The metacarpal index--obsolete in Marfan syndrome!

28 patients with definite, probable or phenotypic Marfan syndrome underwent manual and computerised measurement of their metacarpal indices. Two methods were used from among the several variations quoted in the literature, one involving the average length/width of metacarpals 2-5 (method I), and the other dividing the sum of the lengths by the sum of the widths of these metacarpals (method II). The two methods are not mathematically identical, and a statistically significant difference was noted between them. Only 50% of the children in each group had elevated metacarpal indices, making it a time-consuming method that is indicative only of the phenotype and can be found in normal individuals. It should therefore be considered an obsolete measurement in Marfan syndrome.