Faculty Bibliography

BACKGROUND:Cervical spine (C-spine) injuries cause significant morbidity and mortality among the elderly. Although the population of older-adults ≥65 years in the US is expanding, estimates of the burden and outcome of C-spine injury are lacking. METHODS:The Nationwide Inpatient Sample 2001-2010 was analyzed. International Classification of Diseases codes identified patients with isolated C-spine fractures (ICF) and C-spine fractures with spinal cord injury (CSCI). Annual admission and mortality rates were calculated using US-Census data. RESULTS:A total of 167,278 older-adults were included. Median age was 81 years (IQR=74-86). Most patients were female (54.9%), had Medicare coverage (77.6%), treated in teaching hospitals (63.2%), and falls were the leading injury-mechanism (51.2%). ICF occurred in 91.3%, while CSCI occurred in 8.7% (p<0.001). ICF was more common in ≥85 year-olds and CSCI in 65-69 year-olds (p<0.001). The most common injured C-spine level in ICF was C2-level (47.6%, p<0.001), and in CSCI was C1-C4 level (4.5%, p<0.001). Overall, 15.8% underwent C-spine surgery. Hospitalization rates increased from 26/100,000 in 2001 to 68/100,000 in 2010 (∼167% change, p<0.001). Correspondingly, overall mortality increased from 3/100,000 in 2001 to 6/100,000 in 2010, p<0.001. In-hospital mortality was 11.3%, was strongly associated with increasing age and CSCI (p<0.001). CONCLUSIONS:In summary, C-spine fractures among US older-adults constitute a significant healthcare burden. ICF occur commonly, C2-vertebra fractures are most frequent, while CSCI are linked to increased hospital-resource utilization and worse outcomes. The incidence of C-spine fractures and mortality more than doubled over the past decade; however, proportional in-hospital mortality is decreasing.

Background/UNASSIGNED:Current health-related quality of life (HRQL) metrics used to assess patient outcomes following surgical correction of cervical deformity (CD) are not deformity-specific and thus cannot capture all aspects of a patient's deformity and outcomes. The purpose of this study is to evaluate the sensitivity of different HRQL outcome measures in assessing CD patients' outcomes 1-year post-operatively. Methods/UNASSIGNED:Retrospective review of prospective multi-center database. Inclusion criteria: CD patients ≥18 yrs with pre- and 1-year post-operative radiographs and HRQLs [modified Japanese Orthopaedic Association (mJOA), EuroQol five-dimensions (EQ-5D), neck disability index (NDI)]. Associations between changes in EQ5D and NDI with improvement at 1-year in mJOA scores were assessed by whether or not the patient met the minimum clinically important difference (MCID) as well as whether or not they improved by one or more categories (i.e., change from moderate to mild). Odds ratios reported with 95% confidence intervals. Results/UNASSIGNED:Sixty-three CD patients were included (mean 62 y, 55.6% F). Average baseline NDI scores were 46.75, mJOA was 13.68, and EQ-5D 0.74. Overall baseline myelopathy breakdown: none-9.5%, mild-30.2%, moderate-42.9%, high-17.5%. At 1-year, 46% of patients improved in mJOA, 71.4% NDI, and 65.1% EQ-5D. 19% of patients met mJOA MCID, 44.4% NDI MCID, 19% EQ-5D MCID. One-point improvement in NDI increased the odds of mJOA improvement and reaching mJOA MCID (improvement: OR, 1.06, CI: 1.01-1.10, P=0.01; MCID: OR, 1.06, CI: 1.02-1.11, P=0.006). Improvement in EQ-5D by 0.1 increased the odds of improving in mJOA and reaching mJOA MCID at 1-year (improvement: OR, 3.85, CI: 1.51-9.76, P=0.005; MCID: OR, 3.88, CI: 1.52-9.88, P=0.005). While correlations exist between outcome measures, when modeling these outcomes while controlling for confounders including cSVA change, surgical invasiveness, age and CCI, these HRQLs were not strongly correlated. Conclusions/UNASSIGNED:Improvements in functional outcomes, as defined by mJOA score, were correlated with changes in neck based disability and general health state, defined by NDI and EQ-5D respectively. In an adjusted model, however, these direct relationships were not maintained. A CD-specific HRQL might be more useful for surgeons in assessing patient outcomes using a single metric.

Background/UNASSIGNED:This study aims to describe properties of adult spinal deformity (ASD) revisions relative to primary surgeries and determine clinical variables that can predict revision. ASD is a common pathology that can lead to decreased quality of life, pain, physical limitations, and dissatisfaction with self-image. Durability of interventions for deformity treatment is of paramount concern to surgeons, as revision rates remain high. Methods/UNASSIGNED:Patients undergoing thoracolumbar fusion, five or more levels, for scoliosis (primary diagnosis ICD-9 737.x) were identified on a state-wide database. Primary and revision (returning for re-fusion procedure) surgeries were compared based on demographic, hospital stay, and clinical characteristics. Differences between primary and revision surgeries, and predictors of primary surgeries requiring revision, utilized binary logistic regression controlling for age, comorbidity burden, and levels fused. Results/UNASSIGNED:A total of 1,063 patients (average 7.4 levels fused, mean age: 47.6 years, 69.0% female) undergoing operative treatment for ASD were identified, of which 123 (average 7.1 levels fused, 11.6%, mean age 61.43, 80.5% female) had surgical revision. Primary surgeries were ~0.3 levels longer (P=0.013), used interbody ~11% more frequently (P=0.020), and used BMP ~12% less frequently (P=0.008). Revisions occurred 176.4 days after the primary on average. The most frequent causes of revisions were: 43.09% implant failure, 24.39% acquired kyphosis, and 14.63% enduring scoliosis. After controlling for age, comorbidities, and levels fused older, more comorbid, female, and white-race patients were more likely to be revised. Upon multivariate regression, after controlling for age and levels fused, overall complications remained non-different (OR: 0.8, 95% CI: 0.6-1.2). However, revision remained an independent predictor for infection (OR: 5.5, 95% CI: 2.8-10.5). Conclusions/UNASSIGNED:In a statewide database with individual patient follow up of up to 4 years 10% of ASD patients undergoing scoliosis correction required revision. Revision surgeries had higher infection incidence.

OBJECTIVE Most cervical fixations for atlantoaxial dislocation (AAD) are bilateral and symmetric; however, in the setting of osseous and vascular deformity at the craniovertebral junction, asymmetrical and hybrid fixations are used as "salvage" techniques. Because of the rarity of these cases, hybrid cervical fixations for AAD have not been fully explored. The aim of this study was to evaluate the clinical feasibility and outcomes of posterior hybrid cervical fixations for AAD. METHODS Twenty-one AAD cases were retrospectively studied; 18 had cervical myelopathy with Japanese Orthopaedic Association (JOA) scores ranging from 9 to 16 (mean 13.5). Hybrid fixation techniques included unilateral pedicle screws, transarticular screws, C-2 laminar screws, cervical lateral mass screws, and spinous process screws. During the same period, 82 AAD cases, treated using symmetric traditional fixations, were analyzed as controls. RESULTS Atlantoaxial fixation was performed in 11 cases, while occiput-cervical fixation was used in 10 cases. All cases achieved solid osseous fusion. Anatomical reduction was achieved in 20 cases (95.2%). All 18 cases with myelopathy showed postoperative improvement, with JOA scores ranging from 13 to 17 (mean 15.5). Three cases (14.2%) experienced complications, including delayed wound healing, CSF leakage, and fixation loosening. Hybrid fixation techniques showed significantly greater estimated blood loss when compared with controls (208.1 ± 19.30 ml vs 139.63 ± 8.75 ml, p = 0.001). Operative duration (125.38 ± 6.29 min vs 119.41 ± 3.77 min, p = 0.464), complication rates (14.3% vs 4.9%, p = 0.148), and JOA improvement rates (61% ± 7% vs 49% ± 4%, p = 0.161) showed no significant differences. CONCLUSIONS For ADD with osseous or vascular deformity, posterior cervical reduction and stabilization can be achieved using hybrid techniques, resulting in comparable clinical results to symmetric traditional fixation.

STUDY DESIGN/METHODS:Retrospective review. OBJECTIVE:Determine whether alignment or myelopathy improvement drives patient outcomes after cervical deformity (CD) corrective surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:CD correction involves radiographic malalignment correction and procedures to improve motor function and pain. It is unknown whether alignment or myelopathy improvement drives patient outcomes. METHODS:Inclusion: Patients with CD with baseline/1-year radiographic and outcome scores. Cervical alignment improvement was defined by improvement in Ames CD modifiers. modified Japanese Orthopaedic Association (mJOA) improvement was defined as mild [15-17], moderate [12-14], severe [<12]. Patient groups included those who only improved in alignment, those who only improved in mJOA, those who improved in both, and those who did not improve. Changes in quality-of-life scores (neck disability index [NDI], EuroQuol-5 dimensions [EQ-5D], mJOA) were evaluated between groups. RESULTS:A total of 70 patients (62 yr, 51% F) were included. Overall preoperative mJOA score was 13.04 ± 2.35. At baseline, 21 (30%) patients had mild myelopathy, 33 (47%) moderate, and 16 (23%) severe. Out of 70 patients 30 (44%) improved in mJOA and 13 (18.6%) met 1-year mJOA minimal clinically important difference. Distribution of improvement groups: 16/70 (23%) alignment-only improvement, 13 (19%) myelopathy-only improvement, 18 (26%) alignment and myelopathy improvement, and 23 (33%) no improvement. EQ-5D improved in 11 of 16 (69%) alignment-only patients, 11 of 18 (61%) myelopathy/alignment improvement, 13 of 13 (100%) myelopathy-only, and 10 of 23 (44%) no myelopathy/alignment improvement. There were no differences in decompression, baseline alignment, mJOA, EQ-5D, or NDI between groups. Patients who improved only in myelopathy showed significant differences in baseline-1Y EQ-5D (baseline: 0.74, 1 yr:0.83, P < 0.001). One-year C2-S1 sagittal vertical axis (SVA; mJOA r = -0.424, P = 0.002; EQ-5D r = -0.261, P = 0.050; NDI r = 0.321, P = 0.015) and C7-S1 SVA (mJOA r = -0.494, P < 0.001; EQ-5D r = -0.284, P = 0.031; NDI r = 0.334, P = 0.010) were correlated with improvement in health-related qualities of life. CONCLUSION/CONCLUSIONS:After CD-corrective surgery, improvements in myelopathy symptoms and functional score were associated with superior 1-year patient-reported outcomes. Although there were no relationships between cervical-specific sagittal parameters and patient outcomes, global parameters of C2-S1 SVA and C7-S1 SVA showed significant correlations with overall 1-year mJOA, EQ-5D, and NDI. These results highlight myelopathy improvement as a key driver of patient-reported outcomes, and confirm the importance of sagittal alignment in patients with CD. LEVEL OF EVIDENCE/METHODS:3.

CD development secondary to PJK was recently documented in adult spinal deformity patients after surgical correction for thoracolumbar ASD. This study analyzes surgical management of patients with CD secondary to proximal junctional kyphosis (PJK) versus patients with primary CD. Retrospective review of multicenter cervical deformity (CD) database. CD defined as at least one of the following: C2-C7 coronal Cobb > 10°, cervical lordosis (CL) > 10°, cervical sagittal vertical axis (cSVA) > 4cm, CBVA > 25°. Patients were grouped into those with PJK (UIV +2 < -10°) prior to cervical surgery versus who don't (Non-PJK). Independent t-tests and chi-squared tests compared radiographic, clinical, and surgical metrics between PJK and non-PJK groups. Of 123 eligible CD patients, 26(21.1%) had radiographic PJK prior to cervical surgery. PJK patients had significantly greater T2-T12 thoracic kyphosis (-58.8° vs -45.0°, p = 0.002), cSVA (49.1 mm vs 38.9 mm, p = 0.020), T1 Slope (42.6° vs 28.4°, p < 0.001), TS-CL (44.1° vs 35.6°, p = 0.048), C2-T3 SVA (98.8 mm vs 75.8 mm, p = 0.015), C2 Slope (45.4° vs 36.0°, p = 0.043), and CTPA (6.4° vs 4.6°, p = 0.005). Comparing their surgeries, the PJK group had significantly more levels fused (10.7 vs 7.4, p = 0.01). There was significantly greater blood loss in PJK patients (1158 ± 1063vs 738 ± 793 cc, p = 0.028); operative time, surgical approach, and BMP-2 use were similar (all p > 0.05). PJK patients experienced higher rates of complications 30 and 90 days post-operatively (23.1% vs. 5.2%, p = 0.004; 30.8% vs. 19.6%, p = 0.026), and more instrumentation failure 30 days postoperatively (7.8% vs. 1.0%, p = 0.004). Patients with cervical deformity secondary to PJK had worse baseline CD, despite no differences in HRQL or demographics. Surgical correction of CD associated with PJK required more invasive surgery and had higher complication rates than non-PJK patients, despite achieving similar clinical outcomes.

BACKGROUND:Length of stay (LOS) after surgery for adult spinal deformity (ASD) is a critical period that allows for optimal recovery. Predictive models that estimate LOS allow for stratification of high-risk patients. METHODS:A prospectively acquired multicenter database of patients with ASD was used. Patients with staged surgery or LOS >30 days were excluded. Univariable predictor importance ≥0.90, redundancy, and collinearity testing were used to identify variables for model building. A generalized linear model was constructed using a training dataset developed from a bootstrap sample; patients not randomly selected for the bootstrap sample were selected to the training dataset. LOS predictions were compared with actual LOS to calculate an accuracy percentage. RESULTS:Inclusion criteria were met by 653 patients. The mean LOS was 7.9 ± 4.1 days (median 7 days; range, 1-28 days). Following bootstrapping, 893 patients were modeled (653 in the training model and 240 in the testing model). Linear correlations for the training and testing datasets were 0.632 and 0.507, respectively. The prediction accuracy within 2 days of actual LOS was 75.4%. CONCLUSIONS:Our model successfully predicted LOS after ASD surgery with an accuracy of 75% within 2 days. Factors relating to actual LOS, such as rehabilitation bed availability and social support resources, are not captured in large prospective datasets. Predictive analytics will play an increasing role in the future of ASD surgery, and future models will seek to improve the accuracy of these tools.

BACKGROUND:Cardiac anomalies are prevalent in patients with bony spinal anomalies. Prior studies evaluating incidences of bony congenital anomalies of the spine are limited. The Kids' Inpatient Database (KID) yields national discharge estimates of rare pediatric conditions like congenital disorders. This study utilized cluster analysis to study patterns of concurrent vertebral anomalies, anal atresia, cardiac malformations, trachea-esophageal fistula, renal dysplasia, and limb anomalies (VACTERL anomalies) co-occurring in patients with spinal congenital anomalies. METHODS:Retrospective review of KID 2003-2012. KID-supplied hospital- and year-adjusted weights allowed for incidence assessment of bony spinal anomalies and cardiac, gastrointestinal, urinary anomalies of VACTERL. K-means clustering assessed relationships between most frequent anomalies within bony spinal anomaly discharges; k set to n - 1(n = first incidence of significant drop/little gain in sum of square errors within clusters). RESULTS:There were 12,039,432 KID patients 0-20 years. Incidence per 100,000 discharges: 2.5 congenital fusion of spine, 10.4 hemivertebra, 7.0 missing vertebra. The most common anomalies co-occurring with bony vertebral malformations were atrial septal defect (ASD 12.3%), large intestinal atresia (LIA 11.8%), and patent ductus arteriosus (PDA 10.4%). Top congenital cardiac anomalies in vertebral anomaly patients were ASD, PDA, and ventricular septal defect (VSD); all three anomalies co-occur at 6.6% rate in this vertebral anomaly population. Cluster analysis revealed that of bony anomaly discharges, 55.9% of those with PDA had ASD, 34.2% with VSD had PDA, 22.9% with LIA had ASD, 37.2% with ureter obstruction had LIA, and 35.5% with renal dysplasia had LIA. CONCLUSIONS:In vertebral anomaly patients, the most common co-occurring congenital anomalies were cardiac, renal, and gastrointestinal. Top congenital cardiac anomalies in vertebral anomaly patients were ASD, PDA, and VSD. VACTERL patients with vertebral anomalies commonly presented alongside cardiac and renal anomalies.

STUDY DESIGN/METHODS:Retrospective analysis OBJECTIVE.: To compare long-term outcomes between patients with and without mental health comorbidities who are undergoing surgery for adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA/BACKGROUND:Recent literature reveals that one in three patients admitted for surgical treatment for ASD has comorbid mental health disorder. Currently, impacts of baseline mental health status on long-term outcomes following ASD surgery have not been thoroughly investigated. METHODS:Patients admitted from 2009-2013 with diagnoses of ASD who underwent ≥4-level thoracolumbar fusion with minimum two-year follow-up were retrospectively reviewed using New York State's Statewide Planning and Research Cooperative System (SPARCS). Patients were stratified by fusion length (Short: 4-8-level; Long: ≥9 level). Patients with comorbid mental health disorder (MHD) at time of admission were selected for analysis (MHD) and compared against those without MHD (no-MHD). Univariate analysis compared demographics, complications, readmissions and revisions between cohorts for each fusion length. Multivariate binary logistic regression models identified independent predictors of outcomes (covariates: fusion length, age, female gender, and Deyo score). RESULTS:6,020 patients (MHD: n = 1,631; no-MHD: n = 4,389) met inclusion criteria. Mental health diagnoses included disorders of depression (59.0%), sleep (28.0%), anxiety (24.0%), and stress (2.3%). At two-year follow-up, MHD patients with short fusion had significantly higher complication rates (p = 0.001). MHD patients with short or long fusion also had significantly higher rates of any readmission and revision (all p ≤ 0.002). Regression modeling revealed that comorbid MHD was a significant predictor of any complication (OR: 1.17, p = 0.01) and readmission (OR: 1.32, p < 0.001). MHD was the strongest predictor of any revision (OR: 1.56, p < 0.001). Long fusion most strongly predicted any complication (OR: 1.87, p < 0.001). CONCLUSIONS:ASD patients with comorbid depressive, sleep, anxiety, and stress disorders were more likely to experience surgical complications and revision at minimum of two years following spinal fusion surgery. Proper patient counseling and psychological screening/support is recommended to complement ASD treatment. LEVEL OF EVIDENCE/METHODS:3.