The role of metacarpophalangeal pattern (MCPP) profile analysis in the treatment of triphalangeal thumbs. Description of a method and a case report.

The metacarpophalangeal pattern (MCPP) profile analysis is a method of comparing the length of each of the 19 tubular bones of the hand on the X-ray with the standard length in the normal population according to age and sex. An MCPP plot is a graphic illustration of the MCPP analysis. It is not the exact height of the curve on the MCPP plot which is most important, but the profile which occurs because of the individual lengthening or shortening of the bones. This pattern profile appears to be specific for several congenital malformation syndromes. We have recently used MCPP analysis in planning surgery for triphalangeal thumbs. The percentage of excessive or reduced length of each individual bone of the hand can be read from the MCPP plot and is helpful in calculating a more accurate length for the newly created thumb. MCPP analysis can be used as a diagnostic tool in a number of congenital hand malformations, but may also be helpful in planning surgical treatment of congenital hand malformations when abnormal bone length is involved.