OBJECTIVE Stabilization of the syndesmotic complex by open reduction and internal fixation (ORIF) of the posterior malleolus, restoration of the tibial articular surface, stability of the ankle, posterior tibiofibular ligament and the incisura tibiae, reduction of the fibula into the incisura tibiae by ligamentotaxis. METHODS Unstable ankle fractures (OTA/AO type 44-B3, C1.3, C2.3, C3.3) with involvement of the posterior malleolus (type II-IV according to Bartoníček and Rammelt). METHODS Critical general condition, circulatory disorders, severe soft tissue swelling (if necessary, first external fixator), percutaneous treatment the better alternative. METHODS Positioning in unstable lateral position, dorsolateral approach dorsally of the peroneal tendons, incision of the superficial and deep fascia, retraction of the flexor hallucis longus tendon medially, visualization of the posterior malleolus, reduction and fixation. To treat the lateral malleolus fracture, preparation of a full-thickness flap above the peroneal tendons on the fibula, treatment according to AO principles. For the treatment of the medial malleolus positioning in supine position without changing the sterile covers, medial approach for the medial malleolus, wound closure. METHODS Six weeks partial weight bearing (20 kg), early functional exercise, exercise of the flexor hallucis longus muscle; transition to full weight bearing after clinical and radiological follow-up after 6 weeks RESULTS: Few clinical results on open ORIF of the posterior malleolus have been published. However, most studies found that ORIF resulted in better reconstruction of the distal articular surface and the tibial incisura, better reduction of the fibula into the tibial incisura, stabilization of the distal tibiofibular joint and better clinical results, regardless of fragment size, when compared to closed reduction or untreated fragments.