MRI of the knee in a 22-year-old athlete with a locked knee after a twisting injury shows a sagittal image with two triangular structures resembling two posterior cruciate ligaments in the intercondylar notch. The underlying lesion is:

• A Synovial chondromatosis of the knee joint
• B Complete rupture of the posterior cruciate ligament
• C Discoid lateral meniscus
• D Bucket handle tear of the medial meniscus ✓

Explanation

The double PCL sign is pathognomonic of a bucket handle tear of the medial meniscus: the displaced inner fragment lies in front of the true PCL in the intercondylar notch, mimicking a second PCL on the sagittal image. It accompanies mechanical symptoms such as locking. D torn PCL would appear attenuated or absent rather than duplicated, a discoid meniscus shows a thick bowtie appearance, and synovial chondromatosis produces multiple loose bodies rather than this single sign.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.