Is removal of the implants needed after fixation of burst fractures of the thoracolumbar and lumbar spine without fusion?

Removal versus Retention of Posterior Spinal Implants in Patients with Healed Thoracolumbar Fractures: Analysis of Clinical and Radiographic Outcomes-A Randomized Controlled Trial

Introduction

There is ongoing debate over whether to remove or retain posterior spinal implants following the successful union of thoracolumbar fractures. This study aimed to compare clinical and radiographic outcomes following removal versus retention of posterior spinal implants in patients with healed thoracolumbar fractures.

Methods

All patients who underwent posterior short segment fixation for thoracolumbar (T11-L2) fractures and presented to the outpatient clinic of our institution (level I trauma center) from October 2020 to October 2022 were enrolled in the study. The participants were randomly assigned to one of the two groups. The EQ-5D-5L was the primary outcome of the study. The secondary outcomes were the Oswestry Disability Index (ODI), loss of correction, and incidence of complications.

Results

A total of 52 patients were included in the final analysis with 26 patients in each group. During the 6-month and 1-year follow-up visits, the implant removal group had a statistically significant improvement in the EQ-Index, EQ-VAS, and ODI, while there were no significant differences in these parameters in the implant retention group. There was no significant difference between the two groups regarding loss of correction (P=0.109).

Conclusions

In patients who have undergone posterior instrumentation for thoracolumbar fractures, the removal of implants following fracture consolidation demonstrates enhanced clinical outcomes when compared to retaining the implants. Although loss of correction is marginally higher in the implant removal group than in the retention group, this disparity did not attain statistical significance, nor did it correlate with inferior clinical outcomes. Furthermore, the incidence of complications following implant removal remained minimal. These findings emphasize the favorable efficacy and safety profile of implant removal procedures within this patient population.

Is Removal of Implants Mandatory Following Minimally Invasive Percutaneous Screw-Rod Stabilization Without Fusion for Mono-Segmental Thoracolumbar Fractures in Elderly Patients?

Purpose

Despite the lack of evidence, the current standard of care following posterior pedicle screw-rod stabilization for spinal trauma includes instrumentation removal. This retrospective cohort study aimed to assess the necessity of implant removal in patients aged ≥65 years who underwent minimally invasive pedicle screw-rod fixation for AO type A and B thoracolumbar fractures.

Methods

We evaluated the clinical and radiological outcomes of 57 patients aged ≥65 years with mono-segmental AO type A and B thoracolumbar fractures treated with percutaneous short-segment pedicle screw fixation, and compared the two groups with and without hardware removal. Clinical outcomes included the visual analog scale score for back pain (VAS), Oswestry Disability Index (ODI), residual chronic back pain (RCBP) and implant-related complications. Radiological parameters, such as the vertebral wedge angle (VWA), segmental kyphosis Cobb angle (SKCA), anterior edge height ratio (AEHR) and adjacent intervertebral height index (IHI), were measured.

Results

No significant differences were observed between the two groups in the mean VAS and ODI values at 12 months and final follow-up. The incidence of RCBP in the implant retention group (25.9%) was slightly higher than that in the implant removal group (20%). However, there were no significant differences between the two groups. Both groups showed correction loss over time. An increase in the segmental kyphosis Cobb angle only differed by 2.02° with no significant difference between the two groups at final follow-up (implant removal group A 4.15°, implant removal group 2.13°). However, whether the implant was removed or not, no statistically significant differences were found in the correction loss of SKCA, VWA, IHI, or AEHR between the two groups within the 12-month follow-up period.

Conclusion

Our results suggest that percutaneous short-segment pedicle screw fixation showed similar radiological and functional outcomes in patients aged ≥65 years, regardless of whether the implants were removed after fracture healing.

Thoracolumbar injuries: operative treatment: indications, techniques, timing and implant removal. Current practice

The operative treatment of thoracolumbar fractures is a rapidly evolving improvement in the care of patients with this injury after trauma. This article describes the different techniques and principles. Considerations and methods of treatment are scientifically addressed and illustrated according to the classification and severity of the fracture pattern. The use of computer navigation and optimisation of minimally invasive techniques is inevitable. The timing of surgery as well the removal of the material after fracture healing are also discussed. The operative treatment of spinal fractures is emerging and there is still much more knowledge to gain.

Risk factors for kyphosis recurrence after implant removal in percutaneous osteosynthesis for post-traumatic thoracolumbar fracture

PURPOSE

Short-segment minimally invasive percutaneous spinal osteosynthesis has now become one of the treatments of choice to treat thoracolumbar fractures. The question of implant removal once the fracture has healed is still a matter of debate since this procedure can be associated with loss of sagittal correction. Therefore, we analyzed risk factors for kyphosis recurrence after spinal implants removal in patients treated with short-segment minimally invasive percutaneous spinal instrumentation for a thoracolumbar fracture.

METHODS

A total of 32 patients who underwent implant removal in percutaneous osteosynthesis for post-traumatic thoracolumbar fracture were enrolled in our study. Patient's medical record, operative report and imaging examinations carried out at the trauma and during the follow-up were analyzed.

RESULTS

Every patient experienced fracture union. Vertebral kyphotic angle (VKA) and Cobb angle (CA) improved significantly after stabilization surgery. VKA, CA, upper disk kyphotic angle (UDKA) and lower disk kyphotic angle (LDKA) significantly gradually decreased during follow-up. Traumatic disk injury (p: 0.001), younger age (p: 0.01), canal compromise (p: 0.04) and importance of surgical correction (p < 0.001) were significantly associated with kyphosis recurrence after implant removal. Anterior body augmentation did not affect loss of correction (CA and VKA) during the follow-up period (p: 0.57).

CONCLUSION

Despite correction of the fracture after stabilization, we observed a progressive loss of correction over time appearing even before implant removal. Particular attention should be paid to post-traumatic disk damage or canal invasion, to young patients and to surgical overcorrection of the traumatic kyphosis.

Surgeon reported treatment choices for AO type B and C thoracolumbar fractures without neurological deficits: An expert survey

INTRODUCTION

Less invasive spine surgery (LISS) has become well-established for thoracolumbar burst fractures without neurological deficits. However, notable controversy persists regarding the adequacy of LISS for more unstable AO type B and C injuries, as it does not allow for formal open fusion.

MATERIALS AND METHODS

In this cross-sectional survey experienced spine surgeons of the Dutch Spine Society were invited to participate (56 participants). They were asked to indicate the most appropriate treatment for AO type B1, B2 (L1: A1 and L1: A3), B3 and C (L1: A4) injuries at level Th12-L1. Taking into account: age, AO N0-N1, or polytrauma. Specific agreement between participants was obtained applying Variation Ratio (VR).

RESULTS

A significant level of overall agreement was observed for AO type-B1 injuries with 73.8% of participants opting for percutaneous short-segment fixation (VR 0.775). For AO type-B3 injuries, 79.4% of participants favored percutaneous long-segment fixation (VR 0.794). for AO type-B2 injuries, there was less overall agreement (VR 0.571-0.657). Nonetheless, when considering all AO type-B injuries combined, percutaneous fixation emerged as the most preferred treatment option with substantial agreement (VR 0.871-0.923). Conversely, for AO type-C injuries, there was less agreement among the participants (VI 0.411), 26.5% of them chose additional open spinal fusion.

CONCLUSION

For all AO type-B injuries there was substantial agreement to treat these fractures with percutaneous techniques. For AO type-C injuries, the survey results do not support a consensus. Nevertheless, the responses raise important questions about the necessity of spinal fusion for such injuries.

A Rapid and Safe Minimally Invasive Procedure for Percutaneous Pedicle Screw Removal: A Case-Control Study and Technical Description

Purpose

Percutaneous pedicle screw fixation is a common minimally invasive treatment for traumatic thoracolumbar and lumbar fractures; however, research on hardware removal after successful healing is limited. We aimed to introduce a rapid, safe, minimally invasive, and cost-effective method for percutaneous pedicle screw removal.

Patients and Methods

We conducted a retrospective analysis of demographic (age, sex, body mass index, alcohol use, and current smoking), clinical (hypertension and diabetes mellitus), surgical (affected levels, number of screws, time of surgery, and blood loss), and treatment cost characteristics of 92 patients who had undergone percutaneous pedicle screw removal between May 2016 and February 2023. The first 57 patients underwent the conventional method, and the remaining 35 underwent the modified method. Independent-sample t-tests and chi-square tests were used to compare continuous and categorical variables, respectively, between the two groups.

Results

No significant differences were observed in the demographic parameters, complications, or affected levels between the groups. However, the average surgical time (P=0.000) was significantly shorter, and the average blood loss volume (P=0.002) and total cost (P=0.000) were significantly lower in the modified group than in the conventional group.

Conclusion

Compared with the conventional method, our modified method can shorten the surgical time, reduce blood loss, and reduce the total cost of treatment. It is a quick and safe minimally invasive method that does not require additional surgical instruments and is suitable for implementation in primary hospitals.

Unilateral biportal endoscopic technique combined with percutaneous transpedicular screw fixation for thoracolumbar burst fractures with neurological symptoms: technical note and preliminary report

BACKGROUND

Previous studies on thoracolumbar fractures with neurological symptoms have focused on how to achieve satisfactory fracture reduction, adequate nerve decompression, and stable spinal alignment. With the development of the minimally invasive spine surgery technique, achieving satisfactory treatment results and reducing iatrogenic trauma at the same time has become a new goal of spinal surgery. This research used percutaneous transpedicular screw distraction to partially reduce the fractured vertebrae, followed by completing nerve decompression and reducing residual displacement bone fragments with the assistance of the unilateral biportal endoscopic (UBE) technique to achieve full protection of bone-ligament tissue and obtain good clinical efficacy.

METHODS

Guide wires were safely inserted into the fractured vertebra and adjacent upper and lower vertebra under the surveillance of anteroposterior and lateral X-ray fluoroscopy. Transpedicular screws were implanted via guide wires on the side with mild neurological deficits or bone fragment compression (the opposite side of the endoscopic operation). A titanium rod was installed and moderately distracted to reduce the fractured vertebra. Then, under the guidance of the endoscopic view, the laminectomy and ligamentum flavum resection were completed according to the position of the protruding bone fragment into the spinal canal, and the compressed dural sac or nerve root was fully exposed and decompressed. An L-shaped replacer was used to reduce residual bone fragments. The ipsilateral transpedicular screws and rod were installed and adjusted to match the contralateral side. The drainage tube was indwelled, and the incision was closed. The preoperative and postoperative images of the patients were evaluated, and the recovery of neurological symptoms was observed.

RESULTS

Surgery was successfully completed on all six patients, and no intraoperative conversion to open surgery was performed. Postoperative images showed good reduction of the protruding bone fragment and good placement of all screws. At the last follow-up, the neurological symptoms of all patients returned to normal.

CONCLUSION

The UBE technique combined with percutaneous transpedicular screw fixation in the treatment of thoracolumbar fractures with neurological symptoms can effectively achieve the reduction of displaced bone fragments, improve damaged nerve function, stabilize spinal alignment, and protect the integrity of bone-ligament tissue.

Endoscopic Decompression Combined with Percutaneous Pedicle Screw Fixation for Treating Thoracolumbar Burst Fractures with Neurological Deficits: Technical Note and Early Outcomes

OBJECTIVE

The aim of this study is to introduce surgical technique of endoscopic decompression combined with percutaneous pedicle screw fixation (PPSF) for thoracolumbar burst fractures (TLBFs) with neurological deficits and evaluate its efficacy.

METHODS

A total of 32 patients with TLBFs and neurological deficits who were treated by endoscopic decompression combined with PPSF from June 2018 to August 2019 were included in this study. The effect of decompression was analyzed using canal encroachment ratio, while deformity correction was assessed using the sagittal Cobb angle and the percentage of anterior vertebral height. We also analyzed other clinical outcomes such as visual analog scale, Oswestry Disability Index, and American Spinal Injury Association impairment scale dose.

RESULTS

The patients were followed up for an average of 16 months. Our data showed that the patients' mean operation time was 153.75 minutes, the mean intraoperative blood loss was 48.84 mL, and the mean incision length was 7.78 cm. The canal encroachment ratio decreased from 55.91% ± 12.27% to 12.44% ± 3.91% (P < 0.05), sagittal Cobb angle decreased from 17.09° ± 5.46° to 5.72° ± 3.68° (P < 0.05), while the percentage of anterior vertebral height increased from 53.72% ± 8.99% to 83.22% ± 8.21% (P < 0.05). In addition, there was a significant improvement in the visual analog scale score, Oswestry Disability Index, and American Spinal Injury Association impairment scale classification (P < 0.05). Screw fracture occurred only in one patient during follow-up.

CONCLUSIONS

Endoscopic decompression combined with PPSF in the treatment of TLBFs with neurological deficits is safe and effective, which is a new minimally invasive method for the treatment of such diseases.

The Necessity of Implant Removal after Fixation of Thoracolumbar Burst Fractures—A Systematic Review

Background: Thoracolumbar burst fractures are a common traumatic vertebral fracture in the spine, and pedicle screw fixation has been widely performed as a safe and effective procedure. However, after the stabilization of the thoracolumbar burst fractures, whether or not to remove the pedicle screw implant remains controversial. This review aimed to assess the benefits and risks of pedicle screw instrument removal after fixation of thoracolumbar burst fractures. Methods: Data sources, including PubMed, EMBASE, Cochrane Library, Web of Science, Google Scholar, and Clinical trials.gov, were comprehensively searched. All types of human studies that reported the benefits and risks of implant removal after thoracolumbar burst fractures, were selected for inclusion. Clinical outcomes after implant removal were collected for further evaluation. Results: A total of 4051 papers were retrieved, of which 35 studies were eligible for inclusion in the review, including four case reports, four case series, and 27 observational studies. The possible risks of pedicle screw removal after fixation of thoracolumbar burst fractures include the progression of the kyphotic deformity and surgical complications (e.g., surgical site infection, neurovascular injury, worsening pain, revision surgery), while the potential benefits of pedicle screw removal mainly include improved segmental range of motion and alleviated pain and disability. Therefore, the potential benefits and possible risks should be weighed to support patient-specific clinical decision-making about the removal of pedicle screws after the successful fusion of thoracolumbar burst fractures. Conclusions: There was conflicting evidence regarding the benefits and harms of implant removal after successful fixation of thoracolumbar burst fractures, and the current literature does not support the general recommendation for removal of the pedicle screw instruments, which may expose the patients to unnecessary complications and costs. Both surgeons and patients should be aware of the indications and have appropriate expectations of the benefits and risks of implant removal. The decision to remove the implant or not should be made individually and cautiously by the surgeon in consultation with the patient. Further studies are warranted to clarify this issue. Level of evidence: level 1.

Implant removal after short percutaneous pedicle fixation associated with SpineJack® kyphoplasty: is correction sustained?

PURPOSE

This study objective was to evaluate sagittal correction loss after instrumentation removal in patients treated for thoracic or lumbar compression fractures treated with SpineJack^® kyphoplasty associated with short percutaneous pedicle screw fixation.

METHODS

This retrospective multicenter study was carried out in three major French trauma centers. All patients with a single type A thoracic or lumbar fracture, treated by the studied technique between 2017 and 2020, have been included. Demographic data, fracture type, removal procedure achievement and term were collected. Radiological parameters were measured at five timepoints: pre-operative, intra-operative, immediate post-operative, early post-operative (< 3 months) and at follow-up (1 year). Vertebral wedge angle (angle between the two endplates of the fractured vertebra) and traumatic regional angulation (TRA-calculated by subtracting regional kyphosis from the physiological reference values).

RESULTS

150 patients were included. Mean age was 48.6 ± 17.8 years. Average follow-up was 14.4 ± 3 months. 82 patients had secondary instrumentation removal. Mean time to removal was 6.4 ± 2.4 months. TRA correction loss between immediate post-operative and last follow-up was greater in removal group: 5.1 ± 5.6° versus 2.7 ± 4.7° (p = 0.01). Material was removed earlier in younger patients (p = 0.002). TRA correction loss was similar in the early and late removal groups (p = 0.83). Multivariate analysis identified only Magerl/AO A3 fractures as risk factor for loss of TRA correction (p = 0.007).

CONCLUSION

Instrumentation removal was associated with good radiological outcomes with a non-significant loss of vertebral wedge angle and tolerable loss of traumatic regional angulation (+ 2.4° compared to the no-removal group), even if performed early.

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.

Implant Removal Versus Implant Retention Following Posterior Surgical Stabilization of Thoracolumbar Burst Fractures: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

To compare biomechanical and functional outcomes between implant removal and implant retention following posterior surgical fixation of thoracolumbar burst fractures.

METHODS

A search of the MEDLINE, EMBASE, Google Scholar and Cochrane Databases was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Of the 751 articles initially retrieved, 13 published articles pooling 673 patients were included. Meta-analysis revealed there was a statistically significant improvement in sagittal Cobb Angle by 16.48 degrees (9.13-23.83, p < 0.01) after surgical stabilization of thoracolumbar burst fractures. This correction decremented to 9.68 degrees (2.02-17.35, p < 0.01) but remained significant at the time of implant removal approximately 12 months later. At final follow-up, the implant removal group demonstrated a 10.13 degree loss (3.00-23.26, p = 0.13) of reduction, while the implant retention group experienced a 10.17 degree loss (1.79-22.12, p = 0.10). There was no statistically significant difference in correction loss between implant retention and removal cohorts (p = 0.97). Pooled VAS scores improved by a mean of 3.32 points (0.18 to 6.45, p = 0.04) in the combined removal group, but by only 2.50 points (-1.81 to 6.81, p = 0.26) in the retention group. Oswestry Disability Index scores also improved after implant removal by 7.80 points (2.95-12.64, p < 0.01) at 1 year and 11.10 points (5.24-16.96, p < 0.01) at final follow-up.

CONCLUSIONS

In younger patients with thoracolumbar burst fractures who undergo posterior surgical stabilization, planned implant removal results in superior functional outcomes without significant difference in kyphotic angle correction loss compared to implant retention.

Ground truth generalizability affects performance of the artificial intelligence model in automated vertebral fracture detection on plain lateral radiographs of the spine

BACKGROUND CONTEXT

Computer-aided diagnosis with artificial intelligence (AI) has been used clinically, and ground truth generalizability is important for AI performance in medical image analyses. The AI model was trained on one specific group of older adults (aged≧60) has not yet been shown to work equally well in a younger adult group (aged 18-59).

PURPOSE

To compare the performance of the developed AI model with ensemble method trained with the ground truth for those aged 60 years or older in identifying vertebral fractures (VFs) on plain lateral radiographs of spine (PLRS) between younger and older adult populations.

STUDY DESIGN/SETTING

Retrospective analysis of PLRS in a single medical institution.

OUTCOME MEASURES

Accuracy, sensitivity, specificity, and interobserver reliability (kappa value) were used to compare diagnostic performance of the AI model and subspecialists' consensus between the two groups.

METHODS

Between January 2016 and December 2018, the ground truth of 941 patients (one PLRS per person) aged 60 years and older with 1101 VFs and 6358 normal vertebrae was used to set up the AI model. The framework of the developed AI model includes: object detection with You Only Look Once Version 3 (YOLOv3) at T0-L5 levels in the PLRS, data pre-preprocessing with image-size and quality processing, and AI ensemble model (ResNet34, DenseNet121, and DenseNet201) for identifying or grading VFs. The reported overall accuracy, sensitivity and specificity were 92%, 91% and 93%, respectively, and external validation was also performed. Thereafter, patients diagnosed as VFs and treated in our institution during October 2019 to August 2020 were the study group regardless of age. In total, 258 patients (339 VFs and 1725 normal vertebrae) in the older adult population (mean age 78±10.4; range, 60-106) were enrolled. In the younger adult population (mean age 36±9.43; range, 20-49), 106 patients (120 VFs and 728 normal vertebrae) were enrolled. After identification and grading of VFs based on the Genant method with consensus between two subspecialists', VFs in each PLRS with human labels were defined as the testing dataset. The corresponding CT or MRI scan was used for labeling in the PLRS. The bootstrap method was applied to the testing dataset.

RESULTS

The model for clinical application, Digital Imaging and Communications in Medicine (DICOM) format, is uploaded directly (available at: http://140.113.114.104/vght_demo/svf-model (grading) and http://140.113.114.104/vght demo/svf-model2 (labeling). Overall accuracy, sensitivity and specificity in the older adult population were 93.36% (95% CI 93.34%-93.38%), 88.97% (95% CI 88.59%-88.99%) and 94.26% (95% CI 94.23%-94.29%), respectively. Overall accuracy, sensitivity and specificity in the younger adult population were 93.75% (95% CI 93.7%-93.8%), 65.00% (95% CI 64.33%-65.67%) and 98.49% (95% CI 98.45%-98.52%), respectively. Accuracy reached 100% in VFs grading once the VFs were labeled accurately. The unique pattern of limbus-like VFs, 43 (35.8%) were investigated only in the younger adult population. If limbus-like VFs from the dataset were not included, the accuracy increased from 93.75% (95% CI 93.70%-93.80%) to 95.78% (95% CI 95.73%-95.82%), sensitivity increased from 65.00% (95% CI 64.33%-65.67%) to 70.13% (95% CI 68.98%-71.27%) and specificity remained unchanged at 98.49% (95% CI 98.45%-98.52%), respectively. The main causes of false negative results in older adults were patients' lung markings, diaphragm or bowel airs (37%, n=14) followed by type I fracture (29%, n=11). The main causes of false negatives in younger adults were limbus-like VFs (45%, n=19), followed by type I fracture (26%, n=11). The overall kappa between AI discrimination and subspecialists' consensus in the older and younger adult populations were 0.77 (95% CI, 0.733-0.805) and 0.72 (95% CI, 0.6524-0.80), respectively.

CONCLUSIONS

The developed VF-identifying AI ensemble model based on ground truth of older adults achieved better performance in identifying VFs in older adults and non-fractured thoracic and lumbar vertebrae in the younger adults. Different age distribution may have potential disease diversity and implicate the effect of ground truth generalizability on the AI model performance.

Is removal of the internal fixation after successful intervertebral fusion necessary? A case-control study based on patient-reported quality of life

BACKGROUND

Intervertebral fusion and internal fixation are often applied to patients with lumbar spinal disease. Whether to remove the internal fixation after successful fusion remains uncertain, but such a question needs to be explored in light of concerns regarding patients' quality of life and health insurance. We sought to probe if the removal of internal fixation after successful lumbar intervertebral fusion affects patients' quality of life.

METHODS

This was a real-world retrospective case-control study. Data of 102 patients who had undergone posterior lumbar fusion with cage and internal fixation to treat lumbar degenerative diseases were extracted from a single center from 2012 to 2020. Fifty-one patients had undergone internal fixation removal surgery, and 51 controls who retained internal fixations were matched according to demographic and medical characteristics. The quality of life of patients based on the Medical Outcomes Study Short Form 36 (SF-36) scale and their self-assessment were surveyed.

RESULTS

There was no statistical difference in the overall score of the SF-36 questionnaire between the two groups, but the general health (GH) subscore was lower in the case group than in the control group (P = 0.0284). Among those patients who underwent internal fixation removal, the quality of life was improved after instrument removal as indicated by an increased overall score (P = 0.0040), physical functioning (PF) (P = 0.0045), and bodily pain (BP) (P = 0.0008). Among patients with pre-surgery discomfort, instrument removal generated better outcomes in 25% and poor outcomes in 4.2%. Among patients without pre-surgery discomfort, instrument removal generated better outcomes in 7.4% and poor outcomes in 11.1%.

CONCLUSION

Among patients who achieved successful posterior lumbar internal fixation, whether or not to remove the fixation instruments should be evaluated carefully. In patients experiencing discomfort, instrument removal could improve their quality of life, but the benefits and risks should be comprehensively explained to these patients. Instrument removal should not be routinely performed due to its limited or even negative effect in patients who do not report discomfort before surgery.

Vacuum phenomenon as a predictor of kyphosis after implant removal following posterior pedicle screw fixation without fusion for thoracolumbar burst fracture: a single-center retrospective study

Background

Posterior pedicle screw fixation without fusion has been commonly applied for thoracolumbar burst fracture. Implant removal is performed secondarily after bone union. However, the occurrence of secondary kyphosis has recently attracted attention. Secondary kyphosis results in poor clinical outcomes. The purpose of this was to determine predictors of kyphosis after implant removal following posterior pedicle screw fixation without fusion for thoracolumbar burst fracture.

Methods

This retrospective study reviewed 59 consecutive patients with thoracolumbar burst fracture who underwent implant removal following posterior pedicle screw fixation without fusion. Inclusion criteria were non-osteoporotic fracture and T11-L3 burst fracture. Old age, sex, initial severe wedge deformity, initial severe kyphosis, and vacuum phenomenon were examined as factors potentially associated with final kyphotic deformity (defined as kyphotic angle greater than 25°) or loss of correction. Logistic regression analysis was performed using propensity score matching.

Results

Among the 31 female and 28 male patients (mean age 38 years), final kyphotic deformity was found in 17 cases (29%). Multivariate analysis showed a significant association with the vacuum phenomenon. Loss of correction was found in 35 cases (59%) and showed a significant association with the vacuum phenomenon. There were no significant associations with other factors.

Conclusions

The findings of this study suggest that the vacuum phenomenon before implant removal may be a predictor of secondary kyphosis of greater than 25° after implant removal following posterior pedicle screw fixation without fusion for thoracolumbar burst fracture, but that old age, sex, initial severe kyphosis, and initial severe wedge deformity may not be predictors.

Outcomes in Thoracolumbar and Lumbar Traumatic Fractures: Does Restoration of Unfused Segmental Mobility Correlated to Implant Removal Time?

BACKGROUND

Posterior fixation without fusion can treat thoracolumbar and lumbar traumatic fractures effectively in certain cases. However, whether patients benefit from implant removal and the correlation between the range of motion (ROM) of the involved segments and the removal time have not been determined.

METHODS

From 2018 to 2020, we retrospectively reviewed data of patients with AO spine type A or B thoracolumbar or lumbar traumatic fractures who underwent implant removal. A total of 17 patients (group A), 21 patients (group B), and 12 patients (group C) underwent implant removal after the index surgery within 12 months, between 12 and 24 months, and over 24 months, respectively. Clinical and radiological outcomes, including visual analog scale for back pain, patient satisfaction, Oswestry disability index, and EuroQol 5 dimensions questionnaire, for quality of life and segmental ROM were analyzed.

RESULTS

The average follow-up time was 9.1 ± 5.7 months after implant removal. There were no significant differences in visual analog scale and patient satisfaction among the 3 groups at the same observation time point. Among the 3 groups, patients in group A gained the lowest Oswestry disability index and highest EuroQol 5 dimensions questionnaire scores after removal and at the final follow-up. The best ROM was obtained in group A followed by groups B and C (11.5° ± 6.2°, 5.5° ± 1.6°, and 2.4° ± 0.6°, respectively).

CONCLUSIONS

Immobilization of the involved segments over 24 months may lead to loss of ROM. Regained segmental ROM is correlated negatively with implant removal time, and removal within 12 months promises a better ROM and quality of life.

Comparing porous tantalum fusion implants and iliac crest bone grafts for spondylodesis of thoracolumbar burst fractures: Prospectice Cohort study

The aim of this study was to compare two different techniques of performing one-level spondylodesis for thoracolumbar burst fractures using either an autologous iliac crest bone graft (ICBG) or a porous tantalum fusion implant (PTFI). In a prospective nonrandomized study, 44 patients (20 women, 24 men; average age 43.1 ± 13.2 years) suffering from severe thoracolumbar burst fractures were treated with combined anterior–posterior stabilization. An ICBG was used in 21 cases, and a PTFI was used in the other 23 cases. A two-year clinical and radiographic follow-up was carried out. There were no statistically significant differences in age, sex, localization/classification of the fracture, or visual analog scale (VAS) before injury between the two groups. All 44 patients were followed up for an average period of 533 days (range 173–1567). The sagittal spinal profile was restored by an average of 11.1° (ICBG) vs. 14.3° (PTFI) (monosegmental Cobb angle). Loss of correction until the last follow-up tended to be higher in the patients treated with ICBG than in those treated with PTFI (mean: 2.8° vs. 1.6°). Furthermore, significantly better restoration of the sagittal profile was obtained with the PTFI than with the iliac bone graft at the long-term follow-up (mean: ICBG 7.8°, PTFI 12.3°; p < 0.005). Short-segment posterior instrumentation combined with anterior one-level spondylodesis using either an ICBG or a PTFI resulted in sufficient correction of posttraumatic segmental kyphosis. PTFI might be a good alternative for autologous bone grafting and prevent donor site morbidities.

Back to the future in traumatic fracture shapes of lumbar spine: An analysis of risk of kyphosis after conservative treatment

Introduction:

Nonosteoporotic burst vertebral fracture could commonly be treated with conservative or surgical approach. Currently, decision-making process is based on thoracolumbar (TL) AO spine severity injury score. However, some factors could affect posttraumatic kyphosis (PTK) and could be taken into account. The aim of the present study is to identify if axial and sagittal fracture shape and initial kyphosis are the risk factors for PTK.

Materials and Methods:

All consecutive patients treated between 2016 and 2017 for TL vertebral fracture with conservative treatment were retrospectively evaluated in the study. Only type A3 and A4 vertebral fractures were included in the study. Patients suffering from osteoporosis or other metabolic bone disease, aged above 60 years old were excluded from the study. Initial and 6 months X-ray from injury were analyze to evaluate local kyphosis and region of injury while initial assessment was performed with computed tomography to better identify fracture type and in some cases magnetic resonance imaging to exclude posterior ligament complex injury. Axial and sagittal view of the vertebral plate was analyzed and classified in three shapes according to fragment comminution and dislocation. Statistical analysis was performed trough STATA13 software. Student's t-test was used to evaluate the differences between initial and follow up kyphosis; odds ratio (OR) was used to evaluate the role of initial kyphosis, vertebral sagittal and axial fracture shape as a risk factor for PTK. Kruskal–Wallis test was used to assess the differences among vertebral shape fractures and final kyphosis. Fisher's exact test was used to assess the differences between fracture patterns and final kyphosis.

Results:

An initial kyphosis >10° (OR 36.75 P = 0.015), shape c vertebral plate (OR 147 P = 0.0015), and sagittal shape 3 (OR 32.25 P = 0.0025) are strongly related with PTK. Kruskal–Wallis test revealed a statistically significant difference among axial fracture shape (P < 0.0001) and sagittal fracture shape (P = 0.004) and also for initial kyphosis >10° (P < 0.0001). Fisher's exact test showed a significant difference for final kyphosis among pattern c3 and other patterns of fracture (P = 0.0001).

Conclusions:

A burst type lumbar vertebral fracture affecting a patient with initial local kyphosis >10° and comminution and displacement of vertebral plate and vertebral body is at high risk to develop a local kyphosis >20° in the follow-up if treated conservatively.

Comparison of the Pull-Out Strength between a Novel Micro-Dynamic Pedicle Screw and a Traditional Pedicle Screw in Lumbar Spine

OBJECTIVE

This study aimed to investigate the strength of a novel micro-dynamic pedicle screw by comparing it to the traditional pedicle screw.

METHODS

Forty-five lumbar vertebrae received a traditional pedicle screw on one side and a micro-dynamic pedicle screw on the other side as follows (traditional group vs micro-dynamic group): 15 vertebrae underwent instant pull-out testing; 15 vertebrae underwent 5000-cyclic fatigue loading testing; and 15 vertebrae underwent 10,000-cyclic fatigue loading testing and micro-computed tomography (micro-CT) scanning. The peek pull-out force and normalized peek pull-out force after instant pull-out testing, 5000-cyclic and 10,000-cyclic fatigue loading testing were recorded to estimate the resistance of two types of screws. Bone mineral density was recorded to investigate the strength of the different screws in osteoporotic patients. And the semidiameter of the screw insertion area on micro-CT images after fatigue were compared to describe the performance between screw and bone surface.

RESULTS

The bone mineral density showed a weak correlation with peek pull-out force (r = 0.252, P = 0.024). The peek pull-out force of traditional pedicle screw after 10,000-cyclic fatigue loading were smaller than that of instant pull-out test in both osteoporotic (P = 0.017) and healthy group (P = 0.029), the peek pull-out force of micro-dynamic pedicle screw after 10,000-cyclic fatigue loading was smaller than that in instant pull-out test in osteoporotic group (P = 0.033), but no significant difference in healthy group (P = 0.853). The peek pull-out force in traditional group and micro-dynamic group underwent instant pull-out testing (P = 0.485), and pull-out testing after 5000-cyclic fatigue loading testing (P = 0.184) did not show significant difference. However, the peek pull-out force in micro-dynamic group underwent pull-test after 10,000-cyclic fatigue loading testing was significantly greater than that measured in traditional group (P = 0.005). The normalized peek pull-out force of traditional groups underwent instant pull-out testing, pull-out test after 5000-cyclic and 10,000-cyclic fatigue loading testing significantly decreased as the number of cycles increased (P < 0.001); meanwhile, the normalized peek pull-out force of micro-dynamic groups remained consistent regardless of the number of cycles (P = 0.133). The semidiameter after the fatigue loading test of the traditional screw insertion area was significantly larger than that of the micro-dynamic screw insertion area (P = 0.013).

CONCLUSION

The novel micro-dynamic pedicle screw provides stronger fixation stability in high-cyclic fatigue loading and non-osteoporotic patients versus the traditional pedicle screw, but similar resistance in low-cycle fatigue testing and osteoporotic group vs the traditional pedicle screw.

Healing pattern classification for thoracolumbar burst fractures after posterior short-segment fixation

BACKGROUND

Thoracolumbar burst fractures can be treated with posterior short-segment fixation. However, no classification can help to estimate whether the healed vertebral body will have sufficient stability after implant removal. We aimed to develop a Healing Pattern Classification (HPC) to evaluate the stability of the healed vertebra based on cavity size and location.

METHODS

Fifty-two thoracolumbar burst fracture patients treated with posterior short-segmental fixation without fusion and followed up for an average of 3.2 years were retrospectively studied. The HPC was divided into 4 types: type I - no cavity; type II - a small cavity with or without the violation of one endplate; type III - a large cavity with or without the violation of one endplate; and type IV - a burst cavity with the violation of both endplates or the lateral cortical shell. The intraobserver and interobserver intraclass correlation coefficients (ICCs) of the HPC were assessed. The demographic characteristics and clinical outcomes of the cohort were compared between the stable group (types I and II) and the unstable group (types III and IV). Logistic regression was conducted to evaluate risk factors for unstable healing.

RESULTS

The intraobserver and interobserver ICCs of the HPC were 0.86 (95% CI = 0.74-0.90) and 0.77 (95% CI = 0.59-0.86), respectively. While the unstable healing group (types III and IV) accounted for 59.6% of the patients, most of these patients were asymptomatic. The preoperative Load Sharing Classification (LSC) comminution score may predict the occurrence of unstable healing (OR = 8.4, 95% CI = 2.4-29.7).

CONCLUSIONS

A reliable classification for assessing the stability of a healed vertebra was developed. With type I and II healing, the vertebra is considered stable, and the implant can be removed. With type III healing, the vertebra may have healing potential, but the implant should not be removed unless type II healing is achieved. With type IV healing, the vertebra is considered extremely unstable, and instrumentation should be maintained. Assessing the LSC comminution score preoperatively may help to predict unstable healing after surgery.

Posterior monoaxial screw fixation combined with distraction-compression technology assisted endplate reduction for thoracolumbar burst fractures: a retrospective study

Background

The management of thoracolumbar burst fractures traditionally involves posterior pedicle screw fixation, but it has some drawbacks. The aim of this study is to evaluate the clinical and radiological outcomes of patients with thoracolumbar burst fractures. They were treated by a modified technique that monoaxial pedicle screws instrumentation and distraction-compression technology assisted end plate reduction.

Methods

From March 2014 to February 2016, a retrospective study including 42 consecutive patients with thoracolumbar burst fractures was performed. The patients had undergone posterior reduction and instrumentation with monoaxial pedicle screws. The fractured vertebrae were also inserted screws as a push point. The distraction -compression technology was used as assisting end plate reduction. All patients were followed up at a minimum of 2 years. These parameters including segmental kyphosis, severity of fracture, neurological function, canal compromise and back pain were evaluated in preoperatively, postoperatively and at the final follow-up.

Results

The average follow-up period was 28.9 ± 4.3 months (range, 24-39mo). No patients had postoperative implant failure at recent follow-up. The mean Cobb angle of the kyphosis was improved from 14.2°to 1.1° (correction rate 92.1%). At final follow-up there was 1.5% loss of correction. The mean preoperative wedge angle was improved from 17.1 ± 7.9°to 4.4 ± 3.7°(correction rate 74.3%). The mean anterior and posterior vertebral height also showed significant improvements postoperatively, which were maintained at the final follow-up(P < 0.05). The mean visual analogue scale (VAS) scores was 8 and 1.6 in preoperation and at the last follow-up, and there was significant difference (p < 0.05).

Conclusion

Based on our experience, distraction-compression technology can assist reduction of collapsed endplate directly. Satisfactory fracture reduction and correction of segmental kyphosis can be achieved and maintained with the use of monoaxial pedicle screw fixation including the fractured vertebra. It may be a good treatment approach for thoracolumbar burst fractures.

Treatment of Fractures of the Thoracolumbar Spine: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU)

STUDY DESIGN

consensus paper with systematic literature review.

OBJECTIVE

The aim of this study was to establish recommendations for treatment of thoracolumbar spine fractures based on systematic review of current literature and consensus of several spine surgery experts.

METHODS

The project was initiated in September 2008 and published in Germany in 2011. It was redone in 2017 based on systematic literature review, including new AOSpine classification. Members of the expert group were recruited from all over Germany working in hospitals of all levels of care. In total, the consensus process included 9 meetings and 20 hours of video conferences.

RESULTS

As regards existing studies with highest level of evidence, a clear recommendation regarding treatment (operative vs conservative) or regarding type of surgery (posterior vs anterior vs combined anterior-posterior) cannot be given. Treatment has to be indicated individually based on clinical presentation, general condition of the patient, and radiological parameters. The following specific parameters have to be regarded and are proposed as morphological modifiers in addition to AOSpine classification: sagittal and coronal alignment of spine, degree of vertebral body destruction, stenosis of spinal canal, and intervertebral disc lesion. Meanwhile, the recommendations are used as standard algorithm in many German spine clinics and trauma centers.

CONCLUSION

Clinical presentation and general condition of the patient are basic requirements for decision making. Additionally, treatment recommendations offer the physician a standardized, reproducible, and in Germany commonly accepted algorithm based on AOSpine classification and 4 morphological modifiers.

Magnetic resonance imaging evaluation of intervertebral disc injuries can predict kyphotic deformity after posterior fixation of unstable thoracolumbar spine injuries

The aim of the present study is to identify factors correlated with kyphotic deformity after thoracolumbar spine injuries. We performed a retrospective case-control study with data from thoracolumbar spine fracture patients who were treated with posterior spinal fixation. Patients with a follow-up period shorter than 6 months and who experienced low-energy trauma were excluded. Intervertebral disc injuries (IDIs) were graded from 0 to 3 upon admission in accordance with Sander's classification of traumatic intervertebral disc lesions. Vertebral wedge angles (VWAs) and local kyphosis angles (LKAs) were also measured. Patients were allocated to kyphosis and control groups if they had LKA correction losses of ≥10° and <10°, respectively. Forty-eight patients followed over a median period of 25 months were included. The median correction loss at the site of the injured vertebral body was 2.0°. The median LKA correction loss was 9.0°. Twenty-three and 25 patients were allocated to the kyphosis and control groups, respectively. Univariate analysis revealed that the median age was significantly lower in the kyphosis (35 years) than control group (56 years). The level of injury and IDI severity also significantly differed between groups, with a significantly greater proportion of more severe IDI cases in the kyphosis than control group. Finally, significantly more patients in kyphosis group underwent fusion (kyphosis, 19 vs control, 13) and implant removals (kyphosis, 19 vs control, 10). Multiple regression analysis revealed that IDI severity according to Sander's classification (P = .005; odds ratio, 5.263; 95% confidence interval [CI], 1.637-16.927) and implant removal (P = .011; odds ratio, 7.980; 95% CI, 1.603-39.728) were significantly associated with kyphotic deformity. IDI severity at initial magnetic resonance imaging (MRI) evaluation and implant removal are associated with kyphotic deformity after posterior fixation of thoracolumbar spine injuries. Thus, initial MRI evaluation of IDIs could be used to predict of recurrent kyphosis.

Monosegmental anterior column reconstruction using an expandable vertebral body replacement device in combined posterior-anterior stabilization of thoracolumbar burst fractures

INTRODUCTION

In combined posterior-anterior stabilization of thoracolumbar burst fractures, the expandable vertebral body replacement device (VBRD) is typically placed bisegmentally for anterior column reconstruction (ACR). The aim of this study, however, was to assess feasibility, outcome and potential pitfalls of monosegmental ACR using a VBRD. In addition, clinical and radiological outcome of monosegmental ACR was related to that of bisegmental ACR using the same thoracoscopic technique.

METHODS

Thirty-seven consecutive neurologically intact patients with burst fractures of the thoracolumbar junction (T11-L2) treated by combined posterior-anterior stabilization were included. Monosegmental ACR was performed in 18 and bisegmental ACR in 19 patients. Fracture type and extent of vertebral body comminution were determined on preoperative CT scans. Monosegmental and bisegmental kyphosis angles were analyzed preoperatively, postoperatively and at final radiological follow-up. Clinical outcome was assessed after a minimum of 2 years (74 ± 45 months; range 24-154; follow-up rate 89.2%) using VAS Spine Score, RMDQ, ODI and WHOQOL-BREF.

RESULTS

Monosegmental ACR resulted in a mean monosegmental and bisegmental surgical correction of - 15.6 ± 7.7° and - 14.7 ± 8.1°, respectively. Postoperative monosegmental and bisegmental loss of correction averaged 2.7 ± 2.7° and 5.2 ± 3.7°, respectively. Two surgical pitfalls of monosegmental ACR were identified: VBRD positioning (1) onto the weak cancellous bone (too far cranially to the inferior endplate of the fractured vertebra) and (2) onto a significantly compromised inferior endplate with at least two (even subtle) fracture lines. Ignoring these pitfalls resulted in VBRD subsidence in five cases. When relating the clinical and radiological outcome of monosegmental ACR to that of bisegmental ACR, no significant differences were found, except for frequency of VBRD subsidence (5 vs. 0, P = 0.02) and bisegmental loss of correction (5.2 ± 3.7° vs. 2.6 ± 2.5°, P = 0.022). After exclusion of cases with VBRD subsidence, the latter did not reach significance anymore (4.9 ± 4.0° vs. 2.6 ± 2.5°, P = 0.084).

CONCLUSIONS

This study indicates that monosegmental ACR using a VBRD is feasible in thoracolumbar burst fractures if the inferior endplate is intact (incomplete burst fractures) or features only a single simple split fracture line (burst-split fractures). If the two identified pitfalls are avoided, monosegmental ACR may be a viable alternative to bisegmental ACR in selected thoracolumbar burst fractures to spare a motion segment and to reduce the distance for bony fusion.

Is fusion necessary for thoracolumbar burst fracture treated with spinal fixation? A systematic review and meta-analysis

OBJECTIVE Thoracolumbar fractures account for 90% of spinal fractures, with the burst subtype corresponding to 20% of this total. Controversy regarding the best treatment for this condition remains. The traditional surgical approach, when indicated, involves spinal fixation and arthrodesis. Newer studies have brought the need for fusion associated with internal fixation into question. Not performing arthrodesis could reduce surgical time and intraoperative bleeding without affecting clinical and radiological outcomes. With this study, the authors aimed to assess the effect of fusion, adjuvant to internal fixation, on surgically treated thoracolumbar burst fractures. METHODS A search of the Medline and Cochrane Central Register of Controlled Trials databases was performed to identify randomized trials that compared the use and nonuse of arthrodesis in association with internal fixation for the treatment of thoracolumbar burst fractures. The search encompassed all data in these databases up to February 28, 2016. RESULTS Five randomized/quasi-randomized trials, which involved a total of 220 patients and an average follow-up time of 69.1 months, were included in this review. No significant difference between groups in the final scores of the visual analog pain scale or Low Back Outcome Scale was detected. Surgical time and blood loss were significantly lower in the group of patients who did not undergo fusion (p < 0.05). Among the evaluated radiological outcomes, greater mobility in the affected segment was found in the group of those who did not undergo fusion. No significant difference between groups in the degree of kyphosis correction, loss of kyphosis correction, or final angle of kyphosis was observed. CONCLUSIONS The data reviewed in this study suggest that the use of arthrodesis did not improve clinical outcomes, but it was associated with increased surgical time and higher intraoperative bleeding and did not promote significant improvement in radiological parameters.