Diagnosis is made by standard ankle X rays.  These films should be examined so not to miss a subtle associated fracture to the medial or posterior malleolus, which would indicate a more unstable injury.

     The physician may be called upon to perform a stress view of the ankle to assess ankle stability: 

• This is performed by stabilizing the leg with one hand while the other hand grasps the great toe and everts the foot while an AP film is taken. 
• Widening of the medial joint space on a stress view compared to the non-stress view signifies an unstable ankle mortise (see blue circle on image).