Charcot osteo-arthropathy, a foot pathology most associated with diabetic neuropathy, will strike 50,000 to 70,000 of the 18.2 million people currently diagnosed with diabetes mellitus.

It takes decades for diabetic neuropathy to develop, but the progress of Charcot foot develops in weeks and months. Minor trauma to foot muscles, tendons, ligaments, joints and bones in an insensate environment will often result in their accelerated and progressive destruction.

A baseline X-ray of the affected foot and clinical evaluations by a podiatrist, a pedorthist or orthotist, and a physical therapist will determine the extent of joint instability, joint dislocation and the degree of its subluxation or misalignment in the Charcot foot. Other complications of Charcot foot include the presence of erythrodema (redness), heat, insensitivity, and swelling caused by synovial fluid leaking from the damaged joint capsule. These diagnostic observations are necessary to know the degree and extent of the disease and the strategy to accommodate it.

“During the clinical evaluation, before any decision is made about the most optimal [orthosis] or footwear choice, we will take one of those pediatric stick thermometers…and put that on the sound foot. We will place another one on the affected side. When we see [that] the temperature on the affected side [is] within one degree of the sound side—and the redness [is] diminished—then we feel that the Charcot condition is consolidated and the patient may begin walking again in our choice of protective or accommodative footwear,” states Roger Marzano, CPO, C.Ped., and vice president of clinical services at Yanke Bionics of Ohio.

Marzano says managing Charcot foot always requires reducing the shear and stress forces acting upon the foot. In the most serious cases, the foot’s plantar surface is axially unloaded as much as possible by modifying a plaster mold or modified CAD-CAM carving into a Charcot Restraint Orthotic Walker, or CROW boot . In that worst-case scenario, success may be measured by the number of partial foot or below-knee amputations avoided.

Upgrading the patient’s footwear to a shoe and shoe insert that will significantly minimize any shear between it and the foot is vital, since shear forces cause calluses, and calluses mean trouble for diabetics with peripheral neuropathy, Charcot foot or not. A shoe with a deep, seamless toe box is important in keeping the toes unblemished. A shoe with a spandex-like cloth expandable top may be an asset in that respect as well, so long as the shear force, again, is minimal.

However, Marzano states, “The problem is this: if the patient has a unilateral Charcot condition most practioners are inclined to advocate for custom molded shoes. I hate doing custom molded shoes because most of my patients, invariably, don’t seem to be happy with their appearance. The shoe looks too much like their foot! And they aren’t too happy with that either!”

Some people like to do custom molded shoes from a financial standpoint as well, but Yanke finds greater patient compliance with the orthopedic shoes it will purchase, customize and deliver in 10 days, typically one-third of the time it takes to fabricate a custom molded shoe.

Without custom molded shoes, facilities must customize regular orthopedic shoes because of poor reimbursement by insurance companies and government health agencies. For example, there are multi-lasted, premium grade off-the-shelf orthopedic shoes available to fit a Charcot foot patient that may have a wide forefoot and narrow heel, but few facilities can afford to pay $100 for a shoe that is reimbursed at $126. Generally, the orthotist will chose footwear and inserts that provide the best value, are durable, and will accommodate the various modifications necessary to serve the special needs of diabetic patients who have Charcot foot.

One shoe modification technique Marzano advocates is called the “split and widen.” It can be done on most shoes by the experienced technician. The shoe may be split at any place on the sole: at the forefoot, from the distal metatarsals to the proximal heel breast, at the mid-foot, etc. A visco-elastic polymer, a material resilient and durable enough to alleviate great pressure on relatively small areas, is used to fill the opening. Then two- to three-millimeter soling material is added to finish the job.

This modification doesn’t make a material difference in how it fits back on the patient’s foot. The volume of the shoe depends on its height, width and depth. When it is split and widened from one-half inch to three-quarters of an inch, its volume increases and the resulting length, generally, isn’t altered that much.

“I take patients out of custom molded shoes all the time because of these modifications, and they are so stinking happy that they don’t have to have that Godzilla shoe on any longer,” Marzano states.

Many orthotic and prosthetic facilities like Yanke Bionics also fabricate custom visco-elastic polymer orthoses for their special needs patients. For example, a 335-pound man with a cuboid (bone) stance on the plantar surface of his foot will make a regular, off-the-shelf diabetic insert look like tissue paper in a week. In cases like that, a foam foot impression or a slipper cast will be made, filled with the polymer, sealed with thermocork, modified and fit to the patient’s foot and shoe.

“However, when the practioner is presented with a patient with severe Charcot deformities—when the talar and navicular bones are protruding beyond the medial border of the foot—the lab will not be able to split and widen a shoe to a great extent; then our options start with custom molded shoes with special modifications and go on to CROW boots or patella tendon bearing, clamshell ankle-foot orthoses,” Marzano says.

Gordon Zernich, CP, BOCP, works in the orthotics and prosthetics department of the Veteran’s Affairs Medical Center in Miami, Florida.