Study Protocol for a Randomised Controlled Trial to Investigate the Enhancement of Diabetic Foot Ulcer Healing Using Low-Magnitude High-Frequency Vibration Treatment


 Background: Diabetes has a prevalence of 11.6% in China with diabetic foot ulcerations affecting over 30 million Chinese. 85% of these patients require amputation and 5-year mortality for diabetics is 70% when associated foot ulcers. Clinical trials have shown that standing on whole-body vibration platforms, specifically low-magnitude high-frequency vibration (LMHFV); promotes angiogenesis, enhances muscle bulk and accelerates epithelization. Investigation on diabetic rats with foot wounds found accelerated wound healing, increased perfusion and upregulation of factors such as VEGF, PECAM-1 and PCNA. Hypothesis: We postulate LMHFV will enhance diabetic foot ulcer healing.Methods: Prospective, single-centre, randomised control trial to treat 106 subjects with diabetic foot ulcers.Interventions: The intervention group will stand on LMHFV whole-body vibration platforms for 20min on alternate days for 20 weeks, together with conventional dressing by a trained wound-care nurse as in the control group.Main Outcome Measures: Ulcer size will be measured at multiple time points, the incidence of amputations/infections will be recorded, perfusion via ankle-brachial pressure index will be calculated and foot function via the foot and ankle outcome score will be analysed.Data analysis: Repeated measure of ANOVA to analyze time-point differences and student’s t-test for same time-point comparison.Discussion: This is the first clinical trial to investigate the effect of whole-body vibration on diabetic foot ulcers. It will show us if the results from animal studies will translate into clinically significant results. If positive effects are established, whole-body vibration can be a valuable treatment regime to tackle diabetic foot ulcers.Trial registration: NCT04275804 clinicaltrials.gov (19 Feb 2020)


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'Note: the numbers in curly brackets in this protocol refer to SPIRIT checklist item numbers. The order of the 63 items has been modified to group similar items (see http://www.equator-network.org/reporting-64 guidelines/spirit-2013-statement-defining-standard-protocol-items-for-clinical-trials/) The project has no external funding source.

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The wound size was significantly smaller, blood glucose levels were significantly lower and glucose 113 transporter 4 expression (GLUT 4 immunoblotting) was significantly better in the vibration group. Perfusion in 114 the wound, measured using laser Doppler, was also significantly better in the vibration group and more 115 granulation and epithelial tissue were seen on histology. Platelet endothelial cell adhesion molecule-1 116 (PECAM-1), a signalling molecule that upregulates angiogenesis and endothelialization, was significantly 117 higher in the vibration group. Proliferating cell nuclear antigen was also higher which signifies there was 118 more cell proliferation in the vibration group. Vascular Endothelial Growth Factor (VEGF), which promotes 119 bone formation, haematopoiesis, wound healing as well as angiogenesis was significantly elevated in the 120 vibration group compared to the controls.

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 The duration of dressing will last until participant's wound is healed. If it is not healed 193 after the study period, PI will look into the case to see if other treatments are needed.

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o Alternate day 20-week course of whole-body vibration therapy 195  Alternate day 20min sessions on a self-designed vibration platform with low-196 magnitude high-frequency vibration (35Hz, 0.3g peak-to-peak displacement 197 <0.1mm). Since the participants will return for dressing change on alternate days, the 198 vibration group will also undergo the LMHFV during the same attendance. Interim data analysis will be performed at 20weeks, the investigators will then decide on 210 discontinuing/modifying the intervention based on the judgement of safety and benefits.  The use of LMHFV vibration will not require alteration to usual care pathways (including use of any 225 medication) and these will continue for both trial arms.

Provisions for post-trial care {30} 228
There is no anticipated harm and compensation for trial participation. Usual care pathways will be provided

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• The baseline ulcer size will be measured at 0 weeks and a core interim measurement will be 235 conducted at 20 weeks since 30% of ulcerations will heal at 20 weeks using conventional The early follow-up at 2 weeks will serve as a chance for the participant to voice out difficulties 239 and for the investigator to provide early intervention if required. Subsequent 6-weekly 240 documentation of the change in ulcer size will help decipher the ideal duration of LMHFV 241 therapy.

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The ulcer area will be measured using a digital photograph with a standardized 10mmx10mm 243 ruler square. The image will be sent to an independent, blinded researcher who will calculate 244 the wound size by defining the wound edge using the colour differential in the skin and using 245 the magnetic lasso tool in the Photoshop CS6 software. The ulcer size will be calculated in 246 the photo imaging software SPOT 3.5.5 Window using those standardized squares.

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Bonferroni tests are used for multiplicity adjustment.

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The sample size was calculated by using the primary endpoint of wound size in G*Power 3.1.9.4 (Germany).

Recruitment {15} 291
Participants will be recruited from the patients in the Orthopaedic & Traumatology department at the Prince of 292 Wales Hospital, the tertiary teaching hospital affiliated to CUHK. All patients from the Orthopaedic and 293 Traumatology department will be screened. Those who meet the inclusion and exclusion criteria will be 294 recruited.

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To ensure sufficient recruitment, patients can be recruited from affiliated hospitals such as Alice Ho Miu Ling

Plans for assessment and collection of outcomes {18a} 325
All collected personal data and medical information relevant to this study about the subjects will be strictly 326 confidential. The data can be accessed only by the principal investigator, co-investigators and the research 327 assistant(s) in charge. Subjects will only be identified by a study number and initials in the study database, 328 and no personal identity will be disclosed when study results are being reported and/or published. The data 329 will be kept for an additional 5 years for monitoring. Data that are related to future patient management will 330 be stored in hospital CMS system.

Data management {19} 336
The nurse and research assistant (both reporting directly to the principal investigator) will be responsible for 337 data collection and data entry while the principal investigator will be responsible for data analysis. The 338 principal investigator himself will make decisions to terminate the trail trial if needed. Data quality is ensured 339 by double data entry (the nurse and the research assistant). Electronic data entry will be used.

Confidentiality {27} 342
instead of ANOVA and t-tests in case the data are not normally distributed. A mixed-effect model will be 358 used to analyse the primary outcome. ANOVA will be used for analysing the secondary outcomes.

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Statistical analyses will be performed using IBM SPSS 25 (IBM, Armonk, NY, USA), and statistical 360 significance was considered at p < 0.05. This protocol will follow the CONSORT 2010 statement (BMC 361 Medicine).

Interim analyses {21b} 363
PI will monitor the results and make final decisions. An interim analysis will be performed with week 20 data.

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Ulcer size, time to healing, incidence of amputation, incidence of secondary infection, perfusion and foot 365 function will be used in the interim analysis.

Composition of the data monitoring committee, its role and reporting structure {21a} 395
Data monitoring will be from a committee made up of professorial-grade staff from the department. The data 396 monitoring committee is independent of the study organisers and have no competing interests. During the 397 period of recruitment to the study, interim analyses will be supplied, in strict confidence, to the DMC, together 398 with any other analyses that the committee may request. This may include analyses of data from other 399 comparable trials.

Adverse event reporting and harms {22} 402
The research assistant will contact the participants regularly (once per week) to record any adverse events.

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There should not be any potential harms caused to the participants. Minor adverse events such as itchiness 404 and redness of the lower limbs may be observed. However, the discomfort will disappear shortly after the 405 vibration treatment terminates. If such event occurs, it will be reported to DMEC and relevant regulatory 406 bodies as required indicating expectedness, seriousness, severity, and causality.