Knee Arthroplasty Guide Assembly with Torque Bolt Distraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
During knee arthroplasty, existing methods face challenges in minimizing invasiveness while accurately guiding resections of the femur and tibia, and balancing forces between knee implant components and preserved ligamentous and soft tissue structures for optimal surgical outcomes.
Innovation Solution
A guide assembly using tibial and femoral IM rods connected by a torque bolt for controlled distraction, along with quick-release components and cutting guides that attach to these rods, allowing for precise reference cuts and minimally invasive approaches, while accommodating various flexion angles and ligament tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional resection guides are used to guide femur and tibia resections, then cutting accuracy is improved, but soft tissue invasion and damage increase
Solution Approach 1:
The guide assembly is divided into separate femoral and tibial components that can be independently positioned and secured. The femoral guide attaches to the femur while the tibial guide attaches to the tibia, allowing each guide to be optimized for its specific bone without requiring extensive soft tissue dissection for overall alignment
Solution Approach 2:
The patent uses ligamentous structures and other anatomical features as intermediary references to position the guides. By tethering or referencing these soft tissue structures, the guides achieve accurate positioning without requiring large incisions or extensive soft tissue disruption, thus preserving tissue while maintaining cutting precision
2Stability of the object's composition
If soft tissue structures are preserved to maintain knee support and function, then tissue integrity is improved, but guide positioning stability worsens
Solution Approach 1:
The guides utilize ligamentous structures and anatomical landmarks as intermediary reference points for positioning. These soft tissue structures serve as stable biological references that maintain their integrity while providing reliable positioning cues, eliminating the need to sacrifice tissue stability for guide attachment
Solution Approach 2:
The patent replaces traditional mechanical fixation methods that require extensive soft tissue disruption with positioning systems that reference anatomical features and ligament tensions. This substitution allows guide stabilization through anatomical relationships rather than through aggressive soft tissue attachment
3Reliability
If ligament tensions are used to guide component placement, then functional outcome is improved, but measurement and positioning difficulty increases
Solution Approach 1:
The guide assembly incorporates mechanisms to detect and respond to ligament tensions during positioning. By providing real-time feedback on ligament state, the system enables surgeons to adjust guide placement and component positioning based on actual soft tissue tension, translating qualitative anatomical information into quantitative positioning data
Solution Approach 2:
The patent replaces complex manual assessment of ligament tensions with integrated sensing or mechanical indication systems within the guide assembly. This substitution transforms the difficult task of detecting soft tissue forces into straightforward mechanical or electronic measurements that directly inform component positioning
4Object-affected harmful factors
If minimally invasive approaches are used to access the knee joint, then soft tissue preservation is improved, but instrument support and stability worsen
Solution Approach 1:
The guide assembly is segmented into femoral and tibial components that can be independently supported on each bone. This segmentation allows each guide to draw support from its respective bone structure, eliminating the need for a single large access point while maintaining overall system stability through distributed support
Solution Approach 2:
The system uses intramedullary rods and other anatomical structures as intermediary support elements that extend through minimally invasive access points. These intermediaries provide robust internal support for the guides without requiring extensive soft tissue disruption, bridging the gap between minimal incision size and adequate instrument stability
Data Source
AI summary
An assembly for guiding resection of a femur and tibia of a knee joint in preparation for installing a femoral and tibial knee components. For example, the assembly can include tibial and femoral IM rods to which are connected through a torque bolt that allows controlled adjustment of the distraction of the tibia and femur during cut positioning in a range of flexion angles. Also, the assembly is usable with relatively small, noninvasive approaches to the knee joint by way of relatively narrow, low profile components that attach to tibial and femoral IM rods. Further, the assembly includes several quick-release components to allow fast assembly and disassembly in a surgical setting. Each of these aspects, along with the ability of the assembly to accurately guide initial reference cuts to the tibia and femur, promotes an improved outcome for the patient.