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 villonodular synovitis of the knee.
Material and methods: The mean follow-up was 9 years (maximum: 17 years). The diagnosis was always confirmed at histopathology. There were 12 women and 5 men. The average age at the initial symptoms was 28 years. Six cases were diffuse, 7 localized 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 than 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 was always greater than 90 degrees and flessum always inferior to 10 degrees.
Discussion: Ethiopathogeny of this disease is unclear and no etiopathogenic theory is defined. Magnetic resonance imaging is useful for diagnosis, and absolutely necessary for preoperative tumor localization, and also for survey. In localized types, arthroscopic synovectomy can be performed with success but in diffuse or mixed form an open synovectomy must be performed according to the high rate or recurrence observed after incomplete synovectomy. Synoviorthesis with Yttrium 90 seems to be a good adjuvant for the treatment of recurrent pigmented villonodular synovitis.
Conclusion: Arthroscopy is the treatment of choice for localized forms. We propose a mixed concept with an anterior and parameniscal arthroscopic synovectomy (without meniscectomy), an open synovectomy for the posterior localization, and an open anterior synovectomy when the tumor mass is too voluminous.