Date of Award

January 2022

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)



First Advisor

Brad Yoo

Second Advisor

Jonathan Grauer


The fracture pattern of supination-external rotation injury of the fibula is often reducible by lag screw fixation. This thesis is designed to evaluate biomechanical differences between lag screws inserted from an anterior to posterior direction and from a posterior to anterior direction and if the thickness of the anterior and posterior fibular cortices were similarly correlated. 5 donor-matched pairs of cadaver fibula were harvested and submitted to material testing following 3.5-mm cortical screw insertion from either an anterior to posterior direction or a posterior to anterior direction and screw insertion torque and axial pullout strength were measured. Computed tomography images of 40 patients undergoing preoperative planning for ankle injuries excluding the fibula were examined to define fibular cortical thickness. The anterior cortex of the distal fibula exhibited a radiographically greater thickness than that of the posterior cortex at the same level (p < 0.001). The axial pullout strength of lag screws inserted from posterior to anterior was significantly greater than that of lag screws inserted from anterior to posterior (p < 0.05). Screw insertion torque measurements demonstrated a similar trend although the data did not reach statistical significance (p = 0.056). For supination-external rotation fracture patterns of the distal fibula, posterior to anterior lag screw insertion exhibited superior biomechanical properties when compared to the anterior to posterior approach. These results also correlated with the cortical thickness of bone measured along the anterior fibula.


This is an Open Access Thesis.

Open Access

This Article is Open Access