C1-C2 Spinal Clamp with Ball Socket Joint
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Solution Overview
Problem
Current spinal fusion fixation devices, such as the Harms construct, are invasive and lead to high blood loss and risk of injury to the vertebral artery and nerve root, making them unsuitable for elderly patients with atlantoaxial instability, resulting in high fracture non-union rates and permanent instability.
Innovation Solution
A spinal fusion clamp implant that connects the C1 vertebra to the C2 vertebra using a clamp assembly with opposed jaws that clamp onto the posterior arch of C1, reducing invasiveness by replacing C1 lateral mass screws and utilizing a connection system with polyaxial rods and screws to provide stability without risking the vertebral artery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the Harms construct with C1 lateral mass screws is used for posterior spinal fusion, then construct stability and fusion rates are improved, but surgical invasiveness increases and risk of injury to the vertebral artery and nerve root worsens
Solution Approach 1:
The patent extracts and eliminates the C1 lateral mass screws from the fixation system, replacing them with a C2 pedicle screw and C1-C2 cross-link construct. This removal of the harmful component (C1 lateral mass screw near the vertebral artery) while maintaining the stabilizing function through an alternative configuration directly resolves the contradiction between fusion reliability and surgical safety.
Solution Approach 2:
The C1-C2 cross-link acts as an intermediary element that provides stability and promotes fusion without requiring direct screw placement into the vulnerable C1 lateral mass. The cross-link mediates the mechanical connection between C1 and C2, allowing the construct to achieve fusion rates comparable to the Harms construct while avoiding injury to the vertebral artery and nerve root.
2Stability of the object's composition
If the Harms construct is used for posterior spinal fusion, then construct stability is improved, but blood loss increases due to disturbing capillaries and venous plexus
Solution Approach 1:
By removing the C1 lateral mass screws that require dissection through highly vascular areas, the patent eliminates the source of excessive blood loss while preserving construct stability through the alternative C2 pedicle screw and cross-link configuration. This directly addresses the contradiction between maintaining stability and reducing blood loss.
3Stability of the object's composition
If C1 lateral mass screws are used for fixation, then immediate stability is achieved, but surgical invasiveness and operating time increase
Solution Approach 1:
The patent removes the complex C1 lateral mass screw placement procedure from the surgical approach, replacing it with a simpler C2 pedicle screw and cross-link technique. This extraction of the invasive element maintains immediate stability while significantly reducing surgical complexity and invasiveness.
Data Source
AI summary
A spinal fusion clamp implant that connects two vertebra, preferably the C1 and C2 vertebra. The clamp implant includes a clamp assembly that connects to the C1 vertebra. The clamp assembly includes at least one superior jaw and at least one inferior jaw. The superior jaw and the inferior jaw are opposedly arranged and clamp onto posterior arch of the C1 vertebra. The clamp implant also includes an implant assembly that connects to the implant used in C2, and a connection system that connects the clamp assembly with said C2 implant assembly.