Caring for the CMT-Affected Foot

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Caring for the CMT-Affected Foot (Photos and Graphics at the link)

http://www.mdausa.org/publications/Quest/q135cmt_foot.aspx

by Margaret Wahl

Diane Lareau, 35, of Linwood, Mass., always knew there was something

wrong, but her mother kept telling her she was just pigeon-toed and

that putting her shoes on the wrong feet would fix the problem.

It didn't, and by her late teens, she remembers, her toes were " all

bent and just a mess. It looked like a bird's claw on both feet. I

was actually almost walking on the outsides of my ankles. " She also

had extremely high arches, so that her feet looked like humps. Lareau

finally saw a specialist in her senior year of high school, with

urging from the school nurse, and the problem acquired a name:

Charcot-Marie-Tooth disease, or CMT (see " Faulty Wiring " ).

" They gave me these hard plastic insoles to put inside your shoes for

support for the arches, supposedly to help you walk. Those didn't

work so great. "

Later, in her late 20s and pregnant, Lareau fell from her front porch

and wound up in the emergency room. The only good thing about the

experience was that a doctor there referred her to an orthopedic

surgeon who understood the problems of the CMT-affected foot:

weakness, some loss of sensation, and progressive changes in shape

caused by the action of muscles that aren't receiving the right nerve

signals.

In CMT, " the typical problems with feet are the shape of the arches

and the difficulties with the joints that walking with abnormally

shaped feet causes, " says neurologist Shy, an MDA research

grantee at Wayne State University in Detroit, where he also co-

directs the adult MDA clinic and directs a special CMT clinic. " Not

every single person who has CMT has high arches. Some people have

flat feet. But many patients have abnormal feet. "

Another common problem is hammer toes, so named because the toes are

curved into a shape resembling the hammers that piano keys activate.

Patients' needs vary, Shy says. Some can get by with simple inserts

in their shoes, while others need ankle-foot orthoses (AFOs), which

are lightweight (usually plastic) braces that stabilize the lower leg

and foot.

Only a minority of people with CMT-related foot deformities need

surgery, Shy says.

" In my opinion, when foot deformity is so severe that patients walk

on the sides of their feet or when [a high arch] is ex-treme, it's

worth considering surgery, " Shy says. " Also, when hammer toes are so

severe that patients are developing calluses or blisters on the tops

of their toes, many would consider surgery to straighten the toes. "

The Wayne State clinics provide what Shy describes as " a little bit

of a unique resource. " Treating patients from 37 states and some 15

countries, the specialists in every aspect of CMT start with a

conservative approach before venturing into surgical territory to

treat CMT.

" Generally, we start with shoe inserts and AFOs " to align the foot,

Shy says.

Foot orthotics can often realign the pronated or supinated foot,

reducing stress on weight-bearing joints. " It's extremely uncommon

that somebody doesn't need some sort of orthotic, " says

Hinderer, a physician specializing in physical medicine and

rehabilitation at Wayne State. (An orthotic, or orthosis, is any

supportive device, although the first term is more often used to mean

a shoe insert and the second to mean other kinds of appliances.)

People with CMT also need a good walking or athletic shoe with a

removable insole to make room for the orthotic, Hinderer says. He

likes New Balance and shoes.

" We recommend that people take hold of the shoe and try to twist the

forefoot on it. If it's flexible, it's not going to give you the

support you need. You want one that's fairly rigid. "

The key to foot orthotics, he says, is " to get the ankle and hindfoot

in as close to neutral, or normal, alignment as we possibly can. "

If the patient is walking on the outsides of the feet — supination —

or the insides — pronation — Hinderer generally puts a small pad on

the bottom of the foot orthosis. " We're holding the whole foot in

good alignment. The advantage is that it puts the weight-bearing

joints [where bones meet] into their normal position so they're not

being given extra stress. "

If there's any flexibility left in the foot, Hinderer says, there's

usually a way to hold it in better alignment. " Orthotists [brace

makers] are pretty creative folks. "

But misshapen feet and weak ankles aren't the only problem in CMT.

Another common factor in the disease is a weakening of the muscles in

the front part of the lower leg, those that pull the front of the

foot back and off the ground during walking. When those muscles are

weak, the foot tends to flop down as the person walks, so that he

trips over his own feet.

When foot drop is the first problem in CMT, Hinderer says, an off-the

shelf type of AFO, made of strong, light carbon fiber, works well.

Diane Hardin, 57, holds one of her plastic, open-backed AFOs, which

she says give her more flexibility than orthoses that run up the back

of the leg. " They're not a custom fit, but they're very thin, very

lightweight, and from that standpoint very nice, " Hinderer says. " But

more often than not, we see folks who have had foot changes already,

and that off-the-shelf type of device doesn't accommodate the foot

changes at all. "

A custom-fitted, plastic AFO with a hinge at the ankle joint — for

uneven ground, stairs and driving — is probably the most commonly

prescribed device.

As for vertical support, Hinderer likes AFOs that go up the back of

the leg, although, with a carbon fiber AFO, he says, you can make

some that go up the sides and come around to the front. " We like a

symmetric arrangement, either up the back or up both sides. "

Carbon fiber AFOs are stronger and more expensive than plastic but

provide more options. " You can do more at the ankle with how you

adjust and position, " Hinderer says. " And in terms of design, it's

more open. It's cosmetically perhaps a little better. "

In the triple arthrodesis procedure, three joints (A, B and C) are

fused and immobilized, holding the foot in a corrected position. The

operation is performed less often now than in the past, because it

interferes with the foot's ability to act as a shock absorber.

A single standard plastic AFO, Hinderer says, goes for about $500.

Carbon fiber AFOS are about double that. Insurers usually pay for

AFOs, but not for shoe inserts.

" The biggest thing is that orthotics must fit extremely well to be

effective, " Hinderer says. " People will tolerate orthotics that don't

fit well and keep trying to wear them. They'll say, `I wear them

three hours and they're killing me.' It shouldn't be that way. If

it's fitting really well, the way it should, you should forget it's

on. "

Shy cautions his patients to beware of " miracle " races. " None

of these work for all people, " he says. " Advertising for special

braces should be viewed with caution. "

When Diane Lareau read about carbon fiber AFOs on the Internet, she

decided to have some made for her, at a cost of $1,200 each.

Fortunately, her insurance company paid for them.

" I was excited because they're supposed to be so strong, but what

they don't tell you is there's no support for your heel. They're just

a flat base. "

For the new AFOs to work for her, Lareau found out she'd need to wear

them with shoe inserts, which cost at least $150 each and which her

insurance won't pay for. " So, unfortunately, " she says, " these babies

are hanging in my closet until I can get the money to get them. "

She's staying with her old AFOs for now.

Hinderer says foot surgery is " something people should hold

off on, in my opinion, until they've really pursued good orthotic

fitting, and, if need be, physical or occupational therapy to

supplement that.

" If they're not getting the results they want, then perhaps surgery

is a consideration. But most often we've been able to accomplish a

great deal with noninvasive methods. "

When Hinderer or any other member of the Wayne State team wants to

get an opinion about surgery, he's likely to call Meehan, an

assistant professor in the Orthopaedic Surgery Department at WSU, and

a specialist in repairing feet and ankles.

Meehan doesn't rush into surgery either.

" Typically you start off with conservative measures first, " he says.

He recommends a trial of changing shoes and bracing. If those don't

work, " then you talk surgical options, typically, " he says.

" If a patient comes to me with the fact that they've broken maybe two

or three braces during the course of a year, and [the braces] aren't

holding the deformity, that's a case where you'd start thinking about

surgical options. "

In general, Meehan advises people to postpone surgery until they're

in their 20s or 30s, because muscle imbalances in CMT are still

evolving over time. " If they feel the deformity is progressing and

it's unbraceable, then we recommend it, " he says. " But we don't

recommend it as a preventive measure. "

" Foot surgery is common in CMT, but the types of foot surgery

performed are changing, " Shy says.

" One or two generations ago, many of the procedures were a triple

arthrodesis, which involves bone fusions to stabilize ankles. These

are done less frequently now. There's a concern that any surgery

involving bone fused to bone will cause significant arthritic

problems, including pain, after a number of years. " (Arthritis is any

inflammation of the joints.)

Instead, current surgical approaches more typically involve tendon

transfers [moving tendons] and procedures to correct the angle at

which the foot strikes the ground, Shy says, in an attempt to prevent

future arthritic complications. (See " Moving Tendons. " )

" When children had triple arthrodeses in the past, it was a horrible

thing, because it knocked out their growth plates and left them with

a short, stubby foot, " Meehan says. That kind of procedure can lead

to arthritis by early adulthood, he says.

Another woman with CMT, Diane Hardin, now 57 and living in Madison

Heights, Mich., remembers having triple arthrodeses on both feet back

in 1961 in Ohio, when she was 12 years old.

" I was so pigeon-toed that I tripped over my own feet. I would step

on each foot as I walked. It was just called birth defects at that

time. " Her doctor, wisely, told the family to wait until she was

fully grown before attempting to fix the problem. " I wasn't diagnosed

[with CMT] until after the birth of my second child.

" Basically, my feet are completely fused except for the ankle and one

joint in the center, " she says, " so I don't have a lot of

flexibility. I walk very flat-footed because of it. "

Until she was well into adulthood, it didn't seem to cause many

problems. " I honestly would not have been walking all those years at

all if it was not for the surgery, " she says. But as she got older,

things began to bother her, particularly her left hip and her back.

Her left leg, it was found, is about half an inch longer than her

right, something that occurs in the general population fairly often.

But that small problem plus the fusion of her feet bones may have

been an unfortunate combination.

The joints of the back of the foot, Meehan says, " control a lot of

your side-to-side motion, and they're a big part of shock absorption

when you walk. So if you take that joint out [by fusing it], then you

take away the shock absorption capability, so you tend to get

arthritis in other joints, which take up the load, " he says.

Recently, Hardin had surgery to remove a disc and fuse the third and

fourth vertebrae in her back. That, a lift in her right shoe, new

AFOs and a substantial weight loss have, she says, restored her

mobility and relieved her pain. She believes if her leg length

difference had been identified earlier, she might have been spared at

least some of the pain she's endured over the years.

Meehan says he tries to avoid triple arthrodesis procedures unless a

severe deformity is already causing arthritis in the foot joints. " It

definitely holds the deformity in place, " Meehan says of this fusion

surgery. " It provides you excellent correction. There's no doubt

about that. And it's relatively easy to do. " But most of the time,

it's less than ideal.

The Achilles tendon and plantar fascia often tighten up and can be

surgically released. Tendons can be transferred to new positions,

such as from the inside to the outside or top of the foot.

" The big move among the foot surgeons is to do osteotomies, which are

cuts in the bone to put the bones in a better position, to reshape

the bones, rather than doing fusions, which take motion away and

don't hold up over time, " Meehan says. (Toes, however, may need to be

fused.)

" Sometimes the problem can be as simple as a tight heel cord —

Achilles tendon — that needs to be released, " he says.

A band of connective tissue (fascia) that runs from the heel bone to

the ball of the foot on the sole (plantar surface) often tightens up

as well. A plantar fascia release loosens this connective tissue.

When deformity is involved, Meehan says, " you can do tendon

transfers, using what good motor strength they have left and moving

it to an area where there's a deficiency.

" Typically, they have a very strong posterior [back] tendon on the

inside of the foot, and typically that's one of the strong de-forming

forces. So we try and release that from the inside and move it to the

outside of their ankle, to work in an area where they were strength-

deficient. " Tendons can also be transferred to the top of the foot to

help with lifting it during walking.

About half the time, Meehan says, muscles (which are attached to

bones via tendons) retrain themselves to work in a new position. The

rest of the time, a transferred muscle simply acts like a piece of

rope holding the foot in place.

The procedure " redistributes the forces on the foot and puts the foot

in a better position, so functionally you're better off, " he says.

Neurologist Shy examines Wilton, 6, who may have CMT.

A diagnostic workup for this disorder generally includes a careful

family history, a physical exam, measurements of the speed and

intensity of nerve impulses traveling between the spinal cord and

muscles, and DNA testing.

Since 1998, Diane Lareau has had tendon transfers on both feet, as

well as procedures to release her tight Achilles tendons, remove bony

protrusions from each foot, straighten her toes and cut the tendons

underneath them.

After her surgeries, Lareau was able to walk well with AFOs and New

Balance shoes. After trying all kinds of expensive compression and

moisture-removing stockings, she says, " When it comes down to it,

men's tube socks work wonderfully. You turn them inside out so the

seam doesn't wreck your toes. "

She compensates for being unable to walk very far by doing yoga for

her lower body and a regular gym workout for her upper body, which

isn't as much affected by her CMT.

" The thinner you are the better your legs are. And that's the only

reason I have the will power to stay thin. "

Faulty Wiring - What is CMT?

It's been called everything from " shark's tooth disease " to " charcoal

tooth disease, " and it's usually (and understandably) referred to by

its acronym, CMT. But Charcot-Marie-Tooth disease is actually a

fairly common nerve disorder, with an uncommon name.

Like many diseases lacking a clear cause, CMT was originally named

for three doctors who first described it. In 1886, Jean-

Charcot and Pierre Marie in France and Henry Tooth in England

identified what they thought, erroneously, was a spinal cord disease.

We now know that CMT is a genetic disease of the peripheral nerve

fibers, long " wires " that bundle together to form cablelike

structures, or nerves, that run between the spinal cord and the

periph-ery (outside edges) of the body. The motor nerves carry

signals that cause muscles to move, and the sensory nerves send

signals back to the cord that convey pain, temperature, vibration and

other sensations.

CMT affects some 30 people per 100,000. Since the early 1990s, more

than 20 genes that, when flawed, can cause CMT, have been identified.

Some of these genes are needed in the nerve fibers, while others are

needed to form and maintain myelin, the insulating coating around

each fiber.

Either way, the symptoms are similar: mild to severe weakness,

especially in the hands and feet, often accompanied by mild to

moderate loss of sensation and less often by burning or tingling pain

in those areas, beginning in childhood or adolescence.

Dos and Dont's of CMT-Affected Feet

Protect your feet from blisters and cuts. Examine your feet

frequently for injuries if you've lost sensation, and don't wear

shoes or orthotics that rub. Wounds that aren't healing need prompt

attention.

Avoid scalding yourself. If you lack sensation in your feet, test the

bath water with another part of your body.

Avoid broken bones, which can complicate matters. If you're falling

more than once a month, rethink how you're managing your foot

problems.

Work with specialists who understand CMT, with its unique combination

of weakness, loss of sensation, oddly shaped feet and progressive

course.

Dos and Don'ts When Considering Foot Surgery

Get first and second opinions from qualified professionals. Talk to

your MDA clinic physician, and/or contact the American Orthopaedic

Foot & Ankle Society (www.aofas.org, [800] 235-4855) for a referral.

Prepare yourself for a six- to nine-month process for a major foot

reconstruction, including a hospital stay, casting and physical

therapy. You won't be able to bear weight on the reconstructed foot

for about six to eight weeks.

Don't plan to have both feet operated on at the same time unless you

know you're going to have a lot of reliable help at home.

Don't count on being brace-free. You may still require AFOs or foot

orthotics after surgery.

Sources: Meehan, orthopedic surgeon, and Shy,

neurologist, Wayne State University, Detroit