Femoral Cutting Block With Integrated Sizing for Knee Resection
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Solution Overview
Problem
Existing surgical instruments for knee replacement surgery, particularly those used in kinematic alignment, are time-consuming and prone to errors due to separate size measurement, instrument use, and multiple cutting steps, which can lead to unsatisfactory patient outcomes.
Innovation Solution
A surgical instrument with integrated features such as a cutting block, reference foot, and probe that allows for simultaneous size measurement and cutting, eliminating the need for separate instruments and reducing errors through detachable attachments and adjustable compensating elements for varying anatomical conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate sizing instruments and measuring procedures are used to determine femur size before resection, then sizing precision is improved, but procedural time and instrumental complexity increase
Solution Approach 1:
The patent combines the sizing function and resection guidance function into a single integrated cutting block instrument. The cutting block includes reference surfaces that contact posterior condyles and anterior femoral surfaces to directly determine appropriate resection dimensions while guiding the saw blade, eliminating the need for separate sizing instruments and procedures.
Solution Approach 2:
The cutting block serves multiple functions simultaneously: it acts as a sizing tool by contacting anatomical landmarks (posterior condyles and anterior surfaces), as a resection guide by providing guide slots for the saw blade, and as a reference framework for establishing proper alignment. This multi-functionality reduces instrumental complexity and procedural steps.
2Manufacturing precision
If multiple separate instruments are used for sizing and resection guidance, then measurement and control precision are improved, but instrumental effort and potential sources of error increase
Solution Approach 1:
The patent integrates sizing references and resection guidance into a single cutting block instrument. The block includes posterior reference surfaces contacting condyles and anterior reference surfaces, all integrated with guide slots for the saw blade, eliminating the need for multiple separate instruments and reducing potential alignment errors between different tools.
Solution Approach 2:
The cutting block is divided into functional segments: posterior reference surfaces for contacting condyles, anterior reference surfaces for contacting femoral surfaces, and guide slots for saw blade positioning. These segmented functional elements work together as an integrated system to provide precise sizing and resection guidance.
3Stability of the object's composition
If traditional mechanical alignment approach is used with separate sizing and resection steps, then procedural systematicity is improved, but patient satisfaction and natural joint function decrease
Solution Approach 1:
The patent changes the reference parameters from traditional mechanical alignment (perpendicular to tibial plateau) to kinematic alignment parameters by using posterior condyle surfaces and anterior femoral surfaces as reference points. This parameter change enables restoration of natural joint alignment and kinematics while maintaining procedural systematicity through the integrated cutting block design.
Data Source
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AI summary
The invention relates to a surgical instrument for use in knee replacement surgery, comprising a cutting block with a proximally oriented back surface of the block, which is designed to rest against a distal end face of a resected femur, and with at least one guide slot extending from the back surface of the block to a distally opposite front surface of the block and extending mediolaterally longitudinally, which is designed to receive and guide a saw blade, a reference foot which can be attached or is attached to the cutting block in the region of a posterior underside of the block and has an anteriorly oriented upper surface which – in an attached state of the reference foot – projects proximally beyond the back surface of the block and is designed to rest against posterior condyles of the femur, and comprising a probe,which can be attached or is attached to the upper surface of the cutting block in the area of an anteriorly opposite the lower surface of the block and has a probe tip which - in an attached state of the probe - projects proximally beyond the back of the block and is designed to rest against an anterior surface of the femur.