Pediatric orthopedic cases 29
CASE 29
A 6-month-old baby is referred to your clinic for evaluation of her feet. Her parents and pediatrician are concerned because her feet do not look “normal.” Clinically, both feet have the appearance of the photo shown in Figure 10–49. The Achilles is palpably tight, there is an empty heelpad, the arch does not reconstitute with hyperextension of the great toe, and the talar head is prominent in the plantar surface of the foot.
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Figure 10–49
You want to order imaging studies to evaluate the foot to help you confirm the diagnosis. Which images do you order?
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AP and lateral x-rays of the foot
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AP, lateral, and maximum dorsiflexion view x-rays of the foot
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AP, lateral, and maximum plantarflexion view x-rays of the foot
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AP and lateral x-rays of the tibia
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MRI of the foot
Discussion
The correct answer is (C). This patient has a rocker bottom foot deformity and a clinical description (prominent talar head, no arch reconstitution, Achilles contracture) consistent with a congenital vertical talus. When evaluating the foot radiographically for this condition, the lateral view with the foot in forced plantarflexion is diagnostic. Choice A is not correct because it does not provide you with sufficient information to make the diagnosis. Choice B, which includes an xray of the foot in maximum dorsiflexion, is what you order for evaluation of clubfoot, not CVT. X-rays of the tibia (choice D) are not necessary here and do not help confirm the diagnosis. An MRI of the foot is unnecessary at this time and would require a general anesthetic at this age.
Assuming this is congenital vertical talus, what would you expect to see on the lateral maximum plantarflexion x-ray?
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Irreducible plantar dislocation of the navicular on the talus
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Irreducible dorsal dislocation of the navicular on the talus
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Apparent dislocation of the navicular relative to the talus on the lateral view and then reduction of the navicular on the maximum plantarflexion lateral view
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Normal alignment of the talus and the navicular
Discussion
The correct answer is (B). The navicular is dorsally dislocated on the talus. The xray is shown (Fig. 10–50):
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Figure 10–50
You have confirmed the diagnosis of CVT and explained this to the family. You have educated them that this is a rare condition that occurs in about 1:150,000 births. You have explained that in approximately 50% of patients with CVT, there is an associated neuromuscular disease or chromosomal abnormality, and you therefore are going to refer them to genetics.
For orthopaedic treatment of the feet, you recommend the following:
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Observation, the condition will eventually resolve on its own
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Surgical intervention at age 3
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Serial manipulation and casting only
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Serial manipulation and casting, followed by surgery
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Pantalar release and fusion now
Discussion
The correct answer is (D). CVT will not correct on its own and observation is not appropriate for children with this condition, thus choice A is incorrect. Current treatment involves serial manipulation and casting of the foot to stretch the dorsal soft tissues. In some cases, reduction of the talar head can be obtained. After casting, surgery is needed to reduce the talonavicular joint, lengthen the Achilles, and possibly additional soft tissue releases and transfers depending on the correction obtained with casting and the age of the child. The traditional pantalar release is not usually performed until the patient is over 12 months old, and a fusion is not a first-line treatment for this condition.
Objectives: Did you learn...?
The clinical findings in congenital vertical talus? The radiographic findings in CVT?
Importance of evaluation for other conditions since there is a high rate of associated neuromuscular or chromosomal abnormalities in patients with CVT?
Treatment for patients with CVT?