The Effect of a Heel-unloading Orthosis in Short-term Treatment of Calcaneus Fractures on Physical Function, Quality of Life and Return to Work - a Randomized Controlled Trial
Phase: NA
Conditions: Calcaneus Fracture, Orthopedic Devices Associated With Misadventures
Sponsor: University of Southern Denmark

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Date: 10/01/18 
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Title 
The effect of a heel-unloading orthosis in short-term treatment of calcaneus fractures on physical 
function, quality of life and return to work – a randomized controlled trial 
Acronym 
CALCFRO (Calcaneus Fracture Orthosis) 
Trial registration 
The study needs to be approved by the Ethical Board of the Region of Southern Denmark. It needs to 
be registered at http://apps.who.int/trialsearch/, http://www.euroqol.org/register-to-use-eq-
5d.html. 
Protocol version 
Version: 2.5 
Date: 10/01/18 
Economy and budget 
The financial means are requested from Offerfonden (Rådet for Offerfonden| Adelgade 13 | DK-1304 
København K | Telefon +45 3392 3334 | Fax +45 3920 4505 | E-mail offerfonden@civilstyrelsen.dk). 
Roles and responsibilities 
Hagen Schmal (hagen.schmal@rsyd.dk), principal investigator, Department of Orthopaedics and 
Traumatology, Odense University Hospital, Department of Clinical Research, University of Southern 
Denmark, Denmark 
Lasse Pedersen (lasse.pedersen@rsyd.dk), investigator, Department of Orthopaedics and 
Traumatology, Odense University Hospital 
Anders Holsgaard Larsen (AHLarsen@health.sdu.dk;anders.larsen@rsyd.dk), study design, gait 
analysis, Department of Orthopaedics and Traumatology, Odense University Hospital, Department of 
Clinical Research, University of Southern Denmark, Denmark 
Lonnie Froberg (lonniefroberg@yahoo.dk), study design, patient acquisition, Department of 
Orthopaedics and Traumatology, Odense University Hospital, Denmark 
Julie Ladeby Erichsen (Julie.Ladeby.Erichsen@rsyd.dk), investigator, Department of Orthopaedics and 
Traumatology, Odense University Hospital, Denmark 
Carsten Fladmose Madsen (carsten.f.madsen@rsyd.dk), advisor, patient acquisition, Department of 
Orthopaedics and Traumatology, Odense University Hospital, Denmark 
Introduction 

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Background and rationale 
In the past decades, the scientific focus regarding calcaneus fractures was the choice of operative or 
non-operative treatment modality. Although the evidence is ambiguous [1], recent meta-analyses 
suggest that operative therapy is associated with a higher likelihood to resume pre-injury work, to 
reach a higher level of physical function and fewer problems when wearing shoes. However, non-
operative therapy has significant less complications and infections [2,3]. Typically, aftercare includes 
non- or partial weight bearing, but protocols are different and often not very specific. In fact, there 
are no studies published comparing different procedures or special supporting devices. Recently, a 
heel-unloading orthosis (‘Settner shoe’ [4]) was introduced in aftercare for calcaneus fractures, 
allowing walking by shifting the load to the middle- and forefoot. This orthosis does not only enable 
early mobilization of patients suffering one-sided fractures, but also permits going following two-
sided fractures, avoiding the otherwise necessary wheel-chair mobilization. The ‘Settner shoe’ can be 
applied in non-operative therapy and following operations. Specifically in calcaneus fractures, early 
regain of physical activity has been highlighted as one of the key factors for quality of life and the 
ability to return to work [2,3]. Thus, we hypothesize that mobilization with the ‘Settner shoe’ results 
in higher physical activity within the first 3 months and secondly improves ability to return to work in 
calcaneus fracture patients aged 18-60 years. Further outcome criteria are the American Orthopaedic 
Foot and Ankle Society's (AOFAS) ankle-hindfoot assessment, a 3-dimensional gait analysis, and the 
EQ-5D-3L questionnaire. It is the first trail applying a standardized aftercare in patients suffering from 
calcaneus fractures aiming to improve the non-operative part of treatment. Furthermore, the trial 
clarifies, whether the economical effort for the equipment acquisition is scientifically justified. 
Objectives 
We hypothesize that mobilization with the ‘Settner shoe’ results in higher physical activity within the 
first 3 months after calcaneus fractures. 
Research questions 
Does the application of a heel-unloading orthosis (‘Settner shoe’) independent of operative or non-
operative therapy of a calcaneus fracture improve: 
1.) the physical activity (active minutes per day)? 
2.) the quality of life (EQ-5D-3L)? 
3.) the foot function (AOFAS)? 
4.) the time necessary for return to work in patients between 18 and 60 years? 
Trial design 
The study design is a parallel group, randomized controlled trial with open allocation including all 
patients with calcaneus fractures independent of kind of initial therapy. 
Methods: Participants, interventions, and outcomes 
Study setting 

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All patients treated for calcaneus fracture (DS920* ‘Fraktur af hælben’ according to the Danish SKS-
browser) at the University Hospital Odense are prospectively screened for eligibility and included in 
the trial, if they fulfil the inclusion criteria as listed below. The follow-up period is 6 months. 
Eligibility criteria 
In Denmark, the treatment of calcaneus fractures is regarded as highly specialized, wherefore both 
decision-making and operations are done for the whole Region of Southern Denmark in the 
Department of Orthopaedics and Traumatology at the University Hospital Odense. Therefore, 
patients are screened by consultants of the local trauma section. 
Inclusion criteria: 
• 
Fracture of the calcaneus, which is classifiable according to the Sanders’ classification 
(excludes avulsion fractures) 
• 
Being able to understand Danish or English and answer the questionnaires 
• 
Informed consent 
• 
Age between 18 and 65 years 
Exclusion criteria: 
• 
Pathological fractures 
• 
Immature skeletal system 
• 
Other fractures with influence on weight-bearing 
• 
A soft-tissue situation not allowing the equipment with a ‘Settner shoe’ within 3 weeks after 
treatment (either decision-making for non-operative therapy or open reduction and internal 
fixation) 
Acquiring patient consent 
The participants will be introduced to the study by the medical personnel in a room, where they will 
not be disturbed. It will be assured that patients are allowed (if they wish) to be introduced to the 
study accompanied by a family member or any other person(s) selected by the patient. Patients will 
be given an oral overview of the purpose of the study, a participant information document describing 
the study and potential risk together with a patient consent form, which the patients will sign if they 
decide to participate in the study. The patient can resign from participating in the study without 
giving a reason and without any consequences. Patients are included after the operation or after 
decision for non-operative therapy, but before discharge. 
Interventions 
After operation or decision for non-operative therapy, the schedule for the 2 groups are defined as 
follows: 
Group 1 (treatment without ‘Settner shoe’): 
- mobilization without weight bearing for 6 weeks starting with the day of either decision-making for 
non-operative therapy or open reduction and internal fixation, if needed a cast or another kind of 
orthosis as a Static Walker are applied, then 4 weeks 15-20 kg, 2 weeks 35-45 kg, after that transition 
to full-weight bearing (always only if possible) 

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- X-ray after 6 and 12 weeks; depending on the results, the schedule for weight bearing may be 
adjusted to the need in case of delayed healing or complications related to implants 
Group 2 (treatment with ‘Settner shoe’): 
- mobilization with the custom-made heel-unloading orthosis (‘Settner shoe’) without pads for 6 
weeks, then 2 weeks one pad, 2 weeks 2 pads, 2 weeks 3 pads, after that full-weight bearing without 
any support (always only if possible) 
- X-ray after 6 and 12 weeks; depending on the results, the schedule for weight bearing may be 
adjusted to the need in case of delayed healing or complications related to implants 
The patients of both groups are informed about the aftercare at the time point of inclusion. 
Outcomes 
Primary outcome criterion 
The number of active minutes per day following 3 months (time point 2) is primary outcome 
criterion. 
Secondary outcome criteria 
- 
active minutes per day at time point 1 
- 
portion of highly active periods per day at time point 1 and 2 
- 
the EuroQol 5D-3L questionnaire following 3 months (time point 2) 
Explorative outcome criteria 
- 
AOFAS 
- 
3-dimensional gait analysis 
- 
time point of return to work of patients between 18 and 60 years 
- 
range of motion (ROM) 
Pro- and supination (percent of healthy side or assumed normal mobility) are analyzed. 
- 
pain 
The evaluation includes the medication and a visual-analogue scale (VAS). 
- 
comparison between patients with and without operation 
Patient characteristics beside outcome criteria 
Epidemiology 
• 
age 
• 
sex 
• 
body mass index 
• 
ASA (American Society of Anesthesiologists) physical status classification system 
Injury characteristics 
• 
classification according to Sanders (figure 4) 
• 
classification of open/closed tissue damage (table 1) 
• 
polytrauma (ISS≥16, multiple injuries, monotrauma) 
• 
indication for operation (dislocation, broadening, flattening of Böhler angle etc.) or 
conservative therapy (comorbidity, smoking etc.) 

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• 
the time between the fracture occurred and operation or decision making for non-operative 
therapy 
Healing and treatment characteristics 
• 
bone healing after 3 months: union or delayed healing 
The decision is made based on conventional radiographs including the clinical description of 
complains. 
• 
weight bearing after 3 months  
Is it possible or not? 
• 
hindfoot axis (varus/valgus-deformity, Böhler angle, subtalar osteoarthritis) 
The decision is made based on conventional radiographs and a clinical evaluation. 
• 
type of operation (approach, fixation method, graft) 
Complications 
• 
infection (I) 
• 
deep venous thrombosis (DVT) 
• 
nerve paresis/palsy/disturbed sensibility (N) 
• 
subtalar posttraumatic osteoarthritis (PTOA) 
• 
subtalar instability (SI) 
• 
local mechanical irritation by plate/screws (LI) 
• 
wound irritations (WI) as superficial healing problems or skin edge necrosis 
• 
irritations associated to the use of the custom-made heel-unloading orthosis (‘Settner shoe’) 
Participant timeline 
 

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The clinical and radiological controls correlate with the usual guidelines for treating calcaneus 
fractures at the Odense University Hospital. 
Sample size and power analysis 
The sample size calculation was based on a 33% difference in activity, correlating with a clinical 
relevant difference. Setting the power to 80% and the 2-sided confidence interval to 95% the 
calculation according to the method of Fleiss with continuity correction resulted in 25 patients per 
group. 
Recruitment 
All consultants of the trauma section of the Department of Orthopaedics and Traumatology at the 
University Hospital Odense are involved in the recruitment process of the study. 
Methods: Assignment of interventions (for controlled trials) 
Allocation 
In the period between treatment (either decision-making for non-operative therapy or open 
reduction and internal fixation) and consolidation of the soft-tissue situation, the patients are 
randomized for the aftercare with or without the custom-made heel-unloading orthosis (‘Settner 
shoe’). As soon as the soft-tissue situation allows the adjustment, the patients are referred to an 
orthopaedic shoemaker, who equips the patient accordingly. The randomization is done using the 
tool provided by OPEN. 
Blinding (masking) 
The allocation is not blinded, because it will be obvious to the patient, whether a special shoe is worn 
or not. Furthermore, the treating trauma surgeon needs to initiate the prescription. 
Methods: Data collection, management, and analysis 
Management and collection 
REDCap™ (Research Electronic Data Capture), a secure application for online surveys and databases, 
facilitates data management. The University Hospital Odense is an institutional partner of REDCap™, 
which was especially designed for biomedical research and fulfills all necessary safety features. This is 
supported by the OPEN initiative (Odense Patient data Explorative Network). REDCap™ used with the 
OPEN-platform supports also a randomization function, which is used for the study. 
Statistical methods 
Normally distributed numeric data sets are compared using the paired Student’s t–test. Otherwise or 
in case of non-numeric data, nonparametric tests determine the significance of difference. For 
correlations, Spearman ρ is calculated. Incidences are compared using the chi square test. Otherwise 
or in case of non-numeric data, nonparametric tests as the Mann-Whitney U-test for two and the 
Kruskal-Wallis H-test for multiple variables determine the significance of difference. For correlations, 
Spearman ρ is calculated. 

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Methods: Monitoring 
Data monitoring 
When the study is accepted for OPEN, a data manager will automatically be assigned to the study. 
The data manager will support the data coherence. Furthermore, a yearly data monitoring will be 
done by a study nurse, who is assigned to the project. 
Harms 
Any adverse or severe adverse events will be registered during the trial. Expected are especially local 
mechanical irritations, which are listed in the chapter for registration of patient characteristics beside 
outcome criteria. 
Ethics and dissemination 
Ethics 
The study needs to be approved by the ethical board of the Region of Southern Denmark 
(https://komite.regionsyddanmark.dk/wm258128). 
Patient law/privacy 
All data collected from patients are protected by the Act on Processing of Personal Data and Health 
Act according to Danish Data Protection Agency. The project will be reported to Datatilsynet (under 
“Regionens Paraply 2012-58-0018”). The database is established with OPEN, however, other possible 
related files are stored in a secure Sharepoint 
(https://secure.regionsyddanmark.dk/projektrum/ProTibExPla/SitePages/Startside.aspx). 
Publication 
Reporting will be conducted according to Consolidated Standards of Reporting Trials (CONSORT 
guidelines (http://www.consort-statement.org/) and published in a peer reviewed journal. 
Appendices 
Measurement of physical activity 
For monitoring of activity, the patients are equipped with a Misfit™ Shine (Burlingame, CA, USA) at 
the ankle and an Axivity™ AX3 (Newcastle upon Tyne, UK) at the lateral femur of the unaffected side. 
If there is a fracture at both sides, the trackers are attached to the side with the less complicated 
fracture. The wear time is 7 days. At day 7±14 (discharge) and after 3±0.5 months patients are 
equipped, and activity signals are analyzed by calculating the mean of all acquired 24-hour-data 
during these two periods. Regarding the Misfit™ Shine, only the number of registered steps is 
recorded. Regarding the Axivity™ AX3, the portion of highly active periods per day and the number of 
active minutes, correlating with walking activity, have shown to be most discriminating in the 
preliminary validation study. Therefore, these parameters are selected. Reliability is checked using a 
wear-time analysis based on change of signal vector magnitudes and temperature monitoring. 

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Correlating with these two data points, the EuroQol 5D-3L questionnaire [5] and the AOFAS [6] are 
monitored. 
Classification 
Classification of calcaneus fractures according to Sanders 
 
Figure 3: Axial load is necessary for calcaneus fractures, which should be treated with a heel-
unloading ‘Settner shoe’. 
 

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Figure 4: The fracture classification according to Sanders can group the calcaneus fractures that occur 
following axial load [7]. 
Classification of open fractures according to Gustilo-Anderson 
Gustilo Grade  
Definition 
I  
Open fracture, clean wound, wound <1 cm in length 
II  
Open fracture, wound > 1 cm but < 10 cm in length without extensive soft-tissue 
damage, flaps, avulsions 
III  
Open fracture with extensive soft-tissue laceration (>10 cm), damage, or loss or an 
open segmental fracture. This type also includes open fractures caused by farm 
injuries, fractures requiring vascular repair, or fractures that have been open for 8 
hr prior to treatment 
IIIA  
Type III fracture with adequate periosteal coverage of the fracture bone despite 
the extensive soft-tissue laceration or damage 
IIIB  
Type III fracture with extensive soft-tissue loss and periosteal stripping and bone 
damage. Usually associated with massive contamination. Will often need further 
soft-tissue coverage procedure (i.e. free or rotational flap) 
IIIC  
Type III fracture associated with an arterial injury requiring repair, irrespective of 
degree of soft-tissue injury. 
Table 1: The classification of open fractures according to Gustilo-Anderson [8]. 
Orthosis 
The heel-unloading orthosis (‘Settner shoe’ [4]) can be used for conservative treatment and aftercare 
following surgery. It needs to be assembled out of pre-formed and size-adjusted parts. This is done 
by an orthopaedic shoemaker. The increase of weight bearing is achieved by pads. The first 6 weeks 
the shoe is worn without pads. Then, the first pad is applied. Every 2 weeks a further pad is put in the 
shoe, which is removed after 3 months. Preliminary data suggest that this heel-unloading orthosis 
reduce days of inability to work. 
 
 
Figure 1: heel-unloading orthosis (‘Settner shoe’ [4]) 

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Figure 2: Principle of biomechanical unloading of the heel 
3-dimensional gait analysis 
All outcome calculations will be based on measurements taken during gait using a 3D Vicon MX 
movement analysis system with eight cameras operating at 100 Hz (Vicon, Oxford, UK) and two AMTI 
force-plates (AMTI, OR6-7, Watertown, MA, USA) embedded at floor level, operating at 1,000 Hz. A 
technician experienced in gait analysis and the Vicon system will attach reflective markers that 
reflect infrared light according to the Vicon Plug-in-Gait marker set and model [9]. 
Patient involvement 
The Misfit™ Shine worn at the healthy ankle can be coupled with an android or OS X app, which not 
only provides objective data about patient mobility during early aftercare, but at the same time 
signals feedback to the patient. By this, the patients themselves can control their postoperatively 
increasing activity. This includes a scientifically supported evaluation by the study leader at the 
defined follow-up time points at 6 weeks and 3 months after therapy start. The usual activity data 
published for healthy people are not comparable to this group, because the physical activity from 
patients in a rehabilitation process is usually lower. This way, the patient gets trained to interpret the 
data acquired by the app. 
References 
1. Bruce J, Sutherland A. Surgical versus conservative interventions for displaced intra-articular 
calcaneal fractures. Cochrane Database Syst. Rev. 2013;CD008628.  
2. Meena S, Gangary SK, Sharma P. Review Article: Operative versus nonoperative treatment for 
displaced intraarticular calcaneal fracture: a meta-analysis of randomised controlled trials. J. Orthop. 
Surg. Hong Kong. 2016;24:411–6.  
3. Zhang W, Lin F, Chen E, Xue D, Pan Z. Operative Versus Nonoperative Treatment of Displaced Intra-
Articular Calcaneal Fractures: A Meta-Analysis of Randomized Controlled Trials. J. Orthop. Trauma. 
2016;30:e75-81.  
4. Münch T. Proof of Functionality of the Heel-Unloading Orthosis according to Dr. Settner/Münch. 
Orthop.-Tech. 2002;2:646D145.  

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5. EuroQol Group. EuroQol--a new facility for the measurement of health-related quality of life. The 
EuroQol Group. Health Policy Amst. Neth. 1990;16:199–208.  
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validity of the SF-36, Ankle Osteoarthritis Scale, AOFAS Ankle Hindfoot Score, and Foot Function 
Index in end stage ankle arthritis. Foot Ankle Int. Am. Orthop. Foot Ankle Soc. Swiss Foot Ankle Soc. 
2012;33:57–63.  
7. Sanders R. Intra-articular fractures of the calcaneus: present state of the art. J. Orthop. Trauma. 
1992;6:252–65.  
8. Gustilo RB, Anderson JT. Prevention of infection in the treatment of one thousand and twenty-five 
open fractures of long bones: retrospective and prospective analyses. J. Bone Joint Surg. Am. 
1976;58:453–8.  
9. Kadaba MP, Ramakrishnan HK, Wootten ME. Measurement of lower extremity kinematics during 
level walking. J. Orthop. Res. Off. Publ. Orthop. Res. Soc. 1990;8:383–92.