Radiology Imaging, Diagnostic Imaging, Medical Imaging News, Education, Resources

38 yo M, hurt skiing
Initial findings? Justification for further imaging?

Additional Imaging
Findings on T1 image?
Findings? What additional abnormalities are suspected, if any?

                      T1W1                          FSE Fat sat (farther lateral)

Findings so far? Any additional concern (s)?
Representative Images in the Notch
Any other injury you should specifically look for?

Additional Findings (separate patient)
Summery of all findings & Dx for this case?

ACL Tear & Associations

• Initial (film) images most importantly showed an avulsion fracture from the lateral portion of the proximal tibia. Marked bone edema at this site was confirmed on the MR images.
• This is Segond Fracture, and represents an avulsion of the lateral capsular ligament. It occurs posterior to Gerdy’s tubercle.
• It is important to diagnose this fracture because it is associated with an ACL tear in 75-100%, and a meniscal tear in 67%!

• Additional MR images demonstrate “Kissing Contusions” in the lateral portions of the distal femur and proximal tibia. Seen in > 50% of ACL tears (specific but not highly sensitive).
• Images through intercondylar notch show a large amount of fluid/edema with non-visualization of the ACL: c/w tear.
• Other indirect signs (not shown) include anterior displacement of the tibia (anterior drawer sign) and PCL bowing.
• The ACL is the most commonly injured of the major ligaments in the knee.

Related Findings

• Final images for this case (from a different patient) showed a tear of the medial collateral ligament & the medial meniscus.
•  In conjunction with an ACL tear, this represents the “Terrible Triad of O’donoghue”
• Classically seen as “clipping injury” from football (valgus/abduction type injury)