Pseudomasses in the suprapatellar pouch at arthrography

An arthrographic appearance, confidently diagnosed as synovial chrondromatosis, showed no abnormality at surgery. This experience prompted further investigation which led to the conclusion that a normal variant of the suprapatellar pouch may be confused with synovial masses. Single or multiple pseudomasses in this region may relate to the presence of an embryonic remnant of the synovial folds, the plicae synovialis. If the finding is looked for, with careful arthrographic technique and palpation under fluoroscopic control, along with correlation with the clinical findings, unnecessary arthrotomy may be avoided.