Background Foot involvement is highly prevalent in early RA yet little is understood about the relationship between joint inflammation and damage and foot related impairment and disability .
Objectives To investigate the relationships between foot-related impairment/disability and ultrasound features of joint and tendon inflammation and damage, and clinical indices for pain, function and deformity in early RA.
Methods Patients with early RA attending two regional early arthritis clinics were recruited. Foot related impairment and disability were assessed using the impairment/footwear (FIS-RAIF) and activity/participation (FIS-RAAP) subscales of the FIS-RA scale. Ultrasound imaging was used to dichotomously score joint effusion, synovitis, erosion and power Doppler signal at the ankle, subtalar, talonavicular, calcaneo-cuboid, metatarsophalangeal and inter-phalangeal joints. Tenosynovitis was scored in the tibialis posterior and anterior, peroneal, flexor and extensor tendons. Cumulative scores for both clinical and ultrasound features were calculated for joints (0-28) and tendons (0-14) in both feet. DAS28, HAQ and tender and swollen joint counts of the foot were recorded. Structural deformity was measured using the structural index and gait analysis was used to measure walking speed, peak pressures and contact areas on the plantar foot region.
Results Forty-four early RA patients (33 female/11 male) with a mean ±SD age of 53.1±13.7 years and disease duration of 10.6±8.3 months were studied. 75% of patients were receiving methotrexate and 5% biological therapy. The mean ±SD score for the FIS-RAIFwas 9.9±5.4 and for the FIS-RAAP was 13.82) was 108±75. For FIS-RAIFthere were statistically significant correlations with DAS28 (r=0.357, p=0.03), HAQ (r=0.386, p=0.02), tender joint counts (r =0.44, p=0.01), and tender/swollen tendons (r=0.334, p=0.04). For FIS-RAAP there were statistically significant correlations with DAS28 (r=0.472, p=0.003), HAQ (r=0.751, p<0.001), deformity in the rearfoot (r=0.337, p=0.04), and walking speed (r=-0.336, p=0.04).
Conclusions In this early RA group foot-related impairment and disability are associated with global measures of disease activity and functional disability, deformity in the rearfoot, and clinical indices of joint and tendon swelling and tenderness but not ultrasound detected features.
van der Leeden M et al. 2008. Arthritis Rheum.59:1596-1602
Disclosure of Interest L. Newcombe: None Declared, J. Woodburn: None Declared, D. Porter: None Declared, S. Saunders: None Declared, D. McCarey: None Declared, M. Gupta: None Declared, D. Turner Grant/Research support from: Arthritis Research UK (ref: 17832)