The effectiveness of arthroscopic synovectomy (A-S) for the knee of rheumatoid arthritis (RA) patients was assesssd by comparing the severity of synovial proliferation on MRI before and after the surgery. Twenty-five patients (30 knees) were studied. The mean duration of RA was 6 years and 7 months and the mean age at the time of A-S was 49.0 years. The mean follow-up period was 19 months (range:6-39 months). The preoperative Larsen's classification from grade Ⅰto Ⅳ was 8, 13, 6, and 3 knees, resectively. Synovial proliferation was evaluated by the modified Takeuchi's classification (MRI score). The MRI score was investigated in relationships with the radiographic grade, wet weight of excised tissue, treatment score for RA knees of the Japanese Orthopaedic Association (JOA score), and the CRP value. The MRI score, JOA score, and CRP all significantly improved during follow-up. The radiographic grade showed less progression, the JOA score improved more, and CRP was lower during follow-up in patients with a postoperative MRI score less than 5. The wet weight of excised tissue showed no related with the MRI score. These results suggest that the effectiveness of A-S can be determined by evaluation of improvement of the MRI score.
Magnetic resonance imaging