Restoration of thoracic kyphosis with all pedicle screw system in Lenke 1 AIS patients: if improve after 10-year training

English Keywords:Adolescent idiopathic scoliosis  Thoracic kyphosis  All pedicle screw system

English Abstract:

  【Abstract】 Objectives: To investigate the change of thoracic kyphosis(TK) correction in Lenke 1 adolescent idiopathic scoliosis(AIS) patients with all pedicle screw constructs after 10-year revolution. Methods: In this retrospective study, 80 Lenke 1 AIS patients who underwent posterior correction surgery with all pedicle screw construct in our center were included. 40 patients were selected randomly with the operation time during June 2005 to June 2006, while the other 40 patients were from June 2014 to June 2015. Long-cassette standing upright posterior-anterior and lateral radiographs of the spine and pelvis were taken before and two weeks after surgery. The radiographic parameters including Cobb angle, sagittal vertical axis(SVA), TK, lumbar lordosis(LL), cervical lordosis(CL), pelvic incidence(PI), sacral slope(SS), pelvic tilt(PT). Independent t test was conducted to assess difference in terms of radiographic parameters pre- and post-operatively between 2 groups. Results: The mean age was 14.94±1.78 years old and 14.96±2.01 years old respectively. The baseline TK averaged 14.42°±7.92° in early group and 15.19°±7.90° in recent group. No significant difference was observed in terms of TK at baseline(P=0.681). After posterior correction surgery, TK was restored to 18.58° in early group and 19.23° in recent group. Still, no significant difference was observed(P=0.689). Correlation analysis revealed that TK was significantly correlated to CL both at baseline and post-operation. Conclusions: No improvement was found in TK restoration compared to 10 years ago. The stable outcome may be related to the etiology of AIS or the derotation maneuver in our center.