Samantha R. Horn

Comparative analysis of perioperative complications between a multicenter prospective cervical deformity database and the Nationwide Inpatient Sample database

BACKGROUND CONTEXT Complication rates for adult cervical deformity are poorly characterized given the complexity and heterogeneity of cases. PURPOSE To compare perioperative complication rates following adult cervical deformity corrective surgery between a prospective multicenter database for patients with cervical deformity (PCD) and the Nationwide Inpatient Sample (NIS). STUDY DESIGN/SETTING Retrospective review of prospective databases. PATIENT SAMPLE A total of 11,501 adult patients with cervical deformity (11,379 patients from the NIS and 122 patients from the PCD database). OUTCOME MEASURES Perioperative medical and surgical complications. METHODS The NIS was queried (2001-2013) for cervical deformity discharges for patients ≥18 years undergoing cervical fusions using International Classification of Disease, Ninth Revision (ICD-9) coding. Patients ≥18 years from the PCD database (2013-2015) were selected. Equivalent complications were identified and rates were compared. Bonferroni correction (p<.004) was used for Pearson chi-square. Binary logistic regression was used to evaluate differences in complication rates between databases. RESULTS A total of 11,379 patients from the NIS database and 122 patiens from the PCD database were identified. Patients from the PCD database were older (62.49 vs. 55.15, p<.001) but displayed similar gender distribution. Intraoperative complication rate was higher in the PCD (39.3%) group than in the NIS (9.2%, p<.001) database. The PCD database had an increased risk of reporting overall complications than the NIS (odds ratio: 2.81, confidence interval: 1.81-4.38). Only device-related complications were greater in the NIS (7.1% vs. 1.1%, p=.007). Patients from the PCD database displayed higher rates of the following complications: peripheral vascular (0.8% vs. 0.1%, p=.001), gastrointestinal (GI) (2.5% vs. 0.2%, p<.001), infection (8.2% vs. 0.5%, p<.001), dural tear (4.1% vs. 0.6%, p<.001), and dysphagia (9.8% vs. 1.9%, p<.001). Genitourinary, wound, and deep veinthrombosis (DVT) complications were similar between databases (p>.004). Based on surgicalapproach, the PCD reported higher GI and neurologic complication rates for combined anterior-posterior procedures (p<.001). For posterior-only procedures, the NIS had more device-related complications (12.4% vs. 0.1%, p=.003), whereas PCD had more infections (9.3% vs. 0.7%, p<.001). CONCLUSIONS Analysis of the surgeon-maintained cervical database revealed higher overall and individual complication rates and higher data granularity. The nationwide database may underestimate complications of patients with adult cervical deformity (ACD) particularly in regard to perioperative surgical details owing to coding and deformity generalizations. The surgeon-maintained database captures the surgical details, but may underestimate some medical complications.

Cervical spondylotic myelopathy: National trends in the treatment and peri-operative outcomes over 10 years

BACKGROUND Recent studies show increases in cervical spine surgery prevalence and cervical spondylotic myelopathy (CSM) diagnoses in the US. However, few studies have examined outcomes for CSM surgical management, particularly on a nationwide scale. OBJECTIVE Evaluate national trends from 2001 to 2010 for CSM patient surgical approach, postoperative outcomes, and hospital characteristics. METHODS A retrospective nationwide database analysis provided by the Nationwide Inpatient Sample (NIS) including CSM patients aged 25+ who underwent anterior and/or posterior cervical fusion or laminoplasty from 2001 to 2010. Patients with fractures, 9+ levels fused, or any cancer were excluded. Measures included demographics, hospital data, and procedure-related complications. Yearly trends were analyzed using linear regression modeling. RESULTS 54,348 discharge cases were identified. ACDF, posterior only, and combined anterior/posterior approach volumes significantly increased from 2001 to 2010 (98.62%, 303.07%, and 576.19%; respectively, p<0.05). However, laminoplasty volume remained unchanged (p>0.05). Total charges for ACDF, posterior only, combined anterior/posterior, and laminoplasty approaches all significantly increased (138.72%, 176.74%, 182.48%, and 144.85%, respectively; p<0.05). For all procedures, overall mortality significantly decreased by 45.34% (p=0.001) and overall morbidity increased by 33.82% (p=0.0002). For all procedures except ACDF, which saw a significantly decrease by 8.75% (p<0.0001), length of hospital stay was unchanged. CONCLUSIONS For CSM patients between 2001 and 2010, combined surgical approach increased sixfold, posterior only approach increased threefold, and ACDF doubled; laminoplasties without fusion volume remained the same. Mortality decreased whereas morbidity and total charges increased. Length of stay decreased only for ACDF approach. This study provides clinically useful data to direct future research, improving patient outcomes.

A novel index for quantifying the risk of early complications for patients undergoing cervical spine surgeries

OBJECTIVE It is becoming increasingly necessary for surgeons to provide evidence supporting cost-effectiveness of surgical treatment for cervical spine pathology. Anticipating surgical risk is critical in accurately evaluating the risk/benefit balance of such treatment. Determining the risk and cost-effectiveness of surgery, complications, revision procedures, and mortality rates are the most significant limitations. The purpose of this study was to determine independent risk factors for medical complications (MCs), surgical complications (SCs), revisions, and mortality rates following surgery for patients with cervical spine pathology. The most relevant risk factors were used to structure an index that will help quantify risk and anticipate failure for such procedures. METHODS The authors of this study performed a retrospective review of the National Inpatient Sample (NIS) database for patients treated surgically for cervical spine pathology between 2001 and 2010. Multivariate models were performed to calculate the odds ratio (OR) of the independent risk factors that led to MCs and repeated for SCs, revisions, and mortality. The models controlled for age (< and > 65 years old), sex, race, revision status (except for revision analysis), surgical approach, number of levels fused/re-fused (2-3, 4-8, ≥ 9), and osteotomy utilization. ORs were weighted based on their predictive category: 2 times for revision surgery predictors and 4 times for mortality predictors. Fifty points were distributed among the predictors based on their cumulative OR to establish a risk index. RESULTS Discharges for 362,989 patients with cervical spine pathology were identified. The mean age was 52.65 years, and 49.47% of patients were women. Independent risk factors included medical comorbidities, surgical parameters, and demographic factors. Medical comorbidities included the following: pulmonary circulation disorder, coagulopathy, metastatic cancer, renal failure, congestive heart failure, alcohol abuse, neurological disorder, nonmetastatic cancer, liver disease, rheumatoid arthritis/collagen vascular diseases, and chronic blood loss/anemia. Surgical parameters included posterior approach to fusion/re-fusion, ≥ 9 levels fused/re-fused, corpectomy, 4-8 levels fused/re-fused, and osteotomy; demographic variables included age ≥ 65 years. These factors increased the risk of at least 1 of MC, SC, revision, or mortality (risk of death). A total of 50 points were distributed among the factors based on the cumulative risk ratio of every factor in proportion to the total risk ratios. CONCLUSIONS This study proposed an index to quantify the potential risk of morbidity and mortality prior to surgical intervention for patients with cervical spine pathology. This index may be useful for surgeons in patient counseling efforts as well as for health insurance companies and future socioeconomics studies in assessing surgical risks and benefits for patients undergoing surgical treatment of the cervical spine.

Cervical Alignment Changes in Patients Developing Proximal Junctional Kyphosis Following Surgical Correction of Adult Spinal Deformity

BACKGROUND Proximal junctional kyphosis (PJK) following adult spinal deformity (ASD) surgery is a well-documented complication, but associations between radiographic PJK and cervical malalignment onset remain unexplored. OBJECTIVE To study cervical malalignment in ASD surgical patients that develop PJK. METHODS Retrospective review of prospective multicenter database. Inclusion: primary ASD patients (≥5 levels fused, upper instrumented vertebra [UIV] at T2 or above, and 1-yr minimum follow-up) without baseline cervical deformity (CD), defined as ≥2 of the following criteria: T1 slope minus cervical lordosis < 20°, cervical sagittal vertical axis < 4 cm, C2-C7 cervical lordosis < 10°. PJK presence (<10° change in UIV and UIV + 2 kyphosis) and angle were identified 1 yr postoperative. Propensity score matching between PJK and nonPJK groups controlled for baseline alignment. Preoperative and 1-yr postoperative cervical alignment were compared between PJK and nonPJK patients. RESULTS One hundred sixty-three patients without baseline CD (54.9 yr, 83.9% female) were included. PJK developed in 60 (36.8%) patients, with 27 (45%) having UIV above T7. PJK patients had significantly greater baseline T1 slope in unmatched and propensity score matching comparisons (P < .05). At 1 yr postoperative, PJK patients had significantly higher T1 slope (P < .001), C2-T3 Cobb (P = .04), and C2-T3 sagittal vertical axis (P = .02). New-onset CD rate in PJK patients was 15%, and 16.5% in nonPJK patients (P > .05). Increased PJK magnitude was associated with increasing T1 slope and C2-T3 SVA (P < .05). CONCLUSION Patients who develop PJK following surgical correction of ASD have a 15% incidence of development of new-onset CD. Patients developing PJK following surgical correction of ASD tend to have an increased preoperative T1 slope. Increased progression of C2-T3 Cobb angle and C2-T3 SVA are associated with development of PJK following surgical correction of thoracolumbar deformity.

Epidemiology and national trends in prevalence and surgical management of metastatic spinal disease

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.

Two-Year Results of the Prospective Spine Treatment Outcomes Study: Analysis of Postoperative Clinical Outcomes Between Patients with and without a History of Previous Cervical Spine Surgery

OBJECTIVE History of previous cervical spine surgery is a frequently cited cause of worse outcomes after cervical spine surgery. The purpose of this study was to determine any differences in clinical outcomes after cervical spine surgery between patients with and without a history of previous cervical spine surgery. METHODS A multicenter prospective database was reviewed retrospectively to identify patients with cervical spondylosis undergoing surgery with a minimum 2-year follow-up. Patients were divided into 2 groups: patients with (W) or without (WO) previous history of cervical spine surgery. Statistical analyses of Health-Related Quality of Life scores were analyzed with statistical software to fit linear mixed models for continuous longitudinal outcome. RESULTS A total of 1286 patients (377 W, 909 WO) met criteria for inclusion. Overall, patients in both groups experienced an improvement in their Health-Related Quality of Life scores. However, patients in the W group had significantly decreased improvement compared with WO patients in the Neck Disability Index score and the following SF-36 domain scores: Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Health Transition, and Physical Component Summary at all time points (P < 0.05). There was no statistically significant difference between the W and WO groups in operative time, estimated blood loss, length of stay, or complications (P > 0.05). CONCLUSIONS Patients with a history of previous cervical spine surgery had inferior improvement in quality of life outcome scores. Patients with a history of previous surgical intervention who elect to undergo subsequent surgeries should be appropriately counseled about expected results.

The Influence of Body Mass Index on Achieving Age-Adjusted Alignment Goals in Adult Spinal Deformity Corrective Surgery with Full-Body Analysis at 1 Year

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.

Cost-utility analysis of cervical deformity surgeries using 1-year outcome

BACKGROUND CONTEXT Cost-utility analysis, a special case of cost-effectiveness analysis, estimates the ratio between the cost of an intervention to the benefit it produces in number of quality-adjusted life years. Cervical deformity correction has not been evaluated in terms of cost-utility and in the context of value-based health care. Our objective, therefore, was to determine the cost-utility ratio of cervical deformity correction. STUDY DESIGN This is a retrospective review of a prospective, multicenter cervical deformity database. Patients with 1-year follow-up after surgical correction for cervical deformity were included. Cervical deformity was defined as the presence of at least one of the following: kyphosis (C2-C7 Cobb angle >10°), cervical scoliosis (coronal Cobb angle >10°), positive cervical sagittal malalignment (C2-C7 sagittal vertical axis >4 cm or T1-C6 >10°), or horizontal gaze impairment (chin-brow vertical angle >25°). Quality-adjusted life years were calculated by both EuroQol 5D (EQ5D) quality of life and Neck Disability Index (NDI) mapped to short form six dimensions (SF6D) index. Costs were assigned using Medicare 1-year average reimbursement for: 9+ level posterior fusions (PF), 4-8 level PF, 4-8 level PF with anterior fusion (AF), 2-3 level PF with AF, 4-8 level AF, and 4-8 level posterior refusion. Reoperations and deaths were added to cost and subtracted from utility, respectively. Quality-adjusted life year per dollar spent was calculated using standardized methodology at 1-year time point and subsequent time points relying on maintenance of 1-year utility. RESULTS Eighty-four patients (average age: 61.2 years, 60% female, body mass index [BMI]: 30.1) were analyzed after cervical deformity correction (average levels fused: 7.2, osteotomy used: 50%). Costs associated with index procedures were 9+ level PF (

Differences in primary and revision deformity surgeries: following 1,063 primary thoracolumbar adult spinal deformity fusions over time

76,617), 4-8 level PF (

Developments in the treatment of Chiari type 1 malformations over the past decade

40,596), 4-8 level PF with AF (