title: A technique for calculating limb length inequality and epiphyseodesis timing using the multiplier method and a spreadsheet.
abstract: Limb length inequality and epiphyseodesis timing calculations are common in pediatric orthopedics. The multiplier method developed by Paley et al. has significantly simplified the calculation of ultimate limb length. The calculation of limb length inequality has also become very simple for congenital limb length inequalities. However, the equations for limb length inequality from acquired differences and epiphyseodesis timing are not simple, and are prone to arithmetic errors.
  
  
  
  To limit these errors, we have developed a spreadsheet which finds the appropriate multipliers, solves the equations, and computes the predicted limb length inequality and the appropriate age for an epiphyseodesis.
  
  
  
  This method of using a spreadsheet and the multiplier calculations is quite simple and quick to use in practice. The calculations can be cut and pasted into computerized charts for future reference.
  
  
  
  We recommend this method for clinical use and make it available for public use.
authors.affiliation: Shriners Hospitals for Children, 1645 West 8th Street, Erie, PA, 16505, USA, jsanders@shrinenet.org.
authors.forename: James O
authors.initials: JO
authors.lastname: Sanders
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Khoury
authors.forename: Shyam
authors.initials: S
authors.lastname: Kishan