Application of plantography examination to the assessment of foot deformity in patients with rheumatoid arthritis

Introduction: Rheumatoid arthritis (RA) is a chronic, inflammatory and multiple-system disorder of connective tissue. It frequently affects joints and periarticular structures of feet that constitute a significant supporting element underlying normal gait and motion of the body centre of gravity. The aim of the study was to evaluate foot deformities on the basis of plantography examination in RA patients according to the severity of the disease. Material and methods: The study was performed on 54 RA patients. The control group consisted of 34 volunteers free of any disorders. Plantography examination was carried out by means of a CQ ST2K podoscope. The following parameters were applied to the assessment of the disturbances of foot statics: hallux valgus angle (alpha), Sztriter-Godunow index (KY), Wejsflog's index (Wwp) and Clarke's angle (CL). Results: Markedly higher values of the a angle were noted in RA patients, reflecting the presence of hallux valgus. Moreover, values of the a angle were higher in patients in the third stage of radiological changes than those in the second one. On the other hand, values of Clarke's angle for the right foot were significantly higher in men in the second and third stage of RA compared to the control group. The most common deformities in RA patients include HV and transverse flat foot, more explicit in women in the third stage of RA. Conclusions: Plantography examination has been shown to constitute a useful diagnostic tool for assessment and monitoring of foot deformities in RA patients.