[Results of lengthening 20 humeri]

The aim of the retrospective study was to evaluate the results of 20 performed lengthenings of the humerus in children and adolescents.

Assessment involved totally 20 lengthening procedures having been done in 18 patients, twice as a repeated procedure, in the period 1983-1999. The indication was shortening of humerus approaching at least the amount of 50 millimeters. Proportion of boys and girls was 7/13. The shortening arouse on the base of pyogenic infection in 12, post-traumatically in 3, congenitally in 2 and in one case it was caused by a bone cyst expansion. Mean value of shortening was 83 millimeters. Mean value of age was 12 years, ranging from 7 till 16 years.

Lengthening procedure was performed by the use of different types of external fixation. In most cases Wagner unilateral fixator was used (13 cases). The choice of external fixator was based more on its availability determined by economical reasons. Contrary to Wagner and Orthofix, Ilizarov fixator did not need the common replacement of different sizes of apparatus during lengthening. Osteotomy was routinely performed at the point between the distal and middle thirds of the length of humerus, approach was always associated with visualisation of the radial nerve.

Serial x-rays were consecutively studied to specify the mean value of lengthening--71 millimeters, the mean value of distraction phase--91 days, the mean value of total period of fixation--197 days and the mean value of period determined at its end by the full re-canalisation of the lengthening zone--355 days. Mean value of bone lengthening index was calculated on 13.2 days/1 centimeter, mean value of bone healing index on 28.6 days/1 centimeter, and a modified bone healing index based on full recanalisation of the lengthening zone with a mean value of 44.5 days/1 centimeter. In no one case an additional bone grafting or plate osteosynthesis was necessary. Complications involved 3 cases of transient radial nerve palsy, which spontaneously resolved.

As other reports of humerus lengthening respecting "callotasis method", this study showed almost uneventful distraction and healing This cohort involves a big sample of lengthenings resembling in its size the cohort of Cattaneo et al., the world's biggest group.

It was proved, that the humerus lengthening is a safe method solving successfully the cosmetic problem of length deficiency. It seems, that presumably the keeping up the principle of "callotasis" brings about uneventful treatment programme.