Pilot study on the significance of random intrasite placement of the Semmes–Weinstein monofilament

Abstract

The possible effect of random intrasite placement on the outcome of the Semmes-Weinstein monofilament (SWF) test is not known. We sought to determine the significance of this variable in the diagnosis of loss of protective sensation (LOPS) in patients with diabetes. Forty-five patients with diabetes with history of pedal ulceration (group 1), 81 patients with diabetes without history of ulceration (group 2) and 21 non-diabetic controls (group 3) were studied. The three original sites of the International Consensus on the Diabetic Foot at the hallux, first and fifth sub-metatarsal areas were divided into peripheral and interior zones resulting in a total of six zones. Mean total scores of monofilament test were significantly lower in peripheral zones as compared with interior zones of both feet in all three groups and affected the resulting percentage of loss of protective sensation. Intrasite monofilament placement can significantly affect monofilament test results and the diagnosis of loss of protective sensation. A model that corrects the effect of random intrasite placement is needed.