Correction to: Prior bariatric surgery lowers complication rates following spine surgery in obese patients.

The AHRQ (Agency for Healthcare Research and Quality) has requested the correction of the result Tables 1-3 of this study: All stated numbers below 10 shall be modified to read "<10" instead.

Congenital Etiology Is an Independent Risk Factor for Complications in Adolescents Undergoing Corrective Scoliosis Surgery: Comparison of In-hospital Comorbidities Using Nationwide KID's Inpatient Database.

BACKGROUND: Congenital scoliosis (CS) is associated with more rigid, complex deformities relative to adolescent idiopathic scoliosis (AIS) which theoretically increases surgical complications. Despite extensive literature studying AIS patients, few studies have been performed on CS patients. The purpose of this study was to evaluate complications associated with spinal fusions for CS and AIS. METHODS: A retrospective review of the Kid's Inpatient Database (KID) years 2000 to 2009 was performed. Inclusion: patients under 20 years with ICD-9 diagnosis codes for idiopathic scoliosis (IS-without concomitant congenital anomalies) and CS, undergoing spinal fusion from the KID years 2000 to 2009. Two analyses were performed according to age below 10 years and 10 years and above. Univariate analysis described differences in demographics, comorbidities, intraoperative complications, and clinical values between groups. Binary logistic regression controlling for age, sex, race, and invasiveness predicted complications risk in CS (odds ratios; 95% confidence interval). RESULTS: In total, 25,131 patients included (IS, n=22443; CS, n=2688). For patients under age 10, CS patients underwent 1 level shorter fusions (P<0.001), had fewer comorbidities (P<0.001), and sustained similar complication incidence. In the 10 and over age analysis, CS patients similarly had shorter fusions, but greater comorbidities, and significantly more complications (odds ratio, 1.6; confidence interval, 1.4-1.8). CONCLUSIONS: CS patients have higher in-hospital complication rates. With more comorbidities, these patients have increased risk of sustaining procedure-related complications such as shock, infection, and Adult Respiratory Distress Syndrome. These data help to counsel patients and their families before spinal fusion. LEVEL OF EVIDENCE: Level III-retrospective review of a prospectively collected database.

Incidence of Congenital Spinal Abnormalities Among Pediatric Patients and Their Association With Scoliosis and Systemic Anomalies.

BACKGROUND: Congenital abnormalities when present, according to VACTERL theory, occur nonrandomly with other congenital anomalies. This study estimates the prevalence of congenital spinal anomalies, and their concurrence with other systemic anomalies. METHODS: A retrospective cohort analysis on Health care Cost and Utilization Project's Kids Inpatient Database (KID), years 2000, 2003, 2006, 2009 was performed. ICD-9 coding identified congenital anomalies of the spine and other body systems. OUTCOME MEASURES: Overall incidence of congenital spinal abnormalities in pediatric patients, and the concurrence of spinal anomaly diagnoses with other organ system anomalies. Frequencies of congenital spine anomalies were estimated using KID hospital-and-year-adjusted weights. Poisson distribution in contingency tables tabulated concurrence of other congenital anomalies, grouped by body system. RESULTS: Of 12,039,432 patients, rates per 100,000 cases were: 9.1 hemivertebra, 4.3 Klippel-Fiel, 56.3 Chiari malformation, 52.6 tethered cord, 83.4 spina bifida, 1.2 absence of vertebra, and 6.2 diastematomyelia. Diastematomyelia had the highest concurrence of other anomalies: 70.1% of diastematomyelia patients had at least one other congenital anomaly. Next, 63.2% of hemivertebra, and 35.2% of Klippel-Fiel patients had concurrent anomalies. Of the other systems deformities cooccuring, cardiac system had the highest concurrent incidence (6.5% overall). In light of VACTERL's definition of a patient being diagnosed with at least 3 VACTERL anomalies, hemivertebra patients had the highest cooccurrence of ≥3 anomalies (31.3%). With detailed analysis of hemivertebra patients, secundum ASD (14.49%), atresia of large intestine (10.2%), renal agenesis (7.43%) frequently cooccured. CONCLUSIONS: Congenital abnormalities of the spine are associated with serious systemic anomalies that may have delayed presentations. These patients continue to be at a very high, and maybe higher than previously thought, risk for comorbidities that can cause devastating perioperative complications if not detected preoperatively, and full MRI workups should be considered in all patients with spinal abnormalities. LEVEL OF EVIDENCE: Level III.

Prospective multi-centric evaluation of upper cervical and infra-cervical sagittal compensatory alignment in patients with adult cervical deformity.

PURPOSE: Reciprocal mechanisms for standing alignment have been described in thoraco-lumbar deformity but have not been studied in patients with primary cervical deformity (CD). The purpose of this study is to report upper- and infra-cervical sagittal compensatory mechanisms in patients with CD and evaluate their changes post-operatively. METHODS: Global spinal alignment was studied in a prospective database of operative CD patients. Inclusion criteria were any of the following: cervical kyphosis (CK) > 10°, cervical scoliosis > 10°, cSVA (C2-C7 Sagittal vertical axis) > 4 cm or CBVA (Chin Brow Vertical Angle) > 25°. For this study, patients who had previous fusion outside C2 to T4 segments were excluded. Patients were sub-classified by increasing severity of cervical kyphosis [CL (cervical lordosis): < 0°, CK-low 0°-10°, CK-high > 10°] and cSVA (cSVA-low 0-4 cm, cSVA-mid 4-6 cm, cSVA-high > 6 cm) and were compared for pre- and 3-month post-operative regional and global sagittal alignment to determine compensatory recruitment. RESULTS: 75 CD patients (mean age 61.3 years, 56% women) were included. Patients with progressively larger CK had a progressive increase in C0-C2 (CL = 34°, CK-low = 37°, CK-high = 44°, p = 0.004), C2Slope and T1Slope-CL (p < 0.05). As the cSVA increased, there was progressive increase in C2Slope, T1Slope and TS-CL (p < 0.05) and patients compensated through increasing C0-C2 (cSVA-low = 33°, cSVA-mid = 40°, cSVA-high = 43°, p = 0.007) and pelvic tilt (cSVA-low = 14.9°, cSVA-mid = 24.1°, cSVA-high = 24.9°, p = 0.02). At 3 months post-op, with significant improvement in cervical alignment, there was relaxation of C0-C2 (39°-35°, p = 0.01) which positively correlated with magnitude of deformity correction. CONCLUSIONS: Patients with cervical malalignment compensate with upper cervical hyper-lordosis, presumably for the maintenance of horizontal gaze. As cSVA increases, patients also tend to exhibit increased pelvic retroversion. Following surgical treatment, there was relaxation of upper cervical compensation.

Prior bariatric surgery lowers complication rates following spine surgery in obese patients.

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.

Bone morphogenetic protein in adult spinal deformity surgery: a meta-analysis.

INTRODUCTION: Since its introduction BMP has been utilized in populations with higher rates of malunion, such as adult spinal deformity (ASD) patients. Contradictory conclusions exist in spinal literature regarding the safety and efficacy of the use of BMP in this setting. Previous studies, however, did not distinguish deformity cases from spondylolisthesis or stenosis. The purpose of this study is to evaluate the safety and efficacy of BMP use in spinal fusion surgery for ASD. METHODS: 166 papers were screened after database search. 40 full texts were assessed for eligibility. Five studies were included for meta-analysis. Three were comparative studies between a BMP and non-BMP group, and the other was used to supplement dose-effect analysis. RESULTS: The current meta-analysis found increased odds of developing radiculitis or neurological complications (OR = 2.18, 95% CI, p = 0.02, i 2 = 0), but no other significant relationship between complications commonly attributed to BMP use (tumorigenesis, infections, seroma formation, or osteolysis) and BMP use. BMP patients had decreased rates of pseudarthrosis (OR = 0.23, 95% CI, p = 0.002, i 2 = 0). There was an average dose of 8.75 mg/level in the 417 patients studied, lower than the advised dosage of 12 mg/level. CONCLUSIONS: The current literature shows BMP to be a safe and effective grafting technique in the treatment of ASD. Spine surgeons may currently be using sub-optimal doses of BMP. The benefit of increasing the rate of fusion must be weighed against the increased risk of radiculitis and neurologic complications in this patient population.

Predictors of inpatient morbidity and mortality in adult spinal deformity surgery.

PURPOSE: This nationwide study identifies ASD surgical risk factors for morbidity/mortality. METHODS: NIS discharges from 2001 to 2010 aged 25+ with scoliosis diagnoses, 4+ levels fused, and procedural codes for anterior and/or posterior thoracic and/or lumbar spinal fusion and refusion were included. Demographics, comorbidities and procedure-related complications were determined for each subgroup (degenerative, congenital, idiopathic, other). Multivariate analysis reported as [OR (95% CI)]. RESULTS: 11,982 discharges were identified. Morbidity, excluding device-related, and mortality rates were 50.81 and 0.28%, respectively. Certain comorbidities were associated with increased morbidity/mortality: congestive heart failure (CHF) [1.62 (1.42-1.84)] [5.67 (3.30-9.73)], coagulopathy [3.52 (3.22-3.85)] [2.32 (1.44-3.76)], electrolyte imbalance [2.65 (2.52-2.79)] [4.63 (3.15-6.81)], pulmonary circulation disorders [9.45 (7.45-11.99)] [8.94 (4.43-18.03)], renal failure [1.29 (1.13-1.47)] [5.51 (2.57-11.82)], and pathologic weight loss [2.38 (2.01-2.81)] [7.28 (4.36-12.14)]. Chronic pulmonary disease was associated with higher morbidity [1.08 (1.02-1.14)]; liver disease was linked to increased mortality [36.09 (16.16-80.59)]. 9+ level fusions had increased morbidity vs 4-8 level fusions [1.69 (1.61-1.78)] and refusions [1.08 (1.02-1.14)]. Idiopathic scoliosis was associated with decreased morbidity vs all other subgroups [0.85 (0.80-0.91)]. Age >65 was associated with increased morbidity and mortality vs 25-64 group [1.09 (1.05-1.14)] [3.49 (2.31-5.29)]. Females had increased morbidity [1.18 (1.13-1.23)] and decreased mortality [0.30 (0.21-0.44)]. Mean comorbidity index (0.55) and age (64.38) for degenerative cohort were higher vs all other subgroups (P < 0.0001). CONCLUSIONS: Longer fusions were associated with increased morbidity. Age >65 was associated with increased morbidity/mortality, while females were associated with increased morbidity but decreased mortality. Idiopathic scoliosis had decreased morbidity. Degenerative ASD cases had higher comorbidity indices, potentially due to older age. This study is clinically useful for patient education, surgical decision-making, and optimizing patient outcomes.

A comparative analysis of the prevalence and characteristics of cervical malalignment in adults presenting with thoracolumbar spine deformity based on variations in treatment approach over 2 years.

PURPOSE: Characteristics specific to cervical deformity (CD) concomitant with adult thoracolumbar deformity (TLD) remains uncertain, particularly regarding treatment. This study identifies cervical malalignment prevalence following surgical and conservative TLD treatment through 2 years. METHODS: Retrospective analysis of a prospective, multicenter adult spinal deformity (ASD) database. CD was defined in operative and non-operative ASD patients according to the following criteria: T1 Slope minus Cervical Lordosis (T1S-CL) ≥20°, C2-C7 Cervical Sagittal Vertical Axis (cSVA) ≥40 mm, C2-C7 kyphosis >10°. Differences in rates, demographics, health-related quality of life (HRQoL) scores for Oswestry Disability Index (ODI) and Scoliosis Research Society Questionnaire (SRS-22r), and radiographic variables were assessed between treatment groups (Op vs. Non-Op) and follow-up periods (baseline, 1-year, 2-year). RESULTS: Three hundred and nineteen (200 Op, 199 Non-Op) ASD patients were analyzed. Op patients' CD rates at 1 and 2 years were 78.9, and 63.0 %, respectively. Non-Op CD rates were 21.1 and 37.0 % at 1 and 2 years, respectively. T1S-CL mismatch and cSVA malalignment characterized Op CD at 1 and 2 years (p < 0.05). Op and Non-Op CD groups had similar cervical/global alignment at 1 year (p > 0.05 for all), but at 2 years, Op CD patients had worse thoracic kyphosis (TK), T1S-CL, CL, cSVA, C2-T3 SVA, and global SVA compared to Non-Ops (p < 0.05). Op CD patients had worse ODI, and SRS Activity at 1 and 2 years post-operative (p < 0.05), but had greater 2-year SRS Satisfaction scores (p = 0.019). CONCLUSIONS: In the first study to compare cervical malalignment at extended follow-up between ASD treatments, CD rates rose overall through 2 years. TLD surgery, resulting in higher CD rates characterized by T1S-CL and cSVA malalignment, produced poorer HRQoL. This information can aid in treatment method decision-making when cervical deformity is present concomitant with TLD.

Classifying Complications: Assessing Adult Spinal Deformity 2-Year Surgical Outcomes.

STUDY DESIGN: Retrospective review of prospective database. OBJECTIVE: Complication rates for adult spinal deformity (ASD) surgery vary widely because there is no accepted system for categorization. Our objective was to identify the impact of complication occurrence, minor-major complication, and Clavien-Dindo complication classification (Cc) on clinical variables and patient-reported outcomes. METHODS: Complications in surgical ASD patients with complete baseline and 2-year data were considered intraoperatively, perioperatively (<6 weeks), and postoperatively (>6 weeks). Primary outcome measures were complication timing and severity according to 3 scales: complication presence (yes/no), minor-major, and Cc score. Secondary outcomes were surgical outcomes (estimated blood loss [EBL], length of stay [LOS], reoperation) and health-related quality of life (HRQL) scores. Univariate analyses determined complication presence, type, and Cc grade impact on operative variables and on HRQL scores. RESULTS: Of 167 patients, 30.5% (n = 51) had intraoperative, 48.5% (n = 81) had perioperative, and 58.7% (n = 98) had postoperative complications. Major intraoperative complications were associated with increased EBL (P < .001) and LOS (P = .0092). Postoperative complication presence and major postoperative complication were associated with reoperation (P < .001). At 2 years, major perioperative complications were associated with worse ODI, SF-36, and SRS activity and appearance scores (P < .02). Increasing perioperative Cc score and postoperative complication presence were the best predictors of worse HRQL outcomes (P < .05). CONCLUSION: The Cc Scale was most useful in predicting changes in patient outcomes; at 2 years, patients with raised perioperative Cc scores and postoperative complications saw reduced HRQL improvement. Intraoperative and perioperative complications were associated with worse short-term surgical and inpatient outcomes.

Bariatric Surgery Population at Significantly Increased Risk of Spinal Disorders and Surgical Intervention Compared With Morbidly Obese Patients.

INTRODUCTION: Obesity is associated with acceleration of musculoskeletal degenerative diseases and functional impairment secondary to spinal disorders. Bariatric surgery (BS) is an increasingly common treatment for severe obesity but can affect bone and mineral metabolism. The effect of BS on degenerative spinal disorders is yet to be fully described. The aim of our study was to analyze changes in bariatric patients' risk for spinal degenerative diseases and spinal surgery. METHODS: Retrospective analysis of the prospectively collected New York State Inpatient Database (NYSID) years (2004-2013) using patient linkage codes. The incidence of degenerative spinal diagnoses and spinal surgery was queried using International Classification of Diseases, Ninth Revision (ICD)-9 codes for morbidly obese patients (ICD-9 278.01) with and without a history of BS. The incidence of degenerative spinal diagnoses and spinal surgery was determined using χ tests for independence. Logistic testing controlled for age, sex, and comorbidity burden. RESULTS: A total of 18,176 patients were identified in the NYSID database with a history of BS and 146,252 patients were identified as morbidly obese without a history of BS. BS patients have a significantly higher rate of spinal diagnoses than morbidly obese patients without BS (19.3% vs. 8.1%, P<0.001). Bariatric patients were more likely to have spinal diagnoses and procedures than nonbariatric obese patients (P<0.001). This was mostly observed in lumbar spinal stenosis (5.0%), cervical disk herniation (3.3%), lumbar disk degeneration (3.4%), lumbar spondylolisthesis (2.9%), lumbar spondylosis (1.9%), and cervical spondylosis with myelopathy (2.0%). Spine procedure rates are higher for bariatric patients than nonbariatric overall (25.6% vs. 2.3, P<0.001) and for fusions and decompressions (P<0.001). When controlling for age, sex, and comorbidities (and diagnosis rate with regards to procedure rates), these results persist, with BS patients having a higher likelihood of spinal diagnoses and procedures. In addition, bariatric patients had a lower comorbidity burden than morbidly obese patients without a history of BS. CONCLUSIONS: Morbidly obese BS patients have a dramatically higher incidence of spinal diagnoses and procedures, relative to morbidly obese patients without BS. Further study is necessary to determine if there is a pathophysiological mechanism underlying this higher risk of spinal disease and intervention in bariatric patients, and the effect of BS on these rates following treatment. LEVEL OF EVIDENCE: Level III.

Pre-operative planning and rod customization may optimize post-operative alignment and mitigate development of malalignment in multi-segment posterior cervical decompression and fusion patients.

Patient-specific rods designed based on a particular pre-operative plan are a recent advancement to help achieve desired operative alignment goals. This study investigated the role of pre-operative planning and patient-specific rods on post-operative alignment and outcomes. Patients were grouped according to use of pre-operative planning and patient-specific, pre-contoured rods (PLAN) or absence of planning/rods (NON). Pre-operative and post-operative alignment were measured: cervical sagittal vertical axis (cSVA), cervical lordosis (CL), T1 Slope minus CL (TS-CL). Alignment differences between the groups were assessed using independent and paired samples t-tests. 34 patients were identified (15 PLAN, 19 NON). Pre- and post-operative CL, cSVA and TS were similar between the two groups (p > 0.05), though pre-operative TS-CL was slightly higher in PLAN patients (28.13° versus 18.42°, p = 0.049). There were no improvement differences pre- to post-operative for CL, cSVA and TS between the groups (p > 0.05). However, PLAN patients exhibited a greater correction of TS-CL, with an average of 5.8° decrease versus a 3.5° increase in TS-CL for NON patients (p = 0.015). PLAN patients did not demonstrate a significant change from pre- to post-operative alignment for cSVA or TS-CL (cSVA: 27.5 mm to 31.1 mm, p = 0.255; TS-CL: 28.1° to 22.3°, p = 0.13), though their TS-CL did trend towards significant post-operative improvement. In contrast, NON patients worsened in cSVA and TS-CL post-operatively (cSVA: 21.8 mm to 30.3 mm, p < 0.001; TS-CL: 18.4° to 22.0°, p = 0.035). Multi-segment posterior decompression and fusion patients have the potential to worsen with regards to post-operative alignment without pre-operative planning. Patients with pre-contoured rods and pre-operative planning exhibited a greater correction of TS-CL after surgery than un-planned cases, though limited by the pre-operative difference in cervical-thoracic mismatch between planned and unplanned cases. LEVELS OF EVIDENCE: III.

Traumatic Fracture of the Pediatric Cervical Spine: Etiology, Epidemiology, Concurrent Injuries, and an Analysis of Perioperative Outcomes Using the Kids' Inpatient Database.

BACKGROUND: 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: The Kids' Inpatient Database (KID) was queried. Trauma cases from 2003 to 2012 were identified, and cervical fracture patients were isolated. Demographics, etiologies, fracture levels, procedures, complications, and concurrent injuries were assessed. The t-tests elucidated significance for continuous variables, and χ2 for categoric values. Logistic regressions identified predictors of spinal cord injury (SCI), surgery, any complication, and mortality. Level of significance was P < .05. RESULTS: A total of 11 196 fracture patients were isolated (age, 16.63 years; male, 65.7%; white, 65.4%; adolescent, 55.4%). Incidence significantly increased since 2003 (2003 vs 2012, 2.39% vs 3.12%, respectively), as did Charlson Comorbidity Index (CCI; 2003 vs 2012, 0.2012 vs 0.4408, respectively). Most common etiology was motor vehicle accidents (50.5%). Infants and children frequently fractured at C2 (closed: 43.1%, 32.9%); adolescents and young adults frequently fractured at C7 (closed: 23.9%, 26.5%). Upper cervical SCI was less common (5.8%) than lower cervical SCI (10.9%). Lower cervical unspecified-SCI, anterior cord syndrome, and other specified SCIs significantly decreased since 2003. Complications were common (acute respiratory distress syndrome, 7.8%; anemia, 6.7%; shock, 3.0%; and mortality, 4.2%), with bowel complications, cauda equina, anemia, and shock rates significantly increasing since 2003. Concurrent injuries were common (15.2% ribs; 14.4% skull; 7.1% pelvis) and have significantly increased since 2003. Predictors of SCI included sports injury and CCI. Predictors of surgery included falls, sports injuries, CCI, length of stay, and SCI. CCI, SCIs, and concurrent injuries were predictors of any complication and mortality, all (P < .001). CONCLUSIONS: 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: III. CLINICAL RELEVANCE: 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.

Effect of Obesity on Radiographic Alignment and Short-Term Complications After Surgical Treatment of Adult Cervical Deformity.

OBJECTIVE: We investigated the 30-day complication incidence and 1-year radiographic correction in obese patients undergoing surgical treatment of cervical deformity. METHODS: The patients were stratified according to World Health Organization's definition for obesity: obese, patients with a body mass index of ≥30 kg/m2; and nonobese, patients with a body mass index of <30 kg/m2. The patients had undergone surgery for the treatment of cervical deformity. The patient baseline demographic, comorbidity, and radiographic data were compared between the 2 groups at baseline and 1 year postoperatively. The 30-day complication incidence was stratified according to complication severity (any, major, or minor), and type (cardiopulmonary, dysphagia, infection, neurological, and operative). Binary logistic regression models were used to assess the effect of obesity on developing those complications, with adjustment for patient age and levels fused. RESULTS: A total of 124 patients were included, 53 obese and 71 nonobese patients. The 2 groups had a similar T1 slope minus cervical lordosis (obese, 37.2° vs. nonobese, 36.9°; P = 0.932) and a similar C2-C7 (-5.9° vs. -7.3°; P = 0.718) and C2-C7 (50.1 mm vs. 44.1 mm; P = 0.184) sagittal vertical axis. At the 1-year follow-up examination, the T1 pelvic angle (1.0° vs. -3.1°; P = 0.021) and C2-S1 sagittal vertical axis (-5.9 mm vs. -35.0 mm; P = 0.036) were different, and the T1 spinopelvic inclination (-1.0° vs. -2.9°; P = 0.123) was similar. The obese patients had a greater risk of overall short-term complications (odds ratio, 2.5; 95% confidence interval, 1.1-6.1) and infectious complications (odds ratio, 5.0; 95% confidence interval, 1.0-25.6). CONCLUSIONS: Obese patients had a 5 times greater odds of developing infections after surgery for adult cervical deformity. Obese patients also showed significantly greater pelvic anteversion after cervical correction.

Full-Body Radiographic Analysis of Postoperative Deviations From Age-Adjusted Alignment Goals in Adult Spinal Deformity Correction and Related Compensatory Recruitment.

BACKGROUND: Full-body stereographs for adult spinal deformity (ASD) have enhanced global deformity and lower-limb compensation associations. The advent of age-adjusted goals for classic ASD parameters (sagittal vertical axis, pelvic tilt, spino-pelvic mismatch [PI-LL]) has enabled individualized evaluation of successful versus failed realignment, though these remain to be radiographically assessed postoperatively. This study analyzes pre- and postoperative sagittal alignment to quantify patient-specific correction against age-adjusted goals, and presents differences in compensation in patients whose postoperative profile deviates from targets. METHODS: Single-center retrospective review of ASD patients ≥ 18 years with biplanar full-body stereographic x-rays. Inclusion: ≥ 4 levels fused, complete baseline and early (≤ 6-month) follow-up imaging. Correction groups generated at postoperative visit for actual alignment compared to age-adjusted ideal values for pelvic tilt, PI-LL, and sagittal vertical axis derived from clinically relevant formulas. Patients that matched exact ± 10-year threshold for age-adjusted targets were compared to unmatched cases (undercorrected or overcorrected). Comparison of spinal alignment and compensatory mechanisms (thoracic kyphosis, hip extension, knee flexion, ankle flexion, pelvic shift) across correction groups were performed with ANOVA and paired t tests. RESULTS: The sagittal vertical axis, pelvic tilt, and PI-LL of 122 patients improved at early postoperative visits (P < .001). Of lower-extremity parameters, knee flexion and pelvic shift improved (P < .001), but hip extension and ankle flexion were similar (P > .170); global sagittal angle decreased overall, reflecting global postoperative correction (8.3° versus 4.4°, P < .001). Rates of undercorrection to age-adjusted targets for each spino-pelvic parameter were 30.3% (sagittal vertical axis), 41.0% (pelvic tilt), and 43.6% (PI-LL). Compared to matched/overcorrections, undercorrections recruited increased posterior pelvic shift to compensate (P < .001); knee flexion was recruited in undercorrections for sagittal vertical axis and pelvic tilt; thoracic hypokyphosis was observed in PI-LL undercorrections. All undercorrected groups displayed consequentially larger global sagittal angle (P < .001). CONCLUSIONS: Global alignment cohort improvements were observed, and when comparing actual to age-adjusted alignment, undercorrections recruited pelvic and lower-limb flexion to compensate. LEVEL OF EVIDENCE: 3.

Characterizing Adult Cervical Deformity and Disability Based on Existing Cervical and Adult Deformity Classification Schemes at Presentation and Following Correction.

BACKGROUND: Adult cervical deformity (ACD) classifications have not been implemented in a prospective ACD population and in conjunction with adult spinal deformity (ASD) classifications. OBJECTIVE: To characterize cervical deformity type and malalignment with 2 classifications (Ames-ACD and Schwab-ASD). METHODS: Retrospective review of a prospective multicenter ACD database. Inclusion: patients ≥18 yr with pre- and postoperative radiographs. Patients were classified with Ames-ACD and Schwab-ASD schemes. Ames-ACD descriptors (C = cervical, CT = cervicothoracic, T = thoracic, S = coronal, CVJ = craniovertebral) and alignment modifiers (cervical sagittal vertical axis [cSVA], T1 slope minus cervical lordosis [TS-CL], modified Japanese Ortphopaedic Association [mJOA] score, horizontal gaze) were assigned. Schwab-ASD curve type stratification and modifier grades were also designated. Deformity and alignment group distributions were compared with Pearson χ2/ANOVA. RESULTS: Ames-ACD descriptors in 84 patients: C = 49 (58.3%), CT = 20 (23.8%), T = 9 (10.7%), S = 6 (7.1%). cSVA modifier grades differed in C, CT, and T deformities (P < .019). In C, TS-CL grade prevalence differed (P = .031). Among Ames-ACD modifiers, high (1+2) cSVA grades differed across deformities (C = 47.7%, CT = 89.5%, T = 77.8%, S = 50.0%, P = .013). Schwab-ASD curve type and presence (n = 74, T = 2, L = 6, D = 2) differed significantly in S deformities (P < .001). Higher Schwab-ASD pelvic incidence minus lumbar lordosis grades were less likely in Ames-ACD CT deformities (P = .027). Higher pelvic tilt grades were greater in high (1+2) cSVA (71.4% vs 36.0%, P = .015) and high (2+3) mJOA (24.0% vs 38.1%, P = .021) scores. Postoperatively, C and CT deformities had a trend toward lower cSVA grades, but only C deformities differed in TS-CL grade prevalence (0 = 31.3%, 1 = 12.2%, 2 = 56.1%, P = .007). CONCLUSION: Cervical deformities displayed higher TS-CL grades and different cSVA grade distributions. Preoperative associations with global alignment modifiers and Ames-ACD descriptors were observed, though only cervical modifiers showed postoperative differences.

Rates of Mortality in Lumbar Spine Surgery and Factors Associated With Its Occurrence Over a 10-Year Period: A Study of 803,949 Patients in the Nationwide Inpatient Sample.

BACKGROUND: The rate of mortality in surgical procedures involving the lumbar spine has historically been low, and as a result, there has been difficulty providing accurate quantitative mortality rates to patients in the preoperative planning phase. Awareness of these mortality rates is essential in reducing postoperative complications and improving outcomes. Additionally, mortality rates can be influenced by procedure type and patient profile, including demographics and comorbidities. The purpose of this study is to assess rates and risk factors associated with mortality in surgical procedures involving the lumbar spine using a large national database. METHODS: The Nationwide Inpatient Sample database was reviewed from 2003 to 2012. A total of 803,949 patients age 18 years or older were identified by ICD-9CM procedure codes for spinal fusion or decompression of the lumbar spine. Mortality was stratified based on type of procedure (simple or complex fusion, decompression), patient demographics and comorbidities, and in-hospital complications. Binary logistic regression was used to identify the risk of death while controlling for comorbidities, race, sex, and procedure performed. Significance was defined as P < .05 differences relative to the overall cohort. RESULTS: Mortality for all patients requiring surgery of the lumbar spine was 0.13%. Mortality based on procedure type was 0.105% for simple fusions, 0.321% for complex fusions, and 0.081% for decompression only. Increased mortality was observed demographically in patients who were male (odds ratio [OR]: 1.75; 95% confidence interval [CI]: 1.51-2.03), black (OR: 1.40; CI: 1.10-1.79), ages 65-74 (OR: 1.46; CI: 1.25-1.70), and age 75+ (OR: 2.70; CI: 2.30-3.17). Comorbidities associated with the greatest increase in mortality were mild (OR: 10.04; CI: 7.76-13.01) and severe (OR: 26.47; CI: 16.03-43.70) liver disease and congestive heart failure (OR: 4.57; CI: 3.77-5.53). The complications with the highest mortality rates were shock (OR: 20.67; CI: 13.89-30.56) and pulmonary embolism (OR: 20.15; CI: 14.01-29.00). CONCLUSIONS: From 2003 to 2012, the overall mortality rate in 803,949 lumbar spine surgery patients was 0.13%. Risk factors that were significantly associated with increased mortality rates were male gender, black race, and ages 65-74 and 75+. Comorbidities associated with an increased mortality rate were mild and severe liver disease and congestive heart failure. Inpatient complications with the highest mortality rates were shock and pulmonary embolism. These findings can be helpful to surgeons providing preoperative counseling for patients considering elective lumbar procedures and for allocating resources to treat and prevent perioperative complications leading to mortality. LEVEL OF EVIDENCE: 3.

Vertebral Osteomyelitis: A Comparison of Associated Outcomes in Early Versus Delayed Surgical Treatment.

BACKGROUND: 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: 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: A total of 34 465 patients were identified. Delayed groups were older (same day: 53.5 vs. 7-14-day delay: 61.1) and had a higher Deyo-Charlson score (same day: 0.4901 vs. 14-30-day delay: 1.66), length of stay (same day: 4.2 vs. 14-30-day delay: 34.04 days), and total charges (same day: $63,390.78 vs. 14-30-day delay: $245,752.4), all P < .001. Delayed groups had higher surgical combined-approach rates (same day: 9.1% vs. 14-30-day delay: 31.5%) and lower anterior-approach rates (same day: 42.4% vs. 14-30-day delay: 24.2%). Delayed groups had increased mortality and complication rates. Regressions showed delayed groups as the strongest independent indicators of any complication (14-30-day delay: odds ratio [OR] 3.384), mortality (14-30-day delay: OR 10.658), and neurologic deficits (14-30-day delay: OR 3.464), all P < .001. CONCLUSION: 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: III. CLINICAL RELEVANCE: Medically fit patients may benefit from earlier surgical management in order to reduce risk of postoperative complications, improve outcomes, and reduce overall hospital costs.

Predictors of Hospital Length of Stay and 30-Day Readmission in Cervical Spondylotic Myelopathy Patients: An Analysis of 3057 Patients Using the ACS-NSQIP Database.

BACKGROUND: Hospital length of stay (LOS), 30-day readmission rate, and other metrics are increasingly being used to evaluate quality of surgical care. The factors most relevant to cervical spondylotic myelopathy (CSM) are not yet established. OBJECTIVE: To identify perioperative factors associated with extended LOS and 30-day readmission following elective surgery for CSM. METHODS: Surgical CSM patients at institutions represented by the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) during 2010-2012 were included. Patients with fracture, 9 or more levels fused, or cancer were excluded. Extended LOS was defined as 75th percentile of the cohort. Univariate analysis and multivariate logistic regression identified predictors for extended LOS, 30-day readmission, and reoperation. Linear regression modeling was used to evaluate variables. RESULTS: Three thousand fifty-seven surgical CSM cases were isolated. Age (odds ratio [OR], 1.496), diabetes (OR, 1.691), American Society of Anesthesiologists (ASA) class (OR, 2.081), posterior surgical approach (OR, 2.695), and operative time (OR, 1.008) were all positive predictors (P < 0.05) for extended LOS (≥4 days). Thirty-two percent of the cohort (976 patients) had 30-day readmission data. Among these, 915 patients were not readmitted (93.8%), while 61 (6.2%) were readmitted. Diabetes (OR, 1.460) and ASA class (OR, 2.539) were significant positive predictors for hospital readmission. Age (OR, 0.918) was a negative predictor of re-operation in readmitted patients, and pulmonary comorbidities (OR, 4.584) were a positive predictor (P < 0.05). CONCLUSIONS: Patients with diabetes and higher ASA class were at increased risk for extended LOS and readmission within 30-days. Patients with increased operative time have greater risk for extended LOS. Preoperative pulmonary comorbidities increased reoperation risk, whereas increased age reduced the risk. Attention to these factors may benefit CSM patients.

Adverse Outcomes and Prediction of Cardiopulmonary Complications in Elective Spine Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: 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: 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: 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: 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.

Arm Pain Versus Neck Pain: A Novel Ratio as a Predictor of Post-Operative Clinical Outcomes in Cervical Radiculopathy Patients.

BACKGROUND: Informed patient selection and counseling is key in improving surgical outcomes. Understanding the impact that certain baseline variables can have on postoperative outcomes is essential in optimizing treatment for certain symptoms, such as radiculopathy from cervical spine pathologies. The aim was to identify baseline characteristics that were related to improved or worsened postoperative outcomes for patients undergoing surgery for cervical spine radiculopathic pain. METHODS: Retrospective review of prospectively collected data. Patient Sample: Surgical cervical spine patients with a diagnosis classification of "degenerative." Diagnoses included in the "degenerative" category were those that caused radiculopathy: cervical disc herniation, cervical stenosis, and cervical spondylosis without myelopathy. Baseline variables considered as predictors were: (1) age, (2) body mass index (BMI), (3) gender, (4) history of cervical spine surgery, (5) baseline Neck Disability Index (NDI) score, (6) baseline SF-36 Physical Component Summary (PCS) scores, (7) baseline SF-36 Mental Component Summary (MCS) scores, (8) Visual Analog Scale (VAS) Arm score, and (9) VAS Neck. Outcome Measures: Improvement in NDI (≥50%), VAS Arm/Neck (≥50%), SF-36 PCS/MCS (≥10%) scores at 2-years postoperative. An arm-to-neck ratio (ANR) was also generated from baseline VAS scores. Univariate and multivariate analyses evaluated predictors for 2-year postoperative outcome improvements, controlling for surgical complications and technique. RESULTS: Three hundred ninety-eight patients were included. Patients with ANR ≤ 1 (n = 214) were less likely to reach improvements in 2-year NDI (30.0% vs 39.2%, P = .050) and SF-36 PCS (42.4% vs 53.5%, P = .025). Multivariate analysis for neck disability revealed higher baseline SF-36 PCS (odds ratio [OR] 1.053) and MCS (OR 1.028) were associated with over 50% improvements. Higher baseline NDI were reduced odds of postoperative neck pain improvement (OR 0.958). Arm pain greater than neck pain at baseline was associated with both increased odds of postoperative arm pain improvement (OR 1.707) and SF36 PCS improvement (OR 1.495). CONCLUSIONS: This study identified specific symptom locations and health-related quality of life (HRQL) scores, which were associated with postoperative pain and disability improvement. In particular, baseline arm pain greater than neck pain was determined to have the greatest impact on whether patients met at least 50% improvement in their upper body pain score. These findings are important for clinicians to optimize patient outcomes through effective preoperative counseling.