Predictive values of foot plantar pressure assessment in patients with midfoot deformity secondary to Charcot neuroarthropathy

Abstract

Aims: The principal aim of this study was to identify a cut-off point along the spectrum of peak plantar midfoot pressure that has an optimum combination of sensitivity and specificity to screen for neuropathic ulceration in patients with Charcot neuroarthropathy (CN).

Methods: A 1-year outcome study was performed in twenty-five patients with diabetes, affected with chronic CN midfoot deformity. Peak plantar pressure (PPP) and pressure/time Integral (PTI) in the midfoot region were registered. For selecting the optimal diagnostic cut-off points on the scale of pressure measurement, ROC curves were used.

Results: Twelve (48%) patients developed a plantar midfoot ulcer. Baseline PPP (24.04 ± 6.33 Vs. 12.85 ± 3.29 N/cm2) and PTI (11.89 ± 4.60 Vs. 5.42 ± 2.26 N/cm2/s) were significantly higher in the ulcerated group (p < .001 and p < .001, respectively). Using ROC analyses, optimal cut-off point for PPP was 16.45 N/cm2, yielding a sensitivity of 92% and a specificity of 85%; and for PTI, optimal cut-off point was 7.2 N/cm2/s, yielding a sensitivity of 92% and a specificity of 77%.

Conclusions: Patients with CN midfoot deformity with cut-off values for PPP of 16.45 N/cm2 and PTI of 7.2 N/cm2/s showed an elevated risk of neuropathic ulceration in the plantar area of the midfoot.