Nerves, bones, and joints
Neuropathic osteoarthropathy, or Charcot foot, is an inflammatory process that affects the soft tissues, bones, and joints in the foot or ankle.
A potentially mobility-limiting condition, Charcot foot can be prevented in some cases,
Read on to understand your risk for Charcot foot, as well as tips for proactive behaviors that can help you avoid it or stop its progress.
Charcot foot can result from complete or near-complete numbness in one or both feet or ankles. This condition causes the bones in the foot to become weak, making them prone to damage such as fractures and dislocation.
Because the foot is numb, pain from fractures or other traumas can go unnoticed, leading to additional damage from walking and standing.
As the bones continue to weaken, the joints of the foot can become dislocated or collapse, changing the foot’s shape. The resulting shape is referred to as rocker-bottom foot, since the arch extends down and out, creating a rocker-like appearance.
Charcot foot can also lead to the occurrence of sores, which are hard to heal.
If left untreated, Charcot foot can lead to severe deformity, disability, or amputation.
Charcot foot occurs in three stages:
Stage One: Fragmentation and destruction
This acute, initial stage is marked by symptoms such as redness and significant swelling of the foot and ankle. The area may also feel warm or hot to the touch when compared with the other foot.
Internally, soft tissue swelling and small bone fractures are starting to occur. The result is destruction of the joints and surrounding bone. This causes the joints to lose stability, resulting in dislocation. The bones may even jellify, softening completely.
During this stage, the bottom of the foot may take on a flat or rocker-bottomed appearance. Bony protrusions (plantar prominences) may also appear on the bottom of the foot. If not treated, this stage can last for up to one year.
Stage Two: Coalescence
During this stage, the body attempts to heal the damage done during the first stage. Destruction of the joints and bones slows down, resulting in less swelling, redness, and warmth.
Stage Three: Reconstruction
During this third, final stage, the joints and bones of the foot heal. Unfortunately, they do not go back to their original condition or shape on their own. While no further damage is being done to the foot, it is often left in a deformed, unstable condition.
The foot may also be more prone to the formation of sores and ulcers, which might lead to further deformity or in some cases the need for amputation.
Charcot foot occurs in people who have numbness in their feet and legs. This loss of sensation is the result of a type of nerve damage called peripheral neuropathy.
Charcot foot is most closely associated as a rare complication of diabetes, but peripheral neuropathy is associated with several conditions. These include:
During stage one, Charcot foot may go undiagnosed since X-rays may not yet pick up on the damage starting to occur. For this reason, it’s important to let your doctor know if you have a medical condition that might result in Charcot foot.
In its later stages when it has progressed, imaging technologies such as X-rays and MRIs can be helpful.
In addition to analyzing your symptoms, your doctor will check for signs of neuropathy via a physical exam, a review of your medical history, and tests. These may include:
- Semmes-Weinstein 5.07/10 gram monofilament test, which analyzes sensitivity to pressure and touch in large nerve fibers
- pinprick test, which assesses ability to feel pain
- neurometer test, which identifies peripheral nerve dysfunction such as diabetic neuropathy
Your doctor will also test your tendon reflexes and analyze the muscle tone and strength in your leg and foot.
Treatment for Charcot foot in its early stage is geared towards reducing swelling and heat in the area, as well as stabilizing the foot by keeping it immobile. It’s important to eliminate any weight or pressure on the foot to stop additional damage from being done. This is sometimes referred to as off-loading.
Several low-tech, nonsurgical treatments for Charcot foot may help arrest its progression. These include:
- wearing a protective splint, walking brace, or customized walking boot
- minimizing or eliminating all weight on the affected foot by using a wheelchair, crutches, or a walking scooter
- using an orthotic brace to correct the alignment of the foot
- wearing a contact cast that is fitted specifically to your leg and foot
These supports may be required for several months or longer. During that time, you should regularly see a doctor, who will monitor your progress. If only one foot is affected, your other foot will be monitored for symptoms during this time.
Once your foot has healed, you may be fitted for therapeutic shoes or diabetic footwear to reduce or eliminate your chances of getting Charcot foot in the future.
Your doctor may recommend surgery if your foot has become significantly unstable or if it cannot be braced or supported in any way. You may also require surgery if you have a sore or ulcer that doesn’t heal. Surgical techniques include:
- Reconstructive osteotomy. Also known as realignment bone surgery, this procedure shortens or lengthens a bone in the foot or ankle to alter its alignment and ability to support the joints. A surgeon shortens the bone by cutting it or lengthens the bone by adding a wedge of bone to it.
- Ankle fusion. This procedure uses screws, rods, or plates to lock the ankle joint, prohibiting motion.
- Exostectomy. This is removal of plantar prominences, which might cause ulcers to form.
- Amputation and prosthetic fitting. The foot or portion of the foot is removed, followed by fitting for a prosthetic device.
It’s possible to prevent Charcot foot in some cases:
- If you have diabetes, keeping your blood sugar levels under control can help reduce nerve damage.
- People who have diabetes or who are at risk for neuropathy should avoid damage or trauma to their feet whenever possible: Avoid sports or exercises that may impact your feet, such as kickball or soccer.
- Do self-examinations daily to check for early symptoms.
- If you misuse alcohol or other substances, a 12-step program or other intervention, such as a rehabilitation setting, may help to stop the behavior that is putting you at risk for Charcot foot.
- Follow your doctor’s instructions and get professional checkups on a regular basis.
Charcot foot is a potentially devastating condition, but it can be avoided in some cases. Early detection is crucial for preventing damage and potential amputation.
When caught early, Charcot foot can sometimes be corrected or arrested via low-tech and conservative treatments. In other instances, surgery may be necessary.