Tibial Torsion and Metatarsus Adductus

What is it?

Newborn babies, toddlers, and young children often have minor variations in their lower legs that cause parents and doctors some concern. Variations that make the feet appear to turn inward or outward are "rotational variations." These include "in-toeing" and "out-toeing." "Angular variations" make the knees appear to bend outward ("bow-legs") or inward ("knock knees"). These conditions are considered "variations," not "abnormalities." That is, they are almost always simply part of the normal range of differences among normal children. There are several causes of each.

In children with in-toeing, which is the most common condition:

• The bones of the foot (the "metatarsals") turn slightly to the inside of the foot (doctors call this "metatarsus adductus" or MTA) OR
• The large bone of the lower leg (the tibia) twists slightly to the inside (doctors call this "internal tibial torsion" or ITT) OR
• The large bone in the thigh (the femur) tilts slightly forward (doctors call this "femoral anteversion").

Children with in-toeing have feet that point slightly towards each other in front.

MTA is the most common cause of in-toeing in infants, ITT is most common in toddlers, and femoral anteversion occurs mostly in children ages 4 – 10.

In children with out-toeing, which is much less common:

• The large bone of the lower leg (tibia) twists slightly outward (doctors call this "external tibial torsion" or ETT) OR
• The large bone in the thigh (the femur) tilts slightly backward (doctors call this "femoral retroversion")

Children with out-toeing have feet that are pointed slightly away from each other in front.

In children with "bow legs," the knees appear to bend away from each other. This is because the big bone of the thigh (the femur) and the big bone of the lower leg (the tibia) are at a slight angle pointing outward on each leg. In children with "knock knees," the knees appear to bend towards each other. This is because the femur and the tibia form the opposite kind of angle, which points inwards on each leg. This is why doctors call these the "angular variations."

Seeing a child with any of these variations often causes parents to worry that their children will not walk properly. In earlier times, doctors often prescribed braces, special shoes, or casts for children with these variations. Today, doctors understand that these conditions usually get better on their own once the child starts to walk, run, and bear weight on his or her legs. Braces, special shoes, and casts do not make any of these conditions better, and they can significantly affect a child’s ability to develop normally. They can also damage self-esteem. If your doctor has diagnosed any of these variations in your child, s/he will simply want to see your child regularly and make careful measurements. This will assure both you and your doctor that the rotation or angulation is gradually going away. By the time your child reaches school age, and certainly by the time his or her bones stop growing, the variation will be gone.

Because these variations tend to go away as the child ages, doctors today rarely recommend any specific treatment except observation. As children grow and learn to walk and run, their bones naturally re-shape themselves into the proper alignment. By school age most children’s variations have gone away. Only if an angular or rotational condition lasts beyond puberty and causes significant disability will your doctor recommend surgery. This is very unusual.

These variations are not dangerous to children. Most children, even those with significant rotation or angulation, can run, play sports, dance, hike, and do all the normal activities of childhood without trouble. There is no evidence that these variations make children any more likely to injure themselves in any way.

Although doctors and parents can be re-assured by the knowledge that these conditions will go away with time, children themselves can become self-conscious about them. Please be sure that you explain to your child that being a little bow-legged or having a little in-toeing is entirely normal, and that none of these things need to prevent him or her from doing any activity s/he chooses. You can teach your child to tell other kids that there’s nothing wrong with his or her legs, and also not to keep playing with kids who tease him or her about it.

The main reason that doctors continue to monitor and measure the legs of children with these variations is to be sure they don’t miss some other more serious condition. In earlier times, the disease called rickets could cause severe bowing of the legs. Children who did not absorb enough calcium as the result of calcium or vitamin D deficiency would get rickets. Rickets can still occur, though it is rare. Your doctor will test for rickets if necessary. Some congenital conditions (birth defects) can also cause angular or rotational abnormalities. These usually involve more than one bone or joint. Children with a condition called "Osteogenesis imperfecta," or OI, have bones that break very easily. They can even break bones during birth. Your doctor will have screened your baby carefully to be sure that s/he doesn’t have OI.