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Trial registered on ANZCTR


Registration number
ACTRN12616000552482
Ethics application status
Approved
Date submitted
24/04/2016
Date registered
28/04/2016
Date last updated
1/07/2019
Date data sharing statement initially provided
1/07/2019
Date results provided
1/07/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
Shoe stiffening inserts for pain of the big toe joint of the foot
Scientific title
The effectiveness of shoe stiffening inserts for first metatarsophalangeal joint osteoarthritis: a randomised controlled trial
Secondary ID [1] 289060 0
None
Universal Trial Number (UTN)
Trial acronym
SIMPLE (Shoe stIffening inserts for first MetatarsoPhaLangEal joint osteoarthritis)
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Osteoarthritis of the first metatarsophalangeal joint 298501 0
Condition category
Condition code
Musculoskeletal 298587 298587 0 0
Osteoarthritis

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Full-length shoe stiffening inserts (intervention group): Participants will be provided with a single (or pair if symptoms are bilateral) of full-length shoe stiffening inserts at the baseline assessment. The shoe stiffening inserts are commercially available and are fabricated from 1.5 mm thick semi-rigid pre-pregnated carbon (Carbon Fibre Spring Plate, Paris Orthotics Ltd, Vancouver, Canada) with the following design characteristics: (i) full length that extends from the heel to the tip of the toes, (ii) no arch build-up or contour at the heel, and (iii) contoured design from the posterior to anterior aspect to allow for the toe spring and heel elevation of footwear. To maximise comfort and adherence, the inserts will be covered with 3.2 mm PPT [Registered Trademark] with an Ultralux top layer (PPT2 809 Blue). Cambrelle [Registered Trademark] (Camtex Fabrics Ltd, United Kingdom) will also be applied to the underside of the insert to increase the durability of the insert and to make the insert appear identical to the sham insert.. Participants will be advised to wear the inserts as much as possible during the duration of the study (52 weeks).

Rehabilitation therapy: Both groups will receive a standardised program of physical / rehabilitation therapy. This will be a home-based program self-administered by the participant daily for approximately 30 minutes for 12 weeks, then 3 times per week for the remaining 40 weeks of the trial. Each therapy session will involve: (i) application of a heat pack for 10 minutes, followed by (ii) self-mobilisation of the first metatarsophalangeal joint for 2 minutes (distraction and gliding), (iii) toe flexor strengthening exercises (1 set of 10 isometric contractions each held for 10 seconds), and concluding with (iv) application of a cold pack (10 minutes). If the condition is bilateral, both feet will be treated.

During the baseline assessment, participants will be instructed to perform the exercises correctly and this will be reviewed at 1 and 12 weeks by research personnel blinded to group allocation.. Participants will be provided with all necessary equipment, along with an instruction booklet, so that the exercise program can be performed unsupervised at home. After the 12 week review, participants will be telephoned at monthly intervals by research personnel blinded to group allocation to remind them to perform the therapy (to maximise adherence).

Adherence to the interventions (shoe inserts and rehabilitation therapy) in both groups will be assessed at monthly intervals up to 52 weeks via postal survey. For the shoe insert interventions, participants will provide information regarding the number of hours per day and number of days they have worn their inserts during the previous 4 weeks. For the rehabilitation therapy intervention, participants will provide information regarding the average number of days per week they have performed their exercises during the previous 4 weeks
Intervention code [1] 294564 0
Treatment: Devices
Intervention code [2] 294565 0
Rehabilitation
Comparator / control treatment
Sham inserts (control group): Participants allocated to the control group will receive a single (or pair if symptoms are bilateral) of ‘sham’ shoe inserts that will be designed to not affect first MTPJ dorsiflexion but appear as identical to the shoe stiffening inserts as possible. To achieve this, the shoe stiffening inserts will be modified by removing the distal end of the semi-rigid pre-pregnated carbon shoe stiffening insert (Carbon Fibre Spring Plate, Paris Orthotics Ltd, Vancouver, Canada) so that the anterior edge finishes at the anterior aspect of the heel. The inserts will then be sandwiched between a full length layer of 3.2 mm PPT [Registered Trademark] with an Ultralux top layer (PPT2 809 Blue). A full length piece of Cambrelle [Registered Trademark] (Camtex Fabrics Ltd, United Kingdom) will also be applied to the underside of the insert to increase the durability of the insert and to make the insert appear identical to the shoe stiffening insert.. Participants will be advised to wear the inserts as much as possible during the duration of the study (52 weeks).

Rehabilitation therapy: Both groups will receive a standardised program of physical / rehabilitation therapy. This will be a home-based program self-administered by the participant daily for approximately 30 minutes for 12 weeks, then 3 times per week for the remaining 40 weeks of the trial. Each therapy session will involve: (i) application of a heat pack for 10 minutes, followed by (ii) self-mobilisation of the first metatarsophalangeal joint for 2 minutes (distraction and gliding), (iii) toe flexor strengthening exercises (1 set of 10 isometric contractions each held for 10 seconds), and concluding with (iv) application of a cold pack (10 minutes). If the condition is bilateral, both feet will be treated.

During the baseline assessment, participants will be instructed to perform the exercises correctly and this will be reviewed at 1 and 12 weeks by research personnel blinded to group allocation.. Participants will be provided with all necessary equipment, along with an instruction booklet, so that the exercise program can be performed unsupervised at home. After the 12 week review, participants will be telephoned at monthly intervals by research personnel blinded to group allocation to remind them to perform the therapy (to maximise adherence).

Adherence to the interventions (shoe inserts and rehabilitation therapy) in both groups will be assessed at monthly intervals up to 52 weeks via postal survey. For the shoe insert interventions, participants will provide information regarding the number of hours per day and number of days they have worn their inserts during the previous 4 weeks. For the rehabilitation therapy intervention, participants will provide information regarding the average number of days per week they have performed their exercises during the previous 4 weeks.
Control group
Placebo

Outcomes
Primary outcome [1] 298083 0
Foot pain domain of the Foot Health Status Questionnaire
Timepoint [1] 298083 0
Baseline and at 4, 12, 24 and 52 weeks. Twelve weeks is the primary time-point.
Secondary outcome [1] 323158 0
Foot-related disability (foot function domain of the Foot Health Status Questionnaire).
Timepoint [1] 323158 0
Baseline and at 4, 12, 24 and 52 weeks.
Secondary outcome [2] 323159 0
Severity of pain at the first metatarsophalangeal joint while walking over a flat surface over the past week (via a 100 mm VAS).
Timepoint [2] 323159 0
Baseline and at 4, 12, 24 and 52 weeks.
Secondary outcome [3] 323160 0
Self-reported magnitude of symptom change (using a 15-point Likert scale where the responses range from “A very great deal better” to “A very great deal worse”). 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 [3] 323160 0
4, 12, 24 and 52 weeks.
Secondary outcome [4] 323161 0
Level of physical activity (using the using the Incidental and Planned Exercise Questionnaire).
Timepoint [4] 323161 0
Baseline and at 4, 12, 24 and 52 weeks.
Secondary outcome [5] 323162 0
General health-related quality of life (using the Short-Form-12 Version 2 questionnaire).
Timepoint [5] 323162 0
Baseline, and at 4, 12, 24 and 52 weeks.
Secondary outcome [6] 323163 0
General health-related quality of life (using the EuroQol [EQ-5D] questionnaire.
Timepoint [6] 323163 0
Baseline, and at 4, 12, 24 and 52 weeks.
Secondary outcome [7] 323164 0
Use of paracetamol rescue medication and co-interventions to relieve pain at the first metatarsophalangeal joint will be assessed via a medications consumption diary and postal survey. These surveys have been specifically designed for this study.
Timepoint [7] 323164 0
Monthly up to 12 months (52 weeks).
Secondary outcome [8] 323167 0
Adverse events (such as new pains in the body, rolled ankles, blisters, swelling) will be assessed via postal survey. The survey has been specifically designed for this study.
Timepoint [8] 323167 0
Monthly up to 12 months (52 weeks).
Secondary outcome [9] 323168 0
Adherence to the interventions (shoe inserts and rehabilitation therapy) via postal survey. For the shoe insert interventions, participants will provide information regarding the number of hours per day and number of days they have worn their inserts during the previous 4 weeks. For the rehabilitation therapy intervention, participants will provide information regarding the average number of days per week they have performed their exercises during the previous 4 weeks.
Timepoint [9] 323168 0
Monthly up to 12 months (52 weeks).
Secondary outcome [10] 323239 0
Severity of pain at the first metatarsophalangeal joint during rest over the past week (via a 100 mm VAS).
Timepoint [10] 323239 0
Baseline, and at 4, 12, 24 and 52 weeks.

Eligibility
Key inclusion criteria
(i) Aged at least 18 years, (ii) report having pain in the first metatarsophalangeal joint (MTPJ) on most days for at least 12 weeks, (iii) report having pain rated at least 30 mm on a 100 mm visual analogue scale (VAS), (iv) have pain upon palpation of the dorsal aspect of the first MTPJ and restricted first MTPJ dorsiflexion (less than 64 degrees of dorsiflexion range of motion), (v) be able to walk household distances (>50 meters) without the aid of a walker, crutches or cane, (vi) be willing to have their foot x-rayed, (vii) be willing to attempt to not receive additional interventions (such as shoe modifications, physiotherapy, foot orthoses, intra-articular injections, or surgery) for the first MTPJ pain during the course of the study, (viii) be able to reach feet to perform ‘rehabilitation therapy’ of the first MTPJ, and (ix) be willing to attempt to discontinue consuming any pain relieving medications for first MTPJ OA (except paracetamol [up to 4 grams per day] which will be rescue medication) for at least 14 days prior to the baseline assessment and during the study period. Participants who consume paracetamol for first MTPJ pain need to discontinue its use at least 24 hours prior to the baseline assessment and follow-up assessments at 4, 12, 26 and 52 weeks.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
(i) Previous first MTPJ surgery, (ii) currently pregnant, (iii) significant first metatarsophalangeal joint (MTPJ) deformity including hallux valgus (defined as a score of 2 or 3 using the Manchester scale, (iv) presence of one or more conditions within the foot or ankle that could confound pain and functional assessments of the first MTPJ such as forefoot pain that is not first MTPJ osteoarthritis, (v) presence of any systemic inflammatory condition such as gout or rheumatoid arthritis, (vi) any medical condition that, in the opinion of the investigators, makes the participant unsuitable for inclusion (e.g., clinically important pain in the musculoskeletal system other than the first MTPJ), (vii) an inability to speak and read English, (viii) cognitive impairment (ix) intra-articular injections (such as corticosteroids) at the first MTPJ in the previous 3 months, (x) unwilling to discontinue use of any foot orthotic devices (if currently wearing them) (xi) currently wearing shoe stiffening inserts, (xii) most regularly worn shoes not be able to accommodate the shoe stiffening inserts.

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)
Minimisation (stratified by age and sex)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Sequence generation will be provided by the National Health and Medical Research Council Clinical Trials Centre at the University of Sydney, Sydney, Australia. Participants will be allocated to the intervention or control groups using minimisation incorporating stratifications by age and sex, using an interactive voice response telephone service provided by the NHMRC Clinical Trials Centre at the University of Sydney, Sydney, Australia.
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
The sample size was determined a priori using SPSS Sample Power 3.0 (IBM Corporation, USA) based on the Foot Health Status Questionnaire (FHSQ) pain domain as the primary outcome measure. Using a power of 90%, minimal important difference (MID) of 12.5 points in the foot pain domain of the FHSQ, standard deviation (SD) of 16.8, assuming a 10% drop-out rate, and a significance level set at alpha < 0.05, we estimated that a total of 90 participants will be required.

Statistical analysis will be performed using the intention-to-treat principle for all randomised participants. In participants with bilateral symptoms, the more painful foot will be analysed (or the right foot if they cannot define the more painful foot) 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 use of self-reported magnitude of symptom change, use of co-interventions and adverse events and 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. Continuously-scored outcome measures will be analysed using analysis of covariance with baseline scores, sex, and intervention group entered as independent variables. Ordinal scaled data will be analysed using non-parametric tests. Dichotomous-scaled outcome measures will be compared using relative risk, risk difference, and number needed to treat (NNT).

Recruitment
Recruitment status
Completed
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] 13169 0
3086 - La Trobe University

Funding & Sponsors
Funding source category [1] 293444 0
Government body
Name [1] 293444 0
National Health and Medical Research Council
Country [1] 293444 0
Australia
Primary sponsor type
University
Name
La Trobe University
Address
La Trobe University
Mlbourne
VIC 3086
Country
Australia
Secondary sponsor category [1] 292267 0
Individual
Name [1] 292267 0
Hylton Menz
Address [1] 292267 0
La Trobe University
Melbourne
VIC 3086
Country [1] 292267 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 294888 0
La Trobe University Human Ethics Committee
Ethics committee address [1] 294888 0
Ethics committee country [1] 294888 0
Australia
Date submitted for ethics approval [1] 294888 0
04/12/2015
Approval date [1] 294888 0
13/01/2016
Ethics approval number [1] 294888 0
HEC15-128

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

Contacts
Principal investigator
Name 65338 0
Dr Shannon Munteanu
Address 65338 0
School of Allied Health,
La Trobe University
Melbourne
VIC 3086
Country 65338 0
Australia
Phone 65338 0
+61 3 94795866
Fax 65338 0
Email 65338 0
Contact person for public queries
Name 65339 0
Shannon Munteanu
Address 65339 0
School of Allied Health,
La Trobe University
Melbourne
VIC 3086
Country 65339 0
Australia
Phone 65339 0
+61 3 94795866
Fax 65339 0
Email 65339 0
Contact person for scientific queries
Name 65340 0
Shannon Munteanu
Address 65340 0
School of Allied Health,
La Trobe University
Melbourne
VIC 3086
Country 65340 0
Australia
Phone 65340 0
+61 3 9479 5866
Fax 65340 0
Email 65340 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment


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
SourceTitleYear of PublicationDOI
EmbaseShoe-stiffening inserts for first metatarsophalangeal joint osteoarthritis (the SIMPLE trial): Study protocol for a randomised controlled trial.2017https://dx.doi.org/10.1186/s13063-017-1936-1
EmbaseShoe-stiffening inserts for first metatarsophalangeal joint osteoarthritis: a randomised trial.2021https://dx.doi.org/10.1016/j.joca.2021.02.002
N.B. These documents automatically identified may not have been verified by the study sponsor.