Faculty Bibliography

STUDY DESIGN/METHODS:A prospective case-control study. OBJECTIVE:To analyze global coronal malalignment (GCM) in degenerative lumbar scoliosis (DLS) and to prospectively investigate the performance of priority-matching correction technique on preventing postoperative coronal imbalance. METHODS:A total of 444 DLS inpatients and outpatients were recruited. GCMs were classified into 2 types: Type 1, GCM with thoracolumbar (TL/L) curve as the main contribution on coronal imbalance; Type 2, GCM with lumbosacral (LS) curve as the main contribution on coronal imbalance. Patients receiving priority-matching correction were assigned to Group P-M and receiving traditional correction were assigned to Group T form August 2020. The fundamental principle of priority-matching technique was to first correct the key curve contributing to coronal imbalance rather than the curve with greater magnitude. RESULTS:Type 1 GCM accounted for 45% and Type 2 GCM accounted for 55% of patients. Type 2 GCM was detected to have greater LS Cobb angle and L4 tilt. At 1-year follow-up, 29.8% of patients with Type 2 GCM, whereas 11.7% of patients with Type 1 GCM were observed to have postoperative coronal decompensation. Patients with postoperative imbalance were revealed to have greater preoperative LS Cobb angle and L4 tilt and smaller correction extent of LS curve and L4 tilt. 6.25% of patients developed postoperative coronal imbalance in Group P-M, whereas 40.5% developed in Group T. CONCLUSION/CONCLUSIONS:Highlighting priority and aggressive correction of the key curve to coronal imbalance, priority-matching technique was proved to be able to limit the development of postoperative coronal decompensation.

STUDY DESIGN/METHODS:Retrospective Upright MRI Study. OBJECTIVES/OBJECTIVE:Determine the relationship between lumbar disc herniation and presence of the nerve root sedimentation sign on upright kinematic MRI patients. METHODS:T2-weighted axial upright kMRI images of 100 patients with the presence of disc herniation in at least 1 lumbar disc between L1/L2 and L5/S1 were obtained. Sedimentation sign, spinal canal anterior-posterior (AP) diameter, disc height, disc herniation size, type of herniation, and zone of herniation were evaluated. A positive sedimentation sign was defined as having either the majority of nerve roots running ventrally or centrally in the canal or conglomeration of the nerve roots at the mid-disc level. Herniation types were defined as either no herniation, disc bulge, protrusion, extrusion, or sequestration. Zones of herniation were categorized as either central, lateral, or far lateral. RESULTS:The kappa value of intra-observer reliability was .915. The kappa value of disc levels with a negative sedimentation sign were seen more frequently (n = 326, 65.2%) than those with a positive sedimentation sign (n = 174, 34.8%). The spinal canal AP diameter was significantly decreased at the L3/L4 and L4/L5 level in patients with a positive sedimentation sign. Discs with a positive sedimentation sign had a larger average size of disc herniation compared to those with a negative sign at all levels. A relationship between positivity of the sedimentation sign and disc herniation type was significant at L2/L3, L3/L4, and L4/L5. CONCLUSIONS:Patients with a positive sedimentation sign were seen to have larger disc herniations and more severely degenerated discs.

Study design: This study constitutes a systematic review of the literature. Objective: The aim of this study was to identify and present all available studies that report on the costs of osteobiologics used in anterior cervical discectomy and fusion (ACDF). Methods: The literature was systematically reviewed to identify studies with specific inclusion criteria: (1) randomized controlled trials and observational studies, (2) in adult patients, (3) with herniated disc(s) or degenerative cervical spine disease, (4) reporting on either direct or indirect costs of using specific osteobiologics in an ACDF operation. (5) Only studies in English were included. The quality of the included studies was assessed using the MINORS and RoB 2.0 tools. Results: Overall, 14 articles were included; one randomized controlled trial and 13 observational studies. The most commonly used osteobiologics other than autograft/iliac crest bone graft (ICBG) were allograft and bone morphogenetic protein (BMP). None of the studies was reported to be industry-supported. There was considerable heterogeneity on the reported costs. Overall, most studies reported on surgery-related costs, such as anesthesia, operating room, surgical materials and surgeon"™s fee. Only two studies, both using allograft, reported the exact cost of the osteobiologic used (450 GBP, $700). Some of the studies reported on the cost of care during hospitalization for the surgical operation, such as radiology studies, emergency room costs, cardiologic evaluation, laboratory studies, pharmacy costs, and room costs. Only a few studies reported on the cost of follow-up, reoperation, and physical therapy and rehabilitation. Conclusion: Based on the data of this current systematic review, no recommendations can be made regarding the cost-effectiveness of using osteobiologics in ACDF. Given the high costs of osteobiologics, this remains a topic of importance. The design of future studies on the subject should include cost effectiveness.

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Study Design: Cross-sectional survey. Objective: Although literature does not recommend routine wound drain utilization, there is a disconnect between the evidence and clinical practice. This study aims to explore into this controversy and analyze the surgeon preferences related to drain utilization, and the factors influencing drain use and criterion for removal. Methods: A survey was distributed to AO Spine members worldwide. Surgeon demographics and factors related to peri-operative drain use in 1 or 2-level open fusion surgery for lumbar degenerative pathologies were collected. Multivariate analyses by drain utilization, and criterion of removal were conducted. Results: 231 surgeons participated, including 220 males (95.2%), orthopedics (178, 77.1%), and academic/university-affiliated (114, 49.4%). Most surgeons preferred drain use (186, 80.5%) and subfascial drains (169, 73.2%). Drains were removed based on duration by 52.87% of the surgeons, but 27.7% removed drains based on outputs. On multivariable analysis, significant predictors of drain use were surgeon"™s aged 35-44 (OR = 11.9, 95% CI = 1.2-117.2, P =.034), 45-54 (29.1, 3.1-269.6, P =.003), 55-64 (8.9, 1.4-56.5,.019), and wound closure using coaptive films (6.0, 1.2-29.0, P =.025). Additionally, surgeons from Asia Pacific (OR = 5.19, 95% CI = 1.65-16.38, P =.005), Europe (3.55, 1.22-10.31, P =.020), and Latin America (4.40, 1.09-17.83,.038) were more likely to remove drain based on time duration, but surgeons <5 years of experience (10.23, 1.75-59.71, P =.010) were more likely to remove drains based on outputs. Conclusions: Most spine surgeons worldwide prefer to place a subfascial wound drain for degenerative open lumbar surgery. The choice for drain placement is associated with the surgeon"™s age and use of coaptive films for wound closure, while the criterion for drain removal is associated with the surgeons"™ region of practice and experience.

BACKGROUND CONTEXT/BACKGROUND:Cervical fusion for degenerative disorders carries a known risk of adjacent segment disease (ASD), a complication that often requires surgical intervention to relieve symptoms. Proposed risk factors for development of ASD include both clinical and radiographic patient characteristics. However, the true impact of these risk factors is less understood due to limitations in sample sizes and loss to follow-up in individual studies. PURPOSE/OBJECTIVE:To review and critically examine current literature on the clinical risk factors associated with development of ASD in the cervical spine following ACDF. STUDY DESIGN/METHODS:Systematic Review and Meta-Analysis. METHODS:We systematically reviewed the literature in December 2019 according to the PRISMA guidelines. Methodological quality of included papers and quality of evidence were evaluated according to MINORS and GRADE framework. Meta-analysis was performed to compute the odds ratio(OR)with corresponding 95% confidence interval(CI)for dichotomous data, and mean difference(MD) with 95% CI for continuous variables. RESULTS:6,850 records were obtained using database query. Title/abstract screening resulted in 19 articles for full review, from which 10 papers met the criteria for analysis. There were no significant differences in gender (OR 0.99, 95% CI 0.75-1.30), BMI (MD -0.09, 95% CI -0.46 to 0.29), smoking (OR 1.13, 95% CI 0.80-1.59), alcohol (OR 1.07, 95% CI 0.70-1.64), diabetes (OR 0.85, 95% CI 0.56-1.31), number of segments fused (OR 0.86, 95% CI 0.64-1.16), and preoperative JOA (MD -0.50, 95% CI -1.04 to 0.04). Age (MD 3.21, 95% CI 2.00-4.42), congenital/developmental stenosis (OR 1.94, 95% CI 1.06-3.56), preoperative NDI (MD 4.18, 95% CI 2.11 to 6.26), preoperative VAS (neck) (MD 0.54 95% CI 0.09-0.99), and preoperative VAS (arm) (MD 0.98, 95% CI 0.43-1.34) were found to be statistically significant risk factors. CONCLUSION/CONCLUSIONS:Patients with congenital stenosis, advanced age, and high preoperative NDI are at increased risk of developing ASD.

INTRODUCTION/UNASSIGNED:To date, the available guidance on venous thromboembolism (VTE) prevention in elective lumbar fusion surgery is largely open to surgeon interpretation and preference without any specific suggested chemoprophylactic regimen. RESEARCH QUESTION/UNASSIGNED:This study aimed to comparatively analyze the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) with the use of commonly employed chemoprophylactic agents such as unfractionated heparin (UH) and low molecular weight heparin (LMWH) in lumbar fusion surgery. MATERIAL AND METHODS/UNASSIGNED:An independent systematic review of four scientific databases (PubMed, Scopus, clinicaltrials.gov, Web of Science) was performed to identify relevant articles as per the preferred reporting in systematic reviews and meta-analysis (PRISMA) guidelines. Studies reporting on DVT/PE outcomes of lumbar fusion surgery in adult patients with UH or LMWH chemoprophylaxis were included for analysis. Analysis was performed using the Stata software. RESULTS/UNASSIGNED:Twelve studies with 8495 patients were included in the analysis. A single-arm meta-analysis of the included studies found a DVT incidence of 14% (95%CI [8%-20%]) and 1% (95%CI [-6% - 8%]) with LMWH and UH respectively. Both the chemoprophylaxis agents prevented PE with a noted incidence of 0% (95%CI [0%-0.1%]) and 0% (95%CI [0%-1%]) with LMWH and UH respectively. The risk of bleeding-related complications with the usage of LMWH and UH was 0% (95% CI [0.0%-0.30%]) and 3% (95% CI [0.3%-5%]) respectively. DISCUSSION AND CONCLUSION/UNASSIGNED:Both LMWH and UH reduces the overall incidence of DVT/PE, but there is a paucity of evidence analyzing the comparative effectiveness of the chemoprophylaxis regimens in lumbar fusion procedures. The heterogeneity in data prevents any conclusions, as there remains an evidence gap. We recommend future high-quality randomized controlled trials to investigate in this regard to help develop recommendations on thromboprophylaxis usage.

PURPOSE/OBJECTIVE:Failed back surgery syndrome (FBSS) is a complex and multifaceted condition associated with significant disability and morbidity. The purpose of this study was to investigate the association between FBSS with new incidences of mental health disorders. METHODS:Our cohort included patients diagnosed with FBSS within 12 months of a posterior fusion, laminectomy, or discectomy, identified using The International Classification of Disease, both Ninth and Tenth Revisions (ICD-9 and ICD-10). In the next step, both non-FBSS and FBSS-diagnosed patients were queried for the diagnosis of first-time occurrence of mental health disorders. The incidence of new mental health disorders was determined within 12-months following FBSS diagnosis. RESULTS:FBSS patients were significantly at greater risk than non-FBSS patients of developing all included mental health pathologies: Depression: OR 1.9, 95% CI 1.8-2.0, p < 0.0001); Anxiety: OR 1.5, 95% CI 1.4-1.6, p < 0.0001; Sleep Disorder: OR 1.9, 95% CI 1.7-2.0, p < 0.0001; Bipolar Disorder: OR 1.7, 95% CI 1.5-2.0 p < 0.0001; PTSD: OR 1.5, 95% CI 1.3-1.8, p < 0.0001; Panic Disorder: OR 1.8, 95% CI 1.5-2.1, p < 0.0001; Suicidal Disorder: OR 1.7 95% CI 1.4-2.0, p < 0.0001, ADHD: OR 1.3, 95% CI 1.0-1.5, p = 0.0367. CONCLUSIONS:In the current study, patients diagnosed with FBSS were at a significantly greater risk of developing mental health pathologies. While other studies have suggested pre-surgical psychological support and treatment, the current results suggest that a post-operative psychologic care may also be warranted. By identifying potential psychosocial unforeseen obstacles that occur in patients diagnosed with FBSS, more precise treatment pathways can be developed leading to improved patient outcomes.

PURPOSE/OBJECTIVE:Lumbar fusion is widely used to treat degenerative and traumatic conditions of the spine, with various perioperative complications. This study compared lumbar fusion complications in patients with and without chronic hyperlipidemia. METHODS:Using the MSpine division of the PearlDiver database, patients with or without chronic hyperlipidemia who underwent lumbar fusions were identified. The appropriate Current Procedural Terminology (CPT) codes identified patients with single- or multi-level lumbar spinal fusion surgeries. International Classification of Diseases (ICD-9 and ICD-10) codes identified patients with chronic hyperlipidemia. The surgical and medical complications were obtained utilizing the appropriate ICD-9, ICD-10, and CPT codes. Propensity score matching analysis was used to control for confounding factors. Chi-square test was applied to compare the incidence of complications among different groups. RESULTS:In single-level fusion group, patients with hyperlipidemia had a higher incidence of wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), deep venous thrombosis/pulmonary embolism (P = 0.031), myocardial infarction (P < 0.001) cerebrovascular accident (P < 0.001), renal failure (P < 0.001), sepsis (P < 0.001), and urinary tract infection/incontinence (P < 0.001). In multi-level fusion group, patients with hyperlipidemia had a higher incidence of nerve root injury (P = 0.034), wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), revision (P = 0.002), myocardial infarction (P < 0.001), renal failure (P < 0.001), and urinary tract infection/incontinence (P < 0.001). CONCLUSION/CONCLUSIONS:Following lumbar fusion, patients with chronic hyperlipidemia have an increased risk of perioperative complications, including wound complications, surgical site infection, failed back surgery syndrome, hardware removal, myocardial infarction, renal failure, and urinary tract infection/incontinence.