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: 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.

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.

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.

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.

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.

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.

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

STUDY DESIGN/SETTING: 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, 90-day and 2-year reoperation rates. RESULTS: 353 met the inclusion and exclusion criteria. The FRS/VBQ demonstrated improved predictive ability compared to 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. CONCLUSION: 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.

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.

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.

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.

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.

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.

Anatomic Assessment of L1-S1 Neuroforaminal Dimensions Using Computed Tomography in 1,000 Patients: A Follow-Up Study.

OBJECTIVES: While the radiographic criteria for diagnosing central lumbar stenosis are well described, criteria for diagnosing neuroforaminal stenosis (NFS) are unclear. Prior research has utilized magnetic resonance imaging (MRI) to characterize neuroforaminal dimensions (NFDs). However, this approach has inherent limitations that can adversely impact measurement accuracy. Existing literature on the use of computed tomography (CT) to investigate normal NFDs is limited. The purpose of the present study was to describe normal lumbar NFDs that would aid in the establishment of objective quantitative criteria for the diagnosis of NFS. METHODS: This study evaluated CT imaging of 494 female and 506 male subjects between 18 and 35 years of age to determine normal NFDs, specifically the sagittal anteroposterior width, craniocaudal height, and area. Statistical analyses were performed to assess differences in NFDs according to variables including sex, height, weight, body mass index, and ethnicity. RESULTS: Without differentiating between sides or disc levels, mean NFDs were 8.71 mm for sagittal anteroposterior width, 17.73 mm for craniocaudal height, and 133.26 mm2 for area (n = 10,000 measurements each). Male subjects had larger NFDs than females at multiple levels. Asian and Caucasian subjects had larger NFDs than Hispanic and African American subjects at multiple levels. There were no associations between NFDs and anthropometric factors. CONCLUSIONS: The present study describes normal lumbar NFDs in young, healthy patients. NFDs were influenced by sex and ethnicity but not by anthropometric factors.

Applications of Interpedicular Distance and Anteroposterior Diameter in the Approximation of the Spinal Canal Area.

INTRODUCTION:  Advancements within the field of medicine revolve around increasing the efficiency of diagnosing and subsequently treating patients. One such advancement is measurements of the central canal using artificial intelligence (AI). The authors propose the possibility of AI measuring two linear distances followed by a subsequent approximation via an area equation. The lumbar spinal canal was approximated by an area calculation using the interpedicular distance (IPD) and anteroposterior diameter (AP diameter). The three shapes evaluated were an ellipse, triangle, and rectangle. METHODS:  IPD, AP diameter, and spinal canal area from L1-L5 were measured in 555 patients using the IMPAX6 (Mortsel, Belgium: Agfa-Gevaert) picture archiving and communication system. Subsequently, an approximated area of the lumbar spinal canal, assuming an ellipse shape, was calculated using ellipse equation/approximation. Triangular and rectangular approximations were done using triangle equation/approximation and rectangle equation/approximation, respectively. The equations used are the geometric equations for the area of each shape described. For example, the triangular approximation used the IPD as the base of the triangle and the AP diameter as the height. Thus, the area approximation was calculated by half of the IPD times the AP diameter. RESULTS:  The percent error of the ellipse approximation was the lowest with a range of error from 8.44% at L1 to 15.51% at L5. The triangle approximation again was the second most accurate with a range of error starting at -26.46% at L5 to -30.96% at L1. Lastly, the percentage errors of the rectangle approximation began at 38.07% at L1 to 47.07% at L5. The ellipse and rectangle approximation consistently overestimated the area of the spinal canal, while the opposite was true for the triangle approximation. A combination of these approximations could be used to construct a second-order approximation. The approximations were all highly correlated with the authors' manual measurements. Approximations at the L2 vertebrae were highest with a correlation of 0.934 closely followed by all approximations at L5 with a value of 0.931. Approximations were least correlated with the L4 vertebrae with a value of 0.905. CONCLUSION: The correlation between the approximation equations and the measured values is significantly related. The ellipse equation best predicted the area of the spinal canal followed by the triangle and then the rectangle approximation. The percent error difference of the ellipse approximation at L1 was similar in error compared to other causes of measurement error. Continued investigation into a second-order approximation may yield a more accurate approximation.

The Reoperation, Readmission, and Complication Rates at 30 Days Following Lumbar Decompression for Cauda Equina Syndrome.

Background and objective Cauda equina syndrome (CES) is considered a surgical emergency, and its primary treatment involves decompression of the nerve roots, typically in the form of discectomy or laminectomy. The primary aim of this study was to determine the complication, reoperation, and readmission rates within 30 days of surgical treatment of CES secondary to disc herniation by using the PearlDiver database (PearlDiver Technologies, Colorado Springs, CO). The secondary aim was to assess preoperative risk factors for a higher likelihood of complication occurrence within 30 days of surgery for CES. Methods A total of 524 patients who had undergone lumbar discectomy or laminectomy for CES were identified. The outcome measures were 30-day reoperation rate for revision decompression or lumbar fusion, and 30-day readmissions related to surgery. The patient data collected included medical history and surgical data including the number of levels of discectomy and laminectomy. Results Based on our findings, intraoperative dural tears, valvular heart disease, and fluid and electrolyte abnormalities were significant risk factors for readmission to the hospital within 30 days following surgery for CES. The most common postoperative complications were as follows: visits to the emergency department (63 patients, 12%), surgical site infection (21 patients, 4%), urinary tract infection (14 patients, 3%), and postoperative anemia (11 patients, 2%). Conclusions In the 30-day period following lumbar decompression for cauda equina syndrome, our findings demonstrated an 8% reoperation rate and 17% readmission rate. Although CES is considered an indication for urgent surgery, gaining awareness about reoperation, readmission, and complication rates in the immediate postoperative period may help calibrate expectations and inform medical decision-making.

Double-Plate Technique for Long-Construct Anterior Cervical Discectomy and Fusion.

The standard technique for multilevel anterior cervical discectomy and fusion (ACDF) uses a single plate to span multiple vertebral levels. However, the usage of single long plates is linked to potential hardware failure and screw pullout from stress overload. A single long plate is also more likely to fail at the caudal levels. Furthermore, centering a long plate spanning multiple levels requires simultaneous exposure to anatomy that may require more traction, technical expertise, and a potential increase in operative time. The use of a double-plate technique may be less technically demanding and, at the same time, allow for future revision to be confined to a shorter segment rather than requiring the removal of the entire single plate. In this study, we describe a surgical technique that involves using two plates during three or more levels of ACDF, discussing its advantages and limitations.

Surface anatomical landmarks for spine surgery: A CT-based study of the sternal notch and sternal angle in 1,035 patients.

BACKGROUND: Understanding the location of surface anatomical landmarks in relation to the cervical and thoracic spine is important for a wide array of clinical applications. The objective of this study was to investigate the influence of patient demographic and anthropometric characteristics on the locations of the sternal notch and sternal angle in relation to the spine using computed tomography (CT) of a large cohort of young adult patients without spinal pathology. METHODS: Vertebral levels corresponding to the sternal notch and sternal angle were analyzed using CT of 1,035 patients. Influences of patient height, weight, body mass index (BMI), sex, and ethnicity were assessed. RESULTS: 567 male and 468 female patients were included in this study. Mean patient height, weight, BMI, and age were 1.68 ± 0.11 m, 81.94 ± 24.39 kg, 27.79 ± 7.9 kg/m2, and 25.9 ± 5.9 years. Of the 1,035 patients, 495 were Hispanic or Latino, 321 were Caucasian, 130 were African American, 68 were Asian, 5 were identified as "other," and 16 did not have racial or ethnic data available. The location of the sternal notch in relation to the thoracic spine demonstrated a bimodal distribution pattern clustered at the T2 and T3 vertebral bodies. The location of the sternal angle in relation to the thoracic spine demonstrated a bimodal distribution pattern clustered at the T4 and T5 vertebral bodies. Moderate, negative correlations were observed between patient weight and location of the sternal notch (r = -0.447; p <.001) and sternal angle (r = -0.499; p <.001), respectively. Zero significant correlations were observed between patient height and location of the sternal notch (r = -0.045; p =.377) or sternal angle (r = -0.080; p =.229). A weak, negative correlation was observed between patient BMI and location of the sternal notch (r = -0.378; p <.001). A moderate, negative correlation was observed between patient BMI and location of the sternal angle (r = -0.445; p <.001). The locations of the sternal landmarks did not differ based on patient sex, race or ethnicity. CONCLUSIONS: The location of the sternal notch most frequently corresponds to the T2 or T3 vertebral body, while the sternal angle is most frequently located at the T4 or T5 vertebral body. Increased patient weight is associated with relatively cephalad sternal landmarks. Patient height, sex, and ethnicity are not associated with either sternal landmark.

Comparison of Nonneurological Structures at Risk During Anterior-to-Psoas Versus Transpsoas Surgical Approaches Using Abdominal CT Imaging From L1 to S1.

BACKGROUND: The kidneys, ribs, liver, spleen, and iliac crests can pose access-related issues to the disc space during both anterior-to-psoas (ATP) and transpsoas (TP) surgical approaches. The aim of this study was to identify and compare the presence and degree of obstruction caused by these structures for the ATP and TP approaches bilaterally from L1 to S1 using abdominal computed tomography. METHODS: Presence of obstruction by a given structure was recorded if the structure was within ATP or TP borders. Degree of obstruction was calculated as the quotient of the structure measurement within the ATP or TP approach divided by the entire corridor length at the point of obstruction. RESULTS: The percentage of time the left kidney was present during the ATP vs TP approaches at L1 to L2 was 44% vs 89% (P < 0.001), at L2 to L3 was 26% vs 75% (P < 0.001), and at L3 to L4 was 5% vs 19% (P < 0.001). For the right kidney, these values were 37% vs 78% (P < 0.001), 43% vs 71% (P < 0.001), and 11% vs 18% (P < 0.001). The percentage of time the left rib was present during ATP vs TP approaches was 41% vs 81% (P < 0.001) at L1 to L2 and 11% vs 26% (P = 0.413) at L2 to L3. With respect to the liver, the ATP approach was obstructed 56%, 30%, and 9% of the time at the levels of L1 to L2, L2 to L3, and L3 to L4; the liver was not present in L1 to L4 TP approach. CONCLUSIONS: This study is the first to both characterize and compare nonneurological structures at risk during ATP and TP fusion approaches bilaterally from L1 to S1 using abdominal computed tomography. Findings suggest the ATP approach poses less structures at risk relative to the TP approach with respect to the kidneys, ribs, and iliac crests bilaterally. The TP approach offers advantages compared with ATP approach with respect to the liver and spleen. CLINICAL RELEVANCE: Findings from this study are clinically relevant for ATP and TP surgical approach planning.

Anatomic Assessment of L1-S1 Neuroforaminal Dimensions Using Computed Tomography.

BACKGROUND: Although the radiographic parameters for diagnosing central lumbar canal stenosis are well described, parameters for the diagnosis of neuroforaminal stenosis (NFS) are less well defined. Previous studies have used magnetic resonance imaging (MRI) and radiography to describe neuroforaminal dimensions (NFDs). Those methods, however, have limitations that may substantially distort measurements. Existing literature on the use of computed tomography (CT) to investigate normal NFDs is limited. METHODS: This anatomic assessment evaluated CT imaging of 300 female and 300 male subjects between 18 and 35 years of age to determine normal NFDs, specifically the sagittal anteroposterior width, axial anteroposterior width, craniocaudal height, and area. Statistical analyses were performed to assess differences in NFDs according to variables including sex, age, height, weight, body mass index, and ethnicity. RESULTS: Overall, mean NFDs were 9.08 mm for sagittal anteroposterior width, 8.93 mm for axial anteroposterior width, 17.46 mm for craniocaudal height, and 134.78 mm 2 for area (n = 6,000 measurements each). Male subjects had larger NFDs than females at multiple levels. Both Caucasian and Asian subjects had larger NFDs than African-American subjects at multiple levels. There were no associations between foraminal dimensions and anthropometric factors. CONCLUSIONS: This study describes CT-based L1-S1 NFDs in young, healthy patients who presented with reasons other than back pain or pathology affecting the neuroforamen. Dimensions were influenced by sex and ethnicity but were not influenced by anthropometric factors. LEVEL OF EVIDENCE: Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

An Analysis of Medical Malpractice Litigation due to Intravenous Steroid Treatment for Acute Spinal Cord Injury.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To evaluate the incidence of litigation due to using or foregoing methylprednisolone (MP), naloxone, or tirilazad for treatment of acute spinal cord injury (ASCI) through querying the Westlaw and VerdictSearch databases. SUMMARY OF BACKGROUND DATA: There is historic controversy regarding the use of intravenous steroids for treatment of ASCI. Many highlight that MP continues to be used for ASCI treatment mainly as a defensive medicine tactic due to the fear of malpractice litigation. METHODS: Westlaw and VerdictSearch were queried for cases involving steroid treatment for ASCI between the years 1998 and 2021. Collected data for each case included year of case hearing, verdict ruling, location of filed claim, and the plaintiff's basis of litigation. Cases were reviewed and categorized by two independent reviewers based on the grievance(s) levied by the plaintiff. Inclusion criteria for topic relevance was defined as a plaintiff's basis of litigation resting on a claim of medical malpractice due to the use, or lack thereof, of MP, naloxone, or tirilazad for treatment of ASCI. RESULTS: Upon review of 238 cases, case claims were grouped into five categories based on reason for litigation: Social Security benefits (171), lawsuit due to vaccination (25), medical malpractice unrelated to steroid use (16), fungal infections due to MP injections (4), and other (22). Zero cases were found to be related to lawsuits filed due to steroid use or lack thereof for ASCI treatment. CONCLUSION: Our findings suggest there is limited risk of malpractice litigation due to steroid use or lack thereof in the treatment of ASCI. As such, steroid-related treatment decisions for ASCI should be informed by evidence-based approaches to care not influenced by medicolegal concerns.