[Synovectomy of the knee joint].

PURPOSE OF THE STUDY: In this retrospective study, the results of arthroscopic and open synovectomy and radiosynovectomy with the use of Yttrium-90 colloid are evaluated. MATERIAL: In a group of 48 patients with different underlying diseases, 51 knee joints were treated by synovectomy in the years 1996 to 2001. Of these, 16 knees were treated by arthroscopic synovectomy (ASS group), nine by open synovectomy (OS group) and 26 by Yttrium 90 radiosynovectomy (YR). The average age was 67 years (range, 30 to 81) and average follow-up was 18 months. The patients' diagnoses involved grade I, II and III gonarthritis in three, 21 and 15 cases, respectively, Lyme disease in one patient, gouty arthropathy in one, rheumatoid arthritis in three and pyogenic arthritis in seven cases.
METHODS: The evaluation was based on three aspects as follows: Subjective feelings of the patient: A, no complaints; B, intermittent complaints; C, no improvement. Joint function and range of motion on clinical examination: A, full function; B, slight motion restriction; C, severe restriction. Recurrence of synovitis: A, no recurrence; B, intermittent and short-term recurrence; C, no improvement.
RESULTS: The ASS group showed a high recurrence rate, with no improvement in 44% of the patients. No recurrence was recorded in the OS group. In the patients treated for pyogenic arthritis, 40% had a slight and 40% a severe restriction of joint motion, which is an alarming outcome. In the YR group, radiosynovectomy was effective particularly in the patients with grade I and grade II gonarthritis. DISCUSSION: In our groups, only a low number of patients were diagnosed with rheumatoid arthritis, in contrast to the relevant studies mostly including patients with this disorder. However, the high recurrence rate in our ASS group is in agreement with the results of other authors. In comparison to open synovectomy, with no recurrence of synovitis, arthroscopic synovectomy is less radical and does not involve the fibrous capsule. Therefore, the remaining areas of the synovial membrane may give rise to recurrent synovitis.
CONCLUSIONS: Arthroscopic synovectomy is a minimal invasive but demanding surgical procedure associated with a high recurrence of synovitis. Open synovectomy is a radical intervention with minimum recurrences but is associated with a risk of a restricted range of motion if healing is not complete. It is not suitable for treatment of pyogenic arthritis. Radiosynovectomy is a safe and economic method, with no need of subsequent rehabilitation, which is effective in patients with a milder form of synovitis.