***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE The treatment of thoracolumbar burst fracture is a controversial issue . Although spinal fusion has been a touchstone of spinal fixation , nonfusion technique have become raising its popularity recently . Some studies suggested that nonfusion had several advantages over fusion . The aim of this prospect i ve study was to compare long segment posterior instrumentation with fusion versus long-segment posterior instrumentation without fusion . METHODS For this purpose , 42 consecutive patients were assigned to two groups . Group 1 included 21 patients treated by long segment instrumentation with fusion ( WF ) , whereas Group 2 included 21 patients treated by long segment instrumentation without fusion ( WOF ) .  Long segment instrumentation was hook fixation ( claw hooks attached to second upper vertebra and infralaminar hooks attached to first upper vertebra ) above and pedicle fixation ( pedicle screws attached to first and second lower vertebrae ) below the fractured vertebra . RESULTS Measurements of local kyphosis , sagittal index and anterior vertebral height compression showed that both group had similar outcome at final follow-up . Moreover , there was no difference between the two groups according to low back outcome score . Also , implant failure rate ( 4.7 % ) was quite low in both groups . However , WF group had prolonged operative time , increased blood loss and donor site morbidity . CONCLUSIONS Radiological and clinical parameters demonstrated that spinal fusion is not necessary in long segment posterior instrumentation for the management of thoracolumbar burst fractures The objective of this study was to assess which patient group had better outcomes for management of single level thoracolumbar spinal fractures . We prospect ively collected data on the outcomes of patients having either conservatively managed , traditional open surgery , or minimally interventional surgery ( MIS ) for treatment of a single level thoracolumbar fracture . All patients had previously asymptomatic spines prior to their fractures and had a single level thoracolumbar burst fracture of more than 20 ° kyphosis . Fractures treated operatively , either via open surgery or MIS techniques , were corrected to less than 10 ° of residual kyphosis using a monoaxial pedicle screw construct 2 levels above & 2 levels below the fracture posteriorly only . The metalwork was removed between 6 months and 1 year post operatively to remobilise the spinal segments . All patients were then evaluated at least 6 months after metal work removal and at 18 months post fracture using radiographs and the Oswestry Disability Index (ODI).Those patients treated with MIS techniques demonstrated superior outcomes compared to traditional open techniques and conservative methods of treatment , with significantly reduced hospital stay , better return to work & leisure , and the best chance of restoring their spine to near its pre-injury status . We would recommend MIS techniques as the best way of treating single level thoracolumbar spinal fractures . There is a significant improvement in ODI when treated by MIS over open surgical methods Study Design . A prospect i ve clinical trial was conducted . Objectives . To compare the results of fusion versus nonfusion for surgically treated burst fractures of the thoracolumbar and lumbar spine . Summary of Background Data . The operative results of surgically treated burst fractures with short segmental fixation have been well documented . There is no report comparing the results of fusion and nonfusion . Methods . Fifty-eight patients were included in this study , with the inclusion criteria as follows : neurologically intact spine with a kyphotic angle ≥20 ° , decreased vertebral body height ≥50 % or a canal compromise ≥50 % , incomplete neurologic deficit with a canal compromise < 50 % , complete neurologic deficit , and multilevel spinal injury or multiple traumas . All patients were r and omly assigned to fusion or nonfusion groups , and operative treatment with posterior reduction and instrumentation was carried out . Posterior fusion with autogenous bone graft was performed for the fusion group ( n = 30 ) , and no fusion procedure was done for the nonfusion group ( n = 28 ) . The average follow-up period was 41 months ( range , 24–71 months ) . Results . The average loss of kyphotic angle was not statistically significant between these 2 groups . The radiographic parameters were statistically significantly better in the nonfusion group , including angular change in the flexion-extension lateral view ( 4.8 ° vs. 1.0 ° ) , lost correction of decreased vertebral body height ( 3.6 % vs. 8.3 % ) , intraoperative estimated blood loss ( 303 mL vs. 572 mL ) , and operative time ( 162 minutes vs. 224 minutes ) . The scores on the low back outcome scale were not statistically significant for these 2 groups . Conclusions . The short-term results of short segmental fixation without fusion for surgically treated burst fractures of the thoracolumbar spine were satisfactory . The advantages of instrumentation without fusion are the elimination of donor site complications , saving more motion segments , and reducing blood loss and operative time BACKGROUND The surgical results of treating thoracolumbar and lumbar burst fractures were reported to be comparable between patients with and without fusion in an intermediate-term follow-up . To our knowledge , no prior report has compared the results of fusion and non-fusion with long-term follow-up . METHODS This study was design ed to provide long-term evaluation of patients with a burst fracture of the thoracolumbar and lumbar spine treated with short-segment fixation who were r and omly assigned to a fusion or non-fusion group . Patients older than sixty years of age at the time of injury and those who were lost to follow-up were excluded .  Functional outcomes were evaluated using the Greenough Low-Back Outcome Score and the visual analog scale for back pain . Radiographic outcomes were focused on the vertebral body height of the injured vertebra , the kyphotic angle , and the regional segmental motion . RESULTS Twenty-two patients were enrolled in the non-fusion group , and twenty-four patients were enrolled in the fusion group . The average follow-up period was 134 months ( range , 121 to 161 months ) . The average preoperative kyphotic angle was 16.4 ° for the non-fusion group and 19.5 ° for the fusion group . The average postoperative kyphotic angle was 1.5 ° for the non-fusion group and 4.0 ° for the fusion group . At the time of the latest follow-up , the average kyphotic angle was 13.8 ° for the non-fusion group and 14.7 ° for the fusion group . The average kyphotic angle between the two groups was similar at all follow-up times . A progressive decrease of the kyphotic angle was significant ( p < 0.05 ) with time , regardless of fusion . The radiographic outcomes were similar between these two groups at all follow-up times , as were functional outcomes . More patients in the non-fusion group underwent additional surgery to remove implants . Regional segmental motion was preserved in the non-fusion group , with a mean motion ( and st and ard deviation ) of 4.2 ° ± 1.9 ° . CONCLUSIONS The long-term results of short segmental fixation with and without fusion for burst fractures of the thoracolumbar and lumbar spine were comparable . Regional segmental motion could be preserved without fusion , and bone graft donor site complications could be eliminated . LEVEL OF EVIDENCE Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence Twenty patients with thoracolumbar burst fractures ( type A3 in the classification of Magerl et al. ) were studied prospect ively for the evaluation of clinical , radiographic and functional results . The patients were su bmi tted to surgical treatment by posterior arthrodesis , posterior fixation and autologous transpedicular graft . The patients were followed up for 2 years after surgery and assessed on the basis of clinical ( pain , neurologic deficit , postoperative infection ) , radiographic ( load sharing classification , Farcy´s sagittal index of the fractured segment , relation between traumatic vertebral body height and the adjacent vertebrae ( compression percentage ) , height of the intervertebral disk proximal and distal to the fractured vertebra , rupture or loosening of the implants ) and functional ( return to work , SF-36 ) criteria . Two patients presented a marked loss of correction and required the placement of an anterior support graft . Pain assessment revealed that eight patients ( 44 % ) had no pain ; four ( 22 % ) had occasional pain , three ( 17 % ) moderate pain , and three ( 17 % ) severe pain . According to the classification of Frankel et al. , 17 patients persisted as Frankel E and one patient presented improvement of one degree , becoming Frankel D. The mean value of Farcy´s sagittal index of the injured vertebral segment was 20.67 ° ± 6.15 ° ( range 8 ° –32 ° ) during the preoperative period , 11.22 ° ± 8.09 ° ( range −5 ° to 21 ° ) during the immediate postoperative period , and 14.22 ° ± 7.37 ° ( range 3 ° –25 ° ) at late evaluation . There was a statistically significant difference between the immediate postoperative values and the preoperative and late postoperative values . The compression percentage of the fractured vertebral body ranged from 9.1 to 60 ( mean 28.81 ± 11.51 ) during the preoperative period , from 0 to 60 ( mean : 15.59 ± 14.49 ) during the immediate postoperative period , and from 8 to 60 ( mean : 25.9 ± 13.02 ) at late evaluation . There was a statistically significant difference between the preoperative and postoperative values and between the postoperative and late postoperative values . The height of the proximal intervertebral disk ranged from 6 to 14 mm ( mean 8.44 ± 2.66 ) during the preoperative period , from 6 to 15 mm ( mean 10 ± 2.30 ) during the immediate postoperative period , and from 0 to 11 mm ( mean 7.22 ± 2.55 ) during the late postoperative period . A significant difference was observed between the immediate postoperative values and the preoperative and late postoperative values . The height of the intervertebral disk distal to the fractured vertebra ranged from 7 to 16 mm ( mean 9.94 ± 2.64 ) during the preoperative period , from 5 to 18 mm ( mean 11.61 ± 3.29 ) during the immediate postoperative period , and from 2 to 14 mm ( mean 9.72 ± 3.17 ) during the late postoperative period . There was a significant difference between the immediate postoperative values and the preoperative and late postoperative values . Except for the height of the intervertebral disk proximal to the fractured vertebra , no correlation was detected between the clinical , functional and radiologic results . The results observed in the present study indicate that other , still incompletely defined parameters influence the functional result of thoracolumbar burst fractures The Low-Back Outcome Score has been devised as a new and accurate rating system for patients with low-back pain . Thirteen factors , such as pain , employment , sporting ability , rest required , and activities of daily living , were included ; subjective opinion was excluded . Pain and active pursuits were weighted . Presentation of the score as a question naire , excluding examination findings , eliminated both interobserver variation and observer variation with time . The score was applied retrospectively in a follow-up study of conservatively treated patients and was found to be more comprehensive and more discriminating than the Oswestry Disability Score , the Waddell Disability Rating , or the Waddell Physical impairment Rating . The  Low-Back Outcome Score  is recommended for further evaluation in future prospect i ve studies in low-back pain Objective : The treatment of thoracolumbar burst fracture is a controversial issue . Short-segment ( SS ) pedicle fixation has become a popular treatment option . However , there are several studies regarding the high rate of failure . The aim of this prospect i ve study was to compare SS versus long-segment ( LS ) instrumentation . Methods : For this purpose , 18 consecutive patients were assigned to two groups . Group 1 included nine patients treated by SS pedicle fixation , whereas group 2 included nine patients treated by LS instrumentation . SS instrumentation was pedicle fixation one level above and below the fractured vertebra . LS instrumentation was hook fixation ( claw hooks attached to second upper vertebra and infralaminar hooks attached to first upper vertebra ) above and pedicle fixation ( pedicle screws attached to first and second lower vertebrae ) below the fractured vertebra . Results : As a result , measurements of local kyphosis , sagittal index , and anterior vertebral height compression showed that the LS group had a better outcome at final follow-up ( P < 0.05 ) . Also , the SS group had a 55 % failure rate , whereas the LS group had prolonged operative time and increased blood loss . However , there was no difference between the two groups according to Low Back Outcome Score . Conclusions : In conclusion , radiographic parameters demonstrated that LS instrumentation is a more effective management of thoracolumbar burst fractures . Nevertheless , clinical outcome was the same between the two groups . However , our conclusions were based on posterior-only surgery . Anterior column support would negate the need for LS fixation . Also , SS would have been more successful if two above and two below pedicle screws were used The purpose of this study was to determine whether patients with a burst fracture of the thoracolumbar spine treated by  short segment pedicle screw fixation  fared better clinical ly and radiologically if the affected segment was fused at the same time . A total of 50 patients were enrolled in a prospect i ve study and assigned to one of two groups . After the exclusion of three patients , there were 23 patients in the fusion group and 24 in the non-fusion group . Follow-up was at a mean of 23.9 months ( 18 to 3 
    Output:
    
No significant difference between groups in the final scores of the visual analog pain scale or Low Back Outcome Scale was detected .
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 .
The data review ed 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