Aims: True vertical talus isnÔt to be treated successfully by conservative means alone. Untreated deformities may lead to unability of walking. The aim of the study was to evaluate the outcome of the operation described by Duckworth and Tachdjian in our patients. Methods: During 1975 until 2001 71 feet in 43 patients were operated on. The way of operation was described by Duckworth and Tachdjian. The mean age at the time of operation was þve years. The collectiv consists from 24 boys and 19 girls. Characteristics of the operation were arthrolysis and reposition of the talonavicular joint, lengthening of the achilles tendon and transposition of the anterior and posterior tibial tendon. The results were evaluated prae and postoperative by the Walker-Score and by an adittional questionare. Results: All in all 51 feet of 30 patients could be examined by clinical investigation and radiographs. The follow up was eigth years postoperative in mean. Fourteen obstacles were counted. Ten feet had addittional operative treatment later on. The evaluation by the Walker-Score counted a very good result in 13 feet, a goog in 22, an average in 13 and a poor result in three feet. From the questionaire 16 patients were very content, 36 content, 6 little content and three discontented. Conclusion: the results correlate in the procentual distribution with those described by Duckworth (n=19). Idiopathic deformities reached a higher score (14,6). Unfortunately the patients were presented to the surgeon late so that an early intercention was prevented. One may conclude that early intervention would result in a better outcome