Department of Podiatry

An Introduction to the Total Contact Cast & Ambulatory Fibreglass Boot

The following webpages include information about two types of rigid casting used in podiatry - the Total Contact Cast (TCC) and the Ambulatory Fibreglass Boot (AFB). Below is an introduction to the significance in treating foot ulceration, with indications, contraindications, advantages, disadvantages and patient instructions for each. Linked to this page are comprehensive pictorial guides to application of each of these casts.  Total Contact Cast Application  Ambulatory Fibreglass Boot Application

Introduction

Diabetes Mellitus is a common disease affecting more than 350 000 Australians in 1990 and is estimated to affect 900 000 Australians by the year 2000. Diabetes Mellitus is a condition that has both personal and public health implications. On an individual level Diabetes Mellitus may have enormous emotional, social and economical and physical effects on the individual. Payne &Scott (1997) estimated the annual total inpatient cost for diabetic foot disease in Australia to be $48 - $53 million indicating that Diabetes Mellitus is a financial dilemma for the public health system.

The treatment of diabetic foot ulcers has been a difficult task for Podiatrists and other health professionals in the past. The introduction of Total Contact Casting and Ambulatory Fibreglass Boots as a method of neuropathic ulcer treatment has allowed effective short term healing of plantar wounds by effectively reducing mechanical stresses and pressures on the plantar surface of the foot. Total Contact Casts and Ambulatory Fibreglass Boots allow the patient to be ambulatory and reduces lengthy and expensive hospital costs associated with complete bed rest, nursing care and lower limb amputations. These treatment methods also allow the patient to maintain employment, so there is no income loss for the individual.

Over the years there has been a lot of research undertaken that investigates the effectiveness of Total Contact Casts in the treatment of neuropahtic ulcers. The results in Table.1 prove that the Total Contact Cast reduces the healing rate of neuropathic ulcers. The average healing time from the studies examined is 6.1 weeks. Similarly, the Ambulatory Fibreglass Boot has also shown to reduce healing rates of neuropathic lesions in some cases. However, unlike the Total Contact Cast little research has been conducted using this method of treatment. The average healing time for Ambulatory fibreglass Boots taken from the literature available is 10.7 weeks (Table .1). This has lead researchers to believe that the Total Contact Cast may be the treatment of choice for neuropathic ulcers.

TOTAL CONTACT CAST (TCC)	HEALING RATES (mean healing time	AMBULATORY FIBREGLASS BOOT (AFB)	HEALING RATES (mean healing time)
Borssen and Lithner (1989)	10 weeks	Burden, Jones, Jones & Blandford (1993)	3 months
Gilbey (1991)	4 weeks	Gilbey (1991)	4-6 weeks
Diamond, Mueller & Delitto (1993)	6 weeks	Jones (1990) (Good diabetes control; HbAlc 7% or less)	6.1 weeks
Birke, Novick, Coleman, Patout (1991). Unpublished research.	6 weeks	Jones (1990) (Poor diabetes control; HbAlc 7.1% or more)	19.8 weeks
Walker, Helm & Pullium (1985)	4.4 weeks (Forefoot ulcers)
Boulton, Bowker, Gadia, Lennerman, Caswell, Skyler, Sosenko (1986)	6 weeks
Sinacore, Mueller, Diamond, Blair, Drury & Rose (1987)	6.2 weeks

Table 1: Average healing rates of neuropathic ulcers using TCC & AFB.

THE TOTAL CONTACT CAST

The aim of the Total Contact Cast is to immobilise the foot in order to reduce the vertical forces during gait thus allowing the plantar ulcer or pre-ulcerous lesions to heal. Total Contact Casts also promote healing by controlling lower leg and foot odema and protecting the foot from trauma. (Kominsky 1994).

INDICATIONS FOR TOTAL CONTACT CAST
1. Plantar neuropathic ulcers.
2. The post-operative surgical foot.
3. Active Charcot neuropathic foot.

CONTRAINDICATIONS FOR TOTAL CONTACT CAST
1. Active or acute soft tissue infection.
2. Abcesses, osteomyelitis & gangrene.
3. Ulcer depth greater than ulcer width.
4. Fragile skin
5. Excessive leg or foot swelling
6. Patient unwilling too have cast on extremity
7. Patient unable to comply with follow-up visits
8. Blind
9. Obese
10. Ischaemia ulcers with a doppler pressure < 0.4
11. Patients prone to falls have an increased risk of falling due to the Limb length discrepancy created by the cast.
12. The cast creates a limb length discrepancy which may possibly induce hip and back pain.
(Sinacore, 1988)

ADVANTAGES
1. Reduces healing time of plantar ulcers.
2. Allows patient to maintain ambulation.
3. Reduces excessive plantar pressures.
4. Protects foot from further trauma.
5. Controls odema.
6. Allows patient to continue working.
7. Cost effective.
8. Doesn't require as regular changing compared to other modalities.
(Sinacore, 1988)

DISADVANTAGES
1. Cast cannot be removed.
2. Unable to visually assess for infection or ulcer progress until cast is removed.
3. Joint stiffness and muscle atrophy if immobilization is prolonged
4. Possible skin abrasion or new ulcerations if cast is poorly applied or not monitored
5. Possible foul odour if drainage is excessive.
6. Digital fungal infections due to moist environment in cast.
7. Possible complications due to undiagnosed osteomyelitis after cast is applied.
(Sinacore, 1988)

 Total Contact Cast Application

PRECAUTIONS

Thorough training and practice in cast application is required to ensure success and to reduce possible complications associated with immobilizing an insensate foot.

"Skill in plastercraft is not to be learned from books but only by continuous repitition..One who regards the application of plasters as a menial task is advised to transfer his attention to another speciality" - John Charnley (1950)

The key to minimising potential side effects is strict monitoring of the ulcer, observing the patient's tolerance to the cast and most importantly careful application of the Total Contact Cast. Unless the patient is willing to comply with regular follow up visits casting should not be implemented.
(Sinacore, 1988)

PATIENTS INSTRUCTIONS

The patient must be supplied with a thorough list of written instructions on how to look after the cast and what complications to look out for whilst wearing the cast.

These include;

1. Walk as little as possible. This will put less pressure on the wound thus allowing it to heal faster.
2. The leg with the cast will be longer than the other leg therefore this may put strain on the hip and back if you walk too much.
3. You will be less stable when wearing the cast so the chances of falling are increased. The less you walk the less likely you are to fall. Be careful on slippery or uneven ground.
4. You may wish to use a walking stick for added stability. If you were unsteady before the cast you should use a walker.
5. The cast must not get wet. Take sponge baths instead of normal bathing or showering.
6. Notify the Podiatrist or General Practitioner if any of the following occur;
Any loosening or excessive mobility of the foot in the cast. A space of more than _ inch between the cast and leg is too much.
A smell coming form the cast may indicate infection that started after the cast was put on.
Any sudden tenderness in the inguinal lymph nodes.
Any sudden increase in body temperature, fever or blood sugar levels.
Any pain or discomfort.
Any dents, cracks or other damage to the cast. These may apply dangerous levels of pressure to the leg/foot.
Any drainage on the outside of the cast, particularly in regions not adjacent to the ulcer.
Excessive swelling of the leg or foot, causing the cast to become too tight.

THE AMBULATORY FIBREGLASS BOOT (SCOTCHCAST BOOT)

The aim of the Ambulatory fibreglass Boot is to redistribute foot pressures over the entire surface area of the sole of the foot thereby removing direct pressure from the wound site. It has proven to be effective in treating neuropathic wounds in some cases however as previously mentioned there has been little published research into the healing times associated with its use.

INDICATIONS FOR THE USE AMBULATORY FIBREGLASS BOOT

1. All types of neuropathic ulcers.

2. Neuropathic ulcers under the 1st metatarsal head and those under the hallux respond
well to this treatment. Ulcers under the lesser metatarsal heads also respond well to
treatment. The heel is the most difficult to treat.

3. Mixed neuropathic/ischaemic ulcers may be treated with Ambulatory fiberglass boots however the degree of ischaemia will be the limiting factor as to whether this treatment can be used.

CONTRAINDICATIONS FOR THE AMBULATORY FIBREGLASS BOOT.

1. Ambulatory fibreglass boots are unsuitable for ulcerations which are wider than they are deep. If the ulcer is deeper than it is wide the surface of the ulcer may epithelialise before the base of the ulcer has time to heal. The premature closing of the ulcer would leave a cavity beneath the skin, increasing the potential for abscess formation.
(Kominsky 1994)

2. Certain dorsal and digital ulcers which are inappropriate due to their location.

3. If the patient has an Ankle/Brachial Index (ABI) of 0.35 or less or is diabetic and
has an ABI of 0.45 or less then this treatment is contra-indicated as these ulcers will
probably not heal. (Wilson 1991).

ADVANTAGES

1. Redistribution of foot pressures.
2. Custom built to suit the individual.
3. Rigid and lightweight.
4. Removable for redressing, bathing and sleeping.
5. Patient remains ambulatory.
6. Decreased healing time according to literature.
7. Ability to assess progress of the wound.
8. Inexpensive compared to hospital costs.
(Wilson 1991)

DISADVANTAGES

1. Unaesthetic, bulky and hot
2. Expensive
3. May require an orthotic and possibly specialist footwear.
4. Requires specialist application and therefore is not suitable for every clinical situation.
5. Minimal use on digital ulceration.
6. Contra-indicated in cases of ischaemia.
7. Difficult to walk in due to the limb length discrepancy the cast creates.
8. May increase the instability of patient therefore increase the number of falls.
(Wilson 1991)

 Ambulatory Fibreglass Boot Application

PATIENT INSTRUCTIONS

1. Patients should refrain from vigorous activities which could interfere with healing of the ulcer or cause fractures in the cast due to its lightweight, strong and water resistant properties.

2. Patients may swim, bathe or shower when clinically indicated.

3. Patients should be cautious against accumulation of foreign materials such as sand under the cast. Foreign objects may cause further irritation and cause other ulcerations to develop or cause infection of the existing ulcer if bacteria enters the wound.

4. If the cast becomes wet it should be dried with towels or a hair dryer if necessary.

5. Prolonged or frequent wetting of the cast without drying may produce macerated skin. This is the most frequent complication noticed with the Ambulatory fibreglass boot. (Albert, 1981).

1. Albert SF, 1981, Scotch Cast - An improved Fiber Glass Casting Material for use in Podiatry, Journal of the American Podiatry Association, Vol 71 No 6, June, Pg 338-340.

2. Borssen B, Lithner F, 1989, Plaster Casts in the Management of Advanced Ischaemic and Neuropathic Diabetic Foot Lesions, Diabetic Medicine, June, Pg 720-723.

3. Boulton AJ, Bowker JH, Gadia m, Lemerman RN, Caswell K, Skyler JS, Sosenko JM, 1986, Use of Plaster Casts in the Management of Diabetic Neuropathic Foot Ulcers, Diabetes Care, Vol. 9 No. 2, March/April, Pg 149-151.

4. Burden AC, Jones GR, Jones R, Blandford RL, 1983, Use of the Scotchcast boot in treating diabetic foot ulcers, British Medical Journal, Vol. 286, 14th May.

5. Diamond E, Mueller M, Delitto A, 1993, Effect of Total Contact Cast Immobilisation on Subtalar and Talocrural joint motion in patients with Diabetes Mellitus, Physical Therapy, Vol 73 No. 5, May.

6. Gilbey L, 1991, A biomechanical review researching the treatment of neuropathic plantar ulceration in diabetic patients by the use of the Scotchcast boot, with a comparison of this method and other techniques, The Journal of British Podiatric Medicine, Vol 46, January.

7. Jones GR, 1990, Walking Casts: effective treatment for foot ulcers, Practical Diabetes, July/August, Vol 8 No 4, Pg 131-132.

8. Kominsky SJ, 1994, Outpatient management of pedal complications, Medical and Surgical management of the diabetic foot, Mosby, St Louis, Missouri, pg 234-241.

9. Novick N, Birke JA, Graham SL, Koziatek E, 1992, Effects of a Walking Splint and Total Contact Casts on plantar forces, Journal of Prosthetics and orthotics, Vol. 3 No. 4, Pg 168 - 177.

10. Payne C, 1997, The public health impact of diabetic foot disease, Australian Journal of Podiatric Medicine, Vol 31 No 3, pg 115-118

11. Payne CB & Scott RS, (1997) Discharges from Hospital for Diabetic Foot Disease:1980-1993, Diabetes research and Clinical Practice (in press).

12. Russell C, 1996, The Scotchcast Boot, Winston Churchill Memorial Trust Board,NZ.

13. Sinacore DR, 1988, The Diabetic Foot, Chapter 15 pg 273-291

14. Sinacore DR, Mueller MJ, Diamond JE, Blair VP, Drury D & Rose SJ, (1987) Diabetic Plantar Ulcers by Total Contact Casting, Physical Therapy, Volume 67/No. 10, October, Pg 1543- 1549.

15. Walker SC & Helm PA, Pullium GF Phala A, 1995, Total contact Casting, Sandals and Insoles, Construction and Applications in aTotal Foot-care Program, Clinics in Podiatric Medicine and Surgery, Vol. 12, No. 1, January, Pg 63-74.

16. Wilson RI, 1991, The technique of Scotch Casting, Search News March, The Association of Chief Chiropody Officers Limited.

17. http://www.apta.org/pt-journal/abstracts/sinacor.html

18. http://www.aatp.org/patientinto/cast.html

 

© Emily L Carpenter, 1998.

Content Approved by: Head of Podiatry
Page maintained by: Podiatry Webmaster
Last Updated: August 20th, 2002