Arthroscopic evaluation of synovitis in the knee joints.

It is not always easy to diagnose certain types of monoarthritis of the knee joints. In such cases, it is essential to evaluate the condition of the synovitis both macroscopically and microscopically, as the synovial appearance (synovitis) closely reflects the pathological condition (arthritis) of the knee joints. Arthroscopy is an excellent tool for visualizing and evaluating the condition of the synovium macroscopically. On arthroscopic examination, precise evaluation of the villi often provides clues, enabling accurate diagnosis. In addition, histological sections obtained from biopsy specimens in various cases of synovitis give significant information. In this article, arthroscopic observation and histological sections of various cases of synovitis are compared, and the diagnostic value and limitations of arthroscopic examination are discussed.