this is a medial tibial plateau fracture with a split or depressed component. it is usually the result of a high energy injury and involves a varus force with axial loading at the knee. represent 10% of all tibial plateau fractures. there is high risk of damage to the popliteal artery and peroneal nerve and therefore carry a worse prognosis. may include distraction injuries to lateral collateral ligament, fibular dislocation/fracture, posterolateral corner.