| Hallux Abducto Valgus
Hallux
Valgus is a condition which affects the joint at the base of the
big toe. The condition is commonly called a bunion. The bunion actually
refers to the bump that grows on the side of the first metatarsophalangeal
(MTP) joint. In reality, the condition is much more complex than
a simple bump on the side of the toe. Interestingly, this condition
almost never occurs in cultures that do not wear shoes. Pointed
shoes, such as high heels and cowboy boots, can contribute to the
development of hallux valgus. Wide shoes, with plenty of room for
the toes, lessen the chances of developing the deformity and help
reduce the irritation on the bunion if you already have one. However,
shoes alone are not "solely" to blame for the development
of bunions. Abnormal foot function comes into play in the development
of almost all bunions, and the most common abnormality is over-pronation
or excessive flattening of the foot, easily correctable with an
orthotic.
The term hallux valgus actually
describes what happens to the big toe. Hallux is the medical term
for "big toe", and valgus is an anatomic term that means
the deformity goes in a direction away from the midline of the body.
So, in hallux valgus, the big toe begins to point towards the outside
of the foot. As this condition grows worse, other changes occur
in the foot that make the problem worse. The bone just above the
big toe, the first metatarsal, usually develops too much of an angle
in the other direction. This condition is called metatarsus primus
varus. Metatarsus primus means "first metatarsal", and
varus is the medical term that the deformity goes in a direction
towards the midline of the body. This creates a situation where
the first metatarsal and the big toe now form an angle with the
point sticking out at the inside edge of the ball of the foot. The
bunion that develops is actually a response to the pressure from
the shoe on the point of this angle. At first the bump is made up
of irritated, swollen tissue that is constantly caught between the
shoe and the bone beneath the skin. As time goes on, the constant
pressure may cause the bone to thicken as well, creating an even
larger lump to rub against the shoe.
The symptoms of hallux valgus
usually center around the bunion. The bunion is painful. The severe
hallux valgus deformity is also distressing to many, and becomes
a cosmetic problem. Finding appropriate shoewear can become difficult,
especially for women who desire to be fashionable, but have difficulty
tolerating fashionable shoewear. Finally, increasing deformity begins
to displace the second toe upward, and may create a situation where
the second toe is constantly rubbing on the shoe.
Treatment of hallux valgus
nearly always starts with adapting the shoewear to fit the foot.
In the early stages of hallux valgus, converting from a pointed
toe shoe to a wider box toe shoe may arrest the progression of the
deformity. The pain that arises from the bunion is due to pressure
from the shoe. Treatment focuses on removing the pressure that the
shoe exerts on the deformity. Wider shoes reduce the pressure on
the bunion. Bunion pads may reduce pressure and rubbing from the
shoe. There are also numerous devices, such as toe spacers, that
attempt to splint the big toe and reverse the deforming forces.
If all
conservative measures fail to control the symptoms, then surgery
may be suggested to treat the hallux valgus condition. There are
well over 100 surgical procedures described to treat hallux valgus.
The basic considerations in performing any surgical procedure for
hallux valgus are: to remove the bunion to re-align the bones that
make up the big toe to balance the forces so the deformity does
not return
In some very mild cases of bunion formation, surgery may only be
required to remove the bump that makes up the bunion.
It is more likely that re-alignment of the big toe will also be
necessary. The major decision that must be made, is whether or not
the metatarsal bone will need to be cut and re-aligned as well.
The angle made between the first metatarsal and the second metatarsal
is used to make this decision. The normal angle is around 9-10 degrees.
If the angle is 13 degrees or more, the metatarsal will probably
need to be cut and realigned.
This effectively reduces the angle between the first and second
metatarsal bones, narrowing the foot. The bone is held in the desired
position with a metal screw or pin.
The bone is re-aligned and held in place with screws or metal pins
until it heals. A cast is worn and the patient walks with crutches
or a walker, not bearing any weight on this foot or an extended
period of time. Again, this reduces the angle between the first
and second metatarsal bones.
Re-alignment of the big toe is then done by releasing the tight
structures on the lateral side of the first MTP joint. This includes
the tight joint capsule and the tendon of the adductor hallucis
muscle. As you can see, this muscle tends to pull the big toe inward.
The toe is realigned and the joint capsule on the medial side of
the big toe is tightened to keep the toe straight.
Once the surgery is complete, it will take about eight weeks before
the bones and soft tissues are healed.
After surgery is completed, it is essential that the two factors
that caused the bunion originally be eliminated: Tight shoes must
be avoided and abnormal foot function must be corrected. |