Suprapatellar Plica

Case details: 17 year old male complaints of anterior knee pain with no definite trauma, MRI suggests low signal intensity cord like tortuous structure in the suprapatellar compartment  extending into the femoropatellar joint space - could represent suprapatellar plica.

Teaching points by Dr MGK Murthy, Mr Hari Om, Mr Usman :

1. Knee develops from three separate compartments and the mesenchymal condensans as fore runners of menisci, cruciates  and others in various locations could persist as embryological remnants and represent plicae.

2. Various locations are considered classical for the presence of plicae - suprapatellar (superior patellar)  (commonest),  medial patellar,  infrapatellar  and lateral (least common) (less than 1 %) of all plicae MR. Appears as ridge or  strand to cord like an appearance on all pulse sequences.

3.  Better appreciated in axial plane on arthrogram (plain MR shows on sagittal projection better). 90percent of the adults may show these plicae. However if anterior knee pain is the presenting feature the presence of pliace assumes etiology.

4. May lead to chondromalacia patellae in some. Inflammation / impingement of the structures are other complications.