Evaluation of a New Postoperative Dressing After Hallux Valgus Surgery
Phase: NA
Conditions: Hallux Valgus
Sponsor: Centre Assal for Foot Medicine and Surgery SA

 
 
1 
 
2 
Evaluation of a new postoperative dressing after hallux valgus 
3 
surgery 
4 
 
5 
 
6 
 
7 
 
8 
Research legislation: 
Ordinance on human research (HRO) [1]. 
9 
 
10 
 
11 
Type of Research Project: 
Research project involving human subjects  
12 
 
13 
 
14 
Risk Categorisation:  
Risk category A acc. to ordinance HRO Art.7 
15 
 
16 
 
17 
Project leader: 
 
Dr Victor Dubois-Ferrière 
18 
Centre Assal 
19 
Av. Beau-Séjour 6 
20 
1206 Genève 
21 
022 566 5436 
22 
victor.dubois-ferriere@centre-assal.ch 
23 
 
24 
 
25 
Sponsor:  
 
 
Centre Assal de médecin et chirurgie du pied SA 
26 
 
 
 
 
Av. Beau-Séjour 6 
27 
 
 
 
 
1206 Genève 
28 
 
29 
 
30 
 
31 
 
 
32 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
2/15 
PROTOCOL SIGNATURE FORM    
33 
 
34 
 
35 
Study Title 
 
Evaluation of a new postoperative dressing after hallux 
valgus surgery 
 
 
 
36 
The project leader has approved the protocol version 1 30.04.2025 and confirms hereby to 
37 
conduct the project according to the protocol, the Swiss legal requirements [1, 2], current version 
38 
of the World Medical Association Declaration of Helsinki [3] and the principles and procedures for 
39 
integrity in scientific research involving human beings.  
40 
The project leader has received the ICF and consider it appropriate for use. 
41 
 
42 
 
43 
Project leader: 
44 
 
45 
Site   
 
 
Centre Assal 
46 
Av. Beau-Séjour 6 
47 
1206 Genève 
48 
022 566 5436 
49 
 
50 
Name: 
 
 
Dr Victor Dubois-Ferrière 
51 
 
52 
Date: 
October 15th, 2025 _________ 
Signature:  __________________________  
53 
 
54 
 
55 
 
 
56 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
3/15 
TABLE OF CONTENTS 
57 
TABLE OF CONTENTS 
3 
58 
GLOSSARY OF ABBREVATIONS 
4 
59 
1 BACKGROUND AND PROJECT RATIONALE 
5 
60 
2 PROJECT OBJECTIVES AND DESIGN 
5 
61 
2.1 Hypothesis and primary objective and also secondary objectives 
5 
62 
2.2 Primary and secondary endpoints 
5 
63 
2.3 Project design 
6 
64 
3 PROJECT POPULATION AND STUDY PROCEDURES 
6 
65 
3.1 Project population, inclusion and exclusion criteria 
7 
66 
3.2 Recruitment, screening and informed consent procedure 
7 
67 
3.3 Study procedures 
8 
68 
3.4 Withdrawal and discontinuation 
10 
69 
4 STATISTICS AND METHODOLOGY 
10 
70 
4.1. Statistical analysis plan 
10 
71 
4.2. Handling of missing data 
11 
72 
5 REGULATORY ASPECTS AND SAFETY 
11 
73 
5.1 Local regulations / Declaration of Helsinki 
11 
74 
5.2 Notification of safety and protective measures (HRA Art. 15, HRO Art. 20) 
11 
75 
5.3 Serious events (HRO Art. 21) 
11 
76 
5.4 Procedure for investigations involving radiation sources 
12 
77 
5.5 Amendments 
12 
78 
5.6 End of project 
12 
79 
5.7 Insurance 
12 
80 
6 FURTHER ASPECTS 
12 
81 
6.1 Overall ethical considerations 
12 
82 
6.2 Risk-Benefit Assessment 
13 
83 
7 QUALITY CONTROL AND DATA PROTECTION 
13 
84 
7.1 Quality measures 
13 
85 
7.2 Data recording and source data 
13 
86 
7.3 Confidentiality and coding 
14 
87 
7.4 Retention and destruction of project data and biological material 
14 
88 
8  FUNDING / PUBLICATION / DECLARATION OF INTEREST 
14 
89 
9 REFERENCES 
14 
90 
 
 
91 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
4/15 
GLOSSARY OF ABBREVATIONS 
92 
 
93 
BASEC 
Business Administration System for Ethical Committees 
94 
CRF 
Case report form 
95 
FOPH 
Federal Office of Public Health 
96 
HRA 
Human Research Act 
97 
HRO  
Ordinance on Human 
98 
 
99 
 
 
100 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
5/15 
 
101 
1 
BACKGROUND AND PROJECT RATIONALE  
102 
After hallux valgus surgical correction, a spacer is applied between the first and the second in 
103 
order to maintain the alignment during the soft tissue healing period.1  Serval methods exist such 
104 
as a soft gauze folded between the first and second toe, a spica dressing or a tongue depressor 
105 
wrapped around the medial side of the hallux. 2 These methods often lack reliability because they 
106 
are not tailored to the specific anatomy of the patient. As a result, they can misalign the lesser 
107 
toes—pushing them laterally—instead of properly maintaining the hallux in alignment with the 
108 
foot. Additionally, these techniques are time-consuming and may cause discomfort, which can 
109 
negatively affect patient compliance.  
110 
The goal of the project is to assess the tolerance of a custom-made 3D-printed spacer (3D spacer) 
111 
designed to maintain the alignment of the hallux following surgical correction. Additionally, the 
112 
study aims to evaluate the resulting position of the hallux and the lesser toes. 
113 
 
114 
Risk Category (according to Art. 7 HRO): A 
115 
Rationale: 
116 
This research project falls under Category A because the custom-made spacer is not 
117 
implanted into the body but applied externally to the foot, in a manner similar to orthotic devices.  
118 
The spacer will never be in direct contact with the surgical wound, which is systematically covered 
119 
with a sterile postoperative dressing maintained in place until the wound has fully healed. This 
120 
ensures protection of the surgical site and eliminates any risk of wound contamination from the 
121 
device. 
122 
The spacer is manufactured using thermoplastic polyurethane (TPU), a material that is commonly 
123 
used in orthotic applications and that complies with ISO 10993 standards for biocompatibility. 
124 
Custom-made spacer are manufactured using the HP Jet Fusion 5200 Series printer, a state-of-
125 
the-art industrial technology widely adopted in the medical field, particularly for the production of 
126 
custom orthoses and prostheses. It is based on the Powder Bed Fusion process, which ensures 
127 
high precision, consistent reproducibility, and excellent mechanical properties of the printed parts. 
128 
Hewlett-Packard officially recommends this technology for orthopedic applications. 
129 
Given its external application and the use of biocompatible, well-established materials, the 
130 
intervention is associated with minimal risks and participant burden.  
131 
 
132 
2 
PROJECT OBJECTIVES AND DESIGN  
133 
2.1 Hypothesis and primary objective  
134 
Hypothesis: 
135 
The use of a custom-made 3D-printed spacer following surgical correction of the hallux will be 
136 
well tolerated by patients and will better maintain the alignment of the hallux and lesser toes 
137 
compared to conventional methods (e.g., folded gauze). 
138 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
6/15 
Primary Objective:  
139 
To evaluate the tolerance of a custom-made 3D-printed spacer used postoperatively to maintain 
140 
hallux alignment. 
141 
Secondary Objectives: 
142 
To assess the postoperative alignment of the hallux and the lesser toes using radiographic or 
143 
photographic evaluation.  
144 
To document any complications or adverse events related to the use of the custom-made spacer. 
145 
2.2 Primary and secondary endpoints 
146 
Primary Endpoint: 
147 
 
148 
The variable of primary interest is the tolerance of the custom-made 3D-printed spacer. 
149 
Tolerance will be evaluated at 1 week, 3 weeks, and 5 weeks postoperatively, based on patient-
150 
reported outcomes (e.g., comfort, pain, willingness to continue use) and clinical assessment (e.g., 
151 
skin irritation, redness, pressure marks, or ulceration). 
152 
Rationale for Selection: 
153 
 
154 
Tolerance is the primary endpoint because the spacer represents a novel, patient-specific medical 
155 
device. Before further evaluating its efficacy, it is essential to confirm that the device is well 
156 
tolerated and does not cause discomfort or adverse effects during the postoperative period. This 
157 
will inform its feasibility for broader clinical use. 
158 
Secondary Endpoints: 
159 
Alignment of the hallux, assessed: 
160 
Clinically at 5 weeks (e.g., visual inspection, standardized photographs) 
161 
Radiographically on a weight-bearing foot radiograph at 5 weeks 
162 
Alignment of the lesser toes, assessed: 
163 
Clinically at 5 weeks (e.g., signs of toe drift, or lateral deviation) 
164 
Radiographically at 5 weeks, focusing on toes orientation 
165 
2.3 Project design  
166 
Study Design and Justification: 
167 
This project is a prospective, single-center, exploratory cohort study involving patients who 
168 
undergo surgical correction for hallux valgus. The study aims to assess the tolerance of a 
169 
custom-made 3D-printed spacer and evaluate hallux and lesser toe alignment postoperatively. 
170 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
7/15 
The exploratory design is appropriate, as this is a preliminary investigation into the use of a 
171 
novel, patient-specific device. The main goal is to evaluate feasibility and early clinical 
172 
outcomes, particularly tolerance, before conducting larger-scale or comparative trials. 
173 
The project is conducted at a single center, which ensures standardized surgical techniques, 
174 
consistent postoperative care, and uniform assessment procedures. This setting minimizes 
175 
variability and improves the reliability of the findings for early-stage evaluation. 
176 
In addition to evaluating outcomes in patients using the 3D-printed spacer, we will perform 
177 
a matched comparison with a prospective cohort of patients who will be treated using 
178 
the traditional spacer (e.g., folded gauze). Participants will be allocated to one of the two study 
179 
groups by a simple randomisation procedure using sealed opaque envelopes prepared in 
180 
advance to ensure allocation concealment. This comparative element adds value by 
181 
contextualizing the performance of the new device against standard care, while still maintaining 
182 
the exploratory nature of the project. 
183 
3 
PROJECT POPULATION AND STUDY PROCEDURES 
184 
3.1 Project population, inclusion and exclusion criteria  
185 
Project Population and Sample Size: 
186 
The project will include a total of 20 patients undergoing surgical correction for hallux valgus at 
187 
a single center. These patients will receive a custom-made 3D-printed spacer postoperatively.  
188 
No additional cost will be charged during the study for the custom-made spacer. 
189 
In addition, a prospective control group of 20 patients will be formed. These patients will receive 
190 
the traditional spacer method (e.g., folded gauze) postoperatively. Matching will be based on 
191 
age, gender, and severity of the deformity, ensuring comparability between the two groups 
192 
regarding key variables influencing alignment outcomes. 
193 
Participant Selection and Representation: 
194 
All patients eligible for surgical correction of hallux valgus will be considered for inclusion, 
195 
without restriction based on age or gender, provided they meet the inclusion and exclusion 
196 
criteria. 
197 
At our institution, approximately 80% of patients undergoing hallux valgus surgery are women, 
198 
with a female-to-male ratio of 8:1. We will aim to maintain this natural distribution in our study 
199 
population to ensure representativeness and avoid introducing sex-based selection bias. 
200 
The underrepresentation of men reflects the actual patient population affected by the condition 
201 
and not a result of intentional exclusion. 
202 
Despite the gender imbalance, the findings will remain scientifically valid as they reflect the real-
203 
world demographic of patients undergoing this procedure.  
204 
Recruitment Strategy: 
205 
Participants will be recruited consecutively from patients scheduled for hallux valgus surgery. 
206 
They will be informed about the study and invited to participate during their preoperative 
207 
consultation. Recruitment will continue until the target number of participants (n=20) is reached. 
208 
Inclusion Criteria: 
209 
• 
Signed informed consent 
210 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
8/15 
• 
Diagnosis of hallux valgus with indication for surgical correction 
211 
• 
Undergoing one of the standard hallux valgus surgical procedures at the study center 
212 
• 
Age ≥18 years 
213 
Exclusion Criteria: 
214 
• 
Inability to provide informed consent 
215 
• 
Inability to follow study procedures (e.g. due to cognitive impairment or logistical 
216 
reasons) 
217 
• 
Insufficient knowledge of the project language 
218 
• 
Bilateral surgery 
219 
• 
Kown allergy to TPU 
220 
 
221 
3.2 Recruitment, screening and informed consent procedure 
222 
The project leader explains to each participant the nature of the research project, its purpose, the 
223 
procedures involved, the expected duration, the potential risks and any discomfort it may entail. 
224 
Each participant is informed that the participation in the research project is voluntary and that 
225 
he/she may withdraw from the research project at any time and that withdrawal of consent will 
226 
not affect his/her subsequent medical assistance and treatment. The participants are informed 
227 
that he/she can ask any question. Enough time is given to the participant.  
228 
 
229 
All participants are given an information document and a consent form describing the research 
230 
project. The formal consent of a participant, using the approved consent form, is obtained before 
231 
the participant is enrolled in the research project.   
232 
The participant should read, understand, and voluntarily agree before signing and dating the 
233 
informed consent form, and is given a copy of the signed document. The consent form is signed 
234 
and dated by the participant and the project leader (or her/his designee). The signed consent 
235 
form it is retained as part of the investigation records. 
236 
 
237 
Screening and recruitment: 
238 
Recruitment Location and Procedures: 
239 
Participant recruitment will take place at Centre Assal SA, where all surgical procedures and 
240 
follow-up visits will also be conducted. 
241 
Recruitment Process: 
242 
All patients scheduled to undergo surgical correction of hallux valgus at Centre Assal SA will be 
243 
screened for eligibility. Recruitment will be prospective and consecutive, meaning every eligible 
244 
patient will be informed about the project as part of the standard preoperative consultation. This 
245 
approach ensures an unbiased and representative selection of participants. 
246 
Informed Consent Process: 
247 
Patients will receive oral and written information about the study during their preoperative visit. 
248 
They will be given ample time to consider participation. Patients will be encouraged to ask 
249 
questions and will have the opportunity to clarify any aspects of the project with the clinical or 
250 
research 
team. 
251 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
9/15 
Only after ensuring full understanding and voluntary agreement will written informed consent be 
252 
obtained, in accordance with legal and ethical guidelines. 
253 
Representation of Relevant Population – Age, Sex, and Gender Considerations: 
254 
The recruitment strategy is designed to ensure appropriate representation of the population 
255 
typically affected by hallux valgus. At our center, approximately 80% of patients treated surgically 
256 
for hallux valgus are women, reflecting the epidemiology of the condition. We aim to maintain this 
257 
natural distribution within the study to ensure scientific validity and real-world relevance. 
258 
Men undergoing the same surgical procedure will be included whenever available, to avoid 
259 
unjustified 
exclusion 
of 
any 
gender 
group. 
260 
Patients of all adult age groups will be considered, and no upper age limit is imposed, as long as 
261 
the patient meets the inclusion criteria and can participate in follow-up visits. 
262 
3.3 Study procedures 
263 
The overall project duration is approximately six months, including patient recruitment, 
264 
intervention, and follow-up assessments. The recruitment period is expected to last three to four 
265 
months, continuing until 20 participants undergoing hallux valgus surgery are enrolled. Each 
266 
participant will be involved in the study for five weeks postoperatively, with evaluations conducted 
267 
at scheduled intervals to assess spacer tolerance and alignment outcomes. 
268 
Before surgery, participants provide informed consent during their preoperative consultation. 
269 
Baseline data, including demographic information and preoperative hallux alignment, are 
270 
collected. The custom 3D-printed spacer is fabricated based on individual foot measurements 
271 
obtained through a 3D photograph of the foot and applied immediately after surgical correction. 
272 
A matched retrospective control group, treated with traditional folded gauze spacers, is used for 
273 
comparison, with patients selected based on age, sex, and deformity severity. 
274 
To ensure balanced allocation between the two study groups, a simple randomisation process 
275 
will be implemented. 
276 
A total of 40 opaque sealed envelopes will be prepared in advance, containing 20 assignments 
277 
labeled “PSMT 3D” and 20 labeled “Spacer standard.” 
278 
 
279 
When a patient’s date of surgery is confirmed, the secretary in charge of operating-room 
280 
planning will draw one sealed envelope at random and record the group allocation. 
281 
The envelope will then be opened to determine whether the participant belongs to the PSMT 3D 
282 
or Spacer standard (control) group. 
283 
 
284 
This procedure ensures allocation concealment and prevents any influence from the 
285 
investigators on group assignment. 
286 
Randomisation will continue until all 40 envelopes have been used. 
287 
 
288 
Follow-up visits occur at one week, three weeks, and five weeks post-surgery. During the first 
289 
visit, clinical inspection evaluates spacer fit, skin condition, and initial tolerance, assessed through 
290 
patient-reported comfort and pain levels. The three-week visit repeats these assessments to 
291 
monitor ongoing tolerance. The final visit at five weeks includes a comprehensive evaluation: both 
292 
clinical and radiographic assessments are performed. 3D photographs document foot alignment, 
293 
while weight-bearing X-rays measure hallux and lesser toe positioning. 
294 
Data collection relies on structured questionnaires for subjective tolerance feedback, clinical 
295 
examinations for spacer performance, and imaging for objective alignment verification. Patient-
296 
reported outcomes focus on discomfort, ease of use, and willingness to continue spacer 
297 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
10/15 
application. Clinical assessments note any adverse effects, such as skin irritation or pressure 
298 
marks. Radiographic analysis quantifies alignment changes. 
299 
Potential biases in the study are addressed through specific mitigation strategies. Selection bias, 
300 
arising from the predominance of female participants, is minimized by matching control patients 
301 
based on key demographic and clinical factors. Measurement bias is reduced by standardizing 
302 
imaging protocols and, where feasible, employing blinded assessors for radiographic analysis. 
303 
Recall bias is limited through frequent follow-ups, ensuring timely and accurate patient feedback. 
304 
Attrition bias is managed by closely monitoring participants for complications, encouraging 
305 
compliance, and addressing issues promptly to prevent dropouts. 
306 
 
307 
3.4 Withdrawal and discontinuation 
308 
 
309 
Participants may leave the study for several reasons: if they choose to withdraw their consent, if 
310 
they experience significant discomfort from the 3D-printed spacer, if they miss follow-up visits, if 
311 
new health problems arise, or if they don’t follow study instructions. 
312 
If a participant stops the study early, the research team will conduct a final check-up if possible. 
313 
This includes examining the foot, recording any issues with the spacer, and noting why they left 
314 
the study. Collected data up to that point will still be used for analysis. 
315 
For participants who cannot tolerate the 3D-printed spacer, the study team will replace it with a 
316 
traditional spacer (such as folded gauze) and continue monitoring their progress.  
317 
All personal information is carefully protected. Names and identifying details are removed from 
318 
study records, and any stored materials (like scans or X-rays) are labeled with codes instead. If 
319 
a participant withdraws and requests full data deletion, their information will be securely erased. 
320 
Even if participants leave the study early, their available data may still be analyzed to help 
321 
researchers understand the spacer’s performance. The study team documents all withdrawals to 
322 
ensure transparency and minimize bias in the results. 
323 
 
324 
 
325 
4 
STATISTICS AND METHODOLOGY 
326 
4.1. Statistical analysis plan 
327 
 
328 
Objectives The primary objective of this study is to descriptively evaluate patient tolerance of the 
329 
3D-printed spacer in comparison to traditional methods. 
330 
Sample Size Justification Due to the exploratory nature of this study, a formal power calculation 
331 
was not performed. Instead, the sample size of 20 participants was chosen based on feasibility, 
332 
considering the expected number of eligible patients at the study center within a reasonable 
333 
timeframe. This sample size allows for preliminary assessment of tolerance and alignment 
334 
outcomes while maintaining practical recruitment constraints. 
335 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
11/15 
Analyses will be performed according to the randomised group assignment (“PSMT 3D” vs 
336 
“Spacer standard”) as determined by the sealed-envelope procedure described in Section 3.3. 
337 
 
338 
Statistical Methods for Primary Endpoint (Tolerance) Tolerance will be assessed using patient-
339 
reported outcomes (e.g., Likert scale ratings on comfort and pain). Descriptive statistics (mean, 
340 
standard deviation, frequencies) will summarize these results. Given the exploratory aim and 
341 
limited sample size of this study, tolerance results for the 3D-printed spacer will be reported 
342 
descriptively without formal comparative statistical testing. 
343 
Secondary 
Endpoint 
(Alignment 
of 
Lesser 
Toes) 
344 
Lateral deviation of the lesser toes will be measured radiographically. A two-sample t-
345 
test (or Wilcoxon rank-sum test for non-normal data) will compare alignment between groups. No 
346 
adjustments for multiple testing are planned, as this is an exploratory study. 
347 
4.2. Handling of missing data  
348 
In this study, we do not expect much missing data because the follow-up period is short (only 5 
349 
weeks) and we are closely monitoring a small group of 20 patients. However, if some data is 
350 
missing—for example, if a patient skips a follow-up visit or leaves the study early—we will clearly 
351 
note the reason (such as discomfort or personal reasons) and report it in the final publication. 
352 
5 
REGULATORY ASPECTS AND SAFETY 
353 
5.1 Local regulations / Declaration of Helsinki 
354 
This research project will be conducted in accordance with the protocol, the Declaration of 
355 
Helsinki [3], the Human Research Act (HRA) and the Human Research Ordinance (HRO) [1] as 
356 
well as other locally relevant regulations. The project leader acknowledges his responsibilities as 
357 
both the project leader and the Sponsor. 
358 
5.2 Notification of safety and protective measures (HRA Art. 15, HRO Art. 20) 
359 
If, during the research project, circumstances arise which could jeopardise the safety or health of 
360 
the participants or lead to a disproportionate relationship between the risks and burdens and the 
361 
benefits, all the measures required to ensure protection are to be taken without delay. 
362 
The project leader is promptly notified (within 24 hours) if immediate safety and protective 
363 
measures must be taken during the conduct of the research project. The Ethics Committee will 
364 
be notified via BASEC of these measures and of the circumstances necessitating them within 7 
365 
days. 
366 
5.3 Serious events (HRO Art. 21) 
367 
If a serious event occurs, the research project will be interrupted and the Ethics Committee 
368 
notified on the circumstances via BASEC within 7 days according to HRO Art. 211. 
369 
The project leader reports to the ethics committee on the connection between the event and the 
370 
collection of health-related personal data. At the same time, the project leader submits proposals 
371 
concerning the next steps to be taken. 
372 
 
1 A serious event is defined as any adverse event where it cannot be excluded, that the event is attributable to the 
sampling of biological material or the collection of health-related personal data, and which: 
a. requires inpatient treatment not envisaged in the protocol or extends a current hospital stay; 
b. results in permanent or significant incapacity or disability; or 
c. is life-threatening or results in death. 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
12/15 
Any new relevant information and the outcome to the original Serious Event is reported to the 
373 
ethics committee via BASEC.  
374 
5.4 Procedure for investigations involving radiation sources 
375 
The study includes standard postoperative X-rays at the 5-week follow-up to assess toe 
376 
alignment. These X-rays are part of routine clinical care for hallux valgus surgery, meaning 
377 
patients would receive them regardless of study participation. No additional radiation exposure is 
378 
required for this study. 
379 
5.5 Amendments 
380 
Substantial changes to the project set-up, the protocol and relevant project documents will be 
381 
submitted to the Ethics Committee for approval according to HRO Art. 18 before implementation. 
382 
Exceptions are measures that have to be taken immediately in order to protect the participants.  
383 
 
384 
The following are considered to be substantial changes: 
385 
a. changes affecting the participants’ safety and health, or their rights and obligations; 
386 
b. changes to the protocol which concern the objectives of the research project; 
387 
c. a change of research site or conducting the research project at an additional site; or 
388 
d. a change of project leader or Sponsor. 
389 
 
390 
5.6 End of project 
391 
Upon project completion or discontinuation, the Ethics Committee is notified within 90 days. 
392 
The completion of the research project is defined by the last collection of health-related personal 
393 
data. 
394 
5.7 Insurance 
395 
In the event of project-related damage or injuries, the Sponsor will be liable. The liability coverage 
396 
covers damage occurring up to 10 years after the completion of the research project 
397 
6 
FURTHER ASPECTS 
398 
6.1 Overall ethical considerations 
399 
This study has scientific and social value by addressing an unmet need in postoperative care 
400 
following hallux valgus correction. Existing spacer methods are not patient-specific, often 
401 
uncomfortable, and can lead to suboptimal alignment. The development and assessment of a 
402 
custom-made 3D-printed spacer aims to improve patient comfort, compliance, and clinical 
403 
outcomes. Although the results will be descriptive due to the small sample size, they will contribute 
404 
valuable preliminary data that may inform future, more robust clinical trials. 
405 
Justification of Study Design and Participant Burden 
406 
The study design is justified given the exploratory nature and low risk of the intervention. The 3D-
407 
printed spacer is externally applied and made from commonly used orthotic materials. It replaces 
408 
the folded gauze currently used, without adding any invasive procedure. The burden on 
409 
participants is minimal and limited to routine postoperative care, completion of a tolerance 
410 
questionnaire, and potentially a photographic or radiographic assessment, which are standard in 
411 
this setting. The estimated time commitment and discomfort are negligible. 
412 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
13/15 
Voluntary Participation and Informed Consent 
413 
Participation is entirely voluntary. Informed consent will be obtained from all participants, ensuring 
414 
they understand the study’s purpose, procedures, and their right to withdraw at any time without 
415 
consequence. 
416 
Overall Ethical Balance 
417 
The study presents a fair balance between minimal risk and potential benefit. It offers 
418 
participants the possibility of improved postoperative comfort and outcomes, without exposing 
419 
them to additional burdens. 
420 
 
421 
6.2 Risk-Benefit Assessment  
422 
This study poses minimal risk to participants. The 3D-printed spacer is externally applied and 
423 
made from safe, commonly used orthotic materials. Potential risks include mild discomfort or 
424 
pressure, which can be managed by adjusting or removing the spacer, and a minimal risk of 
425 
allergic reaction. No invasive procedures are involved. 
426 
Data privacy risks are mitigated by coding participant data, storing identifiers separately, and 
427 
using secure, password-protected systems. Only authorized personnel will have access. 
428 
While the study offers no direct medical benefit, participants may experience improved comfort 
429 
and alignment. The findings may benefit future patients by informing better postoperative care 
430 
practices in hallux valgus surgery. 
431 
 
432 
7 
QUALITY CONTROL AND DATA PROTECTION 
433 
7.1 Quality measures  
434 
Radiographic analysis will be conducted by the project leader or a fellowship trained foot and 
435 
ankle surgeon. Statistical analysis will be performed by an independent individual who is not 
436 
involved in the measurements or surgical treatment. 
437 
For quality assurance the Ethics Committee may visit the research sites. Direct access to the 
438 
source data and all project related files and documents must be granted on such occasions. 
439 
 
440 
The project leader has appropriate knowledge and skills in the areas of data security and data 
441 
protection or is able to ensure compliance by calling in appropriate expertise (Art. 4 HRO). 
442 
7.2 Data recording and source data 
443 
Project data will be recorded using an Excel spreadsheet. Source data for the study will include 
444 
medical records, radiological images, and questionnaire responses. Patients will complete the 
445 
questionnaire at home or just after the routine follow-up visits. To ensure data privacy and 
446 
reliability, the Excel file will be stored in a secure, password-protected swiss based cloud system 
447 
(Infomaniak) with controlled access and user rights. The "Track Changes" feature will be enabled 
448 
to monitor any modifications to the data. This approach ensures data traceability and maintains 
449 
data integrity throughout the research project. 
450 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
14/15 
 
451 
7.3 Confidentiality and coding 
452 
Project data will be handled with uttermost discretion and is only accessible to authorized 
453 
personnel who require the data to fulfil their duties within the scope of the research project. On 
454 
the CRFs and other project specific documents, participants are only identified by a unique 
455 
participant number. Coding is done using a method based on the current state of the art that must 
456 
be based on the current state of the art (Art. 26 HRO).  
457 
The project data will be stored in a coded format to ensure participant confidentiality. The 
458 
participant identification list, which links the coded data to individual identities, will be securely 
459 
stored on the project leader's password-protected computer. Both the data file and the 
460 
identification list will be protected with password access to prevent unauthorized or accidental 
461 
disclosure, alteration, deletion, copying, or theft. 
462 
To ensure data traceability and integrity, the Excel file will have the "Track Changes" feature 
463 
enabled to maintain an audit trail of all modifications. Regular backups will be performed on 
464 
secure storage media to prevent data loss or misuse. These measures are in place to ensure 
465 
data security and traceability throughout the project. 
466 
7.4 Retention and destruction of project data and biological material 
467 
The project leader will retain all project data and documents, both electronic and hard copies, for 
468 
a minimum period of 20 years following the completion or early termination of the study. Data will 
469 
be stored securely to prevent unauthorized or accidental disclosure, alteration, deletion, or 
470 
copying. 
471 
Electronic data will be stored in a password-protected Excel file with the "Track Changes" feature 
472 
enabled to ensure traceability. The participant identification list will be stored separately on the 
473 
project leader’s password-protected computer. Regular backups will be performed to prevent data 
474 
loss. 
475 
No biological material will be collected or stored as part of this project. 
476 
Following the completion of the study and subsequent publication of the manuscript, files 
477 
containing radiographic measurements will be deleted. The deletion process will be documented 
478 
to confirm appropriate data disposal. All retained data will be handled in accordance with data 
479 
protection regulations to ensure participant confidentiality. 
480 
 
481 
9 
FUNDING / PUBLICATION / DECLARATION OF INTEREST 
482 
This project has no specific funding sources. The results of the study will be submitted for 
483 
publication in a peer-reviewed orthopedic journal. There are no conflicts of interest to declare. If 
484 
any sex- or gender-related effects are observed during analysis, these findings will be reported in 
485 
the final study report. Conversely, if no such effects are identified, this outcome will also be 
486 
acknowledged in the publication. 
487 
 
488 
10 REFERENCES 
489 
1. 
Ordinance on Human Research with the Exception of Clinical trials (HRO) 
490 

Evaluation of a new postoperative dressing after hallux valgus surgery 
, Version 3, 15 10 2025 
 
 
15/15 
https://www.fedlex.admin.ch/eli/cc/2013/642/en  
491 
2. 
Human Research Act (HRA) 
492 
https://www.fedlex.admin.ch/eli/cc/2013/617/en  
493 
3. 
Declaration of Helsinki  
494 
(https://www.wma.net/policies-post/wma-declaration-of-helsinki-ethical-principles-for-
495 
medical-research-involving-human-subjects ) 
496 
4. 
STROBE statement (doi:10.1016/j.jclinepi.2007.11.008) 
497 
 
498 
 
499 
 
500 
1. 
Coughlin MJ, Jones CP. Hallux valgus: demographics, etiology, and radiographic 
501 
assessment. Foot Ankle Int. Jul 2007;28(7):759-77. doi:10.3113/fai.2007.0759 
502 
2. 
Lewis LK, Chen J, Johnson CS, Adams SB, Jr. Hallux Valgus Bunion Splint: 
503 
Surgical Dressing Technique. Foot Ankle Spec. Feb 2024;17(1_suppl):53S-56S. 
504 
doi:10.1177/19386400231169376 
505 
 
506