Faculty Bibliography

STUDY DESIGN/METHODS:This was a retrospective cohort analysis. OBJECTIVE:To identify the impact of Parkinson disease (PD) on 2-year postoperative outcomes following cervical spine surgery (CSS). SUMMARY OF BACKGROUND DATA/BACKGROUND:(PD) patients are prone to spine malalignment and surgical interventions, yet little is known regarding outcomes of CSS among PD patients. MATERIALS AND METHODS/METHODS:All patients from the Statewide Planning and Research Cooperative System with cervical radiculopathy or myelopathy who underwent CSS were included; among these, those with PD were identified. PD and non-PD patients (n=64 each) were 1:1 propensity score-matched by age, sex, race, surgical approach, and Deyo-Charlson Comorbidity Index (DCCI). Demographics, hospital-related parameters, and adverse postoperative outcomes were compared between cohorts. Logistic regression identified predictive factors for outcomes. RESULTS:Overall, patient demographics were comparable between cohorts, except that DCCI was higher in PD patients (1.28 vs. 0.67, P=0.028). PD patients had lengthier mean hospital stays than non-PD patients (6.4 vs. 4.1 d, P=0.046). PD patients also incurred comparable total hospital expenses ($69,565 vs. $57,388, P=0.248). Individual medical complication rates were comparable between cohorts; though PD patients had higher rates of postoperative altered mental status (4.7% vs. 0%, P=0.08) and acute renal failure (10.9% vs. 3.1%, P=0.084), these differences were not significant. Yet, PD patients experienced higher rates of overall medical complications (35.9% vs. 18.8%, P=0.029). PD patients had comparable rates of individual and overall surgical complications. The PD cohort underwent higher reoperation rates (15.6% vs. 7.8%, P=0.169) compared with non-PD patients, though this difference was not significant. Of note, PD was not a significant predictor of overall 2-year complications (odds ratio=1.57, P=0.268) or reoperations (odds ratio=2.03, P=0.251). CONCLUSION/CONCLUSIONS:Overall medical complication rates were higher in patients with PD, while individual medical complications as well as surgical complication and reoperation rates after elective CSS were similar in patients with and without PD, though PD patients required longer hospital stays. Importantly, a baseline diagnosis of PD was not significantly associated with adverse two-year medical and surgical complications. This data may improve counseling and risk-stratification for PD patients before CSS. LEVEL OF EVIDENCE/METHODS:Level III.

STUDY DESIGN/METHODS:This was a retrospective cohort study. OBJECTIVE:The aim of this study was to investigate associations between time to surgical intervention and outcomes for central cord syndrome (CCS) patients. BACKGROUND:As surgery is increasingly recommended for patients with neurological deterioration CCS, it is important to investigate the relationship between time to surgery and outcomes. MATERIALS AND METHODS/METHODS:CCS patients were isolated in Nationwide Inpatient Sample database 2005-2013. Patients were grouped by time to surgery: same-day, 1-day delay, 2, 3, 4-7, 8-14, and >14 days. Means comparison tests compared patient factors, perioperative complications, and charges across patient groups. Controlling for age, comorbidities, length of stay, and concurrent traumatic fractures, binary logistic regression assessed surgical timing associated with increased odds of perioperative complication, using same-day as reference group. RESULTS:Included: 6734 CSS patients (64% underwent surgery). The most common injury mechanisms were falls (30%) and pedestrian accidents (7%). Of patients that underwent surgery, 52% underwent fusion, 30% discectomy, and 14% other decompression of the spinal canal. Breakdown by time to procedure was: 39% same-day, 16% 1-day, 10% 2 days, 8% 3 days, 16% 4-7 days, 8% 8-14 days, and 3% >14 days. Timing groups did not differ in trauma status at admission, although age varied: [minimum: 1 d (58±15 y), maximum: >14 d (63±13 y)]. Relative to other groups, same-day patients had the lowest hospital charges, highest rates of home discharge, and second lowest postoperative length of stay behind 2-day delay patients. Patients delayed >14 days to surgery had increased odds of perioperative cardiac and infection complications. Timing groups beyond 3 days showed increased odds of VTE and nonhome discharge. CONCLUSIONS:CCS patients undergoing surgery on the same day as admission had lower odds of complication, hospital charges, and higher rates of home discharge than patients that experienced a delay to operation. Patients delayed >14 days to surgery were associated with inferior outcomes, including increased odds of cardiac complication and infection.

Objective/UNASSIGNED:The objective of the study is to investigate which neurologic complications affect clinical outcomes the most following cervical deformity (CD) surgery. Methods/UNASSIGNED:CD patients (C2-C7 Cobb >10°, CL >10°, cSVA >4 cm or chin-brow vertical angle >25°) >18 years with follow-up surgical and health-related quality of life (HRQL) data were included. Descriptive analyses assessed demographics. Neurologic complications assessed were C5 motor deficit, central neurodeficit, nerve root motor deficits, nerve sensory deficits, radiculopathy, and spinal cord deficits. Neurologic complications were classified as major or minor, then: intraoperative, before discharge, before 30 days, before 90 days, and after 90 days. HRQL outcomes were assessed at 3 months, 6 months, and 1 year. Integrated health state (IHS) for the neck disability index (NDI), EQ5D, and modified Japanese Orthopaedic Association (mJOA) were assessed using all follow-up time points. A subanalysis assessed IHS outcomes for patients with 2Y follow-up. Results/UNASSIGNED:= 0.263, 0.163). Conclusions/UNASSIGNED:18% of patients undergoing CD surgery experienced a neurologic complication, with 15% within 3 months. Patients who experienced any neurologic complication had worse mJOA recovery kinetics by 1 year and trended toward worse recovery at 2 years. Of the neurologic complications, central neurologic deficits and spinal cord deficits were the most detrimental.

Background Context: Cervical deformity (CD) correction is becoming more challenging and complex. Understanding the factors that drive optimal outcomes has been understudied in CD correction surgery.
Purpose(s): The purpose of this study is to assess the factors associated with improved outcomes (IO) following CD surgery.
Study Design/Setting: Retrospective review of a single-center database.
Patient Sample: Sixty-one patients with CD. Outcome Measures: The primary outcomes measured were radiographic and clinical 'IO' or 'poor outcome' (PO). Radiographic IO or PO was assessed utilizing Schwab pelvic tilt (PT)/sagittal vertical axis (SVA), and Ames cervical SVA (cSVA)/TS-CL. Clinical IO or PO was assessed using MCID EQ5D, Neck Disability Index (NDI), and/or improvement in Modified Japanese Orthopedic Association Scale (mJOA) modifier. The secondary outcomes assessed were complication and reoperation rates.
Material(s) and Method(s): CD patients with data available on baseline (BL) and 1-year (1Y) radiographic measures and health-related quality of life s were included in our study. Patients with reoperations for infection were excluded. Patients were categorized by IO, PO, or not. IO was defined as 'nondeformed' radiographic measures as well as improved clinical outcomes. PO was defined as 'moderate or severe deformed' radiographic measures as well as worsening clinical outcome measures. Random forest assessed ratios of predictors for IO and PO. The categorical regression models were utilized to predict BL regional deformity (Ames cSVA, TS-CL, horizontal gaze), BL global deformity (Schwab PI-LL, SVA, PT), regional/global change (BL to 1Y), BL disability (mJOA score), and BL pain/function impact outcomes.
Result(s): Sixty-one patients met inclusion criteria for our study (mean age of 55.8 years with 54.1% female). The most common surgical approaches were as follows: 18.3% anterior, 51.7% posterior, and 30% combined. Average number of levels fused was 7.7. The mean operative time was 823 min and mean estimated blood loss was 1037 ml. At 1 year, 24.6% of patients were found to have an IO and 9.8% to have a PO. Random forest analysis showed the top 5 individual factors associated with an 'IO' were: BL Maximum Kyphosis, Maximum Lordosis, C0-C2 Angle, L4-Pelvic Angle, and NSR Back Pain (80% radiographic, 20% clinical). Categorical IO regression model (R 2 = 0.328, P = 0.007) found following factors to be significant: low BL regional deformity (beta = 0.082), low BL global deformity (beta = 0.099), global improve (beta = 0.532), regional improve (beta = 0.230), low BL disability (beta = 0.100), and low BL NDI (beta = 0.024). Random forest found the top 5 individual BL factors associated with 'PO' (80% were radiographic): BL CL Apex, DJK angle, cervical lordosis, T1 slope, and NSR neck pain. Categorical PO regression model (R 2 = 0.306, P = 0.012) found following factors to be significant: high BL regional deformity (beta = 0.108), high BL global deformity (beta = 0.255), global decline (beta = 0.272), regional decline (beta = 0.443), BL disability (beta = 0.164), and BL severe NDI (>69) (beta = 0.181).
Conclusion(s): The categorical weight demonstrated radiographic as the strongest predictor of both improved (global alignment) and PO (regional deformity/deterioration). Radiographic factors carry the most weight in determining an improved or PO and can be ultimately utilized in preoperative planning and surgical decision-making to optimize the outcomes.
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STUDY DESIGN/METHODS:Retrospective review. OBJECTIVE:The aim of this study was to evaluate outcomes of matching Roussouly and improving in Schwab modifier following adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:The Roussouly Classification system of sagittal spinal shape and the SRS-Schwab classification system have become important indicators of spine deformity. No previous studies have examined the outcomes of matching both Roussouly type and improving in Schwab modifiers postoperatively. METHODS:Surgical ASD patients with available baseline (BL) and 1 year (1Y) radiographic data were isolated in the single-center spine database. Patients were classified by their "theoretical" and "current" Roussouly types as previously published. Patients were considered a "Match" if their theoretical and current Roussouly types were the same, or a "Mismatch" if the types differed. Patients were noted as improved if they were Roussouly "Mismatch" preoperatively, and "Match" at 1Y postop. Schwab modifiers at BL were categorized as follows: no deformity (0), moderate deformity (+), and severe deformity (++) for PT, SVA, and PI-LL. Improvement in SRS-Schwab was defined as a decrease in any modifier severity at 1Y. RESULTS:103 operative ASD patients (61.8 years, 63.1% female, 30 kg/m2) were included. At baseline, breakdown of "current" Roussouly type was: 28% Type 1, 25.3% Type 2, 32.0% Type 3, 14.7% Type 4. 65.3% of patients were classified as Roussouly "Mismatch" at BL. Breakdown of BL Schwab modifier severity: PT (+: 41.7%, ++: 49.5%), SVA (+: 20.3%, ++: 50%), PI-LL (+: 25.2%, ++: 46.6%). At 1 year postop, 19.2% of patients had Roussouly "Match". Analysis of Schwab modifiers showed that 12.6% improved in SVA, 42.7% in PI-LL, and 45.6% in PT. Count of patients who both had a Roussouly type "Match" at 1Y and improved in Schwab modifier severity: nine PT (8.7%), eight PI-LL (7.8%), and two SVA (1.9%). There were two patients (1.9%) who met their Roussouly type and improved in all three Schwab. 1Y matched Roussouly patients improved more in health-related quality of life scores (minimal clinically important difference [MCID] for Oswestry Disability Index [ODI], EuroQol-5D-3L [EQ5D], Visual Analogue Score Leg/Back Pain), compared to mismatched, but was not significant (P > 0.05). Match Roussouly and improvement in PT Schwab met MCID for EQ5D more (P = 0.050). Matched Roussouly and improvement in SVA Schwab met MCID for ODI more (P = 0.024). CONCLUSION/CONCLUSIONS:Patients who both matched Roussouly sagittal spinal type and improved in SRS-Schwab modifiers had superior patient-reported outcomes. Utilizing both classification systems in surgical decision-making can optimize postop outcomes.Level of Evidence: 3.

BACKGROUND CONTEXT: A previous study by Pellise et al identified that a lowest instrumented vertebrae (LIV) at the pelvis, frailty, and sagittal deformity (global sagittal alignment [SVA], lordosis gap [PI-LL], T1 sagittal tilt [T1Slope]) were strong preoperative predictors of major complications. In addition to the preoperative predictors, blood loss and surgical time were strong predictors that occur operatively. It is unknown whether being at risk by these criteria has an effect on cost of surgery. PURPOSE: To determine whether previously established risk stratification criteria will reduce operative costs. STUDY DESIGN/SETTING: Retrospective cohort study of a prospectively collected multicenter ASD database. PATIENT SAMPLE: This study included 952 ASD patients. OUTCOME MEASURES: Health-related quality of life measures (HRQLs), quality adjusted life years (QALYs), utility gained, ODI, total cost.
METHOD(S): Adult spinal deformity (ASD) patients with complete baseline (BL) and 2-year (2Y) HRQLs and radiographic data were included. Frailty score, sagittal deformity measures, blood loss, and surgical time were divided into tertiles, with the highest tertile being high risk. Published methods converted ODI to SF-6D. QALYs utilized a 3% discount rate for residual decline to life expectancy (LE, 78.7 years). Cost was calculated using the PearlDiver database and assessed for complications/major complications and comorbidities according to CMS.gov definitions. Cost per QALY at 2Y and LE were calculated for additive risk factors (LIV at pelvis, high frailty, any high sagittal deformity measure, high blood loss, high surgical time). These costs represented national averages of Medicare pay-scales for services within a 30-day window including length of stay and death differentiated by complication/comorbidity, revision, and surgical approach. Internal cost data were based on individual patient DRG codes.
RESULT(S): Of 926 patients included, 118 did not meet any risk criteria, 171 met 1, 207 met 2, 151 met 3, 56 met 4, and 3 met 5 (these 3 patients were excluded due to small sample size). There was a significant trend (R2=0.897) in terms of national average cost at 2-years with increasing amount of risk measures met, as cost increased by $11,566 with each additional risk factor. Amount of risk factors met had a positive correlation to baseline ODI (0: 30.89; 1: 39.66; 2: 46.96; 3: 51.59; 4: 54.69; p<0.001) and 2Y ODI (0: 18.06; 1: 22.55; 2: 27.53; 3: 34.23; 4: 38.54; p<0.001). When analyzing initial surgical cost by DRG code, there was a $3,844 increase in cost per risk factor (R2=0.8703). Patients meeting 2 risk factors had the highest ODI improvement from BL to 2Y (p=0.06). QALYs gained at LE decreased by 0.0756 per risk factor (R2=0.8153). National average cost per QALY at 2Y increased by $45,852 per risk factor (R2=0.4151), and cost per QALY at LE increased by $15,759 per risk factor (R2=0.8822).
CONCLUSION(S): Increasing risk factors involving frailty, baseline deformity, and operative factors reduce cost effectiveness by increasing total cost and reducing QALYs. Preoperative or intraoperative measures to reduce a patient's amount of applicable risk factors would concurrently reduce operative cost and improve cost-effectiveness. Awareness of non-modifiable risk factors may also help educate surgical approach. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT/BACKGROUND:In 2008, the Centers for Medicare and Medicaid Services (CMS) established a list of hospital-acquired conditions (HACs) with significant deleterious effects on both patients and providers. Adult spinal deformity (ASD) surgery is complex and highly invasive, and as such may result in significant morbidity including these HACs. PURPOSE/OBJECTIVE:Identify predictors for developing the most common HACs among adult spinal deformity(ASD) patients undergoing corrective surgery. STUDY DESIGN/SETTING/METHODS:Retrospective analysis PATIENT SAMPLE: 1,171 ASD patients OUTCOME MEASURES: HACs, Health-Related Quality of Life scores(HRQLs), Reoperation, Integrated Health State (IHS) METHODS: ASD pts undergoing surgery (>18yrs, scoliosis ≥20°, SVA≥5cm, PT≥25° and/or TK >60°) with complete data at BL and up to 2 years post-op were included. Patients were stratified by presence of >1 HAC, defined as at least one superficial/deep SSI, UTI, DVT, or PE within a 30-day post-op window. Random forest analysis generated 5,000 Conditional Inference Trees to compute a variable importance table for top predictors of HACs. An area-under-the-curve (AUC) methodology compared normalized HRQL scores between groups to determine an IHS with 2-year follow-up. RESULTS:1,171 pts (59.8yrs, 76.2%F, 28.1kg/m2) underwent corrective ASD surgery, with 1,053 pts in the non-HAC group and 118 in the HAC group. Of these pts, 25.4% had UTI, 15.4% DVT, 19.2% superficial SSI, 20.8% deep SSI, and 19.2% PE. HAC pts were on average older (63.5 vs 59.3, p=0.004) and more often frail (51.3vs39.7%,p=0.021)than non-HAC pts. Postop LOS and reoperation were most associated with HAC groups: [1] LOS>7 days [2] reoperation. Patient-related predictors of HACs were [3] age>50yr, [4] frailty, and [13] BMI>31. Procedure-related predictors of HACs were [5] operative-time >405mins, [6] levels fused >9, EBL>1450mL, and [11] decompression. BL radiographic predictors were [7] PT>20°,[9] PI-LL>6°, [10] TL Cobb angle>15°,[12] SVA C7-S1>29mm. No differences were observed between groups with regards to IHS ODI(0.73vs0.74,p=0.863), SRS(1.3vs1.3,p=0.374), NRS Back (0.6vs0.6,p=0.158). HAC had higher rates of reoperation than non-HAC (0.08 vs 0.01, p=0.066), and any HAC within 30-days of index was a significant predictor of reoperation (OR:2.448 [1.94-3.09],p<0.001). CONCLUSIONS:In a population of ASD patients, HACs were associated with length of stay, reoperation, age, and frailty. Radiographic parameters such as pelvic tilt>20°, PI-LL>6°, & SVA>29mm also increased odds of HACs, and should raise postoperative awareness for HAC development.

BACKGROUND CONTEXT: Both frailty and surgical invasiveness are correlated with increased risk of complications following ASD surgery, yet there is no accepted risk-stratification system combining these factors. PURPOSE: The aim of this study is to ascertain data-driven categories defining the risk for 90-day complications following ASD surgery based on frailty and surgical invasiveness. STUDY DESIGN/SETTING: Retrospective review of a multicenter database. PATIENT SAMPLE: A total of 1,272 surgical ASD patients undergoing spinal fusions >=5 levels OUTCOME MEASURES: Ninety-day complication risk, 90-day complication rate, invasiveness thresholds for increased complications.
METHOD(S): Using a prospective, multicenter database, we identified 1,272 surgical ASD patients undergoing posterior spinal fusion of at least five levels. Patients were separated into three frailty groups based on the ASD-FI frailty index. Within each frailty group, stratum-specific likelihood ratio (SSLR) analyses were performed to define frailty-based surgical invasiveness cutoffs associated with increased risk for 90-day complications. Cutoffs generated through SSLR were confirmed with multivariable logistic regression analysis controlling for age, alignment, and ODI.
RESULT(S): Mean age was 60 +/- 14 years, 74% females. Of 1,272 surgical ASD patients, 319 (35%) were nonfrail (NF), 667 (52%) frail (F), and 286 (23%) severely frail (SF). Mean SI was 93 +/- 35. The mean complication rate was 35.4% for NF, 37% for F and 43.6% for SF. SSLR analysis of NF patients produced 2 complication categories: 33% complication rate for SI < 153 and 73% for SI >= 153. NF patients with SI >= 153 had 4.14x higher odds of complications than NF patients with SI <153 (p=0.04). SSLR analysis of F patients produced 3 complication categories: 26% complication rate for SI < 60, 42% for SI of 60 to 179, and 64% for SI >= 180. Relative to F patients with SI < 60, F patients with SI 60 to 179, and SI >= 180 had 2.4x and 6.7x higher odds of complications, respectively (p<0.01 for both). SSLR analysis of SF patients produced 2 complication categories: 35% complication rate for SI < 82 and 49% complication rate for SI >= 82. SF patients with SI >= 82 had 1.77x higher odds of complications than SF patients with SI < 82 (p=0.04).
CONCLUSION(S): Frailer groups were found to have lower SI cutoffs, indicating the less invasiveness surgeries can be performed on frail patients to minimize complication risk. This risk-stratification system is useful for counselling patients regarding their risk of complication. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Few studies investigate fractional curve correction after long fusion with transforaminal (TLIF) vs anterior lumbar interbody fusion (ALIF) for adult symptomatic thoracolumbar/lumbar scoliosis (ASLS). PURPOSE: Our objective was to compare fractional correction, health-related quality-of-life (HRQL), and complications associated with L4-S1 TLIF vs ALIF in ASLS operative treatment. STUDY DESIGN/SETTING: Retrospective review of a prospectively collected multicenter consecutive case registry. PATIENT SAMPLE: Database enrollment required age >=18 years, scoliosis >=20, sagittal vertical axis (SVA) >=5cm, pelvic tilt >=25, or thoracic kyphosis >=60. OUTCOME MEASURES: Radiographic correction (including L4-S1 fractional curve), HRQL (Oswestry Disability Index [ODI], Short Form-36 [SF-36] scores, Scoliosis Research Society-22 [SRS-22r] scores), and complications.
METHOD(S): Prospective multicenter data was reviewed. Study inclusion required fractional curve >=10degree, thoracolumbar/lumbar curve >=30degree, index TLIF vs ALIF at L4-L5 and/or L5-S1, and minimum 2-year follow-up. TLIF and ALIF patients were propensity-matched using number and type of interbody fusion at L4-S1.
RESULT(S): Of 135 potentially eligible consecutive patients, 106 (78.5%) achieved minimum 2-year follow-up (age=60.6+/-9.3years, women=85.8%, TLIF=44.3%, ALIF=55.7%). Index operations had 12.2+/-3.6 posterior levels, iliac fixation=86.8%, and TLIF/ALIF at L4-L5 (67.0%) and L5-S1 (84.0%). ALIF had greater cage height (10.9+/-2.1 vs 14.5+/-3.0mm, p=0.001) and lordosis (6.3degree+/-1.6degree vs 17.0degree+/-9.9degree, p=0.001) and longer operative duration (6.7+/-1.5 vs 8.9+/-2.5hrs, p<0.001). Final alignment improved significantly (p<0.05): fractional curve (20.2degree+/-7.0degree to 6.9degree+/-5.2degree), maximum coronal Cobb (55.0degree+/-14.8degree to 23.9degree+/-14.3degree), C7-sagittal vertical axis (5.1+/-6.2 to 2.3+/-5.4cm), pelvic tilt (24.6degree+/-8.1degree to 22.7degree+/-9.5degree), and lumbar lordosis (32.3degree+/-18.8degree to 51.4degree+/-14.1degree). Matched analysis demonstrated comparable fractional correction (TLIF=-13.6degree+/-6.7degree vs ALIF=-13.6degree+/-8.1degree, p=0.982). Final HRQL improved significantly (p<0.05): ODI (42.4+/-16.3 to 24.2+/-19.9), SF-36 Physical Component Summary (PCS, 32.6+/-9.3 to 41.3+/-11.7), SRS-22r (2.9+/-0.6 to 3.7+/-0.7). Matched analysis demonstrated worse ODI (30.9+/-21.1 vs 17.9+/-17.1, p=0.017) and PCS (38.3+/-12.0 vs 45.3+/-10.1, p=0.020) for TLIF at last follow-up (despite no difference in these parameters at baseline). Total complication rate per patient was not different (TLIF=76.6% vs ALIF=71.2%, p=0.530), but significantly more TLIF patients had rod fractures (RF) (TLIF=28.6% vs ALIF=7.1%, p=0.036). Multiple regression demonstrated 1-mm increase in L4-L5 TLIF cage height lead to 2.2degree reduction in L4 coronal tilt (p=0.011), and 1degree increase in L5-S1 ALIF cage lordosis lead to 0.4degree increase in L5-S1 segmental lordosis (p=0.045).
CONCLUSION(S): Operative ASLS treatment with L4-S1 TLIF vs ALIF demonstrated comparable fractional curve correction (66.7% vs 64.8%) despite significantly larger, more lordotic ALIF cages. TLIF cage height had significant impact on leveling L4 coronal tilt, whereas ALIF cage lordosis had significant impact on lumbosacral lordosis restoration. Advantages of TLIF may include reduced operative duration; however, associated HRQL was inferior and more RFs were detected in this study. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: ASD is a complex pathology that benefits greatly from surgical treatment despite being associated with high rates of complications. Despite continuous innovation, little is known regarding the association between changes in surgical techniques and complications. PURPOSE: To investigate the evolution of patient profiles and surgical complications across a single prospective multicenter database. STUDY DESIGN/SETTING: Retrospective review of prospective data. PATIENT SAMPLE: This study included 947 adult spinal deformity patients surgically treated between 2008 and 2018. OUTCOME MEASURES: Complication types and rates.
METHOD(S): Surgical ASD patients (TK >60degree, SVA >5cm, PT >25degree or Cobb angle >20degree) with minimum 2-year follow-up were included and stratified into 3 equal groups by date of surgery. Demographic, preoperative data, surgical information, and complications were compared across time using a moving average of 316 patients to delineate those enrolled at the beginning of the study (Early) from the most recent one (Late).
RESULT(S): Among the total, 947/1260 (67%) patients completed their 2-year follow-up with an enrollment rate of 7.7+/-4.1 patients per month. Compared to the Early phase (Oct 2008 and Nov 2012), patients enrolled more recently (Jan 2016 to Jan 2018) were older (Age: 56.7+/-15yovs 64.3+/-12.3), sicker (CCI: 1.46+/-1.6 vs 2.08+/-1.78), more disabled (ODI: 42.6+/-19.4 vs 45.7+/-15.3; PCS: 32.8+/-10.4 vs 29.7+/-8.5), with more pronounced sagittal deformity (SRS-Schwab type N: 26.3% vs 50.9%: PI-LL modifier ++: 37.1% vs 46.8%) (all p<0.05). Changes in surgical treatment included an increase use of IBF (61% vs 69.9%), more ACR/3CO use (21% vs 37%) and a decrease in 3CO rate (21% vs 12%), shorter fusion (11.2+/-4 vs 9.8+/-5), more supplemental rods (0.3% vs 26.9%) and BMP use (64.1% vs 80.1%) (all p<0.05), but no significant difference in invasiveness (91.2+/-37.1 vs 86.0+/-36.9 p=0.06). LOS decrease by 1 day, EBL by 500 cc and rate of ICU stay decrease from 71% to 53% (all p <0.001). There was no significant difference in overall complication rate (73% vs 67.4% p=0.14) despite a significant decrease in major complications requiring a reoperation (27.6% vs17.4% p=0.002) driven by a decrease in implant (8.3% vs 4.1% p=0.032) and radiographic failures (12.7% vs 5.7% p=0.002). Rate of major operative complication decreased (11.8% vs 6.7% p=0.028) while rate of major radiographic complication increased (0.6% vs 5.7% p<0.001) leading to a stable rate of major complications without reoperation (28.3% vs 27.9% p=0.92). No significant difference in minor complication rate (38.7% vs 34.2% p=0.24) The moving average analysis revealed a steady decrease in major complications associated to a reoperation (from 28% to 17%). The lowest peak of major complications (21%) occurred between Feb 2014 and Oct 2016, and the lowest overall complication rate (62%) occurred between July 2014 and Feb 2017.
CONCLUSION(S): Despite an increase in patient complexity including older, more medical morbidities and larger deformities, complication rates did not increase and the rate of complications requiring surgery decreased over time. These findings likely reflect evolutions in practice improvement including use of supplemental rods, PJK prophylaxis, BMP use, and targeting age-appropriate deformity corrections. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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