Effect of different lumbar-iliac fixation and sacral slope for Tile C1.3 pelvic fractures: a biomechanical study.

BACKGROUND: Lumbar-iliac fixation (LIF) is a common treatment for Tile C1.3 pelvic fractures, but different techniques, including L4-L5/L5 unilateral LIF (L4-L5/L5 ULIF), bilateral LIF (BLIF), and L4-L5/L5 triangular osteosynthesis (L4-L5/L5 TOS), still lack biomechanical evaluation. The sacral slope (SS) is key to the vertical shear of the sacrum but has not been investigated for its biomechanical role in lumbar-iliac fixation. The aim of this study is to evaluate the biomechanical effects of different LIF and SS on Tile C1.3 pelvic fracture under two-legged standing load in human cadavers. METHODS: Eight male fresh-frozen human lumbar-pelvic specimens were used in this study. Compressive force of 500 N was applied to the L4 vertebrae in the two-legged standing position of the pelvis. The Tile C1.3 pelvic fracture was prepared, and the posterior pelvic ring was fixed with L5 ULIF, L4-L5 ULIF, L5 TOS, L4-L5 TOS, and L4-L5 BLIF, respectively. Displacement and rotation of the anterior S1 foramen at 30° and 40° sacral slope (SS) were analyzed. RESULTS: The displacement of L4-L5/L5 TOS in the left-right and vertical direction, total displacement, and rotation in lateral bending decreased significantly, which is more pronounced at 40° SS. The difference in stability between L4-L5 and L5 ULIF was not significant. BLIF significantly limited left-right displacement. The ULIF vertical displacement at 40° SS was significantly higher than that at 30° SS. CONCLUSIONS: This study developed an in vitro two-legged standing pelvic model and demonstrated that TOS enhanced pelvic stability in the coronal plane and cephalad-caudal direction, and BLIF enhanced stability in the left-right direction. L4-L5 ULIF did not further improve the immediate stability, whereas TOS is required to increase the vertical stability at greater SS.

Can conservative treatment be effective for thoracolumbar injuries patients with TLICS scores of 4 or 5? An analysis of initial radiological findings and clinical risk factors for treatment failure.

BACKGROUND: This study aimed to assess the outcomes of conservative management in patients with thoracolumbar fractures classified with a Thoracolumbar Injury Classification and Severity (TLICS) score of 4 or 5, and to analyze initial imaging findings and clinical risk factors associated with treatment failure. METHODS: In this retrospective analysis, patients with thoracolumbar fractures and a TLICS score of 4 or 5, determined through MRI from January 2017 to December 2020, were included. Patients undergoing conservative treatment were categorized into two groups: Group 1 (treatment success) and Group 2 (treatment failure), based on initial and 6-month follow-up outcomes. Clinical data were compared between the two groups. Initial radiological assessments included three kyphosis measurements (Cobb angle, Gardner angle, and sagittal index [SI]), anterior and posterior wall height, and central canal compromise (CC). Additionally, risk factors contributing to treatment failure were analyzed. RESULTS: The conservative treatment group comprised 84 patients (mean age, 60.25 ± 15.53; range 22-85; 42 men), with 57 in Group 1 and 27 in Group 2. Group 2 exhibited a higher proportion of women, older age, and lower bone mass density (p = 0.001-0.005). Initial imaging findings in Group 2 revealed significantly greater values for Cobb angle, SI, and CC (p = 0.001-0.045 or < 0.001; with cutoff values of 18.2, 12.8, and 7.8%, respectively), and lower anterior wall height (p = 0.001), demonstrating good to excellent interobserver agreement (0.72-0.99, p < 0.001). Furthermore, osteoporosis was identified as a significant risk factor (odds ratio = 5.64, p = 0.008). CONCLUSION: Among patients with TLICS scores of 4 or 5, those experiencing conservative treatment failure exhibited unfavorable initial radiological findings, a higher proportion of women, advanced age, and osteoporosis. Additionally, osteoporosis emerged as a significant risk factor for treatment failure.

Surgical outcomes of robotic-assisted percutaneous fixation for thoracolumbar fractures in patients with ankylosing spondylitis.

BACKGROUND: Spinal fractures in patients with ankylosing spondylitis (AS) mainly present as instability, involving all three columns of the spine, and surgical intervention is often considered necessary. However, in AS patients, the significant alterations in bony structure and anatomy result in a lack of identifiable landmarks, which increases the difficulty of pedicle screw implantation. Therefore, we present the clinical outcomes of robotic-assisted percutaneous fixation for thoracolumbar fractures in patients with AS. METHODS: A retrospective review was conducted on a series of 12 patients diagnosed with AS. All patients sustained thoracolumbar fractures between October 2018 and October 2022 and underwent posterior robotic-assisted percutaneous fixation procedures. Outcomes of interest included operative time, intra-operative blood loss, complications, duration of hospital stay and fracture union. The clinical outcomes were assessed using the visual analogue scale (VAS) and Oswestry Disability Index (ODI). To investigate the achieved operative correction, pre- and postoperative radiographs in the lateral plane were analyzed by measuring the Cobb angle. RESULTS: The 12 patients had a mean age of 62.8 ± 13.0 years and a mean follow-up duration of 32.7 ± 18.9 months. Mean hospital stay duration was 15 ± 8.0 days. The mean operative time was 119.6 ± 32.2 min, and the median blood loss was 50 (50, 250) ml. The VAS value improved from 6.8 ± 0.9 preoperatively to 1.3 ± 1.0 at the final follow-up (P < 0.05). The ODI value improved from 83.6 ± 6.1% preoperatively to 11.8 ± 6.6% at the latest follow-up (P < 0.05). The average Cobb angle changed from 15.2 ± 11.0 pre-operatively to 8.3 ± 7.1 at final follow-up (P < 0.05). Bone healing was consistently achieved, with an average healing time of 6 (5.3, 7.0) months. Of the 108 screws implanted, 2 (1.9%) were improperly positioned. One patient experienced delayed nerve injury after the operation, but the nerve function returned to normal upon discharge. CONCLUSION: Posterior robotic-assisted percutaneous internal fixation can be used as an ideal surgical treatment for thoracolumbar fractures in AS patients. However, while robot-assisted pedicle screw placement can enhance the accuracy of pedicle screw insertion, it should not be relied upon solely.

Evaluation and Management of Thoracolumbar Spine Trauma in Pediatric Patients: A Critical Analysis Review.

¼ Pediatric thoracolumbar trauma, though rare, is an important cause of morbidity and mortality and necessitates early, accurate diagnosis and management.¼ Obtaining a detailed history and physical examination in the pediatric population can be difficult. Therefore, the threshold for advanced imaging, such as magnetic resonance imaging, is low and should be performed in patients with head injuries, altered mental status, inability to cooperate with examination, and fractures involving more than 1 column of the spine.¼ The classification of pediatric thoracolumbar trauma is based primarily on adult studies and there is little high-level evidence examining validity and accuracy in pediatric populations.¼ Injury pattern and neurologic status of the patient are the most important factors when determining whether to proceed with operative management.

A Novel Leverage Technique Using Monoaxial Pedicle Screw for Reduction of Thoracolumbar Compression Fractures: Surgical Technique and Analysis of Radiological Parameters.

OBJECTIVE: Thoracolumbar compression fractures resulting from high-energy injuries are a common type of spinal fracture. Satisfying reduction of compressive vertebra body is essential for the clinical outcome. However, traditional distraction technique may lead to complications including pedicle screw loosening, pedicle screw breakage, and postoperative back pain because of excessive distraction. In this study, we reported a novel technique for reduction. Additionally, the effect and postoperative radiological parameters of this technique were compared with those of traditional distraction technique. METHODS: The clinical data of 80 patients who had been treated with posterior pedicle screw fixation from January 2019 to December 2020 was retrospectively analyzed. Thirty-six patients were performed with the leverage technique, while 22 patients were treated with the traditional distraction technique. When pedicle screw fixation was performed with either the leverage technique or the traditional distraction technique, fracture reduction was completed with monoaxial pedicle screws using either the leverage maneuver or distraction of adjacent vertebrae. Clinical evaluation, including operation time, hospital stay, blood loss volume, and postoperative complications were collected. The American Spinal Injury Association (ASIA) score for neurological condition and the visual analog scale (VAS) score for pain were used to evaluate the patients' functional outcome. The radiographic analysis included local kyphotic angle (LKA), regional kyphotic angle (RKA), anterior vertebral height (AVH), posterior vertebral height (PVH), and sagittal compression (SC). The student t-test and the χ2-test (or the Fisher exact test) were used to compare the outcome measures between the two groups. RESULTS: The leverage group comprised 36 patients, while 44 patients were included in the distraction group. No statistically significant differences were found in the demographic data. The VAS score in the leverage group (3.0 ± 0.8) was significantly lower than that in the distraction group (4.2 ± 0.6) on postoperative day 1. Total correction of the LKA in the leverage group (11.5 ± 2.5°) was significantly higher than that in the distraction group (7.1 ± 1.3°) (p = 0.0004). Total correction of the RKA was higher in the leverage group (12.1 ± 4.3°) than in the distraction group (6.1 ± 0.9°) (p = 0.005). The ratio of rear pillar /front pillar correction was 0.35 ± 0.13 and 0.89 ± 0.18 in the leverage and distraction groups, respectively (p = 0.014). Total correction of the upper and lower foraminal height in the leverage group was significantly less than that in the distraction group. The leverage group had significantly higher correction of the upper and lower intervertebral space height than the distraction group. CONCLUSIONS: Our novel leverage technique provided better kyphotic reduction and restoration than compared to conventional distraction technique in the surgical treatment of thoracolumbar compression fractures.

The Comparison between Spinal Facet Joint Toothed Plate and Traditional Pedicle Screw-rod on Reduction of Thoracolumbar Fracture.

OBJECTIVE: Thoracolumbar fractures are one of the most common fractures in clinical practice. Surgical intervention is recommended to restore spinal alignment or decompress the nerves when there are unstable fractures or neurological injuries. However, after excessive forward thrust force restoration, facet joint dislocation often occurs between the upper vertebra and the fractured vertebra, which usually leads to unsatisfactory reduction outcomes. Herein, we propose a novel spinal facet joint toothed plate to assist in fracture reduction. The purpose of this study is to evaluate the effectiveness of the new spinal facet joint toothed plate in preventing facet joint dislocation, and its advantages compared to traditional pedicle screw-rod decompression. METHODS: A total of 26 patients in the toothed plate group and 93 patients in the traditional group who experienced thoracolumbar fracture with reduction were retrospectively included. Relevant patients' information and clinical parameters were collected. Furthermore, visual analogue scores (VAS) scores and Oswestry disability index (ODI) scores were also collected. Moreover, imaging parameters were calculated based on radiographs. Correlated data were analyzed by χ2 test and t test. RESULTS: All patients in this study had no postoperative complications. Postoperative VAS scores and ODI scores (p < 0.001) were statistically significant (p < 0.001) in both groups compared with preoperative scores and further decreased (p < 0.001) at final follow-up. In addition, the postoperative vertebral margin ratio (VMR) (p < 0.001) and vertebral angle of the injured vertebrae (p < 0.001) were significantly improved compared with the preoperative period. There were no significant differences in postoperative VAS scores and ODI scores between the two groups. However, toothed plate reduction significantly improved the VMR (p < 0.05) and vertebral angle (p < 0.05) compared with conventional reduction. Ultimately, the total screw accuracy was 98.72% (sum of levels 0 and I), with 100% screw accuracy in the segment related to the tooth plate in the tooth plate group. The dislocation rate was higher in the conventional group (6.45%) than in the new serrated plate repositioning group (0.00%). CONCLUSION: The facet toothed plate assisted reduction method prevents facet joint dislocation and improves fracture reduction compared to traditional reduction technique, hence it could be considered as a novel surgical strategy for thoracolumbar fracture reduction.

Influence of muscle activation on lumbar injury under a specific +Gz load.

PURPOSE: The present study aimed to analyze the influence of muscle activation on lumbar injury under a specific +Gz load. METHODS: A hybrid finite element human body model with detailed lumbar anatomy and lumbar muscle activation capabilities was developed. Using the specific +Gz loading acceleration as input, the kinematic and biomechanical responses of the occupant's lower back were studied for both activated and deactivated states of the lumbar muscles. RESULTS: The results indicated that activating the major lumbar muscles enhanced the stability of the occupant's torso, which delayed the contact between the occupant's head and the headrest. Lumbar muscle activation led to higher strain and stress output in the lumbar spine under +Gz load, such as the maximum Von Mises stress of the vertebrae and intervertebral discs increased by 177.9% and 161.8%, respectively, and the damage response index increased by 84.5%. CONCLUSION: In both simulations, the occupant's risk of lumbar injury does not exceed 10% probability. Therefore, the activation of muscles could provide good protection for maintaining the lumbar spine and reduce the effect of acceleration in vehicle travel direction.

Thoracolumbar fractures patients undergoing posterior pedicle screw fixation can benefit from drainage.

PURPOSE: To explore whether it is necessary to put drain tubes after posterior pedicle screw fixation of thoracolumbar fractures. METHODS: From April 2020 to January 2023, a total of 291 patients with recent thoracolumbar fractures (AO type-A or type-B) who received the pedicle screw fixation operation were enrolled retrospectively. In 77 patients, drain tubes were used in the pedicle screw fixation surgery, while no drain tubes were placed in the other group. After gleaning demographic information and results of lab examination and imageology examination, all data were put into a database. Independent-sample t-tests, Pearson Chi-Square tests, Linear regression analysis, and correlation analysis were then performed. RESULTS: Compared to the control group, the drainage group had significantly lower postoperative CRP levels (P = 0.047), less use of antipyretics (P = 0.035), higher ADL scores (P = 0.001), and lower NRS scores (P < 0.001) on the 6th day after surgery. Other investigation items, such as demographic information, operation time, intraoperative blood loss, body temperature, and other preoperative and postoperative lab results, showed no significant differences. CONCLUSIONS: The use of a drain tube in the pedicle screw fixation of thoracolumbar fractures is correlated with the improvement of patients' living and activity ability and the reduction of inflammation, postoperative fever and pain.

Adjacent vertebral fractures in the lumbar and thoracic spine after balloon kyphoplasty: A finite element analysis.

The purpose of the present study was to mechanically verify after vertebral augmentation (AVA) scores using a finite element method (FEM) with accurate material constants of balloon kyphoplasty (BKP) cement. Representative cases with AVA scores of 1 (case 1), 3 (case 2), and 5 (case 3) among patients with vertebral body fractures who underwent BKP were analyzed. A FEM model consisting of 5 vertebral bodies was created, including the injured vertebral body in each case. The amount of displacement for each load (up to 4000 N) between the upper and lower vertebral bodies of each model was measured. Young modulus of the BKP cement was calculated from actual measurements using the EZ-Test EZ-S (Shimadzu Corporation, Kyoto, Japan). In all cases, the number of shell elements (209,296-299,876), solid elements (1913,029-2417,671), and nodes (387,848-487,756) were similar, indicating that FEM modeling was comparable among the cases. Young modulus of BKP cement, calculated using EZ-Test EZ-S, was 572 MPa. Fractures were detected by compressive forces of 3300 N (upper) and 3300 N (lower), 3000 N (upper) and 3100 N (lower), and 1200 N (upper) and 1200 N (lower) in cases 1, 2, and 3, respectively. The AVA scoring system was mechanically verified using the accurate material constants of BKP cement. A multicenter survey and external validation are therefore required for the clinical implementation of the AVA score.

Comparison Clinical Outcomes of Posterior Short Segment Transpedicular Fixation with or without Injured Vertebra Fixation in Thoracolumbar Burst Fracture: A Retrospective Study.

AIM: To evaluate and compare clinical outcomes between the posterior short-segment pedicle fixation with injured vertebra fixation (PSPFI) and fixation without injured vertebra fixation (PSPF) for thoracolumbar burst fracture (TLBF). MATERIAL AND METHODS: In this retrospective study, a total of 78 patients with TLBF were included and assigned to PSPFI (n=46) and PSPF (n=32) groups. The operative time, blood loss, perioperative complications, Oswestry disability index (ODI), and visual analog pain score (VAS) were examined immediately after surgery, 1 month, 3 months, and 1 year after surgery. Moreover, the postoperative vertebral height correction rate and postoperative Cobb angle correction rate were examined immediately and 1 year after surgery, as well as the corrected vertebral height loss rate and Cobb angle correction loss rate. RESULTS: No significant difference was identified in terms of operative time, blood loss, perioperative complications, ODI, and VAS after surgery (p > 0.05) between the PSPFI and PSPF groups. Moreover, the postoperative vertebral height correction rate and postoperative Cobb angle correction rate showed no difference between the groups as well. However, the PSPFI group had a significantly lower loss rate in terms of corrected vertebral height loss rate and Cobb angle correction loss rate than the PSPF group 1 year after surgery (p < 0.05). CONCLUSION: PSPFI and PSPF achieve similar clinical outcomes. However, posterior short-segment pedicle fixation with injured vertebra significantly maintains vertebral height correction rate and Cobb angle correction rate, which serve as a better choice for the treatment of TLBF.

Comparison Between Intraoperative Target Area Cement-Enhanced Percutaneous Vertebroplasty and Conventional Percutaneous Vertebroplasty for Osteoporotic Thoracolumbar Non-Total Vertebral Fractures.

AIM: To compare the efficacy and feasibility of target area cement-enhanced percutaneous vertebroplasty (PVP) and conventional PVP in osteoporotic thoracolumbar non-total vertebral fractures. MATERIAL AND METHODS: Retrospective analysis of one hundred and two patients treated in our hospital from March 2020 to May 2021 and divided into groups A (targeted) and B (conventional PVP). The Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), anterior vertebral height ratio, intraoperative bleeding, operative time, bone cement volume, complications, and refracture of the injured vertebra were evaluated in both groups. RESULTS: The 2 days and 1-year post-operative VAS and ODI scores improved significantly in both groups (p < 0.05). The 2 days post-operative VAS and ODI scores were better in group A (p < 0.05), and there was no significant difference in the scores between the groups at the last follow-up (p > 0.05). The anterior vertebral height ratios were significantly higher in both groups 2 days postoperatively (p < 0.05); however, there was no significant difference in the 2 days and 1-year post-operative ratios in group A (p > 0.05). The anterior vertebral height ratio reduced in group B after 1 year compared to the 2 days post-operative value (p < 0.05). There was no statistical difference in intraoperative bleeding and the operative time between the groups (p > 0.05), and the bone cement volume was lesser in group A (p < 0.05). Six patients in group A and four patients in group B demonstrated cement leakage, the difference was not statistically significant (p > 0.05). Three patients in group A and 11 patients in group B demonstrated refracture, the difference was statistically significant (p < 0.05). CONCLUSION: Target area cement-enhanced PVP can effectively relieve short-term pain and functional disability and reduce the long-term possibility of secondary collapse. Therefore, it is a technically feasible and efficacious method for the treatment of osteoporotic thoracolumbar non-total vertebral fractures.

Is open anterior advantageous to posterior decompression and reconstruction in fresh A3 to C3/AO type thoracolumbar junction fractures? A systematic review.

INTRODUCTION: Surgical outcomes of open anterior and open posterior approaches, for thoracolumbar A3 to C3/AO type fractures, are compared. METHODS: A PubMed search was conducted from 1990 to 2024 related to anterior, posterior, and combined approaches. Inclusion criteria: Fresh traumatic T10 to L2 fractures, age ≥13 years, ≥10 cases, minimum follow-up 6 months. Exclusion criteria: Cadaveric studies, pathological fractures, reviews, thoracoscopy-assisted, mini-open lateral (MOLA) and minimal invasive anterior or posterior approaches. Coleman Methodology Scores (CMS) (modified for spinal trauma) indicated potential selection bias in the selected studies. PRISMA guidelines were adapted. RESULTS: Nineteen studies with 847 participants were selected. The average CMS quality score was fair. The anterior approach, although it better decompresses the compromised spinal canal, it is also associated with increased surgical complications compared to the posterior approach. The neurological outcome, the loss of correction and the reoperation rate, were similar to both approaches. This systematic review favors posterior approach. CONCLUSIONS: The anterior approach is demanding and is associated with a higher rate of surgical complications compared to the posterior approach. The limitations of the selected studies included inconsistence in the: 1) approaches selection, 2) classifications of the fracture types and the neurological status and 3) variety of instrumentations used. PROSPERO ID: CRD42023484222.

Double Level Non-Contiguous Traumatic Lumbar Disc Herniation Presenting With Cauda Equina Syndrome: A Case Report and Literature Review.

CASE: A 52-year-old man presented with cauda equina syndrome after a motorcycle accident. Magnetic resonance imaging revealed traumatic disc herniation, at L2-L3 and L5-S1 levels without bony injury. He was managed successfully by wide laminectomy and microdiscectomy at both levels with complete neurological recovery at 2-month follow-up. CONCLUSION: With a reported incidence of 0.4%, traumatic disc herniation in the lumbar region is an uncommon occurrence that may resemble a spinal epidural hematoma in acute trauma. Although MRI may not reliably differentiate spinal epidural hematoma from disc herniation, urgent surgical intervention may be required in profound neurological deficits.

Surgical management of lower limb radiculopathy following acute singe-level osteoporotic vertebral fracture of lower lumbar spine in geriatric patient: a retrospective study.

BACKGROUND: Radiculopathy of the lower limb after acute osteoporotic vertebral fractures (OVFs) in the lower lumbar spine is uncommon in geriatric patients. Moreover, surgical intervention is generally recommended in patients who are irresponsive to conservative treatment. Determining an optimum surgical strategy is challenging considering the poor general condition of this population. Thus, herein, we established an algorithm for surgically managing this clinical scenario, hoping to provide a reference for making a surgical decision. METHODS: We retrospectively studied patients who suffered from new-onset radiculopathy of the lower limb after acute single-level OVFs in the lower lumbar spine and eventually underwent surgical intervention at our department. Information on the demographics, bone quality, AO spine classification of the vertebral fracture, pre-existing degenerative changes, including foraminal stenosis and lumbar disc herniation, and surgical intervention type was collected. Additionally, clinical outcomes, including preoperative and postoperative visual analog scale (VAS) scores for back and leg pain, Oswestry disability index (ODI), and MacNab criterion for response to surgery, were evaluated. RESULTS: From September 2019 to December 2021, a total of 22 patients with a mean age of 68.59 ± 9.74 years were analyzed. The most involved vertebra was L5 (54.5%), followed by L4 (27.3%) and L3 (18.2%). Among the 22 patients, 15 (68.2%) were diagnosed with the A1 type fracture of AO classification, and among them, 11 (73.3%) were characterized by the collapse of the inferior end plate (IEP). Three patients (13.6%) suffered from A2-type fractures, whereas four patients (18.2%) suffered from A3-type fractures. Pre-existing degenerative changes were observed in 12 patients (54.5%) of the patients. A total of 16 patients (72.7%) were treated by percutaneous kyphoplasty (PKP). Additionally, three patients underwent posterior instrumentation and fusion, two patients underwent a secondary endoscopic foraminoplasty, and one patient underwent a secondary radiofrequency ablation. The mean follow-up period was 17.42 ± 9.62 months. The mean VAS scores for leg and back pain and ODI decreased significantly after the surgery (P < 0.05). The total satisfaction rate at the last follow-up was 90.9% per the Macnab criterion. CONCLUSION: Patients with OVFs in the IEP are predisposed to suffer from radiculopathy of the lower limb. PKP alone or in combination with other minimally invasive surgical strategies is safe and effective in treating stable fractures. Additionally, aggressive surgical intervention should be considered in patients with unstable fractures or severe foraminal encroachment.

The efficacy of machine learning models in forecasting treatment failure in thoracolumbar burst fractures treated with short-segment posterior spinal fixation.

BACKGROUND: Although short-segment posterior spinal fixation (SSPSF) has shown promising clinical outcomes in thoracolumbar burst fractures, the treatment may be prone to a relatively high failure rate. This study aimed to assess the effectiveness of machine learning models (MLMs) in predicting factors associated with treatment failure in thoracolumbar burst fractures treated with SSPSF. METHODS: A retrospective review of 332 consecutive patients with traumatic thoracolumbar burst fractures who underwent SSPSF at our institution between May 2016 and May 2023 was conducted. Patients were categorized into two groups based on treatment outcome (failure or non-failure). Potential risk factors for treatment failure were compared between the groups. Four MLMs, including random forest (RF), logistic regression (LR), support vector machine (SVM), and k-nearest neighborhood (k-NN), were employed to predict treatment failure. Additionally, LR and RF models were used to assess factors associated with treatment failure. RESULTS: Of the 332 included patients, 61.4% were male (n = 204), and treatment failure was observed in 44 patients (13.3%). Logistic regression analysis identified Load Sharing Classification (LSC) score, lack of index level instrumentation, and interpedicular distance (IPD) as factors associated with treatment failure (P < 0.05). All models demonstrated satisfactory performance. RF exhibited the highest accuracy in predicting treatment failure (accuracy = 0.948), followed by SVM (0.933), k-NN (0.927), and LR (0.917). Moreover, the RF model outperformed other models in terms of sensitivity and specificity (sensitivity = 0.863, specificity = 0.959). The area under the curve (AUC) for RF, LR, SVM, and k-NN was 0.911, 0.823, 0.844, and 0.877, respectively. CONCLUSIONS: This study demonstrated the utility of machine learning models in predicting treatment failure in thoracolumbar burst fractures treated with SSPSF. The findings support the potential of MLMs to predict treatment failure in this patient population, offering valuable prognostic information for early intervention and cost savings.

Lumbar and neck injuries of occupants in different reclining postures.

PURPOSE: With the increasing level of automation in automobiles, the advent of autonomous vehicles has reduced the tendency of drivers and passengers to focus on the task of driving. The increasing automation in automobiles reduced the drivers' and passengers' focus on driving, which allowed occupants to choose a more relaxed and comfortable sitting position. Meanwhile, the occupant's sitting position went from a frontal, upright position to a more relaxed and reclined one, which resulted in the existing restraint systems cannot to keep occupants safe and secure. This study aimed to determine the effects of different reclining states on occupants' lumbar and neck injuries. METHODS: This is an original research on the field of automotive safety engineering. Occupants in different initial sitting positions (25°, 35°, 45°, and 55°) were adapted to changes in seat back angle and restraint systems and placed in the same frontal impact environment. Neck injury indexes, lumbar axial compression force and acceleration, as well as occupant dynamic response during the impact, were compared in different sitting positions. The injury response and kinematic characteristics of occupants in different reclining positions were analyzed by the control variable method. RESULTS: As the sitting angle increased, the occupant's head acceleration decreased, and the forward-lean angle decreased. Occupants in the standard sitting position had the greatest neck injury, with an Nij of 0.95, and were susceptible to abbreviated injury scale 2+ cervical medullary injuries. As the seatback angle increased, the geometric position of the lumbar spine tended to be horizontal, and the impact load transmitted greater forces to the lumbar spine. The occupant's lumbar injury was greatest in the lying position, with a peak axial compression force on the lumbar region of 5.5 KN, which was 2.3 KN greater than in the standard sitting position. CONCLUSION: The study of occupant lumbar and neck injuries based on different recline states can provide a theoretical basis for optimizing lumbar evaluation indexes, which is conducive to the understanding of the lumbar injury mechanism and the comprehensive consideration of occupant safety protection.

Posterior Pedicle Screw Fixation With Indirect Decompression Versus Direct Decompression in Treating Thoracolumbar Burst Fracture: A Systematic Review and Meta-Analysis.

OBJECTIVE: To compare the safety and efficacy between posterior pedicle screw fixation with direct versus indirect decompression in treating patients with thoracolumbar burst fracture. METHODS: This study was conducted on the basis of PRISMA statement. We systematically searched the PubMed and Embase databases up to July 3, 2023. Relevant studies comparing indirect decompression and direct decompression were recruited. Weighted mean differences (WMDs), odds ratios (ORs) and 95% confidence intervals (CIs) were analyzed for continuous and dichotomous data, respectively. P < 0.05 was considered statistically significant. RESULTS: The operation time (WMD: -37.14, 95% CI: [-42.64, 31.64], P < 0.00001, I2 = 0%) and intraoperative blood loss (WMD: -316.82, 95% CI: [-469.80, -163.85], P < 0.0001, I2 = 99%) of indirect decompression group were significantly lower. Percentage of anterior vertebral body height (WMD: 3.98, 95% CI: [2.36, 5.60], P < 0.00001, I2 = 32%) and encroachment rate of the spinal canal (WMD: 1.48, 95% CI: [0.56, 2.40], P = 0.002, I2 = 35%) of indirect decompression group were significantly higher. No statistical difference was identified in grades of neurologic recovery and Cobb angle. CONCLUSIONS: Posterior pedicle screw fixation with indirect decompression was safe and effective for thoracolumbar burst fracture with or without neurologic deficits when posterior longitudinal ligament was intact.

A reduction method for anterior opening displacement in thoracolumbarvertebral fractures with diffuse idiopathic skeletal hyperostosis using the skull clamp-assisted position.

Diffuse idiopathic skeletal hyperostosis (DISH) frequently occurs in the spine, resulting in unstable fractures. Treating thoracolumbar fractures in patients with DISH is often difficult because the anterior opening of the vertebral body is exacerbated by dislocation in the prone position, making reduction difficult. In this study, we introduced a novel skull clamp-assisted positioning (SAP) technique. The patient is placed in a supine position with a skull clamp used in cervical spine surgery before surgery to prevent the progression of dislocation and to restore the patient's position. Using this method, the mean difference in local kyphosis angle improved from -2.9 (±8.4)° preoperatively to 10.9 (±7.7)° postoperatively. Furthermore, posterior displacement decreased from a preoperative mean of 5.5 (±4.3) mm to 0.3 (±0.7) mm postoperatively. Complications such as neurological sequelae, implant fracture, and surgical site infection were not observed through one year of postoperative follow-up. SAP may decrease invasiveness and complications. Longer-term studies and larger sample sizes are needed to establish long-term efficacy and benefits.

Closed Reduction for the Treatment of Traumatic Thoracolumbar Spondylolisthesis.

OBJECTIVE: Thoracolumbar traumatic spondylolisthesis is a relatively rare phenomenon and has poor prognosis due to serious spinal cord or cauda equina injuries. In such cases, closed reduction is a method for restoring the vertebral sequence and may play an important role in the treatment process, although whether it is actually feasible for patients with this condition requires further investigation. The present study included 9 patients with serious thoracolumbar traumatic spondylolisthesis to determine the advantages of closed reduction over total reduction through open surgery. METHODS: Data from 9 patients (cases 1-9), diagnosed with severe thoracolumbar traumatic spondylolisthesis between June 2012 and August 2023, were retrospectively reviewed. Five patients were treated with closed reduction in an emergency department and subsequently underwent delayed internal fixation surgery at least 48 hours after the injury, and 4 with similar serious injuries underwent emergency surgery. The incidence of complications and recovery of the spinal cord or cauda equina were compared between groups. RESULTS: There were no significant differences in demographic characteristics or adverse events between the 2 groups. The reduction group had a shorter surgical duration and less blood loss than the surgery group. Although patients in the surgery group may have experienced more pain, there were no significant differences between the groups in Oswestry Disability Index or Japanese Orthopaedic Association scores. Thus, regardless of whether closed reduction was chosen, patients experienced a similar quality of life for a relatively prolonged period. CONCLUSIONS: Closed reduction may be feasible for serious thoracolumbar traumatic spondylolisthesis, although the safety of this method requires further research.

Finite element analysis of different pedicle screw internal fixations for first lumbar vertebral fracture in different sports conditions.

OBJECTIVE: Lumbar fractures are the most common spinal injuries, and surgery is required for severe fracture. This study aimed to investigate the variations in motion and stress in varying states of activity after minimally invasive and traditional open pedicle screw placement for L1 vertebral fracture stabilization. METHODS: We studied a male volunteer (26 years old) with no history of chronic back pain or lumbar spine trauma. We used the finite element method for this investigation. Using finite element software, we created a three-dimensional model of L1 vertebral compression fracture. We also constructed models for four percutaneous pedicle screws spanning the fractured vertebra and four screws traversing the damaged vertebra with transverse fixation. RESULTS: In all three-dimensional movement directions, the open pedicle fixation system experienced maximum stress higher than its percutaneous counterpart. With axial spinal rotation, von Mises stress on the traditional open pedicle screw was considerably lower than that with percutaneous pedicle fixation, but peak stress was elevated at the transverse connection. Traditional open pedicle fixation displayed less maximum displacement than percutaneous pedicle internal fixation. CONCLUSIONS: During axial spinal movements, high peak stress is observed at the transverse connection. Patients should avoid excessive axial rotation of the spine during recovery.