Short-segment posterior instrumentation combined with anterior spondylodesis using an autologous rib graft in thoracolumbar burst fractures

Effect of different lumbar-iliac fixation and sacral slope for Tile C1.3 pelvic fractures: a biomechanical study

BACKGROUND

Lumbar-iliac fixation (LIF) is a common treatment for Tile C1.3 pelvic fractures, but different techniques, including L4-L5/L5 unilateral LIF (L4-L5/L5 ULIF), bilateral LIF (BLIF), and L4-L5/L5 triangular osteosynthesis (L4-L5/L5 TOS), still lack biomechanical evaluation. The sacral slope (SS) is key to the vertical shear of the sacrum but has not been investigated for its biomechanical role in lumbar-iliac fixation. The aim of this study is to evaluate the biomechanical effects of different LIF and SS on Tile C1.3 pelvic fracture under two-legged standing load in human cadavers.

METHODS

Eight male fresh-frozen human lumbar-pelvic specimens were used in this study. Compressive force of 500 N was applied to the L4 vertebrae in the two-legged standing position of the pelvis. The Tile C1.3 pelvic fracture was prepared, and the posterior pelvic ring was fixed with L5 ULIF, L4-L5 ULIF, L5 TOS, L4-L5 TOS, and L4-L5 BLIF, respectively. Displacement and rotation of the anterior S1 foramen at 30° and 40° sacral slope (SS) were analyzed.

RESULTS

The displacement of L4-L5/L5 TOS in the left-right and vertical direction, total displacement, and rotation in lateral bending decreased significantly, which is more pronounced at 40° SS. The difference in stability between L4-L5 and L5 ULIF was not significant. BLIF significantly limited left-right displacement. The ULIF vertical displacement at 40° SS was significantly higher than that at 30° SS.

CONCLUSIONS

This study developed an in vitro two-legged standing pelvic model and demonstrated that TOS enhanced pelvic stability in the coronal plane and cephalad-caudal direction, and BLIF enhanced stability in the left-right direction. L4-L5 ULIF did not further improve the immediate stability, whereas TOS is required to increase the vertical stability at greater SS.

Analysis of Influencing Factors of Vertebral Height Loss After Pedicle Screw Fixation of Thoracolumbar Fracture

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

To explore the related factors of vertebral height loss (VHL) after pedicle screw fixation of thoracolumbar fracture and to determine the optimum prediction point.

SUMMARY OF BACKGROUND DATA

With the widespread application of thoracolumbar fracture internal fixation, VHL after the operation is increasingly presented. However, there is no unified conclusion on the specific cause of VHL and how to predict it.

METHODS

A total of 186 patients were selected and divided into the loss group (n = 72) and the not-loss group (n = 114) according to whether the fractured vertebral height was lost after the operation. The two groups were compared concerning sex, age, body mass index, osteoporosis self-assessment tool for Asians (OSTA), fracture types, number of fractured vertebrae, preoperative Cobb angle and compression degree, number of screws, and extent of vertebral restore. Univariate analysis and Multivariate logistic regression analysis were performed to identify the independent factors for the VHL with the receiver operating characteristic curve and the optimal prediction value was calculated according to area under the curve.

RESULTS

Multivariate logistic regression analysis showed that OSTA ( P < 0.05) and preoperative vertebral compression ( P < 0.05) were significantly correlated with postoperative VHL, which were independent risk factors for postoperative VHL. The OSTA of 2.32 and the preoperative vertebral compression degree of 38.5% were the best prediction points for postoperative VHL based on the Youden Index analysis.

CONCLUSIONS

The OSTA and preoperative vertebral compression were independent risk factors for VHL. The risk of postoperative VHL was significantly higher when the OSTA was ≤2.32 or the preoperative vertebral compression was ≥38.5%.

LEVEL OF EVIDENCE

Level III.

Effectiveness of the Endplate Reduction Technique Combined With Bone Grafting for the Treatment of Thoracolumbar Fractures by Using Posterior Short-Segment Fixation

Objective: This study aimed to examine the effect of the endplate reduction (EPR) technique combined with bone grafting for treating thoracolumbar burst fractures using posterior short-segmental fixation.Methods: Patients with thoracolumbar fractures admitted between January 2018 and October 2021 were retrospectively analyzed, and those meeting the criteria were assigned to the EPR group and the intermediate screws (IS) group. The vertebral wedge angle (VWA), Cobb angle (CA), anterior vertebral body height (AVBH), middle vertebral body height (MVBH), upper endplate line (UEPL), upper intervertebral angle (UIVA), and upper intervertebral disc height (UIDH) indices were examined and compared preoperatively, first day postoperatively, as well as at 12 months postoperatively.Results: The result indicated that the EPR group achieved better MVBH reduction (p < 0.001), UEPL reduction (p < 0.001), vertebral body fracture healing (p = 0.006), as well as implant breakage (p = 0.04) than the IS group; VWA (p < 0.001), CA (p = 0.005), AVBH (p < 0.001), MVBH (p < 0.001), UEPL (p < 0.001), and UIDH (p < 0.001) were lost after reduction less than those in the IS group. There was no significant difference in operative time (p = 0.315) and intraoperative bleeding (p = 0.274) between the 2 groups.Conclusion: The EPR group achieved better results in repositioning and maintaining MVBH and endplate morphology, with less correction loss after the reduction of the VWA, CA, AVBH, and endplate morphology. The EPR group exhibited a better healing pattern after vertebral fracture and disc degeneration was better relieved.

Surgical consideration for thoracolumbar burst fractures with spinal canal compromise without neurological deficit

Background

For thoracolumbar burst fractures with spinal canal compromise but no neurological deficit, is it necessary to perform additional laminectomy decompression after the currently accepted posterior pedicle-screw internal fixation?

Methods

Patients were divided into two groups: decompression group (Group A) and nondecompression group (Group B). A retrospective analysis of the posterior vertebral body height of the fractured vertebral body, the ratio of the volume of the spinal canal, and the change of the Cobb angle, relative to the corresponding preoperative values, was conducted to analyse the reasons for choosing different surgical methods.

Results

Compared the intraoperative findings after fixation with the preoperative data, in Group A, the posterior vertebral body height of the fractured vertebral body was not significantly restored, the volume ratio of the spinal canal was not significantly improved, and the Cobb angle was not significantly reduced (p ​> ​0.05). In comparison, in Group B, the posterior vertebral body height of the fractured vertebral body was significantly restored, the volume ratio of spinal canal was significantly increased, and the Cobb angle was significantly reduced (p ​< ​0.001).

Conclusion

For patients with thoracolumbar burst fractures with spinal canal compromise but no neurological deficit, if when the posterior intraoperative fixation is performed, the spinal canal fracture is partially recovered, the posterior vertebral body height of the injured vertebrae is significantly restored, the spinal canal volume ratio is significantly increased, and the large kyphosis is corrected, then the indirect decompression without the posterior laminectomy can be performed.

The translational potential of this article

This study contributes to offer treatment ​consideration for ​patients with thoracolumbar burst fracture without neurological symptoms.

A retrospective study evaluating the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar vertebral fractures

OBJECTIVE

To evaluate the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar vertebral fractures.

METHODS

Fifty-six cases of thoracolumbar vertebral fractures treated in our trauma center from October 2012 to October 2013 were included in this study. The fractures were classified by the anteroposterior classification, whereas the severity of intervertebral disc injury was evaluated using magnetic resonance imaging. The Spearman correlation coefficient was used to analyze the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar fractures, whereas a χ2 test was adopted to measure the variability between different fracture types and upper and lower adjacent disc injuries.

RESULTS

The Spearman correlation coefficients between fracture types and the severity of the upper and lower adjacent disc injuries were 0.739 (PU<0.001) and 0.368 (PL=0.005), respectively. It means that the more complex Arbeitsgemeinschaft für Osteosynthesefragen (AO) classifications are the disc injury is more severe. There was also a significant difference in the severity of injury between the upper and lower adjacent discs near the fractured vertebrae (p<0.001).

CONCLUSIONS

In thoracolumbar spinal fractures, the severity of the adjacent intervertebral disc injury is positively correlated with the anteroposterior fracture type. The injury primarily involves intervertebral discs near the fractured end plate, with more frequent and severe injuries observed in the upper than in the lower discs. The presence of intervertebral disc injury, along with its severity, may provide useful information during the clinical decision-making process.

Efficacy of Titanium Mesh Cages for Anterior Column Reconstruction after Thoracolumbar Corpectomy

STUDY DESIGN

This retrospective study was conducted to determine the safety and efficacy of titanium cage reconstruction and anterior plating after thoracolumbar corpectomy.

PURPOSE

To study the clinical and radiological outcome of anterior column reconstruction after thoracolumbar corpectomy.

OVERVIEW OF LITERATURE

Anterior column reconstruction aims to optimize neural decompression with adequate stabilization.

METHODS

A series of 16 patients underwent reconstruction after thoracolumbar corpectomy to treat injury due to trauma (n=10), tuberculosis (n=3), and tumor (n=3). The average duration of follow-up was 18 months (range, 8-58 months). The degree of kyphosis, construct height, and the subsidence of the cage in relation to the vertebral endplates were measured. The approach was thoracoabdominal in 10 cases and retroperitoneal in 6 cases.

RESULTS

Four patients were neurologically intact with Frankel grade E on admission, and all remained intact postoperatively. Of the 6 patients with Frankel grade D, all fully recovered full motor and sensory functions. Of the 6 patients with Frankel grade C, three improved one grade and the other three improved two grades. The mean height of the vertebra before surgery was 41 mm and the mean construct height immediately after surgery and at follow-up was 47 mm and 44 mm, respectively. Solid fusion was observed in all patients. The sagittal alignment of the fractured segment was restored immediately after surgery as a significant decrease in the local kyphotic angle.

CONCLUSIONS

Anterior instrumentation is an effective and safe treatment for thoracolumbar instability with satisfactory clinical and radiological outcomes.

Short Segment Spinal Instrumentation With Index Vertebra Pedicle Screw Placement for Pathologies Involving the Anterior and Middle Vertebral Column Is as Effective as Long Segment Stabilization With Cage Reconstruction: A Biomechanical Study

STUDY DESIGN

An in vitro, cadaveric biomechanical study.

OBJECTIVE

The aim of the present study was to compare single-segment posterior instrumentation and fracture-level screws with single/multilevel posterior fixation and corpectomy in a simulated, unstable burst fracture model.

SUMMARY OF BACKGROUND DATA

The optimal extent of instrumentation for surgical cases of non-neoplastic vertebral body pathologies remains uncertain. Although several clinical studies demonstrate advantages of short segment instrumentation with index-level screws over more extensive corpectomy and anterior-posterior techniques, a comprehensive biomechanical comparison of these techniques is currently lacking.

METHODS

Six bovine spines (T11-L5) were tested in flexion, extension, lateral bending (LB), and axial rotation (AR) following simulated burst fracture at L2. Posterior instrumentation included 1 level above/below (1LF) and 2 levels above/below fracture level (2LF), intermediate or index screws at fracture level (FF), and cross-connectors above/below fracture level (CC). Anterior corpectomy devices included expandable corpectomy spacers with/without integrated screws, ACDi and ACD, respectively FORTIFY-Integrated/FORTIFY; Globus Medical, Inc., PA. Constructs were tested in the following order: (1) Intact; (2) 1LF; (3) 1LF and CC; (4) 1LF and FF; (5) 1LF, CC, and FF; (6) 2LF; (7) 2LF and CC; (8) 2LF and FF; (9) 2LF, CC, and FF; (10) 2LF and ACD; (11) 2LF, ACD, and CC; (12) 1LF and ACDi; (13) 1LF, ACDi, and CC.

RESULTS

During flexion, all constructs except 1LF reduced motion relative to intact (P ≤ 0.05). Anterior support was most stable, but no differences were found between constructs (P ≥ 0.05). Every construct reduced motion in extension, though no differences were found between constructs and intact (P ≥ 0.05). During LB, all constructs reduced motion relative to intact (P ≤ 0.05); 2LF constructs further reduced motion (P ≤ 0.05). No construct returned AR motion to intact, with significant increases in 1LF and ACDi, 2LF and ACD, and 2LF, ACD, and CC (P ≤ 0.05). Cross-connectors and fracture screws reinforced each other in posterior-only constructs, providing maximum stability (P ≥ 0.05).

CONCLUSIONS

This biomechanical comparison study found no significant superiority of combined anterior-posterior constructs over short segment fracture screw fixation, only multilevel posterior instrumentation with and without anterior support, providing increased stability in LB. Biomechanical equivalency suggests that short segment fracture screw intervention may provide appropriate stabilization for non-neoplastic pathologies involving the anterior and middle vertebral columns.

LEVEL OF EVIDENCE

2.