The Importance of Lumbar Curve Flexibility and Apical Vertebral Rotation for the Prediction of Spontaneous Lumbar Curve Correction in Selective Thoracic Fusion for Lenke Type 1 and 2 C Curves: Retrospective Cohort Study with a Mean Follow-Up of More than 10 years

Abstract

Study Design Retrospective analysis of a prospectively collected data. Objective Lumbar flexibility(LF) is generally defined with preoperative side bending films;it is not clear what percentage of LF predicts the spontaneous lumbar curve correction (SLCC) at long term follow up. Aim of this study was to find out cut-off value of preoperative LF,apical vertebra rotation(AVR) and apical vertebral translation(AVT);which may predict more than 50%SLCC. Methods Patients with Lenke 1C&2C curves,treated with posterior STF,with a minimum 10 years follow up were included.The patients who had more than 50% SLCC(Group A) or less than 50% (Group B) were compared in terms of LF,AVR and AVT to understand a cut-off value of those parameters.Statistically, Receiver Operating Characteristic(ROC) test was used. Results Fifty five AIS patients (54F, 1M) with mean age 14 (11-17) were included to study.Thoracic curve correction rate was 75%;lumbar curve correction rate was 59% at the latest follow up.Group A included 45(82%) patients at the latest follow up.Three patients (5%) showed coronal decompensation at early postop and 2 of them became compensated at f/up.ROC analyses showed 69% flexibility as the cut-off value for SLCC ( P < .01).The difference between groups in terms of preop mean AVRs was significant ( P = .029) (Group A = 1.9; Group B = 2.4). Conclusion In Lenke 1C&2C curves,whenever LF on the preoperative bending x-ray is greater than 70% ( P < .01)and AVR is equal or less than grade 2,STF provides satisfactory clinical and radiological SLCC with more than mean 10 years f/up.This flexibility rate and apical vertebral rotation can be helpful in decision making for successful STF.

Reliability Nash and Moe’s Grades in Patients With Adolescent Idiopathic Scoliosis

“…Assessment of the axial plane of AIS, with rotation of the apical vertebra as its most important parameter, has attracted increasing interest in recent years. 1,2,[5][6][7]9,13 The degree of vertebral rotation can be useful for monitoring the progression of scoliosis and assessing treatment results. 5,[14][15][16] Accurate assessment of vertebral rotation allows prediction of curve progression, the degree of correction, and possible decompensation of the coronal balance of the spine in the postoperative period.…”

“…1,2,[5][6][7]9,13 The degree of vertebral rotation can be useful for monitoring the progression of scoliosis and assessing treatment results. 5,[14][15][16] Accurate assessment of vertebral rotation allows prediction of curve progression, the degree of correction, and possible decompensation of the coronal balance of the spine in the postoperative period. 5,6 Behensky et al, 6 in a retrospective review of Lenke type 3C AIS, concluded that rigid rotational deformity of the lumbar curve (vertebral rotation correction of less than 40% in the slopes) results in coronal imbalance in the postoperative follow-up in selective thoracic fusions.…”

“…5,[14][15][16] Accurate assessment of vertebral rotation allows prediction of curve progression, the degree of correction, and possible decompensation of the coronal balance of the spine in the postoperative period. 5,6 Behensky et al, 6 in a retrospective review of Lenke type 3C AIS, concluded that rigid rotational deformity of the lumbar curve (vertebral rotation correction of less than 40% in the slopes) results in coronal imbalance in the postoperative follow-up in selective thoracic fusions. Therefore, accurate estimation of vertebral rotation can avoid unnecessary surgery and its consequent risks.…”

“…3,4 However, the importance of the axial plane, assessed by the degree of vertebral rotation, has been increasingly demonstrated as an important parameter for prognosis and patient satisfaction with treatment results. 1,2,[5][6][7] Due to its simplicity, the Nash & Moe classification is the most widely used method for assessing vertebral rotation. 1,8,9 This method consists of an anteroposterior (AP) radiographic assessment of the spine, in which vertebral rotation is measured according to vertebral pedicle position about the lateral margin of the curve's convexity.…”

Features of Determining Vertebral Rotation in Children With Idiopathic Scoliosis

“…Однако авторами не было выявлено статистических различий между результатами нового метода и ранее разработанными [7]. Также важное значение точность оценки ротации апикальных позвонков имеет при анализе различных типов деформации идиопатического сколиоза и трехмерного анализа полученной послеоперационной коррекции деформации позвоночника [14,15].…”