Abstract: | The paper is concerned with an analysis of the results of arthroscopy of the knee joint in 5 patients with pigmented villonodular synovitis (PVNS). Pathognomonic arthroscopic signs of PVNS like change in the coloring of the synovia, a typical "shaggy" appearance of the synovia, pasty consistence of villi without a vascular pattern were revealed. A conclusion was made that arthroscopy was the most effective method of PVNS diagnosis including the early stage. |