Single-level Posterior Lumbar Fusion Research Articles

Physical Therapy Utilization Following Single Level Posterior Lumbar Fusion.

Retrospective cohort study. Characterize physical therapy (PT) utilization following single-level posterior lumbar fusion (PLF). PLF is a common procedure that is increasing in frequency. Following such surgeries, PT may be considered to facilitate mobilization and return to activities. However, the usage of such therapy has not been well-characterized in the literature. Patients undergoing single-level PLF were identified from the 2010-2021 PearlDiver administrative database. These patients were stratified based on usage of therapy, home versus outpatient therapy, and timing of therapy within the year following surgery. To determine predictors of therapy, patient characteristics were determined and multivariable regressions were performed. A total of 213,240 patients undergoing single-level PLF were identified, of which therapy was done in the year following surgery for 63,231 (29.0%, of which home therapy accounted for 16.5% of therapy visits). Of those who utilized PT, the average number of visits was 10.6±10.6. Home therapy peaked within the first month following surgery and outpatient therapy peaked at month two. Factors associated with any PT following PLF in decreasing odds ratio (OR) were: having commercial insurance (OR: 1.68), being from the Northeast (OR:1.41), age (OR: 1.13 for 70+ of age) female sex (OR: 1.09), and ECI (OR: 1.04 per point) (P<0.001 for all). Of those who received therapy, factors associated with home PT utilization were: being from the Northeast (OR: 2.55), age (OR: 1.91 for 70+ of age), Medicaid insurance (OR: 1.48), female sex (OR: 1.39), and interbody fusion (OR:1.07) (P<0.001 for all). Following single-level PLF, the minority of patients received home or outpatient PT. Of those that did, there was significant variation in the number of visits, with nonmedical factors such as insurance plan and geographic region being strongly associated suggesting room for more consistent practice patterns. III.

Effect of Celiac Disease on Outcomes After Posterior Lumbar Fusion: A Matched Cohort Study

The purpose of this study was to analyze if celiac disease (CD) is associated with increased postoperative complications following single-level posterior lumbar fusion (PLF). A retrospective database review was performed using the PearlDiver dataset. The study population included all patients older than 18years who underwent elective PLF with diagnosis of CD using International Classification of Diseases (ICD) and Current Procedural Terminology (CPT) codes. Study patients were compared with controls for 90-day medical complications and 2-year surgical complications including 5-year reoperation rates. A multivariate logistic regression was used to determine the independent effect of CD on the postoperative outcomes. A total of 909 patients with CD and 4483 patients in the matched control group who underwent primary single-level PLF were included in this study. CD patients had a significantly increased risk of 90-day emergency department (ED) visit (OR 1.28; P=0.020). CD patients also demonstrated higher rates of 2-year pseudarthrosis and instrument failure, but they were statistically comparable (P>0.05). There was no difference in 5-year reoperation rate. There were also no significant differences in 90-day medical complication rate and 2-year surgical complication rate between the two groups. In addition, there were no differences in procedure cost and 90-day cost. For CD patients undergoing PLF, the current study demonstrated increased rate of 90-day ED visit. Our findings may be useful for patient counseling and surgical planning for those with this condition.

Impact of the 2016 American College of Surgeons Guideline Revision on Overlapping Lumbar Fusion Cases at a Large Academic Medical Center

The American College of Surgeons (ACS) updated its guidelines on overlapping surgery in 2016. The objective was to examine differences in postoperative outcomes after overlapping surgery either pre-ACS guideline revision or post-guideline revision, in a coarsened exact matching sample. A total of 3327 consecutive adult patients undergoing single-level posterior lumbar fusion from 2013 to 2019 were retrospectively analyzed. Patients were separated into a pre-ACS guideline revision cohort (surgery before April 2016) or a post-guideline revision cohort (surgery after October 2016) for comparison. The primary outcomes were proportion of cases performed with any degree of overlap, and adverse events including 30-day and 90-day rates of readmission, reoperation, emergency department visit, morbidity, and mortality. Subsequently, coarsened exact matching was used among overlapping surgery patients only to assess the impact of the ACS guideline revision on overlapping outcomes, and controlling for attending surgeon and key patient characteristics known to affect surgical outcomes. After the implementation of the ACS guidelines, fewer cases were performed with overlap (22.0% vs. 53.7%; P < 0.001). Patients in the post-ACS guideline revision cohort experienced improved rates of readmission and reoperation within 30 and 90 days. However, when limited to overlapping cases only, no differences were observed in overlap outcomes pre-ACS versus post-ACS guideline revision. Similarly, when exact matched on risk-associated patient characteristics and attending surgeon, overlapping surgery patients pre-ACS and post-ACS guideline revision experienced similar rates of 30-day and 90-day outcomes. After the ACS guideline revision, no discernable impact was observed on postoperative outcomes after lumbar fusion performed with overlap.

P43. Single-level posterior lumbar fusions in patients with Ehlers Danlos syndrome not found to be associated with increased postoperative adverse events or five-year reoperations

BACKGROUND CONTEXT Ehlers Danlos Syndrome (EDS) is a rare connective tissue disorder that results from mutations in collagen genes. Potentially related to laxity and resultant degenerative changes, adult EDS patients may require posterior lumbar fusion (PLF). However, with low numbers, adequately powered outcome studies have been limited. PURPOSE To investigate the effect of Ehlers Danlos Syndrome on postoperative outcomes and reoperations following PLF. STUDY DESIGN/SETTING Retrospective cohort study using the 2010 - 2020 MSpine Pearldiver dataset. PATIENT SAMPLE Patients with a diagnosis of EDS (any type) were identified using International Classification of Diseases (ICD) codes. Patients over 18 years of age undergoing PLF with or without laminectomy were identified using Current Procedural Terminology (CPT) codes. Patients who had a primary diagnosis code of fractures, infection, neoplasm or were not in the database for at least 90 days following the surgery were excluded. Further, patients who had multilevel fusions or had concurrent anterior fusion were excluded. OUTCOME MEASURES Ninety-day any, severe, and minor adverse events as well as readmissions and five-year reoperations. METHODS Adult patients undergoing single-level PLF (excluding any with anterior procedures) with and without EDS for which at least 90-day follow up was available were identified. Any cases performed for trauma, tumor, or infection were excluded. Single-level PLF EDS patients were then matched 1:4 with PLF non-EDS patients based on age, sex and Elixhauser Comorbidity Index (ECI). Rates of 90-day any, severe, and minor adverse events as well as readmissions were tabulated and compared with chi-square tests. Multivariate logistical regression was then performed (controlling for age, and ECI). Reoperation surgeries over five years were assessed, Kaplan-Meier survival curves generated, and curves of those with and without EDS were compared with log rank test. RESULTS In total, there were 170,100 single-level PLF case identified, of which 242 (0.14%) had EDS. After matching, there were 957 without EDS and 239 with EDS. On multivariate regression, there were no significant differences in 90-day any, severe, or minor adverse events, or readmissions (p>0.05 for each). Over five years, there were also not significant differences in rates of reoperation (p> 0.05). CONCLUSIONS For EDS patients undergoing PLF, the current study identified similar 90-day adverse events and five-year reoperation rates compared to those without EDS. These findings may be useful for patient counseling and surgical planning for those with this rare condition. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Ehlers Danlos Syndrome (EDS) is a rare connective tissue disorder that results from mutations in collagen genes. Potentially related to laxity and resultant degenerative changes, adult EDS patients may require posterior lumbar fusion (PLF). However, with low numbers, adequately powered outcome studies have been limited. To investigate the effect of Ehlers Danlos Syndrome on postoperative outcomes and reoperations following PLF. Retrospective cohort study using the 2010 - 2020 MSpine Pearldiver dataset. Patients with a diagnosis of EDS (any type) were identified using International Classification of Diseases (ICD) codes. Patients over 18 years of age undergoing PLF with or without laminectomy were identified using Current Procedural Terminology (CPT) codes. Patients who had a primary diagnosis code of fractures, infection, neoplasm or were not in the database for at least 90 days following the surgery were excluded. Further, patients who had multilevel fusions or had concurrent anterior fusion were excluded. Ninety-day any, severe, and minor adverse events as well as readmissions and five-year reoperations. Adult patients undergoing single-level PLF (excluding any with anterior procedures) with and without EDS for which at least 90-day follow up was available were identified. Any cases performed for trauma, tumor, or infection were excluded. Single-level PLF EDS patients were then matched 1:4 with PLF non-EDS patients based on age, sex and Elixhauser Comorbidity Index (ECI). Rates of 90-day any, severe, and minor adverse events as well as readmissions were tabulated and compared with chi-square tests. Multivariate logistical regression was then performed (controlling for age, and ECI). Reoperation surgeries over five years were assessed, Kaplan-Meier survival curves generated, and curves of those with and without EDS were compared with log rank test. In total, there were 170,100 single-level PLF case identified, of which 242 (0.14%) had EDS. After matching, there were 957 without EDS and 239 with EDS. On multivariate regression, there were no significant differences in 90-day any, severe, or minor adverse events, or readmissions (p>0.05 for each). Over five years, there were also not significant differences in rates of reoperation (p> 0.05). For EDS patients undergoing PLF, the current study identified similar 90-day adverse events and five-year reoperation rates compared to those without EDS. These findings may be useful for patient counseling and surgical planning for those with this rare condition.

P89. Patient out of pocket cost burden with elective spine surgery

<h3>BACKGROUND CONTEXT</h3> Out-of-pocket (OOP) costs for medical and surgical care can result in substantial financial burden for patients and families. Relatively little is known regarding OOP costs for commercially insured patients receiving spinal fusion surgery. <h3>PURPOSE</h3> The aim of this study is to analyze the trends in OOP costs for common, elective spinal fusion surgeries performed in the hospital inpatient setting. <h3>STUDY DESIGN/SETTING</h3> Retrospective review. <h3>PATIENT SAMPLE</h3> This study utilized an employer-sponsored insurance claims database to analyze billing data of commercially insured patients who underwent elective spinal fusion between 2014 and 2019. Patients who received single-level anterior cervical discectomy and fusion (ACDF) and single-level posterior lumbar fusion (PLF) were identified. <h3>OUTCOME MEASURES</h3> OOP costs associated with the surgical episode and the ratio of OOP costs to total insurer contribution (payments from insurers to providers) were assessed. <h3>METHODS</h3> OOP costs associated with the surgical episode were calculated as the sum of deductible payments, co-payments and co-insurance. Monetary data were adjusted to 2019 dollars. General linear regression, Wilcoxon-Mann-Whitney and Krustal-Wallis tests were utilized for analysis, as appropriate. <h3>RESULTS</h3> In total, 10,225 ACDF and 28,841 PLF patients were analyzed. Most patients in our study sample had preferred provider organization (PPO) insurance plans (ACDF 70.3%, PLF 66.9%). The mean OOP costs for patients, by procedure were: ACDF $3,180 (SD=2,495) and PLF $3,166 (SD=2,529). Total OOP costs increased significantly from 2014 - 2019 for both procedures (p<0.0001). Among the insurance plans examined, patients with high-deductible health plans had the highest OOP costs. The ratio of patient contribution (OOP costs) to total insurer contribution (payments from insurers to providers) was 0.07 for ACDF and 0.04 for PLF. <h3>CONCLUSIONS</h3> Among commercially insured patients who underwent elective spinal fusion, OOP costs increased from 2014 to 2019. The OOP costs for elective spinal fusion represent a substantial and increasing financial burden for patients. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Single-level posterior lumbar fusions in patients with Ehlers Danlos Syndrome not found to be associated with increased postoperative adverse events or five-year reoperations

BackgroundEhlers Danlos Syndrome (EDS) is a rare connective tissue disorder that results from mutations in collagen genes. Potentially related to laxity and resultant degenerative changes, adult EDS patients may require posterior lumbar fusion (PLF). However, with low numbers, adequately powered outcome studies have been limited. The purpose of this study was to investigate risk of complications, readmissions and reoperations in adult patients with EDS following single-level PLF, MethodsA retrospective study using the 2010 to 2020 MSpine Pearldiver dataset was performed. Adult patients undergoing single-level PLF (excluding any with anterior procedures) with and without EDS for which at least 90-day follow up was available were identified. Any cases performed for trauma, tumor, or infection were excluded.Single-level PLF EDS patients were then matched 1:4 with PLF non-EDS patients based on age, sex, and Elixhauser Comorbidity Index (ECI). Rates of ninety-day any, severe, and minor adverse events as well as readmissions were tabulated and compared with chi-square tests. Multivariate logistical regression was then performed (controlling for age, sex, and ECI).Reoperation surgeries over five years were assessed, Kaplan-Meier survival curves generated, and curves of those with and without EDS were compared with log rank test. ResultsIn total, there were 170,100 single-level PLF case identified, of which 242 (0.14%) had EDS. After matching, there were 957 without EDS and 239 with EDS. On multivariate regression, there were no significant differences in 90-day any, severe, or minor adverse events, or readmissions (p>0.05 for each). Over five years, there were also not significant differences in rates of reoperation (p> 0.05). ConclusionsFor EDS patients undergoing PLF, the current study identified similar 90-day adverse events and 5-year reoperation rates compared to those without EDS. These findings may be useful for patient counseling and surgical planning for those with this rare condition.

Patient Out-of-Pocket Cost Burden With Elective Orthopaedic Surgery.

Out-of-pocket (OOP) costs for medical and surgical care can result in substantial financial burden for patients and families. Relatively little is known regarding OOP costs for commercially insured patients receiving orthopaedic surgery. The aim of this study is to analyze the trends in OOP costs for common, elective orthopaedic surgeries performed in the hospital inpatient setting. This study used an employer-sponsored insurance claims database to analyze billing data of commercially insured patients who underwent elective orthopaedic surgery between 2014 and 2019. Patients who received single-level anterior cervical diskectomy and fusion (ACDF), single-level posterior lumbar fusion (PLF), total knee arthroplasty (TKA), and total hip arthroplasty (THA) were identified. OOP costs associated with the surgical episode were calculated as the sum of deductible payments, copayments, and coinsurance. Monetary data were adjusted to 2019 dollars. General linear regression, Wilcoxon-Mann-Whitney, and Kruskal-Wallis tests were used for analysis, as appropriate. In total, 10,225 ACDF, 28,841 PLF, 70,815 THA, and 108,940 TKA patients were analyzed. Most patients in our study sample had preferred provider organization insurance plans (ACDF 70.3%, PLF 66.9%, THA 66.2%, and TKA 67.0%). The mean OOP costs for patients, by procedure, were as follows: ACDF $3,180 (SD = 2,495), PLF $3,166 (SD = 2,529), THA $2,884 (SD = 2,100), and TKA $2,733 (SD = 1,994). Total OOP costs increased significantly from 2014 to 2019 for all procedures (P < 0.0001). Among the insurance plans examined, patients with high-deductible health plans had the highest episodic OOP costs. The ratio of patient contribution (OOP costs) to total insurer contribution (payments from insurers to providers) was 0.07 for ACDF, 0.04 for PLF, 0.07 for THA, and 0.07 for TKA. Among commercially insured patients who underwent elective spinal fusion and major lower extremity joint arthroplasty surgery, OOP costs increased from 2014 to 2019. The OOP costs for elective orthopaedic surgery represent a substantial and increasing financial burden for patients.

Matched Analysis of the Risk Assessment and Prediction Tool for Discharge Planning Following Single-Level Posterior Lumbar Fusion

Predicting patient needs for extended care after spinal fusion remains challenging. The Risk Assessment and Prediction Tool (RAPT) was externally developed to predict discharge disposition after nonspine orthopedic surgery but remains scarcely used in neurosurgery. The present study is the first to use coarsened exact matching-which incorporated patient characteristics known to independently affect outcomes-for 1:1 matching across a large population of single-level, posterior lumbar fusions, to isolate the predictive value of preoperative RAPT score on postoperative discharge disposition. Preoperative RAPT scores were prospectively calculated for 1066 patients undergoing consecutive single-level, posterior-only lumbar fusion within a single, university healthcare system. The primary outcome was discharge disposition. Logistic regression was executed across all patients, evaluating the RAPT score as a continuous variable to predict home discharge. Subsequently, patients were retrospectively clustered into predicted risk cohorts-validated within prior orthopedic joint research-based on the RAPT score (Lowest, Intermediate, and Highest Risk). Coarsened exact matching was performed among predicted risk cohorts, and outcomes were compared between exact-matched groups. Among all patients, single-point increases in the RAPT score (i.e., decrease in predicted risk) were associated a 75% increased odds of home discharge (P < 0.001). Exact-matched analysis demonstrated increased odds of home discharge by 400% when comparing the Lowest versus Highest Risk cohorts (P= 0.004), by 750% when comparing the Intermediate versus Highest Risk cohorts (P < 0.001), and by 200% when comparing the Lowest versus Intermediate Risk cohorts (P < 0.001). The RAPT score, captured in preoperative evaluations, can be highly predictive of discharge disposition following single-level, posterior lumbar fusion.

Using Predictive Modeling and Supervised Machine Learning to Identify Patients at Risk for Venous Thromboembolism Following Posterior Lumbar Fusion.

Retrospective review. To use predictive modeling and machine learning to identify patients at risk for venous thromboembolism (VTE) following posterior lumbar fusion (PLF) for degenerative spinal pathology. Patients undergoing single-level PLF in the inpatient setting were identified in the National Surgical Quality Improvement Program database. Our outcome measure of VTE included all patients who experienced a pulmonary embolism and/or deep venous thrombosis within 30-days of surgery. Two different methodologies were used to identify VTE risk: 1) a novel predictive model derived from multivariable logistic regression of significant risk factors, and 2) a tree-based extreme gradient boosting (XGBoost) algorithm using preoperative variables. The methods were compared against legacy risk-stratification measures: ASA and Charlson Comorbidity Index (CCI) using area-under-the-curve (AUC) statistic. 13, 500 patients who underwent single-level PLF met the study criteria. Of these, 0.95% had a VTE within 30-days of surgery. The 5 clinical variables found to be significant in the multivariable predictive model were: age > 65, obesity grade II or above, coronary artery disease, functional status, and prolonged operative time. The predictive model exhibited an AUC of 0.716, which was significantly higher than the AUCs of ASA and CCI (all, P < 0.001), and comparable to that of the XGBoost algorithm (P > 0.05). Predictive analytics and machine learning can be leveraged to aid in identification of patients at risk of VTE following PLF. Surgeons and perioperative teams may find these tools useful to augment clinical decision making risk stratification tool.

Reimbursement for Orthopaedic Surgeries in Commercial and Public Payors: A Race to the Bottom.

The purpose of this study was to compare surgeon professional fee reimbursement and trends from Medicare versus commercial payors for inpatient orthopaedic surgeries: total knee arthroplasty (TKA), total hip arthroplasty (THA), total shoulder arthroplasty (TSA), anterior cervical diskectomy and fusion (ACDF), and posterior lumbar fusion (PLF). Patients undergoing TKA, THA, TSA, single-level ACDF, and single-level PLF from 2010 to 2018 were queried in a commercially insured claims database. Medicare reimbursements and the work relative value unit (wRVU) of each procedure were obtained from the Medicare Physician Fee Schedule. All costs were adjusted for inflation and reported in 2018 real dollars. Compound annual growth rates were calculated to assess the mean growth rate for each procedure. Linear regression was done to assess trends. On average, payments from Medicare were 57% less than payments from commercial payors. From 2010 to 2018, both Medicare and commercial payments decreased significantly for each surgery (P < 0.05 for all). Compared with inflation-adjusted commercial payments, Medicare payments decreased 2.1 times faster for TKA (-2.1% versus -1.0%), 2.8 times faster for THA (-1.4% versus -0.5%), 1.3 times faster for TSA (-1.0% versus -0.8%), and 1.9 times faster for ACDF (-1.1% versus -0.6%). PLF was the only procedure for which Medicare payments declined slower than commercial payments (-0.6% versus -1.21%). Medicare payments per wRVU markedly declined for TKA (-0.83%), THA (-0.80%), TSA (-0.75%), and ACDF (-1.10%), whereas commercial payments per wRVU for those surgeries showed no notable change. For PLF, there was a notable decrease in both Medicare (-0.63%) and commercial (-1.21%) payments per wRVU. Over the past decade, both commercial and Medicare surgeon payments for commonly performed inpatient orthopaedic surgeries decreased markedly, with Medicare payments decreasing an average of 1.5 times faster than commercial payments. The impact of declining reimbursements on access and quality of care merits additional investigation.

110. Clinical significance of lateral pedicle screw malposition in the lumbar spine

BACKGROUND CONTEXT The risks of pedicle screw malposition have largely focused on medial malposition and neurological injury. Although lateral malposition is considered relatively benign, no previously reported study has focused specifically on clinical outcomes associated with lateral screw malposition. We hypothesize that lateral pedicle screw breach has a negative effect on fusion rates and clinical outcomes following elective single-level posterior lumbar fusion (PLF). PURPOSE Not applicable. STUDY DESIGN/SETTING Not applicable. PATIENT SAMPLE Not applicable. OUTCOME MEASURES Not applicable. METHODS Retrospective review of a prospective multicenter cohort of patients undergoing single-level instrumented PLF with local autograft bone for degenerative disease. Twelve-month postoperative computed tomography (CT) was reviewed for breach direction, severity of screw-associated pedicle breach and fusion status. Patients with lateral breach were compared to patients with no breach. Patients with nonlateral screw malposition were excluded. Outcomes measures included Oswestry Disability Index (ODI), Numerical Pain Rating Scale (NPRS) for back pain, and SF-36 physical function. Improvement in back pain was defined as a ≥35% change (minimal clinically important difference) at follow-up. Outcomes were analyzed using multivariable linear and logistic regression and were adjusted for age, procedure, level, and/or baseline pain score. RESULTS A total of 154 patients underwent 12-month postoperative CT. Forty-five patients (30.6%) demonstrated one or more lateral breaches and were compared to 102 patients with no breach. After adjusting for baseline scores and fusion level, patients with one or more breaches had, on average, ODI score decreases that were 2.44 points less (p=0.454) and SF-36 score increases that were 2.04 points less (p=0.040) than patients with no lateral breach. Breach was also associated with a large decrease in the odds of achieving back pain relief (OR=0.37, 95%CI: 0.15, 0.91) after adjusting for baseline NPRS. There was no observed effect of breach on the odds of non-union (multiple breaches OR=1.97, 95% CI: 0.66, 5.97). CONCLUSIONS The current study did not observe an association between laterally malpositioned pedicle screws and nonunion or disability scores. However, these results are consistent with a modest negative effect on physical functioning scores and self-reported back pain. This suggests that surgeons may anticipate poorer clinical outcomes among patients with laterally malpositioned screws. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Preoperative and Postoperative Spending Among Working-Age Adults Undergoing Posterior Spinal Fusion Surgery for Degenerative Disease

To investigate the health care resource utilization and the associated 6 months preoperative and 6 months postoperative spending among patients undergoing posterior lumbar fusion. We retrospectively reviewed a private insurance claims database for patients who underwent single-level posterior spinal fusion from January 2011 to December 2015. Outpatient health services, prescription pain medications, and inpatient admissions were assessed. Among 25,401 patients (mean age, 52 years; 58% female) in the final cohort, median spending during the period from 6 months before surgery to 6 months after surgery was $60,714 (interquartile range [IQR], $46,961-$79,892)/patient. Preoperative spending accounted for 7% ($121 million) of the total costs, and postoperative spending accounted for 8% ($135 million). Median preoperative spending was $3566 (IQR, $2144-$5857) per patient, with imaging accounting for the highest proportion (33%) of preoperative spending. In the 6 months period preceding surgery, 46% patients received injections and 47% received physical therapy. The median postoperative spending was $1954/patient (IQR, $735-$4416). Total postoperative spending was significantly higher among those not discharged home (median, $7525; IQR, $6779-$19,602) compared with those discharged home (median, $1617/patient; IQR, $648-$4033) and home with home care services (median, $2921; IQR, $1406-$5662) (P < 0.001). Unplanned readmission after posterior spinal fusion was the highest contributor to postoperative spending and the second highest contributor to overall costs. Understanding factors that contribute to the costs in the preoperative and postoperative period in patients undergoing single-level posterior lumbar fusion for degenerative pathology is essential to identify targets for cost containment.

Medicaid Reimbursement for Common Spine Procedures: Are Compensation Rates Consistent?

Health Services Research. The purpose of this study is to determine the variability of Medicaid (MCD) reimbursement for patients who require spine procedures, and to assess how this compares to regional Medicare (MCR) reimbursement as a marker of access to spine surgery. The current health care environment includes two major forms of government reimbursement: MCD and MCR, which are regulated and funded by the state and federal government, respectively. MCD reimbursement rates from each state were obtained for eight spine procedures, utilizing online web searches: anterior cervical decompression and fusion, posterior cervical decompression and fusion, posterior lumbar decompression, single-level posterior lumbar fusion, posterior fusion for deformity (less than six levels; six to 12 levels; 13+ levels), and lumbar microdiscectomy. Discrepancy in reimbursement for these procedures on a state-to-state basis, as well as overall differences in MCD versus MCR reimbursement, was determined. Procedures were examined to identify whether certain surgical interventions have greater discrepancy in reimbursement. The average MCD reimbursement was 78.4% of that for MCR. However, there was significant variation between states (38.8%-140% of MCR for the combined eight procedures). On average, New York, New Jersey, Florida, and Rhode Island provided MCD reimbursements <50% of MCR reimbursements in the region. In total, 20 and 42 states provided <75% and 100% of MCR reimbursements, respectively. Based upon relative reimbursement, MCD appears to value microdiscectomy (84.1% of MCR; P = 0.10) over other elective spine procedures. Microdiscectomy also had the most interstate variation in MCD reimbursement: 39.0% to 207.0% of MCR. Large disparities were found between MCR and MCD when comparing identical procedures. Further research is necessary to fully understand the effect of these significant differences. However, it is likely that these discrepancies lead to suboptimal access to necessary spine care. 4.

Factors Associated with 12-month Return to Work Following One-level Posterior Lumbar Fusion for Grade 1 Degenerative Spondylolisthesis: An Analysis of the Quality Outcomes Database

Abstract INTRODUCTION Return to work (RTW) has become an increasingly important metric of spinal surgery success. Lumbar spondylolisthesis is a relatively common spinal pathology that may manifest as low back pain and/or leg pain, causing functional disability and hindering patients from working and performing activities of daily living. Currently, there is a lack of nationwide data evaluating RTW in lumbar spondylolisthesis. METHODS We queried the Quality Outcomes Database for employed patients that underwent single-level posterior spinal fusion for Meyerding grade I degenerative lumbar spondylolisthesis. We compared cases who returned to work within 12 mo with regard to baseline demographics, comorbidities, clinical characteristics, and patient reported outcomes. A multivariable logistic regression model was fitted for 12-mo RTW adjusting for an array of pre- and intraoperative variables. RESULTS A total of 163 patients with available 12-mo follow-up data (84%) were analyzed. Median age was 57 yr (interquartile range: 51-60 yr) and 57% were females (n = 93). On multivariable analysis, patients that were working at the time of surgery were significantly more likely to RTW compared to those that were not working (OR 4.62, 95% CI 1.42-15.07, P &lt; .001). In addition, college education (OR 3.30, 95% CI 1.18-9.24, P = .02) was associated with significantly higher odds of returning to work compared to high-school or less education. The effect of postcollege education (OR 5.27, 95% CI 1.46-19.05, P = .01), baseline ODI score (OR 0.64, 95% CI 0.34 - 1.21, P = .17) and smoking status (OR 0.45, 95% CI 0.13-1.54, P = .20) were not found to be significant. Model c-statistic was 0.76. CONCLUSION Analysis of data from a national spinal registry revealed that employment status at the time of surgery and education level were the most significant predictors of 12-moh RTW for patients undergoing single-level posterior lumbar fusion for degenerative spondylolisthesis. The findings of the present study may assist surgeons and patients with setting realistic treatment expectations during preoperative discussions.

Assessing the Performance of National Surgical Quality Improvement Program Surgical Risk Calculator in Elective Spine Surgery: Insights from Patients Undergoing Single-Level Posterior Lumbar Fusion

The American College of Surgeons-National Surgical Quality Improvement Program Surgical Risk Calculator is a tool developed to use 21 individual patient characteristics to make predictions for occurrence of 13 general and 2 procedure-specific outcomes. The goal of this study was to evaluate the performance of the Surgical Risk Calculator in predicting outcomes in patients receiving posterior lumbar fusion. American College of Surgeons-National Surgical Quality Improvement Program Participant Use File for 2015 was queried for patients with age ≥18 years undergoing single-level posterior lumbar fusion (PLF) surgery. Individual patient characteristics were entered into the online risk calculator interface to retrieve the predicted estimated risk for perioperative outcomes and complications. Following this, predictive performance was analyzed by computing Brier score, c-statistic, and sensitivity values for all observed outcomes. A total of 2808 patients undergoing single-level PLF were included in the analysis. Overall, a very low incidence of 30-day postoperative complications was observed with the procedure (0.9%-6.3%). Poor predictive performance was found for all outcomes, including readmissions (c-statistic= 0.63; sensitivity= 15.28%; Brier score= 0.048) and returns to operating room (c-statistic= 0.56; sensitivity= 21.05%; Brier score= 0.032). The best performance was observed for venous thromboembolism (c-statistic=0.66: Brier score= 0.008), although sensitivity was poor (3.85%) on account of low incidence. Predictive performance for length of stay revealed good agreement between observed and predicted values with the exception of prolonged predicted hospital stays (>3.5 days). This study assesses the performance of the risk calculator for a homogenous population of patients undergoing a single-level PLF. Although the calculator did not fare well in predicting most outcomes, results need to be interpreted in the context of the low incidence rate of such outcomes.

Continued Inpatient Care After Elective 1- to 2-level Posterior Lumbar Fusions Increases 30-day Postdischarge Readmissions and Complications

This was a retrospective cohort study. The main objective of this article was to investigate the impact of discharge destination on postdischarge outcomes following an elective 1- to 2-level posterior lumbar fusion (PLF) for degenerative pathology. Discharge to an inpatient care facility may be associated with adverse outcomes as compared with home discharge. The 2012-2016 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was used to query for patients undergoing PLFs using Current Procedural Terminology (CPT) codes (22612, 22630, and 22633). Additional levels were identified using CPT-22614, CPT-22632, and CPT-22634. Records were filtered to include patients undergoing surgery for degenerative spine pathologies. Only patients undergoing a single-level or 2-level PLF were included in the study. A total of 23,481 patients were included in the final cohort. A total of 3938 (16.8%) patients were discharged to a skilled care or rehabilitation facility following the primary procedure. Following adjustment for preoperative, intraoperative, and predischarge clinical characteristics, discharge to a skilled care or rehabilitation facility was associated with higher odds of any complication [odds ratio (OR), 1.70; 95% confidence interval (CI), 1.43-2.02], wound complications (OR, 1.73; 95% CI, 1.36-2.20), sepsis-related complications (OR, 1.64; 95% CI, 1.08-2.48), deep venous thrombosis/pulmonary embolism complications (OR, 1.72; 95% CI, 1.10-2.69), urinary tract infections (OR, 1.96; 95% CI, 1.45-2.64), unplanned reoperations (OR, 1.49; 95% CI, 1.23-1.80), and readmissions (OR, 1.29; 95% CI, 1.10-1.49) following discharge. After controlling for predischarge characteristics, discharge to skilled care or rehabilitation facilities versus home following 1- to 2-level PLF is associated with higher odds of complications, reoperations, and readmissions. These results stress the importance of careful patient selection before discharge to inpatient care facilities to minimize the risk of complications. Furthermore, the results further support the need for uniform and standardized care pathways to promote home discharge following hospitalization for elective PLFs. Level III.

Thursday, September 27, 2018 8:30 AM–9:30 AM Best Papers: 109. Healthcare utilization and costs prior to primary single-level posterior lumbar fusions: What happens before surgery?

BACKGROUND CONTEXT With an emphasis toward value-based health care, there have been multiple studies investigating postprocedural costs and their economic impact. However, often times preoperative resource utilization is overlooked and may present an opportunity for curbing excess costs and enhancing quality of care. PURPOSE There is little data with regards to preoperative costs incurred prior to a single level posterior lumbar fusion in the 2 years preceding the surgery. We sought to collate data using a national database to determine health care resource utilization prior to a single-level posterior lumbar fusion. STUDY DESIGN/SETTING This was a retrospective study done using national insurance claim records available through a subcription-based database. PATIENT SAMPLE A total of 10,281 patients undergoing primary single-level posterior lumbar fusion with active records for events occuring 2 years prior to the surgery were included in the final cohort. OUTCOME MEASURES Resource utilization was measured using per patient average reimbursements (PPAR) for each health care category with regards to pre-specified time periods. METHODS The PearlDiver Humana Database was queried for active records of patients undergoing primary single-level posterior lumbar fusions using CPT codes. Preoperative health care utilization was categorized into office visits, physical therapy, radiology, injections (facet blocks or rhizotomies or epidurals), pain medications (NSAIDS or analgesics), muscle relaxants, opioids and procedures (laminectomies). All health care utilization categories were cross-referenced with concurrent diagnoses for degenerative spine pathology to ensure relevant billing records were retrieved. The PPAR were calculated for each health care resource category with regard to specified pre-operative time periods (0-3 months, 0-6 months, 0-1year and 0-2 years). RESULTS Records of 10,281 patients, stratified as 1,408 commercial (C) and 8873 Medicare Advantage (MA) beneficiaries, undergoing primary single-level lumbar fusions were retrieved. Overall spine related care in the 2 years preceding surgery was $8,240,890 and $23,966,498 in the MA and C groups, respectively. Overall 2-year PPARs for each resource category were – office visits (MA=$887.7; C=$1132.5); physical therapy (MA=$553.8; $710.7), radiology (MA=$936.4; C=$2402), injections (MA=$1285, C=$3054.9), pain meds (MA=$127.2; C=$142.9), muscle relaxants (MA=$31.3; C=$41.5), opioids (MA=$71.2; C=$84.8) and procedures (MA=$2402.9; C=$6443.2). The majority of reimbursements for all categories occurred just before the primary procedure with results showing 37%–54% and 40%–57% of the overall PPAR/category being accounted for in the last three months for MA and C beneficiaries, respectively. Of note, 46.3% (MA)/49.5% (C) of the overall PPAR for injections and 45.2% (MA)/52.1% (C) of the overall PPAR for Opioids were accounted for in the last three months. CONCLUSIONS We observed a high utilization of spine-related care in the three months prior to a single level posterior lumbar fusion for both C and MA beneficiaries. As we move toward value based payment models, judicious use of nonsurgical interventions with proven benefit, particularly in patients that ultimately require surgical intervention, will be required to optimize cost-effectiveness. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Can facet joint fluid on MRI and dynamic instability be a predictor of improvement in back pain following lumbar fusion for degenerative spondylolisthesis?

To investigate the relationship between lumbar facet fluid and dynamic instability in degenerative spondylolisthesis (DS), as well as the relationship between facet fluid and patient-reported outcomes following a posterior lumbar fusion. We analyzed consecutive patients with degenerative spondylolisthesis undergoing single level posterior lumbar fusion from December 2010 to January 2013 at a single academic institution. We investigated the relationship between fluid in the facet joint as measured on axial MRI and the presence of dynamic instability. We investigated the impact of facet fluid, Modic changes, and dynamic instability on patient-reported outcomes. There was a significant association between the amount of facet joint fluid and the presence of dynamic instability (p=0.03); as facet fluid increases, the probability of dynamic instability also increases. For every 1mm of facet fluid, there was a 41.6% increase (95% CI 1.8-97) in the odds of dynamic instability. A facet fluid amount less than 0.5mm gave a 90% probability that there was no dynamic instability. The presence of facet fluid and dynamic instability were associated with achieving minimal clinical important difference (MCID) in low back pain following lumbar fusion (p=0.04 and 0.05, respectively). Facet joint fluid is associated with the presence of dynamic instability in DS. The presence of facet fluid and dynamic instability may predict increased likelihood of achieving MCID for improvement in back pain following posterior lumbar fusion.

Trends analysis of rhBMP utilization in single-level posterior lumbar fusion (PLF) in the United States.

A retrospective database review was carried out to evaluate the trends and demographics of rhBMP utilization in single-level posterior lumbar fusion (PLF) in the United States. Patients who underwent single-level PLF from 2005 to 2011 were identified by searching ICD-9 diagnosis and procedure codes in the PearlDiver Patient Records Database (PearlDiver Technologies, Fort Wayne, IN, USA), a national database of orthopaedic insurance records. The year of procedure, age, gender, and region of the United States were recorded for each patient. Results were reported for each variable as the incidence of procedures identified per 100,000 patients searched in the database. Totally 5158 patients had single-level PLF in this study. The average rate of single-level PLF with rhBMP utilization maintained at a relatively stable level (19.1-23.5%) from 2005 to 2009, but sharply decreased to 6.8% in 2010 and 6.9% in 2011. The overall incidence of single-level PLF without rhBMP (1.37 cases per 100,000 patients) was more than five times of the incidence of single-level PLF with rhBMP (0.27 cases per 100,000 patients) (P < 0.01). The average rate of single-level PLF with rhBMP utilization is highest in Midwest (18.7%), followed by West (18.4%), South (16.4%) and Northeast (11.5%). The highest incidence of single-level PLF with rhBMP was observed in the group aged 70-74 years with an incidence of 0.33 per 100,000 patients. The incidence of rhBMP utilization in single-level PLF increased from 2006 to 2009, but dropped to a low level in 2010 and 2011. The Northeast region had the lowest incidence of rhBMP utilization. The group aged 70-74 years trended to have the higher incidence of single-level PLF with rhBMP utilization.