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.

Surgical treatment for spinal metastasis has benefited from improvements in surgical techniques. However, the trends in treatment and outcomes for spinal metastasis surgery have not been well-established in a pediatric population. Patients <20 years old with metastatic spinal tumors undergoing spinal surgery were identified in the KID database. Trends for spinal metastases treatment and patient outcomes were analyzed using weight-adjusted ANOVAs. 333 patients were identified in the KID database. The top five primary diagnoses were metastatic brain/spinal cord tumor (19.8%), metastatic nervous system tumor (15.9%), metastatic bone cancer (13.2%), spinal cord tumor (4.2%), and tumor of ventricles (3.0%). There was an increased incidence of spinal metastasis diagnoses from 2003 to 2012 (88.5-117.9 per 100,000; p < 0.001) and an increased trend in the incidence of surgical treatment for spinal metastasis from 2003 to 2012 (p = 0.014). The average age was 10.19 ± 6.33 years old and 38.4% were female. The average length of stay was 17.34 ± 24.36 days. Average CCI increased over time (2003: 7.87 ± 1.40, 2012: 8.44 ± 1.39; p = 0.006). The most common surgeries were excision of spinal cord/meninges lesions (69.1%) and decompression of spinal canal (38.1%). Length of hospital stay and in-hospital mortality did not change over time (17.34-18.04 days, p = 0.337; 1.6%-2.9%, p = 0.801). 10.5% of patients underwent a posterior fusion and 22.2% had at least one complication (nervous system, respiratory, dysphagia, infection). The overall complication rate remained stable over time (23.4%-21.8%, p = 0.952). Surgical treatment for spinal metastasis in the last decade has increased, though the complication rates, in-hospital mortality, and length of stay have remained stable.

BACKGROUND CONTEXT/BACKGROUND:With advances in the understanding of adult spinal deformity (ASD), more complex osteotomy and fusion techniques are being implemented with increasing frequency. Patients undergoing ASD corrections infrequently require extended acute care, longer inpatient stays, and are discharged to supervised care. Given the necessity of value-based health care, identification of clinical indicators for adverse discharge disposition in ASD surgeries is paramount. PURPOSE/OBJECTIVE:On nationwide and surgeon-created databases, identify predictors of adverse discharge disposition after ASD surgeries and view corresponding differences in charges. STUDY DESIGN/SETTING/METHODS:Retrospective analysis of patients on the National Surgical Quality Improvement Program (NSQIP) database and cost data from Medicare PearlDiver Database. PATIENT SAMPLE/METHODS:Patients undergoing thoracolumbar surgery for correction of ASD. OUTCOME MEASURES/METHODS:Primary: Discharge disposition home vs. not home. Secondary: Cost differences across discharge groups. METHODS:Patients on NSQIP undergoing thoracolumbar ASD-corrective surgery with a primary diagnosis of scoliosis (ICD-9 code 737.x), and over the age of 18 were isolated. Predictors (demographic, clinical, and complications) of not-home (NH; rehab or skilled nursing facility) discharge were analyzed using binary logistic regression controlling for levels fused, decompressions, osteotomies, and revisions. Average 30-day and 90-day costs of care were reported in home, rehab, and skilled nursing facility discharge groups in patients undergoing 8+ level thoracolumbar fusion. RESULTS:1,978 patients undergoing lumbar ASD-corrective surgery were included for analysis (average age: 59.3 years, sex: 64% female). Average length of stay was 6.58 days. Upon multivariate regression analysis, age over 60 years (OR: 0.28 CI: 0.22-0.34) and female sex (p=0.003) were independent predictors of adverse discharge status. Partially dependent pre-operational functional status, defined as reliance on another person to complete some activities of daily living, increased likelihood of adverse discharge disposition (OR:0.57 CI:0.35-0.90). Despite controlling for all clinical variables except for the ones specific to each analysis, Smith-Petersen osteotomy (OR:0.51 CI:0.40-0.64), interbody device placement (OR:0.80 CI:0.64-0.98) and fixation to the iliac (OR:0.54 CI:0.41-0.70) both increased likelihood of adverse discharge. Complications most associated with adverse discharge were UTIs (OR:0.34 CI:0.21-0.57) and blood transfusions (OR:0.42 CI:0.34-0.52). Relative to home-discharge, 30-day costs of care were +$21,061 more expensive in rehab discharges, but not different in skilled nursing facility discharges (+$5,791, p=0.177). 90-day costs of care were $23,815 in rehab discharges (p<0.001), but again not different in skilled nursing facility discharges (+$6,091, p=0.212). CONCLUSIONS:Discharge destination to rehabilitation has a significant impact on cost of thoracolumbar adult spinal deformity surgeries. Patient selection can predict patients at higher risk for discharges to rehab or skilled nursing facility.

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.

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.

Retrospective review of National Inpatient Sample (2000-2012) revealed that 31.28% of musculoskeletal (MSK) patients were found to have in-hospital psychological burdens (PBs). Adult spinal deformity (ASD), degenerative disc disease (DDD) and lung cancer patients had highest PB-prevalence. MSK patients with PB were more often young, white females with increased Deyo index compared to no-PB patients. Patients who underwent spinal revision procedures had higher PB rates than with primary procedures; a converse trend was observed for total hip/knee arthroplasty. Psychological disorders were identified as significant predictors of increased total-hospital charges. Augmenting counseling with psychological screening/support is recommended to complement MSK management.

BACKGROUND CONTEXT/BACKGROUND:Obesity as a comorbidity in spine pathology may increase the risk of complications following surgical treatment. The body mass index (BMI) threshold at which obesity becomes clinically relevant, and the exact nature of that effect, remains poorly understood. PURPOSE/OBJECTIVE:Identify the BMI that independently predicts risk of postoperative complications following lumbar spine surgery. STUDY DESIGN/SETTING/METHODS:Retrospective review of the National Surgery Quality Improvement Program (NSQIP) years 2011-2013. PATIENT SAMPLE/METHODS:A total of 31,763 patients were undergoing arthrodesis, discectomy, laminectomy, laminoplasty, corpectomy, or osteotomy of the lumbar spine. OUTCOME MEASURES/METHODS:Complication rates. METHODS:The patient sample was categorized preoperatively by BMI according to the World Health Organization stratification: underweight (BMI <18.5), normal overweight (BMI 20.0-29.9), obesity class 1 (BMI 30.0-34.9), 2 (BMI 35.0-39.9), and 3 (BMI≥40). Patients were dichotomized based on their position above or below the 75th surgical invasiveness index (SII) percentile cutoff into low-SII and high-SII. Differences in complication rates in BMI groups were analyzed by Bonferroni analysis of variance (ANOVA) method. Multivariate binary logistic regression evaluated relationship between BMI and complication categories in all patients and in high-SII and low-SII surgeries. RESULTS:. The odds ratios for any complication (odds ratio [OR] [95% confidence interval {CI}]; obesity 2: 1.218 [1.020-1.455]; obesity 3: 1.742 [1.439-2.110]), infection (obesity 2: 1.335 [1.110-1.605]; obesity 3: 1.685 [1.372-2.069]), and surgical complication (obesity 2: 1.622 [1.250-2.104]; obesity 3: 2.798 [2.154-3.634]) were significantly higher in obesity classes 2 and 3 relative to the normal-overweight cohort (all p<.05). CONCLUSION/CONCLUSIONS:There is a significant increase in complications, specifically infection and surgical complications, in patients with BMI≥35 following lumbar spine surgery, with that rate further increasing with BMI≥40.

Study Design/UNASSIGNED:Retrospective radiological review. Purpose/UNASSIGNED:To quantify the effect of sitting vs supine lumbar spine magnetic resonance imaging (MRI) and change in anterior displacement of the psoas muscle from L1-L2 to L4-L5 discs. Overview of Literature/UNASSIGNED:Controversy exists in determining patient suitability for lateral lumbar interbody fusion (LLIF) based on psoas morphology. The effect of posture on psoas morphology has not previously been studied; however, lumbar MRI may be performed in sitting or supine positions. Methods/UNASSIGNED:A retrospective review of a single-spine practice over 6 months was performed, identifying patients aged between 18-90 years with degenerative spinal pathologies and lumbar MRIs were evaluated. Previous lumbar fusion, scoliosis, neuromuscular disease, skeletal immaturity, or intrinsic abnormalities of the psoas muscle were excluded. The anteroposterior (AP) dimension of the psoas muscle and intervertebral disc were measured at each intervertebral disc from L1-L2 to L4-L5, and the AP psoas:disc ratio calculated. The morphology was compared between patients undergoing sitting and/or supine MRI. Results/UNASSIGNED:Two hundred and nine patients were identified with supine-, and 60 patients with sitting-MRIs, of which 13 patients had undergone both sitting and supine MRIs (BOTH group). A propensity score match (PSM) was performed for patients undergoing either supine or sitting MRI to match for age, BMI, and gender to produce two groups of 43 patients. In the BOTH and PSM group, sitting MRI displayed significantly higher AP psoas:disc ratio compared with supine MRI at all intervertebral levels except L1-L2. The largest difference observed was a mean 32%-37% increase in sitting AP psoas:disc ratio at the L4-L5 disc in sitting compared to supine in the BOTH group (range, 0%-137%). Conclusions/UNASSIGNED:The psoas muscle and the lumbar plexus become anteriorly displaced in sitting MRIs, with a greater effect noted at caudal intervertebral discs. This may have implications in selecting suitability for LLIF, and intra-operative patient positioning.

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.

INTRODUCTION/BACKGROUND:Patients with lumbar spine and hip disorders may, during the course of their treatment, undergo spinal fusion and THA. There is disagreement among prior studies regarding whether patients who undergo THA and spinal fusion are at increased risk of THA dislocation and other hip-related complications. QUESTIONS/ PURPOSES/UNASSIGNED:Is short or long spinal fusion associated with an increased rate of postoperative complications in patients who underwent a prior THA? PATIENTS AND METHODS/METHODS:A retrospective study of New York State's Department of Health database (SPARCS) was performed. SPARCS has a unique identification code for each patient, allowing investigators to track the patient across multiple admissions. The SPARCS dataset spans visit data of patients of all ages and races across urban and rural locations. The SPARCs dataset encompasses all facilities covered under New York State Article 28 and uses measures to further representative reporting of data concerning all races. Owing to the nature of the SPARCS dataset, we are unable to comment on data leakage, as there is no way to discern between a patient who does not subsequently seek care and a patient who seeks care outside New York State. ICD-9-Clinical Modification codes identified adult patients who underwent elective THA from 2009 to 2011. Patients who had subsequent spinal fusion (short: 2-3 levels, or long: ≥ 4 levels) with a diagnosis of adult idiopathic scoliosis or degenerative disc disease were identified. Forty-nine thousand nine hundred twenty patients met the inclusion criteria of the study. In our inclusion and exclusion criteria, there was no variation with respect to the distribution of sex and race across the three groups of interest. Patients who underwent a spinal procedure (short versus long fusion) had comparable age. However, patients who did not undergo a spinal procedure were older than patients who had short fusion (65 ± 12.4 years versus 63 ± 10.7 years; p < 0.001). Multivariate binary logistic regression models that controlled for age, sex, and Deyo/Charlson scores were used to investigate the association between spinal fusion and THA revisions, postoperative dislocation, contralateral THAs, and total surgical complications to the end of 2013. A total of 49,920 patients who had THAs were included in one of three groups (no subsequent spinal fusion: n = 49,209; short fusion: n = 478; long fusion: n = 233). RESULTS:Regression models revealed that short and long spinal fusions were associated with increased odds for hip dislocation, with associated odds ratios (ORs) of 2.2 (95% CI, 1.4-3.6; p = 0.002), and 4.4 (95% CI, 2.7-7.3; p < 0.001), respectively. Patients who underwent THA and spinal surgery also had an increased odds for THA revision, with ORs of 2.0 (95% CI, 1.4-2.8; p < 0.001) and 3.2 (95% CI, 2.1-4.8; p < 0.001) for short and long fusion, respectively. However, spinal fusions were not associated with contralateral THAs. Further, short and long spinal fusions were associated with increased surgical complication rates (OR = 2.8, 95% CI, 2.1-3.8, p < 0.001; OR = 5.3, 95% CI, 3.8-7.4, p < 0.001, respectively). CONCLUSION/CONCLUSIONS:We showed that spinal fusion in adults is associated with an increased frequency of complications and revisions in patients who have had a prior THA. Specifically, patients who had a long spinal fusion after THA had 340% higher odds of experiencing a hip dislocation and 220% higher odds of having to undergo a revision THA. Further research is necessary to determine whether this relationship is associated with the surgical order, or whether more patient-specific surgical goals of revision THA should be developed for patients with a spinal deformity. LEVEL OF EVIDENCE/METHODS:Level III, therapeutic study.