Cath Lab Digest

O ne of the central tenets of care in the treatment of plantar diabetic foot wounds is reduction of pressure through various devices. One of the most popular of these devices in use in many parts of the world is the Scotchcast boot. Although the Scotchcast boot has been used successfully for nearly two decades in several clinics in the United Kingdom and elsewhere, evidence of treatment outcomes in large populations is sparse.^1,2 The purpose of this study was to evaluate time to healing associated with treatment of diabetic foot ulcers of varying depth using the Scotchcast boot.

Materials and Methods

Data were extracted from the records of 180 patients, 150 (83.3%) male, with a mean age of 55.3 ±10.9 years, who underwent treatment for neuropathic diabetic foot wounds at a university teaching hospital's tertiary care outpatient clinic. Data were abstracted for consecutive patients seeking care at the facility who were treated with the Scotchcast boot. All patients included in the study had been previously diagnosed with diabetes mellitus by their attending physicians. Wounds were described and classified using the University of Texas diabetic foot wound classification system³ and all patients had loss of plantar sensory protective threshold based on biothesiometer test results and the method and criteria defined by Young et al.^4,5 Vascular status was evaluated by pedal pulse palpation. Data from patients were excluded from analysis if acute soft tissue, bone infection, or ischemia had been diagnosed by the treating physician at the time of assessment. The diagnosis of ischemia was made by the absence of more than one foot pulse or a nonaudible signal on Doppler ultrasonography of the dorsalis pedis or posterior tibial pulses the affected extremity.

All patients were treated with the Scotchcast boot as the sole form of pressure relief. Data from patients who received multiple forms of pressure relief during their treatment were not included. The boot was applied using the technique described by Knowles et al⁶ and Burden et al.¹

The Scotchcast boot is a well-padded cast cut away at the ankle (see Figures 1 and 2). It is made removable by cutting away the cast over the dorsum of the foot and making a closure of padding and tape with Velcro® straps. Windows are cut over the ulcers as needed. For large heel ulcers, a removable heel-cap of fiberglass is added. The boot is worn with a cast sandal to increase patient mobility; the Scotchcast protects the ulcer from any pressure while keeping the patient ambulant. Patients were followed at weekly intervals, at which time the wounds were evaluated and debrided if necessary.

Statistical analysis. All descriptive data are presented as mean ± standard deviation. An Analysis of Variance (ANOVA) was used to compare mean age, duration of diabetes, and healing time based on depth. Post hoc tests (Tukey's Studentized Range Test) were used to test differences between different variables. Pearson's test was used to analyze the association between continuous variables (time to healing and wound size) and Student's t-test for independent samples compared differences in time to healing by gender. For all analyses, an alpha level of 0.05 was considered statistically significant.⁷