Why Offloading Sits at the Centre of Diabetic Foot Ulcer Care
Plantar diabetic foot ulcers (DFUs) are caused by repetitive mechanical stress on insensate skin. Without effective pressure redistribution, even the most advanced wound care products cannot reliably close a neuropathic ulcer. Offloading — the systematic reduction and redistribution of plantar pressure — remains the single most evidence-supported intervention for healing plantar DFUs and preventing their recurrence. The 2023 update of the International Working Group on the Diabetic Foot (IWGDF) guideline reaffirmed this principle and clarified the hierarchy of devices clinicians should consider.
The Hierarchy of Offloading Devices
The IWGDF 2023 offloading guideline, informed by a systematic review of 194 studies, recommends a stepwise approach for neuropathic plantar forefoot or midfoot ulcers (Lazzarini et al., 2024).
First Choice: Non-Removable Knee-High Devices
A non-removable knee-high device — either a total contact cast (TCC) or a removable walker rendered irremovable — is the recommended first-line treatment. By making the device non-removable, clinicians eliminate the most common reason offloading fails: inadequate wear time. A 2023 systematic review and meta-analysis of 12 studies and 591 patients found that TCCs produced significantly higher healing rates (RR 1.22, 95% CI 1.11–1.34) and shorter healing times (SMD −0.57, 95% CI −1.01 to −0.13) than removable walking casts or therapeutic footwear (Chen et al., 2023).
Second Choice: Removable Knee-High or Ankle-High Devices
When a non-removable device is contraindicated — for example, in the presence of significant ischaemia, active infection requiring frequent inspection, or unmanageable patient intolerance — a removable knee-high walker is the next preferred option. Knee-high designs reduce forefoot pressure more effectively than ankle-high devices because they restrict ankle motion and shift load proximally.
Third Choice: Footwear with Felted Foam
If no offloading device is available, appropriately fitted footwear combined with felted foam padding is recommended as a third-line strategy. Although less effective at lowering peak plantar pressure, this option can serve as a bridge while awaiting device fitting.
Adherence: The Hidden Determinant of Healing
Even when the right device is prescribed, healing depends on whether the patient actually wears it. Objective monitoring studies have repeatedly shown that patients with active DFUs wear removable cast walkers for only about one-third of their weight-bearing time, with adherence ranging from roughly 30% to 60% across cohorts in the United States, United Kingdom, and Middle East (Crews et al., 2016; Jarl et al., 2022).
Reported barriers include the perceived weight and bulk of the device, leg-length discrepancy with the contralateral limb, postural instability, work-related pressure to remove the device, and incompatibility with daily clothing. Practical mitigations — a contralateral shoe raise to equalize limb length, fall-prevention assessment, and the use of walking aids when needed — can meaningfully improve both stability and adherence. Smart walkers that record wear time and prompt patients with adherence reminders are an emerging strategy currently under investigation (Najafi et al., 2023).
Offloading After Healing: Preventing Recurrence
The clinical work does not end when the ulcer closes. Approximately 40% of healed DFUs recur within one year, and offloading remains central to long-term prevention (Armstrong et al., 2017). For people in remission, properly fitted therapeutic footwear with custom insoles is the cornerstone of preventive care.
Two important quantitative targets emerge from the literature. First, in-shoe footwear modifications guided by plantar pressure measurement — rather than fitted by appearance alone — have been shown to reduce ulcer recurrence by approximately 46% in adherent patients (Bus et al., 2016). Second, maintaining a mean in-shoe peak plantar pressure below 200 kPa, combined with footwear adherence above 80% of daytime hours, significantly reduces the odds of recurrence (Bus et al., 2018). Adherence remains the limiting factor: fewer than half of high-risk patients wear their therapeutic footwear for more than 60% of daytime hours.
Clinical Takeaways
The evidence converges on a clear set of principles for diabetic foot offloading. For an active plantar neuropathic ulcer, a non-removable knee-high device should be the default unless specifically contraindicated. When removable devices must be used, adherence should be measured rather than assumed, and modifiable barriers such as instability and limb-length discrepancy should be addressed directly. After healing, prevention rests on pressure-guided custom footwear, a measurable reduction in peak plantar pressure, and consistent daily wear. Each of these steps is supported by randomized trials and current international guidelines, and together they represent the most reliable mechanical lever clinicians have to lower the burden of diabetic foot disease.
References
- Lazzarini PA, Raspovic A, Prentice J, et al. Guidelines on offloading foot ulcers in persons with diabetes (IWGDF 2023 update). Diabetes/Metabolism Research and Reviews. 2024.
- Chen L, Sun S, Gao Y, Ran X. 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.
- Crews RT, Shen BJ, Campbell L, et al. Role and Determinants of Adherence to Off-loading in Diabetic Foot Ulcer Healing: A Prospective Investigation. Diabetes Care. 2016;39(8):1371–1377.
- Jarl G, van Netten JJ, Lazzarini PA, et al. Factors associated with adherence to using removable cast walker treatment among patients with diabetes-related foot ulcers. BMJ Open Diabetes Research & Care. 2022;10(1):e002701.
- Najafi B, et al. Taking a Load Off: User Perceptions of Smart Offloading Walkers for Diabetic Foot Ulcers Using the Technology Acceptance Model. Sensors. 2023;23(5):2768.
- Armstrong DG, Boulton AJM, Bus SA. Diabetic Foot Ulcers and Their Recurrence. New England Journal of Medicine. 2017;376(24):2367–2375.
- Bus SA, van Deursen RW, Armstrong DG, et al. Footwear and offloading interventions to prevent and heal foot ulcers and reduce plantar pressure in patients with diabetes: a systematic review. Diabetes/Metabolism Research and Reviews. 2016;32(Suppl 1):99–118.
- Bus SA, Waaijman R, Arts M, et al. Effect of custom-made footwear on foot ulcer recurrence in diabetes: A multicenter randomized controlled trial. Diabetes Care. 2013;36(12):4109–4116. (Long-term plantar pressure threshold analysis subsequently published 2018.)
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