Faculty Bibliography

Background/UNASSIGNED:The study aims to evaluate differences in alignment and clinical outcomes between surgical cervical deformity (CD) patients with a subaxial upper-most instrumented vertebra (UIV) and patients with a UIV at C2. Use of CD-corrective instrumentation in the subaxial cervical spine is considered risky due to narrow subaxial pedicles and vertebral artery anatomy. While C2 fixation provides increased stability, the literature lacks guidelines indicating extension of CD-corrective fusion from the subaxial spine to C2. Methods/UNASSIGNED:Included: operative CD patients with baseline (BL) and 1-year postop (1Y) radiographic data, cervical UIV ≥ C2. Patients were grouped by UIV: C2 or subaxial (C3-C7) and propensity score matched (PSM) for BL cSVA. Mean comparison tests assessed differences in BL and 1Y patient-related, radiographic, and surgical data between UIV groups, and BL-1Y changes in alignment and clinical outcomes. Results/UNASSIGNED:. 6.2°). Between UIV groups, there were no differences in BL-1Y changes in HRQLs, overall complication rates, or operative complication rates (all P>0.05). Conclusions/UNASSIGNED:C2 UIV patients showed similar cervical range of motion and baseline to 1-year functional outcomes as patients with a subaxial UIV. C2 UIV patients also showed greater baseline to 1-year horizontal gaze improvement and had complication profiles similar to subaxial UIV patients, demonstrating the radiographic benefit and minimal functional loss associated with extending fusion constructs to C2. In the treatment of adult cervical deformities, extension of the reconstruction construct to the axis may allow for certain clinical benefits with less morbidity than previously acknowledged.

This study sought to assess comorbidity profiles unique to early-onset-scoliosis (EOS) patients by employing cluster analytics and to determine the influence of isolated comorbidity clusters on perioperative complications, morbidity and mortality using a high powered administrative database. The KID database was queried for ICD-9 codes pertaining to congenital and idiopathic scoliosis from 2003, 2006, 2009, 2012. Patients <10 y/o (EOS group) were included. Demographics, incidence and comorbidity profiles were assessed. Comorbidity profiles were stratified by body systems (neurological, musculoskeletal, pulmonary, cardiovascular, renal). K-means cluster and descriptive analyses elucidated incidence and comorbidity relationships between frequently co-occurring comorbidities. Binary logistic regression models determined predictors of perioperative complication development, mortality, and extended length-of-stay (≥75th percentile). 25,747 patients were included (Age: 4.34, Female: 52.1%, CCI: 0.64). Incidence was 8.9 per 100,000 annual discharges. 55.2% presented with pulmonary comorbidities, 48.7% musculoskeletal, 43.8% neurological, 18.6% cardiovascular, and 11.9% renal; 38% had concurrent neurological and pulmonary. Top inter-bodysystem clusters: Pulmonary disease (17.2%) with epilepsy (17.8%), pulmonary failure (12.2%), restrictive lung disease (10.5%), or microcephaly and quadriplegia (2.1%). Musculoskeletal comorbidities (48.7%) with renal and cardiovascular comorbidities (8.2%, OR: 7.9 [6.6-9.4], p < 0.001). Top intra-bodysystem clusters: Epilepsy (11.7%) with quadriplegia (25.8%) or microcephaly (20.5%). Regression analysis determined neurological and pulmonary clusters to have a higher odds of perioperative complication development (OR: 1.28 [1.19-1.37], p < 0.001) and mortality (OR: 2.05 [1.65-2.54], p < 0.001). Musculoskeletal with cardiovascular and renal anomalies had higher odds of mortality (OR: 1.72 [1.28-2.29], p < 0.001) and extLOS (OR: 2.83 [2.48-3.22], p < 0.001). EOS patients with musculoskeletal conditions were 7.9x more likely to have concurrent cardiovascular and renal anomalies. Clustered neurologic and pulmonary anomalies increased mortality risk by as much as 105%. These relationships may benefit pre-operative risk assessment for concurrent anomalies and adverse outcomes. Level of Evidence: III - Retrospective Prognostic Study.

The Clavien-Dindo grading allows for broad comparison of perioperative surgical complications, and a temporal analysis of complications following ASD-corrective surgery. NSQIP database was utilized from 2010 to 2014 to isolate patients. Complications were stratified by Clavien complication (Cc) grade, and patients grouped by highest Cc grade: I, II, III, IV, V. Secondary analysis grouped by minor (I, II, III) and severe (IV, V). Comorbidity burden was assessed with a NSQIP-modified Charlson Comorbidity Index (CCI) and frailty was measured with a 5-factor modified frailty index (mFI). From 2010 to 2014, 2971 patients (57 yrs, 58% F) underwent surgery for ASD (3.4 ± 4.1 levels; surgical approach: 46% anterior, 44% posterior, 10% combined), the rate of which increased 0.01% to 0.13. 32% suffered >1 complication. Patient breakdown by Cc grade: 0% I, 25% II, 3% III, 4% IV, 1% V. Severe Cc patients were more comorbid than minor Cc (CCI 2.8 vs 1.8), had longer operative times (394 min vs 251), and higher rates of osteotomy (29% vs 13%) and iliac fixation (16% vs 5%). Overall CCI (2.1-1.7) and perioperative complication rates (55-29%) decreased, despite increasing surgical invasiveness (2.8-4.5) and increasing frailty score (0.14 ± 0.15 vs 0.16 ± 0.16). Rates of Clavien grade II (39.80-22.20%) and IV (9.40-3.50%) complications also decreased, indicative of surgical improvements and effective preoperative patient selection. The decrease in CCI and increase in the modified frailty score may show that we are becoming more cognizant of discerning of comorbidities, but likely to not to have taken into account frailty, which may have an impact on future health socioeconomics.

STUDY DESIGN/METHODS:Retrospective review OBJECTIVE.: Develop a simplified frailty index for CD patients SUMMARY OF BACKGROUND DATA.: To improve preoperative risk stratification for surgical cervical deformity (CD) patients, a CD frailty index (CD-FI) incorporating 40 health deficits was developed. While novel, the CD-FI is clinically impractical due to the large number of factors needed for its calculation. To increase clinical utility, a simpler, modified CD-FI (mCD-FI) is necessary. METHODS:CD patients (C2-C7 Cobb>10°, CL>10°, cSVA>4 cm, or CBVA>25°) >18yr with preoperative CD-FI component factors. Pearson bivariate correlation assessed relationships between component deficits of the CD-FI and overall CD-FI score. Top deficits contributing to CD-FI score were included in multiple stepwise regression models. Deficits from model with largest R were dichotomized, and the mean score of all deficits calculated, resulting in mCD-FI score from 0 to 1. Patients were stratified by mCD-FI: Not Frail (NF, <0.3), Frail (0.3-0.5), Severely Frail (SF, >0.5). Means comparison tests established correlations between frailty category and clinical outcomes. RESULTS:Included: 121 CD patients (61 ± 11yr, 60%F). Multiple stepwise regression models identified 15 deficits as responsible for 86% of the variation in CD-FI; these factors were used to construct the mCD-FI. Overall, mean mCD-FI was 0.31 ± 0.14. Breakdown of patients by mCD-FI category: NF: 47.9%, Frail: 46.3%, SF: 5.8%. Compared to NF and Frail, SF patients had the longest inpatient hospital stays (P = 0.042), as well as greater baseline neck pain (P = 0.033), inferior NDI scores (P<0.001) and inferior EQ-5D scores (P < 0.001). Frail patients had higher odds of superficial infection (OR:1.1[1.0-1.2]), and SF patients had increased odds of mortality (OR:8.3[1.3-53.9]). CONCLUSIONS:Increased frailty, assessed by mCD-FI, correlated with increased length of stay, neck pain, and decreased health-related quality of life. Frail patients were at greater risk for infection, and severely frail patients had greater odds of mortality. This relationship between frailty and clinical outcomes suggests that mCD-FI offers clinical utility as a preoperative risk stratification tool. LEVEL OF EVIDENCE/METHODS:3.

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.

We developed a predictive model to describe risk factors for complications in cervical deformity surgeries. Cervical deformity (CD) surgical patients are growing in number, but remain under-studied in the literature. CD was defined as at least one of the following: C2-C7 Cobb >10°, CL >10°, cSVA >4 cm, CBVA >25°. Patient demographics and clinical data were assessed as risk factors for medical/surgical complications using multivariate regression models. 123 patients underwent CD surgery (60.6 yrs, 60.8% F). The most common complications were neurologic (24.4%), dysphagia (13.0%), cardiopulmonary (11.4%), infection (9.7%). 51 (41.5%) of patients experienced a medical complication and 73 (59.3%) had a surgical complication. An overall complication was predicted with high accuracy (AUC = 0.79) by the following combinations of factors: higher baseline EQ5D pain and lower baseline EQ5D anxiety/depression scores, and higher cervical and global SVA. A medical complication can be predicted by male gender, baseline mJOA score, and cervical SVA (AUC = 0.770). A surgical complication can be predicted by higher estimated blood loss, lower anxiety scores, and larger global SVA (AUC = 0.739). 64.2% of patients undergoing cervical deformity correction sustained any complication. While the most reliable predictor of the occurrence of a complication involved a cluster of risk factors, a radiographic baseline sagittal parameter of cervical SVA was the strongest isolated predictor for complications across categories. Although these findings are specific to a cervical population with moderate to severe deformities, collectively they can be utilized for pre-operative risk assessment and patient education.

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.

Introduction/UNASSIGNED:This study assessed the incidence and risk factors for pseudarthrosis among primary spine fusion patients. Methods/UNASSIGNED:-tests. Binary logistic regression assessed patient-related and procedure-related predictors for pseudarthrosis. Results/UNASSIGNED:=0.026). Conclusions/UNASSIGNED:Alcoholism and surgical revision are major risk factors for pseudarthrosis in patients undergoing spine fusion.

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.