ABSTRACT
Pigmented villonodular synovitis (PVNS) of the knee is a benign but locally aggressive
disease of synovial proliferation that occurs in localized nodular and diffuse villous
growth patterns. Although inflammatory and neoplastic causes have been hypothesized,
etiology remains unknown. Presenting as unilateral knee pain and swelling, PVNS mimics
other knee ailments. Radiographs are often unremarkable, whereas magnetic resonance
imaging may show characteristic intra-articular masses with signal dropout on T2-weighted
sequences. Pigmented villonodular synovitis is surgically treated with open or arthroscopic
total or partial synovectomy. High recurrence rates are associated with all treatments
of diffuse PVNS. Complications of open synovectomy include arthrofibrosis and wound
breakdown. Total arthroscopic synovectomy is technically demanding but can be advantageous.
Transcondylar notch views, accessory posterior portals, and the posterior transseptal
portal maximize arthroscopic access to the posterior knee. Intra-articular radioisotope
injection and external beam radiation may be beneficial adjuvant therapy for extensive
diffuse and recurrent PVNS of the knee.
