Arthrography of the plica syndrome and its significance.

The plica is a synovial fold inside the knee joint that may become symptomatic if for any reason the fold is converted into a bowstring. In 42 patients with chronic knee problems, arthrograms of the knee were obtained with evidence of the plica syndrome. Twenty-four were asymptomatic, 18 symptomatic, and of these 16 were excised. After a mean follow-up period of 3 years, 10 of the symptomatic patients were free of symptoms, while eight were unchanged or worse. The plica syndrome is not common, and careful assessment must be made by exclusion with clinical examination, double-contrast arthrography, and arthroscopy.