Developmental pattern of tibiofemoral angle in healthy north-east Indian children

PURPOSE Physiological range of tibiofemoral angle (TFA) is poorly defined and may lead to unnecessary therapeutic interventions. Studies on TFA developmental pattern suggest that racial and ethnic differences are present; children in north-east India who have not yet been studied need to be evaluated. PATIENTS AND METHODS Cross-sectional study of clinical TFA, intermalleolar distance and intercondylar distance in 1020 healthy north-east Indian children aged from 2 to 18 years was done. Height, weight and body mass index were also recorded. RESULTS At two years of age the mean TFA was valgus. The values reached a peak of 8.55° (standard deviation (SD) 1.01) valgus at seven years of age. The TFA then gradually stabilised to 3.18° (SD 1.18) valgus by 18 years of age. There was no significant difference in TFA between male and female patients. DISCUSSION The present study is the largest and only the third such study on Indian children and the first on healthy northeast Indian children. By the end of two years most children had valgus angulation. This, along with the peak angulation observed, was similar to most of the other studies. The age at peak angulation and subsequent stabilisation of valgus angulation varied greatly among children of different origins, especially non-Indian children. CONCLUSIONS Data can be used to identify children who require further follow-up/evaluation and can serve as guidelines during deformity correction and future studies. The development of TFA in this cohort is not different from other children of India but differs from children of other ethnic origins.