For the millions of people living with diabetes, a small ulcer on the bottom of the foot is never just a wound. Plantar diabetic foot ulcers (DFUs) are a leading cause of hospitalization, infection, and lower-limb amputation worldwide. Yet one of the most powerful tools for healing them is also one of the most overlooked: offloading, the practice of mechanically redistributing pressure away from the wound. Understanding why offloading works — and which methods work best — is central to modern diabetic foot care.
Why Pressure, Not Just Sugar, Drives Foot Ulcers
Most plantar DFUs develop and persist because of high mechanical stress on the sole of an insensate foot. When peripheral neuropathy removes the protective sensation of pain, a person continues to walk on tissue that is being repeatedly damaged with every step. As the 2023 International Working Group on the Diabetic Foot (IWGDF) guideline states plainly, reducing this mechanical tissue stress is “arguably the most important of multiple interventions needed to heal diabetes-related foot ulcers.” No dressing, antibiotic, or advanced therapy can fully compensate for a wound that is being re-injured thousands of times a day.
This is why offloading sits at the foundation of wound care. The goal is to lower the repetitive plantar pressure and shear forces concentrated at the ulcer site, giving fragile tissue the mechanical rest it needs to close.
The Gold Standard: Non-Removable Knee-High Devices
Decades of research point to a clear hierarchy of offloading options. According to the 2023 IWGDF guideline, the first-choice treatment for a neuropathic plantar forefoot or midfoot ulcer is a non-removable knee-high offloading device — either a total contact cast or a removable walker rendered non-removable.
A 2023 systematic review and meta-analysis of 194 studies quantified the advantage. Pooling 14 controlled trials, the authors found that non-removable devices increased the likelihood of an ulcer healing compared with removable devices (risk ratio 1.24, 95% CI 1.09–1.41), while also improving adherence and reducing infections. A separate review described knee-high devices as “gold” in closing the foot ulcer gap, noting they are typically not only more effective but also safer, faster, and cheaper than alternatives such as therapeutic footwear alone.
Why “Non-Removable” Matters So Much
The decisive ingredient is not the cast material but the fact that the patient cannot take it off. Research on adherence makes the point vividly. In one multicenter study using activity monitors, patients prescribed removable cast walkers wore them for only about 34% of their weight-bearing steps — meaning that for two of every three steps, the wound received no protection at all. A non-removable device closes that gap by enforcing continuous offloading, which is likely the main reason it outperforms its removable counterpart.
When the Gold Standard Isn’t Possible
Non-removable devices are not appropriate for everyone. They are generally avoided when infection or significant ischemia is present, and some patients cannot tolerate them. The IWGDF guideline therefore outlines a stepwise pathway. If a non-removable device is contraindicated or not tolerated, a removable knee-high or ankle-high device is the second choice. If no device is available, appropriately fitting footwear combined with felted foam is the third option.
Felt padding deserves particular attention as an adjunct. A 2025 retrospective study of 59 patients with neuropathic plantar ulcers treated with multilayer felt padding reported that 78% healed within 12 weeks, with a median healing time of 45 days. The authors positioned felt padding as a useful tool especially for patients suspected of low adherence to wearing a removable device.
Surgical Offloading for Stubborn Wounds
When mechanical offloading fails to heal a wound, the source of pressure can sometimes be corrected surgically. The guideline notes that procedures such as Achilles tendon lengthening, metatarsal head resection, or joint arthroplasty may help forefoot ulcers, while a digital flexor tenotomy can address ulcers on the toes caused by flexible deformities. In the meta-analysis, adding tenotomies or tendon lengthening to a device improved healing for these specific ulcer locations, though each carries its own trade-offs, such as new transfer lesions.
Closing the Implementation Gap
Perhaps the most striking theme in the recent literature is not what works, but how rarely the best option is used. Despite strong evidence, knee-high devices are prescribed and accepted far less often than they should be, a problem researchers describe as an “implementation gap” rooted largely in outdated misperceptions. This has prompted interest in personalized offloading — modular devices, advanced manufacturing, and embedded sensors that give real-time feedback on pressure and adherence — to make effective treatment more tolerable and better matched to each patient.
Key Takeaways
Plantar diabetic foot ulcers are primarily a mechanical problem, and offloading is the cornerstone of healing them. The evidence consistently favors non-removable knee-high devices as the first choice, chiefly because they guarantee adherence that removable devices cannot. Removable devices, therapeutic footwear with felt padding, and selected surgical procedures provide a clear secondary pathway when the gold standard is unsuitable. Across every option, the underlying principle is the same: a wound that is protected from repetitive pressure is a wound that can finally heal.
References
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.
Lazzarini PA, Armstrong DG, Crews RT, et al. Effectiveness of offloading interventions for people with diabetes-related foot ulcers: A systematic review and meta-analysis. Diabetes/Metabolism Research and Reviews. 2023;40(3):e3650.
Lazzarini PA, Jarl G. Knee-High Devices Are Gold in Closing the Foot Ulcer Gap: A Review of Offloading Treatments to Heal Diabetic Foot Ulcers. Medicina (Kaunas). 2021;57(9):941.
Ababneh A, Finlayson K, Edwards H, Lazzarini PA. 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):e002640.
Jarl G, Rusaw DF, Terrill AJ, Barnett CT, Woodruff MA, Lazzarini PA. Personalized Offloading Treatments for Healing Plantar Diabetic Foot Ulcers. Journal of Diabetes Science and Technology. 2023;17(1):99–106.
Tong KP, Obradovic KN, Acciani AL, Wortzman N, Kigner S. The Use of Multilayer Felt Padding in the Treatment of Neuropathic Plantar Foot Ulcerations. Journal of the American Podiatric Medical Association. 2025;115(1).
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