Impact of Various Weights in the Intraoperative Skull-Skeletal Traction on Correction of Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A retrospective study. OBJECTIVES: Intraoperative skull-skeletal traction (ISST) facilitates the surgical scoliosis correction, but it is also associated with neurological risk. The objective of the present study was to investigate the impact of various traction weights on neurophysiological change and curve correction in surgery for adolescent idiopathic scoliosis (AIS). METHODS: A retrospective review of a consecutive series of posterior spinal fusions for AIS patients undergoing corrections with the use of ISST by 2 surgeons in one institution was performed. Intraoperative prone, post-traction radiographs were performed on all cases. The cases were divided into 2 groups, high and low traction weights, based on whether the weight used was ≥35% or <35% of body weight. The frequency of neurophysiological changes and the curve correction were compared between the 2 groups. RESULTS: The intraoperative correction magnitudes by ISST were significantly larger in the high ISST group than in the low ISST group (35° vs 26°, P < .001). Changes in motor-evoked potential (MEP) were more frequently observed in the high ISST group (47% vs 26%, P = .049). A multivariate analysis showed that high ISST was associated with 3 times higher risk of MEP change (95% confidence interval = 1.1-8.0, P = .03) and higher final postoperative correction rates (68% vs 60%, P = .001). CONCLUSIONS: The high ISST for AIS was associated with increased intraoperative and ultimate curve corrections, and potentially facilitated better final correction. However, the high weight group was associated with an increased frequency of intraoperative MEP changes.

Using tranexamic acid soaked absorbable gelatin sponge following complex posterior lumbar spine surgery: A randomized control trial.

OBJECTIVES: This paper aims to determine whether the use of Tranexemic Acid (TXA) - soaked absorbable gelatin sponge could more effectively reduce post-operative blood loss and blood transfusion requirements among low-risk adult patients undergoing lumbar spine surgery. METHODS: A total of 90 consecutive patients undergoing surgery for multilevel posterior lumbar degenerative procedures were prospectively randomized into one of three groups: - TXA Soaked Gelfoam group, absorbable gelatin sponge group or control group. Demographic distribution, total drain output, blood transfusion requirement, length of hospital stay, the number of readmissions, and postoperative complications were analyzed. RESULTS: In the TXA Soaked Gelfoam, Gelfoam, and control groups, the respective hemovac drainage at the first 8h postoperatively was 81.06±61.21, 166.73±76.76, and 155.67±92.94ml respectively. The second 8h period drainage for the same groups postoperatively was 46.67±40.09, 55.10±43.43, and 82.50±56.67ml and 23.73±25.56, 32.43±25.81 and 44.20±32.44ml for the third 8h period postoperatively. The duration of the post-operative drain left in the TXA Soaked Gelfoam group was significantly shorter than the Gelfoam and control groups (p=0.019 and 0.000, respectively). The TXA Soaked Gelfoam and Gelfoam also had a significantly shorter hospital stay than the control group (p=0.014, and 0.036, respectively). No patient developed adverse reactions attributable to the tranexamic acid soaked absorbable gelatin sponge. CONCLUSIONS: TXA-soaked absorbable gelatin sponge is a safe, effective treatment for reduction of post-operative blood loss and blood transfusions among low-risk adult patients undergoing lumbar spine surgery.

Does intraoperative cell salvage system effectively decrease the need for allogeneic transfusions in scoliotic patients undergoing posterior spinal fusion? A prospective randomized study.

PURPOSE: To determine the safety and efficacy of intraoperative cell salvage system in decreasing the need for allogeneic transfusions in a cohort of scoliosis patients undergoing primary posterior spinal fusion with segmental spinal instrumentation. METHODS: A total of 110 consecutive scoliosis patients undergoing posterior instrumented spinal fusion were randomized into two groups according to whether a cell saver machine for intraoperative blood salvage was used or not. Data included age, body mass index, perioperative hemoglobin levels, surgical time, levels fused, perioperative estimated blood loss, perioperative transfusions and incidence of transfusion-related complications. A Chi-square test and t tests were performed for intraoperative and perioperative allogeneic transfusion between groups. A regression analysis was performed between selected covariates to investigate the predictive factors of perioperative transfusion. RESULTS: Perioperative allogenic blood transfusion rate was lower in the cell saver group (14.5 versus 32.7%, p = 0.025). Mean intraoperative red blood cell transfusion requirement was also lower (0.21 U/pt versus 0.58 U/pt, p = 0.032). A multivariate analysis demonstrated that no. of fused segments (OR: 1.472; p = 0.005), preoperative hemoglobin level (OR: 0.901; p = 0.001), and the use of cell saver system (OR: 0.133; p = 0.003) had a trend toward significance in predicting likelihood of transfusion. CONCLUSIONS: Cell saver use significantly reduces the need for allogeneic blood in spine deformity surgery, particularly in patients with low preoperative hemoglobin or longer operation time. This study confirms the utility of routine cell saver use during PSF with segmental spinal instrumentation for scoliosis patients.

Association Between rs11190870 Polymorphism Near LBX1 and Susceptibility to Adolescent Idiopathic Scoliosis in East Asian Population: A Genetic Meta-Analysis.

STUDY DESIGN: Meta-analysis to collect all the relevant studies to date to further investigate whether or not the rs11190870 polymorphism is associated with susceptibility to adolescent idiopathic scoliosis (AIS) in East Asian population. OBJECTIVE: To investigate whether or not the rs11190870 polymorphism is associated with susceptibility to AIS in East Asian population. SUMMARY OF BACKGROUND DATA: To date, the single nucleotide polymorphism rs11190870 was identified as the most significant common variant in Japanese females. Three association studies conducted in Chinese Han population from Hong Kong, Yangtze River region, and Southern region of mainland China replicated the association between AIS and rs1190870. However, there is limited published data about the association of rs11190870 with AIS in East Asian population. METHODS: A systematic search of all relevant studies published through August 2013 was conducted using the MEDLINE, EMBASE, OVID, and ScienceDirect. Single nucleotide polymorphism of rs11190870 was evaluated. The included studies were assessed in the analysis of the following allele model: T allele versus C allele for the allele-level comparison; (b) TC + TT versus CC for dominant model of T allele; (c) TT versus TC + CC for recessive model of T allele, and (d) TT versus CC for extreme genotype. RESULTS: Four studies with 8415 total participants (2889 patients with AIS and 5526 controls), who were all East Asian population, were eligible for inclusion. We searched for genotypes T allele versus C allele, TT versus TC + CC, TC + TT versus CC, and TT versus CC in a fixed/random-effects model. The effect summary odds ratios and 95 % confidence intervals were obtained, which shows significant association between rs11190870 and AIS in East Asian populations (all genetic models P < 0.001). Subgroup analyses were conducted according to sex. The results showed a significant association between rs11190870 and AIS in female (all genetic models, P < 0.001) but not in male (all genetic models, P > 0.05). CONCLUSION: The present meta-analysis demonstrated that the T allele of single nucleotide polymorphism rs11190870 may be a major susceptibility locus in the East Asian population with AIS, especially in female. LEVEL OF EVIDENCE: 1.

Safety of surgical treatment for patients with scoliosis and surgically corrected congenital cardiac malformations: a comparison with patients with scoliosis and normal hearts.

OBJECT: The safety of spinal fusion has been poorly studied in children with surgically corrected congenital cardiac malformations (CCMs). The objective of this study was to evaluate the safety of spinal fusion in patients with CCMs following cardiac surgery. METHODS: A retrospective study was conducted on 32 patients with scoliosis who received surgical treatment for their CCMs (CCM group). Sixty-four age- and sex-matched patients with scoliosis and normal hearts who received spinal fusion served as the control group. These 2 groups were compared for demographic distribution, blood loss, transfusion requirements, and incidence of postoperative complications. RESULTS: The ages, curve pattern distributions, and number of levels fused were similar between the 2 groups before spinal fusion. Overall, a total of 7 patients in the CCM group (21.9%) and 5 (7.8%) in the control group had documented postoperative complications. The perioperative allogenic blood transfusion rate and mean red blood cell transfusion requirement in the CCM group were significantly higher than those found in patients in the control group (68.7% vs 28.1%, respectively, p = 0.000; and 2.68 ± 2.76 units/patient vs 0.76 ± 1.07 units/patient, respectively, p = 0.011). In the CCM group, a preoperative major curve magnitude ≥ 80° was the most accurate indicator of an increased risk for a major complication (p = 0.019), whereas no statistically significant correlation was noted between postoperative complications and age, type of congenital heart disease, operative duration, and estimated blood loss during the operation and transfusion. CONCLUSIONS: Spinal fusion subsequent to prior cardiac surgery is relatively safe and effective in correcting the spinal deformity for patients with scoliosis and surgically corrected CCMs. A preoperative major curve magnitude ≥ 80° may be a risk factor in predicting postoperative complications in scoliotic patients with surgically corrected CCMs.

Comparison between subcutaneous closed-suction drainage and conventional closed-suction drainage in adolescent idiopathic scoliosis patients undergoing posterior instrumented spinal fusion: a randomized control trial.

STUDY DESIGN: Prospective, randomized controlled clinical study. OBJECTIVE: To evaluate the efficacy of subcutaneous closed-suction drainage in reducing blood loss as compared with conventional closed-suction drainage in adolescent idiopathic scoliosis cases undergoing posterior instrumented spinal fusion. BACKGROUND: Subcutaneous closed-suction drainage is reported to be a reasonable alternative to intra-articular indwelling closed-suction drainage and to that of no usage of any drainage system in knee arthroplasty. However, little is reported about the use of subcutaneous closed-suction drainage in adolescents idiopathic scoliosis patients undergoing posterior instrumented spinal fusion. METHODS: A total of 105 adolescent idiopathic scoliosis patients undergoing posterior instrumented spinal fusion were randomized into 2 groups of either a subcutaneous drainage or a conventional closed-wound suction drainage system. These 2 groups were compared for demographic distribution, blood loss (hemoglobin/hematocrit changes, transfusion requirements), and incidence of wound problems (requirements for dressing reinforcement, oozing, subcutaneous hematoma, ecchymosis, infection). RESULTS: Mean drainage volume was less (P=0.000) in the subcutaneous closed-wound suction drainage group compared with the conventional closed-wound suction drainage group (42 vs. 631 mL). The groups were statistically similar in terms of hemoglobin and hematocrit values obtained on the third postoperative day (10.60 vs. 9.52 g/dL, P=0.110; 30.85% vs. 27.82%, P=0.226), on discharge (10.90 vs. 9.75 g/dL, P=0.114; 31.10% vs. 28.13%, P=0.147), transfusion requirements (31.2% vs. 45.6%, P=0.133), and incidence of wound problems. However, the core temperature values were higher in subcutaneous closed-wound suction drainage group compared with the conventional closed-wound suction drainage group (P=0.001), and the duration of fever was longer in the former compared with the latter (P=0.008). CONCLUSIONS: The data suggest that subcutaneous closed-suction drainage offers a reasonable alternative to closed-wound suction drainage in adolescents idiopathic scoliosis patients undergoing posterior instrumented spinal fusion.

Upper instrumented vertebral fractures in long lumbar fusions: what are the associated risk factors?

STUDY DESIGN: A retrospective comparative study. OBJECTIVE: To investigate the risk factors associated with upper instrumented vertebral (UIV) fractures in adult lumbar deformity. SUMMARY OF BACKGROUND DATA: Long segment lumbar fusions may lead to junctional failures. The purpose of this study was to determine factors associated with junctional failures. METHODS: Twenty-seven consecutive patients from 2001 to 2008 with minimum 4 levels fused, lower instrumented vertebra (LIV) of L5 or S1, upper instrumented vertebra of T10 or distal, and no previous surgery proximal to the instrumentation were retrospectively reviewed. We describe the UIV angle, the sagittal angle of the upper instrumented vertebra with the horizontal. Patients were divided into 3 groups: group 1, 7 patients with UIV fractures; group 2, 6 patients with other proximal failures; and group 3, 14 patients with no proximal complications. RESULTS: The mean number of levels fused was 5.7 (4-7), 5.2 (4-8), and 6.2 (4-8); mean age was 64.1, 61.8, and 64.1, and mean body mass index was 33.5, 30.0, and 31.6 for groups 1, 2, and 3, respectively (P > 0.05). Osteotomies were performed in 5 of 7 in group 1, 1 of 6 in group 2, and 5 of 14 in group 3. Mean follow-up was 26.3 months. The average intraoperative UIV angle (UIV0) and immediate postoperative UIV angle (UIV1) were 18.6°/15.4° for group 1, 5.7°/5.3° for group 2, and 10.3°/7.1° for group 3 (P < 0.05). Surgical revision rates were higher in group 1 (71%) compared with groups 2 (50%) and 3 (43%). Eight of 11 (73%) patients with upper instrumented vertebra of L1 or L2 had either UIV fracture or other proximal failure compared with 5 of 16 (31%) in patients with upper instrumented vertebra of T10, T11, or T12. CONCLUSION: Our series of long lumbar fusions had a high long-term complication and revision rate. A high UIV angle on intraoperative lateral radiograph was strongly associated with UIV fractures. UIVs of L1 or L2 had a higher rate of adjacent segment or UIV failure.

Accuracy and reliability of MRI quantitative measurements to assess spinal cord compression in cervical spondylotic myelopathy: a prospective study.

STUDY TYPE: Reliability study Introduction: Cervical spondylotic myelopathy (CSM) is the most common spinal cord disorder in persons more than 55 years old. Despite multiple neuroimaging approaches proposed to quantify the spinal cord compromise in CSM patients, magnetic resonance imaging (MRI) remains the procedure of choice by providing helpful information for clinical decision making, determining optimal subpopulations for treatment, and selecting the optimal treatment strategies. However, the validity, reliability, and accuracy of the MRI quantitative measurements have not yet been addressed. OBJECTIVE: To assess the intra- and inter-observer reliability of MRI quantitative measurements of the spinal cord compromise in CSM patients. METHODS: Seventeen CSM patients (13 male) of mean age 54.5 years old were selected from the AOSpine North America database. The patients had different combinations of stenotic levels (1-4 levels) and the clinical severity (range mJOA baseline: 8-18). Asymptomatic or previous surgically treated CSM, active infection, neoplastic disease, rheumatoid arthritis, ankylosing spondylitis, trauma, or concomitant lumbar stenosis were excluded. The patients underwent preoperative MRI using 1.5T (15 patients) and 3T (two patients) scanner, including mid-sagittal T1-weighted, axial and mid-sagittal T2-weighted series. MRI data were analyzed (Mango 2.0 software; Multi-Image Analysis GUI) by four blind raters in three different sessions. Four measurements were analysed: transverse area (TA) (Figure 1), compression ratio (CR) (Figure 2), maximal canal compromise (MCC), and maximal spinal cord compression (MSCC) (Figure 3). The differences for each measurement were evaluated using mixed-effect ANOVA models (ratter, session, ratter x session). The intra- and inter-rater reliability was evaluated with intraclass correlation coefficients (ICC) (Figure 4). Figure 1 Transverse area (TA)Figure 2 Compression ratio (CR = AP/W)Figure 3 Maximal canal compromise (MCC), and maximal spinal cord compression (MSCC). MCC(%) = 1-[Dx/(Da+Db)/2] × 100%; MSCC(%) = 1-[dx/(da+db)/2] × 100%Figure 4 Intraclass correlation coefficients (ICC) Results: The principal findings were: (i) for TA (71.48 ± 12.99mm2), the intra-rater agreement was 0.97 (95% CI, range 0.94-0.99) and the inter-rater agreement was 0.76 (95% CI, range 0.49-0.90); (ii) for CR (0.35 ± 0.04%), 0.94 (95% CI, range 0.88-0.98), and 0.79 (95% CI, range 0.57-0.91) respectively; (iii) for MCC (83.21 ± 2.08%), 0.95 (95% CI, range 0.89-0.98), and 0.64 (95% CI, range 0.28-0.85) respectively; and (iv) for MSCC (82.87 ± 1.52%), 0.93 (95% CI, range 0.86-0.97), and 0.84 (95% CI, range 0.65-0.93) respectively. CONCLUSIONS: Our data suggest that three out of four measurements (TA, CR and MSCC) have acceptable intra- and interreliability coefficients (ICC > 0.75). However, for the maximal canal compromise measure, although the intrareliability was acceptable, the inter-rater reliability was not acceptable (0.64). Based on this study, we recommend that three MRI measures: transverse area, compression ratio and maximal spinal cord compression should be used in the imaging assessment of the spinal cord in CSM patients.