Avulsion fracture of the medial collateral ligament association with Segond fracture.

The Segond fracture is a tibial avulsion injury of the insertion of the middle third of the lateral capsular ligament that is typically associated with anterior cruciate ligament and meniscal tears. The classically assigned mechanism of injury is a combination of internal rotation and varus stress. We report two cases of Segond fractures that presented with a variant pattern including osseous avulsion injuries of the medial collateral ligament at the femoral origin, anterior cruciate ligament tear, and pivot shift-type osseous contusion pattern, suggesting an alternative mechanism of injury that includes dominant valgus stress and external rotation components. Awareness of this pattern may aid radiologists, surgeons, and sport medicine physicians in the accurate diagnosis of this injury complex and initiation of appropriate treatment in a timely fashion.