Predictability of spontaneous thoracic curve correction after anterior thoracolumbar correction and fusion in adolescent idiopathic scoliosis. A retrospective study on a consecutive series of 29 patients with a minimum follow-up of 2 years

Lin

Wang

et al. 2016

Spine

Study Design.Retrospective study.Objective.To study the behavior of the unfused thoracic curve in Lenke type 5C during the follow-up and to identify risk factors for its correction loss.Summary of Background Data.Few studies have focused on the spontaneous behaviors of the unfused thoracic curve after selective thoracolumbar or lumbar fusion during the follow-up and the risk factors for spontaneous correction loss.Methods.We retrospectively reviewed 45 patients (41 females and 4 males) with AIS who underwent selective TL/L fusion from 2006 to 2012 in a single institution. The follow-up averaged 36 months (range, 24–105 months). Patients were divided into two groups. Thoracic curves in group A improved or maintained their curve magnitude after spontaneous correction, with a negative or no correction loss during the follow-up. Thoracic curves in group B deteriorated after spontaneous correction with a positive correction loss. Univariate analysis and multivariate analysis were built to identify the risk factors for correction loss of the unfused thoracic curves.Results.The minor thoracic curve was 26° preoperatively. It was corrected to 13° immediately with a spontaneous correction of 48.5%. At final follow-up it was 14° with a correction loss of 1°. Thoracic curves did not deteriorate after spontaneous correction in 23 cases in group A, while 22 cases were identified with thoracic curve progressing in group B. In multivariate analysis, two risk factors were independently associated with thoracic correction loss: higher flexibility and better immediate spontaneous correction rate of thoracic curve.Conclusion.Posterior selective TL/L fusion with pedicle screw constructs is an effective treatment for Lenke 5C AIS patients. Nonstructural thoracic curves with higher flexibility or better immediate correction are more likely to progress during the follow-up and close attentions must be paid to these patients in case of decompensation.Level of Evidence: 4

Section: Discussionmentioning

confidence: 99%

“…Selective fusion has been widely accepted by spine surgeons. 1–4 Posterior selective thoracolubmar or lumbar (TL/L) fusion is considered a major treatment to Lenke 5C AIS patients with structural TL/L curve and nonstructural or compensatory thoracic curve. Attention has been paid to the prognosis of the unfused thoracic segments.…”

mentioning

confidence: 99%

Higher Flexibility and Better Immediate Spontaneous Correction May Not Gain Better Results for Nonstructural Thoracic Curve in Lenke 5C AIS Patients

Lin

Wang

et al. 2016

Spine

“…Anterior approach instrumentation and fusion has been widely accepted as a reliable and effective treatment for TL/L AIS patients. 2 , 13 , 14 , 19 – 21 However, some studies have found that the anterior method often results in problems with kyphosis, pseudarthrosis, and loss of correction. 1 , 4 Many studies have reported the spontaneous correction of an uninstrumented thoracic curve after anterior thoracolumbar correction and fusion.…”

Section: Discussionmentioning

confidence: 99%

“…Huitema et al 13 and Senkoylu et al 14 showed spontaneous thoracic curve correction after the selective anterior fusion of thoracolumbar and lumbar curves, obtaining satisfactory results in the treatment of AIS. Many studies have also found that the improvement of the unfused thoracic curve occurs through posterior fusion of the TL/L curves.…”

Section: Introductionmentioning

confidence: 99%

Spontaneous Thoracic Curve Correction After Selective Posterior Fusion of Thoracolumbar/Lumbar Curves in Lenke 5C Adolescent Idiopathic Scoliosis

Wang

Wei

et al. 2015

Medicine

Selective fusion of the thoracolumbar/lumbar (TL/L) curve is an effective method for the treatment of Lenke type 5C curves. Several studies have demonstrated that spontaneous correction of the thoracic curve does indeed occur. However, how this correction occurs after isolated posterior segmental instrumentation of the structural lumbar curve has not been well described.The aim of this study was to evaluate the response of the thoracic curve to selective TL/L curve fusion in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS) and assess the correlative clinical outcomes.Thirty-four consecutive patients with Lenke type 5C AIS were included in this study. All patients underwent selective TL/L curve instrumentation and fusion via the posterior approach. Coronal and sagittal radiographs were analyzed before surgery, at 1 week after surgery and at least 2 years after surgery. The preoperative coronal Cobb angle of the major TL/L curve was 45.4° ± 7.0°, and that of the minor thoracic curve was 25.4° ± 8.8°. The major TL/L and minor thoracic curves were corrected to postoperative angles of 9.5° ± 5.0° and 11.2° ± 5.2°, respectively, and measured 10.5° ± 6.0° and 13.4° ± 7.5° at the follow-up, respectively. The supine side-bending average Cobb angle of the thoracic curve was 9.9°. These results demonstrate satisfactory improvements because of coronal and sagittal restoration. Significant correlations were found between the preoperative and early postoperative conditions and the Cobb angle changes of the minor thoracic curve and the major TL/L curves (r = 0.42, P = 0.01). Significant correlations were also observed between the early and final follow-up postoperative conditions and the Cobb angle changes of the minor thoracic curve and the major TL/L curves (r = 0.57, P < 0.001). Significant correlations were observed between increased thoracic kyphosis (TK) and increased lumbar lordosis (LL) in the preoperative and early postoperative conditions (r = 0.36, P = 0.035) and between increased TK and increased LL in the preoperative and final follow-up postoperative conditions (r = 0.51, P = 0.002).Spontaneous correction of the thoracic curve is a reflection of the TL/L curve correction in Lenke 5C AIS patients. Supine side-bending radiographs are an effective method of predicting the spontaneous correction of thoracic curves. The correction of LL is important for maintaining spinal sagittal alignment.

“…If the “residual” TL/L curve was too large, the spontaneous correction of thoracic curve would be incomplete and it may progress during follow-up. On the other hand, Huitema et al [24] reported that spontaneous correction of the thoracic curve is a reflection of the TL/L curve correction in AIS in anterior selective TL/L fusion. It means, the more the TL/L curve was corrected, the more the thoracic curve can spontaneously correct itself.…”

Section: Discussionmentioning

confidence: 99%

Radiographic evaluation of posterior selective thoracolumbar or lumbar fusion for moderate Lenke 5C curves

Lin

Arch Orthop Trauma Surg

et al. 2016

IntroductionPosterior selective thoracolumbar or lumbar (TL/L) fusion with pedicle screw constructs for adolescent idiopathic scoliosis (AIS) has been studied in a few researches. However, few studies have discussed the indication for selective TL/L fusion and the behaviors of its adjacent disc angle. The present study aims to discuss the indication for posterior selective TL/L fusion and the behavior of the adjacent disc angle.Methods45 consecutive cases of AIS undergoing posterior selective TL/L fusion were retrospectively evaluated, with an average follow-up of 36 months. Radiographs were reviewed to determine the coronal curve magnitude and the sagittal alignment preoperatively, postoperatively and at final follow-up. Thoracic curves in groups A had a correction loss of more than 5°, while thoracic curves in group B had a correction loss of not more than 5°.ResultsThe coronal curve magnitude of the TL/L curve averaged 44° preoperatively and it was corrected to 6° immediately with a correction rate of 84.8 %. At final follow-up it was 9° with a correction loss of 3°. The minor thoracic curve was 26° preoperatively, and the convex side bending curve magnitude averaged 8° with a flexibility of 72.7 %. It was corrected to 13° immediately with a spontaneous correction of 48.5 %. At final follow-up it was 14° with a correction loss of 1°. UIVA decreased from 4° to 2° after surgery, and it was 2° at final follow-up. LIVA decreased from 7° to 4° after surgery, and it was 5° at final follow-up. Maximal correction of TL/L curves in group A is significantly less than that in group B. 1 patient received revision surgery to fuse the progressive thoracic curve.ConclusionPosterior selective TL/L fusion with pedicle screw constructs allows for spontaneous thoracic correction and maintains coronal and sagittal balance during the follow-up. Maximal correction instead of undercorrection was recommended for moderate Lenke 5C curves. Disc wedging could be improved after surgery and well maintained during the follow-up.