POS0549 FUNCTIONAL IMPACT OF FOREFOOT INVOLVEMENT IN RHEUMATOID ARTHRITIS
Authors: K. Maatallah, H. Boussaa, H. Riahi, H. Ferjani, W. Triki, M. Habechi, D. Ben Nessib, M. Bouaziz, D. Kaffel, W. Hamdi
Journal: Annals of the Rheumatic Diseases (2021)

Background: Rheumatoid arthritis (RA) is a chronic inflammatory disease that mainly affects small joints of the hands and feet. Foot deformities may affect the patient’s gait, thus compromising their daily activities and autonomy. Objectives: The aim of this study was to analyze its functional impact. Methods: We conducted a cross-sectional study including patients diagnosed with RA according to the ACR/EULAR 2010 criteria. Demographic variables, Foot Function Index (FFI), and Health Assessment Questionnaire (HAQ) scores were analyzed. We collected data on the following clinical variables: The pain Visual Analog Scale (VAS), forefoot deformities, erythrocyte sedimentation rate (ESR), and Disease Activity Score 28 (DAS28). All patients had feet X-rays and the Larsen score was calculated. A blinded radiologist experienced in musculoskeletal imaging using a Philips HD11 device with a high-frequency linear transducer performed ultrasonography (US) of MTP joints. Synovitis was defined as an abnormal hypoechoic synovial tissue within the capsule that is not displaceable and poorly compressible and that may exhibit Doppler signals. The composite synovitis score (power doppler / grayscale ultrasound (PDUS)) was measured for each joint. The US score of each patient was defined by the sum of the composite scores of the joints studied (0-30). A p-value &lt;0.05 was considered significant. Results: We included 31 patients (25 men and six women) with a mean age of 54.8±10.8 years old [32-70]. The mean disease duration was 8.5±7.2 years [1-37]. The mean ESR and DAS28 ESR were 33±26 mm [5-102] and 3.8±1.5 [0.6-7], respectively. Twenty-nine percent of patients had a high disease activity. Metatarsalgia was reported by 54.8% of patients with a mean VAS of 4.5±3.7 [0-9]. Forefoot deformities were noted in 42% of patients: round forefoot in 13% of cases, triangular forefoot in 29% of cases, hallux valgus in 29% of cases, Quintus varus in 29% of cases, and claw toes in 13% of cases. Corns and calluses were noted in 42% and 29% of cases respectively. X-rays showed abnormalities in 75% of patients. The mean Larsen score was 9.8±6.2 [0-28]. US showed synovitis in 46.3% of MTP1, in 53.7% of MTP2, in 48.3% of MTP3, in 42.6% of MTP4, and in 37% of MTP5 joints. Doppler signal was detected in 5.6% of MTP1 and MTP2, and in 3.7% of MTP3, MTP4, and MTP5 joints. The mean US score was 5.3±4.3 [0-15]. The mean FFI was 66.5%. Mean rates of pain, difficulty, and disability were 89.5%, 40%, and 70% respectively. The mean HAQ score was 0.5±0.5 [0-2]. Severe disability was noted in 20% of patients. A significant positive correlation was noted between FFI and, Larsen score (r=0.214, p=0.014) and US score (r=0.420, p=0.021). A significant positive correlation was also noted between HAQ score and, foot pain VAS (r=0.555, p=0.009). Conclusion: Foot involvement is frequently seen in RA. This condition may affect patients’ autonomy. Early diagnosis and appropriate treatment are necessary in order to preserve the quality of life. Disclosure of Interests: None declared