Villonodular synovitis of the knee: a series of 17 cases

Purpose of the study Pigmented villonodular synovitis is a rare pathology found predominantly in the knee. We report management and treatment of 17 cases of pigmented vill onodular synovitis of the knee. Material and methods The mean follow-up was 9 years (maximum: 17 years). The diagnosis was alway s confirmed at histopathology. There were 12 women and 5 men. The average a ge at the initial symptoms was 28 years, Six cases were diffuse, 7 localize d and 4 cases were mixed. Results First treatment was only arthroscopic in 8 cases, and open synovectomy in 6 cases and mixed in 2 cases, Six patients had a recurrence, one had more th an one recurrence. The mean delay for recurrence was 2 years and 5 months, Loss of range of motion was noted in 6 cases, For these 6 cases, flexion wa s always greater than 90 degrees and flessum always inferior to 10 degrees. Discussion Ethiopathogeny of this desease is unclear and no etiopathogenic theory is d efined. Magnetic resonance imaging is useful for diagnosis, and absolutely necessary for preoperative tumor localization, and also for survey. In loca lized types, arthroscopic synovectomy can be performed with success but in diffuse or mixed form an open synovectomy must be performed according to th e high rate or recurrence observed after incomplete synovectomy, Synoviorth esis with Yttrium 90 seems to be a good adjuvant for the treatment of recur rent pigmented villonodular synovitis. Conclusion Arthroscopy is the treatment of choice for localized forms, We propose a mi xed concept with an anterior and parameniscal arthroscopic synovectomy (wit hout meniscectomy), an open synovectomy for the posterior localization, and an open anterior synovectomy when the tumor mass is too voluminous.