms that automatically establish accurate reference surfaces when the clamp is applied to the patella, eliminating the need for complex manual alignment procedures by the surgeon
3Adaptability or versatility
If the cutting block is fixed in position, then the structure is simple, but it cannot accommodate different resection depths and inclinations
Solution Approach 1:
The connector arrangement enables modification of geometric parameters including the angle between reference surface and cutting surface, the distance between these surfaces, and the depth of cut, allowing the same basic structure to accommodate multiple resection scenarios by adjusting these parameters
Solution Approach 2:
The connector arrangement serves multiple functions simultaneously: it positions the cutting block, defines cutting inclination, controls cutting depth, and provides structural support, allowing a single mechanism to handle various resection requirements without requiring multiple specialized devices
Data Source
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AI summary
A cutting assembly for resecting a patient's patella during knee surgery comprises a cutting instrument having a cutting head for cutting the patella on a selected resection plane, and a patella clamp having opposing jaws which can be moved towards one another to clamp the patella between them. The clamp provides a reference surface for engaging the posterior surface of the patella, and a support surface for supporting the cutting head of the cutting instrument, thereby locating the cutting instrument relative to the clamp. The assembly includes a plurality of connector inserts which can be mounted individually or in one or more combinations on or relative to the clamp, providing a physical connection between the reference and support surfaces which defines the inclination of the support surface relative to the reference surface so that the inclination of the support surface relative to the reference surface can be varied by changing one or more of the connector inserts.