Saturday, December 19, 2015

When it snows you notice those pigeon-toes

Intoeing: Part I

With all our climate change, there hasn't really been any serious snow yet (I know, now that I have written this, next week NYC will have a blizzard), so I have come up with the title for this much-anticipated blog post while flying at 30,000 feet over the Rockies, where there is indeed SNOW. Now, at long last, we discuss intoeing! 

As much as every parent worries that their child’s gate is not quite right or that they are constantly falling, intoeing in children, known as "pigeon-toes" is usually caused by a benign condition, and it is something that is usually without permanent sequelae. The most common causes of intoeing can be broken down by age.

Infancy (Birth to 1 year of age): Metatarsus Adductus

The National Library of Medicine
Fetuses have it rough. They have to figure out how to grow and develop while in the confines of the mother’s uterus. Sometimes the genetic material makes for a large fetus in a smaller sized uterus, resulting in metatarsus adductus. Infants of diabetic mothers are at risk for macrosomia (large size) and because of this, metatarsus adductus. It is not always size issues, however, sometimes it is just the position of how the fetus resides in the uterus. At any rate, many infants demonstrate metarasus adductus, medial (inward) deviation of the forefoot relative to the hindfoot. As long as it is flexible, there is no need for Orthopaedic referral. Flexible metatarsus adductus usually resolves on its own and does not require bracing, shoes, or splinting.

Reasons to refer –
Inflexible metarsus adductus is termed metatarsus varus because the bone proximal (closer to the head) is deviated medially (inwardly). This type is treated with serial casting and has good results when casting is begun very early. Therefore, pediatricians and neonatologists know to refer while the baby is in the newborn nursery or NICU for Orthopaedic evaluation in these cases.

Toddlers (1 to 3 years of age): Tibial Torsion
Netters Atlas of Anatomy

In children aged 1 to 3 years of age, the most common cause is tibial torsion. This means that the tibia, the weight-bearing bone of the lower leg is rotated so that the foot and knee are not properly aligned. Internal rotation (causing intoeing) is more common than external rotation (causing out-toeing). Tibial torsion can be unilateral or bilateral, but when it is unilateral, the left side is the more commonly affected side. Parents frequently report that there child is clumsy or trips often. Confirmation of the diagnosis is based on physical examination and measurement of the thigh-foot angle. This is performed by having the child relaxed and lying in prone position (on abdomen/front), with knee and ankle each at 90 degrees. An angle is measured between the line of the thigh and an imaginary line between the second toe to the middle of the heel. A thigh-foot angle greater than 10 degrees represents internal tibial torsion.

In the past, treatments such as splinting, shoe modifications, braces, and exercises were prescribed. However, these have been shown to be of no benefit and are no longer recommended. Tibial torsion rarely has long-term consequences, and it is not a risk factor for degenerative joint disease (arthritis). Rarely, surgery is used as treatment.

Reasons to Refer-

General pediatricians should refer to Orthopaedics for any children with severe internal tibial torsion (greater than 35 degrees of the thigh-foot angle). The normal tibial angle in older children and adults is 10-20 degrees of out-toeing. Children should be followed by their pediatricians at least annually to monitor the regression or lack of regression of intoeing. Greater than 15 degrees at age 5 is unlikely to spontaneous resolve and these children should be referred for surgical correction. The best age for surgical correction is 7-10 years of age.

Any child with external tibial torsion (out-toeing) who has gait disturbance or pain associated with the deformity should be referred to Orthopaedics because these may also need early surgery. External tibia torsion is concerning for cerebral palsy and other neuromuscular disorders.

Differential diagnosis-

-CP and neuromuscular disorders (external tibial torsion, pain, abnormal gait)
-Developmental dysplasia of the hip (limp, clicks on exam, possible leg length discrepancy, abnormal ultrasound)
Internal tibial torsion may cause awkward gait but never a limp. As my Pediatrics Chairman, Dr. Caspe always used to say during my residency, “A child with a limp has something,” meaning they have real pathology.

School-age: Femoral Anteversion

A very blurry Violet sitting in the W
position. I think she was clapping and
dancing, so I'm pretty sure this position
didn't last long!
This is the most common cause over the age of 3. Femoral anteversion is defined as anterior rotation of the femoral neck compared with the transcondylar axis of the knee and the long axis of the femur. This is a bilateral condition and is twice as common in girls as boys. It is often associated with sitting in the W position and the running gait of a child with this condition can be described as “egg-beater” or windmill” in appearance (the thighs medially rotate and the feet outwardly rotate). Femoral anteversion increases in severity until 5 years of age and then resolves on its own by age 10 to 12 and no treatment is required. No radiographic imaging is required for diagnosis or monitoring. Physical exam should include having the patient lie prone with knees flexed to 90 degrees and passively rotating the legs outward, causing the hips to rotate internally. Normal internal hip rotation is 35 to 50 degrees. Children with femoral anteversion have markedly increased internal hip rotation, i.e. 90 degrees. You may also note medial facing patellae while the child is in the standing position.

Happy Holidays, everyone! Violet says I
never stay long in the W position, Mommy!
Anecdotal but no scientific evidence shows that there may be an increased incidence of osteoarthritis of the hip and knee, slipped capital femoral epiphysis, and knee and patella instability in later years. If there is still some femoral anteversion but not enough for surgical correction, hip strengthening exercises can help encourage outward rotation of the femur to counterbalance the internal femoral torsion. Younger children may be more apt to do exercises in the form of games- have them walk backwards, climb the stairs backwards, or walk uphill backwards. Older children and teens can do more formal exercises such as wall squats, bridges, and hip abduction exercises. Also encourage children to avoid sitting in the W position.

Harris E. The intoeing child: etiology, prognosis, and current treatment options. Clin Podiatr Med Surg. 2013 Oct:30(4):531-65.
Li YH, Leong JC. Intoeing gait in children. Hong Kong Med J. 1999 Dec:5(4):360-366.
PREP Online 2013, 2015.

Stay tuned for Part II on Intoeing to see how these anatomical differences relate to athleticism.