Counterbored Bone Screw Locking Receiver for Off-Axis Fixation

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Solution Overview

Problem

Bone screws inserted at non-parallel angles to the longitudinal axis of stabilization plates cause deformation and misalignment, leading to improper fitting and potential disengagement.

Innovation Solution

A bone screw locking receiver with a counterbore and helical threads provides a secure interference fit, allowing coupling at various angles and limiting lateral deformation, ensuring a flush surface and stable fixation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If bone screws are inserted at non-parallel angles to the longitudinal axis of stabilization plates, then the bone screws can be positioned to address complex fracture patterns, but the stabilization plate deforms and the bone screw does not fit flush with the stabilization plate

Engineering Contradiction:

Improveangular adaptabilityVSAvoidfit flush precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The hole in the stabilization plate is segmented into two distinct portions: a first portion (counterbore) and a second portion (threaded section). This segmentation allows the first portion to accommodate off-axis screw insertion while the second portion provides precise threading for secure engagement, resolving the contradiction between angular adaptability and fit precision

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The counterbore portion extends radially outward from the central axis of the hole, creating a stepped configuration that provides lateral clearance. This dimensional change allows the bone screw to be inserted at non-parallel angles without causing lateral deformation of the stabilization plate, while still achieving flush fit through the controlled geometry of the counterbore

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If bone screws are inserted at non-parallel angles, then angular flexibility is improved, but lateral deformation of the stabilization plate occurs

Engineering Contradiction:

Improveinsertion angle flexibilityVSAvoidstructural stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

Dividing the hole into a counterbore portion and a threaded portion allows the counterbore to absorb lateral stresses from off-axis insertion, preventing deformation propagation to the stabilization plate structure, while the threaded portion maintains secure engagement

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The counterbore portion acts as a cushioning element that absorbs and distributes lateral forces before they reach the main body of the stabilization plate. This pre-cushioning effect prevents structural deformation while allowing angular flexibility

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS12440253B2Bone screw locking receiver and bone screw system

Publication Date: 2025.10.14 MIRUS LLC

AI summary

Various implementations described herein include a screw locking receiver. The screw locking receiver includes a receiver frame which has a first surface, a second surface opposite and spaced apart from the first surface, and an inner surface which extends between the first surface and the second surface. The receiver frame defines a cylindrical inner channel having a central axis. The receiver includes a counterbore which extends along a first portion of the inner surface. The receiver includes a plurality of threads extending helically about a second portion of the inner surface. The counterbore has a diameter that is sufficient to accept a screw head having a non-parallel central axis with respect to a central axis of the inner channel when in a fastened position.