Faculty Bibliography

BACKGROUND CONTEXT: Patient-specific, pre-contoured rods are increasingly used in the surgical treatment of spinal pathologies. Previous studies show that pre-contoured rods help to achieve desired postoperative alignment goals, though it is unclear whether these benefits differ by fusion length. PURPOSE: Assess how preoperative planning and patient-specific rods affect the outcomes of patients undergoing posterior cervical fusion surgery. STUDY DESIGN/SETTING: Retrospective review of single-center cases of multilevel posterior cervical surgeries from 2014-2018. PATIENT SAMPLE: This study included 65 patients. OUTCOME MEASURES: Sagittal alignment: cervical sagittal vertical axis (cSVA), cervical lordosis (CL), T1 Slope (T1S) minus CL (TS-CL), and cervical-thoracic pelvic angle (CTPA).
METHOD(S): Patients undergoing posterior cervical fusion with available pre- and postop (3-month, 6-month, or 1-year) cervical radiographs were stratified: those whose surgeries involved preoperative planning and patient-specific, pre-contoured rods (PLAN), and those whose surgeries did not (NON). Independent samples t-tests assessed differences between PLAN and NON groups in alignment, and pre- to postop changes in alignment. Secondary analysis assessed differences in alignment between PLAN and NON groups for patients with lower-most instrumented vertebrae (LIV) above C7-T1, and below.
RESULT(S): Included: 65 patients (55.1+/-9.9 years, 61% female) undergoing posterior cervical fusion (6.2+/-3.7 levels). Mean follow-up was 8.4+/-4.1 months. By group, 47.7% of patients had pre-contoured rods (PLAN, N=31), 53.3% did not (NON, N=34). Preoperatively, PLAN patients presented with greater cervical malalignment (CTPA: 4.0degree vs 2.7degree, p=0.015) and T1 Slope (33degree vs 22degree, p=0.013), but not global (SVA, TPA), or lumbopelvic alignment (PT, PI-LL, all p>0.05). Postoperatively, PLAN patients had greater C2-C7 lordosis than NON patients (18degree vs 7degree, p=0.001), and a trend of superior TS-CL alignment (19degree vs 23degree, p=0.075), but did not differ in any other cervical, global, or lumbopelvic parameters (all p>0.05). PLAN patients also showed superior pre- to postop changes in TS-CL (-7degree vs 2.1degree, p=0.026). Overall, 25% of patients had LIVs above C7-T1 (mean fusion length: 4.8+/-1.1 levels), while 75% had fusions extending lower (10.0+/-5.5 levels). For cases in which fusion extended below C7-T1, PLAN patients showed a trend of greater pre- to postop TS-CL correction (-3degree vs 3degree, p-0.076), more postop CL (14degree vs 6degree, p=0.007), and less lumbopelvic malalignment (PI-LL:-7.1degree vs 0.1degree, p=0.029) and (PT: 14degree vs 19degree, p=0.087), though this result is confounded by greater preop PI-LL and PT deformity for NON patients (both p<0.03). No such differences were observed between PLAN and NON groups for cases in which the LIV was above C7-T1 (all p>0.05).
CONCLUSION(S): For posterior cervical fusion cases, the use of preoperative planning and patient-specific, pre-contoured rods was associated with superior correction of cervical sagittal alignment. For cases in which fusion extended below C7-T1, use of contoured rods was associated with superior postop reciprocal alignment in the lumbopelvic spine, though this may be confounded by differences in preop alignment. For longer fusions, pre-planned and contoured rods may offer greater utility. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: The age-adjusted alignment ideal alignment was proposed in order reduce the occurrence of proximal junctional kyphosis (PJK) in an adult spinal deformity (ASD) population. The normative postoperative age ideal value for the mismatch between pelvic incidence and lumbar lordosis (PI-LL) has yet to be related to the global alignment and proportion (GAP) score postop proportionality. PURPOSE: To assess the impact of normative age-adjusted PI-LL and proportionality via GAP score on postoperative patient-reported outcomes. STUDY DESIGN/SETTING: Retrospective review of single-surgeon adult spinal deformity (ASD) database PATIENT SAMPLE: 140 ASD patients. OUTCOME MEASURES: Health-related quality-of-life (HRQLs); SRS-22r; PJK.
METHOD(S): ASD patients with baseline (BL) and 2-year postoperative (2Y) radiographic and HRQL data were included. Age-adjusted correction groups generated at postoperative follow-up for actual alignment compared to age-adjusted values for PI-LL-adjusted ideal values (matched, overcorrected, undercorrected). GAP Score in the literature includes the four parameters, and an age factor to formulate a sagittal plane score out of 13 (proportional, moderately disproportional [MD], severely disproportional [SD]). GAP improvement scores were noted as less at 2Y compared to BL. Patients were grouped by age-adjusted and 2Y GAP results: Match PI-LL/Proportional GAP, Match PI-LL/Disproportional GAP, Unmatch PI-LL/Proportional GAP, Unmatch PI-LL/Disproportional GAP. Means comparison and chi-squared ANOVA analyses assessed the outcomes between age-adjusted and GAP groups.
RESULT(S): Included: 140 ASD patients (55.5+/-16.4 years, 81% female, 25.2+/-4.7kg/m2). At BL, mean sacral slope: 30.7degree, pelvic tilt: 23degree, pelvic incidence: 53.5degree, PI-LL: 13.3degree, SVA: 61.6 mm, and L1-S1: 40.4degree. BL GAP proportionality: 17.8% proportional, 27.1% MD, 55% SD. PI-LL by baseline GAP proportionality groups: -6.4degree Proportional, -4.6degree MD, 26.8degree SD, p<0.001. Baseline ODI increased significantly with GAP proportionality: 27.3 Proportional, 32.3 MD, 37.4 SD, p=0.050. Assessment of 2Y age-adjusted PI-LL alignment found that 20.3% of patients Matched, 45.1% Overcorrected, and 34.6% Undercorrected. By 2Y GAP results, 32.3% were proportional, 38.5% MD, 29.5% SD (40.5% of patients improved, while 48.5% remained the same, and 11.1% deteriorated in their GAP proportionality). Categorized by the PI-LL age-adjusted/GAP groups: 2.3% Match PI-LL/Proportional GAP, 13.1% Match PI-LL/Disproportional GAP, 30% Unmatch PI-LL/Proportional GAP, 54.6% Unmatch PI-LL/Disproportional GAP. Patients who Unmatched PI-LL/Disproportional in GAP had significantly worse postoperative SRS-Pain scores (1.80 vs 3.53-3.86), SRS-Appearance (3.30 vs 3.69-4.29) and SRS-22 Total scores (2.84 vs 3.80-4.12), all p<0.050. Unmatch PI-LL/Disproportional patients developed PJK at a significantly higher rate by 6-months (66.7% vs 11.8-15.4%), p<0.050. Outcomes were not different between Match PI-LL/Disproportional GAP and Unmatch PI-LL/Proportional GAP groups.
CONCLUSION(S): Collectively over or undercorrecting in age-adjusted mismatch pelvic incidence and lumbar lordosis and becoming disproportional in spinal shape at 2 years led to increased postoperative proximal junctional kyphosis and significantly worse patient-reported outcomes. Surgeons should be wary of the double mal-correction when utilizing these complex realignment schemas. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Navigation assisted and robotics systems are becoming more widespread in their utilization and can be invaluable intraoperative adjuncts during spine surgery. These systems are utilized in hopes of improving surgical accuracy and clinical outcomes. However, there is a lack in specificity of which type of procedures benefit the most from use of navigation versus robotics. PURPOSE: Identify Trends of Navigation and Robotic assisted elective spine surgeries from the onset of inception. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Elective spine patients from (2007-2016). OUTCOME MEASURES: Complications, procedures, levels fused.
METHOD(S): Patients(pts) between 2007-2016 in Nationwide Inpatient Sample (NIS) were isolated by ICD9 codes for Navigation [Nav] or Robotic [Rob]-Assisted surgery. Basic demographics and surgical variables were identified between each group via chi-squared and t-tests. Each system was analyzed from 2009-2015 for trends in usage with specific procedures and specific diagnoses.
RESULT(S): Included 3,759,751 elective spine patients (56.9 yrs, 52.7% F) with 100,488 Nav and 4,724 Rob pts. Nav pts were younger (56.7 vs 62.7) and had a lower comorbidity index (1.8 vs 6.2; all p<0.05). Nav pts also had more decompressions (65% vs 42%), fusions (71% vs 50.5%), anterior (17% vs 16.7%), posterior (58.3% vs 36.8%), and combined approach (7.1%vs 5%) than Rob pts. Overall, complication rates increased for Nav (5.8%-21.7%) and Rob pts (3.3%-18.4%) as well as for 2-3 level fusions (50.4%-52.5%) and (1.3%-3.2%); respectively. Concomitantly, Rob and Nav systems have been used on increasingly invasive spinal procedures (Rob:1.7-2.2; Nav: 3.7-4.6). During this time, the rate of posterior approaches (27.4%-41.3%) increased as well as osteotomies (4%-7%) and spinal fusions (40.9%-54.2%) for Rob pts. However, the rates for anterior approach for Rob procedures has since decreased (14.9%-14.4%). Nav increased for posterior (51.5%-63.9%) and anterior approaches (16.4%-19.2%) despite the decrease rate of osteotomies (2.1%-2.1%) and decompressions (73.6%-63.2%).
CONCLUSION(S): From 2007 to 2016 Robotic and Nav systems have been performed on increasing invasive spine procedures. Robotic systems have shifted from anterior to posterior approaches especially for spinal fusions. While, Navigation computer-assisted procedures have been increasingly used for different approaches, but have decreased in rates of usage for decompression procedures. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Many patients are unable to undergo a major adult spinal deformity (ASD) corrective surgery due to deformity severity, age, comorbidities, and overall frailty status. In order to optimize quality of life in patients with ASD there may be alignment ratios to be prioritized across different presentations of spinal shape. PURPOSE: To prioritize radiographic alignment ratios for alignment. STUDY DESIGN/SETTING: Retrospective review of a single surgeon adult spinal deformity database. PATIENT SAMPLE: A total of 165 patients undergoing ASD corrective surgery OUTCOME MEASURES: Minimal clinically important difference (MCID) for SRS-22r and Oswestry Disability Index (ODI); proximal junctional kyphosis (PJK).
METHOD(S): Included: patients >18yrs undergoing surgery for ASD (scoliosis >=20degree, SVA >=5cm, PT >=25degree, or TK >=60degree) with full baseline (BL) and 2-year (2Y) radiographic parameters and HRQL scores. Patients were stratified by baseline pelvic incidence: low PI (<45), high PI (>=45). Ratios of SRS-Schwab radiographic parameters (PI-LL, SVA, PT) were assessed for quartiles of correction: minimal (<0%), 0-25%, 25-50%, 50-75%, and 75-100%. Target quartiles of correction were assessed within the PI severity groups for achievement of 2Y best clinical outcome as defined by Smith et al: SRS-22 scores >=4.5 and ODI <=15 [BCO] through correlations and stepwise linear regression analysis.
RESULT(S): A total of 165 ASD patients included (56.7+/-16.3yrs, 80.3% female, 25.8+/-5.3kg/m2). By approach, anterior: 0.6%, posterior: 91.2%, and combined approach: 8.2%. Average levels fused: 11.3+/-4.1, operative time: 332 min, estimated blood loss: 1,968 ccs. By baseline PI: 24.3% low PI, 75.7% high PI. (47 patients) of patients met the criteria for BCO, which was evenly distributed among the Roussouly types (p=0.115). For low PI patients, a combination of correcting the PI-LL from 0-25%, SVA 75-100%, and PT 0-25% significantly predicting acquiring the BCO (R2 =0.622, p=0.002). For BCO in high PI patients, a 25-50% correction in PI-LL, SVA minimal, and PT 75-100% (R2 =0.297, p=0.021). Low PI patents who met the three ratios of correction (PI-LL, SVA and PT) had less major complications (11.1% vs 23.1%) compared to other low PI patients. High PI patients who were corrected to the Schwab quartile of ratios underwent less reoperations (6.1% vs 23.3%) and had less PJK occurrence by 2-years postop (20.4% vs 40%), all p<0.05.
CONCLUSION(S): Certain ratios of correction of the SRS-Schwab modifiers contribute to improving clinical outcomes and vary by preoperative spinal shape. Prioritization of global realignment relative lumbo-pelvic mismatch depends on the theoretical contour of the individual patient. Importantly, certain subgroups experience the most clinical benefit from the initial percentages of realignment, which may obviate more aggressive corrections on an individual basis. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: There have been few investigations into national trends in outcomes and costs associated with the assimilation of robotic assisted surgery. In order to improve cost efficiency, further research is needed into the drivers of higher charge ratios. PURPOSE: To evaluate if incorporation of robotic assisted spine surgeries will lead to a rise in cost without a significant improvement in outcomes. STUDY DESIGN/SETTING: Retrospective review of a national patient database between 2010-2016. PATIENT SAMPLE: A total of 4,185 discharges. OUTCOME MEASURES: Cost-to-Charge ratio, length of stay, invasiveness.
METHOD(S): Included: elective spine surgery procedures from 2010-2016 as defined by ICD-9/10-CM codes. Descriptive statistics assessed demographics for the cohort. Rates of open and MIS robot assisted procedures, trends in postoperative complications, length of stay, total charges, CCR and hospital location were assessed. PSM was performed between robotic and nonrobotic spine surgery patients for levels fused. Regression analysis was used to evaluate robot assisted procedures as a predictor of postop complications, extended LOS (LOS above 75th percentile), higher total charges (charges above 75th percentile), higher cost to charge ratio (CCR above 75th percentile), unfavorable discharge and death.
RESULT(S): A total of 4,185 discharges were included (age 59.7 +/- 16.2, 55% female, average severity of illness score 1.87 +/- 0.83). Overall, there has been a significant increase in robot assisted surgeries from 2010 to 2016 increasing from 11 recorded cases to 1,535 in 2016 (p<0.001). There has been a significant increase in total charges from 2010-2016, with a mean high of $455,210.91 in 2011 (p<0.001). However, there has been a decrease in CCR from 2012 to 2016 (0.33 compared to 0.24. p<0.001). Average length of stay has significantly decreased from 9.5 days in 2010 to 4.4 days in 2016 (p<0.001), while 50% of patients have been unfavorably discharged since 2012. When compared to 4,185 invasiveness match non-robotic patients, robot assistance was not significantly associated with higher total charges, however it was significantly associated with higher CCR (OR: 2.4 [2.15-2.69], p<0.001).
CONCLUSION(S): Compared to invasiveness matched nonrobotic patients, robot assisted patients had significantly higher odds of having a high cost to charge ratio for their hospital encounter, despite having similar total charges. Cost to charge increase due to technology may represent an added financial burden that is developing so clinical benefit of new technology is warranted. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: With the increasing emphasis on value-based outcomes in healthcare, there has been an increased focus on the cost of surgical intervention in patients with adult spinal deformity (ASD). However, there is paucity in the literature on the economic impact of an initial nonoperative approach for patients that eventually require surgical intervention. PURPOSE: Investigate the cost utility of nonoperative treatment for ASD STUDY DESIGN/SETTING: Retrospective cohort study of a prospective multicenter adult spinal deformity database. PATIENT SAMPLE: A total of 824 operative (Op) and Nonoperative (N-Op) ASD patients. OUTCOME MEASURES: ODI, SF-6D, Cost per quality adjusted life years (QALY).
METHOD(S): N-Op and Op patients who met database criteria for ASD with complete radiographic and HRQL data at baseline and 2Y were included. A cost analysis was completed on the PearlDiver database assessing average cost of nonoperative treatment prior to surgical intervention based on previously published treatments (NSAID, narcotics, muscle relaxants, epidural steroid injections, physical therapy and chiropractor). Utility data was calculated using ODI converted to SF-6D with published conversion methods. QALYs utilized a 3% discount rate to account for residual decline to life expectancy (78.7 years). Complications, comorbidities (CC), major complications, and comorbidities (MCC) were assessed according to CMS.gov manual definitions. Successful N-Op treatment was defined as a gain in MCID in both ODI and SRS-Pain and failure as a loss in MCID or conversion to operative treatment. Patients with BL ODI <=20 and continued ODI at 2Y <= 20 were considered N-Op successful maintenance. Average utilization of non-operative treatment and cost were applied to our ASD cohort.
RESULT(S): A total of 824 patients were included (58.24yrs, 81% F, 27.1 kg/m2). Overall, 75.5% of patients were operative and 24.5% nonoperative. At baseline operative patients were significantly older, had a greater BMI, increased pelvic tilt, and increased PI-LL (all p<0.05). With respect to deformity, operative patients had higher rates of severe ++ sagittal deformity according to SRS-Schwab modifiers for PT, SVA, and PI-LL (p<0.05). At 2Y, operative patients showed significantly increased rates of a gain in MCID for PCS, ODI, and SRS Activity, Pain, Appearance, and Mental. Virtual Cost-Analysis showed average cost of non-operative treatment 2Y prior to surgical intervention to be $2,041. Overall, nonoperative patients at 2Y had an overall gain in ODI of 0.36, did not show gain in QALY, and nonoperative treatment was determined to be cost ineffective. A subset of N-Op patients however underwent successful maintenance treatment and had a decrease in ODI of -1.1 and a gain in utility of 0.006 at 2Y. If utility gained for this cohort was sustained to life expectancy, patients' cost per QALY was $18,934 compared to a cost per QALY gained of $70,690.79 for posterior-only and $48,273.49 for combined approach operative patients.
CONCLUSION(S): ASD patients undergoing operative treatment at baseline had greater sagittal deformity and greater improvement in HRQL postoperatively compared to nonoperative patients. Additionally, nonoperative patients overall had an increase in ODI and did not show improvement in utility gained. Nonoperative patients with low disability and sagittal deformity underwent successful maintenance and cost-effective treatment. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND:Although epidural steroid injection (ESI) may provide pain relief for patients with degenerative spondylolisthesis in treatment regimens of up to 4 months, it remains unclear whether ESI affects crossover from nonoperative to operative management. METHODS:This retrospective cohort study analyzed 2 groups of surgical candidates with degenerative spondylolisthesis: those who received ESI within 3 months after enrollment (ESI group) and those who did not (no-ESI group). Annual outcomes following enrollment were assessed within operative and nonoperative groups (patients who initially chose or were assigned to surgery or nonoperative treatment) by using longitudinal mixed-effect models with a random subject intercept term accounting for correlations between repeated measurements. Treatment comparisons were performed at follow-up intervals. Area-under-the-curve analysis for all time points assessed the global significance of treatment. RESULTS:The study included 192 patients in the no-ESI group and 74 in the ESI group. The no-ESI group had greater baseline Short Form-36 (SF-36) Bodily Pain scores (median, 35 versus 32) and self-reported preference for surgery (38% versus 11%). There were no differences in surgical rates within 4 years after enrollment between the no-ESI and ESI groups (61% versus 62%). The surgical ESI and no-ESI groups also showed no differences in changes in patient-reported outcomes at any follow-up interval or in the 4-year average. Compared with the nonoperative ESI group, the nonoperative no-ESI group showed greater improvements in SF-36 scores for Bodily Pain (p = 0.004) and Physical Function (p = 0.005) at 4 years, Bodily Pain at 1 year (p = 0.002) and 3 years (p = 0.005), and Physical Function at 1 year (p = 0.030) and 2 years (p = 0.002). Of the patients who were initially treated nonsurgically, those who received ESI and those who did not receive ESI did not differ with regard to surgical crossover rates. The rates of crossover to nonoperative treatment by patients who initially chose or were assigned to surgery also did not differ between the ESI and no-ESI groups. CONCLUSIONS:There was no relationship between ESI and improved clinical outcomes over a 4-year study period for patients who chose or were assigned to receive surgery for degenerative spondylolisthesis. In the nonsurgical group, ESI was associated with inferior pain reduction through 3 years, although this was confounded by greater baseline pain. ESI showed little relationship with surgical crossover. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:Surgical site infections (SSIs) affect 1% to 9% of all spine surgeries. Though previous work has found diabetes mellitus type 2 (DM2) to increase the risk for wound infection, the influence of perioperative hyperglycemia is poorly described. OBJECTIVE:To investigate perioperative hyperglycemia as an independent risk factor for surgical site infection. METHODS:We retrospectively identified patients undergoing operative management of SSIs occurring after spinal surgery for degenerative pathologies. These patients were individually matched to controls based upon age, surgical invasiveness, ICD-10CM, race, and sex. Cases and controls were compared regarding medical comorbidities (including diabetes), postoperative hyperglycemia, and operative time. RESULTS:Patients in the infection group were found to have a higher BMI (33.7 vs 28.8), higher prevalence of DM2 (48.5% vs 14.7%), and longer inpatient stay (8.8 vs 4.3 d). They also had higher average (136.6 vs 119.6 mg/dL) and peak glucose levels (191.9 vs 153.1 mg/dL), as well as greater variability in glucose levels (92.1 vs 58.1 mg/dL). Multivariable logistic regression identified BMI (odds ratio [OR] = 1.13), diabetes mellitus (OR = 2.12), average glucose on the first postoperative day (OR = 1.24), peak postoperative glucose (OR = 1.31), and maximal daily glucose variation (OR = 1.32) as being significant independent predictors of postoperative surgical site infection. CONCLUSION/CONCLUSIONS:Postoperative hyperglycemia and poor postoperative glucose control are independent risk factors for surgical site infection following surgery for degenerative spine disease. These data suggest that, particularly among high-risk diabetic patients, strict perioperative glucose control may decrease the risk of SSI.

BACKGROUND CONTEXT/BACKGROUND:Patients with severe cervical deformity (CD) often have profound deficits in numerous activities of daily living. The association between health status and post-operative radiographic goals is difficult to quantify. PURPOSE/OBJECTIVE:We aimed to investigate the radiographic characteristics of patients who achieved optimal health related quality of life scores following surgery for CD. STUDY DESIGN/METHODS:We performed a retrospective review of a prospectively collected database of patients with spinal deformity. PATIENT SAMPLE/METHODS:One hundred and fifty-three patients with cervical deformity OUTCOME MEASURES: Common health-related quality of life scores (HRQOLs) measurements were taken for patients treated operatively for cervical deformity including neck disability index (NDI), modified Japanese Orthopaedic Association scale (mJOA) for myelopathy and numeric rating scale for neck pain (NRS-neck), METHODS: Surgical patients with severe (can you define severe?) CD were isolated based upon a previously presented discriminant analysis which outlined a combination of preoperative cervical sagittal vertical axis (cSVA), T1 slope, maximum focal kyphosis in extension, C2 slope in extension, and number of kyphotic levels in extension. Those with available preoperative and 1-year postoperative HRQL data were included. Based on a previous study, patients were grouped into 3 distinct sagittal morphotypes of CD: focal deformity (FD), flatneck (FN=large TS-CL and lack of compensation), or cervicothoracic (CT). Post-operative outcomes were defined as "good" if a patient had ≥2 of the 3 following criteria (1) NDI <20 or meeting MCID, (2) mild myelopathy (mJOA≥14), and (3) NRS-Neck ≤5 or improved by ≥2 points from baseline. Within each distinct deformity group, patients with good outcomes were compared to those with poor outcomes (i.e. not meeting the criteria for good) for differences in demographics, HRQL scores, and alignment, via Chi-squared or student's t-tests. RESULTS:Overall, 83 of 153 patients met the criteria of severe CD and 40 patients had complete 1-year follow-up of clinical/radiographic data. Patient breakdown by deformity pattern was: CT (N=13), FN (N=17), and FD (N=17), with 7 patients meeting criteria for both FD and FN deformities. Within the FD cohort, maximal focal kyphosis (i.e. kyphosis at one level) was better corrected in patients with a "good" outcome (p = 0.03). In the FN cohort, patients with "good" outcomes presented pre-operatively with worse horizontal gaze (McGregor Slope 21° vs 6°, p=0.061) and cSVA (72mm vs 60mm, p=0.030). "Good" outcome FN patients showed significantly greater postop correction of horizontal gaze (-25° vs -5°, p = 0.031). In the CT cohort, patients with "good" outcomes had superior global alignment both pre- (SVA: -17mm vs 108mm, p <0.001) and post-operatively (50mm vs 145mm, p=0.001). CT patients with "good" outcomes also had better postop cervical alignment (cSVA 35mm vs 49mm, p=0.030), and less kyphotic segments during extension (p=0.011). In the FD cohort, there were no differences between "good" and "poor" outcomes patients in preoperative alignment; however, "good" outcome patients showed superior changes in postoperative focal kyphosis (-2° vs 5°, p=0.030). Within all three deformity pattern categories, there were no differences between "good" and "poor" outcome patients with respect to demographics or surgical parameters (levels fused, surgical approach, decompression, osteotomy, all p>0.050). CONCLUSIONS:The results of this study show each CD patient's unique deformity must be carefully examined in order to determine the appropriate alignment goals to achieve optimal HRQOLs. In particular, the recognition of the sagittal morphotype can help assist surgeons to aim for specific alignment goals for CT, FN and FD. Distinct deformity specific intra-operative goals include obtaining proper sagittal global/cervical alignment for cervicothoracic patients, correcting maximal focal kyphosis in focal deformity patients, and correcting horizontal gaze for flatneck patients.

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 < 0.001).