Abstract
Background: FPI-6 is considered a quick and simple clinical test in patients with Rheumatoid Arthritis (RA). However, its associations with different clinical and radiolog-ical parameters of the disease are not fully studied.
Aim of Study: To assess the added value of foot radiology to the Foot Postural Index-6 (FPI-6) in assessment of early and late rheumatoid arthritis.
Patients and Methods: The subjects were recruited over a period of 6 months from the Rheumatology outpatient's clinics in Al-Azhar University Hospitals, Egypt. FPI-6 was calculated in 90 subjects, 30 patients with early RA (disease duration 5 years) and 30 age and gender matched control subjects. Foot digital X-rays in the standing position were performed to measure foot angles; TNC (Talonavicular Coverage), first metatarsal talar (1st MT) and Calcaneal Pitch (CP) angles.
Results: Pesplanus valgus was detected in 20% of early and 80% of late RA patients. Patients with late RA showed significantly higher bilateral FPI-6 than both the control subjects and patients with early RA (p=0.001). They also had significantly higher TNC, and 1st MT and lower CP (p=0.001). In RA patients, FPI-6 correlated significantly with both the duration of RA and the foot radiographic changes.
Conclusions: The combined use of FPI-6 with radiological measurements of three angles of plain X-ray in addition to, the collapse of the longitudinal arch; Talonavicular Coverage angle (TNC); Lateral talar-1st metatarsal angle and Calcaneal pitch can be used in the clinical assessment of forefoot abduction and the severity of RA.