The aim of this study was to analyze the longitudinal arch morphology and related factors in primary school children. Five hundred and seventy-nine primary school children were enrolled in the study. Generalized joint laxity, foot progression angle, frontal hindfoot alignment, and longitudinal arch height in dynamic position were evaluated. The footprints were recorded by Harris and Beath footprint mat and arch index of Staheli was calculated. The mean age was 9.23 +/- 1.66 years. Four hundred and fifty-six children (82.8%) were evaluated as normal and mild flexible flatfoot, and 95 children (17.2%) were evaluated as moderate and severe flexible flatfoot. The mean arch indices of the feet was 0.74 +/- 0.25. The percentage of flexible flatfoot in hypermobile and non-hypermobile children was found 27.6 and 13.4%, respectively. There was a statistically significant difference in dynamic arch evaluation between hypermobile and non-hypermobile children. There was a significant negative correlation between arch index and age, and a significant negative correlation between hypermobility score and age. Our study confirms that the flexible flatfoot and the hypermobility are developmental profiles.

Preloaded compression technique was successful in attaining maximum compression rate. During trailing-side insertion, constant pitch design failed to keep compression rate. Variable pitches can be useful to preserve or increase compression rate. In addition, sleeve usage may be more advantageous in thin fragment fixation.