Posterior Spinal Fusion Surgery Research Articles

Risk factors of distal adding-on and appropriate lower instrumented vertebra in posterior corrective spinal fusion surgery for the patients with Lenke type 1A-R and 2A-R adolescent idiopathic scoliosis

Risk factors of distal adding-on and appropriate lower instrumented vertebra in posterior corrective spinal fusion surgery for the patients with Lenke type 1A-R and 2A-R adolescent idiopathic scoliosis

Hidden Blood Loss In Adolescent Idiopathic Scoliosis Patients Undergoing Posterior Spinal Surgery

Purpose: To investigate Hidden blood loss (HBL) and its potential risk factors in adolescent idiopathic scoliosis patients undergoing posterior spinal fusion surgery and elucidate the influence of HBL on postoperative blood transfusion. Methods: We retrospectively studied 765 patients undergoing posterior spine fusion for adolescent idiopathic scoliosis from January 2014 to December 2018. The patient’s demographics, blood loss related parameters, operation and blood loss information were extracted. The association between patient’s characteristics and HBL was analyzed by Pearson or Spearman correlation analysis. Multivariate linear regression analysis was used to determine independent risk factors associated with HBL. Binary logistic regression analysis was used to analyze the influence of HBL on postoperative blood transfusion. Results: A total of 765 patients including 128 males and 637 females (age range 10-18 years) were included in this study. The mean amount of HBL was 693.5±473.4 ml, accounting for 53.9% of the total blood loss. In multivariate linear regression analysis, we found that preoperative Hct (p=0.003) and allogeneic blood transfusion (p 850 ml (P < 0.001, OR: 8.845, 95%CI: 5.806-13.290) was the independent risk factor for postoperative blood transfusion. Conclusion: A large amount of HBL was incurred in adolescent idiopathic scoliosis patients undergoing posterior spinal fusion surgeries. Allogeneic blood transfusion and preoperative Hct were independent risk factors for HBL, while tranexamic acid was negatively related to HBL. HBL and its influential factors should be taken into account when considering the perioperative transfusion management. These patients with HBL greater than 850 ml should be paid more attention in case of postoperative anemia.

Is the axial spinal cord classification predictive of intraoperative neurologic alert for pediatric scoliosis patients? An independent retrospective validation study.

We sought to determine whether the axial spinal cord classification by Sielatycki et al. would be associated with increased intraoperative neuromonitoring (IONM) alerts for pediatric scoliosis patients undergoing posterior spinal fusion (PSF) surgery. Children less than age 19 with scoliosis undergoing PSF were retrospectively reviewed. Axial-T2 MRI of the thoracic apex was reviewed for spinal cord/CSF architecture as described by Sielatycki et al.: Type 1-circular cord with visible CSF, Type 2-circular cord but no visible CSF at apical concavity, and Type 3-cord deformed with no intervening CSF. Intraoperative neuromonitoring reports, operative records and preoperative radiographs were reviewed. 90 patients met the inclusion criteria. Rate of neurologic events was Type 1: 2% (1/41 patients), Type 2: 14.3% (4/28), Type 3: 57.1% (12/21) (Type 1 vs 2 p = 0.06; Type 1 vs 3 p < 0.0001; Type 2 vs 3 p = 0.0017). Three patients with a Type 3 cord awoke with significant deficits. In comparison to Type 1 cords, Type 3 and Type 2 spinal cords were associated with increased coronal and total deformity angular ratios (Type 1 vs 3 p = 0.035 and 0.0054 respectively; Type 1 vs 2 p = 0.042 and 0.03 respectively). There was no difference in gender, diagnosis category, age at surgery, Cobb angle or kyphosis between the three groups. The axial spinal cord classification correlated with IONM alerts and greater severity of spinal deformity in pediatric scoliosis patients. IV, retrospective cohort study.

Machine Learning Predicts the 3D Outcomes of Adolescent Idiopathic Scoliosis Surgery Using Patient-Surgeon Specific Parameters.

Retrospective descriptive, multicenter study. The aim of this study was to predict the three-dimensional (3D) radiographic outcomes of the spinal surgery in a cohort of adolescent idiopathic scoliosis (AIS) as a function preoperative spinal parameters and surgeon modifiable factors. Current guidelines for posterior spinal fusion surgery (PSF) in AIS patients are based on two-dimensional classification of the spinal curves. Despite the high success rate, the prediction of the 3D spinal alignment at the follow-ups remains inconclusive. A data-driven surgical decision-making method that determines the combination of the surgical procedures and preoperative patient specific parameters that leads to a specific 3D global spinal alignment outcomes at the follow-ups can lessen the burden of surgical planning and improve patient satisfaction by setting expectations prior to surgery. A dataset of 371 AIS patients who underwent a PSF with two-year follow-up were included. Demographics, 2D radiographic spinal and pelvic measurements, clinical measurements of the trunk shape, and the surgical procedures were collected prospectively. A previously developed classification of the preoperative global 3D spinal alignment was used as an additional predictor. The 3D spinal alignment (vertebral positions and rotations) at two-year follow-up was used as the predicted outcome. An ensemble learner was used to predict the 3D spinal alignment at two-year follow-up as a function of the preoperative parameters with and without considering the surgeon modifiable factors. The preoperative and surgical factors predicted three clusters of 3D surgical outcomes with an accuracy of 75%. The prediction accuracy decreased to 64% when only preoperative factors, without the surgical factors, were used in the model. Predictor importance analysis determined that preoperative distal junctional kyphosis, pelvic sagittal parameters, end-instrumented vertebra (EIV) angulation and translation, and the preoperative 3D clusters are the most important patient-specific predictors of the outcomes. Three surgical factors, upper and lower instrumented vertebrae, and the operating surgeon, were important surgical predictors. The role of surgeon in achieving a certain outcome clusters for specific ranges of preoperative T10-L2 kyphosis, EIV angulation and translation, thoracic and lumbar flexibilities, and patient's height was significant. Both preoperative patient-specific and surgeon modifiable parameters predicted the 3D global spinal alignment at two-year post PSF. Surgeon was determined as a predictor of the outcomes despite including 20 factors in the analysis that described the surgical moves. Methods to quantify the differences between the implemented surgeon modifiable factors are essential to improve outcome prediction in AIS spinal surgery.Level of Evidence: 3.

Crossing the Cervicothoracic Junction During Posterior Cervical Fusion for Myelopathy Is Associated With Superior Radiographic Parameters But Similar Clinical Outcomes.

For laminectomy and posterior spinal fusion (LPSF) surgery for cervical spondylotic myelopathy (CSM), the evidence is unclear as to whether fusions should cross the cervicothoracic junction (CTJ). To compare LPSF outcomes between those with and without lower instrumented vertebrae (LIV) crossing the CTJ. A consecutive series of adults undergoing LPSF for CSM from 2012 to 2018 with a minimum of 12-mo follow-up were identified. LPSF with subaxial upper instrumented vertebrae and LIV between C6 and T2 were included. Clinical and radiographic outcomes were compared. A total of 79 patients were included: 46 crossed the CTJ (crossed-CTJ) and 33 did not. The mean follow-up was 22.2 mo (minimum: 12 mo). Crossed-CTJ had higher preoperative C2-7 sagittal vertical axis (cSVA) (33.3±16.0vs 23.8±12.4mm, P=.01) but similar preoperative cervical lordosis (CL) and CL minus T1-slope (CL minus T1-slope) (P > .05, both comparisons). The overall reoperation rate was 3.8% (crossed-CTJ: 2.2%vs not-crossed: 6.1%, P=.37). In adjusted analyses, crossed-CTJ was associated with superior cSVA (β = -9.7; P=.002), CL (β = 6.2; P=.04), and CL minus T1-slope (β = -6.6; P=.04), but longer operative times (β = 46.3; P=.001). Crossed- and not-crossed CTJ achieved similar postoperative patient-reported outcomes [Visual Analog Scale (VAS) neck pain, VAS arm pain, Nurick Grade, Modified Japanese Orthopedic Association Scale, Neck Disability Index, and EuroQol-5D] in adjusted multivariable analyses (adjusted P>.05). For the entire cohort, higher postoperative CL was associated with lower postoperative arm pain (adjusted Pearson's r -0.1, P=.02). No postoperative cervical radiographic parameters were associated with neck pain (P>.05). Subaxial LPSF for CSM that crossed the CTJ were associated with superior radiographic outcomes for cSVA, CL, and CL minus T1-slope, but longer operative times. There were no differences in neck pain or reoperation rate.

Neuropathic Pain after Adolescent Idiopathic Scoliosis Correction Surgery.

Study DesignProspective study.PurposeTo 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 LiteraturePost-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.MethodsForty 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.ResultsBased 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).ConclusionsChronic neuropathic pain was uncommon in AIS patients who had undergone PSF surgery. Higher opioid consumption will increase the possibility of developing chronic neuropathic pain.

Pattern of bone marrow lipid composition measures along the vertebral column: A descriptive study of adolescents with idiopathic scoliosis.

There is evidence that the extent of vertebral bone marrow adiposity increases caudally along the vertebral column in children and adolescents. However, no studies have examined the lipid composition of bone marrow along the vertebral column, which may uniquely influence bone acquisition and metabolism during growth independent of the amount of bone marrow adipose tissue. The goal of this study was to characterize the pattern of lipid composition index measures from the thoracic to lumbar spine (T11-L4) among a sample of adolescents with idiopathic scoliosis (AIS) undergoing routine orthopedic surgical care for scoliosis correction. Adolescents between 14 and 18years of age, with a confirmed diagnosis of AIS, and undergoing routine posterior spinal fusion surgery at our institution were initially included for this descriptive study. The surgery yielded transpedicular vertebral body marrow samples from T11 through L4; 11 participants had bone marrow samples from T11 through L2 and 4 of the 11 participants had marrow samples from T11 through L4. Lipid composition index measures, including the saturated, monounsaturated, and polyunsaturated index, were measured using a targeted lipidomics technique. Linear regression equation for the slope (m) and Pearson correlation coefficient (r) was computed to assess the pattern of lipid composition index measures along the vertebral column from T11 to L2 (n=11) and extended analysis to L4. Exploratory analyses were performed to examine the association between the pattern of lipid composition measures (individual slopes) and physical characteristics for T11-L2. For T11-L2, the slope of the saturated index was near 0 (r=0.08; P=0.92), whereas the slopes of the unsaturated indices were approximately opposite of one another: the monounsaturated index exhibited a -0.55 change (r=0.58; P=0.42) per vertebra and the polyunsaturated index exhibited a 0.52 change (r=0.72; P=0.28) per vertebra in the caudal direction from T11-L2. For T11-L4, there were modest changes in slope for the saturated (m=0.12; r=0.30; P=0.57) and monounsaturated (m=-0.68; r=0.74; P=0.09) indices, while the polyunsaturated index slope remained similar (m=0.56; r=0.89; P=0.02). Age, sex, height, body mass, and BMI were not associated with the pattern of any of the lipid composition index measures. Study findings in this small sample of individuals with AIS suggest that the bone marrow saturated index may be relatively stable across T11-L4, while the monounsaturated index may decrease by 0.55-0.68% per vertebra and the polyunsaturated index may increase by 0.52-0.56% per vertebra in the caudal direction.

Causes of lower extremity weaknesses after posterior lumbar spine fusion surgery and therapeutic effects of active surgical exploration

BackgroundThis study was aimed at investigating the causes of lower extremity weaknesses after posterior lumbar spine fusion surgery and looking at subsequent treatment strategies.MethodsPatients who underwent posterior lumbar spine fusion surgery in the Peking University First Hospital between January 2009 and December 2018 were counted. Those who needed secondary surgery because of subsequent lower extremity weaknesses were selected. CT scans and MRIs were used to evaluate the reasons for weaknesses before secondary surgery. Muscle strength was evaluated after surgery.ResultsThirty patients (30/4078, 0.74%) required a secondary surgery because of lower extremity weaknesses after posterior lumbar spine fusion surgery. The main causes of weakness were (1) internal fixation malposition and loosening (11 patients, 36%), (2) epidural hematomas (9 patients, 30%), (3) insufficient decompression (5 patients, 17%), and (4) nerve root edemas (5 patients, 17%). Weakness occurred on average 2.9 days after surgery (1–9 days). Twenty-seven patients (90%) got improved muscle strength after their secondary surgery.ConclusionsIatrogenic neurologic deficits and lower extremity weaknesses were rare complications after posterior lumbar spine fusion surgeries, but important to recognize and manage. The main causes of weakness were internal fixation malposition and loosening, epidural hematomas, insufficient decompression, or root edemas. There may be positive, therapeutic effects to subsequent, active surgical exploration.

Intersite reliability of vertebral bone marrow lipidomics-derived lipid composition among children with varying degrees of bone fragility undergoing routine orthopedic surgery.

Lipidomics, a branch of metabolomics, is an attractive technique to characterize bone marrow lipid composition, which may be associated with skeletal acquisition and homeostasis. However, the reliability of lipidomics-derived lipid composition of the bone marrow is unknown, especially for pediatric populations with bone fragility. The purpose of this study was to evaluate the intersite reliability and standard error of measurement (SEM) of vertebral bone marrow lipid composition at the thoracic (T11/T12) and lumbar (L1/L2) spine determined by targeted lipidomics among children with varying degrees of bone fragility undergoing routine orthopedic surgery. Children aged between 12 and 19years of age, with a confirmed diagnosis of adolescent idiopathic scoliosis or neuromuscular scoliosis and cerebral palsy, and undergoing routine posterior spinal fusion surgery at our institution were initially included in this study. Transpedicular vertebral body bone marrow samples were taken from thoracic (T) or lumbar (L) vertebrae. Further inclusion criteria involved having bone marrow extracted from both T11 and T12 (n=24) or L1 and L2 (n=19). Lipid composition was measured using a targeted lipidomics technique and examined as the saturated, monounsaturated, and polyunsaturated index and as individual fatty acids. Relative and absolute test-retest reliability was assessed using the intraclass correlation coefficient (ICC) and SEM. For the T11/T12 analysis: the ICC and SEM were 0.59 and 1.7% for the saturated index, 0.31 and 6.2% for the monounsaturated index, and 0.44 and 6.1% for the polyunsaturated index; the ICC showed a considerable range for individual fatty acids from 0.07 (fatty acid 20:2) to 0.82 (15:0) with 62.1% of the fatty acids having poor reliability (i.e., ICC<0.50). For the L1/L2 analysis: the ICC and SEM were 0.50 and 2.4% for the saturated index, -0.12 and 6.0% for the monounsaturated index, and 0.00 and 4.9% for the polyunsaturated index; the ICC showed a considerable range for individual fatty acids from -0.34 (18:1_n-9) to 0.88 (15:0 and 18:3_n-3) with 79.3% of the fatty acids having poor reliability. The intersite test-retest reliability was poor-to-moderate for index measures and generally poor for individual fatty acids for the thoracic and lumbar spine. At this time, it is not recommended to pool bone marrow adipose tissue across vertebral sites for bone marrow adiposity research or clinical monitoring for pediatric populations with bone fragility.

Test-Retest Reliability and Correlates of Vertebral Bone Marrow Lipid Composition by Lipidomics Among Children With Varying Degrees of Bone Fragility.

ABSTRACTThe reliability of lipidomics, an approach to identify the presence and interactions of lipids, to analyze the bone marrow lipid composition among pediatric populations with bone fragility is unknown. The objective of this study was to assess the test–retest reliability, standard error of measurement (SEM), and the minimal detectable change (MDC) of vertebral bone marrow lipid composition determined by targeted lipidomics among children with varying degrees of bone fragility undergoing routine orthopedic surgery. Children aged 10 to 19 years, with a confirmed diagnosis of adolescent idiopathic scoliosis (n = 13) or neuromuscular scoliosis and cerebral palsy (n = 3), undergoing posterior spinal fusion surgery at our institution were included in this study. Transpedicular vertebral body bone marrow samples were taken from thoracic vertebrae (T11, 12) or lumbar vertebrae (L1 to L4). Lipid composition was assessed via targeted lipidomics and all samples were analyzed in the same batch. Lipid composition measures were examined as the saturated, monounsaturated, and polyunsaturated index and as individual fatty acids. Relative and absolute test–retest reliability was assessed using the intraclass correlation coefficient (ICC), SEM, and MDC. Associations between demographics and index measures were explored. The ICC, SEM, and MDC were 0.81 (95% CI, 0.55–0.93), 1.6%, and 4.3%, respectively, for the saturated index, 0.66 (95% CI, 0.25–0.87), 3.5%, and 9.7%, respectively, for the monounsaturated index, and 0.60 (95% CI, 0.17–0.84), 3.6%, and 9.9%, respectively, for the polyunsaturated index. For the individual fatty acids, the ICC showed a considerable range from 0.04 (22:2n‐6) to 0.97 (18:3n‐3). Age was positively correlated with the saturated index (r 2 = 0.36; p = 0.014) and negatively correlated with the polyunsaturated index (r 2 = 0.26; p = 0.043); there was no difference in index measures by sex (p > 0.58). The test–retest reliability was moderate‐to‐good for index measures and poor to excellent for individual fatty acids; this information can be used to power research studies and identify measures for clinical or research monitoring. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

227. Is the axial spinal cord classification predictive of intraoperative neurologic alert for pediatric scoliosis patients? A validation study

BACKGROUND CONTEXT Neurologic deficit is a devastating complication in pediatric spinal deformity surgery. Identification of high-risk patients may improve preoperative planning and assist in counseling of patients and families. PURPOSE We proposed to determine if the axial spinal cord classification as described by Sielatycki and Lenke would be associated with a high rate of intraoperative neuromonitoring alerts for pediatric scoliosis patients undergoing posterior spinal fusion surgery. STUDY DESIGN/SETTING Retrospective chart review study. PATIENT SAMPLE A total of 90 pediatric scoliosis patients. OUTCOME MEASURES n/a METHODS Pediatric scoliosis patients undergoing posterior spinal fusion were retrospectively reviewed at a single tertiary referral center. As MRI is not routinely obtained prior to surgery, only those patients with a preoperative MRI showing high quality axial imaging of the apex of the thoracic deformity were included. MRI was reviewed for spinal cord/ CSF architecture as described by Sielatycki and Lenke. Based on this classification there are 3 types of cords. Type 1: circular cord with visible CSF between the cord and the apical concave pedicle. Type 2: circular cord but no visible CSF at apical concavity. Type 3: cord deformed with no intervening CSF. Intraoperative neuromonitoring records and operative reports were reviewed to determine presence of a neurologic alert. Preoperative radiographs were used to measure Cobb angle, kyphosis and deformity angular ratio (total DAR = coronal DAR + sagittal DAR). RESULTS A total of 90 patients met inclusion criteria. Diagnoses included idiopathic scoliosis (74%), followed by congenital (9%), syndromic (7%), neuromuscular/other (10%). Rate of neurologic events was Type 1: 2% (1/41 patients), Type 2: 14.3% (4/28), Type 3: 52% (11/21, p CONCLUSIONS Although there may be bias in the cohort in that only patients considered to be higher risk have preoperative MRI imaging, the axial MRI spinal cord classification correlated with intraoperative neuromonitoring alerts in pediatric scoliosis patients. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Posterior Spinal Correction and Fusion Surgery in Patients with Spinal Muscular Atrophy-Associated Scoliosis for Whom Treatment with Nusinersen Was Planned.

Introduction Spinal muscular atrophy (SMA) is defined as a neuromuscular disorder induced by progressive weakness of the skeletal muscle and is usually accompanied by progressive spinal deformity including scoliosis. The newly developed Nusinersen, which is the first approved drug worldwide for SMA, requires accurate intrathecal injection, which is sometimes difficult in patients with severe spinal deformity. Technical Note For an accurate intrathecal approach in patients who have spinal fusion surgery to treat neuromuscular scoliosis, we have combined an L3 laminectomy with spinal correction and fusion surgery. Here, we review four cases of SMA in patients who underwent the additional L3 laminectomy during surgery to treat spinal scoliosis. A successful intrathecal approach was made using fluoroscopic guidance in all four patients, who were then administered with Nusinersen. Conclusions Our findings show that additional lumbar laminectomy during surgery for spinal scoliosis has effectively allowed for intrathecal injection of Nusinersen.

Association between preoperative hemoglobin levels after iron supplementation and perioperative blood transfusion requirements in children undergoing scoliosis surgery.

In this study, we assessed the association between preoperative hemoglobin and red blood cell transfusion in children undergoing spine surgery after the implementation of our preoperative iron supplementation protocol. We performed a retrospective analysis of patients who underwent posterior spinal fusion surgery between January 2013 and December 2017 and received preoperative iron supplementation. We used uni- and multivariable logistic regression to determine the association between preoperative hemoglobin level and red blood cell transfusion in patients receiving iron supplementation. A total of 382 patients treated with preoperative oral iron were included. Of these, 175 (45.5%) patients were transfused intraoperatively. Multivariable logistic regression analysis revealed nonidiopathic etiology of the scoliosis (OR 4.178 [95% CI: 2.277-7.668], P<.001), the Cobb angle (OR 1.025 [95% CI: 1.010-1.040], P=.001), and number of vertebrae fused (OR 1.169 [95% CI: 1.042-1.312], P=.008) were associated with red blood cell transfusion. In addition, patients with a preoperative hemoglobin≥140g/L (OR 0.157 [95% CI: 0.046-0.540], P=.003), and hemoglobin between 130 and 140g/L (OR 0.195 [95% CI: 0.057-0.669], P=.009) were less likely to be transfused compared with patients with preoperative hemoglobin between 120 and 130g/L (OR 0.294 [95% CI: 0.780-1.082], P=.066) or <120g/L (reference). Our study suggests that higher preoperative hemoglobin levels (>130g/L) are associated with a reduced need for red blood cell transfusion in pediatric patients who have received iron supplementation before undergoing posterior spinal fusion in our institution. The effect of iron supplementation, the optimal dosing, and duration of supplemental iron therapy remains unclear at this time.

Minimally invasive surgery versus standard posterior approach for Lenke Type 1-4 adolescent idiopathic scoliosis: a multicenter, retrospective study.

To compare the safety and efficacy of posterior minimally invasive surgery (MIS) to standard posterior spinal fusion (PSF) surgery for Lenke Type 1-4 adolescent idiopathic scoliosis (AIS). This multicenter retrospective study enrolled 112 patients with Lenke Type 1-4 AIS who treated with MIS (n = 64) or PSF (n = 48) between March 2007 and January 2015. Coronal and sagittal parameters were evaluated before surgery, immediately after surgery, and at the last follow-up. Operative time, level of fusion, intraoperative blood loss, blood transfusion, and intraoperative radiation exposure were recorded. 22-item Scoliosis Research Society questionnaire (SRS-22) was applied for assessment of life quality. The accuracy of pedicle screw placement was assessed according to postoperative computed tomography images, and the complications were collected in follow-up period. The baseline characteristics of 2 groups were matched. There was no significant difference between 2 groups in terms of radiographic parameters immediately after surgery and at the last follow-up. The MIS group had significantly longer operative time, more level of fusion, less intraoperative blood loss, and lower blood transfusion rate (p < 0.001). The evaluation of pain using SRS-22 showed significantly lower score in MIS group (p < 0.05). No significant difference was found between 2 groups in terms of accuracy of pedicle screw placement and complications. Posterior MIS is a safe and effective alternative to standard open approach for Lenke Type 1-4 AIS patients with curves < 70° and reasonable flexibility. Mid-term results showed MIS had the advantages of less blood loss and pain with more fusion segments.

The effect of dexmedetomidine on motor-evoked potentials during pediatric posterior spinal fusion surgery: a retrospective case-control study.

Motor-evoked potentials (MEPs) are frequently used in pediatric posterior spinal fusion surgery (PSFS) to detect spinal cord ischemia. Dexmedetomidine is increasingly being used as an adjunct to total intravenous anesthesia, but its effect on MEP amplitude has been variably reported. The purpose of this study was to evaluate the effect of an infusion of dexmedetomidine on the amplitude of MEPs. We performed a retrospective case-control study of 30 pediatric patients who received a 0.5 µg·kg-1·hr-1 infusion of dexmedetomidine, ten patients who received 0.3 µg·kg-1·hr-1 dexmedetomidine, and 30 control patients who did not receive dexmedetomidine during PSFS. Two neurophysiologists reviewed the MEP amplitudes in six muscle groups at three time points: when the patient was turned prone (baseline; T1), one hour after incision (T2), and after exposure of the spine but before insertion of the first screw (T3). In all muscles tested, the mean MEP amplitude was reduced by T3 when dexmedetomidine was infused at 0.5 µg·kg-1·hr-1. The greatest reduction from baseline MEP amplitude was 829 µV (95% confidence interval, 352 to 1230; P < 0.001) seen in first right dorsus interosseous. When dexmedetomidine was infused at 0.3 µg·kg-1·hr-1, there was a significant reduction in MEP amplitude in four of the six muscles tested at T3 compared with the control group. Dexmedetomidine at commonly used infusion rates of 0.3 µg·kg-1·hr-1 or 0.5 µg·kg-1·hr-1 causes a significant decrease in MEP amplitude during pediatric PSFS. We suggest that dexmedetomidine should be avoided in children undergoing PSFS so as not to confuse the interpretation of this important neurophysiological monitor.

An analysis of the safety and efficacy of dexmedetomidine in posterior spinal fusion surgery for adolescent idiopathic scoliosis: a prospective randomized study.

To evaluate whether use of dexmedetomidine, a centrally acting α2 adrenergic agonist, reduces opioid consumption in PSF. Adolescent idiopathic scoliosis patients who underwent PSF were randomized into morphine (M) and dexmedetomidine (D) group. M group received a 10μg/kg/h IV infusion of morphine for 24h post-surgery, while the D group received a 0.4μg/kg/h IV infusion of dexmedetomidine. Trained nursing staffs recorded hourly vital parameters (blood pressure, pulse rate, respiratory rate, and oxygen saturation). Pain, postoperative nausea/vomiting (PONV), and sedation were rated using: the numerical rating scale (NRS), the PONV scale, and sedation statusscale(SS). Preemptive analgesia with gabapentin and postoperative analgesia with ketorolac and paracetamol were used in both the groups. Any complications in the study groups were recorded. No significant difference was noted between the groups (M vs D) with respect to NRS (3.1 ± 0.8 vs 2.7 ± 0.5) (p = 0.07) and breakthrough analgesia requirements (0.78 vs 0.45) (p = 0.17). A significant difference was noted between the groups with respect to the secondary outcome measures of time to ambulation (56.6 ± 12.7h vs 45.2 ± 7.7h), time to oral analgesics (84.3 ± 20h vs 64.0 ± 15.4h), and time to liquid intake (8.3 ± 1.3h vs 7.2 ± 1.2h). The M group had a higher PONV score (0.46 ± 0.3 vs 0.16 ± 0.1) (p < 0.001) and mean time to bowel opening (112.7 ± 28.4h vs 90.1 ± 20.5h) (p < 0.001). Additionally, the enema or suppository requirements for bowel opening were significantly more (0.59 ± 0.6 vs 0.26 ± 0.4) (p = 0.01) in the M group. Dexmedetomidine provided analgesia comparable to morphine with lower PONV scores. It also reduced the opioid requirements in the PSF patients without additional complications and can therefore be incorporated in pain management protocols.

A Comparative Study on the Use of Ketamine and Apotel Infusion Pump for the Control of Pain After Posterior Fusion Operations: A Randomized Controlled Trial

Background: Postoperative pain has many adverse effects and if not properly controlled, it can cause a wide range of problems. Objectives: The purpose of this study is to compare the results of using ketamine and apotel infusion pumps to control pain after posterior fusion surgery. Methods: In this clinical trial study, 72 patients hospitalized for posterior spine fusion surgery were randomly assigned into two groups, including ketamine infusion pumps (ketamin group) and apotel infusion pumps (apotel group). In the ketamin group, 0.2 mg/kg/h of ketamine was infused to by a pain pump with normal saline to 100 cc. In the apotel group, apotel was used instead of ketamine. The rate of pain was evaluated in recovery, and at 6, 12, 18, 24, and 48 hours after the surgery, based on VAS criteria. The rate of sedation was recorded based on Ramsy score. Results: There was no significant difference between age, sex, BMI, underlying diseases, and smoking in patients with posterior spinal fusion surgery between the groups. Postoperative pain score was significantly lower in the patients with posterior fusion surgery at 6, 12, 18, 24, and 48 hours in the ketamin group compared to the apotel group (P &lt; 0.001). Patients’ satisfaction with the analgesia was significantly higher in the patients at 24 hours (P = 0.001) and 48 hours (P = 0.04) in the ketamine group compared to the apotel. With regards to the Ramsy scores of the patients with posterior fusion surgery, there was no significant difference between the groups (P = 0.16). Conclusions: The use of a ketamine infusion pump can be more effective than an apotel infusion pump to control pain after posterior fusion surgery.

Straighten things out in advance: Palliative care consultation prior to posterior spinal fusion for high-risk neuromuscular scoliosis patients

Introduction: Patients with neuromuscular scoliosis undergo posterior spinal fusion (PSF) surgery with the hopes of preventing respiratory disease, optimizing positioning and functioning, and sometimes to improve pain. While studies show quality of life benefit from PSF for many children with neuromuscular scoliosis, there remains significant post-operative morbidity and even mortality risk. Preliminary studies have attempted to correlate preoperative risk factors with the likelihood of postoperative complications (1). However, the outcomes of PSF in the subset of neuromuscular scoliosis patients who have multifactorial respiratory failure have not been specifically studied …

The C2 Cortical Screw, an Alternative Fixation Technique for the C2 Segment During High Cervical Spine Surgery: Technical Note

For posterior fixation of C2 vertebra (the axis), several fixation techniques such as pedicle screw, laminar screw, and pars screw have been reported. A pedicle screw (PS) is considered the strongest among the techniques, but certain situations make PS fixation impossible or difficult. These include patients with a narrow C2 pedicle or high-riding vertebral artery. We introduced an alternative screw technique for C2 that addressed the aforementioned problems with safely placing it, which we termed a cortical screw (CS) for C2. Among a total of 28 cases using C2 CS for high cervical spine surgery, 2 cases using C2 CS were described. One patient was a 76-year old woman with a gait disturbance and myelopathic symptoms and diagnosed with C1-C2 myelopathy and translational instability. The other case was 54-year old man with posterior neck pain after traffic accident and diagnosed with C1-C2 fracture-dislocation. We used the C2 CS as an alternative technique for high cervical spine surgery in these patients and describe the ideal entry point and trajectory. A postoperative computed tomography scan confirmed proper positioning of the C1 posterior arch screw and C2 CS, with satisfactory reduction of the C2 dens and adequate restoration of the C1-C2 spinal canal. The patient experienced no screw-related postoperative complications, and postoperative 1-year computed tomography images showed that solid union and good alignment of C1-2 segment was achieved. C2 CS can be suitable alternative for C2 screw fixation technique in posterior high cervical spine fusion surgery.

Development of a VR Simulator for Training of Posterior Cervical Spine Fusion Surgery

AbstractIt is important to avoid iatrogenic injuries of nerves and blood vessels during the pedicle screw insertion stage of posterior cervical spine decompression and fusion surgery. First, it is necessary to determine the length and angulation of the pedicle screws for safety and stability. Second, it is necessary to drill precise preparation holes for the pedicle screws using a pedicle probe. In this work, we developed a VR training system for pedicle screw planning and basic drilling skills. The VR system was built with a pen‐style haptic device and a head‐mounted display. Trainees used the haptic pen as a virtual pedicle probe. In order to simulate bone hardness and stress accumulation at the virtual pedicle probe tip in the virtual surgery, we developed a voxel‐based bone drilling simulator. To reduce the heavy load required for voxel processing, the simulator was constructed as a hybrid system that included a removal volume voxel model for drilling areas and a fixed polygonal mesh model for other areas. 3D models of a cervical spine were generated from CT scan images of a patient. This paper evaluated the system through a subjective evaluation by a specialist and via the training results for novice trainees. We discuss the evaluation results and training effectiveness with the simulator. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.