Faculty Bibliography

BACKGROUND: Bone morphogenetic protein (BMP) and allograft containing mesenchymal stem cells (live cell) are popular biologic substitutes for iliac crest autograft used in transforaminal lumbar interbody fusion (TLIF). Use of these agents in the pathogenesis of postoperative radiculitis remains controversial. Recent studies have independently linked minimally invasive (MIS) TLIF with increased radiculitis risk compared to open TLIF. The purpose of this study was to assess the rate of postoperative radiculitis in open and MIS TLIF patients along with its relationship to concurrent biologic adjuvant use. METHODS: Patients ≥18 years undergoing single-level TLIF from June 2012 to December 2018 with minimum 1-year follow-up were included. Outcome measures were rate of radiculitis, intra- and postoperative complications, revision surgery; length of stay (LOS), and estimated blood loss (EBL). RESULTS:= .038, N = 336) compared to other combinations of surgical approach and biologic use. CONCLUSIONS: Neither the MIS approach nor BMP use is an independent risk factor for post-TLIF radiculitis. However, risk of radiculitis significantly increases when they are used in tandem. This should be considered when selecting biological adjuvants for MIS TLIF. LEVEL OF EVIDENCE/METHODS: 3.

STUDY DESIGN/UNASSIGNED:Cadaveric study. OBJECTIVE/UNASSIGNED:To evaluate accuracy, radiation exposure, and surgical time of a new robotic-assisted navigation (RAN) platform compared with freehand techniques in conventional open and percutaneous procedures. METHODS/UNASSIGNED:Ten board-certified surgeons inserted 16 pedicle screws at T10-L5 (n = 40 per technique) in 10 human cadaveric torsos. Pedicle screws were inserted with (1) conventional MIS technique (L2-L5, patient left pedicles), (2) MIS RAN (L2-L5, patient right pedicles), (3) conventional open technique (T10-L1, patient left pedicles), and (4) open RAN (T10-L1, patient right pedicles). Output included (1) operative time, (2) number of fluoroscopic images, and (3) screw accuracy. RESULTS/UNASSIGNED:= .650). CONCLUSION/UNASSIGNED:RAN significantly improved accuracy and decreased radiation exposure in comparison to freehand techniques in both conventional open and percutaneous surgical procedures in cadavers. RAN significantly increased setup time compared with both conventional procedures.

INTRODUCTION/BACKGROUND:Outcomes after anterior cervical diskectomy and fusion (ACDF) and cervical total disk arthroplasty (TDA) are satisfactory, but related morbidity and revision surgery rates are notable. This study sought to determine complication variations among ACDF, TDA, and combined ACDF-TDA as well as predictors of postoperative complications. METHODS:Patients undergoing 1- to 2-level ACDF and/or TDA with at least a 2-year follow-up from 2009 to 2011 were identified from the Statewide Planning and Research Cooperative System database. Patient demographics, hospital-related parameters, mortality, and postoperative outcomes were compared, and their predictors were identified using multivariate logistic regression. RESULTS:A total of 16,510 and 449 individuals underwent ACDF and cervical TDA, respectively, and 201 underwent ACDF-TDA. ACDF-TDA patients had the highest rates of cardiac complications and pulmonary embolism (PE) (P ≤ 0.006), whereas TDA patients had higher individual surgical and device/implant/internal fixation complications (P ≤ 0.025). ACDF-TDA patients experienced the lowest rate of revisions. Cervical TDA increased the odds of any surgical complications (OR = 2.5, P = 0.002), overall complications (OR = 1.57, P = 0.034), and revisions (OR = 2.29, P < 0.001). Deyo index predicted any medical/surgical complications (OR = 1.43 and 1.19, respectively). Female sex was associated with increased odds of readmission (OR 1.30, P < 0.001) but was protective against medical complications (OR = 0.81, P = 0.013). DISCUSSION/CONCLUSIONS:Combined ACDF-TDA procedures were not associated with increases in 2-year individual or overall complications, readmissions, or revisions. LEVEL OF EVIDENCE/METHODS:Level 3-Therapeutic study.

BACKGROUND CONTEXT/BACKGROUND:Considerable debate exists regarding the optimal surgical approach for adult spinal deformity (ASD). It remains unclear which approach, posterior-only or combined anterior-posterior (AP), is more cost-effective. Our goal is to determine the 2-year cost per quality-adjusted life year (QALY) for each approach. PURPOSE/OBJECTIVE:To compare the 2-year cost-effectiveness of surgical treatment for ASD between the posterior-only approach and combined AP approach. STUDY DESIGN/METHODS:Retrospective economic analysis of a prospective, multicenter database PATIENT SAMPLE: From a prospective, multicenter surgical database of ASD, patients undergoing 5 or more level fusions through a posterior-only or AP approach were identified and compared. METHODS:QALYs gained were determined using baseline, 1-year, and 2-year post-operative Short Form 6D. Cost was calculated from actual, direct hospital costs including any subsequent readmission or revision. Cost-effectiveness was determined using cost/QALY gained. RESULTS:The AP approach showed significantly higher index cost than the posterior-only approach ($84,329 vs $64,281). This margin decreased at 2-year follow-up with total costs of $89,824 and $73,904, respectively. QALYs gained at two years were similar with 0.21 and 0.17 in the posterior-only and the AP approaches, respectively. The cost/QALY at two years after surgery was significantly higher in the AP approach ($525,080) than in the posterior-only approach ($351,086). CONCLUSIONS:We assessed 2-year cost-effectiveness for the surgical treatment through posterior-only and AP approaches. The posterior-only approach is less expensive both for the index surgery and at 2-year follow-up. The QALY gained at 2-years was similar between the two approaches. Thus, posterior-only approach was more cost-effective than the AP approach under our study parameters. However, both approaches were not cost-effective at 2-year follow-up.

BACKGROUND CONTEXT: Neurologic complications following adult spinal deformity (ASD) are common and may play a role in the outcomes for our patients. Neurologic complications may include radiculopathy, sensory deficit or motor weakness. The impact that these specific complications have on HRQL is unknown. PURPOSE: Neurologic complications are common following ASD. Understanding their impact on Health-related quality of life (HRQL) measures is critical. STUDY DESIGN/SETTING: Retrospective cohort study of prospective ASD database. PATIENT SAMPLE: Retrospective cohort study, 733 patients. OUTCOME MEASURES: Neurologic complications, HRQL scores.
METHOD(S): ASD patients (>18yrs, scoliosis >=20degree, SVA >=5cm, PT >=25degree and/or TK >60degree). Inclusion criteria was HRQL at baseline (BL) and 1 year, and lower extremity motor score (LEMS) at BL, 6-week and 1-year ODI, SRS22r and SF36 were determined at BL and 1yr LEMS was calculated from 0-50, with 50 designated as normal motor function. Patients were divided into 4 groups: pLEMS (perfect, no deficit), dLEMS (new postop deficit that returned to normal at 1 year), iLEMS (deficit improved from abnormal baseline), and wLEMS (new postop deficit persistent at one year).
RESULT(S): A total of 733 patients were eligible, with 95 (12.96%) reporting neurologic complications (NC). Impact of any NC vs no complication at 1yr was significant for ODI (5.1), PCS (3.6) and SRSpain (0.2) at 1 year (p<0.001 all). For NC vs any other complication, there was still a decrease in ODI (3.9) and PCS (2.4) at 1 year (p<0.01). NC subtype: radiculopathy caused worse outcomes for (4.3) and SRS pain (0.3) (p<0.05), sensory deficit caused worse SRSmental (0.5) (p<0.05), but no HRQL change was detected for motor deficit at 1 year. PLEMS (456/733) had improvement in all HRQL, and these improvements were not different with or w/o NC, or non-NC. Compared to pLEMS w/o complication, dLEMS (62/733) and iLEMS (147/733) were statically similar, however wLEMS (68/733) had worse ODI (7.1), SRStotal (0.3), activity (0.3), mental (0.3), pain (0.3) (p<0.05 all).
CONCLUSION(S): Neurologic complications that occur following ASD have a significant effect on HRQLs. The magnitude of effect is driven by radiculopathy and by lower extremity motor score. LEMS scores that remain normal, return back to normal or improve have similar outcomes, while patients that have continued weakness remain statistically worse at 1 year. 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 is rooted in health related quality of life metrics (HRQLs) that may be subjective, and the 40 factors needed for its calculation limit the index's utility in a clinical setting. PURPOSE: Develop a simplified, modified frailty index for ASD patients STUDY DESIGN/SETTING: Retrospective cohort study PATIENT SAMPLE: A total of 531 ASD patients OUTCOME MEASURES: HRQLs, length of stay (LOS) METHODS: ASD patients (scoliosis>=20degree, SVA>=5cm, PT>=25degree, or TK >=60degree) with baseline (BL) and 2-year HRQL follow up. HRQL components were removed from the FI and top contributors to the ASD-FI score of the remaining were assessed via Pearson correlation, and included in forward multiple stepwise regressions. Factors with the largest R2 value were including in the modified, ASD-FI (clin-ASD-FI). Factors included in the clin-ASD-FI were regressed against mortality, extended length of hospital stay (>8 days), revisions, major complications and weights for the clin-ASD-FI were calculated via Beta/Sullivan. Total clin-ASD-FI score was created with a score from 0 to 1. Linear regression correlated the clin-ASD-FI with ASD-FI scores and published cut-offs for the ASD-FI were used to create the new frailty cutoffs: not frail (NF: < 0.11), frail (F: 0.11-0.21) and severely frail (SF: >0.21). Binary logistic regression assessed odds of complication or reop for frail patients. Logistic regressions were run to determine whether the clin-ASD-FI is superior to previously utilized measures predicting risk (age, ASA, previous FI, and CCI) for complications and reop.
RESULT(S): A total of 531 ASD patients (59.5yrs, 79.5%F). The final stepwise regression model R2 of 0.681: <18.5 or >20 BMI (weight: 0.0625 out of 1), cardiac disease (0.125), disability employment status (0.3125), diabetes mellitus (0.0625), hypertension (0.0625), osteoporosis (0.125), blood clot (0.1875), and bowel incontinence (0.0625). These factors calculated the score from 0 to 1, with a mean cohort score of 0.13+/-0.14. Breakdown by clin-ASD-FI score: 51.8% NF, 28.1% F, 20.2% SF. Increasing frailty severity was associated with longer LOS (NF: 7.0, F: 8.3, SF: 9.2 days; p<0.001). When assessing BL HRQL status between the new clin-ASD-FI groups, ODI, EQ5D, SRS, PCS, MCS, NRS-Back, and NRS-Neck were worse with increasing categorical frailty (all p<0.001). Frailty independently predicted occurrence of any complication (9.357[2.20-39.76], p=0.002) and reop (2.79[0.662-11.72], p=0.162). Specific complications predicted included infection, neurologic, operative, radiographic, and wound complications (OR: 1.69-5, all p<0.001). Chi-square and p-values for the historical risk predictors of complications are as follows: Age(complication: 1.01[1-1.03] p=0.052; reop: 0.999[0.984-1.01] p=0.866), ASA(complication: 1.102[1.20-2.18], p=0.002; reop: 1.31[0.927-1.84], p=0.177), previous frailty index(complication: 8.57[1.66-44.17], p=0.010; reop=2.629[0.498-16.06], p=0.241), CCI(complication: 1.24[1.10-1.40], p<0.001; reop: 1.06[0.943-1.20], p=0.320).
CONCLUSION(S): Utilizing an existing ASD frailty index, we proposed a modified version eliminating the patient-reported components. This index is a true assessment of physiologic status, and represents a superior risk factor to other risk assessment tools for baseline and revision spinal deformity surgery as a result of its immutability with surgery, lack of subjectivity, and ease of use. Future studies should explore external validation of the proposed frailty index. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Recent studies have suggested that for patients with chronic neck pain, both psychological and physical symptoms need to be addressed. Studies have shown that psychological distress is associated with poor outcomes in these patients. The fear avoidance model has been used to explain how maladaptive thoughts and behaviors contribute to chronicity and disability. Cognitive behavioral therapy (CBT) addresses these risk factors through education about pain, modification of maladaptive beliefs, and increasing patient's self-efficacy. PURPOSE: Determine the effectiveness of brief psychological intervention on psychological outcomes in cervical spine surgery. STUDY DESIGN/SETTING: Prospective, blind, and placebo-controlled trial. PATIENT SAMPLE: A total of 42 symptomatic Cervical Degenerative Disorders patients. OUTCOME MEASURES: Distress and Risk Assessment Method (DRAM), Fear Avoidance Beliefs Questionnaire (FABQ), Pain Catastrophizing Scale (PCS), Outcome Expectation Question (OEQ). Neck Disability Index (NDI), modified Japanese Orthopedic Association (mJOA).
METHOD(S): Forty-two patients age >18 with symptomatic cervical degenerative disease have been enrolled in the study. If patients met psychological distress criteria, they were in the treatment group: DRAM >17 and <33, FABQ >49/66, PCS >30/52 or OEQ <=2 (randomized to CBT or Placebo). CBT and Placebo treatment groups had 6 sessions prior to surgery. The control group had no intervention prior to surgery. Baseline and 1-year (1Y) changes were assessed for all outcome measures.
RESULT(S): Forty-two patients were enrolled (53.6 years, BMI 29.4 kg/m2); 23 patients met psychological distress criteria and were randomized into a treatment group (14 CBT vs 9 placebo). Ten patients were in the control group, with nine exceeding DRAM scores to be CBT candidates. At enrollment, the CBT group had greater EQ5D scores (CBT: 10.8, Placebo: 9.5, Control: 7.5, DRAM:8.7) while the Placebo group had greater PCS scores (Placebo: 33.1, CBT: 32.4, Control:18.6, DRAM: 30.8; all p<0.05). From BL to 1Y postop, the CBT patients improved in all psychological-related questionnaires (NDI: 29.2 to 2, PCS: 32.4 to 20.7, FABQ:41.3 to 32.3, mJOA: 2.3 to 3.4, DRAM:12.9 to 16.6). Placebo patients also improved post-operatively, but to a lesser degree in NDI (26.6 to 2), PCS (33.1 to 28.3), and worsened in FABQ (40.4 to 54.1), mJOA(12.5 to 11.8), and DRAM (36.6 to 31.6). In contrast, patients in the control group showed improvement to a much lesser degree than CBT and Placebo patients (NDI: 18.1 to 2, PCS:18.6 to 3.2, FABQ:26.2 to 17.6, mJOA: 15.3 to 16.4). DRAM patients showed minimal changes in psychological- and spine-related questionnaires. Comparing treatment groups at 1Y, CBT pts had significantly lower FABQ scores than Placebo pts (32.3 vs 54.1; p<0.05). CBT pts also had better DRAM scores than the control group at 1Y (30.3 vs 11.4; p=0.03).
CONCLUSION(S): Cognitive behavior treatment can be beneficial in patients undergoing cervical surgery as it was identified in our study to minimize fear avoidance beliefs more than the Placebo group. This type of professional treatment has also shown a steady improvement in all psychological questionnaires and spine related neck disability from baseline to 1-year postoperatively. 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) surgery is complex and may lead to new-onset cervical malalignment and/or proximal junctional kyphosis (PJK). Roussouly et al describes variations in baseline thoracolumbar (TL) shape (Types 1-4), which have been shown to differentially influence surgical ASD outcomes. The effect of morphological shape on patterns of postoperative CD development remains underexplored. PURPOSE: Stratify patients by Roussouly type and assess patterns of conversion from baseline (BL) cervical alignment to postoperative cervical deformity (CD) in patients undergoing thoracolumbar ASD surgery. STUDY DESIGN/SETTING: Retrospective review of a prospective multicenter database of ASD patients. PATIENT SAMPLE: A total of 266 surgical ASD patients. OUTCOME MEASURES: Rate and timing of conversion to CD, rate of PJK, radiographic alignment parameters.
METHOD(S): Operative ASD patients with complete radiographic data at baseline, 6W, 1Y, 2Y, & 3Y intervals were included. Patients were grouped by baseline PI and apex of LL into component types of the Roussouly classification system utilizing pelvic incidence as published by Pizones et al. Patients with no BL CD were postoperatively stratified by Ames CD criteria (TS-CL>20 degree, cSVA>40mm), where CD was defined as fulfilling >1 criteria. Follow-up intervals were established post-ASD surgery, with 6W postop defined as "Early," 6W-1Y "Intermediate," 1-2Y "Late," and 2-3Y "Long." Univariate and Cox regression analyses identified CD conversion rate and PJK rate (<-10degree change in UIV and UIV+2) across Roussouly types 1-4.
RESULT(S): A total of 266 surgical ASD patients (59.7yrs, 77.4% F) with complete radiographic data were included. By Roussouly classification, 9% were Type 1, 15.8% Type 2, 46.6% Type 3, and 28.6% Type 4. 28.6% of ASD patients converted to postop CD (Early: 14.3%, Intermediate: 5.3%, Late: 4.1%, Long: 4.9%). There were no significant differences in CD conversion rate across Roussouly types (1: 33.3%; 2: 28.6%; 3: 26.6%; 4: 30.3%, P=0.895). Types 2 (41.7%), 3 (60.6%), and 4 (43.5%) had their peak rates of conversion in the Early (<6w) window compared to other follow-up intervals, whereas Type 1 patients had a peak rate (50%) between 6w-1Y. Type 2 patients had higher rates of later CD conversion (>1 year) than other types (50% vs 28.1%, P=0.135), while Type 1 patients trended higher rates of earlier CD conversion (<1 year) than other types (33.8% vs 12.5%, P=0.220); these patterns did not reach statistical significance. Across Roussouly Types, among patients who converted to CD, Type 4 had significantly higher rates of ++ SRS-Schwab PT and greater TPA at BL (both p<0.05). Type 4 patients had the highest rate of concurrent PJK with CD conversion (60.9%) compared to Type 1 (50%), Type 2 (50%), or Type 3 (54.5%) (P>0.05). There were no significant change in ODI, PCS, or SRS total among Roussouly Types in patients that converted to CD (p>0.05). Random forest analysis determined the top surgical (levels fused), radiographic (TS-CL), and demographic (frailty) factors associated with CD conversion.
CONCLUSION(S): Baseline thoracolumbar shape as described by the Roussouly classification has a differential effect on timing to CD conversion, though overall rates of CD conversion after TL-ASD correction were similar across Types 1-4. Type 1 patients with a lower apex of lumbar lordosis trended earlier conversion, while Type 2 patients with a higher apex of LL trended conversion beyond 1-year postop. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: For patients with coronary artery disease, the two most common options for intervention are a cardiac stent or a coronary artery bypass graft. Although less invasive, stents may pose a long-term risk for patients undergoing further invasive procedures such as elective spine surgery. This study aimed to provide surgeons with insight on possible major complications for elective spine surgery patients with a history of coronary artery disease. PURPOSE: Investigate outcomes of elective spine fusion patients with prior history of cardiac intervention STUDY DESIGN/SETTING: Retrospective review of the PearlDiver database between the years 2006-2013 PATIENT SAMPLE: A total of 731,173 elective spine fusion patients OUTCOME MEASURES: Comorbidity burden, 30-day and 90-day complications, readmission METHODS: Elective spine fusion patients were isolated with ICD-9 and CPT procedures codes in the PearlDiver database. Patients were stratified by having previous history of a coronary stent (Stent), coronary artery bypass graft (CABG), and no previous heart procedure (No-HP). Means comparison tests (chi-squared and independent samples t-tests, as appropriate) compared differences in demographics, diagnoses, and comorbidities. Logistic regression assessed the odds of 30-day and 90-day postoperative (postop) complications associated with each heart procedure (Odds Ratio [95% confidence interval]). Statistical significance was set p<0.05.
RESULT(S): A total of 731,173 elective spine fusion patients were included. Overall, 8,401 pts underwent a CABG, 24,037 patients Stent, and 698,735 had No-HP prior to spine fusion surgery. Compared to Stent and No-HP patients, CABG patients had higher rates of morbid obesity, chronic kidney disease and diabetes (p<0.001 for all). Stent patients had higher rates of peripheral vascular disease, hypertension, and hyperlipidemia (all p<0.001). Within 30 days postoperatively of index surgery, CABG patients had significantly higher complication rates including pneumonia, cerebrovascular accident (CVA), myocardial infarction (MI), sepsis, and death compared to No-HP (all p<0.001). Stent patients vs No-HF also had higher 30-day postoperative complication rates including pneumonia, CVA, MI, sepsis, and death. Adjusting for age, comorbidities and sex, Stent was significantly predictive of a MI 30-days post-op (OR: 1.90 [1.53-2.34], P<0.001). Additionally, Stent patients compared to CABG patients had 1.99x greater odds of a MI within 30-days (OR: 1.99 [1.26-3.31], p=0.005) and 2.02x greater odds of readmission within 90-days postop (OR: 2.2 [1.53-2.71, p<0.001).
CONCLUSION(S): With regards to spine surgery, coronary artery bypass graft remains the gold standard for risk reduction. Stenting does not appear to minimize risk as significantly as CABG. When assessing patients with a history of coronary artery disease for elective spine fusion surgery, surgeons should be cautious of the significant risk of major complications associated with stents compared to coronary artery bypass grafting. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Frailty is an increasingly recognized characteristic that has been validated across many studies as influencing operative risk. Utilization of frailty indices can allow for its identification of which spine patients may be too high risk for surgical intervention. This may be especially useful when it comes to surgeries that are minimally invasive and are supposed to have decrease perioperative outcomes. PURPOSE: Identify MIS techniques effects in postoperative outcomes in TLIF patients. STUDY DESIGN/SETTING: Retrospective review of a prospective database. PATIENT SAMPLE: TLIF spine patients. OUTCOME MEASURES: Complications, length of stay (LOS), estimated blood loss (EBL).
METHOD(S): Pts that underwent a lumbar spine procedure in a single-center Comprehensive Spine Quality Database. Pts were stratified based on procedural approach (Open [OP] and Minimally invasive Surgery [MIS]). Frailty was then calculated for each resultant group by using 30 variables with a validated method. Based on these scores, pts were categorized no frailty [NF]: <0.09, frail [F]: 0.09-0.18, and severe frailty [SF] >0.18. Groups were then controlled for surgical invasiveness. Chi-squared tests identified the relationship between complications and length of stay among various frailty states given surgical approach (OP vs MIS). These patients were propensity score matched for levels fused. Hospital acquired complications (HACs) were identified based on frailty groups through the use of chi-squared and t-tests for other surgical factors. A logistic regression analysis identified the association between frailty status and surgical, regarding postoperative (postop) outcomes.
RESULT(S): A total of 1,300 TLIF spine patients were isolated (59yrs, 29.3kg/m2). After PSM for levels fused, there were 338 pts for both MIS and OP. MIS pts were older (56.1 vs 53.3; p<0.05) than Op pts and had similar BMI's (29.1 vs 29.7; respectively). However, OP received more posterior approaches and less anterior approaches than MIS pts (p<0.05). By surgical factors: MIS and OP patients had similar LOS (3 vs 2.9days) and EBL (282.8 vs 251.5cc) but differed by Op time (195.7 vs 247.1; p<0.05) respectively. Further breakdown by frailty displayed statistical significance between MIS and OP patients with MIS pts having more F (16% vs 12%) and SF pts (4.3% vs 1.9%) than OP (all p<0.05). FMIS patients had lower postop neurologic complications as compared to FOP pts (4.63% vs 14.8%). However, SFMIS patiens had more post-operative complications than SFOP pts (55.2% vs 23.1%) and increased a pt's likelihood of being SFMIS by 5.4x's (all p<0.05).
CONCLUSION(S): This study displays that when frailty status is taken into account, TLIF MIS patients benefit from this procedure type when analyzed against neurologic complications. However, these patients were seen to suffer more from postop complications but did not differ on any other specific complications or surgical variables. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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