Background: Offloading is the cornerstone of treatment of plantar diabetic foot ulcers. It limits mobility with consequent psychological and cardiovascular side effects, and if devices are removed, healing is delayed.
Methods: We developed three non-removable techniques with increasing offloading potential (multilayer felt sole, felt-fiberglass sole, or total contact casts with ventral windows) and sensors built within. Smartwatch and web apps displayed pressure, temperature, humidity, and steps. They alerted patients, staff, and a telemedicine center when pressure limits (125 kPa) were exceeded. Patients were advised to walk as much as they had done before the ulcer episode. To evaluate the potential of this intervention, we enrolled 20 ambulatory patients in a randomized clinical trial. The control group used the same offloading and monitoring system, but neither patients nor therapists received any information or warnings.
Results: Three patients withdrew consent. The median time to healing of ulcers was significantly shorter in the intervention group compared with controls, 40.5 (95% confidence interval [CI] = 28-not applicable [NA]) versus 266.0 (95% CI = 179-NA) days (P = .037), and increasing ulcer area was observed less frequently during study visits (7.9% vs 29.7%, P = .033). A reduction of wound area by 50% was reached at a median of 10.2 (95% CI = 7.25-NA) versus 19.1 (95% CI = 13.36-NA) days (P = .2). Participants walked an average of 1875 (SD = 1590) steps per day in intervention group and 1806 (SD = 1391) in the control group.
Conclusions: Sensor-assisted wound therapy may allow rapid closure of plantar foot ulcers while maintaining patient's mobility during ulcer therapy.
Keywords: diabetic foot syndrome; diabetic foot ulcer; offloading device; sensor-assisted wound therapy; sensors; total contact cast.