The utility of Vibratip in accurate identification of loss of protective sensation in the contralateral foot of patients admitted with a diabetic foot ulcer

Abstract

Background and aimsDiabetic foot ulcer (DFU) is a debilitating complication of type 2 DM. Complexity of foot examination often precludes proper clinical assessment of the foot during routine evaluation. We assessed the utility of novel device, vibratip, both singly and in combination with standard bedside tools for assessment of loss of protective sensation. Methods75 patients admitted with DFU were included in the study. Clinical examination of the contralateral foot was done - temperature perception, vibration, pinprick sensation, Achilles tendon reflex and Neuropathy disability score were assessed. Testing using 10 g Monofilament, Vibratip and biothesiometer were also done. Considering the biothesiometer as the reference standard, three bedside tests (Vibratip, 10 g monofilament and 128 Hz tuning fork) were compared against it singly and in combinations. ResultsWhen compared against biothesiometer, vibratip performed significantly well with a positive predictive value of 90.3% and specificity of 84.2%. Sensitivity, however, was only 50%. On combining bedside tests, the best combination strategy was seen with vibratip and 10 g monofilament, which improved the sensitivity to 62.5%. Combining all three bedside tests further improved sensitivity to 64.3%. ConclusionAll the patients with an at-risk foot may not be identified with vibratip alone. Nevertheless, an abnormal result is almost always associated with loss of protective sensation, and such persons should be suitably educated. LimitationsDue to small size of the study population, it is not possible to generalize the findings to all patients with diabetes mellitus. A larger study would be required to provide more confirmatory findings.