Minimally invasive scoliosis surgery for adolescent idiopathic scoliosis using posterior mini-open technique

The purpose of this study aimed to analyze and evaluate the radiologic and clinical outcomes of minimally invasive scoliosis surgery (MISS) for correcting adolescent idiopathic scoliosis (AIS) using the mini-open technique. Thirty-four AIS patients who underwent MISS using the mini-open technique for deformity correction. Using two to four 3-centimeter-long skin incisions (mini-open) and tubular retractors, we performed screw fixations, rod assembly, rod derotation maneuver (RD), and bone graft. For thoracoplasty, four to six ribs were resected using the same incisions. Correction was attempted using rod translation and RD maneuvers. Radiological outcomes and clinical outcomes (SRS-22) were evaluated. Mean preoperative Cobb's angle was 61.3° and curve flexibility (major curve) was 26.1%. This angle was corrected to 21.6° with a correction rate of 65.2% (P < 0.001). The coronal balance was not changed significantly. Sagittal vertical axes were corrected from −3.5 mm to 8.6 mm (–22 to 36.3 mm) (P = 0.009). Thoracic kyphosis angles and lumbar lordosis angles were not changed significantly but the values were within normal range. Each score of self-image in the SRS-22 questionnaire as well as the total score were improved significantly (P < 0.001). In conclusion, the MISS for correcting AIS using the mini-open technique showed comparable radiologic and clinical outcomes with fewer complications in patients with non-rigid scoliosis with Cobb's angle between 50° and 80°. Long-term results of this novel MISS using the mini-open technique could further strengthen the rationale for adopting this technique for curve correction in selected cases of AIS.