Offloading is an integral part of the comprehensive algorithm to heal a diabetic foot ulcer (DFU).1 Multiple studies have shown the total contact cast (TCC) is the best modality out of all the available methods to offload the plantar foot ulcer.2,3 In fact, advanced treatments, like expensive cellular- and tissue-based products, are unlikely to be successful without adequate offloading.4
In a large retrospective study from the U.S. Wound Registry, treatment of a DFU with a TCC cost significantly less than treatment without a TCC.5 The cost of care per patient when clinicians used a TCC averaged $11,946 (in 2010) whereas the cost per patient without the use of TCC averaged $22,494. A recent consensus report recommended the use of TCC for all appropriate DFUs.6
Total contact casting is indicated for plantar diabetic foot ulcers, Charcot foot and postoperative offloading. It is contraindicated in those with severe peripheral arterial disease or untreated infection. A TCC may interfere with activities of daily living and clinicians should be cautious with using it in those who are obese or have ataxic gait. When it comes to driving, patients using a TCC should not operate a motor vehicle with automatic transmission if the TCC is on the right foot and should not drive a car with manual transmission if the TCC is on either foot.
Total contact casts work by several mechanisms. The conical shaped leg wedges into the cast and transfers plantar pressure to the tibia. The TCC immobilizes the ankle joint, reducing propulsion and forefoot pressure. The TCC reduces the stride length and decelerates the foot, resulting in reduced plantar pressure. The TCC is also more successful than removable devices because it forces adherence by being irremovable.7
However, there is a large evidence-practice gap. While there is good evidence for using TCCs in offloading DFUs, clinicians do not use TCC with great enough frequency in practice. Reportedly 45 percent of wound care centers do not provide offloading and only 1.7 percent of the wound care centers used TCC.8 While there has been much improvement since the 2008 article by Wu and colleagues, we still have a long way to go.
Addressing Perceptions About Casting Time And Degree Of Difficulty
Clinicians perceive that the cast is technically difficult to apply. This may be true with older cast technology but the newer roll-on cast (TCC-EZ, DermaSciences) requires minimal training. In fact, physicians can train staff to apply the cast, freeing up the doctor to complete other tasks.
A related barrier is the perceived time to apply the cast. A traditional TCC takes about 30 to 45 minutes to apply and dry enough for ambulation. One can apply the TCC-EZ in about five minutes and patients can bear weight in about 15 minutes. There is the fear that the wound could worsen or other wounds could occur. This may happen with improper application, non-adherence or cast failure, but these issues are rare and manageable.
What About Practice Management Issues With TCC?
Organizations are concerned about how to implement the TCC into the patient flow. However, practices can easily address this since patients receive casts weekly and one can build this extra staff time into the visit. Some may be concerned over the storage space for supplies but the cast kits can keep all the supplies in a box in one place.
Practice managers are also worried about the profitability of the cast. But in both typical practice settings (hospital outpatient department and physician office) for wound care, the cast is more profitable than many other procedures and has a 0 day global period. Accordingly, if a patient damages a cast or inadvertently gets it wet, one can change the cast and the practice or facility can bill for the reapplication. Organizations or practices may be concerned with the cost of a cast saw if they do not already have access to one, but they can recoup the upfront investment with just six to eight cast applications.
Easing The Fears And Concerns Of Patients About TCC
The most common patient barrier is concern about transportation to and from the clinic, and driving when the right foot is casted. This requires the involvement of family and friends to ensure the patient has appropriate mobility. Additionally, some patients may qualify for transportation to and from the wound center. Patients are also concerned with limitations in activities of daily living. If there is fear of falling, one can prescribe a walker. For showering, clinicians can recommend various cast protectors to prevent the cast from becoming wet.
In regard to patient education, it is important for them to protect the contralateral leg while they are sleeping. Accordingly, they can sleep with a pillow between their legs or put a pillowcase over the cast. This can prevent abrasions or other injuries to the contralateral leg. There may also be concerns about anyone sleeping in the same bed with the patient and possibly becoming injured by the TCC. Patients who are extremely obese or thin may not be appropriate for a cast kit, and a custom cast could be required. Finally, patients may be fearful or have reservations about the cast saw. Utilization of a cast kit with a padded tibial crest will minimize the risk of injury and keep the patient comfortable during removal. Clinicians can also explain the use of the saw and the low risk of injury.
While it is clear that the best method to offload the plantar diabetic foot ulcer is the TCC, there are perceived barriers to the use of TCC in clinical practice. However, one can overcome these barriers with minimal training, proactive planning and appropriate patient education. In doing so, the use of TCC will be much easier, resulting in an increase in wound healing rates, a decrease in the time to heal and a cost savings in treatment.
Dr. Rogers is the Executive Medical Director of the Amputation Prevention Center at Sherman Oaks Hospital in Los Angeles. He is a co-author of the offloading consensus published in the Journal of the American Podiatric Medical Association in December 2014.
- Snyder RJ, Kirsner RS, Warriner RA III, et al. Consensus recommendations on advancing the standard of care for treating neuropathic foot ulcers in patients with diabetes. Ostomy Wound Manage. 2010;56(4 Suppl):S1-S24.
- Lewis J, Lipp A. Pressure-relieving interventions for treating diabetic foot ulcers. Cochrane Database Syst Rev. 2013:1;CD002302
- Bus SA, Valk GD, Van Deursen RW, et al. The effectiveness of footwear and offloading interventions to prevent and heal foot ulcers and reduce plantar pressure in diabetes: A systematic review. Diabetes Metab Res Rev. 2008;24 (1 Suppl):S162-S180.
- Frykberg RG, Zgonis T, Armstrong DG, et al. Diabetic foot disorders: a clinical practice guideline. J Foot Ankle Surg. 2006;45(5 Suppl):S1-S66.
- Fife CE, Carter MJ, Walker D. Why is it so hard to do the right thing in wound care? Wound Repair Regen. 2010;18(2):154-158.
- Snyder RJ, Frykberg RG, Rogers LC, et al. The management of diabetic foot ulcers through optimal offloading: Building consensus guidelines and practical recommendations to improve outcomes. J Am Podiatr Med Assoc. 2014;104(6):555-567.
- Armstong DG, Nguyen HC, Lavery LA, et al. Offloading the diabetic foot wound: A randomized clinical trial. Diabetes Care. 2001;24(6):1019-1022.
- Wu SC, Jensen JL, Weber AK, et al. Use of pressure offloading devices in diabetic foot ulcers: do we practice what we preach? Diabetes Care. 2008;31(11):2118-2119.