Diabetic foot ulcers (DFUs) remain one of the most consequential complications of diabetes mellitus. Globally, an estimated 6.3% of adults with diabetes have a foot ulcer at any given time, and the lifetime risk reaches 19%–34%. These wounds precede roughly 80% of lower-extremity amputations in people with diabetes, and the five-year mortality after a major amputation exceeds 70% (Armstrong et al., Diabetes Care, 2023). Among modifiable factors determining whether a plantar ulcer heals, mechanical offloading is the single most powerful intervention.
Why Offloading Matters
Most plantar diabetic foot ulcers arise from repetitive mechanical stress on a neuropathic foot that no longer perceives injury. Each step concentrates pressure under a deformed metatarsal head, a Charcot prominence, or a previously ulcerated site. Without redistribution of that load, granulation tissue is repeatedly disrupted and epithelialization stalls. The biomechanical principle behind every offloading device is the same: increase the weight-bearing surface area, alter gait mechanics, or eliminate stance-phase loading on the wound altogether (Bus et al., Diabetes/Metabolism Research and Reviews, 2024).
The 2023 update of the International Working Group on the Diabetic Foot (IWGDF) offloading guideline reinforces this principle with a rigorous evidence base, drawing on a systematic review of 194 studies and 35 meta-analyses to provide GRADE-rated clinical guidance.
The Hierarchy of Offloading Devices
Non-Removable Knee-High Devices
The IWGDF 2023 guideline recommends a non-removable knee-high offloading device — either a total contact cast (TCC) or a removable walker rendered irremovable — as the first-choice intervention for a neuropathic plantar forefoot or midfoot ulcer. A 2023 systematic review and meta-analysis of 12 controlled trials including 591 patients reported that TCCs produced higher healing rates (RR 1.22; 95% CI 1.11–1.34) and shorter healing times than removable alternatives, with healing of uncomplicated neuropathic ulcers often occurring within 6–8 weeks (Wang et al., Frontiers in Endocrinology, 2023). By immobilizing the ankle, a knee-high device redistributes load up the calf and away from the plantar surface, while non-removability eliminates the principal threat to healing: intermittent unprotected weight-bearing.
Removable Knee-High and Ankle-High Devices
When non-removable devices are contraindicated — for example, in the presence of moderate to severe infection, ischemia, or significant exudate requiring frequent dressing changes — a removable knee-high walker is the recommended second choice. Ankle-high devices, including healing sandals and forefoot offloading shoes, are reserved for cases in which knee-high devices are not tolerated, recognizing that they offload less effectively (Lazzarini et al., Diabetes/Metabolism Research and Reviews, 2024).
Adjunctive Techniques
Felted foam, surgical offloading procedures (such as Achilles tendon lengthening or metatarsal head resection), and rigid rocker-bottom shoes can complement device-based offloading in carefully chosen patients. The IWGDF guideline supports surgical offloading for plantar metatarsal head ulcers that fail to heal with conservative care.
The Adherence Gap
The clinical effectiveness of any removable device depends entirely on whether the patient wears it. A 2022 scoping review found that only 28%–60% of patients meet the ≥80% adherence threshold typically required for healing, and a study using dual activity monitors revealed that self-reported adherence (median 90% of daily steps) substantially overestimates objectively measured adherence (median 35%) (Jarl et al., Diabetes & Metabolic Syndrome, 2022). Barriers are predominantly psychosocial rather than biological — device weight, aesthetics, postural instability, fear of falling, discomfort, and limitations on daily activities. This is the strongest argument for non-removable devices when clinically appropriate: they remove adherence from the equation.
Emerging Approaches
Smart insoles and intelligent offloading systems represent a growing area of innovation. A proof-of-concept randomized study of a pressure-sensing smart insole that alerted patients when threshold pressures were exceeded reported a 71% relative reduction in plantar ulcer recurrence at sites identified by the system (Abbott et al., The Lancet Digital Health, 2019). Cyclic pressure-offloading insoles that dynamically redistribute load are also under investigation, addressing the limitation that conventional devices apply a static pressure profile to a dynamic gait.
Clinical Takeaways
Three principles emerge from the current evidence base. First, mechanical offloading is foundational; without it, advanced wound therapies rarely succeed in plantar neuropathic ulcers. Second, device selection should follow the IWGDF hierarchy, with non-removable knee-high devices preferred whenever feasible. Third, adherence is the rate-limiting variable for any removable device, and clinicians should objectively assess wear time and address psychosocial barriers as part of routine wound care. Intelligent offloading technologies may extend pressure redistribution beyond the clinic, particularly for ulcer prevention in high-risk patients.
References
- Armstrong DG, Tan TW, Boulton AJM, Bus SA. Etiology, Epidemiology, and Disparities in the Burden of Diabetic Foot Ulcers. Diabetes Care. 2023;46(1):209–221.
- Bus SA, Armstrong DG, Crews RT, et al. Guidelines on offloading foot ulcers in persons with diabetes (IWGDF 2023 update). Diabetes/Metabolism Research and Reviews. 2024;40(3):e3647.
- Wang L, Shi P, Xu Z, et al. Total contact casts versus removable offloading interventions for the treatment of diabetic foot ulcers: a systematic review and meta-analysis. Frontiers in Endocrinology. 2023;14:1234761.
- Lazzarini PA, Jarl G, Gooday C, et al. Effectiveness of offloading interventions for people with diabetes-related foot ulcers: A systematic review and meta-analysis. Diabetes/Metabolism Research and Reviews. 2024;40(3):e3650.
- Jarl G, van Netten JJ, Lazzarini PA, et al. Offloading treatment in people with diabetic foot disease: A systematic scoping review on adherence to foot offloading. Diabetes & Metabolic Syndrome. 2022;16(5):102493.
- Abbott CA, Chatwin KE, Foden P, et al. Innovative intelligent insole system reduces diabetic foot ulcer recurrence at plantar sites: a prospective, randomised, proof-of-concept study. The Lancet Digital Health. 2019;1(6):e308–e318.
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