Faculty Advisor

Savilonis, Brian J.


The goal of this project was to design an external fixation device used for tibia fractures allowing for controlled axial micromotion at the fracture gap. The main objectives for this device were to exhibit a non-linear stiffness profile while allowing up to a maximum of 2% strain at the fracture gap, eliminating stress shielding while preventing further injury. Our device consisted of a three piece rod: two rigid end pieces connected to a center insert by a compressible material. This material allows the device to compress slightly before the rigid rods take up the load. Prototypes were tested on an Instron and results show that the desired non-linear stiffness is possible. Through the recommended dimensional alterations, this device will allow for a 2% strain at the fracture gap.


Worcester Polytechnic Institute

Date Accepted

January 2002


Biomedical Engineering

Project Type

Major Qualifying Project


Restricted-WPI community only

Advisor Department

Mechanical Engineering