"Lower Extremity Abnormalities in Children" (My Synopsis)

Lower Extremity Abnormalities in Children
P MELA SASS, M.D., and GHINWA HASSAN, M.D., State University of New York–Downstate Medical Center, Brooklyn, New York 
Am Fam Physician. 2003 Aug 1;68(3):461-468.

     Lower extremity abnormalities in children are usually normal variations that resolve on their own. The two types of variations are rotational and angular problems. When a parent brings their child in, it is important to figure out what their exact concerns are. It may be a gait issue, a cosmetic problem, or it may just be pressure from a concerned relative to get it "checked out". A complete medical and family history are needed because these issues can have a developmental or genetic component. The physical exam includes plotting the patient on a growth chart, a neurologic exam, ROM of extremities, and assessment of joint laxity. A trendelenburg test will assess contralateral hip abductor strength. The lateral foot should be observed for flat feet.
     Rotational problems of the lower extremities can be seen if certain angles are greater than two standard deviations from the average. The foot progression angle measures to what degree a person's feet deviate from a straight line while walking. Hip rotation can be measured by having the patient lie prone with the knees bent. Internal hip rotation will present with the patients' legs angled away from each other, whereas external hip rotation will present with the legs crossing eachother. The thigh-foot angle compares the axis of the thigh to the angle of the foot when the knee is bent at 90 degrees. Measuring the distance between medial malleolus or medial femoral condyles (while the legs are together), can determine the amount of genu varum (bow legs) or genu valgum (knock-knees), respectively. Most patients appear genu varum from birth to two years old and then appear genu valgum at 3-7 years old. It is part of normal development. If the deformity is unilateral, greated than two standard deviations, or getting worse, then x rays are warranted.
     There are three causes of intoeing (I remember calling it "pigeon toes" during Chinese jump rope). The first cause is metatarsus adductus. The forefoot is adducted and the lateral forefoot is convexed. The most common cause is intrauterine packing. Flexibility can be assessed by abducting the forefoot. It will usually resolve by the time the child turns one year old. The parent can stretch the child's midfoot, but referral to an orthopedist for serial casting will be needed if the intoeing does not resolve by eight months. The second cause is internal tibial torsion. The most common causes are intrauterine position, sleeping prone, and "sitting on the feet". the knees are facing forward but the tibial torsion causes the feet to be angled inwards. It will resolve by the time the child turns eight years old. If the deformity is significant, then corrective surgery may be needed. The third cause is femoral anteversion. It also has "pigeon toes", but this time there is femoral torsion instead of tibial torsion. Here, the feet and patellar are angled inward. The deformity peaks at 4-6 years, and then slowly resolves. The deformity is benign but surgery can be considered if it is severe.
      Out-toeing is less common than intoeing. The first cause is femoral retroversion  which is the opposite of femoral anteversion. The femur is twisted outwards. It is associated with stress fractures and slipped capital femoral epiphysis. Referral to an orthopedist is recommended if it does not improve within one year. External tibial torsion is the opposite of internal tibial torsion. The tibia rotates laterally to cause the out toeing. It is seen when the child is 4-7 years old. Surgery can be considered in severe cases when the patient is over 10 years old.
     Flat feet is seen when ligament laxity causes the foot to sag during weight bearing. If the arch appears when the child is standing on his or her toes, then the it is not a true flat foot, and treatment is not necessary. If the foot is stiff and painful, then an orthopedic referral is needed.