Results of the Gravity Stress Examination in the Normal Patient Population

In ankle fractures, the result of a gravity stress radiographic examination is clinically used to determine if a patient may need surgical intervention. The purpose of this study is to report the results of a gravity stress examination in the normal patient population. Fifty study participants were prospectively enrolled and complete ankle radiographs were obtained, including a nonweightbearing gravity stress examination. The mean medial clear space in the gravity stress view was 3.6 mm. This compared to a mean medial clear space of 3.3 mm, and 3.1 mm in the anteroposterior and mortise views. These values were statistically significantly different from the gravity stress view (  P = .006 and P < .001, respectively). There was no statistically significant difference between the talar tilt as measured on the anteroposterior and gravity stress radiographs (  P = .22). No participant had medial clear space widening with gravity stress to more than 5.2 mm or an increase in their widening by more than 0.2 mm. In conclusion, this study helps guide surgeons by providing normative radiographic data for a gravity stress examination and supports the notion that measureable medial clear space widening or talar tilt on gravity stress examination represents an unstable injury.

Level II: Prospective.