In a number of recently published articles the use and efficacy of off-loading devices has been questioned (Armstrong et al, 2001). The failure of the off-loading strategy is cited as the reason why some new therapies have failed to produce the expected results (Boulton and Armstrong, 2003).
Moreover, it has been suggested that the use of a non-removable off-loading device should be an essential component of all future trials of new therapies for foot ulcers (Boulton and Armstrong, 2003). In their article, Boulton and Armstrong do not, however, state which device or technique should be adopted as the international standard. Others have criticised the proposal on the grounds that such a constraint might adversely affect the scientific structure and validity of the study (Jeffcoate et al, 2003). Is this really a practical suggestion? Does it negate all of the other off-loading techniques that have been developed since the inception of the technique of total contact casting (TCC) by Brand et al in 1984? While the TCC and the ‘instant TCC’ are now being promoted as the gold standard (for plantar neuropathic ulcers, at least), others have questioned whether they are necessarily the best option for all types of lesion, or for all people.
There are numerous off-loading devices available – the Hope walking sandal (Williams, 1994), the Optima slipper (Whyte 1998), Scotch-cast bootees, to name but a few. There have been few comparisons made between them. There is one published randomised controlled trial of different off-loading devices (Armstrong et al, 2001) that compares a TCC, a removable cast walker (RCW), and a Darco half shoe. It demonstrates that the TCC was associated with the best outcomes and the most effective method of off-loading (Armstrong et al, 2001). However, few other relevant studies have been undertaken.
Additionally, there is no standardised approach to off-loading, which highlights a particular weakness in other types of trials when they state ‘standard off-loading techniques were used’. There is no recognised standard off-loading regimen. Off-loading techniques differ from country to country, unit to unit and clinician to clinician, and are dependent on staff availability, experience, skills and budgets. There is very little research published that effectively evaluates different techniques, or compares one method with another. A recent Cochrane review states ‘there is a need to measure the effectiveness of the range of pressure-relieving interventions for the prevention and treatment of diabetic foot ulcers as there is a small amount of poor quality research in this area’ (Spencer, 2000).
All techniques have the same aim, to offload or reduce the loading on an ulcerated area in order to promote healing. The use of RCWs, such as ‘Aircasts’ (Aircast Incorporated, USA), have grown in popularity perhaps because the technique is perceived to have fewer associated risks than a TCC. This is despite being reported to be less effective than TCCs (Armstrong et al, 2003). This reduction in effectiveness may be due to poor patient compliance and has lead to development of the ‘instant TCC’. This combines the ease of application of a pneumatic walker combined with the permanence of the fibreglass casting tape to make the walker irremovable and therefore increase its effectiveness by addressing the issue of patient compliance (Armstrong et al, 2002).
Patient compliance can be one of the major drawbacks of using TCCs, either persuading the patient to accept the therapy initially or, once they have accepted the therapy, staying with it for the duration of the treatment. Some clinicians believe that TCC is the gold standard technique for treating various diabetic foot problems, but how many of us actually use it as a frontline treatment or offer it as the treatment of choice to patients, either due to lack of time, skills or perceived risk of patient non-compliance?
Reason for the questionnaire
As in every sphere, technology has moved on. With the advent of newer casting materials such as the 3M soft cast tape (a flexible fibreglass tape) has the use of TCC become more acceptable to the patient? Is a TCC made from new materials less likely to cause a cast rub or is it immaterial what the cast is made of and is this aspect dependent upon the skill of the person applying the TCC? Does a cast made of new materials offer the same pressure relief as the original technique of applying a TCC? The answer to all of these questions is ‘we don’t know!’.
Before we can accept the suggestion that any trials of new therapies should employ a non-removable off-loading device, we should examine the scope of off-loading strategies that are in common usage in this country and have an idea of their relative merits and effectiveness.
The aim of the following questionnaire is to answer these questions:
- Who is using which treatment?
- Why are they using it?
- What are they treating?
The more people that complete the questionnaire, the better the picture we will have of the current state of off-loading strategies. Then, perhaps, we can start to build the evidence base that is required.
Please download the PDF of this article to view the survey questions.
The author would like to thank William Jeffcoate for the very pertinent advice he provided and the time he spent reviewing the earlier versions of this article.