Pedicle screw fixation for traumatic fractures of the thoracic and lumbar spine

Thoracic and Lumbar Spine Injury: Evidence-Based Diagnosis, Management, and Outcomes

BACKGROUND

Traumatic thoracolumbar spine injuries are associated with significant morbidity and mortality. Targeted for non-spine specialist trauma surgeons, this systematic scoping review aimed to examine literature for up-to-date evidence on presentation, management, and outcomes of thoracolumbar spine injuries in adult trauma patients.

METHODS

This review was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. We searched four bibliographic databases: PubMed, EMBASE, Web of Science, and the Cochrane Library. Eligible studies included experimental, observational, and evidence-synthesis articles evaluating patients with thoracic, lumbar, or thoracolumbar spine injury, published in English between January 1, 2010 and January 31, 2021. Studies which focused on animals, cadavers, cohorts with N <30, and pediatric cohorts (age <18 years old), as well as case studies, abstracts, and commentaries were excluded.

RESULTS

A total of 2501 studies were screened, of which 326 unique studies were fully text reviewed and twelve aspects of injury management were identified and discussed: injury patterns, determination of injury status and imaging options, considerations in management, and patient quality of life. We found: (1) imaging is a necessary diagnostic tool, (2) no consensus exists for preferred injury characterization scoring systems, (3) operative management should be considered for unstable fractures, decompression, and deformity, and (4) certain patients experience significant burden following injury.

DISCUSSION

In this systematic scoping review, we present the most up-to-date information regarding the management of traumatic thoracolumbar spine injuries. This allows non-specialist trauma surgeons to become more familiar with thoracolumbar spine injuries in trauma patients and provides a framework for their management.

Influence of various pilot hole profiles on pedicle screw fixation strength in minimally invasive and traditional spinal surgery: a comparative biomechanical study

Despite advancements in pedicle screw design and surgical techniques, the standard steps for inserting pedicle screws still need to follow a set of fixed procedures. The first step, known as establishing a pilot hole, also referred to as a pre-drilled hole, is crucial for ensuring screw insertion accuracy. In different surgical approaches, such as minimally invasive or traditional surgery, the method of creating pilot holes varies, resulting in different pilot hole profiles, including variations in size and shape. The aim of this study is to evaluate the biomechanical properties of different pilot hole profiles corresponding to various surgical approaches. Commercially available synthetic L4 vertebrae with a density of 0.16 g/cc were utilized as substitutes for human bone. Four different pilot hole profiles were created using a 3.0 mm cylindrical bone biopsy needle, 3.6 mm cylindrical drill, 3.2-5.0 mm conical drill, and 3.2-5.0 mm conical curette for simulating various minimally invasive and traditional spinal surgeries. Two frequently employed screw shapes, namely, cylindrical and conical, were selected. Following specimen preparation, screw pullout tests were performed using a material test machine, and statistical analysis was applied to compare the mean maximal pullout strength of each configuration. Conical and cylindrical screws in these four pilot hole configurations showed similar trends, with the mean maximal pullout strength ranking from high to low as follows: 3.0 mm cylindrical biopsy needle, 3.6 mm cylindrical drill bit, 3.2-5.0 mm conical curette, and 3.2-5.0 mm conical drill bit. Conical screws generally exhibited a greater mean maximal pullout strength than cylindrical screws in three of the four different pilot hole configurations. In the groups with conical pilot holes, created with a 3.2-5.0 mm drill bit and 3.2-5.0 mm curette, both conical screws exhibited a greater mean maximal pullout strength than did cylindrical screws. The strength of this study lies in its comprehensive comparison of the impact of various pilot hole profiles commonly used in clinical procedures on screw fixation stability, a topic rarely reported in the literature. Our results demonstrated that pilot holes created for minimally invasive surgery using image-guided techniques exhibit superior pullout strength compared to those utilized in traditional surgery. Therefore, we recommend prioritizing minimally invasive surgery when screw implantation is anticipated to be difficult or there is a specific need for stronger screw fixation. When opting for traditional surgery, image-guided methods may help establish smaller pilot holes and increase screw fixation strength.

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

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

Application of the cortical bone trajectory technique in posterior lumbar fixation

The cortical bone trajectory (CBT) is a novel technique in lumbar fixation and fusion. The unique caudocephalad and medial-lateral screw trajectories endow it with excellent screw purchase for vertebral fixation via a minimally invasive method. The combined use of CBT screws with transforaminal or posterior lumbar interbody fusion can treat a variety of lumbar diseases, including spondylolisthesis or stenosis, and can also be used as a remedy for revision surgery when the pedicle screw fails. CBT has obvious advantages in terms of surgical trauma, postoperative recovery, prevention and treatment of adjacent vertebral disease, and the surgical treatment of obese and osteoporosis patients. However, the concept of CBT internal fixation technology appeared relatively recently; consequently, there are few relevant clinical studies, and the long-term clinical efficacy and related complications have not been reported. Therefore, large sample and prospective studies are needed to further reveal the long-term complications and fusion rate. As a supplement to the traditional pedicle trajectory fixation technique, the CBT technique is a good choice for the treatment of lumbar diseases with accurate screw placement and strict indications and is thus deserving of clinical recommendation.

Effection of monoplanar pedicle screw on facet joint degeneration in thoracolumbar vertebral fractures

Background

This study aimed to compare the clinical outcomes and effect on instrument-related facet joints between fixed-axis pedicle screw (FAPS) and monoplanar pedicle screw (MPPS).

Methods

816 pedicle screws of 204 patients with thoracolumbar vertebral fractures (TLVF) who underwent internal fixation surgery were analyzed in this retrospective study. All patients were divided into two groups (FAPS and MPPS). Preoperative, immediate postoperative, and 12–18-months postoperative CT and X-ray, and clinical data, including demographics, preoperative and immediate postoperative Visual Analogue Scale (VAS), blood loss (BL), operation time (OT) and hospital stay time (HST), were collected. Facet joint violation and degeneration grade were evaluated by CT according to Babu’s criteria and Weishaupt’s criteria respectively, and preoperative, immediate postoperative and 12–18-months postoperative anterior body compression index (ABCI) were measured by X-ray.

Results

Postoperative VAS of two groups was lower than preoperative VAS (p < 0.05). BL, OT, and HST were less in MPPS than FAPS, and the difference was statistically significant in BL and HST (p < 0.05) but no in OT (p > 0.05). Immediate postoperative and 12–18-months postoperative ABCI were significantly higher than preoperative (p < 0.05), and the difference of ABCI between immediate postoperative and 12–18-months postoperative were not significant in two groups (p > 0.05). Total violation rate (VR) was about 1.35% (11/816) and FAPS had a lower VR than MPPS, but no significant (p > 0.05). Weishaupt’s criteria revealed that average class (AC) was 0.69 in FAPS and 0.67 in MPPS, and the distribution of degenerated facet joints in two groups did not differ preoperatively (p > 0.05). In 12–18 months postoperatively, AC was significantly higher in FAPS than in MPPS, and the distribution of degenerated facet joints in two groups was significantly different (p < 0.05). The comparison of cranial to caudal joints in two groups revealed that cranial joints had more severe degeneration than caudal joints.

Conclusions

The findings suggested that both MPPS and FAPS were effective for patients with TLVF, but MPPS by percutaneous may be a better choice to avoid adjacent segment degeneration, especially the surgery-involved facet joints degeneration.

Surgical Techniques for Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

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

Application of Spinal Robotic Navigation Technology to Minimally Invasive Percutaneous Treatment of Spinal Fractures: A Clinical, Non-Randomized, Controlled Study

Objective

To introduce a new robotic navigation system that assists pedicle screw implantation and verify the accuracy and stability of the system.

Methods

Pedicle screw placements were performed on the thoracic vertebrae (T)9–Lumbar vertebrae (L)5 thoracolumbar vertebrae of cadavers using robotic guidance. The operative duration, puncture success, correction, and correction time were assessed. Additionally, a total of 30 thoracolumbar fractures from September 2017 until June 2019 were included in a clinical study. Two groups were evaluated: the robotic guidance group and freehand group. Both sexes were evaluated. Mean ages were 47.0 and 49.1 years, respectively, in the robotic and freehand groups. Inclusion criteria was age >18 years and a thoracolumbar fracture. Intervention was the operative treatment of thoracolumbar fractures. Outcome parameters were the operation time, intraoperative bleeding, and fluoroscopic data. The accuracy of the pedicle screw placement and screw penetration rate of the two groups were compared using intraoperative fluoroscopic axial images.

Results

The success rate for 108 one‐time nail placements in cadavers was 88% and two‐time nail placement was 100%. Vertebral punctures at L5 took the longest to perform and achieve correction. Clinically, there were no significant differences in patients' sex, body mass index, age distribution, or intraoperative bleeding between the groups. The average X‐ray exposure time for patients and operators were 37.69 ± 9.24 s and 0 s in the robotic group (significantly lower than in the freehand group: 81.24 ± 6.97 s vs 56.29 ± 7.93 s, respectively). Success rates for one‐time screw placements were 98.64 and 88.46% in the robotic and freehand groups, respectively, which is significant. Screw penetration rates (1.36% vs 11.54%, robotic vs freehand), were significantly different.

Conclusions

The robotic system improved the accuracy and safety of pedicle screw internal fixation and reduced patients' and operators' intraoperative radiation exposure.

Cement Augmented Anterior Reconstruction and Decompression without Posterior Instrumentation: A Less Invasive Surgical Option for Osteoporotic Thoracolumbar Fracture with Cord Compression

Objective

We investigated the clinical and radiological outcomes of a cement augmented anterior reconstruction and decompression without pedicle screw fixation in patients with osteoporotic thoracolumbar vertebral fracture with myelopathy.

Methods

There were 2 male and 6 female patients with thoracolumbar fracture and myelopathy included in the study. The mean follow-up period was more than 1 years. The anterolateral decompression and cement augmented anterior reconstruction with poly(methyl methacrylate) (PMMA) was performed. Demographic data, clinical outcomes, perioperative parameters and radiologic parameter were retrospectively evaluated.

Results

The symptoms due to myelopathy were improved in all patients. The preoperative median visual analog scale score for lower back and leg were 8.5 that improved 4.25 and 3 at last follow up. The preoperative function state showed a median Oswestry Disability Index score 61.5 that improved 33. After surgery, preoperative encroachment of the spinal canal (5.12 mm, 37%) was disappeared. The median height of fractured vertebral body significantly increased from 7.83 to 12.63 mm. At the last follow-up point, the median height was 9.91 mm. The median kyphotic deformity was improved from 22.12° to 14.31°. At the final follow-up, the improvement was preserved (median value: 15.03). The acute complication according to PMMA such as leakage and embolization was none, but adjacent compression fracture as late complication according to cement augmentation was. One patient developed surgical site infection.

Conclusion

On the basis of the preliminary results, we considered that anterolateral decompression and PMMA augmentation might be an optimal method for treating osteoporotic fracture with myelopathy in elderly patients or those with multiple medical comorbidities.

Transforaminal Interbody Impaction of Bone Graft to Treat Collapsed Nonhealed Vertebral Fractures with Endplate Destruction: A Report of Two Cases

Background

A collapsed nonhealed vertebral fracture with endplate destruction is a challenging injury to address, as there is no single definitive treatment. We present two cases using an innovative transforaminal grafting technique to treat these patients. Case Presentation. Case 1: a 72-year-old woman had nonunion of an L1 compression fracture with destruction of both endplates. T12/L1 and L1/L2 transforaminal debridement and impaction of bone graft were performed followed by posterior instrumentation. At three years follow-up, the fusion mass between T12/L1 and L1/L2 was solid and the patient had minimal pain. Case 2: a 62-year-old woman had nonunion of an L1 burst fracture with destruction of the lower endplate. Hemilaminectomy and transforaminal interbody impaction of bone graft was performed. At three years follow-up, the patient had no back pain and a solid fusion. In both cases, local kyphosis was corrected and fusion obtained.

Conclusions

Collapsed nonhealed vertebral body fractures combined with endplate destruction can be successfully treated with a one-step posterior surgery consisting of transforaminal debridement and impaction of bone graft in combination with posterior pedicle instrumentation.

[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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Efficacy of Vertebroplasty in Short-Segment Pedicle Screw Fixation of Thoracolumbar Fractures: A Meta-Analysis

BACKGROUND Short-segment pedicle screw instrumentation provides superior outcomes in treating thoracolumbar fractures. Nevertheless, the effect of intermediate screws on the outcome of short-segment instrumentation at the fracture level has not been specifically analyzed. We performed an update meta-analysis of the effect of additional vertebroplasty on the outcome of short-segment instrumentation to determine the role of screws for patients with fractured vertebra. MATERIAL AND METHODS A systematic literature search was conducted, updated to January 2019, in terms of the efficacy of additional vertebroplasty on the outcome of short-segment instrumentation at the fracture level. After rigorous quality review, we extracted the data from qualified clinical studies. We further analyzed odds ratios (ORs) of the endpoints of interest based on the included trials. RESULTS Compared with the control group, short-segmental fixation combined with intermediate screws restored Cobb angle (P<0.001) and reduced anterior vertebral height compression (P=0.001). However, our results did not reveal statistically significant differences in operative time (P=0.28) or estimated blood loss (P=0.23). A statistically significant difference was observed in mean hospital stay (P=0.02). CONCLUSIONS Reinforcement with fracture-level screw combination can help stabilize the fractures and restore the anatomy. Nevertheless, additional trials and studies with longer follow-ups and on larger populations are warranted to confirm the current findings.

Spinal Reconstruction Techniques for Traumatic Spinal Injuries: A Systematic Review of Biomechanical Studies

STUDY DESIGN

Systematic literature review.

OBJECTIVES

Many studies have provided evidence that short-segment posterior fixation (SSPF-1 level above and 1 below) with screws at the fracture level (SFL) are enough to achieve stability in some injury patterns, such as burst fractures, avoiding the need for circumferential reconstruction and long-segment instrumented fusion (LSIF-at least 2 levels above and 2 below). Given the potential benefits of avoiding unnecessary fusion in mobile healthy spinal segments, we performed a systematic review of biomechanical studies comparing different spinal reconstruction techniques for fractures of the thoracolumbar spine.

METHODS

A systematic literature review was performed in the PubMed and OVID databases of biomechanical studies comparing biomechanical differences between techniques of spine reconstructions.

RESULTS

Eight studies were included and evaluated. Five of 6 studies reported stiffness improvement with SSPF and SFL, even comparable to circumferential fusion for a burst fracture. Two studies reported that LSPF has higher stiffness and restricts range of motion better than SSPF, but inclusion of screws in the fracture level is similar to LSPF (1 study). Finally, although SSPF is less stiff than anterior reconstruction, adding a SFL in SSPF results in similar stiffness than circumferential fusion for unstable burst fractures.

CONCLUSIONS

Biomechanical studies analyzed generally suggested that SFL in SSPF may improve construction stiffness, and can even be compared with long-segment fixation or circumferential reconstruction in some scenarios. This construct option may be used to enhance stiffness in selected injury patterns, avoiding the needs of an additional anterior approach.

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

NCT03384368; Pre-results.

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.

Management of major vascular injury during pedicle screw instrumentation of thoracolumbar spine

OBJECTIVES

Vascular injury is a rare complication of spinal instrumentation. Presentation can vary from immediate hemorrhage to pseudoaneurysm formation. In the literature, surgical approach to repair has varied based on anatomy, acuity of diagnosis, infection, and available technology. In this manuscript, we aim to describe our institutional experience with vascular injuries in thoraco-lumbar spine surgery.

PATIENTS AND METHODS

We report our institutional experience of three cases of vascular injury secondary to pedicle screw misplacement and their management, as well as a review of the literature.

RESULTS

The first case had a history of previous instrumentation and presented with back pain and fever. The patient was taken for instrumentation exploration via a posterior approach. Aortic violation was discovered at T6 intraoperatively during instrumentation removal and the patient underwent emergent endovascular repair. The second case presented with chronic back pain after multiple prior posterior fusions and CT angiogram showing screw perforation on the aorta at T10. The patient underwent elective endovascular repair with synchronous removal of the instrumentation. The third case presented with radicular leg pain 6 months after L4-S1 posterior lumbar interbody fusion, with CT scan demonstrating the left S1 screw abutting the L5 nerve root and common iliac vein. The patient underwent elective instrumentation revision with intraoperative venography.

CONCLUSION

Major vascular injury is a known complication of spinal surgery, especially if it involves instrumentation with pedicle screws. Treatment approach has evolved with the advancement of endovascular technology; however, open surgery remains an option when anatomy or infection is prohibitive. In the elective setting, preoperative planning with attention to surgical approach, positioning, and contingencies, should occur in a multidisciplinary fashion. Repair with an aortic stent-graft cuff may minimize unnecessary coverage of the descending thoracic aorta and intercostal arteries.

Comparing the efficacy of short-segment pedicle screw instrumentation with and without intermediate screws for treating unstable thoracolumbar fractures

It is generally acknowledged that short-segment pedicle screw instrumentation is the preferred surgical method for thoracolumbar fractures. However, the use of short-segment instrumentation with or without intermediate screws at the fracture level remains controversial.We retrospectively evaluated 44 patients (28 men, 16 women) with unstable thoracolumbar fractures. The patients were divided into 2 groups according to the surgical method used. In group 1, 24 patients underwent surgery with a posterior approach via short-segment pedicle screw instrumentation (1 level above and 1 level below the fractured level). In group 2, 20 patients received an additional 2 screws at the fractured vertebrae. Clinical and radiologic parameters were evaluated before surgery and at 1 week, 6 months, and 1 year after surgery.We found no significant difference in the demographic characteristics between the 2 groups. No significant difference was observed in the operative time and intraoperative blood loss between the 2 groups. Clinical outcomes also showed no significant differences between the groups preoperatively or at all follow-up periods. The correction of the Cobb angle (CA) 1 week after surgery was better in group 2, whereas the anterior vertebral body height of the fractured level (AVHF) and compression ratio of the AVHF (AVHFCR) were not significantly different between the 2 groups 1 week after surgery. Moreover, group 2 had better maintenance of restored CA, AVHF, and AVHFCR at the fractured level than did group 1 at 6 months and 1 year postoperatively. In addition, the reduction of mid-sagittal diameter (MSD) of spinal canal 1 week and 1 year after surgery was better in group 2. Besides, bone fragments in the spinal canal have a tendency to be less in group 2 1 week and 1 year after surgery.Reinforcement with intermediate screws for a single thoracolumbar fracture not only enhanced the stability of the internal fixation system, but it was also conducive to the correction of kyphosis and the maintenance of the reduction effects. Furthermore, this method is helpful to restore the spinal canal and reduce the bone fragments in the spinal canal. However, more long-term follow-up studies are needed.

Does Operative or Nonoperative Treatment Achieve Better Results in A3 and A4 Spinal Fractures Without Neurological Deficit?: Systematic Literature Review With Meta-Analysis

STUDY DESIGN

Systematic literature review with meta-analysis.

OBJECTIVE

Thoracolumbar (TL) fractures can be treated conservatively or surgically. Especially, the treatment strategy for incomplete and complete TL burst fractures (A3 and A4, AOSpine classification) in neurologically intact patients remains controversial. The aim of this work was to collate the clinical evidence on the respective treatment modalities.

METHODS

Searches were performed in PubMed and the Web of Science. Clinical and radiological outcome data were collected. For studies comparing operative with nonoperative treatment, the standardized mean differences (SMD) for disability and pain were calculated and methodological quality and risk of bias were assessed.

RESULTS

From 1929 initial matches, 12 were eligible. Four of these compared surgical with conservative treatment. A comparative analysis of radiological results was not possible due to a lack of uniform reporting. Differences in clinical outcomes at follow-up were small, both between studies and between treatment groups. The SMD was 0.00 (95% CI -0.072, 0.72) for disability and -0.05 (95% CI -0.91, 0.81) for pain. Methodological quality was high in most studies and no evidence of publication bias was revealed.

CONCLUSIONS

We did not find differences in disability or pain outcomes between operative and nonoperative treatment of A3 and A4 TL fractures in neurologically intact patients. Notwithstanding, the available scores have been developed and validated for degenerative diseases; thus, their suitability in trauma may be questionable. Specific and uniform outcome parameters need to be defined and enforced for the evaluation of TL trauma.

Which patients risk segmental kyphosis after short segment thoracolumbar fracture fixation with intermediate screws?

INTRODUCTION

The use of intermediate screws in fractured vertebrae has been proposed to decrease the number of fused levels in thoracolumbar fractures and to enable short fixations. The aim of this study was to evaluate the results of this technique and to establish predictive factors involved in loss of segmental kyphosis correction (LKC).

METHODS

Forty-three patients who underwent short-segment spinal fixation with intermediate screws for a thoracolumbar spine fracture in a two-year time period were enrolled in the study. Patients had AO-type A3, A4 and B2 thoracolumbar fractures. Radiological parameters included segmental kyphosis (SK), vertebral wedge angle (VWA) and loss of anterior and posterior vertebral body height. Patients were evaluated up to one-year follow-up. The correlation between LKC and potential risk factors, such as smoking habit, sex, age, neurological status and BMI was evaluated.

RESULTS

Mean preoperative SK was 16.5°±6.5°, and it decreased to 3.4°±3.5° postoperatively (P<0.01). At the one-year follow-up mean SK dropped to 5.5°±3.9° (P<0.01). Mean preoperative VWA was 20.0°±8.1°, and significantly improved to 6.3°±3.1° after surgery (P<0.01). There was a mean LKC of 1.8°±2.1°at one year. LKC mildly correlated with body mass index (BMI, r: +0.31), and obese patients (BMI>30) had an increased risk of LKC at the one-year follow-up (P=0.03; odds ratio [OR]=3.2).

DISCUSSION

Analysis of the radiological data at one-year follow-up showed that all the evaluated parameters were associated with a mild loss of correction, with no impact on the clinical outcomes or implant failure. These findings confirm the trends reported in the literature. The correlation between LKC and clinical features, such as BMI, age, sex, smoking habit and preoperative neurological status was investigated. Interestingly, a positive correlation was observed between BMI and LKC, and obese patients with BMI>30 had an increased risk of LKC at one-year follow-up (OR 3.2); to our knowledge this finding has never before been reported.

CONCLUSION

Short-segment fixation with intermediate screws is a viable technique with positive clinical and radiological outcomes at one-year follow-up. However, surgeons should be aware that in obese patients (BMI>30) this technique is associated with an increased risk of LKC.

LEVEL OF EVIDENCE

3.

Surgical versus non-surgical treatment for thoracolumbar burst fractures without neurological deficit

BACKGROUND

Spinal burst fractures result from the failure of both the anterior and the middle columns of the spine under axial compression loads. Conservative management is through bed rest and immobilisation once the acute symptoms have settled. Surgical treatment involves either anterior or posterior stabilisation of the fracture, sometimes with decompression involving the removal of bone fragments that have intruded into the vertebral canal. This is an update of a review first published in 2006.

OBJECTIVES

To compare the outcomes of surgical with non-surgical treatment for thoracolumbar burst fractures without neurological deficit.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (October 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 8), MEDLINE (1946 to October 2012), EMBASE (1980 to October 2012) and the Chinese Biomedical Literature Database (1978 to October 2012). We also searched trial registers and reference lists of articles.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing surgical with non-surgical treatment of thoracolumbar burst fractures without neurological deficit.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risk of bias and extracted data independently. Only limited pooling of data was done.

MAIN RESULTS

We included two trials that compared surgical with non-surgical treatment for patients with thoracolumbar burst fractures without neurological deficit. These recruited a total of 87 participants and reported outcomes for 79 participants at follow-up of two years or more. Both trials were judged at unclear risk of selection bias and at high risk of performance and detection biases, resulting from lack of blinding.The two trials reported contrasting results for pain and function-related outcomes at final follow-up, and numbers returning to work. One trial found less pain (mean difference (MD) -15.09 mm, 95% CI -27.81 to -2.37; 100 mm visual analogue scale), and better function based on the Roland and Morris disability questionnaire results (MD -5.87, 95% CI -10.10 to -1.64; 24 points = maximum disability) in the surgical group. Based on the same outcome measures, the other trial found the surgical group had more pain (MD 13.60 mm, 95% CI -0.31 to 27.51) and worse function (MD 4.31, 95% CI 0.54 to 8.08). Neither trial reported a statistically significant difference in return to work. There were greater numbers of participants with complications in the surgical group of both trials (21/41 versus 6/38; RR 2.85, 95% CI 0.83 to 9.75; 2 trials), and only participants of this group had subsequent surgery, involving implant removal either for complications or as a matter of course. One trial reported that surgery was over four times more costly than non-surgical treatment.

AUTHORS' CONCLUSIONS

The contradictory evidence provided by two small and potentially biased randomised controlled trials is insufficient to conclude whether surgical or non-surgical treatment yields superior pain and functional outcomes for people with thoracolumbar burst fractures without neurological deficit. It is likely, however, that surgery is associated with more early complications and the need for subsequent surgery, as well as greater initial healthcare costs.