Intramedullary Nail Coupling for One-Handed Instrument Alignment
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Solution Overview
Problem
Conventional systems require both hands to hold the intramedullary nail in position during connection with a targeting and/or nailing instrument, making it complicated to execute the screw connection.
Innovation Solution
A spring clip coupling system that allows a one-handed connection by using a releasable snap connection between the targeting and/or nailing instrument and the nail, with a radially retreating section or a circular spring that temporarily holds the parts in place until a screw connection secures them, reducing the required force for locking and loosening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a screw connection is used to connect the nail and targeting device, then the connection is secure and reliable, but both hands are required to hold the nail and execute the screw connection simultaneously
Solution Approach 1:
The connection process is segmented into two distinct phases: a preliminary snap connection phase that aligns and secures the components temporarily, followed by a final screw connection phase that provides the ultimate secure attachment. This segmentation allows the operator to complete the snap connection with one hand while preparing for the screw connection, resolving the contradiction between reliable connection and ease of operation.
Solution Approach 2:
The snap connection serves as a preliminary action that pre-aligns and temporarily secures the nail and targeting device before the final screw connection. This preliminary engagement ensures proper positioning and reduces the complexity of the subsequent screw connection operation, as the components are already in the correct relative position.
2Stability of the object's composition
If both hands are engaged to hold the nail in position, then the nail can be securely positioned, but the screw connection becomes complicated and time-consuming
Solution Approach 1:
The positioning and connection functions are segmented: the snap connection mechanism provides preliminary positioning stability that allows one-handed operation, while the screw connection provides final secure attachment. This segmentation reduces the time required for connection by allowing the operator to complete the snap connection with one hand while the other hand prepares the screw connection.
Solution Approach 2:
The snap connection acts as an intermediary mechanism that provides temporary stabilization between the initial positioning and the final screw connection. This intermediary step maintains nail positioning stability while freeing one hand to perform the screw connection, thereby reducing overall connection time.
3Reliability
If a strong connection mechanism is used to securely attach the nail and instrument, then the connection is reliable, but significant force is required for assembly and disassembly
Solution Approach 1:
The connection mechanism is segmented into two stages with different force requirements: the snap connection requires minimal force for assembly and disassembly but provides sufficient temporary holding, while the screw connection provides the ultimate reliable attachment. This segmentation allows the system to achieve high reliability through the screw connection while keeping the initial assembly force low through the snap connection.
Solution Approach 2:
The connection system transitions from a static strong connection to a dynamic two-stage connection process. The snap connection provides a lightweight, low-force initial attachment that can be easily engaged and disengaged, while the screw connection provides the final strong attachment. This dynamic approach allows the system to adapt its connection strength to the operational requirements at each stage.
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
Enables one-handed operation for connecting the nail and instrument, reducing the power needed for assembly and disassembly, and allowing for easier handling during nail insertion and removal.
Implementation Method 1
the end section of the connection end of the targeting and/or nailing instrument has a radially retreating or deforming section on its perimeter, such as a spring element, that is deformed radially towards the inside when inserting the end section in the bore-hole section of the nail
Implementation Method 2
a spring circlip can be utilized to lock the connector and the nail in the axial direction. When the circlip is used, the internal bore includes an annular recess extending radially outwardly of the internal bore diameter into the bore wall in a direction generally perpendicular to the axis of the bone nail. The connector engaged to the instrument then includes the circlip which has an outer diameter slightly larger than the diameter of the internal nail bore so that it is deformed inwardly and then expands into the angular recess in the bone nail bore thereby securely locking the nail and the connector in the axial direction.
Data Source
AI summary
An intramedullary nail and targeting and/or nailing instrument are provided, whereby a connection end of the targeting and/or nailing instrument has an axially parallel protrusion and a connection end of the nail has an axially parallel recess in order to couple the targeting and/or nailing instrument. The coupling system couples the targeting/nailing instrument and nail in their rotational position when they contact axially and whereby a connector is also provided in order to connect the targeting and/or nailing instrument and the nail in an axially fixed but also releasable manner. The connection end of the targeting and/or nailing instrument has an end section that engages approximately in one end of the bore-hole section of the nail and the end section and bore-hole section have a deformable element for a releasable snap connection of the parts with the simultaneous contact of the axially parallel protrusion and the axially parallel recess.