1997 William J. Stickel Bronze Award. Comparison of strategies for reducing pressure at the site of neuropathic ulcers

Nagging Pain and Foot Ulcers Can be Treated into Remission

Lower extremity ulcerations are very common in patients with diabetes. These wounds lead to amputation in a surprisingly large percentage of patients with diabetes. The mortality rate following amputation in a patient with diabetes is alarmingly high. Preventive treatment is pivotal to avoid the numerous complications associated with diabetic ulcerations. However, at the onset of ulceration, early treatment under the supervision and guidance of a specialist can result in remission. Diabetic peripheral neuropathy is also a life-altering and debilitating disease. Although some patients experience numbness, some experience pain that can be sharp, shooting, and tingling. Although treatment is challenging and often requires medication, newer modalities, such as stimulation and physical therapy, have shown promise in reversing the devastating effects of peripheral neuropathy.

Knee-High Devices Are Gold in Closing the Foot Ulcer Gap: A Review of Offloading Treatments to Heal Diabetic Foot Ulcers

Diabetic foot ulcers (DFU) are a leading cause of the global disease burden. Most DFUs are caused, and prolonged, by high plantar tissue stress under the insensate foot of a person with peripheral neuropathy. Multiple different offloading treatments have been used to try to reduce high plantar tissue stress and heal DFUs, including bedrest, casting, offloading devices, footwear, and surgical procedures. The best offloading treatments are those that balance the benefits of maximizing reductions in high plantar tissue stress, whilst reducing the risks of poor satisfaction, high costs and potential adverse events outcomes. This review aimed to summarize the best available evidence on the effects of offloading treatments to heal people with DFUs, plus review their use in clinical practice, the common barriers and solutions to using these treatments, and discuss promising emerging solutions that may improve offloading treatments in future. Findings demonstrate that knee-high offloading devices, non-removable or removable knee-high devices worn for all weight-bearing activities, are the gold standard offloading treatments to heal most patients with DFU, as they are much more effective, and typically safer, quicker, and cheaper to use compared with other offloading treatments. The effectiveness of offloading treatments also seems to increase when increased offloading mechanical features are incorporated within treatments, including customized insoles, rocker-bottom soles, controlled ankle motion, and higher cast walls. However, in clinical practice these gold standard knee-high offloading devices have low rates of prescription by clinicians and low rates of acceptance or adherence by patients. The common barriers resulting in this low use seem to surround historical misperceptions that are mostly dispelled by contemporary evidence. Further, research is now urgently required to close the implementation gap between the high-quality of supporting evidence and the low use of knee-high devices in clinical practice to reduce the high global disease burden of DFU in future.

A Critical Look at a Diabetic Foot Randomized Controlled Trial: Can You Ever Have Too Many Patients?

The objective of this article series is to teach approaches for critical appraisal to consumers of medical literature. The aim is to build a deeper understanding of standard procedure in clinical research so clinicians can determine whether medical evidence can be applied to their practices. We will choose published articles with methodological flaws to serve as discussion points. In the first article of this series, we will proceed section by section through an article to teach readers what is usually reported, and illustrate what was done correctly and what was not. Subsequently, later articles in this series of critical appraisals will discuss more focused topics. There were several interesting flaws in our first examined paper. This study provides the unusual flaw of reporting a sample size justification and then exceeding enrollment. In addition, the authors enrolled a relatively large number of subjects (n = 16) that evidently completed the study but were subsequently excluded from analysis because they did not fit the inclusion and exclusion criteria.

Contact Pressures Between the Rearfoot and a Novel Offloading Insole: Results From a Finite Element Analysis Study

Pressure offloading is critical to diabetic foot ulcer healing and prevention. A novel product has been proposed to achieve this offloading with an insole that can be easily modified for each user. This insole consists of pressurized bubbles that can be selectively perforated and depressurized to redistribute weight to the nonulcer region of the foot. However, the effect of the insole design parameters, for example, bubble height and stiffness, on offloading effectiveness is unknown. To this end, a 3-dimensional finite element model was developed to simulate contact between the rearfoot and insole. The geometry of the calcaneus bone and soft tissue was based on the medical images of an average male patient, and material properties and loading conditions based on the values reported in the literature were used. The model predicts that increasing bubble height and stiffness leads to a more effectively offloaded region. However, the model also predicts that increasing stiffness leads to increasing contact pressures on the surrounding soft tissue. Thus, a combination of insole design parameters was determined, which completely offloads the desired region, while simultaneously reducing the contact pressure on the surrounding soft tissue. This design is expected to aid in diabetic foot ulcer healing and prevention.

Effectiveness of offloading interventions to heal foot ulcers in persons with diabetes: a systematic review

BACKGROUND

Offloading interventions are commonly used in clinical practice to heal foot ulcers. The aim of this updated systematic review is to investigate the effectiveness of offloading interventions to heal diabetic foot ulcers.

METHODS

We updated our previous systematic review search of PubMed, EMBASE, and Cochrane databases to also include original studies published between July 29, 2014 and August 13, 2018 relating to four offloading intervention categories in populations with diabetic foot ulcers: (a) offloading devices, (b) footwear, (c) other offloading techniques, and (d) surgical offloading techniques. Outcomes included ulcer healing, plantar pressure, ambulatory activity, adherence, adverse events, patient-reported measures, and cost-effectiveness. Included controlled studies were assessed for methodological quality and had key data extracted into evidence and risk of bias tables. Included non-controlled studies were summarised on a narrative basis.

RESULTS

We identified 41 studies from our updated search for a total of 165 included studies. Six included studies were meta-analyses, 26 randomised controlled trials (RCTs), 13 other controlled studies, and 120 non-controlled studies. Five meta-analyses and 12 RCTs provided high-quality evidence for non-removable knee-high offloading devices being more effective than removable offloading devices and therapeutic footwear for healing plantar forefoot and midfoot ulcers. Total contact casts (TCCs) and non-removable knee-high walkers were shown to be equally effective. Moderate-quality evidence exists for removable knee-high and ankle-high offloading devices being equally effective in healing, but knee-high devices have a larger effect on reducing plantar pressure and ambulatory activity. Low-quality evidence exists for the use of felted foam and surgical offloading to promote healing of plantar forefoot and midfoot ulcers. Very limited evidence exists for the efficacy of any offloading intervention for healing plantar heel ulcers, non-plantar ulcers, and neuropathic ulcers with infection or ischemia.

CONCLUSION

Strong evidence supports the use of non-removable knee-high offloading devices (either TCC or non-removable walker) as the first-choice offloading intervention for healing plantar neuropathic forefoot and midfoot ulcers. Removable offloading devices, either knee-high or ankle-high, are preferred as second choice over other offloading interventions. The evidence bases to support any other offloading intervention is still weak and more high-quality controlled studies are needed in these areas.

Guidelines on offloading foot ulcers in persons with diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. This guideline is on the use of offloading interventions to promote the healing of foot ulcers in people with diabetes and updates the previous IWGDF guideline. We followed the GRADE methodology to devise clinical questions and critically important outcomes in the PICO format, to conduct a systematic review of the medical-scientific literature, and to write recommendations and their rationale. The recommendations are based on the quality of evidence found in the systematic review, expert opinion where evidence was not available, and a weighing of the benefits and harms, patient preferences, feasibility and applicability, and costs related to the intervention. For healing a neuropathic plantar forefoot or midfoot ulcer in a person with diabetes, we recommend that a nonremovable knee-high offloading device is the first choice of offloading treatment. A removable knee-high and removable ankle-high offloading device are to be considered as the second- and third-choice offloading treatment, respectively, if contraindications or patient intolerance to nonremovable offloading exist. Appropriately, fitting footwear combined with felted foam can be considered as the fourth-choice offloading treatment. If non-surgical offloading fails, we recommend to consider surgical offloading interventions for healing metatarsal head and digital ulcers. We have added new recommendations for the use of offloading treatment for healing ulcers that are complicated with infection or ischaemia and for healing plantar heel ulcers. Offloading is arguably the most important of multiple interventions needed to heal a neuropathic plantar foot ulcer in a person with diabetes. Following these recommendations will help health care professionals and teams provide better care for diabetic patients who have a foot ulcer and are at risk for infection, hospitalization, and amputation.

Treatment of modifiable risk factors for foot ulceration in persons with diabetes: a systematic review

BACKGROUND

Prevention of diabetic foot ulcers is important. Preventative treatment mostly targets and aims to improve modifiable risk factors of foot ulceration. While effectiveness of interventions in ulcer prevention has been systematically reviewed, their effectiveness in improving modifiable risk factors is unknown.

METHODS

The available medical scientific literature in PubMed, Excerpta Medica Database, and the Cochrane database was searched for original research studies on six interventions to treat modifiable risk factors for diabetic foot ulceration (ie, education for patients; education for professionals; self-management; pre-ulcer treatment; orthotic interventions; and foot- and mobility-related exercises). We assessed interventions for eight outcomes (ie, patients' knowledge; treatment adherence; professionals' knowledge; pre-ulcers; mechanical stress; neuropathy symptoms; foot/ankle joint mobility; and foot function). Both controlled and noncontrolled studies were selected. Data from controlled studies were assessed for methodological quality by two independent reviewers and extracted and presented in evidence and risk of bias tables.

RESULTS

We included 72 publications (26 with a controlled study design and 46 noncontrolled). We found that structured education may improve foot self-care behaviour of patients, yearly foot examinations, and foot disease knowledge of health care professionals. Callus removal reduces peak plantar pressure. Custom-made therapeutic footwear can be effective in reducing plantar pressure and may reduce callus. Foot- and mobility-related exercises may improve neuropathy symptoms and foot and ankle joint range of motion, while they do not seem to reduce peak plantar pressure; evidence for their effect on foot strength is conflicting.

CONCLUSIONS

Structured education for patients and health care professionals, callus removal, custom-made therapeutic footwear, and foot- and mobility-related exercises may be beneficial for improving modifiable risk factors for foot ulceration. However, we generally found low quality of evidence for interventions targeting modifiable risk factors for ulceration in persons with diabetes, with frequently inconsistent or limited results available per intervention and outcome.

Current Therapeutic Strategies in Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) are the fastest growing chronic complication of diabetes mellitus, with more than 400 million people diagnosed globally, and the condition is responsible for lower extremity amputation in 85% of people affected, leading to high-cost hospital care and increased mortality risk. Neuropathy and peripheral arterial disease trigger deformities or trauma, and aggravating factors such as infection and edema are the etiological factors for the development of DFUs. DFUs require identifying the etiology and assessing the co-morbidities to provide the correct therapeutic approach, essential to reducing lower-extremity amputation risk. This review focuses on the current treatment strategies for DFUs with a special emphasis on tissue engineering techniques and regenerative medicine that collectively target all components of chronic wound pathology.

Postoperative Convalescence

Foot and ankle surgery can impose significant hardship on a patient when carrying out their essential activities of daily living including mobility, sourcing and preparing food, as well as maintaining personal hygiene. Pre-operative planning between the surgeon, patient and caregivers can circumvent most of the challenges imposed by the post-operative restrictions of foot and ankle surgery. Depending on the weight bearing status of the operated extremity, a wide array of durable medical equipment devices are available to provide mobility and safety for the patient. Various devices are also available to protect the patient and the operative site during bathing. Pre-operative gait training can be valuable in selecting the most appropriate mobility aid for the patient, assuring safe ambulation while keeping the operated extremity protected.

Preliminary Evaluation of a Cycling Cleat Designed for Diabetic Foot Ulcers

BACKGROUND

Offloading devices for diabetic foot ulcers (DFU) generally restrict exercise. In addition to traditional health benefits, exercise could benefit DFU by increasing blood flow and acting as thermotherapy. This study functionally evaluated a cycling cleat designed for forefoot DFU.

METHODS

Fifteen individuals at risk of developing a DFU used a recumbent stationary bicycle to complete one 5-minute cycling bout with the DFU cleat on their study foot and one 5-minute bout without it. Foot stress was evaluated by plantar pressure insoles during cycling. Laser Doppler perfusion monitored blood flow to the hallux. Infrared photographs measured foot temperature before and after each cycling bout.

RESULTS

The specialized cleat significantly reduced forefoot plantar pressure (9.9 kPa versus 62.6 kPa, P < .05) and pressure time integral (15.4 versus 76.4 kPa*sec, P < .05). Irrespective of footwear condition, perfusion to the hallux increased (3.97 ± 1.2 versus 6.9 ± 1.4 tissue perfusion units, P < .05) after exercise. Infrared images revealed no changes in foot temperature.

CONCLUSIONS

The specialized cleat allowed participants to exercise with minimal forefoot stress. The observed increase in perfusion suggests that healing might improve if patients with active DFU were to use the cleat. Potential thermotherapy for DFU was not supported by this study. Evaluation of the device among individuals with active DFU is now warranted.

Outcomes Achieved With Use of a Prefabricated Roll-On Total Contact Cast

BACKGROUND

The total contact cast (TCC) is considered the gold standard for offloading of plantar diabetic foot ulcerations, yet its use remains suboptimal for a variety of reasons. Prefabricated TCC systems have been developed to help enhance TCC use. The primary objective of this study was to determine if healing rates obtained with use of a prefabricated roll-on TCC were similar to those reported with conventional TCC use. Secondary outcomes measured were the incidence of iatrogenic ulceration, amputation, and recurrent ulceration, and patient tolerance of the device.

METHODS

A retrospective chart review was performed on all patients in whom TCC was used for treatment of an ulceration at our institution from April 2013 to December 2016. Seventy patients (132 ulcerations) were identified.

RESULTS

An 85.6% healing rate was achieved. Five subjects (7.1%) sustained 11 iatrogenic ulcerations. All resolved with local treatment and continued casting. Thirteen subjects (18.6%) underwent amputation. No amputation occurred because of TCC application technique or use. Fifteen ulcerations (12 subjects, 17.1%) recurred. Greater than 70% resolved with re-initiation of TCC use. Forty-three subjects (61.4%) tolerated use of the prefabricated roll-on TCC.

CONCLUSION

Similar healing rates and reduced rates of iatrogenic ulceration, amputation, and recurrent ulceration were attained with use of a prefabricated roll-on TCC. These results, good patient tolerance, and the reduced administrative and clinical time related to supply acquisition, training, and proper application supports use of this device as a viable alternative to a conventional TCC for treatment of plantar neuropathic foot ulcerations.

LEVEL OF EVIDENCE

Level IV, case series.

The Role of Pressure Offloading on Diabetic Foot Ulcer Healing and Prevention of Recurrence

BACKGROUND

An increased plantar pressure is a causative factor in the development of plantar foot ulcers in people with diabetes mellitus, and ulcers are a precursor of lower extremity amputation.

METHODS

In this article, the evidence is reviewed that relieving areas of increased plantar pressure (ie, offloading) can heal plantar foot ulcers and prevent their recurrence.

RESULTS

Noninfected, nonischemic neuropathic plantar forefoot ulcers should heal in 6 to 8 weeks with adequate offloading. Recent meta-analyses and systematic reviews show that nonremovable knee-high devices are most effective. This is probably because they eliminate the problem of nonadherence with the use of a removable device. Studies show a large discrepancy between evidence-based recommendations on offloading and what is used in clinical practice. Many clinics continue to use methods that are less effective or have not been proven to be effective, while ignoring evidence-based methods. Strategies are proposed to address this issue, notably the adoption and implementation of recent international guidelines by professional societies and a stronger focus of clinicians on expedited healing. For the prevention of plantar foot ulcer recurrence in high-risk patients, 2 recent trials have shown that the incidence of recurrence can be significantly reduced with custom-made footwear that has a demonstrated pressure-relieving effect through guidance by plantar pressure measurements, under the condition that the footwear is worn.

CONCLUSION

This review helps to inform clinicians about effective offloading treatment for healing plantar foot ulcers and preventing their recurrence.

The Applicability of Plantar Padding in Reducing Peak Plantar Pressure in the Forefeet of Healthy AdultsImplications for the Foot at Risk

BACKGROUND

We investigated the effectiveness and durability of two types of plantar padding, the plantar metatarsal pad and the single wing plantar cover, which are commonly used for reducing forefoot plantar pressures.

METHODS

Mean peak plantar pressure and impulse at the hallux and at the first, second, third, and fourth metatarsophalangeal joints across both feet were recorded using the two-step method in 18 individuals with normal asymptomatic feet. Plantar paddings were retained for 5 days, and their durability and effectiveness were assessed by repeating the foot plantar measurement at baseline and after 3 and 5 days.

RESULTS

The single wing plantar cover devised from 5-mm felt adhesive padding was effective and durable in reducing peak plantar pressure and impulse at the first metatarsophalangeal joint (P = .001 and P = .015, respectively); however, it was not found to be effective in reducing peak plantar pressure and impulse at the hallux (P = .782 and P = .845, respectively). The plantar metatarsal pad was not effective in reducing plantar forefoot pressure and impulse at the second, third, and fourth metatarsophalangeal joints (P = .310 and P = .174, respectively).

CONCLUSIONS

These results imply limited applicability of the single wing plantar cover and the plantar metatarsal pad in reducing hallux pressure and second through fourth metatarsophalangeal joint pressure, respectively. However, the single wing plantar cover remained durable for the 5 days of the trial and was effective in reducing the peak plantar pressure and impulse underneath the first metatarsophalangeal joint.

Decreasing Foot Pressures While Implementing Topical Negative Pressure (Vacuum-Assisted Closure) Therapy

Over the past generation, there have been a number of significant advances in wound healing in general. Unfortunately, much of this has not translated into increased success in healing wounds on the sole of the foot. We believe that much of this therapeutic disconnect has to do with an inadequate merging of pressure off-loading technologies and active wound-healing technologies. This article discusses such a merger between removable cast walkers and topical negative pressure (also known as vacuum-assisted closure).

The Use of Best Practice in the Treatment of a Complex Diabetic Foot Ulcer: A Case Report

BACKGROUND AND PURPOSE

Published guidelines for effective management of diabetic foot ulcers (DFU) include total contact casting (TCC). The purpose of this case study is to describe the application of best practice guidelines for the treatment of a diabetic foot ulcer (DFU) in a complex patient where TCC offloading could not be utilized.

CASE DESCRIPTION

The patient was a 47 year-old female with a five-plus year history of a full-thickness DFU on the left plantar mid-foot. Treatment included sharp and ultrasound debridement, the use of a silver hydrofiber dressing, edema management via compression therapy, negative pressure wound therapy, offloading via customized 1/4 inch adhesive-backed felt applied to the plantar foot in addition to an offloading boot and use of a wheelchair, patient education regarding diabetes management, and the application of a bilayered living skin-equivalent biologic dressing.

OUTCOMES

At 15 weeks the wound was closed and the patient was transitioned into diabetic footwear.

DISCUSSION

The felt offloading was a beneficial alternative to TCC. The patient's longer than average healing rate may have been complicated by the duration of her wound, her 41 year history of diabetes, and the fact that gold standard offloading (TCC) was not able to be used. Further research is needed regarding the use of felt for offloading, such as application technique for wounds on different areas of the foot, comparison of different types of felt, and the use of felt in conjunction with various offloading devices.

Footwear and offloading interventions to prevent and heal foot ulcers and reduce plantar pressure in patients with diabetes: a systematic review

BACKGROUND

Footwear and offloading techniques are commonly used in clinical practice for preventing and healing of foot ulcers in persons with diabetes. The goal of this systematic review is to assess the medical scientific literature on this topic to better inform clinical practice about effective treatment.

METHODS

We searched the medical scientific literature indexed in PubMed, EMBASE, CINAHL, and the Cochrane database for original research studies published since 1 May 2006 related to four groups of interventions: (1) casting; (2) footwear; (3) surgical offloading; and (4) other offloading interventions. Primary outcomes were ulcer prevention, ulcer healing, and pressure reduction. We reviewed both controlled and non-controlled studies. Controlled studies were assessed for methodological quality, and extracted key data was presented in evidence and risk of bias tables. Uncontrolled studies were assessed and summarized on a narrative basis. Outcomes are presented and discussed in conjunction with data from our previous systematic review covering the literature from before 1 May 2006.

RESULTS

We included two systematic reviews and meta-analyses, 32 randomized controlled trials, 15 other controlled studies, and another 127 non-controlled studies. Several randomized controlled trials with low risk of bias show the efficacy of therapeutic footwear that demonstrates to relief plantar pressure and is worn by the patient, in the prevention of plantar foot ulcer recurrence. Two meta-analyses show non-removable offloading to be more effective than removable offloading for healing plantar neuropathic forefoot ulcers. Due to the limited number of controlled studies, clear evidence on the efficacy of surgical offloading and felted foam is not yet available. Interestingly, surgical offloading seems more effective in preventing than in healing ulcers. A number of controlled and uncontrolled studies show that plantar pressure can be reduced by several conservative and surgical approaches.

CONCLUSIONS

Sufficient evidence of good quality supports the use of non-removable offloading to heal plantar neuropathic forefoot ulcers and therapeutic footwear with demonstrated pressure relief that is worn by the patient to prevent plantar foot ulcer recurrence. The evidence base to support the use of other offloading interventions is still limited and of variable quality. The evidence for the use of interventions to prevent a first foot ulcer or heal ischemic, infected, non-plantar, or proximal foot ulcers is practically non-existent. High-quality controlled studies are needed in these areas.

Complications of the diabetic foot

The diabetic foot is at high risk for complications because of its role in ambulation. Peripheral neuropathy and peripheral vascular disease can lead to chronic foot ulcers, which are at high risk for infection, in part attributable to areas of high pressure caused by lack of tolerance of the soft tissue and bone and joint deformity. If left untreated, infection and ischemia lead to tissue death, culminating in amputation. Treatment strategies include antibiosis, topical therapies, offloading, debridement, and surgery. A multidisciplinary team approach is necessary in the prevention and treatment of complications of the diabetic foot.

The effects of focused-rigidity casts on forefoot plantar pressures: a pilot investigation

OBJECTIVE

To establish if focused rigidity casts (FRCs) reduce forefoot pressures in healthy participants, and to examine the effects of FRCs on contact area, contact pressure, peak pressure and force–time integral on the forefoot and the plantar pressures of the whole foot in participants with differing foot posture.

METHOD

Thirty-one healthy participants were recruited from a convenience sample of university staff and students. This study employed a repeated measures design, where walking in FRCs was compared with a control (canvas shoe). An in-shoe pressure measuring system was used to record changes in plantar pressure and the foot posture index was used to record foot posture.

RESULTS

A statistically significant reduction in contact pressure (p ≤ 0.000; n=31) and peak pressures(p ≤ 0.002; n=31) was observed in the forefoot. A statistically significant reduction in contact area and contact pressure over the whole foot and rear foot when participants wore the FRC was also found. The greatest decrease occurred in participants with a supinated foot posture while the least occurred in participants with a pronated foot posture. An increase in peak pressure was found in the mid foot for participants with a normal and supinated foot postures when the FRC was worn.

CONCLUSION

The results suggest that FRCs are an effective way of reducing forefoot pressures when compared with the control shoe. FRC’s work by redistributing pressure away from the forefoot to the area of increased rigidity beneath the cast.

Reduction of peak plantar pressure in people with diabetes-related peripheral neuropathy: an evaluation of the DH Pressure Relief Shoe™

Background

Offloading plantar pressure is a key strategy for the prevention or healing of neuropathic plantar ulcers in diabetes. Non-removable walking casts, such as total contact casts, are currently considered the gold-standard for offloading this type of wound. However, alternative methods for offloading that are more cost effective and easier to use are continually being sought. The aim of this study was to evaluate the capacity of the DH Pressure Relief Shoe™ to offload high pressure areas under the neuropathic foot in diabetes.

Methods

A within-subjects, repeated measures design was used. Sixteen participants with diabetic peripheral neuropathy were recruited and three footwear conditions were evaluated in a randomised order: a canvas shoe (the control), the participants’ own standard shoe, and the DH Pressure Relief Shoe™. The primary outcome was peak plantar pressure, measured using the pedar-X® mobile in-shoe system between the three conditions.

Results

Data analysis was conducted on 14 out of the 16 participants because two participants could not complete data collection. The mean peak pressure values in kPa (±SD) for each condition were: control shoe 315.9 (±140.7), participants’ standard shoe 273.0 (±127.1) and DH Pressure Relief Shoe™ 155.4 (±89.9). There was a statistically significant difference in peak plantar pressure between the DH Pressure Relief Shoe™ compared to both the control shoe (p = 0.002) and participants’ standard shoe (p = 0.001). The DH Pressure Relief Shoe™ decreased plantar pressures by 51% compared to the control shoe and by 43% compared to participants’ standard shoe. Importantly, for a couple of study participants, the DH Pressure Relief Shoe™ appeared unsuitable for day-to-day wearing.

Conclusions

The DH Pressure Relief Shoe™ reduced plantar pressures more than the other two shoe conditions. The DH Pressure Relief Shoe™ may be a useful alternative to current offloading modalities used in clinical management of diabetic foot ulceration. However, clinical trials are needed to test their effectiveness for ulcer healing and to ensure they are useable and safe for patients in everyday activities.

Off-loading practices for the wounded foot: concepts and choices

A wound practitioner's best-laid plan of care and strategy for healing an ulcerated foot is doomed to fail without a properly conceived approach based on sound off-loading principles. Wound healing that has stalled despite best-practice techniques may require reevaluation of off-loading choices. This is particularly true in the patient with abnormal foot pathologies. Special considerations are certainly required with neuropathic ulcers; however, any wound on a weight-bearing surface of the foot requires proper off-loading. This discussion explores the basic biomechanical and pathomechanical concepts that modify and influence ambulation and gait patterns. Integration of these concepts into the choices for off-loading to deter pathologic influences will alert the reader of precautionary measures and other factors for consideration. The aim of this column is to provide both an adequate working knowledge of the available off-loading devices and the necessary tools and concepts needed to stimulate wise decision protocols for wound management and healing.

Optimizing the offloading properties of the total contact cast for plantar foot ulceration

AIMS

Total contact casting is the gold standard offloading treatment for plantar foot ulceration, but the optimal technique and preferred materials are poorly defined and not readily prescribed in daily practice. We investigated in-cast pressure offloading in two types of total contact casts vs. a control condition, in patients with plantar foot ulceration.

METHODS

In-cast walking pressures were collected using the Novel Pedar-X system in 20 participants with a plantar foot ulcer in two types of total contact casts: a conventional total contact cast and a cushion-modified total contact cast incorporating an inlay of 6 mm slow-rebound cellular urethane and 6 mm soft cellular urethane. Casts were compared with a canvas cast shoe to establish baseline pressure values.

RESULTS

Compared with the cast shoe, the conventional total contact cast significantly reduced peak pressure at the ulcer site by 44%, mean pressure by 47% and pressure-time integral by 37% (P<0.001), while the cushion-modified total contact cast significantly reduced peak pressure at the ulcer site by 70%, mean pressure by 60% and pressure-time integral by 69% (P<0.001). Plantar pressure across the entire foot and each region of the foot was also reduced with the conventional total contact cast compared with the cast shoe, and further reduced by the cushion-modified total contact cast (P<0.05).

CONCLUSIONS

The offloading properties of the total contact cast can be enhanced with a 12 mm cellular urethane cushion modification. Further well-designed trials are required to understand and validate this cast technique and to demonstrate healing rates and safety in different patient populations.

Dressing plantar wounds with foam dressings, is it too much pressure?

Diabetes and its associated complications have become a major concern locally, nationally and internationally. One such complication is lower extremity amputation, commonly preceded by chronic ulceration. The cause of this tissue breakdown is multi-faceted, but includes an increase in pressure, particularly plantar pressure. As such, the choice of dressing to be applied to a plantar wound should ideally not increase this pressure further. A commonly used and possibly more bulky dressing is the foam dressing. This pilot study investigates the plantar pressures associated with three common foam dressings (Allevyn(®), Lyofoam(®) and Mepilex(®)) compared with a control dressing (Melolin(®)). Twelve healthy males and 19 females [SD] age 36.6 [10.4] were measured using the F-scan plantar pressure measurement system. Substantial variations in individual pressure changes occurred across the foot. No significant differences were identified, once a Bonferroni correction was applied. In healthy adults, it could be concluded that foam dressings do not have any effect on the plantar pressures of the foot. However, the need remains for a robust trial on a pathological population.

Plantar pressure relief using a forefoot offloading shoe

AIM

To assess the effectiveness of the Barouk(®) second-generation postoperative forefoot relief shoes during appropriate use of the shoe on healthy subjects.

MATERIALS AND METHODS

A convenience sample of 35 volunteer subjects (17 women, 18 men) was recruited to participate in this study. Dynamic foot loading was evaluated with inshoe plantar pressure measurements. Subjects were asked to walk two trials at a self-selected speed: (a) in their mass-produced shoes to assess baseline pressure values, defined as 100% and (b) with the Barouk(®) postoperative shoe on the right foot and their own shoe on the left side. Data analysis was tested for statistical differences with paired Student's t-tests (with p<0.05 as a significance level).

RESULTS

The Barouk(®) second-generation postoperative forefoot relief shoes relieved forefoot pressure in all trials. For all 35 volunteers, there was a 79-96% mean peak pressure reduction (p<0.001) of the forefoot except for the fifth metatarsal head during appropriate use of the postoperative shoe. In contrast to the results for the forefoot, a significant increase of the peak pressure values was observed in the heel region. Similar findings were observed for the pressure-time integral values.

CONCLUSION

The data of our study provide evidence that the second-generation Barouk(®) shoe relieve pressure of the forefoot with appropriate use.

Off-loading the diabetic foot for ulcer prevention and healing

BACKGROUND

Retrospective and prospective studies have shown that elevated plantar pressure is a causative factor in the development of many plantar ulcers in diabetic patients and that ulceration is often a precursor of lower extremity amputation. In this article, we review the evidence that relieving areas of elevated plantar pressure (off-loading) can prevent and heal plantar ulceration.

RESULTS

There is no consensus in the literature concerning the role of off-loading through footwear in primary or secondary prevention of ulcers. This is likely due to the wide diversity of intervention and control conditions tested, the lack of information about off-loading efficacy of the footwear used, and the absence of a target pressure threshold for off-loading. Uncomplicated plantar ulcers should heal in 6 to 8 weeks with adequate off-loading. The total contact cast and other nonremovable devices are most effective because they eliminate the problem of nonadherence to recommendations for using a removable device. Conventional or standard therapeutic footwear is not effective in ulcer healing. Recent United States and European surveys show a large discrepancy between guidelines and clinical practice in off-loading diabetic foot ulcers. Many clinics continue to use methods that are known to be ineffective or have not been proven effective, while ignoring methods that have been demonstrated to be efficacious.

CONCLUSIONS

A number of strategies are proposed to address this situation, notably the adoption and implementation of recently established international guidelines, which are evidence-based and specific, by professional societies in the United States and Europe. Such an approach would change the often poor current expectations for healing diabetic plantar ulcers.

Transitional off-loading: an evidence-based approach to pressure redistribution in the diabetic foot

PURPOSE

To enhance the learner's competence in providing pressure redistribution therapy for the diabetic foot.

TARGET AUDIENCE

This continuing education activity is intended for physicians and nurses with an interest in skin and wound care.

OBJECTIVES

After participating in this educational activity, the participant should be better able to: 1. Relate diabetic foot problems to the need for using off-loading devices. 2. Distinguish between the various types of dressings and off-loading devices used for diabetic foot wounds. 3. Apply the "transitional approach" to off-loading the diabetic foot.

Preliminary investigation on the reduction of plantar loading pressure with different insole materials (SRP--Slow Recovery Poron, P--Poron, PPF--Poron +Plastazote, firm and PPS--Poron+Plastazote, soft)

BACKGROUND

The aim of this study is to investigate the amount of pressure reduction for different padding and insole materials commonly used in the podiatry clinic.

METHODS

Plantar pressure were taken for 5 subjects without insoles fitted (BF) in their daily sports shoes, and thereafter with 4 pairs of simple insoles (6.4 mm thick) each as follow: SRP - Slow Recovery Poron, P - Poron, PPF - Poron+Plastazote (firm) and PPS - Poron+Plastazote (soft). In addition, subjects were also tested with semi-compressed felt (SCF) padding with a 1st metatarsophalangeal joint (MTPJ) aperture cut-out bilaterally. Minimum, maximum, mean pressure and peak pressure at the hallux, 1st, 2nd, 3rd/4th and 5th MTPJ across both feet were analysed. Repeated measures ANOVA with post hoc Bonferroni paired wise comparison was used to test for any statistical significance at the 95% confidence level for all pressure data.

RESULTS

PPF was significant in reducing the minimum (p<0.005) and mean pressure (p<0.03) when compared to BF. This accounted for approximately 28% and 27% pressure reduction in minimum and mean pressure respectively. Peak pressure on the 1st MTPJ locality showed significant reduction of 37% and 29% with the use of SCF (p<0.004) and PPF (p<0.004), respectively.

CONCLUSIONS

All 4 commonly used insole materials were able to reduce pressure across the whole foot with PPF achieving significance. Off-loading the 1st MTPJ would still be best achieved with the commonly used plantar metatarsal pad of SCF with the aperture cut-out design.

The efficacy of a removable vacuum-cushioned cast replacement system in reducing plantar forefoot pressures in diabetic patients

BACKGROUND

The purpose of this study was to determine the plantar forefoot offloading efficacy of a new prefabricated vacuum-cushioned cast replacement system designed for foot ulcer treatment in neuropathic diabetic patients.

METHODS

Fifteen diabetic subjects with peripheral neuropathy underwent in-shoe plantar pressure assessment while walking in five different footwear types: a standard vacuum-cushioned system with instantly moldable vacuum cushion and roller outsole, two modified vacuum-cushioned systems, one with flat surface vacuum cushion and one with flat outsole, a forefoot offloading shoe, and a control shoe. Regional peak pressures, pressure-time integrals, and inter-regional load transfers were calculated to determine the mechanical action of the footwear. Perceived walking comfort was tested using a 10-point visual analogue scale.

FINDINGS

Forefoot peak pressures and pressure-time integrals were significantly lower (by 41-56%) in the vacuum-cushioned system compared to control. Compared to the forefoot offloading shoe, the vacuum-cushioned system showed significantly higher metatarsal head peak pressures, similar metatarsal head pressure-time integrals, and significantly lower hallux peak pressures and pressure-time integrals. A major transfer of forefoot load to the midfoot explained the offloading efficacy of the vacuum-cushioned system. Few significant differences were present between the modified and standard vacuum-cushioned systems. Perceived walking comfort was significantly higher in the vacuum-cushioned system (score 6.6) than in the forefoot offloading shoe (score 3.4).

INTERPRETATION

The results showed that the vacuum-cushioned cast replacement system was effective in offloading the plantar forefoot of diabetic patients at risk for ulceration, although the contribution of the instantly moldable vacuum cushion and roller outsole were relatively small. The combined peak pressure, pressure-time integral and walking comfort results indicate that the vacuum-cushioned system may be a useful alternative for the forefoot offloading shoe in offloading the plantar diabetic forefoot.

Plantar pressure relief in the diabetic foot using forefoot offloading shoes

PURPOSE

Forefoot offloading shoes (FOS) are commonly used in clinical practice for treatment of plantar forefoot ulcers in the diabetic foot. The aim of this study was to assess the offloading efficacy of four different FOS models in comparison with a cast shoe and control shoe.

METHODS

In-shoe plantar pressures were measured during walking in each of the six footwear conditions in 24 neuropathic diabetic patients at high risk for plantar foot ulceration. For each of six foot regions, peak pressure, pressure-time integral, and force-time integral were calculated. Load transfer diagrams were developed to assess the footwear mechanisms of action. Perceived walking comfort was measured using a visual analogue scale (VAS). All comparisons between conditions were tested at P<0.05.

RESULTS

Peak pressures and pressure-time integrals at the metatarsal heads and hallux regions were significantly reduced (by 38-58%) in all FOS models when compared with the control shoe. The FOS also relieved metatarsal head peak pressure to a significantly larger extent than the cast shoe (approximately 20%). The load transfer diagrams showed a major transfer of approximately 40% of forefoot load to the midfoot explaining the offloading efficacy of the FOS. Perceived walking comfort was significantly lower in the FOS (VAS score 2.7-5.9) when compared with the control shoe (VAS 8.2) and cast shoe (VAS 6.8).

CONCLUSIONS

The data showed that all FOS models were effective in their primary goal, relieving forefoot pressure in at-risk neuropathic diabetic patients. Therefore, these shoes may be effective in offloading and healing plantar forefoot ulcers, although the low comfort scores should be considered as this may potentially affect adherence to treatment.

Treatment of Charcot foot and ankle with a prefabricated removable walker brace and custom insole

BACKGROUND

Removable walker braces have been used successfully to treat acute and chronic foot and ankle conditions including diabetic foot ulcers. We hypothesized that a removable walker brace may be successfully used in the management of the Charcot foot and ankle.

METHODS

Twenty-five feet and ankles with Charcot arthropathy in 21 patients (bilateral in 4 patients) were treated with a prefabricated, pneumatic removable walker brace fitted with a custom orthotic insole. Follow-up data were collected from patient interview, examination, and radiography.

RESULTS

Brace fitting was accomplished usually with a single visit to the prosthetist or pedorthist/orthotist. At the most recent evaluation, 17 (68%) feet and ankles had consolidation (stage III) of the Charcot arthropathy (average duration of brace use, 29+/-19 weeks) and were subsequently treated with rocker sole shoes, insoles, and ankle foot orthoses; 8 (32%) feet and ankles had ongoing brace treatment. Three feet developed new deformity during brace treatment, but average radiographic parameters of hindfoot to forefoot alignment had minimal change between initial and final radiographs at an average of 36+/-24 weeks after initial radiographic evaluation.

CONCLUSIONS

The prefabricated, pneumatic removable walker brace fitted with a custom insole was successful in the management of the Charcot foot and ankle and had a high satisfaction rate and safety profile despite frequent, albeit usually minor, complications.

Use of pressure offloading devices in diabetic foot ulcers: do we practice what we preach?

OBJECTIVE

Pressure mitigation is crucial for the healing of plantar diabetic foot ulcers. We therefore discuss characteristics and considerations associated with the use of offloading devices.

RESEARCH DESIGN AND METHODS

A diabetic foot ulcer management survey was sent to foot clinics in all 50 states and the District of Columbia in 2005. A total of 901 geographically diverse centers responded. The survey recorded information regarding usage frequency and characteristics of assessment and treatment of diabetic foot ulcers in each center.

RESULTS

Of the 895 respondents who treat diabetic foot ulcers, shoe modifications (41.2%, P < 0.03) were the most common form of pressure mitigation, whereas total contact casts were used by only 1.7% of the centers.

CONCLUSIONS

This study reports the usage and characteristics of offloading devices in the care of diabetic foot ulcers in a broadly distributed geographic sample. Less than 2% of specialists use what has been termed the "gold standard" (total contact cast) for treating the majority of diabetic foot ulcers.

Minimum-incision metatarsal osteotomies

This article focuses on minimal-incision metatarsal osteotomies for treating ulcerative lesions related to hallux valgus deformities and central and fifth metatarsal plantar ulcerations to correct the structural deformity responsible for the ulceration. The authors presented a structured review of the literature regarding complications associated with the use of minimum-incision surgical techniques available for the first, central, and fifth metatarsals and techniques to avoid them. Although a steep learning curve exists with these procedures, the advantage of performing minimum- incision metatarsal osteotomies in high-risk populations allows for rapid and predictable resolution of recalcitrant or recurrent ulcerations through correction of the underlying structural deformity with minimal complications.

The effectiveness of footwear and offloading interventions to prevent and heal foot ulcers and reduce plantar pressure in diabetes: a systematic review

BACKGROUND

Footwear and offloading techniques are commonly used in clinical practice for the prevention and treatment of foot ulcers in diabetes, but the evidence base to support this use is not well known. The goal of this review was to systematically assess the literature and to determine the available evidence on the use of footwear and offloading interventions for ulcer prevention, ulcer treatment, and plantar pressure reduction in the diabetic foot.

METHODS

A search was made for reports on the effectiveness of footwear and offloading interventions in preventing or healing foot ulcers or reducing plantar foot pressure in diabetic patients published prior to May 2006. Both controlled and uncontrolled studies were included. Assessment of the methodological quality of studies and data extraction was independently performed by two reviewers. Interventions were assigned into four subcategories: casting, footwear, surgical offloading and other offloading techniques.

RESULTS

Of 1651 articles identified in the baseline search, 21 controlled studies were selected for grading following full text review. Another 108 uncontrolled and cross-sectional studies were examined. The evidence to support the use of footwear and surgical interventions for the prevention of ulceration is meagre. Evidence was found to support the use of total contact casts and other non-removable modalities for treatment of neuropathic plantar ulcers. More studies are needed to support the use of surgical offloading techniques for ulcer healing. Plantar pressure reduction can be achieved by several modalities including casts, walkers, and therapeutic footwear, but the diversity in methods and materials used limits the comparison of study results.

CONCLUSIONS

This systematic review provides support for the use of non-removable devices for healing plantar foot ulcers. Furthermore, more high-quality studies are urgently needed to confirm the promising effects found in both controlled and uncontrolled studies of footwear and offloading interventions designed to prevent ulcers, heal ulcers, or reduce plantar pressure.

Footwear for the neuropathic patient: offloading and stability

Diabetic neuropathy is related to plantar ulceration through a variety of factors of which increased plantar pressures and loss of protective sensation are the most important. Loss of sensation in the lower limbs is also related to postural instability and an increased risk of falling. Ankle and foot proprioception play an important role in postural control and this sensory function is also affected by neuropathy. It is conceivable that footwear, orthotics, casts and braces used for treatment or prevention of plantar ulceration through offloading of the injured or at-risk foot area can exacerbate the postural instability and risk of falling. This has, however, received very limited attention in the literature. There are studies that have demonstrated that footwear adjustments can influence balance and stability in healthy, elderly subjects. The adjustments made to footwear for the diabetic foot are generally more dramatic and, therefore, are expected to have a greater influence on postural stability. Furthermore, casts and braces tend to deviate even more from normal footwear. This may seriously interfere with normal gait and posture and, therefore, stability. So far the evidence suggests that patients wearing such devices demonstrate markedly reduced activity levels. This reduced activity could add to the effect of offloading. This could also be interpreted to indicate problems with stability. This presentation will review the different types of offloading interventions frequently used for ulcer treatment and prevention and will consider the mechanical effect of these interventions on stability.

Negative pressure wound therapy after partial diabetic foot amputation: a multicentre, randomised controlled trial

BACKGROUND

Diabetic foot wounds, particularly those secondary to amputation, are very complex and difficult to treat. We investigated whether negative pressure wound therapy (NPWT) improves the proportion and rate of wound healing after partial foot amputation in patients with diabetes.

METHODS

We enrolled 162 patients into a 16-week, 18-centre, randomised clinical trial in the USA. Inclusion criteria consisted of partial foot amputation wounds up to the transmetatarsal level and evidence of adequate perfusion. Patients who were randomly assigned to NPWT (n=77) received treatment with dressing changes every 48 h. Control patients (n=85) received standard moist wound care according to consensus guidelines. NPWT was delivered through the Vacuum Assisted Closure (VAC) Therapy System. Wounds were treated until healing or completion of the 112-day period of active treatment. Analysis was by intention to treat. This study has been registered with , number NCT00224796.

FINDINGS

More patients healed in the NPWT group than in the control group (43 [56%] vs 33 [39%], p=0.040). The rate of wound healing, based on the time to complete closure, was faster in the NPWT group than in controls (p=0.005). The rate of granulation tissue formation, based on the time to 76-100% formation in the wound bed, was faster in the NPWT group than in controls (p=0.002). The frequency and severity of adverse events (of which the most common was wound infection) were similar in both treatment groups.

INTERPRETATION

NPWT delivered by the VAC Therapy System seems to be a safe and effective treatment for complex diabetic foot wounds, and could lead to a higher proportion of healed wounds, faster healing rates, and potentially fewer re-amputations than standard care.

Plantar pressure in off-loading devices used in diabetic ulcer treatment

Four off-loading devices used for the treatment of diabetic forefoot ulcers were compared: a custom-molded insole shoe, a cast MABAL shoe, a prefabricated pneumatic walking brace, and a bivalved total contact cast (BTCC). It was anticipated that all devices would significantly reduce forefoot plantar pressure compared with a control shoe. Sixteen healthy volunteers participated. Plantar pressures were evaluated using the Pedar system, while walking speed was determined using an optoelectric timer. Peak pressure (PP) of ten plantar areas and pressure-time integral for the first metatarsal area were analyzed statistically using a repeated measures analysis of variance. Forefoot pressures were significantly reduced compared with the control shoe for all devices (p<0.001). PP was most reduced (by 65.8%) for the BTCC, and pressure-time integral was most reduced for the BTCC and cast MABAL shoe. Small but significant differences between devices in walking speed (p<0.05) could not explain the substantial PP differences between the different devices. Although all off-loading devices resulted in a significant reduction of forefoot plantar pressure, devices differed significantly in the magnitude of pressure reduction. Further research will have to reveal the level of off-loading sufficient for effective treatment of diabetic ulcers.

Keller procedure for the treatment of resistant plantar ulceration of the hallux

A retrospective chart review was performed on 11 patients (13 feet) who underwent a modified Keller procedure for the treatment of recalcitrant neuropathic diabetic ulcers to the plantar aspect of the hallux between 1994 and 1998 to evaluate the postoperative results and complications. Diabetic patients with hallux rigidus, adequate vascular status, documented peripheral neuropathy, and at least 6 months of conservative care for treatment of a Wagner grade I and II ulceration were included in the study. Patients with active soft tissue infections or osteomyelitis were excluded. All primary ulcers healed within 6 months postoperatively. After 1-year of follow-up, 8 feet remained completely free of ulcers and 5 transfer ulcers occurred. Four infections developed; 3 from the surgical wound and 1 from a transfer ulcer. Based on these findings, the modified Keller procedure may be an appropriate intervention for hallux ulcerations provided the surgeon and the patient are aware of its limitations and possible outcomes.

Total contact casting of the diabetic foot in daily practice: a prospective follow-up study

OBJECTIVE

A limited number of clinical trials have shown that the total contact cast (TCC) is an effective treatment in neuropathic, noninfected, and nonischemic foot ulcers. In this prospective data collection study, we assessed outcome and complications of TCC treatment in neuropathic patients with and without peripheral arterial disease (PAD) or (superficial) infection.

RESEARCH DESIGN AND METHODS

Ninety-eight consecutive patients selected for casting were followed until healing; all had polyneuropathy, 44% had PAD, and 29% had infection. Primary outcomes were percentage healed with a cast, time to heal, and number of complications.

RESULTS

Ninety percent of all nonischemic ulcers without infection and 87% with infection healed in the cast (NS). In patients with PAD but without critical limb ischemia, 69% of the ulcers without infection and 36% with infection healed (P < 0.01). In multivariate analyses, PAD, infection, and heel ulcers were associated with a lower percentage healed (all P < 0.05). Median duration of cast treatment was 34 days. New ulcers, all superficial, developed in 9% and preulcerative lesions in 28% of the patients; these skin lesions healed in the cast within a maximum of 13 days.

CONCLUSIONS

In comparison to pure neuropathic ulcers, ulcers with moderate ischemia or infection can be treated effectively with casting. However, when both PAD and infection are present or the patient has a heel ulcer, outcome is poor and alternative strategies should be sought. The high rate of preulcerative lesions stresses the importance of close monitoring during TCC treatment.

It's not what you put on, but what you take off: techniques for debriding and off-loading the diabetic foot wound

The basic etiology of neuropathic diabetic foot wounds involves pressure in conjunction with cycles of repetitive stress, leading to failure of skin and soft tissue. The central tenet of any treatment plan addressing neuropathic diabetic foot wounds is the appropriate debridement of nonviable tissue coupled with adequate pressure relief (off-loading). Although numerous advances have been made in the treatment of diabetic foot wounds, including bioengineered tissues, autologous and exogenous cytokine delivery systems, and potentially effective topical antimicrobial modalities, none will succeed without addressing effective debridement and off-loading. Specific debridement and off-loading techniques are discussed, along with available supporting evidence. This includes the use of the "instant" total contact cast, among other modalities.

The effects of total contact casting materials on plantar pressures

The plaster-based total contact cast (TCC) is effective at reducing high plantar pressures associated with foot ulceration in the patient with diabetes. However, the weight and the lengthy drying time which require nonweightbearing create an inconvenience for the patient. Fiberglass has been commonly used as a substitute for plaster due to the quicker drying time, although little is known about the effects of fiberglass on plantar pressures. The purpose of the study was to compare a plaster-based TCC (PB-TCC) and an all-fiberglass TCC (AF-TCC) using selected plantar pressure parameters for commonly ulcerated regions of the foot. Using a repeated measures design, 10 healthy subjects consented to walk, for four consecutive trials, along a 25-m corridor while wearing a running shoe, PB-TCC, and AF-TCC. For each of the footwear conditions, parameters of peak pressure, pressure-time integral, and contact time for the forefoot, lateral midfoot, and heel regions were recorded using the Pedar trade mark system of plantar pressure measurement. Both the PB-TCC and AF-TCC produced similar peak plantar pressures that were significantly lower (p =.001) than the running shoe. Pressure-time integrals were similar for all footwear conditions and contact time was not altered with footwear type. In summary, the AF-TCC appears to be an effective alternative to the PB-TCC for plantar pressure reduction in the management of neuropathic foot ulceration.

Comparison of forefoot ulcer healing using alternative off-loading methods in patients with diabetes mellitus

OBJECTIVE

To compare the healing rate of forefoot ulcers in patients with diabetes treated using a total contact cast with those treated using alternative off-loading methods. DESIGN Retrospective analysis of healing rates of forefoot ulcers.

SETTING

Louisiana State University Health Sciences Center Diabetes Foot Program, Baton Rouge, LA.

PARTICIPANTS

120 consecutive patients with diabetes mellitus referred for treatment of new, nonsurgical forefoot ulceration.

INTERVENTIONS

Alternative off-loading methods (an accommodative dressing, a healing shoe, a walking splint) or a total contact cast.

MAIN OUTCOME MEASURE

Healing time of forefoot ulcers in days and percentage healed in 12 weeks.

RESULTS

113 of 120 (94%) patients with forefoot ulcers healed in an average of 45.5 +/- 43.4 days. Seven of 120 (5.8%) patients with ulcers either did not heal or were lost to follow-up. Stepwise lognormal regression showed ulcer grade (P <.001, R(2)= 0.11) and width (P =.024, R(2)= 0.05) were significantly related to healing time. After adding ulcer grade (1, 2, or 3) and width into the model, there was no difference between healing time in the accommodative dressing (P =.253), healing shoe (P =.815), and walking splint (P =.525) when compared with the total contact cast. Forefoot ulcers were closed within 12 weeks in at least 81% of cases irrespective of the off-loading method.

CONCLUSION

The healing rate of forefoot ulcerations in patients with diabetes using alternative off-loading methods or a total contact cast appeared to be comparable when the method was selected based on location of ulcer, patient age, and duration of ulceration.

Electric stimulation as an adjunct to heal diabetic foot ulcers: a randomized clinical trial

OBJECTIVE

To evaluate high-voltage, pulse-galvanic electric stimulation as an adjunct to healing diabetic foot ulcers.

DESIGN

Randomized, double-blind, placebo-controlled pilot trial.

SETTING

University medical center.

PATIENTS

Forty patients with diabetic foot ulcers, consecutively sampled. Twenty patients each assigned to treatment and placebo groups. Five patients (2 treated, 3 placebo) withdrew because of severe infection.

INTERVENTIONS

Electric stimulation through a microcomputer every night for 8 hours. The placebo group used identical functioning units that delivered no current. Additional wound care consisted of weekly débridements, topical hydrogel, and off-loading with removable cast walkers. Patients were followed for 12 weeks or until healing, whichever occurred first.

MAIN OUTCOME MEASURES

Proportion of wounds that healed during the study period. Compliance with use of device (in hr/wk), rate of wound healing, and time until healing.

RESULTS

Sixty-five percent of the patients healed in the group treated with stimulation, whereas 35% healed with placebo (p = .058). After stratification by compliance, a significant difference was identified among compliant patients in the treatment group (71% healed), noncompliant patients in the treatment group (50% healed), compliant patients in the placebo group (39% healed), and noncompliant patients in the placebo group (29% healed, linear-by-linear association = 4.32, p = .038). There was no significant difference in compliance between the 2 groups.

CONCLUSION

Electric simulation enhances wound healing when used in conjunction with appropriate off-loading and local wound care.

Quantitative assessment of simultaneous capacitive and resistive plantar pressure measurements during walking

Plantar pressure data were collected simultaneously, during walking, from capacitive and resistive in-shoe pressure measurement systems. Overall mean peak pressure recordings from the resistive system were 32%, 20% and 14% greater than recordings from the capacitive system, at the heel, central metatarsal heads, and great toe, respectively. Placement of one system's insoles above or below the other's somewhat affected peak pressure measurements from both systems, while calibration via air bladder or single limb standing techniques somewhat affected resistive measurements as well. Capacitive measurement variability was 60%, 20% and 22% lower than resistive measurement variability, at the heel, central metatarsal heads, and great toe, respectively. Both systems tended to exhibit greater variability when capacitive insoles were placed above resistive insoles; however, the effects on variability of the experimental insole arrangements were well overshadowed by the overall variability differences between systems.

A new ambulatory foot pressure device for patients with sensory impairment. A system for continuous measurement of plantar pressure and a feed-back alarm

Abnormal and excessive plantar pressure is a major risk factor for the development of foot ulcers in patients with loss of protective pain sensation. Repeated pressure with each step can result in inflammation at specific points, followed by ulcer formation. Patients with peripheral nerve disease are unable to prevent the development of such lesions, which often lead to amputation. For this reason, it has been suggested that a fundamental therapeutic intervention should be the reduction of high plantar pressure. We have developed a portable, battery-operated ambulatory foot pressure device (AFPD) which has two important functions: (1) to determine the areas of high plantar pressure, and (2) to provide an acoustic alarm, adjusted to a specific pressure load, which is triggered when weight-bearing exceeds the predetermined plantar pressure. A memory of plantar pressure parameters allows for downloading of the data and sequential analysis during the investigation period. Such an alarm device could replace the lack of pain sensation and may play an important role in the prevention of ulcer development and lower extremity amputation.

New developments in the biomechanics of the diabetic foot

Biomechanical issues are now widely recognized as being important in the treatment of diabetic foot disease. The purpose of the present review is to identify advances that have occurred since the previous International Conference on the Diabetic Foot in 1995 in the understanding of foot biomechanics in relation to diabetes. Attention continues to be focused on the identification of a threshold plantar pressure that leads to tissue damage. Recent studies have suggested that peak barefoot pressure may be only 65% specific for the development of ulceration. The association between foot deformity and plantar pressure has been the subject of several quantitative studies, but new questions have been raised about the etiology of claw toes. The measurement of shear stress continues to be an elusive goal although several small studies have presented possibly feasible technical approaches. The importance of callus as a precursor to ulceration has been confirmed experimentally and quantitative measures of motor neuropathy have been presented. Although a number of new devices have been introduced as alternatives to the Total Contact Cast, few clinical studies of their efficacy are available yet. New information on the properties of insole materials has been published including data on changes with repeated cycling. Complications of prophylactic surgery have been shown to include a high rate of Charcot fractures. Two new series describing the fixation of such fractures have also been reported. Biomechanical issues have also been addressed in two sets of guidelines for treatment that have recently been published. These many studies confirm the central role of mechanical stress and its relief in the treatment of neuropathic foot problems in diabetes.