Pasha Saba, Cahill Patrick J, Flynn John M, Sponseller Paul, Newton Peter O
Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA.
Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD.
J Pediatr Orthop. 2018 Apr;38(4):e194-e201. doi: 10.1097/BPO.0000000000001136.
Preoperative spinal parameters are used to guide the fusion levels in adolescent idiopathic scoliosis (AIS) spinal surgery. However, the impact of the factors modifiable by the surgeon in varying levels of preoperative patient-specific variables is not fully explored. The goal of this study was to identify the association between axial rotation correction of the lower instrumented vertebra (LIV) and spontaneous correction of the uninstrumented lumbar spine as a function of preoperative 3 dimensional (3D) curve characteristics in Lenke 1 AIS.
Twenty-three Lenke1 AIS with a minimum 2-year follow-up were included. All patients had biplanar spinal x-rays and 3D reconstructions at preoperative, first erect, and 2-year follow-up visits. Five patient factors were measured preoperatively: kyphosis and lumbar modifiers, and thoracic to lumbar curve rotation, translation, and frontal deformity angle ratios. One surgical factor, percentage of LIV rotation correction, was determined from the preoperative and first erect 3D models. A factorial design analysis was implemented to determine the impact of surgical and patient factors, both separately and in combination, on 2-year radiographic outcomes of spontaneous correction of the uninstrumented spine.
Spontaneous lumbar Cobb and lumbar apical rotation correction were predicted significantly by patient and surgical factors, P<0.05. Lumbar modifier, percentage correction of LIV rotation, the interaction between LIV rotation correction and lumbar modifier, and the interaction between LIV rotation correction and thoracic to lumbar apical vertebrae translation ratio correlated significantly to 2-year outcomes of spontaneous lumbar Cobb correction, P<0.05. Lumbar modifier and the interaction between the Cobb ratio and the percentage of the LIV rotation correction correlated significantly to 2-year outcomes of lumbar apical rotation correction, P<0.05.
The relationship between LIV rotation correction and spontaneous lumbar curve correction after selective thoracic fusion varied based on the patient's 3D preoperative curve characteristics. Patients with lumbar modifier C and apical vertebrae translation ratios >1.5 showed improved lumbar Cobb correction in 2-years when 50% or more LIV rotation correction was achieved surgically.
术前脊柱参数用于指导青少年特发性脊柱侧凸（AIS）脊柱手术的融合节段。然而，外科医生可改变的因素在不同水平的术前患者特异性变量中的影响尚未得到充分探索。本研究的目的是确定作为Lenke 1型AIS术前三维（3D）曲线特征函数的下固定椎（LIV）轴向旋转矫正与未固定腰椎的自发矫正之间的关联。
纳入23例Lenke 1型AIS患者，随访至少2年。所有患者在术前、首次直立位和2年随访时均进行了双平面脊柱X光检查和3D重建。术前测量五个患者因素：后凸和腰椎修正因子，以及胸腰段曲线旋转、平移和额状面畸形角比率。一个手术因素，即LIV旋转矫正百分比，由术前和首次直立位3D模型确定。采用析因设计分析来确定手术和患者因素单独及联合对未固定脊柱2年自发矫正的影像学结果的影响。
患者和手术因素对腰椎Cobb角和腰椎顶椎旋转自发矫正有显著预测作用，P<0.05。腰椎修正因子、LIV旋转矫正百分比、LIV旋转矫正与腰椎修正因子之间的相互作用以及LIV旋转矫正与胸腰段顶椎平移比率之间的相互作用与腰椎Cobb角自发矫正的2年结果显著相关，P<0.05。腰椎修正因子以及Cobb角比率与LIV旋转矫正百分比之间的相互作用与腰椎顶椎旋转矫正的2年结果显著相关，P<0.05。
选择性胸段融合术后LIV旋转矫正与腰椎曲线自发矫正之间的关系因患者术前3D曲线特征而异。腰椎修正因子为C且顶椎平移比率>1.5的患者，若手术实现50%或更多的LIV旋转矫正，则2年内腰椎Cobb角矫正改善。
