The timing of epiphysiodesis. A comparative study between the use of the method of Anderson and Green and the Moseley chart.

This retrospective study compares two groups of patients who underwent an epiphysiodesis for leg length discrepancy. In group A (47 patients) the timing of the epiphysiodesis was calculated using the method of Anderson and Green; in group B (36 patients) the Moseley chart was used. A leg length discrepancy of 1.5 cm or less at maturity was considered a satisfactory result. Group A showed 51% good results, group B 63.9%. In both groups, an important source of the poor results was error in calculation and prediction: 30.4% in group A (or 15% of the total), 61.5% in group B (or 22% of the total). The percentage of patients presenting too late was also considerable and accounted for 34.8% of the poor results in group A and for 23.1% in group B. The unpredictability of growth rate is a lesser problem in group B (15.4% of the poor results) than in group A (30.4%). If the uncontrollable causes of poor results are omitted, only 18% of the poor results in the total group of patients could be accounted for by miscalculation.