Limitations of dorsal transpedicular stabilization in unstable fractures of the lower thoracic and lumbar spine: an analysis of 133 patients

Transpedicular Corpectomy and Cage Placement in the Treatment of Traumatic Lumbar Burst Fractures

STUDY DESIGN

Retrospective review.

OBJECTIVE

To review the feasibility of a posterior-only approach for instrumented reconstruction in lumbar burst fractures.

BACKGROUND

Burst fractures of the lumbar spine have been treated through a variety of techniques, including anterior, posterior, or combined approaches. Here we review series of patients undergoing posterior-only transpedicular corpectomy with instrumented fusion for traumatic lumbar burst fracture.

METHODS

All patients treated at the Los Angeles County+University of Southern California (LAC+USC) Medical Center who had sustained traumatic lumbar burst fractures from February 2005 to February 2014 were reviewed.

RESULTS

A total of 178 traumatic lumbar burst fractures were identified of which 89 required operative intervention. Of those 89 operations, 7 patients underwent posterior-only approach for transpedicular corpectomy. Levels operated on were at L1 (4 patients), L2 (1 patient), and L4 (2 patients). The mean age was 35 years of age (range, 21-56 y), and mechanism of injury was either motor vehicle accident (5 patients) or fall (2 patients). Initial neurological examination was American Spinal Injury Association (ASIA) B in 3 patients, ASIA D in 3 patients, and 1 patient was neurologically intact. Mean thoracolumbar injury classification and severity score on presentation was 6.4 (range, 5-8), whereas the mean load sharing classification score was 7.4 (range, 7-9). Of patients who were not immediately lost to follow-up on hospital discharge, mean clinical follow-up was 45.3 months (range, 18.8-68.6 mo), whereas mean radiographic follow-up was 28.8 months (range, 1.3-63.6 mo). At the last known radiographic follow-up, no patient had gross hardware fracture, pseudoarthrosis, or adjacent segment disease. One patient with the longest radiographic follow-up of 63.6 months was noted to have some minimal subsidence of his cage with no other change in his other hardware.

CONCLUSION

A posterior-only approach for transpedicular corpectomy and instrumented fusion is a viable treatment option for lumbar burst fracture which allows for reconstruction of the anterior column while avoiding many of the risks and complications associated with an anterior or combined approach.

Titanium versus polyetheretherketone implants for vertebral body replacement in the treatment of 77 thoracolumbar spinal fractures

Background:

Titanium and polyetheretherketone (PEEK) implants have been used in spinal surgery with low rejection rates. Compared to titanium, PEEK has many advantages, including a density more similar to that of bone, radiolucency, and a lack of artifacts in computed tomography (CT) and magnetic resonance imaging (MRI). In this study, we evaluated the effectiveness of PEEK cages as an alternative to titanium for bone fusion after fractures of the thoracolumbar spine. We also propose a classification to the impaction index.

Methods:

We evaluated 77 patients with fractures of the thoracic or lumbar spine who were treated by anterior fixation with titanium cages (TeCorp®) in 46 (59.7%) patients or PEEK (Verte-stak®) in 31 (40.3%) patients from 2006 to 2012 (Neurological Hospital of Lyon).

Results:

The titanium group achieved 100% fusion, and the PEEK group achieved 96.3% fusion. The titanium systems correlated with higher impact stress directed toward the lower and upper plateaus of the fused vertebrae; there were no nonunions for those treated with titanium group. Nevertheless, there was only one in the PEEK group. There was no significant difference in the pain scale outcomes for patients with ±10 degrees of the sagittal angle. Statistically, it is not possible to associate the variation of sagittal alignment or the impaction with symptoms of pain. The complication rate related to the implantation of cages was low.

Conclusions:

Titanium and PEEK are thus equally effective options for the reconstruction of the anterior column. PEEK is advantageous because its radiolucency facilitates the visualization of bone bridges.

Anterior approach with expandable cage implantation in management of unstable thoracolumbar fractures: Results of a series of 93 patients

INTRODUCTION

Anterior approach indications in unstable thoracolumbar fractures (UTLF) are debated. The aim of this study was to evaluate the results of anterior fixation and expandable prosthetic vertebral body cage (EPVBC) implantation alone or combined with a posterior approach in the management of UTLF.

MATERIALS AND METHODS

Ninety-three patients underwent anterior fixation with implantation of an EPVBC for UTLF from T7 to L5. Long-term kyphosis and vertebral height loss reduction, functional outcomes including visual analogical scale and Oswestry disability index were evaluated.

RESULTS

Anterior fixation led to a significant increase of vertebral body height with a gain of 13% after a previous posterior approach, 38% after a single anterior approach and 65% after combined posterior and anterior approaches (P=0.0001). However, anterior fixation did not significantly enhance the vertebral regional kyphosis angle (P=0.08), except in cases of single anterior approach for thoracic fractures (P=0.03). No significant difference was found between early, 3 months and 1 year postoperative vertebral regional kyphosis angle and vertebral body height (P=0.6). Complete fusion was routinely observed at 1 year postoperatively. rhBMP2 implantation in selected cases appears to be a safe and reliable strategy. No infections or surgical revisions were observed after the anterior approach.

CONCLUSION

Anterior approach and EPVBC implantation, in UTLF, is a safe and effective procedure, providing long-term vertebral body height and kyphosis correction. Adverse effects of anterior approach remain acceptable. Single anterior fixation is a reliable surgical alternative in thoracic fractures without posterior spine segment injury or spinal cord compression. These results prompted us to extend anterior approach indications in oncology and infectious diseases.

Revision surgery for posterior stabilized thoracolumbar fracture using mini-open anterior approach and expandable cage

OBJECTIVE

To evaluate the surgical techniques and outcomes of revision surgery for compromised posterior stabilization or insufficient neurological decompression using anterior mini-open approach and expandable cage.

METHODS

From August 2005 to June 2008, a total of 235 patients were operated on in our center for thoracolumbar fractures with dorsal transpedicular stabilization. Twenty-six of these patients underwent revision surgery, the main reasons being back pain and stagnant neurological recovery. The surgical procedure comprised a single-level thoracolumbar corpectomy and/or canal clearance, followed by an expandable cage reconstruction. The average interval between primary and revision surgery was 5 months (range, 3-11 months). A transthoracic (n= 11) or transthoracic transdiaphragmatic (n= 15) mini-open approach was conducted using a table-mounted retractor.

RESULTS

The operating time averaged 105 min (range, 95-135 min) for the transthoracic approach and 152 min (range, 120-190 min) for the transthoracic plus transdiaphragmatic approach. The overall mean blood loss was 780 ml (range, 550-1700 ml). Over time, the pre-operative neurological deficit improved in 6/7 patients by at least one Frankel/American Spinal Injury Association (ASIA) grade. On a visual analogue scale (VAS) from 0 to 10, the mean local thoracolumbar back pain was relieved significantly from 6.8 before operation to 3.8 at 3 months, 2.4 at 6 months, and 1.5 at 12 months postoperatively. None of the patients developed intercostal neuralgia or post-thoracotomy pain syndromes.

CONCLUSION

For patients with compromised stabilization or insufficient neurological decompression after primary dorsal transpedicular stabilization for thoracolumbar fracture, anterior revision surgery can produce good results. The mini-open anterior approach for corpectomy in the thoracolumbar spine is safe, reliable, and economical. The expandable cage is an excellent alternative for anterior reconstruction.

Correction of Late Traumatic Thoracic and Thoracolumbar Kyphotic Spinal Deformities Using Posteriorly Placed Intervertebral Distraction Cages

Objective:

To assess the safety and stability of thoracic or thoracolumbar deformity correction from a solely posterior approach with placement of modular anterior cages and posterior segmental fixation in one operation.

Methods:

Twenty-eight patients who failed brace trial for 6 months or longer were included in the series. All patients had progressive neurological deficit and/or deformity progression at time of operation. All patients underwent a single operation in the prone position. Segmental fixation was accompanied by anterior column reconstruction using modular cages avoiding nerve root sacrifice. Stackable cages were used for high thoracic deformity. Deformity, Cobb angle, visual analog pain score, and x-ray evaluation of fusion ensued for mean follow-up period of 31 months.

Results:

Patients achieved a mean sagittal deformity correction of 13.3 degrees ± 7.4 standard deviation. Improved or maintained American Spinal Injury Association scores were noted in all patients. The mean time of operation was 334 minutes ± 85 standard deviation, or 6 to 7 hours. At a mean follow-up of 31 months (range, 12–36 mo), the following complications were noted: subsidence greater than 2.5 mm (n = 3), cage migration requiring revision (n = 1), brachial plexopathy from malpositioning (n = 1), and intraoperative cerebrospinal fluid leak managed via lumbar drain (n = 2). Plain and dynamic radiographic evidence of maintained deformity correction was noted in 27 patients.

Conclusion:

Delayed kyphotic deformity correction of the thoracolumbar spine is achieved via a posterior-only approach. At a mean follow-up period of 31 months, sagittal angles remained acceptable. Improved fusion criteria and patient numbers will be required to determine fusion and loss of correction rates over time.

[The dorsal spondylodesis of rotationally unstable thoracic fractures. Is additional ventral stabilization necessary?]

METHODS

A total of 60 patients with solely dorsally reconstructed type C fractures of the thoracic spine admitted between January 2000 and December 2003 were retrospectively evaluated. Stability was determined by measuring kyphosis of the vertebral body, the operated segments and of lateral bending on the basis of plain films and computed tomography immediately postoperatively and after 2 and 19 months.

RESULTS

There were 48% C2, 38% C1 and 13% C3 fractures. Of the injuries, 28% were caused by motorbike accidents, 25% by car accidents, 23% by falling from a height, 13% by suicidal jumps, 3% by ski accidents and 3% for other reasons. A total of 92% of the patients had severe thoracic trauma as attendant injuries, 42% further vertebral fractures, 35% a head injury, 30% an extremity fracture, 15% a clavicle fracture, 8% an abdominal trauma and 7% a fractured pelvis. At 19+/-12 months postoperatively, the angle of the operated segments increased by 4.7 degrees +/-4.0 degrees and that of lateral bending of the operated segments by 0.7 degrees +/-1.8 degrees compared to the immediate postoperative values.

CONCLUSION

In spite of the high instability of the injured spine, the collective examined had no relevant postoperative loss of correction and no increase in lateral bending. Therefore, a solely dorsal reconstruction is sufficient, reasonable and economical.

Timing of thoracic and lumbar fracture fixation in spinal injuries: a systematic review of neurological and clinical outcome

A systematic review of all available evidence on the timing of surgical fixation for thoracic and lumbar fractures with respect to clinical and neurological outcome was designed. The purpose of this review is to clarify some of the controversy about the timing of surgical fracture fixation in spinal trauma. Better neurological outcome, shorter hospital stay and fewer complications have been reported after early fracture fixation. But there are also studies showing no difference in neurological outcome when compared to late treatment. Mortality is another controversial point since a recent report of higher mortality in early treated patients. A systematic review of the literature was preformed. Ten articles were included. Early fracture fixation is associated with less complications, shorter hospital and ICU stay. The effect of early treatment on the neurological outcome remains unclear due to the contradictory results of the included studies. Early thoracic and lumbar fracture fixation results in improvement of clinical outcome, but the effect on neurological outcome remains controversial.

Two column lesions in the thoracolumbar junction: anterior, posterior or combined approach? A comparative biomechanical in vitro investigation

There are various surgical techniques for the treatment of spinal fractures in the thoracolumbar region. Several implants have been developed for anterior or posterior instrumentation. Optimal treatment of unstable thoracolumbar osseous and ligamentous injuries remains controversial. To compare the stabilizing effects of an antero-lateral, thoracoscopically implantable plate system (macsTL, Aesculap, Germany) with the stability provided by a fixateur interne (SOCON, Aesculap, Germany), this in vitro investigation examined six human bisegmental (T12-L2) spinal units. Specimens were tested intact, and with simulation of osseous lesions in the anterior and ligamentous lesions in the posterior column (combined A/B-fracture). While loaded in the main anatomical planes such as flexion/extension, left and right lateral bending and left and right axial rotation with a bending moment of 7.5 Nm in a special testing jigs, motion analysis was performed. Quantitative interpretation of the stabilizing effect was achieved using a contactless three-dimensional motion analysis system. Each specimen was tested in four different scenarios: the first step measured movements of intact spinal segments. For the second step, specimens underwent simulation of combined A/B-fracture provided with bisegmental (T12/L2) antero-lateral fixation and bone strut graft from the iliac crest. For the third step, segments were additionally stabilized by the fixateur interne. The last measurement (fourth step) was performed after removing the anterior instrumentation. Range of motion (ROM) values were compared and statistically evaluated. Compared to the intact specimens the anterior instrumentation of the combined lesion, simulated A/B-fracture, leads to a stabilizing effect in flexion/extension and lateral bending. In contrast to these findings the torsional instability increased for the upper segment and bisegmentally. A maximum rigidity, beyond intact values, was registered for each anatomical plane with the combined instrumentation: antero-lateral and fixateur interne. After removing the anterior screw plate system maximum movements, in all segments for flexion/extension and lateral bending, bisegmentally and for the upper segment in axial rotation, were less than ROM values measured with the anterior system only. With respect to these findings a combined ventro-dorsal stabilization procedure should be considered for ligamentous disruptions of the posterior column in combination with A-fractures in the thoracolumbar junction.

Unstable burst fractures of the thoraco-lumbar junction: treatment by posterior bisegmental correction/fixation and staged anterior corpectomy and titanium cage implantation

BACKGROUND

Controversy exists about the best treatment of unstable thoraco-lumbar (TL) burst fractures. Kyphosis correction and canal decompression in case of a neurological deficit are recognized treatment objectives, and various conservative and surgical strategies have been proposed. This prospective observational study evaluates the benefits and risks of a posterior bisegmental transpedicular correction/fixation and staged anterior corpectomy and titanium cage implantation in unstable TL junction burst fractures.

METHOD

20 consecutive patients with a single-level traumatic unstable burst fracture at the TL junction were operated on by a bisegmental posterior correction/fixation, followed by anterior corpectomy and titanium cage implantation 7-10 days later. The radiological and clinical course is documented over a period of 24 months.

FINDINGS

The mean posttraumatic loss of anterior vertebral body height was 58% (45-70%). The posttraumatic mean regional kyphosis was 16 degrees and could be corrected by the posterior approach to a mean lordosis of 2 degrees. Mean secondary loss of the kyphosis correction was 3 degrees over 24 months. No hardware failure occurred, and construct stability was observed in all 20 patients. One surgical complication occurred during the posterior approach, and three transient surgical complications by the anterior approach. 12 of the 14 patients with an initial neurological deficit recovered an average of 1.5 grades on the ASIA scale. At 24 months postoperatively, the mean regional TL back pain on a VAS (0-10) was 1.6, and the mean pain at the anterior approach site was 1.2.

CONCLUSION

Posterior bisegmental transpedicular correction/fixation and staged anterior corpectomy and titanium cage implantation is a safe and reliable surgical treatment option in unstable TL junction burst fractures. The advantages of this technique are a complete kyphosis correction, immediate stability, maintenance of kyphosis correction, and complete spinal canal decompression in case of a neurological deficit. However, these advantages have to be carefully weighed against the double approach morbidity.