Physiological bowlegs or infantile Blount's disease. Some new aspects on an old problem.

The differentiation between physiological bowlegs and infantile Blount's disease in patients aged 11-30 months is very difficult. Nevertheless, diagnosis is deemed important because treatment of infantile Blount's disease is recommended. Fourteen patients with severe bowing of the legs seen in our outpatient clinic were investigated retrospectively. We examined them and measured the tibiofemoral and metaphyseal/diaphyseal angles in radiographs taken at their first presentation. The finding that the tibiofemoral angle is not helpful in differential diagnosis could be confirmed but, contrary to reports by other authors, neither was the metaphyseal/diaphyseal angle. In view of the spontaneous recovery of all investigated patients, it must be doubted whether a diagnosis of infantile tibia vara can be made in early infancy, and whether infantile Blount's disease is a diagnosis in its own right.