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Background The preoperative assessment of C2 morphology is important for safe instrumentation. Sclerotic changes are often seen in C2 pedicles. Evaluating the diameter measurements solely might not accurately assess the safety of screw insertion. We have proposed a novel grading system of the C2 pedicle that includes sclerosis and evaluated the predictive value of this grading system with the surgeon's safety evaluation. Methods We reviewed and measured the dimensional values in 220 cervical computed tomography angiograms. Additionally, we used a grading system that divides the findings into 5 grades according to the width measurement and degree of sclerosis in the C2 pedicle. Two spine surgeons independently classified the pedicles as follows: safe (minimal risk of pedicle violation), caution needed (caution to minimize pedicle violation), or dangerous (a high risk of pedicle violation). Finally, we compared the measurements and the surgeons' safety assessments. Results A total of 411 pedicles of 203 patients (mean age, 69.5 years; 49.5% women) were included. Of the 411 C2 pedicles, 170 were classified as high risk by ≥1 surgeon. Between the dimensional measurements and grading system, the sclerotic grade showed the best predictive value. Conclusions We have introduced a novel tool to evaluate the safety of C2 pedicle screw placement. Our results suggest that our pedicle width–sclerosis grading system is reproducible and predicts the surgeon's assessment of safe screw placement better than C2 pedicle diametrical measurements alone.

Study DesignRetrospective clinical study.PurposeTo describe postoperative height changes and identify the predictive factors of spinal height (SH) changes among patients with adult spinal deformity (ASD) who underwent circumferential lumbar fusion with instrumentation.Overview of LiteraturePostoperative height changes remain an important issue after spinal fusion surgery that affects the overall satisfaction with surgery. Previous studies of postoperative height change have focused exclusively on young patients with adolescent idiopathic scoliosis (AIS).MethodsWe retrospectively reviewed the clinical and imaging data of ASD patients who underwent lumbar corrective circumferential fusion of ≥3 levels (n=106). SH was defined as the vertical distance between C2 and S1 on a standing lateral image. As potential predictors of postoperative height change, the number of lateral lumbar interbody fusion (LLIF) levels, change in spino-pelvic parameters, total number of levels fused, and pedicle subtraction osteotomies (PSO) were documented. Univariate and multivariate linear regression analyses were performed to identify the predictors of postoperative height change.ResultsThe mean SH change was −2.39±50.8 mm (range, −160 to 172 mm). The univariate analyses showed that the number of LLIF levels (coefficient=10.9, p=0.03), the absolute coronal vertical axis change (coefficient=0.6, p=0.01), and the absolute Cobb angle change (coefficient=−0.9, p=0.03) were significant predictors for height change. Patients with PSOs (n=14) tended to have a shorter height postoperatively (coefficient=−26.1); however, this difference was not significant (p=0.07). Multivariate analyses conducted with variables of pp=0.04, R2=0.11).ConclusionsUtilizing a modified definition of SH used in previous AIS studies, we demonstrated that patients with ASD lose SH postoperatively and that PT change was an independent contributor of SH change.

BackgroundErector spinae plane blocks are used to improve outcomes after spine surgery, but pain frequently outlasts the duration of single injection blocks. We hypothesized continuous erector spinae plane (cESP) catheters would provide superior analgesia. We terminated a prospective double-blinded randomized clinical trial (RCT) comparing outcomes after multilevel spine surgery among patients randomized to saline versus ropivacaine cESP catheters. We present two cases of undesired epidural spread of ropivacaine and discuss etiology, management, and future research directions.Case presentationNine out of 44 patients (planned) enrolled in the RCT; 6/9 were randomized to receive ropivacaine infusions via bilateral cESP catheters. Two patients underwent uncomplicated posterior lumbar fusion and were recovering well with minimal pain and opioid requirements through postoperative day 1. Both had new-onset urinary retention and bilateral lower extremity numbness, weakness and paresthesias (24 and 30 hours after infusion-start time, respectively). One patient underwent MRI, which was remarkable for an epidural fluid collection compressing the thecal sac. Infusions were stopped, cESP catheters were removed and symptoms fully resolved over the next 3–5 hours.ConclusionsUnwanted neuraxial spread of local anesthetic from cESP catheters may be a unique consideration after spine surgery, accounted for by unpredictable local anesthetic distribution within disrupted surgical planes. Future studies are indicated to determine optimal catheter regimens together with guidance for extended monitoring in parallel with further studies of efficacy in spine surgery cohorts.Trial registration numberNCT05494125.

BACKGROUND: Patients’ expectations influence their decisions to undergo surgery for scoliosis, and fulfillment of expectations is an important patient-centered outcome. QUESTIONS/PURPOSES: In a 2-year cohort study, we compared the proportion of expectations fulfilled based on the number of vertebrae involved in surgery between adult lumbar scoliosis patients and controls with other degenerative conditions. METHODS: Patients pre-operatively completed a valid lumbar surgery expectations survey addressing expected improvements for symptoms, function, and psychosocial well-being (scores from 0 to 100; higher score indicates more expectations). Two years post-operatively, the patients completed another survey, this one recording how much improvement they actually experienced; fulfillment was defined as a proportion (i.e., received improvement/expected improvement). The range was 0 (none fulfilled) to > 1 (expectations surpassed). We further analyzed data according to the number of vertebrae involved in the surgery. RESULTS: We included 42 scoliosis patients and 134 controls with similar mean ages (66 vs 64 years, respectively) and pre-operative expectations survey scores (72 vs 70, respectively). When we stratified by

The concept of sagittal spinal malalignment is well established in spinal surgery. However, the effect of musculature on its development has not been fully considered and the position of the pelvis is mostly seen as compensatory and not necessarily a possible cause of sagittal imbalance.This study aimed to investigate the influence of the posterior paraspinal muscles (PPM, erector spinae, and multifidus) and the psoas muscle on spinopelvic and spinal alignment.Retrospective cross-sectional study.Patients undergoing posterior lumbar fusion between 2014 and 2021 for degenerative conditions at a tertiary care center, with preoperative lumbar magnetic resonance imaging (MRI) within 12 months prior the surgery and a preoperative whole spine radiograph were included.PPM and psoas muscle measurements including the cross-sectional area (CSA), the functional cross-sectional area (fCSA), the amount of intramuscular fat (FAT), and the percentage of fat infiltration (FI). Spinopelvic measurements including lumbar lordosis (LL), pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), and sagittal vertical axis (SVA).A T2-weighted MRI-based quantitative assessment of the CSA, the fCSA and the amount FAT was conducted, and FI was further calculated. The regions of interest included the psoas muscle and the PPM on both sides at the L4 level that were summarized and normalized by the patient's height (cmA total of 150 patients (53.3% female) were included in the final analysis with a median age of 65.6 years and a median BMI of 28.2 kg/mThis study demonstrated the potential role of posterior paraspinal muscles and psoas muscle on pelvic retroversion and elucidated the relation to sagittal spinal malalignment. Although we cannot establish causality, we propose that increasing FI

Study design Longitudinal cohort. Objective The aims of this study were to measure concordance between patients' and surgeons' preoperative expectations of lumbar surgery, and determine which member of the dyad more closely predicted fulfillment of expectations, defined as patient-reported status postoperatively. Summary of background data Concordant patient-surgeon expectations reflect effective communication and should foster better outcomes. Methods Preoperatively patients and surgeons completed identical surveys measuring expectations for improvement in symptoms and physical/psychosocial function. Responses ranged from "complete improvement" to "do not have this expectation"; scores for each survey ranged from 0 to 100 (greatest expectations). Concordance between pairs of patient-surgeon scores was measured with the intraclass correlation coefficient (ICC). Postoperatively, fulfillment of expectations was measured from patient-reported amount of improvement received and was calculated as the proportion of patient-reported postoperative score relative to patient-reported preoperative score, and surgeon-reported preoperative score (range 0 [no expectations fulfilled] to >1.2 [expectations surpassed]). Clinical measures included patient-reported spine-related disability. Results For 402 patient-surgeon pairs, mean survey scores were 73 ± 19 (patients) and 57 ± 16 (surgeons); 84% of patients had higher scores than surgeons, mainly due to expecting complete improvement, whereas surgeons expected a lot/moderate/little improvement. The ICC for the entire sample was .31 (fair agreement); for subgroups, the greatest difference in ICC was for patients with more spine-related disability (ICC = .10, 95% confidence interval [CI]:0.00-0.23) versus less disability (ICC = .46, 95% CI: 0.34-0.56). 96% of patients were contacted ≥2.0 years postoperatively. Proportions of expectations fulfilled were 0.79 (0-3.00) (patients) and 1.01 (0-2.29) (surgeons). Thus patients were less likely to anticipate subsequent postoperative status (odds ratio [OR] 0.34, 95% CI 0.25-0.45) versus surgeons who were more likely to anticipate patient-reported postoperative status (OR 2.98, 95% CI: 2.22-4.00). Conclusion Concordance between patients' and surgeons' expectations was fair; due mostly to patients expecting complete improvement whereas surgeons expected a lot/moderate/little improvement. Compared to patients' expectations, surgeons' expectations more closely coincided with patient-reported fulfillment of expectations 2 years postoperatively.Level of Evidence: 1.

Study DesignMatched cohort study.PurposeTo compare and describe the effect of opioid usage on the expectations of lumbar surgery outcomes among patients taking opioids and patients not taking opioids.Overview of LiteratureChronic opioid use is common among lumbar-spine surgery patients. The decision to undergo elective lumbar surgery is influenced by the expected surgery outcomes. However, the effects of opioids on patients’ expectations of lumbar surgery outcomes remain to be rigorously assessed.MethodsA total of 77 opioid users grouped according to dose and duration (54 “higher users,” 30 “lower users”) were matched 2:1 to 154 non-opioid users based on age, sex, marital status, chiropractic care, disability, and diagnosis. All patients completed a validated 20-item Expectations Survey measuring expected improvement with regard to symptoms, function, psychological well-being, and anticipated future spine condition. “Greater expectations” was defined as a higher survey score (possible range, 0–100) based on the number of items expected and degree of improvement expected.ResultsThe mean Expectations Survey scores for all opioid users and all non-users were similar (73 vs. 70, p=0.18). Scores were different, however, for lower users (79) compared with matched non-users (69, p=0.01) and compared with higher users (70, p=0.01). In multivariable analysis, “greater expectations” was independently associated with having had chiropractic care (p=0.03), being more disabled (p=0.002), and being a lower-dose opioid user (p=0.03). Compared with higher users, lower users were also more likely to expect not to need pain medications 2 years after surgery (47% vs. 83%, p=0.003).ConclusionsPatient expectations of lumbar surgery are associated with diverse demographic and clinical variables. A lower dose and shorter duration of opioid use were associated with expecting more items and expecting more complete improvement compared with non-users. In addition, lower opioid users had greater overall expectations compared with higher users.

High body mass index (BMI) is positively correlated with bone mineral density (BMD) in healthy adults; however, the effect of BMI on regional segmental BMDs in the axial skeleton is unclear. In addition, obese patients often have glucose intolerance and patients with lumbar spine pathology commonly have a history of epidural steroid injections (ESIs). The purpose of this study is to evaluate the effect of these patient factors on regional differences in BMD measured by quantitative computed tomography (QCT) in a lumbar fusion patient cohort. The data were obtained from a database comprised of clinical and preoperative CT data from 296 patients who underwent primary posterior lumbar spinal fusion from 2014 to 2017. QCT-vBMDs of L1 to L5, S1 body, and sacral alae were measured. Multivariate linear regression analyses were performed with setting vBMDs as the response variables. As explanatory variables, age, sex, race, current smoking, categorized BMI, diabetes, and ESI were chosen a priori. A total of 260 patients were included in the final analysis. Multivariate analyses demonstrated that obese and morbidly obese patients had significantly higher vBMD in the sacral alae (SA). Diabetes showed independent positive associations with vBMDs in L1, L2, and the SA. Additionally, patients with an ESI history demonstrated significantly lower vBMD in the SA. Our results demonstrate that obesity, diabetes, and epidural steroids affected vBMD differently by lumbosacral spine region. The vBMD of the SA appeared to be more sensitive to various patient factors than other lumbar regions.

Study design Retrospective case series. Objective The aim of this study was to investigate the association of Modic type endplate changes with the risk of severe subsidence after standalone lateral lumbar interbody fusion (SA-LLIF). Summary of background data It has been reported that certain endplate radiolographic features are associated with higher regional bone mineral density (BMD) in the adjacent vertebrae in the lumbar spine. It remains unclear whether these changes have protective effects against osteoporotic complications such as cage subsidence after lumbar surgery. Methods We reviewed patients undergoing SA-LLIF from 2007 to 2016 with a follow-up >6 months. Cage subsidence was assessed utilizing the grading system by Marchi et al. As potential contributing factors for cage subsidence, we measured the endplate volumetric BMD (EP-vBMD) and the standard trabecular volumetric BMD measurement in the vertebral body. Modic changes (MC) on magnetic resonance imaging were measured as a qualitative factor for endplate condition. Univariate analysis and multivariate logistic regression analyses with a generalized mixed model were conducted. Results Two hundred six levels in 97 patients were included in the final analysis. Mean age (± SD) was 66.7 ± 10.7. Sisty-sdpercent of the patients were female. Severe subsidence was observed in 66 levels (32.0%). After adjusting for age, bone morphogenetic protein (BMP) use, and number of levels fused, the presence of MC type 2 was significantly associated with lower risk of severe subsidence (OR = 0.28 [0.09-0.88], P = 0.029). Whereas, EP-vBMD did not demonstrate a statistical significance (p = 0.600). Conclusion The presence of a Modic type 2 change was significantly associated with lower odds of severe subsidence after SA-LLIF. Nonetheless, this significant association was independent from regional EP-vBMD values. This finding suggests that microstructural and/or material property changes associated with Modic type 2 changes might have a protective effect in this patient population. Level of evidence 4.

Background context Clinically, the association between bone mineral density (BMD) and surgical instrumentation efficacy is well recognized. Although several studies have quantified the BMD of the human lumbar spine, comprehensive BMD data for the cervical spine is limited. The few available studies included young and healthy patient samples, which may not represent the typical cervical fusion patient. Currently no large scale study provides detailed BMD information of the cervical and first thoracic vertebrae in patients undergoing anterior cervical spine surgery. Purpose The objective of this study was to determine possible trabecular BMD variations throughout the cervical spine and first thoracic vertebra in patients undergoing anterior cervical discectomy and fusion (ACDF) and to assess the correlation between BMDs of the spinal levels C1-T1. Study Design/Setting This is a retrospective case series. Patient Sample Patients undergoing ACDF from 2015 to 2018 at a single, academic institution with available preoperative CT imaging were included in this study. Outcome Measures The outcome measure was bone mineral density measured by QCT. Methods Patients that underwent ACDF from 2015 to 2018 at a single, academic institution were included in this study. Subjects with previous cervical instrumentation or missing/incomplete preoperative cervical spine CT imaging were excluded. Asynchronous quantitative computed tomography (QCT) measurements of the lateral masses of C1 and the C2-T1 vertebral bodies were performed. For this purpose, an elliptical region of interest (ROI) that consisted exclusively of trabecular bone was selected. Any apparent sclerotic levels that might affect trabecular QCT measurements were excluded from the final analysis. Interobserver reliability of measurements was assessed by calculating the interclass correlation coefficients (ICC). Pairwise comparison of BMD was performed and correlations between the various cervical levels were evaluated. The statistical significance level was set at p Results In all, 194 patients (men, 62.9%) met inclusion criteria. The patient population was 91.2% Caucasian with a mean age of 55.9 years and mean BMI of 28.2 kg/m2. The ICC of cervical QCT measurements was excellent (ICC 0.92). The trabecular BMD was highest in the mid-cervical spine (C4) and decreased in the caudal direction (C1 average = 253.3 mg/cm3, C2 = 276.6 mg/cm3, C3 = 272.2 mg/cm3, C4 = 283.5 mg/cm3, C5 = 265.1 mg/cm3, C6 = 235.3 mg/cm3, C7 = 216.8 mg/cm3, T1 = 184.4 mg/cm3). The BMD of C7 and T1 was significantly lower than those of all other levels. Nonetheless, significant correlations in BMD among all measured levels were observed, with a Pearson's correlation coefficient ranging from 0.507 to 0.885. Conclusions To the authors’ knowledge this is the largest study assessing trabecular BMD of the entire cervical spine and first thoracic vertebra by QCT. The patient sample consisted of patients undergoing ACDF, which adds to the clinical relevance of the findings. Knowledge of BMD variation in the cervical spine might be useful to surgeons utilizing anterior cervical spine plate and screw systems. Due to the significant variation in cervical BMD, procedures involving instrumentation at lower density caudal levels might potentially benefit from a modification in instrumentation or surgical technique to achieve results similar to more cephalad levels.

Many patients retain sedentary lifestyles after lumbar surgery and incur increased risks of adverse health outcomes. The goal of this study was to assess patients’ perspectives about postoperative physical activity. During routine post-lumbar surgery visits in a tertiary care center, 260 patients were asked open-ended questions about their spine and physical activity. Three investigators reviewed responses and determined themed categories. Patients also completed surveys measuring disability, depressive symptoms, anxiety, and fear-avoidance of physical activity. Surgical complexity was assigned based on operative features. Mean age was 63, and 53% were men. Thirty-nine percent thought walking was good for the spine, particularly among those with less fear-avoidance, less disability, and less complex surgery. Spine benefits were cited (42%) for the short-term (“faster recovery”) and long-term (“decreases chances of another surgery”), particularly by younger patients. To increase activity, patients suggested spine-specific techniques (35%, “use railings”) and advised caution (24%, “pace yourself”). The major deterrent was persistent back pain (36%) particularly for those with worse disability, and more depressive symptoms, anxiety, complex surgery, and fear-avoidance. Our findings consistently fit with the Social Cognitive Theory of health behavior which posits a dynamic three-way interaction of personal factors, environmental influences, and behavior. Patients acknowledge short- and long-term benefits of physical activity for their spine and overall health; however, many are deterred from increasing activity by spine-related concerns. Interventions to improve physical activity should foster self-efficacy and self-direction and should be reinforced by members of the spine care team who are knowledgeable about prudent activities.

The purpose of this study is to investigate the predictive value of the hyoid horizontal positional change on the severity of dysphagia and dysphonia (PDD) after anterior cervical discectomy and fusion (ACDF) comparing pre-vertebral soft-tissue thickness (PVST). This is a retrospective observational study with prospectively collected data at a single academic institution. ACDF patients between 2015 to 2018 who had complete self-reported PDD surveys and pre- and postoperative lateral cervical radiographs were included in the analysis. PDD was assessed utilizing the Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI). The hyoid-vertebral distance (HVD) and PVST (the averages of C2 to C7 levels (PVSTC2–7) and all operating levels (PVSTOP)) were assessed preoperatively and upon discharge. The associations among postoperative changes of HVD, PVSTs, and the 4-week HSS-DDI score were evaluated. Of the 268 patients with a HSS-DDI score assessment, 209 patients had complete data. In univariate analyses, HVD and PVSTC2–7 changes demonstrated significant correlations with HSS-DDI, whereas PVSTOP showed no significant association. After adjusting with sex and operating level, the changes in HVD (p = 0.019) and PVSTC2–7 (p = 0.009) showed significant associations with the HSS-DDI score and PVSTOP showed no significant association. PVSTC2-7 could not be evaluated in 12% of patients due to measurement difficulties of PVST at lower levels. We introduce a novel potential predictive marker for PDD after ACDF. Our results suggest that HVD can be utilized for the risk assessment of PDD, especially in PVST unmeasurable cases, which accounts for over 10% of ACDF patients.

We investigated the effect of posterior lumbar fusion surgery on the regional volumetric bone mineral density (vBMD) measured by quantitative computed tomography. Surgery negatively affected the regional vBMD in adjacent levels. Interbody fusion was independently associated with vBMD decline and preoperative epidural steroid injections (ESIs) were associated with less postoperative vBMD decline. Few studies investigate postoperative BMD changes after lumbar fusion surgery utilizing quantitative computed tomography (QCT). Additionally, it remains unclear what preoperative and operative factors contribute to postoperative BMD changes. The purpose of this study is to investigate the effect of lumbar fusion surgery on regional volumetric bone mineral density (vBMD) in adjacent vertebrae and to identify potential modifiers for postoperative BMD change. The data of patients undergoing posterior lumbar fusion with available pre- and postoperative CTs were reviewed. The postoperative changes in vBMD in the vertebrae one or two levels above the upper instrumented vertebra (UIV+1, UIV+2) and one level below the lower instrumented vertebra (LIV+1) were analyzed. As potential contributing factors, history of ESI, and the presence of interbody fusion, as well as various demographic/surgical factors, were included. A total of 90 patients were included in the study analysis. Mean age (±SD) was 62.1 ± 11.7. Volumetric BMD (±SD) in UIV+1 was 115.4 ± 36.9 mg/cm3 preoperatively. The percent vBMD change in UIV+1 was − 10.5 ± 12.9% (p

Objective There have been some reports on the association between spinal balance parameters and regional bone mineral density (BMD), but the results are controversial. The purpose of this study is to evaluate the relationship between spinopelvic parameters and regional volumetric BMDs (vBMDs) measured by quantitative computed tomography (QCT) in the lumbosacral region of patients undergoing lumbar fusion surgery. Methods The data of consecutive patients undergoing posterior lumbar spinal fusion with preoperative computed tomography was reviewed. QCT measurements were conducted in L1–S1 vertebral trabecular bone. The associations between spinopelvic sagittal parameters and vBMDs were evaluated. Multivariate analyses adjusted with age, gender, race, and body mass index were conducted with vBMD as the response variable. Results A total of 144 patients were included in the final analyses. Mean age (± standard deviation) was 65.4 ± 11.8 years. Mean vBMD in L1 (± standard deviation) was 118.3 ± 37.4 mg/cm3. After adjusting by cofactors, lumbar lordosis was negatively associated with vBMDs in all levels from L1 to L5 (% regression coefficients and adjusted R2 values: L1, –0.438, 0.268; L2, –0.556, 0.296; L3, –0.608, 0.362; L4, –0.554, 0.228; L5, –0.424, 0.194), but not in S1. Sacral slope was negatively associated with vBMD only at L4 (% coefficient, –0.588; R2, 0.208). Other parameters were not significantly associated with vBMDs at any levels. Conclusions Higher lumbar lordosis was associated with lower vBMDs in all lumbar spine levels. Our results suggest that BMD is affected not only by metabolic factors but also by the mechanical environment. Further longitudinal studies are needed to elucidate this effect of vBMD on clinical outcomes.

Background Lateral lumbar interbody fusion can be performed without supplemental posterior instrumentation. Previous reports have shown favorable results with stand-alone lateral lumbar interbody fusion (SA-LLIF); however, a reoperation rate of up to 26% has been reported. It remains unclear what perioperative factors are associated with early failure after SA-LLIF. The objective of this study is to determine perioperative factors that increase the risk of early revisions after SA-LLIF. Methods Data of consecutive patients with SA-LLIF were reviewed. All revisions or recommendations for revision surgery within 12 months after the LLIF procedure were documented. As potential contributors, operative levels, preoperative clinical diagnosis, number of fusion levels, and the average L1/L2 quantitative computed tomography–volumetric bone mineral density value were obtained along with other demographic factors. Cage subsidence (grade 0–III as per Marchi et al.), was also evaluated in patients who had radiographs/computed tomography between 6 and 12 months postoperatively (n = 122). Logistic regression analyses were conducted. Results Of 133 eligible patients, 21 (15.8%) underwent revision surgery and 4 (3.0%) were recommended for revision surgery within 1 year primarily because of neurologic symptoms or pain (68%). Baseline demographics showed no significant difference between the revision and the nonrevision group. The average number of levels fused was 2.12 (revision group) and 2.14 (nonrevision group) (P = 0.55). Significantly more patients in the revision group had the diagnosis of foraminal stenosis (64.0% vs. 39.8%; P = 0.04). Conclusions Patients with foraminal stenosis were more likely to have early revision surgery after SA-LLIF primarily because of neurologic symptoms/pain. This information can assist in preoperative discussions and management of patient expectations.

BACKGROUND CONTEXT It has been reported that degenerative disc disease (DDD) is associated with higher spinal bone mineral density (BMD) based on previous studies that used dual X-ray absorptiometry (DXA). However, DDD is often associated with proliferative bone changes and can lead to an overestimation of BMD measured with DXA. Trabecular volumetric BMD (vBMD) in the vertebral body measured with quantitative computed tomography (QCT) is less affected by those changes and can be a favorable alternative to DXA for patients with degenerative spinal changes. PURPOSE The purpose of this study is to investigate the effect of DDD on regional trabecular vBMDs in the vertebral body measured by QCT. STUDY DESIGN/SETTING Cross-sectional observational study at a single academic institution. PATIENTS SAMPLE Consecutive patients undergoing posterior lumbar spinal fusion between 2014 and 2017 who had a routine preoperative CT scan and magnetic resonance imaging (MRI) within a 90-day interval. OUTCOME MEASURES Regional trabecular vBMDs in the vertebral body by QCT. METHODS QCT measurements were conducted in L1–S1 vertebral trabecular bone. Any apparent sclerotic lesions that might affect vBMD values were excluded from the region of interest. The vBMDs of each level were defined as the average vBMD of the upper and lower vertebrae. To evaluate DDD, Pfirrmann grade, Modic grade, total end plate score, and vacuum phenomenon were documented. Univariate regression analysis and multivariate analyses with a linear mixed model adjusted with individual variability of segmental vBMDs were conducted with vBMD as the response variable. RESULTS Of 143 patients and 715 disc levels, 125 patients and 596 discs met our inclusion criteria. Mean vBMD (±standard deviation [SD]) of all levels was 119.0±39.6 mg/cm3. After adjusting for all covariates, Pfirrmann grade was not an independent contributor to vBMD, but the presence of any Modic change (type 1, β=6.8, p≤.001; type 2, β=6.7, p CONCLUSIONS Our results showed that the presence of certain end plate lesions (Modic changes and high TEPS) on MRI was significantly associated with increased regional QCT-vBMDs in the vertebral body, but no significant association was observed with disc nucleus pathology, unless it was associated with a vacuum phenomenon. When end plate lesions with Modic changes and high TEPS are present at the measuring level, care must be taken to interpret vBMD values, which might be overestimations even if the trabecular area appears normal.

This study aims to investigate lumbar spine (LS) volumetric bone density (vBMD) as a risk factor for complications (pseudoarthrosis, instrumentation failure, adjacent fractures), re-operation, and time to complication after fusion. Lumbar spine (LS) fusion surgery is increasingly performed worldwide. Complications after fusion result in significant morbidity and healthcare costs. Multiple factors, including osteoporosis, have been suggested to contribute to risk of complications and re-operation. However, most studies have used DXA, which is subject to artifact in patients with spine pathology, and none have investigated the relationship between BMD and timing of post-operative complications. This study aims to investigate LS volumetric bone density (vBMD) as a risk factor for complications (pseudoarthrosis, instrumentation failure, adjacent fractures), re-operation, and time to complication after fusion. We evaluated a cohort of 359 patients who had initial LS fusion surgery at our institution, had pre-operative LS CTs and post-operative imaging available for review. Demographic factors, smoking status, vBMD, and details of surgical procedure were related to likelihood and timing of post-operative complications. Mean age was 60 ± 14 years, vBMD 122 ± 37 g/cm3. Median follow-up was 11 months. Skeletal complications occurred in 47 patients (13%); 34 patients (10%) required re-operation. Low vBMD (directly measured and estimated using HU) and smoking were associated with increased risk of skeletal complications. Each increase in baseline vBMD of 10 g/cm3 decreased the complication hazard and increased the complication-free duration in time-to-event analysis (hazard ratio 0.91, 95% CI 0.83–0.98, p

The aims of this study were to determine the time trend of demographics, complications, and outcomes for patients undergoing posterior lumbar interbody fusion/transforaminal lumbar interbody fusion (PLIF/TLIF) or anterior lumbar interbody fusion/lateral lumbar interbody fusion (ALIF/LLIF) and to compare the differences in the time trends between both procedures.The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients undergoing PLIF/TLIF and ALIF/LLIF procedures. Outcomes were analyzed for differences between 2 time periods in the PLIF/TLIF and ALIF/LLIF cohorts separately (2009-2013 and 2015-2019). Longitudinal time trends of the 2 procedures were determined by difference-in-differences (DID) analysis. Statistical significance was defined as P 0.05.For both approaches, there was an increase in age and American Society of Anesthesiologists class over time, accompanied by a significant decrease in blood transfusions and morbidity. The DID analysis showed a greater change in age (DID:-1.8%; P0.001), and more patients were rated American Society of Anesthesiologists class 3 (DID: -2.4%; P = 0.033) in the ALIF/LLIF cohort than in the PLIF/TLIF cohort. Length of stay declined significantly over time in both cohorts, with a greater reduction observed for patients who underwent ALIF/LLIF than for patients who underwent PLIF/TLIF (DID: 0.2%; P = 0.014). There were no changes in readmission rates over time in either cohort (PLIF/TLIF DID: 0.6%; P = 0.080; ALIF/LLIF DID: -0.2%; P = 0.696).Time trends for PLIF/TLIF and ALIF/LIIF showed a significant increase in the number of older patients with complex medical status undergoing surgery. Despite these trends, there were decreases in overall postoperative morbidity, incidence of blood transfusion, and length of stay, without increasing readmission. These results suggest general improvement in surgical and perioperative management of lumbar fusion over time with greater gains found in ALIF/LLIF-specific care than in PLIF/TLIF.

The effect of psoas and paraspinal muscle parameters on cage subsidence after minimally invasive techniques, such as standalone lateral lumbar interbody fusion (SA-LLIF), is unknown.This study aimed to determine whether the functional cross-sectional area (FCSA) of psoas and lumbar spine extensor muscles (multifidus and erector spinae), and psoas FCSA normalized to the vertebral body area (FCSA/VBA) differ among levels with severe cage subsidence after SA-LLIF when compared to levels without severe cage subsidence.Retrospective single center cohort study.Patients who underwent SA-LLIF between 2008 and 2020 for degenerative conditions using exclusively polyetheretherketone (PEEK) cages, had a lumbar magnetic resonance imaging (MRI) scan within 12 months, a lumbar computed tomography (CT) scan within 6 months prior to surgery, and a postoperative clinical and radiographic follow-up at a minimum of 6 months were included.Severe cage subsidence.MRI measurements included psoas and combined multifidus and erector spinae (paraspinal) FCSA and FCSA/VBA at the L3-L5 pedicles. Following manual segmentation of muscles on axial T2-weighted images using ITK-SNAP (version 3.8.0), the FCSA was calculated using a custom written program on Matlab (version R2019a, The MathWorks, Inc.) that used an automated pixel intensity threshold method to differentiate between fat and muscle. Mean volumetric bone mineral density (vBMD) at L1/2 was measured by quantitative CT. The primary endpoint was severe cage subsidence per level according to the classification by Marchi et al. Multivariable logistic regression analysis was performed using generalized linear mixed models. All analyses were stratified by biological sex.95 patients (45.3% female) with a total of 188 operated levels were included in the analysis. The patient population was 92.6% Caucasian with a median age at surgery of 65 years. Overall subsidence (Grades 0-III) was 49.5% (53/107 levels) in men versus 58.0% (47/81 levels) in women (p=.302), and severe subsidence (Grades II-III) was 22.4% (24/107 levels) in men versus 25.9% (21/81 levels) in women (p=.608). In men, median psoas FCSA and psoas FCSA/VBA at L3 and L4 were significantly greater in the severe subsidence group when compared to the non-severe subsidence group. No such difference was observed in women. Paraspinal muscle parameters did not differ significantly between non-severe and severe subsidence groups for both sexes. In the multivariable logistic regression analysis with adjustments for vBMD and cage length, psoas FCSA at L3 (OR 1.002; p=.020) and psoas FCSA/VBA at L3 (OR 8.655; p=.029) and L4 (OR 4.273; p=.043) were found to be independent risk factors for severe cage subsidence in men.Our study demonstrated that greater psoas FCSA at L3 and psoas FCSA/VBA at L3 and L4 were independent risk factors for severe cage subsidence in men after SA-LLIF with PEEK cages. The higher compressive forces the psoas exerts on lumbar segments as a potential stabilizer might explain these findings. Additional pedicle screw fixation might be warranted in these patients to avoid severe cage subsidence.

Lisa Oezel,1,2 Alexander P Hughes,1 Ikenna Onyekwere,1,3,* Zhaorui Wang,1,3,* Artine Arzani,1,3 Ichiro Okano,1 Jiaqi Zhu,4 Andrew A Sama,1 Frank P Cammisa,1 Federico Girardi,1 Ellen M Soffin5 1Orthopaedic Surgery, Spine Institute, Hospital for Special Surgery, New York, NY, USA; 2Department of Orthopaedic and Trauma Surgery, University Hospital Duesseldorf, Duesseldorf, Germany; 3Weill Cornell Medical College, New York, NY, 10021, USA; 4Epidemiology & Biostatistics, Hospital for Special Surgery, New York, NY, USA; 5Anesthesiology, Critical Care & Pain Management, Hospital for Special Surgery, New York, NY, USA*These authors contributed equally to this workCorrespondence: Ellen M Soffin, Tel +1 212-606-1206, Email soffine@hss.eduPurpose: Presumed benefits of erector spinae plane blocks (ESPB) include an enhanced safety profile and few complications. There are few large series, which report the incidence of complications associated with ESPB on a procedure-specific basis. The objective of this retrospective cohort study was to estimate the incidence of complications of ESPB in a large series of patients undergoing lumbar spine surgery.Patients and Methods: We included 342 consecutive patients who underwent any primary lumbar spine surgery via posterior approach (November 2018–July 2020). All patients received bilateral ultrasound-guided ESPB. The primary study outcome was the incidence of any perioperative complication, defined a priori as sensory, motor, hematologic, hemodynamic or respiratory complication consistent with plausible contribution from the ESPB. Secondary outcomes included the incidence of numeric rating scale (NRS) pain scores ≥ 7 in the post anesthesia care unit (PACU) and risk factors associated with NRS ≥ 7 (age, sex, ASA class, BMI, opioid tolerance, surgical type, and duration).Results: We did not identify any pre-specified complications associated with ESPB. There was one unilateral pneumothorax, in one patient, deemed unlikely to have been related to ESPB. NRS ≥ 7 was found in 17/342 patients (5%) and was independent of any background differences or risk factors assessed.Conclusion: Ultrasound guided ESPB for lumbar spine surgery was associated with zero complications, no interference with intraoperative neuromonitoring or the early postoperative neurological examination, and low incidence of poorly controlled pain in the PACU. These results help to establish procedure-specific risks and benefits of ESPB for spine surgery.Keywords: erector spinae plane block, complications, block failure, pneumothorax, spine surgery, local anesthetic systemic toxicity

This study aimed at quantifying trabecular volumetric bone mineral density (vBMD) at the external occipital protuberance (EOP) and the upper cervical spine. A retrospective review of patients who underwent non-contrast enhanced computed tomography of the cervical spine that included the occipital bone up to the EOP between 2007 and 2020 was conducted. Measurements of trabecular vBMD were performed in the occipital midline area, with the region of interest extending 4.5 mm above and below the center of the EOP, as well as the C1 lateral masses and the C2 vertebral body using asynchronous quantitative computed tomography. Eighty-six patients (female, 37.2%) were included for analysis. The patient population was 81.4% Caucasian with a mean ± SD age of 62.3 ± 13.1 years. Total bone thickness at the EOP was 16.7 ± 3.4 mm, with a ratio of trabecular to total bone thickness of 0.44. Trabecular vBMD (mean ± SD) was significantly higher at the EOP than at C1 and C2 (EOP = 612.3 ± 145.8 mg/cm3 , C1 average = 290.3 ± 66.5 mg/cm3 , C2 = 305.8 ± 78.8 mg/cm3 ; p 65 years of age, cervical vBMD was significantly lower, but remained high at the EOP. Clinical significance: Trabecular vBMD at the EOP is significantly higher than at the upper cervical vertebrae and remains high in older populations. Together with morphological information about the occipital bone, these results might be helpful for occipitocervical fixation when deciding about uni- or bicortical screw placement at the EOP.

To develop a decision-making pathway for primary SA-LLIF. Furthermore, we analyzed the agreement of this pathway and compared outcomes of patients undergoing either SA-LLIF or 360-LLIF.A decision-making pathway for SA-LLIF was created based on the results of interviews/surveys of senior spine surgeons with over 10 years of experience. Internal validity was retrospectively evaluated using consecutive patients undergoing either SA-LLIF or 360-LLIF between 01/2018 and 07/2020 with 3D-printed Titanium cages. An outcome assessment looking primarily at revision surgery and secondary at cage subsidence, changes in disk and foraminal height, global and segmental lumbar lordosis, duration of surgery, estimated blood loss, and length of stay was carried out.78 patients with 124 treated levels (37 SA-LLIF, 41 360-LLIF) were retrospectively analyzed. The pathway showed a direct agreement (SA-LLIF) of 100.0% and an indirect agreement (360-LLIF) of 95.1%. Clinical follow-up averaged 13.5 ± 6.5 months including 4 revision surgeries in the 360-LLIF group and none in the SA-LLIF group (p = 0.117). Radiographic follow-up averaged 9.5 ± 4.3 months, with no statistically significant difference in cage subsidence rate between the groups (p = 0.440). Compared to preoperative images, patients in both groups showed statistically significant changes in disk height (p 0.001), foraminal height (p 0.001), as well as restoration of segmental lordosis (p 0.001 and p = 0.018). The SA-LLIF group showed shorter duration of surgery, less estimated blood loss and shorter LOS (p 0.001).The proposed decision-making pathway provides a guide to adequately select patients for SA-LLIF. Further studies are needed to assess the external applicability and validity.Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

To compare outcomes of three-dimensional-printed porous titanium (Ti) versus polyetheretherketone (PEEK) cage implantation for stand-alone lateral lumbar interbody fusion (SA-LLIF) in treatment of symptomatic adjacent segment degeneration.Between October 2016 and July 2020, 44 patients (59 levels) underwent stand-alone lateral lumbar interbody fusion with Ti or PEEK cages. The primary outcome was cage subsidence. Secondary outcomes included revision and/or recommendations for revision surgery, back and/or leg pain severity, changes in disc and/or foraminal height, and global and/or segmental lumbar lordosis.The study included 44 patients (21 females) with a mean age at surgery of 61.8 ± 11.5 years, mean radiological follow-up of 12.5 ± 8.2 months, and mean clinical follow-up of 11.0 ± 7.1 months. Overall subsidence rate was significantly less in the Ti versus PEEK group (20% vs. 58.8%, P = 0.004). Revision was recommended to none of the patients in the Ti group and 3 patients in the PEEK group (P = 0.239). Patients in the Ti group showed significantly better improvement in back pain numeric rating scale score (P = 0.001). Disc height (P0.001) and foraminal height restoration (P = 0.011) were statistically significant in the Ti group, whereas only disc height restoration was significant in the PEEK group (P = 0.003).In patients undergoing stand-alone lateral lumbar interbody fusion to treat adjacent segment degeneration, Ti cages had a significantly lower overall subsidence rate compared with PEEK cages. Furthermore, Ti cages resulted in fewer recommendations for revision surgery. Whether greater pain reduction in the Ti group is associated with earlier or higher fusion rates needs to be further elucidated.

The importance of bone status assessment in spine surgery is well recognized. The current gold standard for assessing bone mineral density is dual-energy X-ray absorptiometry (DEXA). However, DEXA has been shown to overestimate BMD in patients with spinal degenerative disease and obesity. Consequently, alternative radiographic measurements using data routinely gathered during preoperative evaluation have been explored for the evaluation of bone quality and fracture risk. Opportunistic quantitative computed tomography (QCT) and more recently, the MRI-based vertebral bone quality (VBQ) score, have both been shown to correlate with DEXA T-scores and predict osteoporotic fractures. However, to date the direct association between VBQ and QCT has not been studied.The objective of this study was to evaluate the correlation between VBQ and spine QCT BMD measurements and assess whether the recently described novel VBQ score can predict the presence of osteopenia/osteoporosis diagnosed with QCT.Cross-sectional study using retrospectively collected data.Patients undergoing lumbar fusion from 2014-2019 at a single, academic institution with available preoperative lumbar CT and T1-weighted MRIs were included.Correlation of the VBQ score with BMD measured by QCT, and association between VBQ score and presence of osteopenia/osteoporosis.Asynchronous QCT measurements were performed. The average L1-L2 BMD was calculated and patients were categorized as either normal BMD (120 mg/cmA total of 198 patients (53% female) were included. The mean age was 62 years and the mean BMI was 28.2 kg/mWe found that the VBQ score showed moderate diagnostic ability to differentiate patients with normal BMD versus osteopenic/osteoporotic BMD based on QCT. VBQ may be an interesting adjunct to clinically performed bone density measurements in the future.

STUDY DESIGN Retrospective database analysis. OBJECTIVE To identify preoperative risk factors for emergency department (ED) visit and unplanned hospital readmission after primary anterior cervical discectomy and fusion (ACDF) at 30 and 90 days. SUMMARY OF BACKGROUND DATA Limited data exist to identify factors associated with ED visit or readmission after primary ACDF within the first 3 months following surgery. METHODS Patients undergoing ACDF from 2005 to 2012 were identified in the Statewide Planning and Research Cooperative System database. Multivariable regression models were created based on patient-level and surgical characteristics to identify independent risk factors for hospital revisit. RESULTS Of 41,813 patients identified, 2514 (6.0%) returned to the ED within 30 days of discharge. Risk factors included age 1, length of stay (LOS) greater than 1 day (OR 1.23), and fusion of > 2 levels (OR 1.17). Four thousand six hundred nine (11.0%) patients returned to the ED within 90 days. Risk factors mirrored those at 30 days. Patients having private insurance or those discharged to rehab were less likely to present to the ED. One thousand three hundred ninety-four (3.3%) patients were readmitted by 30 days. Risk factors included male sex, Medicare, or Medicaid insurance (OR 1.71 and 1.79 respectively), Charlson comorbidity index > 1, discharge to a skilled nursing facility (OR 2.90), infectious/pathologic (OR 3.296), or traumatic (OR 1.409) surgical indication, LOS > 1 day (OR 1.66), or in-hospital complication. 2223 (5.3%) patients were readmitted by 90 days. Risk factors mirrored those at 30 days. No differences in readmission were seen based on race or number of levels fused. Patients aged 18 to 34 were less likely to be readmitted versus patients older than 35. CONCLUSION Insurance status, comorbidities, and LOS consistently predicted an unplanned hospital visit at 30 and 90 days. Although nondegenerative surgical indications and in-hospital complications did not predict ED visits, these factors increased the risk for readmission. LEVEL OF EVIDENCE 3.

Lumbar spine fusion with anterior (ALIF) or lateral (LLIF) approach is a moderately painful procedure associated with significant length of hospital stay (LoS) and opioid requirements. We developed an opioid-sparing analgesic pathway of care for ALIF and LLIF, featuring transversus abdominis plane (TAP) block. In this study, we assessed the feasibility of performing the TAP block as an analgesic adjunct for ALIF or LLIF. This is a prospective feasibility study of 32 patients. All patients received pre-incisional TAP block, regularly scheduled non-opioid analgesics (gabapentin, acetaminophen, ketorolac), and oral tramadol, as needed. The primary feasibility outcomes were rates of recruitment, adherence and adverse events associated with the TAP block. Secondary outcomes included assessment of TAP block efficacy and duration, numeric rating scale (NRS) pain scores, LoS and opioid consumption. Thirty-three patients were approached for the study, and all were enrolled. One patient did not have surgery. All patients received the intervention. There were no block-related adverse events. PACU NRS scores were significantly lower (1.9 ± 3.0) than at postoperative day 1 (POD1; 3.3 ± 2.5). The TAP block was effective in 31/32 patients, with 1 failed block. Median LoS was 26.8 h (IQR 22.8–49.5 h). Median opioid consumption was 57.5 oral morphine equivalents (IQR 30–74.38). One patient required opioid iv patient-controlled analgesia. Applying TAP block to spine surgery is a novel pain management strategy. This study demonstrates high patient acceptance and the general safety of the technique. Although lacking a control arm, these results also provide preliminary data supporting efficacy. These slides can be retrieved under Electronic Supplementary Material.

BACKGROUND CONTEXT Quantitative computed tomography (QCT) of the lumbar spine is used as an alternative to dual-energy X-ray absorptiometry in assessing bone mineral density (BMD). The average BMD of L1-L2 is the standard reportable metric used for diagnostic purposes according to current recommendations. The density of L1 and L2 has also been proposed as a reference value for the remaining lumbosacral vertebrae and is commonly used as a surrogate marker for overall bone health. Since regional BMD differences within the spine have been proposed, it is unclear if the L1-L2 average correlates with the remainder of the lumbosacral spine. PURPOSE The aim of this study was to determine possible BMD variations throughout the lumbosacral spine in patients undergoing lumbar fusion and to assess the correlation between the clinically used L1-L2 average and the remaining lumbosacral vertebral levels. STUDY DESIGN/SETTING This is a retrospective case series. PATIENT SAMPLE Patients undergoing posterior lumbar spinal fusion from 2014 to 2017 at a single, academic institution with available preoperative CT imaging were included in this study. OUTCOME MEASURES The outcome measure was BMD measured by QCT. METHODS Standard QCT measurements at the L1 and L2 vertebra and additional experimental measurements of L3, L4, L5, and S1 were performed. Subjects with missing preoperative lumbar spine CT imaging were excluded. The correlations between the L1-L2 average and the other vertebral bodies of the lumbosacral spine (L3, L4, L5, S1) were evaluated. RESULTS In total, 296 consecutive patients (55.4% female, mean age of 63.1 years) with available preoperative CT were included. The vertebral BMD values showed a gradual decrease from L1 to L3 and increase from L4 to S1 (L1=118.8 mg/cm3, L2=116.6 mg/cm3, L3=112.5 mg/cm3, L4=122.4 mg/cm3, L5=135.3 mg/cm3, S1=157.4 mg/cm3). There was strong correlation between the L1-L2 average and the average of the other lumbosacral vertebrae (L3-S1) with a Pearson's correlation coefficient (r=0.85). We also analyzed the correlation between the L1-L2 average and each individual lumbosacral vertebra. Similar relationships were observed (r value, 0.67–0.87), with the strongest correlation between the L1-L2 average and L3 (r=0.87). CONCLUSIONS Our data demonstrate regional BMD differences throughout the lumbosacral spine. Nevertheless, there is high correlation between the clinically used L1-L2 average and the BMD values in the other lumbosacral vertebrae. We, therefore, conclude the standard clinically used L1-L2 BMD average is a useful bone quantity measure of the entire lumbosacral spine in patients undergoing lumbar spinal fusion.

Background Context Sacral fractures are a rare but potentially devastating complication. Long-fusion constructs, including the sacrum, that do not extend to the pelvis may result in sacral fractures. Besides established risk factors including gender, age, and number of levels fused, body mass index (BMI), pelvic parameters, and bone mineral density (BMD) have also been proposed as potential risk factors for postoperative sacral fractures. The literature supporting this, however, is limited. Purpose The aim of the present study was to assess whether preoperative pelvic parameters, BMI, or BMD of patients with sacral fracture are different compared with age, gender, and fusion level-matched non-fracture controls. Study Design/Setting This is a case-control study. Patient Sample Patients undergoing posterior instrumented fusion at a single academic institution between 2002 and 2016 were included in the study. Outcome Measures The outcome measure was occurrence of a postoperative sacral fracture. Methods Patients with sacral fractures after posterior instrumented spinal fusion, including the sacrum, were retrospectively identified and matched 2:1 with non-fracture controls based on gender, age, and number of levels fused. Patients with concurrent spinopelvic fixation or missing preoperative computed tomography (CT) imaging were excluded. Preoperative sagittal balance was assessed using lateral radiographs. Quantitative computed tomography (QCT) assessment included standard measurements at L1/L2 and additional experimental measurements of the S1 body and sacral ala. Results Twenty-one patients with sacral fracture were matched to non-fracture controls. The majority of the patients with sacral fracture was female (76.2%) and of advanced age (mean 66.4 years). Fracture and control groups were well matched with respect to gender, age, and number of levels fused. Standard measurements at L1/L2 showed no significant difference in BMD between the fracture and the control groups (109.9 mg/cm3 vs. 116.4 mg/cm3, p=.414). Similarly, there was no significant BMD differences between the groups using the experimental measurements of the S1 body (183.6 mg/cm3 vs. 176.2 mg/cm3, p=.567) and the sacral ala (8.9 mg/cm3 vs. 4.8 mg/cm3, p=.616). Mean preoperative pelvic incidence-lumbar lordosis mismatch and pelvic tilt were not significantly different between the groups. Univariate conditional logistic regression analysis revealed that the odds of experiencing a sacral fracture was approximately six times higher for obese patients compared with normal or underweight patients. After controlling for BMI in multivariate conditional logistic regression models, BMD was still not significantly associated with the odds of experiencing sacral fractures. Conclusions To our knowledge, this is the first study to assess the association of preoperative BMD measured by QCT, pelvic parameters, and BMI with postoperative sacral fractures in a large patient cohort. Interestingly, our data do not show any difference in preoperative pelvic parameters and BMD between the groups. This is in line with previous reports that indicate only a few patients with sacral fracture after fusion surgery have clear evidence of osteoporosis. Bone mineral density as a measure of bone quantity, rather than bone quality, may not be as important in these fractures as previously thought. Obesity, however, was associated with higher odds of experiencing postoperative sacral fractures. The present study thereby challenges the widespread concept that obesity is a protective factor against fractures in the elderly. In summary, our results suggest that BMI and gender, more than pelvic parameters and BMD, are risk factors for postoperative sacral fractures.

OBJECTIVE: We measured the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) immunoglobulin G (IgG) antibodies among surgeons and anesthesiologists and associated antibody status with coronavirus disease 2019 (COVID-19) clinical illness. METHODS: A cross-sectional study of SARS-CoV-2 IgG seroprevalence with a survey assessing demographics, SARS-CoV-2 exposure risk, and COVID-19 illness. The primary outcome was the period prevalence of SARS-CoV-2 IgG antibodies associated with COVID-19 illness. RESULTS: One hundred forty three surgeons and anesthesiologists completed both serology and survey testing. We found no significant relationships between antibody status and clinical role (anesthesiologist, surgeon), mode of commuting to work, other practice settings, or place of residence. SARS-CoV-2 IgG seroprevalence was 9.8%. Positive IgG status was highly correlated with presence of symptoms of COVID-19 illness. CONCLUSIONS: These results suggest the relative safety of surgeons and anesthesiologists where personal protective equipment (PPE) is available and infection control protocols are implemented.

OBJECTIVE Opioid stewardship programs combine clinical, regulatory, and educational interventions to minimize inappropriate opioid use and prescribing for orthopedic and spine surgery. Most evaluations of stewardship programs quantify effects on prescriber behavior, whereas patient-relevant outcomes have been relatively neglected. The authors evaluated the impact of an opioid stewardship program on perioperative opioid consumption, prescribing, and related clinical outcomes after multilevel lumbar fusion. METHODS The study was based on a retrospective, quasi-experimental, pretest-posttest design in 268 adult patients who underwent multilevel lumbar fusion in 2016 (preimplementation, n = 141) or 2019 (postimplementation, n = 127). The primary outcome was in-hospital opioid consumption (morphine equivalent dose [MED], mg). Secondary outcomes included numeric rating scale pain scores (0–10), length of stay (LOS), incidence of opioid-induced side effects (gastrointestinal, nausea/vomiting, respiratory, sedation, cognitive), and preoperative and discharge prescribing. Outcomes were measured continuously during the hospital admission. Differences in outcomes between the epochs were assessed in bivariable (Wilcoxon signed-rank or Fisher’s exact tests) and multivariable (Wald’s chi-square test) analyses. RESULTS In bivariable analyses, there were significant decreases in preoperative opioid use (46% vs 28% of patients, p = 0.002), preoperative opioid prescribing (MED 30 mg [IQR 20–60 mg] vs 20 mg [IQR 11–39 mg], p = 0.003), in-hospital opioid consumption (MED 329 mg [IQR 188–575 mg] vs 199 mg [100–372 mg], p < 0.001), the incidence of any opioid-related side effect (62% vs 50%, p = 0.03), and discharge opioid prescribing (MED 90 mg [IQR 60–135 mg] vs 60 mg [IQR 45–80 mg], p < 0.0001) between 2016 and 2019. There were no significant differences in postanesthesia care unit pain scores (4 [IQR 3–6] vs 5 [IQR 3–6], p = 0.33), nursing floor pain scores (4 [IQR 3–5] vs 4 [IQR 3–5], p = 0.93), or total LOS (118 hours [IQR 81–173 hours] vs 103 hours [IQR 81–132 hours], p = 0.21). On multivariable analysis, the opioid stewardship program was significantly associated with decreased discharge prescribing (Wald’s chi square = 9.45, effect size −52.4, 95% confidence interval [CI] −86 to −19.0, p = 0.002). The number of lumbar levels fused had the strongest effect on total opioid consumption during the hospital stay (Wald’s chi square = 16.53, effect size = 539, 95% CI 279.1 to 799, p < 0.001), followed by preoperative opioid use (Wald’s chi square = 44.04, effect size = 5, 95% CI 4 to 7, p < 0.001). CONCLUSIONS A significant decrease in perioperative opioid prescribing, consumption, and opioid-related side effects was found after implementation of an opioid stewardship program. These gains were achieved without adverse effects on pain scores or LOS. These results suggest the major impact of opioid stewardship programs for spine surgery may be on changing prescriber behavior.

Anterior cervical discectomy and fusion (ACDF) is a safe and effective procedure but has approach-related complications like postoperative dysphagia and dysphonia (PDD). Patient-reported outcome measures including the Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) have been used for the assessment of PDD. Various factors have been described that affect ACDF outcomes, and our aim was to investigate the effect of workers' compensation (WC) status.We included patients who underwent ACDF from 2015 to 2018 stratified according to insurance status: WC/non-WC. PDDs were assessed using the HSS-DDI score. We conducted logistic regression analyses. Statistical significance was set at P0.05.We included 287 patients, 44 (15.33%) WC and 243 (84.67%) non-WC. A statistical comparison revealed a clinically relevant difference in the HSS-DDI total score and both subdomains (P = 0.015; dysphagia P = 0.021; dysphonia P = 0.002). Additional logistic regression analysis adjusting for preoperative Neck Disability Index scores resulted in no clinically relevant differences in the HSS-DDI total score and both subdomains (total score P = 0.420; dysphagia P = 0.531; dysphonia 0.315).WC status was associated with a worse HSS-DDI score but could not be shown to be an independent risk factor for PDD. The preoperative NDI score was a strong predictor for PDD with a clinically relevant difference in the HSS DDI score (P0.0001). Surgeon awareness of risk factors for PDD such as WC status, even if it could not be shown as independent, is important as it may influence surgical decision making and managing patient expectations.

BACKGROUND CONTEXT Low muscle volume, also called sarcopenia, is a common condition of aging with a prevalence between 1 and 29% in populations over the age of 50 years. Previous studies have demonstrated evidence that both osteoporosis and sarcopenia coexist, called osteosarcopenia, and these patients are at greater risk for falls, fractures and mortality. In osteoporotic post-menopausal female patients, the prevalence of sarcopenia is around 50%. Recent studies showed that sarcopenic subjects had a 4-fold higher risk of coexisting osteoporosis compared with nonsarcopenic individuals. However, a limited number of studies have been conducted in spine surgery patients. PURPOSE The aim of this study is to investigate the associations between the lean muscle volume (LMV) in paraspinal and proas muscle on MRI and quantitative computed tomography (QCT) volumetric bone mineral density (vBMD) in the lumbosacral region. STUDY DESIGN/SETTING A cross-sectional analysis of a prospectively maintained database at a single academic institution. PATIENT SAMPLE Patients undergoing posterior lumbar fusion surgery between 2014-2020. OUTCOME MEASURES Volumetric BMD measured by QCT in the lumbar spine and sacral ala. METHODS We reviewed an institutional database of posterior lumbar fusion patients. Patients who had ongoing antiosteoporotic therapy with bisphosphonate, denosumab or teriparatide were excluded. Muscle measurements were conducted utilizing a free software program (ITK-SNAP version 3.8) setting regions of interest (ROI) in the bilateral psoas and paraspinal (erector spinae and multifundus) muscles on preoperative T2-weighted axial MR images at the mid-L3 level. The area of fat-free muscle (LMV: lean muscle volume) was calculated using a custom written program on Matlab™ (MATLAB version 2019a, The MathWorks, Inc, Natick, MA, USA). QCT measurements were performed on preoperative CT scans using the Mindways QCT Pro Software (Mindways Software, Inc., Austin, TX, USA). QCT-vBMDs in the standard L1-L2 and bilateral sacral ala were analyzed. Pearson's correlation and linear regression analyses adjusting with age and BMI were performed. Since muscle volume is strongly affected by biological sex, we stratified by sex for all analyses. Statistical significance was set RESULTS Out of 144 patients, 30 patients were excluded due to QCT incompatible CTs or poor quality MRIs for muscle volume measurements. An additional 9 patients were excluded due to ongoing anti-osteoporotic drug therapy. A total of 105 patients (50 male and 55 female) were included in the final analysis. In female patients, there were statistically significant mild to moderate positive correlations between L1-L2 vBMD and LMV in paraspinal and psoas muscles, as well as sacral ala vBMD and paraspinal LMV, whereas there was no significant correlation in male patients. After the adjustment with age and BMI, high paraspinal LMV was an independent factor for high sacral ala vBMD (β=0.04 (95%CI: 0.00-0.14), p=0.040) and high psoas LMV was significantly associated with high L1-L2 vBMD (β=0.04 (95%CI: 0.01-0.14), p=0.025). CONCLUSIONS Our results demonstrated that higher lean muscle volume was significantly associated with higher vBMD in the lumbosacral lesions in women. This association was not observed in men. This might indicate gender differences should be considered for the assessment of osteosarcopenia in spine surgery patients. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Methods to measure bone quality using opportunistic imaging have recently been developed, including quantitative computed tomography (QCT), which allows for site-specific volumetric bone mineral density (vBMD) measurement, such as pedicles or endplates. Studies have shown these site-specific QCT measurements had more predictive value for site-specific complications than standard L1/2 measurements. Recently, MRI-based assessments of the vertebral bone quality (VBQ), which measures trabecular bone quality, were also introduced. However, there have been few studies that investigate the association between site-specific MRI bone assessment and osteoporosis related complications in patients undergoing lumbar interbody fusion. In this work, we created a novel site-specific MRI-based assessment of the endplate bone quality (EBQ) and assessed its predictive value for severe cage subsidence following standalone lateral lumbar interbody (SA-LLIFF) fusion. PURPOSE The purpose is to introduce a novel MRI-based site-specific bone quality assessment, EBQ, and investigate the predictive value of EBQ for severe cage subsidence after SA-LLIF compared with standard VBQ. STUDY DESIGN/SETTING A retrospective observational study at a single academic institution. PATIENT SAMPLE Patients undergoing SA-LLIF between 2008-2019 with available preoperative CT and T1-weighted MRIs of the lumbar spine as well as postoperative lumbar radiographs or CTs. OUTCOME MEASURES Severe cage subsidence (Grade 2 or 3) within 5-14 month after SA-LLIF. METHODS We retrospectively reviewed the records of SA-LLIF patients. Cage subsidence was assessed using the classification of Marchi et al. and severe cage subsidence was defined as grade 2 or 3. We measured VBQ as shown in the original article by Ehresman et al. EBQ was measured using preoperative non-contrast T1-weighted MRIs of the lumbar spine. The regions of interest were the subchondral bones of upper and lower endplates at the operated level, and the average signal intensity of both endplates was divided by that of the cerebrospinal fluid space at the level of L3. As a confounding factor, vBMD was measured using asynchronous QCT. Bivariate and multivariable analysis with generalized linear mixed models were performed with setting binary severe subsidence as the outcome. Statistical significance was set at p=0.05. The quality of fit was assessed using Akaike's information criterion. RESULTS A total of 205 levels in 89 patients were included in the final analysis. There were 50 levels (24.4%) which demonstrated severe subsidence. QCT-vBMD was significantly lower in severe subsidence group (Mean (SD) 97.4 (34.4) vs 110.1(33.4), p=0.021). Both VBQ and EBQ were significantly higher in severe subsidence group (VBQ: Mean (SD) 2.67 (1.08) vs 2.39 (0.44), p=0.010; EBQ Mean (SD) 5.09 (2.20) vs 4.31 (1.09), p=0.001). In multivariate analyses adjusted with QCT-vBMD, EBQ showed significant association with severe cage subsidence (OR (95% confidential interval) = 1.94 (1.36-3.63), p=0.038), whereas VBQ only showed a marginal trend (p=0.071). The EBQ based prediction model for severe subsidence showed better goodness of fit compared to VBQ based model. (AIC EBQ 190 vs VBQ 192). CONCLUSIONS We introduced a novel MRI-based site-specific bone quality assessment. High EBQ was an independent factor for severe cage subsidence after SA-LLIF and the EBQ-based model showed better goodness of fit compared to VBQ-based model. Given the availability of preoperative MRIs, EBQ assessment prior to SA-LIFF may provide insight into a patient's risk for severe subsidence. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Opioid prescribing for patients undergoing orthopedic procedures has been identified as a major contributor to the current opioid crisis in the United States. The rising awareness and more restrictive prescribing guidelines are beginning to affect the practice of medicine. Physicians are looking for alternative methods to effectively control acute pain and improve the treatment of chronic opioid patients. In line with these efforts, hospitals are establishing interventions and policies to address the national epidemic at the institutional level. Our hospital implemented new clinical, regulatory and policy guidelines in 2017 directed toward minimizing opioid use and prescribing while providing adequate analgesia after orthopedic surgery. These included clinical guidelines for managing opioid naive and opioid tolerant patients and/or those with substance abuse disorder, educational programs for patients and prescribers, and surgery-specific prescribing recommendations to limit unnecessary prescribing of opioids. PURPOSE The aim of this study was to describe changes in opioid use and prescribing associated with the implementation of opioid minimizing initiatives in patients undergoing multilevel lumbar fusion. STUDY DESIGN/SETTING A retrospective before-and-after analysis of patients who underwent multilevel lumbar fusion at an orthopedic surgery specialty hospital in New York City. PATIENT SAMPLE Multilevel lumbar fusion patients. OUTCOME MEASURES The primary outcome was postoperative opioid consumption during the hospital stay and the opioid prescribed upon hospital discharge. The secondary outcomes were length of hospital stay (LOS), opioid-induced side effects, and numeric rating scale (NRS) pain scores. Methods The study included data collected between January 1, 2016 – December 31, 2016 (prior to institutional implementation) and between January 1 – December 31, 2019, (after full institutional implementation). The electronic medical records and office notes were retrospectively reviewed for opioid use before and after surgery, and converted to equianalgesic doses (morphine equivalent dose, MED and expressed as milligrams of morphine per day, mg/day). Demographic and perioperative characteristics were compared between the intervention group and control cohort using Wilcoxon signed rank test for continuous variables and fisher's exact test for dichotomous variables and set the statistical significance at p Results A total of 268 multilevel lumbar fusion patients were included in this analysis. 141 (52.6%) patients had surgery in 2016 and 127 (47.4%) underwent surgery in 2019. We found a statically significantly lower opioid consumption during the hospital stay (p Conclusions This study found that after the clinical and policy interventions, opioid consumption, prescribed opioids upon hospital discharge and opioid-related side effects were lower. Despite these gains, there were no changes in reported pain associated with surgery and LOS was unchanged. Our findings demonstrate the efficacy of institutional implementation of a set of interventions to address the national opioid epidemic at the local level. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The thoracic spine is a common location for vertebral fractures as well as instrumentation failure after long spinal fusion procedures. The association between those complications and bone mineral density (BMD) are well recognized. Due to the overlying sternum and ribs in the thoracic spine, projectional BMD assessment tools such as dual energy x-ray absorptiometry (DXA) are limited to the lumbar spine. Quantitative computed tomography circumvents several shortcomings of DXA and allows for level-specific BMD measurements. Studies comprehensively quantifying BMD of the entire thoracic spine in patients undergoing spine surgery are limited. PURPOSE The objective of this study was: (1) to assess the reliability of thoracic QCT measurements, (2) to determine possible level-specific BMD variation throughout the thoracic spine and (3) to assess the correlation between BMDs of the T1-T12 spinal levels. STUDY DESIGN/SETTING Cross-sectional observation study. PATIENT SAMPLE Patients undergoing spine surgery from 2016–2020 at a single, academic institution with available preoperative CT imaging of the thoracic spine were included in this study. OUTCOME MEASURES The outcome measure was BMD measured by QCT. METHODS Patients undergoing spine surgery from 2016–2020 at a single, academic institution with available preoperative CT imaging of the thoracic spine were included in this study. Subjects with previous instrumentation at any thoracic level, concurrent vertebral fractures, a Cobb angle of more than 20 degrees, or incomplete thoracic spine CT imaging were excluded. Asynchronous quantitative computed tomography (QCT) measurements of T1-T12 were performed. To assess inter- and intra-observer reliability, a validation study was performed on 120 vertebrae in 10 randomly selected patients. The interclass correlation coefficient (ICC) was calculated. A pairwise comparison of BMD was conducted and correlations between each thoracic level were evaluated. The statistical significance level was set at p RESULTS 60 patients (men, 51.7%) met inclusion criteria. The study population was 90% Caucasian with a mean age of 62.2 years and a mean BMI of 30.2 kg/m2. The inter- and intra-observer reliability of the thoracic QCT measurements was excellent (ICC of 0.97 and 0.97, respectively). The trabecular BMD was highest in the upper thoracic spine and decreased in the caudal direction (T1 = 182.3 mg/cm3, T2 = 168.1 mg/cm3, T3 = 163.5 mg/cm3, T4 = 164.7 mg/cm3, T5 = 161.4 mg/cm3, T6 = 152.5 mg/cm3, T7 = 143.5 mg/cm3, T8 = 141.3 mg/cm3, T9 = 143.5 mg/cm3, T10 = 145.1 mg/cm3, T11 = 145.3 mg/cm3, T12 = 133.6 mg/cm3). The BMD of all thoracic levels cranial to T6 was statistically higher than the BMD of all levels caudal to T6 (p CONCLUSIONS There is significant regional BMD variation in the thoracic spine depending on spinal level. This BMD variation might contribute to several clinically relevant phenomena. First, vertebral fractures occur most commonly at the thoracolumbar junction including T12. In addition to mechanical reasons, these fractures might be partially attributed to thoracic BMD that is lowest at T12. Second, the optimal upper instrumented vertebra (UIV) for stopping long fusions to the sacrum and pelvis is controversial. The BMD of surgically relevant upper thoracic stopping points (T2-T4) was significantly higher than the BMD of lower thoracic stopping points (T10-T12). Besides stress concentration at the relatively mobile lower thoracic segments, the low BMD at these levels might contribute to previously suggested higher rates of junctional failures with short fusions.

Lateral lumbar interbody fusion (LLIF) and pedicle subtraction osteotomy are common procedures to correct adult spinal deformities. Little is known about returning postoperatively to a high-performance sport such as skiing after spinal surgery. We report a case of an alpine skier who underwent a LLIF procedure combined with a posterior corrective osteotomy and posterior instrumentation, who had difficulties returning to skiing postoperatively because of new spinal biomechanics. The case report describes the possible consequences of spinal sagittal deformity surgery on postoperative skiing. A 63-year-old man with a complex lumbar spinal surgery history showed severe adjacent segment degenerative spondylolistheses at L1-L2 and at L5-S1. A lateral approach at L1-L2 combined with a posterior corrective osteotomy at L3 and instrumentation from T10 to the pelvis were performed. At his 1-year follow up, he made excellent progress and returned to skiing. However, he reported that skiing did not feel the same, and his center of gravity felt as if it shifted backwards. Consequently, he placed a 2-cm wedge in his ski binding, which improved his skiing experience. Sagittal vertical axis changes after spinal surgery affect the biomechanics of the entire body. After surgery, the body's ligaments, muscles, and fascia adapt to the new body posture. Activities such as skiing, where body posture plays an essential role, are particularly affected by spine surgeries. Surgeons should discuss this issue before spinal surgery with patients, especially if patients are involved in high-intensity sports.

Over the past several decades, there has been an upward trend in the total number of spinal fusion procedures worldwide. Advanced spinal fusion techniques with or without internal fixation, additional innovations in surgical approaches, innovative implants including a wide variety of interbody devices, and new alternatives in bone grafting materials are some reasons for the increasing number of spine fusion procedures. Moreover, the indications for spinal fusion have broadened over time. Initially developed for the treatment of instability and deformity due to tuberculosis, scoliosis, and traumatic injury, spinal fusion surgery has now a wide range of indications like spondylolisthesis, congenital or degenerative deformity, spinal tumors, and pseudarthrosis, with degenerative disorders as the most common indication. This review emphasizes current lumbar fusion techniques and their development in the past decades.

Anterior (ALIF) and lateral (LLIF) lumbar interbody fusion is associated with significant postoperative pain, opioid consumption and length of stay. Transversus abdominis plane (TAP) blocks improve these outcomes in other surgical subtypes but have not been applied to spine surgery. A retrospective study of 250 patients was performed to describe associations between TAP block and outcomes after ALIF/LLIF.The electronic medical records of 129 patients who underwent ALIF or LLIF with TAP block were compared to 121 patients who did not. All patients were cared for under a standardized perioperative care pathway with comprehensive multimodal analgesia. Differences in patent demographics, surgical factors, length of stay (LOS), opioid consumption, opioid-related side effects and pain scores were compared in bivariable and multivariable regression analyses.In bivariable analyses, TAP block was associated with a significantly shorter LOS, less postoperative nausea/vomiting and lower opioid consumption in the post-anesthesia care unit (PACU). In multivariable analyses, TAP block was associated with significantly shorter LOS (β - 12 h, 95% CI (- 22, - 2 h); p = 0.021). Preoperative opioid use was a strong predictive factor for higher opioid consumption in the PACU, opioid use in the first 24 h after surgery and longer LOS. We did not find significant differences in pain scores at any times between the groups.TAP block may represent an effective addition to pain management and opioid-reducing strategies and improve outcomes after ALIF/LLIF. Prospective trials are warranted to further explore these associations.

BACKGROUND CONTEXT Postoperative dysphagia and dysphonia (PDD) are prevalent complications after anterior cervical discectomy and fusion (ACDF). Identification of risk factors for these complications is necessary for effective prevention. Recently, patient reported outcome measures (PROM) have been used to determine PDD after ACDF. The Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) is a validated PROM that specifically assesses dysphagia and dysphonia after anterior cervical spine surgery. PURPOSE To identify the perioperative risk factors for PDD utilizing the HSS-DDI. STUDY DESIGN/SETTING Observational study of prospectively collected data at a single academic institution. PATIENT SAMPLE Patients undergoing anterior cervical discectomy and fusion from 2015 to 2019 who enrolled in the prospective data collection. OUTCOME MEASURE The HSS-DDI administered 4 weeks, 8 weeks, and 4-6 months after surgery. METHODS As potential risk factors, the data on demographic factors, analgesic medications, history of psychiatric illness, preoperative sagittal alignment, surgical factors, preoperative diagnoses, and preoperative Neck Disability Index (NDI) scores were collected. Bivariate and multivariable regression analyses utilizing the Tobit model were conducted. RESULTS 291 patients were included in the final analysis. The median HSS-DDI at 4-weeks, 8 weeks, and 4-6 months postoperatively, were 80.7, 92.7, and 98.4, respectively. Multivariable analysis demonstrated that current smoking, previous cervical spine surgery, preoperative C2-7 angle, upper level surgery, multilevel surgery, opioid use, and a high preoperative NDI score, were independent contributing factors to a low HSS-DDI score at 4-weeks follow-up. Intraoperative topical steroid use was an independent protective factor for a low HSS-DDI score. Opioid use and high NDI score remained independent factors at 4-6 months. Sub-domain analysis demonstrated that prior cervical surgery, preoperative C2-7 angle, multilevel surgery, and intraoperative topical steroid use were significant for dysphagia only. Current smoking was significant for dysphonia only. CONCLUSIONS Our results showed that preoperative opioid use and a high preoperative NDI score are novel independent risk factors for postoperative dysphagia and dysphonia in addition to other known factors.