At the Viewbox: Double Segond Fracture

Frontal supine radiograph demonstrates an osseous avulsion along the medial tibial plateau (yellow arrow, Figure A), as well as a more subtle avulsion fracture, a Segond fracture, along the lateral tibial plateau (red arrow, Figure A). What is the avulsion fracture at the medial tibial plateau and its significance?

The “reverse Segond fracture” represents cortical avulsion caused by a tug injury from deep fibers of the medial collateral ligament (MCL) at their attachment to the medial tibial plateau.¹ This fracture is associated with posterior cruciate ligament (PCL) injury and medial meniscal tears, the reverse pattern of conventional Segond fractures.² MRI demonstrates soft-tissue injuries associated with both a Segond fracture (anterior cruciate ligament [ACL] tear - arrow, Figure B) and a reverse Segond fracture (PCL tear - arrow, Figure C). The patient also had a high-grade posterolateral corner injury (not shown).

To our knowledge, this is the first reported case of a double Segond fracture (simultaneous Segond and reverse Segond fractures). In addition to the capsular avulsion fractures of the lateral and medial tibial plateau, the patient had additional findings associated with both injuries. Specifically, there were ACL and lateral meniscal tears (Segond complex), as well as PCL and medial meniscal tears (reverse Segond complex). Knowledge of knee avulsion fractures can help in identifying associated significant soft-tissue injuries.

References

1. Escobedo EM, Mills WJ, Hunter JC. The “reverse Segond” fracture: association with a tear of the posterior cruciate ligament and medial meniscus. Am J Roentgenol 2002;178(4):979-983.
2. Gottsegen CJ, Eyer BA, White EA, et al. Avulsion fractures of the knee: imaging findings and clinical significance. Radiographics 2008; 28(6):1755-1770.