A Study Comparing Computerized Tomographic Progression of Bone Bridging After Subtalar Fusion Using Fully and Partially Threaded Screws

The study was designed by the principal investigator, Dr. Alastair Younger, and the St. Paul\'s Hospital Foot and Ankle Research Group, who will conduct the study. The study is being funded by Acumed LLC, the manufacturer of the Health Canada approved Acutrak 2® - 7.5 fully threaded screw. The purpose of this study is to assess and compare the effectiveness of fully threaded screws versus partially threaded screws in subtalar fusion, in order to determine the effect of the thread configuration on the success of the fusion procedure. Efficacy will be assessed primarily by computed tomography (CT) analysis of percent bone bridging across the subtalar joint at both 12 and 24 weeks post-op. Outcome scores will also be administered to compare general health and foot function between the two groups at baseline and at multiple post-op follow-up visits. Additional resource utilization (i.e. additional clinic and/or hospital admissions) will also be compared between the two groups post-op.