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Purpose: To determine the reliability of pedicle screws placed in children younger than 7 years of age, and to evaluate the effect of pedicle screw insertion on further growth of the vertebra and spinal canal., Methods: A retrospective study of 35 consecutive patients through Jan 2003-Dec 2010 for congenital scoliosis in <7 years children was performed at one spine center. Patients undergoing pedicle screw instrumentation of at least two levels, which had been followed-up for at least 24 months were included. Measurements were performed in instrumented and adjacent non-instrumented levels. The effect of pedicle screw insertion on further growth was evaluated., Results: The average age at surgery was 4.4 year (53 months, range, 23-84 months). 190 segments in 35 patients met the inclusion criteria. 77 segments had no screws and 113 had at least one screw. There was a significant difference between the pre-operative and final follow-up values of the measurement of spinal canal and vertebral body parameters (P < 0.001). No significant difference existed between growth rates of vertebral bodies and the sagittal diameters of spinal canal with or without screws. The growth rates of vertebral bodies in lumbar spine were higher than in thoracic spine in both instrumented and adjacent groups., Conclusion: Pedicle screw instrumentation does not cause a retardation effect on the development of vertebral bodies and the spinal canal in children at an early age. It is a safe and reliable procedure to achieve a stable fixation.

Study Design: An analysis of computed tomography (CT) images of patients with adolescent thoracic idiopathic scoliosis for posterior pedicle screw placement., Objective: To evaluate the relative position of the aorta to the spine by the axial CT scans in patients with right thoracic idiopathic scoliosis, and to discuss the safe trajectory and screw length for posterior pedicle screw placement., Summary of Background Data: Posterior pedicle screw instrumentation and fusion are widely used in the correction of scoliosis. Pedicle screw placement in the thoracic spine implies risk of injuring the aorta. Literatures on the relative position of the aorta to the spine are mostly focused on the anterior surgery. However, few are reported about the posterior surgery., Methods: A total of 47 patients with adolescent right thoracic idiopathic scoliosis who underwent CT scan of total spine before surgery were included in this study. Transverse plane including bilateral pedicles, lamina, and transverse process was selected for measurement from T4 to T12. We defined a new coordinate system, and 5 parameters were measured in each vertebral body from T4 to T12 of the patients. The point where the left pedicle axial line and the base of the left transverse process intersected was defined as the origin of the coordinate system. A line connecting bilateral intersection was defined as x-axis. y-axis perpendicular to the x-axis is drawn ventrally from the origin. The left pedicle-aorta angle (α), the left aorta angle (β), the left pedicle-aorta distance (PAD), the aorta-x-axis distance (AXD), and the vertebral rotation angle (γ) were measured., Results: The values of angles α and β had a tendency of first increasing and then decreasing, and increasing again from T4 to T12. The lowest value of angle α occurred at T10 (7.45±6.10 degrees), followed by T4 (8.89±6.49 degrees), T11 (9.13±7.59 degrees), and T9 (9.74±6.11 degrees). PAD and AXD values had a tendency of decreasing first and then increasing from T4 to T12. The lowest values of PAD and AXD occurred at T6; 25.94±5.33 and 23.64±6.53 mm, respectively. From the cephalad to the caudal spine, angle γ increased first and then decreased. The highest value occurred at T7 (2.32±6.83 degrees), which rotated to the right side. The second largest value occurred at T8 (2.23±7.76 degrees). Statistical analysis indicated that the apical vertebral translation and vertebral rotation angle were significantly positively correlated to angles α and β (P<0.05)., Conclusions: The highest risk of injuring the aorta when placing pedicle screw during posterior scoliosis surgery was at T10, followed by T4, T11, and T9 in right thoracic idiopathic scoliosis. Taking a spine CT scan and evaluating the relative position of the aorta to the thoracic spine before surgery are significant in precise and safe pedicle screw placement.

Introduction: Posterior 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.Methods: 45 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°.Results: The 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.Conclusion: Posterior 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Discusses the use of anterior Texas Scottish Rite Hospital (TSRH) instrumentation for the treatment of scoliosis. Analysis of the clinical outcomes of the patients; Introduction of TSRH bone screws onto the lateral surface of vertebral bodies.