Timing of Surgery and Predictors of Canal Reduction after Short- segment Fixation for Thoracolumbar Burst Fractures

Timing of Surgery and Predictors of Canal Reduction after Short- segment Fixation for 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 Timing of Surgery and Predictors of Canal Reduction after Short- segment Fixation for Thoracolumbar Burst Fractures Hiroyuki Aono, Shota Takenaka, Akinori Okuda, Takeshi Kikuchi, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8026231/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 23 Mar, 2026 Read the published version in European Journal of Trauma and Emergency Surgery → Version 1 posted 8 You are reading this latest preprint version Abstract Purpose In patients with thoracolumbar burst fractures, surgical delay is often unavoidable due to concomitant injuries. Concerns persist that delayed surgery may compromise indirect reduction of retropulsed fragments via ligamentotaxis. This study aimed to determine whether the timing of surgery affects the quality of intracanal fragment reduction and identify independent predictors of successful reduction following short-segment posterior fixation. Methods This multicenter study included 252 patients who sustained a single traumatic thoracolumbar burst fracture and underwent short-segment fixation. The canal compromise ratio (CCR) was measured on pre- and postoperative CT scans, and the reduction rate was calculated using this formula: Reduction rate = (Preoperative CCR − Postoperative CCR) / Preoperative CCR × 100. Multiple logistic regression analysis identified predictors of reduction quality including age, sex, affected level, surgical timing, AO classification, load-sharing score (LSS), preoperative CCR, and concomitant vertebroplasty, Results The study included 141 males and 111 females. The mean time from injury to surgery was 3.8 days. The mean CCR improved from 45% to 24%, yielding a mean reduction rate of 44%. Multiple linear regression analysis revealed that T11 to L1 and AO type B fractures were associated with a significantly higher reduction rate. Notably, the time from injury to surgery showed no significant correlation with reduction quality. Conclusion Short-segment posterior fixation can achieve satisfactory canal reduction through ligamentotaxis, even when surgical intervention is delayed several days after trauma. In polytrauma patients without neurological deficit, a short postponement of surgery may be acceptable to optimize systemic stabilization without compromising spinal canal restoration. thoracolumbar burst fracture short-segment fixation ligamentotaxis canal compromise surgical timing predictors Figures Figure 1 Figure 2 Figure 3 Introduction Thoracolumbar burst fractures represent the most common type of spinal injury requiring surgical management [ 1 – 3 ], accounting for nearly 90% of all spinal fractures at the thoracolumbar junction [ 4 – 5 ]. These injuries typically result from high-energy trauma and involve failure of the anterior and middle columns of the spine base on the Denis classification [ 6 ]. The short-segment posterior fixation technique—pedicle screw instrumentation at the vertebrae adjacent to the fracture—has become widely accepted for these fractures due to its ability to preserve motion segments (with implant removal), achieve deformity correction through ligamentotaxis, and minimize invasiveness. Although early reports in the 1990s raised concerns about high rates of instrumentation failure [ 7 – 9 ], subsequent studies have demonstrated consistently favorable outcomes with modern implant systems [ 10 – 13 ]. The technique effectively restores vertebral height and reduces retropulsed fragments by applying tension through the posterior longitudinal ligament (PLL) with minimal correction loss. However, thoracolumbar burst fractures are often accompanied by concomitant head, thoracic, abdominal, or pelvic injuries, delaying surgical stabilization. In such scenarios, surgeons may worry that postponement could impair indirect reduction of intracanal fragments. Despite these concerns, few large-scale studies have quantitatively analyzed whether surgical timing influences reduction quality. This multicenter study aimed to determine (1) whether the timing of surgery affects the reduction of intracanal fragments achieved by ligamentotaxis and (2) which clinical or radiologic factors independently predict the degree of canal reduction. Materials and Methods Study Design and Population This retrospective multicenter study was conducted across five institutions between September 2006 and April 2025. Inclusion criteria were single thoracolumbar burst fractures (AO types A3, A4, B1, B2) treated with short-segment posterior fixation using ligamentotaxis. Patients with multiple burst fractures, AO type B3 or C injuries, or isolated posterior wall injuries without intracanal fragments were excluded. A total of 252 patients met the criteria (141 men, 111 women; mean age 43 years, range 13–69). Mechanisms of injury included falls from a significant height (n = 170), road traffic crash (n = 62), being struck by an object (n = 9), equestrian accidents (n = 8), and skiing accidents (n = 3). Fracture levels were T11 (n = 8), T12 (n = 35), L1 (n = 108), L2 (n = 69), and L3 (n = 32). Institutional review boards of all participating centers approved the protocol, and the requirement for individual informed consent was waived. We had nothing to disclose concerning this study. Radiological Measurements Pre- and postoperative computed tomography (CT) was obtained in all cases within one week of surgery. Canal compromise was assessed by measuring the anteroposterior canal dimensions at the level of the maximum retropulsed osseous fragment(s) and comparing this value to the average of similar dimensions measured one level above and below the injury. The resulting ratio was defined as the canal compromise ratio (CCR). The reduction rate was then calculated as: (Pre-CCR − Post-CCR)/Pre-CCR×100. Measurements were independently performed by five spine surgeons blinded to clinical data. Fracture severity was also evaluated using the Load-Sharing Score (LSS) [ 8 ] and the AO classification [ 14 ]. Surgical Technique All procedures were performed under general anesthesia with the patient in a prone position. Initial postural reduction was applied before pedicle screw insertion. Instrumentation was placed one level above and below the fracture using Schanz pedicle screws (AO Universal Spine System, DePuy Synthes, n = 215), CD Horizon Longitude (Medtronic, n = 27), or ES2 system (Stryker, n = 10). Ligamentotaxis was achieved by controlled segmental distraction through the rods. Detailed descriptions of the surgical techniques can be found in previous publications [ 11 , 12 ]. Concomitant vertebroplasty was performed in 109 patients (43%). Statistical Analysis All analyses were performed with SPSS v27 (IBM Corp., Armonk, NY). A p value < 0.05 was considered statistically significant. Continuous variables were compared using Welch’s t-test, categorical variables with Fisher’s exact test. Correlations were assessed by Spearman’s rank coefficient and categorized according to Guilford’s criteria [ 15 ]. Multiple linear regression analysis with stepwise selection was used to identify independent predictors of the reduction rate. The dependent variable was the reduction rate; independent variables included age, sex, fracture level (T11–L1 vs L2–L3), surgical timing, preoperative CCR, LSS, AO classification (A3–A4 vs B1–B2), and use of vertebroplasty. Multicollinearity was excluded by verifying that all inter-variable correlation coefficients were < 0.7. Results Timing of Surgery Surgical fixation was performed within 24 hours in 42 patients, within 48 hours in 40, between 3–5 days in 89, and after ≥ 6 days in 81 patients (Figure). The mean delay was 3.8 days (range 0–23). Radiological Outcomes Mean preoperative CCR was 45% (range 5–89%), improving to 24% (range 3–80%) postoperatively, corresponding to a mean reduction rate of 44% (range 5–88%). The mean LSS was 6.7 points (range 4–9). The distribution of LSS was as follows: 19 patients scored of 9, 59 scored 8, 64 scored of 7, 65 scored 6, 35 scored 5, and 10 scored 4. Fracture distribution by AO type was: A3 (n = 91), A4 (n = 78), B1 (n = 19), B2 (n = 64). Statistical Results Univariate analysis revealed that, among dichotomous variables, the reduction rate was significantly higher in patients with T11-L1 fractures compared to those with L2-L3 fractures (Table 1 ). Surgical delay, age, preoperative CCR, and LSS were not significantly correlated with reduction rate (Table 2 ). Multiple linear regression identified two independent predictors of higher reduction rate: fracture level (T11–L1; p = 0.004) and AO type B fracture (p = 0.043, Table 3 ). The scatter plot of reduction rate versus time to surgery demonstrated no linear correlation (r =-0.109, p = 0092, Fig. 3 ). Table 1 Univariate analysis Causal factors N Reduction rate (SD) p-value Gender male 141 44.1 (23.5) female 111 41.9 (18.9) 0.407 t Affected level T11-L1 151 46.8 (21.4) L2-L3 101 38.3 (21.1) 0.004 t Combination of Vertebroplasty with 109 44.8 (24.0) without 143 41.6 (19.3) 0.260 t AO classification A3 or A4 169 41.4 (19.7) B1 or B2 83 47.2 (24.3) 0.050 t SD, standard deviation, t,Welch’s t test was used Table 2 Correlation analysis between reduction rate and other continuous variables. r p-value Age -0.095 0.141 Duration from injury to surgery -1.11 0.089 Preoperative canal compromise ratio -0.015 0.814 Load-sharing score 0.076 0.241 Spearman’s correlation coefficient by rank test was used. Table 3 Multiple linear regression analyses Parameter Unstandardized Standardized p value B SE β t L2 or L3 -8.012 2.760 -0.184 -2.903 0.004 AO type B fracture 5.853 2.877 0.129 2.034 0.043 B , unstandardized coefficients; β , standardized B coefficients; SE, standard error; and t, t-value Discussion Thoracolumbar burst fractures frequently cause canal compromise due to retropulsed bone fragments. Short-segment posterior fixation is widely used for these injuries, providing deformity correction and canal restoration through ligamentotaxis [ 10 – 13 ]. Because these injuries often result from high-energy trauma, patients frequently present with multiple concomitant injuries, and spinal fixation may be delayed until systemic stabilization is achieved. This situation raises concern that delayed surgery might compromise ligamentotaxis-based canal reduction. Previous studies have discussed factors influencing ligamentotaxis, such as fragment displacement or posterior longitudinal ligament impingement [ 16 , 17 ], but have not accounted for fracture morphology or level. The present multicenter analysis addressed these factors comprehensively using AO classification, Load-Sharing Score (LSS), and fracture level. Our findings showed that fracture level and AO type were independent predictors of canal reduction, whereas surgical timing, age, preoperative canal compromise, and LSS were not. Fractures at T11–L1 achieved higher reduction rates than those at L2–L3. This may reflect the unique biomechanical properties of the thoracolumbar junction, which acts as a transition zone between the rigid thoracic and flexible lumbar spine, concentrating stress while maintaining relatively strong ligamentous tension and lower axial load [ 18 – 20 ]. These anatomical and biomechanical characteristics may facilitate more effective indirect reduction through ligamentotaxis. In contrast, lower lumbar levels experience higher compressive forces and weaker posterior ligament support, limiting the efficiency of ligamentotaxis [ 21 , 22 ]. AO type B fractures also exhibited superior reduction compared with type A fractures. The posterior tension-band failure characteristic of type B injuries likely allows greater fragment mobility during distraction, consistent with biomechanical evidence that stepwise sectioning of the posterior ligamentous complex increases spinal motion and neutral zone. Conversely, the intact posterior elements of type A burst fractures contribute to rigid anterior collapse, restricting fragment movement and reducing reduction potential [ 14 , 23 – 25 ]. These findings emphasize that fracture morphology and level play more decisive roles in canal restoration than surgical delay. Surgical timing was not correlated with reduction quality. The mean interval from injury to fixation was 3.8 days, reflecting common clinical conditions. Even with several days of delay, short-segment fixation achieved effective canal restoration, suggesting that the mechanism of ligamentotaxis remains functional during this period. These results are consistent with earlier studies showing no measurable deterioration in reduction with moderate delay. Clinically, this supports prioritizing resuscitation and associated injury management in neurologically intact patients, reserving urgent fixation for those with progressive neurological deficit or severe canal compromise. This study has limitations. Its retrospective design may introduce selection bias, and only radiological outcomes were assessed. The number of patients undergoing surgery beyond seven days was small, limiting sensitivity to detect very late effects. Furthermore, postoperative CT evaluation was limited to the early phase, and subsequent changes could not be assessed. Future prospective studies incorporating neurological and functional outcomes are warranted. Conclusion In conclusion, the timing of surgery does not significantly affect the quality of canal reduction following short-segment posterior fixation for thoracolumbar burst fractures. Reduction success depends primarily on fracture level and morphology, with T11–L1 and AO type B fractures showing superior outcomes. These results suggest that modest surgical delay is acceptable in polytrauma patients without neurological deficit, provided that adequate fixation and ligamentotaxis are achieved. Declarations Author Contribution H.A, A.O, T. K, H.T, K.N acquired the data. H. A wrote the main manuscript text. S.T performed statistical analysis. Y. I provided supervision for the project and manuscript. References Hu R, Mustard CA, Burns C. Epidemiology of incident spinal fracture in a complete population. Spine. 1996;21:492–9. Dai LY, Yao WF, Cui YM, Zhou Q. Thoracolumbar fractures in patients with multiple injuries: diagnosis and treatment-a review of 147 cases. J Trauma. 2004;56:348–55. Dai LY, Jiang SD, Wang XY, Jiang LS. A review of the management of thoracolumbar burst fractures. Surg Neurol. 2007;67:221–31. Gertzbein SD. Scoliosis Research Society. Multicenter spine fracture study. Spine (Phila Pa 1976). 1992;17:528–40. Wood K, Buttermann G, Mehbod A, Garvey T, Jhanjee R, Sechriest V. Operative compared with non-operative treatment of a thoracolumbar burst fracture without neurological deficit. A prospective, randomized study. J Bone Joint Surg Am. 2003;85:773–81. Denis F. The three-column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine. 1983;8:817–31. Ebelke DK, Asher MA, Neff JR, Kraker DP. Survivorship analysis of VSP spine instrumentation in the treatment of thoracolumbar and lumbar burst fractures. Spine 1991; 16: S428–32. McCormack T, Karaikovic E, Gaines RW. The load sharing classification of spine fractures. Spine. 1994;19:1741–4. McLain RF, Sparling E, Benson DR. Early failure of short-segment pedicle instrumentation for thoracolumbar fractures. A preliminary report. J Bone Joint Surg Am. 1993;75:162–7. Toyone T, Tanaka T, Kato D, Kaneyama R, Otsuka M. The treatment of acute thoracolumbar burst fractures with transpedicular intracorporeal hydroxyapatite grafting following indirect reduction and pedicle screw fixation: a prospective study. Spine. 2006;31:E208–14. Aono H, Tobimatsu H, Ariga K, Kuroda M, Nagamoto Y, Takenaka S, et al. Surgical outcomes of temporary short-segment instrumentation without augmentation for thoracolumbar burst fractures. Injury. 2016;47:1337–44. Aono H, Ishii K, Tobimatsu H, Nagamoto Y, Takenaka S, Furuya M, et al. Temporary short-segment pedicle screw fixation for thoracolumbar burst fractures. comparative study with or without vertebroplasty. Spine J. 2017;17:1113–9. Kanna RM, Shetty AP, Rajasekaran S. Posterior fixation including the fractured vertebra for severe unstable thoracolumbar fractures. Spine J. 2015;15:256–64. Reinhold M, Audigé L, Schnake KJ, Ballabarba C, Dai LY, Oner FV. AO spine injury classification system: a revision proposal for the thoracic and lumbar spine. Eur Spine J. 2013;22:2184–201. Guilford JP. Fundamental statistics in psychology and education. New York: McGraw Hill; 1956. Peng Y, Zhang L, Shi T, Lv H, Zhang L, Tang P. Relationship between fracture-relevant parameteres of thoracolumbar burst fractures and the reduction of intara-canal fracture fragment. J Orthop Surg Res. 2015;27:10131. Wang XB, Lu GH, Li J, Wang B, Lu C, Phan K. Posterior distraction and instrumentation cannnot always reduce displaced and rotated posterosuperior fracture fragments in thoracolumbar burst fracture. Clin Spine Surg. 2017;30:E317–322. Resnick DK, Weller SJ, Benzel EC. Biomechanics of the thoracolumbar spine. Neurosurg Clin N Am. 1997;8(4):455–69. Smith HE, Anderson DG, Vaccaro AR, Albert TJ, et al. Anatomy, Biomechanics, and Classification of Thoracolumbar Injuries. Semin Spine Surg. 2010;22(1):2–7. Lu H, Zhang Q, Ding F, Wu Q, Liu R. Establishment and validation of a T12–L2 three-dimensional finite element model of the thoracolumbar segments. Am J Transl Res. 2022;14(3):1606–15. Yoganandan N, Arun MWJ, Stemper BD, Pintar FA, Maiman DJ. Biomechanics of human thoracolumbar spinal column trauma from vertical impact loading. Ann Adv Automot Med. 2013;57:155–66. Panjabi MM, Brand RA, White AA III. Mechanical properties of the human thoracic spine as shown by three-dimensional load-displacement curves. J Bone Joint Surg Am. 1976;58(5):642–52. Li Y, Shen Z, Huang M, Wang X. Stepwise resection of the posterior ligamentous complex for stability of thoracolumbar compression fracture: An in vitro biomechanical investigation. Med (Baltim). 2017 Sep;96(35):e7873. Wu CC, Jin HM, Yan YZ, Chen J, Wang K, Wang JL et al. Biomechanical role of the thoracolumbar ligaments of the posterior ligamentous complex. World Neurosurg. 2018:112; e125-133. Heuer F, Schmidt H, Klezl Z, Claes L, Wilke HJ. Stepwise reduction of functional spinal structures increase range of motion and change lordosis angle. J Biomech. 2007;40(2):271–80. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 23 Mar, 2026 Read the published version in European Journal of Trauma and Emergency Surgery → Version 1 posted Editorial decision: Revision requested 26 Jan, 2026 Reviews received at journal 27 Nov, 2025 Reviewers agreed at journal 12 Nov, 2025 Reviewers agreed at journal 11 Nov, 2025 Reviewers invited by journal 10 Nov, 2025 Editor assigned by journal 09 Nov, 2025 Submission checks completed at journal 07 Nov, 2025 First submitted to journal 04 Nov, 2025 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-8026231","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":543982789,"identity":"c305fd46-240c-40fe-b3c7-1f028e6d386e","order_by":0,"name":"Hiroyuki 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10:04:08","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2192868,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure1jpg.png","url":"https://assets-eu.researchsquare.com/files/rs-8026231/v1/4a3d17cef353e671cb5f119a.png"},{"id":96453701,"identity":"d15b4229-2bd3-4e78-83ce-f61aa254238e","added_by":"auto","created_at":"2025-11-21 10:01:20","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":96298,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure2jpg.png","url":"https://assets-eu.researchsquare.com/files/rs-8026231/v1/2d061a59ce29d24c6b19577f.png"},{"id":96454601,"identity":"8eaa0d51-8bed-4cba-8f8b-b59e7baeb5fe","added_by":"auto","created_at":"2025-11-21 10:02:57","extension":"png","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":174023,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure3JPEG.png","url":"https://assets-eu.researchsquare.com/files/rs-8026231/v1/f44aafc3499604b5be15a03e.png"},{"id":96421660,"identity":"05f666d6-974e-4d49-8bed-f652839cb22b","added_by":"auto","created_at":"2025-11-21 01:04:01","extension":"xml","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64936,"visible":true,"origin":"","legend":"","description":"","filename":"79293817ddb641f1947a0052bc89ed931structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8026231/v1/7ea68266256d177d83ec84ff.xml"},{"id":96453728,"identity":"c3174771-b627-4dd5-a51e-0711d0c6d20b","added_by":"auto","created_at":"2025-11-21 10:01:24","extension":"html","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":73619,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8026231/v1/e29433ea15abf6c82f0bf3b3.html"},{"id":96421644,"identity":"e8c1f571-8473-46c3-b61b-bc1fac0f4868","added_by":"auto","created_at":"2025-11-21 01:04:00","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":579583,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA and B.\u003c/strong\u003e CT scan from a 56-year-old man with an L1 burst fracture, showing changes before and after surgery. \u003cstrong\u003e(A)\u003c/strong\u003e The canal compromise ratio (CCR) was 66% before surgery. \u003cstrong\u003e(B)\u003c/strong\u003e Surgery corrected the CCR to 26%. Therefore, the reduction rate was calculated as being 61% ([66 – 26/66] × 100). \u003cstrong\u003eC and D.\u003c/strong\u003e CT scan from a 34-year-old man with an L3 burst fracture. \u003cstrong\u003e(C)\u003c/strong\u003eThe CCR was 63% before surgery. \u003cstrong\u003e(D)\u003c/strong\u003e Surgery corrected the CCR to 58%. Therefore, the reduction rate was calculated as being 8% ([63 – 58/63] × 100).\u003c/p\u003e","description":"","filename":"Figure1jpg.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8026231/v1/0bc94c0b8380dc839a5e9597.jpg"},{"id":96453694,"identity":"39934635-9651-4db2-aafa-c253477260f4","added_by":"auto","created_at":"2025-11-21 10:01:20","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":468920,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of elapsed time from injury until surgery for all patients.\u003c/p\u003e","description":"","filename":"Figure2jpg.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8026231/v1/f1fc82f9d9da062f4a4695ba.jpg"},{"id":96454470,"identity":"66216a49-8f53-4259-a3ff-ec2750188704","added_by":"auto","created_at":"2025-11-21 10:02:47","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":307942,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation between duration from injury to surgery (day) and reduction angle/reduction rate. Duration from injury from surgery did not affect both reduction angle and reduction rate.\u003c/p\u003e","description":"","filename":"Figure3JPEG.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8026231/v1/223f626f107fc22b91f36894.jpg"},{"id":105755845,"identity":"1c52011a-db3c-47cf-93ff-d9118d6384b9","added_by":"auto","created_at":"2026-03-30 16:31:30","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1881077,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8026231/v1/bf467fd0-ff18-4660-a81e-53d8bbf01d11.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Timing of Surgery and Predictors of Canal Reduction after Short- segment Fixation for Thoracolumbar Burst Fractures","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThoracolumbar burst fractures represent the most common type of spinal injury requiring surgical management [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], accounting for nearly 90% of all spinal fractures at the thoracolumbar junction [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. These injuries typically result from high-energy trauma and involve failure of the anterior and middle columns of the spine base on the Denis classification [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The short-segment posterior fixation technique\u0026mdash;pedicle screw instrumentation at the vertebrae adjacent to the fracture\u0026mdash;has become widely accepted for these fractures due to its ability to preserve motion segments (with implant removal), achieve deformity correction through ligamentotaxis, and minimize invasiveness.\u003c/p\u003e\u003cp\u003eAlthough early reports in the 1990s raised concerns about high rates of instrumentation failure [\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], subsequent studies have demonstrated consistently favorable outcomes with modern implant systems [\u003cspan additionalcitationids=\"CR11 CR12\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The technique effectively restores vertebral height and reduces retropulsed fragments by applying tension through the posterior longitudinal ligament (PLL) with minimal correction loss.\u003c/p\u003e\u003cp\u003eHowever, thoracolumbar burst fractures are often accompanied by concomitant head, thoracic, abdominal, or pelvic injuries, delaying surgical stabilization. In such scenarios, surgeons may worry that postponement could impair indirect reduction of intracanal fragments. Despite these concerns, few large-scale studies have quantitatively analyzed whether surgical timing influences reduction quality.\u003c/p\u003e\u003cp\u003eThis multicenter study aimed to determine (1) whether the timing of surgery affects the reduction of intracanal fragments achieved by ligamentotaxis and (2) which clinical or radiologic factors independently predict the degree of canal reduction.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStudy Design and Population\u003c/h2\u003e\u003cp\u003eThis retrospective multicenter study was conducted across five institutions between September 2006 and April 2025. Inclusion criteria were single thoracolumbar burst fractures (AO types A3, A4, B1, B2) treated with short-segment posterior fixation using ligamentotaxis. Patients with multiple burst fractures, AO type B3 or C injuries, or isolated posterior wall injuries without intracanal fragments were excluded.\u003c/p\u003e\u003cp\u003eA total of 252 patients met the criteria (141 men, 111 women; mean age 43 years, range 13\u0026ndash;69). Mechanisms of injury included falls from a significant height (n\u0026thinsp;=\u0026thinsp;170), road traffic crash (n\u0026thinsp;=\u0026thinsp;62), being struck by an object (n\u0026thinsp;=\u0026thinsp;9), equestrian accidents (n\u0026thinsp;=\u0026thinsp;8), and skiing accidents (n\u0026thinsp;=\u0026thinsp;3). Fracture levels were T11 (n\u0026thinsp;=\u0026thinsp;8), T12 (n\u0026thinsp;=\u0026thinsp;35), L1 (n\u0026thinsp;=\u0026thinsp;108), L2 (n\u0026thinsp;=\u0026thinsp;69), and L3 (n\u0026thinsp;=\u0026thinsp;32). Institutional review boards of all participating centers approved the protocol, and the requirement for individual informed consent was waived. We had nothing to disclose concerning this study.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eRadiological Measurements\u003c/h3\u003e\n\u003cp\u003ePre- and postoperative computed tomography (CT) was obtained in all cases within one week of surgery. Canal compromise was assessed by measuring the anteroposterior canal dimensions at the level of the maximum retropulsed osseous fragment(s) and comparing this value to the average of similar dimensions measured one level above and below the injury. The resulting ratio was defined as the canal compromise ratio (CCR). The reduction rate was then calculated as: (Pre-CCR\u0026thinsp;\u0026minus;\u0026thinsp;Post-CCR)/Pre-CCR\u0026times;100.\u003c/p\u003e\u003cp\u003eMeasurements were independently performed by five spine surgeons blinded to clinical data. Fracture severity was also evaluated using the Load-Sharing Score (LSS) [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] and the AO classification [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\n\u003ch3\u003eSurgical Technique\u003c/h3\u003e\n\u003cp\u003eAll procedures were performed under general anesthesia with the patient in a prone position. Initial postural reduction was applied before pedicle screw insertion. Instrumentation was placed one level above and below the fracture using Schanz pedicle screws (AO Universal Spine System, DePuy Synthes, n\u0026thinsp;=\u0026thinsp;215), CD Horizon Longitude (Medtronic, n\u0026thinsp;=\u0026thinsp;27), or ES2 system (Stryker, n\u0026thinsp;=\u0026thinsp;10). Ligamentotaxis was achieved by controlled segmental distraction through the rods. Detailed descriptions of the surgical techniques can be found in previous publications [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Concomitant vertebroplasty was performed in 109 patients (43%).\u003c/p\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eAll analyses were performed with SPSS v27 (IBM Corp., Armonk, NY). A p value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant. Continuous variables were compared using Welch\u0026rsquo;s t-test, categorical variables with Fisher\u0026rsquo;s exact test. Correlations were assessed by Spearman\u0026rsquo;s rank coefficient and categorized according to Guilford\u0026rsquo;s criteria [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eMultiple linear regression analysis with stepwise selection was used to identify independent predictors of the reduction rate. The dependent variable was the reduction rate; independent variables included age, sex, fracture level (T11\u0026ndash;L1 vs L2\u0026ndash;L3), surgical timing, preoperative CCR, LSS, AO classification (A3\u0026ndash;A4 vs B1\u0026ndash;B2), and use of vertebroplasty. Multicollinearity was excluded by verifying that all inter-variable correlation coefficients were \u0026lt;\u0026thinsp;0.7.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eTiming of Surgery\u003c/h2\u003e\u003cp\u003eSurgical fixation was performed within 24 hours in 42 patients, within 48 hours in 40, between 3\u0026ndash;5 days in 89, and after \u0026ge;\u0026thinsp;6 days in 81 patients (Figure). The mean delay was 3.8 days (range 0\u0026ndash;23).\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eRadiological Outcomes\u003c/h3\u003e\n\u003cp\u003eMean preoperative CCR was 45% (range 5\u0026ndash;89%), improving to 24% (range 3\u0026ndash;80%) postoperatively, corresponding to a mean reduction rate of 44% (range 5\u0026ndash;88%). The mean LSS was 6.7 points (range 4\u0026ndash;9). The distribution of LSS was as follows: 19 patients scored of 9, 59 scored 8, 64 scored of 7, 65 scored 6, 35 scored 5, and 10 scored 4. Fracture distribution by AO type was: A3 (n\u0026thinsp;=\u0026thinsp;91), A4 (n\u0026thinsp;=\u0026thinsp;78), B1 (n\u0026thinsp;=\u0026thinsp;19), B2 (n\u0026thinsp;=\u0026thinsp;64).\u003c/p\u003e\n\u003ch3\u003eStatistical Results\u003c/h3\u003e\n\u003cp\u003eUnivariate analysis revealed that, among dichotomous variables, the reduction rate was significantly higher in patients with T11-L1 fractures compared to those with L2-L3 fractures (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Surgical delay, age, preoperative CCR, and LSS were not significantly correlated with reduction rate (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Multiple linear regression identified two independent predictors of higher reduction rate: fracture level (T11\u0026ndash;L1; p\u0026thinsp;=\u0026thinsp;0.004) and AO type B fracture (p\u0026thinsp;=\u0026thinsp;0.043, Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The scatter plot of reduction rate versus time to surgery demonstrated no linear correlation (r =-0.109, p\u0026thinsp;=\u0026thinsp;0092, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\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\u003eUnivariate analysis\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\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\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCausal factors\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eN\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eReduction rate (SD)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eGender\u003c/span\u003e male\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e141\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e44.1 (23.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003efemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e111\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e41.9 (18.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.407\u003csup\u003et\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eAffected level\u003c/span\u003e T11-L1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e151\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e46.8 (21.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eL2-L3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e101\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e38.3 (21.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.004\u003csup\u003et\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eCombination of Vertebroplasty\u003c/span\u003e with\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e109\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e44.8 (24.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ewithout\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e143\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e41.6 (19.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.260\u003csup\u003et\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eAO classification\u003c/span\u003e A3 or A4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e169\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e41.4 (19.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eB1 or B2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e47.2 (24.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.050\u003csup\u003et\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eSD, standard deviation, t,Welch\u0026rsquo;s t test was used\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eCorrelation analysis between reduction rate and other continuous variables.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\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\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003er\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.095\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.141\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDuration from injury to surgery\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-1.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.089\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePreoperative canal compromise ratio\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.015\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.814\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLoad-sharing score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.076\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.241\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"3\"\u003eSpearman\u0026rsquo;s correlation coefficient by rank test was used.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMultiple linear regression analyses\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eUnstandardized\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003eStandardized\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSE\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eβ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003et\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eL2 or L3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-8.012\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.760\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-0.184\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-2.903\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.004\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAO type B fracture\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.853\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.877\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.129\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.034\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.043\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003cem\u003eB\u003c/em\u003e, unstandardized coefficients; \u003cem\u003eβ\u003c/em\u003e, standardized \u003cem\u003eB\u003c/em\u003e coefficients; SE, standard error; and t, t-value\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThoracolumbar burst fractures frequently cause canal compromise due to retropulsed bone fragments. Short-segment posterior fixation is widely used for these injuries, providing deformity correction and canal restoration through ligamentotaxis [\u003cspan additionalcitationids=\"CR11 CR12\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Because these injuries often result from high-energy trauma, patients frequently present with multiple concomitant injuries, and spinal fixation may be delayed until systemic stabilization is achieved. This situation raises concern that delayed surgery might compromise ligamentotaxis-based canal reduction.\u003c/p\u003e\u003cp\u003ePrevious studies have discussed factors influencing ligamentotaxis, such as fragment displacement or posterior longitudinal ligament impingement [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], but have not accounted for fracture morphology or level. The present multicenter analysis addressed these factors comprehensively using AO classification, Load-Sharing Score (LSS), and fracture level.\u003c/p\u003e\u003cp\u003eOur findings showed that fracture level and AO type were independent predictors of canal reduction, whereas surgical timing, age, preoperative canal compromise, and LSS were not. Fractures at T11\u0026ndash;L1 achieved higher reduction rates than those at L2\u0026ndash;L3. This may reflect the unique biomechanical properties of the thoracolumbar junction, which acts as a transition zone between the rigid thoracic and flexible lumbar spine, concentrating stress while maintaining relatively strong ligamentous tension and lower axial load [\u003cspan additionalcitationids=\"CR19\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThese anatomical and biomechanical characteristics may facilitate more effective indirect reduction through ligamentotaxis. In contrast, lower lumbar levels experience higher compressive forces and weaker posterior ligament support, limiting the efficiency of ligamentotaxis [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. AO type B fractures also exhibited superior reduction compared with type A fractures. The posterior tension-band failure characteristic of type B injuries likely allows greater fragment mobility during distraction, consistent with biomechanical evidence that stepwise sectioning of the posterior ligamentous complex increases spinal motion and neutral zone. Conversely, the intact posterior elements of type A burst fractures contribute to rigid anterior collapse, restricting fragment movement and reducing reduction potential [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. These findings emphasize that fracture morphology and level play more decisive roles in canal restoration than surgical delay.\u003c/p\u003e\u003cp\u003eSurgical timing was not correlated with reduction quality. The mean interval from injury to fixation was 3.8 days, reflecting common clinical conditions. Even with several days of delay, short-segment fixation achieved effective canal restoration, suggesting that the mechanism of ligamentotaxis remains functional during this period. These results are consistent with earlier studies showing no measurable deterioration in reduction with moderate delay. Clinically, this supports prioritizing resuscitation and associated injury management in neurologically intact patients, reserving urgent fixation for those with progressive neurological deficit or severe canal compromise.\u003c/p\u003e\u003cp\u003eThis study has limitations. Its retrospective design may introduce selection bias, and only radiological outcomes were assessed. The number of patients undergoing surgery beyond seven days was small, limiting sensitivity to detect very late effects. Furthermore, postoperative CT evaluation was limited to the early phase, and subsequent changes could not be assessed. Future prospective studies incorporating neurological and functional outcomes are warranted.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, the timing of surgery does not significantly affect the quality of canal reduction following short-segment posterior fixation for thoracolumbar burst fractures. Reduction success depends primarily on fracture level and morphology, with T11\u0026ndash;L1 and AO type B fractures showing superior outcomes. These results suggest that modest surgical delay is acceptable in polytrauma patients without neurological deficit, provided that adequate fixation and ligamentotaxis are achieved.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eH.A, A.O, T. K, H.T, K.N acquired the data. H. A wrote the main manuscript text. S.T performed statistical analysis. Y. I provided\u0026nbsp;supervision\u0026nbsp;for\u0026nbsp;the\u0026nbsp;project\u0026nbsp;and\u0026nbsp;manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHu R, Mustard CA, Burns C. Epidemiology of incident spinal fracture in a complete population. Spine. 1996;21:492\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDai LY, Yao WF, Cui YM, Zhou Q. Thoracolumbar fractures in patients with multiple injuries: diagnosis and treatment-a review of 147 cases. J Trauma. 2004;56:348\u0026ndash;55.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDai LY, Jiang SD, Wang XY, Jiang LS. A review of the management of thoracolumbar burst fractures. Surg Neurol. 2007;67:221\u0026ndash;31.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGertzbein SD. Scoliosis Research Society. Multicenter spine fracture study. Spine (Phila Pa 1976). 1992;17:528\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWood K, Buttermann G, Mehbod A, Garvey T, Jhanjee R, Sechriest V. Operative compared with non-operative treatment of a thoracolumbar burst fracture without neurological deficit. A prospective, randomized study. J Bone Joint Surg Am. 2003;85:773\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDenis F. The three-column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine. 1983;8:817\u0026ndash;31.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEbelke DK, Asher MA, Neff JR, Kraker DP. Survivorship analysis of VSP spine instrumentation in the treatment of thoracolumbar and lumbar burst fractures. Spine 1991; 16: S428\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMcCormack T, Karaikovic E, Gaines RW. The load sharing classification of spine fractures. Spine. 1994;19:1741\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMcLain RF, Sparling E, Benson DR. Early failure of short-segment pedicle instrumentation for thoracolumbar fractures. A preliminary report. J Bone Joint Surg Am. 1993;75:162\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eToyone T, Tanaka T, Kato D, Kaneyama R, Otsuka M. The treatment of acute thoracolumbar burst fractures with transpedicular intracorporeal hydroxyapatite grafting following indirect reduction and pedicle screw fixation: a prospective study. Spine. 2006;31:E208\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAono H, Tobimatsu H, Ariga K, Kuroda M, Nagamoto Y, Takenaka S, et al. Surgical outcomes of temporary short-segment instrumentation without augmentation for thoracolumbar burst fractures. Injury. 2016;47:1337\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAono H, Ishii K, Tobimatsu H, Nagamoto Y, Takenaka S, Furuya M, et al. Temporary short-segment pedicle screw fixation for thoracolumbar burst fractures. comparative study with or without vertebroplasty. Spine J. 2017;17:1113\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKanna RM, Shetty AP, Rajasekaran S. Posterior fixation including the fractured vertebra for severe unstable thoracolumbar fractures. Spine J. 2015;15:256\u0026ndash;64.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eReinhold M, Audig\u0026eacute; L, Schnake KJ, Ballabarba C, Dai LY, Oner FV. AO spine injury classification system: a revision proposal for the thoracic and lumbar spine. Eur Spine J. 2013;22:2184\u0026ndash;201.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGuilford JP. Fundamental statistics in psychology and education. New York: McGraw Hill; 1956.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng Y, Zhang L, Shi T, Lv H, Zhang L, Tang P. Relationship between fracture-relevant parameteres of thoracolumbar burst fractures and the reduction of intara-canal fracture fragment. J Orthop Surg Res. 2015;27:10131.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang XB, Lu GH, Li J, Wang B, Lu C, Phan K. Posterior distraction and instrumentation cannnot always reduce displaced and rotated posterosuperior fracture fragments in thoracolumbar burst fracture. Clin Spine Surg. 2017;30:E317\u0026ndash;322.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eResnick DK, Weller SJ, Benzel EC. Biomechanics of the thoracolumbar spine. Neurosurg Clin N Am. 1997;8(4):455\u0026ndash;69.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSmith HE, Anderson DG, Vaccaro AR, Albert TJ, et al. Anatomy, Biomechanics, and Classification of Thoracolumbar Injuries. Semin Spine Surg. 2010;22(1):2\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLu H, Zhang Q, Ding F, Wu Q, Liu R. Establishment and validation of a T12\u0026ndash;L2 three-dimensional finite element model of the thoracolumbar segments. Am J Transl Res. 2022;14(3):1606\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYoganandan N, Arun MWJ, Stemper BD, Pintar FA, Maiman DJ. Biomechanics of human thoracolumbar spinal column trauma from vertical impact loading. Ann Adv Automot Med. 2013;57:155\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePanjabi MM, Brand RA, White AA III. Mechanical properties of the human thoracic spine as shown by three-dimensional load-displacement curves. J Bone Joint Surg Am. 1976;58(5):642\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi Y, Shen Z, Huang M, Wang X. Stepwise resection of the posterior ligamentous complex for stability of thoracolumbar compression fracture: An in vitro biomechanical investigation. Med (Baltim). 2017 Sep;96(35):e7873.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWu CC, Jin HM, Yan YZ, Chen J, Wang K, Wang JL et al. Biomechanical role of the thoracolumbar ligaments of the posterior ligamentous complex. World Neurosurg. 2018:112; e125-133.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHeuer F, Schmidt H, Klezl Z, Claes L, Wilke HJ. Stepwise reduction of functional spinal structures increase range of motion and change lordosis angle. J Biomech. 2007;40(2):271\u0026ndash;80.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-trauma-and-emergency-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejot","sideBox":"Learn more about [European Journal of Trauma and Emergency Surgery](http://link.springer.com/journal/68)","snPcode":"68","submissionUrl":"https://submission.nature.com/new-submission/68/3","title":"European Journal of Trauma and Emergency Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"thoracolumbar burst fracture, short-segment fixation, ligamentotaxis, canal compromise, surgical timing, predictors","lastPublishedDoi":"10.21203/rs.3.rs-8026231/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8026231/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e\u003cp\u003eIn patients with thoracolumbar burst fractures, surgical delay is often unavoidable due to concomitant injuries. Concerns persist that delayed surgery may compromise indirect reduction of retropulsed fragments via ligamentotaxis. This study aimed to determine whether the timing of surgery affects the quality of intracanal fragment reduction and identify independent predictors of successful reduction following short-segment posterior fixation.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eThis multicenter study included 252 patients who sustained a single traumatic thoracolumbar burst fracture and underwent short-segment fixation. The canal compromise ratio (CCR) was measured on pre- and postoperative CT scans, and the reduction rate was calculated using this formula: Reduction rate = (Preoperative CCR\u0026thinsp;\u0026minus;\u0026thinsp;Postoperative CCR) / Preoperative CCR \u0026times; 100. Multiple logistic regression analysis identified predictors of reduction quality including age, sex, affected level, surgical timing, AO classification, load-sharing score (LSS), preoperative CCR, and concomitant vertebroplasty,\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eThe study included 141 males and 111 females. The mean time from injury to surgery was 3.8 days. The mean CCR improved from 45% to 24%, yielding a mean reduction rate of 44%. Multiple linear regression analysis revealed that T11 to L1 and AO type B fractures were associated with a significantly higher reduction rate. Notably, the time from injury to surgery showed no significant correlation with reduction quality.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eShort-segment posterior fixation can achieve satisfactory canal reduction through ligamentotaxis, even when surgical intervention is delayed several days after trauma. In polytrauma patients without neurological deficit, a short postponement of surgery may be acceptable to optimize systemic stabilization without compromising spinal canal restoration.\u003c/p\u003e","manuscriptTitle":"Timing of Surgery and Predictors of Canal Reduction after Short- segment Fixation for Thoracolumbar Burst Fractures","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-21 01:03:56","doi":"10.21203/rs.3.rs-8026231/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-01-26T08:42:40+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-27T17:18:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"288984436977329739295798263916013748055","date":"2025-11-12T13:53:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"164682134290354202545691608975653562357","date":"2025-11-11T10:49:06+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-11-10T13:15:52+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-11-09T13:03:09+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-11-07T12:54:19+00:00","index":"","fulltext":""},{"type":"submitted","content":"European Journal of Trauma and Emergency Surgery","date":"2025-11-04T08:00:07+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-trauma-and-emergency-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejot","sideBox":"Learn more about [European Journal of Trauma and Emergency Surgery](http://link.springer.com/journal/68)","snPcode":"68","submissionUrl":"https://submission.nature.com/new-submission/68/3","title":"European Journal of Trauma and Emergency Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"3d9697cb-52d2-45de-b2e6-54d7faece3fc","owner":[],"postedDate":"November 21st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-03-30T16:25:57+00:00","versionOfRecord":{"articleIdentity":"rs-8026231","link":"https://doi.org/10.1007/s00068-026-03153-0","journal":{"identity":"european-journal-of-trauma-and-emergency-surgery","isVorOnly":false,"title":"European Journal of Trauma and Emergency Surgery"},"publishedOn":"2026-03-23 16:11:10","publishedOnDateReadable":"March 23rd, 2026"},"versionCreatedAt":"2025-11-21 01:03:56","video":"","vorDoi":"10.1007/s00068-026-03153-0","vorDoiUrl":"https://doi.org/10.1007/s00068-026-03153-0","workflowStages":[]},"version":"v1","identity":"rs-8026231","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8026231","identity":"rs-8026231","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}