Faculty Bibliography

Study Design: Retrospective review of prospective database. Objectives: Vertebral pelvic angles (VPAs) account for complexity in spine shape by assessing the relative position of each vertebra with regard to the pelvis. This study uses VPAs to investigate the shape of the fused spine after T10-pelvis fusion, in patients with adult spinal deformity (ASD), and then explores its association with proximal junctional kyphosis (PJK). Methods: Included patients had radiographic evidence of ASD and underwent T10-pelvis realignment. VPAs were used to construct a virtual shape of the post-operative spine. VPA-predicted and actual shapes were then compared between patients with and without PJK. Logistic regression was used to identify components of the VPA-based model that were independent predictors of PJK occurrence and post-operative shape. Results: 287 patients were included. VPA-predicted shape was representative of the true post-operative contour, with a mean point-to-point error of 1.6-2.9% of the T10-S1 spine length. At 6-weeks follow-up, 102 patients (35.5%) developed PJK. Comparison of the true post-operative shapes demonstrated that PJK patients had more posteriorly translated vertebrae from L3 to T7 (P <.001). Logistic regression demonstrated that L3PA (P =.047) and T11PA (P <.001) were the best independent predictors of PJK and were, in conjunction with pelvic incidence, sufficient to reproduce the actual spinal contour (error <3%). Conclusions: VPAs are reliable in reproducing the true, post-operative spine shape in patients undergoing T10-pelvis fusion for ASD. Because VPAs are independent of patient position, L3PA, T11PA, and PI measurements can be used for both pre- and intra-operative planning to ensure optimal alignment.

STUDY DESIGN/METHODS:Retrospective review of a multicenter comprehensive cervical deformity (CD) database. OBJECTIVE:To develop a novel risk index specific to each patient to aid in patient counseling and surgical planning to minimize postop DJK occurrence. BACKGROUND:Distal junctional kyphosis(DJK) is a radiographic finding identified after patients undergo instrumented spinal fusions which can result in sagittal spinal deformity, pain and disability, and potentially neurological compromise. DJK is considered multifactorial in nature and there is a lack of consensus on the true etiology of DJK. METHODS:CD pts with baseline(BL) and at least 1-year postoperative(1Y) radiographic follow-up were included. A patient-specific DJK score was created through use of unstandardized Beta weights of a multivariate regression model predicting DJK(end of fusion construct to the 2nd distal vertebra change in this angle by<-10° from BL to postop). RESULTS:110 CD pts included(61yrs, 66.4%F, 28.8kg/m2). 31.8% of these pts developed DJK (16.1% 3M, 11.4% 6M, 62.9% 1Y). At BL, DJK pts were more frail and underwent combined approach more (both P<0.05). Multivariate model regression analysis identified individualized scores through creation of a DJK equation: -0.55+0.009(BL Inclination) -0.078(Pre Inflection)+5.9×10-5(BL LIV angle) + 0.43(combine approach) - 0.002(BL TS-CL)- 0.002(BL PT)- 0.031(BL C2-C7)+ 0.02(∆T4-T12)+ 0.63(Osteoporosis)- 0.03(anterior approach) - 0.036( Frail) - 0.032(3 column osteotomy). This equation has a 77.8% accuracy of predicting DJK. A score ≥81 predicted DJK with an accuracy of 89.3%. The BL reference equation correlated with 2Y outcomes of NSR-Back percentage(P=0.003), reoperation(P=0.04), and MCID for EQ. 5D(P=0.04). CONCLUSIONS:This study proposes a novel risk index of DJK development that focuses on potentially modifiable surgical factors as well as established patient-related and radiographic determinants. The reference model created demonstrated strong correlations with relevant two year outcome measures, including axial pain-related symptoms, occurrence of related reoperations, and the achievement of minimal clinically importance differences for EQ. 5D.

STUDY DESIGN/METHODS:Retrospective cohort. OBJECTIVE:To describe the 2-year outcomes for patients undergoing surgical correction of cervical deformity. BACKGROUND:Adult cervical deformity (CD) has been shown to compromise health-related quality of life. While advances in spinal realignment have shown promising short-term clinical results in this parameter, the long-term outcomes of CD corrective surgery remain unclear. METHODS:Operative CD patients >18 years with 2-year (2Y) HRQL/radiographic data were included. Improvement in radiographic, neurologic and HRQL outcomes were reported. Patients with a prior cervical fusion and patients with the greatest and smallest change based on NDI, NRS neck, mJOA were compared using multivariable analysis controlling for age, and frailty, and invasiveness. RESULTS:158 patients were included in this study. By 2Y, 96.3% of patients improved in Ames cSVA modifier, 34.2% in TS-CL, 42.0% in Horizontal gaze modifier, and 40.9% in SVA modifier. Additionally, 65.5% of patients improved in Passias CL modifier, 53.3% in TS-CL modifier, 100% in C2-T3 modifier, 88.9% in C2S modifier, and 81.0% in MGS modifier severity by 2Y. The cohort significantly improved from BL to 2Y in NDI, NRS Neck, and mJOA, all P<0.05. 59.3% of patients met MCID for NDI, 62.3% for NRS Neck, and 37.3% for mJOA. 97 patients presented with at least one neurologic deficit at BL and 63.9% no longer reported that deficit at follow-up. There were 45 (34.6%) cases of DJK (∆DJKA>10° between LIV and LIV-2), of which 17 were distal junctional failure (DJF-DJK requiring reoperation). Patients with the greatest beneficial change were less likely to have had a complication in the 2-year follow-up period. CONCLUSION/CONCLUSIONS:Correction of cervical deformity results in notable clinical and radiographic improvement with most patients achieving favorable outcomes after two years. However, complications including distal junctional kyphosis or failure remain prevalent.

BACKGROUND:Studies have utilized psychological questionnaires to identify the psychological distress among certain surgical populations. RESEARCH QUESTION/OBJECTIVE:Is there an additional psychological burden among patients undergoing surgical treatment for their symptomatic degenerative cervical disease? MATERIALS AND METHODS/METHODS:Patients>18 years of age with symptomatic, degenerative cervical spine disease were included and prospectively enrolled. Correlations and multivariable logistic regression analysis assessed the relationship between these mental health components (PCS, FABQ) and the severity of disability described by the NDI, EQ-5D, and mJOA score. Patient distress scores were compared to previously published benchmarks for other diagnoses. RESULTS:). Increasing neck disability and decreasing EQ-5D were correlated with greater PCS and FABQ(all p<0.001). Patients with severe psychological distress at baseline were more likely to report severe neck disability, while physician-reported mJOA had weaker associations. Compared to historical controls of lumbar patients, patients in our study had greater levels of psychological distress, as measured by FABQ (40.0 vs 17.6;p<0.001) and PCS (27.4 vs 19.3;p<0.001). DISCUSSION AND CONCLUSION/CONCLUSIONS:Degenerative cervical spine patients seeking surgery were found to have a significant level of psychological distress, with a large portion reporting severe fear avoidance beliefs and catastrophizing pain at baseline. Strong correlation was seen between patient-reported functional metrics, but less so with physician-reported signs and symptoms. Additionally, this population demonstrated higher psychological burden in certain respects than previously identified benchmarks of patients with other disorders. Preoperative treatment to help mitigate this distress, impact postoperative outcomes, and should be further investigated. LEVEL OF EVIDENCE/METHODS:Level III.

BACKGROUND:As corrective surgery for cervical deformity (CD) increases, so does the rate of complications and reoperations. To minimize suboptimal postoperative outcomes, it is important to develop a tool that allows for proper preoperative risk stratification. OBJECTIVE:To develop a prognostic utility for identification of risk factors that lead to the development of major complications and unplanned reoperations. METHODS:CD patients age 18 years or older were stratified into 2 groups based on the postoperative occurrence of a revision and/or major complication. Multivariable logistic regressions identified characteristics that were associated with revision or major complication. Decision tree analysis established cutoffs for predictive variables. Models predicting both outcomes were quantified using area under the curve (AUC) and receiver operating curve characteristics. RESULTS:A total of 109 patients with CD were included in this study. By 1 year postoperatively, 26 patients experienced a major complication and 17 patients underwent a revision. Predictive modeling incorporating preoperative and surgical factors identified development of a revision to include upper instrumented vertebrae > C5, lowermost instrumented vertebrae > T7, number of unfused lordotic cervical vertebrae > 1, baseline T1 slope > 25.3°, and number of vertebral levels in maximal kyphosis > 12 (AUC: 0.82). For developing a major complication, a model included a current smoking history, osteoporosis, upper instrumented vertebrae inclination angle < 0° or > 40°, anterior diskectomies > 3, and a posterior Smith Peterson osteotomy (AUC: 0.81). CONCLUSION/CONCLUSIONS:Revisions were predicted using a predominance of radiographic parameters while the occurrence of major complications relied on baseline bone health, radiographic, and surgical characteristics.

STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:Assess changes in outcomes and surgical approaches for adult cervical deformity (ACD) surgery over time. SUMMARY OF BACKGROUND DATA/BACKGROUND:As the population ages and prevalence of cervical deformity increases, corrective surgery has been increasingly seen as a viable treatment. Dramatic surgical advancements and expansion of knowledge on this procedure have transpired over years, but the impact on cervical deformity surgery is unknown. METHODS:ACD patients (≥18 yrs) with complete baseline and up to two-year HRQL and radiographic data were included. Descriptive analysis included demographics, radiographic, and surgical details. Patients were grouped into Early(2013-2014) and Late(2015-2017) by DOS. Univariate and multivariable regression analyses were used to assess differences in surgical, radiographic, and clinical outcomes over time. RESULTS:119 cervical deformity patients met inclusion criteria. Early group consisted of 72 patients, and Late group consisted of 47. Late group had a higher CCI (1.3 vs. 0.72), more cerebrovascular disease (6% vs. 0%, both P<0.05), and no difference in age, frailty, deformity, or cervical rigidity. Controlling for baseline deformity, and age, Late group underwent fewer three-column osteotomies (OR=0.18, 95% CI:0.06-0.76, P=0.014). At last follow-up, Late group had less patients with: a moderate/high Ames horizontal modifier (71.7% vs. 88.2%), and overcorrection in PT (4.3% vs. 18.1%, both P<0.05). Controlling for baseline deformity, age, levels fused, and three-column osteotomies, Late group experienced fewer adverse events (OR =0.15, 95% CI: 0.28-0.8, P=0.03), and neurological complications (OR =0.1, 95% CI:0.012-0.87, P=0.03). CONCLUSION/CONCLUSIONS:Despite a population with greater co-morbidity and associated risk, outcomes remained consistent between early and later time-periods, indicating general improvements in care. The later cohort demonstrated fewer three-column osteotomies, less suboptimal realignments and concomitant reductions in adverse events and neurologic complications. This may suggest greater facility with less invasive techniques.

BACKGROUND:Frailty is influential in determining operative outcomes, including complications, in patients with cervical deformity (CD). OBJECTIVE:To assess whether frailty status limits the highest achievable outcomes of patients with CD. METHODS:Adult patients with CD with 2-year (2Y) data included. Frailty stratification: not frail (NF) <0.2, frail (F) 0.2 to 0.4, and severely frail (SF) >0.4. Analysis of covariance established estimated marginal means based on age, invasiveness, and baseline deformity, for improvement, deterioration, or maintenance in Neck Disability Index (NDI), Modified Japanese Orthopaedic Association (mJOA), and Numerical Rating Scale Neck Pain. RESULTS:One hundred twenty-six patients with CD included 29 NF, 83 F, and 14 SF. The NF group had the highest rates of deterioration and lowest rates of improvement in cervical Sagittal Vertical Axis and horizontal gaze modifiers. Two-year improvements in NDI by frailty: NF: -11.2, F: -16.9, and SF: -14.6 (P = .524). The top quartile of NF patients also had the lowest 1-year (1Y) NDI (7.0) compared with F (11.0) and SF (40.5). Between 1Y and 2Y, 7.9% of patients deteriorated in NDI, 71.1% maintained, and 21.1% improved. Between 1Y and 2Y, SF had the highest rate of improvement (42%), while NF had the highest rate of deterioration (18.5%). CONCLUSION/CONCLUSIONS:Although frail patients improved more often by 1Y, SF patients achieve most of their clinical improvement between 1 and 2Y. Frailty is associated with factors such as osteoporosis, poor alignment, neurological status, sarcopenia, and other medical comorbidities. Similarly, clinical outcomes can be affected by many factors (fusion status, number of pain generators within treated levels, integrity of soft tissues and bone, and deformity correction). Although accounting for such factors will ultimately determine whether frailty alone is an independent risk factor, these preliminary findings may suggest that frailty status affects the clinical outcomes and improvement after CD surgery.

BACKGROUND CONTEXT: The ACS-NSQIP and SpineSage are both easy to use and readily available online perioperative risk calculators The ACS-NSQIP calculator predicts perioperative complications after surgery, but lacks more spine-specific predictors. The SpineSage platform was developed as a tool built for predicting complications in spine surgery. While a limited number of studies have shown it be predictive of both overall and major medical complications in spine surgery, large external validation studies are limited and none have directly compared NSQIP against SpineSage in the same cohort of spine surgery patients. PURPOSE: Assess the ACS-NSQIP Risk Calculator and SpineSage informatics platform for prediction of perioperative complications in spine surgery STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 440 patients undergoing thoracolumbar spine with or without fusion. OUTCOME MEASURES: Any complication, serious complication, pneumonia, cardiac, dural tear, SSI, UTI, VTE, reoperation, death and LOS METHODS: Each patient was entered into the ACS-NSQIP and SpineSage calculators and predicted risk for specific complications were directly compared to actual risks. Paired t-tests compared the differences between calculators and their predictability of complications. Patients were ranked based on risk predicted for each complication and the highest tertile for each was isolated. Multivariate regression controlling for age and gender was used to determine if the highest tertile for each risk calculator had predictability in complications following spine surgery.
RESULT(S): Mean LOS 4.2+3 days, EBL 444+300 mL, operative time 256+240 min, and levels instrumented 2.1+2.3. When assessing the four complications predicted by SpineSage there were significant differences in three of the four variables, as SpineSage underpredicted the risk of all and serious-complications (p.5). Both calculator tertiles were trending towards significance for major medical complications (SpineSage: OR: 2.0, [0.94-4.23], p=.073; ACS-NSQIP: OR: 1.8,[0.96-3.48],p=.067). When examining any medical risk, only ACS NSQIP had significant predictability for any medical complication (OR: 2.1, [1.3-3.3]; p=.003).
CONCLUSION(S): Similar to previous studies, the ACS-NSQIP score underpredicted most complications, with the exception of LOS and death. In contrast to previous studies, our data suggest SpineSage was not predictive of actual rates of complications. As both calculators are highly accessible and provide at least some objective perioperative risk data points, we recommend them as a guiding tool but not as an absolute endpoint for clinical decision making as they may be inaccurate and insensitive. Further, higher powered studies elucidating the findings in this study should be conducted. Additionally, the assessment of these calculators for a specific subset of patients, such as deformity, degenerative or pediatrics, can further help guide clinicians regarding the utility of these calculators for their particular patient populations. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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