Faculty Bibliography

BACKGROUND CONTEXT: There have been few investigations into national trends in the use or outcomes of patients treated with robotic assisted surgery. PURPOSE: To evaluate if incorporation of robotic assisted procedures will lead to a rise in suboptimal outcomes. STUDY DESIGN/SETTING: Retrospective review of a national patient database between 2010-2016. PATIENT SAMPLE: A total of 4,109 weighted hospital discharges. OUTCOME MEASURES: Length of stay, complications, invasiveness.
METHOD(S): Inclusion criteria: elective spine surgery procedures as defined by ICD-9-CM and ICD-10-CM codes. Descriptive statistics assessed demographic information for the cohort. Rates of open and MIS robot assisted procedures were assessed, as well as trends in postoperative complications, and length of stay. Propensity score matching was performed between robotic spine surgery patients and non-robotic spine surgery patients for levels fused. Regression analysis was used to assess robot assisted procedures as a predictor of complications and extended LOS (LOS above 75th percentile), unfavorable discharge, and death during hospitalization.
RESULT(S): A total of 4,109 discharges were included. The overall trends in robotic surgery show a significant increase from 2010 to 2016, increasing from 11 recorded cases to 1,535 in 2016 (p<0.001). The majority of cases were open, however, an increasing percentage of cases have been MIS (8% in 2010 vs 12% in 2016, p<0.001). Average length of stay has significantly decreased from 9.5 days in 2010 to 4.4 days in 2016 (p<0.001). Postoperative hardware complications have significantly decreased from a high of 15.6% of cases in 2011 to 0.3% of cases in 2016, as well as DVTs (9.4% in 2011 vs 0% in 2016, both p<0.001). However, overall complication rates have increased, from 25% in 2011 to 29.3% in 2016 (p<0.001). In an analysis of invasiveness matched non-robot assisted patients, robot assisted surgery was not predictive of extended LOS, unfavorable discharge, total post-operative complications, or death during hospitalization (all p>0.05). Robot assisted surgery was predictive of bleeding complications (hemorrhage and hematoma) compared to non-robot surgery patients (OR: 2.05 [1.10-3.82], p=0.02).
CONCLUSION(S): Robot assisted surgery is an increasing implemented technique in spine surgery, with a significant rise from 2010 to 2016. However, during that period there has been a concurrent rise in postoperative complications. Invasiveness matched robot assisted patients were at significantly higher odds of bleeding complications compared to non-robotic patients. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Although researchers have extensively studied factors predicting clinical outcomes at static time points, assessing rate of recovery after adult spinal deformity (ASD) surgery has largely been ignored. This study aims to address this gap in knowledge by evaluating the impact of frailty and invasiveness on recovery kinetics, using area-under-the-curve (AUC) methodology. PURPOSE: To assess the impact of patient specific and surgical factors on postoperative recovery kinetics. STUDY DESIGN/SETTING: Retrospective review of a prospective, multicenter database. PATIENT SAMPLE: A total of 320 patients were identified from a multicenter database who had minimum 2-year HRQOL follow-up, with preoperative, 6-week and 1-year data available. OUTCOME MEASURES: Our primary outcome measure was integrated health state (IHS) score, a marker of postoperative recovery.
METHOD(S): ASD patients with minimum 2-year follow-up were stratified by frailty and surgical invasiveness. Previously validated ASD-FI scores were used to separate non-frail (<.3) patients from those that there were frail (.3 to.5) and severely frail (>.5). Patients were also stratified by surgical inverness, using ASD-SR, into four quartiles, Q1: <65, Q2: 66-89, Q3: 90-119, Q4: >120. Patient demographics, BMI, CCI and surgical parameters were also collected. To assess recovery kinetics, SRS-22r and ODI scores at 6-weeks, 1-year and 2-year were normalized against preoperative values and graphed as a function of time. AUC was summed across all time points to generate a single IHS score. Multivariate linear regression was used with IHS scores as primary outcome variable.
RESULT(S): A total of 320 patients met the inclusion and exclusion criteria. The mean (SD) patient age was 58.6 (14.7) with 79% female. Overall, 139 were non-frail, 131 frail and 46 severely frail. On univariate analysis, frail and severely frail patients were noted to have worse baseline and 2-year HRQOL scores for SRS pain, activity and ODI; however, when comparing differences in HRQOL across this 2-year period, F and SF were noted to have greater improvements in both SRS and ODI (p<.05). On multivariate regression, frail and severely frail patients, compared to those non-frail, were found to have better IHS scores for ODI, SRS-22r pain, and SRS-22r activity, indicating more favorable recovery (p<.05). In particular, for SRS-22r activity, frail (adjusted beta: 0.37, p=<.01) and severely frail (adjusted beta: 0.74, p=<.01) patients were found to have higher IHS compared to their non-frail counterparts. Similarly, for SRS-22r pain, frail and severely frail patients showed improved recovery with higher IHS scores in comparison to non-frail patients. In contrast to frailty, operative variables, including surgical invasiveness and EBL, were insignificant predictors of IHS scores for either ODI or SRS-22r domains.
CONCLUSION(S): Our results suggest that patient-specific factors, namely frailty, play a larger role in predicting postoperative recovery kinetics, in comparison to surgical factors, which appear to have limited if any impact. Despite frail patients having lower preoperative and 2-year HRQOL scores, they were noted to have higher IHS scores SRS pain, activity, and ODI indicating more favorable recovery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Prior studies demonstrated that symptomatic adult spinal deformity (SASD) is a heterogeneous condition with varying degrees of negative health impact depending on the specific type and severity of deformity. Currently, there is some controversy regarding the subset of SASD with global coronal malalignment (GCM) and its associated health impact. Moreover, few reports have assessed the health impact of this global coronal parameter in comparison to other deformity types. A comparative study of deformity types with severe global malalignment (eg, severe GCM) may provide clinically relevant insights and identify potential differences in demographics and health impact. PURPOSE: To compare demographics and health impact of SASD patients with severe global malalignment (primary sagittal [SAG-only] vs primary coronal [COR-only] vs sagittal+coronal [MIX]). STUDY DESIGN/SETTING: Retrospective analysis of a prospective multicenter database. PATIENT SAMPLE: Enrollment required age >=18 yrs and one of the following: scoliosis >=20degree, sagittal vertical axis (SVA) >=5cm, pelvic tilt >=25degree, and/or thoracic kyphosis >=60degree. OUTCOME MEASURES: Short Form-36 (SF-36) PCS score.
METHOD(S): Consecutive SASD patients from a prospective multicenter database were evaluated for type and severity of global malalignment. Severe alignment thresholds included SVA >=10cm (SAG-only), GCM >=6cm (COR-only), or both SVA >=10cm and GCM >=6cm (MIX). SF-36 PCS scores were compared with U.S. normative values.
RESULT(S): Of 492 SASD patients that met threshold alignment criteria, 463 (94%) completed the SF-36 and were included (78% women, mean age 65 years, mean BMI 28.6 kg/m2, previous spine surgery in 65%). Deformity types were SAG-only (58%), COR-only (19%) and MIX (23%). COR-only had more women (94%, p<0.001), younger age (61 years, p=0.004), and lower BMI (26 kg/m2, p<0.001). Charlson Comorbity Index (CCI) scores and total number of comorbidities were comparable among the deformity types (p>0.05). All deformity types were 'frail' based on ASD-Frailty Index scores (SAG-only [3.9], COR-only [3.1], MIX [4.0]). Overall mean PCS was lower compared to similar age- and gender-matched U.S. normative values (29.0 vs 45.3, p<0.001). Mean PCS was significantly different between deformity types (p<0.001): SAG-only (28.5) vs COR-only (33.1) vs MIX (27.0). PCS offsets from normative population scores were significantly different between deformity types (p=0.001): SAG-only (-16.6) vs COR-only (-13.4) vs MIX (-18.2).
CONCLUSION(S): Demographic comparisons demonstrated significantly more women, younger age, and lower BMI in the COR-only deformity type. Severe global malalignment (SVA >=10cm and/or GCM >=6cm) had substantial debilitating impact on health, with MIX deformity type (i.e., severe global sagittal and coronal malalignment) experiencing the greatest health impact. 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: Adult spinal deformity (ASD) correction involves complex, invasive procedures. However, it is unknown how metabolic syndrome affects the cost efficiency of ASD surgery. PURPOSE: Investigate the differences in ASD surgery cost for metabolic syndrome patients. STUDY DESIGN/SETTING: Retrospective review of a single center ASD database. PATIENT SAMPLE: A total of 557 ASD patients. OUTCOME MEASURES: Complications, revisions and costs.
METHOD(S): ASD patients (scoliosis >=20degree, SVA>=5cm, PT >=25degree, or TK >=60degree) >=18, undergoing >=4 level fusions were included. Descriptive analysis assessed mean baseline demographic, radiographic and surgical data were assessed. Patients diagnosed with: BMI >30, diabetes mellitus, and HTN were classified metabolic syndrome patients (MetS). Independent samples T-tests assessed baseline differences in SVA, PT, PI-LL, and levels fused between MetS and non-MetS patients. Total surgery costs for MetS and non-MetS ASD patients were compared. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims. Complications and comorbidities (CC) and major complications and comorbidities (MCC) were assessed according to CMS.gov manual definitions.
RESULT(S): A total of 557 patients met inclusion criteria. Baseline demographics and surgical details: age 60.8 +/- 13.2, 67.5% female, BMI 28.3 +/- 6.67, 6.2% anterior approach, 81.0% posterior approach, 12.8% combined approach, 10.4 +/- 3.9 levels fused, op time 423.5 +/- 166.4 minutes, EBL 2061.4 +/- 1631.5 cc, LOS 7.6 +/- 5.4 days. 11 MetS patients were included. There was no significant difference in BL SVA (54.2degree vs 70.3degree), PT (26.7degree vs 23.7degree), PI-LL (16.4degree vs 21.2degree), or levels fused between groups (10.5 vs 10.6) (all p>0.05). Twenty-seven percent of MetS patients experienced a CC or MCC, with 18% undergoing revisions within 90 days (vs 13.2% and 3.2% for non-MetS, p<0.05). The average costs of surgery for MetS patients was $68,004.06 vs $48,726.40 for non-MetS patients (p<0.05).
CONCLUSION(S): Metabolic syndrome is a growing concern among health care providers. In metabolic syndrome patients undergoing corrective adult spinal deformity surgery, the total costs of surgery was 28.4% higher for metabolic syndrome patients ($68,004.06 vs $48,726.40). Optimizing modifiable factors like diabetes or BMI in preoperative patients may have an impact on cost effectiveness. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: The choice of surgical approach in CD surgery is often dictated by surgeon preference and experience. This choice could significantly impact the costs and outcomes of an operation, therefore the approaches should be analyzed in order to determine the optimal approach from a cost-utility perspective. The cost utility of different surgical approaches in cervical deformity (CD) has not been investigated in the literature. PURPOSE: Investigate the cost utility of differing approaches in operative CD patients. STUDY DESIGN/SETTING: Retrospective review of a prospective multicenter cervical deformity database. PATIENT SAMPLE: A total of 105 CD patients. OUTCOME MEASURES: Costs, EuroQol-5D (EQ-5D), Quality adjusted life years (QALYs), Cost per quality adjusted life years.
METHOD(S): Included CD patients (C2-C7 Cobb>10degreeor CK>10degree, cSVA>4cm or CBVA>25degree) >18yr with follow-up (1-year) surgical and health related quality of life scores. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims. QALYs and cost per QALY were calculated using a 3% discount rate to account for residual decline to life expectancy (78.7 years). After accounting for complications, LOS, revisions, and death, cost per QALY at 1Y and life expectancy [LE] were calculated for surgical approach (anterior-only, posterior-only [excluding PSO and VCR to account for differences in instrumentation], combined). In a subanalysis, approach groups were propensity-score matched for TS-CL to account for baseline (BL) deformity.
RESULT(S): A total of 105 CD patients met inclusion criteria (61.9 yrs, 63% female, 28.6kg/m2, CCI: 0.97). By approach, 21.9% underwent anterior only, 37.1% posterior only and 41% combined approaches. Average number of levels fused was 6.9, with a mean EBL of 948 ml and total operative time of 544.2 minutes. Mean EQ5D at BL was 0.74+/-0.07 and at 1Y was 0.79+/-0.08 (a difference of 0.05+/-0.08). Average difference in EQ5D from BL to 1Y was significant (p=0.002) across approach: 0.093 anterior-only, 0.021 posterior-only, 0.044 combined. 13% (3) of anterior-only patients underwent a revision, 10.3% (4) of posterior and 13.9% (6) of combined approaches. The average costs per surgery for CD patients at 1-year undergoing surgery by anterior approach was $27,640.75, $38,499.44 posterior-only, and $36,553.41 combined approach (p>0.05).The cost per QALY was higher for posterior-only patients at 1-year ($948,946.81) compared to anterior-only ($152,616.65) and combined ($424,110.14), p<0.001. If the utility gained was sustained to life expectancy, the cost per QALY for the anterior-only group was $21,665.87, posterior-only was $134,715.06 and combined approach was $60,207.82., p<0.001. After PSM for TS-CL, 15 patients remained in each group. The cost per QALY remained higher for posterior-only patients at 1-year and LE (both p<0.050).
CONCLUSION(S): After accounting for comorbidities, complications, revisions, and death, all surgical approaches showed improvement in postoperative EQ5D scores, however posterior approach demonstrated overall lower cost effectiveness. CD patients who underwent anterior-only approach had the lowest average costs for CD corrective surgery, as well as the lowest cost per QALY (best cost-effectiveness) compared to posterior and combined approaches. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Based on biomechanical studies, the use and type of interbody device at the lumbosacral junction creates variable stress/strain on the lumbopelvic fixation. This variability may lead to differential failure mechanisms and rates within following correction of adult spinal deformity (ASD). PURPOSE: We aimed to evaluate the relationship of lumbosacral interbody presence and type with lumbopelvic fixation failure after ASD correction utilizing iliac (IS) or S2 alar iliac (S2AI) screws. STUDY DESIGN/SETTING: Retrospective review of prospective, multicenter ASD database. PATIENT SAMPLE: A total of 342 patients. OUTCOME MEASURES: Pelvic fixation loosening, IS/S2AI screw fracture, S1 screw fracture, rod fracture (below L4), revision surgery, pseudarthrosis, HRQLs.
METHOD(S): Inclusion criteria consisted of patients with ASD (coronal Cobb >=20degree, sagittal vertical axis (SVA) >=5cm, pelvic tilt >=25degree and/or thoracic kyphosis >60degree) >=18 years old and 2yr f/u who underwent >5 level fusion with pelvic fixation. Patients with prior L5-S1 fusion were excluded. Patients were divided into three groups based on the lumbosacral interbody fusion strategy (none, ALIF, TLIF/PLIF). Univariate testing via one-way ANOVA and chi-square tests, and multivariate logistic regression, accounting for significant confounders, were used to examine the difference between the three groups in regard to pseudarthosis, pelvic fixation loosening, rod fracture and revision surgery. Level of significance=p<0.05.
RESULT(S): A total of 342 patients met inclusion criteria (L5-S1 interbody groups: none=164, ALIF=87, TLIF=91). The three groups were similar in terms of baseline comorbidities, gender, BMI, pelvic fixation type (iliac screws vs S2AI), and use of BMP2 posteriorly. There were differences in rate of interbody BMP2 use (ALIF 22.9%, TLIF 48.35%, p=0.0001), use of unilateral pelvic fixation (none 7.36%, ALIF 19.8%, TLIF 3.29%, p=0.0001) and age (none 65.41, ALIF 60.47, TLIF 63.81, p=0.0005). Multivariate logistic regression revealed ALIF at L5-S1 was associated with lower odds of pseudarthrosis (OR 0.16, p-0.026) and rod fracture (OR 0.19, p=0.012) compared to no interbody fusion, while TLIF was no different than no interbody. There were no differences between groups in regard to pelvic fixation loosening or revision surgery.
CONCLUSION(S): The use of ALIF at L5-S1 during correction of ASD protects against fixation failure at the lumbopelvic junction compared to the use of TLIF or no interbody. This more protective effect of ALIF at the lumbosacral junction may allow for selective unilateral pelvic fixation for ASD surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: The International Spine Study Group (ISSG) and the European Spine Study Group (ESSG) developed an adult spinal deformity (ASD) specific risk calculator based on the largest and most granular, prospective ASD database. The calculators utilize preoperative radiographic, surgical, and patient-specific variables in order to predict patient-reported outcomes and complication rates at 2 years. PURPOSE: Assess the ISSG-ESSG risk calculator usability in a single institution ASD population. STUDY DESIGN/SETTING: Retrospective cohort study- single surgeon institution. PATIENT SAMPLE: ASD pts: A total of 631 patients undergoing surgery for adult spinal deformity. OUTCOME MEASURES: Improvement from BL SRS-22 [Pain, Function, total], major complications, Oswestry Disability Index (ODI).
METHOD(S): ASD pts were isolated in the single-center ASD Database 2013-2020. Frail pts were isolated (Frail[F] 0.3>0.5). Basic demographics were assessed for these F pts via chi-squared and t-tests. Each F patient was inputted into the ESSG risk calculator to identify individual predictive rates for postoperative 2-year HRQL outcomes as well as major complications. These calculated predicted outcomes were analyzed against those identified from the ASD database in order to validate the calculator predictability in a single center institution via Brier scores. Having a score closer to 1 means the EESG calculator is not predictive of that specific outcome. A score closer to 0 meant the EESG calculator was a predictive tool for that factor.
RESULT(S): A total of 631 ASD pts were isolated (55.8;16.8yrs, 26.68kg/m², 0.95+/-1.3CCI). Of these patients, 7.8% were frail. Fifty percent of frail pts received an interbody fusion, 58.3% received a decompression, and 79.2% had an osteotomy. Surgical details: mean operative time 342.9+/-94.3minutes, mean estimated blood loss 2131.82+/-1011mL, and an average length of stay 7.12+/-2.5days. The EESG calculator predicted the likelihood of improvement for the following HRQL's ODI(86%), SRS-22 Mental Health (71.1%), SRS-22 Total (87.6%), major complication (53.4%). The single institution had lower percentages of improvement in ODI (24.6%), SRS-22 Mental Health (21.3%), SRS-22 Total (25.1%), and lower presence of major complication (34.8%). The calculated Brier scores identified the calculator's predictability for each factor: ODI (0.24), SRS-22 Mental Health (0.21), SRS-22 Total (0.25), major complication (0.28).
CONCLUSION(S): The newly developed ESSG-ISSG risk-assessment tool has a wide application in single institutions as it accurately predicts 2-year outcomes for various SRS-22 questionnaires and development of major complications. 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: MBDs are often implicated in or contribute to degenerative disc disease (DDD). Yet, there is limited long-term, postoperative outcome data on the impact of MBDs on 2-year outcomes following 2-3-level lumbar fusion for DDD. PURPOSE: To determine if DDD patients with MBDs have comparable outcomes to those without MBDs following lumbar fusion. STUDY DESIGN/SETTING: Retrospective cohort. PATIENT SAMPLE: New York State Statewide Planning and Research Cooperative System was reviewed from 2009-2013 to identify all patients with DDD who underwent short, lumbar fusion (2-3-levels) with >=2-year follow-up OUTCOME MEASURES: Two-year outcome rates (medical/surgical complications and reoperations).
METHOD(S): The New York State Statewide Planning and Research Cooperative System was reviewed from 2009-2013 to identify all patients with DDD who underwent short, lumbar fusion (2-3 levels) with >=2-year follow-up. Patients with and without MBD (vitamin D deficiency, hyperparathyroidism, osteomalacia, and rickets) were identified. Any patients with osteoporosis or other systemic/endocrine disorders affecting bone quality were excluded. Traumatic, infectious, and neoplastic surgical indications were excluded. Cohorts were compared for demographics and 2-year outcome rates (medical/surgical complications and reoperations). Logistic regression was used to identify covariates associated with medical/surgical complications and revisions.
RESULT(S): A total of 28,959 patients were included (MBD, n=380 (1.33%); no-MBD, n=28,579). MBD pts were older (56.4 vs 53.1 years) and more often female (65.5% vs 49.80%) than no-MBD pts (all p<0.001). MBD pts had longer hospital stays (4.57 days vs 4.11 days, p=0.026), but charges were similar. MBD pts incurred higher rates of wound complications (11.8% vs 6.0%), acute renal failure (11.1% vs 4.7%), pneumonia (9.2% vs 4.4%), and implant related complications (12.1% vs 7.0%); all p<0.001. Rates of pseudarthrosis, PE, pulmonary complications, and UTI were similar between groups. MBDs were associated with developing both medical complications (OR=1.55) and surgical complications (OR=1.79), both p<0.001.
CONCLUSION(S): MBD patients have an increased risk of 2-year postop comps and reoperations following short lumbar fusion for DDD compared to patients without MBD when controlling for demographics and comorbidity profile. These data underscore the importance of preoperative screening and optimization in this patient population. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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