Congenital Malalignment of the Foot
Congenital Malalignment of the Foot
The foot is an amazing part of our anatomy. It is tough and resilient, yet sensitive enough to feel breadcrumbs when walking across the floor. Its primary function is to carry and to transfer the body's weight during walking and running. Anatomically, the 26 bones of the foot are joined and held together by ligaments forming multiple joints that enable the foot to move during the walking cycle. As a result, the foot easily adjusts to uneven surfaces. The foot is poorly adapted to long periods of standing and is less fatigued by walking or running. The functions of weight bearing and weight transfer of the feet work in harmony with the rest of the body, especially the lower extremities. Therefore, the relationship of the foot to the body as a whole, especially the alignment of the hip, knee, and ankle, must be considered during a medical examination for foot problems. Many congenital (present-at-birth) malalignment problems improve with growth; however, some require evaluation, treatment, and, occasionally, surgery.
Intoeing and outtoeing
One
congential problem children can have is with their toes turning in or out,
called intoeing or outtoeing (Fig. 1). Intoeing or outtoeing can originate
from the hips to the midfoot or anywhere in between. Other causes of intoeing
or outtoeing are internal tibial torsion and external tibial torsion (the
tibias turn toward or away from each other, respectively). Mild cases generally
straighten with growth, but sometimes a Denis-Browne night bar is needed
when the child begins walking. In severe cases, surgery is required to
align the hip, knee, and ankle.
Bowlegs and knock-knees
When we are born, we are usually
bowlegged. At around 2 years of age, the legs straighten, and then at about
2-1/2 to 4 years, there is progression toward knock-knees. During that
period of time, the feet adapt as the alignment of the legs changes during
growth. For the most part, bowlegs and knock-knees will straighten with
growth; if they don't, however, evaluation and treatment are essential.
Blount's disease (growth abnormality in the tibia, which is the inner and larger bone in the lower leg), rickets (abnormal development in growing bones, sometimes due to poor absorption of calcium and phosphorus), and injury to the growth areas of the bones can be associated with bowlegs and should be ruled out by a physician. Severe knock-knees (the knees may actually "knock" together) can be caused by uneven growth of the tibia. Surgery can correct this problem while the bones are still growing. Putting surgical staples into the inner area of the growth plate of the tibia slows growth, while the outer area of the growth plate continues growing. Over time, this evens the growth of the tibia and straightens the leg.
Metacarpus adductus
Metacarpus adductus may look like
intoeing, but it is actually the curving in of the forepart of the foot.
For children 3 to 6 months of age, treatment consists of a series of casts
placed on the affected foot or feet and changed every two weeks for two
to three months, followed by corrective shoes.
Clubfoot
Clubfoot
is rarely seen in an adult born in the Western Hemisphere because it is
apparent at birth and usually treated early in life. Clubfoot is a deformity
in which the foot turns in with the sole facing the other foot instead
of the ground (Fig. 2). An orthopaedist applies adhesive strapping or plaster
casts to the leg and foot after the ligaments are stretched and held in
proper alignment. Initially, the casts are changed twice a week because
the baby grows so fast there is a danger of the cast becoming too tight
and cutting off blood flow. As growth slows, the changing of the casts
slows also. If casts fail to correct the problem, then pins can be placed
surgically to correctly align the foot. After the pins are inserted, the
foot is placed in a cast for six weeks. After the pins and cast are removed,
a short cast is placed on the leg for 2 to 2-1/2 months, followed by the
nightly use of a Denis-Browne night bar to correct any intoeing or outtoeing.
The flat foot and high arch
Two common problems involving the
forefoot are flat feet and an extremely high arch. Flat feet can be a result
of incomplete formation of the joints of the hind part of the foot, which
then cause flattening of the longitudinal (from toe to heel) arch. This
condition is usually corrected with a surgical procedure on the hind part
of the foot to reestablish the arch. There are also individuals who are
born with a flat-foot deformity that results from incorrectly aligned joints
in the mid-portion of the foot. These misaligned joints can cause pain,
which is treated with orthotics such as arch supports. In rare cases, surgical
reconstruction may be required to correct the problem.
Uneven leg lengths can pose a problem with the feet, as well as with the hips and knees. For instance, unequal leg lengths cause the foot on the longer leg to assume a flat-foot posture in an effort to decrease the height of the foot, whereas the foot on the short leg turns inward with a high-arched position to lengthen the extremity. Excessive external rotation (the hips turning out from the midline of the body) predisposes a person to a flat-foot deformity, whereas excessive internal rotation (the hips turning toward the midline) predisposes one to a foot with a relatively high arch. When the discrepancy is mild, a heel lift is recommended; for more severe cases, however, surgery may be required.
Evaluation of foot deformities must be considered in relationship to the body as a whole, with a thorough history and examination of the lower extremities. Congenital malalignment problems often improve with growth; those that don't, however, require evaluation, treatment, and possibly surgery to achieve proper alignment. The good news is that most congenital malalignment problems have a solution, whether it is provided by nature or by an orthopaedist.
John R. Stephenson, M.D.
Columbus, Georgia
Further Reading:
Alfandre J. In-Toeing
in Children. Hughston Health Alert. 2000;12(3):3.
Hunter SC. Forefoot
Deformities. Hughston Health Alert. 2000;12(3):1-2.
O'Connor PL. Footworks: The Patient's Guide
to the Foot and Ankle. Kalamazoo, MI: PL Patrick O'Connor; 1988.
