What is Metatarsus Adductus?
Metatarsus adductus, also referred to as metatarsus varus, is a common foot deformity seen at birth that is characterised by a sharp, inward turning of the forefoot or front half of the foot. The metatarsus is a set of bones found in the middle portion of the foot. Each foot has 5 metatarsal bones, each of which is attached to the phalanges of the toes. The condition is believed to occur as a result of the position of the infant within the womb where the feet are angled inward at the instep. It is more commonly noted in first-born children.
Causes of Metatarsus Adductus
The exact cause of metatarsus adductus remains unclear. However, multiple factors may put your baby at risk of developing metatarsus adductus, including:
- Inadequate amniotic fluid when the baby is in the womb
- Sleeping posture of the baby (babies sleeping on their belly may escalate the likelihood of inward angling of the feet).
- Familial history of metatarsus adductus
- Position of the baby in the womb, particularly with breech presentations
Complications Associated with Metatarsus Adductus
Babies born with metatarsus adductus may be at a higher risk for developmental dysplasia of the hip (DDH), a medical condition of the hip joint in which the head of the femur (thighbone) slides in and out of its socket as the socket is too hollow to retain the joint intact. DDH can also cause leg length discrepancy or prompt your baby to walk with a limp.
Signs and Symptoms of Metatarsus Adductus
Some of the common symptoms of metatarsus adductus include:
- High-arched foot
- Wide space between the big toe and the second toe
- Walking or running with feet turned inward instead of straight
Diagnosis of Metatarsus Adductus
In order to diagnose metatarsus adductus, your child’s physician will conduct a physical examination of the foot, where the foot is manipulated passively to find out if your child has flexible or nonflexible metatarsus adductus. Passive manipulation involves placing gentle pressure on the forefoot to align it with the heel. If the forefoot is difficult to align, then your baby has nonflexible metatarsus adductus (stiff foot), and if it can be easily aligned, your baby has flexible metatarsus adductus.
The physician will also obtain a complete birth history of the child as well as a family history to find out if any of the family members had metatarsus adductus.
X-rays may be ordered in the case of nonflexible metatarsus adductus to obtain detailed images of the internal tissues and bones of the foot and for severe cases of bone deformity.
Treatment for Metatarsus Adductus
The treatment for metatarsus adductus will depend upon the severity of the case and your child’s general health, age, and symptoms. The main objective of the treatment is to straighten the posture of the heel and the forefoot. Treatment methods may include:
- Observation: In this method of treatment, your child’s foot is monitored as most cases of flexible forefoot will improve on its own without needing any treatment.
- Stretching or passive manipulation exercises: In this method, your physician teaches you how to perform passive manipulation and stretching exercises on your child’s feet to correct the foot deformity over a period of time in the cases of flexible metatarsus adductus.
- Casts: Your physician may opt for casting as a treatment method when your child’s foot has failed to respond to a stretching program. During this treatment, long leg casts are used to help straighten soft tissues of the front half of the foot. Your child’s physician will change the casts every one to two weeks and monitor the progress.
- Straight last shoes: If your child’s physician notes that the foot is responding to casting treatment, he may employ straight last shoes to help grasp the forefoot in a proper position. These special shoes are designed without a curve in their bottom.
- Surgery: Surgery is only employed for severe cases of metatarsus adductus and if the condition is persistent. The surgery involves releasing the forefoot joints and using fixation devices such as plates, screws, or casts to hold the forefoot in position as it heals.