Plantar pressures in diabetic patients with foot ulcers which have remained healed.

Aims: The recurrence of foot ulcers is a significant problem in people with diabetic neuropathy. The purpose of this study was to measure in-shoe plantar pressures and other characteristics in a group of neuropathic patients with diabetes who had prior foot ulcers which had remained healed.
Methods: This was an epidemiological cohort study of patients from diabetes clinics of two Swedish hospitals. From a database of 2625 eligible patients, 190 surviving patients with prior plantar ulcers of the forefoot (hallux or metatarsal heads) caused by repetitive stress were identified and 49 patients agreed to participate. Barefoot and in-shoe plantar pressures were measured during walking. Data on foot deformity, activity profiles and self-reported behaviour were also collected.
Results: Mean barefoot plantar peak pressure at the prior ulcer site (556 kPa) was lower than in other published series, although the range was large (107-1192 kPa). Mean in-shoe peak pressure at this location averaged 207 kPa when measured with an insole sensor. Barefoot peak pressure only predicted approximately 35% of the variance of in-shoe peak pressure, indicating variation in the efficacy of the individual footwear prescriptions (primarily extra-depth shoes with custom insoles).
Conclusions: We propose that the mean value for in-shoe pressures reported in these patients be used as a target in footwear prescription for patients with prior ulcers. Although plantar pressure is only one factor in a multifaceted strategy to prevent ulcer recurrence, the quantitative focus on pressure reduction in footwear is likely to have beneficial effects.