Change in Plantar Pressure and Plain Radiography in Pediatric Flexible Flatfoot: A Retrospective Cohort Study

To investigate longitudinal changes in plantar pressure examinations and plain radiographs and to assess the correlations between these two modalities in pediatric patients with flexible flatfoot (FFF).

Pediatric patients diagnosed with FFF were analyzed in this retrospective cohort study. Medical records were reviewed to collect data on plain radiographs and plantar pressure examinations. Changes in radiographic angles and plantar pressure parameters were analyzed over a follow-up period exceeding 1 year. Statistical analyses included paired t-test, Wilcoxon signed rank test, and Spearman's correlation analysis.

A total of 52 subjects was included in the plantar pressure analysis, with a mean age of 9.9 years at the first visit and a median follow-up duration of 52 months. The lateral tarso-first metatarsal angle decreased by 1.3° (p<0.001) and calcaneal inclination angle increased by 2.5° (p<0.001) in these patients. The percentage value of midfoot width (WMF) divided by forefoot width (WFF) decreased by an average of 9.8% p (p<0.001), and the maximal pressure on the medial midfoot (MMF) decreased by 1.6 N/cm2 (p<0.001). However, no correlations were found between plantar pressure and radiographic changes.

During follow-up of patients with FFF, the maximal pressure on the MMF and the ratio of WMF to WFF decreased in successive plantar pressure examinations. Changes observed in plantar pressure and plain radiographs were not consistent, indicating that these two testing modalities can complement each other.