In patients with diabetic peripheral neuropathy, the existence of a minor lesion is the strongest predictor of a plantar foot ulcer recurrence, according to findings published in Diabetes Care.
Additionally, researchers found that the use of preventive footwear was protective against the recurrence of plantar foot ulcers.
Using data obtained from a randomized controlled trial on the effectiveness of preventive footwear, researchers evaluated 171 patients meeting the following criteria: presence of diabetes, peripheral neuropathy, a newly healed plantar foot ulcer and a prescription for custom-made footwear designed to prevent ulcers.
For the study, patients were enrolled at 10 participating sites. The researchers used 10 g Semmes-Weinstein monoï¬lament and vibration perception threshold testing to verify the loss of protective sensation resulting from peripheral neuropathy.
The study’s primary outcome was plantar foot ulcer recurrence within 18 months. Plantar foot ulcer was defined as a full-thickness skin lesion penetrating through the dermis at the plantar side of the foot. Photographs were taken at each study visit or at such time as an ulcer was observed and were independently assessed by three diabetic foot experts.
The researchers created a multivariable, multilevel logistic regression model of plantar foot ulcer recurrence, which included the following: demographic data, disease-related factors, existence of minor lesions, barefoot and in-shoe plantar peak pressure, footwear compliance and number of strides per day.
The investigators found recurrent ulcers in 71 patients. They identified the following as significant independent predictors: existence of minor lesions (OR=9.06; 95% CI, 2.98-27.57) daily variation in stride count (OR=0.93; 95% CI, 0.89-0.99) and combined duration of past foot ulcers (OR=1.03; 95% CI, 1.00-1.06). For the 41 recurrences thought to be caused by undetected repetitive trauma, the significant independent predictors were the existence of minor lesions (OR=10.95; 95% CI, 5.01-23.96), in-shoe peak pressure <200 kilopascal (kPa) with adherence to footwear >80% (OR=0.43; 95% CI, 0.2-0.94), barefoot peak pressure (OR=1.11; 95% CI, 1-1.22) and daily variation in number of strides (OR=0.91; 95% CI, 0.86-0.96).
“The study showed that diabetic patients with plantar foot ulcer recurrence can be properly classified based on a combination of disease-related, biomechanical and behavioral risk factors,” the researchers wrote. “Furthermore, clear targets for prevention of ulcer recurrence have been obtained.”