Headless Bone Screw with Movable Sleeve for Compression
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Solution Overview
Problem
Current bone compression and fixation devices often fail to achieve optimal contact between bone fragments, leading to slower healing due to inadequate compression and potential movement of fragments, especially in cases where screw heads interfere with bone joints or lack sufficient bone stock.
Innovation Solution
A two-piece bone screw device comprising a shaft and a sleeve with distinct thread pitches and diameters, allowing for improved compression without a screw head, along with a wire device and a flexible-to-rigid bone fixation system, enabling precise alignment and stabilization of bone fragments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional bone screws with screw heads are used, then bone fragments can be compressed, but the screw heads may interfere with bone joints or lack sufficient bone stock for proper seating
Solution Approach 1:
The invention extracts and removes the screw head component from the bone screw design, creating a headless compression device. The compression function is achieved through a sleeve that travels along the shaft, eliminating the interfering screw head while maintaining the essential bone compression capability. This resolves the contradiction by removing the harmful element (screw head) that interferes with bone joints and insufficient bone stock.
2Reliability
If current bone compression devices are used, then some compression is achieved, but optimal contact between bone fragments is not achieved, leading to slower healing
Solution Approach 1:
The invention segments the bone screw into two distinct components: a shaft with threaded sections and a separate movable sleeve. This segmentation allows the sleeve to independently travel along the shaft and apply precise compression forces to bring bone fragments into optimal contact. The segmented design enables better control over compression precision, directly improving bone fragment alignment and contact quality for faster healing.
3Manufacturing precision
If a two-piece design with distinct thread pitches is used, then improved compression and alignment are achieved, but device complexity increases
Solution Approach 1:
The invention merges multiple functions into the shaft component: it serves as the structural backbone, provides threading for bone engagement, incorporates different pitch sections for differential compression, and acts as a guide for the movable sleeve. By combining these functions into a single integrated shaft rather than separate components, the design achieves precise bone fragment alignment while minimizing overall device complexity.
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
Enhances bone fragment alignment and stabilization, facilitating faster healing by achieving greater compression and minimizing fragment movement, while being adaptable for various anatomical needs and bone densities.
Implementation Method 1
the distal section having a first external male screw thread and a minor diameter, the proximal section having a second external male screw thread... a sleeve having an internal female screw thread configured to mate with the second male screw thread
Data Source
AI summary
A bone screw, for drawing first and second bone fragments together, includes a shaft having a distal section and a proximal section. The distal section has a first external male screw thread and a minor diameter. The proximal section has a second external male screw thread. A major diameter of the distal section is larger than a major diameter of the proximal section. The bone screw includes a sleeve that has an internal female screw thread configured to mate with the second male screw thread. A distal portion of the sleeve has an outer diameter. The outer diameter is equal to or smaller than the minor diameter of the distal section of the shaft.