Design and Prototyping of Modular External Fixator

Overview

The current design of the Ilizarov external fixator is heavy, it impedes X-ray imaging, and is difficult to install. These characteristics affect the patient’s comfort, doctor’s ability to see the fracture healing, and the doctor’s choice of using the fixator. The goal of this project is to design and prototype modular external fixator with integrated sensing capabilities for optimized orthopedic recovery. This new design will allow for a lighter weight, easier to image and track fracture healing, and simpler to install device.

Objectives

The new external fixator design will allow for a lighter weight, easier to image and track fracture healing,
and simpler to install device. The design was developed and optimized using a design decision matrix,
mechanical testing, Finite Element Analysis, and 3D printing techniques.

Approach

• Preliminary research
• Preliminary testing on deformation and electrical resistance method to determine best approach
• Concept selection for the modular pieces and connector pieces
• Inventor drawings for modular pieces and connecting pieces
• 3D printed modular pieces and connecting pieces
• Assembled geometric prototype
• Mechanical testing to determine functionality of concept
• Inventor model for FEA testing
• Finite Element Analysis to determine deformation in rings without testing

Outcomes

• Tracked the bone healing process from
a fully broken tibia to a fully healed tibia
• Found a material that has the desired
mechanical properties and that can be
rapidly prototyped and 3D printed
• Made the modular pieces and
connecting pieces of a material that will
be translucent on X-ray
• Designed a fixator that is modular and
has the ability to be assembled for all
unique tibia fracture types