TOTAL KNEE ARTHROPLASTY IN PATIENTS WHO HAVE PIGMENTED VILLONODULAR SYNOVITIS

We reviewed the results of all eighteen total knee arthroplasties that had been performed at the Mayo Clinic between 1974 and 1992 for the t reatment of pigmented villonodular synovitis. The diagnosis had been c onfirmed histologically in all patients, Fourteen patients had diffuse disease, which was active in eleven and inactive in three, and four h ad focal disease. In addition to the arthroplasty, the eleven patients who had active diffuse disease were managed with a complete synovecto my and the four patients who had focal disease had a partial synovecto my. The three remaining patients had a history of diffuse pigmented vi llonodular synovitis but had no evidence of disease at the time of the arthroplasty, so a synovectomy was not performed. At an average of 9. 9 years (range, 3.6 to 20.1 years) after the arthroplasty, fourteen of the eighteen total knee prostheses were well fixed and functioning sa tisfactorily. The average knee score was 89 points (range, 80 to 99 po ints) and the average functional score was 77 points (range, 20 to 100 points) for these fourteen patients. The four failures were in patien ts who had active diffuse disease at the time of the arthroplasty. Thr ee of the failures were due to aseptic loosening, and one was due to r ecurrence of the disease. Sixteen patients had no evidence of recurren ce when they were last seen, at an average of 10.3 years (range, 3.6 t o 20.1 years) after the arthroplasty. The two patients who had a recur rence were among the eleven who had active diffuse disease. In one of these patients, the recurrence was diagnosed at the time of a revision arthroplasty performed because of aseptic loosening. The other patien t had two recurrences, necessitating an above-the-knee amputation.