Intervertebral Fusion Implant Positioning Device with Anti-Rotational Constraint
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Solution Overview
Problem
Existing devices for positioning implants during intervertebral fusion surgeries face challenges in allowing rotational freedom while maintaining precise positioning, often requiring complex and costly systems that are cumbersome and difficult for surgeons to handle.
Innovation Solution
A device with a handle and rod featuring an axial retention assembly with a gripper and an external anti-rotational constraint assembly, allowing selective clamping and releasing configurations, and a manoeuvring element that converts rotation into gripper movement, enabling easy rotation of the implant around its central pin, which is also the centre of rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the implant is completely released before definitive positioning, then the surgeon has maximum freedom of positioning, but the surgical procedure becomes more complex and time-consuming
Solution Approach 1:
The implant is pre-loaded into the gripper before insertion, allowing the surgeon to position it definitively in a single continuous motion without releasing it beforehand. This preliminary preparation eliminates the need for complex release-and-reposition maneuvers during surgery.
Solution Approach 2:
The gripper acts as an intermediary mechanism that maintains continuous engagement with the implant throughout the positioning process. It provides a stable interface that allows rotation and positioning while keeping the implant securely held, eliminating the need for complete release.
2Ease of operation
If the centre of rotation is moved away from the implant, then the implant can be rotated while connected to the rod, but the operating area of the device increases and the system becomes more complicated
Solution Approach 1:
The device is segmented into distinct functional components: the gripper that engages the implant, the rod that provides leverage, and the handle that the surgeon operates. This segmentation allows the centre of rotation to remain at the implant while each component performs its specific function independently.
Solution Approach 2:
The complex rotation control mechanisms and centre of rotation adjustment systems found in prior art are extracted and eliminated. The invention achieves rotation capability through the simple mechanical advantage of the rod-lever system acting on the gripper, without requiring additional rotational joints or control mechanisms.
3Reliability
If a toothed coupling system is used to control implant rotation, then safety and versatility are improved, but the device becomes extremely expensive and cumbersome
Solution Approach 1:
The invention employs simple, inexpensive mechanical components rather than complex expensive systems. The smooth rod with gripper uses basic mechanical principles that are reliable yet inexpensive to manufacture, avoiding the need for costly toothed couplings, splines, or precision-machined rotational control mechanisms.
Solution Approach 2:
Instead of using a complex toothed coupling system to transmit rotational motion from the handle to the implant, the invention inverts the approach: the surgeon applies force to the rod to directly rotate the implant through mechanical advantage, eliminating the need for intermediate transmission mechanisms.
Data Source
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AI summary
A device for positioning an implant for intervertebral fusion, comprising a handle (2), a rod (3) protruding from the handle (2) along a main direction (A) of extension of the device up to its free end (3a) and coupling means (6) for coupling with an implant (50) for intervertebral fusion operatively active at said free end (3a). Said coupling means (6) comprise an axial retention assembly (7) provided with a gripper (9) formed at the free end (3a) of the rod (3) and selectively operable between a clamping and a releasing configuration, and an anti-rotational constraint assembly (8) selectively movable between a locking position, in which it is arranged around said axial retention assembly (7) and abuts said implant (50) to prevent its rotation, and a disengagement position, in which it leaves the implant (50) free to rotate in the gripper (9).