The indications for surgical treatment of ankle instability include:

complete rupture of ligaments with acute instability of the ankle joint, which seriously disrupts biomechanics and prevents the patient from returning to normal activity,
another habitual ankle sprain, which could not be brought about by conservative treatment to a state in which the patient could function freely without pain symptoms,
chronic mechanical instability, when conservative treatment does not bring the results expected by the patient, e.g. alleviating pain,