Patients Undergoing Lumbar Fusion Research Articles

Exploring the impact of body mass index on the accuracy of vertebral bone quality in determining bone mineral density in patients undergoing lumbar fusion surgery

Exploring the impact of body mass index on the accuracy of vertebral bone quality in determining bone mineral density in patients undergoing lumbar fusion surgery

Lumbar Fusion Surgical Prophylaxis Using Cefazolin vs. Vancomycin in the Penicillin-Allergic Patient.

Retrospective cohort study. To compare peri- and postoperative infection rates among patients with mild to moderate penicillin allergies who receive cefazolin vs vancomycin as prophylaxis for lumbar fusion. Additionally, we sought to determine if patients receiving cefazolin exhibited any clinical symptoms suggestive of drug-induced hypersensitivity reactions, and to compare those rates to patients who received vancomycin. Cefazolin has been historically linked to hypersensitivity reactions in penicillin-allergic patients due to cross-reactivity. As a result, vancomycin is often given to these patients instead. To our knowledge, no studies have directly compared these two antibiotics in penicillin-allergic patients undergoing lumbar fusion. Patients with mild to moderate documented penicillin allergies who underwent lumbar fusion from 2017-2022 and received prophylactic cefazolin or vancomycin were studied. Demographic, surgical information, and hospital length of stay (LOS) were recorded. We identified drug sensitivity reactions, in hospital infections, 90-day readmissions related to infectious etiologies and need for irrigation and debridement (I&D) to treat a surgical site infection. 222 patients received cefazolin, while 180 received vancomycin. Patients receiving vancomycin had more medical comorbidities, while patients receiving cefazolin had slightly more levels fused. No significant differences existed between cohorts in postoperative infection rate. One patient given cefazolin developed a mild drug-induced skin reaction that was treated with topical steroids. No significant differences existed between cohorts in 90-day readmissions or need for I&D surgery. On bivariate analysis, patients given cefazolin had a longer LOS but this was attributed to confounding variables on multivariate analysis. Cefazolin and vancomycin are comparable at preventing postoperative infections among patients with mild to moderate documented reactions to penicillin. Our findings also suggest that penicillin-allergic patients are not at higher risk of developing drug-related hypersensitivity reactions in response to cefazolin exposure when compared to those who received vancomycin.

Enhanced recovery after surgery (ERAS) improves outcomes in elderly patients undergoing short-level lumbar fusion surgery: a retrospective study of 333 cases

BackgroundDegenerative lumbar disease significantly impairs the quality of life in elderly individuals, with short-segment lumbar degenerative disease being particularly prevalent. When conservative treatment proves ineffective, surgical intervention becomes the optimal choice for managing lumbar disease. The implementation of Enhanced Recovery After Surgery (ERAS) in spinal surgery has been progressively refined, leading to greater patient benefits. However, age and the associated decline in physiological function remain critical factors influencing surgical decision-making. Currently, there is a paucity of research focused on elderly patients undergoing lumbar fusion surgery to substantiate that advanced age does not diminish the benefits derived from ERAS in this demographic.MethodsThis is a retrospective cohort study of prospectively collected data. Patients who underwent short-segment (1 or 2 segments) transforaminal lumbar interbody fusion (TLIF) under the care of the same surgical team at our institution were recruited, and divided into no-ERAS-elder, ERAS-elder, and ERAS-younger groups. Subsequently, time to physiological function recovery and other outcomes were compared.ResultsThe outcomes of the ERAS-elder group (n = 113) and the no-ERAS-elder group (n = 120) were compared. The overall physiological function recovery was significantly faster (6.71 ± 2.6 days vs. 8.6 ± 2.67 days, p = 0.01) in the ERAS-elder group. Next, the outcomes of the ERAS-elder group (n = 113) were compared with those of the ERAS-younger group (n = 100), and no significant difference in total physiological function recovery was found between the two groups (6.71 ± 2.6 days vs. 6.14 ± 1.63 days, p = 0.252).ConclusionsThis study shows that the implementation of the ERAS program can effectively shorten the recovery time of physiological function in elderly patients after short-segment lumbar surgery, reduce the incidence of some complications, alleviate pain, and significantly shorten the length of hospital stay. ERAS enables elderly patients to achieve outcomes comparable to those of younger patients.

Enhanced Recovery After Surgery Protocols in One- or Two-Level Posterior Lumbar Fusion: Improving Postoperative Outcomes.

Background/Objectives: Enhanced recovery after surgery (ERAS) protocols optimize perioperative care and improve recovery. This study evaluated the effectiveness of ERAS in one- or two-level posterior lumbar fusion surgeries, focusing on perioperative medication use, pain management, and functional outcomes. Methods: Eighty-eight patients undergoing lumbar fusion surgery between March 2021 and February 2022 were allocated into pre-ERAS (n = 41) and post-ERAS (n = 47) groups. Outcomes included opioid and antiemetic consumption, pain scores (numerical rating scale (NRS)), functional recovery (Oswestry Disability Index (ODI) and EuroQol 5 Dimension (EQ-5D)), and complication rates. Pain was assessed daily for the first four postoperative days and at 6 months. Linear Mixed Effects Model analysis evaluated pain trajectories. Results: The post-ERAS group showed significantly lower opioid (p = 0.005) and antiemetic (p < 0.001) use. No significant differences were observed in NRS pain scores in the first 4 postoperative days. At 6 months, the post-ERAS group reported significantly lower leg pain (p = 0.002). The time:group interaction was not significant for back (p = 0.848) or leg (p = 0.503) pain. Functional outcomes at 6 months, particularly ODI and EQ-5D scores, showed significant improvement in the post-ERAS group. Complication rates were lower in the post-ERAS group (4.3% vs. 19.5%, p = 0.024), while hospital stay and fusion rates remained similar. Conclusions: The ERAS protocol significantly reduced opioid and antiemetic use, improved long-term pain management and functional recovery, and lowered complication rates in lumbar fusion patients. These findings support the implementation of ERAS protocols in spinal surgery, emphasizing their role in enhancing postoperative care.

Diabetes and heart disease do not affect short-term lumbar fusion outcomes accounting for other risk factors in a matched cohort analysis

ObjectivesComprehensive preoperative management involves the identification and optimization of medical comorbidities while avoiding excessive healthcare utilization. While diabetes and heart disease are major causes of morbidity that can worsen surgical outcomes, further study is needed to evaluate how well current perioperative strategies mitigate their risks. This study employs an exact matching protocol to isolate the effects of both diabetes and cardiovascular disease on spine surgery outcomes. Methods4680 consecutive patients undergoing single-level, posterior-only lumbar fusion were retrospectively enrolled. Univariate logistic regression was performed on comorbidity subgroups, then coarsened exact matching (CEM) was employed for patients with diabetes or cardiovascular disease. Patients were matched 1:1 on ten patient and procedural characteristics known to affect neurosurgical outcomes. Separate pairs of exact-matched cohorts were generated to isolate both cardiovascular disease (matched n = 192), and diabetes (matched n = 380). Primary outcomes were surgical complications; length of stay; discharge disposition (home vs. non-home); and 30- and 90-day Emergency Department (ED) visits, readmissions, reoperations, and mortality. ResultsCardiovascular disease and diabetes subgroups were not associated with short term outcomes after matching to control for confounders. Compared to univariate statistics, this method demonstrates that confounding control variables may drive outcomes more than these comorbidities themselves. ConclusionBetween otherwise exactly matched patients undergoing lumbar fusion, diabetes and cardiovascular disease posed no greater risk of short-term adverse outcomes. This suggests proper selection criteria for surgical candidates and effective current perioperative strategies to mitigate these common comorbidities. Further studies are warranted to assess and optimize the cost-effectiveness of preoperative management for patients with common comorbidities.

Preoperative Symptom Duration and the Effect on Clinical Outcomes and PROMIS-PF in Patients Undergoing Lumbar Fusion Surgery.

Retrospective Review. The purpose of this study is to examine the effect of preoperative symptom duration on postoperative clinical outcomes for patients undergoing lumbar fusion surgery. Lumbar fusion surgery can be significantly beneficial for lumbar spondylolisthesis and spinal stenosis. Surgical treatment is typically preceded by some amount of non-operative intervention and there isn't a consensus on the optimal timing between symptom onset and surgical intervention. A retrospective review of 144 patients undergoing a 1-3 level lumbar fusion from June 2020 to December 2023 was performed. Demographics, preoperative symptom onset, primary diagnosis, and surgical procedure were compared between patients with less than or greater than 2 years of symptoms. Postoperative outcomes and PROMIS-PF were compared between groups. Univariate and multivariate analyses were performed. 52 (36.1%) had symptoms for 2 years or longer while 92 (63.9%) had symptoms for less than 2 years. There was no difference in demographics, procedure type, primary diagnosis, or preoperative symptoms between those who had symptoms for greater than or less than 2 years. Those who had symptoms for 2+ years had a significantly lower change in PF (4.7±7.1 vs. 7.7±9.0; P=0.029) and lower rate of MCID achievement (44.2% vs. 65.2%; P=0.023). There was no difference in outcomes by symptom duration. On multivariate analysis those with symptoms of 2 years or more were 2.4 times less likely to achieve an MCID (OR: 0.42, 95% CI: 0.19 to 0.92; P=0.031). Patients undergoing lumbar fusion with greater than 2 years of symptoms prior to surgery have a smaller increase in PROMIS-PF and are less likely to achieve MCID on PROMIS-PF. Further study is needed in order to determine the optimal timing for lumbar fusion surgery following symptom onset.

P295. Teriparatide use in osteopenic patients undergoing lumbar fusion

P295. Teriparatide use in osteopenic patients undergoing lumbar fusion

An evaluation of fusion status following lumbar fusion surgery utilizing multi-planar computed tomography.

To report the rate of fusion in a sample of patients undergoing lumbar fusion surgery and assess interrater reliability of computed tomography (CT)-based parameters for the assessment of fusion. All adult patients who underwent lumbar fusion surgery from 2017 to 2021 were retrospectively identified. Patient demographics and surgical characteristics were collected through chart review of the electronic medical records. CT scans were reviewed independently by two attending spine surgeons and two spine fellows. Fusion was defined as evidence of bone bridging in any one of (1) posterolateral gutters, (2) facets, or (3) interbody (when applicable) on any CT views. Evidence of screw haloing was indicative of nonunion. Interrater reliability was determined using cohen's kappa. Afterwards, a consensus agreement for each component of fusion was reached between participants. The overall fusion rate among all procedures was 63/69 (91.3%). Overall 22/25 (88.0%) TLIF, 16/19 (84.2%) PLDF, 3/3 (100%) LLIF, and 22/22 (100%) circumferential fusions experienced a successful fusion. Interrater reliability was good for interbody fusion (k = 0.734) and moderate for all other measures (k = 0.561 for posterolateral fusion; k = 0.471 for facet fusion; k = 0.458 for screw haloing). Overall, interrater reliability as to whether a patient had a fusion or nonunion was moderate (k = 0.510). There was only moderate interrater reliability across most radiographic measures used in assessing lumbar fusion status. Reliability was highest when evaluating the presence of interbody fusion. The majority of fusions occurred across the facet joints.

Does Surgical Day of Week Affect Patient Outcomes and Hospital Costs Following Lumbar Fusion?

Background As the population ages, surgical intervention for degenerative spine conditions is increasing, and this causes a commiserate increase in healthcare expenditures associated with these procedures. Little research has been done on the effect of early-week versus later-week surgeries on patient outcomes, cost, and length of stay (LOS) in patients undergoing lumbar fusion surgery. The purpose of this study is to compare LOS, patient outcomes, and hospital costs between patients having surgery early in the week and later in the week. Methods A retrospective review of 771 patients undergoing a one-, two-, or three-level lumbar fusion from December 2020 to December 2023 at a single institution was performed. Demographics, surgical details, postoperative outcomes and cost were compared between patients who had surgery on Monday, Tuesday, and Wednesday, to those having surgery Thursday or Friday. Univariate and multivariate analyses were performed to compare the groups. Results There were no differences in age, sex, BMI, race, American Society of Anesthesiology (ASA) scores, Charlson Comorbidity Index (CCI) scores, number of operative levels or inpatient/outpatient status between early- and late-week surgeries. Postoperatively the only significant difference was cost, late-week surgeries were, on average, $3,697 more expensive than early-week surgeries ($26,506 vs. $22,809; p<0.001). On multivariate analysis late-week surgeries were 2.47 times more likely to have a non-home discharge (OR: 2.47, 95% CI: 1.24 to 4.95; p=0.010) and 2.19 times more likely to have a 30-day readmission (OR: 2.19, 95% CI:1.01 to 4.74; p=0.044) Additionally, late-week surgeries were $2,041.55 (β:2,041.55, 95% CI: 804.72 to 3,278.38; p=0.001) more expensive than early-week surgeries. Conclusions At our institution, patients undergoing one- to three-level lumbar fusion surgery on Thursday or Friday had a higher risk of non-home discharge, 30-day readmission, and incurred higher cost than those having early-week surgery. Further research is needed to elucidate the reasons for these findings and to evaluate interventions aimed at improving outcomes for patients undergoing surgery later in the week.

Interpretable Machine Learning Models Based on SHapley Additive exPlanations for Predicting the Risk of Cerebrospinal Fluid Leakage in Lumbar Fusion Surgery.

Retrospective study. The objective of this investigation was to formulate and internally verify a customized machine learning (ML) framework for forecasting cerebrospinal fluid leakage (CSFL) in lumbar fusion surgery. This was accomplished by integrating imaging parameters and employing the SHapley Additive exPlanation (SHAP) technique to elucidate the interpretability of the model. Given the increasing incidence and surgical volume of spinal degeneration worldwide, accurate predictions of postoperative complications are urgently needed. SHAP-based interpretable ML models have not been used for CSFL risk factor analysis in lumbar fusion surgery. Clinical and imaging data were retrospectively collected from 3505 patients who underwent lumbar fusion surgery. Six distinct machine learning models were formulated: extreme gradient boosting (XGBoost), decision tree (DT), random forest (RF), support vector machine (SVM), Gaussian naive Bayes (GaussianNB), and K-nearest neighbors (KNN) models. Evaluation of model performance on the test dataset was performed using performance metrics, and the analysis was executed through the SHAP framework. CSFL was detected in 95 out of 3505 patients (2.71%). Notably, the XGBoost model exhibited outstanding accuracy in forecasting CSFLs, with high precision (0.9815), recall (0.6667), accuracy (0.8182), F1 score (0.7347), and AUC (0.7343). Additionally, through SHAP analysis, significant predictors of CSFL were identified, including ligamentum flavum thickness, zygapophysial joint degeneration grade, central spinal stenosis grade, decompression segment count, decompression mode, intervertebral height difference, Cobb angle, intervertebral height index difference, operation mode, lumbar segment lordosis angle difference, Meyerding grade of lumbar spondylolisthesis, and revision surgery. The combination of the XGBoost model with the SHAP is an effective tool for predicting the risk of CSFL during lumbar fusion surgery. Its implementation could aid clinicians in making informed decisions, potentially enhancing patient outcomes and lowering healthcare expenses. This study advocates for the adoption of this approach in clinical settings to enhance the evaluation of CSFL risk among patients undergoing lumbar fusion.

MRI-based pedicle bone quality score: correlation to quantitative computed tomography bone mineral density and its role in quantitative assessment of osteoporosis

BACKGROUND CONTEXTBone quality in the pedicle region generally determines screw pullout strength, insertion torque, and vertebral body loading characteristics. Dual-energy X-ray absorptiometry (DEXA), as the gold standard for evaluating bone mineral density (BMD), cannot measure the BMD of specific parts, such as pedicle, and DEXA is limited in many ways. Recent studies have shown a correlation between the magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score and BMD measured using DEXA or quantitative computed tomography (QCT). However, no studies have been reported on the MRI-based pedicle bone quality (PBQ) score. Moreover, few studies have investigated the relationship between MRI-based PBQ and osteoporosis. PURPOSETo create a new site-specific MRI-based PBQ assessment method and assess its diagnostic capacity in patients with normal BMD and osteopenia/osteoporosis. STUDY DESIGN/SETTINGA retrospective study. PATIENT SAMPLEA total of 156 patients underwent lumbar fusion surgery for chronic low back pain at our hospital between 2021 and 2022, with lumbar QCT and T1-weighted MRI performed before surgery. OUTCOME MEASURESCorrelation of the PBQ score with QCT BMD, and the association between the PBQ score and presence of osteopenia/osteoporosis. METHODSBMD of the lumbar was calculated as the mean BMD of the L1 and L2 vertebral bodies on the basis of asynchronous QCT measurements. The PBQ score, which is the average of the bone quality values of both pedicles on the basis of site-specific T1-weighted sagittal MRI images, was calculated by dividing the median signal intensity of the L1–L4 pedicles by the signal intensity of the cerebrospinal fluid at the L3 level. The interobserver reliability of the PBQ score was assessed using the intraclass correlation coefficient (ICC). A receiver operating characteristic curve was drawn, and the area under the curve (AUC) was calculated to assess the predictive performance of PBQ for osteoporosis. The PBQ score was compared with QCT BMD, as the gold standard, using Pearson correlation analysis. RESULTSIn total, 156 patients participated in this study, including 51 in the Normal BMD group and 105 in the osteopenia/osteoporosis group. The PBQ score in the osteopenia/osteoporosis group was significantly higher than that in the normal BMD group (3.19±0.55 vs. 2.84±0.51, p<.001). The VBQ and PBQ scores were calculated by 2 authors and were in good agreement (intraclass correlation coefficient=0.949 and 0.929, respectively). Pearson's test showed a significant negative correlation between PBQ and QCT BMD (r=−0.4887, p<.001). The optimal cutoff PBQ score to differentiate patients with osteopenia/osteoporosis from those with normal BMD was 3.160, with a sensitivity of 66.7%, specificity of 72.5%, and AUC of 0.776. The PBQ score correlated more strongly with QCT BMD (r=−0.4887) than VBQ (r=−0.4078). CONCLUSIONSIn this study, we propose a novel, MRI-based pedicle-specific bone quality score. This is the first study to investigate the relationship between the PBQ score and QCT BMD. The PBQ score showed diagnostic utility, differentiating between patients with osteopenia/osteoporosis and those with normal BMD (AUC=0.776), and the PBQ score correlated more strongly with QCT BMD than VBQ.

Distal Lumbar Lordosis is Associated With Reoperation for Adjacent Segment Disease After Lumbar Fusion for Degenerative Conditions.

A single centre retrospective review. Recent studies have suggested that distal lordosis (L4-S1, DL) remains constant across all pelvic incidence (PI) subgroups, whilst proximal lordosis (L1-L4, PL) varies. We sought to investigate the impact of post-operative DL on adjacent segment disease (ASD) requiring reoperation in patients undergoing lumbar fusion for degenerative conditions. Patients undergoing 1-3 level lumbar fusion with the two senior authors between 2007-16 were included. Demographic and radiographic data were recorded. Univariate, multivariate binary logistic regression, and Kaplan Meier survivorship analyses were performed. 335 patients were included in the final analysis. Most had single (67%) or two (31%) level fusions. The mean follow-up was 64-month. Fifty-seven patients (17%) underwent reoperation for ASD at an average of 78-month post-operatively (R group). The R group had a significantly lower mean post-operative DL (27.3 vs 31.1 deg, P < .001) and mean PI (55.5 vs 59.2 deg, P < .05). On univariate analysis, patients with a post-operative DL of <35 deg had higher odds of reoperation for ASD than those with a post-operative DL of ≥35 deg (OR 2.7, P = .016). In the multivariate model, post-operative DL, low/average PI, and spondylolisthesis were all significantly associated with reoperation for ASD. This study provides preliminary support to an association between post-operative distal lumbar lordosis and risk of reoperation for ASD in patients undergoing fusions for degenerative conditions. Further multicentre prospective study is needed to independently confirm this association and identify the impact of restoration of physiological distal lumbar lordosis on long term patient outcomes.

Comparing Opioid Utilization and Costs for Surgical Management of Single-Level Spondylolisthesis: A National Claims Database Analysis

IntroductionThe rise in degenerative lumbar spondylolisthesis (DLS) cases has led to a significant increase in fusion surgeries, which incur substantial hospitalization costs and often necessitate chronic opioid use for pain management. Recent evidence suggests that single-level low-grade DLS outcomes are comparable whether a fusion procedure or decompression alone is performed, sparking debate over the cost-effectiveness of these procedures, particularly with the advent of minimally invasive techniques reducing the morbidity of fusion. This study aims to compare chronic opioid utilization and associated costs between decompression alone and decompression with instrumented fusion for single-level degenerative lumbar spondylolisthesis. Material and methodsUsing data from the PearlDiver database, a retrospective database analysis was conducted. We analyzed records of Medicare and Medicaid patients undergoing lumbar fusion or decompression from 2010 to 2022. Patient cohorts were divided into decompression alone (DA) and decompression with instrumented fusion (DIF). Chronic opioid use, pain clinic visits, and total costs were compared between the two groups at 90 days, 1 year, and 2 years post-surgery. TheoryDoes DIF offer a more cost-effective approach to managing DLS in terms of chronic opioid use in single-level DLS patients. ResultsThe study revealed comparable chronic opioid use and pain clinic visits between DA and DIF groups at 90 days and 1 year. However, total costs associated with opioid prescriptions as well as surgical aftercare were significantly higher in the DIF group at 90 days (p < 0.05), 1 year (p < 0.05), and 2 years (p < 0.05) post-surgery compared to the DA group. ConclusionsThis study highlights the higher costs associated with DIF up to 2 years post-surgery despite comparable symptom improvement when compared to DA and DIF at the 1-year interval. DA emerges as a more financially favorable option, challenging the notion of fusion's cost-offsetting benefits. While further investigation is needed to understand underlying cost drivers and optimize outcomes, our findings emphasize the necessity of integrating clinical and economic factors in the management of single-level DLS.

A Comparative Study of Wound Infections Following Wound Closure Using Staples and Absorbable Sutures Among Obese Patients Undergoing Lumbar Fusion Surgery.

Background Infections of the wounds, organs, or spaces that develop following surgery are known as surgical site infections (SSIs). Theincidence of wound infections in obese patients undergoing lumbar spine surgery with the use of absorbable sutures versus staples for skin closurehas not been studied previously. Materials and methods We conducted a retrospective observational study in our hospital where cases of lumbar spine surgery meeting the inclusion criteria were chosen retrospectively from March 2021 to March 2023. A total of 40patients aged >18 years and <75 years who underwent lumbar spine surgery were covered by this investigation. Two cohorts with 20 patients in each were chosen from thepopulation. Group A used a skin stapler to close wounds, whereas group B used absorbable sutures. The number of wound infections was the main result. Using SPSS version 23.0 (IBM SPSS Statistics, Armonk, NY), all data were analyzed after being entered into an Excel sheet (MicrosoftCorp., Redmond, WA). Results A total of 40 participants were included in this study, and it revealed that there was no discernible variation in the groups' mean age or gender distribution. There is a significantly higher incidence of SSI in the absorbable suture group (35%) compared to the staplegroup (15%). The mean duration in days for the development of SSI in the absorbable suture group (9.86±2.12) was early compared to the staple group (12.67±2.08), which was statistically significant (p<0.05). Conclusion Compared to absorbable sutures, the current study showed a decreased incidence of surgical site infection in obese individuals receiving skin staples for wound closure.

Dislodgment Effects of Different Cage Arrangements in Posterior Lumbar Interbody Fusion: A Finite Element Study.

The vertebral cage has been widely used in posterior lumbar interbody fusion. The risk of cage dislodgment is high for patients undergoing lumbar fusion surgery. Therefore, the main objective of this study was to use a lumbar fusion model to investigate the effects of cage dislodgment on different cage arrangements after PLIF. Finite element analysis was used to compare three PEEK cage placements, together with the fibula-type cage, with respect to the four kinds of lumbar movements. The results revealed that a horizontal cage arrangement could provide a better ability to resist cage dislodgment. Overall lumbar flexion movements were confirmed to produce a greater amount of cage slip than the other three lumbar movements. The lower part of the lumbar fusion segment could create a greater amount of cage dislodgment for all of the lumbar movements. Using an autograft with a fibula as a vertebral cage cannot effectively reduce cage dislodgment. Considering the maximum movement type in lumbar flexion, we suggest that a horizontal arrangement of the PEEK cage might be considered when a single PEEK cage is placed in the fusion segment, as doing so can effectively reduce the extent of cage dislodgment.

Elevated Serum Alkaline Phosphatase is an Independent Predictor of Complications After Lumbar Spinal Fusion

BackgroundAlkaline phosphatase (ALP) is an enzyme which has been proven useful as a biomarker for bone turnover and inflammation. We hypothesized that high serum ALP levels are associated with increased complication rates following lumbar spinal fusion. MethodsLumbar spinal fusion procedures from 2005-2019 were queried from the national Surgical Quality Improvement Program (NSQIP) database. Serum alkaline phosphatase levels were stratified into low <44 IU/L, normal 44-147 IU/L, and high >147 IU/L. A risk-adjusted multivariate logistic regression was used to analyze ALP as an independent risk factor for complications. ResultsA total of 16,441 patients who underwent lumbar fusion procedures were included. Adjusted multivariate logistic regression analysis demonstrated that patients with a high serum ALP level had a significantly increased risk for developing septic shock (OR 4.68, 95% CI 1.83-11.97), pneumonia (OR 2.89, 95% CI 1.59-5.25), requiring a transfusion (OR 2.09, 95% CI 1.68-2.59), reoperation within 30 days (OR 1.68, 95% CI 1.12-2.52), readmission within 30 days (OR 1.60, 95% CI 1.16-2.21), increased length of stay (OR 1.87, 95% CI 1.49-2.36), and nonhome discharge (OR 2.18, 95% CI 1.80-2.66). Clinical RelevanceSerum alkaline phosphatase is a valuable and readily available tool for preoperative risk stratification of patients undergoing lumbar spinal fusion. ConclusionsElevated serum ALP in patients undergoing lumbar fusion procedures is associated with increased risk for multiple in-hospital complications as well as higher rates of readmission and reoperation.

Abdominal Aortic Calcification is Associated with Degeneration of The Paraspinal Muscles - A Retrospective cross-sectional Study.

Retrospective cohort study. To analyze the relationship of abdominal aortic calcification (AAC) and a reduction in the cross-sectional area (CSA) and the fatty infiltration (FI) of the paravertebral muscles in patients undergoing lumbar fusion surgery. Both AAC and paraspinal muscle degeneration have been shown to be associated with poorer outcomes after surgical treatment of degenerative diseases of the lumbar spine. However, there is a lack of data on the association between AAC and paraspinal muscle changes in patients undergoing spine surgery. We retrospectively analyzed patients undergoing lumbar fusion for degenerative spinal pathologies. Muscular and spinal degeneration were measured on magnetic resonance imaging (MRI). AAC was classified on lateral lumbar radiographs. The association of AAC and paraspinal muscle composition was assessed by a multivariate regression analysis adjusted for age, sex, body mass index (BMI), comorbidities, and lumbar degeneration. A total of 301 patients was included. Patients with AAC showed significantly higher degrees of intervertebral disc and facet joint degeneration as well as higher total endplate scores at the L3/4 level. The univariable regression analysis showed a significant positive correlation between the degree of AAC and the FI of the erector spinae (b=0.530, P<0.001) and multifidus (b=0.730, P<0.001). The multivariable regression analysis showed a significant positive correlation between the degree of AAC and the FI of the erector spinae (b=0.270, P=0.006) and a significant negative correlation between the degree of AAC and the CSA of the psoas muscle (b=-0.260, P=0.003). This study demonstrates a significant and independent association between AAC and degeneration of the erector spinae and the psoas muscles in patients undergoing lumbar fusion. As both AAC and degeneration of paraspinal muscles impact postoperative outcomes negatively, preoperative assessment of AAC may aid in identifying patients at higher risk after lumbar surgery.

Socioeconomic disparities in lumbar fusion rates were exacerbated during the COVID-19 pandemic

BackgroundThe COVID-19 pandemic disrupted healthcare access and utilization throughout the US, with variable impact on patients of different socioeconomic status (SES) and race. We characterize pre-pandemic and pandemic demographic and SES trends of lumbar fusion patients in the US. MethodsAdults undergoing first-time lumbar fusion 1/1/2004–3/31/2021 were assessed in Clinformatics® Data Mart for patient age, geographical location, gender, race, education level, net worth, and Charlson Comorbidity Index (CCI). Multivariable regression models were used to evaluate the significance of trends over time, with a focus on pandemic trends 2020–2021 versus previous trends 2004–2019. ResultsThe total 217,204 patients underwent lumbar fusions, 1/1/2004–3/31/2021. The numbers and per capita rates of lumbar fusions increased 2004–2019 and decreased in 2020 (first year of COVID-19 pandemic), with large variation in geographic distribution. There was overall a significant decrease in proportion of White patients undergoing lumbar fusion over time (OR=0.997, p<.001), though they were more likely to undergo surgery during the pandemic (OR=1.016, p<.001). From 2004–2021, patients were more likely to be educated beyond high school. Additionally, patients in the highest (>$500k) and lowest (<$25k) net worth categories had significantly more fusions over time (p<.001). During the pandemic (2020–2021), patients in higher net worth groups were more likely to undergo lumbar fusions ($150k–249k & $250k–499k: p<.001) whereas patients in the lowest net worth group had decreased rate of surgeries (p<.001). Lastly, patients’ CCI increased significantly from 2004 to 2021 (coefficient=0.124, p<.001), and this trend held true during the pandemic (coefficient=0.179, p<.001). ConclusionsTo the best of our knowledge, our work represents the most comprehensive and recent characterization of SES variables in lumbar fusion rates. Unsurprisingly, lumbar fusions decreased overall with the onset of the COVID-19 pandemic. Importantly, disparities in fusion patients across patient race and wealth widened during the pandemic, reversing years of progress, a lesson we can learn for future public health emergencies.

Outcomes in Lumbar Fusion Patients Stratified by the Clinical and Radiographic Degenerative Spondylolisthesis (CARDS) Classification System.

Background and objective The Meyerding classification system remains the most common classification system for spondylolisthesis based on the percentages of vertebral translation. However, the majority of patients with degenerative disease fall into Grade 1, limiting its utility in this subset of patients. The Clinical and Radiographic Degenerative Spondylolisthesis (CARDS) classification system provides a simple radiographic framework for classifying degenerative lumbar spondylolisthesis (DLS) patients by incorporating disc height, kyphosis, and anterior translation. The purpose of this study was to evaluate how clinical characteristics, treatments, and outcomes vary across different CARDSgroups in patients undergoing one- or two-level lumbar fusion for DLS. Methods The patients were classified into one of the following four CARDS groups - Type A: advanced disc space collapse with no evidence of kyphosis; Type B: partially preserved disc space with less than 5.0 mm of translation; Type C: partially preserved disc space with greater than 5.0 mm of translation; and Type D: kyphotic alignment. Univariate analyses were performed to compare demographics, symptoms, clinical outcomes, and Patient-Reported Outcomes Measurement Information System (PROMIS) physical (PH) and mental health (MH) scores across groups. Results Ninety-one patients were included in the study. Based on the CARDS classification, there were three (3%) Type A patients, 25 (28%) Type B, 58 (64%) Type C, and five (5%) Type D. No significant differences in baseline demographics, symptom duration, or PROMIS scores were observed across groups. Interbody utilization varied, ranging from 19% in CARDS C (n=11) to 60% in CARDS B (n=15) and D (n=3) patients (p=0.005). Thirty-day clinical outcomes were similar across groups. At an average follow-up of 8.9 months, improvements in PROMIS PH and MH scores and rates of clinically significant improvement were similar across groups. Conclusions Based on our findings, patients undergoing lumbar fusion for DLS present with similar demographic and clinical characteristicsand experience similar clinical and patient-reported outcomes when stratified using the CARDS classification system. Posterolateral fusion (PLF) can be effective for various radiographic presentations of DLS. Further research is warranted to assess the utility of CARDS in preoperative planning.

Risks associated with chronic cannabis use on opioid use, length of stay, and revision rate for patients undergoing posterior lumbar interbody fusion

BACKGROUND CONTEXTOpioids are commonly prescribed to treat spinal pain, especially those undergoing surgery. Cannabis has been suggested as an agent that can modulate opioid needs in these patients. PURPOSETo investigate the effect of cannabis use on perioperative opioid requirement and revision surgery rate in patients undergoing lumbar fusion. STUDY DESIGNRetrospective cross-sectional study. PATIENT SAMPLEA total of 48,499 patients from PearlDiver national database who underwent posterior lumbar interbody fusion. OUTCOME MEASURESOpioid-use rates, MME, length of stay, and revision rates. METHODSUsing PearlDiver, we identified patients for posterior lumbar interbody fusion (PLIF), cannabis use disorder, revision lumbar fusion, demographics, and comorbidities. Cannabis users and non-users were propensity matched for age, sex, and tobacco use. Pre and postoperative cumulative morphine milli equivalence (MME) were calculated. Opioid-use rates, MME, length of stay (LOS), and revision rates were compared using univariate analysis. Revision rates were compared using Kaplan-Meyer log-rank analysis, and logistic and cox regression. RESULTSOf 48,499 patients undergoing PLIF, 3.4% were identified as chronic cannabis users. They were younger, and more likely to be male and use tobacco. They had a higher rate and amount of opioid use within 90-days preoperatively, and 90- and 365-days postoperatively, after controlling for age, sex, and tobacco use. Cannabis users had longer LOS (4.4 vs 4.0 days), and a higher rate of revision surgery (6.9% vs 3.2%). Log-rank analysis, as well as logistic and cox regression confirmed an increased revision rate. Concurrent tobacco and cannabis use also had an additive effect on revision rate to 8.1%, compared with those who used only cannabis (5.4%) or tobacco (4.5%). CONCLUSIONSChronic cannabis use is associated with an increased preoperative and long-term postoperative opioid use, a longer length of stay, and an increased revision rate.