Radiographic measurement of infantile tibia vara.

The reproducibility of the radiographic measurement of 30 pairs of tibiae being treated for bowing was evaluated. Two methods of measurement were used. The first was the metaphyseal-diaphyseal angle of Levine and Drennan; the second, a metaphyseal-metaphyseal angle based on Cobb's angle for measuring scoliosis. Statistical analysis comparing the two methods showed no significant differences except for an increase in the angle in more severe cases measured by the metaphyseal-metaphyseal method, indicating distal tibial as well as proximal involvement. Computer digitization correlated extremely well with manual measurements. The metaphyseal-diaphyseal measurement is quite reproducible, and may allow early diagnosis and treatment of tibia vara.