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In 2012, 4.8 mil l ion deathswere attributed to diabetes,and 471 billion USD was spenton diabetes-related healthcare,worldwide.1 The number of

people with diabetes is increasing inevery country1, including the UnitedStates, in which diabetes affects25.8 million people, or 8.3% of thepopulation.2 Furthermore, up to25% of people with diabetes willdevelop a foot ulcer during theirlifetime,3 with one in five requiringan amputation.4 In 2006, about65,700 non-traumatic lower-limbamputations were performed onpeople with diabetes.2

An interdisciplinary team ap-proach to limb salvage—toe andflow—involving primary care physi-cians, podiatric surgeons, vascularsurgeons, orthopedic surgeons, plas-tic surgeons, infectious disease spe-cialists, diabetologists, general sur-geons, and pedorthist/prosthetistshas been shown to lower amputa-tion rates and complications in peo-ple with diabetic foot wounds.5,6 Acombined vertical and horizontalstrategy for wound healing incorpo-rates the primary components of acomprehensive amputation preven-tion program.7

The vertical strategy refers to cov-ering important structures and fillingdefects with negative pressure woundtherapy (NPWT), while the horizontalstrategy includes the use of skin graft-ing, bio-engineered skin substitutes,

and aggressive off-loading.The formation of a diabetic foot

ulcer is largely the result of repetitive,moderate stress applied to a neuro-pathic foot during ambulation.8 Inlacking the ability to adequately re-spond to pain, patients with neuropa-

thy often sustain breaches in theirskin the way sensate people maywear holes in their socks. Thus, it canbe said that these patients lack the“gift of pain.”

While there is no treatment avail-able that completely mitigates the ef-fects of neuropathy, the preventionand treatment of wounds in peoplewith diabetes is largely based on a re-distribution of pressure. Several of-floading modalities exist which, tovarying degrees, redistribute pressurein the diabetic foot. However, there isonly a small number of case serieswhich explore the frequency and rateof wound-healing associated withthese devices.

In general, total contact casting(TCC) is considered to be the gold-

standard, offloading modality with re-spect to diabetic foot wounds.9 TCCinvolves a well-molded, minimallypadded cast, which maintains contactwith the entire plantar foot and lowerleg. It has been shown to reduce pres-sure at the site of ulceration by

84%–92,10 and has demonstratedhealing rates, in noninfected, nonis-chemic, plantar diabetic foot woundsof 72%–100%.11-16 Throughout gait,peak plantar pressures are highest inthe forefoot; thus, the true effective-ness of TCC may lie in its ability totransmit pressure from the forefoot tothe rearfoot, or cast wall.17,18

Besides off-loading, TCC has sev-eral implicit features which make itespecially effective in preventing andhealing diabetic foot wounds. For ex-ample, TCC can protect the foot frominfection, and may play a role inedema reduction.19 Perhaps, most im-portantly, TCC is irremovable, whichguarantees patient compliance. Casesinvolving soft tissue infection, os-

Here’s a (very) brief guideto off-loading diabetic foot ulcers.

It’s Not What YouPut on the Wound

BY ADAM L. ISAAC, DPM

Continued on page 68

The formation ofa diabetic foot ulcer is largely the result

of repetitive, moderate stressapplied to a neuropathic foot during ambulation.

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teomyelitis, and ischemia are typicallycontraindications for TCC,20 and itmay not be an appropriate treatmentfor heel wounds.18

Furthermore, TCC can make ac-

tivities such as sleeping and bathingdifficult for patients, and as such canbe regarded as a nuisance.21

Other FactorsCost of materials and lack of reim-

bursement are important factorswhich may limit the widespread useof TCC. Many offices and wound cen-ters lack the skilled personnel and re-sources necessary for a comprehen-sive off-loading program involvingTCC. Wu, et al.22 reported in 2008 thatamong 895 centers involved in the ac-tive treatment of diabetic foot ulcers,only 1.7% used TCC for the majorityof their treatment. Moreover, usingdata extrapolated from the “Eurodi-ale” Study,” Prompers and col-leagues23 found that among a sub-group of patients with neuropathicplantar forefoot or midfoot ulcers,TCC was prescribed in only 18% ofcases. Remarkably, as reported byFife et al.,24 the average cost of treat-ment with TCC is about half as much,

per patient, asthe cost of treat-ment withoutTCC. There areseveral products

currently available which facilitatethe simple, easy, and fast applicationof TCC (Figure 1).

Removable Cast WalkersRemovable cast walkers (RCW)

may provide a good alternative toTCC. Pressure reduction with certainRCWs has been shown to be equiva-lent to TCC10, and more recently,Faglia, et al.25 reported RCW to be as

effective as TCC in reducing woundsize and increasing healing rates indiabetic foot ulcers. RCW allows forfrequent wound inspection, as well asmore consistent application of topicaland advanced wound care modalities.

Patients gener-ally feel more com-fortable in RCW and

enjoy the freedom that its name im-plies. However, the ability of patientsto remove the offloading device repre-sents a potential pitfall of RCW. In astudy conducted by Armstrong et al.,26

in which the activity of patients un-dergoing treatment for diabetic footwounds was recorded using hiddenaccelerometers, patients were foundto have worn their offloading deviceless than 30% of the time.

In an effort to maintain the of-floading capacity of RCW and encour-age patient compliance, an instanttotal contact cast (iTCC) has been de-scribed, which involves wrapping anRCW with a layer of cohesive ban-dage, plaster or fiberglass (Figure 2).27

Thus, it is difficult for patients to re-

The average cost of treatmentwith TCC is about half as much,

per patient, as thecost of treatment without TCC.

Continued on page 70

Figure 2: Instant total contact cast (iTCC)

Figure 1: (a,b). Application of TCC-EZ® http://www.dermasciences.com/products/advanced-wound-care/tcc-ez/

Patients generally feelmore comfortable in RCW and enjoy the freedom

that its name implies.

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move. In a randomized controlledtrial conducted by Katz et al.,28 woundhealing was demonstrated as often inpatients undergoing therapy withiTCC as with TCC (80% vs. 74%).Furthermore, Armstrong and col-leagues29 noted substantial differencesin wound healing between patients

being offloaded with iTCC and tradi-tional RCW (83% versus 52% at 12weeks).

There are many other off-load-ing modalities which redistributepressure in the diabetic foot, such ashalf shoes, healing san-dals, and felted foam;and it has even beenpostulated that changingthe strut height of anRCW (i.e., ankle vs.knee-high) may improvepatient comfort and sta-bility without significant-ly affecting off-loading(Figure 3).30 It is also im-portant to realize thatwhat is designed forwound prevention maynot necessarily translateinto wound healing. For example,therapeutic shoes may allow asmuch as 900% more forefoot pres-sure, as compared to the offloadingcapability of TCC and RCW.10

Recently, advanced wound careand diabetic limb salvage has beenmarked by incredible advances inbiotechnology and engineering. How-ever, the so-called “low-technology”treatment of diabetic foot ulcers—wound care, debridement, and pres-sure reduction—may represent thetrue keys to success. Furthermore, thekey to off-loading may depend asmuch on selecting the appropriate de-vice as it does on patient comfort andcompliance. Finding the right balanceis paramount. PM

References1 International Diabetes Federation.

IDF Diabetes Atlas, 5th ed. Brussels, Bel-gium: International Diabetes Federation,2011. http://www.idf.org/diabetesatlas

2 Centers for Disease Control and Pre-vention. National diabetes fact sheet: na-tional estimates and general informationon diabetes and prediabetes in the United

States, 2011. Atlanta, GA: U.S. Depart-ment of Health and Human Services, Cen-ters for Disease Control and Prevention,2011.

3 Singh N, Armstrong DG, Lipsky BA.Preventing Foot Ulcers in Patients With Di-abetes. JAMA. 2005;293(2):217-228.

4 Lavery LA, Armstrong DG, Wunder-lich RP, Mohler MJ, Wendel CS, LipskyBA. Risk factors for foot infections in indi-viduals with diabetes. Diabetes Care. 2006Jun;29(6):1288-93.

5 Armstrong DG, Mills JL. Toward aChange in Syntax in Diabetic Foot Care:Prevention equals Remission. J Amer PodMed Assoc. 2013:In Press.

6 Rogers LC, Andros G, Caporusso J,Harkless LB, Mills JL Sr, Armstrong DG.Toe and flow: essential components andstructure of the amputation preventionteam. J Am Podiatr Med Assoc. 2010 Sep-Oct;100(5):342-8.

7 Armstrong DG, Andros G. Use ofnegative pressure wound therapy to helpfacilitate limb preservation. Int Wound J.2012 Aug;9 Suppl 1:1-7.

8 Boulton AJM. The importance of ab-normal foot pressure and gait in causation

of foot ulcers. In: Connor H, Boulton AJM,Ward JD, eds. The Foot in Diabetes.Chichester, UK: John Wiley and Sons;1987:11–26.

9 American Diabetes Association. Con-sensus development conference on diabet-ic foot wound care. Diabetes Care.1999;22(8):1354.

10 Lavery LA, Vela SA, Lavery DC,Quebedeaux TL. Reducing dynamic footpressures in high-risk diabetic subjectswith foot ulcerations. A comparison oftreatments. Diabetes Care. 1996;19(8):818–821.

11 Armstrong DG, Lavery LA, BushmanTR. Peak foot pressures influence the heal-ing time of diabetic foot ulcers treatedwith total contact casts. J Rehabil Res Dev.1998;35(1):1–5.

12 Walker SC, Helm PA, Pulliam G.Chronic diabetic neuropathic foot ulcera-tions and total contact casting: healing ef-fectiveness and outcome probability (ab-stract). Arch Phys Med Rehabil. 1985;66:574.

13 Walker SC, Helm PA, Pulliam G.Total contact casting and chronic diabeticneuropathic foot ulcerations: healing rates

by wound location. ArchPhys Med Rehabil. 1987;68:217–221.

14 Sinacore DR, MuellerMJ, Diamond JE. Diabeticplantar ulcers treated by totalcontact casting. Phys Ther.1987;67:1543–1547.

15 Myerson M, Papa J,Eaton K, Wilson K. The totalcontact cast for managementof neuropathic plantar ulcer-ation of the foot. J BoneJoint Surg. 1992; 74A(2):261–269.

16 Helm PA, Walker SC,Pulliam G. Total contact casting in diabet-ic patients with neuropathic foot ulcera-tions. Arch Phys Med Rehabil. 1984;65:691–693.

17 Shaw JE, Hsi WL, Ulbrecht JS,Norkitis A, Becker MB, Cavanagh PR. Themechanism of plantar unloading in totalcontact casts: implications for design andclinical use. Foot Ankle Int. 1997;18:809–817.

18 Armstrong DG, Stacpoole-Shea S.Total contact casts and removable castwalkers: mitigation of plantar heel pres-sure. J Am Podiatr Med Assoc. 1999;89:50–53.

19 Mueller MJ, Diamond JE, SinacoreDR, et al. Total contact casting in treat-ment of diabetic plantar ulcers. Controlledclinical trial. Diabetes Care. 1989;12(6):384–388.

The key to off-loadingmay depend as much on selecting the

appropriate device as it does on patient comfortand compliance.

Continued on page 72

Figure 3: Mean pressure reduction based on strut height in RCW. From: Crews RT,Sayeed F, Najafi B. Impact of strut height on off-loading capacity of removable castwalkers. Clin Biomech (Bristol, Avon). Mar 30, 2012.

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20 Wu SC, Crews RT, Armstrong DG.The pivotal role of offloading in the man-agement of neuropathic foot ulceration.Curr Diab Rep. 2005;5(6):423–429. Re-view.

21 Lavery LA, Fleishli JG, Laughlin TJ,et al. Is postural instability exacerbated byoff-loading devices in high risk diabeticswith foot ulcers? Ostomy Wound Manage.1998;44(1):26–34.

22 Wu SC, Jensen JL, Weber AK,Robinson DE, Armstrong DG. Use of pres-sure offloading devices in diabetic foot ul-cers: do we practice what we preach? Dia-betes Care. 2008 Nov;31(11):2118-9.

23 Prompers L, Huijberts M,Apelqvist J, Jude E, Piaggesi A, BakkerK, Edmonds M, Holstein P, Jirkovska A,Mauricio D, Tennvall GR, Reike H,Spraul M, Uccioli L, Urbancic V, VanAcker K, Van Baal J, Van Merode F,Schaper N. Delivery of care to diabeticpatients with foot ulcers in daily practice:results of the Eurodiale Study, a prospec-tive cohort study. Diabet Med. 2008 Jun;25(6):700-7.

24 Fife CE, Carter MJ, Walker D. Why

is it so hard to do the right thing in woundcare? Wound Repair Regen. 2010 Mar-Apr;18(2):154-8.

25 Faglia E, Caravaggi C, Clerici G,Sganzaroli A, Curci V, Vailati W, SimonettiD, Sommalvico F. Effectiveness of remov-able walker cast versus non-removablefiberglass off-bearing cast in the healing ofdiabetic plantar foot ulcer: a randomizedcontrolled trial. Diabetes Care. 2010Jul;33(7):1419-23.

26 Armstrong DG, Lavery LA, KimbrielHR, Nixon BP, Boulton AJ. Activity pat-terns of patients with diabetic foot ulcera-tion: patients with active ulceration maynot adhere to a standard pressure off-load-ing regimen. Diabetes Care.2003;26(9):2595–2597.

27 Armstrong DG, Short B, EspensenEH, Abu-Rumman PL, Nixon BP, BoultonAJ. Technique for fabrication of an “in-stant” total contact cast for treatment ofneuropathic diabetic foot ulcers. J Am Po-diatr Med Assoc. 2002;92:405–408.

28 Katz IA, Harlan A, Miranda-PalmaB, et al. A randomized trial of two irre-movable off-loading devices in the man-

agement of plantar neuropathic diabeticfoot ulcers. Diabetes Care. 2005; 28(3):555–559.

29 Armstrong DG, Lavery LA, Wu S,Boulton AJ. Evaluation of removable andirremovable cast walkers in the healing ofdiabetic foot wounds: a randomized con-trolled trial. Diabetes Care. 2005;28:551–554.

30 Crews RT, Sayeed F, Najafi B. Im-pact of strut height on offloading capacityof removable cast walkers. Clin Biomech(Bristol, Avon). 2012 Mar 30.

Dr. Isaac graduatedfrom the Temple Uni-versity School of Podi-atric Medicine in 2009,and currently holds theposition of Clinical In-structor and Fellowof the Department ofSurgery/SouthernArizona Limb Salvage

Alliance (SALSA) at the University of Arizonain Tucson.