P03 Service evaluation of ankle damage in a single centre paediatric cohort of juvenile idiopathic arthritis

Abstract

Poster presentation Tuesday 8 October Background The ankle is one of the most commonly affected joints in juvenile idiopathic arthritis (JIA) and ankle joint damage is a known complication. The frequency of ankle damage in modern JIA cohorts is unknown and optimal management pathways are unclear. Magnetic resonance imaging (MRI) is the most sensitive imaging modality for the assessment of joint damage. The aim of this analysis was to investigate the demographics, disease features and management of JIA patients with MRI changes consistent with ankle damage. Methods A single-centre, retrospective study over a four year period was conducted. JIA cases with damage based on MRI features were included in the study. MRI was reviewed by an experienced musculoskeletal radiologist and joint damage was defined as radiological evidence of cartilage loss or joint space narrowing. A standardised electronic pro forma was used to record demographics, disease features and treatments received. Results Fifty one JIA cases had an MRI scan during the study period and 16/51 (31%) had radiological evidence of ankle damage at a median interquartile range (IQR) follow-up of 7.6 (6.9 – 11.0) years; 7/16 (44%) had developed bilateral ankle damage. The median (IQR) duration of symptoms at diagnosis was 2(1.0-10.5) months. The mean age at diagnosis and at detection of ankle damage was 5.2 years and 12.1 years respectively. The most frequent JIA subtype was oligo-articular extended (50%), and 50% were ANA positive. The median (IQR) duration between detection of ankle damage and first episode of ankle synovitis was 5.4 (4.6 – 6.4) years. Ankle synovitis was present at diagnosis in 10/16 (62%). Median (IQR) number of ankle corticosteroid injections before the ankle damage was detected was 3 (2-3), one patient had evidence of damage at diagnosis. Median (IQR) number of any type of ankle imaging done before the ankle damage was detected was 1 (1-3). The median (IQR) time to start methotrexate from diagnosis was 6 (0 - 29.5) months and median (IQR) number of biologic and synthetic DMARDs used at follow-up were 3.5 (2.2 – 4.0). 7/16 (44%) patients had undergone an orthopaedic surgical procedure for their ankle damage. Conclusion Ankle synovitis at presentation and an extended oligo-articular disease course were common in this cohort of children and young people (CYP) with JIA and ankle damage. Ankle damage is an important challenge in JIA; a substantial number of this cohort ultimately required surgical intervention. There is an urgent need to develop a care pathway designed to improve early recognition and management of evolving ankle joint damage in JIA. Our analysis suggests that attention may need to focus on CYP presenting with ankle synovitis, particularly those who develop a poly-articular disease course, may merit high levels of vigilance with be at particularly high risk. Conflicts of Interest The authors declare no conflicts of interest.