CROW Brace to treat severe deformity in high risk patients.

CROW - Charcot Restraint Orthotic Walker

What is a CROW Brace?

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The Charcot Restraint Orthotic Walker, or CROW, is a stable boot designed to accommodate and support a foot with Charcot neuroarthropathy. The CROW consists of a fully enclosed ankle/foot orthotic with a rocker-bottom sole.  It is a common treatment used after the acute charcot foot has calmed down.

 

What is Charcot deformity?

This occurs when bones and joints in the foot fracture, break up or pop out of place with minimal or no known direct injury. In the United States, this deformity is most commonly seen in people with diabetes. The foot first enters an acute stage of swelling, warmth and redness, which eventually diminish. Broken bones and dislocations can occur, causing severe deformities of the foot and ankle. Some patients develop pain or ulcers when the affected foot becomes deformed. CN can affect the other foot or happen again in the same foot. The foot does not regain its normal shape. 

What is a CROW made of?

The boot is custom made for each patient’s foot. The outer shell consists of two plastic or fiberglass clamshell pieces that fit and are strapped together with Velcro. It is sturdy and can prevent other bones from cracking or breaking and can be walked on. The bottom of the boot has a rounded rocker-bottom shape. The boot contains a custom, removable foam insole. Each insole is adjusted to distribute weight equally and also to support the ankle joint.

 

What does the boot do?

The CROW functions by providing even support to the entire foot, especially to areas that are overstressed due to the neuroarthropathy. These deformities often cause the foot to bend out of shape. The resulting stress on the foot can cause ulcers, which can develop into severe infections if left untreated. By distributing pressure equally throughout the leg and foot, the CROW removes excessive forces and gives the foot time to heal. It is easier to use than a cast, can be removed for wound care and washing, and is more durable.

 

Which patients can use the CROW?

Patients with acute Charcot can begin using the CROW after the swelling has receded. This can take months.  Patients with mild to moderate deformities will benefit most from the CROW. Patients with severe  deformities or extreme foot/ankle instability may need surgery instead of using the CROW.

 

How does it affect daily life?

Fortunately, the CROW is adaptable to daily life. Because of the clamshell design, the patient can easily remove the boot in order to keep the foot clean and sleep better. In addition, its fitted shape and good support allow people to return to walking, standing and driving more normally.

 

What are typical outcomes?

The most important outcome is that patients are able to continue to bear weight while minimizing pressure and giving the foot a chance to heal. Healing may require many months. However, the disease process may return and/or affect the other foot, so regular and lifelong monitoring of the condition is necessary.

 

What are the possible complications?

Despite the sturdiness of the boot and the distribution of forces, the bones of the foot could still break. The foot could develop open sores, though the boot is designed to prevent it. As always with Charcot deformity, some joints may heal incorrectly or not at all. Unfortunately, other factors such as poor glucose control and bad nutrition can prevent healing despite use of a CROW.

 

Frequently Asked Questions

What options do I have when my foot is still swollen?Patients often wear special casts until their feet stop swelling enough for them to use a CROW. The cast serves to stabilize the foot and prevent unstable motion, similar to the CROW. However, unlike the CROW, these casts cannot be removed.

Limb Preservation: Total Contact Casting

Diabetics with neuropathic ulcers affect at least one quarter of all diabetics in the United States, and according to Wounds Research, approximately 1 in 5 of these individuals will eventually require an amputation of their foot. Total contact casting has recently become more popular as an option for foot protection, and to mediate the excessive wear and tear that some diabetic foot sores suffer.

What is total contact casting?

As the name suggests, this technique, which is used by many diabetic foot specialists, is a thin cast that is applied to the entire plantar surface area of the foot, as well as the lower leg. Based on its design, the cast can take up as much at 92 percent of the pressure from the ulcer site. Since ulcers often occur on parts of the foot or leg that are repeatedly impacted through daily movement, it is important that they receive as much padding as possible without affecting an individual’s normal walking patterns. Although total contact casting provides relief from certain pressures, the cast works with the natural human gait to make sure that no section of the foot or leg is required to take on excessive weight or pressure.

Does it always work?

Total contact casting has been shown to be effective in the healing of foot and lower leg ulcers, but only those that are noninfected. According to current research, the success rate is between 72 and 100 percent in most patients. A study conducted at the University Hospital Maastricht in the Netherlands examined how total contact casts would fare on infected patients, and of the 28 patients in the study group, only 36 percent showed signs of healing. The study group recommended that individuals with infected diabetic ulcers look toward alternative treatments for healing, according to the American Diabetes Association.

Surgery may become necessary in conjunction with acute infections.

Overview of the Charcot disease

What is it?

Charcot arthropathy, also known as Charcot foot and ankle, is a syndrome in patients who have neuropathy or loss of sensation. It includes fractures and dislocations of bones and joints that occur with minimal or no known trauma.​

Symptoms and Clinical Presentation

​Initially, there may be swelling, redness and increased warmth of the foot and ankle. Later, when fractures and dislocations occur, there may be severe deformities of the foot and ankle, including collapse of the midfoot arch (often called rocker bottom foot) or instability of the ankle and hindfoot. The syndrome progresses through three general stages:

•Stage 1 (acute, development-fragmentation): marked redness, swelling, warmth; early radiographs show soft tissue swelling, and bony fragmentation and joint dislocation may be noted several weeks after onset
•Stage 2 (subacute, coalescence): decreased redness, swelling and warmth; radiographs show early bony healing
•Stage 3 (chronic, reconstruction-consolidation): redness, swelling, warmth resolved; bony healing or nonunion and residual deformity are frequently present.

Cause (including risk factors) 

Charcot foot occurs in patients with peripheral neuropathy resulting from diverse conditions including diabetes mellitus, leprosy, syphilis, poliomyelitis, chronic alcoholism or syringomyelia. Repetitive microtrauma that exceeds the rate of healing may cause fractures and dislocations. Changes in circulation may cause resorption of bone, weakening the bone and increasing susceptibility to fracture and dislocation. 

Anatomy 

Charcot arthropathy may affect any part of the foot and ankle, including (in decreasing order of frequency) the midfoot, hindfoot, ankle, heel and forefoot.  Multiple regions may be involved concurrently.  Fractures and dislocations frequently involve several bones and joints, with extensive fragmentation and deformity. 

Diagnosis 

Time between onset of symptoms and diagnosis may be several weeks or months. Delay in diagnosis may or may not affect the end result because gross instability may occur even if prompt diagnosis is made. Diagnosis is based on a high index of suspicion for this problem in patients with neuropathy. Increased redness, swelling and warmth may be the only early signs. Some patients have pain. Early radiographs may show soft tissue swelling with no bony changes, but repeat radiographs several weeks later may show bone and joint changes.

Treatment Options 

Non-Surgical: Non-operative treatment includes a protective splint, walking brace, orthosis or cast. Early weightbearing is allowed in stage 1 by 41 percent of specialists and in stage 2 by 49 percent of specialists, and other specialists recommend non-weightbearing. After stable healing is noted in stage 3, treatment includes accommodative footwear with protective orthoses.Surgical: Selected patients with instability in the early stages may be treated with open reduction and internal fixation and fusion. In the later stages, surgical options may include realignment osteotomy and fusion (correction of deformity) or ostectomy (removal of bony prominence that could cause an ulcer ). 

* Sometimes the surgery can fail, and this is commonly because of improper or inadequate fixation, poor glucose management, obesity, noncompliance, and even infection.