4.

Purpose: This study aims to derive a formula to predict post-operative height increment in Lenke 1 and Lenke 2 adolescent idiopathic scoliosis (AIS) patients using preoperative radiological parameters. Methods: This study involved 70 consecutive Lenke 1 and 2 AIS patients who underwent scoliosis correction with alternate-level pedicle screw instrumentation. Preoperative parameters that were measured included main thoracic (MT) Cobb angle, proximal thoracic (PT) Cobb angle, lumbar Cobb angle as well as thoracic kyphosis. Side-bending flexibility (SBF) and fulcrumbending flexibility (FBF) were derived from the measurements. Preoperative height and post-operative height increment was measured by an independent observer using a standardized method.

To investigate the prevalence and the associated risk factors of chronic neuropathic pain symptoms using painDETECT questionnaire in adolescent idiopathic scoliosis (AIS) patients who underwent posterior spinal fusion (PSF) surgery. Overview of Literature: Post-lumbar surgery syndrome is a disease entity that describes neuropathic pain following spinal surgery. However, few studies have investigated the prevalence and risk factors for neuropathic pain in pediatric population undergoing corrective spinal surgery. Methods: Forty AIS patients were recruited. Demographic, preoperative, and postoperative data were recorded. The magnitude and characteristics of postoperative pain were assessed using the painDETECT questionnaire through telephone enquiries at intervals of 2, 6, 12, and 24 weeks. Statistical analyses were followed by Pearson correlation test to determine the relationship between pain scores at 6, 12, and 24 weeks with the risk factors. Results: Based on the painDETECT questionnaire, 90% of the patients had nociceptive pain, and 10% had a possible neuropathic pain component at 2 weeks postoperatively as per a mean painDETECT score of 7.1±4.5. Assessments at 6, 12, and 24 weeks showed that no patients had neuropathic pain with painDETECT scores of 4.4±3.2, 2.9±2.9, and 1.5±2.0, respectively. There was a significant correlation between total postoperative morphine use during 48 hours after the surgery and a tendency to develop neuropathic pain (p=0.022). Conclusions: Chronic neuropathic pain was uncommon in AIS patients who had undergone PSF surgery. Higher opioid consumption will increase the possibility of developing chronic neuropathic pain.

Objective: To compare construct stiffness of cortical screw (CS)-rod transforaminal lumbar interbody fusion (TLIF) construct (G2) versus pedicle screw (PS)-rod TLIF construct (G1) in the standardized porcine lumbar spine. Methods: Six porcine lumbar spines (L2-L5) were separated into 12 functional spine units. Bilateral total facetectomies and interlaminar decompression were performed for all specimens. Non-destructive loading to assess stiffness in lateral bending, flexion and extension as well as axial rotation was performed using a universal material testing machine. Results: PS and CS constructs were significantly stiffer than the intact spine except in axial rotation. Using the normalized ratio to the intact spine, there is no significant difference between the stiffness of PS and CS: flexion (1.41 + 0.27, 1.55 + 0. Conclusion:The CS-rod TLIF construct provided comparable construct stiffness to a traditional PS-rod TLIF construct in a 'standardized' porcine lumbar spine model.