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.

Analysis of factors associated with the failure of treatment in thoracolumbar burst fractures treated with short-segment posterior spinal fixation.

BACKGROUND: The treatment of thoracolumbar burst fractures continues to pose challenges. Although short-segment posterior spinal fixation (SSPSF) has shown satisfactory clinical outcomes, it is accompanied by a relatively high rate of treatment failure. This study aimed to assess factors associated with treatment failure in thoracolumbar burst fractures treated with SSPSF. METHODS: The clinical data of 241 consecutive patients with a traumatic thoracolumbar burst fracture who underwent SSPSF at our center between Apr 2016 and Apr 2021 were retrospectively reviewed. Patients were divided into two groups (failure of the treatment group and non-failure of the treatment group). We compared potential risk factors for the failure of treatment including age, gender, body mass index, smoking, diabetes, vertebral body compression rate, use of crosslinks, percentage of anterior height compression, presence of index level instrumentation, Cobb angle, interpedicular distance (IPD), canal compromise, Load Sharing Classification (LSC) score, use of posterolateral fusion, and pain intensity between the two groups. RESULTS: A sum of 137 (56.8%) males and 104 (43.2%) females were enrolled where the mean age and follow-up of the participants were 48.34 ± 10.23 years and 18.67 ± 5.23 months, respectively. Treatment failure was observed in 34 cases (14.1%). The results of the binary logistic regression analysis revealed that the lack of index level instrumentation (OR 2.21; 95% CI 1.78-3.04; P = 0.014), LSC score (odds ratio [OR] 2.64; 95% confidence interval [95% CI], 1.34-3.77; P = 0.007), and IPD (OR 1.77; 95% CI 1.51-2.67; P = 0.023) were independently associated with a higher rate of failure of treatment. CONCLUSIONS: The findings of this study revealed that increased rates of treatment failure in thoracolumbar burst fractures treated with SSPSF were associated with factors such as the absence of index level instrumentation, higher LSC scores, and larger IPD. These findings could be helpful in the proper management of patients with unstable thoracolumbar burst fractures.

Thoracic and lumbar spine trauma classification systems fail to predict post-traumatic kyphotic deformity.

Background: Post-traumatic kyphosis of the thoracic and lumbar spine can lead to pain and decreased function. MRI has been advocated to assess ligament integrity and risk of kyphosis. Methods: All thoracic and lumbar spine MRI performed for evaluation of trauma over a 3-year period at a single institution were reviewed. Patients were included if there was an MRI showing a vertebral body fracture and follow-up radiographs. Two observers retrospectively reviewed all radiographs, CT and MRI scans, and classified injuries based on the Denis, TLICS, AO and load sharing classification systems. Change in kyphosis between injury and follow-up studies was measured. The initial radiology reports made at time of patient injury were compared to the retrospective interpretations. Results: There were 67 separate injuries in 62 patients. Kyphosis measuring ≥ 10° developed despite an intact PLC in 6/14 nonoperative cases, and 3/7 surgically treated cases; when PLC was partially injured, it developed in 6/10 cases (8 treated nonoperatively, 2 treated operatively. Thirty injuries had complete disruption of PLC by MRI, 24 treated with fusion. Kyphosis ≥ 10° developed in 3/6 treated nonoperatively, and 8/24 treated with fusion. Development of kyphosis was independent of degree of vertebral body comminution. It developed equally in patients with Grade 2 and Grade 3 Denis injuries. It developed in patients with intact PLC when multiple vertebrae were involved and/or there was compressive injury to anterior longitudinal ligament (ALL). There was high interobserver variability in assessment of severity of ligamentous injury on MRI. Conclusions: Classification systems of thoracic and lumbar spine injury and integrity of the PLC failed to predict the risk of development of post-traumatic kyphotic deformity.

The Relationship Between Falling Distance and Trauma Severity Among Fall Injury Survivors Who Were Transported to a Trauma Center.

Introduction Falls from >6 meters have been shown to cause multiple traumas and serious injuries. However, especially among fall survivors who were transported to trauma centers, the relationship between falling distance and trauma severity remains unclear. This study aimed to investigate the relationship between falling distance and trauma severity among fall injury survivors who were transported to a trauma center and clarify the characteristics of trauma among survivors of falls from high places from an orthopedic surgeon's perspective. Methods We retrospectively reviewed the medical records of 65 fall injury survivors who were transported to a trauma center for falling distance; whether the fall was a suicide attempt; abdominal, chest, and head trauma; the numbers of upper-limb, lower-limb, and spinal vertebral fractures; McCormack load-sharing classification score; unstable pelvic fracture; Frankel classification; injury severity score (ISS); and duration of intensive care unit (ICU) and hospital stay. We evaluated the correlations between falling distance and the other factors and compared all factors between those falling <6 meters and those falling >6 meters. Results Falling distance was weakly positively correlated with durations of ICU and hospital stay. The percentage of cases that were suicide attempts, the number of lower-limb fractures, the McCormack load-sharing classification score, and the durations of ICU and hospital stay were significantly higher among those falling from >6 meters than among those falling from <6 meters. Conversely, there were no significant differences in abdominal trauma, chest trauma, head trauma, number of upper-limb fractures, number of vertebral fractures, unstable pelvic fracture, or Frankel classification between the two groups. Conclusion The findings indicate that falling from a higher distance may increase lower-limb and vertebral fracture severity and may lead to longer ICU and hospital stays among fall injury survivors who are transported to trauma centers.

Classifications and level of evidence trends from the most influential literature on thoracolumbar burst fractures: A bibliometric analysis.

Background: There are known classifications that describe thoracolumbar (TL) burst type injury but it is unclear which have the most influence on management. Our objective is to investigate the association of classification publications with the quantity and type of the most influential articles on TL burst fractures. Methods: Web of Science was searched, and exclusion and inclusion criteria were used to extract the top 100 cited articles on TL burst fractures. The effects on type, number, and other variables were separated into four eras as defined by four major classification publications. Results: 30 out of the top 100 articles represent level 1 or 2 evidence. The most influential journal was Spine, accounting for 35 articles and 4,537 citations. The highest number of articles (53) was published between the years 1995-2005, culminating with the Thoracolumbar Injury Severity Classification Score (TLICS) paper. After 2005, there was an increase in average citations per year. Following 2013, the number of highly influential articles decreased, and systematic reviews (SRs) became a larger proportion of the literature. There was a statistically significant increase in the level of 1 and 2 evidence articles with time until the publication of TLICS. The predictive value of time for higher levels of evidence was only seen in the pre-2005 years (AUC: 0.717, 95% CI 0.579-0.855, p = 0.002). Conclusions: In 1994, two articles marked the beginning of an era of highly influential TL burst fracture literature. The 2005 TLICS score was associated with a preceding increase in LOE and productivity. Following 2005, the literature saw a decrease in productivity and an increase in systematic review/meta-analysis (SR-MAs). These trends represent an increase in scholarly discussion that led to a systematic synthesis of the existing literature after publication of the 2005 TLICS article.

Load-Sharing Classification Score as Supplemental Grading System in the Decision-Making Process for Patients With Thoracolumbar Injury Classification and Severity 4.

BACKGROUND: Patients with Thoracolumbar Injury Classification and Severity (TLICS) score of 4 fall into a gray zone between surgical and conservative management. The integrity of posterior ligamentous complex (PLC) evaluated by magnetic resonance imaging (MRI) contributes to surgical decision-making. Load-sharing classification (LSC) may provide a modifier to further guide decision-making in these patients. OBJECTIVE: To evaluate associations between LSC score and MRI acquisition, compromise of PLC on MRI, and surgical intervention in TLICS 4 patients. METHODS: A cohort of 111 neurologically intact patients with isolated thoracolumbar burst fracture with TLICS 4 was evaluated. LSC score was determined based on degree of comminution (1-3), apposition (1-3), and kyphosis (1-3), total composite score of 3 to 9. RESULTS: Overall, 44 patients underwent MRI, 15 had PLC injury, and 32 (28.8%) underwent surgery. LSC score was higher in patients who had an MRI (median 6 vs 3, P < .001) and patients who had surgery (median 7 vs 4, P < .001). In univariate logistic regression, LSC score was associated with MRI acquisition (odds ratio [OR] 1.7; 1.32-2.12; P < .001), presence of PLC injury on MRI (OR 1.5; 1.2-2.0; P = .002) and, in multivariate logistic regression, undergoing surgical intervention (OR 3.7; 2.3-5.9; P < .001), independent of MRI or PLC injury. CONCLUSION: LSC score in neurologically intact patients with isolated thoracolumbar burst fracture with TLICS 4 was independently associated with operative intervention. The application of LSC may further guide decision-making in this patient group.

Assessment of load-sharing thoracolumbar injury: A modified scoring system.

BACKGROUND: Many classification systems of thoracolumbar spinal fractures have been proposed to enhance treatment protocols, but none have achieved universal adoption. AIM: To develop a new patient scoring system for cases with thoracolumbar injury classification and severity score (TLICS) = 4, namely the load-sharing thoracolumbar injury score (LSTLIS). METHODS: Based on thoracolumbar injury classification and severity score, this study proposes the use of the established load-sharing classification (LSC) to develop an improved classification system (LSTLIS). To prove the reliability and reproducibility of LSTLIS, a retrospective analysis for patients with thoracolumbar vertebral fractures has been conducted. RESULTS: A total of 102 cases were enrolled in the study. The scoring trend of LSTLIS is roughly similar as the LSC scoring, however, the average deviation based on the former method is relatively smaller than that of the latter. Thus, the robustness of the LSTLIS scoring method is better than that of LSC. LSTLIS can further classify patients with TLICS = 4, so as to assess more accurately this particular circumstance, and the majority of LSTLIS recommendations are consistent with actual clinical decisions. CONCLUSION: LSTLIS is a scoring system that combines LSC and TLICS to compensate for the lack of appropriate inclusion of anterior and middle column compression fractures with TLICS. Following preliminary clinical verification, LSTLIS has greater feasibility and reliability value, is more practical in comprehensively assessing certain clinical circumstances, and has better accuracy with clinically significant guidelines.

The Predictive Value of the Load Sharing Classification Concerning Sagittal Collapse and Posterior Instrumentation Failure: A Systematic Literature Review.

STUDY DESIGN: Systematic review. OBJECTIVE: In 1994, the Load Sharing Classification (LSC) was introduced to aid the choice of surgical treatment of thoracolumbar spine fractures. Since that time this classification system has been commonly used in the field of spine surgery. However, current literature varies regarding its use and predictive value in relation to implant failure and sagittal collapse. The objective of this study is to assess the predictive value of the LSC concerning the need for anterior stabilization to prevent sagittal collapse and posterior instrumentation failure. METHODS: An electronic search of PubMed, Medline, Embase, and the Cochrane Library was performed. Inclusion criteria were (1) cohort or clinical trial (2) including patients with thoracolumbar burst fractures (3) whose severity of the fractured vertebrae was assessed by the LSC. RESULTS: Five thousand eighty-two articles have been identified, of which 21 articles were included for this review. Twelve studies reported no correlation between the LSC and sagittal collapse or instrumentation failure in patients treated with short-segment posterior instrumentation (SSPI). Seven articles found no significant relation; 5 articles found no instrumentation failure at all. The remaining 9 articles experienced failure in patients with a high LSC or recommended a different surgical technique. CONCLUSIONS: Although the LSC was originally developed to predict the need for anterior stabilization in addition to SSPI, many studies show that SSPI only can be sufficient in treating thoracolumbar fractures regardless of the LSC. The LSC might have lost its value in predicting sagittal collapse and posterior instrumentation failure.

[Posterior short-segment fixation including the fractured vertebra for severe unstable thoracolumbar fractures].

Objective: To discuss the effectiveness of posterior short-segment fixation including the fractured vertebra for severe unstable thoracolumbar fractures using pedicle screw fixation. Methods: Between May 2008 and July 2013, 52 patients of severe unstable thoracolumbar fractures were treated through posterior short-segment fixation including the fractured vertebra using pedicle screw fixation. There were 33 males and 19 females with an age of 21-56 years (mean, 37.9 years). The causes of thoracolumbar burst fractures included fall from height in 32 cases, traffic accidents in 16 cases, and others in 4 cases. The load sharing classification (LSC) score was 7-9 (mean, 7.85). The levels involved included T 11 in 4 cases, T 12 in 19 cases, L 1 in 25 cases, and L 2 in 4 cases. According to Frankel classification, there were 2 cases of grade A, 4 cases of grade B, 8 cases of grade C, 11 cases of grade D, and 27 cases of grade E. The rate of spinal canal occupying was 24.2%-76.7% (mean, 47.1%). The time from injury to operation was 3-5 days (mean, 3.6 days). The effectiveness was assessed by the changes of injured vertebral Cobb angle, anterior vertebral height, and the Frankel grading at pre- and post-operation. Results: The operation time was 85-127 minutes (mean, 106.5 minutes). The intraoperative blood loss was 90-155 mL (mean, 137.6 mL). All the incision healed at first intension. Forty-seven patients were followed up 19-27 months (mean, 23.2 months), and no incision infection, screw loosening, or other internal fixation failures was found during follow-up. The injured vertebral Cobb angle and anterior vertebral height at immediate after operation or at last follow-up were significantly improved when compared with preoperative values ( P<0.001). There was a loss of injured vertebral Cobb angle and anterior vertebral height at last follow-up, but no significant difference was found between at immediate after operation and at last follow-up ( P>0.05). The Frankel grade improved by 0-2 grades at last follow-up, showing significant difference when compared with preoperative grades ( Z=15.980, P=0.003). Conclusion: Posterior short-segment fixation including the fractured vertebra for severe unstable thoracolumbar fractures (LSC≥7) using pedicle screw fixation can correct the kyphosis deformity, restore vertebral body height, and aviod the need of anterior reconstruction.

Reliability and Agreement of Different Spine Fracture Classification Systems: An Independent Intraobserver and Interobserver Study.

OBJECTIVE: Currently, no spinal classification system has achieved universal acceptance. Therefore, it is important to choose a reliable classification within clinical practice. The objective of this study was to determine and compare the intraobserver and interobserver agreement of the Load Sharing Classification (LSC), the Thoracolumbar Injury Classification System (TLICS), and the AOSpine Thoracolumbar Spine Injury Classification System. METHODS: In this web-based intraobserver and interobserver study (www.spine.hostei.com), plain radiographs and computed tomographic scans of traumatic thoracolumbar fractures (T12-L2) were evaluated. By use of a questionnaire, fractures were classified according to the LSC, the TLICS, and the AOSpine classification. Data were analyzed with SPSS (Version 21, 76 Chicago, Illinois, USA). Intraobserver and interobserver agreement was determined by the Cohen κ. Statistical significance was defined as P < 0.05. RESULTS: Data from 91 patients were classified twice by 7 board-certified spine surgeons. The intraobserver and interobserver reliability considering the LSC total score was noted as fair (intraobserver/interobserver reliability: κ = 0.26/0.22). Considering the resulting TLICS total score, a moderate intraobserver agreement (κ = 0.41) was noted, whereas the interobserver results presented only fair reliability (κ = 0.23). In contrast to the LSC and the TLICS, the AOSpine classification showed substantial agreement considering the fracture type (A;B;C) (intraobserver/interobserver reliability: κ = 0.71/0.61) and moderate agreement considering the fracture subtype (e.g., A0;A1;…;B1;…) (intraobserver/interobserver reliability: κ = 0.57/0.48). CONCLUSION: In conclusion, the reliability of the AOSpine fracture classification is superior to the TLICS and the LSC. Therefore, this classification system could best be applied within clinical practice.

Risk factor analysis for predicting vertebral body re-collapse after posterior instrumented fusion in thoracolumbar burst fracture.

BACKGROUND CONTEXT: In the posterior instrumented fusion surgery for thoracolumbar (T-L) burst fracture, early postoperative re-collapse of well-reduced vertebral body fracture could induce critical complications such as correction loss, posttraumatic kyphosis, and metal failure, often leading to revision surgery. Furthermore, re-collapse is quite difficult to predict because of the variety of risk factors, and no widely accepted accurate prediction systems exist. Although load-sharing classification has been known to help to decide the need for additional anterior column support, this radiographic scoring system has several critical limitations. PURPOSE: (1) To evaluate risk factors and predictors for postoperative re-collapse in T-L burst fractures. (2) Through the decision-making model, we aimed to predict re-collapse and prevent unnecessary additional anterior spinal surgery. STUDY DESIGN: Retrospective comparative study. PATIENT SAMPLE: Two-hundred and eight (104 men and 104 women) consecutive patients with T-L burst fracture who underwent posterior instrumented fusion were reviewed retrospectively. Burst fractures caused by high-energy trauma (fall from a height and motor vehicle accident) with a minimum 1-year follow-up were included. The average age at the time of surgery was 45.9 years (range, 15-79). With respect to the involved spinal level, 95 cases (45.6%) involved L1, 51 involved T12, 54 involved L2, and 8 involved T11. Mean fixation segments were 3.5 (range, 2-5). Pedicle screw instrumentation including fractured vertebra had been performed in 129 patients (62.3%). OUTCOME MEASURES: Clinical data using self-report measures (visual analog scale score), radiographic measurements (plain radiograph, computed tomography, and magnetic resonance image), and functional measures using the Oswestry Disability Index were evaluated. METHODS: Body height loss of fractured vertebra, body wedge angle, and Cobb angle were measured in serial plain radiographs. We assigned patients to the re-collapse group if their body height loss progressed greater than 20% at any follow-up time compared with immediate postoperative body height loss; we assigned the remaining patients to the well-maintained group. The chi-square test and t test of SPSS were used for comparison of differences between two groups and multiple logistic regression analysis for risk factor evaluation. Through the decision tree analysis of statistical package R, a decision-making model was composed, and a cutoff value of revealed risk factors and re-collapse rate of each subgroup were identified. The present study wassupported by the University College of Medicine Research Fund (university to which authors belong). There was no external funding source for this study. The authors have no conflict of interest to declare. RESULTS: Re-collapse occurred in 31 of 208 patients (14.9%). In this group, age, the proportion of male gender, preoperative height loss, and preoperative wedge angle were significantly greater than the well-maintained group. Multivariable logistic regression analysis identified two independent risk factors: age (adjusted odds ratio 1.084, p=.002) and body height loss (adjusted odds ratio 1.065, p=.003). According to the decision-making tree, age (>43 years) was the most discriminating variable, andpreoperative body height loss (>54%) was the second. In this model, the re-collapse rate was zero in ages less than 43 years, and among those remaining, nearly 80% patients with greater than 54% of body height loss belonged to the re-collapse group. CONCLUSIONS: The independent predictors of re-collapse after posterior instrumented fusion for T-L burst fracture were the age at operation (>43 years old) and preoperative body height loss (>54%). Careful assessment using our decision-making model could help to predict re-collapse and prevent unnecessary additional spinal surgery for anterior column support, especially in young patients.

Posterior short-segment fixation including the fractured vertebra for severe unstable thoracolumbar fractures / 中国修复重建外科杂志

Objective: To discuss the effectiveness of posterior short-segment fixation including the fractured vertebra for severe unstable thoracolumbar fractures using pedicle screw fixation.

Comparison of unilateral versus bilateral pedicle screw fixation at the level of fracture using posterior short-segment pedicle instrumentation in the treatment of severe thoracolumbar burst fractures.

BACKGROUND: Thoracolumbar burst fractures (TBFs) are often followed by bilateral pedicle screw fixation (BPSF) at the level of fracture using posterior short-segment pedicle instrumentation (SSPI). There has been increasing support for unilateral pedicle screw fixation (UPSF) in an attempt to reduce complications and costs. The aim of this study was to compare the clinical and radiologic results of UPSF versus BPSF at the level of fracture using SSPI in the treatment of severe TBFs. METHODS: The records of 42 consecutive patients with severe TBFs who underwent SSPI were divided into 2 groups according to the number of screws in the fracture level, including 20 patients (five screws) in UPSF group and 22 patients (six screws) in BPSF. Different clinical and radiological parameters were recorded before surgery, after surgery, and 1.5 years after operation. The patients'clinical outcomes were assessed using visual analog scale (VAS), and Oswestry Disability Index (ODI). For radiological evaluation, changes in local kyphosis angle (LKA), vertebral wedge angle (VWA), and anterior vertebral height (AVH) were investigated using plain radiographs. RESULTS: Mean follow-up was 18.3 months for UPSF group and 19.0 months for BPSF group (P > 0.05). There were no significant differences in the age, gender, fracture type and site in both groups. Radiologically, no statistically difference was observed between the two groups in corrected rate of LKA, VWA, or AVH(all P > 0.05). With respect to clinical variants including VAS and ODI scores, there were also no significant differences. However, the UPSF group seemed to have advantages over BPSF group in operative time, blood loss, postoperative drainage, hospitalization time (P > 0.05). Especially, implant cost for the BPSF group was 22% greater than the UPSF group. No serious complications occurred in our study. In all cases, fusions healed well and no revision surgery was performed for loss of correction or failure of instrumentation during follow-up. CONCLUSIONS: The present study is the first to demonstrate that patients undergoing SSPI with UPSF as compared with BPSF for the treatment of severe TBFs had similar clinical and radiologic outcomes.

Posterior short-segment fixation in thoracolumbar unstable burst fractures - Transpedicular grafting or six-screw construct?

OBJECTIVES: Early implant failure and donor-site complication remain a concern in patients with thoracolumbar burst fracture underwent one-above and-below short-segment posterior pedicle screw fixation with fusion. Our aim was to evaluate the results of short-segment pedicle instrumentation enforced by two augmenting screws or injectable artificial bone cement in the fractured vertebra, and compare the differences between these two PATIENTS AND METHODS: We conducted a retrospective clinical and radiographic study. Twenty-seven patients were treated with a six-screw construct (group 1), and twenty-nine patients underwenta four-screw construct and fractured vertebra augmentation by injectable calcium sulfate/phosphate cement (group 2). Posterior or posterolateral fusions were not performed in both groups. The severity of the fractured vertebra was evaluated by the load-sharing classification (LSC). Local kyphosis and anterior body height of the fractured vertebra were measured and were follow-up at least 2 years. Any implant failure or loss of correction >10° degrees at the final was defined as failure of surgery. Patients' clinical results were assessed by the Denis scale. RESULTS: Blood loss and operation time were less in group 1 (126.2±9.7 vs. 267.6±126.1ml, p<0.001 and 141.2±48.7 vs. 189.8±16.4min, p<0.001). Immediately after surgery, group 2 had a better local kyphosis angle (3.7±5.3 vs.6.0±4.1°, p=0.047) and acquired more anterior body height (94.9%±7.6% vs. 84.9%±10.0%, p<0.001). Both groups had similar clinical results (pain score: 1.5±0.8vs. 1.4±0.6, p=0.706; work score: 1.7±0.9 vs. 1.6±1.0, p=0.854). Group 1 had 3 cases of surgery failure; group 2 had 8 cases of implant failure (p=0.121). The average LSC score of these 11 patients with surgical failure was 7.2. CONCLUSION: Thesix-screw construct had the advantage of shorter operating time, less blood loss, and lower failure rate. For those patients with anLSC score ≧7, posterior short-segment instrumentation should be used cautiously.

Nine issues about clinical application of thoracolumbar injury classification and severity score / 中华创伤骨科杂志

Spinal fractures are a big challenge to orthopedists.Thoracolumbar Injury Classification and Severity Score (TLICS),a newly developed evaluation system for thoracolumbar fractures,has proved to be valid and reliable in the last decade.However,there have still been many problems in the clinical application of TLICS in China.We discussed nine issues about the clinical application of TLICS in this article,hoping to promote better understanding and application of TLICS in Chinese spinal surgeons in their daily practice.

Nine issues about clinical application of thoracolumbar injury classification and severity score / 中华创伤骨科杂志

Spinal fractures are a big challenge to orthopedists.Thoracolumbar Injury Classification and Severity Score (TLICS),a newly developed evaluation system for thoracolumbar fractures,has proved to be valid and reliable in the last decade.However,there have still been many problems in the clinical application of TLICS in China.We discussed nine issues about the clinical application of TLICS in this article,hoping to promote better understanding and application of TLICS in Chinese spinal surgeons in their daily practice.

Comparison of short-segment pedicle fixation with versus without inclusion of the fracture level in the treatment of mild thoracolumbar burst fractures.

BACKGROUND: A review of the literature showed that posterior short-segment fixation including the fractured vertebra (PSFFV) has better outcomes in the treatment of thoracolumbar burst fractures(TBFs) than patients with short-segment pedicle screw fixation(SSPF) alone. However, its efficacy in mild TBFs with load-sharing scores of 3 and 4 points has not been specifically analyzed. The aim of this study was to compare the clinical, functional and radiologic results of PSFFV with SSPF for mild TBFs and to determine whether the screws in the fractured vetebra were necessary for these patients. METHODS: In this retrospective study, sixty-nine patients with mild TBFs were divided into 2 groups according to the number of instrumented levels. Group A included 34 patients treated by SSPF (four screws:one level above and below the fracture), and Group B included 35 patients treated by PSFFV (six screws: including the fractured vertebra). Clinical and radiologic parameters were evaluated before surgery, after surgery, and at follow-up. They included clinical outcomes: visual analog scale (VAS), Oswestry Disability Index (ODI). Being a radiology-based study, the radiologic measures included vertebral wedge angle (VWA), and anterior vertebral height (AVH). RESULTS: A sum of 69 patients (34 patients in Group A and 35 patients in Group B) were enrolled in the study. The patients in both the groups showed similar outcomes with regards to age, gender, fracture type and site. We did not find any statistically difference between the two groups in corrected rate of VWA or AVH (P > 0.05). In terms of clinical variants such as VAS and ODI scores, there were also no significant differences. However, the SSPF had advantages over PSFFV method in operative time, blood loss, postoperative drainage and postoperative hospitalization time (P > 0.05). There were no serious complications occurring during our study, such as infection, blood vessel injury, spinal cord or nerve root injury. No patient needed revision for loss of correction or failure of instrumentation. CONCLUSIONS: SSPF alone is a safe and effective surgical method for restoration and maintenance of vertebral column stability in treating mild TBFs. It gives excellent clinical and radiological results regardless of whether the fractured vertebra is included in the fixation or not.

Biomechanical comparison of short-segment posterior fixation including the fractured level and circumferential fixation for unstable burst fractures of the lumbar spine in a calf spine model.

OBJECTIVE There has been a transition from long- to short-segment instrumentation for unstable burst fractures to preserve motion segments. Circumferential fixation allows a stable short-segment construct, but the associated morbidity and complications are high. Posterior short-segment fixation spanning one level above and below the fractured vertebra has led to clinical failures. Augmentation of this method by including the fractured level in the posterior instrumentation has given promising clinical results. The purpose of this study is to compare the biomechanical stability of short-segment posterior fixation including the fractured level (SSPI) to circumferential fixation in thoracolumbar burst fractures. METHODS An unstable burst fracture was created in 10 fresh-frozen bovine thoracolumbar spine specimens, which were grouped into a Group A and a Group B. Group A specimens were instrumented with SSPI and Group B with circumferential fixation. Biomechanical characteristics including range of motion (ROM) and load-displacement curves were recorded for the intact and instrumented specimens using Universal Testing Device and stereophotogrammetry. RESULTS In Group A, ROM in flexion, extension, lateral flexion, and axial rotation was reduced by 46.9%, 52%, 49.3%, and 45.5%, respectively, compared with 58.1%, 46.5%, 66.6%, and 32.6% in Group B. Stiffness of the construct was increased by 77.8%, 59.8%, 67.8%, and 258.9% in flexion, extension, lateral flexion, and axial rotation, respectively, in Group A compared with 80.6%, 56.1%, 82.6%, and 121.2% in Group B; no statistical difference between the two groups was observed. CONCLUSIONS SSPI has comparable stiffness to that of circumferential fixation.

Radiological Outcome of Short Segment Posterior Instrumentation and Fusion for Thoracolumbar Burst Fractures.

STUDY DESIGN: Retrospective study. PURPOSE: To evaluate the radiological outcome of the surgical treatment of thoracolumbar burst fractures by using short segment posterior instrumentation (SSPI) and fusion. OVERVIEW OF LITERATURE: The optimal surgical treatment of thoracolumbar burst fractures remains a matter of debate. SSPI is one of a number of possible choices, yet some studies have revealed high rates of poor radiological outcome for this SSPI. METHODS: Patients treated using the short segment instrumentation and fusion technique at the Spinal Injuries Center (Iizuka, Fukuoka, Japan) from January 1, 2006 to July 31, 2012 were selected for this study. Radiographic parameters such as local sagittal angle, regional sagittal angle, disc angle, anterior or posterior height of the vertebral body at admission, postoperation and final observation were collected for radiological outcome evaluation. RESULTS: There were 31 patients who met the inclusion criteria with a mean follow-up duration of 22.7 months (range, 12-48 months). The mean age of this group was 47.9 years (range, 15-77 years). The mean local sagittal angles at the time of admission, post-operation and final observation were 13.1°, 7.8° and 14.8°, respectively. There were 71% good cases and 29% poor cases based on our criteria for the radiological outcome evaluation. The correction loss has a strong correlation with the load sharing classification score (Spearman rho=0.64, p<0.001). CONCLUSIONS: The loss of kyphotic correction following the surgical treatment of thoracolumbar burst fracture by short segment instrumentation is common and has a close correlation with the degree of comminution of the vertebral body. Patients with high load sharing scores are more susceptible to correction loss and postoperative kyphotic deformity than those with low scores.

Relationships between posterior ligamentous complex injury and radiographic parameters in patients with thoracolumbar burst fractures.

INTRODUCTION: The purpose of this study was to determine whether radiographic findings associated with thoracolumbar burst fractures could also indicate the presence of posterior ligamentous complex (PLC) injuries, which were identified through short-tau inversion-recovery (STIR)-weighted MRI. PATIENTS AND METHOD: Sixty-four patients were surgically treated for thoracolumbar burst fractures between April 2007 and February 2014 at our institution. Twenty-four patients were excluded from this study because of the lack of STIR-weighted MRIs, and therefore 40 patients were included in this study. The patients were divided into two groups based upon the integrity of the PLC, which was evaluated using STIR-weighted MRI: a P group with a PLC injury and a C group without such injury. The following radiographic parameters were evaluated: loss of vertebral body height (LOVBH), local kyphosis (LK), vertebral body translation, canal compromise (sagittal transverse ratio, STR), interlaminar distance (ISD), supraspinous distance (SSD) and interspinous distance (ISD). Frankel scale score and total severity score (load sharing and thoracolumbar injury classification systems, respectively) were also evaluated. RESULTS: Preoperative STIR-weighted MRI showed that 25 patients had a PLC injury (P group: 15 men and 10 women), and 15 patients did not have a PLC injury (C group: 8 men and 7 women). More patients in the P group had an LK>20°: 14 patients in the P group and 1 patient in the C group (p<0.01). The % SSD differed between the P and C groups (118.8%±53.4% and 88.0%±24.3%, respectively; p<0.05). Multivariate logistic analysis showed that an LK>20° was a risk factor for PLC injury in patients with thoracolumbar burst fractures (odds ratio, 55.5 [95% confidence interval, 1.30-2360.1]; p<0.05). CONCLUSIONS: These results demonstrate that while LOVBH, vertebral body translation, and canal compromise do not correlate significantly with the presence of a PLC injury in patients with thoracolumbar fractures, an LK>20° and increased % SSD are associated with a PLC injury.