Pivoting Reference Plane Surgical Instrument for Femur Cutting Alignment
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Solution Overview
Problem
Existing surgical instruments for knee replacement operations, particularly those using kinematic alignment, lack precision and simplicity in checking the orientation of cutting blocks for distal femur resection, leading to potential misalignment and unsatisfactory patient outcomes.
Innovation Solution
A surgical instrument with a fastening device, sensing device, and bearing device that allows for precise and adjustable positioning of a reference plane relative to the femur, enabling accurate orientation of the cutting block through pivoting, translational, and rotational movements, with direct or indirect fastening options.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed reference plane is used for checking cutting block orientation, then the device construction is simple, but the positioning precision and bearing accuracy against the anterior surface of the femur are insufficient
Solution Approach 1:
The reference plane is made movable relative to the fastening device through a bearing device with at least one pivoting bearing having an anteroposteriorly oriented pivot axis. This dynamic adjustment mechanism allows the reference plane to be positioned precisely against the anterior surface of the femur while maintaining a relatively simple construction by using a single degree of freedom pivoting motion rather than multiple adjustment mechanisms.
2Adaptability or versatility
If the reference plane is fixed relative to the fastening device, then the device construction is simple, but the adaptability to different femur anatomies and orientations is limited
Solution Approach 1:
The bearing device enables dynamic adaptation to different femur anatomies by allowing the reference plane to pivot about an anteroposteriorly oriented axis. This single pivoting degree of freedom provides sufficient adaptability for various anatomical configurations without introducing complex multi-axis adjustment mechanisms, thereby maintaining device simplicity while enhancing versatility.
Data Source
AI summary
A surgical instrument and surgical instrument system for use in a knee replacement operation. The surgical instrument includes a fastening device configured for direct or indirect releasable fastening to a cutting block for the distal resection of a femur, a sensing device with a posteriorly oriented reference plane configured to bear against an anterior surface of the femur, and a bearing device for positioning the reference plane. The bearing device includes at least one pivoting bearing with an anteroposteriorly oriented pivot axis, about which the reference plane can be moved pivotably relative to the fastening device.