Table 3.

The general states of two groups of clinical cases

Index	P group (n = 17)	S group (n = 16)	P-value
Age (year)	35.6 ± 9.9	39.8 ± 11.4	0.277
Sex (male:female)	13:4	11:5	0.619
Sacral fracture type (I:II:III)	5:10:2	5:11:0	0.364
Follow-up time (month)	25.5 ± 5.7	23.0 ± 5.6	0.217

Note: The statistics for age and follow-up time used a two-sample t-test; the statistics for sex used a chi-square test with a four-fold table; the statistics for sacral fracture type used a chi-square test with a R × C table.