this is a combined cleavage and compression fracture and involves vertical split of the lateral condyle combined with depression of the adjacent load bearing part of the condyle. caused by a valgus force on the knee; it is a low energy injury, typically seen in individuals of the 4th decade or older with osteoporotic changes in bone. most common, and make up 75% of all tibial plateau fractures. there is a 20% risk of distraction injuries to the medial collateral ligament. may include distraction injury to the medial collateral ligament or anterior cruciate ligament.