Predictive Value of Foot Pressure Assessment as Part of a Population-Based Diabetes Disease Management Program

Abstract

OBJECTIVE -To evaluate the effectiveness of dynamic plantar pressure assessment to determine patients at high risk for neuropathic ulceration. In choosing the cut point, we looked for an optimum combination of sensitivity and specificity of plantar pressure to screen for neuropathic ulceration.RESEARCH DESIGN AND METHODS -A total of 1,666 consecutive individuals with diabetes (50.3% male) presenting to a large urban managed care-based outpatient clinic were enrolled in this longitudinal 2-year outcome study. Patients received a standardized medical and musculoskeletal assessment at the time of enrollment, including evaluation in an onsite gait laboratory.RESULTS -Of the entire population, 263 patients (15.8%) either presented with or developed an ulcer during the 24-month follow-up period. As expected, baseline peak plantar pressure was significantly higher in the ulcerated group than in the group who did not ulcerate (95.5 Ϯ 26.4 vs. 85.1 Ϯ 27.3 N/cm 2 , P Ͻ 0.001). There was also a trend toward increased pressure with increasing numbers of foot deformities, as well as with increasing foot risk classification (P ϭ 0.0001). Peak pressure was not a suitable diagnostic tool by itself to identify high-risk patients. After eliminating patients without loss of protective sensation, using receiver operating characteristic (ROC) analysis, the optimal cut point, as determined by a balance of sensitivity and specificity, was 87.5 N/cm 2 , yielding a sensitivity of 63.5% and a specificity of 46.3%.CONCLUSIONS -The data from this evaluation continue to support the notion that elevated foot pressure is an important risk factor for foot complications. However, the ROC analysis suggests that foot pressure is a poor tool by itself to predict foot ulcers. Diabetes Care 26:1069 -1073, 2003N europathic foot ulcers in individuals with diabetes are precipitated by a combination of pressure and cycles of repetitive stress (1,2). Identification, quantification, and mitigation of pressure and cycles of stress (activity) are thought to be important components in risk assessment and management of patients both before and after ulceration (3-8).Several investigators have evaluated populations of high-risk patients to identify strata of foot pressures that might assist in assessment. Boulton et al. (9) reported that pressures were Ͼ110 N/cm 2 for every subject with a foot ulcer, suggesting a threshold pressure below which individuals would not ulcerate. Only 31% of individuals with diabetes without a history of ulceration demonstrated abnormal peak foot pressures based on the criteria of Boulton et al. However, it is not clear if a threshold pressure level exists because other reports have identified lower peak foot pressures at sites of neuropathic ulceration than those identified by . For instance, diabetic subjects with peak plantar pressures Ͼ65 N/cm 2 have been shown to be at a six times greater risk for ulceration than subjects with pressures below this value (3). In a previous case-control study, our group was unable to identify...

High prevalence of ischaemia, infection and serious comorbidity in patients with diabetic foot disease in Europe. Baseline results from the Eurodiale study

“…Although relatively high rates of non-plantar foot ulceration (40-50%) have previously been observed [1,26], earlier studies and guidelines focused on plantar foot ulceration in neuropathic patients. Examples include plantar pressure measurements [12], insoles for the prevention of plantar forefoot and midfoot ulcers [27], and total contact casting [14]. There are very few studies on the management of nonplantar ulcers, despite the fact that healing rates might be lower in dorsal compared with plantar ulcers [28].…”

“…In many centres, patients with neuropathic or mildly neuroischaemic ulcers are treated in foot clinics, while patients with severe ischaemia and deep foot infections are admitted to surgical wards. From several studies there emerges a 'classic' picture of a patient with a neuropathic ulcer on the plantar surface of the foot [1,8,11,12]; with optimal therapy >80% of these 'uncomplicated' ulcers can heal within 3 months [13][14][15]. One might therefore question whether some studies provide an image of diabetic foot disease that is biased towards the least complicated foot ulcers or a specific subset of patients.…”

The diabetic foot: from art to science. The 18th Camillo Golgi lecture

“…However, subsequent studies have suggested that other risk factors, such as callus, are more predictive of future ulceration [46], and that foot pressure is a poor tool when used alone to predict ulceration [57].…”

Ankle ROM and stiffness measured at rest and during gait in individuals with and without diabetic sensory neuropathy

“…Recent studies implicate limited passive dorsiflexion (DF) range of motion (ROM) and increased passive ankle stiffness as key factors contributing to increased plantar loading [5][6][7][8][9][10]. Limited ankle DF ROM and/or increased stiffness may result from the effects of longstanding hyperglycemia on connective tissue [11] and are hypothesized to restrain forward progression of the tibia on the fixed foot during the stance phase of walking.…”