The infrapatellar plica is one of 4 plicas in the knee:

• Medial Patella Plica.

• Suprapatellar Plica.

• Infrapatellar plica.

• Lateral Patellar plica.

• Attaches to anterior intercondylar notch and inferior pole patella.

• Runs through Hoffa's Fat Pad.

• In the joint the infrapatellar plica runs superior and parallel to ACL.

• • The normal appearance of the infrapatellar plica on MRI varies.

   

  • You may not see it at all (most common).

   

  • Or you may see a thin curvilinear region of lower signal running through Hoffa's fat as in the image.

   

  • There should be no high signal seen on STIR/ T2FS along the course of the infrapatellar plica.