Off-loading Devices Research Articles

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.

Reduction of Plantar Pressure Using a Prototype Pressure-Relieving Dressing

It is accepted that pressure relief is among the most important aspects in treating diabetic foot ulcers. Clinically, a variety of off-loading devices are used to redistribute pressure away from the area of ulceration to improve wound healing. The incorporation of pressure-relieving properties in a wound care dressing for the treatment foot ulcers is a new and interesting concept, although currently there is no dressing available that contains specific pressure-relieving qualities. We therefore aimed to investigate the efficacy of a prototype pressure-relieving dressing (PRD) designed to off-load pressure under individual plantar metatarsal head areas. To establish the pressure-reducing efficacy, the PRD was investigated in patients with intact feet only. The study had institutional review board approval, and all participants gave informed consent. Eighteen diabetic patients with peripheral neuropathy but without active foot ulceration were recruited from the Manchester Diabetes Centre. Other inclusion criteria were peak plantar pressure >500 kPa and no peripheral vascular disease. Participants visited the gait laboratory on 3 consecutive days. Dynamic plantar pressures were measured during barefoot walking using the optical pedobarograph (1). Following baseline plantar pressure measurement on day 1, the metatarsal head with the highest plantar pressure was covered with the prototype PRD, after which pressure measurement was repeated. The center of the dressing pad was applied over the bony prominence of the target metatarsal head …

A Randomized Trial of Two Irremovable Off-Loading Devices in the Management of Plantar Neuropathic Diabetic Foot Ulcers

The purpose of this study was 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. In a prospective, randomized, controlled trial, 41 consecutive diabetic patients with chronic, nonischemic, neuropathic plantar foot ulcers were randomly assigned to one of two groups: a RCW rendered irremovable by wrapping it with a single layer of fiberglass casting material (i.e., an iTCC) or a standard TCC. Primary outcome measures were the proportion of patients with ulcers that healed at </=12 weeks, healing rates, complication rates, cast placement/removal times, and costs. The proportions of patients with ulcers that healed within 12 weeks in the iTCC and TCC groups were 80 and 74%, respectively (94 and 93%, respectively, when patients who were lost to follow-up were excluded). Survival analysis (healing rates) was statistically equivalent in the two groups, as were complication rates, but with a trend toward benefit in the iTCC group. The iTCC took significantly less time to place and remove than the TCC with 39% and 36% reductions, respectively. There was also an overall lower cost associated with the use of the iTCC compared with the TCC. 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.

Foot problems in diabetes: an overview.

Diabetes is the leading cause of nontraumatic lower-extremity amputations in the United States. Most amputations are preceded by an ulcer, and ulcers are costly in their own right. Most ulcers are neuropathic in etiology and plantar in location. They occur typically at sites of high mechanical loading because of repetitive trauma in people with loss of pain sensation. In an adequately perfused limb, such ulcers are not difficult to heal. When they are properly mechanically off-loaded, approximately 90% of these wounds heal in approximately 6 weeks. The reference standard off-loading device is the total contact cast, but other reasonably efficacious methods exist. Screening and implementation of preventive measures in the high-risk patient are highly recommended and can reduce the incidence of ulceration. All patients with diabetes should be screened annually for loss of protective sensation, with the 10-g Semmes-Weinstein monofilament being the easiest tool to use. Education to prevent complications should be implemented for all patients with loss of protective sensation.

Activity patterns of patients with diabetic foot ulceration: patients with active ulceration may not adhere to a standard pressure off-loading regimen.

To evaluate the activity of patients with diabetic foot ulcerations and their adherence to their pressure off-loading device. We enrolled 20 subjects treated for neuropathic diabetic foot wounds corresponding to University of Texas grade 1 stage A. All were off-loaded using a removable cast walker (RCW). We recorded the total activity (measured in activity steps per day) taken on a waist-worn computerized accelerometer. We subsequently correlated this to activity recorded on an RCW-mounted accelerometer, which was not readily accessible to the patient. There were a mean 1219.1 +/- 821.2 activity units (steps) taken per patient per day. Patients logged significantly more daily activity units with the protective RCW off than with it on (873.7 +/- 828.0 vs. 345.3 +/- 219.1, P = 0.01). This amounts to only 28% of total daily activity recorded while patients were wearing their RCW. Although a total of 30% of the patients in the study recorded more daily activity units while wearing the device, this subset most adherent to their off-loading regimen still only wore the device for a total of 60% of their total daily activity. Subjects with diabetic foot ulcerations appear to wear their off-loading devices for only a minority of steps taken each day. This may partially explain the poor results reported from many trials of agents designed to help speed the healing of these wounds. Control of this important aspect of care with less easily removable devices may increase the prevalence of healing.