TOE Study: Treatment and Gait Analysis fOllowing an Excised Lesser Toe

A Feasibility Randomised Controlled Study to Examine the Effect of Otoform Toe Dividers in the Treatment of Patients With Diabetes Mellitus Following a Lesser Toe Amputation

Summary of study

The study will examine patients with Diabetes Mellitus (DM) who have had a lesser toe amputations (LTA) (toes 2nd3rd,4th or 5th). It is currently not understood how this affects the way patients walk and foot function. No previous studies have been undertaken to examine this and its potential for causing further ulceration risk.

This study is a feasibility study. It is designed to see if it is possible to undertake a large, randomised trial. It will explore how participants are recruited, kept in the study and how easy it is to follow the study protocol.

Aim of the study

Establish the feasibility of a corresponding full scale investigation into to the effectiveness of a toe divider made from Otoform for patients with DM following an LTA.

Study Design

1. Participants will be recruited from Mid Yorkshire NHS teaching Hospital.
2. Participants will be randomised to receive either standard care or an otoform toe divider.
3. Participants age, gender, medical history, medication and blood sugar levels will be recorded.
4. Vascular and neurological assessments, foot posture and toe deformities will be undertaken and recorded.
5. All participants will have pressures measured on the plantar aspects of both feet.
6. Follow up visits will be arranged every 6 weeks for12 months for all participants to monitor foot health and changes in walking pattern and pressure redistribution.
7. If an ulceration or other foot complication occurs, the participants will be removed from the study and appropriate treatment given (the rescue arm of the study).

The study is currently being undertaken in part fulfil a PhD and because the research questions have not previously been answered.

The main study questions are:

1. Can a large scale randomised control trial been undertaken using the methodology of the feasibility study?
2. How does gait and foot function change after an LTA in patients with DM?
3. Does an Otoform toe divider improve foot function and affect pressure redistribution reducing the risk of ulcerations?
4. Can the research learn how to research, write, execute and evaluate a feasibility study as part of her PhD?

There is no previous research examining the effects that DM and an LTA have on gait and foot structure or the use of toe dividers manufactured from otoform as a treatment following an LTA. It is not known why these patients are at risk of developing further ulcerations and where on the foot these are likely to be. It is known that up to 60% of patients who have DM and an LTA require further surgery including revision surgery, further minor amputations or major amputations. None of the studies that established this did not look at why. This study aims in part to answer this.

This subject area has also been selected as toe dividers are routinely given to patients and there is anecdotal evidence to support this but how effective they have not been studied. It has also been chosen as there are no current guidelines or recommendation on how to treat this patient group. An Otoform toe divider has been selected as it is the most used material from which toe dividers are made. This was established after a questionnaire was sent to health care workers involved in the care of patients with DM and LTA. The questionnaire asked what treatments were used and what materials were chosen and why. This questionnaire has fulfilled the first part of the researchers PhD. Further material testing at the University of Huddersfield's engineering department found that Otoform was more effective in dealing with compression and deformation forces than other materials commonly involved (silicone gel and semi compressed felt). The other two materials were found not to withstand these forces as well as Otoform. Semi compressed felt could also not be washed which created a hygiene issue.

The study has been design to run over a 12 month period as previous studies have suggested that if a participants going to develop an ulceration it will be within the first 12 months after a lesser toe amputation. 12 months has also been selected to examine both the short and long term effects of wearing a toe divider. 6 weeks has been chosen to review participants to examine any changes in foot health. The methodology has been reviewed at each stage with the researcher by her supervision team which is comprised of researchers, clinicians and a statistician. The methodology has also been discussed with patients and clinicians.

The results from the initial visit will be compared with the literature to establish how participants in this study compare to participants in other studies that examined gait in those without DM, in DM without neuropathy and DM with neuropathy but without any amputations. It has been chosen to do this as several studies have already been undertaken to examine the gait patterns in these patient groups. It would be unethical to ask participants to take part in a study when this information is already available.

Patients, their careers and the public have been involved in the development of the study through speaking to patients and through the James Lund Alliance. The James Lund Alliance is a not-for-profit organisation, established in 2006 to look at health priorities, medical uncertainties and unanswered medical questions (James Lund, 2024a). Priorities are set by bringing together patients, carers, and clinicians (James Lund, 2024a). Under the priority "vascular conditions", one area pertinent to this study is the Diabetic Foot (James Lund, 2024b). The questions under "Diabetic Foot" relevant to this study are:

2) What are effective methods of preventing further amputations following a toe amputation? 7) What is the most effective way to prevent DFUs returning? (James Lund Alliance, 2021a).

The study has been discussed and read by patients who attend a diabetes centre who have had a LTA. The discussion bought to attention that participants may not be able to afford to attend the clinics so home visits or reimbursement for parking charges may be required.

Only participants with capacity will be included in the study. The researcher undertaking the study has had the necessary training to assess if an individual has the capacity to provide informed consent to take part in the study. Where English is not the participants first language, an interpreting service is available to allow the participant to understand the study and provide the necessary consent.

It is appreciated that participants may not be able to commit for a 12 month period but as no previous studies have been undertaken it is not known if this is possible. As the study is a feasibility study the boundaries of the study are being explore and if drop out is too high then the protocol may need to be adjusted to reflect this. It is also appreciated that there is a potential risk of an ulcer forming as the toe divider may rub. To reduce this risk the toe dividers are custom made to each individual participant and they will be monitored every 6 weeks.

As the researcher is also a clinician there is the potential that she may know some of the participants recruited for the study. The conflict of interest will be kept to a minimum by explaining the purpose of the study what treatments will be received and what treatments. This will enable patients expectations to be managed.

There are potential benefits to be gained from taking part in the study. These include improvement in balance, the potential to keep toes in a better position post operatively, a pressure map of the patient's foot which highlights areas that may ulcerate before they do. This currently is not a service that is offered within the trust where the research will take place but has been shown by previous studies to reduce the risk of ulceration.

Inclusion Criteria:

1. Participants over the age of 18.
2. Participants with DM and a lesser toe amputation.
3. Participants who wish to take part and provide informed written consent
4. Participants who are mobile (including those who use walking aids).

Exclusion Criteria

1. Participants under the age of 18.
2. Participants who do not have DM.
3. Participants who have active ulcerations or surgical sites.
4. Participants who had had a 1st toe and/or ray amputation.
5. Participants with neuroarthropathy or other marked foot deformities.
6. Participants who already wear a toe divider.
7. Participants who have a known allergy to the silicone or catalyst being used.
8. Participants who are immobile.