Perspectives on walking in individulas with rheumatoid arthritis and juvenile idiopathic arthritis

Abstract

Background and aim: Gait deviations in individuals with Rheumatoid Arthritis (RA) and Juvenile Idiopathic Arthritis (JIA) have previously been demonstrated as a consequence of active disease. During the last decade, pharmacological treatments have dramatically improved outcomes but the effect on gait dynamics is not fully understood. The overall aim of this thesis was to enhance the understanding of the effect of pharmacological interventions on gait dynamics in individuals with RA and JIA. Moreover, we aimed to evaluate the usability of measures of overall gait quality which could facilitate future comparisons between groups and after interventions. In Study I the aim was to evaluate the usability of the Gait Deviation Index (GDI) as a measure of overall gait quality in adults with RA. The aim of Study II was to determine the effects of anti-Tumor Necrosis Factor Alpha (TNF-α) treatment on gait dynamics in individual with RA. Study III aimed to evaluate the occurrence, clinical characteristics and prognostic factors associated with ankle arthritis in children with JIA. The aim of Study IV was to evaluate the effects of Intra-Articular Corticosteroid Injections (IACI) in the foot on gait dynamics and patient-relevant outcomes in children with JIA.

Participants and methods: In Study I, 63 adults with RA and 59 healthy controls were included in a retrospective and cross-sectional study. Gait dynamics, obtained by three dimensional (3D) gait analysis and represented by the GDI, were analyzed and related to walking speed, physical disability and pain. In Study II, 16 adults with RA were included, and gait dynamics, obtained by 3D gait analysis, and disease characteristics were analyzed at baseline and three months after anti-TNF-α treatment. In Study III, 440 children with JIA were followed for the first eight years of disease in a population based cohort. The occurrence of ankle arthritis was assessed and related to clinical characteristics, and to disease outcome. In Study IV, 43 children with JIA were included and followed for three months after foot IACI treatment. Gait dynamics and disease characteristics were assessed at baseline, and at three weeks and three months after treatment.

Results: In Study I, the GDI was found to be a useful measure of overall gait quality in individuals with RA. In Study II, treatment with anti-TNF-α improved gait dynamics in adults with RA, but significant gait deviations were still present after treatment. In Study III, ankle arthritis was found to be common in JIA, related to a polyarticular disease course in young children, and was associated with failure to achieve remission. In Study IV, as a result of IACI treatment improvements were identified in foot-related disability and inflammatory joint symptoms, but gait dynamics were unchanged.

Conclusion: We recommend the use of measures of overall gait quality, such as the GDI, to quantify gait deviations in individuals with RA and JIA. This measure adds an aspect of dynamic function to arthritis care and facilitates comparisons of gait dynamics between groups or over time and between gait dynamics and other types of outcome measures. Gait deviations persist despite pharmacological treatment, indicating that the biomechanical perspective is important when evaluating walking disability. Ankle arthritis is common in JIA, predicts a polyarticular disease course in young children and is associated with failure to achieve remission. We suggest that ankle arthritis should be taken into account in the assessment of prognosis and choice of treatment strategy in JIA.