What is Metatarsus Adductus?

There are many deformities of the foot which a person can have from birth or may present later in life of which Metatarsus Adductus is one which can be observed clearly in infancy or in the childhood years. In Metatarsus Adductus, the forefoot deviates more towards the inside when compared to the hindfoot. This condition is also known by the name of Metatarsus Varus or Hooked-Foot. Metatarsus Adductus is seen more in children who have dysplasia or torticollis and constitutes to about 1% of all births which takes place in the United States. There is no known cause of Metatarsus Adductus but studies have suggested some sort of compression within the uterus which can cause this but this has not been proved as of yet. Some studies conducted of the fetus which have been shown to have Metatarsus Adductus when the baby is born have showed a subluxed tarsometatarsal joint and a misshapen medial cuneiform joint.

The exact cause of Metatarsus Adductus is still a matter of ongoing research but it is seen that 1 out of every 1000 children is born with this condition. Also seen is that this condition is seen predominantly during the first pregnancy of the mother hence there can be some sort of intrauterine pressure causing this condition as one of the studies have suggested although it has not been proven as of yet. It is also seen that children born with Metatarsus Adductus have increased incidences of developing hip dysplasia so they need to be monitored for that.

Below mentioned is the factsheet about Metatarsus Adductus;

• Metatarsus adductus is a medical condition more often than not seen at birth but this condition is a benign one and mostly corrected without needing any treatment to speak of.
  In some cases of acute Metatarsus Adductus, casting may be required for children less than a year of age so that this condition is corrected rapidly.
• There have been rare cases of surgical procedure being required for correcting this deformity and that too in children more than 3 years of age. This is done by releasing the abductor hallucis which becomes overactive in Metatarsus Adductus.
• Another procedure which has been found to be effective has been an opening-wedge medial cuneiform osteotomy in children older than 5 years of age and who have severe Metatarsus Adductus.

An infant with Metatarsus Adductus will present with clinical feature of a visible foot deformity in which the forefoot is fixed in adductus relative to the hindfoot. The shape of the lateral border of the foot becomes in convex in shape while the medial border becomes concave in shape. The forefoot stays in a supinated position. The hindfoot takes a slightly valgus position. For mild cases of Metatarsus Adductus, slight fondling of the foot corrects the deformity whereas in more moderately severe forms of this deformity a physician is able to correct it. There is also presence of intoeing of the foot with ambulation in children more than 3 years of age who have Metatarsus Adductus.

Metatarsus Adductus is a condition which can be visualized clearly in an infant at birth hence normally there are no particular studies needed as such for its diagnosis. A simple physical examination is good enough for its diagnosis. Additionally, the physician will also obtain a family history of the child to see if any other family member ever had this condition or not. Radiologic studies are not normally required for diagnosing Metatarsus Adductus, although at times x-rays may be ordered for some forms of Metatarsus Adductus which is called as nonflexible Metatarsus Adductus. A nonflexible Metatarsus Adductus is a condition in which it is difficult to align the forefoot and the heel.

Normally, Metatarsus Adductus is a benign condition and the condition corrects itself on its own with time and growth of the baby even though some studies have recommended passive stretching as a form of treatment to facilitate rapid correction, although it has not been proven as of yet. Apart from stretching, specially made shoes called reverse last shoes are given for the child to wear for a minimum of four to six months and that too in acute cases of Metatarsus Adductus. Serial casting is also a form of treatment to correct Metatarsus Adductus and this is done in children between the ages of six months to a year. Once the casting phase of treatment is completed then splinting is done to maintain the correction.

Only in very rare cases is a surgery required to correct Metatarsus Adductus, especially for children below the age of 4, as mild cases of Metatarsus Adductus resolve by the time the child reaches age 4. In case of failure of correction even after serial casting is done then a surgical procedure which involves release of the abductor hallucis is done and has been shown to be effective in correcting the problem.

The complications postsurgery for Metatarsus Adductus is the same as with any form of surgical procedure in the form of painful scars postsurgery. The sural nerve branches may get exposed during the procedure and injury to those nerves may occur. If there is some sort of damage to the growth plate then it may lead to some complications like an angular deformity. In some cases where surgery involves releasing of the medial capsules of tarsometatarsal joints, recurrence of the deformity has taken place and hence this form of surgery is no longer recommended. Prolonged casting for this condition can also lead to another foot deformity called as skewfoot deformity or increased hindfoot valgus.

References:

Also Read:

• What Are The First Symptoms Of Patent Ductus Arteriosus & How Do You Test For It?
• Metatarsal Stress Fracture: Symptoms, Causes, Treatment, Prognosis, Recovery
• Know What is Skewfoot or Serpentine Foot and its Treatment