Bottom-Loading Anchor Assembly with Radial Retention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current anchor assemblies for connecting structures, such as in spinal procedures, lack improved designs that enhance versatility and securement mechanisms, particularly in allowing multi-axial positioning and secure anchoring of rods to bones.

Innovation Solution

The development of a bottom-loading anchor assembly with a head member, compression member, and retaining member configuration that allows the anchor to be inserted from the bottom, featuring a channel with a ramp for radial expansion and securement, enabling multi-axial positioning and secure anchoring of rods to bones.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a traditional top-loading anchor assembly is used, then the anchor can be securely inserted into bone, but the anchor cannot be positioned in multiple axial orientations

Engineering Contradiction:
Improvemulti-axial positioning capabilityVSAvoidanchor assembly structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The anchor assembly is divided into separate functional components: a head member with a passageway, an anchor with a drive interface, a compression member, and a retaining member. This segmentation allows each component to perform its specific function independently while enabling multi-axial positioning through the interaction of these segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retaining member is configured to move between a first position that allows the anchor to be inserted and a second position that secures the anchor in the head member. This dynamic positioning mechanism enables the assembly to adapt during insertion and then lock into place, providing both versatility and security.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the anchor is inserted from the top, then the insertion path is straightforward, but the anchor cannot be securely retained after insertion

Engineering Contradiction:
Improveanchor retention securityVSAvoidinsertion complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The anchor assembly uses a bottom-loading configuration where the anchor is inserted from the distal end of the head member rather than from the proximal end. This inversion of the traditional insertion approach allows the compression member to be compressed distally, which in turn causes the retaining member to expand radially and secure the anchor in place.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The compression member changes its compression parameter during insertion, being compressed as the anchor is inserted into the bone. This parameter change is transmitted through the head member to cause the retaining member to expand radially, transitioning from a non-retaining state to a secure retained state.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the retaining member is expanded radially to secure the anchor, then the anchor is firmly retained, but the insertion process becomes more complex

Engineering Contradiction:
Improveanchor securementVSAvoidretention mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The retaining member is nested within the head member and is radially expandable. When the compression member is compressed, it transmits force to the retaining member, causing it to expand radially from a compressed state to a secured state. This nested configuration allows the retention mechanism to be compact during insertion and then expand to provide secure anchoring.

Inventive Principle:
Principle #7Nested doll (Nesting)

4Adaptability or versatility

If the anchor assembly allows multi-axial positioning, then versatility is improved, but the structural stability is reduced

Engineering Contradiction:
Improveangular positioning capabilityVSAvoidassembly structural stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The retaining member is pre-configured to expand radially and engage the anchor head in advance of final positioning. This preliminary action of expansion and engagement provides structural stability to the assembly, allowing the anchor to be securely retained while still permitting multi-axial positioning through the designed自由度 of the head member and anchor interface.

Inventive Principle:
Principle #10Preliminary action

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 anchor assembly provides enhanced securement and versatility by allowing multi-axial positioning of anchors, facilitating better stabilization of structures like vertebrae through the use of a compression member and retaining member that radially expands to secure the anchor within the head member.

Implementation Method 1

a retention member that radially expands to secure the anchor within the head member

Methodology Applied
Scientific EffectRadial expansion:

Data Source

PatentEP2991570B1Bottom-loading anchor assembly
Publication Date: 2019.08.14 DEGEN MEDICAL INC
  • EP2991570B1 patent drawingFigure 1~2
  • EP2991570B1 patent drawingFigure 3~3A
  • EP2991570B1 patent drawingFigure 4~4A

AI summary

Anchor assemblies useful for connecting structures to each other are described. An anchor assembly includes a head member and an anchor. In the fully assembled anchor assembly, the anchor is partially disposed within the head member. During assembly, the proximal end of the anchor can be inserted into an opening defined by a distal end of the head member. A retaining member maintains a portion of the anchor within a portion of the head member after assembly. In an embodiment, a compression member enables movement of the retaining member within the head member to allow insertion of a portion of the anchor and subsequent maintenance of the portion of the anchor within a portion of the head member.