Intra and Inter-Observer Reliability and Repeatability of Metatarsus Adductus Angle in Recreational Football Players: A Concordance Study

Metatarsus adductus (MA) is a congenital foot deformity often unrecognized at birth. There is adduction of the metatarsals, supination of the subtalar joint, and plantarflexion of the first ray. The aims of this study were to assess the intra and inter-reader reliability of the radiographic MA measurement angles used in the literature. Methods: All consecutive recreational football players who practice activity more than 5 h/week over 21 years of age with MA by roentgenographic evaluation on weight-bearing dorsoplantar images were included in a cross-sectional study. Controls were matched to cases according to age and gender. We assess all radiographic measurements to evaluate metatarsus adductus with the different measurements frequently used in the literature: Sgarlato, modified Sgarlato, Rearfoot, Root, Engel, modified Engel, Kite, Kilmartin, modified Kilmartin, Simons, and Laaveg & Ponseti. Results: The variables measured in 80 weight-bearing dorsoplantar foot radiographs show excellent reliability ranging p > 0.900 in Sgarlato and modified Sgarlato with low SEM, CV, and MCD. Rearfoot, Root, Engel, modified Engel, Kite, Kilmartin, Simons, Laaveg & Ponseti, and modified Kilmartin’s angles showed intra or inter reliability with ICC lower than <0.900, systematic differences between intersession or inter observers, or high MCD value. Conclusion: It is more suitable to measure the MA angle with the Sgarlato and modified Sgarlato techniques to show higher reliability and repeatability for intra and inter-observer.