Table 3.
Diagnostic accuracy of radiographs for identification of elbow fracture patterns
| Elbow fracture pattern | PRH | No PRH | TT | No TT | PMVRI | No PMVRI | AOFD | No AOFD | POFD | No POFD | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Reference standard | |||||||||||||||
| Correct | 307 | 204 | 511 | 731 | 656 | 1387 | 222 | 70 | 292 | 294 | 71 | 365 | 939 | 375 | 1314 |
| Other pattern | 517 | 2841 | 3358 | 263 | 2219 | 2482 | 245 | 3332 | 3577 | 213 | 3291 | 3504 | 138 | 2417 | 2555 |
| Totals | 824 | 3045 | 3869 | 994 | 2875 | 3869 | 467 | 3402 | 3869 | 507 | 3362 | 3869 | 1077 | 2792 | 3869 |
| Diagnostic performance characteristics | |||||||||||||||
| Sensitivity** | 60% | 53% | 76% | 81% | 71% | ||||||||||
| Specificity† | 85% | 89% | 93% | 94% | 95% | ||||||||||
| Accuracy‡ | 81% | 76% | 92% | 93% | 87% | ||||||||||
| Positive predictive value§ | 37% | 74% | 48% | 58% | 87% | ||||||||||
| Negative predictive value# | 93% | 77% | 98% | 98% | 87% | ||||||||||
AOFD = anterior fracture dislocation; PMRVI = posteromedial varus rotational injury; POFD = posterior olecranon fracture dislocation; PRH = posterior radial head fracture dislocation; TT = terrible triad; ** proportion of patients with an elbow fracture pattern X classified as pattern X (true positives); †proportion of patients with no elbow fracture pattern X fracture dislocation classified as not having pattern X (true negatives); ‡proportion of patients who are correctly classified by the test. Proportion of true positive and true negatives; §probability that a patient with a positive plain radiograph for elbow fracture pattern X has pattern X; #probability that a patient with negative plain radiographs does not have pattern X.