Oblique lateral interbody fusion at L5-S1: feasibility, surgical approach window, incision line, and influencing factors.

PURPOSE: The primary aim of this study was to describe the feasibility, surgical approach window (SAW), and incision line (IL) for oblique lateral interbody fusion at L5-S1 (OLIF51) using computed tomography (CT). A secondary aim was to identify associations among approach characteristics and demographic and anthropometric factors. METHODS: We performed a radiographic study of 50 male and 50 female subjects who received abdominal CT imaging. SAW was measured as the distance from the midline to the medial border of the iliac vessel. IL was measured at the skin surface corresponding to the distance between the center of the disc space and SAW lateral margin. OLIF51 feasibility was defined as the existence of at least a 1-cm SAW without retraction of soft tissues. RESULTS: For the left side, the OLIF51 SAW and IL were 12.1 ± 4.6 and 175.1 ± 55.3 mm. For the right side, these measures were 10.0 ± 4.3 and 185.0 ± 52.5 mm. Correlations of r = 0.648 (p < 0.001) and r = 0.656 (p < 0.001) were observed between weight and IL on the left and right sides, respectively. OLIF51 was not feasible 23% of the time. CONCLUSION: To our knowledge, this is the largest CT study to determine the feasibility of performing an OLIF51. Without the use of retraction, OLIF51 is not feasible 23% of the time. Left-sided OLIF51 allows for a larger surgical approach window and smaller incision compared to the right side. Larger incisions are required for adequate surgical exposure in patients with higher weight.

Comparison of L1-S1 neuroforaminal dimensions derived from plain film radiography versus computed tomography.

PURPOSE: To compare measurements of lumbar neuroforaminal dimensions (NFD) derived from plain film radiography (PFR) and computed tomography (CT) of young patients without spinal pathology. METHODS: We analyzed 213 patients between 18 and 35 years of age without spinal pathology who received PFR and CT within one year of each other. NFD were defined as foraminal height, sagittal anterior-to-posterior width, and area. Statistical analyses assessed correlations and differences between PFR- and CT-derived NFD measurements. RESULTS: 111 subjects were female and 102 were male. Significant differences between PFR- and CT-derived NFD measurements were observed for all levels L1-S1, with those for foraminal height listed as follows: 4.10 mm at L1-L2, 1.58 mm at L2-L3, 3.23 mm at L3-L4, 4.27 mm at L4-L5, and 1.75 mm at L5-S1. Regarding foraminal area, these differences were 72.20, 73.45, 61.80, 35.38, and 16.18 mm2, respectively. PFR-derived measurements of NFD were larger compared to those derived from CT across all levels (p < .001). Only weak (0 ≤ r ≤ .4) or moderate (.4 ≤ r ≤ .7) correlations were observed between PFR- and CT-derived NFD measurements for all levels from L1-S1. CONCLUSION: This study describes 9585 measurements from L1-S1 of neuroforaminal measurements derived from CT and plain film radiography from a sample of young patients without spinal pathology. Among these patients, plain film measurements of the neuroforamina are larger compared to those derived from CT for all levels from L1-S1. There is poor correlation and reliability between plain film and CT measurements of neuroforaminal dimensions.

Comparison of cervical, thoracic, and lumbar vertebral bone quality scores for increased utility of bone mineral density screening.

PURPOSE: To evaluate the associations among the validated lumbar vertebral bone quality (VBQ) score, and cervical and thoracic VBQ scores. METHODS: Radiographic records of 100 patients who underwent synchronous MRI of the cervical, thoracic, and lumbar spine were retrieved. DEXA-validated lumbar VBQ was calculated using median signal intensity (MSI) of the L1-L4 vertebrae and L3 CSF. VBQ was derived as the quotient of MSIL1-L4 divided by MSICSF. Cervical and thoracic VBQ were similarly obtained using C3-C6 and C5 CSF, and T5-T8 and T7 CSF, respectively. Paired sample t-tests were used to evaluate differences among regional VBQ scores. Independent sample t-tests were used to identify sex differences in VBQ. Regression models with one-way analysis of variance (ANOVA) were constructed to identify associations among all permutations of anthropometric and regional VBQ measures. RESULTS: Mean cervical, thoracic, and lumbar VBQ scores were 3.06 ± 0.89, 2.60 ± 0.77, and 2.47 ± 0.61, respectively. Mean differences of .127 (p = 0.045) and - 0.595 (p < 0.001) were observed between thoracic and lumbar, and cervical and lumbar VBQ scores. Correlations of 0.324, 0.356, and 0.600 (p < 0.001) were found between cervical and lumbar, cervical and thoracic, and thoracic and lumbar VBQ scores. Regression with ANOVA predicting lumbar VBQ in relation to cervical and thoracic VBQ demonstrated R Square values of 0.105 and 0.360 (p < 0.001), and ß coefficient values of 0.471 and 0.217 (p < 0.001), respectively. CONCLUSION: Thoracic VBQ provides values representative of the validated lumbar VBQ score. Cervical VBQ scores are distinct from lumbar VBQ scores and do not provide adequate surrogate values of lumbar VBQ.

CT-based analysis of oblique lateral interbody fusion from L1 to L5: location of incision, feasibility of safe corridor approach, and influencing factors.

PURPOSE: The primary aim was to measure the safe corridor (SC), surgical incision anterior margin (AM), and posterior margin (PM) for OLIF bilaterally from L1 to L5. The secondary aim was to determine the feasibility of approach via the SC. The tertiary aim was to analyze the influence of demographic and anthropometric factors on OLIF parameters. METHODS: We performed a radiographic analysis of 100 subjects who received an abdominal CT. Measurements of the AM, PM, and SC were obtained as well as patient age, sex, height, weight, and BMI. The intraclass correlation coefficient was used to evaluate interrater reliability. To assess associations among variables, Pearson's correlation tests and multivariate linear regression models were constructed. Sex differences were analyzed using Student's t tests. RESULTS: At L1-2, L2-3, L3-4, and L4-5, the PM was 6.6, 8.2, 9.4, and 10.2 cm on the left side and 7.2, 7.7, 8.8, and 9.5 cm on the right side in relation to the disk space center. The SC was less than 1 cm 1%, 3%,3%, and 18% of the time on the left side, and 15%, 12%,29%, and 60% on the right side. None of the anthropometric factors demonstrated a strong correlation with incision location. SC was larger on the left side. Interrater ICC was .934. CONCLUSIONS: This study is the first to provide guidelines on the appropriate location of the incision line during OLIF based on SC from L1 to L5. SC measurements do not vary by sex. OLIF is more feasible via a left-sided approach.

Intra- and inter-observer reliability of the novel vertebral bone quality score.

PURPOSE: To assess the intra- and inter-observer reliability of the novel vertebral bone quality (VBQ) scoring system. METHODS: Four orthopedic surgery residents at various levels of training (PGY1-4) evaluated 100 noncontrast, T1-weighted MRIs of the lumbar spine. VBQ was calculated as quotient of the median of L1-L4 average signal intensity (SI) and the L3 cerebral spinal fluid (CSF) SI, as described by Ehresman et al. All measurements were repeated 2 weeks later. We performed a stratified analysis based on patient history of instrumentation, pathology, and MRI manufacturer/magnet strength to determine their effect on VBQ reliability. Spinal pathologies included compression fracture, burst fracture, vertebral osteomyelitis, epidural abscess, or neoplasm. The interclass correlation coefficient (ICC) two-way mixed model on absolute agreement was used to analyze inter-rater and intra-rater reliability. ICC less than 0.40 was considered poor, 0.40-0.59 as fair, 0.60-0.74 as good, and greater than 0.75 as excellent. RESULTS: Intra-observer reliability was excellent (≥ 0.75) for all four observers. When stratified by history of spinal instrumentation or spinal pathology, all raters showed excellent intra-observer reliability except one (0.71 and 0.69, respectively). When stratified by MRI manufacturer, intra-observer reliability was ≥ 0.75 for all raters. Inter-observer reliability was excellent (0.91) and remained excellent (≥ 0.75) when stratified by history of spinal instrumentation, spinal pathology, or MRI-manufacturer. CONCLUSIONS: VBQ scores from spine lumbar MRIs demonstrate excellent intra-observer and inter-observer reliability. These scores are reliably reproduced in patients regardless of previous instrumentation, spinal pathology, or MRI manufacturer/magnetic field strength.

The Impact of Diversity, Equity, and Inclusion on Spinal Research - Asking Different Questions.

In recent years, the field of spine surgery has seen significant advancements in surgical techniques alongside a growing emphasis on diversity, equity, and inclusion (DEI). This review explores the significant impact of DEI on spine surgery, recognizing its potential to drive innovation, improve patient outcomes, and address healthcare disparities. Shifting paradigms in research through diverse perspectives is crucial, as they broaden the scope of inquiry and challenge existing standards. Efforts to promote diversity in medicine, including targeted outreach and mentorship initiatives, are essential in cultivating a more inclusive workforce. Despite progress, ongoing challenges such as unconscious biases and systemic barriers persist, underscoring the need for continued commitment to DEI principles. Embracing diverse perspectives and asking unconventional questions pave the way for a comprehensive understanding of spinal health and equitable healthcare delivery.

Migration of Bullet Fragment 11 Years after Initial Gunshot Wound leads to Cervical Prevertebral Abscess: A Case Report.

Introduction: Literature showcases conflicting findings regarding the outcomes of ballistic fragment removal from the spine in gunshot wounds (GSW) patients. Further research in this area is needed to better comprehend the nuances of risks and benefits surrounding ballistic fragment removal from the spine in GSW patients. In this case report, we discuss the late-onset cervical prevertebral abscess which developed when a previously embedded bullet fragment migrated into the retropharyngeal space 11 years after an initial GSW. Case Report: A 29-year-old male sustained a gunshot wound to the face in 2011. He was stabilized with a posterior C3-C6 lateral mass instrumentation and fusion. There were no attempts to remove the bullet fragments. In 2023, the patient returned with worsening neck pain. Imaging demonstrated a retropharyngeal abscess with interval rotation of the ballistic fragment by 90°. An abscess was noted anterior to the cervical vertebrae with a freely mobile ballistic fragment within. Conclusion: This case highlights several questions: What is the criteria for radiographic surveillance of retained hardware? If there is documented movement, should this trigger further investigation? What complications can occur that warrant careful removal?

Prediction of In-Hospital Mortality Following Vertebral Fracture Fixation in Patients With Ankylosing Spondylitis or Diffuse Idiopathic Skeletal Hyperostosis: Machine Learning Analysis.

BACKGROUND: Ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) are distinct pathological entities that similarly increase the risk of vertebral fractures. Such fractures can be clinically devastating and frequently portend significant neurological injury, thus making their prevention a critical focus. Of particular significance, spinal fractures in patients with AS or DISH carry a considerable risk of mortality, with reports on 1-year injury-related deaths ranging from 24% to 33%. As such, the purpose of this study was to conduct machine learning (ML) analysis to predict postoperative mortality in patients with AS or DISH using the Nationwide Inpatient Sample Healthcare Cost and Utilization Project (HCUP-NIS) database. METHODS: HCUP-NIS was queried to identify adult patients carrying a diagnosis of AS or DISH who were admitted for spinal fractures and underwent subsequent fusion or corpectomy between 2016 and 2018. Predictions of in-hospital mortality in this cohort were then generated by three independent ML algorithms. RESULTS: An in-hospital mortality rate of 5.40% was observed in our selected population, including a rate of 6.35% in patients with AS, 2.81% in patients with DISH, and 8.33% in patients with both diagnoses. Increasing age, hypertension with end-organ complications, spinal cord injury, and cervical spinal fractures each carried considerable predictive importance across the algorithms utilized in our analysis. Predictions were generated with an average area under the curve of 0.758. CONCLUSIONS: This study's application of ML algorithms to predict in-hospital mortality among patients with AS or DISH identified a number of clinical risk factors relevant to this outcome. CLINICAL RELEVANCE: These findings may serve to provide physicians with an awareness of risk factors for in-hospital mortality and, subsequently, guide management and shared decision-making among patients with AS or DISH.

Analysis of reasons for medical malpractice litigation due to anterior cervical discectomy and fusion.

Background: Anterior cervical discectomy and fusions (ACDF) are among the most common cervical spine operations, with over 137,000 surgeries performed annually. Understanding reasons underlying malpractice pertaining to ACDF may inform physicians of practices to improve delivery of patient care and mitigate malpractice. The aim of our study was to analyze the causes and outcomes for lawsuits pertaining to ACDF. Methods: The Westlaw Edge and Verdict Search databases were queried for malpractice claims utilizing the keywords "anterior cervical discectomy and fusion" and "ACDF". Inclusion criteria was based on relevance of case grievance(s) to ACDF. Data collected included date of case hearing, plaintiff demographics, defendant specialty, verdict ruling, location of filed claim, monetary award, and sustained injuries. Results: Fifty cases were included in this study after excluding 1933 cases. Of the 50 cases, 34 (68%) resulted in a defendant outcome, 8 (16%) resulted in a plaintiff outcome, and 8 (16%) resulted in settlement. Plaintiff verdicts resulted in an average monetary payment of $9.70 million, while settlements resulted in an average payment of $2.06 million. Reasons for litigation were divided into 10 categories, most commonly improper postoperative management (20%), hardware failure (18%), intraoperative error (14%), off-label use of implants (14%), and insufficient informed consent (12%). Conclusions: Malpractice claims due to ACDF are associated with higher frequencies of plaintiff verdicts and higher monetary costs compared to other spinal surgery procedures. There does not appear to be supporting evidence that spinal cord neuromonitoring is mandatory for ACDF procedures from a medicolegal standpoint.

Decompression Alone vs Decompression and Fusion: Spin in Abstracts of Systematic Reviews and Meta-Analysis.

STUDY DESIGN: Cross-sectional. OBJECTIVES: Spin, a prevalent bias, can distort outcomes in well-validated research. Treatment of lumbar stenosis with spondylolisthesis through decompression alone (DA) vs decompression and fusion (DF) remains a controversial topic. We aimed to identify the prevalence of spin in meta-analyses and systematic reviews regarding DA vs DF in the treatment of spinal stenosis with concomitant degenerative spondylolisthesis. METHODS: MEDLINE, Web of Science, and Google Scholar were searched for meta-analyses and systematic reviews comparing DA vs DF treatment of lumbar spinal stenosis accompanied by degenerative spondylolisthesis. Each study was evaluated for the nine most severe spin types. We also explored the association between spin and methodological quality of a systematic review using the revised A Measurement Tool to Assess Systematic Reviews appraisal tool. RESULTS: The search yielded 1506 articles, of which 13 met inclusion. It was found that 46.2% (6/13) of the articles contained spin within the abstract. Of the nine most severe types, type 5 was found to be the most prevalent (4/13, 30.8%), followed by types 9 (2/13, 15.4%), 3 (1/13, 7.7%), 4 (1/13, 7.7%), and 6 (1/13, 7.7%). Spin types 1, 2, 7 and 8 were not found. According to AMSTAR-2, 53.8% (7/13) of the studies were appraised as "critically low" quality and 46.2% (6/13) as "low" quality. CONCLUSION: This study demonstrated the presence of spin in 46.2% of abstracts pertaining to the treatment for spinal stenosis with degenerative spondylolisthesis. Spine surgeons should learn to recognize spin as they review articles before implementing them into practice.

Application of machine learning algorithms to predict 30-day hospital readmission following cement augmentation for osteoporotic vertebral compression fractures.

Objective: Osteoporosis is a common skeletal disease that greatly increases the risk of pathologic fractures and accounts for approximately 700,000 vertebral compression fractures (VCFs) annually in the United States. Cement augmentation procedures such as balloon kyphoplasty (KP) and percutaneous vertebroplasty (VP) have demonstrated efficacy in the treatment of VCFs, however, some studies report rates of readmission as high as 10.8% following such procedures. The purpose of this study was to employ Machine Learning (ML) algorithms to predict 30-day hospital readmission following cement augmentation procedures for the treatment of VCFs using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Methods: ACS-NSQIP was queried to identify patients undergoing either KP or VP from 2011 to 2014. Three ML algorithms were constructed and tasked with predicting post-operative readmissions within this cohort of patients. Results: Postoperative pneumonia, ASA Class 2 designation, age, partially-dependent functional status, and a history of smoking were independently identified as highly predictive of readmission by all ML algorithms. Among these variables postoperative pneumonia (p < 0.01), ASA Class 2 designation (p < 0.01), age (p = 0.002), and partially-dependent functional status (p < 0.01) were found to be statistically significant. Predictions were generated with an average AUC value of 0.757 and an average accuracy of 80.5%. Conclusions: Postoperative pneumonia, ASA Class 2 designation, partially-dependent functional status, and age are perioperative variables associated with 30-day readmission following cement augmentation procedures. The use of ML allows for quantification of the relative contributions of these variables toward producing readmission.

Normative Measurements of L1 to S1 Neuroforaminal Dimensions Derived From Plain Film Radiography, Computed Tomography, and Magnetic Resonance Imaging.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To report normative measurements of L1 to S1 lumbar neuroforamina on plain film radiography (PFR), computed tomography (CT), and magnetic resonance imaging (MRI), accounting for patients' sex and ethnicity. BACKGROUND: The quantitative criteria fothe diagnosis of neuroforaminal stenosis remains unknown. Acquiring a thorough understanding of normative foraminal dimensions is a key step in formulating objective parameters for neuroforaminal stenosis. PATIENTS AND METHODS: We measured 988 images from 494 patients between 18 and 35 years old without spinal pathology who received PFR, CT, or MRI within 1 year of each other. Neuroforaminal measurements were defined as the height, area, and sagittal and axial widths. Statistical analyses were performed to assess relationships among PFR, CT, and MRI-derived neuroforaminal measurements, as well as the influence of patients' sex and ethnicity. RESULTS: 330 PFR, 377 CT, and 281 MRI were measured. Of these, 213 PFR and CT, 117 PFR and MRI, and 164 MRI and CT intrapatient images were compared. Statistically significant differences were observed among PFR, CT, and MRI measurements across all levels L1 to S1. PFR measurements were larger compared with those derived from CT and MRI. Weak-to-moderate correlations were observed between PFR and CT, PFR and MRI, and CT and MRI, with the magnitude of correlation decreasing caudally from L1 to S1. Variations in neuroforaminal anatomy were observed based on sex and ethnicity. CONCLUSION: This study reports 25,951 measurements of normal L1 to S1 neuroforaminal anatomy assessed by PFR, CT, and MRI. The values reported in this study may be used as normative reference measurements of the lumbar neuroforamina. PFR measurements of the neuroforamina are larger compared with those derived from CT and MRI across all levels from L1 to S1. There is a poor correlation between PFR, CT, and MRI when measuring the lumbar neuroforamina. Differences in neuroforaminal anatomy are evident based on patients' sex and ethnicity.

Adding Vertebral Bone Quality to the Fusion Risk Score: Does It Improve Predictions of Postoperative Complications?

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: The current study evaluates whether the addition of the Vertebral Bone Quality (VBQ) score to the Fusion Risk Score (FRS) improves its ability to predict perioperative outcomes. SUMMARY OF BACKGROUND DATA: The FRS was developed to assess preoperative risk in patients undergoing thoracic and lumbar fusions. It includes patient-derived and surgical variables, but it does not include one that directly accounts for bone health. The VBQ score allows assessment of bone quality and has been shown to correlate to DEXA-measured bone mineral density (BMD) scores. METHODS: The VBQ score was weighted based on a regression model and then added to the FRS (FRS/VBQ). The ability of the two scores to predict the outcomes was then assessed using the area under the curve (AUC). PATIENT SAMPLE: Patients undergoing elective thoracic and lumbar spinal fusion from January 2019 to June 2020 were included. OUTCOME MEASURES: The study evaluated various perioperative adverse outcomes, including major and minor adverse events, discharge other than home, extended length of stay, 90-day emergency department visits, 90-day readmission, and 90-day and 2-year reoperation rates. RESULTS: A total of 353 met the inclusion and exclusion criteria. The FRS/VBQ demonstrated improved predictive ability compared with the FRS alone when evaluating 90-day reoperation. Both scores showed fair predictive ability for any adverse event, major adverse events, minor adverse events, and 2-year reoperation rates, with AUCs ranging from 0.700 to 0.737. Both had poor predictive ability for the other outcomes. CONCLUSIONS: Adding VBQ to the FRS significantly enhances its predictive accuracy for reoperation rate. This updated risk score provides a more comprehensive understanding of a patient's preoperative risk profile, aiding both patients and physicians in assessing surgical risks and optimizing outcomes through preoperative risk stratification. LEVEL OF EVIDENCE: 3.

Morphometric analysis of cervical disc space height and interpedicular distance using computed tomography.

Background: This study utilized computed tomography (CT) to establish normative radiographic morphometric measurements of cervical disc space height (DSH) and interpedicular distance (IPD) and document the influence of patient sex, race, ethnicity, and anthropometric characteristics. Methods: Cervical CTs of 1000 patients between 18 and 35 years of age without known spinal pathology were reviewed. Statistical analyses included the assessment of associations between patient height, weight, sex, race, and ethnicity regarding DSH and IPD. Results: Irrespective of disc level, average DSH measurements were as follows: anterior height of 2.6 ± 1.0 mm, middle height of 4.1 ± 1.2 mm, and posterior height of 1.8 ± 1.0 mm. IPD was only measured between C3 and C7 vertebrae, and irrespective of disc level, the mean IPD measurement was 21.1 ± 1.5 mm. Significant differences for anterior, middle, posterior DSH, and IPD were observed in all disc levels. Significant differences in DSH and IPD were observed for all anthropometric factors of sex, race, and ethnicity relative to vertebral level. Males had significantly larger DSH and IPD measurements across all vertebral levels compared to females. Caucasians had larger DSH and IPD at select vertebral levels compared to African Americans and Hispanics. Conclusion: This study describes measurements of DSH and IPD between C2 and T1 levels in 1000 healthy 18-35-year-old subjects without known pathology. DSH and IPD measurements varied based on patient sex, race, ethnicity, and disc level.

Association Between Vertebral Bone Quality Score and Dual-Energy X-ray Absorptiometry for the Assessment of Bone Mineral Density in Adolescent Patients.

BACKGROUND: The MRI-based vertebral bone quality (VBQ) score is an assessment tool for bone mineral density (BMD) that has been validated in adults against the clinical standard of dual-energy X-ray absorptiometry (DEXA). However, VBQ has yet to be validated against DEXA for use in adolescents. This study evaluated the associations between adolescent VBQ scores, DEXA Z-scores, and BMD values. METHODS: The radiographic records of 63 consecutive patients between the ages of 11 and 21 who underwent MRI of the abdomen and pelvis and DEXA of the spine and hip were retrieved. The collected radiographic data consisted of the MRI-based VBQ score, DEXA Z-score, and BMD values of the femoral neck, L1-4 vertebrae, and total body. The VBQ score was calculated by taking the median signal intensity (MSI) from L1-L4 and the SI of the L3 cerebrospinal fluid (CSF). The VBQ score was derived as the quotient of MSIL1-L4 divided by SICSF. RESULTS: A mean VBQ score of 2.41 ± 0.29 was observed. Strong correlations of -0.749 (p<0.0001) and -0.780 (p<0.0001) were detected between the VBQ score and DEXA femoral neck and spine Z-scores, respectively. Correlations between VBQ score and DEXA femoral neck, spine, and total body BMD scores were -0.559 (p<0.0001), -0.611 (p<0.0001), and -0.516 (p<.0001), respectively. No significant correlations were found between the VBQ score and age, BMI, weight, or height. A mean difference in VBQ score of -0.155 (p=0.035) was observed between sexes. VBQ demonstrated moderate predictive ability for DEXA-derived Z-scores and BMD scores. CONCLUSIONS: VBQ scores were strongly correlated with DEXA Z-scores and moderately correlated with BMD values. The VBQ score can also be used by adolescent patients as an accessory tool to assess bone health.

Social determinants of health and disparities in spine surgery: a 10-year analysis of 8,565 cases using ensemble machine learning and multilayer perceptron.

BACKGROUND CONTEXT: The influence of SDOH on spine surgery is poorly understood. Historically, researchers commonly focused on the isolated influences of race, insurance status, or income on healthcare outcomes. However, analysis of SDOH is becoming increasingly more nuanced as viewing social factors in aggregate rather than individually may offer more precise estimates of the impact of SDOH on healthcare delivery. PURPOSE: The aim of this study was to evaluate the effects of patient social history on length of stay (LOS) and readmission within 90 days following spine surgery using ensemble machine learning and multilayer perceptron. STUDY DESIGN: Retrospective chart review. PATIENT SAMPLE: 8,565 elective and emergency spine surgery cases performed from 2013 to 2023 using our institution's database of longitudinally collected electronic medical record information. OUTCOMES MEASURES: Patient LOS, discharge disposition, and rate of 90-day readmission. METHODS: Ensemble machine learning and multilayer perceptron were employed to predict LOS and readmission within 90 days following spine surgery. All other subsequent statistical analysis was performed using SPSS version 28. To further assess correlations among variables, Pearson's correlation tests and multivariate linear regression models were constructed. Independent sample t-tests, paired sample t-tests, one-way analysis of variance (ANOVA) with post-hoc Bonferroni and Tukey corrections, and Pearson's chi-squared test were applied where appropriate for analysis of continuous and categorical variables. RESULTS: Black patients demonstrated a greater LOS compared to white patients, but race and ethnicity were not significantly associated with 90-day readmission rates. Insured patients had a shorter LOS and lower readmission rates compared to non-insured patients, as did privately insured patients compared to publicly insured patients. Patients discharged home had lower LOS and lower readmission rates, compared to patients discharged to other facilities. Marriage decreased both LOS and readmission rates, underweight patients showcased increased LOS and readmission rates, and religion was shown to impact LOS and readmission rates. When utilizing patient social history, lab values, and medical history, machine learning determined the top 5 most-important variables for prediction of LOS -along with their respective feature importances-to be insurance status (0.166), religion (0.100), ICU status (0.093), antibiotic use (0.061), and case status: elective or urgent (0.055). The top 5 most-important variables for prediction of 90-day readmission-along with their respective feature importances-were insurance status (0.177), religion (0.123), discharge location (0.096), emergency case status (0.064), and history of diabetes (0.041). CONCLUSIONS: This study highlights that SDOH is influential in determining patient length of stay, discharge disposition, and likelihood of readmission following spine surgery. Machine learning was utilized to accurately predict LOS and 90-day readmission with patient medical history, lab values, and social history, as well as social history alone.

Correlations among MRI-based cervical and thoracic vertebral bone quality score, CT-based Hounsfield Unit score, and DEXA t-score in assessment of bone mineral density.

BACKGROUND: Further optimization of the validated vertebral bone quality (VBQ) score using magnetic resonance imaging (MRI) may expand its clinical utility for bone mineral density (BMD) assessment. This study evaluated the correlations among cervical and thoracic VBQ scores, the validated Hounsfield Unit (HU) measured on computed tomography (CT), and dual-energy x-ray absorptiometry (DEXA) values. METHODS: We retrieved the medical and radiographic records of 165 patients who underwent synchronous MRI of the cervical and thoracic spine, as well as DEXA and CT imaging of the spine obtained within 1 year of each other between 2015 and 2022. Radiographic data consisted of the MRI-based cervical and thoracic VBQ scores, CT-based HU, and DEXA T-scores of the spine and hip. Patient age, sex, body mass index (BMI), and ethnicity were also obtained. RESULTS: Mean cervical and thoracic VBQ scores were 3.99 ± 1.68 and 3.82 ± 2.11, respectively. Mean HU and DEXA T-scores of the spine and hip were 135.75 ± 60.36, -1.01 ± 1.15, and -0.47 ± 2.27. All correlations among VBQ, HU, and DEXA were insignificant except for weak correlations between cervical and thoracic VBQ, and cervical VBQ and HU. No correlations were observed between radiographic scores and patient age or BMI. No differences based on ethnicity or sex were observed with respect to cervical or thoracic VBQ, HU, or DEXA. CONCLUSION: Cervical and thoracic VBQ scores are distinct from Hounsfield Unit and DEXA values. VBQ scoring in the cervical and thoracic spine is not influenced by patient age, ethnicity, sex, or BMI.

Correlations among Cervical, Thoracic, and lumbar Hounsfield Unit measurements for assessment of bone mineral density.

OBJECTIVE: Bone mineral density assessment using Hounsfield Unit (HU) currently depends upon the availability of computed tomography (CT) of the lumbar spine. The primary aim of this study was to evaluate the associations among HU measurements of the cervical (CHU), thoracic (THU), and lumbar (LHU) spine. The secondary aim of this study was to analyze the influence of patient demographic and anthropometric characteristics on HU measurements. METHODS: Radiographic records of 165 patients who underwent CT of the cervical, thoracic, and lumbar spine were retrieved. The CHU, THU, and LHU were calculated by obtaining the mean signal intensity from the medullary portions of C3-C7, T8-T12, and L1-L4 vertebral bodies. RESULTS: Mean CHU, THU, and LHU values were 266.26 ± 88.69, 165.57 ± 55.06, and 166.45 ± 51.38. Significant differences of 100.69, 99.81, and 0.88 were observed between CHU and THU (p <.001), CHU and LHU (p <.001), and THU and LHU (p =.023). Correlations of 0.574, 0.488, and 0.686 were observed between CHU and THU (p <.001), CHU and LHU (p <.001), and THU and LHU (p <.001). No differences in HU based on sex, age, height, weight, or ethnicity were observed. Multivariate regression models demonstrated R2 values of 0.770 - 0.790 (p <.001) in prediction of LHU. CONCLUSIONS: Hounsfield Unit measurements derived from the cervical and thoracic spine correlate with the validated lumbar Hounsfield Unit. Hounsfield Unit measurements do not vary based on sex, ethnicity, age, height, or weight.

Normative Measurements of L1-S1 Segmental Angulation, Disk Space Height, and Neuroforaminal Dimensions Using Computed Tomography.

BACKGROUND AND OBJECTIVES: To establish normative anatomic measurements of lumbar segmental angulation (SA) and disk space height (DSH) in relation to neuroforaminal dimensions (NFDs), and to uncover the influence of patient demographic and anthropometric characteristics on SA, DSH, and NFDs. METHODS: NFDs, SA, and anterior, middle, and posterior DSH were measured using computed tomography of 969 patients. NFDs were defined as sagittal anterior-to-posterior width, foraminal height, and area. Statistical analyses were performed to assess associations among SA, DSH, NFDs, and patient height, weight, body mass index, sex, and ethnicity. RESULTS: SA and DSH measurements increased moving caudally from L1 to S1. Foraminal width decreased moving caudally from L1 to S1. Foraminal height and area demonstrated unimodal distribution patterns with the largest values clustered at L2-L3 on the right side and L3-L4 on the left. Significant differences in SA, DSH, and NFD measurements were observed based on the disk level. Inconsistent, marginal NFD differences were observed based on laterality. Across all disk levels, only weak-to-moderate correlations were observed between SA and DSH in relation to NFDs. Patient height, weight, and body mass index were only weakly associated with SA, DSH, and NFDs. Based on patient sex, significant differences were observed for SA, DSH, and NFD measurements from L1 to S1, with males demonstrating consistently larger values compared with females. Based on patient race and ethnicity, significant differences in SA and NFD measurements were observed from L1 to S1. CONCLUSION: This study describes 48 450 normative measurements of L1-S1 SA, DSH, and NFDs. These measurements serve as representative models of normal anatomic dimensions necessary for several applications including surgical planning and diagnosis of foraminal stenosis. Normative values of SA and DSH are not moderately or strongly associated with NFDs. SA, DSH, and NFDs are influenced by sex and ethnicity, but are not strongly or moderately influenced by patient anthropometric factors.

Morphometric analysis of cervical neuroforaminal dimensions from C2-T1 using computed tomography of 1,000 patients.

BACKGROUND: Race and sex differences are not consistently reported in the literature. Fundamentally, anatomical differences of cervical neuroforaminal dimensions (CNFD) amongst these groups would be important to know. PURPOSE: To establish normative radiographic morphometric measurements of CNFD and uncover the influence of patient sex, race, and ethnicity while also considering anthropometric characteristics. STUDY DESIGN: Retrospective radiographic morphometric study. PATIENT SAMPLE: A total of 1,000 patients between 18 and 35 years of age who were free of spinal pathology. OUTCOME MEASURES: Foraminal height, axial width, and area of cervical neural foramen. METHODS: Cervical CTs were reviewed to measure CNFD, defined as follows: foraminal height, axial width, and area. Statistical analyses were performed to assess associations between CNFD, and patient height, weight, sex, race, and ethnicity. RESULTS: CNFD measurements followed a bimodal distribution pattern moving caudally from C2-T1. Irrespective of disc level, cervical CNFD were as follows: left and right widths of 6.6±1.5 and 6.6±1.5 mm, heights of 9.4±2.4 and 9.4±3.2 mm, and areas of 60.0±19.5 and 60.6±20.7 mm2. Left and right foraminal width were highest at C2-C3 and lowest at C3-C4. Left and right foraminal height were highest at C7-T1 and C6-C7, respectively and lowest at C3-C4. Left and right foraminal areas were highest at C2-C3 and lowest at C3-C4. Significant differences were observed for all CNFD measurements across disc levels. CNFD did not vary based on laterality. Significant CNFD differences were observed with respect to patient sex, race, and ethnicity. Male height and area were larger compared to females. In contrast, female foraminal width was larger compared to males. The Asian cohort demonstrated the largest foraminal widths. White and Hispanic patients demonstrated the largest foraminal heights and areas. Black patients demonstrated the smallest foraminal widths, heights, and areas. Patient height and weight were only weakly correlated with CNFD measurements across all levels from C2-T1. CONCLUSIONS: This study describes 36,000 normative measurements of 12,000 foramina from C2-T1. CNFD measurements vary based on disc level, but not laterality. Contrasting left- versus right-sided neuroforamina of the same level may aid in determining the presence of unilateral stenosis. Patient sex, race, and ethnicity are associated with CNFD, while patient anthropometric factors are weakly correlated with CNFD.