Purpose: Rheumatoid arthritis (RA) frequently affects the finger joints. Persistent synovitis is believed to cause not only bone destruction but also various deformities of the hands. For this reason, synovectomy of the finger joints is attempted when chronic swelling of the synovium of finger joints does not respond to any conservative treatment. The purpose of this study is to evaluate the effectiveness of surgical synovectomy of finger joints in RA patients.

Method: Forty-six finger joints (MP 24; Steinbrocker Stage II: 8, Stage III: 16) (PIP 22; Stage I: 5, Stage II: 9, Stage III: 8) of 20 patients with rheumatoid arthritis who had synovectomy were examined at an average of 20 months follow-up (range 14–43 months). The active motion exercises of the operated fingers started as early as 2 or 3 days after surgery. The results of synovectomy in these patients were evaluated by pain, range of motion, and radiograph.

Results: Pain was relieved (Visual analogue scale MP: 6.5→1.4, PIP: 6.2→0.7), swelling was diminished in all and only a little loss of motion was observed (arc of motion MP: 59.8→53.4, PIP: 75.5→69.6) after surgery. Radiological bone changes progressed in 4 (17%) MP and 3 (14%) PIP joints. Deformities (ulnar drift or subluxation) after surgery developed in 3 (12%) MP-joints.

Conclusion: Synovectomy performed on finger joints of RA patients were evaluated. From the results of this clinical study we recommend synovectomy of finger joints in RA patients before bone changes, when chronic synovitis of finger joints does not respond to any conservative treatment.

Aims: The concept of balancing ßexion and extension gap during total knee arthroplasty (TKA) is reported to be crucial. However, difþculties in 1)deþning the ideal distraction force to create a gap, and 2)equalizing ßexion and extension gap are often encountered during TKA for rheumatoid arthritis (RA). This study was performed to analyze these difþculties biomechanically in vivo. Methods: 35 knee at randomly selected TKA for RA were studied as follows. After soft tissue balancing, distraction force for both gaps was applied by ligament balancer. Force was gradually increased with recording the length of the gap created by consecutive force, in order to obtain load-elongation curve for each case. Results: Load-elongation curve showed various patterns, indicating soft tissues including ligamentous structure has been altered its biomechanical property due to the variety of rheumatoid pathology. If ideal force for extension gap was determined at the point when low stiffness changes to high stiffness in the curve, it would be about 120–200N. This force differed reasonably in each case. However, measured ßexion gap curve hardly reached this force in more than 60% of the35 knee, presumably due to functional loss of posterior structures. Interestingly, this phenomenon was often unpredictable at examination before the operation. Conclusions: Ideal tension for þlling the gap with implant seems to be different in each case from load-elongation curve analysis. From this study, we raise question to the concept of equal ßexion and extension gap. This concept, although sounds attractive, is often difþcult to obtain in rheumatoid knee. This observation may suggest which type of TKA (þxed or mobile) is safer for replacing the rheumatoid knee.