Faculty Bibliography

STUDY DESIGN/METHODS:Prospective multicenter analysis of adult spinal deformity (ASD) patients. OBJECTIVE:The aim of this study was to introduce the lumbar pelvic angle (LPA), a novel parameter of spinopelvic alignment. SUMMARY OF BACKGROUND DATA/BACKGROUND:The T1 pelvic angle (TPA), a measure of global spinopelvic alignment, correlates with health-related quality of life (HRQOL), but it may not be measureable on all intraoperative x-rays. In patients with previous interbody fusion at L5-S1, the plane of the S1 endplate can be blurred, creating error in pelvic incidence and lumbar lordosis (PI-LL) measure. The LPA is more readily measured on intraoperative imaging than the TPA. METHODS:ASD patients were included with either coronal Cobb angle >20°, sagittal vertical axis (SVA) >5 cm, thoracic kyphosis >60°, or pelvic tilt (PT) >25°. Measures of disability included Oswestry Disability Index (ODI), Scoliosis Research Society (SRS), and Short Form (SF)-36. Baseline and 2-year follow-up radiographic and HRQOL outcomes were evaluated. Linear regressions compared LPA with radiographic parameters and HRQOL. RESULTS:A total of 852 ASD patients (407 operative) were enrolled (mean age 53.7). Baseline LPA correlated with PI-LL (r = 0.79), PT (r = 0.78), TPA (r = 0.82), and SVA (r = 0.61) (all P < 0.001). PI-LL, LPA, and TPA correlated with ODI (r = 0.42/0.29/0.45), SF-36 physical component score (-0.43/-0.28/-0.45) SRS (-0.354/-0.23/-0.37) with all P < 0.001. At 2 years' follow-up, LPA correlated with PI-LL (r = 0.77), PT (r = 0.78), TPA (r = 0.83), and SVA (r = 0.57) (all P < 0.001). Categorizing patients by increasing LPA (<7°; 7°-15°; >15°) revealed progressive increases in all HRQOL, PI-LL (-3.2°/12.7°/32.4°), and TPA (9.7°/20.1°/34.6°) with all P < 0.001. Moderate disability (ODI = 40) corresponded to LPA 10.1°, PI-LL 12.6°, and TPA 20.6°. Mild disability (ODI = 20) corresponded to LPA 7.2°, PI-LL 4.2°, and TPA 14.7°. CONCLUSION/CONCLUSIONS:LPA correlates with TPA, PI-LL, and HRQOL in ASD patients. LPA can be used as an intraoperative tool to gauge correction with a target LPA of <7.2°. LPA predicts global alignment, as it correlates with baseline and 2-year TPA and SVA. Along with the cervical-thoracic pelvic angle and TPA, LPA completes the fan of spinopelvic alignment. LEVEL OF EVIDENCE/METHODS:3.

Study Design/UNASSIGNED:Retrospective cohort study. Objectives/UNASSIGNED:The purpose of this study was to report incidence of cardiopulmonary complications in elective spine surgery, demographic and surgical predictors, and outcomes. Understanding the risks and predictors of these sentinel events is important for risk evaluation, allocation of hospital resources, and counseling patients. Methods/UNASSIGNED:A retrospective review of the National Surgical Quality Improvement Program (NSQIP) was performed on 60 964 patients undergoing elective spine surgery (any region; laminectomy, arthrodesis, discectomy, or laminoplasty) between 2011 and 2013. Incidence of myocardial infarction, cardiac arrest, unplanned reintubation, on ventilator >48 hours, perioperative pneumonia, and pulmonary embolism was measured. Demographic and surgical predictors of cardiopulmonary complications and associated outcomes (length of stay, discharge disposition, and mortality) were measured using binary logistic regression controlling for confounders. Results/UNASSIGNED:Incidence rates per 1000 elective spine patients were 2.1 myocardial infarctions, 1.3 cardiac arrests, 4.3 unplanned intubations, 3.5 on ventilator >48 hours, 6.1 perioperative pneumonia, and 3.7 pulmonary embolisms. In analysis of procedure, diagnosis, and approach risk factors, thoracic cavity (odds ratio = 2.47; confidence interval = 1.95-3.12), scoliosis diagnosis, and combined approach (odds ratio = 1.51; confidence interval = 1.15-1.96) independently added the most risk for cardiopulmonary complication. Cardiac arrest had the highest mortality rate (34.57%). Being on ventilator greater than 48 hours resulted in the greatest increase to length of stay (17.58 days). Conclusions/UNASSIGNED:Expected risk factors seen in the Revised Cardiac Risk Index were applicable in the context of spine surgery. Surgical planning should take into account patients who are at higher risk for cardiopulmonary complications and the implications they have on patient outcome.

Study Design/UNASSIGNED:Retrospective case-control study. Objectives/UNASSIGNED:To identify incidence and risk factors for percutaneous endoscopic gastrostomy (PEG) tube placement after anterior cervical fusion (ACF). Methods/UNASSIGNED:Adult patients undergoing elective ACF with/without corpectomy for spondylosis from 2002 to 2011 were identified using the Nationwide Inpatient Sample database. The primary outcome measure was PEG tube placement; secondary outcomes included in-hospital mortality, total hospital charges, and discharge disposition. Multiple regression analyses were conducted to identify independent predictors of PEG tube placement. Results/UNASSIGNED:< .001). Conclusions/UNASSIGNED:The incidence of PEG tube placement after ACF was 0.13% in this study. Identified risk factors included age >65, corpectomy, fusion of ≥3 segments, and various comorbidities. Additionally, there may be increased risk of in-hospital mortality, hospital charges, and nonroutine discharges among these patients.

OBJECTIVE:The primary driver (PD) of cervical malalignment is important in characterizing cervical deformity (CD) and should be included in fusion to achieve alignment and quality-of-life goals. This study aims to define how PDs improve understanding of the mechanisms of CD and assesses the impact of driver region on realignment/outcomes. METHODS:Inclusion: radiographic CD, age >18 years, 1 year follow-up. PD apex was classified by spinal region: cervical, cervicothoracic junction (CTJ), thoracic, or spinopelvic by a panel of spine deformity surgeons. Primary analysis evaluated PD groups meeting alignment goals (by Ames modifiers cervical sagittal vertical axis/T1 slope minus cervical lordosis/chin-brow vergical angle/modified Japanese Orthopaedics Association questionnaire) and health-related quality of life (HRQL) goals (EuroQol-5 Dimensions questionnaire/Neck Disability Index/modified Japanese Orthopaedics Association questionnaire) using t tests. Secondary analysis grouped interventions by fusion constructs including the primary or secondary apex based on lowest instrumented vertebra: cervical, lowest instrumented vertebra (LIV) ≤C7; CTJ, LIV ≤T3; and thoracic, LIV ≤T12. RESULTS:A total of 73 patients (mean age, 61.8 years; 59% female) were evaluated with the following PDs of their sagittal cervical deformity: cervical, 49.3%; CTJ, 31.5%; thoracic, 13.7%; and spinopelvic, 2.7%. Cervical drivers (n = 36) showed the greatest 1-year postoperative cervical and global alignment changes (improvement in T1S, CL, C0-C2, C1 slope). Thoracic drivers were more likely to have persistent severe T1 slope minus cervical lordosis modifier grade at 1 year (0, 20.0%; +, 0.0%; ++, 80.0%). Cervical deformity modifiers tended to improve in cervical patients whose construct included the PD apex (included, 26%; not, 0%; P = 0.068). Thoracic and cervicothoracic PD apex patients did not improve in HRQL goals when PD apex was not treated. CONCLUSIONS:CD structural drivers have an important effect on treatment and 1-year postoperative outcomes. Cervical or thoracic drivers not included in the construct result in residual deformity and inferior HRQL goals. These factors should be considered when discussing treatment plans for patients with CD.

Background/UNASSIGNED:Risk of death is important in counseling patients and improving quality of care. Incidence of death in cervical surgery is not firmly established due to its rarity and limited sample sizes, particularly in the context of different surgeries, demographics, and risk factors. Particularly, different patient risk profiles may have varying degrees of risk in terms of surgeries, comorbidities, and demographics. This study aims to use a large patient cohort available on a national database to study the prevalence of death associated with cervical spine surgery. Methods/UNASSIGNED:< .05 differences relative to overall cohort. Results/UNASSIGNED:< .001. Conclusion/UNASSIGNED:In 342 477 cervical spine surgery patients an overall mortality rate of 0.32% was reported. The rate was 3.91% in a cohort of 5933 patients with congestive heart failure and 3.79% in a cohort of 6947 patients with paraplegia. These findings are consistent with previous estimates and may help counsel patients and improve in-hospital safety. Level of Evidence/UNASSIGNED:3.

Background/UNASSIGNED:Effects of nonoperative treatments on surgical outcomes for patients who failed conservative management for cervical spine pathologies remain unknown. The objective is to describe conservative modality use in patients indicated for surgery for degenerative cervical spine conditions and its impact on perioperative outcomes. Methods/UNASSIGNED:tests were performed to determine differences between groups and impact on outcomes. Results/UNASSIGNED: < .05). Conclusions/UNASSIGNED:Radiculopathy patients receiving epidurals returned to work after 1 year more frequently. PT was associated with shorter hospitalizations, greater SF-36 bodily pain norm and physical component score improvements, and increased return-to-work rates after 1 and 2 years. No statistically significant nonoperative treatment was associated with return-to-work rate in myelopathy patients. Clinical Relevance/UNASSIGNED:These findings suggest certain preoperative conservative treatment modalities are associated with improved outcomes in radiculopathy patients.

STUDY DESIGN/METHODS:Consensus-building using the Delphi and nominal group technique. OBJECTIVE:To establish best practice guidelines using formal techniques of consensus building among a group of experienced spinal deformity surgeons to avert wrong-level spinal deformity surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:Numerous previous studies have demonstrated that wrong-level spinal deformity occurs at a substantial rate, with more than half of all spine surgeons reporting direct or indirect experience operating on the wrong levels. Nevertheless, currently, guidelines to avert wrong-level spinal deformity surgery have not been developed. METHODS:The Delphi process and nominal group technique were used to formally derive consensus among 16 fellowship-trained spine surgeons. Surgeons were surveyed for current practices, presented with the results of a systematic review, and asked to vote anonymously for or against item inclusion during three iterative rounds. Agreement of 80% or higher was considered consensus. Items near consensus (70% to 80% agreement) were probed in detail using the nominal group technique in a facilitated group meeting. RESULTS:Participants had a mean of 13.4 years of practice (range: 2-32 years) and 103.1 (range: 50-250) annual spinal deformity surgeries, with a combined total of 24,200 procedures. Consensus was reached for the creation of best practice guidelines (BPGs) consisting of 17 interventions to avert wrong-level surgery. A final checklist consisting of preoperative and intraoperative methods, including standardized vertebral-level counting and optimal imaging criteria, was supported by 100% of participants. CONCLUSION/CONCLUSIONS:We developed consensus-based best practice guidelines for the prevention of wrong-vertebral-level surgery. This can serve as a tool to reduce the variability in preoperative and intraoperative practices and guide research regarding the effectiveness of such interventions on the incidence of wrong-level surgery. LEVEL OF EVIDENCE/METHODS:Level V.

Minimally invasive surgical (MIS) techniques offer promising improvements in the management of thoracolumbar trauma. Recent advances in MIS techniques and instrumentation for degenerative conditions have heralded a growing interest in employing these techniques for thoracolumbar trauma. Specifically, surgeons have applied these techniques to help manage flexion- and extension-distraction injuries, neurologically intact burst fractures, and cases of damage control. Minimally invasive surgical techniques offer a means to decrease blood loss, shorten operative time, reduce infection risk, and shorten hospital stays. Herein, we review thoracolumbar minimally invasive surgery with an emphasis on thoracolumbar trauma classification, minimally invasive spinal stabilization, surgical indications, patient outcomes, technical considerations, and potential complications.

Background/UNASSIGNED:Chiari malformations type 1 (CM-1), a developmental anomaly of the posterior fossa, usually presents in adolescence or early adulthood. There are few studies on the national incidence of CM-1, taking into account outcomes based on concurrent diagnoses. To quantify trends in treatment and associated diagnoses, as retrospective review of the Kid's Inpatient Database (KID) from 2003-2012 was conducted. Methods/UNASSIGNED:-tests for categorical and numerical variables, respectively. Trends in diagnosis, treatments, and outcomes were analyzed using analysis of variance (ANOVA). Results/UNASSIGNED:4.7%). Seven point four percent of patients experienced at least one peri-operative complication (nervous system, dysphagia, respiratory most common). Patients with concurrent hydrocephalus had increased; nervous system, respiratory and urinary complications (P<0.006) and syringomyelia increased the rate of respiratory complications (P=0.037). Conclusions/UNASSIGNED:CM-1 diagnoses have increased in the last decade. Despite the decrease in overall complication rates, fusions are becoming more common and are associated with higher peri-operative complication rates. Commonly associated diagnoses including syringomyelia and hydrocephalus, can dramatically increase complication rates.