Five-year clinical and radiological results of combined anteroposterior stabilization of thoracolumbar fractures

The AO Spine Thoracolumbar Injury Classification System and Treatment Algorithm in Decision Making for Thoracolumbar Burst Fractures Without Neurologic Deficit

STUDY DESIGN

Prospective Observational Study.

OBJECTIVE

To determine the alignment of the AO Spine Thoracolumbar Injury Classification system and treatment algorithm with contemporary surgical decision making.

METHODS

183 cases of thoracolumbar burst fractures were reviewed by 22 AO Spine Knowledge Forum Trauma experts. These experienced clinicians classified the fracture morphology, integrity of the posterior ligamentous complex and degree of comminution. Management recommendations were collected.

RESULTS

There was a statistically significant stepwise increase in rates of operative management with escalating category of injury (P < .001). An excellent correlation existed between recommended expert management and the actual treatment of each injury category: A0/A1/A2 (OR 1.09, 95% CI 0.70-1.69, P = .71), A3/4 (OR 1.62, 95% CI 0.98-2.66, P = .58) and B1/B2/C (1.00, 95% CI 0.87-1.14, P = .99). Thoracolumbar A4 fractures were more likely to be surgically stabilized than A3 fractures (68.2% vs 30.9%, P < .001). A modifier indicating indeterminate ligamentous injury increased the rate of operative management when comparing type B and C injuries to type A3/A4 injuries (OR 39.19, 95% CI 20.84-73.69, P < .01 vs OR 27.72, 95% CI 14.68-52.33, P < .01).

CONCLUSIONS

The AO Spine Thoracolumbar Injury Classification system introduces fracture morphology in a rational and hierarchical manner of escalating severity. Thoracolumbar A4 complete burst fractures were more likely to be operatively managed than A3 fractures. Flexion-distraction type B injuries and translational type C injuries were much more likely to have surgery recommended than type A fractures regardless of the M1 modifier. A suspected posterior ligamentous injury increased the likelihood of surgeons favoring surgical stabilization.

Anterior Column Reconstruction of Destructive Vertebral Osteomyelitis at the Thoracolumbar Spine with an Expandable Vertebral Body Replacement Implant: A Retrospective, Monocentric Radiological Cohort Analysis of 24 Cases

BACKGROUND

Vertebral osteomyelitis (VO) often necessitates surgical intervention due to bone loss-induced spinal instability. Anterior column reconstruction, utilizing expandable vertebral body replacement (VBR) implants, is a recognized approach to restore stability and prevent neurological compromise. Despite various techniques, clinical evidence regarding the safety and efficacy of these implants in VO remains limited.

METHODS

A retrospective cohort analysis, spanning 2000 to 2020, was conducted on 24 destructive VO cases at a Level 1 orthopedic trauma center. Diagnosis relied on clinical, radiological, and microbiological criteria. Patient demographics, clinical presentation, surgical interventions, and radiological outcomes were assessed.

RESULTS

The study included 24 patients (62.5% male; mean age 65.6 ± 35.0 years), with 58% having healthcare-associated infections (HAVO). The mean radiological follow-up was 137.2 ± 161.7 weeks. Surgical intervention significantly improved the bi-segmental kyphotic endplate angle (BKA) postoperatively (mean -1.4° ± 13.6°). However, a noticeable loss of correction was observed over time. The study reported a mortality rate of 1/24.

CONCLUSIONS

Anterior column reconstruction using expandable VBR effectively improved local spinal alignment in destructive VO. However, the study underscores the necessity for prolonged follow-up and continuous research to refine surgical techniques and postoperative care. Addressing long-term complications and refining surgical approaches will be pivotal as the field progresses.

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.

Risk Factors for Cage Subsidence in Minimally Invasive Lateral Corpectomy for Osteoporotic Vertebral Fractures

Introduction

This study aims to investigate risk factors for cage subsidence following minimally invasive lateral corpectomy for osteoporotic vertebral fractures.

Methods

Eight males and 13 females (77.2±6.0 years old) with osteoporotic vertebral fractures who underwent single corpectomy using a wide-footprint expandable cage with at least a 1-year follow-up were retrospectively included. The endplate cage (EC) angle was defined as the angle between the vertebral body's endplate and the cage's base on the cranial and caudal sides. A sagittal computed tomography scan was performed immediately after surgery and at the final follow-up, with cage subsidence defined as subsidence of ≥2 mm on the cranial or caudal side. Risk factors were analyzed by dividing cases into groups with (n=6) and without (n=15) cage subsidence.

Results

No significant differences were noted in age, bone mineral density, number of fixed vertebrae, sagittal parameters, preoperative and final kyphosis angle, amount of kyphosis angle correction, bone union, screw loosening, and number of other vertebral fractures preoperatively and 1-year postoperatively between the two groups. No difference was noted in cranial EC angle, but a significant difference was noted in caudal EC angle in the group with (10.7±4.1°) and without (4.7±4.2°) subsidence (P=0.008). Logistic regression analysis with the dependent variable as presence or absence of subsidence showed that caudal EC angle (>7.5°) was a significant factor (odds ratio: 20, 95% confidence interval: 1.655-241.7, P=0.018).

Conclusions

In minimally invasive lateral corpectomy for osteoporotic vertebral fractures, a cage tilted more than 7.5° to the caudal vertebral endplate is a risk factor for cage subsidence. The cage should be placed as perpendicular to the endplate as possible, especially to the caudal vertebral body, to avoid cage subsidence.

Long-term outcomes of the nano-hydroxyapatite/polyamide-66 cage versus the titanium mesh cage for anterior reconstruction of thoracic and lumbar corpectomy: a retrospective study with at least 7 years of follow-up

BACKGROUND

The nano-hydroxyapatite/polyamide-66 (n-HA/PA66) cage is a biomimetic cage with a lower elastic modulus than the titanium mesh cage (TMC). This study aimed to compare the long-term outcomes of the n-HA/PA66 cage and TMC in the anterior reconstruction of thoracic and lumbar fractures.

METHODS

We retrospectively studied 113 patients with acute traumatic thoracic or lumbar burst fractures, comprising 60 patients treated with the TMC and 53 treated with the n-HA/PA66 cage for anterior reconstruction following single-level corpectomy. The radiographic data (cage subsidence, fusion status, segmental sagittal alignment) and clinical data (visual analogue scale (VAS) for pain and Oswestry Disability Index (ODI) for function) were evaluated preoperatively, postoperatively, and at final follow-up after a minimum 7-year period.

RESULTS

The n-HA/PA66 and TMC groups had similar final fusion rates (96.2% vs. 95.0%). The cage subsidence at final follow-up was 2.3 ± 1.6 mm with subsidence of more than 3 mm occurring in 24.5% in the n-HA/PA66 group, which was significantly lower than the respective values of 3.9 ± 2.5 mm and 58.3% in the TMC group. The n-HA/PA66 group also had better correction of the bisegmental kyphotic angle than the TMC group (7.1° ± 7.5° vs 1.9° ± 8.6°, p < 0.01), with lower loss of correction (2.9° ± 2.5° vs 5.2° ± 4.1°, p < 0.01). The mean ODI steadily decreased after surgery in both groups. At final follow-up, the ODI and VAS were similar in the TMC and n-HA/PA66 groups.

CONCLUSIONS

The n-HA/PA66 cage is associated with excellent radiographic fusion, better maintenance of the height of the fused segment, and better correction of kyphosis than the TMC during 7 years of follow-up after one-level anterior corpectomy. With the added benefit of radiolucency, the n-HA/PA66 cage may be superior to the TMC in anterior reconstruction of thoracic or lumbar fractures.

Increased incidence of vertebral fractures in German adults from 2009 to 2019 and the analysis of secondary diagnoses, treatment, costs, and in-hospital mortality

The aim of this cross-sectional study was to present the nationwide rates of hospitalized patients with vertebral fractures over one decade and to comprehensively analyze the treatment characteristics and direct costs incurred in 2019. Therefore, the trends in the incidence rate were quantified based on annual ICD-10 diagnosis codes from all German medical facilities between 2009 and 2019, provided by the Federal Statistical Office (Destatis). The ICD-10 Codes "S12.0-2; S22.0-; S32.0-, and S32.1-2" were evaluated. The relative change from 2009 through 2019 was determined. Using data from the Institute for Hospital Remuneration Systems (InEK) for 2019 the secondary diagnoses, OPS-codes, intensive care unit (ICU) treatment, in-hospital mortality, the proportion of G-DRGs and cumulative costs were evaluated. The documented number of vertebral fractures increased by 45.6% between 2009 and 2019 to an incidence of 150.7 per 100,000 inhabitants. The lumbar spine was most commonly affected with an incidence of 70.5/100,000 inhabitants in 2019 (46.8% of all vertebral fractures). The highest increases were seen in the numbers of subaxial cervical fractures (+ 121.2%) and sacral fractures (+ 306.6%). Of all vertebral fractures in 2019, 63.7% were diagnosed in women and 69.0% in patients aged 70 years or older. Osteoporosis was documented in 17.9% of cases as a concomitant diagnosis. In 10.1% of all cases, an ICU treatment was documented. The in-hospital mortality was 2.0% in 2019. I68D was the most frequently used G-DRG code, accounting for 33.3% of cases. The total direct costs for inpatient treatment in 2019 amounted to €589,205,715. The evaluation of 955,091 vertebral fractures showed a sharp increase in the nation-wide incidence rate. The presented age and sex distribution, the comorbidity profile and the in-hospital mortality rate indicate the importance of comprehensive geriatric assessment and emphasize the need for spinal care centers to be established.

Extended salvage surgery after high-dose chemoradiation therapy for tumors in the cervico-thoracic junction with invasion of the chest wall and the spine: a case series

The treatment of malignant tumors localized in the upper thoracic cavity and involving the spine at the cervico-thoracic junction (CTJ) is challenging. We report on three patients with malignant tumors invading the thoracic inlet and the spine at the CTJ. All three patients underwent radical tumor resection and 360° spine fusion following the posterior pedicle screw instrumentation and anterior vertebrectomy combined with implantation of an expandable titanium cage. Postoperatively, a mild paresis with hypesthesia of the ipsilateral arm occurred in one patient because of brachial plexus involvement. Two patients were still alive at last follow-up after 83 and 143 months, the third patient succumbed to tumor progression 13 months after extended salvage surgery. We display the possibilities of extended 'salvage' therapy in well-selected patients that were deemed hopeless regarding neurological function, biomechanical stability and tumor control after multiple courses of combined radio-chemotherapy.

Comparison of mini-open, anteroinferior psoas approach and mini-open, direct lateral transpsoas approach for lumbar burst fractures: A retrospective cohort study

OBJECTIVE

We evaluated the effect of a novel modified OLIF technique (anteroinferior psoas approach, AIPA) for anterior decompression reconstruction in lumbar burst fractures, and compared the clinical, radiological outcomes and approach-related complications with the mini-open, lateral transpsoas approach (LTPA).

METHODS

From March 2016 to November 2019, 68 patients with lumbar burst fractures underwent one-stage monosegmental posterior/anterior surgery from L1-L4 segments. 35 patients included in AIPA and 33 patients in LTPA group underwent anterior decompression reconstruction. The clinical, radiological and functional evaluation outcomes were recorded during the 16-60 months follow-up period.

RESULTS

At the latest follow up, neurological state of one or more ASIA grades were achieved in AIPA (90.9%) and LTPA group (94.9%). No significant differences were noted between the two groups regarding preoperative and postoperative Cobbs angle. The surgery time (192.29 vs. 230.47 min, P = 0.02) in AIPA group was better compared with LTPA. The AIPA showed better improvement on Oswestry Disability Index (43.4% vs. 60.8%, P < 0.05) and Mental Component Score (49.0% vs. 43.7%, P < 0.05) one month after surgery, but no difference at the latest follow-up. 10 patients (9 in LTPA and 1 in AIPA) experienced temporary motor deficits in hip flexor and groin or thigh numbness, which disappeared six months after surgery.

CONCLUSIONS

Compared with lateral transpsoas approach, anterior decompression reconstruction via mini-open, anteroinferior psoas approach was a safe and less invasive approach, with fewer approach-related complications in the treatment for unstable lumbar burst fractures.

Surgical fixation of pathologic and traumatic spinal fractures using single position surgery technique in lateral decubitus position

STUDY DESIGN

Retrospective Case Series.

OBJECTIVES

This study aims to determine complications, readmission, and revision surgery rates in patients undergoing single position surgery (SPS) for surgical treatment of traumatic and pathologic thoracolumbar fractures.

METHODS

A multi-center review of patients who underwent SPS in the lateral decubitus position (LSPS) for surgical management of traumatic or pathologic thoracolumbar fractures between January 2016 and May 2020 was conducted. Operative time, estimated blood loss (EBL), intraoperative complications, postoperative complications, readmissions, and revision surgeries were collected.

RESULTS

A total of 12 patients with a mean age of 45 years (66.67% male) were included. The majority of patients underwent operative treatment for acute thoracolumbar trauma (66.67%) with a mean injury severity score (ISS) of 16.71. Mean operative time was 175.5 min, mean EBL of 816.67 cc. Five patients experienced a complication, two of which required revision surgery for additional decompression during the initial admission. All ambulatory patients were mobilized on postoperative day 1. The mean hospital length of stay (LOS) was 9.67 days.

CONCLUSION

The results of this case series supports LSPS as a feasible alternative to the traditional combined anterior-posterior approach for surgical treatment of pathologic and thoracolumbar fractures. These results are similar to reductions in operative time, EBL, and LOS seen in the elective spine literature with LSPS.

LEVEL OF EVIDENCE

IV.

Classification and Radiological Diagnosis of Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

The aim of this review to determine recommendations for classification and radiological diagnosis of thoracolumbar spine fractures. Recommendation was made through a literature review of the last 10 years. The statements created by the authors were discussed and voted on during 2 consensus meetings organized by the WFNS (World Federation Neurosurgical Societies) Spine Committee. The literature review was yielded 256 abstracts, of which 32 were chosen for full-text analysis. Thirteen papers evaluated the reliability of a classification system by our expert members and were also chosen in this guideline analysis. This literature review-based recommendation provides the classification and radiologic diagnosis in thoracolumbar spine fractures that can elucidate the management decision-making in clinical practice.

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

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

Radiological and mid- to long-term patient-reported outcome after stabilization of traumatic thoraco-lumbar spinal fractures using an expandable vertebral body replacement implant

Background

For the treatment of unstable thoraco-lumbar burst fractures, a combined posterior and anterior stabilization instead of a posterior-only instrumentation is recommend in the current literature due to the instability of the anterior column. Data on restoring the bi-segmental kyphotic endplate angle (BKA) with expandable vertebral body replacements (VBR) and on the mid- to long-term patient-reported outcome measures (PROM) is sparse.

Methods

A retrospective cohort study of patients with traumatic thoraco-lumbar spinal fractures treated with an expandable VBR implant (Obelisc™, Ulrich Medical, Germany) between 2001 and 2015 was conducted. Patient and treatment characteristics were evaluated retrospectively. Radiological data acquisition was completed pre- and postoperatively, 6 months and at least 2 years after the VBR surgery. The BKA was measured and fusion-rates were assessed. The SF-36, EQ-5D and ODI questionnaires were evaluated prospectively.

Results

Ninety-six patients (25 female, 71 male; age: 46.1 ± 12.8 years) were included in the study. An AO Type A4 fracture was seen in 80/96 cases (83.3%). Seventy-three fractures (76.0%) were located at the lumbar spine. Intraoperative reduction of the BKA in n = 96 patients was 10.5 ± 9.4° (p < 0.01). A loss of correction of 1.0 ± 2.8° at the first follow-up (t1) and of 2.4 ± 4.0° at the second follow-up (t2) was measured (each p < 0.05). The bony fusion rate was 97.9%. The total revision rate was 4.2%. Fifty-one patients (53.1% of included patients; age: 48.9 ± 12.4 years) completed the PROM questionnaires after 106.4 ± 44.3 months and therefore were assigned to the respondent group. The mean ODI score was 28.2 ± 18.3%, the mean EQ-5D VAS reached 60.7 ± 4.1 points. Stratified SF-36 results (ISS < and ≥ 16) were lower compared to a reference population.

Conclusion

The treatment of traumatic thoraco-lumbar fractures with an expandable VBR implant lead to a high rate of bony fusion. A significant correction of the BKA could be achieved and no clinically relevant loss of reduction occurred during the follow-up. Even though health related quality of life did not reach the normative population values, overall satisfactory results were reported.

Establishing the Injury Severity of Subaxial Cervical Spine Trauma: Validating the Hierarchical Nature of the AO Spine Subaxial Cervical Spine Injury Classification System

STUDY DESIGN

Global cross-sectional survey.

OBJECTIVE

The aim of this study was to validate the AO Spine Subaxial Cervical Spine Injury Classification by examining the perceived injury severity by surgeon across AO geographical regions and practice experience.

SUMMARY OF BACKGROUND DATA

Previous subaxial cervical spine injury classifications have been limited by subpar interobserver reliability and clinical applicability. In an attempt to create a universally validated scheme with prognostic value, AO Spine established a subaxial cervical spine injury classification involving four elements: injury morphology, facet injury involvement, neurologic status, and case-specific modifiers.

METHODS

A survey was sent to 272 AO Spine members across all geographic regions and with a variety of practice experience. Respondents graded the severity of each variable of the classification system on a scale from zero (low severity) to 100 (high severity). Primary outcome was to assess differences in perceived injury severity for each injury type over geographic regions and level of practice experience.

RESULTS

A total of 189 responses were received. Overall, the classification system exhibited a hierarchical progression in subtype injury severity scores. Only three subtypes showed a significant difference in injury severity score among geographic regions: F3 (floating lateral mass fracture, P = 0.04), N3 (incomplete spinal cord injury, P = 0.03), and M2 (critical disk herniation, P = 0.04). When stratified by surgeon experience, pairwise comparison showed only two morphological subtypes, B1 (bony posterior tension band injury, P = 0.02) and F2 (unstable facet fracture, P = 0.03), and one neurologic subtype (N3, P = 0.02) exhibited a significant difference in injury severity score.

CONCLUSION

The AO Spine Subaxial Cervical Spine Injury Classification System has shown to be reliable and suitable for proper patient management. The study shows this classification is substantially generalizable by geographic region and surgeon experience, and provides a consistent method of communication among physicians while covering the majority of subaxial cervical spine traumatic injuries.Level of Evidence: 4.

Surgical Management of Thoracolumbar Burst Fractures: Surgical Decision-making Using the AOSpine Thoracolumbar Injury Classification Score and Thoracolumbar Injury Classification and Severity Score

The management of thoracolumbar burst fractures is controversial with no universally accepted treatment algorithm. Several classification and scoring systems have been developed to assist in surgical decision-making. The most widely accepted are the Thoracolumbar Injury Classification and Severity Score (TLICS) and AOSpine Thoracolumbar Injury Classification Score (TL AOSIS) with both systems designed to provide a simple objective scoring criteria to guide the surgical or nonsurgical management of complex injury patterns. When used in the evaluation and treatment of thoracolumbar burst fractures, both of these systems result in safe and consistent patient care. However, there are important differences between the 2 systems, specifically in the evaluation of the complete burst fractures (AOSIS A4) and patients with transient neurological deficits (AOSIS N1). In these circumstances, the AOSpine system may more accurately capture and characterize injury severity, providing the most refined guidance for optimal treatment. With respect to surgical approach, these systems provide a framework for decision-making based on patient neurology and the status of the posterior tension band. Here we propose an operative treatment algorithm based on these fracture characteristics as well as the level of injury.

Influence of endplate size and implant positioning of vertebral body replacements on biomechanics and outcome

BACKGROUND

Spinal stabilization by an anterior vertebral body replacement is frequently used in patients suffering from destroyed vertebral bodies. The aim of this study was to analyse (i) the choice of endplate size and positioning of vertebral body replacements in daily patient care and (ii) if these factors have an influence on clinical and radiological outcomes.

METHOD

Patients' outcomes were analysed three years after vertebral body replacement implantation using the visual analogue scale spine score. Safe zones on the vertebral body endplates were defined. Overall endplate coverage and implant subsidence were evaluated by CT and X-ray. Compression tests were performed on 22 lumbar vertebral bodies to analyse endplates sizes' influence on subsidence.

FINDING

Mean coverage of the vertebral body's superior and inferior endplates by the vertebral body replacement was 27.8% and 30.8%, respectively. Mean overlap of the safe zone by the implant was 49.8% and 40.6%. Mean subsidence was 1.1 ± 1.2 mm, but it did not have any effect on the outcome. In the compression tests, no significant difference (p = 0.468) was found between the two endplate sizes.

INTERPRETATION

Coverage of vertebral body endplates and positioning of implants in the safe zone did not entirely comply with the given recommendations. The amount of endplate coverage had no influence on subsidence or long-term outcomes in daily patient care. On the other hand, correct positioning of the implant may influence its subsidence.

Isolated unstable burst fractures of the fifth lumbar vertebra: functional and radiological outcome after posterior stabilization with reconstruction of the anterior column: About 6 cases and literature review

INTRODUCTION

L5 burst fractures represent a small percentage of all spine fractures. Treatment strategy has not yet been standardized. Anatomical features and their biomechanical characteristics create fracture patterns which differ from those at the thoracolumbar junction. The objective of this study was to evaluate L5 burst fracture surgical treatment outcomes after posterior stabilization and reconstruction of the anterior column.

PATIENTS AND METHODS

Six patients with fifth lumbar isolated unstable burst fractures were analyzed. Medical records, radiographs, and clinical scores were obtained. The results were evaluated based on restoration of vertebral body height, spinal lordosis/kyphosis, canal compromise and sagittal alignment at several phases of treatment.

RESULTS

No patient showed neurologic deterioration, regardless of treatment. The median preoperative anterior vertebral height was 41mm and postoperative was 48mm. The median preoperative kyphotic angle as measured by Cobb angle (local and regional) was 21.5 degrees and 33 degrees which improved respectively by 7.5 and 5.5 degrees following instrumentation. The median amount of backward protrusion of bony fragment into the canal was measured at 67% preoperatively and at 35% postoperatively. There were no pseudarthrosis and anterior arthrodesis solid fusion was visible in all cases. There were a sagittal alignment restoration. At one year of follow up, fusion was obtained in all the cases, all patients had minimal to moderate disability using Oswestry Disability Index. The ability to return to work revealed a good-to-excellent long-term result.

DISCUSSION

The results of treatment of 5th lumbar unstable burst fractures with posterior stabilization and reconstruction of the anterior column show benefit on durable functional outcome, spine stabilization and radiologic parameters.

LEVEL OF EVIDENCE

IV, retrospective study.

In vitro comparison of personalized 3D printed versus standard expandable titanium vertebral body replacement implants in the mid-thoracic spine using entire rib cage specimens

BACKGROUND

Expandable titanium implants have proven their suitability as vertebral body replacement device in several clinical and biomechanical studies. Potential stabilizing features of personalized 3D printed titanium devices, however, have never been explored. This in vitro study aimed to prove their equivalence regarding primary stability and three-dimensional motion behavior in the mid-thoracic spine including the entire rib cage.

METHODS

Six fresh frozen human thoracic spine specimens with intact rib cages were loaded with pure moments of 5 Nm while performing optical motion tracking of all vertebrae. Following testing in intact condition (1), the specimens were tested after inserting personalized 3D printed titanium vertebral body replacement implants (2) and the two standard expandable titanium implants Obelisc™ (3) and Synex™ (4), each at T6 level combined with posterior pedicle screw-rod fixation from T4 to T8.

FINDINGS

No significant differences (P < .05) in primary and secondary T1-T12 ranges of motion were found between the three implant types. Compared to the intact condition, slight decreases of the range of motion were found, which were significant for Synex™ in primary flexion/extension (-17%), specifically at T3-T4 level (-46%), primary lateral bending (-18%), and secondary lateral bending during primary axial rotation (-53%). Range of motion solely increased at T8-T9 level, while being significant only for Obelisc™ (+35%).

INTERPRETATION

Personalized 3D printed vertebral body replacement implants provide a promising alternative to standard expandable devices regarding primary stability and three-dimensional motion behavior in the mid-thoracic spine due to the stabilizing effect of the rib cage.

Traumatic Fractures of the Thoracic Spine

The majority of traumatic vertebral fractures occur at the thoracolumbar junction and the lumbar spine and less commonly at the mid-thoracic and upper thoracic spine. In accordance, a high number of articles are dealing with thoracolumbar fractures focusing on the thoracolumbar junction. Nonetheless, the biomechanics of the thoracic spine differ from the thoracolumbar junction and the lumbar vertebral spine. The aim of this review is to screen the literature dealing with acute traumatic thoracic vertebral fractures in patients with normal bone quality. Thereby, the diagnostic of thoracic vertebral body fractures should include a CT examination. Ideally, the CT should include the whole thoracic cage particularly in patients suffering high energy accidents or in those with clinical suspicion of concomitant thoracic injuries. Generally, concomitant thoracic injuries are frequently seen in patients with thoracic spine fractures. Particularly sternal fractures cause an increase in fracture instability. In case of doubt, long segment stabilization is recommended in patients with unstable mid- und upper thoracic fractures, particularly in those patients with a high grade of instability.

Early versus delayed corpectomy in thoracic and lumbar spine trauma. A long-term clinical and radiological retrospective study

AND BACKGROUND DATA

Many authors have demonstrated the necessity of reconstruction of the anterior column in spinal trauma with vertebral body collapse or nonunion. There is no publication comparing the result depending on the time between trauma and anterior reconstruction of the vertebral body.

OBJECTIVE

To compare long-term clinical and radiological results between early and late anterior vertebral body reconstruction with expandable cages in patients with thoracic and lumbar spine trauma.

HYPOTHESIS

An early anterior reconstruction of thoracolumbar fractures provides better clinical and radiological outcomes than a delayed one.

MATERIALS AND METHODS

A retrospective clinical study was carried out with 44 consecutive patients with injuries of the thoracic and lumbar spine treated operatively with combined posterior stabilization and anterior reconstruction with an expandable implant for vertebral body replacement. All patients were evaluated with EOS full-spine radiograph and CT-scan. The mean follow-up was 5.1 years. Clinical result was evaluated with ODI, SF12, VAS back pain, return to work and sport. Radiological result was evaluated with regional kyphosis angle (RKA) evolution, fusion rate and sagittal alignment. In Group A, twenty-nine patients underwent an early anterior reconstruction within 3 weeks after trauma. The indication of vertebral body reconstruction was placed after post-operative CT-scan for a Mc Cormack score≥7. In Group B, fifteen patients underwent a late anterior reconstruction after diagnosis of nonunion by the combination of pain and CT-scan after 1 year.

RESULTS

Clinical scores and scales were significantly better for patients operated early in Group A. Return to work and activities were significantly more important in Group A too. The mean RKA correction with posterior reduction was 9.3°. The secondary anterior approach permit to reduce 2.9° more. At last follow-up, the loss of reduction was 4.3°. There was no significant difference between groups for those results. No difference in fusion rate was observed between groups. There was no significant difference between groups in the sagittal alignment excepted for SVA that was higher for Group B while remaining under a normal value of 50mm.

CONCLUSION

Early anterior vertebral body reconstruction for fractures gives better clinical results than delayed reconstruction for patients with diagnosis of nonunion in patients with thoracic and lumbar spine trauma. Moreover, the shorter the time from trauma to operation, the better the sagittal reduction of kyphosis. The use of expandable titanium cage is a good way to perform and maintain this reduction.

LEVEL OF EVIDENCE

IV, retrospective study.

Thoracoscopic Correction of Post-traumatic Kyphosis with an Expandable Cage: Radiologic and Patient-Reported Outcomes

Study Design

Retrospective cohort study.

Purpose

To determine the long-term functional and radiological outcomes after thoracoscopic post-traumatic kyphosis (PTK) correction (PTKC).

Overview of Literature

PTK after insufficient treatment of unstable fractures usually presents with pain and decreased back function. The results of PTKC using a minimally invasive thoracoscopic approach with an anterior titanium cage have not previously been reported.

Methods

Data in this study were collected from all patients who underwent thoracoscopic PTKC with an expandable cage between 2007 and 2017. Kyphosis and intervertebral body height were assessed on radiographic material. Quality of life (QOL) and functional outcome scores were determined by the Euroquol 5 dimensions (EQ5D) and the Oswestry Disability Index (ODI). Additionally, satisfaction and subjective symptom improvement were determined.

Results

Fourteen patients were treated for symptomatic PTK using a combined thoracoscopic anterior and posterior approach. Nine patients received initial conservative fracture treatment and five patients underwent initial posterior fracture fixation. All patients presented with pain and without neurologic injury. The mean time between injury and PTKC was 15.4 months. Cobb angle (CA) improved with 10.6° immediately after PTKC. During the first follow-up, 4.8° kyphosis correction was lost, but CAs remained stable at longer follow-up. Bony fusion was achieved in 92% of the patients after 16 months. The majority of patients reported an improvement of symptoms 85 months after surgery, satisfaction with and willingness to undergo the procedure again. The mean EQ5D index score was 0.71 and the mean ODI score was 22.3.

Conclusions

The results of minimally invasive thoracoscopic PTKC using an expandable cage were satisfactory. The majority of the patients were satisfied after treatment and no neurological complications occurred. Functional and QOL scores were fairly good. Whereas some postoperative kyphosis correction was lost over time, bony fusion was achieved in the majority of the patients. The thoracoscopic approach minimizes surgical morbidity, does not lead to serious complications, and provides a good option for PTKC.

Biomechanical Study of a Novel, Expandable, Non-Metallic and Radiolucent CF/PEEK Vertebral Body Replacement (VBR)

Vertebral body replacement is well-established to stabilize vertebral injuries due to trauma or cancer. Spinal implants are mainly manufactured by metallic alloys; which leads to artifacts in radiological diagnostics; as well as in radiotherapy. The purpose of this study was to evaluate the biomechanical data of a novel carbon fiber reinforced polyetheretherketone (CF/PEEK) vertebral body replacement (VBR). Six thoracolumbar specimens were tested in a six degrees of freedom spine tester. In all tested specimens CF/PEEK pedicle screws were used. Two different rods (CF/PEEK versus titanium) with/without cross connectors and two different VBRs (CF/PEEK prototype versus titanium) were tested. In lateral bending and flexion/extension; range of motion (ROM) was significantly reduced in all instrumented states. In axial rotation; the CF/PEEK combination (rods and VBR) resulted in the highest ROM; whereas titanium rods with titanium VBR resulted in the lowest ROM. Two cross connectors reduced ROM in axial rotation for all instrumentations independently of VBR or rod material. All instrumented states in all planes of motion showed a significantly reduced ROM. No significant differences were detected between the VBR materials in all planes of motion. Less rigid CF/PEEK rods in combination with the CF/PEEK VBR without cross connectors showed the smallest reduction in ROM. Independently of VBR and rod material; two cross connectors significantly reduced ROM in axial rotation. Compared to titanium rods; the use of CF/PEEK rods results in higher ROM. The stiffness of rod material has more influence on the ROM than the stiffness of VBR material.

[Thoracolumbar spinal fractures in the elderly : Classification and treatment]

Thoracolumbar fractures in the elderly are frequently associated with osteoporosis. Osteoporosis can cause fractures or be a significant comorbidity in traumatic fractures. The OF classification is based on conventional X‑ray, computed tomography (CT) scan and magnetic resonance imaging (MRI). It is easy to use and provides a clinically relevant classification of the fractures. Therapeutic decisions are made based on the clinical and radiological situation by using the OF score. The score takes the current clinical situation including patient-specific comorbidities into consideration. The treatment recommendations are based on an expert consensus opinion and include conservative and operative options. If surgery is indicated, vertebral body augmentation, percutaneous stabilization and even open surgery can be used.

Retroperitoneal Extrapleural Approach for Corpectomy of the First Lumbar Vertebra : Technique and Outcome

Objective

Corpectomy of the first lumbar vertebra (L1) for the management of different L1 pathologies can be performed using either an anterior or posterior approach. The aim of this study was to evaluate the usefulness of a retroperitoneal extrapleural approach through the twelfth rib for performing L1 corpectomy.

Methods

Thirty consecutive patients underwent L1 corpectomy between 2010 and 2016. The retroperitoneal extrapleural approach through the 12th rib was used in all cases to perform single-stage anterior L1 corpectomy, reconstruction and anterior instrumentation, except for in two recurrent cases in which posterior fixation was added. Visual analogue scale (VAS) was used for pain intensity measurement and ASIA impairment scale for neurological assessment. The mean follow-up period was 14.5 months.

Results

The sample included 18 males and 12 females, and the mean age was 40.3 years. Twenty patients (67%) had sensory or motor deficits before the surgery. The pathologies encountered included traumatic fracture in 12 cases, osteoporotic fracture in four cases, tumor in eight cases and spinal infection in the remaining six cases. The surgeries were performed from the left side, except in two cases. There was significant improvement of back pain and radicular pain as recorded by VAS. One patient exhibited postoperative neurological deterioration due to bone graft dislodgement. All patients with deficits at least partially improved after the surgery. During the follow-up, no hardware failures or losses of correction were detected.

Conclusion

The retroperitoneal extrapleural approach through the 12th rib is a feasible approach for L1 corpectomy that can combine adequate decompression of the dural sac with effective biomechanical restoration of the compromised anterior load-bearing column. It is associated with less pulmonary complication, no need for chest tube, no abdominal distention and rapid recovery compared with other approaches.

Subsidence Rates After Lateral Lumbar Interbody Fusion: A Systematic Review

OBJECTIVE

The evidence regarding the consequences of subsidence with lateral lumbar interbody fusion (LLIF) has been sparse. The objective of this study is to calculate the incidence of subsidence and reoperation for subsidence after LLIF. A secondary outcome examined the quantitative degree of subsidence by calculating the percent change in the height of the intervertebral space secondary to interbody subsidence at various postoperative follow-up times.

METHODS

Following the MOOSE (Meta-analysis [and Systematic Review] Of Observational Studies in Epidemiology) guidelines, a systematic review searched for all cohort studies that focused on subsidence rates after LLIF, including extreme lateral interbody fusions (XLIFs) and direct lateral interbody fusion. Neoplastic, infectious, and/or metabolic indications for LLIF were similarly excluded because these diseases may compromise bone quality and, thus, confound the rate of cage subsidence. Corpectomies were removed from the systematic review because 1) indications for removal of vertebral body typically reflect those excluded diseases and 2) subsidence refers to a different biomechanical process.

RESULTS

This systematic review identified a subsidence incidence with LLIF of 10.3% (N = 141/1362 patients in 14 articles) and reoperation rate for subsidence of 2.7% (N = 41/1470 patients in 16 articles). In the secondary outcome measure, the disc height decreased from 5.6% after 3 months, 6.0% after 6 months, and 10.2% after 12 months, to 8.9% after 24 months (P < 0.001).

CONCLUSIONS

Subsidence after LLIF carries a nonnegligible risk that may be incorporated in surgical consent discussions in selected patients.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Combined anteroposterior fixation using a titanium cage versus solely posterior fixation for traumatic thoracolumbar fractures: A systematic review and meta-analysis

Study Design:

Systematic review with meta-analysis.

Objective:

Additional anterior stabilization might prevent posterior implant failure, but over time, the disadvantageous of bone grafts have become evident. The objective of this systematic review was to compare risks and advantages of additional anterior stabilization with a titanium cage to solely posterior fixation for traumatic thoracolumbar fractures.

Methods:

An electronic search was performed in the literature from 1980 to March 2016. Studies comparing only posterior with anteroposterior fixation by means of a titanium cage were included in this study. Data extraction and Cochrane risk of bias assessment were done by two independent authors. In addition, the PRISMA statement was followed, and the GRADE approach was used to present results.

Results:

Of the 1584 studies, two randomized controlled trials (RCTs) and one retrospective cohort study were included in the meta-analysis. The RCTs reported evidence of high quality that anteroposterior stabilization maintained better kyphosis correction than posterior stabilization alone. However, these results were neutralized in the meta-analysis by the cohort study. Implant failure was reported by one study, in the posterior group. No differences in follow-up visual analog scale scores, neurologic improvement, and complications were found. Operation time, blood loss, and hospital stay all increased in the anteroposterior group.

Conclusions:

Patients with a highly comminuted or unstable fracture could benefit from combined anteroposterior stabilization with a titanium cage, for some evidence suggests this prevents loss of correction. However, large randomized studies still lack. There is a risk of cage subsidence, and increased perioperative risks have to be considered when choosing the optimal treatment.

Anterior Lumbar Corpectomy with Expandable Titanium Cage Reconstruction: A Case Series of 42 Patients

BACKGROUND

Burst fractures involve the anterior and middle columns with an intact posterior column. Deforming forces are magnified at areas of transition, making the thoracolumbar junction highly susceptible to injury.

METHODS

This is a retrospective review of 42 consecutive patients who underwent single-level anterior lumbar corpectomy using an obelisc expandable titanium cage and lateral fixation for traumatic lumbar burst fractures.

RESULTS

Myelopathy and sensory dysfunction were the most frequent neurologic deficits initially, occurring in 16 (38%) and 15 (36%) patients, respectively, which both decreased to 5 (13%). At follow-up, 26 patients (68%) were able to ambulate independently. No patient had significant cage displacement or needed cage replacement. Subsidence was minimal in 32 of 39 patients (82%). There were no hardware infections or surgical site infections. Options for stabilization include posterior instrumentation and fusion, anterior corpectomy with interbody fusion, and combination procedures. We believe anterior stabilization is superior because the aim is structural restoration of anterior and middle columns. The aim of posterior fixation is to replace the posterior tension band, which is not affected. There are 3 major surgical components to consider. First is anterior versus posterior decompression of the spinal canal. Second is the choice of autograft or titanium graft. Third is whether to stabilize posteriorly or anterolateral.

CONCLUSIONS

Anterior corpectomy with an expandable titanium cage and lateral rod fixation is safe and effective with minimal complications. It is a viable alternative to posterior decompression and instrumentation.

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.

Temporary short-segment pedicle screw fixation for thoracolumbar burst fractures: comparative study with or without vertebroplasty

BACKGROUND CONTEXT

Short-segment posterior spinal instrumentation for thoracolumbar burst fracture provides superior correction of kyphosis by an indirect reduction technique, but it has a high failure rate.

PURPOSE

The purpose of the study we report here was to compare outcomes for temporary short-segment pedicle screw fixation with vertebroplasty and for such fixation without vertebroplasty.

STUDY DESIGN

This is a prospective multicenter comparative study.

PATIENT SAMPLE

We studied 62 consecutive patients with thoracolumbar burst fracture who underwent short-segment posterior instrumentation using ligamentotaxis with Schanz screws with or without vertebroplasty.

OUTCOME MEASURES

Radiological parameters (Cobb angle on standing lateral radiographs) were used.

METHODS

Implants were removed approximately 1 year after surgery. Neurologic function, kyphotic deformity, canal compromise, and fracture severity were evaluated prospectively.

RESULTS

After surgery, all patients with neurologic deficit had improvement equivalent to at least one grade on the American Spinal Injury Association impairment scale and had fracture union. Kyphotic deformity was reduced significantly, and reduction of the vertebrae was maintained with and without vertebroplasty, regardless of load-sharing classification. Although no patient required additional anterior reconstruction, kyphotic change was observed at disc level mainly after implant removal with or without vertebroplasty.

CONCLUSIONS

Temporary short-segment fixation yielded satisfactory results in the reduction and maintenance of fractured vertebrae with or without vertebroplasty. Kyphosis recurrence may be inevitable because adjacent discs can be injured during the original trauma.

Instrumented Circumferential Fusion in Two Stages for Instable Lumbar Fracture: Long-Term Results of a Series of 74 Patients on Sagittal Balance and Functional Outcomes

OBJECTIVE

To report the radiologic and functional results of a multicenter, prospective case series of patients with comminuted lumbar fractures treated with 2-stage circumferential arthrodesis.

METHODS

A multicenter prospective case series of 74 patients with comminuted lumbar fractures was analyzed. The strategy entailed initial posterior osteosynthesis, followed by physical replacement with an expandable titanium cage filled with autologous bone via retroperitoneal lumbotomy. The mechanism of lesion formation and epidemiologic characteristics were recorded. Clinical and quality-of-life analyses (visual analog scale [VAS], Oswesty Disability Index [ODI], Short Form 12 [SF-12]) were performed over a minimum observation period of 1 year. Radiologic parameters, including deformity measurements, were recorded at each evaluation. Fusion was analyzed by means of a 1-year monitoring scan.

RESULTS

The mean patient age was 38.1 years, and median duration of follow-up was 2.1 years (interquartile range, 1.3-2.9). The distribution of fractures according to the Magerl classification scheme was as follows: A, 64.8%; B, 16.7%; C, 18.5%. At the last follow-up, fusion was considered certain in 57 cases (77%). The mean VAS score was 2.1 ± 1.3, mean ODI was 14.7 ± 8.0, mean SF-12 Physical Component Summary score was 43.2 ± 9.3, and mean SF-12 Mental Component Summary score was 50.8 ± 5.9. Correction of the regional sagittal deformity was significant during the postoperative period, with a mean increase in lordosis of 9.0° (P < 0.0001). The loss of mean correction at the last follow-up (-2.9°) was not significant.

CONCLUSIONS

Circumferential arthrodesis, including posterior osteosynthesis and physical replacement with an expandable cage and autologous graft, is applicable to the treatment of comminuted lumbar fractures. A high rate of fusion was obtained with significant and long-lasting correction of the sagittal deformity. Functional scores measured at 1 year suggest mild disability. The ODI, SF-12, and VAS scores were positively correlated with fusion at the last follow-up.

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.

A New Vertebral Body Replacement Strategy Using Expandable Polymeric Cages

We have developed a novel polymeric expandable cage that can be delivered via a posterior-only surgical approach for the treatment of noncontained vertebral defects. This approach is less invasive than an anterior-only or combined approach and much more cost-effective than currently used expandable metal cages. The polymeric expandable cage is composed of oligo poly(ethylene glycol) fumarate (OPF), a hydrogel that has been previously shown to have excellent nerve and bone tissue biocompatibility. OPF hydrogel cages can expand to twice their original diameter and length within a surgical time frame following hydration. Modulation of parameters such as polymeric network crosslink density or the introduction of charge to the network allowed for precise expansion kinetics. To meet specific requirements due to size variations in patient vertebral bodies, we fabricated a series of molds with varied diameters and explored the expansion kinetics of the OPF cages. Results showed a stable expansion ratio of approximately twofold to the original size within 20 min, regardless of the absolute value of the cage size. Following implantation of a dried OPF cage into a noncontained vertebral defect and its in situ expansion with normal saline, other augmentation biomaterials, such as poly(propylene fumarate) (PPF), can be injected to the lumen of the OPF cage and allowed to crosslink in situ. The OPF/PPF composite scaffold can provide the necessary rigidity and stability to the augmented spine.

Direct Midline Posterior Corpectomy and Fusion of a Lumbar Burst Fracture with Retrospondyloptosis

BACKGROUND

Traumatic burst fractures of the lumbar spine can result in significant neurologic injury and mechanical instability. The ideal surgical approach for the treatment of unstable lumbar spine burst fractures remains debatable.

CASE DESCRIPTION

A 37-year-old man presented with severe neurologic injury including loss of motor function below the level of the iliopsoas muscles bilaterally, saddle anesthesia, and absent rectal tone, after a fall from 18.28 m (60 ft). Computed tomography showed an L4 vertebral body comminuted burst fracture with complete posterior translation of L4 over L5. The patient was taken to the operating room for an L4 corpectomy and L2-S1 posterior fusion. The L4 vertebral body was visualized posterior to the posterior elements of L5 and resected in a piecemeal fashion. Because the thecal sac had been completely transected, a visible path down the L3-L4 and L4-L5 disk spaces was apparent, allowing direct posterior discectomies at these levels and completion of the L4 segment resection. The use of a direct posterior approach resulted in minimal blood loss, correction of sagittal alignment, and satisfactory outcomes comparable with the standard posterior transpedicular approach. Construct stability and solid bony fusion have been maintained for 4 years postoperatively.

CONCLUSIONS

The use of a direct midline posterior corpectomy approach may be considered for patients with lumbar burst fractures, high-grade neurologic injury, and transection of the thecal sac.

Minimally Invasive Posterior Decompression Combined With Percutaneous Pedicle Screw Fixation for the Treatment of Thoracolumbar Fractures With Neurological Deficits: A Prospective Randomized Study Versus Traditional Open Posterior Surgery

STUDY DESIGN

Prospective randomized cohort study.

OBJECTIVE

To compare the surgical results of minimally invasive posterior decompression combined with percutaneous pedicle screws fixation (minimally invasive surgery [MIS]) and posterior open surgery (OS) for the treatment of thoracolumbar fracture with neurological deficits.

SUMMARY OF BACKGROUND DATA

Thoracolumbar fracture with neurological deficits usually undergoes surgical intervention. OS can achieve satisfied results, but the main disadvantage is approach-related complications. No study, however, focused on the treatment of this disease by MIS through posterior approach.

METHODS

Sixty consecutive cases of thoracolumbar fractures with neurological deficits were randomized into MIS group and OS group. Incision length, blood loss, postoperative drainage volume, hospitalization days, blood transfusion rate, analgesic use rate, and x-ray exposure time were used to evaluate the perioperative information and Visual Analog Scale (VAS), Japanese Orthopedics Association (JOA) score, and American Spinal Injury Association grade for patients' symptom. For radiological assessment, sagittal Cobb angle, percentage of vertebral height, and vertebral wedging angle were measured.

RESULTS

Fifty-nine of sixty patients were followed-up for at least 12 months. MIS group was superior in perioperative information (P < 0.05), except in the operative time (P = 0.165) and x-ray time (P = 0.000). The operative time seemed longer in MIS group, but no significant difference was found. The x-ray time was significantly higher in MIS group. The mean Visual Analog Scale and Japanese Orthopedics Association scores of the final follow-up in MIS group were better than that in OS group (P < 0.05). Patients in both group achieved a similar neurological recovery according to American Spinal Injury Association grade (P = 0.760). A broken screw was found in one patient in MIS group and a broken rod in one patient in OS group.

CONCLUSION

MIS group has achieved the similar effect of OS group and it can minimize the approach-related complication. It also faced with some shortages, such as larger radiation dose and longer learning curve.

LEVEL OF EVIDENCE

2.

The Thoracolumbar AOSpine Injury Score

Study Design Survey of 100 worldwide spine surgeons. Objective To develop a spine injury score for the AOSpine Thoracolumbar Spine Injury Classification System. Methods Each respondent was asked to numerically grade the severity of each variable of the AOSpine Thoracolumbar Spine Injury Classification System. Using the results, as well as limited input from the AOSpine Trauma Knowledge Forum, the Thoracolumbar AOSpine Injury Score was developed. Results Beginning with 1 point for A1, groups A, B, and C were consecutively awarded an additional point (A1, 1 point; A2, 2 points; A3, 3 points); however, because of a significant increase in the severity between A3 and A4 and because the severity of A4 and B1 was similar, both A4 and B1 were awarded 5 points. An uneven stepwise increase in severity moving from N0 to N4, with a substantial increase in severity between N2 (nerve root injury with radicular symptoms) and N3 (incomplete spinal cord injury) injuries, was identified. Hence, each grade of neurologic injury was progressively given an additional point starting with 0 points for N0, and the substantial difference in severity between N2 and N3 injuries was recognized by elevating N3 to 4 points. Finally, 1 point was awarded to the M1 modifier (indeterminate posterolateral ligamentous complex injury). Conclusion The Thoracolumbar AOSpine Injury Score is an easy-to-use, data-driven metric that will allow for the development of a surgical algorithm to accompany the AOSpine Thoracolumbar Spine Injury Classification System.

Two-Nation Comparison of Classification and Treatment of Thoracolumbar Fractures: An Internet-Based Multicenter Study Among Spine Surgeons

STUDY DESIGN

Web-based multicenter study.

OBJECTIVE

The aim of the study was to assess and compare the management strategy for traumatic thoracolumbar fractures between German and Dutch spine surgeons.

SUMMARY OF BACKGROUND DATA

To date, there is no evidence-based treatment algorithm for thoracolumbar spine fractures, thereby an international controversy concerning optimal treatment exists.

METHODS

In this web-based multicenter study (www.spine.hostei.com), computed tomography scans of traumatic thoracolumbar fractures (T12-L2) were evaluated by German and Dutch spine surgeons. Supplementary case-specific information such as age, sex, height, weight, neurological status, and injury mechanism were provided.By using a questionnaire, fractures were classified according to the AO-Magerl Classification, followed by 6 questions concerning the treatment algorithm. Data were analyzed using SPSS (Version 21, 76, Chicago, IL). The interobserver agreement was determined by using Cohen κ. Statistical significance was defined as P < 0.05.

RESULTS

Twelve surgeons (6 per country) evaluated each 91 cases. The fractures were classified as AO Type A in 82% (898 votes), Type B in 14% (150 votes), and Type C in 4% (44 votes). No significant difference concerning the AO Classification between German and Dutch spine surgeons was found. Overall German spine surgeons had a lower threshold concerning the indication for surgical treatment (Ger 87% vs. NL 30%; P < 0.05). There was a consensus about operative stabilization of AO Type B and C injuries and injuries with neurologic deficit, whereas a discrepancy in the therapeutic algorithm for AO Type A fractures was observed. This difference was most pronounced regarding the indication for posterior (Ger 96.6%; NL 41.2%; P < 0.05) and circumferential stabilization (Ger 53.4%; NL 0%; P < 0.05) for burst fractures.

CONCLUSION

There is a consensus to stabilize AO Type B and C fractures, whereas country-specific differences in the treatment of Type A fractures, especially in case of burst fractures, occur. Prospective, controlled multicenter outcome studies may provide more evidence in optimal treatment for thoracolumbar fractures.

LEVEL OF EVIDENCE

2.

Is there a regional difference in morphology interpretation of A3 and A4 fractures among different cultures?

OBJECT The aim of this study was to determine if the ability of a surgeon to correctly classify A3 (burst fractures with a single endplate involved) and A4 (burst fractures with both endplates involved) fractures is affected by either the region or the experience of the surgeon. METHODS A survey was sent to 100 AOSpine members from all 6 AO regions of the world (North America, South America, Europe, Africa, Asia, and the Middle East) who had no prior knowledge of the new AOSpine Thoracolumbar Spine Injury Classification System. Respondents were asked to classify 25 cases, including 6 thoracolumbar burst fractures (A3 or A4). This study focuses on the effect of region and experience on surgeons' ability to properly classify these 2 controversial fracture variants. RESULTS All 100 surveyed surgeons completed the survey, and no significant regional (p > 0.50) or experiential (p > 0.21) variability in the ability to correctly classify burst fractures was identified; however, surgeons from all regions and with all levels of experience were more likely to correctly classify A3 fractures than A4 fractures (p < 0.01). Further analysis demonstrated that no region predisposed surgeons to increasing their assessment of severity of burst fractures. CONCLUSIONS A3 and A4 fractures are the most difficult 2 fractures to correctly classify, but this is not affected by the region or experience of the surgeon; therefore, regional variations in the treatment of thoracolumbar burst fractures (A3 and A4) is not due to differing radiographic interpretation of the fractures.

A Worldwide Analysis of the Reliability and Perceived Importance of an Injury to the Posterior Ligamentous Complex in AO Type A Fractures

Study Design Survey of spine surgeons. Objective To determine the reliability with which international spine surgeons identify a posterior ligamentous complex (PLC) injury in a patient with a compression-type vertebral body fracture (type A). Methods A survey was sent to all AOSpine members from the six AO regions of the world. The survey consisted of 10 cases of type A fractures (2 subtype A1, 2 subtype A2, 3 subtype A3, and 3 subtype A4 fractures) with appropriate imaging (plain radiographs, computed tomography, and/or magnetic resonance imaging), and the respondent was asked to identify fractures with a PLC disruption, as well as to indicate if the integrity of the PLC would affect their treatment recommendation. Results Five hundred twenty-nine spine surgeons from all six AO regions of the world completed the survey. The overall interobserver reliability in determining the integrity of the PLC was slight (kappa = 0.11). No substantial regional or experiential difference was identified in determining PLC integrity or its absence; however, a regional difference was identified (p < 0.001) in how PLC integrity influenced the treatment of type A fractures. Conclusion The results of this survey indicate that there is only slight international reliability in determining the integrity of the PLC in type A fractures. Although the biomechanical importance of the PLC is not in doubt, the inability to reliably determine the integrity of the PLC may limit the utility of the M1 modifier in the AOSpine Thoracolumbar Spine Injury Classification System.

Risk Factors for the Failure of Spinal Burst Fractures Treated Conservatively According to the Thoracolumbar Injury Classification and Severity Score (TLICS): A Retrospective Cohort Trial

BACKGROUND

The management of thoracolumbar (TL) burst fractures is still controversial. The thoracolumbar injury classification and severity score (TLICS) algorithm is now widely used to guide clinical decision making, however, in clinical practice, we come to realize that TLICS also has its limitations for treating patients with total scores less than 4, for which conservative treatment may not be optimal in all cases.

PURPOSE

The aim of this study is to identify several risk factors for the failure of conservative treatment of TL burst fractures according to TLICS algorithm.

METHODS

From June 2008 to December 2013, a cohort of 129 patients with T10-l2 TL burst fractures with a TLISC score ≤3 treated non-operatively were identified and included into this retrospective study. Age, sex, pain intensity, interpedicular distance (IPD), canal compromise, loss of vertebral body height and kyphotic angle (KA) were selected as potential risk factors and compared between the non-operative success group and the non-operative failure group.

RESULTS

One hundred and four patients successfully completed non-operative treatment, the other 25 patients were converted to surgical treatment because of persistent local back pain or progressive neurological deficits during follow-up. Our results showed that age, visual analogue scale (VAS) score and IPD, KA were significantly different between the two groups. Furthermore, regression analysis indicated that VAS score and IPD could be considered as significant predictors for the failure of conservative treatment.

CONCLUSION

The recommendation of non-operative treatment for TLICS score ≤3 has limitations in some patients, and VAS score and IPD could be considered as risk factors for the failure of conservative treatment. Thus, conservative treatment should be decided with caution in patients with greater VAS scores or IPD. If non-operative management is decided, a close follow-up is necessary.

Can a Thoracolumbar Injury Severity Score Be Uniformly Applied from T1 to L5 or Are Modifications Necessary?

Study Design Literature review. Objective The aim of this review is to highlight challenges in the development of a comprehensive surgical algorithm to accompany the AOSpine Thoracolumbar Spine Injury Classification System. Methods A narrative review of the relevant spine trauma literature was undertaken with input from the multidisciplinary AOSpine International Trauma Knowledge Forum. Results The transitional areas of the spine, in particular the cervicothoracic junction, pose unique challenges. The upper thoracic vertebrae have a transitional anatomy with elements similar to the subaxial cervical spine. When treating these fractures, the surgeon must be aware of the instability due to the junctional location of these fractures. Additionally, although the narrow spinal canal makes neurologic injuries common, the small pedicles and the inability to perform an anterior exposure make decompression surgery challenging. Similarly, low lumbar fractures and fractures at the lumbosacral junction cannot always be treated in the same manner as fractures in the more cephalad thoracolumbar spine. Although the unique biomechanical environment of the low lumbar spine makes a progressive kyphotic deformity less likely because of the substantial lordosis normally present in the low lumbar spine, even a fracture leading to a neutral alignment may dramatically alter the patient's sagittal balance. Conclusion Although the new AOSpine Thoracolumbar Spine Injury Classification System was designed to be a comprehensive thoracolumbar classification, fractures at the cervicothoracic junction and the lumbosacral junction have properties unique to these junctional locations. The specific characteristics of injuries in these regions may alter the most appropriate treatment, and so surgeons must use clinical judgment to determine the optimal treatment of these complex fractures.

The surgical algorithm for the AOSpine thoracolumbar spine injury classification system

PURPOSE

The goal of the current study is to establish a surgical algorithm to accompany the AOSpine thoracolumbar spine injury classification system.

METHODS

A survey was sent to AOSpine members from the six AO regions of the world, and surgeons were asked if a patient should undergo an initial trial of conservative management or if surgical management was warranted. The survey consisted of controversial injury patterns. Using the results of the survey, a surgical algorithm was developed.

RESULTS

The AOSpine Trauma Knowledge forum defined that the injuries in which less than 30% of surgeons would recommend surgical intervention should undergo a trial of non-operative care, and injuries in which 70% of surgeons would recommend surgery should undergo surgical intervention. Using these thresholds, it was determined that injuries with a thoracolumbar AOSpine injury score (TL AOSIS) of three or less should undergo a trial of conservative treatment, and injuries with a TL AOSIS of more than five should undergo surgical intervention. Operative or non-operative treatment is acceptable for injuries with a TL AOSIS of four or five.

CONCLUSION

The current algorithm uses a meaningful injury classification and worldwide surgeon input to determine the initial treatment recommendation for thoracolumbar injuries. This allows for a globally accepted surgical algorithm for the treatment of thoracolumbar trauma.