Semimembranosus-Tibial Collateral Ligament Bursa

The semimembranosus-tibial collateral ligament bursa is a U-shaped structure that wraps around the anterior expansion of the semimembnanosus tendon. It is positioned between the semimembranosus-gastrocnemius (cupcake in the diagram) and middle collateral ligament bursae superiorly and the pes anserinus bursa (Canada goose in the diagram) inferiorly. The semimembranosus-tibial collateral ligament bursa does not communicate the adjacent bursae or with the knee joint.

The U shape of the bursa (blue) is formed by deep and superficial arms. The deep arm (dotted line) is located between the semimembranosus tendon and the medial tibial condyle. The superficial arm (solid line) is located between the semimembranosus tendon and the medial collateral ligament (tibial collateral ligament). The two arms join along the anterosuperior margin of the semimembranosus tendon ("elbow").

Special thanks to Dr. Luke Yoon for the case.

References

• Demeyere N, De Maeseneer M, Van Roy P, Osteaux M, Shahabpour M. Imaging of semimembranosus bursitis: MR findings in three patients and anatomical study. JBR-BTR. 2003 Nov-Dec;86(6):332-4.
• Hennigan SP, Schneck CD, Mesgarzadeh M, Clancy M. The semimembranosus-tibial collateral ligament bursa. Anatomical study and magnetic resonance imaging. J Bone Joint Surg Am. 1994 Sep;76(9):1322-7.
• Rothstein CP, Laorr A, Helms CA, Tirman PF. Semimembranosus-tibial collateral ligament bursitis: MR imaging findings. AJR Am J Roentgenol. 1996 Apr;166(4):875-7.