[Lengthening Osteotomy of the Calcaneus in the Treatment of the Flat Foot in Children - Short-term Results.].

The aim of this communication is to provide both clinical and radiological evaluation of short-term results of the lengthening osteotomy of the anterior part of the calcaneus after Evans in the treatment of the flat foot in children and determine indication criteria of this operation. In the 1996-1999 period 35 feet were operated on in 23 children (13 boys, 10 girls), 12 children underwent bilateral surgery in the interval of 6-12 months. The average age at the time of surgery was 10,5 years and the age range 4,3-18,5. Most operations were performed in the age range of 11-15 years (16 operations). Indication to the operation was a symptomatic flexible pes planus (29 times), the flat foot with a neurogenic defect twice, with talus obliquus twice, deformity after the treatment of pes equinovarus congenitus once and the flat foot after a burn injury once. The period of postoperative follow-up ranged between 3 months and 2,5 years. The evaluation focussed on subjective complaints, clinical finding, plantogram and radiological indicators of flat foot. For the purpose of the objectivization of the shortening of the lateral pillar of the foot the so called talocalcanear differential index was monitored under weightbearing from the lateral radiograph. This index was calculated on the basis of the difference of the distance between the distal edge of talus and the calcaneus against the length of the medial pillar of the foot. The postoperative monitoring did not record any infection complications or failure of the surgical technique. Based on the subjective evaluation the condition in 21 patients with the operation of 32 feet (91 %) improved after the surgery and in 2 patients with the operation of 3 feet (9 %) the condition did not improve. In no patient the complaints were worse. Valgus position of the heel of all patients was corrected after the surgery to the normal. There was no functional limitation of the ankle and subtalar joints in any of the patients. Plantograms changed after the surgery by 2 degrees in 16 feet (52 %), by 1 degree in 13 feet (42 %), the plantogram did not change in 2 feet (6 %). Plantogram got to its normal in 12 feet operated on (38 %). Radiological evaluation showed in all feet operated on a change in the course of the joint line of the Chopart joint in both projections and the monitored angles either improved or became normal. Tolacalcanear differential index descreased except for one foot in all feet operated on. This index was directly proportionate to the preoperative and postoperative clinical finding or to the severity of the flat foot or the correction according to the plantogram and on average it was preoperatively four times higher than in normal healthy feet. In most operated feet a shift was found in the calcaneocuboid joind which did not have any relation to the subjective evaluation. Radiological indicators did not correspond unequivocally to the resulting subjective evaluation of the operation but in the case of a satisfactory clinical correction of the deformity of the foot both the subjective evaluation and radiological correction were mostly very good. The lengthening osteotomy of the calcaneus is a safe surgical method which leads to a significant clinical and radiological correction of the valgus deformity of the hindfoot and elevation of the foot arch. Indicated to the surgery are symptomatic flat feet with the symptoms of eversion in the subtalar joint and shortening of the lateral pillar in the radiograph which are not fixed by articular contractures. It is recommended to evaluate the shortening and lengthening of the lateral pillar of the foot according to the proposed talocalcanear differential index which can be used for the indication consideration as well as for the evaluation of the correction achieved. Key words: flat foot in children, surgical treatment, lengthening osteotomy of the calcaneus, radiological evaluation.