Nested Bone Anchor Locking Device Prevents Element Loss
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Solution Overview
Problem
Existing locking devices for securing rod-shaped elements in bone anchors lack enhanced safety during surgical manipulation, particularly risking the second locking element to back out or get lost during instrument errors or adjustments.
Innovation Solution
A locking device comprising a first locking element with an internal second locking element that is nested and protected against separation, ensuring the second locking element cannot escape or get lost, facilitating secure handling and enhanced safety during surgery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the second locking element is designed to be removable from the first locking element, then the locking device can be disassembled for separate storage or replacement, but the second locking element may back out or get lost during surgical manipulation
Solution Approach 1:
The second locking element is nested within the first locking element in a contained relationship. The second locking element fits inside the hollow cylindrical body of the first locking element, with its longitudinal axis aligned with the bore axis of the first locking element. This nesting structure ensures that the second locking element remains contained and cannot escape during surgical manipulation, while still allowing for controlled assembly and disassembly when needed.
2Reliability
If the second locking element is contained within the first locking element, then safety is enhanced by preventing backing out or loss, but the handling complexity increases during surgery
Solution Approach 1:
The design uses a nested structure where the second locking element is contained within the first locking element. The first locking element has a hollow cylindrical body with a bore that receives the second locking element. The second locking element has a diameter smaller than the bore diameter, allowing it to fit inside while maintaining longitudinal alignment. This nesting provides containment and safety while keeping the structure relatively simple and manageable during surgical procedures.
Data Source
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AI summary
A locking device for securing a rod-shaped element in a receiving part of a bone anchor, comprising: a first locking member (6, 600, 6') having a first end (61, 601) and a second end (62, 602) provided with an external thread (63, 603) on at least a portion thereof, a coaxial bore (64, 604) passing entirely through the first locking member the coaxial bore having a bore axis (C) and an internal thread (65, 605) provided in at least a portion of said bore, a second locking member (7, 700, 7') having a first end (71, 701) and a second end (72, 702), an outer surface with an external thread (73, 703) in at least a portion thereof which cooperates with the internal thread provided at said bore of the first locking member, wherein the second locking member is movable along the bore axis by rotating it and wherein a path of advancement of the second locking member is limited towards the first end by a first stop (66, 606c) and towards the second end (62b, 606d) by a second stop.