TABLE 1. Evaluation of X-ray bead tracking accuracy using the four foot cast beads. Inter-bead distances measured 10 times by electronic calipers (mean ± standard deviation) are compared to mean inter-bead distances from each of our 14 repeatable trials. P-values were calculated using a two-tailed Students t-test assuming unequal variance. The difference was less than 0.3 mm in all cases.
|
Inter-bead Distance |
Calipers (mm) |
X-ray (mm) |
Difference |
p-value |
|
tarsometatarsus-II |
34.9 ± 0.35 |
35.2 ± 0.07 |
0.303 |
0.026 |
|
tarsometatarsus-III |
90.5 ± 0.40 |
90.7 ± 0.06 |
0.191 |
0.184 |
|
tarsometatarsus-IV |
71.6 ± 0.29 |
71.8 ±0.05 |
0.200 |
0.077 |
|
II-III |
71.8 ± 0.15 |
71.6 ± 0.05 |
0.179 |
0.008 |
|
II-IV |
71.5 ± 0.27 |
71.4 ± 0.06 |
0.088 |
0.373 |
|
III-IV |
53.8 ± 0.27 |
54.0 ± 0.05 |
0.189 |
0.053 |
