Age / Sex : 54 / F

Chief complaint: Right knee pain

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

(답안은 한 개만 보내주시기 바랍니다)

Courtesy: 김선정 (Seon Jeong Kim), 인제대학교 해운대백병원 (Inje University Haeundae Paik Hospital)

Anterior meniscofemoral ligament of medial meniscus (anteromedial meniscofemoral ligament)

Discussion

Findings:

Linear dark signal intensity band-like structure is seen at intercondylar notch, parallel to ACL on T2-SPIR sagittal image. It arises from the anterior horn of medial meniscus and extends along the superior surface of ACL to medial cortex of lateral femoral condyle, just anterior to ACL.

Differential Diagnosis:

Displaced meniscal fragment (on coronal image)

Intact ACL (in case of ACL rupture)

Infrapatellar plica (ligamentum mucosum)

Diagnosis:  

Anterior meniscofemoral ligament of medial meniscus (anteromedial meniscofemoral ligament)

Discussion:

Anomalous insertion of the anterior horn of the medial is rare. Anterior meniscofemoral ligament of medial meniscus is the rarest form of the anomalous insertion (0.44%).

It consists of an anomalous fibrous band distinctly covering the all length of the anterior cruciate

ligament to attach the anterior horn of the medial meniscus to the posterolateral wall of the femoral intercondylar fossa.

Clinical significance and treatment of this lesion have been still controversial: some authors suggested that this lesion was related to knee pain and many patients were relieved after resection, but the others disagreed to that.

References:

1. Coulier B1, Himmer O. Anteromedial meniscofemoral ligament of the knee: CT and MR features in 3 cases. JBR-BTR. 2008 ;91(6):240-4.

2. Anderson AF, et al. The anterior meniscofemoral ligament of the medial meniscus: case series. Am J Sports Med 2004;32:1035-40.

3. Soejima T, et al. Anteromedial meniscofemoral ligament. Arthroscopy 2003;19:90-5.

4. Nakajima T, et al. Symptomatic anomalous insertion of the medial meniscus. Arthroscopy 2005;21:629.