A simple calculation for the timing of epiphysial arrest: a further report.

The accuracy of a previously described calculation for the timing of epiphysiodesis, in the management of leg length discrepancy, has been improved modifications in the way in which the calculation has been applied. The value of the method is confirmed by a study of 94 patients who had reached maturity; 94.1 per cent of these then had discrepancies within three-quarters of an inch of that calculated and 85.1 per cent within half an inch. Over-retardation of growth was more common than insufficient retardation and was partially compensated by calculating for a discrepancy at maturity. A further 34 patients were not available for assessment at maturity but were included in analyses of the conditions for which epiphysiodesis was performed and of early complications from the operation. Both early and late complications were minor and infrequent.