Rod Insertion Instrument Lockable Hinge Joint
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Solution Overview
Problem
Existing rod insertion instruments for dorsal spinal column stabilization often result in over-stressing of soft tissue during the insertion of fixation rods into pedicle screws, due to limited control over the orientation of the fixation rod and stability issues during the insertion process.
Innovation Solution
A rod insertion instrument featuring a gripping head rotationally fixed to a tube section via a lockable hinge joint, allowing unconstrained pivoting of the tube section during fixation rod insertion, which minimizes tissue stress by enabling free movement and support at the skin incision without active control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the gripping head is fixed at a marginal angle of approximately 30° with respect to the tube section, then good control and minimal invasiveness during fixation rod insertion is achieved, but over-stressing of soft tissue occurs during set screw fixation
Solution Approach 1:
The hinge joint enables dynamic adjustment of the angle between the tube section and gripping head during the insertion process. The joint can be locked in different angular positions, allowing the system to transition from a fixed angled configuration during insertion to a different configuration during set screw fixation, thereby avoiding soft tissue over-stressing while maintaining insertion control
2Stability of the object's composition
If the fixation rod is directly pivotably fixed onto the rod insertion instrument, then stable connection is achieved, but orientation control during insertion becomes insufficient
Solution Approach 1:
The instrument is segmented into a tube section and a gripping head that can pivot relative to each other via the hinge joint. This segmentation allows independent optimization: the tube section maintains stability during insertion, while the gripping head can be precisely oriented and locked at the required angle, achieving both stable connection and precise orientation control
3Adaptability or versatility
If the fixation rod is adjustable and fixable at the distal end of the rod insertion instrument, then orientation flexibility is improved, but the design becomes relatively complex
Solution Approach 1:
The hinge joint acts as an intermediary mechanism between the tube section and gripping head, providing angular adjustment and locking capabilities without requiring complex mechanisms at the distal end of the instrument. This intermediary joint simplifies the overall design while achieving the desired orientation flexibility
Data Source
AI summary
Described is a rod insertion instrument for the insertion of a fixation rod in the tulips of adjacent pedicle screws in the context of a dorsal spinal column stabilization. It has a grip portion, a tube section adjoining it and a gripping head carried by the tube section, in which gripping head the fixation rod is rotationally fixedly and angularly stably receivable with its proximal end. In order to minimize accidental tissue compression during the fixing of the fixation rod into the pedicle screws, the gripping head is attached to the tube section exclusively via a lockable joint with which there is enabled an unconstrained pivoting movement of the tube section toward the fixation rod during the process of fixing the fixation rod to the pedicle screw.