Treatment Of Thoracolumbar Burst Fractures Research Articles

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Evaluation and Treatment of Patients With Thoracolumbar Spine Trauma: Novel Surgical Strategies

Treatment of thoracolumbar burst fractures has traditionally involved spinal instrumentation with fusion performed with standard open surgical techniques. Novel surgical strategies, including instrumentation without fusion and percutaneous instrumentation alone, have been considered less invasive and more efficient treatments. To review the current literature and determine the role of fusion in instrumented fixation, as well as the role of percutaneous instrumentation, in the treatment of patients with thoracolumbar burst fractures. The task force members identified search terms/parameters and a medical librarian implemented the literature search, consistent with the literature search protocol (see Appendix I), using the National Library of Medicine PubMed database and the Cochrane Library for the period from January 1, 1946 to March 31, 2015. A total of 906 articles were identified and 38 were selected for full-text review. Of these articles, 12 articles met criteria for inclusion in this systematic review. There is grade A evidence for the omission of fusion in instrumented fixation for thoracolumbar burst fractures. There is grade B evidence that percutaneous instrumentation is as effective as open instrumentation for thoracolumbar burst fractures. Does the addition of arthrodesis to instrumented fixation improve outcomes in patients with thoracic and lumbar burst fractures? It is recommended that in the surgical treatment of patients with thoracolumbar burst fractures, surgeons should understand that the addition of arthrodesis to instrumented stabilization has not been shown to impact clinical or radiological outcomes, and adds to increased blood loss and operative time. Strength of Recommendation: Grade A. How does the use of minimally invasive techniques (including percutaneous instrumentation) affect outcomes in patients undergoing surgery for thoracic and lumbar fractures compared to conventional open techniques? Stabilization using both open and percutaneous pedicle screws may be considered in the treatment of thoracolumbar burst fractures as the evidence suggests equivalent clinical outcomes. Strength of Recommendation: Grade B The full version of the guideline can be reviewed at: https://www.cns.org/guideline-chapters/congress-neurological-surgeons-systematic-review-evidence-based-guidelines/chapter_12.

Treatment of thoracolumbar burst fractures with intelligent inflated reduction combined with percutaneous pedicle screw fixation

To evaluate the clinical outcome of intelligent inflated reduction combined with percutaneous pedicle screw fixation in treating thoracolumbar burst fractures. The clinical data of 22 patients with thoracolumbar burst fractures of single segment treated from January 2013 to December 2015 were retrospectively analyzed. There were 12 males and 10 females, aged from 32 to 56 years old with an average of (42.4±8.6) years. Self-made intelligent pneumatic reset instrument was applied to 22 cases under anaesthesia reduction, and then percutaneous pedicle screw fixation was performed. Clinical features were observed and the clinical effects were evaluated by VAS, ODI, kyphotic angle (Cobb angle) and the injured vertebral anterior border height before and after operation. All the patients were followed up from 1 to 2.5 years with an average of 18 months. All fractures obtained bone healing, no complications such as loosening, displacement, breakage of pedicle screw and kyphosis were found. Preoperative, 1 week postoperative, and final follow-up, VAS scores of lumbar pain were 7.82±0.85, 3.09±0.92, 1.05±0.72;ODI scores were 84.2±11.2, 46.3±9.0, 12.2±4.3;Cobb angle were (16.3±5.4)°, (3.7±2.2)°, ( 5.5±2.6)°; the injured vertebral anterior border heights were (59.5±7.8)%, (86.9±6.0)%, (83.5±5.5)%, respectively. There was significant differences in VAS, ODI scores between any two times(P<0.05). At 1 week postoperative and final follow-up, Cobb angle, injuried vertebral anterior border height were obviously improved (P<0.05), and there was no significant difference between postoperative 1 week and final follow-up (P>0.05). It is safe and feasible surgical technique that intelligent inflated reduction combined with percutaneous pedicle screw fixation for thoracolumbar burst fractures. It has advantage of little trauma, reliable fixation, and less complication, etc. Therefore, it is a better choice for single-segment thoracolumbar burst fractures.

Extent and location of fixation affects the biomechanical stability of short- or long-segment pedicle screw technique with screwing of fractured vertebra for the treatment of thoracolumbar burst fractures: An observational study using finite element analysis.

Intermediate screw fixation at the fracture level has been widely accepted to treat thoracolumbar burst fractures, but no study has shown the effect of the extent and location of fixation. The effect of the extent and location of fixation on short- or long-segment pedicle screw fixation through intermediate screw fixation at the fracture level in the treatment of thoracolumbar burst fractures is discussed.Posterior intermediate screw fixation techniques in treating T12 vertebral fracture models were simulated and compared using finite element methods; the fixation techniques included M3-L1 (bilateral 3 monoaxial pedicle screw fixation from L1 to T11), M3-L2, M4-L1 (bilateral 4 monoaxial pedicle screw fixation from L1 to T10), M4-L2, M4-L3, and M5-L2 (bilateral 5 monoaxial pedicle screw fixation from L2 to T10). Range of motion (ROM) and largest von Mises stress (LVMS) of the instrumentations were recorded and analyzed.No significant differences were observed in the mean ROM of all states of motion between the M3-L1 model and the other fixation models except for M5-L2. The LVMS of the pedicle screws and rods all occurred during flexion. The LVMS values of the pedicle screws were larger in the M3-L2 fixation model and M4-L3 fixation model than in the other fixation models. The M3-L1 model presented a significantly smaller mean LVMS of the pedicle screws in all states of motion than the M3-L2 model (P = .026). The LVMS values of the rods were larger in the M3-L2 fixation model, M4-L3 fixation model, and M4-L2 fixation model than in the other fixation models. No significant differences were observed in the mean LVMS of the rods in all states of motion among all the fixation models.When choosing short-segment pedicle screw fixation with the screwing of fractured vertebrae to treat thoracolumbar fractures, we suggest M3-L1 over M3-L2. More severe injuries can be considered to identify an alternative treatment to long-segment monoaxial pedicle fixation constructs such as the M4-L1 and M5-L2 techniques.

Posterior spinal canal decompression with screw fixation and reconstruction of three vertebral column for thoracolumbar burst fractures complicated with nerve injury

To explore the feasibility and clinical effect of posterior spinal canal decompression with pedicle screw fixation and reconstruction of anterior and middle vertebral column for thoracolumbar burst fractures complicated with nerve injury. A total of 36 patients with thoracolumbar burst fractures treated from March 2011 to April 2016 were enrolled in the retrospective study. There were 20 males and 16 females, aged from 21 to 52 years old with an average of 37.6 years. All the fractures were located on a single segment, 8 cases of T11₁₁, 10 cases of T₁₂, 12 cases of L₁, 6 cases of L₂. According to thoracolumbar injury classification and severity score(TLICS) system, the score was 7 to 9 points, with an average of 7.4 points. According to the America Spine Injury Association(ASIA) grade, 4 cases were type A, 10 cases were type B, 14 cases were type C, 8 cases were type D. All the patients underwent posterior spinal canal decompression with pedicle screw fixation and reconstruction of anterior and middle vertebral column. The recovery of nerve function was evaluated by ASIA grading. The correction of kyphosis(Cobb angle), the volume change of injuried spinal canal, the change of anterior border height of injury vertebra which can be observed by X-rays;the internal fixation loosening and breakage and all the information of bone fusion were recorded. All the operations were successful, the mean operative time and intraoperative blood loss were(2.8±0.3) h (2.1 to 3.5 h) and (880±120) ml(550 to 1 350 ml), respectively. All the incisions got primary healing. All the patients were followed up for 12 to 28 months with an average of 18.4 months. All the patients obtained satisfactory bone fusion. No pseudoarticulation formation was found, and there was no loosening, breakage of pedicle screws or displacement of titanium mesh. Neurological function was improved in different degree, except in one patient with grade A and another one with grade B. According to the ASIA grade, there were 1 case of type A, 1 case of type B, 7 cases of type C, 10 cases of type D and 17 cases of type E, postoperatively. At 3 days after operative, the anterior border height of injury vertebra, Cobb angle and the volume changes of injury spinal canal were obviously improved(P<0.05), and there was no significant difference between postoperative at 3 days and final follow-up(P>0.05). Spinal canal decompression with screw fixation and reconstruction of anterior and middle vertebral column through posterior midline approach is a safe and effective method in the treatment of thoracolumbar burst fractures with nerve injury, it is worthy to be popularized. It can complete the spinal canal decompression of 360 degree, reduction of fractures and reconstruction of vertebral three-column at the same time through a single posterior approach. The advantages includes less trauma, perfect decompression, good stability and etc.

Short segment percutaneous pedicle screw fixation after direct spinal canal decompression in thoracolumbar burst fractures: An alternative option

To investigate the surgical results of percutaneous pedicle screw fixation (PPSF) after spinal canal decompression via a small laminectomy for the treatment of thoracolumbar burst fractures. Twenty-seven patients underwent PPSF after spinal canal decompression via small laminectomies between April 2009 and April 2015. Inclusion criteria consisted of a single-level, closed, thoracolumbar burst fracture and neurological symptoms. Decompression was performed via a small laminectomy, followed by PPSF, including at the level of the fractured vertebra. Cobb angle, vertebral wedge angle, and vertebral body index were each measured from lateral radiographs before and after surgery, and at last follow-up. Neurological assessment was made using the Frankel grading system. The average follow-up period was 26 months. The preoperative average Cobb angle was 15.8° ± 6.6°, and significantly decreased to 6.5° ± 6.2° postoperatively (p < 0.001). Average Cobb angle at last follow-up increased slightly to 8.9° ± 6.9°, but this was not significant (p = 0.112). The preoperative average vertebral wedge angle was 20.6° ± 6.3°, and decreased significantly to 12.2° ± 6.2° postoperatively (p < 0.001). The vertebral body index significantly decreased from 0.58 ± 0.11 to a postoperative value of 0.78 ± 0.10 (p < 0.001). Clinically, no patient deteriorated subsequent to surgery. Percutaneous pedicle screw fixation after spinal canal decompression via small laminectomy provides significant kyphotic correction and improved neurological outcome while offering decreased surgical morbidity. This may be applied as an effective primary surgery in select patients with TLBFs with neurologic symptoms.

Finite Element Study to Evaluate the Biomechanical Performance of the Spine After Augmenting Percutaneous Pedicle Screw Fixation With Kyphoplasty in the Treatment of Burst Fractures.

Percutaneous pedicle screw fixation (PPSF) is a well-known minimally invasive surgery (MIS) employed in the treatment of thoracolumbar burst fractures (TBF). However, hardware failure and loss of angular correction are common limitations caused by the poor support of the anterior column of the spine. Balloon kyphoplasty (KP) is another MIS that was successfully used in the treatment of compression fractures by augmenting the injured vertebral body with cement. To overcome the limitations of stand-alone PPSF, it was suggested to augment PPSF with KP as a surgical treatment of TBF. Yet, little is known about the biomechanical alteration occurred to the spine after performing such procedure. The objective of this study was to evaluate and compare the immediate post-operative biomechanical performance of stand-alone PPSF, stand-alone-KP, and KP-augmented PPSF procedures. Novel three-dimensional (3D) finite element (FE) models of the thoracolumbar junction that describes the fractured spine and the three investigated procedures were developed and tested under mechanical loading conditions. The spinal stiffness, stresses at the implanted hardware, and the intradiscal pressure at the upper and lower segments were measured and compared. The results showed no major differences in the measured parameters between stand-alone PPSF and KP-augmented PPSF procedures, and demonstrated that the stand-alone KP may restore the stiffness of the intact spine. Accordingly, there was no immediate post-operative biomechanical advantage in augmenting PPSF with KP when compared to stand-alone PPSF, and fatigue testing may be required to evaluate the long-term biomechanical performance of such procedures.

Comparison of Wiltse\u2019s paraspinal approach and open book laminectomy for thoracolumbar burst fractures with greenstick lamina fractures: a randomized controlled trial

BackgroundPosterior short-segment pedicle screw fixation is used to treat thoracolumbar burst fractures. However, no randomized controlled studies have compared the efficacy of the two approaches––the Wiltse’s paraspinal approach and open book laminectomy in the treatment of thoracolumbar burst fractures with greenstick lamina fractures.Materials and methodsPatients with burst fractures of the thoracolumbar spine without neurological deficit were randomized to receive either the Wiltse’s paraspinal approach (group A, 24 patients) or open book laminectomy (group B, 23 patients). Patients were followed postoperatively for average of 27.4 months. Clinical and radiographic data of the two approaches were collected and compared.ResultsOur results showed the anterior segmental height, kyphotic angle, visual analog scale (VAS) score, and Smiley-Webster Scale (SWS) score significantly improved postoperatively in both groups, indicating that both the Wiltse’s paraspinal approach and open book laminectomy can effectively treat thoracolumbar burst fractures with greenstick lamina fractures. The Wiltse’s paraspinal approach was found to have significantly shorter operating time, less blood loss, and shorter length of hospital stay compared to open book laminectomy. However, there were two (2/24) patients in group A that had neurological deficits postoperatively and required a second exploratory operation. Dural tears and/or cauda equina entrapment were subsequently found in four patients in group B and all two patients of neurological deficits in group A during operation. No screw loosening, plate breakage, or other internal fixation failures were found at final follow-up.ConclusionsThe results demonstrated that either of the two surgical approaches can achieve satisfactory results in treating thoracolumbar burst fractures in patients with greenstick lamina fractures. However, if there is any clinical or radiographic suspicion of a dural tear and/or cauda equina entrapment pre-operation, patients should receive an open book laminectomy to avoid a second exploratory operation. More research is still needed to optimize clinical decision-making regarding surgical approach.

Acute and Hyper-acute Thoracolumbar Corpectomy for Traumatic Burst Fractures Using a Mini-open Lateral Approach

Retrospective chart review. The purpose of this study was to examine the feasibility of acute (<24 hours) and hyperacute (<8 hours) treatment of thoracolumbar burst fractures to maintain or improve spinal injury scores. Historically, treatment of spinal burst fractures within 24 hours from injury was considered an "acute" treatment timeframe. Patient polytrauma triage, multiple surgical specialty, and hospital resource coordination affect time to treatment. The mini-open lateral approach for thoracolumbar corpectomy obviates the need for an approach surgeon, which may allow for early surgical intervention. Sixteen patients treated within 24 hours with a mini-open lateral corpectomy for traumatic spinal pathology were reviewed for preoperative, perioperative, and postoperative data. Neurologic status was assessed using American Spinal Injury Association (ASIA) scores. Fractures occurred primarily from L1 to L3. Wide-footprint expandable titanium devices were used in 75% of patients. All patients received supplemental fixation. Average time from injury to admission to the hospital (emergency room [ER]) was 1.8 hours, with an average time from the ER to operating room (OR) of 8.2 hours and an average OR time of 2.7 hours. Eight patients required ≤8 hours from injury event to surgical initiation, whereas seven patients required between 8 and 24 hours for surgery initiation (one patient with incomplete surgical timing record). Blood loss averaged 646 mL without intraoperative complication. One perioperative complication occurred and one patient developed an asymptomatic inferior vertebral body fracture. Length of hospital stay averaged 6 days. At last follow-up, nearly all patients experienced full or near-complete neurologic recovery with at least one ASIA grade improvement seen in 73% and 20% of patients improving two grades or more. These results suggest that mini-open lateral approaches allow immediate decompression through hyperacute (<8 hours) treatment of spinal burst fractures in eligible patients. Additionally, low perioperative and postoperative morbidity allows for hastened recovery. 4.

Treatment of thoracic or lumbar burst fractures with Balloon Assisted Endplate Reduction using Tricalcium Phosphate cement: histological and radiological evaluation

BackgroundShort-segment pedicle-screw instrumentation is frequently used to stabilize thoracolumbar burst fractures. A recognized disadvantage of this procedure is recurrent kyphosis from intervertebral disc creep into the fractured central endplate. Balloon Assisted Endplate Reduction (BAER) using Tricalcium Phosphate bone cement (TCP) enables elevation of the centrally depressed endplate. Our objective was to evaluate the bone-tissue response to TCP and to analyse whether BAER using TCP can prevent recurrent kyphosis after removal of the instrumentation.MethodsFourteen patients with traumatic thoracolumbar burst fractures were operated with BAER using TCP in combination with short-segment instrumentation. Nine months after surgery, instrumentation was removed and transpedicular biopsies were taken for histological and histochemical analysis. Roentgenograms pre- and postoperatively and at latest follow-up after removal of the instrumentation were evaluated.ResultsAverage follow-up was 2.6 years. Analysis of the biopsies showed a variable degree of bone remodelling with incorporation of TCP into newly formed bone matrix. No extensive foreign body reactions, inflammation, granulomatous responses or tissue necrosis were observed. Wedge-angle, kyphosis-angle and both the anterior-posterior and central-posterior vertebral body height ratios improved significant postoperatively (p < 0.001). After removal of the instrumentation no significant differences in wedge-angle or height ratios were seen (p = 0.12). The kyphosis-angle increased four degrees (p = 0.01).ConclusionTCP showed good histological osseointegration with no adverse events. TCP can therefore be safely used and could be beneficial in treatment of thoracolumbar burst fractures. BAER with TCP in combination with short-segment instrumentation might reduce recurrence of deformity even after removal of the instrumentation in comparison to short-segment instrumentation alone.Trial registrationThis study is registered at the at the Dutch Trial Registry (NTR3498).

Treatment of thoracolumbar burst fractures with short-segment pedicle instrumentation and recombinant human bone morphogenetic protein 2 and allogeneic bone grafting in injured vertebra

To investigate the effect of preventing the loss of correction and vertebral defects after thoracolumbar burst fractures treated with recombinant human bone morphogenetic protein 2 (rhBMP-2) and allogeneic bone grafting in injured vertebra uniting short-segment pedicle instrumentation. A prospective randomized controlled study was performed in 48 patients with thoracolumbar fracture who were assigned into 2 groups between June 2013 and June 2015. Control group ( n=24) received treatment with short-segment pedicle screw instrumentation with allogeneic bone implanting in injured vertebra; intervention group ( n=24) received treatment with short-segment pedicle screw instrumentation combining with rhBMP-2 and allogeneic bone grafting in injured vertebra. There was no significant difference in gender, age, injury cause, affected segment, vertebral compression degree, the thoracolumbar injury severity score (TLICS), Frankel grading for neurological symptoms, Cobb angle, compression rate of anterior verterbral height between 2 groups before operation ( P>0.05). The Cobb angle, compression rate of anterior vertebral height, intervertebral height changes, and defects in injured vertebra at last follow-up were compared between 2 groups. All the patients were followed up 21-45 months (mean, 31.3 months). Bone healing was achieved in 2 groups, and there was no significant difference in healing time of fracture between intervention group [(7.6±0.8) months] and control group [(7.5±0.8) months] ( t=0.336, P=0.740). The Frankel grading of all patients were reached grade E at last follow-up. The Cobb angle and compression rate of anterior verterbral height at 1 week after operation and last follow-up were significantly improved when compared with preoperative ones in 2 groups ( P<0.05). There was no significant difference in Cobb angle and compression rate of anterior verterbral height between 2 groups at 1 week after operation ( P>0.05), but the above indexes in intervention group were better than those in control group at last follow-up ( P<0.05). At last follow-up, there was no significant difference of intervertebral height changes of internal fixation adjacent upper position, injured vertebra adjacent upper position, injured vertebra adjacent lower position, and internal fixation adjacent lower position between 2 groups ( P>0.05). Defects in injured vertebra happened in 18 cases (75.0%) in control group and 5 cases (20.8%) in intervention group, showing significant difference ( χ2=14.108, P=0.000); and in patients with defects in injured vertebra, bone defect degree was 7.50%±3.61% in control group, and was 2.70%±0.66% in intervention group, showing significant difference ( t=6.026, P=0.000). Treating thoracolumbar fractures with short-segment pedicle screw instrumentation with rhBMP-2 and allogeneic bone grafting in injured vertebra can prevent the loss of correction and vertebral defects.

Effectiveness of pedicle screw inclusion at the fracture level in short-segment fixation constructs for the treatment of thoracolumbar burst fractures: a computational biomechanics analysis

When treating thoracolumbar burst fractures (BF), short-segment posterior fixation (SSPF) represents a less invasive alternative to the traditional long-segment posterior fixation (LSPF) approach. However, hardware failure and loss of sagittal alignment have been reported in patients treated with SSPF. Including pedicle screws at the fracture level in SSPF constructs has been proposed to improve stiffness and reliability of the construct. Accordingly, the biomechanical performance of the proposed construct was compared to LSPF via a computational analysis. Pedicle screws at fracture level improved the performance of the short-segment construct. However, LSPF still represent a biomechanically superior option for treating thoracolumbar BF.

Is fusion necessary for thoracolumbar burst fracture treated with spinal fixation? A systematic review and meta-analysis.

OBJECTIVE Thoracolumbar fractures account for 90% of spinal fractures, with the burst subtype corresponding to 20% of this total. Controversy regarding the best treatment for this condition remains. The traditional surgical approach, when indicated, involves spinal fixation and arthrodesis. Newer studies have brought the need for fusion associated with internal fixation into question. Not performing arthrodesis could reduce surgical time and intraoperative bleeding without affecting clinical and radiological outcomes. With this study, the authors aimed to assess the effect of fusion, adjuvant to internal fixation, on surgically treated thoracolumbar burst fractures. METHODS A search of the Medline and Cochrane Central Register of Controlled Trials databases was performed to identify randomized trials that compared the use and nonuse of arthrodesis in association with internal fixation for the treatment of thoracolumbar burst fractures. The search encompassed all data in these databases up to February 28, 2016. RESULTS Five randomized/quasi-randomized trials, which involved a total of 220 patients and an average follow-up time of 69.1 months, were included in this review. No significant difference between groups in the final scores of the visual analog pain scale or Low Back Outcome Scale was detected. Surgical time and blood loss were significantly lower in the group of patients who did not undergo fusion (p < 0.05). Among the evaluated radiological outcomes, greater mobility in the affected segment was found in the group of those who did not undergo fusion. No significant difference between groups in the degree of kyphosis correction, loss of kyphosis correction, or final angle of kyphosis was observed. CONCLUSIONS The data reviewed in this study suggest that the use of arthrodesis did not improve clinical outcomes, but it was associated with increased surgical time and higher intraoperative bleeding and did not promote significant improvement in radiological parameters.

Comparative study on treatment of thoracolumbar burst fractures with bone grafting by transpedicular approach and by interlaminal small fenestration

To investigate the effectiveness and long-term stability of small fenestration vertebral bone grafting and transpedicular bone grafting in the treatment of Denis types A and B thoracolumbar burst fractures. Between January 2012 and February 2014, 50 patients with Denis type A or B thoracolumbar burst fractures were treated with vertebroplasty and pedicle screw rod fixation system, and the clinical data were retrospectively analyzed. Small fenestration vertebral bone grafting by trans-interlaminar approach was used in 30 cases (group A), and bone grafting by unilateral transpedicular approach was used in 20 cases (group B). X-ray and CT examinations of the thoracolumbar vertebrae were performed routinely before and after operation. There was no significant difference in sex, age, cause of injury, time from injury to operation, fracture type, injury segment, and preoperative Frankel classification, the percentage of the anterior body height of the injured vertebra, and visual analogue scale (VAS) score between two groups ( P>0.05). There was significant difference in preoperative Cobb angle of kyphosis between two groups ( P<0.05). The Cobb angle of kyphosis, the percentage of the anterior body height of the injured vertebra, and the recovery of neurological function were recorded and compared between two groups. The patients were followed up for 16-31 months (mean, 19.1 months) in group A and for 17-25 months (mean, 20.2 months) in group B. Primary healing of incisions was obtained in the two groups; no nerve injury and other operative complications occurred. The neurological function was improved in varying degrees in the other patients with neurological impairment before operation except patients at grade A of Frankel classification. The lumbar back pain was relieved in two groups. There was significant difference in VAS score between before operation and at 3 months after operation or last follow-up in two groups ( P<0.05), but no significant difference was found between at 3 months and last follow-up in two groups and between two groups at each time point after operation ( P>0.05). X-ray examination showed that there was no breakage of nail and bar, or dislocation and loosening of internal fixation during follow-up period. The bone grafts filled well and fused in the fractured vertebra. The vertebral height recovered well after operation. The percentage of the anterior body height of the in-jured vertebra and Cobb angle of kyphosis at 1 week, 3 months, and last follow-up were significantly better than preope-rative ones in two groups ( P<0.05), but there was no significant difference between different time points after operation ( P>0.05), and between two groups at each time point after operation ( P>0.05). For Denis types A and B thoracolumbar burst fractures, vertebral bone grafting and pedicle screw internal fixation through interlaminal small fene-stration or transpedicular approach can restore the vertebral height, correct kyphosis, and maintain the vertebral stability, which reduce the risk of complications of loosening and breakage of internal fixators. The appropriate bone grafting approach can be chosen based on the degree of spinal canal space occupying, collapse of vertebral and spinal cord injury.

Treatment of thoracolumbar burst fractures by short-segment pedicle screw fixation using a combination of two additional pedicle screws and vertebroplasty at the level of the fracture: a finite element analysis

BackgroundTraditional one-above and one-below four-screw posterior short-segment instrumentation is used for unstable thoracolumbar burst fractures. However, this method has a high rate of implant failure and early loss of reduction. The purpose of this study was to use finite element (FE) analysis to determine the effect of treating thoracolumbar burst fractures by short-segment pedicle screw fixation using a combination of two additional pedicle screws and vertebroplasty at the level of the fracture.MethodsAn intact T11-L1 spine FE model was created from the computed tomography images of a male subject. Four fixation models with posterior fusion devices (pedicle screws, rods, cross-link) were established to simulate an unstable thoracolumbar fracture with different fusion surgeries: short-segment fixation with: 1) a link (S-L); 2) intermediate bilateral screws (S-I); 3) a link and calcium sulfate cement (S-L-C); 4) intermediate bilateral screws and calcium sulfate cement (S-I-C). Different loading conditions (flexion, extension, lateral bending, and axial rotation) were applied on the models and analyzed with a FE package. The range of motion (ROM), and the maximum value and distribution of the implant stress, and the stress in the facet joint, were compared between the intact and fixation models.ResultsThe ROM in flexion, extension, axial rotation, and lateral bending was the smallest in the S-I-C model, followed by the S-I, S-L-C, and S-L models. Maximum von Mises stress values were larger under lateral bending and axial rotation loadings than under flexion and extension loading. High stress was concentrated at the crosslink and rod junctions. Maximal von Mises stress on the superior vertebral body for all loading conditions was larger than that on the inferior vertebral body. The maximal von Mises stress of the pedicle screws during all states of motion were 265.3 MPa in S-L fixation, 192.9 MPa in S-I fixation, 258.4 MPa in S-L-C fixation, and 162.3 MPa in S-I-C fixation.ConclusionsShort-segment fixation with two intermediate pedicle screws together with calcium sulfate cement at the fractured vertebrae may provide a stiffer construct and less von Mises stress of the pedicle screws and rods as compared to other types of short-segment fixation.

Unilateral Wiltse intermuscular approach and contralateral decompression for the treatment of thoracolumbar burst fracture

To compare the clinical effects and multifidus muscle injury of different approaches, including unilateral Wiltse intermuscular approach and intramuscular approach combined with contralateral decompression, in treating thoracolumbar burst fracture. Forty-three patients with thoracolumbar burst fracture were enrolled in the study from January 2010 to December 2014, including 29 males and 14 females with an average age of 42.3 years old(ranged from 21 to 64 years old). The patients were treated with posterior pedicle screw fixation and unilateral decompression and were divided into Wiltse intermuscular approach group (group A) and intramuscular approach group (group B) according to surgical approach. Operation time and intraoperative bleeding were recorded for all patients; visual analogue scale(VAS) was compared 1 d preoperatively, 1 week, 12 months postoperatively between two groups; preoperation and 12 months postoperatively, the fractured vertebral canal and two-sides multifidus muscle of the same section were observed and compared by CT measure between two groups. All the patients were follow-up for 14 to 21 months with an average of 16.3 months. Partial wound non-healing occurred in 3 patients and the wound ultimately healing after debridgement suture and change dressings. No screw breakage was found. There was significant difference in operation and intraoperative bleeding operation between two groups (P<0.05), while there was no significant difference in VAS score of 1 d preoperatively, 1 week, 12 months postoperatively between two groups(P>0.05). As for CT measurement results, postoperative vertebral canal narrow ratio was significant decreased in all patients(P<0.05), while perioperative changes of the two-sides multifidus muscle cross section area and density were significant in group A (P<0.05), but there was no significant difference in group B (P>0.05). Neurologic status of all patients got recovery at final follow-up. The method of unilateral Wiltse intermuscular approach combined with contralateral decompression for the treatment of thoracolumbar burst fracture has good clinical effects, also it is less invasive and less damage to multifidus muscle compared with intramuscular approach.

Investigation of stress-strain state in spinal model for various methods of surgical treatment of thoracolumbar burst fractures (Рart one)

There are different views on the treatment of burst fractures of the lower thoracic and lumbar spine. Some specialists pre­fer conservative methods of treatment, others use a spinal fu­sion of 360° (anterior and posterior). However, questions of the extent of fixation, its strength, the possibility of correc­tion of deformation from the posterior approach, the feasibil­ity of performing laminectomy, etc. are discussed. Objective: to create a finite element biomechanical model of an burst frac­ture of the ThXIIvertebra body in the ThIX–LVvertebra block and analyze the stress-strain state in different fixation types. Methods: three computational models of the ThIX–LVvertebra block were created with the destruction of 50 % of the body volume of the ThXIIvertebra and fixation: 1) ThIXand LV; 2) ThIX, ThXIIand LI; 3) ThX, ThXIand LI, LII, as well as variants of the model with destruction of vertebral pedicles. Results: with the verti­cal load, the posterior spinal column is the most stressed, and the maximum stresses (45.9–46.6 MPa) in the fixing structures are located in the rods. In the case of fixation by 6 screws, the stresses in the rods are reduced by approximately 20 % (to 37.7–38.1 MPa). With the use of 8 screws, the total stress level compared to the fixation of 4 and 6 screws significantly decreased, in particular in the block of vertebrae LI–LValmost twice. Damage to the posterior support complex in the form of vertebral arches fracture led to a significant increase in ten­sion (by 17 %) in the injured vertebral body only in a model with 4 screws. Conclusions: the use of any transpedicular fixa­tion leads to a decrease in stress in the damaged vertebra. With an increase in the number of screws in the fixing structure, the level of stresses decreases, but the pattern of their distribu­tion in the spine does not change.

The clinical application of lateral extracavitary approach in the treatment of thoracolumbar burst fractures

Objective To explore the outcome of lateral extracavitary approach to anterior lateral decompression and bone fusion and internal fixation operation for thoracolumbar burst fracture with nerve injury. Methods The clinical data of 22 patients with thoracolumbar (T11-L2) burst fracture with nerve injury of lateral extracavitary approach to anterior lateral decompression and bone fusion and internal fixation operation were analyzed. The radiographic data of cobb angle, vertebral height compression percentage and spinal canal encroachment rate were compared. All data were collected pre-operation, post-operation and at last follow-up. According to clinical manifestations, recovery of neurological function before and after operation assessed by the American Spinal Injury Association (ASIA) classification and improvement rate of Japanese Orthopaedic Association (JOA) score from post-operation to last follow-up were compared. Results All 22 cases were followed up after operation for (18.0±7.2) months. The Cobb angle in pre-operative was (20.532±4.045)°, in post-operation days was (5.936±1.081)°, in last follow-up was (6.564±0.984)°. The difference was statistically significant before and after operation (t=14.822, P=0.000). Same difference at the last follow-up and preoperative comparison (t=16.134, P=0.000). There was no significant difference between the last follow-up and postoperative (t=-1.834, P=0.081). The percentage of vertebral height compression in pre-operative was (51.182±7.670)%, post-operation days was (91.773±2.308)%, in last follow-up was (90.545±4.284)%. At the post-operative, there was a significant difference compared with preoperative (t=-21.509, P=0.000). Between the last follow-up and preoperative aiso a significant difference (t=-18.990, P=0.000). No significant difference between the last follow-up and postoperative (t=1.528, P=0.141). The spinal canal encroachment rate in Preoperative was (34.818±5.142)%, post-operation days was (3.155±0.578)%, in last follow-up was (3.300±0.478)%. A significant difference between the postoperative and preoperative (t=29.136, P=0.000). In the same sense, the last follow-up compared with preoperative (t=28.304, P=0.000). To the contrary, no significant difference between the last follow-up and post-operative (t=-1.560, P=0.134). The ASIS score of patients there are 2 patients with complete injury, 12 patients received 1 levels of improved, and 8patients obtained 2 levels. The improvement rate of JOA score was improved in different degree expect 2 patients with complete injure, postoperative patients with excellent and good were 14 cases and 19 were followed up at the last follow-up. The excellent and good rate of post-operation was 86.363%, the excellent and good rate of the last follow-up was 63.645%, obviously improve between them. Conclusion The operation of lateral extracavitary approach to anterior lateral decompression and bone fusion and internal fixation can correct spinal kyphosis, restore and maintain vertebral height effectively, decompress the spinal canal completely and obtain satisfactory recovery in never function in the treatment of thoracolumbar burst fracture with nerve injury, which is an effective surgery. Key words: Lateral extracavitary approach; Ventrolateral decompression; Thoracolumbar; Brust fracture

Balloon vertebroplasty reinforced by injectable calcium sulfate cement versus posterolateral fusion for treatment of thoracolumbar burst fractures

Objective To compare the clinical curative effects of balloon vertebroplasty reinforced by injectable calcium sulfate cement(CSC) and posterolateral fusion after short-segment pedicle screw fixation through the fractured vertebra in treatment of thoracolumbar bumt fractures. Methods From February 2012 to May 2015, 68 cases patients with single thoracolumbar burst fracture were admitted in Orthopaedics and Traumatology Department of Traditional Chinese Medicine Hospital of Gaozhou, and were randomly divided into two observation group and control group, each group with 34 cases.Observation group were treated by short-segment pedicle screw fixation through the fractured vertebra followed by transpedicular balloon reduction of the endplate and CSC injection, the control group were underwent posterolateral fusion in addition to short-segment pedicle screw fixation through the fractured vertebra.The 2 groups were compared at preoperation, and the last follow-up in terms of visual analog pain score(VAS), Oswestry disability index(ODI), anterior height ratio of the injured vertebra, middle height ratio of the injured vertebra, the vertebral wedge angle and the sagittal Cobb angle. Results The patients were followed up from 12 to 54 months.All the measure indexes at the last follow-up were significantly improved than those at preoperation in all the patients(P 0.05). At the last follow-up, the observation group showed a significantly less loss than the control group regarding the corrections of anterior height ratio of the injured vertebra((93.6±3.4) vs.(81.8±4.8)), middle height ratio of the injured vertebra((90.7±3.8) vs.(78.9±5.1)), the veaebral wedge angle((5.7±1.9) ° vs.(8.8±3.0) °) and the sagittal Cobb angle((5.2±2.1) ° vs.(7.9±2.4) °)(t=4.143, 5.786, 4.819, 4.465, P<0.05). Conclusion In treatment of thoracolumbar burst fractures, compared with posterolateral fusion, balloon vertebroplasty reinforced by injectable CSC can better restore the shape of injured vertebral body and stability of the anterior and middle columns in the early period, can also reduce losses of corrections, and keep the function of the spinal motion segment. Key words: Spinal Fractures; Fracture fixation; Calcium sulfate; Bone cement

Comparison of curative effect of unilateral and bilateral vertebral pedicle screw instrumentation for treatment of thoracolumbar burst fractures

Objective To compare the efficacy of unilateral and bilateral pedicle screw instrumentation for treatment of thoracolumbar burst fractures. Methods A retrospective case-control analysis was made on 50 patients with thoracolumbar burst fractures free from neurological deficit admitted between January 2008 and October 2013. There were 37 males and 13 females, aged from 24 to 51 years (mean, 36 years). Injuries were caused by high falls in 23 patients, traffic accidents in 18 and crashing accidents in 9. Distribution of the injured segment was T11 in 6 patients, T12 in 16, L1 in 20 and L2 in 8. Based on the surgical procedures, the patients were assigned to unilateral pedicle screw fixation group (n=35) and bilateral pedicle screw fixation group (n=15). Operation time, intraoperative blood loss and hospital length of stay were recorded. Visual analogue scale (VAS), Oswestry disability index (ODI), kyphotic angle and anterior vertebral height were evaluated before surgery, after surgery and at 1-year follow-up. Results No screw lessening, screw breakage or infection occurred at 1-year follow-up. Unilateral and lateral pedicle screw instrumentation groups revealed no significant differences in operation time [(81.4± 10.0)min vs. (83.3±13.6)min], intraoperative blood loss [(194.0±65.4)ml vs. (212.0±61.9)ml] and hospital length of stay [(10.3±1.3)d vs. (9.9±1.5)d] (P>0.05). After operation, VAS and ODI in unilateral pedicle screw instrumentation group (3 points, 73.9) showed no significance from these in lateral pedicle screw instrumentation group (2 points, 72.1) (P>0.05). VAS was within 1 point and ODI was within 20 at 1-year follow-up, showing no significant differences between the two groups (P>0.05). After operation, correction of kyphotic Cobb angle and restoration of anterior vertebral body height in unilateral pedicle screw instrumentation group (8°, 26.7%) showed no significance from these in lateral pedicle screw instrumentation group (11°, 32.1%) (P>0.05). Loss of local kyphotic Cobb angle and anterior vertebral body height in unilateral pedicle screw instrumentation group (2°, 3%) showed no significance from these in lateral pedicle screw instrumentation group (1°, 2%) at 1-year follow-up (P>0.05). Conclusion Both methods have comparable efficacy in restoring vertebral height and improving spinal kyphosis for treatment of thoracolumbar burst fractures. Key words: Spinal fractures; Fracture fixation, internal; Pedicle screws

Bi-Pedicle Fixation of Affected Vertebra in Thoracolumbar Burst Fracture.

Burst fractures of the spine account for 14% of all spinal injuries and more than 50% of all thoracolumbar trauma. However, there is ambiguity while choosing the right treatment plan. Short Segment Pedicle screw Fixation (SSPF) has become an increasingly popular method of treatment of thoracolumbar burst fractures, providing the advantage of incorporating fewer motion segments in the fixation. Various biomechanical studies showed that the use of pedicle screws could achieve stable construct within short-segment fixation. To evaluate the efficacy of SSPF using longest possible screws in both pedicles of fractured vertebra. A retrospective chart review of 25 single burst thoracolumbar fracture patients, operated between May 2009 to 2015 in a tertiary care trauma center, was conducted. Preoperative and post-operative plain radiographs were evaluated for kyphotic angulations using the traditional Cobb method. Anterior Vertebral Height (AVH), Posteriors Vertebral Height (PVH) were measured preoperatively and immediate postoperatively. Average percentage loss of AVH and mid-sagittal height were calculated on preoperative and postoperative X-rays on follow up. Fourteen men and 11 women with an average age of 42.92 years comprised the study population. Mean age at the time of operation was 34.5±14.2 years. Mean operation time was 168±72 (minutes). Average hospitalization time was 9±7 (days). Mean blood loss was 515±485 (ml). There were two cases of postoperative infection and implant failure each. A mean of 15.2° of kyphosis correction was attained from pre-operation to post-operation (p<0.0001). Although, there was a 15° average improvement of kyphosis post-fixation, loss of correction over time was nearly 8°, resulting in a 7° mean correction of kyphosis. A mean loss of AVH on postoperative radiograph was 6.12% and maintained 12.4% at the time of review (p<0.001). Similarly, there was 32.8% mid-sagittal height loss at time of injury, which was improved to only 12.6% as compare to initial height loss (p<0.0001). In this study, we propose SSPF using longest possible screws in both pedicle of fractured vertebra. Bi-pedicular fixation gives significant radiological corrections.