Two - stage surgical treatment of idiopathic scoliosis in patients with incomplete bone growth

Background: Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine with a Cobb angle >10° and axial rotation. In cases of deformity progression to more than > 50 °, regardless of bone maturity, surgical treatment is indicated. In most cases, final fusion with pedicle screw systems are used, which limits the spine growth in patients with incomplete bone growth. Aims: to describe the surgical technique and experience of using the LSZ growing system as a 2-stage surgical treatment of AIS. Materials and methods: a retrospective analysis of patients with AIS who underwent 2-stage surgical treatment was performed. Patients treated with the LSZ growing system were observed for an average of 40.5 months (range 23-64 months) and for 4 years after the replacement of the LSZ growing systems with pedicle screw systems. Descriptive statistics methods were used to analyze the data obtained. Results: Eleven patients (10 girls, 1 boy) with an average age of 12.2 ± 0.87 SD at the time of 1st surgery were treated. All patients had incomplete bone growth with Risser test 0 to 2. The average blood loss during the 1st surgery was 145.45±90.7 ml, the 2nd surgery 209.1 ±66.4 ml. The average duration of the 1st surgery was 85±16.88 minutes, the 2nd surgery 152.72 ± 17.94 minutes. The preoperative Cobb angle of the thoracic curve was 64.55±3.21°, the lumbar curve 46±5.52°. After treatment with the LSZ growing system, the thoracic curve was corrected to 17.63± 5.14°, the lumbar curve to 9.2± 5.45°. Before replacing the LSZ growing system, the angle of the thoracic curve was 21.1±4.18°, the lumbar curve 14±3.61°. After placement of the pedicle screw system, the thoracic curve angle was 11.45±4.84°, the lumbar curve 6.4±4.72°. The final percentages of correction for the thoracic and lumbar curves were 82.1 ±7.91 % and 85.64±5.47%, respectively. Neurological and infectious complications were not observed. Conclusions: Using the LSZ growing system allows to perform a primary correction and stabilization of spinal deformity in patients with AIS with incomplete bone growth, minimizing the risks of deformity progression and not preventing normal growth of the spine. Due to the advantages of the LSZ system, primary surgical intervention, is performed fairly quickly, with limited blood loss relative to the severity of the disease and without disturbing the bone anatomy, which allows for replacement of the LSZ growing system with less risks, compared with other revision interventions in this group of patients.