Imaging Case of the Week 128

These left knee x-rays are from a 20 year old who has twisted his knee and is complaining of knee pain and swelling. What 3 abnormal features can you note on the image provided?


Left knee APLateral knee x-ray

[peekaboo_link name=”Answer”]Answer[/peekaboo_link] [peekaboo_content name=”Answer”]


The 3 abnormal features on the knee x-ray are:

1. Segond fracture: there is a small curvilinear bone fragment lying lateral to the lateral tibial plateau.

2. Compression injury to the lateral femoral condyle on the lateral x-ray

3. Knee effusion

Segond fractureKnee effusionSegond fracture is a fracture associated with an internal derangement of the knee. A small bony fragment is pulled off the posterior lateral tibial joint line by an avulsion of the lateral joint capsule; this is almost always associated with an ACL tear. The presence of a compression injury to the lateral femoral condyle is also commonly seen with an ACL tear.

This patient should have his knee immobilised in a splint and referred to an orthopaedic specialist.

Reference: Fundamentals of Diagnostic Radiology by Brant and Helms, 4th edition




3 thoughts on “Imaging Case of the Week 128

  1. Hi.

    Segond fracture and knee effusion.

    ??suprapatellar effusion too.

    Can’t figure out if there’s another abnormality.

    • Hi Simon,

      Thank you for your query. You can view the answer at the end of the post. The 3rd abnormality is the compression type injury to the lateral condyle of femur which is also seen in association with an ACL tear. When the dent is more pronounced, it is referred to as the lateral condylar notch sign.


Comments are closed.