This author says total contact casts offer key biomechanical benefits, have extensive literature support and facilitate quicker healing of plantar diabetic foot ulcers.
By Lee C. Rogers, DPM
Offloading is one of the central concepts to healing the diabetic foot ulcer.1,2 It is usually pressure (combined with neuropathy) that leads to an ulcer. Therefore, we must relieve the pressure in order to achieve wound healing.
There are essentially two types of offloading: internal and external. Internal offloading occurs via surgical procedures, like an exostectomy or tendo-Achilles lengthening, to relieve pressure. External offloading occurs when applying external implements to redistribute pressure. When no ulcer is present, many types of orthoses or devices can help relieve pressure to prevent ulcers. But when an ulcer is present, one must consider several factors to determine the best method to offload and heal the ulcer.
First, it is important to understand that all ulcers will benefit from offloading, regardless of their location. Added pressure delays wound healing. The plantar foot may be the most difficult surface to achieve good offloading with because of the added stress of weightbearing and the necessities for the patient to perform activities of daily living. Therefore, it is necessary to prescribe a device that can remove pressure while the patient bears some weight.
Second, one must assess the wound status, treat infection and evaluate and manage peripheral artery disease (PAD). For wounds with copious drainage, clinicians must employ strategies to prevent the wound drainage from macerating the wound. This includes dressing choice, more frequent total contact cast (TCC) changes or the use of a more readily removable device.
Third, consider other patient factors. In patients who must drive, a non-removable device on the right foot might be dangerous and increase the risk of a car accident. Warn all patients not to drive if they wear an irremovable, fixed-ankle device on the right foot. The TCC is more customized than a removable cast walker. Therefore, in cases when more deformity or edema is present, a customized device may be a better option to prevent friction and possible skin breakdown from a non-custom device.
What Advantages Does The TCC Have Over Removable Cast Walkers?
As far as the research is concerned, authors have shown that TCC is the best method for offloading the plantar foot.3–7 Let us consider the TCC’s mechanism of action.
Weight transfer to the tibia. Due to the conical shape of the tibial segment of the leg, some of the downward force of the weight transfers to the hard cast, which removes pressure from the plantar foot. In this case, the cast acts as an exoskeleton, much like a crab or insect has a hard skeleton on the outside and the soft tissues on the inside.
Eliminated ankle motion. A properly applied cast keeps the ankle at neutral. This prevents plantarflexion and reduces force at the forefoot and midfoot.
Shortened stride length. Due to eliminated ankle motion, the treated lower extremity cannot transition completely through all phases of gait. Heel strike and propulsion are minimized. This results in less contact time on the ground and fewer ground reactive forces.
Fewer steps per day. The nature of ambulating with a cast on is cumbersome and patients take fewer steps per day, thus reducing the cycles of repetitive stress on the foot.
In a randomized controlled trial, Armstrong and coworkers compared a half-shoe, a removable cast walker and a total contact cast for plantar diabetic foot ulcers.3 The TCC healed 90 percent of wounds in half the time as the half-shoe and patients who wore TCCs took less than half the steps per day as patients took wearing half-shoes. Another study comparing a windowed TCC to an offloading shoe found an 81 percent healing rate in the TCC group in an average of 2.3 months versus a 70 percent healing rate in 4.5 months for the half-shoe.4
Several consensus documents on the diabetic foot recommend the use of the total contact cast as the primary method to offload the diabetic foot ulcer. The National Diabetes Education Initiative recommends “(offloading) with a total contact cast or irremovable fixed ankle walking boot.”5 According to the International Working Group on the Diabetic Foot (now D-Foot International), “To heal a neuropathic plantar forefoot ulcer without ischemia or uncontrolled infection in a patient with diabetes, offload with a non-removable knee-high device with an appropriate foot-device interface.”6 A consensus publication in the Journal of the American Podiatric Medical Association notes that the “Total contact cast is the preferred method for offloading diabetic plantar foot ulcers, as it has most consistently demonstrated the best healing outcomes and is a cost-effective treatment.”2 According to the American Podiatric Medical Association and the Society for Vascular Surgery, “In patients with plantar DFU, we recommend offloading with a total contact cast (TCC) or irremovable fixed ankle walking boot.”1 The World Union of Wound Healing Societies says TCC is “the ‘gold standard’ method of offloading for plantar DFUs.”7
Addressing The Barriers To TCC Use
While TCC is the best method to offload the plantar diabetic foot ulcer, it is not right for every patient. Do not use a TCC in the face of untreated infection. Additionally, while a TCC is not strictly contraindicated in patients with impaired perfusion, one should exercise caution in using a TCC for these patients. In fact, some recent reports tout the benefits of TCC in patients with mild to moderate PAD.8,9 Of course, when possible, one should address perfusion as part of the pathway in treating diabetic foot ulcers.1
Despite all the pros of using TCC for plantar diabetic foot ulcers, there are several barriers to implementation. These barriers can be clinician-related, organization-related or patient-related. Even though some have described the TCC as the “gold standard,” it does not have widespread use. A study published a decade ago found that of almost 900 wound centers, just 4 percent of the centers used TCCs.10 In an analysis of 108,000 patient visits to hospital-based wound centers, TCC was in use for only 6 percent of eligible diabetic foot ulcers.10,11
Physicians should consider the TCC a valuable part of their toolbox for treating plantar diabetic foot ulcers. Despite the precautions and implementation barriers, the benefits outweigh the risks in a majority of cases. Most studies have shown higher TCC healing rates at half the time in comparison with other modalities. With that in mind, the TCC is the preferred method for offloading uncomplicated plantar DFUs.
Dr. Rogers is the Medical Director of the Amputation Prevention Centers of America in White Plains, NY.
1. Hingorani A, LaMuraglia GM, Henke P, et al. The management of diabetic foot: A clinical practice guideline by the Society for Vascular Surgery in collaboration with the American Podiatric Medical Association and the Society for Vascular Medicine. J Vasc Surg. 2016;63(2 Suppl):3S - 21S.
2. Snyder RJ, Frykberg RG, Rogers LC, et al. The management of diabetic foot ulcers through optimal off-loading: building consensus guidelines and practical recommendations to improve outcomes. J Am Podiatr Med Assoc. 2014;104(6):555-567.
3. Armstrong DG, Nguyen HC, Lavery LA, van Schie CH, Boulton AJ, Harkless LB. Off-loading the diabetic foot wound: a randomized clinical trial. Diabetes Care. 2001;24(6):1019-1022.
4. Ha Van G, Siney H, Hartmann-Heurtier A, Jacqueminet S, Greau F, Grimaldi A. Nonremovable, windowed, fiberglass cast boot in the treatment of diabetic plantar ulcers: efficacy, safety, and compliance. Diabetes Care. 2003;26(10):2848-2852.
5. National Diabetes Education Initiative. Diabetes Foot Care Guidelines Off-Loading Foot Ulcers. Available at www.ndei.org/diabetic-foot-care-joint-guidelines-off-loading-diabetic-foot-ulcers.aspx.html . Accessed January 31, 2019.
6. Bus SA, Armstrong DG, van Deursen RW, et al. IWGDF guidance on footwear and offloading interventions to prevent and heal foot ulcers in patients with diabetes. Available at http://iwgdf.org/files/2015/website_footwearoffloading.pdf Accessed January 31, 2019.
7. World Union of Wound Healing Societies. Local management of diabetic foot ulcers. Wounds International. Available at http://www.wuwhs2016.com/files/WUWHS_DFUs_web.pdf . Accessed January 31, 2019.
8. Arnold JF, Marmolejo V. Outcomes achieved with use of a prefabricated roll-on total contact cast. Foot Ankle Int. 2017;38(10):1126-1131.
9. Tickner A, Klinghard C, Arnold JF, Marmolejo V. Total contact cast use in patients with peripheral arterial disease: a case series and systematic review. Wounds. 2018;30(2):49-56.
10. 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.
11. 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.
This author says controlled ankle motion (CAM) walkers are easy for
patients to use and have good adherence in contrast with total contact casts.
By Jason Hanft, DPM
Total contact casting (TCC) is considered the gold standard for efficacy in the treatment of diabetic plantar wounds. The treatment outcomes of casting with a variety of types of contact casts are excellent.
Dating back to the original papers on contact casting for diabetic plantar wounds, the wound healing outcomes and limited complications associated with TCC have been superior to those of many other modalities.1 I have also published or co-authored a number of articles and book chapters touting the efficacy, safety, low rate of complications and increased rate of limb salvage with the use of TCC.2–4
However, for nearly as long as the TCC has been in use, there has been resistance to utilization by both practitioners and patients. Patients refuse the TCC due to limitations on walking and standing, inability to work with the cast in place, and a myriad of complaints that really come down to the interference with their activities of daily living while wearing the TCC.
Professionals claim the TCC has risks associated with its use and that it is too difficult and time-consuming to apply. One potential solution to these complaints was introduced over a decade ago in the form of the TCC-EZ (Derma Sciences).
The TCC-EZ was invented to provide the same excellent outcomes as the traditional contact casts but to decrease the time and increase simplicity of application as well as creating a lighter, more patient-friendly cast. The success of the TCC-EZ system has spawned a number of other contact cast systems over the years, all designed to increase patient acceptance and clinician utilization. Yet we continue to have extremely poor TCC utilization by professionals and low patient acceptance.
Researchers estimate only 2.2 to 10 percent utilization of TCCs for qualifying diabetic plantar wounds.5–7 Perhaps even more alarming is the continued rise in frequency of avoidable complications, such as infection and amputations, that are directly linked to diabetic plantar wounds.5,6
How CAM Walkers Can Succeed Where TCCs Fail
This lack of utilization and acceptance of TCC has severely limited the potential of this fantastic tool in the fight to heal diabetic wounds.
It is not a failing of the TCC but rather a failure to actually consider the proper question. The question is not what is the best device to facilitate healing of plantar diabetic foot wounds but rather, which device will both patients and professionals accept and utilize to facilitate healing of plantar diabetic foot wounds?
Due to the perceived difficulties and risks with casting, many professionals have resorted to using devices more readily accepted by patients to assist in healing plantar diabetic foot wounds that have the characteristics of the TCC.8–10
The controlled ankle motion (CAM) walker is one of these devices. It limits ankle motion, distributes force across a larger surface area, protects the wound, decreases plantar pressure, slows the speed of gait and decreases strain rate to the plantar surface of the foot. These are all desirable qualities in a device utilized to assist in healing plantar diabetic foot wounds.
Although originally intended for use as fracture or trauma braces for lower extremity injuries, CAM walkers have been appropriated and adapted for the treatment of plantar diabetic foot wounds. Intended to be easy to apply with a higher level of acceptance by patients, the CAM walker has a higher level of utilization for treatment of plantar diabetic ulcers than the TCC. Literature reports vary but in general terms, patients are three to seven times more likely to use CAM walkers than a TCC.8–10 Controlled ankle motion walkers have demonstrated their ability to offload the plantar surface of the foot for over 30 years. Although the mechanical properties of the CAM walker may not be superior to the TCCs, they are most certainly superior to standard forms of footwear.11,12
Searching For An Ideal Offloading Device
Is the TCC or the CAM walker the ultimate device for treatment of diabetic plantar wounds? The answer is no for both devices.
The argument against removable devices such as the CAM walker for the treatment of diabetic plantar wounds has always been an issue of adherence. Removable devices allow patients to decide whether to utilize the device. Yet how many professionals have asked their patients with diabetic plantar wounds to put on and take off a CAM walker? Do patients remove the walker and have no idea how to reapply it properly? Can the patient even reach his or her foot to manage the assortment of straps and closures? Have we as professional wound care providers asked the patients why they do not wear their removable devices?
The actual patient responses are astounding but they basically boil down to issues of the difficulty of use of CAM walkers, social stigma associated with the device and the inability of the patient to conduct his or her activities of daily living with the removable device in place.
We as professionals have failed to direct our treatment modalities with proper consideration of the patient. This is not an adherence issue but rather an attempt to improve utilization without complete consideration of the end user, the patient.
To really have an effect on the overall outcomes in wound healing as well as limit complications and infection, the ideal next generation of removable devices for the treatment of diabetic plantar wounds should:
• maximize the ground force reduction;
• control the strain rate to the tissues on the plantar surface of the foot;
• protect the wound;
• be easy to apply and remove;
• exhibit a typical footwear appearance to obviate the stigma associated with current protective footwear; and
• provide feedback to the patient and professional on the status and function of the device and the condition of the wound and extremity.
In the meantime, if patients will use the CAM walker more readily and professionals who are not comfortable utilizing the TCC will dispense the CAM walker, then at least some degree of offloading is occurring, resulting in healing a higher percentage of plantar diabetic foot wounds. Healing of these wounds ultimately leads to reduced complications, amputations and money saved for the entire health care system. Based on this information, I believe that the high utilization rate, ease of use and high degree of adherence associated with the CAM walker make it superior to the TCC for treatment of plantar diabetic wounds.
Dr. Hanft is the Director of Podiatric Education and the Director of Research with the Podiatric Residency Program at the South Miami Hospital in Miami. He is in private practice at the Foot and Ankle Institute of South Florida in Miami. Dr. Hanft is a Fellow of the American College of Foot and Ankle Surgeons.
1. Coleman WC, Brand PW, Birke JA. The total contact cast. A therapy for plantar ulceration on insensitive feet. J Am Podiatry Assoc. 1984; 74(11):548-52.
2. Snyder RJ, Kirsner RS, Warriner RA 3rd, Lavery LA, Hanft JR, Sheehan P. Consensus recommendations on advancing the standard of care for treating neuropathic foot ulcers in patients with diabetes. Ostomy Wound Manage. 2010;56(4 Suppl):S1-24.
3. Snyder RJ, Hanft JR. Diabetic foot ulcers--effects on QOL, costs, and mortality and the role of standard wound care and advanced-care therapies. Ostomy Wound Manage. 2009;55(11):28-38.
4. Hanft JR, Hall DT, Kapila A. A guide to preventive offloading of diabetic foot ulcers. Podiatry Today. 2011; 24(12):60–67.
5. Fife CE, Carter MJ, Walker D, et al. Diabetic foot ulcer off-loading: The gap between evidence and practice. Data from the US Wound Registry. Adv Skin Wound Care. 2014;27(7):310-6.
6. US Wound Registry. CRD 1: process measure: adequate offloading of diabetic foot ulcers at each visit. Available at https://uswoundregistry.com/Files/Approved/non-MIPS_US%20Wound%20Registry%200001.pdf .
7. 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):2118–9.
8. Faglia E, Caravaggi C, Clerici G, et al. Effectiveness of removable walker cast versus nonremovable fiberglass off-bearing cast in the healing of diabetic plantar foot ulcer. A randomized controlled trial. Diabetes Care. 2010; 33(7):1419–23.
9. Gutekunst DJ, Hastings MK, Bohnert KL, et al. Removable cast walker boots yield greater forefoot off-loading than total contact casts. Clin Biomech. 2011; 26(6):649–54.
10. Faglia E, Caravaggi C, Clerici G, et al. Effectiveness of removable walker cast versus nonremovable fiberglass off-bearing cast in the healing of diabetic plantar foot ulcer: a randomized controlled trial. Diabetes Care. 2010; 33(7):1419–23.
11. Bus SA, Waaijman R, Arts M, et al. Effect of custom-made footwear on foot ulcer recurrence in diabetes: a multicenter randomized controlled trial. Diabetes Care. 2013; 36(12):4109–16.
12. 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(Suppl 1):S162-80.
13. Snyder RJ, Frykberg RG, Rogers LC, et al. The management of diabetic foot ulcers through optimal off-loading: building consensus guidelines and practical recommendations to improve outcomes. J Am Podiatr Med Assoc. 2014; 104(6):555–67.
14. Lavery LA, Vela SA, Lavery DC, Quebedeaux TL. Reducing dynamic foot pressures in high-risk diabetic subjects with foot ulcerations: a comparison of treatments. Diabetes Care. 1996; 19(8):818–821.
15. Piaggesi A, Macchiarini S, Rizzo L, et al. An off-the-shelf instant contact casting device for the management of diabetic foot ulcers: a randomized prospective trial versus traditional fiberglass cast. Diabetes Care. 2007; 30(3):586-90.
16. Lavery LA, Higgins KR, La Fontaine J, et al. Randomised clinical trial to compare total contact casts, healing sandals and a shear-reducing removable boot to heal diabetic foot ulcers. Int Wound J. 2014; 12(6):710–15.
17. Lavery LA, Vela SA, Lavery DC, Quebedeaux TL. Total contact casts: pressure reduction at ulcer sites and the effect on the contralateral foot. Arch Phys Med Rehabil. 1997; 78(11):1268–1271.
18. Armstrong DG, Lavery LA, Wu S, Boulton AJ. Evaluation of removable and irremovable cast walkers in the healing of diabetic foot wounds: a randomized controlled trial. Diabetes Care. 2005; 28(3):551–554.
19. Armstrong DG, Lavery LA, Nixon BP, Boulton AJM. It’s not what you put on, but what you take off: Techniques for debriding and off-loading the diabetic foot wound. Clin Infect Dis. 2004; 39(Suppl 2):S92–99.