Expandable Spinal Implant Using Threaded Gear Mechanism
Solution Overview
Problem
Current polyetheretherketone (PEEK) based expandable corpectomy devices for spinal treatments are prone to breaking under high anatomical loads due to their weaker material properties compared to metals like titanium or stainless steel, limiting their effectiveness in providing mechanical support for spinal disorders.
Innovation Solution
A spinal implant system featuring modular, expandable components with curved designs and threaded mechanisms that allow for adjustable expansion and alignment along lordotic curves, utilizing PEEK materials in combination with other biocompatible materials to enhance structural integrity and fit within anatomical spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PEEK material is used for expandable corpectomy devices, then biocompatibility and corrosion resistance are improved, but mechanical strength and load-bearing capacity deteriorate
Solution Approach 1:
The patent employs composite construction by integrating a PEEK outer shell with an internal metallic reinforcement structure. The PEEK material provides biocompatibility and corrosion resistance, while the embedded metal framework (titanium or stainless steel) supplies the necessary mechanical strength and load-bearing capacity. This composite approach allows the device to simultaneously achieve chemical inertness and structural integrity.
2Adaptability or versatility
If expandable design is implemented, then adaptability to anatomical variations is improved, but device complexity increases
Solution Approach 1:
The patent implements a dynamic expandable structure where the corpectomy device can change its dimensions post-implantation. The device features an expandable body with movable components that allow adjustment of the anterior-posterior diameter to match the patient's specific anatomical requirements. This dynamic capability enables a single device design to accommodate various vertebral body sizes and shapes.
Solution Approach 2:
The expandable device is divided into multiple segments including an outer shell, internal reinforcement structure, and expandable mechanisms. This segmentation allows independent optimization of each component's function while maintaining overall device coherence. The modular design facilitates controlled expansion through mechanical actuation of the segmented components.
3Adaptability or versatility
If curved design is used to match lordotic curves, then anatomical fit is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent incorporates pre-formed curved geometries in the corpectomy device to match the natural lordotic curvature of the spine. The device features controlled radii of curvature in specific regions that correspond to anatomical landmarks, enabling better integration with the patient's spinal anatomy. These curved designs are integrated into the expandable and modular structure, allowing the curvature to be maintained during expansion.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system provides improved mechanical support and stability for spinal implants by allowing for customizable expansion and alignment, reducing the risk of device failure under anatomical loads while maintaining biocompatibility and adaptability to various spinal conditions.
Implementation Method 1
A driver comprises a gear configured to engage the gear teeth such that rotation of the driver relative to the first member and the second member rotates the second member relative to the first member to translate the second member relative to the first member along the longitudinal axis
Implementation Method 2
The second member comprises a second thread engaged with the first thread. The collar comprises a third thread. The sleeve comprises a fourth thread engaged with the third thread
Data Source
AI summary
A spinal implant includes a first member that is curved along an axis between opposite ends. The first member defines a bore and a first thread. A second member is positioned in the bore and is curved between opposite ends. The second member includes a second thread engaged with the first thread. The second thread includes a series of gear teeth. A third member is positioned in the bore and is curved between opposite ends and includes opposite ends. A driver includes a gear configured to engage the gear teeth such that rotation of the driver relative to the first member and the second member rotates the second member relative to the first member to translate the second member relative to the first member along the axis. Systems and methods are disclosed.