Kwan Mun Keong, Lee Sin Ying, Fam Sze Khiong, Tan Yee Wern Evonne, Ngan Chun Hong, Chandirasegaran Saturveithan, Chiu Chee Kidd, Chan Chris Yin Wei
Department of Orthopaedic Surgery, Faculty of Medicine, National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Eur Spine J. 2025 Feb;34(2):610-624. doi: 10.1007/s00586-024-08602-1. Epub 2024 Dec 30.
To devise a mathematical model for estimating the intraoperative lowest instrumented vertebra (LIV) tilt angle using preoperative supine left side-bending (LSB) radiographs in adolescent idiopathic scoliosis (AIS) patients with Lenke type 1 and 2 (non-AR curves), and to review its clinical and radiological outcomes.
The mathematical model for the adjusted LSB LIV tilt angle (α) measured preoperatively, was expressed as the sum of preoperative LSB LIV tilt angle (x) and LIV displacement angle (y) (α = x + y). This model was validated through inter-rater and intra-rater analysis in Part I of the study. The α angle derived was applied to estimate the intraoperative LIV tilt angle. In part II of the study, clinical and radiological outcomes of 50 Lenke type 1 and 2 (non-AR curves) AIS patients operated using the α angle were reviewed. The difference between the intraoperative LIV tilt angle achieved (β) and the preoperative α angle was determined (∆LIV tilt angle = β-α).
The α angle had excellent inter-rater and intra-rater intraclass correlation coefficients (0.982; 0.907). 42 patients had positive ∆LIV tilt angles whereas 8 patients had negative ∆LIV tilt angles. The overall incidence of distal adding-on (AO) was 10.0% (n = 5/50). Patients with negative ∆LIV tilt angles had a higher incidence of distal AO (n = 4/8, 50.0%) than patients with positive ∆LIV tilt angles (n = 1/42, 2.4%) (p = 0.001).
Achieving an intraoperative LIV tilt angle (β) greater than or equal to the preoperative α angle derived (β ≥ α) may help avoid the distal AO phenomenon.
设计一种数学模型，用于通过术前仰卧位左侧弯（LSB）X线片估计青少年特发性脊柱侧凸（AIS）Lenke 1型和2型（非AR曲线）患者术中最低固定椎体（LIV）倾斜角，并回顾其临床和放射学结果。
术前测量的调整后LSB LIV倾斜角（α）的数学模型表示为术前LSB LIV倾斜角（x）与LIV位移角（y）之和（α = x + y）。该模型在研究的第一部分通过评分者间和评分者内分析进行了验证。得出的α角用于估计术中LIV倾斜角。在研究的第二部分，回顾了50例使用α角进行手术的Lenke 1型和2型（非AR曲线）AIS患者的临床和放射学结果。确定术中实现的LIV倾斜角（β）与术前α角之间的差异（ΔLIV倾斜角 = β - α）。
α角具有出色的评分者间和评分者内组内相关系数（0.982；0.907）。42例患者的ΔLIV倾斜角为正，而8例患者的ΔLIV倾斜角为负。远端附加（AO）的总体发生率为10.0%（n = 5/50）。ΔLIV倾斜角为负的患者远端AO的发生率（n = 4/8，50.0%）高于ΔLIV倾斜角为正的患者（n = 1/42，2.4%）（p = 0.001）。
实现术中LIV倾斜角（β）大于或等于得出的术前α角（β≥α）可能有助于避免远端AO现象。
