Dynamic External Fixator for Bone Realignment
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Solution Overview
Problem
Current external fixation systems for bone reconstruction lack precision and control in moving wires to align fractured bones effectively, providing insufficient control over wire movement and force application.
Innovation Solution
An external fixation system with a dynamic fixator featuring a ring element and adjustable devices allowing multi-axis movement, including linear, vertical, and angular adjustments, to accurately realign broken bones by attaching k-wires or half pins to the ring element and adjustable devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If wires are bent prior to being attached to the open ring member to apply force to move bones together, then force application capability is improved, but control over wire movement and force amount deteriorates
Solution Approach 1:
The patent transforms the static bent wire configuration into a dynamic adjustable system. The wire can be moved along the ring member using a screw mechanism that allows precise control over wire position and force application. This dynamic adjustment capability resolves the contradiction by enabling both force application and controlled wire movement through the mechanical advantage of the threaded connection.
2Stability of the object's composition
If a rigid body external fixation ring is used to immobilize and realign bones, then bone stabilization is improved, but precision and control in wire movement deteriorates
Solution Approach 1:
The patent introduces an intermediary adjustment mechanism (screw thread system) between the rigid ring member and the wire. This intermediary device acts as a mediator that translates rotational motion of the screw into precise linear movement of the wire, thereby maintaining bone stabilization through the rigid ring while achieving precise control over wire position and force application.
3Ease of manufacture
If wires are attached to the open ring member by wire/rod nuts, then ease of attachment is improved, but control over force application and wire movement deteriorates
Solution Approach 1:
The patent replaces the static wire/rod nut attachment with a dynamic screw adjustment mechanism. The wire is threaded through the ring member and secured with a screw that can be rotated to adjust wire tension and position. This maintains ease of attachment while dramatically improving control over force application through the mechanical advantage of the threaded connection, allowing incremental adjustments during the bone healing process.
Data Source
AI summary
An external fixation system and method for realigning, compressing or distracting broken bones has a planar ring element with an adjustable device having a body releasably mounted on the ring element. The adjustable device includes a first member for movement in a direction generally perpendicular to the ring element. A second member is mounted on the first member for movement in a direction parallel to the first member and with respect to a circumference of the planar ring element. The method includes inserting a k-wire through a first piece of bone and affixing the k-wire to the ring element. Then inserting a second k-wire through a second piece of bone and affixing the k-wire to the adjustable device second member. The pieces of bone are realigned, compressed or distracted by adjusting at least one of a first and second adjustable members forming the device.