Abstract
Purpose: The purpose of this study is to define the geographic patterns of partial avascular necrosis (AVN) of the talar body and to determine whether there were any predictors of both the location and occurrence of partial AVN. Materials and Methods: Nineteen patients with fracture of the talar neck treated by open reduction and internal fixation and followed up for more than 1 year were analyzed. The radiographs were examined 6 to 8 weeks after the operation for Hawkins sign and if it was not observed, magnetic resonance scans were performed. The three-dimensional analysis was performed using Mimics 17.0 (Materialise). The incidence of collapse and time to operative intervention was recorded. Results: Partial AVN of the talar body was observed in six out of 19 patients. The avascular segment of the talar body was located predominantly in the anterolateral portion. The average volume of the avascular segment was $289mm^3$, and it occupied 1% of total volume of the talus, and 10% of the talar dome. Collapse occurred in one patient in the area of the avascular process. There were no observable trends with regard to Hawkins classification, incidence of collapse, or time to operative intervention to the location of the avascular segment. Conclusion: Partial AVN can occur after fracture of the talar neck. The predominant location of the avascular segment was the anterolateral portion of the talar body. This information may be helpful to understanding the process of avascular necrosis of the talar body.
