[Upper metaphyseal lengthening of the tibia. Report of 57 cases in children and adolescents].
INTRODUCTION: The authors reviewed 57 upper metaphyseal lengthenings of the tibia. They especially studied complications in order to evaluate this method. MATERIAL AND METHODS: Fifty seven tibial lengthenings in 47 children and adolescents were reviewed. All lengthenings were performed according to the callotasis technique, using Judet's lengthener in the first 15 cases, the, OF-Garches Orthofix in 42 cases. All the callotasis principles were applied: delayed elongation, 1 mm per day distraction, one month neutralization after elongation period, then dynamization before removing the apparatus. Particularities were: a) metaphyseal osteotomy of the upper tibia, b) screw fixation and osteotomy of the fibula, c) classical dynamization according to De Bastiani and Aldegheri in 29 cases, dynamization by a silastic collar (OF-Dyna-Ring) in 28 cases. METHODS: Severity of complications was classified according to Caton: none, benign, serious (needed reoperation or reanesthesia) and severe (sequel). Complications and rate of lengthenings without complication or with benign complications were studied relative to etiology, age, amount of lengthening and the stage of program in which they occurred. A table summarizes data of all the lengthenings. RESULTS: Lengthening was 52.3 mm in average. Healing time (number of days to lengthen and to fuse the bone divided by the number of lengthened centimeter) was 40 in average (range: 20-105): it was 45.6 days per cm when using classical dynamization and only 34.3 with silastic collar dynamization (p = 0.002). Total of complications was 59 out of 57 lengthenings. 21 complications were benign, 37 serious and 1 severe (partial motor palsy of the foot). Thirty two (56 per cent) lengthenings were performed without unforeseen procedure or anesthesia. There were 4 intra-operative complications: 1 vascular lesion, 1 incomplete osteotomy and 2 malpositioned half screws. Complications of elongation period were the most numerous, 4 transient palsies, 6 knee contractures (2 led to a supracondylar fracture), 6 equinism (4 needed an Achilles tendon lengthening), 12 valgus deviations in which 9 were realigned using OF-Garches fixator without reoperation, 1 serious depression occurred in a bilateral lengthening. Consolidation was achieved without complication in 52 cases. Complications were: 1 refracture (fourth lengthening of the same tibia), 1 delayed union, 1 non-union, 2 late deviations. DISCUSSION: Rate of nervous and joint complications is close to that of other series. However, a high osteotomy decreases the consequences on the foot without increasing knee contracture in flexion. The ability to realign during the elongation period appears to be a prevention of valgus deformity compared to Wagner's technique. The authors's distractor is better tolerated than Ilizarov's. Problems with consolidation are rare, less than 9 per cent of the cases. CONCLUSION: A modular distractor improves the results of tibial lengthening; realignment is possible before, during or after the elongation. OF-Orthofix is easy to apply and well-tolerated by the patient, especially in bilateral lengthenings. Performing a high osteotomy, the callus is thick and the consolidation is quickly achieved and safe. A well-thought dynamization using Orthofix Dyna-Ring decreases the treatment time which is 35 days per centimeter in average.