Arthroscopic Classification of Suprapatellar Plica and Medial Synovial Plica

In the previous arthroscopic studies, the ratio of presence and type of plica was somewhat different. We arthroscopically investigated and classified suprapatellar plica and medial synovial plica in a Japanese population. Subjects and Methods: The anatomy of suprapatellar plica and medial synovial plica was studied arthroscopically in 130 knees. Original diagnosis of patients included in this study were 53 meniscal injuries, 51 ACL injuries, 17 osteoarthritis, 5 popliteal cysts, 3 osteochondritis dissecans, and 1 synovial osteochondromatosis. Results: The suprapatellar plica was present 73.8% and classified into 6 types which were arch type, medial type, lateral type, perforated type, pillar type and complete type. The medial synovial plica was present 62.3% and classified into 4 types which were narrow type, medium type, broad type and perforated type. No relationship between age and the pattern of the suprapatellar plica or medial synovial plica could be found. There was no trend to be correlation between the type of suprapatellar plica and medial synovial plica. Conclusion: We classified suprapatellar plica by only location and shape of plica and medial synovial plica by the size of plica.