|
Charcot arthropathy, or neuropathic arthropathy, is a condition
that affects some diabetic patients with peripheral neuropathy (loss
of sensation) after eight to 10 years. Jean Martin Charcot was a
French physician who in 1868 described neuropathic arthropathy
primarily in patients with advanced syphilis. At that time, people
with diabetes did not live very long because insulin was unavailable
to treat diabetes. Once insulin was available and diabetes
treatable, it was in the 1930s that neuropathic arthropathy was
recognized in diabetics. It may also occur with several other
diseases that affect the sensory nervous system (alcoholism,
leprosy, syphilis, Charcot-Marie-Tooth Disease to name a few). In
the United States, diabetes is the number-one cause.

So what do all these terms mean?
Neuropathy is a term used to describe problems with the nervous
system. In diabetics this is called peripheral neuropathy and
affects the sensory nervous system to the peripheral, or farther,
points of the body (i.e. feet and hands) causing loss of feeling or
numbness. Diabetic neuropathy also involves the autonomic
(involuntary) nervous system which controls regulation of blood
vessels and may result in increased blood flow to the limb,
contributing to swelling and osteoporosis of the bones as the
Charcot process occurs. Arthropathy is a term used to describe a
problem with a joint. Therefore, neuropathic arthropathy is used to
describe problems with joints related to lack of nerve system input.
It is believed that as the peripheral neuropathy progresses in
long-standing diabetes, the joints are unable to recognize the
forces put across them and the relative positions of the various
joints, sustaining microtrauma or microfractures because the body
does not adjust to these forces and positions.. It would therefore
be reasonable to assume that most cases of neuropathic arthropathy
would occur in the lower extremities, with their weight-bearing
function. This is indeed the case, although on occasion other joints
can be involved.
When does neuropathic arthropathy occur?
Most patients who develop neuropathic arthropathy have peripheral
neuropathy after being diabetic about 10 years or longer. So a
patient with juvenile-onset diabetes (as a child) may develop this
in his 20s or 30s. However, most patients with Charcot arthropathy
are in their 40s or older, as more patients have adult-onset
diabetes.
What are the signs and symptoms of Charcot arthropathy or
neuropathic arthropathy?
There are three stages to Charcot arthropathy. The first stage is a
fragmentation or destruction stage. During this stage, as the
process begins, the joint and surrounding bone is destroyed. The
bone fragments, the joint becomes unstable and in some cases the
bone is completely reabsorbed. This stage is clinically identified
by significant swelling (often with little pain to the patient)
erythema (redness), and warmth or heat to the area. It is easy to
see why this is often confused with an infection, especially as
there is often no history of injury or trauma. As the bones and
joint are affected, fractures and instability develop and the joints
can dislocate or shift the bones in relationship to each other. This
can lead to severe deformity of the foot and ankle. Often the
midfoot joints are affected and the result is a very flat foot which
is wide where the normal foot narrows in the arch. Bony prominences
often develop on the plantar (bottom) surface of the foot. Diagnosis
and early treatment at this stage is important to try to minimize
the bone destruction and deformity. This process may last as long as
six to 12 months.
The second stage is termed coalescence. During this stage the acute
destructive process slows down and the body begins to try and heal
itself. The swelling and heat begin to disappear. Once the acute
process is resolved and the healing on-going, the third stage
begins. This is a consolidation or reconstruction phase during which
the bones and joints heal. Unfortunately, the foot is often
deformed, and if there has been enough destruction, there may be
residual instability. Fitting shoes may be very difficult,and
prescription footwear and diabetic orthotics (shoe inserts) are
important to help prevent ulcer formation over deformed areas.
How is Charcot arthropathy treated?
Once the diagnosis is made (for most patients in the first stage)
there are several important treatment goals. The first is to get the
heat and swelling under control. The second is to support or
stabilize the foot to minimize deformity. A total contact cast is
applied by trained personnel. This cast has more padding than a
standard cast and is often applied with the toes completely covered
to prevent foreign objects (gravel, stones, etc.) from getting in
the cast. The cast will need to be changed frequently initially as
it will get loose very quickly as the swelling is controlled. Once
the initial swelling is controlled and the patient is tolerating the
casts without skin problems, the cast change interval may be
lengthened to two to four weeks. Another alternative is fabrication
of a custom walking boot for diabetics. The foot must be supported
until all heat and swelling has resolved. This may occur in several
months but more commonly requires six to 12 months. Minimizing
weight-bearing on the affected foot/ankle is also important.
Realistically this is extremely difficult for the patient with
diabetic neuropathy and should be encouraged. Assistive aides such
as a walker or cast are recommended. During this period the patient
will be seen frequently in the office. Continued education about
diabetic foot care and Charcot arthropathy is necessary. Also,
support of the various stages of anger and denial concerning this
rather profound change is necessary. After the first stage is
completed, molds for appropriate diabetic footwear, orthotics and
braces (if needed) are made. During treatment it is important to
check the noninvolved foot and protect it, as that foot is doing
much more work.
For patients who develop deformities that are unshoeable or
bracable, or who develop unbracable instability, surgery may be
considered. The timing for this surgery is important. Surgery done
during stage one has a high complication rate, often with
fragmentation of any grating done. Sometimes, however, surgery must
be done during this stage due to joint instability. Another option
for severe deformity/instability is amputation and prosthetic
fitting. Patients often have multiple medical problems which must be
taken into account in consideration for any surgery.
Long-term management of patients with Charcot Arthropathy is
important. Once the patient is stable, periodic checkups (six to
twelve month intervals) with a qualified foot and ankle specialist
is important to identify early complications, address footwear,
orthotic and brace issues, and continue patient education regarding
the care of diabetic feet and the special needs of the patient with
Charcot arthropathy. Patients should be counseled to seek medical
care if they develop any redness, selling, or heat in their feet, as
this could be the start of another Charcot process.
Last updated:
November 25, 2003
|