Why Are We Missing The Boat When Offloading Diabetic Foot Ulcers?

Doug Richie Jr. DPM FACFAS

I am presenting a lecture about offloading diabetic foot ulcerations at this year’s Midwest Podiatry Conference. In preparation, I reviewed a recent review paper by Peter Cavanagh, PhD, a respected authority on the subject of offloading the diabetic foot.1 He is also one of the pioneers of research in lower extremity biomechanics. Cavanagh’s findings are astounding.

Despite the fact that there is overwhelming evidence that non-removable offloading devices are the gold standard for treating diabetic foot ulcers, the majority of clinicians (including podiatric physicians) do not subscribe to this intervention.

In a study published in Diabetes Care in 2008, Stephanie Wu, DPM, and colleagues reported the results of a survey of 901 clinical practices within the United States.2 This study revealed that only 1.7 percent of the centers surveyed utilized the total contact cast, which is considered the best modality in offloading diabetic foot ulcerations. The authors note that 41.2 percent of the clinics used shoe modification and 15.2 percent of the practices used removable cast walkers (i.e. walking boots). Cavanagh’s paper goes on to reveal other studies that show clinicians worldwide resisting the utilization of non-removable offloading devices in the treatment of diabetic foot ulcerations.1,3,4

What is remarkable about these findings is that research has not shown footwear modification to be an effective means of offloading diabetic foot ulcerations.5 Authors have shown walking boots and total contact casts to be far more effective than footwear and actually quite similar in their ability to reduce plantar pressures in neuropathic feet.5,6

My friend and co-blogger on this site, David Armstrong, DPM, PhD, MD, however, has published an eye-opening study revealing that patients with diabetic ulcers wore their walking boot for only 29 percent of the total steps they took during a 24-hour period.7 This led to the concept of an irremovable cast walker, which involves applying fiberglass casting tape around a walking boot in order to keep the patient from taking the device off. This type of walking boot can produce healing rates similar to total contact casts.8

It is unclear whether the majority of podiatric physicians routinely convert walking boots into irremovable devices by wrapping them with fiberglass when treating diabetic foot ulcers. In the study by Wu and co-workers, only 15 percent of the centers surveyed used walking boots.2 Yet a recent survey of 363 podiatric physicians revealed that 80 percent of the podiatric practitioners favored walking boots or post-op shoes in the treatment of diabetic foot ulcers.9 Only 11 percent utilized total contact casts.

Are Reimbursement Factors And Ease Of Application Driving Offloading Methods?

This is interesting given the fact that we do not receive reimbursement for walking boots and post-op shoes for Medicare patients when we dispense them for the sole purpose of offloading a foot ulcer. If podiatric physicians are using walking boots 80 percent of the time to treat diabetic foot ulcers, then they must be charging their Medicare patients cash or the majority of their patients may have private insurance that covers walking boots for this application. The survey did not distinguish between removable versus irremovable walking boots but my impression is that the vast majority of podiatric physicians do not wrap fiberglass tape around a walking boot to make it non-removable for their patients with diabetes.9

Why do podiatric physicians and other specialists fail to follow the “gold standard” of offloading when treating diabetic foot ulcerations? Is this a question of reimbursement? The answer is clearly no when one compares the cost and reimbursement of casts for total contact casts to the costs and reimbursement of walking boots.

Many practitioners are surprised to learn that Medicare will not pay for the dispensing of a walking boot if the sole purpose is to offload a foot ulcer. While some clinicians have been prescribing and billing Medicare for walking boots to treat diabetic foot ulcerations, they should be cautious since this practice is not legal.

A similar misunderstanding now exists about the use of ankle foot orthoses (AFOs) for fall prevention in Medicare eligible patients (see my recent blog at http://tinyurl.com/6ta3q3l ). The American Podiatric Medical Association recently issued a bulletin regarding the use of walking boots and AFOs to treat ulcers as well as the question of using AFOs for fall prevention. See http://www.multibriefs.com/briefs/apma/031512_2.pdf .

Conversely, Medicare will pay for the weekly application of a total contact cast, which over a six-week period can provide a reimbursement over $900. Critics point out that application of a total contact cast is time consuming and has a learning curve for technicians or clinicians before they gain confidence in this modality.

Despite adequate reimbursement, the overall cost of time and materials do not always make sense from a practice management standpoint. However, the total contact cast option may be more feasible in comparison to the alternative situation of charging Medicare patients cash for the walking boot and then billing for the fiberglass materials to convert the boot into a non-removable device.

So if reimbursement is not driving physician decision making when selecting an offloading modality for diabetic patients, what is affecting this process? It appears that patient preference is the driving force. Certainly, patients resist a non-removable device because of impaired balance, bathing, sleeping and driving restrictions and an inability to monitor the wound. Patients will plead with their doctor to avoid a cast and it appears that we are quick to acquiesce. Certainly, it also appears that clinicians may be taking the easy way out by focusing on simple footwear modifications as an attempt to offload a diabetic foot ulcer. Yet the science has shown that this is the least effective option available.1

In Conclusion

The point is physicians have to be more proactive with their patients when it comes to offloading diabetic foot ulcerations. Even though it is less desirable for the patient, the use of non-removable offloading devices is the gold standard. If a clinician is not comfortable with applying a total contact cast, then the option is to charge the Medicare patient cash for a walking boot and then make the device non-removable by applying a roll of fiberglass casting tape over the boot.

As Cavanagh demonstrates in his excellent review of the subject, the science is overwhelming in supporting the efficacy of non-removable devices to offload diabetic foot ulcerations.1 The challenge is finding alternative solutions for patients who clearly cannot tolerate such devices. On the other hand, clinicians must hold the line and do the right thing when implementing non-removable devices for the vast majority of patients with diabetic ulcers who can be safely treated with these interventions.

References

1. Cavanagh PR, Bus SA. Off-loading the diabetic foot for ulcer prevention and healing. J Am Podiatr Med Assoc. 2010; 100(5):360-368.

2. Wu SC, Jensen JL, Weber AK, Robinson DE, Armstrong DG. Use of pressure offloading devices in diabetic foot ulcers. do we practice what we preach? Diabetes Care. 2008; 31(11):2118–2119.

3. Fife CE, Carter MJ, Walker D. Why is it so hard to do the right thing in wound care? Wound Repair Regen. In press.

4. Prompers L, Huijberts M, Apelqvist J, et al. Delivery of care to diabetic patients with foot ulcers in daily practice: results of the Eurodiale Study, a prospective cohort study. Diabet Med. 2008; 25(6):700-7.

5. Fleischli JG, Lavery LA, Vela SA, Ashry H, Lavery DC. 1997 William J Stickel Bronze Award: Comparison of strategies for reducing pressure at the site of neuropathic ulcers. J Podiatr Med Assoc. 1997; 87(10):466–472.

6. Beuker BJ, Van Deursen RW, Price P, et al. Plantar pressure in off-loading devices used in diabetic ulcer treatment. Wound Repair Regen. 2005; 13(6):537-42.

7. Armstrong DG, Lavery LA, Kimbriel HR, et al. Activity patterns of patients with diabetic foot ulceration: patients with active ulceration may not adhere to a standard pressure off-loading regimen. Diabetes Care. 2003; 26(9):2595-7.

8. Armstrong DG, Lavery LA, Wu S, et al. Evaluation of removable and irremovable cast walkers in the healing of diabetic foot wounds: a randomized controlled trial. Diabetes Care. 2005; 28(3):551-4.

9. Donoghue SK. PM’s 29th Annual Survey: Racing ahead in the post-recession. Podiatr Manage. 2012; 31(2):93-144.

Comments

I agree with you Dr Richie. As the diabetic foot steadily becomes recognized as a "malignant disease," guidelines and standards of care become more relevant in our daily practice.

Additionally, there is no shortage of evidence-based medicine reflecting the efficacy of total contact casting (TCC). Cam cast boots do not have the same rate of healing as the TCC and they tend to collect drainage and odor rather quickly.

As Caroline Fife, MD, has said, “I strongly believe that if you are not committed to offloading in your clinic, you are NOT properly treating diabetic foot ulcers."

Thank you for your article.

Add new comment