[Ulnar lengthening in osteochondroma (multiple cartilagenous exostoses) of the forearm].

The osteochondroma is the most frequent bone tumor to occur during the period of growth. The multiple hereditary form often involves the forearms. Depending on localisation and size of the tumor, shortening of the bones in the forearm, angular malalignments and functional impairment of the wrist and elbow joints may result. Early diagnosis and surgery in the growing child can prevent these complications. 13 children were operated on altogether 15 forearms. In nine cases lengthening of the ulna was necessary to correct ulnar instability of the wrist as well as improving the support of the carpus and preventing dislocation of the radial head.