Purpose: To compare the safety and efficacy of posterior minimally invasive surgery (MIS) to standard posterior spinal fusion (PSF) surgery for Lenke Type 1-4 adolescent idiopathic scoliosis (AIS).
Methods: This multicenter retrospective study enrolled 112 patients with Lenke Type 1-4 AIS who treated with MIS (n = 64) or PSF (n = 48) between March 2007 and January 2015. Coronal and sagittal parameters were evaluated before surgery, immediately after surgery, and at the last follow-up. Operative time, level of fusion, intraoperative blood loss, blood transfusion, and intraoperative radiation exposure were recorded. 22-item Scoliosis Research Society questionnaire (SRS-22) was applied for assessment of life quality. The accuracy of pedicle screw placement was assessed according to postoperative computed tomography images, and the complications were collected in follow-up period.
Results: The baseline characteristics of 2 groups were matched. There was no significant difference between 2 groups in terms of radiographic parameters immediately after surgery and at the last follow-up. The MIS group had significantly longer operative time, more level of fusion, less intraoperative blood loss, and lower blood transfusion rate (p < 0.001). The evaluation of pain using SRS-22 showed significantly lower score in MIS group (p < 0.05). No significant difference was found between 2 groups in terms of accuracy of pedicle screw placement and complications.
Conclusion: Posterior MIS is a safe and effective alternative to standard open approach for Lenke Type 1-4 AIS patients with curves < 70° and reasonable flexibility. Mid-term results showed MIS had the advantages of less blood loss and pain with more fusion segments.
Keywords: Adolescent idiopathic scoliosis (AIS); Complications; Minimally invasive surgery (MIS); Pedicle screw placement; Posterior spinal fusion (PSF).