Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12623001304628
Ethics application status
Approved
Date submitted
21/11/2023
Date registered
14/12/2023
Date last updated
1/06/2024
Date data sharing statement initially provided
14/12/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
Insoles for big toe joint osteoarthritis: the SOLE randomised controlled trial
Scientific title
Effect of insoles on severity of joint pain when walking for first metatarsophalangeal joint osteoarthritis: the SOLE randomised controlled trial
Secondary ID [1] 310053 0
Nil known
Universal Trial Number (UTN)
Trial acronym
SOLE
Linked study record

Health condition
Health condition(s) or problem(s) studied:
First metatarsophalangeal joint osteoarthritis 330589 0
Condition category
Condition code
Musculoskeletal 327424 327424 0 0
Osteoarthritis

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The intervention group will receive three pairs of cushioned insoles. The cushioned insoles will be flat 6mm blue EVA 120 (Shore A 20) shoe insoles. Insoles will be trimmed and fitted into participant’s footwear at the initial visit by the trial coordinator. This initial visit will last 90 minutes. At this time, participants will be advised to wear the insoles at all times when wearing shoes for 12 weeks, changing to a new pair of insoles every 4 weeks. Participants will complete a logbook to monitor adherence, in the fourth, eighth and twelfth week of their study involvement.
Intervention code [1] 326461 0
Treatment: Devices
Comparator / control treatment
Participants in the control group will be provided with three pairs of sham flat 2mm blue EVA 450 (Shore A 65) insole that are similar in appearance to the cushioned insole. The sham insoles will be trimmed and fitted to the participant’s footwear at the initial visit by the trial coordinator. This initial visit will last 90 minutes. At this time, participants will be advised to wear them at all times when wearing shoes for the 12 weeks. Participants will complete a logbook to monitor adherence, in the fourth, eighth and twelfth week of their study involvement.

Control group
Placebo

Outcomes
Primary outcome [1] 335287 0
Severity of first MTP joint pain during walking.

Scored on an 11-point numerical rating scale (NRS) for average overall first MTP joint pain on walking in the last week.
Timepoint [1] 335287 0
Baseline, 12 weeks post-intervention commencement (primary timepoint).
Secondary outcome [1] 423774 0
Foot Health Status Questionnaire (FHSQ) pain subscale.

Scored using 4 questions related to foot pain, each rated on a 5-point Likert scale from 1 (not at all) to 5 (extremely).
Timepoint [1] 423774 0
Baseline, 12 weeks post-intervention commencement.
Secondary outcome [2] 423775 0
FHSQ physical function subscale.

Scored using 4 questions related to how much foot pain interferes with specific activities, each rated on a 5-point Likert scale from 1 (not at all) to 5 (extremely).
Timepoint [2] 423775 0
Baseline, 12 weeks post-intervention commencement.
Secondary outcome [3] 423776 0
Severity of first MTP joint pain overall.

Scored on an 11-point NRS for average overall first MTP joint pain in the last week.
Timepoint [3] 423776 0
Baseline, 12 weeks post-intervention commencement.
Secondary outcome [4] 423777 0
Achievement of a global improvement in pain.

Scored using a 7-point global rating of change Likert scale from with response options ranging from “much worse” to “much better” when compared to baseline.
Timepoint [4] 423777 0
12 weeks post-intervention commencement.
Secondary outcome [5] 423778 0
Achievement of a global improvement in physical function.

Scored using a 7-point global rating of change Likert scale from with response options ranging from “much worse” to “much better” when compared to baseline.
Timepoint [5] 423778 0
12 weeks post-intervention commencement.
Secondary outcome [6] 423779 0
Quality of life (AQoL-6D).

Scored using the 20-item Assessment of Quality of Life II Instrument (6D version), which covers the topics of independent living, relationships, mental health, coping, pain and senses to come up with one overall value representing quality of life.
Timepoint [6] 423779 0
Baseline, 12 weeks post-intervention commencement.
Secondary outcome [7] 423780 0
Physical Activity Scale for the Elderly (PASE) score.

A self-reported assessment of physical activity, covering occupational, household and leisure items over the past week with one overall value representing physical activity level.
Timepoint [7] 423780 0
Baseline, 12 weeks post-intervention commencement.
Secondary outcome [8] 423781 0
Brief Fear of Movement Scale for Osteoarthritis.

Scored from 6 statements regarding fear of injury/re-injury due to movement on a 4-point Likert scale from 1 = “strongly disagree” to 4 = “strongly agree”.
Timepoint [8] 423781 0
Baseline, 12 weeks post-intervention commencement.
Secondary outcome [9] 429063 0
Use of OA treatments

Participants will complete a custom-developed table to indicate the frequency of use (over the past 12 weeks) of a range of pain and arthritis medications and co-interventions.
Timepoint [9] 429063 0
Baseline, 12 weeks post-intervention commencement.
Secondary outcome [10] 429064 0
Adverse events

Adverse events will be defined as any new problem experienced in the study foot or elsewhere in the body deemed by the participant to be a result of the insoles or participating in the RCT AND at least one of i) that caused increased pain and/or interfered with function for two days or more, and/or ii) resulted in the participant seeking treatment from a health professional. These will be self-reported by participants using a custom-developed table.
Timepoint [10] 429064 0
12 weeks post-intervention commencement.
Secondary outcome [11] 429065 0
Pain at other sites (hips, knees, ankles, other foot sites, spine)

Scored as (1) number of pain sites, and (2) using an 11-point NRS for average overall pain in the last week for each site.
Timepoint [11] 429065 0
Baseline, 12 weeks post-intervention commencement.
Secondary outcome [12] 429066 0
Foot pain location

Participants will indicate their foot pain location by indicating a number that corresponds to a pain location on a foot manikin.
Timepoint [12] 429066 0
Baseline, 12 weeks post-intervention commencement.
Secondary outcome [13] 429067 0
Self-rated adherence with wearing insoles over 12 weeks

Rated by participants using an 11-point NRS for overall adherence over the 12 weeks where 0=insoles not worn at all when wearing shoes and 10=insoles worn completely as instructed when wearing shoes.
Timepoint [13] 429067 0
12 weeks post-intervention commencement.
Secondary outcome [14] 429068 0
Percentage of time wearing the study insoles when wearing shoes per day

Insole, and shoe wear, will be recorded daily in a log book for a one week snapshot every month.
Timepoint [14] 429068 0
Baseline, 4, 8 and 12 weeks post-intervention commencement.
Secondary outcome [15] 429120 0
Number of participants who stopped wearing the study insoles

Participants will indicate whether they stopped wearing the study insoles at any point during the 12 weeks on a categorical scale (Yes or No).
Timepoint [15] 429120 0
12 weeks post-intervention commencement.

Eligibility
Key inclusion criteria
i) aged greater than or equal to 45 years,
ii) report first MTP joint pain on most days of the month for the past 12 weeks,
iii) report a minimum pain score of 4 on an 11-point numerical rating scale during walking over the previous week,
iv) evidence of radiographic OA (a score of 2 or more for osteophytes or joint space narrowing according to a radiographic atlas), and
v) report either no morning joint-related stiffness in the 1st MTP joint, or morning stiffness that lasts no longer than 30 minutes.
Minimum age
45 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
i) previous first MTP joint surgery or planned foot surgery on the affected side in the next 12 weeks,
ii) current use of foot orthoses, custom footwear or ankle braces,
iii) current primary use of high heels, thongs or other shoes that preclude ability to wear insoles,
iv) had any first MTP joint injections on the affected side in the past 6 months or planned foot injections in next 12 weeks,
v) self-report any other current muscular, joint or neurological condition affecting lower limb function,
vi) pain in another foot or ankle location that is greater than the pain in the study first MTP joint,
vii) self-report any systemic or inflammatory joint disease (eg rheumatoid arthritis),
viii) Moderate to severe hallux valgus based on a hallux abductus angle greater than 20 degs on xray,
ix) current or planned use of a gait aid in the next 12 weeks,
x) current or planned treatment for their first MTP joint OA in the next 12 weeks,
xi) inability to understand written/spoken English,
xii) unable to commit to study requirements (eg wearing insoles, attending appointments, completing outcomes),
xiii) currently taking part in another OA study.

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)
The person who will determine if a potential participant is eligible for inclusion in the trial will be unaware, when this decision is made, to which group the participant will be allocated. The randomisation schedule will be concealed in a password protected computer database. A member of the research team will maintain and access the schedule and reveal allocation to the Trial Coordinator as each participant requires randomisation.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The randomisation schedule will be prepared by the biostatistician. Randomisation will occur according to a 1: 1 allocation (permuted block sizes 6 to 12). The schedule will be stored on a password-protected website (REDCap) maintained by a researcher not involved in either participant recruitment or administration of primary/secondary outcome measures. Group allocation will be revealed by this same researcher after baseline primary/secondary outcomes have been completed.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
A total sample size of 108 (54 per arm) is required to detect the minimal clinically important difference (MCID) of 1.8 units in the primary outcome, change in pain on NRS, between groups with 90% power and an alpha of 0.05, assuming a conservative between-participant standard deviation (SD) of 2.6 and a correlation between baseline and 12-week post-intervention scores of 0.25 based on our previous RCT and with 20% attrition.

Data will be analysed on an intention-to-treat basis. A biostatistician (Li) will analyse blinded data according to a Statistical Analysis Plan that we will develop and publish on the CHESM website prior to data analysis commencing. Main comparative analyses between groups will be performed using intention-to-treat. Multiple imputation will be used if the primary outcome has greater than 5% missing data. For the primary outcome, differences in mean change in walking first MTP joint pain (baseline minus follow-up) will be compared between groups using a linear regression model, adjusted for baseline values. Continuous secondary outcomes will be analysed using similar approaches to the primary outcome. To aid clinical interpretation of the primary outcome, the proportion of participants in each group that show an improvement that reaches or exceeds the MCID in change in NRS walking first MTP joint pain (greater than or equal to 1.8 units) will be calculated. For binary outcomes, groups will be compared using risk ratios and risk differences, using log-binomial regression models. The number of participants who experience an adverse event will be compared between groups using Poisson regression. A sensitivity analysis will estimate treatment effects assuming full adherence (defined as wearing insoles for greater than or equal to 70% of the time when wearing shoes), using an instrumental variables approach. Standard diagnostic plots will be used to check model assumptions.

To assess whether the effect of the intervention on the primary outcome is moderated by any of the pre-specified moderators of BMI, first MTP joint range of motion, or peak hallux plantar pressure, interaction terms between randomised group and each of these variables will be included in regression models for the primary outcome at 12 weeks, for each potential effect modifier separately. The rationale for the a priori choice of treatment effect modifiers is as follows:

• BMI- we hypothesise that either a higher or lower BMI may moderate pain reductions with cushioned insoles (relative to sham insoles). Pain reductions in those with a higher BMI may be lower based on the likelihood that a greater mass will compress the cushioning properties of the cushioned insoles, rendering them less capable of leading to symptomatic benefits. Alternatively, pain reductions in those with a higher BMI may be greater given that those with a higher BMI will have higher loads in the hallux and first MTP joint and therefore may have more potential to benefit from the cushioned insoles.
• First MTP joint range of motion- we hypothesise that pain reduction with the cushioned insoles (relative to sham insoles) will be greater in those with less range of motion compared to those with more range of motion, given reduced first MTP joint ROM increases first MTP joint loading, and therefore these participants may have a greater propensity for pain reduction.
• Peak hallux plantar pressure- we hypothesise that pain reduction with the cushioned insoles (relative to sham insoles) will be greater in those with higher hallux plantar pressures compared to those with lower hallux plantar pressure, as they have a greater scope for pressure reductions with cushioned insoles, and thus greater potential for pain reduction.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
15/01/2024
Actual
15/02/2024
Date of last participant enrolment
Anticipated
30/06/2025
Actual
Date of last data collection
Anticipated
30/09/2025
Actual
Sample size
Target
108
Accrual to date
15
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 314219 0
Government body
Name [1] 314219 0
Australian Government Department of Health: Medical Research Future Fund
Country [1] 314219 0
Australia
Primary sponsor type
University
Name
The University of Melbourne
Address
Office of Research, Ethics and Integrity Research, Innovation & Commercialisation Level 5, Alan Gilbert Building, 161 Barry Street, Carlton, University of Melbourne VIC 3010
Country
Australia
Secondary sponsor category [1] 316153 0
None
Name [1] 316153 0
Address [1] 316153 0
Country [1] 316153 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 313343 0
University of Melbourne Human Research Ethics Committee
Ethics committee address [1] 313343 0
Office of Research Ethics and Integrity Research, Innovation & Commercialisation Level 5, Alan Gilbert Building, 161 Barry Street, Carlton, The University of Melbourne, Victoria 3010 Australia
Ethics committee country [1] 313343 0
Australia
Date submitted for ethics approval [1] 313343 0
22/05/2023
Approval date [1] 313343 0
26/06/2023
Ethics approval number [1] 313343 0

Summary
Brief summary
We are conducting a clinical trial to determine if cushioned shoe insoles are an effective treatment for big toe joint osteoarthritis. The participants will wear their allocated insoles at all times when wearing shoes for a 12 week period.

The two different groups in this study are:
1. Cushioned insoles
2. Placebo insoles

We will evaluate the effectiveness of the different insoles on pain and physical function at 12 weeks. Primary and secondary outcomes will be collected via online survey at baseline and 12 weeks.

Our hypothesis is that flat cushioned shoe insoles will result in a greater improvement in pain and physical function for individuals suffering with first MTP OA.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 127810 0
A/Prof Kade Paterson
Address 127810 0
Centre for Health Exercise and Sports Medicine Department of Physiotherapy Level 7, Alan Gilbert Building, 161 Barry Street, Carlton, The University of Melbourne, VIC, 3010
Country 127810 0
Australia
Phone 127810 0
+61 3 8344 0425
Fax 127810 0
Email 127810 0
kade.paterson@unimelb.edu.au
Contact person for public queries
Name 127811 0
Mr Sam Shearer
Address 127811 0
Centre for Health Exercise and Sports Medicine Department of Physiotherapy Level 7, Alan Gilbert Building, 161 Barry Street, Carlton, The University of Melbourne VIC 3010
Country 127811 0
Australia
Phone 127811 0
+61 4 1163 6804
Fax 127811 0
Email 127811 0
sam.shearer@unimelb.edu.au
Contact person for scientific queries
Name 127812 0
A/Prof Kade Paterson
Address 127812 0
Centre for Health Exercise and Sports Medicine Department of Physiotherapy Level 7, Alan Gilbert Building, 161 Barry Street, Carlton, The University of Melbourne VIC 3010
Country 127812 0
Australia
Phone 127812 0
+613 8344 0425
Fax 127812 0
Email 127812 0
kade.paterson@unimelb.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Deidentified individual participant data of published results only.
When will data be available (start and end dates)?
Immediately following publication to 15 years following publication.
Available to whom?
Available to researchers by request on a case-by-case basis at the discretion of the principal researcher.
Available for what types of analyses?
Meta analyses.
How or where can data be obtained?
From the principal researcher (email: kade.paterson@unimelb.edu.au), with the appropriate Data Sharing Agreements as approved by the sponsor (the University of Melbourne).


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
19614Study protocol  kade.paterson@unimelb.edu.au Upon direct request to the principal researcher
19615Statistical analysis plan  kade.paterson@unimelb.edu.au Upon direct request to the principal researcher



Results publications and other study-related documents

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