Predictions of lower limb growth are based upon historical data, collected from patients who had coexistent poliomyelitis. By utilising standardised longitudinal prospective European data, our objective was to generate superior estimates for the age and rate at which lower limb skeletal maturity is reached; thus improving the timing of epiphysiodesis, for the management of leg length discrepancy.

The Avon Longitudinal Study of Parents and Children of the 90s (ALSPAC) is a longitudinal cohort study of children recruited antenatally 2. Using a previously validated Multiplier Method, a sequence of leg length multipliers were calculated for each child.

15,458 individuals were recruited to the ALSPAC study; and of those whose growth was measured, 52% were boys and 48% girls, each with an average of eight recording episodes. 25,828 leg length multiplier (LLM) values were calculated with final recordings taken at a mean age of 15.5 years.

From this data, the age at which girls reach skeletal maturity (LLM=1) is 11 months later than previously calculated and for boys nearly 9 months earlier. With nearly 4000 more children recruited in this cohort than preceding studies, this study brings increased power to future leg length calculations.