Isolated subtalar arthrodesis causes loss of ankle mobility

Objective: To evaluate and quantify, through physical examination, loss of ankle mobility in patients undergoing subtalar fusion, in comparison to the contralateral side. Methods: A total of 12 patients who underwent unilateral isolated subtalar arthrodesis for different conditions were selected. The assessment was performed with the aid of a goniometer, measurements of the bilateral range of motion of the tibiotarsal joint, in closed chain weight-bearing and open chain non-weight-bearing. The same foot and ankle surgeon performed all measurements. Results: The operated side achieved significantly lower range of motion values in the closed chain weight-bearing test compared to the contralateral side, with a mean difference of 5.4° (p=0.029) for dorsiflexion and 7.6° (p=0.006) for plantar flexion. No statistically significant difference was found in the open chain test. Conclusion: Isolated subtalar joint arthrodesis leads to reduced range of motion in the ipsilateral ankle. Level of Evidence III; Therapeutic Study; Comparative Retrospective Study.