Charcot's foot

November 21, 2008

Charcot Foot: A Potenial Risk Factor for Diabetic Patients

Charcot Foot: A Potential Risk Factor for Diabetic Patients, is a valuable

report on an under diagnosed problem written by Webb, Doctor of

Pharmacy

Candidate, FAMU. You may want to print this out and hand it to your

patients.

The condition known as Charcot arthropathy or Charcot foot has become an

elevated risk factor for the diabetic population. The American College of

Foot

and Ankle Surgeons say that Charcot foot's prevalence appears to be growing

as more Americans are diagnosed with diabetes. This condition is classified

as a pedal neuropathic joint disease that progressively deteriorates weight

bearing joints, usually in the in the foot or ankle. The acute phase of the

condition is characterized by edema, erythema, and elevated foot

temperature. It causes significant trauma and injury to the bony structure

of the foot.

If gone untreated this complication could lead to foot deformities causing

abnormal pressure, foot ulcers, and possibly amputation. Once this condition

occurs it can not be reversed, but damage can be stopped if it is detected

early.

The exact cause is unknown but there are two theories that attempt to

explain the pathogenesis of Charcot foot. The neurotraumatic theory suggests

that

cumulative mechanical strain on patients with nerve damage leads to

progressive fractures. While the neurovascular theory claims that

there is increased blood flow the lower limbs due to sympathetic inervation.

The subsequent loss of vasomotor control allows blood vessels to dilate,

thus

increasing peripheral blood flow. The increased blood flow causes

arteriovenous shunting which accounts for hyperemia and bone growth. Most

cases often

occur in patients suffering from diabetic peripheral neuropathy or other

neuropathic conditions. Nerve damage decreases the bodies ability to sense

stimuli,

especially pain, and decreases muscular reflexes. Repetitive trauma leads

to the physical damage of ligaments, cartilage, and bone. In a recent study

it was discovered that obesity combined with neuropathy can significantly

increase the incidence of developing neuropathic arthropathy.

According to the American Diabetes Association 60-70% of diabetic patients

develop nerve damage that could possibly lead to Charcot arthropathy, 0.5%

of

those patients eventually patients with diabetes alone were approximately

59% more likely to develop Charcot foot. Patients with neuropathy were 14

times

more likely, and patients with both diabetes and neuropathy were 21 times

more likely to develop the complication. It was also reported that diabetic

patients

between the ages of 55-65 years old diagnosed for more that 6 years and

possessing an A1c greater than 7% are associated with an increased incidence

of

Charcot arthropathy.

Charcot foot occurs in three stages commonly called Eichenholtz stages.

Stage 1 is the acute inflammatory phase characterized by swelling, redness,

and

increased warmth. If radiographs are performed they will often show

fractures and dislocations. The primary concern in this stage is to rule out

a possible

infection such as cellulitis, a common condition in diabetic patients. Stage

2 is defined as the subacute phase that shows signs of healing, decreased

swelling, elevated foot temperature, and radiographic indications of

osteoclastic activity. Stage 3 is the chronic or " cool " phase that is marked

by the

consolidation and resolution of inflammation.

Diagnosis of Charcot foot should be made by a clinical examination. Making

a proper diagnosis can be difficult due to the fact that this condition can

often mimic cellulitis or deep vein thrombosis (DVT). " It may also be

difficult to make a diagnosis due to peripheral neuropathy masking pain

stimuli.

It is important to remember that pain and tenderness can be diminished or

completely absent. A physician should do laboratory tests such as a

radiograph

and nuclear scan to differentiate from Charcot foot and an infection.

Radiographs can potentially reveal bony destruction, fragmentation, and bony

remodeling

which are all signs of Charcot foot. Swelling of the foot and lower legs are

often associated with the presence of DVT's. According to physicians the

foot

is predominantly swollen in Charcot arthrophy as compared to cases of DVT

where the swelling is located predominantly in the lower legs.

Findings on plain radiographs can be normal during the acute phase of

Charcot foot. Radiographic changes take time to develop and may appear

absent during

initial scans. The potentially false reading also makes diagnosing this

condition difficult. If Charcot foot is suspected treatment and a series of

radiographs

should be preformed.

NICE guidelines suggest that patients strongly suspected of Charcot foot

should be referred to a diabetic foot care specialist. Patients should be

properly

immobilized using a weightbearing total contact cast or an Aircast boot.

Immobilization and protection of the foot are the recommended approaches to

managing

the acute Charcot process. Strict immobilization of the foot and ankle with

a weightbearing total contact should be conducted for 3-6 months. A study

published

in Foot and Ankle International discovered that patients who used total

contact casts decreased their risk of developing ulcerations and were able

to wear

custom footwear in about 9 weeks.

Patients should be educated on Charcot foot complications, protective

footwear and routine foot care. Once the casts can be removed a brace is

commonly

used to protect against foot injury. Braces can remain on the foot for 6 to

24 months. After the braces are no longer needed custom foot wear is then

utilized

to relieve pressure. Custom orthopedic footwear is considered to be long

term management for the prevention of Charcot foot complications. Lastly

regularly

scheduled foot care by an orthopevdist or podiatrist should be considered as

a life long preventative measure.

Proposed treatments of the Charcot porcess have included the use of

Bisphosphonates. According to SIGN guidelines there is not sufficient

evidence to support

the routine use of bisphosphonates for the treatment of Charcot foot.

However a recent study indicated that Bisphosphontes could be helpful in

stopping

the acute phase of arthropathy in some patients. The use of pamidronate

resulted in decreased erythema, temperature, and bone growth. Additionl

research

is need to further evaluated this drugs efficacy.

References:

Sommer TC, et al.Charcot foot:The diagnostic dilemma.AmFamPhysician.2001 Jun

15;65(12):2436-8

Sella EJ, Barrette C. Staging of Charcot neuroarthropathy along the medial

column of the foot in the diabetic patient.J Foot Ankle Surg.1999;38:34-40

3. Caputo GM, et al. The Charcot foot in diabetes: six key

points.AmFamPhysician.1998;57(11):2705-10

4. Stuck RM, et al. Charcot arthropathy risk elevation in the

diabetes population.American Journal of Medicine.2008;121(11):1008-1010.

6. Pinzer MS, et al. Treatment of Eichenholtz stage I Charcot foot

arthorpathy with a weightbearing total contact cast.2006;27(5):324-329.

7. Eichenholtz SN.Charcot joints.Springfield,Ill.:,1966

8. Guidelines 55 section 7:Management of dibetes foot diseases.SIGN

(2001).

9. Type 2 Diabetes: prevention and management of foot

problems.Nice(2004).

10. Rozbruch RS. Limb Lengthening and Reconstruction Surgery.CRC

Press,2006.

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This article originally posted November 19, 2008 and appeared in

Issue 443

Past five issues:

Issue 443 |

Issue 442 |

Issue 441 |

Issue 440 |

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