Metacarpophalangeal relations in 21 Danish patients with achondroplasia.

Hand radiographs of 21 Danish patients suffering from achondroplastic chondrodystrophia were obtained to study the metacarpophalangeal relations. Mean pattern profiles based on z-scores were made for males, females, children, and adults. Metacarpal index and relative slenderness for metacarpals and proximal phalanges were calculated. The second to fourth metacarpals and third and fourth proximal phalanges were disproportionately short, and the distal phalanges were disproportionately long. The relation between hand size and height seemed to be the same for the achondroplasts as for normal persons. The metacarpal sign was found in four of the 21 patients.