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Trial registered on ANZCTR


Registration number
ACTRN12623000953639
Ethics application status
Approved
Date submitted
25/08/2023
Date registered
4/09/2023
Date last updated
11/08/2024
Date data sharing statement initially provided
4/09/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
Shoe inserts for midfoot osteoarthritis pain
Scientific title
The efficacy of foot orthoses for midfoot osteoarthritis: a randomised controlled trial
Secondary ID [1] 310354 0
None
Universal Trial Number (UTN)
Trial acronym
FOMO
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Osteoarthritis of the midfoot joints 331084 0
Condition category
Condition code
Musculoskeletal 327874 327874 0 0
Osteoarthritis

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Prefabricated foot orthoses (Formthotics™ manufactured by Foot Science International, Christchurch, New Zealand).

Each participant will receive two pairs of foot orthoses to be fitted in the shoes they wear most regularly. The foot orthoses will be full-length arch contouring devices, manufactured from a single-density polyethylene closed cell foam that will support the arch of the foot. The foot orthoses will be fitted by a registered Podiatrist and will be modified with the addition of a 4° medium density varus wedge if the Foot Posture Index is >7. They will then be heated and placed in the participant’s footwear. The participant will be required to stand in their footwear with the heated foot orthoses to enable the devices to mould to their feet. This is standard clinical care using this intervention. Participants will be advised to use the foot orthoses in their footwear for as much time as they can during the day, for the 12 weeks of the trial. Adherence will be monitored by recording the average days per week, plus the average number of hours per day the participant has worn the foot orthoses, assessed via online questionnaires at each four-weekly timepoint.

Clinical guideline-based information and support: both groups will receive a standardised education package derived from clinical guidelines for management of osteoarthritis regarding midfoot osteoarthritis, osteoarthritis flares, advice around exercise such as activity modification, weight loss, the use of topical non-steroidal anti-inflammatory drugs (NSAIDs), and footwear advice.
Intervention code [1] 326751 0
Treatment: Devices
Comparator / control treatment
Sham inserts (control group).

Each participant will receive two pairs of shoe inserts to be fitted in the shoes they wear most regularly. Participants in the control group will be provided with a sham flat 3mm prefabricated insole for each foot that is the same colour, density and has the same branding as the contoured foot orthoses used in the intervention group, but without the heel and arch support. The sham inserts will be fitted by a registered Podiatrist. Participants will be advised to use the sham inserts in their footwear for as much time as they can during the day, for the 12 weeks of the trial. Adherence will be monitored by recording the average days per week, plus the average number of hours per day the participant has worn the foot orthoses, assessed via online questionnaires at each four-weekly timepoint.

Clinical guideline-based information and support: both groups will receive a standardised education package derived from clinical guidelines for management of osteoarthritis regarding midfoot osteoarthritis, osteoarthritis flares, advice around exercise such as activity modification, weight loss, the use of topical non-steroidal anti-inflammatory drugs (NSAIDs), and footwear advice.
Control group
Placebo

Outcomes
Primary outcome [1] 335720 0
Average pain in the midfoot whilst walking in the last 7 days, scored using an 11-point numerical rating scale (NRS) with terminal descriptors of 0 (“no pain”) and 10 (“worst pain imaginable”).
Timepoint [1] 335720 0
Assessed at baseline and at 4, 8 and 12 weeks. 12 weeks is the primary end-point.
Secondary outcome [1] 425307 0
Function (using the walking/standing subscale of the Manchester-Oxford Foot Questionnaire).
Timepoint [1] 425307 0
Assessed at baseline, 4, 8 and 12 weeks.
Secondary outcome [2] 425308 0
Self-reported Global Rating of Change (GROC): Participants’ perception of overall treatment effect, assessed with the question “With respect to your midfoot osteoarthritis, how would you describe yourself now compared to the start of the study?”, using a 15-point Likert scale response (ranging from “a very great deal worse” to “a very great deal better”).

This variable will then be dichotomised into the categories of ‘effective’ (‘a very great deal better’, ‘a great deal better’, ‘a good deal better’, ‘moderately better’) and ‘ineffective’ ('somewhat better', ‘a little better’, ‘about the same, hardly any better at all’, ‘no change’, 'about the same, hardly any worse at all’, ‘a little worse’, ‘somewhat worse’, ‘moderately worse’, ‘a good deal worse’, ‘a great deal worse’, ‘a very great deal worse’).
Timepoint [2] 425308 0
Assessed at 12 weeks.
Secondary outcome [3] 425309 0
Level of physical activity (using the Incidental and Planned Exercise Questionnaire).
Timepoint [3] 425309 0
Assessed at baseline and 12 weeks.
Secondary outcome [4] 425310 0
General health-related quality of life (using the Short-Form-12 Version 2 questionnaire).
Timepoint [4] 425310 0
Assessed at baseline and 12 weeks.
Secondary outcome [5] 425311 0
Use of co-interventions to relieve pain at the midfoot will be assessed via an online survey specifically designed for this study.
Timepoint [5] 425311 0
Assessed at 4, 8 and 12 weeks.
Secondary outcome [6] 425312 0
Adverse events (such as new pains in the body, rolled ankles, blisters, swelling) will be assessed via an online survey specifically designed for this study.
Timepoint [6] 425312 0
Assessed at 4, 8 and 12 weeks.

Eligibility
Key inclusion criteria
(i) Aged 18 years and over
(ii) Pain in the midfoot joints that has been present for at least 3 months, located in at least one area in a predetermined dorsal midfoot region, that is aggravated by weightbearing activities
(iii) Average pain in the midfoot when walking during the last 7 days is rated at least 3 out of 10 in severity on an 11-point numerical rating scale (NRS) (where 0 represents "no pain" and 10 represents the "worst pain imaginable")
(iv) Have radiographic evidence of midfoot osteoarthritis confirmed using the La Trobe University Atlas of foot osteoarthritis – a minimum score of 1 for either observations of joint space narrowing or osteophytes in at least one of the midfoot joints in either radiographic view
(v) Able to walk household distances (>50 metres) without walking aids
(vi) Willing to regularly wear shoes that will accommodate shoe inserts
(vii) Willing to attempt to not receive additional interventions during the study period
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
(i) Previous ipsilateral foot surgery or planning surgery in the next 12 weeks
(ii) Osteoarthritis secondary to other issues such as major trauma
(iii) Presence of other foot or ankle condition(s) or have pain in another location that is greater than the pain in the midfoot
(iv) Any musculoskeletal or systemic medical conditions (e.g., suspected inflammatory joint disease, neurological) that could make the participant unsuitable for inclusion or confound pain and functional assessments of the midfoot
(v) Any inability to speak and read English
(vi) Any treatment that includes the use of any foot orthoses (including shock absorption shoe inserts), ankle braces and/ or, received intra-articular injections at the midfoot in the previous 12 weeks
(vii) Dementia or any cognitive impairment

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
An independent person who is not involved in the study will upload an allocation sequence to REDCap™ (Vanderbilt University), a web-based electronic data capture system designed for the collection of clinical data in electronic format. The randomisation feature in REDCap™ facilitates allocation concealment by having different user rights. None of the assessors screening participants and allocating participants will have user rights to access the uploaded allocation sequence. Potential participants must complete informed consent prior to assessors using the randomisation feature in REDCap™. During allocation, the assessor will have to click a 'randomize' button in order to receive the group allocation for enrolled participants - which is a feature in REDCap™ that blinds all assessors to the central randomisation list.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants will be randomised on a 1:1 ratio with random permuted block sizes of 4 and 6, using an online randomisation service (www.sealedenvelope.com) by an independent person who is not involved in the study design, recruitment or data analysis.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Treatment efficacy will be assessed by between group comparisons at 12 weeks (primary endpoint) for pain severity (severity of average midfoot pain whilst walking in the last 7 days) using the 11-point numerical rating scale.

An a priori power analysis was conducted using G*Power version 3.1.9.7 for sample size estimation. Using an allocation ratio of 1:1, power of 80%, minimal clinically important difference of 1.1 points, standard deviation of 2.2 points, alpha set at 0.05, and allowing a 10% participant loss to follow-up, a sample size of at least 140 participants (i.e., approximately 70 per group) will be required.

Statistical analysis will be performed using the most recent version of SPSS version using the intention-to-treat principle for all randomised participants. In participants with bilateral symptoms, the more painful side will be analysed (or the right lower limb if they cannot define the more painful side) to maintain independence of data.

Multiple imputation will be used to replace any missing data using five iterations, with sex, age, baseline scores, and group allocation as predictors. The exception will be for the variables adherence, adverse events, co-interventions, and global change in symptoms where no data substitution will be applied.

Standard tests to assess continuous data for normal distribution will be used and transformation carried out if required.

Differences in the primary and secondary outcome measures between the two groups will be compared. Continuous-scaled outcome measures will be analysed using analysis of covariance (ANCOVA) with baseline scores, and intervention group entered as independent variables. Both 95% confidence intervals and p-values will be generated where appropriate. Dichotomous-scaled outcome measures (number of participants reporting adverse events, frequency of co-interventions) will be compared using relative risk, risk difference, and number needed to treat. Both 95% confidence intervals and p-values will be generated where appropriate. Intervention adherence will be compared using independent groups t tests.

A sensitivity analysis will be conducted to estimate treatment effects on the primary outcome where multiple imputation will be used to handle missing data. We will check the robustness of our findings using the following conditions:
(i) Complete case analysis - analyse participants who provide outcome data
(ii) Last observation carried forward

A sensitivity analysis will also be undertaken to estimate treatment effects on the primary outcome assuming full adherence (per-protocol analysis). Full adherence will be defined as participants reporting wearing the shoe inserts for an average of at least 35 hours per week.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment postcode(s) [1] 41084 0
3086 - La Trobe University

Funding & Sponsors
Funding source category [1] 314559 0
Charities/Societies/Foundations
Name [1] 314559 0
Australian Podiatry Education and Research Foundation (APERF)
Country [1] 314559 0
Australia
Primary sponsor type
University
Name
La Trobe University
Address
La Trobe University
Corner Kingsbury Drive and Plenty Road
Bundoora VIC 3086
Country
Australia
Secondary sponsor category [1] 316517 0
None
Name [1] 316517 0
Address [1] 316517 0
Country [1] 316517 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 313596 0
La Trobe University Human Ethics Committee
Ethics committee address [1] 313596 0
Ethics committee country [1] 313596 0
Australia
Date submitted for ethics approval [1] 313596 0
16/06/2023
Approval date [1] 313596 0
17/07/2023
Ethics approval number [1] 313596 0
HEC23237

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 128690 0
Prof Shannon Munteanu
Address 128690 0
Discipline of Podiatry, La Trobe University, Corner Kingsbury Drive and Plenty Road, Bundoora VIC 3086
Country 128690 0
Australia
Phone 128690 0
+61 3 94795866
Fax 128690 0
Email 128690 0
Contact person for public queries
Name 128691 0
Polly Lim
Address 128691 0
Discipline of Podiatry, La Trobe University, Corner Kingsbury Drive and Plenty Road, Bundoora VIC 3086
Country 128691 0
Australia
Phone 128691 0
+61 3 94791411
Fax 128691 0
Email 128691 0
Contact person for scientific queries
Name 128692 0
Shannon Munteanu
Address 128692 0
Discipline of Podiatry, La Trobe University, Corner Kingsbury Drive and Plenty Road, Bundoora VIC 3086
Country 128692 0
Australia
Phone 128692 0
+61 3 94795866
Fax 128692 0
Email 128692 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Individual, non-identified numerical rating scale (NRS) data, underlying published results only.
When will data be available (start and end dates)?
Start: immediately following publication
End: No end date
Available to whom?
Other researchers upon reasonable request
Available for what types of analyses?
Individual participant data (IPD) analysis
How or where can data be obtained?
Subject to approvals by the Principal Investigator, Prof Shannon Munteanu ([email protected])


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.