Angular, rotational and gait variants — formative SAQs

SAQ 1 (10 marks) — The bowlegged two-year-old

Stem: A mother brings her two-year-old son to the clinic because his legs are still bowed and his feet turn in when he walks. He walked at eleven months, he is otherwise well, and his growth and milestones are normal. On examination the bowing is symmetric, painless, and the intercondylar distance is four centimetres; his feet intoe and the thigh-foot angle is negative. Outline your assessment, the developmental basis, and your management. ^{[1] [4]}

Model answer

Assessment and placement on the developmental curve (3 marks). This child has two overlapping normal variants — physiologic genu varum resolving and internal tibial torsion. The Salenius and Vankka curve shows the leg is bowed at birth, straightens to neutral around two years, then develops physiologic valgus peaking at three to four years. A symmetric, painless bowing at age two with a normal gait onset sits on the curve. The negative thigh-foot angle locates the intoeing at the tibia, the typical site for the toddler, and the rotational profile places the torsion on the limb. ^{[1] [3]}

Red-flag screen (2 marks). I screen for the features that move a bowleg off the developmental curve: progression after two years, asymmetry or unilateral bowing, pain, short stature, dysmorphism, and a delayed walking. This child is symmetric, painless, walked on time, and has normal growth and milestones, so the screen is negative. A positive screen would redirect to a weight-bearing radiograph and the measurement of the proximal tibial metaphyseal-diaphyseal angle to exclude infantile Blount disease, and to biochemistry if rickets were suspected. ^{[4] [9]}

Management (5 marks). The management is observation, reassurance, and a safety-net. No brace, no special shoe, and no orthotic is indicated, because the contemporary evidence confirms these devices do not speed the correction of intoeing. I counsel the family on the developmental curve and the expected timeline, I measure and document the intercondylar distance and the thigh-foot angle with a photograph for follow-up, and I review in six to twelve months. I teach that sitting cross-legged is encouraged for the tibial torsion. I give a clear safety-net to return if the bowing worsens, becomes asymmetric, or if any pain or limp emerges. ^{[3] [4]}