The surgical tibiotalar angle: A radiologic study

Background., Many studies on cadaver specimens describe the hindfoot anatomy, but few measures have been defined and quantified on radiographs. Our aim was to determine the tibiotalar angle using the tibial tuberosity as a reference point. Methods: The tibiotalar angle, using the tibial tuberosity as reference point, was measured on anteroposterior views of 168 ankles. Bilateral radiographs were obtained in 75 patients. Results: The tibiotalar angle was 92.4 degrees (SD = 3.1) without significant intraindividual difference on the radiographs examined bilaterally. More varus was found in women and with increased age. Conclusions: The tibial tuberosity is a reliable reference point for the measurement of the tibiotalar angle and is used in numerous operative procedures of the hindfoot. If the angle cannot be measured because of progressed destruction, the measurement can be obtained from the contralateral leg, as no significant intraindividual difference was found in the tibiotalar angle (p < 0.001).