[Pigmented villonodular synovitis. Case reports and review of the literature].

Because this disease is so rare the optimum treatment of pigmented villonodular synovitis (PVNS), in particular the diffuse form differs in the literature. The most important surgical procedures are arthroscopic and open synovectomy. The prevention of disease progression, as well as joint destruction and dysfunction, depends upon the early diagnosis of PVNS. During 1994 and 1995, we treated four cases of PVNS surgically and followed the patients for a time period of more than 12 months. Two patients were treated with complete synovectomy, one patient underwent partial synovial resection, and in the final case an arthrodesis was performed. Our results indicate that an MRI is essential for diagnosis and treatment planning. For the localized form of PVNS, it appears that a partial synovectomy is appropriate. However, in the event of diagnostic uncertainty or obvious diffuse involvement of the synovium, a total synovectomy is indicated because of the high recurrence rate. In our study, all four patients had disease involving secondary bony lesions and, in one case, joint destruction. Based on our findings, it is clear that early surgical therapy is the only recommended curative intervention. The decision regarding the surgical approach, arthroscopic versus open, depends on the form of PVNS, the extent of the disease and secondary changes of the joint.