Smith-Petersen osteotomy effectiveness compared to anterior release procedures in surgical treatment of Lenke type I idiopathic scoliotic deformities

Abstract

Introduction: rigid idiopathic scoliosis deformities are traditionally treated using a two-stage approach. However, multilevel Smith-Petersen osteotomies allow to mobilize the main curve and to omit the anterior release stage. Materials and methods: the results of 72 patients aged from 14 to 21 years with an idiopathic scoliosis of Lenke type I and angle of deformity from 70° to 90° (average angle 81.3°) were analyzed. In 35 patients, one-stage treatment was performed in combination with multilevel Smith-Petersen osteotomies. In 38 patients – two-stage operative treatment (anterior release + posterior fusion) was performed. In all patients, the deformities were rigid (correction of less than 25% with the traction test). All patients were examined radiographically. Radiographs were performed right after surgery and 3, 6 and 12 months after surgery. Results. In-group I the average degree of deformity was 72.67 °. The mobility of the main curve in all cases was below 25%. All patients underwent SPO (from 5 to 8 levels). Correction and fixation were carried out using hybrid and screw instrumentation. The average correction angle was 49.94 ° or 68.7%. In-group II the average degree of deformity was 73.92°. The mobility of the main curve was below 25%. All patients underwent anterior release (4 to 6 levels of discectomy). Over the next 7-14 days, halo-gravity traction was carried out. The second stage was performed using posterior correction and fusion using hybrid or screw instrumentation. The average correction angle was 48.73°, or 65.9%. Conclusion: the use of Smith-Petersen osteotomy in patients with rigid idiopathic Lenke type I scoliosis with a degree of deformity between 70° and 90° allows for one-step correction that yields comparable results with two-stage surgical treatment. The number of SPO levels should be at least 5.