Normal development of the knee angle in healthy Indian children: a clinical study of 215 children

Purpose Physicians should be aware of the physiological variations of the knee angle in the local population to avoid unnecessary intervention in normal children. The normal development of the knee angle in children has been studied in various ethnic groups. However, there is a scarcity of such literature for Indian children. Methods Using clinical methods, the tibiofemoral angles (TFAs) were measured in 215 healthy Indian children ranging from 2 to 15 years of age. A record of the inter-malleolar distance (IMD) and intercondylar distance (ICD) was also kept of all of the subjects. Results We found that physiological varus rarely persists beyond 2 years of age in Indian children. A progressive increase in knee valgus occurs after 2 years of age, with peak knee valgus averaging almost 8 degrees at around 6 years of age. Thereafter, the valgus at the knee decreases and, after the age of 10 years, stabilizes to around 4-5 degrees in most of the children. Indian girls show, overall, more valgus alignment of the knees as compared to boys. Conclusions The overall pattern of development might be slightly different in Indian children, especially in Indian girls, with early reversal of physiological varus (<2 years of age) and a late peak of maximal valgus at the knee (6 years of age). Varus after 3 years seems atypical for Indian children. We provide an elaborate set of data for the mean TFA of different age groups and believe that this data could be of potential benefit to the physicians while evaluating lower limb alignment in Indian children aged 2-15 years.