For people living with diabetes, a foot ulcer is among the most serious complications of the disease. The estimated lifetime incidence of foot ulceration in people with diabetes ranges from 19% to 34%, and recurrence after healing is common — roughly 40% of patients develop a new ulcer within one year. Most of these wounds are neuropathic plantar ulcers that form on the sole of an insensate foot, where ordinary walking concentrates mechanical stress on tissue that can no longer signal pain. Because pressure is what creates these ulcers, relieving that pressure — a practice clinicians call offloading — is fundamental to healing them. The 2023 International Working Group on the Diabetic Foot (IWGDF) guideline describes offloading as arguably the most important of the multiple interventions needed to heal a diabetes-related foot ulcer.
Why Mechanical Stress Drives Diabetic Foot Ulcers
Diabetic peripheral neuropathy gradually erodes the protective sensation that normally warns a person of injury or excessive pressure. Without that feedback, a patient may walk for hours on a developing wound without discomfort. Neuropathy also contributes to foot deformity and altered gait, which raise plantar pressure under the metatarsal heads and other bony prominences. Repeated loading of these high-pressure areas damages tissue, and once the skin breaks down, continued weight-bearing prevents the wound from closing. This is why wound dressings, antibiotics, and good blood glucose control, although important, are not sufficient alone: as long as the ulcer bears mechanical stress with every step, healing is impaired. Reducing peak plantar pressure at the wound is therefore the central mechanical objective of treatment.
Total Contact Casting and the Hierarchy of Offloading Devices
The most thoroughly studied offloading method is the total contact cast (TCC), a well-moulded, minimally padded cast that distributes load across the entire lower leg and foot rather than the wound itself. A 2015 systematic review concluded that total contact casts produced better healing rates, shorter healing times, and greater reductions in ulcer size than other devices, while noting complications such as skin maceration, abrasion, and infection that require careful application and monitoring.
The 2023 IWGDF guideline organises offloading into a clear hierarchy. For a neuropathic plantar forefoot or midfoot ulcer, the first-choice treatment is a non-removable, knee-high offloading device — either a total contact cast or a prefabricated walker rendered irremovable. A removable knee-high or ankle-high device is the second choice when a non-removable device is contraindicated or not tolerated. Appropriately fitting footwear combined with felted foam is reserved as a third-choice option. When non-surgical offloading fails to heal a plantar ulcer, surgical approaches such as Achilles tendon lengthening or metatarsal head resection may be considered.
Removable or Non-Removable? The Role of Adherence
The difference between a removable and a non-removable device is not the cast material — it is human behaviour. A device that the patient can take off will, predictably, sometimes be taken off, and every unprotected step delivers full pressure to the wound.
The clinical impact is measurable. A 2023 analysis comparing patients in total contact casts with patients in removable cast walkers found that 93% of ulcers healed in the non-removable cast group, compared with 65% in the removable group. Among ulcers that healed, average healing time was about 77 days with the total contact cast versus 138 days with the removable walker. The same study recorded step activity and found that patients in removable walkers took more daily steps, supporting the long-standing explanation that removability undermines healing by allowing more loading of the wound. This is the central reason guidelines favour non-removable devices despite the convenience of removable ones.
A Gap Between Evidence and Everyday Practice
Despite consistent evidence, gold-standard offloading remains underused. A 2023 survey of prosthetic and orthotic practitioners in Sweden found that 86% provided modified off-the-shelf footwear with insoles for neuropathic forefoot ulcers — an approach guidelines specifically advise against as a primary treatment — while only 20% provided total contact casts and none provided non-removable knee-high walkers. The authors linked this pattern to limited awareness of which devices are considered the standard of care. Narrowing the gap between guideline recommendations and routine practice is widely viewed as an achievable way to improve ulcer outcomes.
Protecting the Foot After the Ulcer Heals
Wound closure is not the end of mechanical risk. Newly healed skin is fragile, and the deformities and pressure patterns that caused the original ulcer remain. The 2023 IWGDF prevention guideline recommends that patients at moderate-to-high risk be prescribed therapeutic footwear with a demonstrated plantar-pressure-relieving effect during walking, specifically to reduce the risk of recurrent plantar ulceration. A 2016 systematic review reached a similar conclusion, finding that the strongest evidence for preventing recurrence supports therapeutic footwear that relieves plantar pressure and is consistently worn, alongside daily monitoring of foot skin temperature. As with active treatment, the recurring theme is that controlling mechanical stress — and patient use of the prescribed device — determines the outcome.
Conclusion
Offloading is the mechanical foundation of diabetic foot ulcer care. The evidence consistently shows that distributing pressure away from the wound speeds healing, that non-removable knee-high devices outperform removable alternatives largely because they cannot be set aside, and that pressure-relieving footwear remains important long after a wound has closed. The key clinical takeaway is straightforward: a diabetic foot ulcer cannot reliably heal, or stay healed, while it continues to bear the load of every step.
References
- Armstrong DG, Boulton AJM, Bus SA. Diabetic Foot Ulcers and Their Recurrence. New England Journal of Medicine. 2017;376(24):2367–2375. doi:10.1056/NEJMra1615439
- 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. 2023;40(3):e3647. doi:10.1002/dmrr.3647
- de Oliveira ALM, Moore Z. Treatment of the diabetic foot by offloading: a systematic review. Journal of Wound Care. 2015;24(12):560–570. doi:10.12968/jowc.2015.24.12.560
- Wendland DM, Kline PW, Bohnert KL, Biven TM, Sinacore DR. Offloading of Diabetic Neuropathic Plantar Ulcers: Secondary Analysis of Step Activity and Ulcer Healing. Advances in Skin & Wound Care. 2023;36(4):194–200. doi:10.1097/01.ASW.0000919476.24220.cc
- Gigante I, Sigurjónsdóttir ED, Jarl G, Hellstrand Tang U. Offloading of diabetes-related neuropathic foot ulcers at Swedish prosthetic and orthotic clinics. Diabetes/Metabolism Research and Reviews. 2023;39(4):e3611. doi:10.1002/dmrr.3611
- Bus SA, Sacco ICN, Monteiro-Soares M, et al. Guidelines on the prevention of foot ulcers in persons with diabetes (IWGDF 2023 update). Diabetes/Metabolism Research and Reviews. 2023;40(3):e3651. doi:10.1002/dmrr.3651
- van Netten JJ, Price PE, Lavery LA, et al. Prevention of foot ulcers in the at-risk patient with diabetes: a systematic review. Diabetes/Metabolism Research and Reviews. 2016;32(Suppl 1):84–98. doi:10.1002/dmrr.2701
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