[Injuries to the thoracic and lumbar spine]

Thoracolumbar injuries: non operative treatment: indications, management

INTRODUCTION

Thoracolumbar spine injuries can result from various traumatic events such as falls, motor vehicle accidents, and sports injuries. While surgical intervention is often indicated for complex fractures and in case of neurological deficits, non-operative treatment remains a viable option for certain types of injuries.

AIMS

This manuscript aims to provide a comprehensive overview of the specific indications and treatment options of non-operative thoracolumbar spine injuries. It seeks to provide evidence-based recommendations for selecting patients suitable for conservative management based on fracture type and stability, absence of neurological deficits, spine deformity, integrity of the posterior ligament complex and patient specific factors.

Is restoration of vertebral body height after vertebral body fractures and minimally-invasive dorsal stabilization with polyaxial pedicle screws just an illusion?

INTRODUCTION

Thoracolumbar spine fractures often require surgical treatment as they are associated with spinal instability. Optimal operative techniques and treatment are discussed controversially. Aim of our prospective cohort study was to investigate the sagittal alignment after reduction, the secondary loss of reduction and the subjective outcome as well as the causal correlation of these parameters after minimally invasive stabilization of thoracic and lumbar fractures with polyaxial pedicle screws.

MATERIALS AND METHODS

In a single-center study, a total of 78 patients with an average age of 61 ± 17 years who suffered a fracture of the thoracic or lumbar spine were included and subjected to a clinical and radiological follow-up examination after 8.5 ± 8 months. The kyphotic deformity was measured by determining the vertebral body angle, the mono- and bi-segmental wedge angle at three time points. The patients' subjective outcome was evaluated by the VAS spine score.

RESULTS

After surgical therapy, a significant reduction of the traumatic kyphotic deformity was shown with an improvement of all angles (vertebral body angle: 3.2° ± 4.4°, mono- and bi-segmental wedge angle: 3.1° ± 5.6°, 2.0° ± 6.3°). After follow-up, a significant loss of sagittal alignment was observed for all measured parameters with a loss of correction. However, no correlation between the loss of reduction and the subjective outcome regarding the VAS spine scale could be detected.

CONCLUSION

The minimally invasive dorsal stabilization of thoracic and lumbar spine fractures with polyaxial pedicle screws achieved a satisfactory reduction of the fracture-induced kyphotic deformity immediately postoperatively with a floss of reduction in the further course. However, maybe the main goal of this surgical procedure should be the prevention of a complete collapse of the vertebral body instead of a long-lasting restoration of anatomic sagittal alignment.

LEVEL OF EVIDENCE

II.

[Treatment of trauma-related vertebral body fractures of the thoracic and lumbar spine with orthotic devices : A review]

BACKGROUND

Trauma-related fractures of the thoracic and lumbar spine occur after exposure to high kinetic energy. To assign patients to the correct kind of treatment the AO spine classification is used.

OBJECTIVE

The aim was to describe the role of orthotic devices in the treatment of thoracic and lumbar fractures in the nondegenerative spine.

MATERIAL AND METHODS

A review of the literature was carried out according to the PRISMA protocol (Preferred Reporting Items for Systematic reviews and Meta-Analyses) in PubMed, ScienceDirect, Cochrane and Google.Scholar. A total of 118 potentially important publications were found and 16 studies with a prospective study design could be included in this analysis. RoB 2 (Cochrane Risk of Bias tool in the second Version) in the case of randomized studies and the ROBINS‑I (Risk Of Bias In Nonrandomised Studies of Interventions) for nonrandomized studies were used to assess publication quality. The level of evidence was determined according to AHCPR (Agency for Health Care Policy and Research).

RESULTS

In the case of fractures (AO types A0-A3) without degenerative changes in the bone structure of the thoracic and lumbar spine without indications for operative procedure, conservative treatment with analgesia, physiotherapy and early mobilization is recommended and orthotic treatment is not superior. Surgical treatment, even in cases where conservative treatment was possible, led to improved functionality and pain sensation faster but there were no differences in the long-term results. Assessing the neurological functional deficit, the functional success of the treatment and the kyphosis angle were measured in different ways, reducing the extent of comparability. Although mainly a level of evidence Ib-IIa could be assigned, nearly all included studies had a high risk of bias.

CONCLUSION

In individual cases treatment with an orthotic device could be a helpful add-on in conservative treatment of fractures in the thoracic and lumbar spine. A treatment with orthotic devices alone cannot be recommended in these cases.

Lag-Screw Osteosynthesis in Thoracolumbar Pincer Fractures

STUDY DESIGN

Biomechanical.

OBJECTIVE

This study evaluates the biomechanical properties of lag-screws used in vertebral pincer fractures at the thoracolumbar junction.

METHODS

Pincer fractures were created in 18 bisegmental human specimens. The specimens were assigned to three groups depending on their treatment perspective, either bolted, with the thread positioned in the cortical or cancellous bone, or control. The specimens were mounted in a servo-hydraulic testing machine and loaded with a 500 N follower load. They were consecutively tested in 3 different conditions: intact, fractured, and bolted/control. For each condition 10 cycles in extension/flexion, torsion, and lateral bending were applied. After each tested condition, a computed tomography (CT) scan was performed. Finally, an extension/flexion fatigue loading was applied to all specimens.

RESULTS

Biomechanical results revealed a nonsignificant increase in stiffness in extension/flexion of the fractured specimens compared with the intact ones. For lateral bending and torsion, the stiffness was significantly lower. Compared with the fractured specimens, no changes in stiffness due to bolting were discovered. CT scans showed an increasing fracture gap during axial loading both in extension/flexion, torsion, and lateral bending in the control specimens. In bolted specimens, the anterior fragment was approximated, and the fracture gap nullified. This refers to both the cortical and the cancellous thread positions.

CONCLUSION

The results of this study concerning the effect of lag-screws on pincer fractures appear promising. Though there was little effect on stiffness, CT scans reveal a bony contact in the bolted specimens, which is a requirement for bony healing.

Evaluation of Software-Based Metal Artifact Reduction in Intraoperative 3D Imaging of the Spine Using a Mobile Cone Beam CT

The aim of our study was to evaluate whether software-based artifact reduction can achieve an improved image quality, using intraoperative 3D imaging in spinal surgery. A total of 49 intraoperative 3D image datasets of patients, who underwent surgery with pedicle screw placement, were retrospectively evaluated. The visibility of anatomical structures and the diameter of the pedicle screws were examined, with and without the application of the artifact reduction software. All software prototypes can improve the visibility of anatomical structures (P < 0.01), except MAR (metal artifact reduction) combined with IRIS (iterative reconstruction in image space) (P = 0.04). The algorithms MAR and MAR-2 can reduce the blooming artifacts significantly (P < 0.01), but SL (Shepp & Logan) cannot (P = 0.08-0.988). In summary, software-based artifact reduction for intraoperative 3D datasets can improve the current image quality. Additional information regarding the implant placement and the fracture reduction is therefore generated for the surgeon.

Spinal cord injury in the setting of traumatic thoracolumbar fracture is not reliably associated with increased risk of associated intra-abdominal injury following blunt trauma: An analysis of a National Trauma Registry database

PURPOSE

There is a common opinion that spinal fractures usually reflect the substantial impact of injuries and therefore may be used as a marker of significant associated injuries, specifically for intra-abdominal injury (IAI). The impact of concomitant spinal cord injury (SCI) with the risk of associated IAI has not been well clarified. The aim of this study was to evaluate the incidence and severity of IAIs in patients suffering from spinal fractures with or without SCI.

METHODS

A retrospective cohort study using the Israeli National Trauma Registry was conducted. Patients with thoracic, lumbar and thoracolumbar fractures resulting from blunt mechanisms of injury from January 1, 1997 to December 31, 2018 were examined, comparing the incidence, severity and mortality of IAIs in patients with or without SCI. The collected variables included age, gender, mechanism of injury, incidence and severity of the concomitant IAIs and pelvic fractures, abbreviated injury scale, injury severity score, and mortality. Statistical analysis was performed using GraphPad InStat ® Version 3.10, with Chi-square test for independence and two sided Fisher's exact probability test.

RESULTS

Review of the Israeli National Trauma Database revealed a total of 16,878 patients with spinal fractures. Combined thoracic and lumbar fractures were observed in 1272 patients (7.5%), isolated thoracic fractures in 4967 patients (29.4%) and isolated lumbar fractures in 10,639 patients (63.0%). The incidence of concomitant SCI was found in 4.95% (63/1272), 7.65% (380/4967) and 2.50% (266/10639) of these patients, respectively. The overall mortality was 2.5%, proving higher among isolated thoracic fracture patient than among isolated lumbar fracture counterparts (11.3% vs. 4.6%, p < 0.001). Isolated thoracic fractures with SCI were significantly more likely to die than non-SCI counterparts (8.2% vs. 3.1%, p < 0.001). There were no differences in the incidence of IAIs between patients with or without SCI following thoracolumbar fractures overall or in isolated thoracic fractures; although isolated lumbar fractures patients with SCI were more likely to have renal (3.4% vs. 1.6%, p = 0.02) or bowel injuries (2.3% vs. 1.0%, p = 0.04) than the non-SCI counterparts.

CONCLUSION

SCI in the setting of thoracolumbar fracture does not appear to be a marker for associated IAI. However, in a subset of isolated lumbar fractures, SCI patient is associated with increased risks for renal and bowel injury.

[Minimally invasive posterior and anterior stabilization of the thoracolumbar spine after traumatic injuries]

Injuries of the thoracolumbar junction are the most common fractures of the spine due to their anatomical position and load. Common classification systems differentiate between stable and unstable injuries and thus also between operative and conservative therapy. The majority of injuries can be treated conservatively; however, unstable injuries require surgical treatment for a variety of reasons. In the grey area between stable and unstable injuries, a clinical decision based on clinical experience is necessary in order to select the best treatment. A wide variety of parameters must be included and a change in strategy from conservative to operative may also be necessary. Posterior instrumentation is the most common procedure; purely anterior stabilization is rarely used. The length of the instrumentation/spondylodesis depends on bone quality, age of the patient, and fracture. The decision as to whether anterior operative treatment should be performed depends on fracture morphology, success of reduction, and the resulting stability. The open surgical procedure is increasingly being replaced by minimally invasive procedures in posterior and anterior techniques but can be an advantage in complex injuries (B and C injuries according to AO). Hybrid procedures are also possible. This also applies to the treatment of osteoporotic fractures, since a clear assignment between traumatic and osteoporotic cause is not always easy and possible. This article describes the principles, the possible indications, and limitations of minimally invasive posterior and anterior stabilization.

[Adjacent segment degeneration following spinal fusion of vertebral fractures in paraplegic patients]

The effects of adjacent segment degeneration (ASD) after spinal fusion of vertebral fractures have previously not been demonstrated in patients with trauma-related paraplegia. The aim of this study was to evaluate the role of ASD in patients with paraplegia caused by vertebral fractures and to observe whether there is a difference between unilateral or combined spinal fusion in long-term results regarding the degeneration of cranial or caudal adjacent spinal segments. A total of 111 paraplegic patients with an average age of 45 years who underwent spinal fusion of vertebral fractures were observed in a retrospective longitudinal study with a follow-up period of 4 years. Conventional X‑ray images and magnetic resonance imaging (MRI) scans were used to assess the ASD in the adjacent free vertebral segments cranial and caudal to the spinal fusion using the following elements: ventral spondylophytes, intervertebral space, intervertebral disc signal in MRI, posterior spondylophytes, facet joint arthrosis, bone bridging and ossification of the anterior longitudinal ligament. Additionally, the classification by the American Spinal Injury Association (ASIA) impairment scale and spinal cord independence measure version 3 score were surveyed. The 4‑year incidence of radiographically detectable ASD was 3-12 % in this study. The majority of ASDs were observed in the cranial segments adjacent to the interbody fusion. The dorsoventral spinal fusion showed the least effects on the adjacent segments. In conclusion, a concept of prompt surgery using short dorsoventral segment fusion carried out by an interdisciplinary paralysis center is recommended. The role of natural degeneration processes and whether they are influenced by iatrogenic manipulation through the vertebral stabilization is unclear. For this reason it is important to further investigate strategies for ASD reduction in the future to ensure the best possible treatment success including the lowest degree of additional impairments for this special patient group.

The Conservative Treatment of Traumatic Thoracolumbar Vertebral Fractures

BACKGROUND

The conservative treatment of traumatic thoracolumbar vertebral fractures is often not clearly defined.

METHODS

This review is based on articles retrieved by a systematic search in the PubMed and Web of Science databases for publications up to February 2018 dealing with the conservative treatment of traumatic thoracolumbar vertebral fractures. The search initially yielded 3345 hits, of which 35 were suitable for use in this review.

RESULTS

It can be concluded from the available original clinical research on the subject, including three randomized controlled trials (RCTs), that the primary diagnostic evaluation should be with plain x-rays, in the standing position if possible. If a fracture is suspected on the plain films, computed tomography (CT) is indicated. Magnetic resonance imaging (MRI) is additionally advisable if there is a burst fracture. The spinal deformity resulting from the fracture should be quantified in terms of the Cobb angle. The choice of a conservative or operative treatment strategy is based on the primary stability of the fracture, the degree of deformity, the presence or absence of disc injury, and the patient's clinical state. Our analysis of the three RCTs implies that early functional therapy without a corset should be performed, although treatment in a corset may be appropriate to control pain. Follow-up x-rays should be obtained after mobilization and at one week, three weeks, six weeks, and twelve weeks.

CONCLUSION

Further comparative studies of the indications for surgery and specific conservative treatment modalities would be desirable.

[Trauma of the lumbar spine and the thoracolumbar junction]

CLINICAL/METHODICAL ISSUE

Patients who have experienced high energy trauma have a particularly high risk of suffering from fractures of the thoracic and lumbar spine. The detection of spinal injuries and the correct classification of fractures before surgery are not only absolute requirements for the implementation of appropriate surgical treatment but they are also decisive for the choice of surgical procedure.

STANDARD RADIOLOGICAL METHODS

By the application of spiral computed tomography (CT) crucial additional information on the morphology of the fracture can be gained in order to estimate the fracture type and possibly the indications for specific surgical treatment options. Magnetic resonance imaging (MRI) is ideally suited to provide valuable additional information regarding injuries to the discoligamentous structures of the spine.

PERFORMANCE

Magerl et al. developed a comprehensive classification especially for injuries of the thoracic and lumbar spine, which was adopted by the working group for osteosynthesis (AO). This is based on a 2‑pillar model of the spinal column. The classification is based on the pathomorphological characteristics of fractures recognizable by imaging. The injury pattern is of particular importance.

ACHIEVEMENTS

In spinal trauma a distinction is made between stable and unstable fractures. The treatment of spinal injuries depends on the severity of the overall injury pattern.

PRACTICAL RECOMMENDATIONS

Besides adequate initial treatment at the scene, a trauma CT should be immediately carried out in order that no injuries are overlooked and to ensure a rapid decision on the treatment procedure.

Radiological Results and Clinical Patient Outcome After Implantation of a Hydraulic Expandable Vertebral Body Replacement following Traumatic Vertebral Fractures in the Thoracic and Lumbar Spine: A 3-Year Follow-Up

STUDY DESIGN

A prospective monocentric study.

OBJECTIVE

The aim of the current study was the analysis of patient outcome and radiological results 3 years after implantation of a hydraulic expandable vertebral body replacement (VBR) system.

SUMMARY OF BACKGROUND DATA

Around 70% to 90% of all traumatic spinal fractures are located in the thoracic and lumbar spine. Dorso-ventral stabilization is a frequently used procedure in traumatic vertebral body fracture treatment. VBR systems can be used to bridge bony defects. In the current study, a new VBR expanded by water pressure with adjustable endplates is used.

METHODS

All patients who suffered a singular traumatic fracture to a thoracic or lumbar vertebral body (Th 5-L 5) in the period from November 2009 to December 2010 and (i) underwent dorsal instrumentation and (ii) afterwards received the implantation of a hydraulic VBR were included in this study. The clinical outcome (visual analogue scale [VAS] spine score, questionnaire) and radiological findings (sagittal angle, implant subsidence, and implant position) 3 years after implantation were analyzed.

RESULTS

The follow-up was successful for n = 47 patients (follow-up rate: 89%). Most of the patients (n = 40) were "generally/very satisfied" with their outcome. The mean rating of the VAS spine score was 65.2 ± 23.1 (range: 20.5-100.0). The analysis of the radiological data showed an average subsidence of the implants of 1.1 ± 1.2 mm (range 0.0-5.0 mm). After the initial operation, the local sagittal angle remained stable in the follow-up 3 years later both for the thoracic spine and lumbar spine. Furthermore, no change in the implant's position was observed.

CONCLUSION

The implantation of a hydraulically expandable VBR allows a permanent stable fixation after traumatic fractures of the thoracic and lumbar spine.

LEVEL OF EVIDENCE

2.

[Trisegmental fusion by vertebral body replacement : Outcome following traumatic multisegmental fractures of the thoracic and lumbar spine]

BACKGROUND

Around 5% of all trauma patients suffer from spinal trauma. Spinal fractures are mainly located in the thoracic and lumbar spine. For multisegmental vertebral fractures categorized as instable, combined dorsal instrumentation and ventral stabilization is recommended. Numerous vertebral body replacement systems are available for ventral stabilization.

OBJECTIVES

The aim of the current study was to analyze radiological results following the implantation of a hydraulic expandable vertebral body replacement and the evaluation of patients' outcome three years after implantation.

MATERIALS AND METHODS

All patients who suffered traumatic multisegmental fractures of the thoracic or lumbar spine in the period from September 2009 to September 2012 were included in this study. Patients with additional injuries or abnormal sensitivity or motor function were excluded from the current study. All patients underwent dorsal percutaneous instrumentation. Afterwards, implantation of the vertebral body replacement was performed via the mini-open approach at our level I trauma center. In the computed tomography and X‑ray imaging, the sagittal kyphotic angle was measured. Furthermore, the clinical outcome (patients' satisfaction, VAS spine score) was analyzed using a questionnaire.

RESULTS

During the above mentioned period, seven patients (four female; three male) underwent dorsal instrumentation and ventral trisegmental fusion and were identified fitting the inclusion/exclusion criteria and thus could be included in the study. Most fractures were located in the thoracic-lumbar junction and were categorized A4 according to the AO Spine classification system. The analysis of the radiological data showed a pre-operative average traumatic segmental angle of 18.1 ± 14.9°, which could be decreased by reposition procedure to 6.4 ± 1.7°. The complete follow-up, including the data three years after implantation of the vertebral body implant, was available for three patients. The traumatic segmental angle remained stable in the follow-up three years later. In one case, a subsidence of the implant of 1.5 mm was observed, having no influence on the patients' satisfaction. All three patients indicated to be very satisfied with their outcome. The VAS spine score rating was in the range between 62.4 and 70.2.

CONCLUSIONS

The current study shows that in the case of multisegmental fractures complete reposition by ligamentotaxis and by the percutaneous instrumentation system is possible. In addition to the percutaneous dorsal instrumentation, the implantation of a hydraulically expandable vertebral body replacement may allow a stable fusion after complex traumatic fractures of the thoracic and lumbar spine. Patients are very satisfied with their outcome after this procedure.

Percutaneous extrapedicular vertebroplasty with expandable intravertebral implant in compression vertebral body fracture in pediatric patient-technical note

PURPOSE

The aim of the article is to present the new extrapedicular percutaneous technique for posttraumatic vertebral column fracture.

METHODS

A 15-year-old boy needed a surgical Th8 posttraumatic vertebral body (VB) compressive fracture reduction due to insufficient conservative treatment and consistent severe clinical symptoms. After 6 months of external Jevett long-roll brace stabilization, progressive sagittal balance disturbance of thoracic kyphosis was measured and persistent clinical symptoms were observed. It was decided to present a surgical technique method allowing to attempt to reduce VB fracture, rebalance the vertebral column (VC) without any motion limitation, and decrease clinical symptoms. The procedure was performed percutaneously from extrapedicular approach with intravertebral implant (Spine Jack®-Vexim™) and cement (Interface®-Vexim™) under fluoroscopic imaging (Ziehm™ 8000®).

RESULTS

The whole procedure was uneventful. Now, the child is free from clinical symptoms and the partial reduction of VB fracture was achieved. The patient has been followed for 3 months. In the control CT scans, the VB fracture reduction is stable and no progression of thoracic kyphosis angle is observed. Furthermore since the surgical procedure, the patient is clinical symptom free.

CONCLUSION

The extrapedicular percutaneus technique of VB fracture reduction with intravertebral fixation allowed to partially reduce the VB compressive fracture, rebalance the VC without any motion limitation, avoid external long-roll brace, and eliminate clinical symptoms. The procedure is minimally invasive, fast, and clinically effective. However, the technique should be restricted only to carefully selected clinical cases.

Dose effects and image quality: is there any influence by bearing devices in whole-body computed tomography in trauma patients?

BACKGROUND

Stable bearing devices are often utilized by prehospital first responders in modern management of severely injured patients. It is not known whether these devices influence radiation exposure or image quality in whole-body computed tomography (WBCT). Additionally, manufacturers currently provide no specifications concerning these criteria. This investigation analyzed the influence of nine different bearing devices on these specified criteria.

METHODS

The influence of nine different bearing devices on radiation exposure and image quality in WBCT was investigated. The dose-length-product (DLP100) was obtained through use of a CT-ionisation chamber placed in the centre of a 32 cm CT-phantom and compared with a reference value. Moreover, the results were calculated as effective dose data E (mSv). The image quality was assessed by three expert radiologists using the following scoring scale (0=no artefacts; 1=minor artefacts; 2=clearly artefacts; 3=massive artefacts).

RESULTS

Out of nine bearing devices examined, four showed significantly higher (2.5-4.5%, p<0.05) DLP100 and five showed no significant difference between DLP100 and the reference value. The image quality was classified in the categories "0", "1", "2" and "3" in 4, 3, 1 and 1 case, respectively.

CONCLUSIONS

In diagnostic producers using WBCT, bearing devices may be associated with relevant increases in radiation dose and can affect the image assessability. Some bearing devices are associated with no significant influence on radiation dose and reduction of image quality. Considering all results to get the best balance between image quality and radiation dose, aluminium and metal-free devices should be preferred.

[Osteoporotic vertebral body fractures of the thoracolumbar spine. Diagnostics and therapeutic strategies]

In cases of severe osteoporosis vertebral body fractures of the thoracolumbar spine can occur without any relevant trauma. Initially, a standardized diagnostic algorithm is recommended to detect acute vertebral body fractures and to be able to interpret the individual fracture stability. Aim of the therapy is to assure a relatively pain-free mobilization while maintaining vertebral spine alignment. A conservative therapy concept is initiated in patients with stable fractures. In cases of persistent pain, reduced mobility or increased kyphotic misalignment minimally invasive cement augmented therapy strategies are chosen. In cases of unstable fracture morphology a more complex therapy concept has to be chosen such as hybrid stabilization. A great deal of experience is needed for revision surgery. In such cases reconstructive, multi-segmental techniques might be necessary and the instrumentation should surpass the apex of kyphosis.

[Hardware removal after spinal instrumentation]

Because of the increasing number of patients with surgically treated injuries of the spine we more often have to answer the question of indication for hardware removal. In the cervical spine and after anterior instrumentations of the thoracic and lumbar spine hardware removal is only indicated as part of the management of postoperative complications. After dorsal instrumentation for fractures of the thoracic and lumbar spine, implant-associated discomfort is possible. In addition, in non-fusion procedures there is the risk of implant failure. In these cases the hardware should be removed. If the consolidation of the fracture is in doubt, a preoperative CT scan is useful.

Risk of graft fracture after dorso-ventral thoraco-lumbar spondylodesis: is there a correlation with graft size?

STUDY DESIGN

Retrospective clinical study in patients with dorso-ventral thoraco-lumbar spondylodesis.

OBJECTIVE

To investigate whether the ratio between graft cross sectional area and the surface area of the adjacent endplates has any effect on the midterm stability of the spondylodesis. Dorso-ventral spondylodesis in the region of the thoraco-lumbar spine is one of the most frequent operations in orthopaedic surgery. Anterior stabilization with autologous iliac crest graft currently is a standard approach in many hospitals. Although numerous recommendations are given how to perform this technique, no clinical advice is available with regard to minimum graft size.

METHODS

Sixty-four-slice CT-scans were obtained from 82 patients 4-12 months after posterior spondylodesis with anterior implantation of iliac crest graft and stabilization with an internal fixator. The scans were analyzed using image analysis software. First, the cross sectional area of the graft was calculated and then the surface area of the adjacent endplates. The ratio between graft cross sectional area and endplate surface area was then calculated from these two values. The grafts were then evaluated in sagittal reconstruction for signs of fracture.

RESULTS

The probability for graft fracture in autologous tricortical grafts was >0.1% (p < 0.001) if the graft cross sectional area exceeded 23.9% of the surface area of the adjacent endplates. Patients with lower ratio values had a higher fracture risk and below a value of 10% all grafts fractured.

CONCLUSION

The relationship between graft cross sectional area and adjacent endplate area has an important effect on graft midterm stability in ventral spondylodesis of the thoraco-lumbar spine. In our opinion, the risk of graft fractures in dorso-ventral spondylodesis can be reduced by implantation of an appropriately sized graft without any additional procedures or instrumentation.

[Reconstruction after spinal fractures in the thoracolumbar region]

The morbidity of anterior approaches has significantly influenced the development of therapeutic concepts for the treatment of thoracolumbar spine fractures. Minimally-invasive techniques such as mini-open and endoscopic have enlarged the numbers of anterior reconstruction after spinal fractures in the thoracolumbar region. These minimally-invasive approaches have been facilitated by the development of special implants adapted to the new technique and to the local anatomical requirements.Two multi center studies in Germany (MCSI and II) showed the trend towards minimal invasive procedures and anterior approaches in the German speaking spine centers. Since the first report on thoracoscopic anterior procedures in Germany in 1997 a growing number of spine centers established this method. There is still no evidence based high level literature to substantiate a significant benefit for the patients by anatomical reduction and reconstruction of the anterior spinal column. However, there are some reports on better short outcomes in radiological parameters as well as better clinical results in 5 to 8 year follow-ups.The minimal invasive anterior approach seems to be advantageous for the patients by reducing significantly additive operation morbidity. It has become more important over the last two decades for anterior reconstruction after trauma and posttraumatic malalignment of the thoracolumbar spine.

[Radiological comparison between two procedures for ventral spondylodesis: autologous iliac crest bone graft vs bovine bone graft]

BACKGROUND

The objective of this study was the radiological evaluation of osseous integration of autologous iliac crest graft and bovine bone graft after spondylodesis based on a standardized score.

MATERIAL AND METHODS

Spondylodesis was performed on 18 sheep, divided into 2 groups, 1 with an autologous iliac crest graft and the other with a bovine bone graft. Computed tomography was performed 12 and 24 weeks postoperatively. The osseous integration was assessed by the Tübinger Score.

RESULTS

The evaluation of the CT scans demonstrated a significantly better osseous integration of the autologous iliac crest graft compared to the bovine bone graft.

CONCLUSIONS

Based on our results, the bovine bone graft as a transplant for spondylodesis is inadvisable.

[Treatment of polytrauma in the intensive care unit]

The treatment of severely injured trauma patients (polytrauma) is one of the outstanding challenges in medical care. Early in the initial course the patient's diagnostics have to be scrupulously reevaluated by an interdisciplinary team (tertiary trauma survey) to reduce deleterious sequelae of missed injuries after the initial assessment. Severely injured patients stay in intensive care for an average of 11 days. During this time the patient's therapy has to ensure a high quality evidence-based intensive care treatment and simultaneously has to be tailored to the current individual injuries. Because of the fact that the damage control strategy is gaining increasing acceptance, the intensive care unit plays a pivotal role in the critical time between emergency and elective surgery. Therefore a close cooperation between physicians of the intensive care unit and all surgical disciplines involved is essential to reach the aim of therapeutic efforts. After survival of emergency treatment patients with severe trauma should be reintegrated into social and occupational life as soon as possible.

[Instrumental fixation in spinal surgery. Particular characteristics in patients with manifest osteoporosis]

A number of factors need to be borne in mind in the planning and performance of instrumental fixation of the spine in patients with osteoporosis. Improved implant anchoring using special screws and cement augmentation can help to avoid implant dislocations. Nevertheless, particular attention should be paid to spinal balance in these patients.

Effect of graft size on graft fracture rate after anterior lumbar spinal fusion in a sheep model

STUDY DESIGN

Sheep anterior spinal fusion model with autogenous and xenogenous bone grafts.

OBJECTIVE

To investigate whether the relationship between cross-sectional area of the bone graft and area of the adjacent vertebral endplates has an effect on graft fracture rate.

SUMMARY OF BACKGROUND DATA

Anterior spondylodesis with autogenous iliac crest transplant is a frequently performed operation to stabilize spinal motion segments but to date no precise recommendations with respect to minimum graft size are available in the literature.

METHODS

Anterior spondylodesis using autogenous and xenogenous grafts of constant size in combination with an angular stable plate (Macs TL). Autogenous iliac crest graft was inserted in eight sheep and xenogenic, commercially available bovine graft (Tutobone) in the additional eight animals. The surface areas of the endplates of the fused intervertebral space were calculated using CT scans and contact radiographs of the specimens obtained after 24 weeks. The graft itself was evaluated for fractures and osteolysis.

RESULTS

A fracture occurred in tricortical, autogenous grafts if the graft cross-sectional area was less than 21% of the area of the adjacent endplates. All xenogenic grafts fractured and therefore a comparable value could not be determined.

CONCLUSION

The results clearly indicate that the relation between graft cross-sectional area and endplate area defines the survival or fracture of the graft in anterior spinal fusion. Although it is difficult to directly apply the results to the clinical situation it is suggested to choose a sufficiently large graft, in order to reduce the risk of autogenous graft fracture in anterior spondylodesis.

ATLS(R) and damage control in spine trauma

Substantial inflammatory disturbances following major trauma have been found throughout the posttraumatic course of polytraumatized patients, which was confirmed in experimental models of trauma and in vitro settings. As a consequence, the principle of damage control surgery (DCS) has developed over the last two decades and has been successfully introduced in the treatment of severely injured patients. The aim of damage control surgery and orthopaedics (DCO) is to limit additional iatrogenic trauma in the vulnerable phase following major injury. Considering traumatic brain and acute lung injury, implants for quick stabilization like external fixators as well as decided surgical approaches with minimized potential for additional surgery-related impairment of the patient's immunologic state have been developed and used widely. It is obvious, that a similar approach should be undertaken in the case of spinal trauma in the polytraumatized patient. Yet, few data on damage control spine surgery are published to so far, controlled trials are missing and spinal injury is addressed only secondarily in the broadly used ATLS(R) polytrauma algorithm. This article reviews the literature on spine trauma assessment and treatment in the polytrauma setting, gives hints on how to assess the spine trauma patient regarding to the ATLS(R) protocol and recommendations on therapeutic strategies in spinal injury in the polytraumatized patient.

How to prevent overlooking cervical spine injuries: pitfalls in spinal diagnostics

Many patients with a cervical spine injury do not show clinical signs of the injury. Therefore, cervical spine trauma may not be recognized, especially in unconscious and multiply injured patients. Due to proximity to the spinal cord, neurological deficits inclusive of complete tetraplegia are possible. Since cervical spine injuries are typically associated with injuries at other spinal levels, accurate knowledge of the trauma mechanism is essential. Even mild clinical symptoms need to be carefully evaluated in a standardized fashion with clinical and radiological examinations including plane X-rays and possibly CT scans.

[Management of spine injuries in polytraumatized patients]

The management of spine injuries in polytraumatized patients remains a great challenge for the diagnostic procedures and institution of appropriate treatment by integrating spinal trauma treatment into the whole treatment concept as well as following the treatment steps for the injured spine itself. The established concept of "damage control" and criteria regarding the optimal time and manner for operative treatment of the injured spine in the polytrauma setting is presented and discussed.

Schockraummanagement bei Verletzungen der Wirbels�ule im Rahmen eines Polytraumas

Injuries to the spine are often part of life-threatening multiple trauma. In this review diagnostics and emergency room management were investigated in order to formulate effective recommendations for the emergency strategy. Clinical trials were systematically collected (MEDLINE, Cochrane, and hand searches) and classified into evidence levels (1 to 5 according to the Oxford system). The patient's history and clinical symptoms have low rates for specificity and positive predictive value, whereas their negative predictive value and sensitivity are high between 90 and 100%, respectively. CT imaging reaches higher rates for sensitivity, specificity, and positive and negative predictive values in comparison to conventional radiographic series. The patient's history should be asked and clinical investigation should be done in any case. Imaging diagnostics preferably as multislice spiral CT should be performed after stabilization of the patient's general condition and before admission to the intensive care unit.