Polyaxial Pivot Housing for External Fixation Adjustment
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Solution Overview
Problem
Conventional external fixation systems for orthopedic procedures are difficult and time-consuming to adjust, posing risks to surgeons due to the need for manual loosening and tightening of clamps during fracture reduction, and expose them to X-ray fields.
Innovation Solution
A polyaxial pivot housing system that allows for easy assembly and flexible adjustment of external fixation frames, enabling surgeons to align and stabilize bone fragments without additional tools, using a polyaxial pivot housing with a locking mechanism that provides provisional and definitive locking capabilities to facilitate precise bone alignment and stabilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional external fixation systems are used, then bone stabilization is achieved, but adjustment is difficult and time-consuming
Solution Approach 1:
The pivot housing incorporates a dynamic locking mechanism that transitions from a locked state (during assembly) to an unlocked state (during adjustment), enabling easy modification of the frame configuration without manual loosening of clamps
Solution Approach 2:
The system includes self-adjusting components where the pivot housing automatically maintains positioning through its internal locking mechanism, eliminating the need for continuous manual intervention to maintain frame stability during adjustment
2Adaptability or versatility
If manual clamp loosening and tightening is performed during fracture reduction, then bone alignment adjustment is possible, but surgeon safety is compromised due to X-ray exposure
Solution Approach 1:
The frame is pre-configured with polyaxial pivot housings that allow for preliminary positioning and provisional locking, enabling the surgeon to establish initial bone alignment before definitive locking, reducing the need for repeated X-ray exposure during adjustments
Solution Approach 2:
The pivot housing acts as an intermediary mechanism between the clamp and the bone fragments, providing a controlled adjustment interface that allows bone alignment modification without requiring direct manual manipulation of clamps under X-ray guidance
3Reliability
If clamps are tightly secured to stabilize bone fragments, then bone stabilization is improved, but adjustment flexibility is reduced
Solution Approach 1:
The locking mechanism transitions from a dynamic state (allowing adjustment) to a static locked state (providing stability), enabling the system to provide both adjustment flexibility and bone stabilization reliability at different stages of the surgical procedure
Solution Approach 2:
The provisional locking capability provides a buffer state that allows for initial stabilization with the understanding that adjustments can still be made, cushioning against the need for complete disassembly or major frame modifications later in the procedure
Data Source
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AI summary
A polyaxial pivot housing for an external fixation system, comprising a collet body having a threaded portion; a spherical member configured to be partially received by a cavity that is formed in the collet body, the spherical member having a threaded post that is configured to attach to a support member of an external fixation frame; and a threaded locking collar that is configured to orientationally lock the threaded post with respect to the external fixation frame by compressing the spherical member into the cavity as the threaded locking collar is mated with the threaded portion of the collet body.