Faculty Bibliography

BACKGROUND/UNASSIGNED:Cannabis is the most commonly used recreational drug in the USA. Studies evaluating cannabis use and its impact on outcomes following cervical spinal fusion (CF) are limited. This study sought to assess the impact of isolated (exclusive) cannabis use on postoperative outcomes following CF by analyzing outcomes like complications, readmissions, and revisions. METHODS/UNASSIGNED:The New York Statewide Planning and Research Cooperative System (SPARCS) was queried for patients who underwent CF between January 2009 and September 2013. Inclusion criteria were age ≥18 years and either a minimum 90-day (for complications and readmissions) or 2-year (for revisions) follow-up surveillance. Patients with systemic disease, osteomyelitis, cancer, trauma, and concomitant substance or polysubstance abuse/dependence were excluded. Patients with a preoperative International Classification of Diseases, 9th Edition, Clinical Modification (ICD-9-CM) diagnosis of isolated cannabis abuse (Cannabis) or dependence were identified. The primary outcome measures were 90-day complications, 90-day readmissions, and two-year revisions following CF. Cannabis patients were 1:1 propensity score-matched by age, gender, race, Deyo score, surgical approach, and tobacco use to non-cannabis users and compared for outcomes. Multivariate binary stepwise logistic regression models identified independent predictors of outcomes. RESULTS/UNASSIGNED:432 patients (n=216 each) with comparable age, sex, Deyo scores, tobacco use, and distribution of anterior or posterior surgical approaches were identified (all p>0.05). Cannabis patients were predominantly Black (27.8% vs. 12.0%), primarily utilized Medicaid (29.6% vs. 12.5%), and had longer LOS (3.0 vs. 1.9 days), all p≤0.001. Both cohorts experienced comparable rates of 90-day medical and surgical, as well as overall complications (5.6% vs. 3.7%) and two-year revisions (4.2% vs. 2.8%, p=0.430), but isolated cannabis patients had higher 90-day readmission rates (11.6% vs. 6.0%, p=0.042). Isolated cannabis use independently predicted 90-day readmission (Odds Ratio=2.0), but did not predict any 90-day complications or two year revisions (all p>0.05). CONCLUSION/UNASSIGNED:.

STUDY DESIGN/METHODS:Retrospective review of prospective multicenter data. OBJECTIVES/OBJECTIVE:This study aimed to investigate the shape of TK before and after fusion in ASD patients treated with long fusion. METHODS:test. RESULTS:= .032). CONCLUSIONS:Posterior spinal fusion for ASD alters the magnitude and shape of thoracic kyphosis. While 60% of patients had a normal TK at baseline, 30% of those patients developed iatrogenic hyperkyphosis postoperatively. Patients with baseline hypokyphosis were more likely to be corrected to normal TK than hyperkyphotic patients. Future research should investigate TK restoration in ASD and its impact on clinical outcomes and complications.

STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:Understand the benefit of addressing malalignment in revision surgery for PJK. SUMMARY OF BACKGROUND DATA/BACKGROUND:Proximal junctional kyphosis(PJK) is a common cause of revision surgery for ASD patients. During a revision, surgeons may elect to perform a proximal extension of the fusion, or also correct the source of the lumbo-pelvic mismatch. METHODS:Recurrent PJK following revision surgery was the primary outcome. Revision surgical strategy was the primary predictor(proximal extension of fusion alone compared to combined sagittal correction and proximal extension). Multivariable logistic regression determined rates of recurrent PJK between the two surgical groups with lumbo-pelvic surgical correction assessed through improving ideal alignment in one or more alignment criteria(Global Alignment and Proportionality[GAP],Roussouly-type, and Sagittal Age-Adjusted Score[SAAS]). RESULTS:151 patients underwent revision surgery for PJK. PJK occurred at a rate of 43.0%, and PJF at 12.6%. Patients proportioned in GAP post-revision had lower rates of recurrent PJK(23% vs. 42%;OR: 0.3,95% CI:[0.1-0.8];P=0.024). Following adjusted analysis, patients who were ideally aligned in 1 of 3 criteria (Matching in SAAS and/or Roussouly matched and/or achieved GAP proportionality) had lower rates of recurrent PJK (36% vs. 53%;OR: 0.4,95% CI:[0.1-0.9];P=0.035) and recurrent PJF(OR: 0.1,95% CI:[0.02-0.7];P=0.015). Patients ideally aligned in 2 of 3 criteria avoid any development of PJF(0% vs. 16%, P<0.001). CONCLUSION/CONCLUSIONS:Following revision surgery for proximal junctional kyphosis, patients with persistent poor sagittal alignment showed increased rates of recurrent proximal junctional kyphosis compared with patients who had abnormal lumbo-pelvic alignment corrected during the revision. These findings suggest addressing the root cause of surgical failure in addition to proximal extension of the fusion may be beneficial.

STUDY DESIGN/METHODS:Retrospective review of a prospectively enrolled adult spinal deformity (ASD) database. OBJECTIVE:To investigate what patient factors elevate the risk of sub-optimal outcomes after deformity correction. BACKGROUND:Currently, it is unknown what factors predict a poor outcome after adult spinal deformity surgery, which may require increased pre-operative consideration and counseling. METHODS:Patients >18yrs undergoing surgery for ASD(scoliosis≥20°, SVA≥5 cm, PT≥25°, or TK≥60°). An unsatisfactory outcome was defined by the following categories met at 2Y: (1) clinical: deteriorating in ODI at 2Y f/u (2) complications/reop: having a reoperation and major complication were deemed high risk for poor outcomes postoperatively (HR). Multivariate analyses assessed predictive factors of HR patients in adult spinal deformity patients. RESULTS:633 ASD (59.9 years, 79%F, 27.7 kg/m2, CCI: 1.74) were included. Baseline severe Schwab modifier incidence (++): 39.2% PI-LL, 28.8% SVA, 28.9% PT. 15.5% of patients deteriorated in ODI by 2 years, while 7.6% underwent a reoperation and had a major complication. This categorized 11 (1.7%) as HR. HR were more comorbid in terms of arthritis (73%) heart disease (36%) and kidney disease (18%), P<0.001. Surgically, HR had greater EBL (4431ccs), underwent more osteotomies (91%), specifically Ponte(36%) and Three Column Osteotomies(55%), which occurred more at L2(91%). HR underwent more PLIFs (45%) and had more blood transfusion units (2641ccs), all P<0.050. The multivariate regression determined a combination of a baseline DRAM score in the 75th percentile, having arthritis and kidney disease, a baseline right lower extremity motor score ≤3, cSVA >65 mm, C2 slope >30.2°, CTPA >5.5° for an R2 value of 0.535 (P<0.001). CONCLUSIONS:When addressing adult spine deformities, poor outcomes tends to occur in severely comorbid patients with major baseline psychological distress scores, poor neurologic function, and concomitant cervical malalignment.

OBJECTIVE:The aim of this study was to investigate whether surgery for high-risk patients is being optimized over time and if poor outcomes are being minimized. METHODS:Patients who underwent surgery for cervical deformity (CD) and were ≥ 18 years with baseline and 2-year data were stratified by year of surgery from 2013 to 2018. The cohort was divided into two groups based on when the surgery was performed. Patients in the early cohort underwent surgery between 2013 and 2015 and those in the recent cohort underwent surgery between 2016 and 2018. High-risk patients met at least 2 of the following criteria: 1) baseline C2-7 Cobb angle > 15°, mismatch between T1 slope and cervical lordosis ≥ 35°, C2-7 sagittal vertical axis > 4 cm, or chin-brow vertical angle > 25°; 2) age ≥ 70 years; 3) severe baseline frailty (Miller index); 4) Charlson Comorbidity Index (CCI) ≥ 1 SD above the mean; 5) three-column osteotomy as treatment; and 6) fusion > 10 levels or > 7 levels for elderly patients. The mean comparison analysis assessed differences between groups. Stepwise multivariable linear regression described associations between increasing year of surgery and complications. RESULTS:Eighty-two CD patients met high-risk criteria (mean age 62.11 ± 10.87 years, 63.7% female, mean BMI 29.70 ± 8.16 kg/m2, and mean CCI 1.07 ± 1.45). The proportion of high-risk patients increased with time, with 41.8% of patients in the early cohort classified as high risk compared with 47.6% of patients in the recent cohort (p > 0.05). Recent high-risk patients were more likely to be female (p = 0.008), have a lower BMI (p = 0.038), and have a higher baseline CCI (p = 0.013). Surgically, high-risk patients in the recent cohort were more likely to undergo low-grade osteotomy (p = 0.003). By postoperative complications, recent high-risk patients were less likely to experience any postoperative adverse events overall (p = 0.020) or complications such as dysphagia (p = 0.045) at 2 years. Regression analysis revealed increasing year of surgery to be correlated with decreasing minor complication rates (p = 0.030), as well as lowered rates of distal junctional kyphosis by 2 years (p = 0.048). CONCLUSIONS:Over time, high-risk CD patients have an increase in frequency and comorbidity rates but have demonstrated improved postoperative outcomes. These findings suggest that spine surgeons have improved over time in optimizing selection and reducing potential adverse events in high-risk patients.

BACKGROUND:Height gain following a surgical procedure for patients with adult spinal deformity (ASD) is incompletely understood, and it is unknown if height gain correlates with patient-reported outcome measures (PROMs). METHODS:This was a retrospective cohort study of patients undergoing ASD surgery. Patients with baseline, 6-week, and subanalysis of 1-year postoperative full-body radiographic and PROM data were examined. Correlation analysis examined relationships between vertical height differences and PROMs. Regression analysis was utilized to preoperatively estimate T1-S1 and S1-ankle height changes. RESULTS:This study included 198 patients (mean age, 57 years; 69% female); 147 patients (74%) gained height. Patients with height loss, compared with those who gained height, experienced greater increases in thoracolumbar kyphosis (2.81° compared with -7.37°; p < 0.001) and thoracic kyphosis (12.96° compared with 4.42°; p = 0.003). For patients with height gain, sagittal and coronal alignment improved from baseline to postoperatively: 25° to 21° for pelvic tilt (PT), 14° to 3° for pelvic incidence - lumbar lordosis (PI-LL), and 60 mm to 17 mm for sagittal vertical axis (SVA) (all p < 0.001). The full-body mean height gain was 7.6 cm, distributed as follows: sella turcica-C2, 2.9 mm; C2-T1, 2.8 mm; T1-S1 (trunk gain), 3.8 cm; and S1-ankle (lower-extremity gain), 3.3 cm (p < 0.001). T1-S1 height gain correlated with the thoracic Cobb angle correction and the maximum Cobb angle correction (p = 0.002). S1-ankle height gain correlated with the corrections in PT, PI-LL, and SVA (p < 0.001). T1-ankle height gain correlated with the corrections in PT (p < 0.001) and SVA (p = 0.03). Trunk height gain correlated with improved Scoliosis Research Society (SRS-22r) Appearance scores (r = 0.20; p = 0.02). Patient-Reported Outcomes Measurement Information System (PROMIS) Depression scores correlated with S1-ankle height gain (r = -0.19; p = 0.03) and C2-T1 height gain (r = -0.18; p = 0.04). A 1° correction in a thoracic scoliosis Cobb angle corresponded to a 0.2-mm height gain, and a 1° correction in a thoracolumbar scoliosis Cobb angle resulted in a 0.25-mm height gain. A 1° improvement in PI-LL resulted in a 0.2-mm height gain. CONCLUSIONS:Most patients undergoing ASD surgery experienced height gain following deformity correction, with a mean full-body height gain of 7.6 cm. Height gain can be estimated preoperatively with predictive ratios, and height gain was correlated with improvements in reported SRS-22r appearance and PROMIS scores. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:Adult spinal deformity (ASD) represents a major cause of disability in the elderly population in the United States. Surgical intervention has been shown to reduce disability and pain in properly indicated patients. However, there is a small subset of patients in whom nonoperative treatment is also able to durably maintain or improve symptoms. OBJECTIVE:To examine the factors associated with successful nonoperative management in patients with ASD. METHODS:We retrospectively evaluated a cohort of 207 patients with nonoperative ASD, stratified into 3 groups: (1) success, (2) no change, and (3) failure. Success was defined as a gain in minimal clinically importance difference in both Oswestry Disability Index and Scoliosis Research Society-Pain. Logistic regression model and conditional inference decision trees established cutoffs for success according to baseline (BL) frailty and sagittal vertical axis. RESULTS:In our cohort, 44.9% of patients experienced successful nonoperative treatment, 22.7% exhibited no change, and 32.4% failed. Successful nonoperative patients at BL were significantly younger, had a lower body mass index, decreased Charlson Comorbidity Index, lower frailty scores, lower rates of hypertension, obesity, depression, and neurological dysfunction (all P < .05) and significantly higher rates of grade 0 deformity for all Schwab modifiers (all P < .05). Conditional inference decision tree analysis determined that patients with a BL ASD-frailty index ≤ 1.579 (odds ratio: 8.3 [4.0-17.5], P < .001) were significantly more likely to achieve nonoperative success. CONCLUSION:Success of nonoperative treatment was more frequent among younger patients and those with less severe deformity and frailty at BL, with BL frailty the most important determinant factor. The factors presented here may be useful in informing preoperative discussion and clinical decision-making regarding treatment strategies.

STUDY DESIGN/METHODS:This is a multicenter, prospective cohort study. OBJECTIVE:This study tests the hypothesis that the elimination of lower limb compensation in patients with adult spinal deformity (ASD) will significantly increase the magnitude of sagittal malalignment. SUMMARY OF BACKGROUND DATA/BACKGROUND:ASD affects a significant proportion of the elderly population, impairing functional sagittal alignment and inhibiting the overall quality of life. To counteract these effects, patients with ASD use their spine, pelvis, and lower limbs to create a compensatory posture that allows for standing and mobility. However, the degree to which each of the hips, knees, and ankles contributes to these compensatory mechanisms has yet to be determined. METHODS:Patients undergoing corrective surgery for ASD were included if they met at least one of the following criteria: complex surgical procedure, geriatric deformity surgery, or severe radiographic deformity. Preoperative full-body x-rays were evaluated, and age and pelvic incidence -adjusted normative values were used to model spine alignment based upon three positions: compensated (all lower extremity compensatory mechanisms maintained), partially compensated (removal of ankle dorsiflexion and knee flexion, with maintained hip extension), and uncompensated (ankle, knee, and hip compensation set to the age and pelvic incidence norms). RESULTS:A total of 288 patients were included (mean age 60 yr, 70.5% females). As the model transitioned from the compensated to uncompensated position, the initial posterior translation of the pelvis decreased significantly to an anterior translation versus the ankle (P.Shift: 30 to -7.6 mm). This was associated with a decrease in pelvic retroversion (pelvic tilt: 24.1-16.1), hip extension (SFA: 203-200), knee flexion (knee angle: 5.5-0.4), and ankle dorsiflexion (ankle angle: 5.3-3.7). As a result, the anterior malalignment of the trunk significantly increased: sagittal vertical axis (65-120 mm) and G-SVA (C7-ankle from 36 to 127 mm). CONCLUSIONS:Removal of lower limbs compensation revealed an unsustainable truncal malalignment with two-fold greater SVA.

STUDYDESIGN/METHODS:Retrospective cohort study of a prospectively collected multi-center adult spinal deformity (ASD) database. OBJECTIVE:To compare staged procedures to same-day interventions and identify the optimal time interval between staged surgeries for treatment of ASD. BACKGROUND:Surgical intervention for ASD is invasive and complex procedure that surgeons often elect to perform on different days (staging). Yet, there remains a paucity of literature on the timing and effects of the interval between stages. METHODS:ASD patients with two-year (2Y) data undergoing an anterior/posterior (A/P) fusion to the ilium were included. Propensity score matching (PSM) was performed for number of levels fused, number of interbody devices, surgical approaches, number of osteotomies/three-column osteotomy (3CO), frailty, Oswestry Disability Index (ODI), Charlson Comorbidity Index (CCI), revisions, sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), and UIV to create balanced cohorts of Same-Day and Staged surgical patients. Staged patients were stratified by intervening time-period between surgeries, using quartiles. RESULTS:176 PSM patients were included. Median interval between A/P staged procedures was 3 days. Staged patients had greater operative time and lower ICU stays postop (P<0.05). At 2Y, staged compared to same day showed a greater improvement in T1 slope - cervical lordosis (TS-CL), C2 sacral slope (C2SS), and SRS-Schwab SVA (P<0.05). Staged patients had higher rates of minimal clinically-important difference (MCID) for 1Y SRS-Appearance and 2Y physical component summary (PCS) scores. Assessing different intervals of staging, patients at the 75th percentile interval showed greater improvement in 1Y SRS Pain and Total postop as well as SRS Activity, Pain, Satisfaction, and Total scores (P<0.05) compared to patients in lower quartiles. Compared to the 25th percentile, patients reaching the 50th percentile interval were associated with increased odds of improvement in Global Alignment and Proportion (GAP) score proportionality (9.3[1.6-53.2], P=0.01). CONCLUSIONS:This investigation is among the first to compare multicenter staged and same day surgery anterior/posterior adult spinal deformity patients fused to ilium using propensity-matching. Staged procedures resulted in significant improvement radiographically, reduced ICU admissions, and superior patient reported outcomes compared to same day procedures. An interval of at least three days between staged procedures is associated with superior outcomes in terms of GAP score proportionality.

STUDY DESIGN/METHODS:Retrospective Cohort Study. OBJECTIVE:Assess whether modifying spinal alignment goals to accommodate frailty considerations will decrease mechanical complications and maximize clinical outcomes. SUMMARY OF BACKGROUND DATA/BACKGROUND:The Global Alignment and Proportion(GAP) score was developed to assist in reducing mechanical complications, but has had less success predicting such events in external validation. Higher frailty and many of its components have been linked to development of implant failure. Therefore, modifying the GAP score with frailty may strengthen its ability to predict mechanical complications. METHODS:We included 412 surgical ASD patients with two-year(2Y) follow-up. Frailty was quantified using the ASD modified Frailty Index(mASD-FI). Outcomes: proximal junctional kyphosis(PJK) and failure(PJF), major mechanical complications, and 'Best Clinical Outcome'(BCO), defined as ODI<15 and SRS-22 Total>4.5. Logistic regression analysis established a six-week score based on GAP score,frailty and ODI US-Norms. Logistic regression followed by conditional inference tree(CIT) analysis generated categorical thresholds. Multivariable logistic regression analysis controlling for confounders was used to assess the performance of the frailty modified GAP score. RESULTS:Baseline frailty categories: 57% Not Frail,30% frail,14% severely frail. Overall, 39% of patients developed PJK, 8% PJF, 21% mechanical complications, 22% underwent reoperation, and 15% met BCO. The modified ASD-FI demonstrated correlation with developing PJF, mechanical complications, undergoing reoperation, and meeting BCO at 2Y(all P<0.05). Regression analysis generated the following equation: Frailty-Adjusted Realignment Score(FAR Score) =0.49*mASD-FI + 0.38*GAP Score. Thresholds for the FAR score(0-13): Proportioned:<3.5,Moderately Disproportioned:3.5-7.5,Severely Disproportioned:>7.5. Multivariable logistic regression assessing FAR Score demonstrated associations with mechanical complications, reoperation, and meeting Best Clinical Outcome by two years(all P<0.05), whereas the original GAP score was only significant for reoperation. CONCLUSION/CONCLUSIONS:This study demonstrated adjusting alignment goals in adult spinal deformity surgery for a patient's baseline frailty status and disability may be useful in minimizing the risk of complications and adverse events, outperforming the original GAP score in terms of prognostic capacity. LEVEL OF EVIDENCE/METHODS:III.