J Korean Soc Radiol.  2019 May;80(3):574-578. 10.3348/jksr.2019.80.3.574.

MRI Findings of Accessory Popliteus Muscle: A Case Report

• Hahn HJ
• Shim JC
• Kim KH
• Lee KE
• Hwang DH
• Lee GJ
• Kim HK

• KMID: 2454038
• DOI: http://doi.org/10.3348/jksr.2019.80.3.574

Abstract

Accessory muscles located in the region of the popliteal fossa are very rare. MRI scan performed in a 52-year-old man with right knee pain revealed an anomalous muscle in the region of the popliteal fossa. Considering the muscle originated from the medial side of the lateral head of the gastrocnemius muscle and attached to the posteromedial articular capsule of the knee joint, it is consistent with the accessory popliteus muscle, previously reported. To our best knowledge, MRI finding about the accessory popliteus muscle has been reported in only one case. We present a case of the accessory popliteus muscle incidentally identified on MRI.

MeSH Terms

Head
Humans
Joint Capsule
Knee
Knee Joint
Magnetic Resonance Imaging*
Middle Aged
Muscle, Skeletal
Muscles

Figure

• 

  Fig. 1 MR images of the accessory popliteus muscle in a 52-year-old man who presented with right knee pain. A. Axial intermediate-weighted TSE image (TR/TE, 4000/36) shows the accessory popliteus muscle (asterisk) originating from the medial side of the lateral head of the gastrocnemius muscle (arrow). B. At 10.5 mm below the level of (A), the accessory popliteus muscle (asterisk) passes anterior to the popliteal artery (arrow) within the deep popliteal fossa. C. Coronal intermediate-weighted TSE image (TR/TE, 4000/36) demonstrates the accessory popliteal muscle (asterisk) coursing in an inferomedial direction, parallel to the normal popliteus muscle (arrow). D. Sagittal intermediate-weighted TSE image (TR/TE, 4000/36) shows the accessory popliteus muscle (asterisk) inserting into the posteromedial articular capsule (arrow). TE = echo time, TR = repetition time, TSE = turbo spin echo A B

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