Offloading the High Risk Foot

Strategies for Reduction of Plantar and Peripheral Pressure Areas for Treatment and Prevention of Skin Breakdown

Introduction

This presentation will provide strategies for pressure reduction of high risk foot conditions such as peripheral neuropathy, peripheral vascular disease and rheumatoid arthritis. It is vital to understand that high risk foot conditions are multifactorial, and that pressure reduction alone will not provide adequate prevention or treatment, but is a necessary component of high risk foot management.

Peripheral Neuropathy

Sensory neuropathy causes significant reduction of awareness of pressure.

Pressure is a factor in 90% of ulcers related to sensory neuropathy.

Control of pressure reduces the risk of skin breakdown.

Pressure reduction is vital to healing when skin breakdown has occurred.

There are many causes of peripheral neuropathy, with diabetes being primary but not exclusive.

Peripheral Vascular Disease

Peripheral vascular disease reduces the blood supply to the skin affecting the ability to repair damage resulting from excessive pressure.

Pressure reduction improves the local vascularity by limiting mechanical and hydrostatic forces that impede blood supply.

Rheumatoid Arthritis

Rheumatoid arthritis can result in significant osseus deformities.

These deformities make shoe fitting a challenge, and can lead to pressure ulcerations.

Typical risk areas include metatarsal heads and dorsal phalangeal joints as the toes frequently develop hammer deformities and the metatarsal heads become exposed due to plantar pad migration and loss of toe levers.

Shoe Fitting

Proper shoe fitting is essential for risk management with the high risk foot.

Local reduction of vascularity can result from even small amounts of pressure.

Shoes should be fit to ensure no pressure against the toes or metatarsal joints and should easily accommodate foot orthoses.

Shoes with obvious seams should be avoided. Shoe size can be assessed by comparing the

shoe insole against the foot without the shoe on. This frequently demonstrates the inappropriateness of the width and depth of the shoe.

Shoe fitting Challenges

Patients with peripheral neuropathy frequently complain that proper fitted shoes feel too large. This complaint is common. The neuropathic foot will better sense shoes that are too small, so proper fitting shoes will feel big and cumbersome. Educating the patient with peripheral neuropathy about proper shoe fit improves compliance and understanding, and allows the patient to feel like they are more in control of their own condition.

Shoe Fitting Challenges

Patients with rheumatoid deformities require significant depth and width to accommodate hammer toes.

Shoes will have to be fitted to allow foot orthoses for reduction of metatarsal head pressure.

Velcro closures may be necessary to allow the patient to donn and doff the shoes.

Foot Orthoses for Pressure Management

Foot orthoses can reduce pressure on risk areas of the feet like metatarsal heads or the ends of the toes.

Foot orthoses for the high risk foot should have little or no corrective forces, as the neuropathic patient cannot perceive excessive pressure resulting from attempts at biomechanical correction.

Soft materials are recommended, and reassessment of these orthoses is required to ensure adequate padding remains as wear and tear are applied.

Offloading Devices for Treatment of Pressure Ulcerations

Offloading devices can include total contact casts, removable cast walkers with custom insoles and healing sandals.

Each of these devices have been shown to significantly improve healing times.

Device selection criteria depends on each individual and their ability to safely ambulate.

Total Contact Casts

Total contact casts have long been the method of choice for offloading pressure ulcers.

Primary advantage is forced compliance Require highly skilled cast technician to achieve

consistent results. Contraindicated for patients with infection. Expensive treatment as cast requires removal and

replacement with every clinical visit.

Removable Cast Walkers

Cost effective, as wound can be inspected without need for new device.

Not contraindicated for infection. Pressure reduction is excellent. Can be difficult for patients with

ambulation problems. Requires provider skilled in provision of

soft custom orthoses. May require height accommodation for

contralateral shoe.

Total Contact Casts versus Removable Cast Walkers

Studies have been published comparing the effectiveness of total contact casts to commercially available removable cast walkers.

These studies have shown that the total contact cast can be more effective for offloading pressure ulcers, but data collected from the removable cast walkers did not incorporate a custom foot orthosis, an essential component of the removable cast walker.

Therefore these studies are not useful comparisons for the methods suggested in this presentation.

Healing Sandals

Not as effective as removable cast walkers.

Less environmental protection. Less cumbersome, easier to ambulate for

some clients. Requires skilled provider. The Darco© Wound Care Shoe System is

the healing sandal of choice, as it allows for inclusion of a custom foot orthosis, and incorporates an excellent forefoot rocker.

Selection of Removable Cast Walkers

Several manufacturers supply removable cast walkers with a variance of characteristics.

The Aircast© Walker provides excellent protection, but is very rounded on the plantar surface, and can be hard to walk in for some clients.

The DeRoyal© Walker comes with a kit for making the custom insole, and is low profile, reducing the need for contralateral compensation.

The Royce© Walker employs removable plugs to reduce pressure at the ulcer site, but may create a hammock effect around the wound.

Example of Healing With a Removable Cast Walker

44 year old male with diabetes. 280 lbs., ceased smoking Feb.

2001. Vascular supply intact. Ulcer is located at first metatarsal

head. Picture taken Oct. 4, 2002.

Provision of Removable Cast Walker

Walker will be fitted with soft custom liner moulded to the foot.

The ulcer itself will be relieved locally to reduce plantar pressure.

This liner will be fitted into the removable cast walker.

Dispensing the Removable Cast Walker

Safe ambulation is imperative.

Varieties of walkers are available, ensure the best available walker is used.

Functional leg length discrepancies may have to be accommodated on contralateral shoe.

Ensure that the patient can donn and doff the walker, or has adequate assistance to do so.

Follow-up

Ulcer has healed significantly.

Skin color is very good, no sign of infection.

Picture taken Oct. 16, 2002.

Conclusion

Pressure management is an essential adjunct to the treatment regime of those with high risk foot conditions.

Shoes can be an important part of prevention of pressure ulcerations, and depend on proper fit.

Foot orthoses can play a role in diminishing pressure areas on the plantar surface.

Pressure ulcerations can be treated with offloading devices such as healing sandals, removable cast walkers, and total contact casts.

Prevention and treatment of pressure ulcers can best be accomplished by an interdisciplinary team.