Can L3/4 disc angle be a factor for a long-term postoperative outcome in adolescent idiopathic scoliosis with lumbar modifier C and fused to L3?

Abstract

Introduction: The purpose of this study is to evaluate the long-term postoperative results of patients with idiopathic scoliosis (AIS) with lumbar modifier C and LIV selected as L3, and to determine whether DD could be predicted from preoperative X-ray parameters.

Methods: A total of 44 patients with AIS met the inclusion criteria: 1) female diagnosed with AIS with lumbar modifier C, 2) PSF or Anterior and PSF, 3) L3 as the LIV, 4) 11-20 years of age at the time of surgery, and 5) MRI and X-ray images at 10 years postoperatively.

Results: DD at unfused lumbar intervertebral discs was identified in 48% of the patients at 10 years postoperatively. The selected patients were classified into 2 groups based on DD occurrence. Preoperative and postoperative 10 years L3/4 disc angle (DA) exhibited significant differences between two groups. The incidence of DD markedly increased at the preoperative L3/4DA greater than 5°.

Conclusion: In the AIS patients with lumbar modifier C and LIV at L3, it was suggested that not only postoperative but also preoperative wedge formation of the L3/4 disc was closely related to the occurrence of disc degeneration in the long-term postoperative period.