Plantar pressure redistribution

Recommendations

Identify and Treat the Cause
1 Perform a physical examination of the foot to identify structural deformity, decreased joint mobility, callus and areas of increased pressure. Level of Evidence
Not Assessed
2 Examine the patient’s gait for abnormal patterns and risk of falls. Level of Evidence
Not Assessed
3 Examine the patient’s footwear for areas of pressure and suitability. Level of Evidence
Not Assessed
4 Perform radiography and pressure mapping as required to determine risk of ulceration and pressure offloading modality selection. Level of Evidence
Not Assessed


Address patient-centered Concerns
5 Provide individualized education to enhance Glycemic control, Adherence to treatment, Plantar pressure redistribution/daily foot inspection. (GAP) Level of Evidence
Not Assessed
6 Provide appropriate patient education to improve adherence and facilitate wound healing. Level of Evidence
Not Assessed


Provide Local Wound Care
7 Provide plantar pressure redistribution if there is loss of protective sensation (shoes, orthotics/pneumatic walker, contact cast) Level of Evidence
Not Assessed
8 Select and implement an effective pressure offloading device, depending on the clinical goal. Level of Evidence
Not Assessed


Provide Organizational Support
9 Establish and empower an interprofessional team to work with Persons With Diabetes (PWD). Level of Evidence
Not Assessed


Background

Plantar Pressure Redistribution (Pressure Offloading)

Diabetes is associated with a variety of bony or structural foot deformities, including hammer toe, claw toe, bunions, pes planus or cavus, reduction in joint mobility and Charcot neuroarthropathy. Deformity, limited joint mobility and neuropathy result in repetitive stress on the plantar aspect of the diabetic foot during weight bearing. This mechanism predisposes to skin damage and ulceration. Redistributing plantar pressure from high-pressure areas can reduce the risk of ulceration and is a requirement for healing if ulceration has already occurred. Pressure over bony prominences may result in formation of callus, which may also increase plantar pressure. Callus removal significantly reduces pressure.

Assessment of the diabetic foot should include identification of deformities and areas of increased pressure. Gait assessment provides information about changes in balance, mobility and abnormal weight bearing that may increase the risk of falls. Examination of the patient’s footwear may reveal abnormal wear patterns. Radiography and pressure mapping may be useful in identifying deformities, determining ulcer risk or selecting an offloading device.

Effective plantar pressure redistribution uses an external device to reduce the pressure (pounds per square inch, PSI) over the wound site during weight bearing. The effectiveness of any pressure offloading device depends on patient adherence to constant use (every step taken). Appropriate patient education is therefore critical.

Selection of the appropriate downloading device is determined primarily by the ulcer location and severity. Well-fitted normal footwear; extra-depth or –width footwear plus a custom-made total contact orthotic (CMTCO) of shock-absorbing material; a rocker sole; healing sandal; removable walker; or total-contact cast (TCC) are all effective pressure downloading modalities. Crutches, walkers and wheelchairs may be ineffective due to the functional needs of patients.

The lightly padded TCC maintains contact with the entire plantar aspect of the foot and the lower leg. The effectiveness of the TCC in treating most uninfected nonischemic ulcers may result from uniform pressure distribution, protection form infection, reduction in edema and forced adherence. The lightweight removable walker is a boot that redistributes plantar pressure over the entire plantar surface of the foot. Its removable nature facilitates wound inspection and treatment but may reduce adherence. The TCC and the removable pneumatic walker are the first-choice pressure downloading devices. The Darco healing sandal can be used if problems exist with gait and balance. Healing sandals are not, however, as efficient as a TCC or a removable walker. A rocker sole, a device that can be applied to most approved extra-depth, walking or running shoes, is effective for ulcer prevention but not for healing. With the exception of the TCC, these devices are all used with a CMTCO.

References

Essential Publications
1 Pressure relieving devices to protect or treat the foot of persons with diabetes Quality Indicator
 Type: Systematic review
Spencer S. Pressure relieving interventions for preventing and treating diabetic foot ulcers. Cochrane Database of Systematic Reviews 2000, Issue 3. Art. No.: CD002302. DOI: 10.1002/14651858.CD002302.
This good quality Cochrane systematic review (2000) was conducted to assess the effectiveness of pressure relieving interventions in the prevention and treatment of diabetic foot ulcers; it is the only systematic review on this topic. The 4 included RCTs had small sample sizes, methodological flaws (e.g., lack of blinding, alternate rather than random allocation, no a priori sample size determination), and the data could not be combined due differences in patients, interventions and outcomes. The results provided little evidence of the effectiveness of orthotic devices or therapeutic shoes for preventing foot ulcers. One RCT (Mueller, 1989) indicates limited evidence in subjects with diabetic foot ulcers of the effectiveness of total contact casts compared with standard treatment (wet to dry dressings only) for improving healing rates (proportion of subjects healed) and time to healing. This review illustrates gaps and provides recommendations about directions and methodological issues to incorporate for future research about the value of pressure relieving and off-loading interventions for the prevention and treatment of diabetic foot ulcers.
2 Total contact casting Quality Indicator
 Type: RCT
Piaggesi A, Macchiarini S, Rizzo L, Palumbo F Tedischi A, Nobili LA, Leporati E, Scire V, Teobaldi I, Del Prato S. 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.
This recent comparison of total contact casting (nonremovable fiberglass cast), n=20) with an off-the-shelf irremovable device (Optima Diab walker, n=20) was performed in outpatients with forefoot plantar ulcers for at least 3 weeks with an area wider than 1 cm2, graded 1A or 2A (Texas University classification), and type 1 or type 2 diabetes for at least 5 years, with peripheral neuropathy. Healing rate (proportion of subjects with complete reepithelialization) and time to heal were not significantly different between the groups, but the cost per patient (727.29 + 491.25 versus 162.5 + 57.75 euros) of the Optima Diab walker was significantly less (P<0.001). In addition, application and removal time were reduced significantly and patient satisfaction was greater for the Optima Diab walker. Occurrence of adverse events was similar between the groups. This study indicates that the use of an off-the-shelf irremovable walking device is as safe and effective, but less costly than total contact casting in managing patients with foot ulcers due to diabetic neuropathy.
3 Total contact casting versus removable casting Quality Indicator
 Type: RCT
Armstrong DG, Lavery LA, Wu S, Boulton AJM. 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.
In this study the use of a removable cast walker (RCW) n=27 was compared with the same RCW wrapped with cohesive bandage to create an “instant total contact cast” (iTCC) n=23 to determine if less success with RCW was due to patients’ lack of adherence with the pressure relieving regimen in patients with foot ulcers and diabetic neuropathy who were treated for 12 weeks or until healing. It was found that a higher proportion of patients’ ulcers healed at 12 weeks in the iTCC group than in the RCW group (82.6 vs. 51.9%, P=0.02; OR 1.8 (95% CI 1.1-2.9)). Patients with healed ulcers that healed who were treated with an iTCC healed significantly more quickly (41.6 ± 18.7 versus 58.0 ± 15.2 days, P=0.02). There is a trade-off between healing and periwound maceration, as experienced by more subjects in the iTCC group compared with the RCW group (68.2% or 15 patients versus 37.5% or 9 patients, P=0.04; OR 1.8 (95% CI 1.0-3.3)). This well-designed study seems to indicate that patient adherence with wearing a removable cast could be limiting their ability to heal and the time to healing of foot ulcers.
4 Total contact casting versus instant total contact casting Quality Indicator
 Type: RCT
Katz IA, Harlan A Miranda-Palma B, Prieto-Sanchez L, Armstrong DG, Bowker JH, Mizel MS, Boulton AJM. A Randomized Trial of Two Irremovable Off-Loading Devices in the Management of Plantar Neuropathic Diabetic Foot Ulcers. Diabetes Care 2005;28(3):555-559.
(Parallel study to Armstrong 2005) This study was conducted to compare the effectiveness of a removable cast walker (RCW) rendered irremovable (iTCC) with the total contact cast (TCC) in the treatment of diabetic neuropathic plantar foot ulcers. There was no difference between the TCC n=20 and iTCC n=21groups in the proportions of patients with ulcers that healed in less than or equal to 12 weeks, 74 ± 45 and 80 ± 41%, respectively (P=0.65). There was also no difference in complications with a relative risk reduction of 41% and absolute risk reduction of 27% (P=0.09) between the TCC and iTCC groups. the iTCC may be equally efficacious, faster to place, easier to use, and less expensive than the TCC in the treatment of diabetic plantar neuropathic foot ulcers.
5 Pressure off-loading – adherence to off-loading regimen Quality Indicator
 Type: Longitudinal study (1 group)
Armstrong DG, Lavery LA, Kimbriel HR, Nixon BP, Boulton AJM. 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):2595-2597.
This study illustrates that patients do not adhere to wearing RCW during activity as often as they ought. Accelerometers were installed at patients’ waists and hidden in the RCW. It was found that patients wore the RCW less than 30% of the total activity time. It was this result that prompted the work on instant total contact casting (iTCC).
6 Pressure off-loading to prevent reulceration – comparison of footwear Quality Indicator
 Type: RCT
Reiber GE, Smith DG, Wallace C, Sullivan K, Hayes S, Vath C, Maciejewski ML, Yu O, Heagerty PJ, LeMaster J. Effect of Therapeutic Footwear in Foot Reulceration in Patients with Diabetes: A randomized controlled trial. JAMA 2002;287(19):2552-2558.
This well-conducted 2-year study of persons with diabetes and without severe foot deformity illustrates no advantage of prescribing therapeutic shoes and inserts for the reduction of foot reulceration. Between August 1997 and December 1998, subjects were randomly allocated to 3 groups: Groups (1) and (2) received 3 pairs of therapeutic shoes, and (1) received 3 pairs of customized medium density cork inserts with a neoprene closed-cell cover (n=121) and (2) received 3 pairs of prefabricated, tapered polyurethane inserts with a brushed nylon cover (n=119). Group (3), the control group, wore their usual footwear (n=160). Two-year cumulative reulceration incidence was 15%, 14%, and 17% for the 3 groups respectively. For the group with cork inserts compared for controls, the relative risk for persons with one or more reulcerations was RR 0.88 (95% CI 0.51to 1.52). For the group with prefabricated inserts compared for controls, the relative risk for persons with one or more reulcerations was RR 0.85 (95% CI 0.48to 1.48). People without sensation were much more likely to experience reulceration; the RR was 3.68 (95% CI 1.81 to 7.49).
7 Pressure off-loading to achieve ulcer healing Quality Indicator
 Type: RCT
Armstrong DG, Nguyen HC, Lavery LA, van Schie CHM, Boulton AJM, Harkless LB. Off-Loading the Diabetic Foot Wound: A randomized clinical trial. Diabetes Care 2001;24(6):1019-1022.
This is a small, randomized trial comparing the proportion of healed ulcers in subjects treated using TCC (n=10) compared with removable cast walker (RCW) (n=20), and half shoes (n=24). More ulcers healed with TCC 80.5% than with RCW 65% or half-shoes 58.3%. At 12 weeks, the proportion of healing was significantly greater in the TCC group than with the other modalities (89.5% vs. 61.4%, P=0.026, odds ratio 5.4, 95% CI 1.1 to 26.1). The mean time to healing was shorter for those using TCC compared with half-shoes (33.5 + 5.9 vs. 61.0 + 6.5 days, P = 0.005) but not compared with RCW (50.4 + 7.2 days, P=0.07). The discussion of the following advantages and disadvantages of TCC is helpful in planning appropriate treatment options: advantages include mitigating pressure, controlling edema, protecting from infection, forcing compliance, and curtailing activity; disadvantages include lack of trained personnel to apply TCC, potential skin irritation with improper application, inability to make daily assessments or treatments, difficulty bathing and sleeping; contraindicated for wounds with infections of osteomyelitis.
8 TCC Versus other off-loading devices Quality Indicator
 Type: Non-randomized controlled trial
Udovichenko O, Galstyan G. Efficacy of Removable Casts in Difficult to Off-Load Diabetic Foot Ulcers: A comparative study. The Diabetic Foot 2006;9(4):204-208.
TCC for those who accepted n=14 and alternative off-load methods (half-shoe or bed rest) for those who refused n=13. Larger wounds were observed in the TCC group at baseline (Wound equivalent radius (Reqv in mm) 13.3 + 3.1 versus 6.7 + 1.4, P<0.05). After 6 months, healing of ulcers was observed in 75% of subjects in the TCC group versus 46% in the alternative methods group. This reference is included because it is a different group of researchers than most who have published in this topic area and it is recent. Allocation of subjects to groups was not randomized, therefore biased, and wounds larger in TCC group – should have been at a disadvantage, but the rate of healing was better nonetheless. The authors indicated they could not randomize for ethical reasons.
9 Comparison of TCC with traditional dressing treatment Quality Indicator
 Type: RCT
Mueller MJ. Diamond JE. Sinacore DR. Delitto A. Blair VP 3rd. Drury DA. Rose SJ. Total contact casting in treatment of diabetic plantar ulcers. Controlled clinical trial. Diabetes Care 1989;12(6):384-8.
This study indicates benefits and disadvantages of Total Contact Casting (TCC). It is one of the included studies in the Registered Nurses Association of Ontario (RNAO)Assessment and management of foot ulcers for people with diabetes guideline (2005). This article may be the earliest best article on this topic.
10 Comparison of foot pressures in different types of pressure relieving foot devices Quality Indicator
 Type: Non-randomized controlled trial
Lavery LA, Vela SA, Lavery DC, Quebedeaux TL. Reducing dynamic foot pressures in high-risk diabetic subjects with foot ulcer … Diabetes Care 1996;19(8):818-821.
This study compares the ability of TCC, DH pressure relief walkers, Aircast pneumatic walker, 3D Dura Steppers, CAM Walkers, P.W. Minor Xtra Depth shoes commercially available therapeutic shoes to reduce mean peak plantar foot pressures over neuropathic ulcers under the great toe (n=5), the first metatarsal (n=10), and the 2nd to 5th metatarsal (n=10) in people with diabetes. Pressures experienced using six devices were compared with those obtained using a rubber-soled canvas Oxford. DH removable walker was as effective as TCC in reducing foot pressures at all ulcer sites. This seems to be the key article that establishes the ability of various devices to reduce foot pressure over ulcer sites.
11 Pressure Relief through Custom Insoles Quality Indicator
 Type: Cohort study (2 groups)
Owings TM, Woerner JL, Frampton JD, Cavanagh PR, Botek G. Custom therapeutic insoles based on both foot shape and plantar pressure measurement provide enhanced pressure relief. Diabetes Care. 2008 May;31(5):839-44. Epub 2008 Feb 5.
The purpose of this study was to determine whether custom insoles designed based on the shape and pressure distribution of the patient’s foot are effective in removing plantar pressure. 20 patients with 70 areas of elevated pressure were provided with pressure relieving insoles, and the pressure concentration was alleviated in 64 of 70 cases. These results show that measurement of plantar pressure in designing custom insoles is effective at pressure offloading in patients with elevated plantar pressure.
12 Neuropathy and High Foot Pressures Quality Indicator
 Type: Prospective Correlation study
Frykberg RG, Lavery LA, Pham H, Harvey C, Harkless L, Veves A. Role of neuropathy and high foot pressures in diabetic foot ulceration. Diabetes Care. 1998 Oct;21(10):1714-9.
The purpose of this study was to investigate the role of neuropathy and high foot pressure in the development of diabetic foot ulcers. One significant benefit of this study is the size and diversity of the population. The results demonstrate that both neuropathy and high foot pressure are associated with diabetic foot ulceration. Furthermore, joint mobility and plantar pressure have greater correlation with ulceration in Caucasian populations than in African-American or Hispanic populations.
13 Peak foot pressure during walking Quality Indicator
 Type: Correlation study
Morag E, Cavanagh PR. Structural and functional predictors of regional peak pressures under the foot during walking. J Biomech. 1999 Apr;32(4):359-70.
The purpose of this study was to examine structural and functional factors which are predictors of peak pressure during walking. This study is able to successfully identify etiology behind elevated plantar pressure, and also proposes important areas for future research
14 Foot Pressure Assessment Quality Indicator
 Type: Longitudinal study (1 group)
Lavery LA, Armstrong DG, Wunderlich RP, Tredwell J, Boulton AJ. Predictive value of foot pressure assessment as part of a population-based diabetes disease management program. Diabetes Care. 2003 Apr;26(4):1069-73.
The purpose of this study is to evaluate the ability of plantar pressure assessment to predict patients at high risk of ulceration. The results showed that elevated pressure is effective in determining patients at risk for foot ulcerations. These results, however, contradict the results obtained by ROC analysis.
15 Alternative off-loading methods Quality Indicator
 Type: Retrospective Analysis
Birke JA, Pavich MA, Patout Jr CA, Horswell R. Comparison of forefoot ulcer healing using alternative off-loading methods in patients with diabetes mellitus. Adv Skin Wound Care. 2002 Sep-Oct;15(5):210-5.
The purpose of this study was to compare alternative off-loading methods (an accommodative dressing, a healing shoe, a walking splint) with total contact casts. The results showed that both methods provide comparable results when the treatment strategy is selected based on the patients age, and duration and location of the ulcer.
16 Football dressing for off-loading Quality Indicator
 Type: Retrospective Analysis
Rader AJ, Barry TP. The football: an intuitive dressing for offloading neuropathic plantar forefoot ulcerations. Int Wound J. 2008 Mar;5(1):69-73. Epub 2008 Jan 3.
The purpose of this study was to follow up on a pilot study regarding a new dressing known as the football dressing. This follow up study showed that the football dressing is easy to apply, presents reliable healing rates and is inexpensive. All of these benefits make the football dressing a legitimate dressing for offloading neuropathic plantar forefoot ulcerations.
17 Ankle Equinus Quality Indicator
 Type: Prevalence study
Lavery LA, Armstrong DG, Boulton AJ; Diabetex Research Group. Ankle equinus deformity and its relationship to high plantar pressure in a large population with diabetes mellitus. J Am Podiatr Med Assoc. 2002 Oct;92(9):479-82
The purpose of this study is to determine the prevalence of ankle equinus, and to determine its relationship with high plantar pressure. The results showed that patients who have had diabetes for longer periods of time were more likely to develop ankle equinus. In order to prevent amputation, it is essential to have a high index of suspicion for this condition, then to address it appropriately


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