Metatarsus Adductus is a common deformity affecting the feet of newborns and young children. In this condition, the feet curve inwards rather than pointing straight ahead and occasionally the toes spread widely.
Also known as:
- Metatarsus Varus – this term usually refers to the fixed form of metatarsus adductus that requires treatment
Symptoms
Metatarsus adductus is usually noticed in the first few weeks of life. The signs include:
- The front half of the foot curves inwards, while the heel and ankle look normal
- The outer edge of the foot looks curved rather than straight
- A gap between the big toe and the second toe, which may sit wide apart
- The sole of the foot has a bean shape when looked at from below
- One or both feet may be affected
The condition does not cause pain, and it does not stop a baby crawling or learning to walk.
Causes
The cause is not always clear. It is thought to relate to the position of the baby’s feet in the womb, particularly where there was less room than usual towards the end of pregnancy.
It is not caused by anything the parents did, and it is not the result of the way a baby is held, carried or dressed.
Risk Factors
Metatarsus adductus is more likely where there was less room in the womb. Factors associated with it include:
- A first pregnancy, where the womb is tighter
- A twin or multiple pregnancy
- Low fluid around the baby during pregnancy
- A breech position
- A family history of metatarsus adductus
Babies with metatarsus adductus are also checked for hip dysplasia, which is a little more common in this group.
Investigations
Your doctor will examine your baby’s feet and gently try to straighten them. The key question is whether the foot is flexible or fixed:
- A flexible foot can be straightened past the midline with gentle pressure
- A partly flexible foot straightens to the midline but no further
- A fixed foot cannot be straightened by hand
X-rays are not usually needed. They may be used in an older child, or where the foot is fixed and treatment is being planned.
Complications
The great majority of children have no lasting problems. Where the foot is fixed and not treated, difficulties that can follow include:
- A foot shape that persists into childhood and adult life
- Difficulty fitting shoes
- Callouses along the outer border of the foot
- Discomfort with sport in later childhood
Treatment
Most feet straighten on their own within the first year or two of life and need no treatment at all. Where treatment is needed it depends on how flexible the foot is:
- For a flexible foot, gentle stretching at each nappy change, shown to you by your doctor or physiotherapist
- For a partly flexible or fixed foot, a series of plaster casts changed every week or two, usually started in the first months of life
- Straight-last or reverse-last shoes, sometimes used after casting
- Surgery, which is rarely needed and only considered in an older child whose foot is fixed and causing problems
Casting works best when it is started early, while the foot is at its most mouldable.
Prevention
Metatarsus adductus develops before birth and cannot be prevented. What makes a difference is having the foot checked early, so that a fixed foot is treated while casting works best.