The role of dynamic plantar pressures in diabetic foot ulcers.

OBJECTIVE: The significance of plantar pressure studies in detecting sites of plantar ulceration in diabetic patients was investigated. RESEARCH DESIGN AND METHODS: A total of 97 diabetic patients participated in this study. History and physical data, such as history of smoking, type of diabetes, ankle/brachial indexes, and the presence of protective sensory threshold, were collected. Using the EMED-SF plantar pressure analyzer, dynamic pressure variables, such as normalized peak pressure of maximum pressure picture (MPP), pressure-time integral (PTI), and force-time integral (FTI), were measured in each foot. Statistical analysis included descriptive statistics and analyses of variance. RESULTS: Out of 97 patients, 34 patients had no history of neuropathy and plantar ulceration (the diabetic control [DC] group). Another 14 patients had neuropathy with no previous history of plantar ulcers (the DN group), whereas the remainder of the patients had a history of peripheral neuropathy with plantar ulceration (the DU group). There were significant increases in MPP (P < 0.004) and PTI (P < 0.0004) levels in the DU group when compared with the DC group with the highest pressure present under the 4th and 5th metatarsal heads. No statistical significance existed among groups when comparing FTI levels. CONCLUSIONS: Neuropathic patients have an increase in dynamic plantar foot pressures placing them at risk for plantar ulceration. Instruments such as the EMED-SF system can be helpful in detecting possible sites of plantar ulcerations by locating the areas of maximum pressure.

Enchondroma of the proximal phalanx.

Enchondromas are the most commonly seen benign tumors of the small bones of the foot. If symptomatic, these tumors often require surgical excision. Foot surgeons must weigh the surgical alternatives with respect to relief of symptoms, prognosis, cosmesis, and function. The authors present a typical case presentation of a solitary enchondroma in a phalanx.

Preoperative imaging for soft tissue tumors of the foot.

Soft tissue imaging modalities are both available and effective. This manuscript describes the use of plain film radiography, ultrasound, and magnetic resonance imaging in both the diagnosis and preoperative planning of a calcified soft tissue tumor of the heel. The soft tissue tumor being presented was secondary to multiple corticosteroid injections.

Prevention and treatment of foot problems in diabetes mellitus. A comprehensive program.

This discussion was selected from the weekly staff conferences in the Department of Medicine, University of California, San Francisco. Taken from a transcription, it has been edited by Nathan M. Bass, MD, PhD, Associate Professor of Medicine, under the direction of Lloyd H. Smith, Jr, MD, Professor of Medicine and Associate Dean in the School of Medicine.

Dynamic plantar pressure analysis. Comparing common insole materials.

A comparison of five commonly used insole materials (Spenco, PPT, Plastazote, Nickelplast, and Pelite) was made to evaluate their effectiveness in reducing plantar vertical pressures on human subjects during walking. With the use of the EMED-SF pedograph force plate system, dynamic measures of vertical force, force-time integral, peak plantar pressure, pressure-time integral, and area of foot-to-ground contact were compared with the force plate covered with each of the insole materials and without any interface material.

Dynamic pressure analysis of the diabetic charcot foot.

Charcot foot is a form of neuropathic osteoarthropathy, occurring in one or more joints of the foot and ankle. It is a destructive process that alters the weightbearing areas of the foot and, in many cases, results in a rocker-bottom deformity. The authors present quantitative results of dynamic pressure analysis of Charcot foot with the EMED SF pressure analysis system and propose ways in which this information may be used in the evaluation and treatment of this deformity.

Prevalence of foot pathology and lower extremity complications in a diabetic outpatient clinic.

Multiple risk factors interplay in the formation of foot ulceration and/or limb amputation in the diabetic patient. This study defines the prevalence of foot pathology, lower extremity complications, and known risk factors for ulceration in a cross-sectional analysis of 92 diabetic patients in a Veterans Affairs Metabolic Clinic. Sixteen percent of patients had a history of lower extremity complications including pedal ulceration and/or amputation, previously requiring 1480 hospital days of care. Sixty-eight percent of patients had structural pathology in the foot, including: 51 percent callus, 32 percent hammertoes, 8 percent bunions, and 1 percent Charcot foot. Thirty-four percent of patients were insensate, while 25 percent had autonomic neuropathy. Twenty-two percent of patients had atherosclerosis obliterans as defined by an ankle brachial index less than 0.9; 13 percent suffered from intermittent claudication. The following pathologies were significantly more prevalent in diabetic patients with a history of ulceration and/or amputation compared to those patients without ulceration or amputation: hammertoe deformity (p less than .0001), abnormal cutaneous pressure sensation (p less than .05), abnormal R-R interval (p less than .05), intermittent claudication (p less than .05), and abnormal ankle brachial index (p less than .05). An important finding was that 41 percent of insensate patients were not aware of their sensory deficit. In addition, two-thirds of the patients with vascular disease had palpable pulses. All patients with diabetes should be entered into a basic foot education program. The high prevalence of lower extremity pathology coupled with the inadequacy of history and physical examination in detecting neuropathy and vascular disease emphasize the need for vigorous screening to determine whether patients are at high risk of ulceration/amputation. These patients should be entered into aggressive prophylactic treatment programs.

High-resolution ultrasound in the preoperative and postoperative assessment of distal metatarsal osteotomy. Preliminary report.

High-resolution sonography was used to study eight patients with suspected plantarflexed metatarsals and associated painful pedal callousities to determine metatarsal head position as the etiology of the pressure keratosis. Ultrasonography demonstrated a plantarflexed metatarsal head in all eight patients. Using both 5 and 10 MHz transducers, the plantarflexed metatarsal position could be accurately assessed and thus could aid in determining the degree of surgical correction necessary to properly realign the depressed metatarsal. Ultrasonography also allowed a noninvasive and accurate assessment of the surgical correction postoperatively in five of the eight patients. This preliminary study suggests that high-resolution sonography has applicability in accurately assessing metatarsal position. In addition, this new technique is noninvasive and presents insights concerning the amount of surgical correction necessary for realignment without increased risk or pain to the patient.

Aesthesiometry: quantification of cutaneous pressure sensation in diabetic peripheral neuropathy.

The Semmes-Weinstein pressure aesthesiometer, which measures cutaneous pressure sensation, was used for quantifying sensory loss in diabetic peripheral neuropathy. Eighty subjects comprising four groups were tested: nondiabetic controls (Group C); non-neuropathic, diabetic controls (Group DC); diabetic subjects with neuropathy and without a history of pedal ulcerations (Group DN); and, diabetic subjects with a history of or active pedal ulceration (Group DU). Cutaneous pressure sensation of 10 dorsal and plantar sites on the foot were tested, using a method of interval comparison modeled after the two-alternative forced choice algorithm. The sensitivity threshold level was defined as the lightest probe in which the subject accurately chose the correct interval in at least 2 out of 3 trials. The mean sensitivity threshold level for Group DC was not significantly increased (p greater than .05) compared to Group C. In contrast, patients with neuropathy (Group DN or DU) showed a significantly higher mean sensitivity threshold (p less than .001) than either Group C or DC. In addition, this technique demonstrated that patients in Group DU had a mean sensitivity threshold that was statistically higher (p less than .001) than Group DN, although both groups of patients had symptomatic neuropathy. This study provides a direct demonstration that decreased sensation of pressure occurs in the feet of diabetic patients with a history of ulceration. The best discrimination between groups is obtained by requiring that three of the six plantar forefoot sites have a sensitivity threshold level of greater than 5.07 log (0.1 mg) force as the risk discriminator level. Semmes-Weinstein aesthesiometry should now be tested in a prospective study to demonstrate its effectiveness in determining those patients at great risk of developing foot ulcers.

Use of liquid crystal thermography in the evaluation of the diabetic foot.

Liquid crystal thermography (LCT) was used to determine temperature variations on the plantar surface of feet. The purpose was to identify thermal emission patterns associated with diabetic foot ulcers. Three population groups were screened: group I, 16 nondiabetic controls; group II, 21 diabetic patients with no history of pedal ulcers; and group III, 28 diabetic patients with active pedal ulceration or history of foot ulcerations. The results demonstrate a generalized increase in plantar foot temperature in group III compared with groups I and II. Temperature readings under metatarsal heads 1-5, great toe, heel, and lateral band were significantly increased (P less than .01) in group III. Additionally, the warm lateral surface displayed by group III patients was not significantly different in temperature from the medial arch of the foot. In groups I and II, the lateral band was significantly cooler (P less than .01) than the medial arch. In group III patients with active ulceration on only one foot, no significant difference in temperature was found between the foot with active ulceration compared with the contralateral nonulcerated foot. When patients with active pedal ulceration were compared with patients with a history of foot ulcers, no significant difference in temperature was seen at five of seven sites tested. A warm concentric color band surrounding active plantar ulcers was identified in group III. This pattern extended from the center of the ulcer to a distance of 8 mm. A significant change in temperature (P less than .01) was noted at 6- and 8-mm distances from the center of the ulcer. In addition, a mottled thermographic pattern was observed more frequently in group III patients than in groups I and II.(ABSTRACT TRUNCATED AT 250 WORDS)

Sonography of the sole of the foot. Evidence for loss of foot pad thickness in diabetes and its relationship to ulceration of the foot.

The hypothesis that loss of tissue mass in the foot contributes to foot ulceration in diabetics has never been quantitated. We developed normal criteria for the thickness of the sole of the foot at the heel, and the five metatarsal heads of both feet, using high-resolution ultrasound (10 MHz). We studied 24 normal patients ranging in weight from 125 to 250 lbs. We examined the soles of the feet of 38 diabetics without foot ulcers and 11 diabetics with foot ulcers or a history of foot ulcers who were in the same weight range as the normals. Of statistical significance, the heel thickness in controls was greater than that of the diabetics, which in turn was greater than that of the diabetics with foot ulcers. The thickness of the sole over the first and second metatarsals was also greater in the controls compared with diabetics. We conclude that high-resolution ultrasound is an effective determinant of the thickness of the sole of the foot and that diabetics have variations from the norm in the heel and at the first and second metatarsal heads.