Treatment of unstable thoracolumbar junction burst fractures with short- or long-segment posterior fixation in magerl type a fractures

Tracing the evolving dynamics and research hotspots of spinal cord injury and surgical decompression from 1975 to 2024: a bibliometric analysis

Background

Exploration of the benefits and timing of surgical decompression in spinal cord injury (SCI) has been a research hotspot. However, despite the higher volume and increasing emphasis on quality there remains no bibliometric view on SCI and surgical decompression. In this study, we aimed to perform bibliometric analysis to reveal the core countries, affiliations, journals, authors, and developmental trends in SCI and surgical decompression across the past 50 years.

Methods

Articles and reviews were retrieved from web of science core collection between 1975 and 2024. The bibliometrix package in R was used for data analysis and visualizing.

Results

A total of 8,688 documents were investigated, indicating an ascending trend in annual publications. The USA and China played as the leaders in scientific productivity. The University of Toronto led in institutional productions. Core authors, such as Michael G. Fehlings, showed high productivity, and occasional authors showed widespread interests. Core journals like Spine and Spinal Cord served as beacons in this field. The interaction of core authors and international collaboration accentuated the cross-disciplinary feature of the field. Prominent documents emphasized the clinical significance of early decompression in 24 h post SCI.

Conclusion

Based on comprehensive bibliometric analysis and literature review, we identified the hotspots and future directions of this field: (1) further investigation into the molecular and cellular mechanisms to provide pre-clinical evidence for biological effects of early surgical decompression in SCI animal models; (2) further evaluation and validation of the optimal time window of surgical decompression based on large cohort, considering the inherent heterogeneity of subpopulations in complicated immune responses post SCI; (3) further exploration on the benefits of early decompression on the neurological, functional, and clinical outcomes in acute SCI; (4) evaluation of the optimal surgical methods and related outcomes; (5) applications of artificial intelligence-based technologies in spinal surgical decompression.

Comparison of the Clinical and Radiologic Outcomes of Two Treatment Methods in Patients with Thoracolumbar Junction Distraction Fracture: Short- versus Long-Segment Posterior Stabilization

BACKGROUND

 We compare the radiologic and clinical results between the short-segment fixation and the long-segment fixation in the thoracolumbar junction distraction fractures.

METHODS

 We retrospectively reviewed the prospectively recorded data of patients who underwent posterior approach and pedicle fixation treatment for thoracolumbar distraction fracture (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association AO/OTA 5-B) with a minimum of 2 years of follow-up. A total of 31 patients were operated on; they were divided into two groups: (1) patients treated with short-level fixation (SLF; one level above and below the fracture level) and (2) patients treated with long-level fixation (LLF; two levels above and below the fracture level). The clinical outcomes were evaluated with the neurologic status, operation time, and time to surgery. The functional outcomes were evaluated with the Oswestry Disability Index (ODI) questionnaire and visual analog scale (VAS) at the final follow-up. Radiologic outcomes were measured with the local kyphosis angle, anterior body height, posterior body height, and sagittal index of the fractured vertebra.

RESULTS

 SLF was performed in 15 patients and LLF was performed in 16 patients. The average follow-up period was 30.13 ± 11.3 months for the SLF group and 35.3 ± 17.2 months for group 2 (p = 0.329). The two groups were similar in regard to age, gender, follow-up period, fracture level, fracture type, and pre- and postoperative neurologic status. The operating time was significantly shorter in the SLF group than in the LLF group. There were no significant differences between the groups in all radiologic parameters, ODI score, and VAS.

CONCLUSION

 SLF was associated with a shorter operation time and allowed the preservation of two or more segments of vertebral motion.

Should the level of the posterior instrumentation combined with the intermediate screw be a short segment or a long segment in thoracolumbar fractures with fusion to the fractured segment?

PURPOSE

It was aimed to compare the results of long segment posterior instrumentation with intermediate pedicular screw + fusion at the level of the fractured segment including one vertebra above and one below the fractured vertebra (LSPI) and short segment posterior instrumentation with intermediate pedicular screw + fusion at the level of the fractured segment including one vertebra above and one below the fractured vertebra (SSPI) in the surgical treatment of thoracolumbar vertebral fractures.

METHODS

Ninety patients with thoracolumbar vertebral (T11-L2) fractures operated between March 2015 and February 2022 were included in this retrospective study. The patients were divided into two groups as those who underwent LSPI (n, 54; age, 40.3) and those who underwent SSPI (n, 36; age, 39.7). Radiological evaluations like vertebral compression angle (VCA), vertebral corpus heights (VCH), intraoperative parameters, and complications were compared between the groups.

RESULTS

Correction in early postoperative VCA was statistically significantly better in LSPI (p = 0.003). At 1-year follow-up, postoperative VCA correction was significantly more successful in LSPI (p = 0.001). There was no difference between the two groups in terms of correction loss in VCA measured at 1-year follow-up. There was no statistically significant difference between the two groups in terms of postoperative VCH, VCH at 1-year follow-up, and correction loss in VCH.

CONCLUSION

LSPI provides better postoperative kyphosis correction of the fractured vertebra than SSPI. Regarding the segment level of posterior instrumentation, there was no difference between the two groups in terms of the loss of achieved correction of VCA, ABH, and PBH at 1-year follow-up. Operating a thoracolumbar fracture with LSPI will lengthen the operation and increase the number of intraoperative fluoroscopies compared to SSPI.

Short segment posterior fixation of unstable thoracolumbar vertebral fractures with fractured vertebra augmentation with intermediate pedicle screw - a clinicoradiological analysis

INTRODUCTION

Unstable thoracolumbar burst fractures are routinely encountered in orthopedic practice. Recently, short-segment fixation with pedicle screw augmentation of the fractured vertebra for unstable thoracolumbar burst fractures has gained popularity. Nonetheless, the maintenance of the kyphotic correction during the follow-up period remains controversial. This study aimed to examine the clinical-radiological outcomes, complications, and functional outcomes of fractured vertebrae augmentation with intermediate pedicle screws in short-segment instrumentation in acute thoracolumbar spine fractures.

METHODS

This retrospective study was conducted in the Department of Orthopedics, All India Institute of Medical Sciences, Jodhpur, using medical records from January 2021 to October 2022. Parameters such as local kyphosis correction, loss of kyphotic correction at final follow-up, anterior body height correction (%), and loss of correction (%) at final follow-up were measured as primary outcomes. Various other parameters such as operative time, blood loss, length of hospital stay, and visual analog scale were measured as secondary outcomes.

RESULTS

The mean correction obtained via surgery in the immediate postoperative period was 13.7±2.3 degrees. The mean loss of correction at the final follow-up was 4.1±2.0 degrees, and the mean final local kyphotic angle was 7.2±2.4 degrees (P<0.05). The mean correction obtained via surgery in the immediate postoperative period was 37.2%±9.0%. The mean loss of correction at the final follow-up was 10.5%±5.3%, and the mean final anterior vertebral body height maintained was 72%±11.0% (P<0.05).

CONCLUSION

Short-segment posterior fixation with pedicle screw augmentation achieves good correction of local kyphotic angle and anterior vertebral height in the immediate postoperative period, but some loss of correction at final follow-up is common. In our study, the loss of correction corresponded directly to the load-sharing score.

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.

Percutaneous Pedicle Screw for Thoracolumbar Fractures: A Long-term Follow-up

Objective:  This is a retrospective cohort study to analyze the long-term outcomes of thoracolumbar spine fracture patients who underwent minimally invasive percutaneous fixation. Methods:  The cases of 17 patients with thoracolumbar spine fractures who had percutaneous fixation between 2009 and 2011 were the subject of a retrospective analysis. Clinical and radiographic variables were collected. For the clinical evaluation the questionnaires SF-36 and Oswestry were used. Radiographic parameters were evaluated using fracture's classification based on Magerls's criteria, the fractured vertebra's wedging angle, and the affected segment's segmental Cobb angle. The measures were made at different stages: before surgery, immediately after surgery, one year later, and at a late follow-up (5 years later). Trauma associated injuries, post-surgical and implant related complications were among the additional information taken into account. Results:  The SF-36 questionnaire showed averages above 63,5% in all domains in the late postoperative data (from 5 years after the surgery). Oswestry questionnaire answers showed minimal or no physical limitations in 80% of the patients with a mean score of 10,8%±10,5. The average preoperative Cobb angle value was 5,53° ± 13,80° of kyphosis, the immediate postoperative 2,18° ± 13,38° of kyphosis, one year postoperative 5,26 ± 13,95° of kyphosis, and the late follow-up 8,78° ± 15,06° of kyphosis. The mean correction was 3,35°, and mean loss of correction was 6,6°. There were no complications observed, no case of neurological deficit, infection or implant failure occurred. Conclusion:  Thoracolumbar vertebrae fractures can be surgically treated with positive late clinical and radiological outcomes and low complication rates using a minimally invasive percutaneous method.

Surgical treatment of traumatic fractures of the thoracic and lumbar spine: A systematic review

Introduction

The treatment of traumatic thoracic and lumbar spine fractures remains controversial. To date no consensus exists on the correct choice of surgical approach and technique.

Research question

to provide a comprehensive up-to-date overview of the available different surgical methods and their quantified outcomes.

Methods

PubMed and EMBASE were searched between 2001 and 2020 using the term 'spinal fractures'. Inclusion criteria were: adults, ≥10 cases, ≥12 months follow-up, thoracic or lumbar fractures, and surgery <3 weeks of trauma. Studies were categorized per surgical technique: Posterior open (PO), posterior percutaneous (PP), stand-alone vertebral body augmentation (SA), anterior scopic (AS), anterior open (AO), posterior percutaneous and anterior open (PPAO), posterior percutaneous and anterior scopic (PPAS), posterior open and anterior open (POAO) and posterior open and anterior scopic (POAS). The PO group was used as a reference group.

Results

After duplicate removal 6042 articles were identified. A total of 102 articles were Included, in which 137 separate surgical technique cohorts were described: PO (n = 75), PP, (n = 39), SA (n = 12), AO (n = 5), PPAO (n = 1), PPAS (n = 1), POAO (n = 2) and POAS (n = 2).

Discussion and conclusion

For type A3/A4 burst fractures, without severe neurological deficit, posterior percutaneous (PP) technique seems the safest and most feasible option in the past two decades. If needed, PP can be combined with anterior augmentation to prevent secondary kyphosis. Furthermore, posterior open (PO) technique is feasible in almost all types of fractures. Also, this technique can provide for an additional posterior decompression or fusion. Overall, no neurologic deterioration was reported following surgical intervention.

The effect of the size of pedicle screw on the long-term radiological and clinical results of short-segment posterior instrumentation in the management of thoracolumbar vertebral fractures

OBJECTIVE

It was aimed at evaluating the effect of the size of the pedicle screw placed on the fractured vertebra on the long-term radiological and clinical results of short-segment posterior instrumentation applied in the surgical treatment of thoracolumbar vertebral fractures.

METHODS

This retrospective study included 36 patients who underwent short-segment posterior instrumentation surgery for a single-level thoracolumbar (T11-L2) fracture between January 2015 and March 2021. The patients included in the study were divided into 2 groups according to the size of the pedicle screw placed in the fractured vertebra (group A: intermediate screw 4.5 mm, ≤35 mm+less than 50% of the vertebral corpus length, m/f: 13/4, n: 17, age: 36.5; group B: intermediate screw 5.5 mm, ≥40 mm+more than 70% of the vertebral corpus length, m/f: 11/8, n: 19, age: 42.6). All patients were periodically evaluated clinically and radiologically. Vertebral compression angle (VCA), anterior and posterior vertebral body height (ABH-PBH), intraoperative parameters (instrumentation time and intraoperative fluoroscopy number), and complications were compared between the 2 groups.

RESULTS

Both groups were comparable with respect to age, sex, level of injury, AO classification, mechanism of injury, and American Spinal Cord Injury Association impairment scale. Restoration of VCA and vertebral corpus heights was achieved sufficiently in both groups after operation (P < .0001). There was no significant difference between the 2 groups in terms of early postoperative VCA, VCA measured at final follow-up, or loss of correction in VCA. At the last follow-up, PBH was statistically significantly better preserved in group B (P=.0424). There was no difference between the 2 groups in terms of operation time and the number of intraoperative fluoroscopies. Implant failure was observed in 1 patient in group A.

CONCLUSION

This study has revealed that using a long, thick pedicle screw placed in the fractured vertebra can better preserve the PBH at the final follow-up. No correlation was found between the size of the intermediate screw and the preservation of the correction in the postoperative vertebral heights and VCA during the follow-up.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Long-segment versus short-segment fixation through a posterior approach for tuberculous spondylodiscitis of the mid-thoracic spine in adults: a study of mid- to long-term efficacy

BACKGROUND

This retrospective study aimed to perform a comparative evaluation of the mid- to long-term efficacy of long-segment and short-segment fixations via the posterior approach as a treatment for tuberculous spondylodiscitis in the mid-thoracic spine.

METHODS

A total of 95 patients with tuberculous spondylodiscitis in the mid-thoracic spine underwent surgery via the posterior approach including single-stage posterior debridement, interbody fusion, and pedicle screw fixation. Long-segment fixations were performed for 46 patients (group A), while short-segment fixations were performed for the other 49 patients (group B). Clinical and radiological outcomes were assessed during mid- to long-term follow-up.

RESULTS

The average follow-up periods for groups A and B were 75.5±11.8 and 76.8±11.6 months, respectively. The operative time and intraoperative blood loss were lower in group B than in group A (P<0.05). Both management approaches significantly corrected the kyphotic deformity detected either in the early postoperative period or at the final visit after long-term follow-up (P>0.05). Bony fusion was generated after average periods of 10.8±2.1 months and 11.0±2.0 months in groups A and B, respectively. Favorable outcomes were observed on assessment of neurological function and patients' well-being at the final follow-up.

CONCLUSIONS

No therapeutic differences were observed between long-segment and short-segment fixation as surgical treatment for mid-thoracic Pott's disease during mid- to long-term follow-up. Kyphotic deformity and neurological impairment were significantly relieved via both posterior fixation approaches, with patients' well-being reaching a favorable level. Moreover, short-segment fixation led to less blood loss and required a shorter operative time.

[Surgical management of acute traumatic spinal cord injury : Stability vs. functionality]

BACKGROUND

Traumatic spinal cord injuries represent a devastating condition in the lives of those affected, with physical, emotional, and economic burdens for the patients themselves, their social environment, and society as a whole.

OBJECTIVE

Surgical approach and techniques in traumatic spinal cord injuries.

RESULTS

Traumatic spinal cord injuries should be surgically treated as soon as possible, but at least within 24 h of injury. If accompanying dural injuries occur, suturing or applying a patch is the primary method of choice. Early surgical decompression is essential, particularly in cervical spinal cord injuries. Stabilization in terms of instrumentation or fusion is inevitable and should be carried out over short segments to maintain the functionality of the cervical spine. Long-distance dorsal instrumentation with prior reduction in thoracolumbar spinal cord injuries provides high stability and preserved functionality in patients. Injuries to the thoracolumbar junction often require a two-stage anterior treatment.

CONCLUSION

Early surgical decompression, reduction, and stabilization of traumatic spinal cord injuries within 24 h are recommended. While short-segment stabilization is recommended in the cervical spine in addition to decompression, instrumentation should be over long segments in the thoracolumbar spine to provide the necessary stability while maintaining functionality.

The efficacy of different segments fixation for treatment thoracolumbar fractures: A Bayesian network meta-analysis

BACKGROUND

We did this network meta-analysis to comprehensively compare the efficacy of different segments [intermediate segment (IS), short segment (SS) and long segment (LS)] in the fixation of thoracolumbar fractures.

METHODS

We searched studies from inception until January 20, 2023 through PubMed, Embase, Web of Science, and the Cochrane Library. All studies comparing different segments in the fixation of thoracolumbar fractures were included in this meta-analysis. Outcomes were anterior vertebral height ratio (AVHR), sagittal Cobb angle (SCA), visual analogue scale score, and implant failure rate. This network meta-analysis was performed by R software with gemtc package.

RESULTS

Finally, a total of 22 studies were finally included in this network meta-analysis. IS (WMD 2.43, 95% CrI 2.04-2.91) was more effective than SS in terms of the AVHR, and the difference was statistically significant. IS was more effective than LS in reducing SCA (WMD -2.87, 95% CrI -3.79 to -1.96) with statistically significant. Compared with SS, IS significantly reduced the SCA with statistically significant (WMD -2.52, 95% CrI -3.31 to -1.72). IS (WMD -2.87, 95% CrI -3.78 to -1.96) was more effective than LS, and the difference was statistically significant. Moreover, IS (WMD -2.52, 95% CrI -3.31 to -1.72) was more effective than SS, and the difference was statistically significant.

CONCLUSION

IS was associated with a significant reduction in SCA, implant failure rate, and visual analogue scale compared to SS and LS, while having the most favorable impact on AVHR among all the treatments assessed.

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.

Long-Segment Versus Short-Segment Pedicle Screw Fixation Including Fractured Vertebrae for the Management of Unstable Thoracolumbar Burst Fractures

Background For the treatment of unstable thoracolumbar fractures, this study compared the results of short-segment fixation with fracture level inclusion (SSFIFL) with long-segment pedicle fixation (LSPF). Methodology In this prospective case series study conducted from January 2015 to January 2019, 80 patients with partial spinal cord lesions were investigated. For the comparison, two groups of 40 patients each were chosen and treated with SSFIFL and LSPF. The outcomes were measured using pre and postoperative radiological parameters and clinical parameters. The radiographic variables included the kyphotic angle with loss of correction, kyphotic deformation, and the Beck index. Mean blood loss, operative time, and cost-effectiveness were also examined for clinical indicators such as the American Spinal Injury Association Impairment Scale, Visual Analog Scale (VAS), and Oswestry Disability Index (ODI). Results There were no substantial variations between the groups regarding age or gender, trauma etiology, fracture level, or fracture pattern. Between the two categories, there appeared to be no notable change in radiological indicators such as kyphotic angle, kyphotic deformation, and Beck index at the end of follow-up (p = 0.120, 0.360, and 0.776, respectively). Both groups had similar neurological outcomes (p = 0.781). In terms of ODI and VAS, statistically, there was no discernible difference (p = 0.567 and 0.161, respectively). In this study, however, there was less surgical time, blood loss, and implant cost (p = 0.05). Conclusions When fracture level is included in a short-segment fixation, the radiological and clinical results are comparable to long-segment posterior fixation. Ultimately, this treatment has proven to be not only a motion segment-saving procedure but also cost-effective.

Does Instrumentation of the Fractured Level in Thoracolumbar Fixation Affect the Functional and Radiological Outcome?

STUDY DESIGN

Retrospective comparative study.

OBJECTIVES

To compare radiological and functional outcomes of patients with fixation constructs utilizing pedicle screw stabilization at the fracture level (FL group) versus patients with non-fracture level (NFL group) fixation in single level fractures of the thoracolumbar junction (T11-L1).

METHODS

53 patients of whom fracture level screw was used in 34 (FL group) were compared to 19 patients in NFL group. Radiological parameters analyzed were sagittal index, bi-segmental kyphosis (Cobb) angle and degree of vertebral height restoration. Prospectively collected patient reported functional outcomes and post-operative complications were also studied. Stepwise regression analysis adjusted by age, gender and functional scores was performed to account for the small numbers and unequal sizes of the groups.

RESULTS

Back pain score was significantly lower in the FL group (P < 0.025). Core Outcome Measures Index scores and leg pain scores, though low in the FL group, were not statistically significant. The regression analysis showed that the inclusion of the fracture-level screw was independently associated with a greater change in sagittal index and vertebral height restoration post-operatively. Sagittal index was maintained through to final follow up as well. The bi-segmental Cobb's angle correction was not associated with fracture-level screw construct. There was no significant difference between the groups for revision surgery, deep infection, implant failure or length of hospital stay.

CONCLUSION

The inclusion of the fracture-level pedicle screws in the fixation construct significantly improves the immediate and final measured radiological parameters, with improved functional scores in single level unstable vertebral fractures of the thoracolumbar junction.

Effect of the intermediate pedicle screws and their insertion depth on sagittal balance and functional outcomes of lumbar fracture

OBJECTIVE

This study aimed to examine the effect of the intermediate pedicle screws and their insertion depth on sagittal balance and functional outcomes of lumbar fracture.

METHODS

This study reviewed 1,123 patients with lumbar fractures between January 2015 and June 2019, and 97 patients were ultimately enrolled in this study: Group A: 32 patients in the four-pedicle screws fixation group; Group B: 28 patients in the six-pedicle screws fixation with long intermediate pedicle screws group; Group C: 37 patients in the six-pedicle screws fixation with short intermediate pedicle screws group. The radiographic outcomes were assessed with lumbar lordosis (LL), segmental lordosis (SL), fractured vertebral lordosis (FL), sacral slope (SS), pelvic incidence (PI), and pelvic tilt (PT). The visual analog scale (VAS) and the Oswestry disability index (ODI) scores were used for assessing functional outcomes.

RESULTS

The PI, PT, and SS showed no significant differences between the three groups (P > 0.05). Compared with Group A, Groups B and C showed better FL, SL, and LL 1 month after operation (5.96 ± 1.67/4.81 ± 1.49 vs. 8.78 ± 2.90, 24.39 ± 3.80/23.70 ± 4.10 vs. 20.09 ± 3.33, 39.07 ± 3.61/39.51 ± 3.23 vs. 36.41 ± 3.11, P < 0.05) and at final follow-up (8.75 ± 1.40/6.78 ± 1.70 vs. 11.31 ± 2.61, 22.11 ± 3.39/23.70 ± 4.10 vs. 17.66 ± 2.60, 38.04 ± 3.49/39.51 ± 3.23 vs. 35.41 ± 3.11, P < 0.05). The FL of Group C were significantly better than those of Group B 1 month after operation (4.81 ± 1.49 vs. 5.96 ± 1.67, P < 0.05) and at final follow-up (6.78 ± 1.70 vs. 8.75 ± 1.40, P < 0.05). No significant differences in VAS and ODI were found between Group A and Group B (P > 0.05). There were also no significant differences in VAS and ODI between Group A and Group C (P > 0.05). However, The VAS and ODI of Group C showed better than Group B 1 month after operation (3.05 ± 0.70 vs. 3.54 ± 0.79, 17.65 ± 3.41 vs. 19.71 ± 2.35, P < 0.05) and at final follow-up (2.19 ± 0.46 vs. 2.57 ± 0.57, 13.81 ± 2.20 vs. 15.57 ± 1.73, P < 0.05).

CONCLUSIONS

Both four-pedicle screw fixation and six-pedicle screw fixation were effective in treating lumbar fracture. However, six-pedicle screw fixation with short intermediate pedicle screws showed better radiographic and functional outcomes after surgery. Therefore, we recommend six-pedicle screws fixation with short intermediate pedicle screws for the long-term recovery of sagittal balance and function.

Selecting proper distal fusion level in severe thoracolumbar kyphosis secondary to late osteoporotic vertebral compression fracture to limit distal complications

BACKGROUND

Surgical treatment of severe thoracolumbar kyphosis (TLK) secondary to late osteoporotic vertebral compression fracture (OVCF) presents several challenges to spine surgeons. Proper selection of distal fusion level is an important issue in surgical planning to decrease the likelihood of distal mechanical complications. This study was designed to compare the clinical and radiographic outcomes in elderly patients suffering from severe TLK related with late OVCF between different distal fusion strategies and to recommend a superior distal fusion level for these patients.

METHODS

A total of 57 consecutive subjects with a minimum follow-up of two years were retrospectively reviewed. TLK was defined as the hyperkyphosis with an apex below T10. Severe TLK was defined as the Cobb angle of kyphosis ≥60°. Patients fused to sagittal stable vertebra (SSV) were assigned to Group SSV, while those fused to the vertebra above and below SSV were assigned to Groups SSV- and SSV+, respectively. Bone cement was used to enhance pedicle screw fixation. Clinical and radiographic results were collected and compared between different groups.

RESULTS

Deformity corrections and living quality improvements at the latest follow-up were superior in Group SSV than Group SSV- with shorter fusion levels, while to the equal extent with Group SSV+ with longer fusion levels. 7 cases of distal complications were observed in Group SSV-. Negatively balanced lowest instrumented vertebra was revealed to be the independent factor predicting distal complications. Patients' satisfaction of their surgical management was greater in Group SSV than Group SSV- (83.2 ± 4.4% vs. 70.5 ± 10.9%, P = 0.024), while comparable with Groups SSV + SSV+ (84.8 ± 5.7%).

CONCLUSIONS

Fusion to SSV with cement-augmented pedicle screws could limit the development of distal junctional mechanical complications after surgical treatment for severe TLK secondary to late OVCF in elderly patients, while achieves satisfactory deformity correction with the preservation of necessary lumbar motility.

Analysis of a Hybrid Spine Fixation Approach for the Treatment of Unstable Thoracolumbar Fractures

Introduction The treatment of unstable thoracolumbar burst fractures and fracture dislocations of the thoracolumbar spine remains ever evolving. Anterior or posterior approaches both have equal efficacy, but the posterior approach has been preferred in our study due to its ease of application, less extensile nature, and reduced intra-operative bleeding. Posterior approaches can employ short-segment fixation or long-segment fixation techniques. Long segment fixation may need implant removal later to increase mobility in nonfusion surgeries. The thoracolumbar segment is a transition zone where the thoracic spine is a less flexible zone, and the lumbar spine is a more flexible zone. Lumbar motion is important to preserve. Hence, we proposed to study spinal fixation two levels above and one level below the fracture for stabilization. This may provide increased stability along with preservation of the motion segment at the lumbar level. Methods We retro-prospectively reviewed the results of unstable thoracolumbar junction fractures with incomplete or intact neurology in 34 consecutive cases operated with alternate two above and one below fixation approach between June 2018 and June 2019 at our institute. Five cases were excluded due to incomplete follow up and the remaining 29 patients were included in the study. Regular follow-up in the postoperative period at three, six, and 12 months was conducted. Data analysis was done by SPSS software version 22 (IBM Corp., Armonk, NY). Results Twenty-nine patients were included in the study out of which 16 were males and 13 were females. The average age was 36.31±1.46 years (range, 14-60 years). The average follow-up duration was 14.31 months. The average injury to surgery interval was 7.17±7.31 days (range, 1-30 days). On analysis via paired t-test, pre-operative kyphotic angle (mean=20.06±8.34º) improved to immediate post-operative (mean=8.44±5.76º, p=0.0001). The postoperative kyphotic angle at 12 months follow-up showed significant stability (Mean=14.13±5.27º, p=0.0001). A median average pre-operative neurological compromise was ASIA score C and Frankel Grade C and the median average disability was an ODI score of 61%-80%. At the end of 12 months of follow-up the median average neurological compromise improved to ASIA Score D and Frankel Grade D and the median average disability improved to an ODI score of 21%-40%. Conclusion Two levels above and one level below hybrid pedicle screw fixation with decompression for the treatment of unstable thoracolumbar fractures with partial and intact neurology was successful within the limited time frame we had for follow-up in preserving progressive post-operative kyphosis, preserving one-motion segment, improving the neurological outcome and disability of the patients without any major complications.

Outcome of Long-Segment Fixation versus Inclusion of the Fractured Level in Short-Segment Fixation for Thoracolumbar Junction Fractures

Objective  The aim of this study was to compare the radiological outcomes of long-segment fixation and short-segment fixation, including the fracture level in patients treated for thoracolumbar junction fractures.

Methods  Data collected from records of patients with thoracolumbar junction fractures who were operated at our department. Neurological evaluation was done using American Spinal Injury Association classification score. Radiological parameters used were the Cobb's angle, vertebral body compression ratio, the anteroposterior spinal canal diameter, and the anterior and the posterior vertebral body heights. Patients were divided into two groups: group A included patients who underwent long-segment fixation and group B included patients who underwent short-segment fixation with inclusion of the fracture level.

Results  The mean preoperative Cobb angle was 22.51 degrees in group A and 19.37 degrees in group B. Both groups showed improvement in the postoperative Cobb angle as the mean in group A was 14.17 degrees and in group B was 11.77 degrees. The mean preoperative compression ratio in group A was 82.8%, while in group B it was 76%. The postoperative mean in group A was 89.2%, while in group B, it was 84%. The mean preoperative anterior vertebral body height of the fractured vertebra in group A was 16.7 mm, while in group B, it was 15.18 mm. The mean preoperative posterior vertebral body height in group A was 16.33 mm and that of group B was 19.41 mm. The mean postoperative anterior vertebral body height in group A was 17.66 mm and that of group B was 17.10 mm. The mean postoperative posterior vertebral body height in group A was 17.11 mm and that of group B was 20.79 mm.

Conclusion  Posterior short-segment fixation with additional screws at the fracture level provides similar—if not better—clinical and radiological outcomes to long-segment fixation in the treatment of thoracolumbar junction fractures.

Effect of pedicle screw placement into the fractured vertebra in management of unstable thoracolumbar and lumbar fractures

BACKGROUND

Pedicle screw insertion at the level of the fractured vertebra has been shown to improve clinical and radiological outcomes in unstable thoracolumbar and lumbar fractures, albeit this requires further evidence. The study aims to evaluate the effect of pedicle screw placement on the fractured vertebra in such cases.

METHODS

A prospective study included adult patients with thoracolumbar and lumbar fractures treated with short-segment posterior instrumentation with a pedicle screw into the fractured vertebra. Anterior vertebral body height loss, kyphotic angle and degree of spinal canal compromise were measured preoperatively and postoperatively in radiographs and CT scans. The neurological status was followed up for one year of the postoperative period.

RESULTS

The study included a total of 30 patients. Five patients (16.7%) had grade C, three patients (10%) had grade D, and 22 patients (73.3%) had grade E neurological status. The mean (SD) preoperative kyphotic angle, vertebral body height and canal compromise were 5.54 (5.35), 39.67% (8.04), and 31.59% (10.62), respectively. Postoperatively there was a significant canal decompression, with a mean postoperative spinal canal compromise of 5.53% (SD=7.70; p-value <0.001). At the end of one year of follow-up, the radiological evaluation showed a correction of the kyphotic angle to 6.62 (SD=2.57; p-value <0.001), and the mean anterior vertebral body height was 70.38% (SD=11.25; p-value <0.001). At the end of one year, there was a significant overall neurological recovery with a final neurological status of grade D in 5 (16.7%) and grade E in 25 patients (83.3%). There was no significant association between canal decompression and neurology at the end of the one-year follow-up.

CONCLUSION

Unstable thoracolumbar and lumbar fractures surgically treated with short-segment fixation with an additional intermediate screw can achieve significant restoration of vertebral body height and correction of kyphotic angle without any added complications.

Is It Necessary to Remove the Implants After Fixation of Thoracolumbar and Lumbar Burst Fractures Without Fusion? A Retrospective Cohort Study of Elderly Patients

Objective

Fractures of the thoracolumbar spine are the most common fractures of the spinal column. This retrospective cohort study aimed to determine whether it is necessary to remove implants of patients aged over 65 years after the fixation of thoracolumbar and lumbar burst fractures without fusion.

Methods

This retrospective cohort study included 107 consecutive patients aged ≥65 years without neurological deficits, who underwent non-fusion short posterior segmental fixation for thoracolumbar or lumbar burst fractures. Outcome measures included the visual analog score (VAS), Oswestry Disability Index (ODI), residual symptoms, complications, and imaging parameters. Patients were divided into groups A (underwent implant removal) and B (implant retention) and were examined clinically at 1, 3, 6, and 12 months postoperatively and annually thereafter, with a final follow-up at 48.5 months.

Results

Overall, 96 patients with a mean age of 69.4 (range, 65–77) years were analyzed. At the latest follow-up, no significant differences were observed in functional outcomes and radiological parameters between both groups, except in the local motion range (LMR) (P = 0.006). Similarly, between preimplant removal and the latest follow-up in group A, significant differences were found only in LMR (P < 0.001). Two patients experienced screw breakage without clinical symptoms. Significant differences were only found in operation time, blood loss, ODI, and fracture type between minimally invasive group and open group.

Conclusions

Similar radiological and functional outcomes were observed in elderly patients, regardless of implant removal. Implant removal may not be necessary after weighing the risks and benefits for elderly patients. Patients should be informed about the possibility of implant breakage and accelerating degeneration of adjacent segments in advance.

Comparison of different segments in the fixation of thoracolumbar fractures: a Bayesian network meta-analysis

BACKGROUND

Posterior internal fixation (PIF) is commonly used in the treatment of thoracolumbar fracture (TLF), but there is still no standard for the number of fixed segments. The objective of this meta-analysis was to evaluate the efficacy and safety of short segment (SS), intermediate segment (IS) and long segment (LS) in the fixation of TLF.

METHODS

Two authors independently searched through PubMed, Embase, Cochrane Library and Web of Science for studies of thoracolumbar fracture treated by posterior internal fixation, which were published until the end of April 2021. The Aggregate Data Drug Information System (ADDIS) software was used for data evaluation according to the Markov chain Monte Carlo (MCMC) method based on the Bayesian theorem.

RESULTS

Nineteen trials evaluating a total of 970 patients were enrolled in these studies, of which 340 in the SS group, 429 in the IS group and 201 in the LS group. For anterior vertebral height ratio (AVHR), IS had the highest AVHR, LS had the second highest AVHR. IS also ranked first in reducing visual analogue scale (VAS), SS ranked second. For sagittal Cobb's angle (SCA), LS had the lowest SCA and IS had the second lowest SCA. In terms of adverse events, IS had the lowest implant failure rate and LS had the second lowest implant failure rate.

CONCLUSIONS

IS may be the most desirable treatment option for TLF in reducing SCA, implant failure rate, VAS, and improving AVHR. However, more randomized controlled trials are needed to verify these results.

One-Year Clinical Outcomes of Minimal-Invasive Dorsal Percutaneous Fixation of Thoracolumbar Spine Fractures

Introduction: Minimal-invasive instrumentation techniques have become a workhorse in spine surgery and require constant clinical evaluations. We sought to analyze patient-reported outcome measures (PROMs) and clinicopathological characteristics of thoracolumbar fracture stabilizations utilizing a minimal-invasive percutaneous dorsal screw-rod system. Methods: We included all patients with thoracolumbar spine fractures who underwent minimal-invasive percutaneous spine stabilization in our clinics since inception and who have at least 1 year of follow-up data. Clinical characteristics (length of hospital stay (LOS), operation time (OT), and complications), PROMs (preoperative (pre-op), 3-weeks postoperative (post-op), 1-year postoperative: eq5D, COMI, ODI, NRS back pain), and laboratory markers (leucocytes, c-reactive protein (CRP)) were analyzed, finding significant associations between these study variables and PROMs. Results: A total of 68 patients (m: 45.6%; f: 54.4%; mean age: 76.9 ± 13.9) were included. The most common fracture types according to the AO classification were A3 (40.3%) and A4 (40.3%), followed by B2 (7.46%) and B1 (5.97%). The Median American Society of Anesthesiologists (ASA) score was 3 (range: 1−4). Stabilized levels ranged from TH4 to L5 (mean number of targeted levels: 4.25 ± 1.4), with TH10-L2 (12/68) and TH11-L3 (11/68) being the most frequent site of surgery. Mean OT and LOS were 92.2 ± 28.2 min and 14.3 ± 6.9 days, respectively. We observed 9/68 complications (13.2%), mostly involving screw misalignments and loosening. CRP increased from 24.9 ± 33.3 pre-op to 34.8 ± 29.9 post-op (p < 0.001), whereas leucocyte counts remained stable. All PROMs showed a marked significant improvement for both 3-week and 1-year evaluations compared to the preoperative situation. Interestingly, we did not find an impact of OT, LOS, lab markers, complications, and other clinical characteristics on PROMs. Notably, a higher number of stabilized levels did not affect PROMs. Conclusions: Minimal-invasive stabilization of thoracolumbar fractures utilizing a dorsal percutaneous approach resulted in significant PROM outcome improvements, although we observed a complication rate of 13.2% for up to 1 year of follow-up. PROMs were not significantly associated with clinicopathological characteristics, technique-related variables, or the number of targeted levels.

Risk Factors for Postoperative Loss of Correction in Thoracolumbar Injuries Caused by High-Energy Trauma Treated via Percutaneous Posterior Stabilization without Bone Fusion

Background and Objectives: Percutaneous pedicle screws were first introduced in 2001, soon becoming the cornerstone of minimally invasive spinal stabilization. Use of the procedure allowed adequate reduction and stabilization of spinal injuries, even in severely injured patients. This decreased bleeding and shortened surgical time, thereby optimizing outcomes; however, postoperative correction loss and kyphosis still occurred in some cases. Thus, we investigated cases of percutaneous posterior fixation for thoracolumbar injury and examined the factors affecting the loss of correction. Materials and Methods: Sixty-seven patients who had undergone percutaneous posterior fixation for thoracolumbar injury (AO classifications A3, A4, B, and C) between 2009 and 2016 were included. Patients with a local kyphosis angle difference ≥10° on computed tomography at the postoperative follow-up (over 12 months after surgery) or those requiring additional surgery for interbody fusion were included in the correction loss group (n = 23); the no-loss group (n = 44) served as the control. The degree of injury (injury level, AO classification, load-sharing score, local kyphosis angle, cuneiform deformity angle, and cranial and caudal disc injury) and surgical content (number of fixed intervertebral vertebrae, type of screw used, presence/absence of screw insertion into the injured vertebrae, and presence/absence of vertebral formation) were evaluated as factors of correctional loss and compared between the two groups. Results: Comparison between each group revealed that differences in the wedge-shaped deformation angle, load-sharing score, degree of cranial disc damage, AO classification at the time of injury, and use of polyaxial screws were statistically significant. Logistic regression analysis showed that the differences in wedge-shaped deformation angle, AO classification, and cranial disc injury were statistically significant; no other factors with statistically significant differences were found. Conclusion: Correction loss was seen in cases with damage to the cranial intervertebral disc as well as the vertebral body.

Long-segment fixation VS short-segment fixation combined with kyphoplasty for osteoporotic thoracolumbar burst fracture

Background

To retrospectively compare clinical and radiological results of long-segment fixation (LF) and six-screw short-segment fixation combined with kyphoplasty (SSFK) for osteoporotic thoracolumbar burst fracture (OTBF).

Methods

Forty patients affected by OTBF with mean age of 61.85 years were included in this study. The mean follow-up period was 13.63 months. Twenty-four patients were treated by SSFK, and 16 patients were treated by LF. Clinical outcomes, radiological parameters and complications were assessed and compared.

Results

The mean operative time and blood loss were 89.71 ± 7.62 min and 143.75 ± 42.51 ml for SSFK group, respectively; 111.69 ± 12.25 min (P < 0.01) and 259.38 ± 49.05 ml (P < 0.01) for LF group, respectively. The two groups were similar in terms of preoperative radiological and clinical results. Compared with preoperative values, both groups achieved significant improvement in terms of VAS, ODI, Cobb angle and anterior vertebral body height (AVH) ratio at final follow-up. However, during the follow-up period, significant loss of Cobb angle and AVH ratio were observed for both groups. Five cases (20.83%) of asymptomatic cement leakage were observed in SSFK group. One case of implant failure and two cases of adjacent or non-adjacent vertebral fractures were observed in LF group.

Conclusions

Both SSFK and LF are safe and effective for treatment of OTBF. Comparatively, SSFK is less invasive and can preserve more motion segments, which may be a more valuable surgical option in some elderly patients. A high-quality randomized controlled study is required to confirm our finding in the future.

Efficacy and Radiographic Analysis of Minimally Invasive Posterior Mono-Axial Pedicle Screw Fixation in Treating Thoracolumbar Burst Fractures

Background: The purpose of this study was to evaluate the effectiveness of minimally invasive posterior mono-axial pedicle screws fixation in the treatment of thoracolumbar burst fractures. Methods: In the present study, we analyzed 98 patients retrospectively who had thoracolumbar burst fractures without a neurological deficit. Patients were divided into two groups: mono-axial pedicle screw fixation group (n = 52) and poly-axial pedicle screw fixation group (n = 46). We collected clinical data (visual analog scale (VAS) score for back pain) and included radiographic measurements. Results: Sagittal index was significantly improved at postop and last follow-up in the mono group and the poly group. The mono group was better for reducing and maintaining anterior vertebral height. For the mono group, the mean postoperative regional kyphosis correction rate was 62.31%, and correction loss was 14.18% in late follow-up. For the poly group, the mean postoperative regional kyphosis correction rate was 52.17%, and correction loss was 33.42% in late follow-up. The mono-axial pedicle screw group had a good correction rate and reduced the risks of correction loss. The mean VAS scores for back pain improved by 2.4/2.5 and 3.8/4.2 for the mono and poly groups, respectively. There was no significant difference between groups. Conclusions: The mono-axial pedicle screw fixation was better for reducing and maintaining anterior vertebral height and regional kyphosis. Therefore, the mono-axial pedicle screw is a better optional instrumentation to treat thoracolumbar vertebral fractures.

Surgical Techniques for Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

To formulate the specific guidelines for the recommendation of thoracolumbar fracture regarding surgical techniques and nonfusion surgery. WFNS (World Federation of Neurosurgical Societies) Spine Committee organized 2 consensus meeting. For nonfusion surgery and thoracolumbar fracture, a systematic literature search in PubMed and Google Scholar database was done from 2010 to 2020. The search was further refined by excluding the articles which were duplicate, not in English or were based on animal or cadaveric subjects. After thorough shortlisting, only 50 articles were selected for full review in this consensus meeting. To generate a consensus, the levels of agreement or disagreement on each item were voted independently in a blind fashion through a Likert-type scale from 1 to 5. The consensus was achieved when the sum for disagreement or agreement was ≥ 66%. Each consensus point was clearly defined with evidence strength, recommendation grade, and consensus level provided. A magnitude of prospective papers were analyzed to formulate consensus on various surgical techniques that can be employed to address different types of thoracolumbar fractures. Surgical treatment of thoracolumbar fractures can be a better option over the nonoperative approach, especially for those who cannot tolerate months in an orthosis or cast, such as those with multiple extremity injuries, skin lesions, obesity, and so forth. It generally allows early mobilization, less hospital stay, reduced pulmonary complications, and better correction of sagittal balance. Current available literature fails to demonstrate any statistically significant benefit of fusion surgery over nonfusion in thoracolumbar fractures.

Clinical long-term consequences of thoraco-lumbar spine fracture and osteosynthesis

OBJECT

Although traumatic spine fractures can be treated by osteosynthesis, their long-term clinical, social, and familial consequences are less known. The aim of this study was to assess these global consequences to a very long-term (at least more than 12 years after the fracture).

METHODS

Two groups, one composed of 30 patients operated for a thoracolumbar fracture by posterior fixation and one with 30 controls (who never had a spinal fracture) matched for age, sex, job and time of follow-up were studied. Patients and control subjects had to answer to 3 questionnaires: one about clinical, familial, and socio-professional changes, and 2 back pain (Dallas and Eifel) scales.

RESULTS

The mean patient follow-up was 14.5 years (from 12 to 18 years, sd 2.3) - control subjects, 15 years. The majority (56%) of the fractures occurred at T12/L1 level. At last follow-up, the chronic low back pain concerned 20 (66,7%) patients versus 11 (36.7%) control subjects (p=0.03); more patients (13 patients - 43.3%) consumed analgesics than control (5 persons - 16.6%) subjects (p=0.04). A large majority (13 patients, 57%) had sick leaves that exceeded 6 months. The loss of wage due to traumatism or chronic low back pain was also significant (p=0.002) between patients and matched controls over the period. At follow-up, the mean Eifel score for the whole patients' cohort was significaty superior compared to control group (4.7 [sd 3.75] vs. 2.6 [sd 4.2], p=0.008). Dallas score was superior in the patient's group for the daily, work-leisure activities and sociability aspect (p<0.05).

CONCLUSION

Chronic back pain, long sick leaves, changes in professional and familial life, the very long-term postoperative outcome of patients could be more difficult than expected in a majority of patients operated for thoracolumbar fracture. In order to facilitate the back to work and reduce these long-term consequences, we propose that guidelines about job resume in traumatic spinal fractures should be established along with early occupational medicine consultations.

LEVEL OF EVIDENCE

III; retrospective case control study.

Comparison of Posterior Fixation Strategies for Thoracolumbar Burst Fracture: A Finite Element Study

The management of thoracolumbar (TL) burst fractures remained challenging. Due to the complex nature of the fractured vertebrae and the lack of clinical and biomechanical evidence, currently, there was still no guideline to select the optimal posterior fixation strategy for TL burst fracture. We utilized a T10-L3 TL finite element model to simulate L1 burst fracture and four surgical constructs with one- or two-level suprajacent and infrajacent instrumentation (U1L1, U1L2, U2L1, and U2L2). This study was aimed to compare the biomechanical properties and find an optimal fixation strategy for TL burst fracture in order to minimize motion in the fractured level without exerting significant burden in the construct. Our result showed that two-level infrajacent fixation (U1L2 and U2L2) resulted in greater global motion reduction ranging from 66.0 to 87.3% compared to 32.0 to 47.3% in one-level infrajacent fixation (U1L1 and U2L1). Flexion produced the largest pathological motion in the fractured level but the differences between the constructs were small, all within 0.26 deg. Comparisons in implant stress showed that U2L1 and U2L2 had an average 25.3 and 24.8% less von Mises stress in the pedicle screws compared to U1L1 and U1L2, respectively. The construct of U2L1 had better preservation of the physiological spinal motion while providing sufficient range of motion reduction at the fractured level. We suggested that U2L1 is a good alternative to the standard long-segment fixation with better preservation of physiological motion and without an increased risk of implant failure.

Thoracolumbar Burst Fracture: McCormack Load-sharing Classification: Systematic Review and Single-arm Meta-analysis

STUDY DESIGN

A systematic review and single-arm meta-analysis of randomized clinical trials.

OBJECTIVE

The aim of this study was to evaluate whether the load-sharing classification (LSC) is reliable to predict the best surgical approach for thoracolumbar burst fracture (TBF).

SUMMARY OF BACKGROUND DATA

There is no previous review evaluating the efficacy of the use of LSC as a guide in the surgical treatment of burst fractures.

METHODS

On April 19th, 2019, a broad search was performed in the following databases: EMBASE, PubMed, Cochrane, SCOPUS, Web of Science, LILACS, and gray literature. This study was registered on the International Prospective Register of Systematic Reviews. We included clinical trials involving patients with TBF undergoing posterior surgical treatment, classified by load-sharing score, and that enabled the analysis of the outcomes loss of segmental kyphosis and implant failure (IF). We performed random- or fixed-effects models meta-analyses depending on the data homogeneity. Heterogeneity between studies was estimated by I2 and τ2 statistics.

RESULTS

The search identified 189 references, out of which nine studies were eligible for this review. All articles presenting LSC up to 6 proved to be reliable in indicating that only posterior instrumentation is necessary, without screw failures or loss of kyphosis correction. For cases where the LSC was >6, only 2.5% of the individuals presented IF upon posterior approach alone. For loss of kyphosis correction, only 5% of patients had this outcome where LSC >6. For both outcomes together, we had 6% of postoperative problems (I2 = 77%, τ2 < 0.0015, P < 0.01).

CONCLUSION

Load-sharing scores up to 6 are 100% reliable, only requiring posterior instrumentation for stabilization. For scores >6, the risk of implant breakage and loss of kyphosis correction in posterior fixation alone is low. Thus, other factors should be considered to define the best surgical approach to be adopted.Level of Evidence: 1.

Outcomes of Thoracolumbar Fracture-Dislocation Managed by Short-Segment and Long-Segment Posterior Fixation: A Single-Center Retrospective Study

BACKGROUND

Long-segment posterior fixation has been used as a mainstay treatment of spine fracture-dislocations. Studies using short-segment posterior fixation in cases of thoracolumbar fracture-dislocation are limited. We describe our experience of 26 patients with thoracolumbar fracture-dislocation treated by short-segment or long-segment posterior spinal fixation and fusion.

METHODS

This is a single-center retrospective study of 26 patients with thoracolumbar fracture-dislocation treated by long-segment (group 1, n = 12) and short-segment posterior instrumentation (group 2, n = 14). Clinical (visual analog scale [VAS], Oswestry Disability Index [ODI]), neurological (American Spinal Injury Association [ASIA] scale), radiological (kyphotic angle, translational percentage, and displacement angle), and surgical (blood loss, operative time) outcomes and complications were recorded with each method. The mean follow-up period was 8.64 months (6-20 months).

RESULTS

The mean duration of surgery was 3.92 ± 0.67 hours in group 1 and 3.21 ± 0.54 hours in group 2, and mean blood loss was 583.33 ± 111.5 mL and 478.6 ±112.2 mL in groups 1 and 2, respectively (P < .05). There was no radiologically visible pseudarthrosis, implant failure, or screw breakage in either group at follow up with no statistically significant difference between the 2 groups with regard to the radiological outcome (P > .05). Two patients in group 1 and 6 patients in group 2 improved after surgery at least 1 ASIA grade. VAS and ODI improved in both groups at the final follow up.

CONCLUSIONS

Short-segment fixation can be used for treating fracture-dislocation patients, as it results in less blood loss, decreased intraoperative time, and saves fusion segments with similar radiological and clinical outcomes as long-segment fixation.

LEVEL OF EVIDENCE

3.

Short- versus long-segment posterior spinal fusion with vertebroplasty for osteoporotic vertebral collapse with neurological impairment in thoracolumbar spine: a multicenter study

Background

Vertebroplasty with posterior spinal fusion (VP + PSF) is one of the most widely accepted surgical techniques for treating osteoporotic vertebral collapse (OVC). Nevertheless, the effect of the extent of fusion on surgical outcomes remains to be established. This study aimed to evaluate the surgical outcomes of short- versus long-segment VP + PSF for OVC with neurological impairment in thoracolumbar spine.

Methods

We retrospectively collected data from 133 patients (median age, 77 years; 42 men and 91 women) from 27 university hospitals and their affiliated hospitals. We divided patients into two groups: a short-segment fusion group (S group) with 2- or 3-segment fusion (87 patients) and a long-segment fusion group (L group) with 4- through 6-segment fusion (46 patients). Surgical invasion, clinical outcomes, local kyphosis angle (LKA), and complications were evaluated.

Results

No significant differences between the two groups were observed in terms of neurological recovery, pain scale scores, and complications. Surgical time was shorter and blood loss was less in the S group, whereas LKA at the final follow-up and correction loss were superior in the L group.

Conclusion

Although less invasiveness and validity of pain and neurological relief are secured by short-segment VP + PSF, surgeons should be cautious regarding correction loss.

Posterior short segment pedicle screw fixation for the treatment of thoracolumbar fracture

The choice of the type of stabilization device in the osteosynthesis of dorso-lumbar spine fractures remains a subject of controversy. The present study aims to evaluate the efficiency of short segment in patients suffering post-traumatic thoracolumbar fractures. This study was conducted in the Department of Orthopedic Surgery and Traumatology of the Habib Bourguiba University Hospital, Sfax, Tunisia. All our patients had a spinal osteosynthesis via the posterior approach with a short segment pedicle screw fixation. We established a record of the pre and post-operative data, the functional results in the post-operative stage during the follow-up period and in retrospect according to the Denis Pain Scale, as well as the Oswestry score. The correction was evaluated by determining the relative gain and loss at the last period of retrospect: vertebral kyphosis, regional kyphosis, Gardner Segment Kyphotic Deformity (GSKD), and computed tomography (CT) scan in retrospect to check the quality of the arthrodesis. The average Oswestry score was 14%. Twenty-nine patients had an Oswestry score ≤40%. The relative gain obtained postoperatively was 57.3% for vertebral kyphosis, 67.2% for regional kyphosis and 71.3% for Gardner kyphosis deformity; while the loss of correction at the last follow-up was 0.6° for vertebral kyphosis, 1.5° for regional kyphosis and 0.9° for GSKD. No cases of non-union were reported. The short segment fixation makes it possible to limit operating time, the abundance of bleeding and the aggression of the soft tissues.

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.

Long-term Behavior of Single-level Thoracic and Lumbar Fractures Treated With Pedicle Screw Fixation

STUDY DESIGN

This was a retrospective cohort study to objectively analyze the behavior of single-level thoracic (T), thoracolumbar (TL), and lumbar (L) fractures treated with posterior instrumentation alone and to understand which factors influence the ability to restore and maintain normal spinal alignment.

SUMMARY OF BACKGROUND DATA

Posterior screw fixation of dorsal and lumbar spine fractures allows fracture stabilization, correction of kyphotic deformity and restoration of vertebral height. The load-sharing classification identifies fractures that may need anterior instrumentation.

MATERIALS AND METHODS

Patients submitted to pedicle screw fixation of single-level T, TL, and L fractures were retrospectively analyzed. Data on patient demographics, neurological injury [American Spinal Injury Association (ASIA) score], and comorbidities were collected. Fractures were classified according to their anatomic region (T, TL, or L) and using the AO Spine and the load-sharing classifications. Local kyphosis angle, Cobb angle (CA), and changes in anterior vertebral height (AVH) were measured, to quantify intraoperative correction and loss of correction at 6 weeks and at last follow-up. A multivariate analysis was performed to identify the factors influencing the intraoperative correction and the loss of correction over time.

RESULTS

From a total of 230 fractures, 115 patients with a mean age of 51.48 years were included. Pedicle screw fixation achieved a significant intraoperative correction of the CA, local kyphosis angle, and AVH. This correction was partially lost over time, but, at last follow-up, radiographic parameters were still significantly better than preoperatively. A regression model identified that age and body mass index influenced the correction of CA; ASIA classification influenced the correction of AVH.

CONCLUSION

Posterior screw fixation allows for the restoration of spinal alignment, but this correction is less effective in elderly people and in patients with higher body mass index and higher degree of neurological injury.Level of Study: Level III.

Biomechanical Assessment of Vertebroplasty Combined with Cement-Augmented Screw Fixation for Lumbar Burst Fractures: A Finite Element Analysis

A hybrid fixation method, using a combination of vertebroplasty and cement-augmented screws, has been demonstrated as a useful technique for securing osteoporotic burst fractures. The purpose of this study was to assess changes in the range of motion (ROM) and stress in the spine after treating a lumbar burst fracture with this hybrid method. Five finite element models were developed: (a) intact lumbar spine (INT), (b) INT with vertebroplasty at L3 (AwC), (c) two-segment fixation of AwC (AwC-TSF), (d) AwC-TSF model with cement-augmented screws (AwC-TSF-S), and (e) INT with an L3 burst fracture treated with two-segment fixation (TSF). After loading, the models were evaluated in terms of the ROM of each motion segment, stiffness of fusion segments, and stresses on the endplates and screws. The results showed that the TSF model has a larger ROM at the instrumented segments than both the AwC-TSF and AwC-TSF-S models. The stiffness at L2–L4 under extension and lateral bending in AwC-TSF, AwC-TSF-S and TSF was approximately nine times greater than the INT model. In conclusion, the hybrid fixation method (AwC-TSF-S) results in a stiffer construct and lower ROM at instrumented segments, which may also reduce the risk of fracture of adjacent vertebrae.

Surgical treatment of traumatic thoracolumbar fractures: a retrospective review of 101 cases

PURPOSE

To evaluate the outcomes of vertebral stabilisation after acute traumatic thoracolumbar fractures, correlating the outcome with patient clinical data, type and location of fracture, presence of neurological damage, timing of surgical intervention and number of instrumented levels. The results have been evaluated also through the AO classification and AOSIS score.

METHODS

Retrospective analysis of 101 patients with traumatic thoracolumbar injuries from T3 to L5 operated 2011-2016 by posterior or antero-posterior fixation. The demographic data, trauma dynamics, number and type of fractures, associated lesions, timing of surgery, hospital stay, AOSIS score, RKA, SF-36 and ODI scores, pre- and post-operative neurological condition (ASIA grade), possible complications and re-interventions were evaluated for each patient.

RESULTS

Fractures mainly involved the region between T11 and L2. The probability of medullary involvement increases with the increase in severity of the main fracture type with no relation with the vertebral region. Type B and C fractures were common in the thoracic region and rare in the thoracolumbar junction. ODI and SF-36 scores were significantly better in patients with a lower AOSIS score, specifically in lesions classified as type A, amyelic and with no comorbidity. No difference was found in the clinical scores between thoracic, thoracolumbar and lumbar fractures, nor between male and female patients. None of the 10 patients with ASIA A lesion at presentation achieved any degree of recovery: 50% of them had a thoracic lesion. Re-intervention rate was 15%. Hospital stay was significantly higher in patients with type C fractures, and complication rate was on average 14% (7% in type A fractures, 16% in B and 25% in C).

CONCLUSIONS

This study confirmed the validity of the posterior approach in the surgical treatment of thoracolumbar fractures. Outcomes and complication risks are related to fracture severity. Surgical treatment can be recommended even with an AOSIS score of two or three. The combined antero-posterior approach could be useful in cases with LSC > 8, especially in the thoracolumbar region. The degree of neurological recovery depends on fracture type, location, ASIA score and presence of comorbidities. Early intervention in myelic patients allows for a better prognosis. Level of evidence III retrospective case series.

Current status of short segment fixation in thoracolumbar spine injuries

Short segment fixation aims to restore spinal stability and alignment in thoracolumbar spine injuries while preserving spinal motion by decreasing the levels of spine involved in fixation. In its simplest form it applies to fixation one level above and one level below the fractured vertebra. It has proven effective with good clinical, functional and radiological results in well selected cases. However not insignificant rates of sagittal collapse and recurrence of kyphosis with or without clinical implications have also been reported. Most of the failures were attributed to lack of anterior column integrity and relatively inferior robustness of earlier posterior short segment constructs. With better understanding of fracture biomechanics, better implant designs and evolution of strategies to increase the biomechanical strengths of posterior constructs, the rates of kyphosis recurrence and implant failure have been significantly reduced. Although there is lack of robust evidence to guide a surgeon to the best approach for a particular fracture, adhering to basic biomechanical principals increases the efficacy and reliability of short segment fixation. This narrative review highlights the status of short segment fixation in dorsolumbar spine injuries with emphasis on patient selection and strategies to increase effectiveness and reduce failures of short segment fixation.

Short-Segment Instrumentation with Fractured Vertebrae Augmentation by Screws and Bone Substitute for Thoracolumbar Unstable Burst Fractures

BACKGROUND

For thoracolumbar burst fractures, traditional four-screw (one above and one below) short-segment instrumentation is popular and has a high failure rate. Additional augmentation at the fractured vertebrae is believed to reduce surgical failure. The purpose of this study was to examine the clinical and radiographic results of patients who underwent short-segment posterior instrumentation with augmentation by screws and bone substitutes at the fractured vertebrae and to compare these data to those of patients who underwent long-segment instrumentation for thoracolumbar burst fractures.

METHODS

The study group had twenty patients who underwent short-segment instrumentation with additional augmentation by two screws and bone substitutes at the fractured vertebrae. The control group contained twenty-two patients who underwent eight-screw long instrumentation without vertebra augmentation. Local kyphosis and the anterior body height of the fractured vertebrae were measured. The severity of the fractured vertebrae was evaluated with the load sharing classification (LSC). Any implant failure or loss of correction >10° at the final follow-up was defined as surgical failure.

RESULTS

Both groups had similar distributions in terms of age, sex, the injured level, and the mechanism of injury before operation. During the operation, the study group had significantly less blood loss (136.0 vs. 363.6 ml, p=0.001) and required shorter operating times (146.8 vs. 157.5 minutes, p=0.112) than the control group. Immediately after surgery, the study group had better correction of the local kyphosis angle (13.4° vs. 11.9°, p=0.212) and restoration of the anterior height (34.7% vs. 31.0%, p=0.326) than the control group. At the final follow-up, no patients in the study group and only one patient in the control group experienced surgical failure.

CONCLUSIONS

Patients with thoracolumbar burst fractures who received six-screw short-segment posterior fixators with augmentation at the level of the fractured vertebrae via injectable artificial bone substitute achieved satisfactory clinical and radiographic results, and this method could replace long-segment instrumentation methods used in unstable thoracolumbar burst fractures.

Posterior Thoracolumbar Instrumented Fusion for Burst Fractures: A Meta-analysis

STUDY DESIGN

This was a meta-analysis study.

OBJECTIVE

To compare different posterior spine fixation methods for burst fracture fixation.

SUMMARY OF BACKGROUND DATA

This study was performed to elucidate if the current body of literature supports one posterior spinal fusion fixation method for burst fracture to minimize the rate of implant failure and progression of posttraumatic kyphosis.

MATERIALS AND METHODS

An extensive electronic search was conducted using PubMed for pertinent articles. The articles were examined against the inclusion and exclusion criteria. Data pertaining to kyphosis angle, Frankel score, vertebral level, blood loss, operation time, hospital stay, postoperative bracing, instrument failure, complications, and follow-up were collected. A random effects model was chosen due to variation among the individual studies' patient populations and surgical methods.

RESULTS

A total of 23 publications were eventually deemed eligible according to the criteria and included into this study. The group with 2 levels above and 1 below with intermediate screws had the greatest maintenance of spine kyphosis and lowest implant failure at final follow-up (P<0.001). There was no difference between the periods of hospital stay (P=0.788) and blood loss (P=0.154) among different tiers.

CONCLUSIONS

A fixation method consisting of 2 levels above and 1 below with intermediate screws for the thoracolumbar burst fractures showed the highest correction of kyphosis angle both at immediate and final follow-up and also the lowest implant failure at final follow-up.

The stability of long-segment and short-segment fixation for treating severe burst fractures at the thoracolumbar junction in osteoporotic bone: A finite element analysis

The majority of compressive vertebral fractures in osteoporotic bone occur at the level of the thoracolumbar junction. Immediate decompression is often required in order to reduce the extent of neurological damage. This study evaluated four fixation methods for decompression in patients with thoracolumbar burst fractures, and presented the most suitable method for osteoporotic patients. A finite element model of a T7–L5 spinal segment was created and subjected to an L1 corpectomy to simulate a serious burst fracture. Five models were tested: a) intact spine; 2) two segment fixation (TSF), 3) up-three segment fixation (UTSF), below-three segment fixation (BTSF), and four segment fixation (FSF). The ROM, stiffness and compression ratio of the fractured vertebra were recorded under various loading conditions. The results of this study showed that the ROM of the FSF model was the lowest, and the ROMs of UTSF and BTSF models were similar but still greater than the TSF model. Decreasing the BMD to simulate osteoporotic bone resulted in a ROM for the four instrumented models that was higher than the normal bone model. Of all models, the FSF model had the highest stiffness at T12-L2 in extension and lateral bending. Similarly, the compression ratio of the FSF model at L1 was also higher than the other instrumented models. In conclusion, FSF fixation is suggested for patients with osteoporotic thoracolumbar burst fractures. For patients with normal bone quality, both UTSF and BTSF fixation provide an acceptable stiffness in extension and lateral bending, as well as a favorable compression ratio at L1.

Modified pedicle screw placement at the fracture level for treatment of thoracolumbar burst fractures: a study protocol of a randomised controlled trial

INTRODUCTION

The optimal treatment for burst fractures of the thoracolumbar spine is controversial. The addition of screws in the fractured segment has been shown to improve construct stiffness, but can aggravate the trauma to the fractured vertebra. Therefore, optimised placement of two pedicle screws at the fracture level is required for the treatment of thoracolumbar burst fractures. This randomised controlled study is the first to examine the efficacy of diverse orders of pedicle screw placement and will provide recommendations for the treatment of patients with thoracolumbar burst fractures.

METHODS AND ANALYSIS

A randomised controlled trial with blinding of patients and the statistician, but not the clinicians and researchers, will be conducted. A total of 70 patients with single AO type A3 or A4 thoracolumbar fractures who are candidates for application of short-segment pedicle screws at the fractured vertebral level will be allocated randomly to the distraction-screw and screw-distraction groups at a ratio of 1:1. The primary clinical outcome measures will be the percentage loss of vertebral body height, screw depth in the injured vertebrae and kyphosis (Cobb angle). Secondary clinical outcome measures will be complications, Visual Analogue Scale scores for back and leg pain, neurological function, operation time, intraoperative blood loss, Japanese Orthopaedic Association score and Oswestry Disability Index. These parameters will be evaluated preoperatively, intraoperatively, on postoperative day 3, and at 1, 3, 6, 12 and 24 months postoperatively.

ETHICS AND DISSEMINATION

The Institutional Review Board of the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University have reviewed and approved this study (batch: LCKY2018-05). The results will be presented in peer-reviewed journals and at an international spine-related meeting after completion of the study.

TRIAL REGISTRATION NUMBER

NCT03384368; Pre-results.

Intermediate screws or kyphoplasty: Which method of posterior short-segment fixation is better for treating single-level thoracolumbar burst fractures?

PURPOSE

To compare intermediate screws (IS) with kyphoplasty (KP) in posterior short-segment fixation (PSSF) for patients with single-level thoracolumbar burst fractures.

METHODS

Between 2010 and 2016, 1465 patients were retrospectively reviewed; 48 patients were enrolled with a minimal follow-up of 2 years. Perioperative and functional outcomes were compared. The regional Cobb angle (CA) was included in radiographic analysis. Implant failures or CA correction loss over 10° were regarded as surgical failures. Multiple linear regression was performed to investigate the risk factors of kyphosis recurrence.

RESULTS

Fluoroscopic time (23.7 ± 3.6 vs. 79.3 ± 12.1 s, p < 0.001), operative time (109.6 ± 13.1 vs. 123.8 ± 19.0 min, p = 0.006) and blood loss (104.6 ± 34.9 vs. 129.1 ± 21.7 ml, p = 0.005) were all lower in the IS group. The KP group had lower Visual Analogue Scale scores (3.3 ± 0.9 vs. 2.7 ± 0.8, p = 0.028) and greater anterior body height (ABH) (30.3 ± 9.0 vs. 36.3 ± 11.0%, p = 0.044) after surgery, and less correction loss (5.6 ± 2.7 vs. 0.4 ± 1.2%, p < 0.001). Both groups had a CA correction loss of 4° with a 10% failure rate. The A3 Magerl subclassification, smaller preoperative ABH and smaller postoperative CA had positive correlations with CA correction loss.

CONCLUSION

PSSF with KP provides better back pain relief, greater ABH reduction and less correction loss, while IS has the advantages of less operative time, fluoroscopic time and blood loss. Magerl subclassification of burst fracture is a potential predictor for recurrent kyphosis. Reducing fractured vertebral body height rather than segmental curvature may be more important in PSSF.

STUDY DESIGN

Retrospective, non-randomized controlled study. These slides can be retrieved under Electronic Supplementary Material.

Outcomes of Including Fracture Level in Short- Segment Fixation for Th oracolumbar Fracture Dislocation

STUDY DESIGN

This was a prospective study of 50 patients of thoracolumbar fracture dislocation treated at a single institution with short-segment fixation with the inclusion of fracture level.

PURPOSE

To assess the outcomes of including the fracture level in short-segment fixation for thoracolumbar fracture dislocation.

OVERVIEW OF LITERATURE

Traditionally, thoracolumbar fracture dislocation is treated with long-segment posterior fixation. However, to save motion segments, short-segment fixation has been used instead in many cases of thoracolumbar trauma.

METHODS

In this study, 50 patients with thoracolumbar fracture dislocation were treated with short-segment fixation with inclusion of the fracture level; patients with pathological fractures or with a McCormack load-sharing score >6 were excluded. The 50 patients were prospectively followed for at least 1 year. The duration of surgery, blood loss, and complications were noted. The Visual Analog Scale (VAS) score was used to measure pain, and the American Spinal Injury Association (ASIA) scale was used to determine the neurological status at follow-up. Preoperative, immediate postoperative, and final follow-up X-rays were used to measure the kyphotic angle using Cobb's method.

RESULTS

The mean age of our patients was 33.4 years, and the male:female ratio was 1.9:1. The mean follow-up period was 18.4 months (range, 12-23 months). Injuries were mainly at the thoracolumbar junction area (T11-L2, 41 cases, 82%). The average duration of surgery was 94.6 minutes, and the average blood loss was 394.8 mL. Postoperative infection occurred in two cases and implant failure in one case. The kyphosis angle values were as follows: average preoperative, 26.80°±14.50°; immediate postoperative, 4.30°±8.70°; and final follow-up, 5.50°±110°. The ASIA scale and VAS score at final follow-up showed improvement.

CONCLUSIONS

Inclusion of the fracture level in short-segment fixation for thoracolumbar fracture dislocation (McCormack load-sharing score ≤6) gives good kyphosis correction and correction maintenance. It can also obviate the need for traditional long-segment fixation.

Biomechanical effects of USS fixation with different screw insertion depths on the vertebrae stiffness and screw stress for the treatment of the L1 fracture

OBJECTIVE

To evaluate the biomechanical effects of internal fixation with different screw insertion depths on vertebrae stiffness and screw stress for L1 fracture.

METHODS

The established L1 fracture was fixed with 10 different depths of screw insertion: 10-100% screw-path length (SPL). Loading on the T12 endplate was simulated.

RESULTS

Screws inserted to 60-100% depths has a higher axial displacement of screw against injured vertebrae and maximum stress of screws compared to those of screws inserted to 30-50% depths and 10-20% (P< 0.05). No significant difference was noted among 60-100% SPL groups. Under single loading condition, the incidence rate of maximum stress of each screw ranged from 16.7-50.0%. Chi-square test showed superior screw has a higher incidence rate of maximum stress than inferior screw (P< 0.05).

CONCLUSIONS

Screws inserted to 60% depth or more can achieve effective strength to withstand the postoperative height correction loss of the L1 vertebrae fracture. However, continuous prolonged depth of screw insertion did not significantly increase the effective strength of the screw against injured vertebrae and maximum equivalent stress of screws. The incidence rate of the maximum stress of each screw in correlated with position of screw insertion but not associated with the screw insertion depth.

Short-segment decompression and fixation for thoracolumbar osteoporotic fractures with neurological deficits

Objective

We assessed our results of short-segment decompression and fixation for osteoporotic thoracolumbar fractures with neurological deficits.

Methods

We evaluated 20 elderly patients (age, 60–89 years; mean, 73.2 years) with osteoporotic thoracolumbar fractures and neurological deficits. They underwent short-segment decompression and fixation and followed up for 40.6 (range, 24–68) months. A visual analog scale (VAS) and the Oswestry Disability Index (ODI) were used to measure back pain and disability. We also analyzed patients’ radiologic findings and neurological status. Perioperative and postoperative complications were recorded.

Results

At the latest follow-up, the average VAS score for back pain and ODI scores had significantly improved. The radiologic assessment showed significant improvements in local kyphosis, anterior vertebral height, and the vertebral wedge angle compared with the original measures. Neurological function also improved in 18 of 20 patients. No major complications occurred perioperatively. Our techniques included preservation of the posterior ligament complex, decortication of facet joints for fusion, no tapping to increase the screw insertional torque, pre-contouring of the rods according to the “adaptive” curve obtained from postural reduction, and postoperative spinal bracing.

Conclusions

Posterior short-segment decompression and fixation could be an effective surgical option for osteoporotic thoracolumbar burst fractures with neurological deficits.