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Myocardial infarction (MI), and its predictive factors, has been an understudied complication following spine operations. The objective was to assess the risk factors for perioperative MI in elective spine surgery patients as a retrospective case control study. Elective spine surgery patients with a perioperative MI were isolated in the NSQIP. The relationship between MI and non-MI spine patients was assessed using chi-squared and independent samples t-tests. Univariate/multivariate analyses assessed predictive factors of MI. Logistic regression with stepwise model selection was employed to create a model to predict MI occurrence. The study included 196,523 elective spine surgery patients (57.1 yrs, 48%F, 30.4 kg/m

Multidisciplinary patient-reported outcomes are a critical part of assessing patients to better understand their well-being during treatment. The use of multidisciplinary patient-reported outcomes is recommended in many areas of medicine. The Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29) has been utilized as a common measurement language across universally relevant domains, including pain, mood, sleep, social participation, and function. Retrospective analysis of prospectively collected data was performed. Subjects were identified and consecutively enrolled upon entry into chronic pain centers across 24 sites in the United States. The PROMIS-29 v2.1 and the numerical rating scale (NRS) were recorded. The pain impact score and the Health Utilities Index Mark 3 (HUI-3) were calculated. Statistical differences were assessed between genders and among age groups comprising subjects less than 40, 41–60, 61–80, and over 80 years of age. A total of 19,546 patients were assessed over the enrollment period from 2018 to 2020. The PROMIS-29 v2.1 was evaluated across the seven domains, along with the numerical rating sale (NRS). The mean scores of the population for PROMIS SF v1.0 Pain Interference 4a, PROMIS SF v1.0 Sleep Disturbance 4a, PROMIS SF v1.0 Fatigue 4a, PROMIS SF v1.0 Anxiety 4a, PROMIS SF V1.0 Depression 4a, PROMIS SF v2.0 Ability to Participate in Social Roles and Activities 4a, and PROMIS SF v1.0 Physical Function 4a, measuring pain interference, sleep disturbance, fatigue, anxiety, depression, social participation, and physical function, were 64.61, 57.19, 58.50, 53.94, 54.45, 40.06, and 36.23, respectively. Pain intensity was 6.38 on an 11-point NRS scale. The pain impact score (PIS) and health utilities index mark 3 (HUI-3) scores, calculated across the designated age groups, were 33.19 and 0.67, respectively. Statistical differences were observed for the domains of sleep disturbance and physical function for age groups less than 40 and greater than 80 years of age. This data set is the first published normative data set describing the PROMIS-29 assessment in the chronic pain population. The patient population is more homogeneous than expected, and females were found to have higher levels of dysfunction.

Psychiatric diagnoses (PD) present a significant burden on elective surgery patients and may have potentially dramatic impacts on outcomes. As ailments of the spine can be particularly debilitating, the effect of PD on outcomes was compared between elective spine surgery patients and other common elective orthopedic surgery procedures. This study included 412,777 elective orthopedic patients who were concurrently diagnosed with PD within the years 2005 to 2016. 30.2% of PD patients experienced a post-operative complication, compared to 25.1% for non-PD patients (p 0.001). Mood Disorders (bipolar or depressive disorders) were the most commonly diagnosed PD for all elective Orthopedic procedures, followed by anxiety, then dementia (p 0.001). Logistic regression analysis found PD to be a significant predictor of higher cost to charge ratio (CCR), length of stay (LOS), and death (all p 0.001). Between, hand, elbow, and shoulder specialties, spine patients had the highest odds of increased CCR and unfavorable discharge, and the second highest odds of death (all p 0.001).

BACKGROUND CONTEXT Numerous advances have been made in the field of spine fusion, such as minimally invasive (MIS) or robotic-assisted spine surgery. However, it is unknown how these advances have impacted the cost of care. PURPOSE Compare the economic outcomes of lumbar spine fusion between open, MIS, and robot-assisted surgery patients. STUDY DESIGN/SETTING Retrospective review of a single center spine surgery database. PATIENT SAMPLE Three hundred sixty propensity matched patients. OUTCOME MEASURES Costs, EuroQol-5D (EQ5D), cost per quality adjusted life years (QALY). METHODS Inclusion criteria: surgical patients >18 years undergoing lumbar fusion surgery. Patients were categorized into 3 groups based on procedure type: open, MIS, or robotic. Open patients undergoing poster spinal fusion were considered as the control group. MIS patients included those undergoing transforaminal or lateral lumbar interbody fusion with percutaneous screws. Robotic patients were those undergoing robot-assisted fusion. Propensity score matching was performed between all groups for the number of levels fused. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims for ICD-9 codes. For robotic cases, costs were reflective of operational fees and initial purchase cost. Complications and comorbidities and major complications and comorbidities were assessed according to CMS.gov manual definitions. QALYs and cost per QALY were calculated using a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs per QALY were calculated for both 1 year and life expectancy, assuming no loss of benefit. A 10,000 trial Monte Carlo simulation with probabilistic sensitivity analysis (PSA) assessed our model parameters and costs. RESULTS Three hundred sixty propensity matched patients (120 open, 120 MIS, 120 robotic) met inclusion criteria. Descriptive statistics for the cohort were: age 58.8±13.5, 50% women, BMI 29.4±6.3, operative time 294.4±119.0, LOS 4.56±3.31 days, estimated blood loss 515.9±670.0 cc, and 2.3±2.2 average levels fused. Rates of post-op complications were significantly higher in robotic cases versus open and MIS (43% vs. 21% and 22% for open and MIS, p .05). After factoring in complications, revisions, and purchasing and operating fees, the costs of robotic cases was significantly higher than both open and MIS surgery ($60,047.01 vs. $42,538.98 open and $41,471.21 MIS). In a subanalysis of 42 patients with baseline (BL) and 1Y EQ5D data, the cost per QALY at 1Y for open, MIS, and robot-assisted cases was $296,624.48, $115,911.69, and $592,734.30. If utility gained was sustained to life expectancy, the cost per QALY was $14,905.75, $5,824.71, $29,785.64 for open, MIS, and robot-assisted cases. Results of the PSA were consistent with MIS surgery having the most incremental cost effectiveness when compared to open and robotic surgery. CONCLUSIONS Numerous advances have been made in the field of spine surgery, however, there has been limited discussion of the effect these advances have on economic outcomes. When matched for levels fused, robot-assisted surgery patients had significantly higher rates of complications and 30% higher costs of surgery compared to minimally invasive and open spine surgery patients. While 1 year economic outcomes were not optimal for robotic surgery cases, the projected costs per QALYs at life expectancy were well below established acceptable thresholds. The above findings may be reflective of an educational learning curve and emerging surgical technologies undergoing progressive refinement.

Background: Adolescent idiopathic scoliosis (AIS) is a common cause of spinal deformity in adolescents. AIS can be associated with certain intraspinal anomalies such as syringomyelia (SM). This study assessed the rate o f SM in AIS patients and compared trends in surgical approach and postoperative outcomes in AIS patients with and without SM. Methods: The database was queried using ICD-9 codes for AIS patients from 2003–2012 (737.1–3, 737.39, 737.8, 737.85, and 756.1) and SM (336.0). The patients were separated into two groups: AIS-SM and AIS-N. Groups were compared using t-tests and Chi-squared tests for categorical and discrete variables, respectively. Results: Totally 77,183 AIS patients were included in the study (15.2 years, 64% F): 821 (1.2%) – AIS-SM (13.7 years, 58% F) and 76,362 – AIS-N (15.2 years, 64% F). The incidence of SM increased from 2003–2012 (0.9 to 1.2%, P = 0.036). AIS-SM had higher comorbidity rates (79 vs. 56%, P < 0.001). Comorbidities were assessed between AIS-SM and AIS-N, demonstrating significantly more neurological and pulmonary in AIS-SM patients. 41.2% of the patients were operative, 48% of AIS-SM, compared to 41.6% AIS-N. AIS-SM had fewer surgeries with fusion (anterior or posterior) and interbody device placement. AIS-SM patients had lower invasiveness scores (2.72 vs. 3.02, P = 0.049) and less LOS (5.0 vs. 6.1 days, P = 0.001). AIS-SM patients underwent more routine discharges (92.7 vs. 90.9%). AIS-SM had more nervous system complications, including hemiplegia and paraplegia, brain compression, hydrocephalous and cerebrovascular complications, all P < 0.001. After controlling for respiratory, renal, cardiovascular, and musculoskeletal comorbidities, invasiveness score remained lower for AIS-SM patients (P < 0.001). Conclusions: These results indicate that patients concordant with AIS and SM may be treated more cautiously (lower invasiveness score and less fusions) than those without SM.

Obesity has risen to epidemic proportions within the United States. As the rates of obesity have increased, so has its prevalence among patients undergoing adult spinal deformity (ASD) surgery. The effect of obesity on the cost efficiency of corrective procedures for ASD has not been effectively evaluated.To investigate differences in cost efficiency of ASD surgery for patients stratified by body mass index (BMI).Retrospective review of a single-center ASD database.Five hundred five ASD patients.Complications, revisions, costs, EuroQol-5D (EQ5D), quality-adjusted life years (QALYs), cost per QALY.ASD patients (scoliosis≥20°, SVA≥5 cm, PT≥25°, or TK ≥60°) ≥18, undergoing ≥4 level fusions were included. Patients were stratified into NIH-defined obesity groups based on their preoperative BMI: underweight 18.5(U), normal 18.5 to 24.9 (N), overweight 25.0 to 29.9 (O), obese I 30.0 to 34.9 (OI), obese II 35.0 to 39.9 (OII), and obesity class III 40.0+ (OIII). Total surgery costs for each ASD obesity group were calculated. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims. Overall complications and major complications were assessed according to CMS definitions. QALYs and cost per QALY for obesity groups were calculated using an annual 3% discount up to life expectancy (78.7 years).In all, 505 patients met inclusion criteria. Baseline demographics and surgical details were: age 60.8±14.8, 67.6% female, BMI 28.8±7.30, 81.0% posterior approach, 18% combined approach, 10.1±4.2 levels fused, op time 441.2±146.1 minutes, EBL 1903.8±1594.7 cc, and LOS 8.7±10.7 days. There were 17 U, 154 N patients, 151 O patients, 100 OI, 51 OII, and 32 OIII patients. Revision rates by obesity group were: 0% U, 3% N patients, 3% O patients, 5% OI, 4% OII, and 6% for OIII patients. The total surgery costs by obesity group were: $48,757.86 U, $49,688.52 N, $47,219.93 O, $50,467.66 OI, $51,189.47 OII, and $53,855.79 OIII. In an analysis of patients with baseline and 1 Y EQ5D follow-up, the cost per QALY by obesity group was: $153,737.78 U, $229,222.37 N, $290,361.68 O, $493,588.47 OI, $327,876.21 OII, and $171,680.00 OIII. If that benefit was sustained to life expectancy, the cost per QALY was $8,588.70 U, $12,805.72 N, $16,221.32 O, $27,574.77 OI, $18,317.11 OII, and $9,591.06 for OIII.Among adult spinal deformity patients, those with BMIs in the obesity I, obesity II, or obesity class III range had more expensive total surgery costs. When assessing 1 year cost per QALY, obese patients had costs 32% higher than nonobese patients ($224,440.61 vs. $331,048.23). Further research is warranted on the utility of optimizing modifiable preoperative health factors for patients undergoing corrective adult spinal deformity surgery.

STUDY DESIGN Retrospective review. OBJECTIVE Identify co-occurring perioperative complications and associated predictors in a population of patients undergoing surgery for adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA Few studies have investigated the development of multiple, co-occurring complications following ASD-corrective surgery. Preoperative risk stratification may benefit from identification of factors associated with multiple, co-occurring complications. METHODS Elective ASD patients in National Surgical Quality Improvement Program (NSQIP) 2005 to 2016 were isolated; rates of co-occurring complications and affected body systems were assessed via cross tabulation. Random forest analysis identified top patient and surgical factors associated with complication co-occurrence, using conditional inference trees to identify significant cutoff points. Binary logistic regression indicated effect size of top influential factors associated with complication co-occurrence at each factor's respective cutoff point. RESULTS Included: 6486 ASD patients. The overall perioperative complication rate was 34.8%; 28.5% of patients experienced one complication, 4.5% experienced two, and 1.8% experienced 3+. Overall, 11% of complication co-occurrences were pulmonary/cardiovascular, 9% pulmonary/renal, and 4% integumentary/renal. By complication type, the most common co-occurrences were transfusion/urinary tract infection (UTI) (24.3%) and transfusion/pneumonia (17.7%). Surgical factors of operative time ≥400 minutes and fusion ≥9 levels were the strongest factors associated with the incidence of co-occurring complications, followed by patient-specific variables like American Society of Anesthesiologists (ASA) physical status classification grade ≥2 and age ≥65 years. Regression analysis further showed associations between increasing complication number and longer length of stay (LOS), (R2 = 0.202, P

STUDY DESIGN Single institution retrospective clinical review. OBJECTIVE To investigate the relationship between levels fused and clinical outcomes in patients undergoing open and minimally invasive surgical (MIS) lumbar fusion. SUMMARY OF BACKGROUND DATA Minimally invasive spinal fusion aims to reduce the morbidity associated with conventional open surgery. As multilevel arthrodesis procedures are increasingly performed using MIS techniques, it is necessary to weigh the risks and benefits of multilevel MIS lumbar fusion as a function of fusion length. METHODS Patients undergoing

Study Design: Retrospective cohort study of prospective patients undergoing minimally invasive lumbar fusion at a single academic institution. Objective: To assess differences in perioperative outcomes between primary and revision MIS (minimally invasive surgical) lumbar interbody fusion patients and compare with those undergoing corresponding open procedures. Methods: Patients ≥18 years old undergoing lumbar interbody fusion were grouped by surgical technique: MIS or open. Patients within each group were propensity score matched for comorbidities and levels fused. Patient demographics, surgical factors, and perioperative complication incidences were compared between primary and revision cases using means comparison tests, as appropriate. Results: Of the 214 lumbar interbody fusion patients included after propensity score matching, 44 (21%) cases were MIS, and 170 (79%) were open. For MIS patients, there were no significant differences between primary and revision cases in estimated blood loss (EBL; 344 vs 299 cm3, P = .682); however, primary cases had longer operative times (301 vs 246 minutes, P = .029). There were no differences in length of stay (LOS), intensive care unit LOS, readmission, and intraoperative or postoperative complications (all P > .05). For open patients, there were no differences between primary and revision cases in EBL ( P > .05), although revisions had longer operative times (331 vs 278 minutes, P = .018) and more postoperative complications (61.7% vs 23.8%, P < .001). MIS revision procedures were shorter than open revisions (182 vs 213 minutes, P = .197) with significantly less EBL (294 vs 965 cm3, P < .001), shorter inpatient and intensive care unit LOS, and fewer postoperative complications (all P < .05). Conclusions: Clinical outcomes of revision MIS lumbar interbody fusion were similar to those of primary surgery. Additionally, MIS techniques were associated with less EBL, shorter LOS, and fewer perioperative complications than corresponding open revisions.

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. Patients10 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 Retrospective cohort study. Objective This study aimed to evaluate the utility of the modified frailty index (mFI-5) in a population of patients undergoing spine surgery. Summary of background data The original modified frailty index (mFI-11) published as an American College of Surgeons National Surgical Quality Improvement Program 11-factor index was modified to mFI-5 after variables were removed from recent renditions. Methods Surgical spine patients were isolated using current procedural terminology codes. mFI-11 (11) and mFI-5 (5) were calculated from 2005 to 2012. mFI was determined by dividing the factors present by available factors. To assess correlation, Spearman rho was used. Predictive values of indices were generated by binary logistic regression. Patients were stratified into groups by mFI-5: not frail (NF, 0.5). Means comparison tests analyzed frailty and clinical outcomes. Results After calculating the mFI-5 and the mFI-11, Spearman rho between the two indices was 0.926(P 0.05). With increase in severity, postoperative rates of morbidities and complications increased. Conclusion The five-factor National Surgical Quality Improvement Program modified frailty index is an effective predictor of postoperative events following spine surgery. Severity of frailty score by the mFI-5 was associated with increased morbidity and mortality. The mFI-5 within a surgical spine population can reliably predict post-op complications. This tool is less cumbersome than mFI-11 and relies on readily accessible variables at the time of surgical decision-making.Level of Evidence: 3.

Study Design: Retrospective review of single institution. Objective: To assess the relationship between Patient-Reported Outcomes Measurement Information System (PROMIS) and Oswestry Disability Index (ODI) scores in thoracolumbar patients. Methods: Included: Patients ≥18 years with a thoracolumbar spine condition (spinal stenosis, disc herniation, low back pain, disc degeneration, spondylolysis). Bivariate correlations assessed the linear relationships between ODI and PROMIS (Physical Function, Pain Intensity, and Pain Interference). Correlation cutoffs assessed patients with high and low correlation between ODI and PROMIS. Linear regression predicted the relationship of ODI to PROMIS. Results: A total of 206 patients (age 53.7 ± 16.6 years, 49.5% female) were included. ODI correlated with PROMIS Physical Function ( r = −0.763, P < .001), Pain Interference ( r = 0.800, P < .001), and Pain Intensity ( r = 0.706, P < .001). ODI strongly predicted PROMIS for Physical Function ( R2 = 0.58, P < .001), Pain Intensity ( R2 = 0.50, P < .001), and Pain Interference ( R2 = 0.64, P < .001); however, there is variability in PROMIS that ODI cannot account for. ODI questions about sitting and sleeping were weakly correlated across the 3 PROMIS domains. Linear regression showed overall ODI score as accounting for 58.3% ( R2 = 0.583) of the variance in PROMIS Physical Function, 63.9% ( R2 = 0.639) of the variance in Pain Interference score, and 49.9% ( R2 = 0.499) of the variance in Pain Intensity score. Conclusions: There is a large amount of variability with PROMIS that cannot be accounted for with ODI. ODI questions regarding walking, social life, and lifting ability correlate strongly with PROMIS while sitting, standing, and sleeping do not. These results reinforce the utility of PROMIS as a valid assessment for low back disability, while indicating the need for further evaluation of the factors responsible for variation between PROMIS and ODI.

Study design Retrospective analysis of prospective data from the degenerative spondylolisthesis (DS) arm of the Spine Patient Outcomes Research Trial. Objective The aim of this study was to identify risk factors for reoperation in patients treated surgically for DS and compare outcomes between patients who underwent reoperation with nonreoperative patients. Summary of background data Several studies have examined outcomes following surgery for DS, but few have identified risk factors for reoperation. Methods Analysis included patients with neurogenic claudication (>12 weeks), clinical neurological signs, spinal stenosis, and DS on standing lateral x-rays. Univariate and multivariate analyses were used to investigate patient characteristics and risk factors. Treatment effects (TEs) were calculated and compared between study groups. Results Of 406 patients, 72% underwent instrumented fusion, 21% noninstrumented fusion, and 7% decompression alone. At 8 years, the reoperation rate was 22%, of which 28% occurred within 1 year, 54% within 2 years, 70% within 4 years, and 86% within 6 years. The reasons for reoperation included recurrent stenosis or progressive spondylolisthesis (45%), complications such as hematoma, dehiscence, or infection (36%), or new condition (14%). Reoperative patients were younger (62.2 vs. 65.3, P = 0.008). Significant risk factors were use of antidepressants (P = 0.008, hazard ratio [HR] 2.08) or having no neurogenic claudication upon enrollment (P = 0.02, HR 1.82). Patients who were smokers, diabetics, obese, or on workman's compensation were not at greater risk for reoperation. At 8-year follow-up, scores for SF-36 bodily pain (BP), Oswestry Disability Index, American Academy of Orthopaedic Surgeons/Modems version (ODI), and stenosis frequency index were better in nonreoperative patients. TE favored nonreoperative patients for SF-36 BP, physical function, ODI, Stenosis Bothersomeness Index, and satisfaction with symptoms (P Conclusion The incidence of reoperation for patients with DS was 22% 8 years following surgery. Patients with a history of no neurogenic claudication and patients taking antidepressants were more likely to undergo reoperation. Outcome scores and TE were more favorable in nonreoperative patients. Level of evidence 2.

STUDY DESIGN A retrospective review of a prospectively collected database, the Nationwide Inpatient Sample (NIS), years 2003 to 2012. OBJECTIVES The aim of this study was to examine trends in the management of scoliosis in elderly (age >75 yrs) patients from 2003 to 2012. SUMMARY OF BACKGROUND DATA Scoliosis incidence rises with increasing age, and age has been shown to be an independent risk factor for surgical complications in scoliosis surgery. Previous studies have displayed increasing surgical frequency on elderly scoliotic patients in the last decade, but have not investigated complications in the same years. METHODS ICD-9 coding identified elderly (age ≥75 yrs) patients with a primary diagnosis of scoliosis undergoing lumbar fusion or decompression. Analysis of variance (ANOVA) comparisons and linear trend analysis described changes from 2003 to 2012 in surgical invasiveness (Mirza scale: levels fused/decompressed/instrumented and by approach), intraoperative complications, and Charlson Comorbidity Index (CCI). Secondary outcome measures included cost and discharge outcomes. RESULTS Eight thousand one elderly patients with ASD from 2003 to 2012 were included for analysis. Fusion incidence increased on average 13.8% per year (P

There has been limited discussion as to whether spine surgery patients are benefiting from shorter in-patient hospital stays or if they are incurring higher rates of readmission and complications secondary to shortened length of stays. Included in this study were 237,446 spine patients >18yrs and excluding infection. Patients with Clavien Grade 5 complications in 2015 had the lowest mean time to readmission after initial surgery in all years at 12.44 ± 9.03 days. Pearson bivariate correlations between LOS ≤ 1 day and decreasing days to readmission was the strongest in 2016.). Logistic regression analysis found that LOS ≤ 1 day showed an overall increase in the odds of hospital readmission from 2012 to 2016 (2.29 [2.00–2.63], 2.33 [2.08–2.61], 2.35 [2.11–2.61], 2.27 [2.06–2.49], 2.33 [2.14–2.54], all p

The aim of this study was to investigate the cost utility of treating non-frail versus frail or severely frail adult spinal deformity (ASD) patients. 79 surgical ASD patients >18 years with available frailty and ODI data at baseline and 2-years post-surgery (2Y) were included. Utility data was calculated using the ODI converted to the SF-6D. QALYs utilized a 3% discount rate to account for decline to life expectancy (LE). Costs were calculated using the PearlDiver database. ICER was compared between non-operative (non-op.) and operative (op.) NF and F/SF patients at 2Y and LE. When compared to non-operative ASD, the ICER was $447,943.96 vs. $313,211.01 for NF and F/SF at 2Y, and $68,311.35 vs. $47,764.61 for NF and F/SF at LE. Frail and severely frail patients had lower cost per QALY compared to not frail patients at 2Y and life expectancy, and had lower ICER values when compared to a non-operative cohort of ASD patients. While these results support operative correction of frail and severely frail patients, it is important to note that these patients are often at worse baseline disability, which is closely related to frailty scores, and have more opportunity to improve postoperatively. Furthermore, there may be a threshold of frailty that is not operable due to the risk of severe complications that is not captured by this analysis. While future research should investigate economic outcomes at extended follow up times, these findings support the cost effectiveness of ASD surgery at all frailty states.

STUDY DESIGN This was a retrospective cohort study. OBJECTIVE The aim of this study was to investigate associations between time to surgical intervention and outcomes for central cord syndrome (CCS) patients. BACKGROUND As surgery is increasingly recommended for patients with neurological deterioration CCS, it is important to investigate the relationship between time to surgery and outcomes. MATERIALS AND METHODS CCS patients were isolated in Nationwide Inpatient Sample database 2005-2013. Patients were grouped by time to surgery: same-day, 1-day delay, 2, 3, 4-7, 8-14, and >14 days. Means comparison tests compared patient factors, perioperative complications, and charges across patient groups. Controlling for age, comorbidities, length of stay, and concurrent traumatic fractures, binary logistic regression assessed surgical timing associated with increased odds of perioperative complication, using same-day as reference group. RESULTS Included: 6734 CSS patients (64% underwent surgery). The most common injury mechanisms were falls (30%) and pedestrian accidents (7%). Of patients that underwent surgery, 52% underwent fusion, 30% discectomy, and 14% other decompression of the spinal canal. Breakdown by time to procedure was: 39% same-day, 16% 1-day, 10% 2 days, 8% 3 days, 16% 4-7 days, 8% 8-14 days, and 3% >14 days. Timing groups did not differ in trauma status at admission, although age varied: [minimum: 1 d (58±15 y), maximum: >14 d (63±13 y)]. Relative to other groups, same-day patients had the lowest hospital charges, highest rates of home discharge, and second lowest postoperative length of stay behind 2-day delay patients. Patients delayed >14 days to surgery had increased odds of perioperative cardiac and infection complications. Timing groups beyond 3 days showed increased odds of VTE and nonhome discharge. CONCLUSIONS CCS patients undergoing surgery on the same day as admission had lower odds of complication, hospital charges, and higher rates of home discharge than patients that experienced a delay to operation. Patients delayed >14 days to surgery were associated with inferior outcomes, including increased odds of cardiac complication and infection.

In the current value-based healthcare climate where spine surgery is shifting to the ambulatory setting, factors influencing postop length of stay (LOS) are important to surgeons and hospital administrators. Pre-op patient factors including diagnosis of radiculopathy and myelopathy have yet to be investigated in this context. Operative pts ≥ 18Y with primary diagnoses of cervical myelopathy (M), radiculopathy (R), or myeloradiculopathy (MR) were included and propensity score matched by invasiveness score (Mirza et al.). Top-quartile LOS was defined as extended. M&R patients were compared using Chi2 & independent t-tests. Univariate tests assessed differences in preop patient and surgical data in M&R pts and extended/non-extended LOS. Stepwise regression analysis explored factors predictive of LOS. 718 operative pts (54.5 yrs, 41.1%F, 29.1 kg/m2, mean CCI 1.11) included (177 M, 383 R, and 158 MR). After PSM, 345 patients remained (115 in each diagnosis). 102 patients had E-LOS (Avg: 5.96 days), 41 M patients (mean 7.1 days), 28 R (5.9 days), and 33 MR (4.6 days). Regression showed predictors of E-LOS in R pts (R2 = 0.532, p = 0.043): TS-CL, combined and posterior approach, LIV, UIV, op time, Lactated Ringer’s, postoperative complications. Predictors of E-LOS in M pts (R2 = 0.230, p

Study design A retrospective subgroup analysis was performed on surgically treated patients from the lumbar spinal stenosis (SpS) arm of the Spine Patient Outcomes Research Trial (SPORT), randomized, and observational cohorts. Objective To identify risk factors for reoperation in patients treated surgically for SpS and compare outcomes between patients who underwent reoperation with those who did not. Summary of background data SpS is one of the most common indications for surgery in the elderly; however, few long-term studies have identified risk factors for reoperation. Methods A post-hoc subgroup analysis was performed on patients from the SpS arm of the SPORT, randomized and observational cohorts. Baseline characteristics were analyzed between reoperation and no-reoperation groups using univariate and multivariate analysis on data 8 years postoperation. Results Of the 417 study patients, 88% underwent decompression only, 5% noninstrumented fusion, and 6% instrumented fusion. At the 8-year follow-up, the reoperation rate was 18%; 52% of reoperations were for recurrent stenosis or progressive spondylolisthesis, 25% for complication or other reason, and 16% for new condition. Of patients who underwent a reoperation, 42% did so within 2 years, 70% within 4 years, and 84% within 6 years. Patients who underwent reoperation were less likely to have presented with any neurological deficit (43% reop vs. 57% no reop, P = 0.04). Patients improved less at follow-up in the reoperation group (P Conclusion In patients undergoing surgical treatment for SpS, the reoperation rate at 8-year follow-up was 18%. Patients with a reoperation were less likely to have a baseline neurological deficit. Patients who did not undergo reoperation had better patient reported outcomes at 8-year follow-up compared with those who had repeat surgery. Level of evidence 2.

BACKGROUND CONTEXT In the current value-based health care climate where spinal surgery is shifting to the ambulatory setting, factors influencing postoperative patient length of stay (LOS) have significance to both surgeons and hospital administrators. Underlying patient factors including the diagnosis of radiculopathy and myelopathy have not been investigated in this context. PURPOSE Identify predictors extended LOS(E-LOS) between myelopathy(M), radiculopathy(R), and patients with both (MR). STUDY DESIGN/SETTING Retrospective review of a single-center stereographic database. PATIENT SAMPLE A total of 718 surgical cervical spine patients. OUTCOME MEASURES Postoperative LOS, patient factors, preoperative HRQL, complications, predictors of E-LOS. METHODS Surgical cervical spine patients ≥18yrs diagnosed with M or R primary diagnoses were isolated in the single-center Comprehensive Spine Quality Database (Quality). Patients were stratified by surgical approach: Anterior, Posterior or Combined. Top-quartile LOS values were labeled as extended. M and R patients were compared using chi-squared and independent samples t-tests, as appropriate. Univariate tests assessed differences in baseline patient-related and surgical data between M and R, and extended/non-extended LOS. Univariate/multivariate analyses were run to assess predictive factors of E-LOS in each diagnosis group. Regression with stepwise model selection was employed to explore factors potentially significant in predicting LOS. RESULTS A total of 718 patients (54.5 years, 41.1%F, 29.1kg/m2). Mean CCI score: 1.11. Within the cohort, 177 patients (24.7%) had a diagnosis of myelopathy, 383 (53.3%) radiculopathy, and 22% with a diagnosis of myeloradiculopathy. Patients with M primary diagnosis were significantly older (62.2 vs 49.8yrs, p CONCLUSIONS Independent of surgical approach, patients with a primary diagnosis of myelopathy, though older aged and higher comorbidity profile, had consistently longer overall postop LOS when compared to radiculopathy or myeloradiculopathy patients. The heightened risk in myelopathy patients for extended LOS should be considered when determining admission status for patients undergoing cervical spine surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The Roussouly Classification system of sagittal spinal shape and the SRS-Schwab adult spinal deformity (ASD) classification system have become important indicators of spine deformity. No prior studies have examined the outcomes of matching both Roussouly type and improving in Schwab modifiers postoperatively. PURPOSE Evaluate outcomes of matching Roussouly Type and improving in Schwab modifier following ASD surgery. STUDY DESIGN/SETTING Retrospective review of single-center ASD database. PATIENT SAMPLE A total of 103 ASD patients. OUTCOME MEASURES Roussouly types, Schwab modifiers, Health Related Quality of Life scores(HRQLs): Minimal Clinical Important Difference for ODI, EQ5D, VAS Leg B Type 2: PI 60°); (2) “current” Roussouly type (1: SS 45°), as previously published. One year (1Y) matched Roussouly: preoperative mismatched (Between ‘actual’ and ‘theoretical’ patients that matched at 1Y. Schwab modifiers at BL were identified: non-, moderate and severe deformity (0, +, ++) for PT, SVA, and PI-LL. Schwab improvement was defined as a decrease in a modifier at one year. RESULTS A total of 103 ASD patients (61.8yrs, 63.1%F, 30kg/m2). By surgical approach, 79.6% posterior, 10.7% combined, 2.9% anterior). Average levels fused: 4.6. BL breakdown of ‘current; Roussouly type: 28% Type 1, 25.3% Type 2, 32.0% Type 3, 14.7% Type 4. BL Roussouly mismatch: 65.3%. Breakdown BL Schwab modifiers: PT (0: 8.7%, +: 41.7%, ++: 49.5%), SVA (0: 29.7%, +: 20.3%, ++: 50%), PI-LL mismatch (0: 28.2%, +: 25.2%, ++: 46.6%). At one year, 19.2% of patients matched Roussouly target type, while according to Schwab modifiers, 12.6% improved in SVA, 42.7% in PI-LL, and 45.6% in PT. Patients who both met Roussouly type and improved in a Schwab by the modifiers: 9 PT (8.7%), 8 PI-LL (7.8%), 2 SVA (1.9%). There were 2 patients (1.9%) who met their Roussouly type and improved in all 3 Schwab modifiers. One year (1Y) matched Roussouly patients improved more in HRQLs (MCID for ODI, EQ5D, VAS Leg/Back Pain), when compared to mismatched Roussouly, but was not significant(P>0.05). Match Roussouly and improvement in PT Schwab met MCID for EQ5D significantly more (33.3% vs 10.6%, p=0.050). Matched Roussouly and PI-LL Schwab had more patients meet MCID for all HRQLs, yet none were significant, p>0.05. Matched Roussouly and improvement in SVA Schwab met MCID for ODI significantly more (p=0.024). CONCLUSIONS Patients who both matched Roussouly sagittal spinal type and improved in SRS-Schwab modifiers had superior patient-reported outcomes at 1-year. Utilizing both classification systems in surgical decision making can optimize postop patient outcomes. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Although epidural steroid injection (ESI) has been shown to provide adequate pain relief for degenerative spondylolisthesis patients in treatment regimens up to months, it remains unclear whether the use of ESI affects the rate of crossover from nonoperative to operative management. PURPOSE Investigate the relationship between epidural steroid injections and rates of surgical crossover for degenerative spondylolisthesis patients. STUDY DESIGN/SETTING Retrospective review of prospectively collected data from 13 spine centers. PATIENT SAMPLE Degenerative spondylolisthesis patients from both the randomized and concurrent observational cohorts of the Spine Patient Outcomes Research Trial (SPORT). OUTCOME MEASURES Primary: Surgical crossover rates. Secondary: health related quality of life outcome (HRQL) measures (SF-36, ODI, Sciatica and Leg Pain Bothersomeness Indices), self-reported improvement METHODS Included: surgical candidates >18yrs with degenerative spondylolisthesis. Excluded: patients receiving ESI before enrollment. Those who received ESI within 3 months of enrollment (ESI) and those who did not (no-ESI) were compared for differences in baseline characteristics. Outcomes at 1-year, 2-year, 3-year, and 4-year intervals following enrollment were assessed within operative and nonoperative groups using longitudinal mixed–effect models with random subject intercept term to account for correlations between repeated measurements. Treatment comparisons were performed at follow-up intervals. Area under the curve analysis for all time points assessed global significance of treatment. RESULTS Included: 266 patients (192 no-ESI, 74 ESI). Patient groups did not differ in age, sex, BMI, or comorbidity burden (all p>0.05). No-ESI had greater baseline SF-36 body-pain scores (38±20 vs 30±16, p=0.002) and self-reported surgical preference (38% vs 11%, p 0.05). Surgical ESI and no-ESI patients showed no differences in postoperative HRQL changes at any follow-up interval, or in 4-year average HRQL outcomes. Non-operative no-ESI patients showed greater 4-year average improvement in SF-36 body pain (no-ESI: 17.8, ESI: 7.8, p=0.004) and physical function (no-ESI: 13.1, ESI: 4.3, p=0.005) than non-operative ESI patients. These improvements in SF-36 body pain were greater for non-operative no-ESI patients at 1-year (p=0.002) and 3-years (p=0.005); improvements in SF-36 physical function were greater for non-operative no-ESI patients at 1-year (p=0.030) and 2-years (p=0.002). Of patients that were initially non-operative, there was no difference between ESI and no-ESI groups in surgical crossover rates (ESI: 52%, no-ESI: 39%, p=0.15). For operative patients, crossover rates to non-operative treatment did not differ between ESI and no-ESI groups (ESI: 23%, no-ESI: 16%, p=0.38). CONCLUSIONS For surgical degenerative spondylolisthesis patients, there was no relationship between ESI and improved clinical outcomes over a 4-year study. For nonoperative patients, ESI was associated with inferior pain reduction through 3 years of follow-up; however, this was confounded by higher levels of baseline pain. ESI showed little relationship with surgical crossover. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

BACKGROUND CONTEXT As surgery is increasingly recommended for patients with neurologic deterioration secondary to central cord syndrome (CCS), it is important to investigate the relationship between time to surgery and patient outcomes. The merits of early vs delayed surgical treatment remain controversial in the literature. PURPOSE Investigate associations between time to surgical intervention and surgical outcomes for CCS patients STUDY DESIGN/SETTING Retrospective review of Healthcare Cost and Utilization Project's Nationwide Inpatient Sample (NIS) PATIENT SAMPLE A total of 9,246 weighted inpatient discharges. OUTCOME MEASURES Complication rates, discharge destination, length of hospital stay (LOS). METHODS CCS patients (ICD-9 codes 952.03, 952.08, 952.13, 952.18) were isolated in the NIS database 2005-2013. Operative patients were grouped by time to intervention: same day as admission, 1-day delay, 2-day, 3-day, 4-7 days, 8-14 days, and >14 days. As appropriate, analysis of variance and chi-squared tests compared demographics, Charlson Comorbidity Index (CCI) scores, surgical details, LOS, discharge status, periop complications and total charges across patient groups. Controlling for age, CCI and concurrent traumatic fractures, binary logistic regression assessed surgical timing associated with increased odds of perioperative complication, using same-day patients as a reference group (odds ratio [95% confidence interval]). RESULTS Included: 6,734 CSS patients (59±16yrs, 26%F, mean CCI: 1.2±1.6). Overall rate of surgical treatment was 64.1%, with rates of surgery increasing from 2005 (50.0%) to 2013 (73.0%, p 14 days. Timing groups did not differ in trauma status at admission (shock or hemorrhage, p=0.261); however, age differed between groups (min: 1 day [58±15 years], max: >14 days [63±13 years], p 14 days to surgery had increased odds of periop cardiac (7.0 [1.6-30.0]) and infection (6.1 [2.2-16.3]) complications. All timing groups beyond 3 days showed increased odds of VTE: 4-7 days (3.0 [1.6-5.5]), 8-14 days (3.0 [1.4-6.3]), 14+ days (5.6 [2.3-13.6]). Same-day surgery was also associated with lower total hospital charges than delayed surgery ($87,741 vs $118,815-$272,901, p CONCLUSIONS Patients undergoing surgery for CCS on the same day as admission showed significantly lower odds of complication, hospital charges, and higher rates of discharge to home than patients that experienced a delay to operation. In contrast, patients delayed >14 days to surgery were associated with inferior outcomes, including increased odds of cardiac complication and infection. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Persistent lumbopelvic malalignment following ASD-corrective surgery may impair quality of life and result in persistent pathologic compensation in the lower extremities. Patient-specific age- and BMI-adjusted alignment targets have been proposed to improve alignment outcomes; however, it is unclear whether reaching these postop targets reduces rates of pelvic nonresponse following surgery. PURPOSE Assess the relationship between pelvic nonresponse to ASD-corrective surgery and persistent lower-extremity compensation. STUDY DESIGN/SETTING Single center retrospective review. PATIENT SAMPLE Fifty-eight ASD patients. OUTCOME MEASURES Sagittal alignment. METHODS Included: surgical ASD patients with full-spine X-ray imaging at pre- and early postop follow-up ( RESULTS Following propensity score matching, PNR (N=29) and PR (N=29) patients did not differ in age, sex, BMI or preop sagittal spinal alignment (all p>0.05); however, PNR patients presented with less knee flexion (9° vs 14°, p=0.043). Groups did not differ in levels fused (10.8 vs 10.8, p=0.974) or osteotomy (93% vs 92%, p=0.902). Postop, PNR patients had inferior lumbopelvic alignment in PT (30° vs 17°), PI-LL (17° vs 3°), and greater global malalignment for TPA (27° vs 15°, all p 0.05). For patients with severe preop SVA deformity, overcorrection relative to ideal postop PT targets was associated with lower rates of pelvic non-response (under: 12%, match: 18%, over: 71%, p CONCLUSIONS Pelvic nonresponders following ASD-corrective surgery had higher rates of persistent compensatory action in the lower extremities. Patients with severe preop PT deformity who were surgically overcorrected with respect to ideal PI-LL had lower rates of postop pelvic nonresponse, indicating that for severely malalignmed patients, existing alignment targets may need to be adjusted to optimize alignment outcomes. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The Miller et al adult spinal deformity frailty index (ASD-FI) correlates with increased complication risk after surgery; however, its development was not rooted in clinical outcomes, and the 40 factors needed for its calculation limit the index's utility in a clinical setting. PURPOSE Develop a simplified, weighted frailty index for ASD patients. STUDY DESIGN/SETTING Retrospective review of prospective ASD database. PATIENT SAMPLE A total of 50 ASD patients. OUTCOME MEASURES Health-related quality of life questionnaires: Oswestry Disability Index (ODI), SRS-22r, pain catastrophizing scale, Numerif Rating Scale (NRS) for Leg Pain. METHODS ASD patients (scoliosis≥20°, SVA≥5cm, PT≥25°, or TK ≥60°) with baseline ASD-FI component factors. Component ASD-FI parameters contributing to overall ASD-FI score were assessed via Pearson correlation. Top significant, clinically relevant factors were regressed against ASD-FI score to generate the modified ASD-FI (mASD-FI). Factors comprising the mASD-FI were regressed against the incidence of medical complications; weights for mASD-FI factors were calculated from these regression coefficients via the beta/Sullivan method. Total mASD-FI score was calculated by summing weights of expressed parameters, resulting in a score ranging from 0 to 21. Linear regression correlated ASD-FI and mASD-FI scores, and previously published ASD-FI cutoffs were used to generate corresponding mASD-FI frailty cutoffs: not frail (NF, 12). Analysis of variance assessed the relationship between increasing frailty category and validated baseline measures of patient pain and disability. RESULTS Included: 50 ASD patients (52±20yrs, 78% female). All the following preoperative factors correlated with ASD-FI score (all p 30 kg/m2 (weight: 5), depression (weight: 5), difficulty climbing stairs (3), presence of >3 medical comorbidities (2), leg weakness (2), difficulty getting dressed (1), bladder incontinence (1), and patient-reported deterioration in health within the past year (1). These factors were used to calculate the overall population's mean mASD-FI score: 5.7±5.2. Combined, these factors comprising the mASD-FI showed a trend of predicting the incidence of medical complications (Nagelkerke R2=0.558, Cox & Snell R2=0.399, p=0.065). Overall patient breakdown by mASD-FI frailty category: NF (70%), frail (12%), SF (18%). Increasing frailty category was associated with significant impairments in validated measures of disability, including ODI score (NF: 23.4, frail: 45.0, SF: 49.3, p CONCLUSIONS This study modifies an existing ASD frailty index and proposes a weighted, shorter mASD-FI. The mASD-FI relies less on patient-reported variables, and weights component factors by their contribution to adverse outcomes. As increasing mASD-FI score is associated with inferior clinical measures of pain and disability, the mASD-FI may serve as a valuable tool for preoperative risk assessment. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The Adult Spinal Deformity Frailty Index (ASD-FI), a validated modality for quantifying frailty, stratifies patients into categories not frail (NF), frail (F) and severely frail (SF). However, the cost of treating each frailty state is unknown. PURPOSE Investigate the cost utility of treating not frail versus frail or severely frail ASD patients. STUDY DESIGN/SETTING Retrospective review of a prospective single center adult spinal deformity database. PATIENT SAMPLE A total of 79 operative and non operative ASD patients ≥18 years old, with baseline and 2Y ASD-FI and Oswestry Disability Index (ODI) scores. OUTCOME MEASURES ODI, SF-6D, Cost per quality adjusted life years (QALY), Incremental Cost Effectiveness, Ratio (ICER). METHODS Inclusion criteria was surgical ASD (scoliosis≥20°, SVA≥5cm, PT≥25°, or thoracic kyphosis ≥60°) patients >18 years with available frailty and ODI data at BL and 2-years post op. Independent T-Tests assessed baseline radiographic differences in PT, PI-LL, and Schwab SVA modifier status between NF vs. F/SF patients. Utility data was calculated using the ODI converted to the SF-6D using published conversion methods. QALYs utilized a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs were calculated using the PearlDiver database. After accounting for complications, LOS, revisions, and death, cost per QALY at 2Y and life expectancy were calculated for NF, and F/SF patients. ICER was compared between non op and operative NF and F/SF patients at 2Y and life expectancy. RESULTS Seventy-nine ASD patients met inclusion criteria. Descriptive statistics for the cohort were: age 51.0±6.8, 76% women, BMI 26.7±6.8, 54% osteotomy, 54% decompression, and 11.6±4.2 average levels fused. At BL, there were 48 NF, 26 F, and 4 SF pts. The average BL frailty for NF pts was 0.13±0.08, 0.39±0.06 for F, and 0.59±0.08 for SF pts. There were no differences in PT, PI-LL, or severe SVA Schwab modifier grades between NF or F/SF pts (all p>0.05). At 2-year follow up, there was no difference in the average cost of ASD surgery, $91,068.98 for NF patients and $90,888.53 for F/SF pts (p>0.05). The cost per QALY was higher for NF pts at 2 years vs F/SF pts ($464,239.62 vs. $321,107.89, p CONCLUSIONS Frail and severely frail patients had lower cost per QALY compared to not frail patients at 3 years and life expectancy. In addition, when compared to a non operative cohort of ASD patients, frail and severely frail patients had lower ICER values. While these results support operative correction of frail and severely frail patients, it is important to note that these patients are often at worse baseline disability, which is closely related to frailty scores, and have more opportunity to improve postoperatively. In addition, there may be a threshold of frailty that is not operable due to the risk of severe complications that is not captured by this analysis. While future research should investigate economic outcomes at extended follow-up times, these findings support the cost effectiveness of ASD surgery at all frailty states. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The Patient-Reported Outcomes Measurement Information System (PROMIS) is a comprehensive self-report measurement tool with patient functions, symptoms, behaviors, and mental health outcomes. Little work has been done correlating PROMIS physical health domain metrics with established adult spinal deformity (ASD) classifications such as SRS-Schwab. PURPOSE To correlate sagittal alignment components via the SRS-Schwab classification system with established PROMIS domains in a cohort of ASD patients. STUDY DESIGN/SETTING Retrospective review of a single-center stereoradiographic database. PATIENT SAMPLE A total of 41 ASD patients with complete baseline radiographic and PROMIS data. OUTCOME MEASURES PROMIS physical health domain metrics (Pain Intensity [PI], Physical Function [PF], Pain Interference [Interference]), SRS-Schwab modifiers (SVA, PI-LL, PT) METHODS Surgical ASD patients (SVA≥5cm, PT≥25° or TK ≥60°) ≥18 years old with available baseline (BL) radiographic and PROMIS data were isolated in the single-center comprehensive Spine Quality Database (Quality). Patients were classified according to SRS-Schwab deformity modifiers(0,+,++) for SVA, PI-LL and PT. Descriptives and univariate analyses compared population-weighted PROMIS scores for PI, PF and Interference across ASD deformity modifiers. Conditional Tree Analysis (CTA) with logistic regression sampling established cut-off points for PROMIS scores predicting severe malalignment (++) at BL compared to mild or moderate (0,+). RESULTS A total of 41 patients (58.95 yrs,75.6%F,29.1kg/m2) met inclusion criteria. BL SRS modifiers were as follows: SVA 51.2%, 2.4%, 46.3% (0,+,++); PI-LL 27.3%, 12.1%, 60.6%(0,+,++); PT 18.2%, 36.4%, 45.5% (0,+,++). Mean cohort PI score was 94.2±6.0, mean PF score 8.95±10.1, mean Inter score 57.84±5.46. PF and Interference differed significantly across low and high SVA groups, with low SVA having significantly higher PF (13.50 vs 3.68,p 0.05). Low PI-LL pts had significantly higher PF than pts with ++PI-LL (19.3 vs 4.15,p=0.001) and trended lower PI and Inter without significance. No significant differences in PI, PF or Inter were found across PT groups (all p>0.05). CTA found a PI score>98 or PF score 98) and PF ( 0.05). Pain Interference did not predict SRS metrics to a significant degree (all p>0.05). CONCLUSIONS Inferior PROMIS scores of pain intensity and physical function predicted increasingly severe SRS sagittal modifiers at baseline, specifically severe sagittal vertical axis and lumbopelvic mismatch. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

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.To identify perioperative factors associated with extended LOS and 30-day readmission following elective surgery for CSM.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.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 (P0.05).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.

The causes and epidemiology of traumatic cervical spine fracture have not been described with sufficient power or recency. Our goal is to describe demographics, incidence, cause, spinal cord injuries (SCIs), concurrent injuries, treatments, and complications of traumatic cervical spine fractures.A retrospective review was carried out of the Nationwide Inpatient Sample. International Classification of Disease, Ninth Revision E-codes identified trauma cases from 2005 to 2013. Patients with cervical fracture were isolated. Demographics, incidence, cause, fracture levels, concurrent injuries, surgical procedures, and complications were analyzed. t tests elucidated significance for continuous variables and χA total of 488,262 patients were isolated (age, 55.96 years; male, 60.0%; white, 77.5%). Incidence (2005, 4.1% vs. 2013, 5.4%), Charlson Comorbidity Index (2005, 0.6150 vs. 2013, 1.1178), and total charges (2005, $71,228.60 vs. 2013, $108,119.29) have increased since 2005, whereas length of stay decreased (2005, 9.22 vs. 2013, 7.86) (all P 0.05). The most common causes were motor vehicle accident (29.3%), falls (23.7%), and pedestrian accidents (15.7%). The most frequent fracture types were closed at C2 (32.0%) and C7 (20.9%). Concurrent injury rates have significantly increased since 2005 (2005, 62.3% vs. 2013, 67.6%). Common concurrent injuries included fractures to the rib/sternum/larynx/trachea (19.6%). Overall fusion rates have increased since 2005 (2005, 15.7% vs. 2013, 18.0%), whereas decompressions and halo insertion rates have decreased (all P0.05). SCIs have significantly decreased since 2005, except for upper cervical central cord syndrome. Complication rates have significantly increased since 2005 (2005, 31.6% vs. 2013, 36.2%). Common complications included anemia (7.7%), mortality (6.6%), and acute respiratory distress syndrome (6.6%).Incidence, complications, concurrent injuries, and fusions have increased since 2005. Length of stay, SCIs, decompressions, and halo insertions have decreased. Indicated trends should guide future research in management guidelines.

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.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.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 (P0.05). There was no statistically significant difference between the W and WO groups in operative time, estimated blood loss, length of stay, or complications (P0.05).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.

BACKGROUND CONTEXT Computer adaptive testing facilitates quicker administration of patient-relevant questions. The Patient Reported Outcome Measurement Information System (PROMIS) instruments of Physical Function, Pain Intensity and Pain Interference have been shown to correlate with established patient outcome metrics, though this relationship has yet to be investigated in relation to patient satisfaction. PURPOSE The aim of this study was to study the relationship between PROMIS and VAS scores and patient satisfaction in thoracolumbar patients. STUDY DESIGN/SETTING Retrospective review of single institution clinical data and patient-reported outcome measures. PATIENT SAMPLE A total of 208 spine patients with a thoracolumbar (TL) diagnosis. OUTCOME MEASURES ODI, Visual Analog Scale (VAS) for Back and Leg pain, Scoliosis Research Society 22 (SRS-22); Patient Reported Outcome Measurement Information System (PROMIS). METHODS Inclusion was patients greater than 18 years with a diagnosis related to the thoracolumbar spine (stenosis, disc herniation, low back pain, disc degeneration, spondylolysis most commonly). Bivariate correlations assessed the linear relationships of PROMIS scores (Physical Function, Pain Intensity, and Pain Interference) and ODI with VAS Leg and Back pain scores and patient satisfaction (SRS-22) questions specific to patient satisfaction of their back shape and back management. Linear regression predicted the relationship of PROMIS to VAS and satisfaction outcomes. Statistical significance was set at P RESULTS A total of 208 patients with a thoracolumbar diagnosis were included (age 58.39 ± 73.32 years, 49% female). VAS back pain scores (r=0.673, P CONCLUSIONS VAS Back Pain scores predicted PROMIS Pain Intensity scores as strongly as ODI, though ODI outperformed in predicting PROMIS Physical Function and Pain Interference. Conversely, PROMIS Pain Intensity predicted VAS Back Pain stronger than ODI, though ODI outperformed the other two PROMIS domains. Patients’ satisfaction of the shape of their back and their back management were significantly correlated with PROMIS scores in all three domains.

BACKGROUND CONTEXT Common indications for transforaminal lumbar interbody fusion (TLIF) include foraminal stenosis, degenerative disc disease and spondylolisthesis. Although minimally invasive surgical techniques (MIS) for TLIF have been shown to provide adequate postoperative sagittal alignment, it is unclear whether these procedures result in adequate reduction of canal compressive forces. PURPOSE Assess baseline to postoperative changes in cross-sectional canal area in patients undergoing minimally invasive transforaminal lumbar interbody fusion. STUDY DESIGN/SETTING Retrospective clinical review of a prospective surgeon-maintained MIS database. PATIENT SAMPLE A total of 16 patients undergoing MIS TLIF. OUTCOME MEASURES Spinal canal cross-sectional area, stenotic levels. METHODS Consecutive patients >18years undergoing transforaminal lumbar interbody fusion via minimally invasive surgical technique were included. Patients with preoperative lumbar MRIs and postoperative lumbar MRI or CT scans were assessed for spinal canal cross sectional area at operative interspace levels. Stenotic levels were defined as canal cross sectional area RESULTS Overall, 16 patients met inclusion criteria and underwent minimally invasive transforaminal lumbar interbody fusion. Mean patient age was 54.3±12.1years, 63% of patients were female, and mean Charlson Comorbidity Index score was 0.86±1.10. Patients presented with three primary diagnoses: herniated nucleus pulposis (36.8%), stenosis (42.1%) and spondylosis (21.1%). On average, patients underwent fusions spanning 1.69±1.13 levels, and 37.5% of patients underwent multilevel fusion. 93.7% of cases involved laminotomy, 31.3% laminectomy, 81.3% foraminotomy. Mean operative time was 349 minutes and blood loss was 389±486 ccs. From baseline to postoperative intervals, 87.5% of patients showed an increase in mean operative interspace canal cross sectional area, with the overall cohort showing significant improvement in canal cross sectional area (207.6 mm2 to 301.6 mm2, p CONCLUSIONS Following minimally invasive transforaminal lumbar interbody fusion, patients showed a significant increase in spinal canal cross sectional area. This increase in canal cross sectional area corresponded with an overall decrease in the rate of lumbar stenosis, suggesting MIS TLIF procedures have the potential to provide adequate relief of spinal canal compressive forces.

BACKGROUND CONTEXT Computer adaptive testing is becoming increasingly common in assessing patient outcomes. The Patient Reported Outcome Measurement Information System (PROMIS) instruments of Physical Function, Pain Intensity and Pain Interference have been shown to correlate with established patient outcome metrics, though this relationship has yet to be investigated for patients with thoracolumbar spinal pathologies. PURPOSE The aim of this study was to study the relationship between PROMIS and ODI scores in thoracolumbar patients. STUDY DESIGN/SETTING Retrospective review of single institution clinical data and patient-reported outcome measures. PATIENT SAMPLE A total of 208 spine patients with a thoracolumbar (TL) diagnosis. OUTCOME MEASURES Legacy metrics: Oswestry Disability Index (ODI), Patient Reported Outcome Measurement Information System (PROMIS). METHODS Inclusion was patients greater than 18 years of age with a diagnosis related to the thoracolumbar spine (most common diagnoses included spinal stenosis, disc herniation, low back pain, disc degeneration, spondylolysis). Bivariate correlations assessed the linear relationships between ODI and PROMIS scores (Physical Function, Pain Intensity, and Pain Interference). Correlation cutoffs were used to assess patients with high and low correlation between ODI and PROMIS domains. Linear regression predicted the relationship of ODI to PROMIS outcomes. Statistical significance was set at P RESULTS A total of 208 patients with a thoracolumbar diagnosis were included (age 58.39 ± 73.32 years, 49% female). ODI correlated with PROMIS Physical Function (r=−0.737, P CONCLUSIONS There is a large amount of variability in PROMIS scores that ODI cannot account for. Certain ODI questions, such as walking, social life, and lifting ability correlate strongly with PROMIS while ODI questions such as sitting, standing and sleeping do not correlate well with PROMIS. Further work is required to assess these discrepancies and tease out the factors contributing to these differences.

BACKGROUND CONTEXT Bariatric surgery for morbid obesity helps to address common comorbidity burdens, including decreasing rates of myocardial infarction and stroke. The increased mechanical stresses on the spine caused by morbid obesity predispose patients to various spinal pathologies and are concerning for spinal surgeons, with previous studies suggesting poorer outcomes than the general population. The effects of bariatric surgery on diminishing spinal complaints or symptoms have yet to be elucidated in the literature. PURPOSE To assess the rate in which various spinal symptoms diminish after bariatric surgery. STUDY DESIGN/SETTING Retrospective analysis of the prospectively collected New York State Inpatient Database (NYSID) years (2004-2013). PATIENT SAMPLE A total of 4,351 patients who underwent bariatric surgery with at least one identified spinal diagnosis present before bariatric surgery. OUTCOME MEASURES Time from bariatric surgery until disappearance of specific spinal complaint, percentage of unresolved spinal complaints with 2-year follow-up. METHODS Retrospective analysis of the prospectively collected (NYSID) years 2004-2013. Patient linkage codes allow identification of multiple and return inpatient stays within the time frame analyzed (720 days). Inclusion criteria were bariatrics surgery patients with one or more visits prior to and after bariatric procedure (excluding pts with RESULTS A total of 4,351 bariatric surgery pts with a preop spinal diagnosis by ICD-9 were analyzed. Lumbar pts: 1,049 had stenosis, 774 spondylosis, 648 degeneration, 249 spondylolisthesis, 72 disc herniation. Cervical pts: 581 disc herniation, 376 had stenosis, 366 spondylosis, 236 degeneration. Cumulative resolution rates at 90-day, 180-day, 360-day, and 720-day follow-up were as follows: lumbar stenosis (48%,67.6%,79%,91%), lumbar herniation (61%,77%,86%,93%), lumbar spondylosis (47%,65%,80%,93%), lumbar spondylolisthesis (37%,58%,70%,87%), lumbar degeneration (37%,56%,72%,86%). By cervical region: cervical stenosis (48%,70%,84%,94%), cervical herniation (39%,58%,74%,87%), cervical spondylosis (46%, 70%,83%, 94%), cervical degeneration (44%,64%,78%,89%). Lumbar herniation pts saw significantly higher 90d-resolution than cervical herniation pts (p CONCLUSIONS Over 50% of bariatric patients diagnosed with a cervical or lumbar pathology before weight-loss surgery no longer sought inpatient care for their respective spinal diagnosis by 180 days postop. Lumbar herniation had significantly higher resolution than cervical herniation by 90d, whereas cervical degeneration and stenosis resolved at higher rates than corresponding lumbar pathologies by 180d and 1-year follow-up, respectively. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The efficacy of surgical intervention for central cord syndrome (CCS) is shown in the literature; however, it is unclear whether disparities in patient presentation and treatment exist between those who initially undergo operative treatment and those who delay operative treatment. PURPOSE In a population of CCS patients, assess disparities in presentation and treatment between those undergoing immediate surgery and those who delay operative treatment. STUDY DESIGN/SETTING Retrospective analysis of New York State Inpatient Database years 2004-2013. PATIENT SAMPLE A total of 1,301 CCS patients (ICD-9 codes 952.03, 952.08, 952.13, 952.18). OUTCOME MEASURES Time to surgery, length of stay (LOS). METHODS Patient-specific linkage codes allowed longitudinal tracking of inpatient stays within the study period. Demographics, comorbidities (Charlson Comorbidity Index [CCI]), complications, and surgical factors, including Mirza invasiveness score, were compared between CCS patients that initially underwent surgery (Initial) and patients that delayed operative treatment (Delayed) using Chi-squared tests and independent samples t-tests as appropriate. Similar tests assessed differences in demographics and comorbidity burden between nonoperative patients and surgical crossover patients. RESULTS Included: 1,301 CCS patients (62±16 yrs, 27% female). Follow-up rate was 67.3%; mean follow-up time was 515±707 days. By level of CCS injury, 61.0% of patients were injured between C1 and C4, 59.2% between C5-C7, 1.0% between T1-T6, and 0.6% between T7-T12. Overall, 800 (61%) patients underwent surgical treatment (procedural breakdown: 80% fusion, 59% decompression, including 38% discectomy and 23% other decompression of the spinal canal). Of the surgical patients, 621 (78%) had surgery at first recorded hospital visit, while 179 (22%) experienced a delay before surgical treatment. For patients that delayed treatment, mean time to surgery was 203±358 days. Initial and Delayed patients did not differ in sex (p=0.109) or CCI (p=0.894), though Initial patients were younger than Delayed (60±15 yrs vs 63±13, p=0.016) and had lower rates of diabetes and valvular disease (both p 0.05). Patients who delayed operative treatment did not differ from nonop patients in age (63±13 vs 63±17, p=0.802) or CCI (1.04±1.49 vs 1.06±1.49, p=0.923); however, Delayed patients had higher rates of diabetes (26% vs 18%, p=0.037), neurologic disorders (7% vs 1%, p CONCLUSIONS Although patients managed with initial surgical treatment of CCS had longer hospital stays and were treated with more invasive procedures, perioperative complications did not differ. Twenty-two percent of CCS patients crossed over from nonoperative to operative treatment, with a mean time to crossover of 203 days. Patients who crossed over to operative care were more comorbid than patients who remained nonoperative, indicating comorbidity burden may play a role in the decision to operate. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Psychiatric diagnoses (PD) present a significant burden on elective surgery patients and may have potentially dramatic impacts on outcomes. As ailments of the spine can be particularly debilitating, the effect of PD on outcomes was compared between elective spine surgery patients and other common elective orthopedic surgery procedures. PURPOSE Investigate the rates of PD in elective orthopedic procedures. STUDY DESIGN/SETTING Retrospective review of the National Inpatient Database 2007-2013. PATIENT SAMPLE A total of 15,434,393 weighted hospital discharges. OUTCOME MEASURES Rates of PD, post-operative complications, length of stay (LOS), cost to charge (CCR), discharge location, and death. METHODS Inclusion criteria: elective orthopedic surgery procedures from 2007-2013 as defined by ICD-9-CM codes. Exclusion criteria: emergency, trauma, or non-elective surgery. Patients were grouped as shoulder, elbow, hand, spine, hip, knee, or foot/ankle. Descriptive statistics assessed demographics. Rates of DSM-IV PD, as classified by single-level CCS – diagnoses, and perioperative complications, were assessed for each orthopedic group.Logistic regression analysis assessed PD as a predictor of complications, extended LOS (LOS above 75th percentile), higher cost to charge ratio (CCR above 75th percentile), unfavorable discharge (not routine discharge), and death during hospitalization. RESULTS A total of 4,528,121/15,434,393 discharges (age: 61.02 ± 15.48, female: 57%, CCI: 0.91 ± 1.28) included in the analysis had PD. For all elective spine surgery patients, the overall rate of PD increased from 2007-2013 (32.3%, 33.8%, 34.6%, 37.1%, 37.2%, 39.1%, 40.7%, p CONCLUSIONS Psychiatric diagnoses have an immense impact on the treatment and outcomes of patients undergoing elective orthopedic procedures. Afflicted patients are more likely to have higher cost surgeries, extended length of stays, and death during their admission. More discussion is warranted on the possible utility of preoperative mental health treatment for these patients. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Recent studies show similar clinical outcomes between primary and revision lumbar interbody fusion procedures performed using conventional open techniques. As an increasing number of lumbar fusions are performed using minimally invasive surgical (MIS) techniques, it is important to assess the corresponding complication risks between primary and revision lumbar interbody fusion procedures. PURPOSE Assess differences in perioperative outcomes between primary and revision MIS lumbar interbody fusion patients, and compare to those of patients undergoing corresponding procedures utilizing an open technique. STUDY DESIGN/SETTING Retrospective chart review at single academic institution. PATIENT SAMPLE A total of 154 lumbar interbody fusion patients (77 primary, 77 revision; 44 MIS, 110 open). OUTCOME MEASURES Perioperative complications, length of stay (LOS), estimated blood loss (EBL) METHODS Patients >18 years undergoing primary and revision lumbar interbody fusion were propensity score matched (PSM) for comorbidities and levels fused. Cases were grouped by surgical technique: MIS or open. demographics, charlson comorbidity index (CCI) scores, surgical factors, and perioperative complications incidences were compared between primary and revision cases using means comparison tests, as appropriate. Significance was set to p RESULTS Included: 154 lumbar interbody fusion patients (62±12 year, 62%F, 29±6 kg/m2). Fourty-four (29%) cases were MIS, and 110 (71%) were open. Proportion of revision cases within the MIS and open groups were 40.9% and 53.6%, respectively. Within both MIS and open groups, there were no differences between primary and revision cases in age, sex, BMI, CCI, or levels fused (all p>.05). For both MIS and open patients, there were no differences between primary and revision cases in surgical approach, rates of laminectomy, or number of interbodies (all p>.05). For both MIS and open techniques, primary and revision patients did not differ in EBL, op time, LOS, or ICU LOS (all p>.05). Similarly, within both MIS and open groups, there were no differences between primary and revision surgeries in overall rates of postop complications, including cardiac, pulmonary, urinary, infection, and anemia complications (all p>.05). Primary MIS cases had higher rates of intraoperative complications as compared to revision cases (19% vs. 0.0%, p=.048), unlike open procedures, in which primary cases had lower intraoperative complication rates (0% vs. 7%, p=.058). Whereas MIS and open groups did not differ in operative time of primary surgery (279 minutes vs. 280, p=.976), MIS revision procedures were shorter than open (244 minutes vs. 296, p=.024). For both primary and revision procedures, there were no differences between MIS and open groups in overall rates of postoperative complications(all p>.05); however, primary MIS cases had higher intraoperative complication rates than primary open cases (19% vs. 0%, p=.001). CONCLUSIONS Clinical outcomes of revision MIS lumbar interbody fusion were similar to those of primary surgery, with no differences in operative time, inpatient length of stay, blood loss, or rates of postoperative complications. Despite higher intraoperative complication rates for primary MIS fusions, postoperative clinical outcomes were similar between MIS and open groups for both primary and revision procedures. These results point to revision MIS lumbar interbody fusion as a comparable alternative to similar fusions preformed using conventional open techniques. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Recent research has identified increased C2-T3 angle as a risk factor for persistent sagittal malalignment following thoracolumbar surgery. Despite this, no ideal cervicothoracic alignment thresholds exist in the literature. As several studies have demonstrated a clear relationship between the normal aging spine and sagittal spinal alignment, such ideal-alignment thresholds should also account for patient age. PURPOSE This study proposes age-specific cervicothoracic alignment targets using previously published age-specific normative Neck Disability Index (NDI) values. STUDY DESIGN/SETTING Single center retrospective review. PATIENT SAMPLE A total of 223 patients with available biplanar full-body stereographic x-rays. OUTCOME MEASURES C2-T3 lordosis; Neck Disability Index score. METHODS Patients >18 years with cervical sagittal vertical axis RESULTS Overall, 223 patients (50±20years, 65% F) met inclusion criteria, presenting with a mean sagittal vertical axis (SVA) of 17.8±47.7 mm, cervical SVA 19.8±11.2 mm, T1 Slope-C2-C7 lordosis 24.7°±16.2°, and C2-T3 of 2.1°±16.5°. At baseline, increased C2-T3 angle was significantly correlated with both NDI score (r=0.266, p 75 years: 27.8. Liner regression analysis showed a significant relationship between NDI score, age, and baseline cervicothoracic alignment, as assessed by C2-T3 angle (r=0.497, p 75 years: 6.7°. CONCLUSIONS Significant relationships exist between age, neck disability, and cervicothoracic alignment, suggesting broad measurements across the cervicothoracic junction may be clinically relevant in predicting postoperative outcomes of surgical spine deformity patients. Taking into account patient age and USA-normative values of neck disability, this study offers a set of ideal age-adjusted alignment targets for C2-T3. By proposing a set of normative, age-specific cervicothoracic alignment targets, this study better facilitates individual optimization of surgical planning.

BACKGROUND CONTEXT A T1 Slope minus cervical lordosis (TS-CL) angle of 20° has been described in the literature as a significant cutoff to define cervical deformity, however recent studies suggest that this cutoff needs to be redefined. PURPOSE The aim of this study was to develop a novel TS-CL threshold indicative of moderate to severe cervical disability. STUDY DESIGN/SETTING Single-center retrospective review. PATIENT SAMPLE A total of 69 cervical patients indicated for surgical treatment were included. OUTCOME MEASURES T1 slope minus cervical lordosis, neck disability index (NDI). METHODS Patients age 18years old with a primary cervical diagnosis indicated for surgical treatment were included. Patients with active infection, tumors or trauma were excluded. We tested possible cutoffs for TS-CL against the percentage of individuals meeting normative, mild, moderate (>25) and severe (>35) NDI scores at baseline. The TS-CL cutoff with the highest sensitivity to predict a normative, mild, moderate (>25) and severe (>35) NDI score was selected. RESULTS A total of 69 cervical patients indicated for surgical treatment were included (mean age 55.4±9.9years, 45% female, mean BMI 29.1±6.6 kg/m2). The average baseline NDI score was 39.9±20.9 for this cohort. At baseline, average TS-CL was 27.3°±18.8°, CL was 1.7°±17.6°, cSVA was 28.3 mm±17.3 mm. Spino-pelvic alignment parameters at baseline were as follows: PT 16.1°±8.3°, PI-LL −2.8°±11.9°, TK 38.8°±12.7° and SVA −6.3 mm±51.8 mm. Using previously established TS-CL severity breakdowns, 13 (18.8%) patients had mild TS-CL ( 20°). Using this cutoff of 20° as severe TS-CL, it did not correlate with NDI score (P=.390). After testing possible cutoffs of TS-CL that relate to moderate to severe NDI scores, a novel cutoff of 30.65° for TS-CL was related to an NDI score of ³25 points. CONCLUSIONS In a cohort of cervical surgery patients, a novel cutoff of 30.65°for TS-CL was predictive of moderate to severe neck disability, as described as an NDI score greater than or equal to 25 points. This criterion can be applied to cervical spine patients to better assess cervical disability.

BACKGROUND CONTEXT Current preoperative planning for surgical adult spinal deformity (ASD) patients takes into account patient age when establishing postoperative alignment targets for sagittal vertical axis (SVA), pelvic tilt (PT) and spino-pelvic-mismatch (PI-LL). Patient height and pelvic incidence (PI), however, have yet to be evaluated for their individual effects on achieving age-adjusted alignment targets. PURPOSE This study assesses the individual effects of patient height and PI on age-adjusted alignment outcomes of surgical ASD patients. STUDY DESIGN/SETTING Single center retrospective review. PATIENT SAMPLE A total of 205 operative ASD patients. OUTCOME MEASURES Postoperative alignment parameters (PT, SVA, PI-LL, and SS); health-related quality of life (HRQL) scores. METHODS Surgical ASD patients >18 years with full-body stereographic x-ray imaging at baseline (BL) and early postoperative follow-up ( 75th) for both BL height and PI. Correction groups were generated at postoperative follow-up for actual alignment compared to age-adjusted ideal values for PT, PI-LL, and SVA, and PI-adjusted ideal alignment values for SS, as derived from clinically relevant formulas. Chi-squared tests assessed differences in rates of matching age-adjusted alignment ideal (±10years threshold for age-adjusted targets; −7° to 5° measured minus ideal for SS target) across height and PI groups. Subanalysis of patients matching age-adjusted alignment ideal used ANOVA to compare clinical outcomes across height and PI groups. RESULTS Included: 205 ASD patients (59±16 year, 64% F, 27±6 kg/m2). Following surgery, patients showed significant improvement in PT, PI-LL and SVA (all p .05). Height groups also did not differ in age or BMI (all p>.05), although female patients comprised a greater proportion of the low (96% F vs. 4% M) and normative (75% F vs. 25% M) height groups (p 0.05). Although there were no differences across PI groups in rates of achieving ideal alignment for PI-LL, SVA or SS (all p>.05), patients with high PI reached age-adjusted ideal alignment for PT at a significantly lower rate (15%) than patients with normative (36%) or low PI (33%, p=.031). Of the 58% of patients that matched any adjusted alignment target in early follow-up, there were no significant differences in postoperative HRQL outcomes across patient height or PI groups (all p>.05). CONCLUSIONS Patients with high pelvic incidence reached ideal postoperative age-adjusted PT alignment at a significantly lower rate than patients with normative and low pelvic incidence. In contrast, patient height had no impact on postoperative age-adjusted alignment outcomes. These results suggest that current postoperative ideal alignment targets may warrant adjustment to account for the morphological factor of pelvic incidence.

BACKGROUND CONTEXT Increased usage of computer adaptive testing such as Patient Reported Outcome Measurement Information System (PROMIS) aims to improve the capture of high quality patient outcomes. Recent work has shown correlations between PROMIS and the Oswestry Disability Index (ODI), but not specifically in a thoracolumbar population using the PROMIS Physical Function, Pain Intensity and Pain Interference computer adaptive domains. PURPOSE The aim of this study was to study the relationship between PROMIS and ODI scores in thoracolumbar patients. STUDY DESIGN/SETTING Retrospective review of single institution clinical data and patient-reported outcome measures. PATIENT SAMPLE A total of 208 spine patients with a thoracolumbar (TL) diagnosis. OUTCOME MEASURES Legacy metrics: Oswestry Disability Index (ODI), PROMIS. METHODS Inclusion was patients greater than 18years with a diagnosis related to the thoracolumbar spine (stenosis, disc herniation, low back pain, disc degeneration, spondylolysis most commonly). Bivariate correlations assessed the linear relationships between ODI and PROMIS scores (Physical Function, Pain Intensity and Pain Interference). Linear regression predicted the relationship of ODI to PROMIS outcomes. Statistical significance was set at P RESULTS A total of 208 patients with a thoracolumbar diagnosis were included (age 58.39±73.32years, 49% female). ODI strongly correlated with PROMIS Physical Function (r=−0.737, P CONCLUSIONS The well-established patient reported outcome ODI correlated strongly with PROMIS domains. ODI score strongly predicts PROMIS scores for all three components (Physical Function, Pain Intensity, Pain Interference) for thoracolumbar spine patients.