Angled Compression Screw for Small Bone Fusion
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Solution Overview
Problem
Current surgical fixation methods for small bones and osteotomies, particularly in interphalangeal joints, often result in sub-optimal outcomes due to lack of functional flexion and adequate compression across the joint during fusion.
Innovation Solution
A compression screw with a threaded leading portion and an intermediate shaft portion forming an angle of 12° to 25°, which is joined to a trailing head portion configured for anti-rotational stability and compression, allowing for percutaneous insertion and minimizing tissue damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If straight distal interphalangeal joint fusion is performed, then joint stability is achieved, but finger dexterity and grip strength are compromised
Solution Approach 1:
The patent employs an asymmetric angled screw design with a specific angle (12° to 25°) that deviates from the traditional straight fusion approach. This asymmetric configuration allows the screw to maintain joint stability while preserving functional flexion, thereby improving finger dexterity and grip strength compared to straight fusion
2Ease of operation
If k-wire fixation is used for angled fusion, then functional flexion is provided, but immobilization protocol fails and complications occur
Solution Approach 1:
The patent replaces the mechanical k-wire fixation system with a compression screw system that provides both angular correction and stable fixation. The screw design with specific angle and compression capability substitutes the unreliable k-wire immobilization protocol, achieving both functional flexion and reliable fixation without the complications associated with k-wire failure
3Strength
If compression screws are used for joint fusion, then reliable strong repair is achieved, but functional flexion benefit is lost
Solution Approach 1:
The patent introduces a dynamic angled screw design that allows for functional flexion while maintaining strong compression across the joint. The specific angle configuration (12° to 25°) enables the screw to provide both the mechanical strength of compression fixation and the functional benefit of flexion, unlike traditional compression screws that eliminate movement
4Stability of the object's composition
If traditional screw insertion is used, then fixation is achieved, but soft tissue, cartilage and vascular damage occurs
Solution Approach 1:
The patent employs a percutaneous insertion technique with a specifically designed screw configuration that minimizes damage to surrounding soft tissues, cartilage, and vasculature. The local approach through small incisions with controlled insertion path reduces the harmful effects on adjacent structures while achieving stable fixation
5Force
If screw head is positioned at bone surface, then compression is provided, but screw prominence and irritation occur
Solution Approach 1:
The patent designs the screw head to be nested within the bone structure, with a configuration that allows the head to be inserted into the bone without damaging it. The head is sized and shaped to support the bone from the inside and fit in the narrow confines of the intramedullary channel, providing compression while avoiding screw prominence on the digit tip or intrusion into the fat pad
Data Source
AI summary
The present invention relates to a device and system for surgical fixation of small bones, small bone fragments, and osteotomies and more particularly to compression screw having a threaded leading portion which is joined to a section that is free from threads, and which includes an angle or from 12° to 25° in a plane through the longitudinal axis of the screw and a portion which is joined to a head having a configuration that is intended to provide anti-rotational stability and compression through the device.