Dual-Drive Bone Screw for Sacroiliac Joint Fusion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current surgical systems for treating musculoskeletal disorders, particularly spinal pathologies, face challenges in providing stable fixation and reducing stress on joints like the sacroiliac joint, often resulting in incomplete relief of symptoms and potential complications such as nerve damage and implant fracture.

Innovation Solution

A surgical implant system featuring a dual-drive bone screw with a lag configuration and cannulated compression capability, designed for sacroiliac joint fusion, which includes a distal thread for engaging the sacral bone and a non-threaded proximal section for compression, along with a washer for enhanced fixation, made from materials like titanium and PEEK, and employing surgical navigation and nerve monitoring to minimize complications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If multiple screws are used to stabilize the sacroiliac joint, then the stability and fixation strength are improved, but the stress on each implant increases and the complexity of the surgical procedure increases

Engineering Contradiction:
Improvefixation strengthVSAvoidsurgical procedure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The single screw is segmented into two functional portions: a lag screw portion for compression and a cancellous bone screw portion for anchoring. This segmentation allows one implant to perform multiple functions that previously required multiple separate implants, reducing overall system complexity while maintaining fixation strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dual-drive bone screw is designed as a multi-functional implant that simultaneously provides compression capability (lag screw function) and anchoring capability (cancellous bone screw function). This universal design eliminates the need for multiple separate screws, reducing surgical procedure complexity while maintaining or improving fixation strength through integrated functionality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If traditional single-drive screws are used, then the device complexity is low, but the compression control precision and fixation stability are insufficient

Engineering Contradiction:
Improvecompression control precisionVSAvoiddual-drive mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The dual-drive mechanism enables dynamic and independent control of the two screw portions. The first drive controls the lag screw portion for compression while the second drive controls the cancellous bone screw portion for anchoring. This dynamic control allows precise adjustment of compression forces independent of anchoring depth, improving compression control precision despite increased device complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The dual-drive mechanism acts as an intermediary system that mediates between the surgeon's control inputs and the complex mechanical actions of compression and anchoring. By providing separate drive interfaces, the system translates simple rotational inputs into precise, independent control of compression and anchoring functions, improving control precision while managing complexity through intuitive operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If compression is applied during sacroiliac joint fusion, then the bone fusion speed is improved, but the shear stress on the implant increases

Engineering Contradiction:
Improvebone fusion speedVSAvoidshear stress on implant
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The screw is segmented into compression and anchoring portions that can be controlled independently. This segmentation allows compression to be applied optimally for bone fusion while the anchoring portion is independently optimized to bear the resulting shear stresses, enabling both fast fusion and reduced implant stress.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dual-drive mechanism enables independent adjustment of compression parameters (force, rate) and anchoring parameters (depth, engagement). By optimizing these parameters separately, the system achieves maximum compression for rapid bone fusion while simultaneously optimizing anchoring strength to withstand the shear stresses generated by compression, thus resolving the contradiction between fusion speed and implant stress.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2964118B1Surgical implant system
Publication Date: 2021.11.17 WARSAW ORTHOPEDIC INC
  • EP2964118B1 patent drawingFigure 1
  • EP2964118B1 patent drawingFigure 2~3
  • EP2964118B1 patent drawingFigure 4~5

AI summary

A surgical instrument includes a first member defining a longitudinal axis and including a drive interface engageable with a first surface of a bone fastener. The first surface is configured for penetrating a sacrum. A second member includes a drive interface engageable with a second surface of the bone fastener to translate the second surface relative to the first surface such that the second surface engages an outer non-articular surface of an ilium to draw separated articular surfaces of the sacrum and the ilium into fixation. In some embodiments, systems and methods are disclosed. Systems and methods are disclosed.