Presentation
Painful right knee
Patient Data
Torn lateral meniscus with superomedial and posterior flipped anterior horn. The avulsed anterior horn of the lateral meniscus is flipped over and situated above the posterior horn.
Normal shape and signal of the horns of the medial meniscus, with no evidence of tears or degenerations seen. Normal course and intensity of both cruciate ligaments.
Abundant effusion.
Suprapatellar plica noticed, with no related cartilaginous erosions.
Case Discussion
MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. This case features the following signs of meniscal tear:
- absent bow tie appearance of the lateral meniscus
- ghost meniscus: empty location of the anterior horn of the lateral meniscus
- disproportionate posterior horn sign: avulsed anterior horn of the lateral meniscus that is flipped over and situated above the posterior horn
- flipped meniscus sign or flipped fragment sign
Case courtesy, Prof. Dr. Khaled Matrawy, Professor of radiology, Alexandria university, Egypt.