Spinal Tether Locking Mechanism with Compliance Member
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Solution Overview
Problem
Current spinal implants for treating discogenic pain and related conditions are invasive, irreversible, and prone to mechanical failure due to uneven force distribution and complex assembly, leading to unreliable and less effective pain relief.
Innovation Solution
A fastening mechanism and method for securely locking a tether to restrict spinal flexion using a constraint device with a clamp body and fastener element, providing adjustable resistance to flexion and extension, and featuring a compliance member to distribute forces evenly, allowing for less invasive and reversible implantation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current spinal implants are used to restrict spinal flexion, then pain relief is provided, but the implants are invasive and irreversible
Solution Approach 1:
The tether is made adjustable and reversible, allowing dynamic modification of the implantation. The fastening mechanism enables the tether to be tightened or loosened and completely removed if needed, transforming the static, irreversible implant into a dynamic, reversible system that maintains pain relief while reducing invasiveness concerns
Solution Approach 2:
The implant allows adjustment of the tether tension and positioning parameters post-implantation. The fastening mechanism enables modification of the tether's mechanical properties and position, allowing optimization of pain relief while minimizing initial invasiveness through reversible adjustment
2Stability of the object's composition
If current spinal implants are used to restrict spinal flexion, then motion restriction is achieved, but mechanical failure occurs due to uneven force distribution
Solution Approach 1:
The compliance member is positioned specifically at the fastening point where force concentration occurs. This local compliance element distributes the mechanical load evenly across the tether and fastening mechanism, preventing stress concentration and reducing the risk of mechanical failure while maintaining spinal segment stabilization
Solution Approach 2:
The compliance member acts as a pre-installed cushioning element that absorbs and distributes mechanical forces before they can cause damage. By placing this compliant element at the critical fastening point, the system preemptively protects against uneven force distribution and potential mechanical failure
3Stability of the object's composition
If current spinal implants are used to restrict spinal flexion, then spinal segment stabilization is provided, but the implants are irreversible
Solution Approach 1:
The fastening mechanism creates a dynamic connection between the tether and anchor that can be easily adjusted or completely reversed. This allows the spinal segment stabilization to be maintained initially, then modified or removed if needed, providing both stability and reversibility that were previously contradictory
4Reliability
If complex assembly mechanisms are used in spinal implants, then secure locking is achieved, but device complexity increases
Solution Approach 1:
The fastening mechanism extracts the essential function of secure locking from a complex multi-component system and implements it through a simple, integrated design. The fastening element and compliance member work together as a unified, minimally complex system that achieves reliable tether locking without the need for complex assembly mechanisms
Data Source
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AI summary
Fastening mechanisms for releasably locking a tether are provided. The mechanisms find application with orthopedic internal-fixation implants and make the implants more reliable and their implantation less invasive. A method for releasably locking a tether comprises advancing the tether through a tether aperture in a clamp body. The tether enters the tether aperture in a first plane and exits in a second plane generally transverse to the first plane. Positioning a fastener element in a fastener aperture in the clamp body captures the tether between the clamp body and the fastener element thereby releasably locking the tether in position relative to the clamp body.