Clinical validity of radiographic parameters for evaluating pediatric foot deformities: correlation with pedobarographic analysis.

BACKGROUNDS: Pediatric foot deformities disrupt biomechanics and can lead to long-term musculoskeletal complications. Radiographic parameters, particularly the anteroposterior talo-1st metatarsal angle (AP talo-1MT), are widely used; however, their accuracy may be compromised in the presence of hallux valgus. The clinical utility of the anteroposterior talo-2nd metatarsal angle (AP talo-2MT) has not been well established. This study evaluated radiographic parameters by correlating them with pedobarographic indices, hypothesizing that AP talo-2MT would demonstrate comparable or superior functional associations to AP talo-1MT.

METHODS

We retrospectively reviewed 64 pediatric patients with hindfoot varus (n = 32) or valgus (n = 32) deformities who underwent weight-bearing radiographs and pedobarographic testing between 2017 and 2024. Radiographic variables included AP talo-1MT, AP talo-2MT, talonavicular coverage, hallux valgus angle, intermetatarsal angle, lateral talo-1MT, calcaneal pitch, and naviculocuboid overlap. Pedobarographic outcomes comprised surface area, mean pressure, and pressure-time integral across forefoot, midfoot, and hindfoot regions. Interobserver reliability was assessed using intraclass correlation coefficients (ICCs). Group differences were analyzed with t-tests and effect sizes, and age-adjusted partial correlations were calculated to evaluate associations.

RESULTS

All radiographic parameters demonstrated excellent reliability (ICC 0.872-0.996). Significant differences were observed in AP talo-1MT, AP talo-2MT, lateral talo-1MT, and naviculocuboid overlap between hindfoot varus and valgus groups (all p < 0.001). Pedobarographic analysis revealed distinct loading patterns, especially in midfoot and lateral regions. Both AP talo-1MT and AP talo-2MT correlated with total foot surface area and midfoot loading indices; AP talo-2MT demonstrated comparable associations and larger discriminative effect sizes between hindfoot varus and valgus.

CONCLUSION

AP talo-2MT demonstrated excellent reliability and showed comparable functional associations to AP talo-1MT. It may be a useful complementary radiographic parameter for evaluating pediatric foot deformities, but further validation in broader cohorts and predefined subgroups is needed.

LEVEL OF EVIDENCE: Level III, retrospective cross-sectional study.