On MRI of the knee, the 'double PCL sign' is pathognomonic of which injury?

• A Complete posterior cruciate ligament tear
• B Anterior cruciate ligament avulsion
• C Lateral meniscus discoid variant
• D Bucket-handle tear of the medial meniscus ✓

Explanation

The 'double PCL sign' on sagittal MRI occurs when the flipped, displaced meniscal fragment of a bucket-handle tear comes to lie inferior and parallel to the posterior cruciate ligament, creating the appearance of two PCL-like structures. This is a reliable secondary sign of bucket-handle meniscal tear. A torn PCL itself appears thickened or discontinuous, not duplicated. ACL avulsion and discoid meniscus have distinct MRI appearances.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.