What are offloading modalities?

These are modalities that are employed to help off-weight/load an area of pressure to help give tissue time to heal without repetitive stress which leads to delayed wound healing.

What is the gold standard of offloading modalities?

Total contact cast is considered by diabetic foot specialists to be the gold standard off-weighting modality. This technique involves a molded and minimally padded cast that maintains contact with the entire plantar aspect of the foot and the lower leg. Total contact casting has shown to be successful in healing 75 to 100% of diabetic neuropathic ulcerations.. Healing time ranges from one month to eight weeks.

Coleman W, The Total Contact Cast, A Therapy for Plantar Ulceration on Insensitive Feet, JAPMA,1984;74:548-52.

Armstrong DC, Peak Foot Pressures Influence Healing Time of Diabetic Ulcers Treated with Total Contact Casting., J Rehabil Res Dev 1998;35:1-5.

When is offloading indicated?

All neuropathic ulcerations need to be offloaded. By definition, neuropathic ulcerations on the plantar aspect of the foot develop secondary to neuropathy and increase in plantar peak pressures along with shear stress. Hence decreasing the peak plantar pressures and transverse shear forces is the most appropriate treatment. This is accomplished by offloading the ulcer site.

How long should a patient be offloaded?

A patient should be off loaded as long as an ulceration persist and then should have accommodations made to shoe gear to help decrease the chances of re-ulceration.

What offloading modalities are available?

There are many offloading modalities available including but not limited to: the total contact cast, removable cast walkers, half shoes, felted foam, crutches, walkers, and wheel chairs. The patient must be kept in mind when choosing a certain modality because compliance is always a concern when an offloading device is used or when the patient is to be non weight bearing.

How do I choose the appropriate offloading device?

Assessment of the factors causing the ulceration must be taken into account. The patient?s compliance must also be taken into account with any modality employed.

The best offloading modality is one that patient will be most compliant with. This may often require a compromise between the physician and patient. Although the gold standard is a total contact cast, this may not be the most practical choice for many of your patients.

How do I apply a Total Contact Cast?

A well molded, minimally padded cast that maintains contact with the entire plantar aspect of the foot and lower leg should be applied to the patient. Total contact cast application is a technician dependent procedure and requires practice. It takes approximately 25-30 minutes to apply the cast.

Shaw JE, The Mechanism of Plantar Unloading in Total Contact Casts:Implications for Design and Clinical Use, Foot Ankle Int 1997;18:809-17.

How effective are offloading devices?

There are many published works that show that this is the best way to help heal chronic neuropathic ulcerations.

Hartsell HD., Fellner C., Saltzman CL. Pneumatic Bracing and Total Contact Casting Have Equivocal Effects on Plantar Pressure Relief. Foot and Ankle International 22:6 2001.

Baumhauer JF., Werey R., McWilliams JH., Shereff MJ.: A Comparison Study of Plantar Foot Pressures in a Standard shoe, Total Contact Cast and Prefabricated Pneumatic Walking Brace. Foot and Ankle Int 18:26-33. 1997

Lavery LA., Vela SA., Lavery DC., Quebedeaux TL.: Reducing Dynamic Foot Pressures in High Risk Diabetics with Foot Ulcerations: a Comparison of Treatment. Diabetes Care19:818-821, 1996.

Is felt-to-foam effective?

Felt/foam dressings have shown to have success in off-weighting plantar neuropathic ulcerations and lowering peripheral pressure on the skin adjacent to the ulceration. This is a relatively easy and quick modality to use when trying to offload plantar ulcerations. Felt/Foam can be combined with another offloading modality like a below-the-knee walking boot.

Armstrong DG, Liswood PJ., Todd WF., Potential Risks of Accommodative Padding in the Treatment of Neuropathic Ulcerations. Ostomy/Wound Management 41:7 1995.

David G. Armstrong, DPM, et al. , WOUNDS 2000; 12(6 suppl B): 30B-34B (review Article)