Quadruple PCL Appearance: An Undescribed MRI Sign of Bucket-Handle Tear?

Clinical Findings:

A 40-year-old male patient presented with severe knee pain and locking following a knee trauma sustained during an amateur soccer match.

MRI Findings:

On sequential sagittal fat-suppressed proton density images obtained from lateral to medial, a complete tear of the anterior cruciate ligament (yellow arrows) is identified. At the level of the posterior cruciate ligament (PCL), a previously undescribed imaging sign—the quadruple PCL sign—is observed (blue arrow: posterior cruciate ligament; green arrow: Humphrey ligament; white arrows: displaced and folded meniscal fragments).

Coronal images demonstrate displacement of the medial meniscus into the intercondylar region, consistent with a bucket-handle tear. On axial images, the characteristic “V sign”, also suggestive of a bucket-handle tear, is present (white arrows).

The double PCL sign is a well-established MRI finding seen in approximately 80% of bucket-handle meniscal tears. A triple PCL sign has been reported in case studies involving simultaneous medial and lateral bucket-handle tears. However, the quadruple PCL sign observed in this case has not been previously described in the literature. This appearance likely results from a combination of the intact posterior cruciate ligament, a preserved Humphrey ligament, and displaced/folded meniscal fragments.

We recommend thorough evaluation for possible bucket-handle tears in cases where more than two PCL-like structures are observed on MRI. It is also important to consider that the meniscofemoral ligaments—Humphrey and Wrisberg—may contribute to this imaging appearance.