Coupling Sleeve Torque Control for Bone Anchor Alignment
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Solution Overview
Problem
Current spinal fixation systems face challenges in efficiently and accurately attaching spinal rods to bone anchors during orthopedic procedures, particularly in maintaining rotational alignment and torque control during set screw installation.
Innovation Solution
A coupling sleeve system that includes a torque limiting attachment, a driver bit, a coupling sleeve, and a retention tip, which facilitates rotational coupling between a bone power tool and a bone anchor, allowing for precise alignment and torque management during set screw installation, utilizing a unitary construction with splines and grasping members for secure engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional manual attachment methods are used for set screw installation, then flexibility and simplicity are maintained, but rotational alignment precision and torque control are insufficient
Solution Approach 1:
The coupling sleeve acts as an intermediary component that connects the bone power tool to the bone anchor, enabling precise rotational alignment and torque control during set screw installation. The sleeve includes splines that engage with both the power tool and the bone anchor, serving as a mediator that transfers rotational motion while maintaining alignment precision.
Solution Approach 2:
The attachment system is divided into multiple functional segments: the coupling sleeve for alignment, the splines for rotational coupling, the driver bit for set screw engagement, and the torque limiting attachment for controlled fastening. This segmentation allows each component to perform its specific function optimally while working together as an integrated system.
2Productivity
If bone power tool is used for set screw installation, then installation speed and consistency are improved, but rotational torque surges can cause disengagement or stripping
Solution Approach 1:
The torque limiting attachment is designed to cushion against rotational torque surges before they can cause disengagement or stripping. The attachment includes features that limit maximum torque transmission, protecting the set screw and bone anchor from excessive forces that could compromise engagement stability during high-speed power tool operation.
Solution Approach 2:
The coupling sleeve and splines create a feedback mechanism where rotational motion is continuously monitored and controlled. The splines engage in a way that provides tactile feedback on torque levels, allowing the system to maintain reliable engagement by adjusting to resistance variations during the installation process.
3Manufacturing precision
If rotational coupling is implemented between bone power tool and bone anchor, then installation precision is enhanced, but device complexity and risk of torque-related failures increase
Solution Approach 1:
The coupling sleeve serves as a protective intermediary between the bone power tool and the bone anchor, allowing rotational coupling for precision installation while filtering out harmful torque surges. The sleeve's design transmits only controlled rotational motion while blocking excessive forces that could damage the set screw or bone anchor.
Solution Approach 2:
The torque limiting attachment converts potentially harmful torque surges into beneficial controlled torque transmission. By designing the attachment to limit maximum torque, the system transforms what would be damaging force spikes into safe, controlled rotational forces that maintain precision without risking damage to the bone anchor or set screw.
Data Source
AI summary
A coupling sleeve for a bone power tool and a bone anchor is provided. The coupling sleeve includes a proximal collar, a distal collar, and a central portion. The proximal collar defines a first opening that is configured to interface with a bone power tool. The distal collar defines a second opening that is configured to interface with a retention feature for a pedicle screw. The central portion extends between the proximal collar and the distal collar. The proximal collar, the distal collar, and the central portion cooperate to define a passageway between the first opening and the second opening.