Faculty Bibliography

STUDY DESIGN/METHODS:Retrospective review of prospectively collected data. OBJECTIVE:To assess the clinical impact and economic burden of the three most common hospital-acquired conditions (HACs) that occur within 30-day postoperatively for all spine surgeries and to compare these rates with other common surgical procedures. SUMMARY OF BACKGROUND DATA/BACKGROUND:HACs are part of a non-payment policy by the Centers for Medicare and Medicaid Services and thus prompt hospitals to improve patient outcomes and safety. METHODS:Patients more than 18 years who underwent elective spine surgery were identified in American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2013. Primary outcomes were cost associated with the occurrence of three most common HACs. Cost associated with HAC occurrence derived from the PearlDiver database. RESULTS:Ninety thousand five hundred fifty one elective spine surgery patients were identified, where 3021 (3.3%) developed at least one HAC. Surgical site infection (SSI) was the most common HAC (1.4%), then urinary tract infection (UTI) (1.3%) and venous thromboembolism (VTE) (0.8%). Length of stay (LOS) was longer for patients who experienced a HAC (5.1 vs. 3.2 d, P < 0.001). When adjusted for age, sex, and Charlson Comorbidity Index, LOS was 1.48 ± 0.04 days longer (P < 0.001) and payments were $8893 ± $148 greater (P < 0.001) for patients with at least one HAC. With the exception of craniotomy, patients undergoing common procedures with HAC had increased LOS and higher payments (P < 0.001). Adjusted additional LOS was 0.44 ± 0.02 and 0.38 ± 0.03 days for total knee arthroplasty and total hip arthroplasty, and payments were $1974 and $1882 greater. HACs following hip fracture repair were associated with 1.30 ± 0.11 days LOS and $4842 in payments (P < 0.001). Compared with elective spine surgery, only bariatric and cardiothoracic surgery demonstrated greater adjusted additional payments for patients with at least one HAC ($9975 and $10,868, respectively). CONCLUSION/CONCLUSIONS:HACs in elective spine surgery are associated with a substantial cost burden to the health care system. When adjusted for demographic factors and comorbidities, average LOS is 1.48 days longer and episode payments are $8893 greater for patients who experience at least one HAC compared with those who do not. LEVEL OF EVIDENCE/METHODS:3.

STUDY DESIGN/METHODS:Retrospective analysis of 2 prospectively collected multicenter databases, one for cervical deformity (CD) and the other for general adult spinal deformity. OBJECTIVE:To investigate the relative quality-of-life and disability burden in patients with uncompensated cervical, thoracolumbar, or cervical and thoracolumbar deformities. SUMMARY OF BACKGROUND DATA/BACKGROUND:The relative quality-of-life burden of cervical and thoracolumbar deformities have never been compared with each other. This may have significant implications when deciding on the appropriate treatment intervention for patients with combined thoracolumbar and cervical deformities. METHODS:When defining CD C2-C7 sagittal vertical axis (SVA)>4 cm was used while a C7-S1 SVA>5 cm was used to defined thoracolumbar deformity. Patients with both SVA criteria were defined as "combined." Primary analysis compared patients in the different groups by demographic, comorbidity data, and quality-of-life scores [EuroQOL 5 dimensions questionnaire (EQ-5D)] using t tests. Secondary analysis matched deformity groups with propensity scores matching based on baseline EQ-5D scores. Differences in disease-specific metrics [the Oswestry Disability Index, Neck Disability Index, modified Japanese Orthopaedic Association questionnaire (mJOA)] were analyzed using analysis of variance tests and post hoc analysis. RESULTS:In total, 212 patients were included in our analysis. Patients with CD only had less neurological deficits (mJOA: 14.6) and better EQ-5D (0.746) scores compared with patients with combined deformities (11.9, 0.716), all P<0.05. Regarding propensity score-matched deformity cohorts, 99 patients were matched with similar quality-of-life burden, 33 per deformity cohort. CD only patients had fewer comorbidities (1.03 vs. 2.12 vs. 2.70; P<0.001), whereas patients with combined deformity had more baseline neurological impairment compared with CD only patients (mJOA: 12.00 vs. 14.25; P=0.050). CONCLUSIONS:Combined deformity patients were associated with the lowest quality-of-life and highest disability. Furthermore, regarding deformity cohorts matched by similar baseline quality-of-life status (EQ-5D), patients with combined deformities were associated with significantly worse neurological impairments. This finding implies that quality of life may not be a direct reflection of a patient's disability status, especially in patients with combined cervical and thoracolumbar deformities. LEVEL OF EVIDENCE/METHODS:Level III.

STUDY DESIGN/METHODS:This is a retrospective review of a single surgeon cervical deformity (CD) database. OBJECTIVE:Quantitatively describe the cervical extensor musculature in a CD population, and delineate associations between posterior musculature atrophy and progressive sagittal deformity. SUMMARY OF BACKGROUND DATA/BACKGROUND:While fatty infiltration (FI; ie, posterior musculature atrophy) of lumbar extensor musculature has been associated with pain and deformity, little is known of the relationship between FI, CD, cervical sagittal alignment, and functionality. METHODS:CD patients [TS-CL>20 degrees, C2-C7 Cobb>10 degrees, CL>10 degrees, cervical sagittal vertical axis (cSVA)>4 cm, or chin-brow vertical angle>25 degrees] 18 years old and above, undergoing spinal fusion, with baseline T2-weighted magnetic resonance images were included. FI was assessed using dedicated imaging software at each intervertebral level from C2-C7. FI was gauged as a ratio of fat-free muscle cross-sectional area over total muscle cross-sectional area, with lower values indicating increasing FI. Influence of BL C2-C7 FI on patient-reported outcome measures (PROMs) and alignment was investigated. Multiple linear regression analysis (covariates: age, sex, body mass index, C2-C7 FI ratio) determined predictors of postoperative sagittal alignment and PROMs. RESULTS:Thirty-eight patients were included (age: 56.6, sex: 73.7% female, body mass index: 30.1, Charlson Comorbidity Index 0.61). BL deformity presentation: TS-CL 27.4 degrees, CL 2.1 degrees, cSVA: 27.2 mm. Mean baseline C2-C7 FI ratio was 0.65±0.11. Worsening FI was associated with malaligned baseline cSVA (rs=0.389, P=0.019), T1SS (rs=0.340, P=0.062), and impaired gait (rs=0.358, P=0.078). FI was not associated with BL PROMs (P>0.05). Following surgical intervention, regression models determined BL C2-C7 FI ratio as the strongest predictor of 1-year postoperative cSVA (β=-0.482, P=0.007, R=0.317). No associations between BL FI and postoperative PROMS or alignment parameters were observed (P>0.05). CONCLUSIONS:Patients with significant CD demonstrate alterations in the posterior extensor musculature of the cervical spine. Atrophic changes with FI of these muscle groups is associated with worsening CD and is an important predictor of postoperative sagittal alignment. LEVEL OF EVIDENCE/METHODS:Level III.

Background/UNASSIGNED:Informed patient selection and counseling is key in improving surgical outcomes. Understanding the impact that certain baseline variables can have on postoperative outcomes is essential in optimizing treatment for certain symptoms, such as radiculopathy from cervical spine pathologies. The aim was to identify baseline characteristics that were related to improved or worsened postoperative outcomes for patients undergoing surgery for cervical spine radiculopathic pain. Methods/UNASSIGNED:Retrospective review of prospectively collected data. Patient Sample: Surgical cervical spine patients with a diagnosis classification of "degenerative." Diagnoses included in the "degenerative" category were those that caused radiculopathy: cervical disc herniation, cervical stenosis, and cervical spondylosis without myelopathy. Baseline variables considered as predictors were: (1) age, (2) body mass index (BMI), (3) gender, (4) history of cervical spine surgery, (5) baseline Neck Disability Index (NDI) score, (6) baseline SF-36 Physical Component Summary (PCS) scores, (7) baseline SF-36 Mental Component Summary (MCS) scores, (8) Visual Analog Scale (VAS) Arm score, and (9) VAS Neck. Outcome Measures: Improvement in NDI (≥50%), VAS Arm/Neck (≥50%), SF-36 PCS/MCS (≥10%) scores at 2-years postoperative. An arm-to-neck ratio (ANR) was also generated from baseline VAS scores. Univariate and multivariate analyses evaluated predictors for 2-year postoperative outcome improvements, controlling for surgical complications and technique. Results/UNASSIGNED:= .025). Multivariate analysis for neck disability revealed higher baseline SF-36 PCS (odds ratio [OR] 1.053) and MCS (OR 1.028) were associated with over 50% improvements. Higher baseline NDI were reduced odds of postoperative neck pain improvement (OR 0.958). Arm pain greater than neck pain at baseline was associated with both increased odds of postoperative arm pain improvement (OR 1.707) and SF36 PCS improvement (OR 1.495). Conclusions/UNASSIGNED:This study identified specific symptom locations and health-related quality of life (HRQL) scores, which were associated with postoperative pain and disability improvement. In particular, baseline arm pain greater than neck pain was determined to have the greatest impact on whether patients met at least 50% improvement in their upper body pain score. These findings are important for clinicians to optimize patient outcomes through effective preoperative counseling.

Background/UNASSIGNED:The rate of mortality in surgical procedures involving the lumbar spine has historically been low, and as a result, there has been difficulty providing accurate quantitative mortality rates to patients in the preoperative planning phase. Awareness of these mortality rates is essential in reducing postoperative complications and improving outcomes. Additionally, mortality rates can be influenced by procedure type and patient profile, including demographics and comorbidities. The purpose of this study is to assess rates and risk factors associated with mortality in surgical procedures involving the lumbar spine using a large national database. Methods/UNASSIGNED:< .05 differences relative to the overall cohort. Results/UNASSIGNED:Mortality for all patients requiring surgery of the lumbar spine was 0.13%. Mortality based on procedure type was 0.105% for simple fusions, 0.321% for complex fusions, and 0.081% for decompression only. Increased mortality was observed demographically in patients who were male (odds ratio [OR]: 1.75; 95% confidence interval [CI]: 1.51-2.03), black (OR: 1.40; CI: 1.10-1.79), ages 65-74 (OR: 1.46; CI: 1.25-1.70), and age 75+ (OR: 2.70; CI: 2.30-3.17). Comorbidities associated with the greatest increase in mortality were mild (OR: 10.04; CI: 7.76-13.01) and severe (OR: 26.47; CI: 16.03-43.70) liver disease and congestive heart failure (OR: 4.57; CI: 3.77-5.53). The complications with the highest mortality rates were shock (OR: 20.67; CI: 13.89-30.56) and pulmonary embolism (OR: 20.15; CI: 14.01-29.00). Conclusions/UNASSIGNED:From 2003 to 2012, the overall mortality rate in 803,949 lumbar spine surgery patients was 0.13%. Risk factors that were significantly associated with increased mortality rates were male gender, black race, and ages 65-74 and 75+. Comorbidities associated with an increased mortality rate were mild and severe liver disease and congestive heart failure. Inpatient complications with the highest mortality rates were shock and pulmonary embolism. These findings can be helpful to surgeons providing preoperative counseling for patients considering elective lumbar procedures and for allocating resources to treat and prevent perioperative complications leading to mortality. Level of Evidence/UNASSIGNED:3.

BACKGROUND:Despite the potential for profound impact of adult cervical deformity (ACD) on function and health-related quality of life (HRQOL), there are few high-quality studies that assess outcomes of surgical treatment for these patients. OBJECTIVE:To determine the impact of surgical treatment for ACD on HRQOL. METHODS:We conducted a prospective cohort study of surgically treated ACD patients eligible for 1-yr follow-up. Baseline deformity characteristics, surgical parameters, and 1-yr HRQOL outcomes were assessed. RESULTS:Of 77 ACD patients, 55 (71%) had 1-yr follow-up (64% women, mean age of 62 yr, mean Charlson Comorbidity Index of 0.6, previous cervical surgery in 47%). Diagnoses included cervical sagittal imbalance (56%), cervical kyphosis (55%), proximal junctional kyphosis (7%) and coronal deformity (9%). Posterior fusion was performed in 85% (mean levels = 10), and anterior fusion was performed in 53% (mean levels = 5). Three-column osteotomy was performed in 24% of patients. One year following surgery, ACD patients had significant improvement in Neck Disability Index (50.5 to 38.0, P < .001), neck pain numeric rating scale score (6.9 to 4.3, P < .001), EuroQol 5 dimension (EQ-5D) index (0.51 to 0.66, P < .001), and EQ-5D subscores: mobility (1.9 to 1.7, P = .019), usual activities (2.2 to 1.9, P = .007), pain/discomfort (2.4 to 2.1, P < .001), anxiety/depression (1.8 to 1.5, P = .014). CONCLUSION/CONCLUSIONS:Based on a prospective multicenter series of ACD patients, surgical treatment provided significant improvement in multiple measures of pain and function, including Neck Disability Index, neck pain numeric rating scale score, and EQ-5D. Further follow-up will be necessary to assess the long-term durability of these improved outcomes.

STUDY DESIGN/METHODS:Retrospective analysis. OBJECTIVE:To improve understanding of the impact of comorbid mental health disorders (MHDs) on long-term outcomes following cervical spinal fusion in cervical radiculopathy (CR) or cervical myelopathy (CM) patients. SUMMARY OF BACKGROUND DATA/BACKGROUND:Subsets of patients with CR and CM have MHDs, and their impact on surgical complications is poorly understood. METHODS:Patients admitted from 2009 to 2013 with CR or CM diagnoses who underwent cervical surgery with minimum 2-year surveillance were retrospectively reviewed using New York State's Statewide Planning and Research Cooperative System. Patients with a comorbid MHD were compared against those without (no-MHD). Univariate analysis compared demographics, complications, readmissions, and revisions between MHD and no-MHD cohorts. Multivariate binary logistic regression models identified independent predictors of outcomes (covariates: age, sex, Charlson/Deyo score, and surgical approach). RESULTS:A total of 20,342 patients (MHD: n = 4819; no-MHD: n = 15,523) were included. MHDs identified: depressive (57.8%), anxiety (28.1%), sleep (25.2%), and stress (2.9%). CR patients had greater prevalence of comorbid MHD than CM patients (P = 0.015). Two years postoperatively, all patients with MHD had significantly higher rates of complications (specifically: device-related, infection), readmission for any indication, and revision surgery (all P < 0.05); regression modeling corroborated these findings and revealed combined surgical approach as the strongest predictor for any complication (CR, odds ratio [OR]: 3.945, P < 0.001; CM, OR: 2.828, P < 0.001) and MHD as the strongest predictor for future revision (CR, OR: 1.269, P = 0.001; CM, OR: 1.248, P = 0.008) in both CR and CM cohorts. CONCLUSION/CONCLUSIONS:Nearly 25% of patients admitted for CR and CM carried comorbid MHD and experienced greater rates of any complication, readmission, or revision, at minimum, 2 years after cervical spine surgery. Results must be confirmed with retrospective studies utilizing larger national databases and with prospective cohort studies. Patient counseling and psychological screening/support are recommended to complement surgical treatment. LEVEL OF EVIDENCE/METHODS:3.

Introduction: Cervical deformity (CD) correction has becomeincreasingly complex and challenging. Osteotomies are commonlyperformed to correct sagittal malalignment, however the risks andbenefits of performing a major osteotomy for cervical deformitycorrection have been understudied. The purpose of this study was toinvestigate the risks and benefits of performing a major osteotomy forCD correction.Methods: Retrospective review of a multicenter prospective CDdatabase. CD was defined as at least one of the following: C2-C7Cobb [10, CL [10, cSVA [4 cm, CBVA [25. Patientsstratified based on having a major osteotomy (MAJ-pedicle subtraction osteotomy or vertebral column resection) or minor (MIN).Propensity score matching (PSM) was performed controlling forbaseline cSVA and T1S. Flexibility of the deformity was assessedusing C2-C7 lordosis and T1S change greater than 10 betweenflexion and extension. Independent t-tests and Chi Squared tests wereused to assess differences between MAJ and MIN.Results: 89 CD patients were included (62 years, 65%F). 19 (21.3%)CD patients underwent a MAJ osteotomy. MAJ and MIN had nodifferences in any baseline radiographic parameters, with the exception of cSVA (MAJ: 59.3 mm, MIN: 41.9 mm, p = 0.007). AfterPSM for cSVA, 38 patients were included (60 years, 60%F). 19(21.3%) CD patients underwent a MAJ osteotomy (14 pedicle subtraction osteotomy, 5 vertebral column resection). MAJ patientsunderwent more invasive surgeries, with more levels fused (10.6 vs7.1, p <0.001) and blood loss (1442 cc vs 802 cc, p = 0.036),despite similar operative time and intra-and post-operative complication rates as MIN patients. At 3 M post-op, MAJ and MIN patientshad similar NDI, mJOA, and EQ5D scores, however by 6M and 1Ypost-op MAJ patients reached MCID for NDI less than MIN patients(10.5 vs 57.9%, p = 0.003). Comparing patients with fixed versusnon-fixed CL, MAJ patients with non-fixed lordosis trended towardsimprovement in NDI (p = 0.30) but also trended towards highercomplication (78 vs 43%, p = 0.182) and reoperation rates (44 vs 0%,p = 0.069) than fixed deformities. Rigid deformities trended towardsimprovement in TS-CL (43% improve vs 33%, p = 0.54) and cSVA(14 vs 0%, p = 0.49) for MAJ patients and lower complication rate(MIN most commonly had DJK and reoperation) (43 vs 100%,p = 0.09).Conclusions: Cervical deformity patients who underwent a majorosteotomy had similar clinical outcomes at 3-months but worseclinical outcomes at 6-months and 1-year, assessed by NDI and EQ-5D, as compared with patients with minor osteotomies, in partbecause patients undergoing major osteotomies have more severedeformities and have more prolonged recovery kinetics. Patients withflexible curves showed similar alignment and clinical outcomes butincreased complication risk when undergoing a major osteotomy.Contrarily, patients with rigid deformities who underwent a majorosteotomy trended towards radiographic and clinical improvementand lower rates of DJK and reoperation

Background: Recent studies suggest non-routine discharge, includingdischarge to inpatient rehab and skilled nursing facilities, is associatedwith increased cost of care. Given the rising prevalence of cervicaldeformity (CD)-corrective surgery and the necessity of value-basedhealthcare, it is important to identify indicators for non-routine discharge in surgical CD patients.Study Design: Retrospective review of prospective, multicenter CDdatabase.Methods: Included: Surgical CD patients (C2-C7 Cobb [10,CL [10, cSVA [4 cm, or CBVA [25) [18 years with discharge and baseline (BL) radiographic data. Non-routine dischargedefined: inpatient rehab or skilled nursing facility. ConditionalInference Decision Trees identified predictors of non-routine discharge, and cut-off points at which predictors have a global effect.A Conditional Variable Importance Table used non-replacementsampling set of 3000 Conditional Inference trees to identify influential patient/surgical factors. Binary logistic regression indicated effectsize of influential factors at significant cut-off points. Means comparison testing assessed the relationship between non-routinedischarge and reop/HRQL outcomes.Results: Included: 138 patients (61 +/- 10 years, 63%F) undergoingCD-corrective surgery (8.2 +/- 4.6 levels; 49% posterior-onlyapproach, 16% anterior-only, 35% combined). 29% of patientsexperienced non-routine discharge (21% inpatient rehab, 8% SNF).BL cervical and upper-cervical malalignment was the strongest predictor of non-routine discharge: [1] C1 slope [14 (OR:8.4 [95%CI:3.1-22.7]), [3] C2 slope [57 (OR: 7.0 [2.6-18.3]), [4] TSCL [57 (OR: 5.9 [2.2-15.9]), [14] C0 slope[-0.66 (OR: 4.2[1.9-9.3]), [15] cSVA [40 mm (OR: 4.6 [2.0-10.9]), [18] McGregor's slope [1.9 (OR: 4.1 [1.7-9.9]). Patient-related predictors ofnon-routine discharge were [2] BL gait impairment (OR: 5.29[2.3-12.4]), [8] age [59 years (OR: 4.3 [1.6-11.1]), [10] apex of CDprimary driver [C7 (OR: 3.9[1.8-8.6]), and [13] admission tosurgical ICU (OR: 5.4 [1.9-14.8]). Experiencing 2 or more complications was predictive of non-routine discharge (OR: 4.2 [1.9-9.2]),but the only specific complications predictive of non-routone discharge were EBL [900 cc (OR: 3.6 [1.7-7.7]) and presence of anyneuro complication (OR: 2.8 [1.8-8.4]). The only surgical predictor ofnon-home discharge was [12] fusion[8 levels (OR: 4.0 [1.8-9.0]).LOS [6 days was also predictive of non-routone discharge (OR: 4.0[1.8-8.9]). There was no relationship between non-routine dischargeand reop within 3 months (P = 0.249), 6 months (P = 0.793), or1 year (P = 0.814) of index procedure. Despite no differences in BLEQ-5D (P = 0.946), non-routine patients had inferior 1-year postopEQ-5D scores (non-routine: 0.75, home: 0.79, P = 0.044).Conclusions: Preop cervical malalignment was a top predictor ofnon-routine discharge in surgical CD patients. Age, driver of deformity, and [8 level fusion also predicted non-routine discharge, andshould be taken into account to improve resource allocation andpatient counseling

Summary: In cervical deformity surgery, failure to correct cSVA andC2 slope (C2S) is associated with poor clinical outcomes. Currentsurgical planning and intraoperative measurements are limited tocervical lordosis (CL) correction. By predicting T1 Slope (T1S)change from baseline to 3 month postop and adding a correctionfactor for the change in distal junctional kyphosis angle (DJKA),cSVA and C2S can be predicted more accurately.Hypothesis: While correction of CL is commonly used to predictpost-op alignment, post-op cSVA, and C2S can be predicted betterusing additional variables.Design: Prospective cohort study.Introduction: Cervical malalignment is associated with severe disability. Currently, surgical planning and intraop measurements ofcorrection are limited to CL change. We aim to develop a predictivemodel for postop cSVA C2S and T1S using more than CL change.Methods: A prospective database of operative CD patients wasanalyzed. Inclusion criteria were cervical kyphosis [10, cervicalscoliosis [10, cSVA [4 cm or CBVA [25. The patients wererandomly filtered to include 66.7% of the cohort for model development. Predictive models were developed to estimate post-op T1S,cSVA, and C2S using linear regression. The new predictive equationswere validated in the remaining 33.3% of the cohort.Results: 153 patients with CD met inclusion criteria. T1S changedsignificantly (32.4-35.2, p =.05) from baseline to 3M follow-up.The mean DJKA change was-6.59. 101 patients were included inmodel development. To predict post-opT1S, CLchange and preT1Sexplained 62.4% of the variability of data (R2 = 0.624). By includingDJKA, R2 improved to 0.724. When predicting postop cSVA,CLchange and preop cSVA accounted for 57.2% of variability(R2 = 0.572). With change in DJKA, the R2 improved to 0.661. Themodel was optimized with the change in T1S (R2 = 0.777). Pre-opC2S and CLchange lead to poor predictability in post-op C2S(R2 = 0.348). Using DJKA change, the R2 improved to 0.550. Byincluding DJKA and T1S change, the model was optimized(R2 = 0.926).The predictive equations were applied to the remaining 52 patientsusing the mean DJKA (-6.59) for the DJKA variable and the T1Schange calculated for the predictive model. Predicted postop alignments correlated to postop T1S, cSVA, and C2S (R = 0.712,R = 0.736, and R = 0.584 respectively, p <0.01).Conclusions: Realignment in CD surgery is critical to obtain optimaloutcomes. Current surgical planning of CD does not accurately predict postop cSVA and C2S. A reliable predictive model is presentedfor cSVA and C2S using changes in T1S and DJKA