Comparison between subtalar joint quantitative kinematic 4-D CT parameters in healthy volunteers and patients with joint stiffness or chronic ankle instability: A preliminary study

Abstract Objective to compare quantitative kinematic 4-D CT parameters between healthy volunteers and pathologic patients (joint stiffness or chronic ankle instability). Methods Thirteen healthy volunteers without previous ankle trauma, 18 patients with clinical subtalar joint stiffness and 10 patients with chronic ankle instability diagnosed based on clinical and imaging findings were prospectively evaluated with 4-D CT. This study was approved by the local ethics committee and all patients signed an informed consent. The subtalar joint was evaluated during a prono-supination cycle. Two angles and two distances between the talus and the calcaneus were measured semi-automatically and independently by two readers. Measurement variations were compared in these three different groups. Results There were statistically significant differences between axial and coronal talocalcaneal angles of healthy volunteers and patients with joint stiffness (p  Conclusion Quantitative analysis in 4D CT can provide an objective criteria for the differentiation between healthy volunteers and patients with subtalar joint stiffness and chronic ankle instability.