BACKGROUND: The development of pedicle screw-based posterior spinal instrumentation is recognized as one of the major surgical treatment methods for thoracolumbar burst fractures. However, the appropriate level in posterior segment instrumentation is still a point of debate. To assesses the long-term results of two-level and three-level posterior fixations of thoracolumbar burst fractures that have load-sharing scores of 7 and 8 points. METHODS: From January 1998 to May 2009, we retrospectively analyzed clinical and radiologic outcomes of 45 patients with thoracolumbar burst fractures of 7 and 8 points in load-sharing classification who were operated on using two-level posterior fixation (one segment above and one segment below: 28 patients, group I) or three-level posterior fixation (two segments above and one segment below: 17 patients, group II). Clinical results included the grade of the fracture using the Frankel classification, and the visual analog score was used to evaluate pain before surgery, immediately after surgery, and during follow-up period. We also evaluated pain and work status at the final follow-up using the Denis pain scale. RESULTS: In all cases, non-union or loosening of implants was not observed. There were two screw breakages in two-level posterior fixation group, but bony union was obtained at the final follow-up. There were no significant differences in loss of anterior vertebral body height, correction loss, or change in adjacent discs. Also, in clinical evaluation, there was no significant difference in the neurological deficit of any patient during the follow-up period. CONCLUSIONS: In our study, two-level posterior fixation could be used successfully in selected cases of thoracolumbar burst fractures of 7 and 8 points in the load-sharing classification.
Adult ; Back Pain ; Female ; Follow-Up Studies ; Fracture Fixation, Internal/adverse effects/instrumentation/methods/*statistics & numerical data ; Humans ; Lumbar Vertebrae/*injuries/physiopathology/*surgery ; Male ; Middle Aged ; Pedicle Screws ; Postoperative Complications ; Retrospective Studies ; Spinal Fractures/physiopathology/*surgery ; Thoracic Vertebrae/*injuries/physiopathology/*surgery ; Treatment Outcome

OBJECTIVETo investigate the clinical outcomes of semicircular decompression in treating old thoracolumbar fractures and intractable neuropathic pain.

METHODSFrom September 2009 to September 2013, 21 patients with old thoracolumbar fracture and intractable neuropathic pain were treated with semicircular decompression. Among initial surgery, posterior pedicle screw fixation was used in these patients, with or without laminectomy. All patients were male, range in age from 20 to 28 years old with an average of (25.00±2.38) years. Vertebral body residual bone block resulted in intra-spinal placeholder more than 50%. All patients were complete spinal cord injury (ASIA grade) or cauda equina injury. VAS scores was from 6 to 10 points with the mean of 7.14±0.91. In these patients, MRI, CT, X-rays were performed; denomination and dosage of analgesics were recorded; nerve function and pain status were respectively evaluated by ASIA grade and VAS score before and after operation.

RESULTSAll patients were followed up from 8 to 32 months with an average of (17.29±6.02) months. All bone fragments of spinal canal were removed and spinal cord decompressions were achieved. At final follow-up, VAS scores were from 0 to 8 points with an average of (2.43±2.46) points, and were obviously reduced than peroperative data (P<0.05). Eleven cases of them stopped analgesic intake and 7 cases reduced using. Three patients' symptoms and VAS scores were not improved.

CONCLUSIONOld thoracolumbar fractures and intractable neuropathic pain need receive imaging examination as soon as possible and consider semicircular decompression therapy if bone fragments were in vertebral canal and spinal canal stenosis existed. This therapy can effectively relieve pain and profit nerve functional recovery.

Adult ; Decompression, Surgical ; methods ; Humans ; Lumbar Vertebrae ; injuries ; surgery ; Male ; Neuralgia ; etiology ; surgery ; Pain, Intractable ; etiology ; surgery ; Spinal Fractures ; physiopathology ; surgery ; Thoracic Vertebrae ; injuries ; surgery ; Visual Analog Scale ; Young Adult

OBJECTIVETo study the curative effect of postural reduction with instrumental reduction in treatment of flexion-distraction thoracolumbar fractures.

METHODSA retrospective study was performed on 43 patients with single thoracolumbar flexion-distraction fractures admitted from August 2009 to August 2011, included 28 males and 15 females with an average age of 44 years old (34 to 56 years old). All patients were treated with postural reduction with instrumental reduction. The kyphosis (Cobb angle) recovery of injured vertebral height and complication were analyzed. The visual analogue scale(VAS) and com-plications were followed up and recorded.

RESULTSThere was no difference in recovery of injured vertebral posterior height among preoperative, 1 week and 1 year after operation (P > 0.05). There were significantly difference in kyphosis (Cobb angle) and recovery of injured vertebral anterior height between preoperative and postoperative at 1 week (P < 0.05). There was no difference in kyphosis (Cobb angle) and recovery of injured vertebral anterior height between 1 week and 1 year after operation (P > 0.05). VAS significantly improved from preoperative (7.2 +/- 1.2) to (0.8 +/- 0.7) at 1 year after operation (t = 18.47, P < 0.001).

CONCLUSIONPostural reduction with instrumental reduction is effective for thoracolumbar flexion-distraction fractures and it is beneficial to the recovery of vertebral height and saggital alignment.

Adult ; Female ; Fracture Fixation, Internal ; adverse effects ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Spinal Fractures ; physiopathology ; surgery ; Thoracic Vertebrae ; injuries ; physiopathology ; surgery ; Visual Analog Scale

Adult ; Aneurysm, Dissecting ; diagnosis ; physiopathology ; Aneurysm, False ; Coronary Aneurysm ; diagnosis ; physiopathology ; Coronary Vessels ; pathology ; physiopathology ; Humans ; Male ; Myocardial Infarction ; diagnosis ; physiopathology ; Thoracic Injuries ; complications ; physiopathology ; Young Adult

BACKGROUNDPosterior pedicle screw device is widely used in treatment of thoracolumbar burst fractures. As the clinical operation is not based upon quantitative data of adjustments, the results are not optimal. At present, no study has assessed the associations between the device adjustments and the restoration of stiffness. We investigated the biomechanical effects that adjustments of a pedicle screw device had on the burst fracture, and explored an optimal adjustment.

METHODSBurst fractures were produced at L1 vertebra in 24 fresh calf spines (T12-L3). The specimens were divided into four groups at random. Pedicle screw devices were attached to T13 and L2. Four device adjustments, consisting of distraction and extension, were applied. Adjustment 1 was pure 6° extension, adjustment 2 was pure 5 mm distraction, adjustment 3 was 6° extension followed by 5 mm distraction, and adjustment 4 was 5 mm distraction followed by 6° extension. The effect of each adjustment on the stiffness restoration, anatomical reduction, and neural decompression for the burst fractures was analyzed and evaluated.

RESULTSPure extension (Group 1) produced the closest segment height and the least restoration of the canal to the intact. Pure distraction (Group 2) restored stiffness most, but with only 60% stiffness of the intact value, and lost the segmental angle most to the intact. The combination of extension-distraction (Group 3 and Group 4) produced the maximum reduction of the anatomy and restoration of the canal in the burst fracture, and the least stiffness restoration. The sequence of extension and distraction did not affect stiffness restoration, anatomical reduction, and neural decompression.

CONCLUSIONSThe device adjustments affected stiffness restoration, anatomical reduction, and neural decompression. The combined extension-distraction adjustment may be the most suitable considering the anatomical reduction and neural decompression, but the stiffness decreased the most; it should be considered to reconstruct L1 vertebra.

Animals ; Biomechanical Phenomena ; Cattle ; Female ; Fracture Fixation, Internal ; instrumentation ; Lumbar Vertebrae ; injuries ; surgery ; Male ; Spinal Fractures ; physiopathology ; surgery ; Thoracic Vertebrae ; injuries ; surgery

PURPOSE: The proposed the thoracolumbar injury classification system (TLICS) for thoracolumbar injury cites the integrity of the posterior ligamentous complex (PLC). However, no report has elucidated the severity of damage in thoracic and lumbar injury with classification schemes by presence of the PLC injury. The purpose of this study was to accurately assess the severity of damage in thoracic and lumbar burst fractures with the PLC injuries. MATERIALS AND METHODS: One hundred consecutive patients treated surgically for thoracic and lumbar burst fractures were enrolled in this study. There were 71 men and 29 women whose mean age was 36 years. Clinical and radiologic data were investigated, and the thoracolumbar injury classification schemes were also evaluated. All patients were divided into two groups (the P group with PLC injuries and the C group without PLC injuries) for comparative examination. RESULTS: Fourth-one of 100 cases showed PLC injuries in MRI study. The load sharing classification score was significantly higher in the P group [7.8+/-0.2 points for the P group and 6.9+/-1.1 points for the C group (p<0.001)]. The TLICS (excluded PLC score) score was also significantly higher in the P group [6.2+/-1.1 points for the P group and 4.0+/-1.4 points for the C group (p<0.001)]. CONCLUSION: The presence of PLC injury significantly influenced the severity of damage. In management of thoracic lumbar burst fractures, evaluation of PLC injury is important to accurately assess the severity of damage.
Adolescent ; Adult ; Aged ; Female ; Humans ; Ligaments, Articular/*injuries ; Lumbar Vertebrae/*injuries ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Retrospective Studies ; Spinal Fractures/*classification/*physiopathology/surgery ; Thoracic Vertebrae/*injuries ; Young Adult

BACKGROUNDThoracolumbar burst fracture is a common clinical injury, and the fracture mechanism is still controversial. The aim of this research was to study the formation of intracanal fracture fragments in thoracolumbar burst fractures and to provide information for the prevention of thoracolumbar bursts fractures and reduction of damage to the nervous system.

METHODSA nonlinear three-dimensional finite element model of T11-3 segments was established, and the injury processes of thoracolumbar bursts were simulated. The intact finite element model and the finite element model after the superior articular were impacted by 100 J of energy in different directions. The distribution and variation of stress in the superior posterior region of the L1 vertebral body were analyzed. Abaqus 6.9 explicit dynamic solver was used as finite element software in calculations.

RESULTSA three-dimensional nonlinear finite element model of the thoracolumbar spine was created. In the intact model, stress was concentrated in the superior posterior region of the L1 vertebral body. The stress peak was a maximum for the extension impact load and a minimum for the flexion impact load. The stress peak and contact force in the facet joint had close correlation with time. The stress peak disappeared after excision of the superior articular process.

CONCLUSIONSThe three-dimensional nonlinear finite element model was suitable for dynamic analysis. The contact force in the facet joint, which can be transferred to the superior posterior vertebral body, may explain the spinal canal fragment in thoracolumbar burst fractures.

Adult ; Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Lumbar Vertebrae ; injuries ; Male ; Models, Biological ; Spinal Canal ; Spinal Fractures ; physiopathology ; Stress, Mechanical ; Thoracic Vertebrae ; injuries

OBJECTIVE: To establish a 3D finite element model of the complete human thoracic cage, and to perform a biomechanical analysis. METHODS: The multislice computed tomography (MSCT) images of human thorax were obtained and used to develop a 3D reconstruction and a finite element model of the thoracic cage by finite element modeling software. The right hypochondrium area of the model was simulated to sustain the frontal impacts by a blunt impactor with velocities of 4, 6 and 8 m/s, and the distribution of stress and strain after the impact of the model was analyzed. RESULTS: A highly anatomically simulated finite element model of human thoracic cage was successfully developed with a fine element mean quality which was above 0.7. The biomechanical analysis showed that the thoracic cage revealed both local bending and overall deformation after the impact. Stress and strain arose from the initial impact area of the ribs, and then spread along the ribs to both sides, at last concentrated in the posterior side of the ribs and near the sternum. Impacts with velocities of 6 m/s and 8 m/s were predicted to cause rib fractures when the strain of the ribs were beyond the threshold values. CONCLUSION The finite element modeling software is capable of establishing a highly simulated 3D finite element model of human thoracic cage. And the established model could be applicable to analyze stress and strain distribution of the thoracic cage under forces and to provide a new method for the forensic identification of chest injury.
Adult ; Cadaver ; Computer Simulation ; Finite Element Analysis ; Forensic Medicine ; Humans ; Imaging, Three-Dimensional ; Male ; Models, Biological ; Multidetector Computed Tomography ; Stress, Mechanical ; Thoracic Injuries/physiopathology* ; Thorax/physiology* ; Wounds, Nonpenetrating/physiopathology*

OBJECTIVETo investigate the feasibility and safety of the treatment for thoracolumbar fractures with pedicle screw at the fracture level and vertebroplasty via paraspinal approach.

METHODSFrom August 2007 to August 2010, 22 old patients with thoracolumbar fractures were treated with pedicle screw at the fracture level and vertebroplasty via paraspinal approach. There were 14 males and 8 females, ranging in age from 60 to 71 years (mean, 64.6 years). The time from injury to surgery varied from 1 to 4 d (mean,2.7 d). All the patients suffered from single thoracolumbar fractures and located at T11 in 2 cases, at T12 in 5 cases, at L1 in 11 cases and at L2 in 4 cases. According to the Denis fracture classification, there were 6 compression fractures and 16 burst fractures. The mean preoperative load-sharing classification of spine fractures was 5.4 score. The mean preoperative thoracolumbar injury classification and scoring was 5.2. Based on the ASIA neurologic grading system, preoperative neurological function was grade B in 2 cases,grade C in 3 cases, grade D in 7 cases and grade E in 10 cases. The neurological function, vertebral central and anterior height, kyphotic angle of the vertebral fractures by radiographs and visual analog scale were calculated pre-operatively, post-operatively and at the last follow-up.

RESULTSMedian operating time was 60.8 min (ranged from 50 to 95 min) and median blood loss was 84 ml (ranged from 50 to 130 ml). The operative incisions were healed well. The duration of follow-up averaged 21.6 months (ranged from 12 to 48 months). The anterior vertebral body height was corrected from preoperative (52.3 +/- 10.3) % to postoperative (6.1 +/- 4.2) % and (6.8 +/- 5.4) % at the last follow-up. The central vertebral body height was corrected from preoperative (38.9 +/- 11.2) % to postoperative (8.3 +/- 4.7) % and (9.4 +/- 4.5)% at the last follow-up. The Cobbs angle of the injured vertebral segment was corrected from preoperative (19.5 +/- 9.5) degrees to postoperative (4.3 +/- 4.1) degrees and (6.2 +/- 4.7) degrees at the last follow-up. The VAS scores reduced from preoperative 8.56 +/- 0.88 to post-operative 3.48 +/- 0.91 and 3.20 +/- 0.92 at the last follow-up. The postoperative neurologic function of all 22 patients improved 1 to 2 degrees except 10 patients of grade E. There were no instances of instrumentation failure and no patient had persistent postoperative back pain.

CONCLUSIONThe pedicle screw at the fracture level and vertebroplasty via paraspinal approach has the advantages of less invasive and blood loss, and could prevent the development of kyphosis and offers improvement of the spinal cord function. Furthermore, it could decrease the risks of postoperative back pain and the failure of instrumentation.

Aged ; Bone Screws ; Female ; Humans ; Lumbar Vertebrae ; diagnostic imaging ; injuries ; surgery ; Male ; Middle Aged ; Recovery of Function ; Retrospective Studies ; Spinal Cord ; physiopathology ; Spinal Fractures ; diagnostic imaging ; physiopathology ; surgery ; Thoracic Vertebrae ; diagnostic imaging ; injuries ; surgery ; Tomography, X-Ray Computed ; Vertebroplasty ; instrumentation

OBJECTIVETo explore efficacy of modified funnel method for transpedicular bone grafting in treating thoracolumbar vertebras fracture.

METHODSFrom May 2006 to November 2011, 35 patients (19 males and 16 females, ranged in age from 21 to 66 years with an average of 34.6 years) with thoracolumbar vertebras fracture were treated by posterior pedicle screw fixation, reduction and modified funnel method for transpedicular autogenous iliac bone grafting. Of the 35 cases, 9 cases were severe compression fracture and 26 cases were burst fracture. The anterior body height and Cobb's angle of injured vertebral were measured by X-ray; the effect of implantation bone and CT value were assessed by radiograph CT scan; Nerve function were evaluated according to Frankel's neurological function classification and back pain were evaluated by visual analogue scale (VAS).

RESULTSThirty-two patients were followed up from 18 to 37 months with an average of 19.7 months. No nerve injuries aggravated, and 11 patients with partial nerve injuires preoperatively were improved at least 1 level recovery postoperatively; Breakage or loosen of screws were not found. Vertebral bone grafting filled well, bone fusion were got after 6 months' treatment and without cavity gap in grafting bone area. The anterior vertebral height was improved respectively from preoperative (50.17 +/- 8.26)% to postoperative (90.79 +/- 4.85)%, and (90.34 +/- 4.03)% at the final follow-up. The Cobb's angle improved from preoperative (28.7 +/- 6.24) degrees to postoperative (7.26 +/- 3.79) degrees, with (7.34 +/- 4.05) degrees at the final follow-up. CT value of injured vertebras at the final follow-up were significantly higher than adjacent vertebras'. The average VAS was 1.06.

CONCLUSIONPosterior pedicle screw fixation, reduction and modified funnel method for transpedicular autogenous iliac bone grafting is a feasible and safe method for the treatment of thoracolumbar vertebras fracture. It can effectively prevent bone loss of injured vertebral height, progressive deformity of kyphosis, and keep spinal movement function at the maximum.

Adult ; Aged ; Bone Transplantation ; methods ; Female ; Humans ; Lumbar Vertebrae ; diagnostic imaging ; injuries ; surgery ; Male ; Middle Aged ; Recovery of Function ; Spinal Cord ; physiopathology ; Spinal Fractures ; diagnostic imaging ; physiopathology ; surgery ; Thoracic Vertebrae ; diagnostic imaging ; injuries ; surgery ; Tomography, X-Ray Computed ; Treatment Outcome ; Young Adult