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Figure. Photograph of the patient in a normal standing position with excessive internal rotation of the left leg.
A 20-year-old woman presents with knee and hip pain on the left side that has persisted for several years. The patient works as a waitress and experiences pain when standing and walking during long shifts. As an adolescent, she saw a physician to treat her left lower leg rotational deformity; instead of invasive surgery she opted for conservative treatment. The photograph (Figure) shows the patient in a normal standing position with excessive internal rotation of the left leg.
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Intoe or pigeon-toe positioning is a common pediatric deformity that usually resolves by adolescence. The 3 main causes of intoeing include metatarsus adductus, tibial torsion, and femoral anteversion.1 Metatarsus adductus is an inward turning of the forefoot and usually resolves before 6 months of age.1 Rotational deformities of the tibia and femur are seen in older children and continue to resolve by ages 8 to 10 years.1
Hip rotation in patients with tibial torsion and femoral anteversion can be measured with the patient in the prone position and the knee flexed at 90° with the ankle in a neutral position.2 Measuring the amount of internal rotation of each hip and comparing the hips side-by-side helps identify abnormalities. The normal range of hip internal rotation is between 20° and 60°.1,2
Thigh-foot angle can be measured in the same position with the ankle in a neutral position. While standing over the feet, the angular difference between the axis of the foot and axis of the thigh is measured. The thigh-foot axis is normally less than 10° of external rotation.3
Radiographs may be useful in picking up contributing factors to intoeing such as hip dysplasia, early arthritis, metatarsus adductus, and a cavus foot but are not helpful in assessing rotational deformities. Three dimensional imaging with computed tomography (CT) or magnetic resonance imaging (MRI) is a more accurate way to measure hip, tibia, and ankle rotation.3
Increased femoral anteversion can cause instability at the hip, which can lead to articular cartilage damage and labral tears. Femoral anteversion also causes patella maltracking which can predispose patients to patellafemoral pain and arthritis.1-3
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants.
References
1. Gruskay JA, Fragomen, AT, Rozbruch RS. Idiopathic rotational abnormalities of the lower extremities in children and adults. JBJS Rev. 2019;7(1):e3.
2. Buly RL, Sosa BR, Poultsides LA, Caldwell E, Rozbruch SR. Femoral derotation osteotomy in adults for version abnormalities. J Am Acad Orthop Surg. 2018;26(19):e416-e425.
3. Shirley E. Internal tibial torsion. OrthoBullets. Updated October 10, 2018. Accessed November 2, 2020. https://www.orthobullets.com/pediatrics/4060/internal-tibial-torsion.
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