Faculty Bibliography

BACKGROUND CONTEXT: Despite multiple reports showing favorable long-term functional outcomes following adult spinal deformity (ASD) correction, it is still unclear which patient factors may impact the sustainability of these outcomes. PURPOSE: To assess the sustainability of functional gains following ASD correction and determine predictors for postoperative loss of patient functionality. STUDY DESIGN/SETTING: Retrospective cohort. PATIENT SAMPLE: A total of 689 ASD patients. OUTCOME MEASURES: Sustained clinical benefit, Oswestry Disability Index (ODI), reoperation, mechanical failure, proximal junctional failure (PJF) METHODS: ASD patients with baseline (BL) and three-year (3Y) follow-up data were considered for analysis. Only patients who met the definition of sustained clinical benefit (SCB) at one-year (1Y) were included: 1)Passias et al's threshold for ODI (ODI<31.3), 2) did not develop PJF, and 3) did not have a reoperation for a mechanical failure. Patient groups were created by those who met SCB at 3Y, and those who did not. SCB outcomes were also reported at five-years (5Y) postoperatively. Means comparison tests assessed differences in patient groups. Factors predicting SCB were identified using adjusted regression and conditional inference tree (CIT) analysis.
RESULT(S): A total of 157 patients met inclusion criteria and had SCB at 1Y. Patient breakdown for SCB was 75.0% at 3Y. Gender (78% vs 81%), BMI (25.5 vs 26.4), levels fused (10.6 vs 10.5), operative time (345 vs 362 min), and surgical invasiveness were similar between groups, all P>.05. Following surgery, patient groups were similarly aligned to Lafage et al's age-adjusted PT, PI-LL, and SVA, all P>.05. Regression and CIT analysis adjusting for BL deformity determined that patients who met SCB at 3Y were 95.4% less likely to have an ASD-mFI score > 11 (.046[.005-.420], p=0.006), 73.1% less likely to be older than 55 years at DOS (.269[.091-.798], p=.018), 69.4% less likely to have a CCI score > 0(.306[.116-.811], p=.017), and 86.9% less likely to have a BL EQ5D score <.723 (.131[.029-.585], p=.008). Adjusted for patients without follow-up, sustained clinical benefit at 5Y was 57.9%. Predictors of SCB from 3Y to 5Y included age, CCI and EQ5D, all P <.05.
CONCLUSION(S): Sustained clinical benefit was maintainable for 75.0% of the operative ASD cohort at 3Y. Similarly, a 57.9% maintenance rate of sustained clinical benefit at 5Y reflects the longevity of ASD correction. Independent predictors of sustained clinical benefit included age, frailty, comorbidities and the patient health state. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Current radiographic thresholds have shown inconsistent correlation with clinical outcomes. However, it has not been determined at what point in presenting deformity does sagittal correction tremendously improve clinical outcomes following cervical deformity surgery. PURPOSE: Define baseline thresholds in cervical parameters that, when exceeded, benefit dramatically from surgical correction to achieve ideal clinical outcomes. STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 290 ACD patients. OUTCOME MEASURES: Clinical outcomes, radiographic alignment.
METHOD(S): CD patients with baseline (BL) and 2-year (2Y) data included. Parameters assessed: C2 slope (C2S), C2-C7 Lordosis, C2-C7 SVA (cSVA), T1 Slope (T1S), TS-CL.
Outcome(s): Virket al Good Clinical Outcome (GCO): [Meeting 2 of 3: 1) an NDI>20 or meeting MCID, 2) mJOA >=14), 3) an NRS-Neck<=5 or improved by 2 or more points from baseline]. Binary logistic regression assessed each parameter to determine if correction was more likely needed to achieve GCO. Conditional inference tree (CIT) run machine learning analysis generated baseline thresholds for each parameter, above which, correction was necessary to achieve GCO.
RESULT(S): Included: 105 CD patients. There were 57 (54%) of patients achieving GCO by 2Y. Correction was necessitated when baseline C2S was above 20degree (OR: 6.8, [1.6-28.9]; p=.01) and when baseline C2-C7 Lordosis was below 10degree (OR: 16, [2.4-107.5]; p=.004). Patients presenting with a cSVA above 20 mm more often achieved clinical success when corrected (74.2% vs 0.0%, p<.001). A baseline T1 slope above 23degree was 16 times more likely to reach GCO with correction than those below this threshold (p=.005). TS-CL more likely required correction to reach GCO when above 26degree at baseline (OR: 7.0, [1.7-29.1]; p=.007). When assessing patients above both the cSVA and C2S threshold versus the remaining cohort, these patients more likely met GCO when corrected in either parameter (OR: 22.5, [3.3-152.0]; p=.001).
CONCLUSION(S): Our study highlighted the importance of correction and the threshold at which it dramatically impacts clinical success. These new thresholds delineate patients obtaining superior benefit for sagittal correction and may better increase the utility gained from surgical intervention for cervical deformity. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Evidence on long-term surgical recovery in adult spinal deformity (ASD) patients who are both frail and have an invasive procedure is limited. PURPOSE: This study aims to evaluate frail and invasive patients with 5-year recovery kinetics. We hypothesize that patients who are both frail and have invasive surgeries will have adverse postoperative recovery kinetics STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: A total of 133 ASD patients with complete HRQOL data at preoperative, 1-year, 2-year, 5-year follow-up were included. OUTCOME MEASURES: Integrated Health State Scores (IHS) in Oswestry Disability Index (ODI), Short-form 36 (SF-36) physical (PCS) and mental (MCS) component score, and Scoliosis Research Society (SRS)-22r measures METHODS: ASD-FI scores were used to stratify non-frail (0.3) patients. ASD-SR scores were used to stratify low invasive (90) surgeries. Using ASD-FI and ASD-SR, patients were separated into four cohorts: non-frail low invasive (NFLI), frail low invasive (FLI), non-frail high invasive (NFHI), and frail high invasive (FHI). HRQOLs at 1 year, 2 years, and 5 years were normalized against preoperative values. AUC was calculated across time points to generate an integrated health state score (IHS). Multivariable linear regression was used to compare IHS scores of FLI, NFHI, and FHI to NFLI while controlling for age, gender, comorbidity, and radiographic alignment.
RESULT(S): Of 633 eligible ASD patients, 339 had 5-year follow-up. Of those, 125 patients with complete HRQOL data at preoperative, 1-year, 2-year, and 5-year visits were included; 27.2% (34) were NFLI, 20.0% (25) were FLI, 26.4% (33) were NFHI, and 26.4% (33) were FHI. Using NFLI as the referent, FLI and NFHI did not have differences in ODI, MCS, PCS or SRS-22r IHS scores (P >0.05). On multivariable analysis of integrated health scores, FHI had higher MCS (7.6 vs 5.47; P=0.0188), SRS activity (6.97 vs 5.67; P=0.0004), SRS pain (8.49 vs 6.4; P=0.001), SRS appearance (8.97 vs 6.81; P=0.0014), SRS satisfaction (11.71 vs 7.97; P=0.0033), and SRS total (7.49 vs. 6.09; P=0.0002), indicating more improved recovery over a 5-year period. Patients who were FHI had higher rates of complications (P <0.05).
CONCLUSION(S): Despite having more complications, patients who were frail and underwent more invasive surgeries were more likely to have greater overall improvement in activity, pain, and satisfaction over a 5-year period relative to preoperative baseline. Our results suggest that frailty in combination with invasiveness do not hinder long-term postoperative recovery kinetics, in comparison to frailty or invasiveness alone. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Several studies have suggested that Hounsfield units (HU) in the spine are associated with increased complications for adult spinal deformity (ASD) patients. PURPOSE: The aim of this study is to assess whether there exists a threshold for HU that is associated with increased blood loss following ASD surgery. We hypothesize that HU below thresholds on spinal CT are predictive of increased blood loss during surgery and implant complications within 90 days after surgery for ASD. STUDY DESIGN/SETTING: Retrospective analysis. PATIENT SAMPLE: ASD patients who had HU measured in the spine were identified from a multicenter database. OUTCOME MEASURES: High Intraoperative blood loss and implant complications within 90 days of surgery.
METHOD(S): HU at L1, upper instrumented vertebrae (UIV) and total averages were assessed. Threshold linear regression with Bayesian information criteria was utilized to identify optimal cut-offs for predicting high blood loss (>2100mL, top 25% by volume) or any implant complications within 90 days. Implant complications included loosening, breakage and dislocation of rods or screws. Multivariable logistic regression was utilized controlling for age, gender, comorbidity, osteotomy and levels fused.
RESULT(S): Of 527 patients included, the mean age was 61+/-14. Mean L1 HU was 154.59+/-87, UIV HU was 175.1+/-304, and total average HU was 165+/-168. There were 59 patients with high blood loss (mean 5,026+/-233ml) and 467 with low blood loss (1,331+/-39.5ml). Threshold regression analysis identified that a cut-off of =140.33 was optimal for predicting high blood loss and =99.75 total average HU was optimal for predicting implant complications within 90 days of surgery. On multivariable analysis, L1 HU less than 140 was associated with 1.57x higher odds of high blood loss (P=0.032). Total average HU less than 100 was associated with a 3.6x higher odds of having an implant related failure within 90 days of surgery (P=0.035).
CONCLUSION(S): In this prospective multi-center study, Those with L1 HU=140 had a 1.52x higher odds of high blood loss. Patients with an average HUof =100 have 3.6x higher odds of implant related complication within 90 days of surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: The Dubousset Functional Test (DFT) is a novel functional assessment tool. It has been shown that patients with spinal pathology take significantly longer to complete the DFT than do control patients. There has been a recent focus in the literature on using functional assessment to predict patient outcomes. PURPOSE: To investigate the relationship between patients' performance of the novel four-component functional test proposed by Dubousset, sagittal alignment and patient-reported outcome measures PROMs. STUDY DESIGN/SETTING: Prospective, single center study. PATIENT SAMPLE: Patients presenting to a single institution for lumbar degenerative disease or spinal deformity. OUTCOME MEASURES: The correlation between time to complete DFT, radiographic measures of sagittal alignment and PROMs.
METHOD(S): This is a prospective, single-center study including primary patients who presented for evaluation of lumbar degenerative disease and spinal deformity. DFT is a test which assesses 4 domains: Up and Walking Test (UWT), Steps Test (ST), Down and Sitting Test (DST), Dual Tasking Test (DTT). The UWT asks the patient to sit-to-stand unassisted, walk 5 m, and sit unassisted. ST asks the patient to ascend 3 steps, turn, and descend 3 steps. DST asks the patient to sit from standing, and then stand from sitting, both unassisted. Finally, DTT asks the patient to walk 5 m and back while counting down from 50 by 2. Each test was timed, and performance was scored in seconds required to finish the test. Spinopelvic radiographs and PROMs (EQ5D, ODI, SF12) were collected. DFT performance was stratified by 40th (Fast) and 60th (Slow) percentile cutoffs. Radiographic sagittal parameters were compared between groups. Regression models were built to predict DFT domains performances using alignment parameters.
RESULT(S): A total of 55 patients were included (52y, 66%F, BMI 25.6). Patients in all DFT Slow domains had significantly worse ODI (all above 40), EQ5D (all below 0.5), and worse SF12_PCS (all below 32) except DTT Slow patients who had a comparable PCS to Fast. UWT Slow patients had significantly greater PI-LL (15 vs 2), lower LL (45 vs 60), and greater PT (22 vs 12); DTT Slow had greater PT (22 vs 11); DST Slow had greater PT (23 vs 12), and greater PI-LL (13 vs 1); ST and DTT slow patients had comparable radiographic parameters to ST and DTT Fast; however, they were older (59 vs 43 ys) (all p <0.05). Greater PT correlated with longer time to perform UWT and DST (r=0.451, r=0.488, respectively, p < 0.05). Greater PI-LL correlated with longer UWT (r=0.349) and loss of LL with longer ST (r=0.416), all p <0.05. Notably, loss of L4-S1 correlated with slower UWT (r=0.377, p <0.05). Regression models revealed that PT, PI-LL and SVA together predict UWT with r=0.472, DST with r=0.370, DTT with r=0.310, and ST with r=0.149.
CONCLUSION(S): The Dubousset Functional Test correlates with sagittal radiographic parameters and PROMs. PT, SVA, and PI-LL were able to predict up to 25% of patients' performance on the functional testing. Although radiographic parameters are helpful in guiding ASD treatment, they should be supplemented with other forms of patients' assessment which may include functional testing. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Pelvic incidence (PI) serves as the cornerstone for many deformity classifications and realignment schema to create a more individualized realignment target for each patient. Yet, previous literature has linked high PI to problematic outcomes following corrective surgery, including mechanical complications and hip pathologies. PURPOSE: Investigate if patients with high pelvic incidence have increased risk for complications and poor clinical outcomes following ASD surgery. STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 689 ASD patients. OUTCOME MEASURES: Clinical Outcomes (ODI, SF-36 PCS, MCS), mechanical failure, surgical details.
METHOD(S): ASD patients with 2-year (2Y) data included. Groups: PI >65degree (HighPI) versus PI < 65degree (NormPI). Means comparison tests assessed differences in demographics, surgical details and outcomes between groups. Multivariate analysis controlling for baseline age, frailty, baseline PI-LL, and history of prior fusion, analyzed complication rates and clinical improvement between groups.
RESULT(S): Included: 445 ASD patients. There were 94 (21%) patients presented with a BL pelvic incidence greater than 65degree (HighPI). HighPI patients were older (63 yrs), shorter, with higher BMI and frailty (all p<.05). HighPI were more likely to have had a prior fusion (OR: 1.9, [1.2-3.1]). HighPI were more likely to present with lower physical functioning scores, and severe pelvic compensation (OR: 5.5, [3.4-8.9]) and global deformity (OR: 3.5, [2.2-5.6]). During surgery, HighPI underwent more 3COs (OR: 1.8,[1.1-3.1]) and fusion to pelvis (OR: 2.1,[1.1-3.9]). Upon correction, adjusted analysis revealed HighPI were more likely to be undercorrected in each age-adjusted parameter compared to LowPI (OR: 4.8, [2.9-7.8]). Yet, HighPI patients were less likely to deteriorate within in-construct PI-based alignment (relative lordosis and lordosis distribution) (OR: 0.3,[0.1-0.9]). While not different at six weeks, HighPI were more likely to deteriorate in PI-based global alignment and pelvic compensation from six weeks to two years (OR: 3.2, [1.6-6.5]). This translated to a higher likelihood of developing a major or mechanical complication by 2Y (OR: 1.6, [1.04-2.6]) via adjusted analysis.
CONCLUSION(S): High pelvic incidence is associated with increased frailty, decreased physical functioning, and more severe lumbopelvic and global deformity upon presentation for adult spinal deformity correction. These patients are more often undercorrected by age-adjusted standards and deteriorate in out-of-construct alignment over time even when adequately corrected, leading to higher mechanical complications by two years. Despite our focus on PI-adjusted alignment, we have still not optimized treatment for the patient with high pelvic incidence. Further research should target which surgical techniques and strategies can achieve better results in this population. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adult spinal deformity (ASD) patients undergoing surgery risk neurological decline following surgery. However, surgery may be the key in improving outcomes in patients starting with lower extremity motor deficits at baseline (BL). We aim to analyze the improvement in neurological outcomes of ASD patients undergoing spinal reconstruction with BL and 6-week postoperative lower extremity motor scores (LEMS). PURPOSE: The aim of this study is to analyze the improvement in neurological outcomes of adult patients undergoing deformity surgery with baseline abnormal LEMS. STUDY DESIGN/SETTING: Multicenter, prospective cohort. PATIENT SAMPLE: A total of 205 patients were included in the study. OUTCOME MEASURES: Patient and procedural factors that lead to the improvement in neurological outcomes of adult patients undergoing deformity surgery with baseline abnormalLEMS.
METHOD(S): ASD patients ages = 18 were prospectively studied from 2018-2021. All patients underwent an instrumented PSF with a few also having an ASF of the lumbar spine. Patients were dichotomized based on BL LEMS (NML = 50, ABML < 50). The ABNML group was then dichotomized based on whether LEMS improved overall from BL or experienced no change or declined by first postoperative follow-up (PO) and various factors were analyzed and compared using standard statistical tests.
RESULT(S): Of the 205 patients evaluated, 134 (65.4%) were NML and 71 were ABNML (34.3%) at BL. Among the 71 patients with ABML LEMS at BL, 49% (N=35) improved to NML levels, 21% (N=15) improved from BL levels but not to NML, 20% (N=14) remained the same, and 10% (N=7) declined further at 6week PO. Compared to ABNML patients with no change or a decline in LEMS at first PO, patients who improved overall (70%; N=50) had significantly more decompressions performed (86% vs 57%; p=0.0092), and had more PCOs performed intraoperatively (90% vs 62%, p=0.0074). There were no statistical differences between the groups in age, BL LEMS, BMI, total instrumented vertebrae (TIV), EBL, and OR time. Overall, the number of patients with NML LEMS at 6 weeks PO increased by 7.5% (65.4% to 70.2%; p<.0001).
CONCLUSION(S): Seventy percent of patients with ABML LEMS at BL improved their motor strength by the first PO visit, while 30% stayed the same or declined. ABNML patients who improved from BL had significantly more decompressions performed and, surprisingly, more PCOs performed. Interestingly, patient factors between the two groups demonstrated no statistical differences further highlighting that improvement may be influenced by the differences in surgical techniques. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Patients with less severe adult spinal deformity undergo surgical correction and often achieve good clinical outcomes. However, it is not well understood how much clinical improvement is due to sagittal correction. PURPOSE: Derive baseline thresholds in radiographic parameters that, when exceeded, result in dramatic clinical improvement from surgical correction. STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 689 ASD patients. OUTCOME MEASURES: Radiographic alignment, clinical outcomes (ODI SCB).
METHOD(S): ASD patients with BL and 2-year (2Y) data included. Parameters assessed: SVA, PI-LL, PT, T1PA, L4-S1 Lordosis, C2-C7 SVA (cSVA), C2-T3 and C2 Slope (C2S).
Outcome(s): Good Outcome (GO): [Meeting either: 1) SCB for ODI by 2Y (change greater than 18.8), or 2) ODI 4.5 by 2Y. Binary logistic regression assessed each parameter to determine if correction was more likely needed to achieve GO. Conditional inference tree (CIT) run machine learning analysis generated baseline thresholds for each parameter, above which, correction was necessary to achieve GO.
RESULT(S): Included: 447 ASD patients. There were 223 (50%) patients achieving GO by 2 years. Binary logistic regression analysis demonstrated correction of all 5 thoracolumbar parameters (SVA, T1PA, PI-LL, PT, L4-S1) were more often needed to achieve GO (all p.001). Of patients with baseline T1PA above 20degree, 95% required correction to meet Good Outcome (95% vs 54%, p.001). CIT-generated thresholds were significant for each parameter, with a baseline C2 slope above 15degree necessitating correction more often to obtain clinical success (OR: 8.1, [4.1-16.2]; p.001).
CONCLUSION(S): Our study highlights there is a tipping-point beyond which sagittal correction has an exponential influence on clinical improvement, reflecting the line where deformity becomes a significant contributor to disability. These new thresholds delineate patients suitable for sagittal correction, as opposed to conventional treatment of degenerative disc processes. Adherence to these benchmarks may improve the utility gained from surgical intervention for degenerative conditions and deformity. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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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.