A novel radiographic index for the diagnosis of posterior acromioclavicular joint dislocations.
Date
2014
Type:
Artículo
item.page.extent
5
item.page.accessRights
item.contributor.advisor
ORCID:
Journal Title
Journal ISSN
Volume Title
Publisher
Baltimore, Williams & Wilkins.
item.page.isbn
item.page.issn
item.page.issne
item.page.doiurl
item.page.other
item.page.references
Abstract
BACKGROUND:
Posterior acromioclavicular (AC) joint dislocations are frequently misclassified because posterior translation of the clavicle is difficult to evaluate in Zanca radiograph views. A novel radiographic index was used in this study to accurately diagnose posterior dislocations of the AC joint.
HYPOTHESIS:
This novel index has a high degree of accuracy for the diagnosis of posterior AC joint dislocations.
STUDY DESIGN:
Cohort study (diagnosis); Level of evidence, 2.
METHODS:
This was an analytic, descriptive study of 150 patients with different grades of AC injuries according to the Rockwood classification (30 patients for each grade of injury: I, II, III, IV, and V). The diagnosis of an AC injury was made both clinically and radiographically by using comparative Zanca and axillary views. Two measurements were performed in Zanca views: the coracoclavicular distance and the AC width distance. A width index was calculated for each patient. The Student t test, Bonferroni test, logistic regression, linear regression, and receiver operating characteristic (ROC) curves were used for statistical analysis. Forty cases were impartially selected to obtain a κ concordance value.
RESULTS:
The average value of the AC width index per group (according to the Rockwood classification) was as follows: type I, 2.1% (range, -12% to 25%); type II, 4.2% (range, -19% to 29%); type III, 19.1% (range, -59% to 91%); type IV, 110.3% (range, 47% to 181%); and type V, -3.8% (range, -71% to 62%). There was a significant difference between the average width index in the patients with type IV injuries and those in the remaining groups (P < .05). The ROC curve showed that a width index of 60% has a sensitivity of 95.7% and specificity of 97.5%, with a positive predictive value of 96.7% and negative predictive value of 95.6% to predict a type IV injury. Intraobserver reliability was rated as substantial agreement for each of 3 observers; the interobserver reliability of the 3 independent raters was almost perfect.
CONCLUSION:
An AC width index of ≥60% is highly accurate for the diagnosis of a posterior AC joint dislocation, with high intraobserver and interobserver concordance.
Description
item.page.coverage.spatial
item.page.sponsorship
Citation
American Journal Sports Medicine, 2014, 42(1) :112-116
Keywords
Acromioclavicular joint dislocation, Diagnosis, Instability, Radiograph, Radiographic index, Shoulder, Sport-specific injuries