Relationship of ankle joint involvement with subtalar destruction in patients with rheumatoid arthritis. A 20-year follow-up study

Aims. In the present study we evaluated radiographically involvement of the ankle joint and its relationship to destruction of the subtalar joint in r heumatoid arthritis (RA). Methods. An inception cohort of 103 patients with seropositive RA was followed over a period of 20 years. Follow-up examinat ions were conducted after onset, 1, 3, 8, 15, and 20 years from entry. A to tal of 83 patients attended the 15-year and 68 patients the 20-year follow- up. Radiographic evaluation was performed using a lateral weight-bearing an kle radiograph. A simplified grading was applied for the talocrural joint, in which the ankles (patients) were divided into three groups: no changes, minor changes and major changes. In the end-point analysis the last radiogr aph was assigned. Subtalar destruction was recorded (Larsen grade greater t han or equal to 2). Severity of RA in different groups was evaluated using the Larsen score of 0-100 of hands and feet. Difference between patient gro ups was evaluated using Cuzick's test. Results. At the endpoint major chang es of the ankles were detected in seven patients (7%) only, minor changes w ere observed in 17 patients (16%). The first minor involvement of the ankle was observed at the three-year follow-up in two patients. First major chan ges were detected at the 15-year follow-up in three ankles of two patients. Subtalar pathology preceded that of TC joint in all ankles with major chan ges. In 17 patients with minor changes, simultaneous subtalar pathology was observed in all but two ankles, while preceding subtalar involvement was r adiographically manifest in 13 of 21 ankles. The means of Larsen scores of 0-100 were in the three ankle grading groups 40, 54 and 63, respectively. C uzick's test for the trend was highly significant (P < 0.001). No reconstru ctive surgery was performed on the ankle joint during the follow-up, wherea s the subtalar joint complex was fused cumulatively in 12 patients. Conclus ions. The ankle joint is involved in a late stage of RA and is usually affe cted only in the patients with severe disease, Subtalar pathology precedes the changes in the talocrural joint almost regularly. Joint Bone Spine 2001 ; 68 : 154-7. (C) 2001 Editions scientifiques et medicales Elsevier SAS.