Oblique Bone Pin Fixing Block for Stable External Frame
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Solution Overview
Problem
Current bone fixators using transverse pins are prone to loosening and breakage due to bending stresses, leading to instability and potential infection, requiring cumbersome and heavy external frames for secure fixation.
Innovation Solution
The use of obliquely placed bone pins within a fixing block system that allows for non-orthogonal insertion and secure attachment to an external frame, providing a more stable and versatile fixation method by engaging more of the bone surface and distributing stress effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If transverse pins are used for bone fixation, then the bone can be stabilized, but the pins are subject to bending stresses from muscle contraction and weight bearing, leading to pin loosening, breakage, or stress fracture
Solution Approach 1:
The patent transitions from transverse pin insertion (horizontal dimension) to oblique pin insertion at angles between 15-75 degrees relative to the bone surface (adding angular dimension). This dimensional change allows pins to engage the bone cortex more effectively, distributing stresses along the pin length rather than concentrating bending moments at the pin-bone interface, thereby improving reliability while maintaining stability
2Stability of the object's composition
If multiple transverse pins are placed per bone segment to preserve alignment and stability, then bone stability is improved, but the frame becomes more unwieldy and weighty
Solution Approach 1:
The patent changes the insertion angle parameter from 90 degrees (transverse) to oblique angles between 15-75 degrees. This parameter modification allows each pin to provide more effective stabilization per unit length, reducing the number of pins needed and consequently decreasing the overall frame weight and complexity while maintaining bone stability
3Stability of the object's composition
If transverse pins are used, then bone fixation is achieved, but pins may need to be applied at considerable distance from rings, requiring a cumbersome superstructure
Solution Approach 1:
By introducing oblique insertion angles, the patent enables pins to reach the bone cortex at more favorable locations closer to the external rings. This angular dimensionality change eliminates the need for cumbersome superstructures, as pins can be positioned optimally without requiring extended transverse reaches, thereby simplifying the overall frame configuration
Data Source
AI summary
A system is provided for stabilizing bone. The system includes a fixing block, a pin having a far end which is adapted to be fixed directly into bone and a near end which enters the fixing block, and a frame on which the fixing block is fixable. The pin enters the fixing block in a non-orthogonal manner in order to permit the pin to enter the bone with an orientation which is non-orthogonal to the bone's surface, thereby permitting the pin to engage more of the bone.