The Charcot Restraint Orthotic Walker, or CROW, is a rigid boot designed to accommodate and support a foot and ankle with Charcot neuroarthropathy (CN), also known as Charcot arthropathy.
CROW boot consists of a fully enclosed ankle/foot orthotic with a rocker-bottom sole. Your foot and ankle orthopaedic surgeon may recommend this treatment to reduce pain, minimize further deformity, and prevent ulcer development after acute CN has calmed down.
CN occurs when bones and joints in the foot break or pop out of place with minimal or no known direct injury. In the United States, this deformity most commonly occurs in people with diabetes.
The foot first enters an acute stage of swelling, warmth, and redness that can be mistaken for an infection. Broken bones and dislocations can occur, causing severe deformities of the foot and ankle. Some patients develop pain, calluses, or even ulcers when the affected foot becomes deformed. CN can affect the other foot or happen again in the same foot. If not protected, the foot may continue to deform and will not regain its normal shape.
Patients with acute CN can begin using the CROW boot after swelling has gone down; however, that can take months. Patients with mild to moderate CN deformities will benefit most from the CROW boot. Patients with severe CN deformities or extreme foot/ankle instability may need surgery instead of using the CROW boot.
Image of a CROW boot with a hard plastic shell and Velcro fasteners.
The CROW is custom-made for each patient's foot. The outer shell consists of two plastic or fiberglass clamshell pieces — one for the front of the foot and one for the back — that are strapped together with Velcro. It is sturdy and can be walked on, and it prevents other bones from cracking or breaking. The bottom of the boot has a rounded rocker-bottom shape. The boot contains a custom, removable foam insole that is adjusted to distribute weight equally and support the ankle joint.
The CROW boot provides even support to the entire foot, especially to areas that are overstressed due to the CN. CN 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.
Fortunately, the CROW boot is adaptable to daily life. Because of the clamshell design, you can easily remove the boot in order to keep the foot clean and sleep better. In addition, its fitted shape and good support allow you to return to walking, standing, and driving more normally. Even though the CROW is removable, it is important that you continue to use it daily and regularly as directed by your surgeon.
Most importantly, you will be able to continue putting weight on your foot while minimizing pressure and giving the foot a chance to heal. Healing may require many months. However, CN may return and/or affect the other foot, so regular and lifelong monitoring of the condition is necessary.
Despite the sturdiness of the boot and the distribution of forces, the bones of the foot could still break down further. Due to lowered ability to detect pressures that are too high in the neuropathic foot, the foot could develop open sores, even though the boot is designed to prevent this.
As always with Charcot deformity, some joints may heal incorrectly or not at all. Unfortunately, other factors such as poor circulation and glucose control, malnutrition, obesity, and chronic swelling can prevent healing despite use of a CROW.
Patients often wear special casts called "total contact 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 at home.
Your foot and ankle orthopaedic surgeon may have an orthotist in their office who will make the CROW for you, or you may be referred to an outside orthotist.
Most insurance companies will cover a CROW, but you should consult with your insurance company after your foot and ankle orthopaedic surgeon provides the prescription.
Unfortunately, any individual who develops neuropathy can develop CN. The best advice is simple to give, but often difficult to follow. Taking the following steps will markedly reduce the risk of developing CN:
Original article by Jeanne Yu, MD
Contributors/Reviewers: Jeffrey Feinblatt, MD; Vinayak Sathe, MD
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