Bone Anchor Expansion Structure for Stable Fixation and Removal
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Solution Overview
Problem
Current bone anchoring implants face issues with unstable anchoring in bone tissue, causing damage and mispositioning during implantation and removal, which affects the reliability and ease of insertion.
Innovation Solution
A bone anchoring implant with a tubular body and a complementary rod design, featuring reversed thread pitches, allows for stable expansion and secure fixation by utilizing complementary internal and external threads to expand the tubular body within the bone, ensuring easy implantation and removal without causing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conical section with radial homothetic expansion is used, then the implant can be inserted into bone tissue, but the anchoring stability is reduced and removal becomes difficult
Solution Approach 1:
The patent applies asymmetry by creating a non-homothetic expansion where the distal portion of the implant has a different expansion characteristic compared to the proximal portion. Specifically, the distal portion expands more significantly to engage with the bone cortex, while the proximal portion maintains a more controlled expansion. This asymmetric expansion pattern provides both easy insertion through the proximal portion and stable anchoring through the distal portion, resolving the contradiction between ease of insertion and anchoring stability.
2Reliability
If the implant causes damage to bone tissue during insertion, then anchoring can be achieved, but the reliability of the implant is compromised
Solution Approach 1:
The patent employs dynamics by implementing a two-stage expansion mechanism. During insertion, the proximal portion expands to facilitate passage through the bone. Once positioned, the distal portion expands to create stable anchoring. This dynamic, staged expansion allows the implant to adapt its expansion characteristics during different phases of implantation, achieving reliable anchoring while minimizing bone tissue damage by avoiding excessive expansion forces during the insertion phase.
3Reliability
If the implant is designed for stable anchoring, then fixation reliability is improved, but the ease of removal is reduced
Solution Approach 1:
The patent applies segmentation by dividing the implant body into distinct functional portions: a proximal portion for easy insertion and a distal portion for stable anchoring. The proximal portion can be removed relatively easily since it was designed with controlled expansion, while the distal portion provides the necessary stability through its enhanced expansion and bone engagement. This segmentation allows the implant to simultaneously achieve stable anchoring and facilitate easy removal of the proximal portion, resolving the contradiction between fixation stability and ease of removal.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The implant provides stable and secure anchoring in bone tissue, facilitating easy insertion and removal while minimizing damage, enhancing osseointegration and reducing the need for additional bone graft materials.
Implementation Method 1
generating the expansion of said tubular body, thanks to the external diameter of the stem which is greater than the internal diameter of the tubular body, at least on a distal portion, by deformation of the tubular body during the penetration of the stem into the tubular body
Data Source
Figure 1a
Figure 1b~3a
Figure 3b~3c
AI summary
The present invention relates to a bone anchoring implant with optimised expansion, comprising a tubular body (2) and a rod (1), the outer profiles of the rod (1) and the inside of the tubular body (2) of which are complementary, the implant being expandable between a rest configuration, wherein a stop mechanism reciprocally locks the tubular body (2) and the rod (1) due to the reversal of their two respective screw pitches, such that they provide in a radially expandable configuration: a proximal fulcrum, a distal fulcrum, a "central" fulcrum located between said two fulcrums, formed by the cooperation between the outer diameter of the rod (1) and the inner diameter of the tubular body (2) which induce an outer diameter of the tubular body (2) at the central fulcrum greater than the outer diameter of the tubular body (2) at the proximal fulcrum.