Table 1.

Mean age at last radiographic record of each group

	Number of lower legs	Mean age, y
Group A	51	14.5 (range, 4.4 to 36.0)
Group B	29	10.9 (range, 4.4 to 20.8)
Group C	20	12.6 (range, 4.7 to 32.1)
Group D	26	11.4 (range, 4.1 to 32.1)