Mind the Gap: Interpedicular Widening as a Superior Predictor of Neurological Deficit Over Kyphosis in Thoracolumbar Burst Fractures

Mind the Gap: Interpedicular Widening as a Superior Predictor of Neurological Deficit Over Kyphosis in Thoracolumbar Burst Fractures | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Mind the Gap: Interpedicular Widening as a Superior Predictor of Neurological Deficit Over Kyphosis in Thoracolumbar Burst Fractures Anmol Anand, Nitish Jagdish Jyoti, Prashant Tank, Aditya Chaubey, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7311829/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Purpose: To compare the predictive value of interpedicular distance (IPD) widening, local kyphosis, and anterior vertebral body height loss in assessing injury severity and neurological deficit in traumatic thoracolumbar burst fractures. Methods: A retrospective analysis of 56 patients with traumatic thoracolumbar burst fractures was conducted. Radiographic parameters including interpedicular distance at the fracture level, average interpedicular distance, local kyphosis angle, and anterior vertebral body height were recorded. Neurological status was assessed using the ASIA Impairment Scale. Correlation analyses were performed to evaluate the relationship between radiographic measures and neurological status. Results: The percentage increase in interpedicular distance showed a moderate negative correlation with ASIA grade (r = -0.51), indicating worse neurological status with greater widening. Local kyphosis was also negatively correlated with ASIA grade (r = -0.40). A weak positive correlation was found between IPD widening and anterior vertebral body height loss (r = 0.25), while the correlation between height loss and ASIA grade was weak (r = -0.19). Conclusion: Among the radiographic parameters studied, interpedicular distance widening correlated most strongly with neurological deficit in thoracolumbar burst fractures, followed by local kyphosis. Loss of anterior vertebral height showed weaker association. These findings suggest that IPD widening may be a more sensitive indicator of injury severity in clinical evaluation. Thoracolumbar burst fractures Interpedicular distance Kyphosis Neurological deficit ASIA impairment scale Figures Figure 1 Figure 2 Introduction Traumatic thoracolumbar burst fractures are common injuries that result from high-energy axial loads, such as motor vehicle accidents or falls from height, and account for approximately 10–20% of all spinal injuries [ 1 ]. These fractures typically involve failure of the anterior and middle columns of the spine, and may be associated with retropulsion of bony fragments into the spinal canal, posing a risk to the neural elements [ 2 ]. Prompt and accurate assessment of fracture severity is essential for guiding surgical versus conservative management and for predicting neurological outcomes [ 3 ]. Radiographic parameters play a critical role in this assessment. Among the commonly evaluated features are vertebral body height loss, local kyphosis angle, and interpedicular distance (IPD) widening [ 4 ]. Local kyphosis has traditionally been considered a surrogate for spinal instability, particularly in flexion-compression injuries [ 5 ]. In contrast, IPD widening reflects transverse plane displacement and may suggest posterior column disruption, especially in burst fractures [ 6 ]. While some studies suggest that local kyphosis correlates with canal compromise or neurological injury [ 7 ], others propose that IPD widening may be a more reliable marker of burst severity and canal intrusion [ 8 ]. Additionally, anterior vertebral body height loss is frequently used in scoring systems such as TLICS, but its standalone predictive value for neurological status remains inconsistently reported [ 9 ]. Given this ongoing uncertainty, the aim of our study was to evaluate and compare the correlation of interpedicular distance widening, local kyphosis angle, and anterior vertebral body height loss with neurological impairment, as assessed by the ASIA score, in patients with thoracolumbar burst fractures. Clarifying which radiological parameter best reflects neurological injury may enhance radiographic assessment protocols and inform clinical decision-making in spine trauma care. Materials and methods Study design and setting This was a retrospective observational study conducted at a tertiary-level trauma center in India. After obtaining appropriate institutional ethical clearance, clinical and radiological data were retrieved from medical records and imaging databases for all patients diagnosed with thoracolumbar burst fractures over a defined period. Patient selection Fifty-six consecutive patients with traumatic thoracolumbar burst fractures (T10–L4) treated between [January 2021 to December 2023] were included. Inclusion criteria were, age > 18 years, radiologically confirmed burst fracture pattern involving the anterior and middle columns, and availability of pre-treatment radiographs or CT scans. Patients with pathological fractures, incomplete imaging, or prior spinal surgery were excluded. Radiographic evaluation Radiographic analysis was performed on lateral and anteroposterior spinal radiographs. The following parameters were measured: Interpedicular Distance (IPD) : Measured at the fracture level and one vertebra above and below. The percentage increase in IPD was calculated relative to the average of adjacent levels. Local kyphosis angle : Measured using the Cobb method between the superior endplate of the vertebra above and the inferior endplate of the vertebra below the fractured segment. Anterior Vertebral Body Height (AVBH) : Measured at the anterior margin of the fractured vertebra and compared with the average height of the vertebrae above and below to calculate the percentage loss. All radiographic measurements were performed by two independent observers and averaged to minimize interobserver variability. Neurological assessment Neurological function was graded at the time of presentation using the American Spinal Injury Association (ASIA) Impairment Scale, ranging from ASIA A (complete injury) to ASIA E (normal neurological function). Statistical analysis All statistical analyses were performed using Microsoft Excel and Python 3.10. Continuous variables were presented as means ± standard deviation (SD). Categorical variables were presented as counts and percentages. Pearson correlation coefficients were used to assess the relationship between: percentage increase in IPD and ASIA grade, local kyphosis and ASIA grade, percentage loss of AVBH and ASIA grade and radiographic parameters in relation to each other. A p-value < 0.05 was considered statistically significant. Results Patient demographics and injury characteristics A total of 56 patients with traumatic thoracolumbar burst fractures were included. The most commonly involved vertebral levels were L1, L2, and T12. Neurological grading at presentation, based on the ASIA Impairment Scale, was distributed as follows: ASIA A (n = 9), ASIA B (n = 6), ASIA C (n = 6), ASIA D (n = 6), and ASIA E (n = 27). Radiographic measurements The mean percentage increase in interpedicular distance (IPD) at the level of fracture was 18.88% ± 21.16%. The mean local kyphosis angle was 19.44° ± 7.48°, and the mean percentage loss of anterior vertebral body height (AVBH) was 41.54% ± 15.56%. Correlation analysis Correlation analysis demonstrated that the percentage increase in IPD had a moderate negative correlation with ASIA grade (r = -0.51), indicating that greater IPD widening was associated with worse neurological status. Local kyphosis also showed a moderate negative correlation with ASIA grade (r = -0.4), while the percentage loss of AVBH exhibited only a weak negative correlation (r = -0.19). These findings suggest that among the evaluated radiographic parameters, IPD widening had the strongest association with neurological impairment. Additional correlation analysis is summarized in Table 1 . Notably, a moderate positive correlation was found between local kyphosis and AVBH loss (r = 0.51), and between IPD widening and kyphosis (r = 0.38). Figure 1 illustrates the mean percentage increase in IPD by ASIA grade, showing a clear trend of increasing widening with worsening neurological deficit. Figure 2 shows scatter plots of key correlations. Table 1 Correlation matrix [Pearson’s (r) correlation coefficient] Parameter pair Pearson (r) coefficient Percentage IPD vs ASIA grade -0.51 Kyphosis vs ASIA grade -0.40 Percentage AVHB loss vs ASIA grade -0.19 Percentage IPD vs kyphosis 0.38 Percentage IPD vs percentage AVHB loss 0.25 Kyphosis vs percentage AVHB loss 0.51 Measurement reliability Radiographic measurements showed excellent reliability. The intraclass correlation coefficients (ICCs) ranged from 0.87 to 0.93 for intra-observer and inter-observer variability. Discussion Thoracolumbar burst fractures present a unique clinical challenge due to the variability in spinal instability and risk of neurological compromise. Accurate radiological evaluation is critical for determining severity and guiding treatment. In this study, we aimed to identify which radiographic parameters—interpedicular distance (IPD) widening, local kyphosis, or anterior vertebral body height loss—most strongly correlate with neurological status in patients with traumatic thoracolumbar burst fractures. Our findings demonstrated that IPD widening had the strongest negative correlation with ASIA grade (r = − 0.51), indicating a higher degree of widening was associated with worse neurological outcomes. This supports prior research suggesting that transverse expansion of the pedicles may reflect posterior column disruption or severe vertebral retropulsion, both of which may contribute to canal compromise [ 1 , 2 ]. Local kyphosis also showed a moderate negative correlation with neurological status (r = − 0.40), though less pronounced than IPD widening. Kyphotic angulation, traditionally regarded as a marker of anterior and middle column failure, has been inconsistently linked to neurological impairment in the literature [ 3 ]. Our data suggest that while kyphosis reflects biomechanical deformity, it may not be as sensitive a predictor of cord injury as interpedicular expansion. Loss of anterior vertebral body height (AVBH) showed the weakest correlation with neurological deficit (r = − 0.19), reinforcing prior suggestions that vertebral height collapse alone is insufficient to assess severity [ 4 ]. Furthermore, correlations between radiographic parameters revealed that kyphosis and AVBH loss were moderately related (r = 0.51), suggesting that AVBH loss contributes to spinal angulation but may not directly influence the degree of neural injury. The current findings are clinically relevant. While traditional scoring systems like the TLICS incorporate kyphosis and height loss, our data suggest that IPD widening may serve as a more sensitive and under-recognized indicator of neurological injury. In acute settings where MRI is unavailable or inconclusive, simple measurements of IPD on plain radiographs may provide valuable insight into the extent of neural compromise. Limitations This study has its limitations. First, the retrospective nature of data collection and relatively small sample size limit generalizability. Second, the ASIA score was recorded at presentation, and longitudinal outcomes were not assessed. Finally, although interobserver agreement was strong, radiographic measurements may be influenced by patient positioning and image quality. Conclusion Our findings underline the importance of IPD as a better yardstick over local kyphosis and AVBH with regards to the neurological injury. This is of particular interest in resource constrained settings. Hence, IPD measurements in routine radiographic assessment should be included. Prospective studies with larger cohorts are warranted to validate these findings. Incorporating advanced imaging metrics (e.g., canal compromise on CT or MRI) and evaluating post-treatment outcomes could further clarify the prognostic utility of IPD and other radiological indicators. Declarations Author Contribution A.A.: Methodology, investigation, formal analysis, writing –original draft. N.J.J.: Investigation, validation, writing – review & editing. P.T.: Investigation, data curation. A.C.: Investigation, data curation. K.F.: Project administration, supervision, validation, writing – review & editing. The manuscript has been read and approved by all the authors, that the requirements for authorship as stated earlier in this document have been met, and that each author believes that the manuscript represents honest work. Data Availability The data that support the findings of this study are available from the corresponding author upon reasonable request. References Magerl F, Aebi M, Gertzbein SD, Harms J, Nazarian S (1994) A comprehensive classification of thoracic and lumbar injuries. Eur Spine J 3:184–201 McCormack T, Karaikovic E, Gaines RW (1994) The load sharing classification of spine fractures. Spine (Phila Pa 1976) 19:1741–1744 Mirza SK, Mirza AJ, Chapman JR, Anderson PA (2002) Classifications of thoracic and lumbar fractures: rationale and supporting evidence. J Am Acad Orthop Surg 10:364–377 Vaccaro AR, Lehman RA Jr, Hurlbert RJ et al (2005) A new classification of thoracolumbar injuries: the importance of injury morphology, PLC integrity, and neurological status. Spine (Phila Pa 1976) 30:2325–2333 Vaccaro AR, Zeiller SC, Hulbert RJ et al (2005) The thoracolumbar injury severity score: a proposed treatment algorithm. J Spinal Disord Tech 18:209–215 Denis F (1983) The three-column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine (Phila Pa 1976) 8:817–831 Joaquim AF, Patel AA (2013) Thoracolumbar spine fractures: evaluation and surgical decision-making. J Craniovertebr Junction Spine 4:3–9 Rajasekaran S, Kanna RM, Shetty AP (2015) Role of MRI in assessment of canal compromise, cord compression, and injury severity in thoracolumbar fractures. Spine J 15:635–646 Dai LY, Jiang LS, Wang XY (2009) Posterior short-segment fixation with or without fusion for thoracolumbar burst fractures: a five to ten-year follow-up. J Bone Joint Surg Am 91:1033–1041 McCormack T, Karaikovic E, Gaines RW (1994) The load sharing classification of spine fractures. Spine (Phila Pa 1976) 19:1741–1744 Mirza SK, Mirza AJ, Chapman JR, Anderson PA (2002) Classifications of thoracic and lumbar fractures: rationale and supporting evidence. J Am Acad Orthop Surg 10:364–377 Magerl F, Aebi M, Gertzbein SD, Harms J, Nazarian S (1994) A comprehensive classification of thoracic and lumbar injuries. Eur Spine J 3:184–201 Vaccaro AR, Lehman RA Jr, Hurlbert RJ et al (2005) A new classification of thoracolumbar injuries: the importance of injury morphology, PLC integrity, and neurological status. Spine (Phila Pa 1976) 30:2325–2333 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7311829","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":502233522,"identity":"7aa9d759-255e-47ee-a749-701b00aadae3","order_by":0,"name":"Anmol Anand","email":"","orcid":"","institution":"All India Institute of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Anmol","middleName":"","lastName":"Anand","suffix":""},{"id":502233523,"identity":"99ae9eb9-0d43-474b-826a-5f7a55239c2e","order_by":1,"name":"Nitish Jagdish Jyoti","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA40lEQVRIie3RMQrCMBSA4VcC6RLt2oJ4hoBQFcGzCEKnegORgtDRszgVx5ZgpohrN4eCgzgogtBFfEHnNqNg/iEkkI8kBMBm+8UIQO4klFAQOS79ngEhH+I5cqYJMzvGSQCCteJ62U6GrlcU9a7rcqkel3I5YuCK/baJjNcEREdRwtUhm8QSL8aiqGwiXCBxUiTlIRvEFInPwlZS1JqcrudB/DIkeQdJkChSLVIzwoUmHsiQLDY+o61vORbVvU7lHL+yesTPVd9zhWwk3+QcB+rrKTXYrltOcSA3w902m832Z70BCTFIhrPAgJMAAAAASUVORK5CYII=","orcid":"","institution":"All India Institute of Medical Sciences","correspondingAuthor":true,"prefix":"","firstName":"Nitish","middleName":"Jagdish","lastName":"Jyoti","suffix":""},{"id":502233524,"identity":"da5a9700-9ca4-40bf-acff-e003146ac903","order_by":2,"name":"Prashant Tank","email":"","orcid":"","institution":"All India Institute of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Prashant","middleName":"","lastName":"Tank","suffix":""},{"id":502233525,"identity":"f0d9f55e-fdc9-47a3-91ee-2d810205f545","order_by":3,"name":"Aditya Chaubey","email":"","orcid":"","institution":"All India Institute of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Aditya","middleName":"","lastName":"Chaubey","suffix":""},{"id":502233526,"identity":"f60a01b1-aaf8-40ca-8c72-cb3119208ae0","order_by":4,"name":"Kamran Farooque","email":"","orcid":"","institution":"All India Institute of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Kamran","middleName":"","lastName":"Farooque","suffix":""}],"badges":[],"createdAt":"2025-08-06 16:38:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7311829/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7311829/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":89592127,"identity":"fbaf71d4-b130-42e0-8a67-3799f4bc6312","added_by":"auto","created_at":"2025-08-21 16:11:47","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":994117,"visible":true,"origin":"","legend":"\u003cp\u003eMean percentage increase in IPD by ASIA grade.\u003c/p\u003e","description":"","filename":"Fig1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7311829/v1/706d5f26d6ed503a0dc3a95c.jpeg"},{"id":89592119,"identity":"52122b1b-a59b-4547-9492-516d25b95c62","added_by":"auto","created_at":"2025-08-21 16:11:47","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1180047,"visible":true,"origin":"","legend":"\u003cp\u003e(a) % IPD vs local kyphosis. (b) % IPD vs % AVBH Loss. (c) ASIA grade vs local kyphosis (using numeric scale: A=1, E=5).\u003c/p\u003e","description":"","filename":"Fig2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7311829/v1/8141b8e5332af291f3280373.jpeg"},{"id":90447888,"identity":"24f22843-0290-4528-889a-8c2869fc9602","added_by":"auto","created_at":"2025-09-02 21:01:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2663006,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7311829/v1/22317334-56e3-4a9f-aa9f-8de7350f0b77.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Mind the Gap: Interpedicular Widening as a Superior Predictor of Neurological Deficit Over Kyphosis in Thoracolumbar Burst Fractures","fulltext":[{"header":"Introduction","content":"\u003cp\u003eTraumatic thoracolumbar burst fractures are common injuries that result from high-energy axial loads, such as motor vehicle accidents or falls from height, and account for approximately 10\u0026ndash;20% of all spinal injuries [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. These fractures typically involve failure of the anterior and middle columns of the spine, and may be associated with retropulsion of bony fragments into the spinal canal, posing a risk to the neural elements [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Prompt and accurate assessment of fracture severity is essential for guiding surgical versus conservative management and for predicting neurological outcomes [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eRadiographic parameters play a critical role in this assessment. Among the commonly evaluated features are vertebral body height loss, local kyphosis angle, and interpedicular distance (IPD) widening [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Local kyphosis has traditionally been considered a surrogate for spinal instability, particularly in flexion-compression injuries [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. In contrast, IPD widening reflects transverse plane displacement and may suggest posterior column disruption, especially in burst fractures [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eWhile some studies suggest that local kyphosis correlates with canal compromise or neurological injury [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], others propose that IPD widening may be a more reliable marker of burst severity and canal intrusion [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Additionally, anterior vertebral body height loss is frequently used in scoring systems such as TLICS, but its standalone predictive value for neurological status remains inconsistently reported [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eGiven this ongoing uncertainty, the aim of our study was to evaluate and compare the correlation of interpedicular distance widening, local kyphosis angle, and anterior vertebral body height loss with neurological impairment, as assessed by the ASIA score, in patients with thoracolumbar burst fractures. Clarifying which radiological parameter best reflects neurological injury may enhance radiographic assessment protocols and inform clinical decision-making in spine trauma care.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStudy design and setting\u003c/h2\u003e\u003cp\u003eThis was a retrospective observational study conducted at a tertiary-level trauma center in India. After obtaining appropriate institutional ethical clearance, clinical and radiological data were retrieved from medical records and imaging databases for all patients diagnosed with thoracolumbar burst fractures over a defined period.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003ePatient selection\u003c/h3\u003e\n\u003cp\u003eFifty-six consecutive patients with traumatic thoracolumbar burst fractures (T10\u0026ndash;L4) treated between [January 2021 to December 2023] were included. Inclusion criteria were, age\u0026thinsp;\u0026gt;\u0026thinsp;18 years, radiologically confirmed burst fracture pattern involving the anterior and middle columns, and availability of pre-treatment radiographs or CT scans. Patients with pathological fractures, incomplete imaging, or prior spinal surgery were excluded.\u003c/p\u003e\n\u003ch3\u003eRadiographic evaluation\u003c/h3\u003e\n\u003cp\u003eRadiographic analysis was performed on lateral and anteroposterior spinal radiographs. The following parameters were measured:\u003c/p\u003e\u003cp\u003e\u003col\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eInterpedicular Distance (IPD)\u003c/b\u003e: Measured at the fracture level and one vertebra above and below. The percentage increase in IPD was calculated relative to the average of adjacent levels.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eLocal kyphosis angle\u003c/b\u003e: Measured using the Cobb method between the superior endplate of the vertebra above and the inferior endplate of the vertebra below the fractured segment.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eAnterior Vertebral Body Height (AVBH)\u003c/b\u003e: Measured at the anterior margin of the fractured vertebra and compared with the average height of the vertebrae above and below to calculate the percentage loss.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003c/ol\u003e\u003c/p\u003e\u003cp\u003eAll radiographic measurements were performed by two independent observers and averaged to minimize interobserver variability.\u003c/p\u003e\n\u003ch3\u003eNeurological assessment\u003c/h3\u003e\n\u003cp\u003eNeurological function was graded at the time of presentation using the American Spinal Injury Association (ASIA) Impairment Scale, ranging from ASIA A (complete injury) to ASIA E (normal neurological function).\u003c/p\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eAll statistical analyses were performed using Microsoft Excel and Python 3.10. Continuous variables were presented as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD). Categorical variables were presented as counts and percentages. Pearson correlation coefficients were used to assess the relationship between: percentage increase in IPD and ASIA grade, local kyphosis and ASIA grade, percentage loss of AVBH and ASIA grade and radiographic parameters in relation to each other. A p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003ePatient demographics and injury characteristics\u003c/h2\u003e\u003cp\u003eA total of 56 patients with traumatic thoracolumbar burst fractures were included. The most commonly involved vertebral levels were L1, L2, and T12. Neurological grading at presentation, based on the ASIA Impairment Scale, was distributed as follows: ASIA A (n\u0026thinsp;=\u0026thinsp;9), ASIA B (n\u0026thinsp;=\u0026thinsp;6), ASIA C (n\u0026thinsp;=\u0026thinsp;6), ASIA D (n\u0026thinsp;=\u0026thinsp;6), and ASIA E (n\u0026thinsp;=\u0026thinsp;27).\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eRadiographic measurements\u003c/h3\u003e\n\u003cp\u003eThe mean percentage increase in interpedicular distance (IPD) at the level of fracture was 18.88% \u0026plusmn; 21.16%. The mean local kyphosis angle was 19.44\u0026deg; \u0026plusmn; 7.48\u0026deg;, and the mean percentage loss of anterior vertebral body height (AVBH) was 41.54% \u0026plusmn; 15.56%.\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eCorrelation analysis\u003c/h2\u003e\u003cp\u003eCorrelation analysis demonstrated that the percentage increase in IPD had a moderate negative correlation with ASIA grade (r = -0.51), indicating that greater IPD widening was associated with worse neurological status. Local kyphosis also showed a moderate negative correlation with ASIA grade (r = -0.4), while the percentage loss of AVBH exhibited only a weak negative correlation (r = -0.19). These findings suggest that among the evaluated radiographic parameters, IPD widening had the strongest association with neurological impairment.\u003c/p\u003e\u003cp\u003eAdditional correlation analysis is summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Notably, a moderate positive correlation was found between local kyphosis and AVBH loss (r\u0026thinsp;=\u0026thinsp;0.51), and between IPD widening and kyphosis (r\u0026thinsp;=\u0026thinsp;0.38). Figure\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the mean percentage increase in IPD by ASIA grade, showing a clear trend of increasing widening with worsening neurological deficit. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows scatter plots of key correlations.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eCorrelation matrix [Pearson\u0026rsquo;s (r) correlation coefficient]\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameter pair\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePearson (r) coefficient\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePercentage IPD vs ASIA grade\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.51\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eKyphosis vs ASIA grade\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.40\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePercentage AVHB loss vs ASIA grade\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.19\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePercentage IPD vs kyphosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePercentage IPD vs percentage AVHB loss\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.25\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eKyphosis vs percentage AVHB loss\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.51\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003eMeasurement reliability\u003c/h2\u003e\u003cp\u003eRadiographic measurements showed excellent reliability. The intraclass correlation coefficients (ICCs) ranged from 0.87 to 0.93 for intra-observer and inter-observer variability.\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThoracolumbar burst fractures present a unique clinical challenge due to the variability in spinal instability and risk of neurological compromise. Accurate radiological evaluation is critical for determining severity and guiding treatment. In this study, we aimed to identify which radiographic parameters—interpedicular distance (IPD) widening, local kyphosis, or anterior vertebral body height loss—most strongly correlate with neurological status in patients with traumatic thoracolumbar burst fractures.\u003c/p\u003e\u003cp\u003eOur findings demonstrated that IPD widening had the strongest negative correlation with ASIA grade (r = − 0.51), indicating a higher degree of widening was associated with worse neurological outcomes. This supports prior research suggesting that transverse expansion of the pedicles may reflect posterior column disruption or severe vertebral retropulsion, both of which may contribute to canal compromise [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eLocal kyphosis also showed a moderate negative correlation with neurological status (r = − 0.40), though less pronounced than IPD widening. Kyphotic angulation, traditionally regarded as a marker of anterior and middle column failure, has been inconsistently linked to neurological impairment in the literature [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Our data suggest that while kyphosis reflects biomechanical deformity, it may not be as sensitive a predictor of cord injury as interpedicular expansion.\u003c/p\u003e\u003cp\u003eLoss of anterior vertebral body height (AVBH) showed the weakest correlation with neurological deficit (r = − 0.19), reinforcing prior suggestions that vertebral height collapse alone is insufficient to assess severity [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Furthermore, correlations between radiographic parameters revealed that kyphosis and AVBH loss were moderately related (r = 0.51), suggesting that AVBH loss contributes to spinal angulation but may not directly influence the degree of neural injury.\u003c/p\u003e\u003cp\u003eThe current findings are clinically relevant. While traditional scoring systems like the TLICS incorporate kyphosis and height loss, our data suggest that IPD widening may serve as a more sensitive and under-recognized indicator of neurological injury. In acute settings where MRI is unavailable or inconclusive, simple measurements of IPD on plain radiographs may provide valuable insight into the extent of neural compromise.\u003c/p\u003e"},{"header":"Limitations","content":"\u003cp\u003eThis study has its limitations. First, the retrospective nature of data collection and relatively small sample size limit generalizability. Second, the ASIA score was recorded at presentation, and longitudinal outcomes were not assessed. Finally, although interobserver agreement was strong, radiographic measurements may be influenced by patient positioning and image quality.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOur findings underline the importance of IPD as a better yardstick over local kyphosis and AVBH with regards to the neurological injury. This is of particular interest in resource constrained settings. Hence, IPD measurements in routine radiographic assessment should be included. Prospective studies with larger cohorts are warranted to validate these findings. Incorporating advanced imaging metrics (e.g., canal compromise on CT or MRI) and evaluating post-treatment outcomes could further clarify the prognostic utility of IPD and other radiological indicators.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eA.A.: Methodology, investigation, formal analysis, writing \u0026ndash;original draft. N.J.J.: Investigation, validation, writing \u0026ndash; review \u0026amp; editing. P.T.: Investigation, data curation. A.C.: Investigation, data curation. K.F.: Project administration, supervision, validation, writing \u0026ndash; review \u0026amp; editing. The manuscript has been read and approved by all the authors, that the requirements for authorship as stated earlier in this document have been met, and that each author believes that the manuscript represents honest work.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe data that support the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMagerl F, Aebi M, Gertzbein SD, Harms J, Nazarian S (1994) A comprehensive classification of thoracic and lumbar injuries. Eur Spine J 3:184\u0026ndash;201\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMcCormack T, Karaikovic E, Gaines RW (1994) The load sharing classification of spine fractures. Spine (Phila Pa 1976) 19:1741\u0026ndash;1744\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMirza SK, Mirza AJ, Chapman JR, Anderson PA (2002) Classifications of thoracic and lumbar fractures: rationale and supporting evidence. J Am Acad Orthop Surg 10:364\u0026ndash;377\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVaccaro AR, Lehman RA Jr, Hurlbert RJ et al (2005) A new classification of thoracolumbar injuries: the importance of injury morphology, PLC integrity, and neurological status. Spine (Phila Pa 1976) 30:2325\u0026ndash;2333\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVaccaro AR, Zeiller SC, Hulbert RJ et al (2005) The thoracolumbar injury severity score: a proposed treatment algorithm. J Spinal Disord Tech 18:209\u0026ndash;215\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDenis F (1983) The three-column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine (Phila Pa 1976) 8:817\u0026ndash;831\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJoaquim AF, Patel AA (2013) Thoracolumbar spine fractures: evaluation and surgical decision-making. J Craniovertebr Junction Spine 4:3\u0026ndash;9\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRajasekaran S, Kanna RM, Shetty AP (2015) Role of MRI in assessment of canal compromise, cord compression, and injury severity in thoracolumbar fractures. Spine J 15:635\u0026ndash;646\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDai LY, Jiang LS, Wang XY (2009) Posterior short-segment fixation with or without fusion for thoracolumbar burst fractures: a five to ten-year follow-up. J Bone Joint Surg Am 91:1033\u0026ndash;1041\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMcCormack T, Karaikovic E, Gaines RW (1994) The load sharing classification of spine fractures. Spine (Phila Pa 1976) 19:1741\u0026ndash;1744\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMirza SK, Mirza AJ, Chapman JR, Anderson PA (2002) Classifications of thoracic and lumbar fractures: rationale and supporting evidence. J Am Acad Orthop Surg 10:364\u0026ndash;377\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMagerl F, Aebi M, Gertzbein SD, Harms J, Nazarian S (1994) A comprehensive classification of thoracic and lumbar injuries. Eur Spine J 3:184\u0026ndash;201\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVaccaro AR, Lehman RA Jr, Hurlbert RJ et al (2005) A new classification of thoracolumbar injuries: the importance of injury morphology, PLC integrity, and neurological status. Spine (Phila Pa 1976) 30:2325\u0026ndash;2333\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Thoracolumbar burst fractures, Interpedicular distance, Kyphosis, Neurological deficit, ASIA impairment scale","lastPublishedDoi":"10.21203/rs.3.rs-7311829/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7311829/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose:\u003c/strong\u003e To compare the predictive value of interpedicular distance (IPD) widening, local kyphosis, and anterior vertebral body height loss in assessing injury severity and neurological deficit in traumatic thoracolumbar burst fractures.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e A retrospective analysis of 56 patients with traumatic thoracolumbar burst fractures was conducted. Radiographic parameters including interpedicular distance at the fracture level, average interpedicular distance, local kyphosis angle, and anterior vertebral body height were recorded. Neurological status was assessed using the ASIA Impairment Scale. Correlation analyses were performed to evaluate the relationship between radiographic measures and neurological status.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e The percentage increase in interpedicular distance showed a moderate negative correlation with ASIA grade (r = -0.51), indicating worse neurological status with greater widening. Local kyphosis was also negatively correlated with ASIA grade (r = -0.40). A weak positive correlation was found between IPD widening and anterior vertebral body height loss (r = 0.25), while the correlation between height loss and ASIA grade was weak (r = -0.19).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e Among the radiographic parameters studied, interpedicular distance widening correlated most strongly with neurological deficit in thoracolumbar burst fractures, followed by local kyphosis. Loss of anterior vertebral height showed weaker association. These findings suggest that IPD widening may be a more sensitive indicator of injury severity in clinical evaluation.\u003c/p\u003e","manuscriptTitle":"Mind the Gap: Interpedicular Widening as a Superior Predictor of Neurological Deficit Over Kyphosis in Thoracolumbar Burst Fractures","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-21 16:11:42","doi":"10.21203/rs.3.rs-7311829/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"541055cf-fcf7-4f67-929f-c0d819cf5ebd","owner":[],"postedDate":"August 21st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-02T20:53:17+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-21 16:11:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7311829","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7311829","identity":"rs-7311829","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}