Anchor-in-Anchor Bone Fixation System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bone fixation systems face challenges in securely attaching fixation devices to underlying bone, as screws can become dislodged during normal anatomical function, compromising the attachment and stability of the fixation devices.
Innovation Solution
The anchor-in-anchor fixation system, which includes a first bone anchor with a shaft and head configured to attach to underlying bone, and a second bone anchor that is inserted into the head of the first anchor, forming a stable triangular load-bearing plane that resists migration and provides enhanced stability by allowing the second anchor to attach at various angles, thereby securing the fixation device more reliably.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single bone anchor is used to attach fixation devices to underlying bone, then the device complexity is reduced, but the reliability of attachment is compromised due to potential dislodgement during normal anatomical function
Solution Approach 1:
The patent implements an anchor-in-anchor configuration where a second bone anchor is inserted into the head of a first bone anchor. The second anchor includes a shaft that passes through the head of the first anchor and engages with underlying bone structure, creating a nested arrangement. This nesting principle allows the second anchor to provide additional stabilization and prevent dislodgement of the first anchor, thereby improving attachment reliability without requiring a completely separate fixation system.
2Reliability
If multiple bone anchors are inserted to enhance stability, then the reliability of fixation is improved, but the device complexity and difficulty of insertion increase
Solution Approach 1:
By nesting the second anchor within the head of the first anchor, the patent reduces the spatial footprint and visual complexity of the fixation system. The nested configuration allows two anchors to function together as a unified stabilization mechanism, providing enhanced reliability while maintaining a more compact and manageable device structure compared to using multiple separate anchors distributed across the bone surface.
3Adaptability or versatility
If the bore axis and shaft axis define an acute angle, then the adaptability of the anchor system is improved for various insertion angles, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies local quality by creating a specific angular relationship between the bore axis and shaft axis of the first bone anchor. The head of the first anchor is designed with a bore that is angled relative to the shaft axis, allowing the second anchor to be inserted at a specific angle. This localized angular feature provides adaptability for various insertion approaches while the precision is maintained through controlled manufacturing of the angular relationship in the anchor head geometry.
Data Source
Figure 1
Figure 2A~2C
Figure 3
AI summary
An anchor-in-anchor fixation system is provided for securing underlying structure, such as bone. The fixation system includes a first bone anchor having a shaft for fixation to underlying bone, and a head that defines an internal bore. A second bone anchor extends through the bore and into underlying bone. A fixation assembly is also provided that includes one or more fixation systems coupled to an auxiliary attachment member configured for long bone fixation, spinal fixation, or fixation of other bones as desired.