[Villonodular synovitis of the knee].

The authors report the main results of a study of 12 cases of villous nodular synovitis of the knee. The distribution according to age and sex is in agreement with the data in the literature. The delay between the first sign and the first consultation was, on average, 1.5 years, varying from a few days to 12 years. This long history is due to the usual mildness of the symptoms. The delay between the first consultation and the diagnosis, less variable is, on average, 6 months; this is due to difficulty in diagnosis. More than the extent of the lesions, it seems that the macroscopic appearance dictates the symptoms: villous synovitis or sessile villonodular synovitis, whether diffuse or partial, manifests itself mainly by serous blood-stained effusions; pediculated nodular synovitis, diffuse or localised, is characterised by symptoms on movement. Straight X ray was negative in all the cases reported here. Arthrography gave the diagnosis in 6 of the 9 cases where it was carried out. Arthroscopy was the best examination; in all cases where it was carried out, the macroscopic appearance of the synovial membrane permitted the diagnosis which was confirmed by biopsy under direct vision. Synoviorthesis may give good results, especially radio-isotopic synoviorthesis.