Faculty Bibliography

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).
METHOD(S): 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]).
RESULT(S): 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<0.001). The most common mechanisms of injury were falls (30.3%), pedestrian accidents (6.9%), assault (3.2%) and bicycle-related injury (2.7%). Of the patients that underwent surgery, 52.0% underwent fusion (62.4% 2-3 levels, 33.2% eight-levels, 0.5% 9+ levels), 30.1% discectomy, and 13.8% other exploration/decompression of the spinal canal. Breakdown by time to procedure was: 38.5% same day, 16.1% 1 day, 9.6% 2 days, 7.5% 3 days, 16.2% 4-7 days, 8.3% 8-14 days, and 2.7% >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<0.001). Relative to other groups, same-day patients had the lowest LOS (7.7+/-9.8 days vs 9.4-37.3 days, p<0.001) highest rates of home discharge (42.09% vs 30.9%-14.4%, p<0.001). Same-day patients showed a trend of lower perioperative neurologic complications (0.4%) than 1-day (0.6%) and 2-day (1.0%) patients, while patients delayed 3+ days had the lowest (0.1%, p=0.144). Patients delayed >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<0.001).
CONCLUSION(S): 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.
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BACKGROUND CONTEXT: Returning to full-time work postoperatively is important to employed adults undergoing surgical treatment of adult spinal deformity (ASD). It is important for both patients and providers to have realistic expectations of returning to work after surgery, and to understand the extent to which more invasive surgery may modify a patient's return to work. PURPOSE: Our purpose was to identify the frequency of employed ASD patients who are working full-time postoperatively, and the impact of surgical invasiveness on the percentage of patients who are working full time postoperatively at various time points. STUDY DESIGN/SETTING: Retrospective review of a prospective, multicenter database. PATIENT SAMPLE: A total of 255 ASD patients were identified in a multicenter database who were employed prior to surgery and eligible for 2-year follow-up. Of these patients, 188 (74%) had 2-year follow-up or returned to work at any point within 2 years postoperatively and were included in the final cohort. OUTCOME MEASURES: Our primary outcome was returning to full-time work following surgery.
METHOD(S): Working full-time was defined as reporting 75-100% of normal work/school activity per question 9 of the Scoliosis Research Society Version 22-revised (SRS-22r) questionnaire. Surgical invasiveness was measured according to the ASD Surgical and Radiographical (ASD-SR) invasiveness index, a tool that has been developed and validated to measure the invasiveness of ASD surgery. Patients were separated into high invasiveness (HI) or low invasiveness (LI) groups for ASD-SR scores above and below 100, respectively based on previously established invasiveness categories. Chi-squared and fisher exact test were used to compare categorical variables.
RESULT(S): Mean age of patients was 51 +/- 15 years of age, 79% females. Overall, 69% of these employed patients were working full-time preoperatively, 15% were working full-time at 6-weeks, 70% at 6 months, 83% at 1-year and 84% at 2-years. The percentage of patients working full time was significantly improved at 2-years compared to preoperatively (p<0.001). The difference in patients returning to full-time work in HI and LI groups was significantly different at 6-weeks (5% in high invasiveness vs 19% with low invasiveness, p=0.03), and this difference decreased to non-significant levels at 6-months, 1-year and 2-years (p>0.05).
CONCLUSION(S): The majority of employed adults will return to full-time work following ASD surgery. More patients are working full time at 2-years postoperatively compared to preoperatively, and patients with higher invasiveness surgery may have a delay in return-to-work in the immediate postoperative period. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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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.
METHOD(S): ASD patients (scoliosis>=20degree, SVA>=5cm, PT>=25degree, or TK >=60degree) 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,<7), frail (7-12), severely frail (SF,>12). Analysis of variance assessed the relationship between increasing frailty category and validated baseline measures of patient pain and disability.
RESULT(S): Included: 50 ASD patients (52+/-20yrs, 78% female). All the following preoperative factors correlated with ASD-FI score (all p<0.039), and combined, accounted for 85.0% (p<0.001) of the variation in ASD-FI score: BMI <18.5 kg/m2 or >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<0.001), SRS-22r score (NF: 3.5, frail: 2.6, SF: 2.4, p=0.001), pain catastrophizing scale score (NF: 41.9, frail: 32.4, SF: 27.6, p<0.001), and NRS Leg Pain (NF: 2.3, frail: 7.2, SF: 5.6, p=0.001).
CONCLUSION(S): 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.
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BACKGROUND CONTEXT: Chronic opioid use is an emergent public health issue in the United States. Opioids are regularly prescribed to patients with adult spinal deformity (ASD) for postoperative pain. Therefore, the potential for chronic postoperative opioid use is a significant concern for patients undergoing surgery for ASD. It is important to patients, surgeons and policymakers to understand preoperative risk factors for prolonged opioid use in ASD patients who were not using opioids regularly prior to surgery. PURPOSE: To demonstrate demographic and surgical factors associated with increased risk of chronic opioid use following surgery in ASD patients who were not regularly using opioids preoperatively. STUDY DESIGN/SETTING: Retrospective review of a multicenter database. PATIENT SAMPLE: A total of 760 ASD patients were identified in a multicenter database eligible for 2-year follow-up. Of these patients, 547 (72%) had complete baseline and 2-year responses to question 11 of the Scoliosis Research Society version 22r (SRS-22r), which allowed us to categorize patients into opioid users and non-opioid users. Of these, 251/547 patients (46%) were not using opioids regularly prior to surgery and included in our analysis. OUTCOME MEASURES: Our primary outcome was chronic postoperative opioid use, and secondary outcome was patient satisfaction.
METHOD(S): Among patients who were not using opioids regularly prior to surgery, those reporting routine opioid use at 1 or 2-year follow-up were classified as CU (chronic user), while patients reporting no opioid use at both 1 and 2 years after surgery were classified as NC (no chronic use). Odds of CU vs NC were examined in relation to factors of interest, controlling for history of previous substance use disorder and baseline radiographic deformity. Satisfaction was assessed using the satisfaction domain of the SRS-22r.
RESULT(S): Mean age of patients was 55 +/- 17 years, 78% females. Overall, patients were using opioids until 3.2 +/- 7.7 months postoperatively. A total of 176 patients (78%) were classified as NC and 51 (22%) CU. Factors associated with significantly increased odds of CU compared with NC included smoking (OR 3.44, 95% CI: 1.06 - 11.11; p=0.039), and each additional point worse on the back pain Numeric Rating Scale (NRS) (OR 1.24, 95% CI: 1.06 - 1.46; p=0.008) SRS-22r Activity domain (OR 1.99, 95% CI: 1.27 - 3.09; p=0.002) and SRS-22r Mental Health domain (OR 1.50, 95% CI: 1.06 - 2.11; p=0.022). Notable factors that were not significantly associated with chronic use included gender, C7-S1 sagittal vertical axis, prior spine surgery, elderly age, number of levels fused, 3-column osteotomy and at least one major complication (p>0.05). CU had worse SRS-22r satisfaction scores at 2 years compared with NC (4.33 +/-.93 vs 3.80 +/- 0.17, p=0.001).
CONCLUSION(S): The majority of opioid nonusers prior to ASD surgery will not become chronic users following surgery. Factors associated with chronic opioid use include smoking, higher baseline back pain, worse preoperative functional status, and worse mental health. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: While corrective procedures for cervical deformity (CD) have significantly advanced, little is known what impact neurologic sequlae have on the postoperative recovery process. PURPOSE: Investigate which neurologic complications affect clinical outcomes the most following CD surgery. STUDY DESIGN/SETTING: Retrospective review of a prospective multicenter adult cervical deformity database. PATIENT SAMPLE: A total of 66 operative adult CD patients. OUTCOME MEASURES: Neurologic complication rates and Integrated Health State for the Neck Disability Index (NDI), EuroQol-5D (EQ-5D), and the Modified Japanese Orthopedic Association score (mJOA).
METHOD(S): CD patients (C2-C7 Cobb>10degree, CL>10degree, cSVA>4cm, or CBVA>25degree)>18yr with follow up surgical and HRQL data were included. Descriptive analyses assessed demographics. Neuro comps assessed were: C5 motor deficit, central neuro deficit, nerve root motor deficits, nerve sensory deficits, radiculopathy and spinal cord deficits. Neuro comps were classified as major (M) or minor, then: intra-operative, before discharge, before 30 days, before 90 days, and after 90 days. The rates of persistent neurologic deficits were assessed at 1 and 2 years. HRQL outcomes were assessed at 3M, 6M, 1Y and 2Y. Integrated health state (IHS) for the NDI, EQ5D, and mJOA were assessed using all follow up time points.
RESULT(S): A total of 66 operative CD patients were included. Baseline demo and surgery data: 61 years old, 63% female, BMI 29.7, op time 531.6 +/- 275.5, EBL 924.2 +/- 729.5, 49% posterior only approach, 18% anterior only approach, 33% combined. 34 (21%) patients experienced a total of 31 neurologic complications in the postoperative period (15M). In total, there were 7 radiculopathy, 6 motor deficits, 6 sensory deficits, 5 C5 motor deficits, 2 central neuro deficits, 2 spinal cord deficits, and 2 other. Motor deficits were the most common major complication (8), 4 of which were C5. Of the intraoperative complications, there were 3M, while 23% of patients had complications before discharge (5M). A total of 39% of neurologic complications occurred before 30 days (7M) and 71% before 90 days (12M), 16% were after 90 days (2M). A total of 12% of neuro comp patients went on to have revision surgery within 6 months, and 18% within 2 years. While normalized 6M mJOA scores were worse between neuro comp and no comp patients (1.00 +/- 0.12 vs 1.11 +/- 0.19, p=0.024), there was no significant difference in 2Y IHS for the NDI, EQ5D or mJOA (all p>0.05). When assessing individual comps, central neurologic deficits and spinal cord deficit patients had the worst outcomes at 1Y (2.6 and 1.8 times worse normalized NDI scores, p=0.04, no improvement in EQ5D, 8% decrease in EQ5D). Patients with sensory deficits had the best NDI and EQ5D outcomes at 1Y (31% decrease in NDI, 8% increase in EQ5D). One-half of neuro comp patients had persistent neurologic deficits at 1Y, and 21% at 2Y, however, there was no difference in outcomes at any time point (all p>0.05). Experiencing a nerve sensory deficit or spinal cord deficit correlated with revision surgery (r=0.241, 0.283, p<0.05).
CONCLUSION(S): A total of 21% of patients undergoing CD surgery experienced a neurologic complication, with 71% occurring within 6 months. While patients who experienced any neurologic complication had worse mJOA scores at 6M, there was no significant difference in recovery kinetics at 2Y. Of the neurologic complications, central neurologic deficits and spinal cord deficits were the most detrimental. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Cervical deformity (CD) correction is becoming more challenging and complex. Understanding the factors that drive optimal outcomes has been understudied in CD corrective surgery. PURPOSE: To weight baseline factors on impact upon outcomes following CD surgery. STUDY DESIGN/SETTING: Retrospective review of a single-center database. PATIENT SAMPLE: A total of 61 cervical patients. OUTCOME MEASURES: Two outcomes were measured: 'improved outcome'(IO):(1) radiographic improvement: 'non-deformed' Schwab PT/SVA, Ames cSVA/TS-CL, (2) clinical: MCID EQ5D, NDI, or improve in mJOA modifier, (3) complications/reop: no reop or major complications; 'poor outcome'(PO):(1) radiographic deterioration: 'moderate' or 'severely' deformed Schwab SVA/PT, Ames cSVA/TS-CL, (2) clinical: not meeting MCID EQ5D, NDI worsening in mJOA modifier; (3) complications/reop: reoperation or complications.
METHOD(S): CD patients included: full baseline (BL) and 1-year (1Y) radiographic measures and HRQLs. Reoperation for infection excluded. Patients were categorized by IO, PO or not. Random forest assessed ratios of predictors for IO and PO. Categorical regression models predicted how BL regional deformity (Ames cSVA, TS-CL, horizontal gaze), BL global deformity (Schwab PI-LL, SVA, PT), regional/global change (BL to 1Y), BL disability (mJOA score) and BL pain/function impact outcomes.
RESULT(S): A total of 61 patients were included (55.8yrs, 54.1% F). Surgical approach: 18.3% anterior, 51.7% posterior, 30% combined. Avg levels fused: 7.7. Mean operative time: 823min, EBL:1037ccs. At 1Y, 24.6% had an IO, 9.8% PO. Random forest analysis showed the top 5 individual factors associated with an IO: BL Maximum Kyphosis, Maximum Lordosis, C0-C2, L4 Pelvic Angle, and NSR Back Pain (80% radiographic, 20% clinical). Categorical IO regression model (R2=0.328,p=0.007): low BL regional deformity (beta=-0.082), low BL global deformity (beta=-0.099), global improve (beta=0.532), regional improve (beta=0.230), low BL disability (beta=0.100), low BL NDI (beta=0.024). Random forest demonstrated of the top 5 individual baseline factors associated with PO, 80% were radiographic: BL CL Apex, DJK angle, cervical lordosis, T1 slope and NSC Neck Pain. Categorical PO regression model (R2=0.306,p=0.012): high BL regional deformity (beta=-0.108), high BL global deformity (beta=-0.255), global decline (beta=0.272), regional decline (beta=0.443), baseline disability (beta=-0.164), BL severe NDI (>69)(beta=0.181).
CONCLUSION(S): Categorical weight demonstrated radiographic as the strongest predictor of both improved (global alignment) and poor outcome (regional deformity/deterioration). Radiographic factors carry the most weight in determining an improved or poor outcome, and can be ultimately utilized in preoperative planning and surgical decision-making in order to optimize outcomes. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND:Interplay between degenerative hip and spine conditions (Hip-Spine Syndrome [HiSS]) warrants effective communication between respective surgeons. We identified radiographic parameters to distinguish a subset of patients with HiSS by evaluating hip osteoarthritis (HOA) in patients with and without spinopelvic malalignment, categorizing patients into respective HiSS types, and comparing radiographic parameters. METHODS:All patients with full-body orthogonal radiography from 2013 to 2016 were reviewed (n = 1,389). Using sagittal/coronal hip radiographs, HOA (Kellgren-Lawrence Grade) was noted, and pelvic incidence-lumbar lordosis mismatch (PI-LL) > 10° was considered spinal malalignment. Patients groups included non-HiSS (PI-LL ≤ 10°/Grade 0/n = 444), Hip (PI-LL ≤ 10°/Grade 3-4/n = 78), Spine (PI-LL > 10°/Grade 0/n = 297), or Hip-Spine (PI-LL > 10°/Grade 3-4/n = 30). Parameters were compared using ANOVA with post-hoc Bonferroni analysis. RESULTS:HiSS Hip type patients had less hip extension capability compared with non-HiSS, Spine, and Hip-Spine type patients, reflected by lowest pelvic tilt (PT)/sagittal retroversion (11.3° versus 16.5°/29.2°/25.2°, respectively) and less hip extension per sacrofemoral angle (10.1° versus 19.5°/28.4°/23.1°, respectively) (P < 0.001), as well as 4.7° increase in anterior tilt/sagittal anteversion compared with age-matched individuals. Hip-Spine type patients had less pelvic retroversion than Spine type patients (P = 0.045); these differences were greater when referenced to age-matched individuals (P < 0.001). Hip-Spine type patients had less hip extension than Spine type patients (P = 0.013). Hip type patients had greater knee flexion than non-HiSS type patients (6.4° versus 2.6°; P < 0.001). Moreover, Hip-Spine type patients had comparable lower extremity alignment compared with Spine type patients, except for greater posterior pelvic shift. CONCLUSION/CONCLUSIONS:Our novel HiSS categorization used established classification methods and supported PT use to potentially improve the ability to discern HiSS types/pathologies in a subset of patients with HOA and spinal sagittal malalignment. HOA grade 3 to 4 with PT <15° are categorized as Hip type and those with PT >25° are Hip-Spine type with sagittal malalignment, which may impact acetabular arthroplasty component placement.

It's increasingly common for surgeons to operate on more challenging cases and higher risk patients, resulting in longer op-time and inpatient LOS. Factors predicting extended op-time and LOS for cervical deformity (CD) patients are understudied. This study identified predictors of extended op-time and length of stay (LOS) after CD-corrective surgery. CD patients with baseline (BL) radiographic data were included. Patients were stratified by extended LOS (ELOS; >75th percentile) and normal LOS (N-LOS; <75th percentile). Op-time analysis excluded staged cases, cases >12 h. A Conditional Variable Importance Table used non-replacement sampling set of Conditional Inference trees to identify influential factors. Mean comparison tests compared LOS and op-time for top factors. 142 surgical CD patients (61 yrs, 62%F, 8.2 levels fused). Op-time and LOS were 358 min and 7.2 days; 30% of patients experienced E-LOS (14 ± 13 days). Overlapping predictors of E-LOS and op-time included levels fused (>7 increased LOS 2.7 days; >5 increased op-time 96 min, P < 0.001), approach (anterior reduced LOS 3.0 days; combined increased op-time 69 min, P < 0.01), BMI (>38 kg/m² increased LOS 8.1 days; >39 kg/m² increased op-time 17 min), and osteotomy (LOS 2.0 days, op-time 62 min, P < 0.005). BL cervical parameters increased LOS and op-time: cSVA (>42 mm increased LOS; >50 mm increased op-time, P < 0.030), C0 slope (>@-0.9° increased LOS, >0.3° increased op-time, P < 0.003.) Additional op-time predictors: prior cervical surgery (p = 0.004) and comorbidities (P = 0.015). Other predictors of E-LOS: EBL (P < 0.001), change in mental status (P = 0.001). Baseline cervical malalignment, levels fused, and osteotomy predicted both increased op-time and LOS. These results can be used to better optimize patient care, hospital efficiency, and resource allocation.

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

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