Faculty Bibliography

Background/UNASSIGNED:The study aimed to characterize trends in incidence, etiology, fracture types, surgical procedures, complications, and concurrent injuries associated with traumatic pediatric cervical fracture using a nationwide database. Methods/UNASSIGNED:< .05. Results/UNASSIGNED:< .001). Conclusions/UNASSIGNED:Since 2003, incidence, complications, concurrent injuries, and fusions have increased. CCI, SCI, falls, and sports injuries were significant predictors of surgical intervention. Decreased mortality and SCI rates may indicate improving emergency medical services and management guidelines. Level of Evidence/UNASSIGNED:III. Clinical Relevance/UNASSIGNED:Clinicians should be aware of increased case complexity in the onset of added perioperative complications and concurrent injuries. Cervical fractures resultant of sports injuries should be scrutinized for concurrent SCIs.

STUDY DESIGN:Retrospective review of KID Inpatient Database (KID) from 2003, 2006, 2009, and 2012. OBJECTIVES:The aim of this study was to evaluate the impact of advances in spinal surgery on patient outcomes in the treatment of Scheuermann kyphosis (SK). SUMMARY OF BACKGROUND DATA:SK is one of the most common causes of back pain in adolescents. Trends in diagnoses and surgical treatment and approach to SK have not been well described. METHODS:SK patients aged 0-20 years in KID were identified by ICD-9 code 732.0. KID-supplied year- and hospital-trend weights were used to establish prevalence. Patient demographics, surgical details, and outcomes were analyzed with analysis of variance. RESULTS:A total of 1,070 SK patients were identified (33.2% female), with increasing incidence of SK diagnosed from 2003 to 2012 (3.6-7.5 per 100,000, p < .001). The average age of operative patients was 16.1±2.0 years and did not change (16.27-16.06 years, p = .905). The surgical rate has not changed over time (72.8%-72.8%, p = .909). Overall, 96.3% of operative patients underwent fusion, with 82.2% of cases spanning ≥4 levels; in addition, 8.6% underwent an anterior-only surgery, 74.6% posterior-only, and 13.6% combined approach. From 2003 to 2012, rates of posterior-only surgeries increased (62.4%-84.4%, p < .001) whereas the rate of combined-approach surgeries decreased (37.6%-8.8%, p < .001). Overall complication rates for SK surgeries have decreased (2003: 20.9%; 2012: 11.9%, p = .029). Concurrently, the rate of ≥4-level fusions has increased (43.5%-89.6%, p < .001), as well as the use of Smith-Peterson (7.8%-23.6%, p < .001) and three-column osteotomies (0.0%-2.7%, p = .011). In subanalysis comparing posterior to combined approaches, complication rates were significantly different (posterior: 9.88%, combined: 19.46%, p = .005). Patients undergoing a combined approach have a longer length of stay (LOS) than patients undergoing a posterior-only approach (7.8 vs. 5.6 days, p < .001). CONCLUSIONS:Despite unchanged demographics and operative rates in SK, there has been a shift from combined to isolated posterior approaches, with a concurrent increase in levels treated. A combined approach was associated with increased complication rates, LOS, and total charges compared to isolated approaches. Awareness of these inherent differences is important for surgical decision making and patient education. LEVELS OF EVIDENCE:Level III.

Background: For surgical adult spinal deformity (ASD) patients, incorporating restoration of appropriate Roussouly Classificaion shape into surgical planning may improve outcomes. With the introduction and use of the SRS-Schwab ASD classification system, it's important to compare the utility of both classification frameworks as they relate to surgical outcomes.
Purpose(s): Compare outcomes of surgical ASD patients classified by both Roussouly and Schwab systems.
Method(s): Retrospective review of prospective ASD database. ASD patients were grouped by theoretical Roussouly type (1: PI<45-, LL apex below L4; 2: PI<45-, LL apex above L4-L5 space; 3: 45-Result(s): Included: 515 ASD patients (59 +/- 14yrs, 80%F). Preop breakdown of current Roussouly types: Type 1 (10%), Type 2 (54%), Type 3 (24%), Type 4 (12%). Preop mismatch between current and theoretical types was 60%. By 2Y, 16% of patients matched Roussouly types. Matched and Mismatched groups did not differ in rates of reaching MCID for any HRQL metrics by 2Y (all p[0.1). Reop, PJK, and complications did not differ between Matched and Mismatched (all p[0.1), though Mismatched patients showed a trend of increased instrumentation failure (17% vs 26%, p = 0.080). By 2Y, 28% of patients improved in PT Schwab modifier, 37% in SVA, and 46% in PI-LL. Patients that improved in PT modifier reached MCID at higher rates for ODI and SRS Activity by 2Y, and had lower rates of instrumentation failure than those that did not (Table 1). Patients that both Matched Roussouly at 2Y and improved in all Schwab modifiers met MCID for ODI and SRS Activity at higher rates than patients that did not. Roussouly Match patients that improved in Schwab PT met SRS Activity MCID at a higher rate, and had less renal, infection, and neurologic complications than patients that did not. Roussouly Match patients that improved in Schwab SVA also had superior SF-36 scores and fewer cardiopulmonary complications (all p<0.05).
Conclusion(s): For surgical ASD patients, isolated restoration of sagittal spinal shape per the Roussouly system was not associated with superior clinical outcomes or complications by 2Y. In contrast, improvement in PT, per SRS-Schwab system, was associated with improvement in low-back disability by 2Y. Collectively, patients that matched Roussouly type and improved in Schwab modifiers had superior complication and patient-reported outcomes by 2Y. These results indicate concurrent consideration of both classification systems may offer utility in establishing optimal realignment targets

BACKGROUND:Surgical treatments for adult cervical spinal deformity (ACSD) are often complex and have high complication rates. OBJECTIVE:To assess all-cause mortality following ACSD surgery. METHODS:ACSD patients presenting for surgical treatment were identified from a prospectively collected multicenter database. Clinical and surgical parameters and all-cause mortality were assessed. RESULTS:Of 123 ACSD patients, 120 (98%) had complete baseline data (mean age, 60.6 yr). The mean number of comorbidities per patient was 1.80, and 80% had at least 1 comorbidity. Surgical approaches included anterior only (15.8%), posterior only (50.0%), and combined anterior/posterior (34.2%). The mean number of vertebral levels fused was 8.0 (standard deviation [SD] = 4.5), and 23.3% had a 3-column osteotomy. Death was reported for 11 (9.2%) patients at a mean of 1.1 yr (SD = 0.76 yr; range = 7 d to 2 yr). Mean follow-up for living patients was 1.2 yr (SD = 0.64 yr). Causes of death included myocardial infarction (n = 2), pneumonia/cardiopulmonary failure (n = 2), sepsis (n = 1), obstructive sleep apnea/narcotics (n = 1), subsequently diagnosed amyotrophic lateral sclerosis (n = 1), burn injury related to home supplemental oxygen (n = 1), and unknown (n = 3). Deceased patients did not significantly differ from alive patients based on demographic, clinical, or surgical parameters assessed, except for a higher major complication rate (excluding mortality; 63.6% vs 22.0%, P = .006). CONCLUSION/CONCLUSIONS:All-cause mortality at a mean of 1.2 yr following surgery for ACSD was 9.2% in this prospective multicenter series. Causes of death were reflective of the overall high level of comorbidities. These findings may prove useful for treatment decision making and patient counseling in the context of the substantial impact of ACSD.

Chiari malformations are structural defects in the posterior fossa where the cerebellum displaces caudally into the foramen magnum and upper spinal canal. These malformations are classified by severity as Types 1-4, each presenting with different associated and/or concurrent conditions and anomalies. The aim of this study was to utilize a nationwide database to study patients with Chiari malformations including their concurrent diagnoses and associated anomalies. Using a retrospective review of the Nationwide Inpatient Sample (NIS) database from 2003 to 2012, Chiari malformations were assessed by Chiari type and rates of concurrence for various additional anomalies were evaluated using cross-tabulations. There were 305,726 national cases of Chiari Type 1, 119,632 cases of Chiari Type 2, 15,540 cases of Type 3, and 79,663 cases of Type 4. Overall 44.3% of Chiari patients have at least one concurrent anomaly. Stratified by Chiari Type, 7.1% of Type 1 patients, 12.3% of Type 2, and 100% of Type 3 and 4 have at least one concurrent anomaly. The most common isolated neurologic associations were tethered cord, syringomyelia, and hydrocephalus, while the most common anomaly clusters were syringomyelia and scoliosis in Type 1 (0.63), tethered cord syndrome and scoliosis (0.72%) in Type 2, encephalocele and acquired hydrocephalus (11.45%) in Type 3, and reduction deformity of the brain with acquired hydrocephalus (15.95%) in Type 4. Chiari malformations have strong associations with other abnormalities outside of known relationships in the current classification. While neurologic abnormalities are most common, additional body systems are frequently involved especially with worsening hindbrain defects.

BACKGROUND:Bariatric surgery (BS) is an increasingly common treatment for morbid obesity that has the potential to effect bone and mineral metabolism. The effect of prior BS on spine surgery outcomes has not been well established. The aim of this study was to assess differences in complication rates following spinal surgery for patients with and without a history of BS. METHODS:Retrospective analysis of the prospectively collected New York State Inpatient Database (NYSID) years 2004-2013. BS patients and morbidly obese patients (non-BS) were divided into cervical and thoracolumbar surgical groups and propensity score matched for age, gender, and invasiveness and complications compared. RESULTS:One thousand nine hundred thirty-nine spine surgery patients with a history of BS were compared to 1625 non-BS spine surgery patients. The average time from bariatric surgery to spine surgery is 2.95 years. After propensity score matching, 740 BS patients were compared to 740 non-BS patients undergoing thoracolumbar surgery, with similar comorbidity rates. The overall complication rate for BS thoracolumbar patients was lower than non-BS (45.8% vs 58.1%, P < 0.001), with lower rates of device-related (6.1% vs 23.2%, P < 0.001), DVT (1.2% vs 2.7%, P = 0.039), and hematomas (1.5% vs 4.5%, P < 0.001). Neurologic complications were similar between BS patients and non-BS patients (2.3% vs 2.7%, P = 0.62). For patients undergoing cervical spine surgery, BS patients experienced lower rates of bowel issues, device-related, and overall complication than non-BS patients (P < 0.05). CONCLUSIONS:Bariatric surgery patients undergoing spine surgery experience lower overall complication rates than morbidly obese patients. This study warrants further investigation into these populations to mitigate risks associated with spine surgery for bariatric patients.

STUDY DESIGN/METHODS:Retrospective analysis of 2 prospectively collected multicenter databases, one for cervical deformity (CD) and the other for general adult spinal deformity. OBJECTIVE:To investigate the relative quality-of-life and disability burden in patients with uncompensated cervical, thoracolumbar, or cervical and thoracolumbar deformities. SUMMARY OF BACKGROUND DATA/BACKGROUND:The relative quality-of-life burden of cervical and thoracolumbar deformities have never been compared with each other. This may have significant implications when deciding on the appropriate treatment intervention for patients with combined thoracolumbar and cervical deformities. METHODS:When defining CD C2-C7 sagittal vertical axis (SVA)>4 cm was used while a C7-S1 SVA>5 cm was used to defined thoracolumbar deformity. Patients with both SVA criteria were defined as "combined." Primary analysis compared patients in the different groups by demographic, comorbidity data, and quality-of-life scores [EuroQOL 5 dimensions questionnaire (EQ-5D)] using t tests. Secondary analysis matched deformity groups with propensity scores matching based on baseline EQ-5D scores. Differences in disease-specific metrics [the Oswestry Disability Index, Neck Disability Index, modified Japanese Orthopaedic Association questionnaire (mJOA)] were analyzed using analysis of variance tests and post hoc analysis. RESULTS:In total, 212 patients were included in our analysis. Patients with CD only had less neurological deficits (mJOA: 14.6) and better EQ-5D (0.746) scores compared with patients with combined deformities (11.9, 0.716), all P<0.05. Regarding propensity score-matched deformity cohorts, 99 patients were matched with similar quality-of-life burden, 33 per deformity cohort. CD only patients had fewer comorbidities (1.03 vs. 2.12 vs. 2.70; P<0.001), whereas patients with combined deformity had more baseline neurological impairment compared with CD only patients (mJOA: 12.00 vs. 14.25; P=0.050). CONCLUSIONS:Combined deformity patients were associated with the lowest quality-of-life and highest disability. Furthermore, regarding deformity cohorts matched by similar baseline quality-of-life status (EQ-5D), patients with combined deformities were associated with significantly worse neurological impairments. This finding implies that quality of life may not be a direct reflection of a patient's disability status, especially in patients with combined cervical and thoracolumbar deformities. LEVEL OF EVIDENCE/METHODS:Level III.

STUDY DESIGN/METHODS:This is a retrospective review of a single surgeon cervical deformity (CD) database. OBJECTIVE:Quantitatively describe the cervical extensor musculature in a CD population, and delineate associations between posterior musculature atrophy and progressive sagittal deformity. SUMMARY OF BACKGROUND DATA/BACKGROUND:While fatty infiltration (FI; ie, posterior musculature atrophy) of lumbar extensor musculature has been associated with pain and deformity, little is known of the relationship between FI, CD, cervical sagittal alignment, and functionality. METHODS:CD patients [TS-CL>20 degrees, C2-C7 Cobb>10 degrees, CL>10 degrees, cervical sagittal vertical axis (cSVA)>4 cm, or chin-brow vertical angle>25 degrees] 18 years old and above, undergoing spinal fusion, with baseline T2-weighted magnetic resonance images were included. FI was assessed using dedicated imaging software at each intervertebral level from C2-C7. FI was gauged as a ratio of fat-free muscle cross-sectional area over total muscle cross-sectional area, with lower values indicating increasing FI. Influence of BL C2-C7 FI on patient-reported outcome measures (PROMs) and alignment was investigated. Multiple linear regression analysis (covariates: age, sex, body mass index, C2-C7 FI ratio) determined predictors of postoperative sagittal alignment and PROMs. RESULTS:Thirty-eight patients were included (age: 56.6, sex: 73.7% female, body mass index: 30.1, Charlson Comorbidity Index 0.61). BL deformity presentation: TS-CL 27.4 degrees, CL 2.1 degrees, cSVA: 27.2 mm. Mean baseline C2-C7 FI ratio was 0.65±0.11. Worsening FI was associated with malaligned baseline cSVA (rs=0.389, P=0.019), T1SS (rs=0.340, P=0.062), and impaired gait (rs=0.358, P=0.078). FI was not associated with BL PROMs (P>0.05). Following surgical intervention, regression models determined BL C2-C7 FI ratio as the strongest predictor of 1-year postoperative cSVA (β=-0.482, P=0.007, R=0.317). No associations between BL FI and postoperative PROMS or alignment parameters were observed (P>0.05). CONCLUSIONS:Patients with significant CD demonstrate alterations in the posterior extensor musculature of the cervical spine. Atrophic changes with FI of these muscle groups is associated with worsening CD and is an important predictor of postoperative sagittal alignment. LEVEL OF EVIDENCE/METHODS:Level III.

BACKGROUND:The impact of obesity on global spinopelvic alignment is poorly understood. This study investigated the effect of body mass index on achieving alignment targets and compensation mechanisms after corrective surgery for adult spinal deformity (ASD). METHODS:Retrospective review of a single-center database. Inclusion: patients ≥18 years with full-body stereographic images (baseline and 1 year) and who met ASD criteria (sagittal vertical axis [SVA] >5 cm, pelvic incidence minus lumbar lordosis [PI-LL] >10°, coronal curvature >20° or pelvic tilt >20°). Patients were stratified by age (<40, 40-65, and ≥65 years) and body mass index (<25, 25-30, and >30). Postoperative alignment was compared with age-adjusted ideal values. Prevalence of patients who matched ideals and unmatched (undercorrected/overcorrected) was assessed. Health-related quality of life (HRQL) scores, alignment, and compensatory mechanisms were compared across cohorts using analysis of variance and temporally with paired t tests. RESULTS:A total of 116 patients were included (average age, 62 years; 66% female). After corrective surgery, obese and overweight patients had more residual malalignment (worse PI-LL, T1 pelvic angle, pelvic tilt, and SVA) compared with normal patients (P < 0.05). In addition, obese and overweight patients recruited more pelvic shift (obese, 62.36; overweight, 49.80; normal, 31.50) and had a higher global sagittal angle (obese, 6.51; overweight, 6.35; normal, 3.40) (P < 0.05). Obese and overweight patients showed lower overcorrection rates and higher undercorrection rates (P < 0.05). Obese patients showed worse postoperative HRQL scores (Scoliosis Research Society 22 Questionnaire, Oswestry Disability Index, visual analog scale-leg) than did overweight and normal patients (P < 0.05). Obese and overweight patients who matched age-adjusted alignment targets for SVA or PI-LL showed no HRQL improvements (P > 0.05). CONCLUSIONS:After surgery, obese patients were undercorrected, showed more residual malalignment, recruited more pelvic shift, and had a greater global sagittal angle and worse HRQL scores. The benefits from age-adjusted alignment targets seem to be less substantial for obese and overweight patients.

Background/UNASSIGNED:The recommended timing of surgical intervention for vertebral osteomyelitis (VO) is controversial; however, most studies are not sufficiently powered. Our goal was to investigate the associated effects of delaying surgery in VO patients on in-hospital complications, neurologic deficits, and mortality. Methods/UNASSIGNED:Retrospective review of the National Inpatient Sample. Patients who underwent surgery for VO from 1998 to 2013 were identified using codes from the International Classification of Disease, Ninth Revision, Clinical Modification. Patients were stratified into groups based on incremental delay of surgery: 0-day delay (same-day surgery), 1-day delay, 2-day delay, 3- to 6-day delay, 7- to 14-day delay, and 14- to 30-day delay. Univariate analysis compared demographics and outcomes between groups. Multivariate logistic regression models calculated independent predictors of any complication, mortality, and neurologic deficits. A 0-day delay was the reference group. Results/UNASSIGNED: < .001. Conclusion/UNASSIGNED:VO patients who operate within 24 hours of admission are more likely to have desirable outcomes. Patients with delayed surgery had a significantly increased risk of developing any complication, mortality, and discharging with neurologic deficits. Level of Evidence/UNASSIGNED:III. Clinical Relevance/UNASSIGNED:Medically fit patients may benefit from earlier surgical management in order to reduce risk of postoperative complications, improve outcomes, and reduce overall hospital costs.