Combined partial arthroscopic synovectomy and radiation therapy for diffuse pigmented villonodular synovitis of the knee.

We present the results of combined partial arthroscopic synovectomy and low-dose external-beam radiation therapy (RT) in the treatment of diffuse pigmented villonodular synovitis (PVNS) of the knee. Mechanical synovectomy is an effective tool in treating PVNS of the knee, but when used alone it may be insufficient to eliminate all affected tissue. Intra-articular radiation or external-beam radiation may be added to mechanical synovectomy to treat recurrence but is not routinely done at the time of initial synovectomy. Combining intra-articular synovectomy with RT at the initial treatment for PVNS of the knee may reduce the recurrence rate. We present a prospective study of the treatment of 22 patients with clinical, ultrasonic, and histologically confirmed findings of diffuse PVNS of the knee. Characteristic clinical findings included pain, swelling, and erythema. These patients were treated by the Arthroscopic Surgery Group of the Orthopaedic Service at the Hospital "Hermanos Ameijeiras" in Havana, Cuba from 1990 to 1998. The protocol included anterior (patellofemoral, medial, and lateral) arthroscopic synovectomy and postoperative RT with a total dose of 2,600 cGy. This combination therapy was effective in reducing symptoms of pain and edema, and in improving overall function of patients. Nineteen patients (86%) had good or excellent results at an average follow-up of 33 months (range, 26 to 76 months). Three patients had residual stiffness and swelling, 2 of whom also had pain. Three had clinically and ultrasonically confirmed recurrence of disease and were treated with repeat arthroscopic synovectomy without harmful effects from RT. In all of the cases requiring repeat arthroscopic synovectomy, we observed fibrous bands secondary to reorganization of synovial inflamed tissue, meniscal retraction, and microscopic findings of fibrosis and cellular paucity. Partial arthroscopic synovectomy combined with low-dose RT in anti-inflammatory doses produced good results in the treatment of PVNS without significant complications in our patient series. Partial arthroscopic synovectomy of the knee for PVNS may be combined with RT to reduce the risk of disease recurrence. Adjuvant RT should also be considered for patients receiving a radical synovectomy to treat inaccessible or hidden disease sites. Rates of recurrence with combined partial (anterior) synovectomy and RT approach that of complete synovectomy in this series. Combining RT with radical arthroscopic synovectomy might further reduce recurrence rates.