Flexible-to-Rigid Bone Fixation Device with Expandable Grippers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current bone fracture fixation methods, such as intramedullary rods and external fixation, are invasive, cause trauma, and have complications like infection and prolonged recovery, while lacking effective minimally invasive solutions for osteoporotic and fractured bones.
Innovation Solution
A bone fixation device with a flexible-to-rigid body and actuable grippers that can be inserted through a single portal, deployed within the bone, and remotely actuated to stabilize fractures, reducing trauma and allowing for easier insertion and removal, made from biocompatible materials like titanium and polymers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If intramedullary rods or external fixation are used for bone fracture fixation, then fracture stabilization is achieved, but surgical trauma and infection risk increase
Solution Approach 1:
The device is divided into multiple segments including a proximal anchor, a distal anchor, and an expandable mesh body with multiple struts. This segmentation allows minimally invasive insertion through separate portals while maintaining reliable fracture stabilization through distributed anchoring points along the bone length.
Solution Approach 2:
The expandable mesh body is inserted in a compressed or collapsed state through a minimally invasive portal, then expanded in situ within the medullary cavity. This nesting approach reduces the initial insertion size and surgical trauma while achieving the full functional size for effective fracture fixation.
2Reliability
If conventional fixation devices are used, then fracture fixation is provided, but recovery time is prolonged
Solution Approach 1:
The expandable mesh body is pre-formed with a specific geometric configuration that enables self-expansion or controlled expansion to the final fixation shape. This preliminary preparation allows rapid deployment during surgery, reducing operative time and facilitating faster patient recovery.
3Stability of the object's composition
If rigid fixation devices are inserted, then fracture stability is achieved, but insertion difficulty and bone damage increase
Solution Approach 1:
The device transitions from a flexible, compressible insertion state to a rigid, expanded fixation state. The mesh body and struts are designed to be flexible during insertion to navigate the medullary cavity easily, then lock into a rigid configuration upon expansion to provide stable fracture fixation.
Solution Approach 2:
The mesh body is constructed from flexible struts that can be compressed or collapsed for minimally invasive insertion through small portals. Once positioned, these same struts expand to form a rigid-like structure that provides stable fracture fixation, combining the benefits of flexibility during insertion and rigidity during fixation.
4Object-affected harmful factors
If expandable devices are deployed, then minimally invasive insertion is achieved, but device complexity increases
Solution Approach 1:
The device utilizes controlled parameter changes, specifically the expansion ratio of the mesh body and the deployment sequence of struts, to manage complexity. By designing the expansion mechanism to follow predictable geometric progression and using standardized strut configurations, the apparent complexity is reduced while maintaining minimally invasive benefits.
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
The device provides effective, minimally invasive bone reinforcement and fracture fixation, reducing trauma, infection risks, and recovery time, while allowing for axial, torsional, and angular adjustments during surgery and easy removal after healing.
Implementation Method 1
The device may be made from shape memory alloy or superelastic alloy, and may be deployed and expanded within the bone using the shape memory and/or superelastic properties of the material
Implementation Method 2
The device may be made from shape memory alloy or superelastic alloy, and may be deployed and expanded within the bone using the shape memory and/or superelastic properties of the material
Data Source
AI summary
A bone fixation device is provided with an elongate body having a longitudinal axis and having a first state in which at least a portion of the body is flexible and a second state in which the body is generally rigid, an actuateable gripper disposed at one or more locations on the elongated body, a hub located on a proximal end of the elongated body, and an actuator operably connected to the gripper(s) to deploy the gripper(s) from a retracted configuration to an expanded configuration. Methods of repairing a fracture of a bone are also disclosed. One such method comprises inserting a bone fixation device into an intramedullary space of the bone to place at least a portion of an elongate body of the fixation device in a flexible state on one side of the fracture and at least a portion of a hub on another side of the fracture, and operating an actuator to deploy at least one gripper of the fixation device to engage an inner surface of the intramedullary space to anchor the fixation device to the bone. Alternative gripper designs are disclosed that may be used in various combinations.