FRI0744-HPR The association of local disease activity and forefoot deformities with plantar pressure in patients with rheumatoid arthritis and forefoot symptoms: a cross-sectional study in the amsterdam foot cohort
Authors: A. Konings-Pijnappels, M. Tenten-Diepenmaat, R. Dahmen, J. Dekker, J. Twisk, L. Roorda, M. van der Leeden
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background:</h3> In patients with rheumatoid arthritis (RA), both high and low forefoot plantar pressures have been reported in the literature (1–3). Understanding of contributing factors to forefoot pressure alterations can help to better formulate and specify goals for treatment with foot orthoses or therapeutic footwear. <h3>Objectives:</h3> Investigate the association of local disease activity and forefoot deformity with plantar pressure in RA patients with forefoot symptoms. <h3>Methods:</h3> A cross sectional study was conducted in the Amsterdam Foot (AMS-foot) cohort, using data of 172 consecutive patients with RA and forefoot symptoms. Peak pressure (PP) and pressure time integral (PTI) in the forefoot were measured with a pressure platform. Forefoot deformity was measured with the Platto score. Forefoot disease activity was defined as swelling and/or pain measured by palpation of the metatarsophalangeal (MTP) joints. The forefoot was divided in a medial, central and lateral region, in which the following conditions could be present: 1) no abnormality, 2) disease activity, 3) deformity or 4) deformity and disease activity. A multilevel analysis was performed using condition per forefoot region as the independent variable and PP or PTI in the corresponding region as the dependent variable. <h3>Results:</h3> Statistically significant higher PP and PTI were found in forefoot regions when deformities were present (RR 1.2, CI 1.1–1.3, P&lt;0.0001), compared to forefoot regions without forefoot abnormalities. No significant differences in PP and PTI were found when solely local disease activity was present in forefoot regions (RR 1.0, CI 0.9 – 1.2, p=0.749 and RR 1.0, CI 0.8 – 1.2, p=0.850 respectively). <h3>Conclusions:</h3> Deformities in the medial, central and lateral forefoot regions are related to higher plantar pressures measured in these regions. The absence of an association between local disease activity and plantar pressure might be explained by the low prevalence of MTP pain or swelling as detected by palpation. Future research with ultrasound measurements to detect disease activity is recommended to reveal the effect of forefoot disease activity on plantar pressure. <h3>References</h3> 1. van der Leeden M, Steultjens M, Dekker JHM, Prins APA, Dekker J. Forefoot joint damage, pain and disability in rheumatoid arthritis patients with foot complaints: The role of plantar pressure and gait characteristics. Rheumatology2006;45(4):465–9. 2. Turner DE, Woodburn J. Characterising the clinical and biomechanical features of severely deformed feet in rheumatoid arthritis. Gait Posture2008;28(4):574–80. 3. Bowen CJ, Culliford D, Allen R, Beacroft J, Gay A, Hooper L, et al. Forefoot pathology in rheumatoid arthritis identified with ultrasound may not localise to areas of highest pressure: cohort observations at baseline and twelve months. J Foot Ankle Res. 2011;4(1):25. <h3>Disclosure of Interest:</h3> None declared