Threaded Insert for Implant Fixation

Solution Overview

Problem

Existing implant fixation methods, such as bone screws, often experience loosening due to infections or bone weakening, leading to unstable implant attachment and increased manufacturing costs for implants with threaded internal bores, which are difficult to produce, especially for long bore holes.

Innovation Solution

The development of threaded inserts for implants with a cylindrical or shaped design that can be securely housed within the implant body, featuring external ridges and internal threads for engagement with fasteners, allowing for improved fixation and attachment using an insertion tool, and various attachment methods like interference fit, snap fit, or welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If threaded internal bores are provided on implants to prevent bone screw loosening, then fixation reliability is improved, but manufacturing complexity and cost increase due to specialized machining requirements

Engineering Contradiction:

Improvefixation reliabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The implant system is divided into separate components: an unthreaded implant body and a separate threaded insert. The insert contains the internal threads and is inserted into the implant body after the implant is manufactured. This segmentation allows the implant body to be manufactured using simple drilling without specialized threading equipment, while the threaded functionality is provided by the separate insert component.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The threaded insert acts as an intermediary component between the implant body and the bone screw. It provides the threaded engagement surface needed for secure fastening while allowing the implant body itself to remain structurally simple and easy to manufacture. The insert mediates between the simple drilled hole in the implant and the threaded bone screw.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If threaded internal bores are provided on all bore holes of standardized implants, then fixation reliability is improved, but manufacturing time and cost increase

Engineering Contradiction:

Improvefixation reliabilityVSAvoidmanufacturing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The implant system is divided into separate components: an unthreaded implant body and a separate threaded insert. The insert contains the internal threads and is inserted into the implant body after the implant is manufactured. This segmentation allows the implant body to be manufactured using simple drilling without specialized threading equipment, while the threaded functionality is provided by the separate insert component.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The threading parameter is changed from being an integral part of the implant body to being a property of a separate insert component. This allows the implant body to be manufactured with simple geometric parameters (drilled holes), while the threading parameters are applied only to the insert, reducing overall manufacturing complexity and time.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If bone screws are used to secure implants, then fixation is achieved, but bone screw loosening may occur due to infections or bone weakening leading to implant detachment

Engineering Contradiction:

Improvefixation capabilityVSAvoidretention stability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system transitions from direct bone screw-to-implant engagement to a two-stage engagement: the bone screw first engages with the threaded insert, which is already securely positioned within the implant body. This dynamic arrangement allows the insert to absorb and distribute loads, reducing stress on the bone-screw interface and preventing loosening even when bone quality deteriorates over time.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10792155B2Threaded insert for implant

Publication Date: 2020.10.06 HOWMEDICA OSTEONICS CORP

AI summary

Disclosed herein are implants with threaded inserts and methods for attaching the same to the implants. The threaded insert may define a first external dimension and include an internally threaded hole to receive a fastener. The implant may include a receiving hole with a proximal portion having a proximal diameter and a distal portion having a distal diameter. The distal diameter may be greater than the proximal diameter and substantial the same as the first dimension of the insert to secure the insert in the receiving hole. A method of attaching a threaded insert to a receiving hole of an implant with an insertion tool is also disclosed.