Bone Fixation Plate Clips for Screw Retention and Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Micromotion between orthopedic hardware and bone can cause loosening and backout of screws, leading to instability in bone fracture stabilization.
Innovation Solution
A bone fixation system with clips that flex outward to accommodate fasteners, minimizing backout by maintaining their position through wedging and resilient return to an unflexed state, and a removal tool for easy extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If rigid plates and screws are used to stabilize bone fractures, then bone stability is improved, but micromotion between hardware and bone causes screw loosening and backout
Solution Approach 1:
The patent changes the physical state of the clip from rigid to resilient/flexible, allowing it to deform elastically under load. This parameter change enables the clip to accommodate micromotion between the screw and bone while maintaining retention, preventing screw backout while preserving bone stability.
Solution Approach 2:
The clip is designed as a dynamic component that can flex and deform in response to applied forces. When the screw is inserted, the clip deforms to allow passage, then returns to its original shape to lock the screw in place. This dynamic behavior allows the system to adapt to micromotion without losing screw retention.
2Reliability
If clips are added to prevent screw backout, then screw retention is improved, but device complexity increases
Solution Approach 1:
The clip is designed to function automatically without requiring additional tools or manual intervention. When the screw is inserted through the clip, the clip's resilient nature causes it to deform and then return to its original shape, automatically locking the screw in place. This self-service mechanism prevents screw backout while adding minimal complexity to the system.
Solution Approach 2:
The retention function is separated from the screw itself and implemented through a distinct clip component. This segmentation allows the clip to be optimized for retention while the screw maintains its primary function of bone fixation, reducing overall system complexity through functional decomposition.
3Device complexity
If traditional screws are used without anti-backout features, then device complexity is reduced, but micromotion causes loosening and instability
Solution Approach 1:
The clip acts as an intermediary component between the screw and the bone. It mediates the interaction by providing a compliant interface that absorbs micromotion while maintaining screw retention. This intermediary function protects the fracture stability without requiring complex modifications to the screw itself.
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
Prevents unwanted rotation and loosening of fasteners, ensuring stable fracture stabilization and facilitating easy removal without additional tools.
Implementation Method 1
a resilient clip may be positioned in a cavity of a bone fixation plate. As a fastener enters a fastener hole of the bone fixation plate, a head of the fastener may contact the resilient clip. The resilient clip may flex outward to allow passage of the head of the fastener. As the fastener is inserted into the fastener hole, the resilient clip may return to an unflexed state from the flexed state.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A bone fixation assembly is disclosed. The bone fixation assembly may include a bone fixation plate including a fastener hole and a cavity adjacent to the fastener hole. The bone fixation assembly may also include a clip. The clip may include a body having a partial circular shape, the body positioned at least partially in the cavity. The clip may further include a plurality of tabs extending inward relative to the partial circular shape of the body, each tab having a convex shape extending inward relative to the partial circular shape of the body, wherein the body and the plurality of tabs are positioned below a top surface of the bone fixation plate.