Three dimensional radiological imaging of normal lower-limb alignment in children

Purpose Our study aimed at evaluating age- and gender-specific references describing lower-limb alignment in a large population of children using an accurate and reliable method (EOS 2D/3D). Methods From our database, we selected 523 EOS records suitable for 3D modelling representing age groups between two and 16 years in which no relevant deviation influencing lower-limb biomechanics could be observed (the majority of the examined population had mild scoliosis). We performed reconstruction of both lower limbs, thus obtaining the value of the mechanical tibiofemoral angle (mTFA) and the femoral mechanical axis-femoral shaft angle (FM-FS) and calculated the anatomical tibiofemoral angle (aTFA) from previous parameters. Statistical analysis was carried out using the Kolmogorov-Smirnov test, Spearman correlation, regression analysis and Welch test. Results The aTFA reaches its maximum by the age of three years: 13.07A degrees in boys and 10.73A degrees in girls; it then varies similar to 4.44A degrees in both genders. By the age of three years, the mTFA reaches 8.04A degrees in boys and 4.85A degrees in girls; it starts to decrease to -1.47A degrees in boys and 0.13A degrees in girls. By the age of three years, FM-FS increases to 5.02A degrees in boys, then fluctuates at similar to 4.08A degrees, while in girls, it increases to 5.87A degrees, then fluctuates at similar to 4.24A degrees. Conclusions The pattern found in this study confirms the results of previous publications investigating Caucasian populations; however, absolute values differ significantly in several cases.