Guide to Vertical Talus
What is "vertical talus?"
The talus is the bone of the foot that makes up the lower part of the ankle
joint. In congenital vertical talus (CVT) there is abnormal positioning
of the talus and navicular bone (another bone of the foot) which leads
to a rigid, flat foot. The navicular bone slides on top of the talus bone.
The hind foot (or part of the foot closest to the heel) points down towards
the floor while the forefoot (nearest the toes) points upward. In essence,
this condition is a dislocation of several bones in the foot.
Is this condition hereditary?
It is not known and probably varies from case to case. Some studies do
show a genetic component.
What are the signs and symptoms of vertical talus?
When a baby is born, the appearance of the foot is not as striking as one
might think. The foot has a convexity of the sole. This can be thought
of as a reversal of the normal arch of the foot (i.e. the curve is upside
down). There is also a crease on the outside/top portion of the foot. As
the child walks, a callous forms on the sole of the foot right under where
the talus touches the ground. If this is left untreated, it can lead to
a flat foot and pain by the time the child reaches adolescence or early
adulthood. At this point, wearing shoes becomes awkward and the patient
may walk in a strange manner.
most typical gait pattern (or manner of walking) is called the "peg
leg gait." The patient bears all of the weight on the protruding
talus bone on the bottom of the foot without being able to touch the
heel to the ground. The forefoot also does not touch the ground to
any considerable extent, therefore not allowing the patient to push
off the forefoot to prepare the transfer of weight to the other side
of the body.
causes vertical talus?
It is thought that abnormal pressure placed on the foot while the fetus is
inside the uterus can lead to vertical talus. Others think that a muscle imbalance
causes the condition. In either case, a stiff hind foot causes the forefoot
to ride up on top of the talus, thereby destabilizing the entire foot.
What is the treatment?
The condition must be recognized early and treated aggressively. If not treated,
this can lead to the development of a significant callous on the bottom of
the foot, breakdown of the skin, and a poor push off that hinders the ability
to walk correctly. Surgery is preferred before the child reaches the age of
two. Sometimes casting and manipulation of the foot are used before surgery
to help stretch the tissues, but these are not effective alone.
Surgery consists of opening the foot and fusing the joint between the talus
and navicular bone. Other tendons that may be contracted and cause the foot
to take on an abnormal posture should be lengthened (such as the Achilles tendon
or heel cord). Older children may require more complicated procedures such
as fusing the talus to the bone in the heel. Complications of surgery include
stiffness of the foot or the need for further surgery to correct the defects.
What is the prognosis?
The prognosis is poor if left untreated. It is good if detected early and treated
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