Search

Abstract: Unstable spine fractures commonly occur in the setting of a polytraumatized patient. The aim of management is to balance the need for early operative stabilization and prevent additional trauma due to the surgery. Recent published literature has demonstrated the benefits of early stabilization of an unstable spine fracture particularly in patients with higher injury severity score (ISS). We report two cases of polytrauma with unstable spine fractures stabilized with a minimally invasive percutaneous pedicle screw instrumentation system as a form of damage control surgery. The patients had good recovery from the polytrauma injuries. These two cases illustrate the role of minimally invasive stabilization, its limitations and technical pitfalls in the management of unstable spine fractures in the polytrauma setting as a form of damage control surgery. [ABSTRACT FROM AUTHOR]

The incidence of traumatic spine fractures (TSF) is increasing worldwide, with a reported annual incidence of up to 32.8 per 100000 persons. However, there are only a few cases of spine fractures reported in adolescent idiopathic scoliosis (AIS) patients after posterior spinal fusion (PSF) in the literature. Fractures adjacent to fusion blocks that extend into the lower lumbar spine pose a unique challenge as stabilization of such fractures might require an extension of instrumentation to L5 or the pelvis. We report a novel surgical technique where bilateral pedicle and cortical screws at L4 and supplementary rods that connect the cortical screws to the main rods via dominos were implemented for optimizing the distal anchorage for TSF stabilization following an L3 Chance fracture in an AIS patient who had undergone T4-L2 posterior spinal fusion.

Study Design: Retrospective study., Purpose: To report the perioperative and radiological outcomes of single-stage posterior passive correction and fusion (SSPPCF) in adolescent patients who present with congenital scoliosis., Overview of Literature: The surgical treatment for congenital scoliosis is complex. There is no definitive guide on surgical options for skeletally matured adolescent patients who have congenital scoliosis., Methods: Patients with congenital scoliosis who underwent SSPPCF using a pedicle screw system were reviewed. We identified the following three surgical indications: (1) hemivertebra or wedge vertebra over the thoracic or thoracolumbar region with structural lumbar curves, (2) hemivertebra or wedge vertebra at the lumbar region with significant pelvic obliquity or sacral slanting, and (3) mixed or complex congenital scoliosis. The demographic, perioperative, and radiographic data of these patients were collected., Results: Thirty-four patients were reviewed. The mean patient age was 14.6±3.4 years. There were 13 hemivertebrae, three wedged vertebrae, two butterfly vertebrae, three hemivertebrae with butterfly vertebra, eight unsegmented bars, and five multiple complex lesions. The average surgical duration was 219.4±68.8 minutes. The average blood loss was 1,208.4±763.5 mL. Seven patients required allogeneic blood transfusion. The mean hospital stay duration was 6.1±2.5 days. The complication rate was 11.8% (4/34): one patient had severe blood loss, one had rod breakage, and two had distal adding-on. The Cobb angle reduced from 65.9°±17.4° to 36.3°±15.3° (p<0.001) with a correction rate (CR) of 44.8%±17.4%. The regional kyphotic angle decreased from 39.9°±20.5° to 27.5°±13.9° (p=0.001) with a CR of 19.3%±49.6%. Radiographic parameters (radiographic shoulder height, clavicle angle, T1 tilt, cervical axis, pelvic obliquity, coronal balance, and apical vertebral translation) showed significant improvement postoperatively., Conclusions: SSPPCF was a feasible option for adolescent patients with congenital scoliosis who were skeletally matured.

Study Design: Retrospective study., Objective: To assess the learning curve of a dual attending surgeon strategy in severe adolescent idiopathic scoliosis patients., Summary of Background Data: The advantages of a dual attending surgeon strategy in improving the perioperative outcome in scoliosis surgery had been reported. However, the learning curve of this strategy in severe scoliosis had not been widely studied., Methods: A total of 105 patients with adolescent idiopathic scoliosis with Cobb angle of 90° or greater, who underwent posterior spinal fusion using a dual attending surgeon strategy were recruited. Primary outcomes were operative time, total blood loss, allogeneic blood transfusion requirement, length of hospital stay from time of operation and perioperative complications. Cases were sorted chronologically into group 1: cases 1 to 35, group 2: cases 36 to 70, and group 3: case 71 to 105. Mean operative time (≤193.3 min), total blood loss (≤1612.2 mL), combination of both and allogeneic blood transfusion were the selected criteria for receiver operating characteristic analysis of the learning curve., Results: The mean Cobb angle was 104.5° ± 12.3°. The operative time, total blood loss, and allogeneic blood transfusion requirement reduced significantly for group 1 (220.6 ± 54.8 min; 2011.3 ± 881.8 mL; 12 cases) versus group 2 (183.6 ± 36.7 min; 1481.6 ± 1035.5 mL; 3 cases) and group 1 versus group 3 (175.6 ± 38.4 min; 1343.7 ± 477.8 mL; 3 cases) (P < 0.05). There were six perioperative complications. Fifty-seven cases were required to achieve the preset criteria (mean operative time and mean total blood loss) (area under the curve 0.740; P < 0.001; sensitivity 0.675; specificity 0.662)., Conclusion: There was significant improvement in operative time and total blood loss when comparing group 1 versus group 2 and group 1 versus group 3. The cut-off point for the learning curve was 57 cases when the preset criteria were fulfilled (≤193.3 min operative time and ≤1612.2 mL of total blood loss).Level of Evidence: 4., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Knowledge on the factors affecting the correction rate (CR) aids in the surgical planning among severe idiopathic scoliosis (IS) patients. This study aimed to investigate the independent factors affecting CR among patients with severe IS (Cobb angle ≥ 90°) who underwent single-staged posterior spinal fusion (PSF)., Methods: We retrospectively reviewed 128 severe IS patients who underwent single-staged PSF. Factors including age, height, weight, body mass index, Risser sign, Lenke subtypes, preoperative major Cobb angle, side bending major Cobb angle, side bending flexibility (SBF), motion segments of the major curve, AR curve, number of levels fused, screw density, operative time and postoperative major Cobb angle were analysed using linear regression analysis., Results: The mean age was 15.5 ± 4.5 years with mean Risser sign of 3.1 ± 1.6. The mean preoperative Cobb, SBF, postoperative Cobb and CR were 102.8 ± 12.3°, 37.5 ± 13.7%, 44.4 ± 13.5° and 57.2 ± 10.8%, respectively. From stepwise multiple linear regression analysis, SBF, Risser sign and AR curve were the independent predictive factors for CR, with R 2 value of 0.345 (p < 0.001). CR can be predicted using the formula: 47.21 + (0.34 × SBF)-(1.47 × Risser sign) + (3.69 × AR), where AR = 1 and non-AR = 0., Conclusion: The flexibility of the major curve, Risser sign and AR curve were the most important predictors for CR in a single-staged PSF among patients with severe IS.

Study Design: Prospective study., Objective: To determine the parents'/patients' perception on the informed consent process prior to posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) patients., Summary of Background Data: Understanding parents/patients perspective on the process is important in order to achieve the goal of consent and prevent medico-legal implications., Methods: Fifty AIS patients operated between August 2019 and November 2019 were prospectively recruited. Parents'/patients' perceptions on three sections were evaluated: the process of the informed consent, specific operative risk which they were most concerned with and the accountability of surgeons for the surgical risks. These data were ranked and scored using a 5-point Likert Scale. Preferences were reported in mean and standard deviation. Differences in terms of preferences were studied using One-way analysis of variance (ANOVA) analysis and deemed significant when P < 0.05., Results: There were 30 females (60.0%) and 20 males (40.0%) with a mean age of 41.8 ± 10.6 years. Majority of parents/patients preferred the inform consent to be explained more than once (P = 0.021), once during clinic consultation and once during admission (4.2 ± 1.0). Consent taking by both attending surgeons was preferred (4.5 ± 0.6) compared with other healthcare providers, P < 0.001. Death (60.0%) and neurological deficit (30.0%) were the two most concerned surgical risks. Parents/patients would still hold the surgeon accountable for any complications despite signing the informed consent and they felt that surgeons were directly responsible for screw-related injuries (3.9 ± 0.9), neurological injury (3.8 ± 0.9), and intraoperative bleeding (3.7 ± 0.9)., Conclusion: Parents/patients preferred the attending surgeons to personally explain the informed consent, more than once with the use of visual aid. They would still hold the surgeons accountable when complications occur despite acceptance of the informed consent., Level of Evidence: 2.

Study Design: Cross-sectional survey., Objective: The aim of this study was to investigate the impact of COVID-19 pandemic on the clinical practices of spine surgeons within the Asia Pacific region., Summary of Background Data: COVID-19 pandemic had changed spine surgeons' clinical practices and their concerns toward personal and family risk of infection., Methods: This cross-sectional survey was carried out from May 4, 2020 to June 4, 2020. The questionnaire was administered using REDCAP. The online questionnaire includes four sections. First section includes surgeon's demographics, background, type of clinical practice, and status of pandemic in their country. Second section includes volume and the type of spine surgery practice before the COVID pandemic. Third section includes changes of clinical practice during the pandemic and the last section was regarding their concern on COVID transmission., Results: Total of 222 respondents from 19 countries completed the questionnaire. During the pandemic, 92.3% of the respondents felt their clinical practice was affected. 58.5% respondents reported reduced outpatient clinic hours and 74.6% respondents reported reduced operation theatre hours due to the enforcement by the hospital administration. The mean reduction of clinic volume for all countries was 48.1%. There was a significant reduction in the number of surgeries performed in Japan, Malaysia, India, Philippines, and South Korea. This was due to reduced patient load. More than 60% of respondents were worried being infected by COVID-19 virus and >68% were worried of transmission to their family members., Conclusion: COVID-19 pandemic has significantly affected the clinical and surgical practice of spine surgeons in the Asia Pacific region. Clinics were closed or the practice hours reduced. Similarly, surgical theaters were closed, reduced, or limited to semi-emergency and emergency surgeries. Spine surgeons were moderately concerned of contracting COVID-19 during their clinical practice but were extremely concerned to transmit this disease to their family members., Level of Evidence: 4.

Growth hormone secreting pituitary tumor or gigantism has not been previously reported to be associated with rapid progression of scoliosis in the literature. However, there are some reports indicating scoliosis can be worsened by growth hormone therapy in children and adolescents. A 19-year-old boy was referred to our institution for the treatment of a right thoracolumbar scoliosis. The Cobb angle had worsened from 29° to 83° over two years' duration. He attained puberty at the age of 13. He had a previous history of slipped upper femoral epiphysis (SUFE), which was operated in 2015, with no clinical features of gigantism. Preoperative assessment was performed. He was diagnosed with growth hormone secreting pituitary macroadenoma by magnetic resonance imaging with a high serum level of insulin-like growth factor-I (IGF-I). Computed tomography (CT) of the pancreas showed a pancreatic endocrine tumor. The patient was later diagnosed with multiple endocrine neoplasia type 1 (MEN 1). He underwent endoscopic endonasal excision of the pituitary mass and distal pancreatectomy. This case indicates that growth hormone secreting pituitary macroadenoma could result in rapid progression of scoliosis.

Study Design: Retrospective propensity score matching study., Objective: To investigate whether menses affect intraoperative blood loss in female adolescent idiopathic scoliosis (AIS) patients undergoing posterior spinal fusion (PSF) surgeries., Summary of Background Data: There were concerns whether patients having menses will have higher intraoperative blood loss if surgery were to be done during this period., Methods: This study included 372 females who were operated between May 2016 to May 2019. Fifty-five patients had menses during surgery (Group 1, G1) and 317 patients did not have menses during surgery (Group 2, G2). Propensity score matching (PSM) analysis with one-to-one, nearest neighbor matching technique and with a match tolerance of 0.001 was used. The main outcome measures were intraoperative blood loss (IBL), volume of blood salvaged, transfusion rate, preoperative hemoglobin, preoperative platelet, preoperative prothrombin time, preoperative activated partial thromboplastin time (APTT), international normalized ratio (INR), and postoperative hemoglobin. Postoperative Cobb angle and correction rate were also documented., Results: At the end of PSM analysis, 46 patients from each group were matched and balanced. The average operation duration for G1 was 140.8 ± 43.0 minutes compared with 143.1 ± 48.3 minutes in G2 (P = 0.806). The intraoperative blood loss for G1 was 904.3 ± 496.3 mL and for G2 was 907.9 ± 482.8 mL (P = 0.972). There was no significant difference in terms of normalized blood loss (NBL), volume of blood salvaged during surgery, preoperative hemoglobin, postoperative hemoglobin, hemoglobin drift, estimated blood volume (EBV), IBL per EBV and IBL per level fused (P > 0.05). No postoperative complications were encountered in both groups. On average, the postoperative hospital stay was 3.5 ± 0.8 days for both groups (P = 0.143)., Conclusion: Performing corrective surgery during the menstrual phase in female AIS patients is safe without risk of increased blood loss., Level of Evidence: 4.

Background Context: Biopsy is important to obtain microbiological and histopathological diagnosis in spine infections and tumors. To date, there have been no prospective randomized trials comparing fluoroscopic guided and computed tomography (CT) transpedicular biopsy techniques. The goal of this study was to evaluate the accuracy, safety, and diagnostic outcome of these two diagnostic techniques., Purpose: To evaluate the accuracy, safety, and diagnostic outcome of fluoroscopic guided and CT transpedicular biopsy techniques., Study Design: Prospective randomized trial., Patient Sample: Sixty consecutive patients with clinical symptoms and radiological features suggestive of spinal infection or malignancy were recruited and randomized into fluoroscopic or CT guided spinal biopsy groups. Both groups were similar in terms of patient demographics, distribution of spinal infections and malignancy cases, and the level of biopsies., Outcome Measures: The primary outcome measure was diagnostic accuracy of both methods, determined based on true positive, true negative, false positive, and false negative biopsy findings. Secondary outcome measures included radiation exposure to patients and doctors, complications, and postbiopsy pain score., Methods: A transpedicular approach was performed with an 8G core biopsy needle. Specimens were sent for histopathological and microbiological examinations. Diagnosis was made based on biopsy results, clinical criteria and monitoring of disease progression during a 6-month follow up duration. Clinical criteria included presence of risk factors, level of inflammatory markers and magnetic resonance imaging findings. Radiation exposure to patients and doctors was measured with dosimeters., Results: There was no significant difference between the diagnostic accuracy of fluoroscopic and CT guided spinal biopsy (p=0.67) or between the diagnostic accuracy of spinal infection and spinal tumor in both groups (p=0.402 for fluoroscopy group and p=0.223 for CT group). Radiation exposure to patients was approximately 26 times higher in the CT group. Radiation exposure to doctors in the CT group was approximately 2 times higher compared to the fluoroscopic group if a lead shield was not used. Lead shields significantly reduced radiation exposure to doctors anywhere from 2 to 8 times. No complications were observed for either group and the differences in postbiopsy pain scores were not significant., Conclusions: The accuracy, procedure time, complication rate and pain score for both groups were similar. However, radiation exposure to patients and doctors were significantly higher in the CT group without lead protection. With lead protection, radiation to doctors reduced significantly., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Study Design: Retrospective study., Objective: To investigate the relationship between a +ve postoperative Upper Instrumented Vertebra (UIV) (≥0°) tilt angle and the risk of medial shoulder/neck and lateral shoulder imbalance among Lenke 1 and 2 Adolescent Idiopathic Scoliosis (AIS) patients following Posterior Spinal Fusion., Summary of Background Data: Current UIV selection strategy has poor correlation with postoperative shoulder balance. The relationship between a +ve postoperative UIV tilt angle and the risk of postoperative shoulder and neck imbalance was unknown., Methods: One hundred thirty-six Lenke 1 and 2 AIS patients with minimum 2 years follow-up were recruited. For medial shoulder and neck balance, patients were categorized into positive (+ve) imbalance (≥+4°), balanced, or negative (-ve) imbalance (≤-4°) groups based on T1 tilt angle/Cervical Axis measurement. For lateral shoulder balance, patients were classified into +ve imbalance (≥+3°) balanced, and -ve imbalance (≤-3°) groups based on Clavicle Angle (Cla-A) measurement. Linear regression analysis identified the predictive factors for shoulder/neck imbalance. Logistic regression analysis calculated the odds ratio of shoulder/neck imbalance for patients with +ve postoperative UIV tilt angle., Results: Postoperative UIV tilt angle and preoperative T1 tilt angle were predictive of +ve medial shoulder imbalance. Postoperative UIV tilt angle and postoperative PT correction were predictive of +ve neck imbalance. Approximately 51.6% of patients with +ve medial shoulder imbalance had +ve postoperative UIV tilt angle. Patients with +ve postoperative UIV tilt angle had 14.9 times increased odds of developing +ve medial shoulder imbalance and 3.3 times increased odds of developing +ve neck imbalance. Postoperative UIV tilt angle did not predict lateral shoulder imbalance., Conclusion: Patients with +ve postoperative UIV tilt angle had 14.9 times increased odds of developing +ve medial shoulder imbalance (T1 tilt angle ≥+4°) and 3.3 times increased odds of developing +ve neck imbalance (cervical axis ≥+4°)., Level of Evidence: 4.

Study Design: Retrospective study., Objective: This study looked into whether crossbar can reliably measure Upper Instrumend Vertebra (UIV) tilt angle intraoperatively and accurately predict the UIV tilt angle postoperatively and at final follow-up., Summary of Background Data: Postoperative shoulder imbalance is a common cause of poor cosmetic appearance leading to patient dissatisfaction. There were no reports describing the technique or method in measuring the UIV tilt angle intraoperatively. Therefore, this study was designed to look into the reliability and accuracy of the usage of intraoperative crossbar in measuring the UIV tilt angle intraoperatively., Methods: Lenke 1 and 2 Adolescent Idiopathic Scoliosis patients who underwent instrumented Posterior Spinal Fusion using pedicle screw constructs with minimum follow-up of 24 months were recruited for this study. After surgical correction, intraoperative UIV tilt angle was measured using a crossbar. Immediate postoperative and final follow up UIV tilt angle was measured on the standing anteroposterior radiographs., Results: A total of 100 patients were included into this study. The reliability of the intraoperative crossbar to measure the optimal UIV tilt angle intraoperatively was determined by repeated measurements by assessors and measurement by different assessors. We found that the intra observer and inter observer reliability was very good with intraclass correlation coefficient values of >0.9. The accuracy of the intraoperative crossbar to measure the optimal UIV tilt angle intraoperatively was determined by comparing this measurement with the postoperative UIV tilt angle. We found that there was no significant difference (P>0.05) between intraoperative, immediate postoperative, and follow-up UIV tilt angle., Conclusions: The crossbar can be used to measure the intraoperative UIV tilt angle consistently and was able to predict the postoperative UIV tilt angle. It was a cheap, simple, reliable, and accurate instrument to measure the intraoperative UIV tilt angle.

Study Design: Retrospective study of a prospectively-collected data., Objective: To determine whether the severity of the curve magnitude in Lenke 1 and 2 Adolescent Idiopathic Scoliosis (AIS) patients affects the distance and position of the aorta from the vertebra., Summary of Background Data: There were studies that looked into the position of the aorta in scoliotic patients but none of them documented the change in distance of the aorta to the vertebra in relation to the magnitude of the scoliosis., Methods: Patients with Lenke 1 and 2 AIS who underwent posterior spinal fusion using pedicle screw construct and had a preoperative computed tomography (CT) scan performed were recruited. The radiological parameters measured on preoperative CT scan were: Aortic-Vertebral Distance (AVD), Entry-Aortic Distance (EAD), Aortic-Vertebral angle (AVA), Pedicle Aorta angle/Aortic Alpha angle (α angle), and Aortic Beta angle (β angle)., Results: Thirty-nine patients were recruited. Significant moderate to strong positive correlation was found between AVD and Cobb angle from T8 to T12 vertebrae (r = 0.360 to 0.666). The EAD was generally small in the thoracic region (T4-T10) with mean EAD of less than 30 mm. Among all apical vertebrae, the mean AVD was 5.9 ± 2.2 mm with significant moderate-strong positive correlation to Cobb angle (r = 0.580). The mean α angle was 37.7 ± 8.7° with significant weak positive correlation with Cobb angle (r = 0.325)., Conclusion: The larger the scoliotic curve, the aorta was located further away from the apical vertebral wall. The aorta has less risk of injury from the left lateral pedicle screw breach in larger scoliotic curve at the apical region. The distance from the pedicle screw entry point to the wall of the aorta was generally small (less than 30 mm) in the thoracic region (T4-T10)., Level of Evidence: 4.

Study Design: Retrospective study of prospectively collected data., Objective: To analyze the incidence and the patterns of medial and lateral shoulder discordance among Lenke 1 and 2 patients., Summary of Background Data: Postoperative shoulder imbalance (PSI) is still common in Lenke 1 and 2 adolescent idiopathic scoliosis (AIS). This could be due to presence of medial dan lateral shoulder discordance., Methods: One hundred fifty-one Lenke 1 and 2 AIS patients were recruited. Lenke 1 curves were subclassified into Lenke 1-ve (flexible) (proximal thoracic side bending [PTSB] Cobb angle <15°) and 1+ve curves (stiff) (PTSB Cobb angle between 15° and 24.9°). T1 tilt represented "medial shoulder balance" and radiological shoulder height (RSH) represented "lateral shoulder balance." We categorized patients into three concordant shoulder pattern types (medial balanced/lateral balanced [MBLB], medial imbalanced+ve/lateral imbalanced+ve (MI+ve/LI+ve), medial imbalanced-ve/lateral Imbalanced-ve (MI-ve/LI-ve), and six discordant shoulder pattern types., Results: The mean age was 16.2 ± 5.7 years. Eighty-one patients (53.6%) had concordant pattern and 70 patients (46.4%) had discordant pattern. Lateral shoulder imbalance was noted in 35.1% of patients and medial shoulder imbalance in 43.7% of patients. In Lenke 1-ve curves, 35 patients (68.6%) had concordant shoulder imbalance with medial imbalanced-ve/lateral imbalanced-ve (MI-ve/LI-ve) being the commonest pattern (68.6%). In Lenke 1+ve curves, 33 patients (55.0%) had concordant shoulder pattern with medial balanced/lateral balanced (MB/LB) being the commonest type (57.6%). In Lenke 2 AIS, 27 patients (67.5%) had discordant pattern with medial imbalanced+ve/lateral balanced (MI+ve/LB) being the commonest pattern (44.4%) (P value = 0.002)., Conclusion: 46.4% Lenke 1 and 2 AIS patients had shoulder discordant pattern. This was more prevalent in Lenke 2 curves (67.5%). In Lenke 1-ve (flexible) curves, MI-ve/LI-ve pattern was the commonest pattern. In Lenke 1+ve curves (stiff), there were almost equal number of concordant and discordant shoulder pattern. In Lenke 2 patients, the most common pattern was MI+ve/LB., Level of Evidence: 4.

Study Design: Case report., Objective: To describe the technical difficulties on performing posterior spinal fusion (PSF) on a pacemaker-dependent patient with complete congenital heart block and right thoracic scoliosis., Summary of Background Data: Congenital complete heart block requires pacemaker implantation at birth through thoracotomy, which can result in scoliosis. Corrective surgery in this patient was challenging. Height gain after corrective surgery may potentially cause lead dislodgement. The usage of monopolar electrocautery may interfere with the function of the implanted cardiac device., Methods: A 17-year-old boy was referred to our institution for the treatment of right thoracic scoliosis of 70°. He had underlying complete congenital heart block secondary to maternal systemic lupus erythematosus. Pacemaker was implanted through thoracotomy since birth and later changed for four times. PSF was performed by two attending surgeons with a temporary pacing inserted before the surgery. The monopolar electrocautery device was used throughout the surgery., Results: The PSF was successfully performed without any technical issues and complications. Postoperatively, his permanent pacemaker was functioning normally. Three days later, he was recovering well and was discharged home from hospital., Conclusion: This case indicates that PSF can be performed successfully with thoughtful anticipation of technical difficulties on a pacemaker-dependent patient with underlying congenital heart block., Level of Evidence: 5.

Objective: This study analyses the quantity of local bone graft obtained from different anatomical parts of the posterior elements during corrective surgery for Adolescent Idiopathic Scoliosis patients., Summary of Background Data: Locally harvested autogenous bone graft eliminates possible donor site morbidity and has all the important basic bone graft properties such as osteoinductivity, osteogenicity and osteoconductivity. Its usage was reported to be adequate to achieve fusion but none had quantifies the amount of local bone graft harvested., Methods: Total of 40 AIS patients were recruited in the study. All posterior spinal fusion surgeries were performed by the same dual surgeons and same anesthetist with a single observer collecting and measuring bone grafts harvested. The bone grafts harvested from each respective posterior element (spinous processes, laminas, facets and transverses processes) and measured accordingly., Results: There were 36 females and 4 males. Amongst cases recruited, there were 32% Lenke 1, 28% Lenke 2, 8%Lenke 3, 22%Lenke 5 and 10% Lenke 6. Total thoracic levels involved were 333, whereas lumbar levels were 81. The mean total weight of bone graft obtained per case was 36.5 ± 13.7 g. The total weight of lumbar bone graft to the number of lumbar fusion levels (4.5 ± 1.2 g/fusion level) was significantly higher than the total weight of thoracic bone graft to the number of thoracic fusion levels (3.2 ± 1.2 g/fusion level). The amount of bone graft was obtained was highest from lumbar spinous process (42%), followed by thoracic spinous process (32%), lumbar lamina (29%), lumbar facet (28%), thoracic lamina (25%), thoracic facet (22%), and thoracic transverse process (21%)., Conclusions: Lumbar vertebra provided more bone graft than thoracic vertebra. Spinous processes contributed the highest amount of local bone graft in the thoracic and lumbar spine.

Background Context: In Lenke 1C and 2C curves, the choice between selective thoracic fusion (STF) versus non-selective thoracic fusion as the optimal surgical treatment is controversial., Objective: This study aimed to assess the radiological and clinical outcome of patients with Lenke 1C and 2C curves treated with STF., Study Design: This is a retrospective study., Patient Sample: A total of 44 patients comprised the study sample., Methods: Forty-four patients with Lenke 1C and 2C curves with adolescent idiopathic scoliosis who underwent STF were reviewed. Radiological parameters and Scoliosis Research Society (SRS)-22r scores were assessed preoperatively, postoperatively, and on final follow-up. The incidence of coronal decompensation, lumbar decompensation, and adding-on phenomenon were reported., Results: Mean follow-up duration was 45.1±12.3 months and mean age was 17.0±5.1 years. The preoperative middle thoracic and thoracolumbar/lumbar (MT:TL/L) Cobb angle ratio was 1.4±0.3 and the MT:TL/L apical vertebra translation (AVT) ratio was 1.6±0.8. Final follow-up coronal balance was -13.0±11.5 mm, main thoracic AVT was 6.9±11.8 mm, and lumbar AVT was -20.4±13.8 mm (p<.05). Lumbar Cobb angle improved from 47.5°±7.8° to 24.9°±8.2° after operation and 23.3°±9.8° at final follow-up. The spontaneous lumbar curve correction rate was 50.9%. There were 9 patients (20.5%) who had coronal decompensation, 4 patients (9.1%) who had lumbar decompensation, and 11 patients (25.0%) who had adding-on phenomenon. We did not perform any revision surgery. The SRS-22r scores improved significantly in the overall scores, self-image, and mental health domain., Conclusions: Selective thoracic fusion led to improvement in the radiological and clinical outcome for patients with Lenke 1C and 2C. Although no patients required revision surgery, the rate of coronal decompensation, lumbar decompensation, and adding-on phenomenon are significant., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Study Design: Retrospective study., Objective: To investigate the association between postoperative upper instrumented vertebrae (UIV) tilt angle with postoperative medial shoulder and neck imbalance., Summary of Background Data: Studies had found that current recommendations for UIV selection were not predictive of good postoperative shoulder balance., Methods: A total of 98 patients with adolescent idiopathic scoliosis with Lenke 1/2 curves who underwent posterior spinal fusion between 2013 and 2014 with minimum follow-up of 2 years were recruited. Radiological parameters: UIV tilt angle, T1 tilt, cervical axis, and clavicle angle were measured preoperatively, postoperatively, and at final follow-up., Results: Mean age was 16.2 ± 6.2 years. Mean follow-up was 37.9 ± 6.5 months. There were 73.5% Lenke 1 and 26.5% Lenke 2 curves. Significant factors affecting postoperative T1 Tilt were postoperative UIV tilt angle, preoperative T1 tilt, and preoperative UIV tilt angle. Postoperative UIV tilt angle and preoperative cervical axis were significant factors affecting cervical axis at final follow-up. UIV level was not significant independent factor that affected postoperative T1 tilt and cervical axis. There was strong correlation between postoperative UIV tilt angle and T1 tilt for the whole cohort (P < 0.001), when UIV was at T2 (P < 0.001), T3 (P < 0.001), and T4 (P < 0.001). Postoperative UIV tilt angle also had significant correlation with cervical axis when UIV was at T2 (P = 0.021) and T3 (P = 0.009)., Conclusion: Postoperative UIV tilt angle was an independent factor, which had significant correlation with postoperative T1 tilt and cervical axis measurement. There was strong correlation between postoperative UIV tilt angle and T1 tilt for the whole cohort, when UIV was at T3 and T4. There was very strong correlation between postoperative UIV tilt angle and T1 tilt when UIV was at T2. There was also moderate and significant correlation between postoperative UIV tilt angle and cervical axis for the whole cohort., Level of Evidence: 2.

Background Context: Selection of upper instrumented vertebra for Lenke 5 and 6 curves remains debatable, and several authors have described different selection strategies., Objective: This study analyzed the flexibility of the unfused thoracic segments above the "potential upper instrumented vertebrae (UIV)" (T1-T12) and its compensatory ability in Lenke 5 and 6 curves using supine side bending (SSB) radiographs., Study Design: A retrospective study was used., Patient Sample: This study comprised 100 patients., Outcome Measures: The ability of the unfused thoracic segments above the potential UIV, that is, T1-T12, to compensate in Lenke 5 and 6 curves was determined. We also analyzed postoperative radiological outcome of this cohort of patients with a minimum follow-up of 12 months., Methods: Right and left SSB were obtained. Right side bending (RSB) and left side bending (LSB) angles were measured from T1 to T12. Compensatory ability of thoracic segments was defined as the ability to return to neutral (center sacral vertical line [CSVL]) with the assumption of maximal correction of lumbar curve with a horizontal UIV. The Lenke 5 curves were classified as follows: (1) Lenke 5-ve (mobile): main thoracic Cobb angle <15° and (2) Lenke 5+ve (stiff): main thoracic Cobb angle 15.0°-24.9°. This study was self-funded with no conflict of interest., Results: There were 43 Lenke 5-ve, 31 Lenke 5+ve, and 26 Lenke 6 curves analyzed. For Lenke 5-ve, >70% of thoracic segments were able to compensate when UIV were at T1-T8 and T12 and >50% at T9-T11. For Lenke 5+ve, >70% at T1-T6 and T12, 61.3% at T7, 38.7% at T8, 3.2% at T9, 6.5% at T10, and 22.6% at T11 were able to compensate. For Lenke 6 curve, >70% at T1-T6, 69.2% at T7, 19.2% at T8, 7.7% at T9, 0% at T10, 3.8% at T11, and 34.6% at T12 were able to compensate. There was a significant difference between Lenke 5-ve versus Lenke 5+ve and Lenke 5-ve versus Lenke 6 from T8 to T11. There were no significance differences between Lenke 5+ve and Lenke 6 curves from T1 to T11., Conclusions: The compensatory ability of the unfused thoracic segment of Lenke 5+ve curves was different from the Lenke 5-ve curves, and it demonstrated characteristics similar to the Lenke 6 curves., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Study Design: A prospective cohort study., Objective: The aim of this study was to determine the feasibility of an accelerated recovery protocol for Asian adolescent idiopathic scoliosis (AIS) patients undergoing posterior spinal fusion (PSF)., Summary of Background Data: There has been successful implementation of an accelerated recovery protocol for AIS patients undergoing PSF in the western population. No similar studies have been reported in the Asian population., Methods: Seventy-four AIS (65 F, 9 M) patients scheduled for PSF surgery were recruited. The accelerated protocol encompasses preoperative regime, preoperative day of surgery counseling, intraoperative strategies, an accelerated postoperative rehabilitation and pain management regime. All patients were operated using a dual attending surgeon strategy. Outcome measures included pain scores at five time intervals, length of stay, and detailed recovery milestones. Any complications or readmissions during the first 4 months postoperative period were recorded., Results: Mean duration of operation was 2.2 ± 0.3 hours with a mean blood loss of 824.3 ± 418.2 mL. No patients received allogenic blood transfusion. The mean length of stay was 3.6 ± 0.6 days. Surgical wound pain score was 6.4 ± 2.1 at 12 hours, which reduced to 5.0 ± 2.0 at 60 hours. Abdominal pain peaked at 36 hours with pain scores 2.4 ± 2.9. First liquid intake was at 5.2 ± 7.5 hours, urinary catheter removal at 18.7 ± 4.8 hours, sitting up at 20.6 ± 9.1 hours, ambulation at 27.2 ± 0.5 hours, consumption of solid food at 32.2 ± 0.5 hours, first flatus at 39.0 ± 0.7 hours, and first bowel movement at 122.1 ± 2.0 hours. The complication rate was 1.4% due to superficial wound infection with one patient failed to comply with the accelerated protocol., Conclusion: An accelerated recovery protocol following PSF for AIS is feasible without increasing the complication or readmission rates. The total length of stay was 3.6 days and this is comparable with the outcome in western population., Level of Evidence: 4.

Purpose: This study aimed at studying the accuracy and safety of extra-pedicular screw insertion for dysplastic pedicles in AIS comparing cannulated screw system versus conventional screw system., Methods: 104 AIS patients with 1524 pedicle screws were evaluated using CT scan. 302 screws were inserted in dysplastic pedicles using fluoroscopic guidance technique. 155 screws were inserted using a cannulated system (Group 1), whereas 147 screws were inserted using standard screws (Group 2). The pedicle perforations were assessed using a classification by Rao et al.; G0: no violation; G1: <2 mm perforation; G2: 2-4 mm perforation; and G3: >4 mm perforation). For anterior perforations, the pedicle perforations were assessed using a modified grading system (Grade 0: no violation, Grade 1: less than 4 mm perforation; Grade 2: 4 mm to 6 mm perforation; and Grade 3: more than 6 mm perforation)., Results: The perforation rate in Group 1 was 4.5% and in Group 2 was 15.6% (p = 0.001). Most of the perforations were anterior perforations (53.3%). The anterior perforation rate in Group 1 was 1.9% compared to 8.8% in Group 2 (p = 0.009). Group 1 has a medial perforation rate of 1.3% compared to Group 2, 6.1% (p = 0.031). The rate of critical pedicle perforation in Group 1 was 2.6% and in Group 2 was 6.8% (p = 0.102). In Group 1, there were no critical medial perforation but there was one G2 lateral perforation, one G2 superior perforation and two G3 anterior perforations. In Group 2, there were three G2 medial perforations, one G2 lateral perforation, one G2 anterior perforation and five G3 anterior perforations., Conclusion: Usage of cannulated screw system significantly increases the accuracy of pedicle screw insertion in dysplastic pedicles in AIS.

Study Design: Randomized controlled trial., Objective: The present study investigated the effectiveness of chewing gum on promoting faster bowel function and its ability to hasten recovery for patients with adolescent idiopathic scoliosis (AIS) after posterior spinal fusion (PSF) surgery., Summary of Background Data: Sham feeding with chewing gum had been reported to reduce the incidence of postoperative ileus by accelerating recovery of bowel function., Methods: We prospectively recruited and randomized 60 patients with AIS scheduled for PSF surgery into treatment (chewing gum) and control group. The patient-controlled anesthesia usage, wound pain score, abdominal pain score, nausea score, and abdominal girth were assessed and recorded at 12, 24, 36, 48, and 60 hours postoperatively. The timing for the first fluid intake, first oral intake, sitting up, walking, first flatus after surgery, first bowel opening after surgery, and duration of hospital stay were also assessed and recorded., Results: We found that there were no significant differences (P > 0.05) in patient-controlled anesthesia usage, wound pain score, abdominal pain score, nausea score, and abdominal girth between treatment (chewing gum) and control groups. We also found that there were no significant difference (P > 0.05) in postoperative recovery parameters, which were the first fluid intake, first oral intake, sitting up after surgery, walking after surgery, first flatus after surgery, first bowel opening after surgery, and duration of hospital stay between both groups. The wound pain was the worst at 12 hours postoperatively, which progressively improved in both groups. The abdominal pain progressively worsened to the highest score at 48 hours in the treatment group and 36 hours in the control group before improving after that. The pattern of severity and recovery of wound pain and abdominal pain was different., Conclusion: We found that chewing gum did not significantly reduce the abdominal pain, promote faster bowel function, or hasten patient recovery., Level of Evidence: 1.

The prevalence of neuropathic low back pain differs in different ethnic populations. The aims of the study are to determine its frequency and associations in a multi-ethnic cohort of Asian low back pain patients. This was a cross-sectional study of low back patients seen at the University of Malaya Medical Centre, Kuala Lumpur, Malaysia. Neuropathic low back pain patients were identified using the painDETECT questionnaire and compared with non-neuropathic (unclear or nociceptive) low back pain patients, in terms of socio-demographic and clinical factors, pain severity (numerical pain rating scale, NPRS), disability (Roland Morris Disability Questionnaire, RMDQ), as well as anxiety and depression (Hospital Anxiety and Depression Scale, HADS). Of 210 patients, 26 (12.4%) have neuropathic low back pain. Neuropathic pain is associated with non-Chinese ethnicity, higher body mass index and pain radiation below the knee. Patients with neuropathic pain have significantly higher NPRS and RMDQ scores, and there are more subjects with anxiety on HADS. However, there are no differences between the groups in age, gender, pain duration or underlying diagnosis of low back pain. The prevalence of neuropathic low back pain in a multi-ethnic Malaysian cohort is lower than previously reported in other populations with possible differences between ethnic groups. It is associated with greater pain severity, disability and anxiety.

Study Design: Retrospective review of CT scan., Objective: To investigate the accuracy and safety of pedicle screws placed in adolescent idiopathic scoliosis (AIS) patients., Summary of Background Data: The reported pedicle screws perforation rates for corrective AIS surgery vary widely from 1.2% to 65.0%. Knowledge regarding the safety of pedicle screws in scoliosis surgery is very important in preventing complications., Methods: This study investigates the accuracy and safety of pedicle screws placed in 140 AIS patients. CT scans were used to assess the perforations that were classified according to Rao et al (2002): grade 0, grade 1 (<2 mm), grade 2 (2-4 mm), and grade 3 (>4 mm). Anterior perforations were classified into grade 0, grade 1 (<4 mm), grade 2 (4-6 mm), and grade 3 (>6 mm). Grade 2 and 3 (excluding lateral grade 2 and 3 perforation over thoracic vertebrae) were considered as critical perforations., Results: A total of 2020 pedicle screws from 140 patients were analyzed. The overall total perforation rate was 20.3% (410 screws) with 8.2% (166 screws) grade 1, 2.9% (58 screws) grade 2 and 9.2% (186 screws) grade 3 perforations. Majority of the perforations was because of lateral perforation occurring over the thoracic region, as a result of application of extrapedicular screws at this region. When the lateral perforations of the thoracic region were excluded, the perforation rate was 6.4% (129 screws), grade 2, 1.4% (28 screws) and grade 3, 0.8% (16 screws). There were only two symptomatic left medial grade 2 perforations: one screw at T12 presented with postoperative iliac crest numbness and another screw at L2 presented with radicular pain that subsided with conservative treatment. There were six anterior perforations abutting the right lung, four anterior perforations abutting the aorta, two anterior perforations abutting the esophagus, and one abutting the trachea was noted., Conclusion: Pedicle screws insertion in AIS has a total perforation rate of 20.3%. After exclusion of lateral thoracic perforations, the overall perforation rate was 8.6% with a critical perforation rate of 2.2% (44/2020). The rate of symptomatic screw perforation leading to radicular symptoms was 0.1%. There was no spinal cord, aortic, esophageal, or lung injuries caused by malpositioned screws in this study., Level of Evidence: 4.

Background Context: The clinical application of recombinant bone morphogenetic protein in spinal surgery has been shown to be safe and effective. However, its use in minimally invasive spine surgery has been limited to anterior interbody fusion procedures. To date, no study has evaluated the feasibility of percutaneous posterolateral fusion in the spine utilizing recombinant bone morphogenetic protein-2 (rhBMP-2)., Purpose: To evaluate the feasibility of percutaneous posterolateral fusion in the spine utilizing rhBMP-2., Study Design: Animal study., Methods: This is an animal research model involving 32 New Zealand white rabbits stratified into 4 study groups: control, autogenous iliac crest bone graft (ICBG), demineralized bone matrix (DBM), and rhBMP-2 groups, with 8 study subjects per group. The rhBMP-2 group was subdivided into the open technique (right side) and the percutaneous technique groups (left side). Fusion was graded at 6 weeks and 3 months after plain radiography, computed tomography, and clinical assessment with the following grading system: grade A, no bone formation; grade B, non-bridging bone formation; grade C, fusion; and grade D, fusion with ectopic bone formation., Results: No fusion was noted in the placebo and the DBM groups. However, in the DBM group, bone formation occurred in 37.5% of the subjects. The rhBMP-2 group had a higher fusion rate compared with the ICBG group at 6 weeks and 3 months. The fusion rate for the ICBG, the rhBMP-2 (open), and the rhBMP-2 (percutaneous) groups were 37.5%, 87.5%, and 50.0% at 6 weeks and 50.0%, 100.0%, and 62.5% at 3 months, respectively. Ectopic bone formation occurred in 12.5% of the cases in the rhBMP-2 (percutaneous) group and in 25.0% of the cases in the rhBMP-2 (open) group., Conclusions: Usage of rhBMP-2 is feasible for percutaneous posterolateral fusion of the lumbar spine in this animal model. However, a more precise delivery system might improve the fusion rate when the percutaneous technique is used. A significant rate of ectopic bone formation occurred when rhBMP-2 was used.

Study Design: Case report., Objective: To report the successful rehabilitation and the training progress of an elite high performance martial art exponent after selective thoracic fusion for Adolescent Idiopathic Scoliosis (AIS)., Summary of Background Data: Posterior spinal fusion for AIS will result in loss of spinal flexibility. The process of rehabilitation after posterior spinal fusion for AIS remains controversial and there are few reports of return to elite sports performance after posterior spinal fusion for AIS., Methods: We report a case of a 25-year-old lady who was a national Wu Shu exponent. She was a Taolu (Exhibition) exponent. She underwent Selective Thoracic Fusion (T4 to T12) using alternate level pedicle screw placement augmented with autogenous local bone graft in June 2014. She commenced her training at 3-month postsurgery and the intensity of her training was increased after 6 months postsurgery. We followed her up to 2 years postsurgery and showed no instrumentation failure or lost of correction., Results: After selective thoracic fusion, her training process consisted of mainly speed training, core strengthening, limb strengthening, and flexibility exercises. At 17 months of postoperation, she participated in 13th World Wu Shu Championship 2015 and won the silver medal., Conclusion: Return to elite high-performance martial arts sports was possible after selective thoracic fusion for AIS. The accelerated and intensive training regime did not lead to any instrumentation failure and complications., Level of Evidence: 2.

Background Context: With an increased cost of adolescent idiopathic scoliosis (AIS) surgery over the past 10 years, improvement of patient safety and optimization of the surgical management of AIS has become an important need. A dual attending surgeon strategy resulted in reduction of blood loss and complication rate., Purpose: This study aimed to investigate the perioperative outcome of posterior selective thoracic fusion in Lenke 1 and 2 AIS patients comparing a single versus a dual attending surgeon strategy., Study Design: A prospective cohort study was carried out., Patient Sample: The study sample comprised 60 patients OUTCOME MEASURE: Operative duration, blood loss, postoperative hemoglobin, need for transfusion, morphine usage, and duration of hospital stay were the outcome measures., Methods: A total of 116 patients who underwent posterior selective thoracic fusion from two centers were prospectively recruited. The patients were grouped into Group 1 (single surgeon) and Group 2 (two surgeons). One-to-one matching analysis using "propensity score-matched cohort patient sampling method" was done for age, gender, height, weight, preoperative Cobb angle, number of fusion level, and Lenke classification. The outcome measures included operative duration, blood loss, postoperative hemoglobin, need for transfusion, morphine usage, and duration of hospital stay. This study was self-funded with no conflict of interest., Results: From 86 patients who were operated by the two surgeons (Group 2), 30 patients were matched with 30 patients who were operated by a single surgeon (Group 1). Group 2 (164.0±25.7 min) has a significantly shorter operation duration (p=.000) compared with Group 1 (257.3±51.4 min). The total blood loss was significantly more (p=.009) in Group 1 (1254.7±521.5 mL) compared with Group 2 (893.7±518.4 mL). There were seven patients (23.3%) in Group 1 who received allogenic blood transfusion (p<.05). The morphine usage and average hospital stay were significantly lower in Group 2, 22.4±10.7 mg and 3.4±0.7 days, respectively (p<.05). In Group 1, there was one patient who developed a superficial wound infection. No other major complications were noted., Conclusions: A dual attending surgeon strategy was superior to a single surgeon strategy in posterior selective thoracic fusion in Lenke 1 and 2 AIS patients and will lead to a faster operation, reduced intraoperative blood loss, reduced risk of allogenic transfusion, reduced morphine requirement, and shorter hospital stay., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: To assess the pattern of intra-operative blood loss at various surgical stages comparing between single and two surgeons., Methods: Lenke 1 and 2 adolescent idiopathic scoliosis (AIS) patients who underwent instrumented posterior spinal fusion (PSF) surgery from two centres between June 2014 and December 2015 were prospectively recruited into this study. The patients were grouped into Group 1 (single surgeon) and Group 2 (two surgeons). One to one matching using 'prospective propensity score-matched cohort patient sampling method' was done. The surgery was divided into six stages: stage 1-exposure, stage 2-screw insertion, stage 3-release, stage 4-correction, stage 5-corticotomies and bone grafting and stage 6-closure., Results: A total of 116 patients were recruited. Of 86 patients who were operated by the two surgeons, 30 patients were matched with 30 patients that were operated by a single surgeon. Operation duration was significantly longer in Group 1 (257.3 ± 51.4 min) compared to Group 2 (164.0 ± 25.7 min). The total blood loss was significantly higher in Group 1 (1254.7 ± 521.5 mL) compared to Group 2 (893.7 ± 518.4 mL). Total blood loss/level fused was significantly higher in Group 1 (117.5 ± 42.8 mL/level) compared to Group 2 (82.6 ± 39.4 mL/level). Group 1 had significantly higher blood loss and blood loss/level fused for stages 1, 2 and 3. Group 2 had lower incidence of allogenic blood transfusion., Conclusions: In PSF surgery for AIS patients, two-surgeon strategy was associated with shorter operation duration, lesser blood loss and lower incidence of allogenic blood transfusion.

Purpose: To directly compare the safety of fluoroscopic guided percutaneous thoracic pedicle screw placement between Caucasians and Asians., Methods: This was a retrospective computerized tomography (CT) evaluation study of 880 fluoroscopic guided percutaneous pedicle screws. 440 screws were inserted in 73 European patients and 440 screws were inserted in 75 Asian patients. Screw perforations were classified into Grade 0: no violation; Grade 1: <2 mm perforation; Grade 2: 2-4 mm perforation; and Grade 3: >4 mm perforation. For anterior perforations, the pedicle perforations were classified into Grade 0: no violation, Grade 1: <4 mm perforation; Grade 2: 4-6 mm perforation; and Grade 3: >6 mm perforation., Results: The inter-rater reliability was adequate with a kappa value of 0.83. The mean age of the study group was 58.3 ± 15.6 years. The indications for surgery were tumor (70.3 %), infection (18.2 %), trauma (6.8 %), osteoporotic fracture (2.7 %) and degenerative diseases (2.0 %). The overall screw perforation rate was 9.7 %, in Europeans 9.1 % and in Asians 10.2 % (p > 0.05). Grade 1 perforation rate was 8.4 %, Grade 2 was 1.2 % and Grade 3 was 0.1 % with no difference in the grade of perforations between Europeans and Asians (p > 0.05). The perforation rate was the highest in T1 (33.3 %), followed by T6 (14.5 %) and T4 (14.0 %). Majority of perforations occurred medially (43.5 %), followed by laterally (25.9 %), and anteriorly (23.5 %). There was no statistical significant difference (p > 0.05) in the perforation rates between right-sided pedicle screws and left-sided pedicle screws (R: 10.0 %, L: 9.3 %)., Conclusions: There were no statistical significant differences in the overall perforation rates, grades of perforations, direction of perforations for implantation of percutaneous thoracic pedicle screws insertion using fluoroscopic guidance between Europeans and Asians. The safety profile for this technique was comparable to the current reported perforation rates for conventional open pedicle screw technique.

Purpose: Patients with Fontan circulation have increased cardio-respiratory risk during major spinal surgery. We report a case of severe scoliosis with a Cobb angle of 123.3° in a 16-year-old boy with Fontan circulation treated with single stage posterior segmental pedicle screw instrumentation and fusion., Methods: Case report., Results: The use pre-operative halo-ring traction for a duration of 6 weeks in this case lead to improvement in cobb angle from 123.3°, kyphotic angle 87.1° to cobb angle of 78.0°, kyphotic angle 57.2° (on bending and stress films). The operation was completed in 150 min, blood loss 1050 ml (25 ml/kg), and cell salvage of 490 ml. He was immediately extubated post correction, but monitored in ICU for a day. Total length of stay was 8 days without any perioperative morbidity or allogeneic blood transfusion. Final post-operative radiograph showed a cobb angle of 44.2°, kyphotic angle 22.8°. Follow up at 27 months showed solid union with no significant loss of correction., Conclusion: From this case experience, pre-operative halo traction is a useful surgical strategy in patients with Fontan circulation with severe kyposcoliosis to achieve adequate correction without additional osteotomies to minimize the risk of surgical correction.

Purpose: To introduce a new clinical neck tilt grading and to investigate clinically and radiologically whether neck tilt and shoulder imbalance is the same phenomenon in AIS patients., Methods: 89 AIS Lenke 1 and 2 cases were assessed prospectively using the new clinical neck tilt grading. Shoulder imbalance and neck tilt were correlated with coracoid height difference (CHD), clavicle\rib intersection distance (CRID), clavicle angle (CA), radiographic shoulder height (RSH), T1 tilt and cervical axis., Results: Mean age was 17.2 ± 3.8 years old. 66.3 % were Lenke type 1 and 33.7 % were type 2 curves. Strong intraobserver (0.79) and interobserver (0.75) agreement of the clinical neck tilt grading was noted. No significant correlation was observed between clinical neck tilt and shoulder imbalance (0.936). 56.3 % of grade 3 neck tilt, 50.0 % grade 2 neck tilt patients had grade 0 shoulder imbalance. In patients with grade 2 shoulder imbalance, 42.9 % had grade 0, 35.7 % grade 1, 14.3 % grade 2 and only 7.1 % had grade 3 neck tilt. CHD, CRID, CA and RSH correlated with shoulder imbalance. T1 tilt and cervical axis measurements correlated with neck tilt., Conclusions: In conclusion, neck tilt is distinct from shoulder imbalance. Clinical neck tilt has poor correlation with clinical shoulder imbalance. Clinical neck tilt grading correlated with cervical axis and T1 tilt whereas clinical shoulder grading correlated with CHD, RSH CRID and CA.

Introduction: Hip arthroplasty is commonly performed worldwide. The objective of this study was to determine the diameter of the femoral head in the Malaysian population in relation to gender and race (i.e. among Malay, Chinese and Indian patients)., Methods: This was a retrospective cross-sectional study performed between January 1995 and December 2006, evaluating the femoral head diameters of all patients aged 50 years and above who underwent hemiarthroplasty at two major hospitals in Malaysia., Results: A total of 945 femoral heads (663 women, 282 men) were evaluated. The mean age of the patients in our cohort was 75.2 ± 9.4 (range 50-101) years. The mean femoral head diameter (with intact articular cartilage) was 44.9 ± 3.2 (range 38-54) mm. In our study, men had a significantly larger mean femoral head diameter than women (47.7 ± 2.8 mm vs. 43.7 ± 2.4 mm; p < 0.05). Patients of Chinese ethnicity were also found to have significantly larger femoral head diameters, when compared among the three races studied (p < 0.05)., Conclusion: Malaysians have a mean femoral head diameter of 44.9 ± 3.2 mm. Among our patients, Chinese patients had a significantly larger femoral head size than Malay and Indian patients. We also found that, in our cohort, men had significantly larger femoral head diameters than women.

Introduction: Studies of sacral pedicle anatomy have been reported in the European population. However, the feasibility for the use of S1, S2 and S2-ilium screws has not been fully investigated in the Asian population., Purpose: To assess feasibility, morphometric parameters and safety of S1, S2 and S2-ilium screw insertion in the Asian population., Method: 180 three dimensional computed tomography (CT) scans of pelvis (90 males and 90 females) with contrast were analysed using Mimics(®) version 13.1 (Materialise, Belgium) software. All parameters were measured using this programme., Result: The safety medial trajectory of S1 pedicle screw was 11.8 ± 3.9 to 37.1 ± 4.5° in males and 11.7 ± 3.1 to 35.9 ± 4.4° in females. The screw length was from 35.0 ± 3.0 to 58.3 ± 3.1 mm in males and from 31.9 ± 2.6 to 53.1 ± 3.5 mm in females. Right S1 pedicle screws were safe as long as the anterior cortical penetration of quadrant 2, 3 and 4 were avoided. On the left, it was safe for the screws to exit at quadrant 1, 2 and 3. The lateral trajectory of S2 sacral alar screw was from 0 to 32.6 ± 3.3° in males and from 0 to 33.6 ± 3.5° in females. The screw length was from 23.9 ± 3.2 to 53.1 ± 4.1 mm in males and from 23.0 ± 2.5 to 53.2 ± 4.5 mm in females. For S2 screws, on the right side, the frequency of the internal iliac artery location was 7.2, 38.3, 47.2 and 1.7% for quadrants 1, 2, 3 and 4, whereas on the left side, the frequency was 7.8, 50.6, 33.9 and 2.2% for quadrants 1, 2, 3 and 4. For S2-ilium screws, the lateral trajectory was from 39.3 ± 3.1 to 50.4 ± 6.1° in males and from 39.5 ± 3.1 to 50.2 ± 5.9° in females. The screw lengths were from 85.3 ± 22.2 to 122.6 ± 11.4 mm and from 86.4 ± 22.7 to 122.2 ± 11.9 mm in males and females, respectively., Conclusion: The application of S1, S2 and S2-ilium screws are feasible. The amount of medial angulation and the ideal screw length in the Asian population must be borne in mind during insertion. Right S1 screws carry higher risk of injury to the internal iliac artery when the anterior cortical penetration occurs due to the course of the iliac vessels.

Background: Various lateral mass screw fixation methods have been described in the literature with various levels of safety in relation to the anterior neurovascular structures. This study was designed to radiologically determine the minimum lateral angulations of the screw to avoid penetration of the vertebral artery canalusing three of the most common techniques: Roy-Camille, An, and Magerl., Materials and Methods: Sixty normal cervical CT scans were reviewed. A minimum lateral angulation of a 3.5 mm lateral mass screw which was required to avoid penetration of the vertebral artery canal at each level of vertebra were measured., Results: The mean lateral angulations of the lateral mass screws (with 95% confidence interval) to avoid vertebral artery canal penetration, in relation to the starting point at the midpoint (Roy-Camille), 1 mm medial (An), and 2 mm medial (Magerl) to the midpoint of lateral mass were 6.8° (range, 6.3-7.4°), 10.3° (range, 9.8-10.8°), and 14.1° (range, 13.6-14.6°) at C3 vertebrae; 6.8° (range, 6.2-7.5°), 10.7° (range, 10.0-11.5°), and 14.1° (range, 13.4-14.8°) at C4 vertebrae; 6.6° (range, 6.0-7.2°), 10.1° (range, 9.3-10.8°), and 13.5° (range, 12.8-14.3°) at C5 vertebrae and 7.6° (range, 6.9-8.3°), 10.9° (range, 10.3-11.6°), and 14.3° (range, 13.7-15.0°) at C6 vertebrae. The recommended lateral angulations for Roy-Camille, Magerl, and An are 10°, 25°,and 30°, respectively. Statistically, there is a higher risk of vertebral foramen violation with the Roy-Camille technique at C3, C4 and C6 levels, P < 0.05., Conclusions: Magerl and An techniques have a wide margin of safety. Caution should be practised with Roy-Camille's technique at C3, C4, and C6 levels to avoid vertebral vessels injury in Asian population.

Purpose: Pedicle screw instrumentation has superior biomechanical as well as clinical outcome. Thoracic pedicles show great variation in different population groups, particularly in Asians who have been shown to have smaller pedicle dimensions. Although plain radiographs are widely performed prior to spine surgery, no studies have been done so far to investigate whether the thoracic pedicle profile on plain radiographs affect thoracic pedicle screw insertion. Therefore, this is a cadaveric study aimed to determine the relationship between plain radiographic thoracic pedicle profile in Asians and the outcome of pedicle screw insertion in the thoracic spine., Methods: A pre-insertion radiograph with an enlargement reference scale was performed and surgeons were blinded to the plain radiographic morphometry of the thoracic pedicles. From the pre-insertion radiograph, the normalized pedicle width and height (which controls for any magnification error) as well as the pedicle width:body width (PWBW) and pedicle width:pedicle height (PWPH) ratio was derived. 240 pedicle screws were inserted in ten Asian cadavers from T1 to T12 using the funnel technique. 5.0 mm screws were used from T1 to T6 while 6.0 mm screws were used from T7 to T12. Perforations were detected by direct visualization via wide laminectomies after pedicle screw insertion. The outcome of thoracic pedicle screw insertion was correlated with the radiological profile using independent t-test. Pearson correlation coefficient was used to investigate the correlation between the ratios and the normalised pedicle width and height., Results: The narrowest pedicle width is from T3 to T6 determined from normalized measurement of the pedicle width. T5 pedicle width is the smallest measuring 4.1 ± 1.3 mm. The overall perforation rate is 10.4% (25 perforations). There is only one significant perforation. There were twice as many lateral and inferior perforations compared to the medial perforations. 48% of the perforations occurred at T1, T2 and T3. Pedicles <4.0 mm in width and upper thoracic pedicles are risk factors for pedicle perforation. The normalised pedicle width has a high degree of linear correlation with PWBW and a normalised pedicle width of 4.0 mm correlated with a PWBW ratio of 0.3., Conclusions: Plain radiographic thoracic pedicle morphometry has an influence on the outcome of thoracic pedicle screw insertion in Asian cadavers. Pedicle width <4.0 mm is associated with higher risk of pedicle perforation. This critical value corresponds to a PWBW ratio of 0.3. Identification of such pedicle profile warrants full evaluation of the morphometry of the thoracic pedicles and possibly extra-pedicular techniques should be employed to avert the risk of critical pedicle perforation.

The objective of this cadaveric study is to determine the safety and outcome of thoracic pedicle screw placement in Asians using the funnel technique. Pedicle screws have superior biomechanical as well as clinical data when compared to other methods of instrumentation. However, misplacement in the thoracic spine can result in major neurological implications. There is great variability of the thoracic pedicle morphometry between the Western and the Asian population. The feasibility of thoracic pedicle screw insertion in Asians has not been fully elucidated yet. A pre-insertion radiograph was performed and surgeons were blinded to the morphometry of the thoracic pedicles. 240 pedicle screws were inserted in ten Asian cadavers from T1 to T12 using the funnel technique. 5.0 mm screws were used from T1 to T6 while 6.0 mm screws were used from T7 to T12. Perforations were detected by direct visualization via a wide laminectomy. The narrowest pedicles are found between T3 and T6. T5 pedicle width is smallest measuring 4.1 +/- 1.3 mm. There were 24 (10.0%) Grade 1 perforations and only 1 (0.4%) Grade 2 perforation. Grade 2 or worse perforation is considered significant perforation which would threaten the neural structures. There were twice as many lateral and inferior perforations compared to medial perforations. 48.0% of the perforations occurred at T1, T2 and T3 pedicles. Pedicle fracture occurred in 10.4% of pedicles. Intra-operatively, the absence of funnel was found in 24.5% of pedicles. In conclusion, thoracic pedicle screws using 5.0 mm at T1-T6 and 6.0 mm at T7-T12 can be inserted safely in Asian cadavers using the funnel technique despite having smaller thoracic pedicle morphometry.