Charcot Arthropathy

Charcot arthropathy is named after the French physician Charcot.  It is a potentially catastrophic condition that can occur in feet with loss of sensation.  While there are many conditions that can cause loss of sensation in the feet (including alcohol abuse, among others), diabetes mellitus is the most common cause of sensory loss leading to Charcot arthropathy.

Predisposition to Charcot arthropathy is primarily determined by sensation loss.  However, other factors usually also play a role, including a) injury or overuse, and b) changes in bone circulation and bone condition.

The process starts with abnormal stresses on bones or joints created by injury, overuse, tight calf muscle, or other abnormalities of walking.  These abnormal stresses can begin to cause microscopic injury to susceptible bones or joints.  However, because sensation is impaired, the pain that would normally be present with early, microscopic injury to the bones and joints is absent.  With the lack of pain, the injury process to the bones and joints continues on to cause fractures and dislocations.   In most cases, pain is felt no more than a mild ache, or not at all.  The only clue to progressive catastrophic collapse of the bones and joints in many cases is swelling and changing architecture of the foot.

The diagnosis is usually made by examination and radiographs (x-rays).  Special tests are usually not required.  Examination usually shows significant swelling and warmth.  Observable deformity may be present.  Examination of sensation will be abnormal.  Radiographs (x-rays) will typically show striking fractures and dislocations – completely disproportionate to the amount of discomfort that is felt.

Because pain is usually absent, diagnosis is usually not made early in the process, but rather later, once fractures and dislocations have become severe.  If the process is diagnosed early, collapse and disfigurement of the foot or ankle can possibly be prevented.

The most commonly affected part of the foot and ankle is the midfoot and arch area.  The ankle, hindfoot, and forefoot (ball of the foot) can also be affected.   It is very common to find that the calf muscle is quite tight.

The treatment of Charcot arthropathy is an evolving science.  The first step to caring for an acute Charcot arthropathy is to prevent further destruction and to promote healing – usually with a cast and elimination of weight bearing, if possible.  Arresting the process may take months.  Once the process is arrested, transition to custom footwear or bracing is commonly employed.  In severely deformed feet or ankles, surgery may be employed.

Initial Phase Treatment:

• Cast immobilization.  It is important to protect the injured bones and joints to prevent further injury and deformity, and to allow them to heal. The cast period may last as little as 6 weeks, but typically longer – sometimes months.  One of the risks of casting a limb with poor sensation is cast-induced ulcerations.  We will be vigilant of this, but it is important for you to report to us is the cast feels loose, and to remain non-weight-bearing.  It is also important for you to contact us if you experience any warning signals, such as fever, chills, or calf pain.
• Non-weight Bearing.  Just as important as the cast, it is important to avoid all weight bearing on the affected limb to allow the Charcot process to resolve.  We can provide you crutches, or order you a walker or wheelchair.  You may alternatively wish to use a “knee caddy”. These are not covered by Kaiser Permanente.
• Rest and elevate your limb as much as possible daily.
• Bone stimulator.  In some cases, we will order a bone stimulator for you to use daily for prescribed periods.  The bone stimulator may assist a more rapid healing process.
• Surgery.  Surgery is rarely performed during this period.  In some cases, it can be helpful to restore and stabilize the alignment of the foot or ankle while the Charcot process subsides.

Later Phase Treatments (once the acute Charcot process has subsided):

• Custom shoes and insoles.  We will want you to wear custom shoes and insoles on an ongoing basis.  We will order them to be made for you by a contracted prosthetics and orthotics outfit.
• Custom braces.  Occasionally, the severity of the problem requires more than custom shoes and insoles.  If the need is present, a custom brace may be ordered for you.  We will order them to be made for you by a contracted prosthetics and orthotics outfit.  Kaiser Permanente typically covers the brace (paying 80% typically).
• Perform calf stretching exercises for 30-60 seconds on each leg at least two times per day.  Stand an arm’s length away from the wall, facing the wall. Lean into the wall, stepping forward with one leg, leaving the other leg planted back. The leg remaining back is the one being stretched. The leg being stretched should have the knee straight (locked) and the toes pointed straight at the wall. Stretch forward until tightness is felt in the calf. Hold this position without bouncing for a count of 30-60 seconds. Repeat the stretch for the opposite leg.
• Nightly and daily foot and ankle inspection.  Check your feet and ankles for signs of recurrent swelling or new sores/ulcers.  Report these kinds of changes to us as soon as possible.
• Follow the instructions listed in the document: “Preventive Care for Patients with Sensation or Circulation Loss in the Feet ”
• Surgery.  In some cases, surgery might be discussed.   Some surgeries involve removal of bony prominences, with or without lengthening the Achilles/calf muscle.  In other cases, more complex surgeries may be reviewed, with the goal of reconstructing the foot and ankle alignment.
• Removal of bony prominence, with or without lengthening the Achilles/calf muscle.  This type of surgery is designed to reduce the risk of foot ulceration and reduce the risk of recurrent Charcot process.  The surgery generally involves general or spinal anesthesia, but in some cases can be performed under local anesthesia with intravenous sedation.  After the surgery, you would be typically be in a cast and non-weight bearing for about 6 weeks.  You would then return to custom shoes and custom insoles once the healing is sufficient.
• Reconstructive surgery of the foot and ankle.  This type of surgery is designed to: a) improve the foot and ankle alignment, b) reduce the risk of foot ulceration, and c) reduce the risk of recurrent Charcot process.  The surgery generally involves general or spinal anesthesia, but in some cases can be performed under local anesthesia with intravenous sedation.  After the surgery, you would be typically be in a cast and non-weight bearing for 12 weeks or more.  You would then return to custom shoes and custom insoles once the healing is sufficient.
• Risks of surgery.  Surgery carries significant potential risks.  Loss of limb and infection being but two.