Result of arthroscopic treatment of pigmented villonodular synovitis of the knee.

PURPOSE:
We report 10 years' experience in arthroscopic treatment of pigmented villonodular synovitis (PVNS) of the knee in a series of patients affected by the localized or diffuse form of the disease. The purpose of the study is to critically examine the results of arthroscopic synovectomy in the knee affected by PVNS, to determine the safety and effectiveness of the procedure.

TYPE OF STUDY:
Retrospective case analysis.

METHODS:
The study population consists of 19 patients, with an average follow-up of 60 months (minimum, 12; maximum, 128). All patients underwent knee arthroscopy. The 3 standard portals were used; posteromedial and posterolateral portals were added if required. Four patients were affected by localized PVNS and were subject to partial synovectomy with excision of the pathologic tissue. The remaining 15 patients presented a diffuse form of PVNS; 7 of them underwent extended arthroscopic synovectomy and 8 underwent partial synovectomy. The diagnosis was confirmed by synovial biopsy.

RESULTS:
In the group affected by the localized form of PVNS, the arthroscopic local excision resulted in a complete and persistent regression of the pathology. Among the patients affected by the diffuse form of PVNS, clinical results were better and the recurrence rate was lower in the group treated with extended synovectomy. No relevant complications were encountered. In particular, no cases of infection, stiffness, or neurovascular lesions were seen.

CONCLUSIONS:
Arthroscopic synovectomy is an appropriate treatment for knee PVNS. Extended synovectomy must be performed in all cases of diffuse PVNS.