SunBurst (StUdy oN Burst Fractures) - a National, Multicenter, Register-based, Randomized Controlled Trial on Thoracolumbar Burst Fractures
Phase: NA
Conditions: Thoracolumbar Burst Fracture
Sponsor: Uppsala University

CLINICAL STUDY PROTOCOL 
 
 
 
 
SunBurst- StUdy oN Burst fractures 
 
 
Clinicaltrials identifier: 
NCT05003180 
 
Version Number: 
2.0 
Date: 
2024-05-21 
 
 
Research Body: 
Uppsala University 
Principal investigator: 
Paul Gerdhem, Uppsala University hospital 
Co-investigators: 
Simon Blixt, Uppsala University hospital, Peter Försth, Aleris 
Elisabethsjukhuset, Sebastian Mukka, Umeå University Hospital, Olof 
Westin, Sahlgrenska University Hospital 
SFR research 
coordinator 
Monica Sjöholm, Uppsala University 
Central research 
coordinators 
Catharina Strömstedt, Uppsala University Hospital, Luigi Belcastro and Maria 
Wikzén, Karolinska University Hospital 
Site investigators 
Sweden: Lukas Bobinski, Umeå University Hospital, Anastasios 
Charalampidis, Karolinska University Hospital, Freyr Gauti Sigmundsson, 
Anders Joelson, Örebro University Hospital, Ted Eneqvist, Södersjukhuset, 
Anders Olai, Linköping University Hospital, Anders Möller, Ralph Hasserius 
Skåne University Hospital, Erik Vestberg, Kalmar County Hospital, Martin 
Kempny, Halmstad County Hospital, Håkan Löfgren, Abd-Ali Riyad, Ryhov 
County Hospital, Andreas Westberg, Central Hospital of Västerås. 
 
Norway: Filip Dolatowski, Oslo University Hospital, Truls Hanestad, 
Haukeland University Hospital, Abdullah Cetinkaya, Akershus University 
Hospital, Anne Kristin Reve, Aksel Paulsen, Stavanger University Hospital, 
Sivert Hammer, St. Olavs Hospital. 
 
 
 

 
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SYNOPSIS 
 
Title: SunBurst- StUdy oN Burst fractures 
 
 
Rational for conducting the study: Treatment for thoracolumbar burst fractures ranges from 
no treatment to operative treatment. Current treatment evidence is based on retrospective or 
observational studies and a few small randomized controlled trials. The aim of this study is to 
compare operative versus non-operative treatment for thoracolumbar burst fractures.  
 
Study design: Randomized controlled clinical trial 
 
Study population: Individuals aged 18 through 66 years 
 
Number of individuals: 202 
 
Inclusion criteria: 
• Written informed consent 
• Age 18 through 66 years 
• Single level thoracolumbar burst fracture 
 
Exclusion criteria: 
• Neurological injury of the spinal cord or cauda equina 
• Definite rupture of the posterior tension band 
• Anchylosing spinal disorder spanning the fracture area 
 
Primary outcome variable:  
The primary outcome will be Oswestry Disability Index, a measure of back function at 1 year. 
 
 
Study period: Sep 1st 2021-Dec 31st 2036 (estimated) 
 
 

 
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SIGNATURE PAGE 
I confirm that I have read and understood this protocol and that I will work according to the 
protocol. By my signature, I agree to personally supervise the conduct of this study in my affiliation 
and to ensure its conduct in compliance with the protocol, informed consent, IRB/EC procedures, 
the Declaration of Helsinki, and local regulations governing the conduct of clinical studies. 
 
 
 
 
2023-01-19 
Signature Principal Investigator 
 
Date (yyyy-mm-dd)  
 
Paul Gerdhem 
Printed name of Principal Investigator 
 
 
 
 
 
Signature Head of Department 
 
Date (yyyy-mm-dd)  
 
 
Printed name of Head of Department 
 
 
 
 
 
 
 
 
 
 
 
 
 
Copy for study site; to remain with study protocol 
 
 

 
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SIGNATURE PAGE 
I confirm that I have read and understood this protocol and that I will work according to the 
protocol. By my signature, I agree to personally supervise the conduct of this study in my affiliation 
and to ensure its conduct in compliance with the protocol, informed consent, IRB/EC procedures, 
the Declaration of Helsinki, and local regulations governing the conduct of clinical studies. 
 
 
 
 
 
2023-01-19 
Signature Principal Investigator 
 
Date (yyyy-mm-dd)  
 
Paul Gerdhem 
Printed name of Principal Investigator 
 
 
 
 
 
Signature Head of Department 
 
Date (yyyy-mm-dd)  
 
 
Printed name of Head of Department 
 
 
 
 
 
 
 
 
 
 
 
 
 
Copy for study group; to be kept by study coordinator 

 
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CONTACT DETAILS 
 
Role 
Name 
Address 
Phone 
E-mail 
Research body 
 
Uppsala 
University 
Institutionen för 
kirurgiska 
vetenskaper, Ortopedi 
och Handkirurgi, 
Akademiska sjukhuset, 
751 85 Uppsala 
018-471 0000 
 
Principal 
Investigator 
Paul 
Gerdhem 
Institutionen för 
kirurgiska 
vetenskaper, Ortopedi 
och Handkirurgi, 
Uppsala Universitet 
och VO ortopedi och 
handkirurgi, 
Akademiska sjukhuset, 
Uppsala 
0736-994409 
paul.gerdhem@uu.se 
 
Resarcher/PhD-
student 
Simon Blixt 
VO ortopedi och 
handkirurgi, 
Akademiska sjukhuset 
och Institutionen för 
kirurgiska 
vetenskaper, Ortopedi 
och Handkirurgi, 
Uppsala Universitet 
0702-518628 
simon.blixt@akademiska.s
e 
Co-Investigator 
Peter Försth 
Aleris 
Elisabethsjukhuset 
Uppsala 
0705-561729 
peter.forsth@surgsci.uu.se 
Co-Investigator 
Sebastian 
Mukka 
Norrlands 
universitetssjukhus 
0730-867111 
sebastian.mukka@umu.se 
Co-investigator 
Olof Westin 
Sahlgrenska 
universitetssjukhuset 
0739-521538 
olof.westin@gu.se 
Central study 
coordinator 
Maria 
Wikzén and 
Luigi 
Belcastro 
Karolinska 
Universitetssjukhuset 
Huddinge, K54, 14186 
Stockholm 
0723-615755 
0736-994845 
maria.wikzen@regionstock
holm.se 
luigi.belcastro@regionstock
holm.se 
Study 
Coordinator 
SFR 
Monica 
Sjöholm 
Swedish Fracture 
register and Uppsala 
University 
0704-250043 
monica.sjoholm@uu.se 
 
Investigators 
 
 
Site investigator 
Lukas 
Bobinski 
Umeå University 
Hospital 
 
lukas.bobinski@umu.se 
Site investigator 
Freyr Gauti 
Sigmundsso
n,  
Anders 
Joelson 
Örebro University 
Hospital 
 
freyr.sigmundsson@region
orebrolan.se 
anders.joelson@oru.se 
Site investigator 
Anastasios 
Charalampidi
s 
Karolinska University 
Hospital 
 
anastasios.charalampidis@
regionstockholm.se 

 
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Site investigator 
Ted Eneqvist 
Södersjukhuset 
 
ted.eneqvist@regionstockh
olm.se 
Site investigator 
Anders Olai 
Linköping University 
Hospital 
 
anders.olai@regionostergot
land.se 
Site investigator 
Ralph 
Hasserius, 
Anders 
Möller 
Skåne University 
Hospital 
 
ralph.hasserius@skane.se 
anders.k.moller@skane.se 
Site investigator 
Erik Vestberg 
Kalmar County 
Hospital 
 
erik.vestberg@regionkalma
r.se 
Site investigator 
Martin 
Kempny 
Halmstad County 
Hospital 
 
martin.kempny@regionhall
and.se 
Site investigator 
Håkan 
Löfgren, 
Abd-Ali 
Riyad 
Ryhov County Hospital 
 
hakan.lofgren@rjl.se 
riyad.abd-ali@rjl.se 
Site investigator 
Andreas 
Westberg 
Central Hospital of 
Västerås 
 
andreas.westberg@regionv
astmanland.se 
Site investigator 
Filip 
Dolatowski 
Oslo University 
Hospital 
 
fido@ous-hf.no 
Site investigator 
Truls 
Hanestad 
Haukeland University 
Hospital 
 
truls.rokne.hanestad@hels
e-bergen.no 
Site investigator 
Abdullah 
Cetinkaya 
Akershus University 
Hospital 
 
abdullah.cetinkaya@ahus.n
o 
Site investigator 
Anne Kristin 
Reve, Aksel 
Paulsen 
Stavanger University 
Hospital 
 
anne.kristin.reve@sus.no, 
aksel.paulsen@sus.no 
 
Site investigator 
Sivert 
Hammer 
St. Olavs Hospital 
 
sivert.hammer@stolav.no 
Investigator/Res
ponsible health 
economy 
Gylfi 
Olafsson 
Westfjords Health 
Care Institute, Iceland 
 
gylfi@gyl.fi 
Investigator/Res
ponsible 
imaging 
Mari Hänni 
Uppsala University 
Hospital 
 
mari.hanni@akademiska.se 
MRI 
radiographer 
Hernani 
Vieira 
Uppsala University 
Hospital 
018-6119879 
hernani.vieira@surgsci.uu.s
e 
 
 
Protocol 
amendments 
Paragraph 
Page 
Date 
Version No 
Surgical 
treatment 
5.1. 
16 
2021-12-14 
1.9.2 
Treatment 
cross-over 
control group 
5.4.2 
17 
2021-12-14 
1.9.2 
Ethics 
10. 
23 
2021-12-14 
1.9.2 
Amendments 
11.1. 
24 
2021-12-14 
1.9.2 
Authorship 
12.1. 
25 
2021-12-14 
1.9.2 
Amendments 
11.1. 
24 
2023-07-16 
1.9.4 
Contact details 
 
5 
2024-05-21 
2.0 
Ethics 
10. 
23 
2024-05-21 
2.0 

 
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TABLE OF CONTENTS 
1. 
Introduction ...................................................................................................................... 10 
1.1. 
Background ..................................................................................................................... 10 
1.2. 
Rationale for conducting this study .................................................................................. 10 
1.3. 
Ethical issues ................................................................................................................... 11 
2. 
Study Objectives and Endpoints ...................................................................................... 11 
2.1. 
Primary objective ............................................................................................................. 11 
2.2. 
Secondary objectives ....................................................................................................... 11 
3. 
Study Design and Procedures ......................................................................................... 11 
3.1. 
Overall study design and flow chart ................................................................................. 11 
3.2. 
Rationale for study design ............................................................................................... 12 
3.3. 
Study visits ...................................................................................................................... 13 
4. 
Study Population ............................................................................................................. 14 
4.1. 
Inclusion criteria ............................................................................................................... 14 
4.2. 
Exclusion criteria ............................................................................................................. 15 
4.3. 
Subject enrollment and randomization ............................................................................. 15 
4.4. 
Discontinuation and withdrawal of subjects ...................................................................... 16 
4.4.1. 
Premature termination of the study .................................................................................. 16 
4.5. 
Re-screening ................................................................................................................... 16 
5. 
Study Treatments ............................................................................................................ 16 
5.1. 
Surgical treatment............................................................................................................ 16 
5.2. 
Non-surgical treatment .................................................................................................... 17 
5.3. 
Blinding ............................................................................................................................ 17 
5.4. 
Randomization ................................................................................................................. 17 
5.4.1. 
Platform problems inflicting screening and randomization ................................................ 17 
5.4.2. 
Treatment cross-over control group ................................................................................. 17 
5.5. 
Concomitant medication .................................................................................................. 18 
6. 
Study Measurements and Variables ................................................................................ 18 
6.1. 
Primary variable ............................................................................................................... 18 
6.2. 
Secondary variables ........................................................................................................ 18 
7. 
Statistics .......................................................................................................................... 20 
7.1. 
Sample size calculation ................................................................................................... 20 
7.2. 
Statistical analysis ........................................................................................................... 20 
7.2.1. 
Interim analyses .............................................................................................................. 22 
8. 
Data Management ........................................................................................................... 22 
8.1. 
Recording of data ............................................................................................................ 22 
8.2. 
Data storage and management........................................................................................ 23 
9. 
Quality Control and Quality Assurance ............................................................................ 23 
9.1. 
Audits and inspections ..................................................................................................... 23 
10. 
Ethics............................................................................................................................... 23 
10.1. 
Informed consent ............................................................................................................. 23 
10.2. 
Subject data protection .................................................................................................... 24 
10.3. 
Insurances ....................................................................................................................... 24 
11. 
Protocol Deviations and Amendments ............................................................................. 24 

 
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11.1. 
Amendments ................................................................................................................... 24 
12. 
Report and publications ................................................................................................... 25 
12.1. 
Authorship ....................................................................................................................... 25 
13. 
Study Timetable ............................................................................................................... 25 
13.1. 
Study period .................................................................................................................... 25 
13.2. 
Definition of “End of study” ............................................................................................... 26 
14. 
List of References ............................................................................................................ 27 
Appendix 1  - Imaging ................................................................................................................. 29 
Appendix 2 – ICD and KVÅ codes .............................................................................................. 30 
 
 
 
 

 
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LIST OF ABBREVIATIONS 
Abbreviation 
Explanation 
rRCT 
Register-based Randomized Controlled Trial 
SFR 
Swedish Fracture Register 
NPR 
National Patient Register 
CT 
Computed Tomography 
MRI 
Magnetic Resonance Imaging 
ODI 
Oswestry Disability Index 
SMFA 
Short Musculoskeletal Function Assessment 
EQ-5D-5L 
EQ-5D five level 
 
 
 

 
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1. INTRODUCTION  
1.1. Background 
The overall purpose is to improve treatment of thoracolumbar fractures. Thoracolumbar fractures 
are common and occur at all ages. A thoracolumbar fracture has a large impact on the individual 
and may be associated with long time disability. 
Most of the spine fractures occur in the thoracolumbar region, usually defined as the region 
between the tenth through the second or third lumbar vertebra. This region is more prone to 
injuries since it is the interface between the stiffer thorax and the mobile lumbar spine (Denis 
1983).  
We will use the newly developed Swedish Fracture Register (SFR) as a basis for this first ever 
nationwide register based randomized controlled trial on vertebral fractures. The results may be 
immediately implemented and treatment optimized. In Norway, the same information will be 
collected from questionnaires, medical records, and a secure web application. 
1.2. Rationale for conducting this study 
Current treatment evidence is based on retrospective or observational studies and a few small 
randomized controlled trials. The randomized controlled trial in this project can delineate the 
treatment efficacy of operative and non-operative treatment for thoracolumbar burst fractures. Also, 
it helps allocating money to interventions that do the most good.   
Reasons for surgical treatment include fast mobilization and return to normal activities, prevention 
of spinal deformity development, or the development of neurological problems (Rajasekaran 2010).   
Over the years most of the treatment studies of thoracolumbar fractures have been retrospective. 
Only a few randomized trials exist (Abudou, Chen et al. 2013, Wallace, McHugh et al. 2019). 
Thoracolumbar burst fractures that account for around 45% of the thoracolumbar injuries is one of 
the areas of most controversy. For thoracolumbar burst fractures, a meta-analysis of the only two 
existing randomized trials found no advantage for surgery over brace treatment , and a meta-
analysis of another two randomized trials found no advantage of brace treatment over no brace 
treatment (Wallace, McHugh et al. 2019). All the existing trials suffer from few participants. In 
meta-analyses, 87 individuals have been randomized to surgery or brace (Abudou, Chen et al. 
2013), and 119 individuals have been randomized to either brace or no brace (Wallace, McHugh et 
al. 2019). A recent search for the writing of the current application has not revealed any new 
published studies with high level of evidence.  
A search of ongoing clinical trials revealed the following two studies. An observational study on 
burst fracture with or without suspected posterior ligamentous injury treated with or without surgery 
with 208 planned participants (https://clinicaltrials.gov/ct2/show/NCT02827214). A randomized 
study will compare brace and no brace in individuals with thoracolumbar burst and compression 
fractures with 200 planned participants (https://clinicaltrials.gov/ct2/show/NCT03952182).  
Due to the relatively scarcity of evidence a current practice variation is evident, ranging from 
surgery to brace to no treatment other than analgesics within Sweden (2017), as well as 

 
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worldwide. No evidence exists on the cost-effectiveness of the intervention under consideration. 
Health economic analyses are important to improve allocation of scarce healthcare resources and 
have the potential of decreasing waste. 
1.3. Ethical issues 
We think it is important to evaluate the effect of surgical compared to non-surgical management in 
thoracolumbar burst fractures. Both non-surgical and surgical care are available today and routine 
care. The current situation with scarcity of evidence leads to a practice variation, ranging from 
surgery to brace to no treatment other than analgesics. We do not know whether unnecessary 
surgery is performed, which could possibly be associated with complications, or the opposite, if 
surgery should be offered frequently and result in a faster return to activity and maybe fewer 
complications than non-surgical management. Although this study require that 50% of the 
randomized study subjects go through surgery with the potential risk this entails (e.g. general 
anesthesia, infection and bleeding), surgery is not an uncommon practice today. However, non-
surgical management is also common. A failed non-surgical management may result in later need 
for surgery, which possibly result in poorer outcome and longer sick leave. We expect that this 
adequately powered study could answer the research questions and that the results measure up in 
relation to the ethical issues and the uncertainty of best care today. 
2. STUDY OBJECTIVES AND ENDPOINTS 
2.1. Primary objective 
1) The primary objective is to compare patient-reported outcome for two common treatments for 
thoracolumbar burst fractures, surgical stabilization and non-surgical care. Patient-reported 
outcome is primarily assessed with the back-specific patient-reported outcome questionnaire, 
Oswestry Disability Index (Fairbank and Pynsent 2000).  
2.2. Secondary objectives 
The secondary objectives of this study are to evaluate whether: 
2) surgical stabilization result in shorter time to return to work, 
3) surgical stabilization result in fewer collected doses of analgesics (opiods and non-opioids) 
compared to non-surgical care, 
4) surgical care result in fewer adverse events than non-surgical care, 
5) surgical care is cost effective as compared to non-surgical care, 
6) the associated cost is different between treatment arms, both in aggregate or by its components 
(both direct healthcare costs and indirect costs e.g. sick leave), 
7) radiographs are needed to monitor non-surgical treatment and surgical treatment outcome of 
thoracolumbar burst fractures, 
8) patients with thoracolumbar burst fractures included in a randomized controlled trial have the same 
outcomes as patients in an observational study with identical inclusion criteria. 
3. STUDY DESIGN AND PROCEDURES 
3.1. Overall study design and flow chart 
This is an international, multicenter open label parallel assignment randomized controlled trial 
(RCT) (Figure 1). The trial will use a pragmatic approach. The Swedish centers will use the SFR 

 
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infrastructure and other existing databases for outcome assessments, making this a register-based 
RCT (rRCT) for the Swedish part of the study (Wennergren, Ekholm et al. 2015, Morgonskold, 
Warkander et al. 2019). Due to the nature of the study, comparing a surgical and a non-surgical 
treatment alternative, an open approach is the most feasible design. Blinding of the patients and 
health care personnel will not be done. Patient-reported outcomes will however be assessed 
without influence of the care giver.  
Based on earlier studies and data from the SFR we estimate that 250 individuals yearly are treated 
for thoracolumbar burst fractures in Sweden and could be eligible for the RCT. Our time plan 
includes study start (mid 2021), last patient included (2025) and last 1-year follow-up (2026). 
Registry outcome data, and similar data collected from questionnaires and medical records in 
Norway, are planned to be collected at 5 and 10 years. The study may have come to an end 2036. 
However, delays in similar studies are not uncommon.  
 
Figure 1. Study design randomized controlled trial. 
3.2. Rationale for study design 
The rRCT study design in Sweden enables us to perform a national multicenter randomized 
controlled trial with a large sample size. Primary outcome is based on patient-reported outcome 
which will be collected on paper and through the SFR platform. In addition, important outcomes will 
be retrieved from health data registers and radiographic images. The Swedish personal identity 

 
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number (PIN) allows the investigator to cross-check registers on an individual level. Data on 
fracture classification, age, sex, type of trauma, time of diagnosis and time of treatment will be 
collected in the SFR. The study may be expanded internationally by collecting similar data from 
questionnaires, medical records, by secure web application. In Norway, the same data will be 
collected and processed using questionnaires, medical records, and the secure web application 
RedCap. Delabeled radiographic images will be sent using password-protected and encrypted 
hard disk drives. 
 
Randomization in Sweden will be done within the SFR registry-platform after informed consent has 
been obtained from the patient. In Norway, randomization will be done using the web application 
RedCap. Further variables will be registered by cross-checking with the National Board of Health 
and Welfare (National Patient Register, Swedish Prescribed Drug Register), Swedish Social 
Insurance Agency (Försäkringskassan) and Statistics Sweden. Mortality is automatically cross-
checked with the Swedish Cause of Death Register and available in the SFR. The same variables 
will be collected from questionnaires and medical records in Norway. 
3.3. Study visits 
Patients will be assessed at the time of fracture, at about 4 months, and 1 year (Figure 1, Table 1). 
There will be one formal clinical follow-up visit in addition to the local clinical routines, at 1 year. 
Additional follow-ups at 5 and 10 years through registry data in Sweden and from questionnaires 
and medical records in Norway are planned. We do not exclude the possibility that patients will be 
asked to provide patient-reported outcomes also at these time points. To minimize data loss 
reminders for patient-reported outcome data will be made (Table 1). 
 
 

 
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Table 1. Study activities. 
Visit 1 
Visit 2 
Visit 3 
 
 
Screening and 
randomization 
 
 
 
Day: 
Initial visit 
3-4 months 
1 year 
5 years 
10 years 
Informed consent 
X 
 
 
 
 
Demography 
X 
 
 
 
 
Inclusion/exclusion criteria 
X 
 
 
 
 
Randomization 
X 
 
 
 
 
Patient-reported outcome data  
X*a 
X** a 
X* a 
(X** a) 
(X** a) 
Imaging 
CT/MRI 
CT 
CT/MRI/standing 
spine radiograph 
 
 
Registry data  
X 
X 
X 
X 
X 
*ODI collected on paper. SMFA and EQ-5D-5L are collected through the SFR platform. All patient-reported outcomes are 
collected from questionnaires and medical records in Norway.  
**ODI, SMFA, EQ-5D-5L collected on paper 
a If patient-reported outcome measure (PROM) data is not captured as planned reminders on paper or telephone will be 
made. It is possible to capture all PROM data by telephone if paper or web-based collection does not work (Martin, 
Yaszemski et al. 2019).  A specific telephone interview version of EQ-5D-5L is available. For SMFA and ODI the 
standard questionnaire will be used. 
4. STUDY POPULATION 
4.1. Inclusion criteria 
• 
Age 18 to 66 years 
• 
Patients with a single level burst fracture type A3 or A4 between thoracic vertebra (T10) and 
lumbar vertebra 3 (L3) (Figure 2) (Reinhold, Audigé et al. 2013). 
Individuals with co-existing fractures in same level pedicles and same level or adjacent level 
posterior structures (lamina, transverse processes and/or spinous processes) are eligible for study 
inclusion if the posterior tension band is determined patent or indeterminate.  
Individuals with minor fractures in adjacent vertebra/es (minor avulsions of the vertebral body, 
lamina, transverse processes, spinous processes) are eligible for study inclusion as long as these 
minor fractures in themselves would not have resulted in any treatment.  
Individuals with vertebral body or posterior structure edema seen on magnetic resonance imaging 
(MRI) outside the computer tomography (CT) defined fracture area are eligible for study inclusion.  
Individuals with kyphosis in the fracture are eligible for study inclusion if the posterior ligamentous 
structures are patent or indeterminate (as determined on MRI). 
Patients with single level root compromise of minor importance are eligible for study inclusion. 
• 
Consent for study participation. 

 
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Figure 2. Drawings from the Swedish Fracture Register of type A3 and A4 burst fractures. Fracture 
type A3 is a burst fracture involving one endplate and the posterior wall of the vertebral body. 
Fracture type A4 is a burst fracture involving both endplates and the posterior wall of the vertebral 
body. 
 
4.2. Exclusion criteria 
• 
Unable to consent, no consent given, or not informed. 
• 
Individuals with neurological injury involving more than a single level root, i.e. spinal cord and/or 
cauda equina injury are excluded. 
• 
Individuals with definite rupture of the posterior tension band (through bony and/or ligamentous 
structures) are excluded.  
• 
Individuals with anchylosing spinal disorders spanning the fracture area are excluded. 
• 
Individuals not deemed suitable for operative or non-operative treatment due to co-morbidities are 
excluded.  
• 
Examples of such co-morbidities is established osteoporosis that would impair the possibility to 
maintain integrity of spinal implants, pathological fractures, severe cardiac or pulmonary 
compromise, or other systemic disease that would result in such high anesthesiologic risk that 
surgery would not be attempted.  
• 
Individuals already included in the study cannot be randomized again if they get an additional 
spine fracture. 
4.3. Subject enrollment and randomization 
When data for the fractured individual is entered by the treating physician in close connection to 
the fracture event in the SFR, a message will appear on the screen if the individual fulfills the 
inclusion criteria.  
 
The treating physician is instructed to contact the closest university hospital (all have 24-hour spine 
surgery service) to cross-check the inclusion criteria before randomization.  
 
In the event that a patient is not entered into the SFR by the treating physician, it is our experience 
that the university hospitals on call spine surgery services is often contacted to discuss treatment 
and eligible patients are thereby identified. All Swedish university hospitals and county hospitals 
that perform surgery on spine fractures are involved in the study.  
 
In Norway, the site investigators will screen patients for eligibility using RedCap. Subject eligibility 
will be established in the SFR for Swedish patients and in RedCap for Norwegian patients before 
treatment randomization. The study information and consent form can be printed from the SFR 
website or the RedCap website. Subjects will be randomized strictly sequentially, as subjects are 

 
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eligible for randomization. If a subject discontinues from the study, the subject number will not be 
reused, and the subject will not be allowed to re-enter the study.  
 
Randomization procedure 
 
Randomization will be performed through the Spine service at one of the participating hospitals. To 
enter the randomization module on the SFR website in Sweden, patient and fracture data already 
entered by the non-university hospital must be deleted, and be replaced by data entered into the 
university hospital SFR website. In Norway randomization will be performed in RedCap after the 
screening questions have been answered. 
 
Mistakenly randomized individuals 
 
In the event that an individual does not fulfill the inclusion criteria and was mistakenly randomized, 
the central study coordinator and steering committee must be informed by the participating clinic. 
The event will be noted in the study log book. The randomized individual will not be replaced by 
another in the study.  
4.4. Discontinuation and withdrawal of subjects 
Subjects are free to discontinue their participation in the study at any time. This will not affect 
further treatment. Patients will be withdrawn from study if the patient withdraws consent. Already 
collected study data for these patients will be kept in the study database, however new data, 
including data from registries will not be added. Patients prematurely withdrawn from the study will 
not be replaced. 
4.4.1. 
Premature termination of the study 
The study group may decide to stop the trial or part of the trial at any time. Furthermore, the 
investigator should promptly inform the Ethics Committee and provide a detailed written 
explanation. 
4.5. Re-screening 
The patient can be screened for study inclusion again, by the SFR online screening module in 
Sweden or by RedCap in Norway, if no active treatment, such as surgery or brace treatment, has 
been initiated. 
5. STUDY TREATMENTS 
5.1. 
Surgical treatment 
Surgical stabilization is performed. The recommended surgical procedure is posterior fixation with 
either open or minimally invasive approach. Based on the available evidence, pedicle screw should 
be inserted one level above and below the fractured vertebra, without fusion or decompression 
(Chi, Eichholz et al. 2019). If feasible, pedicle screws are inserted also in the fractured vertebra. 
However, the study is pragmatical and the choice of surgical procedure and numbers of vertebrae 
fixated will be at the discretion of the surgeon. The choice of supplier and brand of implants are 

 
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based on the established practice at of each participating center. Brace treatment will not be used 
postoperative. Early ambulation after surgery is encouraged. Surgery is to be performed within 2 
weeks from the injury. Physiotherapy and other measures of rehabilitation are prescribed on an 
individual basis. Additional surgery for removal of implants is optional and can be done according 
to local routines.  
5.2. 
Non-surgical treatment 
No surgical stabilization is performed. Early ambulation after treatment randomization is 
encouraged. Evidence for an effect of brace treatment on pain, disability and kyphosis on less 
severe thoracolumbar burst fractures (type A3) is lacking, but only based on two small studies 
(Wallace, McHugh et al. 2019). Data on the effect of brace versus no brace in the more severe 
burst fractures (type A4) is missing. The research group’s clinical experience of patients with more 
severe burst fractures (type A4) is a possible role of a brace in the short term treatment of pain. 
Therefore, brace treatment may be offered up to 3 months for pain relief. The brace is a standard 
three-point hyperextension brace which is fairly comfortable to use. The choice of supplier and 
brand of brace are based on the preference of each participating center. The brace will only be 
used upon mobilization. Brace use will be estimated by the patient at the 3-4 month follow-up, but 
time in brace may possibly be estimated by a temperature timing device (to be decided). 
Physiotherapy and other measures of rehabilitation are prescribed on an individual basis.  
5.3. Blinding 
The study design comparing a surgical to a non-surgical treatment does not allow blinding. Patient-
reported outcomes will however be assessed without influence of the care giver.  
5.4. Randomization 
Randomization will be performed by the web-based platform of the Swedish Fracture Register in 
Sweden and by the web application RedCap in Norway using an allocation sequence hidden from 
the healthcare personnel and provided by a statistician at Uppsala Clinical Research Center and 
independent from the study. Sweden and Norway will have separate allocation sequences. The 
subjects are randomized in a 1:1 ratio, without stratification.  
5.4.1. 
Platform problems inflicting screening and randomization  
Platform problems are expected to be few and of short duration. Screening and randomization will 
in such cases be postponed until the platform is in working order again.   
5.4.2. 
Treatment cross-over control group 
In case of the uncommon event of neurological compromise after inclusion in the study 
(Rajasekaran 2010), the reason for this has to be assessed. If this is due to canal compromise or 
progressing kyphosis, surgery may be advisable. Inability to initiate mobilization in a patient due to 
intense pain despite adequate analgesics and possibly a brace, may be a reason to resort to 
surgical treatment. A change in treatment will be documented in the Swedish Fracture Register in 
Sweden or in RedCap in Norway.  
An increasing kyphosis at follow ups is not a reason for treatment change since no evident relation 
between kyphosis and patient-reported outcome has been described (Rajasekaran 2010). Initial 

 
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extent of canal compromise or an increase in canal compromise during follow-up is not a reason 
for treatment change in the absence of neurological symptoms (Rajasekaran 2010).  
5.5. Concomitant medication 
Patient will receive their ordinary medications and the standard pre- and postoperative treatment at 
each participating center. 
6. STUDY MEASUREMENTS AND VARIABLES 
6.1. Primary variable 
• 
The primary variable/outcome of this RCT is Oswestry Disability Index (ODI) score 1 year after the 
fracture. ODI is a back specific index measuring disability due to back pain (Fairbank and Pynsent 
2000). It is the recommended instrument for studies concerning back pain. It consists of 10 
questions with six answer alternatives (from no problems to severe problems) on different aspects 
of back function and back pain. An index from 0-100 is calculated. An ODI of 0–20 indicate minimal 
disability, 21–40; moderate disability, 41–60; severe disability, 61–80; severely crippled, 81–100; 
bed-bound. We assume that individuals before the fracture have ODI on par with population-based 
data. At best, ODI after thoracolumbar fracture treatment approaches prefracture levels. 
Population-based data indicate a mean ODI of 8 for adults (Tonosu, Takeshita et al. 2012, Endler, 
Ekman et al. 2019).  
 
ODI data after thoracolumbar fracture are scarce. Mean ODI was 36 two years after surgical 
treatment of thoracolumbar fractures in one study (Wei, Liu et al. 2010) . In Swespine, mean ODI 
was 22 one year after surgical treatment (unpublished data). In 27 non-surgically treated 
individuals mean ODI was 11 two decades or more after a burst fracture (Moller, Hasserius et al. 
2007) .  
ODI is not part of the SFR and will be collected by paper in Sweden and Norway (Table 1). To 
minimize data loss reminders for patient-reported outcome data will be made (Table 1) (Martin, 
Yaszemski et al. 2019). The primary endpoints will be 1 year after the patient has been 
randomized. Data from other registries in Sweden will be collected retrospectively. 
 
If one question is left blank or missed, the ODI score is calculated as the percentage of the 
answered questions. If more than one box is marked for a question, the highest value will be 
counted (Fairbank and Pynsent 2000). 
6.2. Secondary variables 
See also 2.2 above. In summary, the secondary objectives of this study are to evaluate if surgical 
stabilization compared to non-surgical care result in outcome advantages such as health related 
quality of life, shorter time to return to work, less consumption of analgesics and fewer adverse 
events. Costs associated with the treatments will also be compared.   
 
The secondary variables are listed below.  
 
• 
Short Musculoskeletal Function Assessment (SMFA) is an instrument designed to measure the 
functional status of patients with various musculoskeletal disorders (Ponzer, Skoog et al. 2003). It 
consists of two parts, the dysfunction index based on 34 questions on difficulty performing certain 

 
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tasks, and the bother index based on 12 questions on how much the patients are bothered in 
certain areas of life. The dysfunction and bother indexes are calculated from the questions and 
range from 0 (best) to 100 (worst). SMFA is also distributed to patients with other types of fracture 
in the SFR.  
 
• 
The EQ-5D-5L is a generic quality of life instrument and consists of five dimensions/questions 
concerning mobility, self-care, usual activities, pain/discomfort and anxiety/depression (Burström, 
Teni et al. 2020). Each dimension has 5 answer alternatives: from no problems to extreme 
problems. An index can be calculated and depending on baseline value set used the index runs 
between approximately -0.2 (worst possible health) to 1.0 (best possible health). The EQ-5D-5L 
will be used for health economic analyses. The EQ-VAS is part of the EQ-5D and registers the 
patient’s self-rated health on a visual analogue scale (from 0 to 100; best). EQ-5D-5L is distributed 
also to patients with other types of fracture in the SFR.  
 
Surgical data and complications 
• 
Detailed surgical data will be collected through the SFR, radiographs and hospital files. Additional 
spine surgeries (diagnosis and type of surgical procedure) will be identified in the SFR and the 
National Board of Health and Welfare National Patient Register (NPR). Inpatient admissions, 
hospital stay and adverse events (postoperative infection, deep vein thrombosis and pulmonary 
emboli) will be collected from the NPR.  
 
Imaging: radiology and magnetic resonance imaging 
Minimum study imaging and time points are as follows. For imaging details, see Appendix. 
Standard preoperative investigation involves a computer tomography (CT) and magnetic 
resonance imaging (MRI) of the injured and adjacent segments. All preoperative MRIs are 
interpreted at a central site. Non-surgically treated cases are as per standard routine investigated 
with a CT or standing radiograph at about two weeks. At the 3-4 month follow-up a CT is 
performed, as part of routine assessment. A CT and whole spine standing radiograph (coronal and 
sagittal) is performed at 12 months. MRI of the thoracolumbar spine is performed at 12 months. 
Degree of fracture compression, local and global kyphosis, adjacent segment degeneration, and 
extent of any soft tissue/ligamentous injuries will be registered.  
 
Analgesics and antibiotics 
• 
Collected doses of analgesics and antibiotics from pharmacies will be collected from the National 
Board of Health and Welfare Swedish Prescribed Drug Register in Sweden and from 
questionnaires and medical records in Norway. 
 
Sick leave 
• 
Data on sick leave will be collected from the Swedish Social Insurance Agency 
(‘Försäkringskassan’). The ‘Longitudinal integrated database for health insurance and labour 
market studies’ available at Statistics Sweden may be used to retrieve data on unemployment and 
loss of income due to the fracture. In Norway the same data will be collected from questionnaires 
and medical records. 
 
Mortality 

 
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• 
Mortality, including cause of death will be collected from the SFR and/or the National Board of 
Health and Welfare Mortality Register in Sweden. In Norway information on mortality will be 
collected from medical records. 
7. STATISTICS 
7.1. Sample size calculation 
The primary outcome is the Oswestry Disablity Index (ODI) at 1 year. How large a difference in 
ODI should be between two groups to be clinically relevant is not known. Often the ODI minimal 
clinical difference (MCID) is used as an estimate of a clinically relevant group difference. MCID for 
ODI has been estimated to be around 10  (Copay, Glassman et al. 2008). In previous studies the 
SD for ODI is between 10 and 20, with lower values seen after surgical treatment of thoracolumbar 
fractures than after degenerative lumbar spine conditions (Copay, Glassman et al. 2008, Wei, Liu 
et al. 2010).. 
 
To identify a minimal clinical important difference (MCID) in the ODI of 10 with a standard deviation 
of 20 with alpha=0.05 and power of 90%, a sample size of 84 patients in each group is needed. To 
account for a loss to follow-up of up to 20%, 101 patients in each group is needed in the 
randomized controlled trial.  
7.2. Statistical analysis 
Data from the different groups will be compared based on the 'intention to treat' principle. An 
intention to treat (ITT) analysis means that all patients, regardless of treatment change, loss to 
follow-up or drop-out, remain in the analysis of the group to which they were randomized. 
Sensitivity analyses will be performed comparing the 'intention to treat' data against a per-protocol 
data, i.e. patients who exclusively complied with the treatment. Missing data will be handled with 
case-by-case exclusion/censoring. 
To test differences in continuous variables measured on at least interval scale between two 
independent groups the Student’s t-test for uncorrelated means will be used. The non-parametrical 
Mann-Whitney test will be used to test non normal data. In order to evaluate hypotheses of 
variables in contingency tables, the Chi-square test will be used or, in the case of small, expected 
frequencies, Fisher's Exact Test. Regression analysis will be used in order to evaluate the 
dependency between variables and a correlation coefficient analysis will be used in order to test 
independence between variables. In addition to that descriptive statistics will be used to 
characterize the data; means and 95% confidence intervals will be used for parametric data, 
medians and interquartile ranges for non-parametric data, and number (proportions) for categorical 
data. Independent statistical expertise will perform the statistical analysis. 
 
Sick leave/time to return to work is measured by using data from the Swedish Social Insurance 
Agency (Försäkringskassan, https://www.forsakringskassan.se/statistik/kontakta-statistikenheten) 
in Sweden or data collected from questionnaires and medical records in Norway and will be 
stratified based on the presence or absence of sick leave before the fracture event. Data on total 
time on sick leave (full time or part time; variables “sjuk- och rehabiliteringspenning” or “sjuk- och 
aktivitetsersättning”) as well as the diagnosis used for sick leave will be collected. Analyses will be 

 
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performed for dichotomous data at different time points, 4 months and 1 year after the fracture with 
Chi-square tests and Fisher’s exact tests. 
 
Data on collected analgesics and antibiotics from pharmacies will be collected from the National 
Board of Health and Welfare Swedish Prescribed Drug Register 
(https://www.socialstyrelsen.se/statistik-och-data/register/alla-register/lakemedelsregistret/) in 
Sweden and from questionnaires and medical records in Norway. Data from baseline until the 1-
year follow-up will be collected as amount of collected analgesics. Since different opioids may be 
used, conversion to morphine equivalents may be done. Data on other analgesics will be collected. 
Data on any prescribed antibiotics will be collected. Data on costs for the prescribed 
pharmaceuticals will be collected. Anatomic Therapeutic Chemical classification system (ATC) 
codes will be used to group the pharmaceuticals. Collected prescriptions will be assessed as 
dichotomous data (collected/not collected) at different time intervals; 0 to 4 months, >4 months to 1 
year with Chi-square tests. Total amount of collected opioids (continuous data consisting of 
morphine equivalents) will be compared with the Student’s t-test or the Mann-Whitney test, 
depending on distribution.  
 
Adverse events will be collected as (a) any spine surgery (and reason for) during the follow-up 
(from the SFR and the NPR in Sweden and by RedCap in Norway), (b) postoperative infection 
(from the SFR or diagnosed in the NPR based on diagnosis codes in Sweden and from 
questionnaires and medical records in Norway) and prescribed and collected antibiotics in close 
relation to the fracture (from the Swedish Prescribed Drug Register in Sweden and from 
questionnaires and medical records in Norway) during the follow-up. These will be analyzed as 
dichotomous variables with Chi-square or Fisher’s exact tests.  
 
Data on costs on the individual level will be collected. These consists of costs for the inpatient and 
outpatient visits (including surgery, radiographs, braces) collected from the treating hospital, 
analgesic and antibiotic treatments (collected from the Swedish Prescribed Drug Register in 
Sweden and from questionnaires and medical records in Norway), cost for sick leave (collected 
from the Swedish Social Insurance Agency and/or Statistics Sweden in Sweden and from 
questionnaires and medical records in Norway). Working status at baseline and at follow-ups will 
be collected from the ‘Longitudinal integrated database for health insurance and labor market 
studies’ available at Statistics Sweden for Swedish patients and the earnings lost due to the 
fracture will be estimated. In Norway patients will be asked to state the number of outpatient and 
telephone contacts (physician, nurse, physiotherapist) the fracture and treatment have resulted in 
at the 4 month and the 1-year follow-up. They will also be asked to state other expenses they have 
had in relation to the fracture and be asked to estimate the earnings lost due to the fracture. 
Quality-adjusted life years (QALYs) will be calculated for each group (as measured by EQ-5D-5L). 
Combining cost and QALY yields incremental cost-effectiveness ratio (ICER) of the surgical 
intervention as compared to non-surgical care. To quantify the uncertainty around estimates, 
bootstrapping will be used. This allows the creation of the cost-effectiveness plane (a chart 
showing differences in outcomes and costs on each axis).  
 
This ICER will then be compared to commonly used estimates of ICERs of other interventions 
(mainly surgeries and pharmaceutical interventions). Given the uncertainty around the official 
thresholds of willingness to pay for healthcare interventions, a cost-effectiveness acceptability 
curve will be drawn, showing the likelihood of the surgical intervention of being cost-effective given 
different levels of willingness to pay.  
 

 
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In general, health economic evaluations should include the whole duration of effects a particular 
intervention has. If large differences between groups exist still at 1-year follow-up, a horizon effect 
could bias the results. A horizon effect makes interventions with high upfront costs and slow 
recuperation of these investments less attractive compared with cheap interventions with higher 
later costs and/or worse long-term health outcomes. A health-economic model populated with data 
from the SFR in Sweden, from RedCap, questionnaires and medical records in Norway and 
published sources will be created to estimate the possibility and extent of this bias. Also, the model 
will be used to correct for this bias. 
7.2.1. 
Interim analyses 
The study plan intends complete inclusion and 1-year follow-up before analysis, therefore an 
interim analysis is not planned. 
8. DATA MANAGEMENT  
8.1. Recording of data 
Data will be collected from several sources (Table 2). Data primarily collected by the SFR will upon 
request from the research group be transferred from the SFR into the study database, with the 
exception of the screening question answers that will be entered into the study database from the 
SFR interface. Patient-reported outcome data will depending on type of data and time point be 
collected by the SFR or the central study coordinator. 
Table 2. Collection of data. 
Country 
Sweden 
Norway 
        Collected by    Central study 
coordinator 
SFR 
Study database 
at SFR 
NPR 
Pharma-
ceutical 
register 
Social 
Insurance 
Agency 
/Statistics 
Sweden 
Questionnaires 
and medical 
records 
Hard disk 
drive 
RedCap 
Type of data 
 
 
 
 
 
 
 
 
 
ODI 
X 
 
 
 
 
 
X 
 
 
SMFA 
 
X* 
 
 
 
 
X 
 
 
EQ-5D-5L 
 
X* 
 
 
 
 
X 
 
 
Other questionnaire 
data 
X 
 
 
 
 
 
X 
 
 
Images 
X 
 
 
 
 
 
 
X 
 
Fracture classification 
 
X 
 
 
 
 
 
 
X 
Screening question 
answers 
 
 
X 
 
 
 
 
 
X 
Additional spine 
surgery 
 
X 
 
X 
 
 
 
 
X 
Adverse events 
 
 
 
X 
 
 
X 
 
 
Analgesics/antibiotics 
 
 
 
 
X 
 
X 
 
 
Sick leave data 
 
 
 
 
 
X 
X 
 
 
*Collected by central study coordinator at 3/4 months 

 
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8.2. Data storage and management 
All data should be recorded, handled and stored in a way that allows its accurate reporting, 
interpretation and verification. All source data including informed consents from each participating 
study center, a copy of the completed study database, original protocol with amendments and the 
final report will be stored at the Karolinska University Hospital for a minimum period of 10 years 
after termination of the trial. All informed consents and data collected in Norway will be stored at 
each Norwegian study site for 5 years after the study ending.  
 
At the conclusion of the study, the occurrence of any protocol deviations will be determined. After 
these actions have been completed and the database has been declared to be complete and 
accurate, it will be locked and available for data analysis. 
9. QUALITY CONTROL AND QUALITY ASSURANCE 
The coordinator will have regular contacts with the clinic to verify informed consents of participating 
subjects, to confirm that facilities remain acceptable, that the investigational team is adhering to the 
protocol, to verify inclusion/exclusion criteria, study main endpoints. The investigator should ensure 
that all persons assisting with the trial are adequately informed and trained about the protocol and 
their trial related duties.  
9.1. Audits and inspections 
Authorized representatives of the study group may perform audits or inspection at the center. The 
investigator must ensure that all study documents are accessible for auditing and inspection. The 
purpose of an audit or inspection is to examine all study-related activities and documents 
systematically and independently, to determine whether these activities were conducted, and data 
were recorded, analyzed and accurately reported according to the protocol, and any applicable 
regulatory requirements. 
10. ETHICS 
The study will be performed in accordance with the protocol, with the latest version of the 
Declaration of Helsinki, and applicable regulatory requirements. The Swedish Ethical Review 
Authority has approved the study (dnr: 2021-00011, date of issue 2021-02-15, dnr: 2023-07942-
02, date of issue 2024-01-02). 
 
The Principal Investigator is responsible for informing the Ethics review board of any amendment 
to the protocol, in accordance with local requirements.  
10.1. Informed consent 
The investigator at each center will ensure that the subject is given written information about the 
nature, purpose and possible risks and benefits of the study. Subjects must also be notified that 
they are free to discontinue from the study at any time. The subject should be given the opportunity 
to ask questions and allowed time to consider the information provided. The original, signed 
Informed Consent Form (ICF) must be stored at the study site. For Swedish patients, a copy of the 
signed ICF is kept by the central study location. In Norway, a copy of the signed ICF will be stored 
at the respective trial centers.  

 
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The monitor(s) will be granted direct access to the subject’s original medical records for verification 
of clinical trial procedures and/or data, without violating the confidentiality of the subject, to the 
extent permitted by the applicable laws and regulations and that, by signing a written informed 
consent form, the subject is authorizing such access. 
10.2. Subject data protection  
The Informed Consent Form will incorporate wording that complies with relevant data protection 
and privacy legislation, and about the collection of data for the purposes of the study. 
The Informed Consent Form will explain that study data will be collected from questionnaires, 
hospital files, images and health databases/registries and will be stored in a computer database, 
maintaining confidentiality in accordance with national data legislation.  
10.3. Insurances 
The study subjects are covered by the Swedish Patient Injury Act in Sweden and by Norwegian 
System of Patient Injury Compensation in Norway. 
11. PROTOCOL DEVIATIONS AND AMENDMENTS 
Modifications to the signed protocol are only possible through approved protocol amendments and 
with the agreement of all responsible persons. Details of non-substantial amendments are to be 
clearly noted in the amended protocol. 
 
In case of a substantial protocol amendment (e.g. change of; main purpose of the trial, 
primary/secondary variable, measurement of primary variable), the concerned Ethics Committee 
must be informed and should be asked for its opinion/approval prior implementation of amended 
protocol, as to whether a full re-evaluation of the ethical aspects of the study is necessary by the 
committee. This should be fully documented. 
 
The Investigator must not implement any deviation from, or change to the protocol, without 
discussion with, and agreement by the study group and prior review and documented 
approval/favorable opinion of the amendment from the relevant ethics committee, except where it 
is necessary to eliminate an immediate hazard to study subjects, or where the change(s) involves 
only logistical or administrative aspects of the study (e.g. change of telephone numbers). 
 
databases/registries and will be stored in a computer database, maintaining confidentiality in 
accordance with national data legislation.  
11.1. Amendments 
The protocol has been updated 2023-01-19 with added study sites in Sweden, including Halmstad, 
Jönköping, Kalmar and Västerås, and Norway, including Akershus, Bergen, Oslo, and Stavanger. 
Sentences describing how the study design and data collection are modified for Norwegian 
patients have been added to Synopsis, 1.1, 3.1, 3.2, 3.3, 4.3, 4.5, 5.4, 6.1, 6.2, 7.2, 8.1, 10.1 and 
10.3. 
 

 
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The protocol has been updated 2023-07-16 with added study site in St Olavs Hospital in Norway. 
 
The wording of section 5.1. about surgical treatment has been adjusted to clarify that posterior 
fixation is the recommended treatment, but other surgical methods are allowed within the study to 
the surgeon’s discretion. 
 
Information clarifying when treatment cross-over is acceptable within the study has been added to 
5.4.2 with the heading “Treatment cross-over control group”. 
 
The dnr from The Swedish Ethical Review Authority has been corrected from 2020-00011 to 2021-
00011 in section 10. 
 
The protocol has been updated 2024-05-21. The update includes change of Research Body from 
Karolinska Hospital to Uppsala University, added ethical amendment in section 10. and updated 
contact details. 
 
Information about the authorship guidelines that will be followed for the final manuscript have been 
added to section 12.1. 
12. REPORT AND PUBLICATIONS. 
After completion of the study, the results will be analyzed and a clinical study report will be 
prepared. Upon study completion and finalization of the study report the results of this trial will be 
either submitted for publication and/or posted in a publicly accessible database of clinical trial 
results. 
12.1. Authorship 
The ICMJE guidelines for authorship (ICMJE) will be implemented in the writing and publication of 
the final report and any side-projects that uses the trials database. Minimum requirements include: 
 
• 
Substantial contributions to the design of the trial and/or contribution with data from at least 
5 patients in the trial 
• 
Drafting the work or revising it critically for important intellectual content 
• 
Final approval of the final manuscript and choice of journal 
• 
Agreement to be accountable for all aspects of the work in ensuring that questions related 
to the accuracy or integrity of any part of the work are appropriately investigated and 
resolved 
 
All participating investigators that don’t fulfil all four criteria will be mentioned as part of the 
SunBurst study group. 
13. STUDY TIMETABLE 
13.1. Study period 
Estimated subject enrollment start: 2021-09-01 

 
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Estimated subject enrollment stop: 2025-12-31  
Estimated subject last 1-year follow-up: 2026-12-31 
Estimated study end: 2036-12-31 
13.2. Definition of “End of study” 
End of study is defined as the last follow-up of the last subject.  
 

 
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14. LIST OF REFERENCES 
 
(2017). "Svenska Frakturregistret årsrapport 2017." Available at: 
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Abudou, M., X. Chen, X. Kong and T. Wu (2013). "Surgical versus non-surgical treatment for thoracolumbar 
burst fractures without neurological deficit." Cochrane Database Syst Rev(6): Cd005079. 
Burström, K., F. S. Teni, U. G. Gerdtham, R. Leidl, G. Helgesson, O. Rolfson and M. Henriksson (2020). 
"Experience-Based Swedish TTO and VAS Value Sets for EQ-5D-5L Health States." Pharmacoeconomics 
38(8): 839-856. 
Chi, J. H., K. M. Eichholz, P. A. Anderson, P. M. Arnold, A. T. Dailey, S. S. Dhall, J. S. Harrop, D. J. Hoh, S. 
Qureshi, C. H. Rabb, P. B. Raksin, M. G. Kaiser and J. E. O'Toole (2019). "Congress of Neurological Surgeons 
Systematic Review and Evidence-Based Guidelines on the Evaluation and Treatment of Patients With 
Thoracolumbar Spine Trauma: Novel Surgical Strategies." Neurosurgery 84(1): E59-e62. 
Copay, A. G., S. D. Glassman, B. R. Subach, S. Berven, T. C. Schuler and L. Y. Carreon (2008). "Minimum 
clinically important difference in lumbar spine surgery patients: a choice of methods using the Oswestry 
Disability Index, Medical Outcomes Study questionnaire Short Form 36, and pain scales." Spine J 8(6): 968-
974. 
Denis, F. (1983). "The three column spine and its significance in the classification of acute thoracolumbar 
spinal injuries." Spine (Phila Pa 1976) 8(8): 817-831. 
Endler, P., P. Ekman, H. Ljungqvist, T. B. Brismar, P. Gerdhem and H. Möller (2019). "Long-term outcome 
after spinal fusion for isthmic spondylolisthesis in adults." Spine J 19(3): 501-508. 
Fairbank, J. C. and P. B. Pynsent (2000). "The Oswestry Disability Index." Spine (Phila Pa 1976) 25(22): 2940-
2952; discussion 2952. 
ICMJE. "Defining the Role of Authors and Contributors."   Retrieved December 14, 2022, from 
http://www.icmje.org/recommendations/browse/roles-and-responsibilities/defining-the-role-of-authors-
and-contributors.html. 
Keynan, O., C. G. Fisher, A. Vaccaro, M. G. Fehlings, F. C. Oner, J. Dietz, B. Kwon, R. Rampersaud, C. Bono, J. 
France and M. Dvorak (2006). "Radiographic measurement parameters in thoracolumbar fractures: a 
systematic review and consensus statement of the spine trauma study group." Spine (Phila Pa 1976) 31(5): 
E156-165. 
Kuo, C. H., W. C. Huang, J. C. Wu, T. H. Tu, L. Y. Fay, C. L. Wu and H. Cheng (2018). "Radiological adjacent-
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Appendix 1  - Imaging 
Imaging: radiology and magnetic resonance imaging 
 
Computed tomography (CT)  
CT is performed of the fractured area according to clinical routines at the participating hospitals 
and should include at least one follow-up at 3 to 4 months. An additional CT is performed at the 1-
year follow-up. The CT must include the fractured vertebra/es and two vertebras above and below. 
 
Magnetic Resonance Imaging (MRI) 
MRI is performed according to clinical routine at the time of the fracture. An additional MRI is 
performed at the 1-year follow-up. A specific protocol has been developed for optimal imaging of 
soft tissues and is available from the department of radiology, Uppsala University Hospital (please 
contact Hernani Vieira by mail: hernani.vieira@surgsci.uu.se, or by telephone: 018-6119879 to 
acquire the protocol). We encourage its use for all patients with vertebral fractures.  
 
Standing radiographs 
A standing anteroposterior (or posteroanterior) and sagittal whole spine radiograph is taken at the 
1-year follow-up. The examination must be calibrated (to allow distance measuring).  
 
Measurements on images 
Degree of fracture compression, local and global kyphosis, adjacent segment degeneration, and 
extent of any soft tissue injuries will be registered. 
 
The degree of fracture compression is measured as the percentage of anterior vertebral 
compression compared to the adjacent intact vertebrae seen on the sagittal view. The formula 
described by Keynan et al. will be used (Keynan, Fisher et al. 2006).  
 
[(V1 + V3)/2 − V2]/(V1 + V3)/2) 
V1 = intact vertebra above fracture 
V2 = fractured vertebra 
V3 = intact vertebra below fracture 
 
Local kyphosis is measured according to the sagittal Cobb angle, i.e, the angle of a line parallel to 
the superior endplate of the vertebra above the fracture and a line parallel to the inferior endplate 
of the vertebra below the fracture (Polly, Kilkelly et al. 1996, Keynan, Fisher et al. 2006)  
 
Global kyphosis is measured as the angle of a line parallel to the superior endplate of the 
maximally tilted superior vertebra and a line parallel to the inferior endplate of the maximally tilted 
inferior endplate seen on the sagittal whole standing radiograph. 
 
Adjacent segment degeneration is registered as any form of listhesis, disc herniation or 
degeneration, hypertrophic facet joints and spinal stenosis seen on MRI 1 year after fracture 
compared to the initial MRI performed before randomization (Park, Garton et al. 2004, Kuo, Huang 
et al. 2018). Vertebrae above and below the fracture, or above and below the fixation in case of 
surgically treated patients, will be analyzed. 
 
Soft tissue injuries of the posterior tension band will be registered on the initial MRI scan. The 
posterior tension band consists of the following structures: 

 
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• 
Supraspinous ligament 
• 
Interspinous ligament 
• 
Ligamentum flavum 
• 
Facet capsules 
• 
Thoracolumbar fascia 
 
Each structure will be categorized as intact, incompletely disrupted or disrupted (Vaccaro, Rihn et 
al. 2009). ‘Intact’ indicates no change in MRI signal. ‘Incompletely disrupted’ indicates that there is 
a visible change in MRI signal such as edema, but complete disruption cannot be identified with 
certainty. ‘Disrupted’ indicates that there is a clear change in MRI signal compatible with a definite 
disruption. The posterior tension band as a whole will be categorized as intact or indeterminate. 
Patients with complete disruption of the posterior tension band are not eligible for the study. 
Appendix 2 – ICD and KVÅ codes 
Possible diagnostic codes 
ICD-10 code  
Description in Swedish  
 
Medicinska komplikationer 
I26 
I26.0: Lungemboli med uppgift om akut cor pulmonale. I26.9: Lungemboli utan 
uppgift om akut cor pulmonale 
I80 
Flebit och tromboflebit i ven 
I20-I25 
Ischemiska hjärtsjukdomar (inklusive detaljerade diagnoser) 
N39.0 
Urinvägsinfektion utan angiven lokalisation 
N30.9 
Cystit ospecificerad 
N30.0 
Akut cystit 
J13-J17.0 + 
J18 
Pneumoni (ospec + olika bakteriella agens) 
 
Kovariater 
I20-I25 
Ischemiska hjärtsjukdomar (inklusive detaljerade diagnoser) 
E10-E14 
Diabetes 
 
Kirurgiska komplikationer 
M84.1J 
Utebliven läkning/pseudartros i torakalryggen 
M84.1K 
Utebliven läkning/pseudartros i ländryggen 
T81.0 
Blödning/hematom 
T81.4 
Infektion efter kirurgiska och medicinska ingrepp som ej klassificeras på annan 
plats (sårinfektion) 
T81.8 
Annan specificerad komplikation till kirurgiska och medicinska ingrepp som ej 
klassificeras på annan plats 
T81.8W 
Annan specificerad komplikation till kirurgiska och medicinska ingrepp som ej 
klassificeras på annan plats 
T84.2 
Mekanisk komplikation av instrument för inre fixation av andra skelettben 
 
 

 
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Possible surgical codes 
ICD-10 
code/Klassifikation 
av vårdåtgärder 
(KVÅ) 
Description in Swedish 
ABC33 
Dekompression av nervrötter i bröstryggraden 
ABC36 
Dekompression av nervrötter i ländryggraden 
ABC53 
Dekompression av ryggmärgen och nervrötter i bröstryggraden 
ABC56 
Dekompression av ryggmärgen och nervrötter vid degenerativa förändringar i ländryggraden 
ABC63 
Dekompression av ryggmärgen i bröstryggraden 
ABC66 
Dekompression av ryggmärgen i ländryggraden 
ABC99 
Annan dekompressiv operation av ryggmärgen eller nervrötter 
AWW99 
Annan reoperation på nervsystemet 
NAG39  
Främre fusion utan fixationsmaterial 
NAG49  
Främre fusion med intern fixation 
NAG69  
Bakre fusion utan fixation 
NAG79  
Bakre fusion med fixation 
NAG99  
Annan excision, rekonstruktion eller fusion av leder i kotpelare 
NAJ89  
Osteosyntes av fraktur i kotpelare med annan eller kombinerad metod 
NAS99  
Annan operation vid infektion i kotpelare 
NAT29 
Bakre korrektion av deformitet 
NAT19 
Främre korrektion av deformitet 
NAK19 
Partiell eller total excision av kota 
NAU49 
Extraktion av implantat/osteosyntesmaterial 
NAW49 
Sutur av sårruptur i kotpelare eller nacke 
NAW59 
Reoperation för ytlig infektion i kotpelare eller nacke 
NAW69 
Reoperation för djup infektion i kotpelare eller nacke 
NAW89 
Reoperation för djup blödning i kotpelare eller nacke 
NAW99 
Annan reoperation i kotpelare eller nacke