Doornberg, J Bone Joint Surg Am 2006 - Two and Three-Dimensional Computed Tomography for the Classification and Management of Distal Humeral Fractures. Evaluation of Reliability and Diagnostic Accuracy - Article Summary

Two and Three-Dimensional Computed Tomography for the Classification and Management of Distal Humeral Fractures. Evaluation of Reliability and Diagnostic Accuracy

Doornberg, Ring, et al.·J Bone Joint Surg Am·2006·148 citations·Diagnostic study

Background

Complex fractures of the distal part of the humerus can be difficult to characterize on plain radiographs and two-dimensional computed tomography scans. We tested the hypothesis that three-dimensional reconstructions of computed tomography scans improve the reliability and accuracy of fracture characterization, classification, and treatment decisions.

Methods

5 independent observers evaluated 30 consecutive intra-articular fractures of the distal part of the humerus for the presence of 5 fracture characteristics: a fracture line in the coronal plane; articular comminution; metaphyseal comminution; the presence of separate, entirely articular fragments; and impaction of the articular surface.
Fractures were also classified according to the AO/ASIF Comprehensive Classification of Fractures and the classification system of Mehne and Matta.
2 rounds of evaluation were performed and then compared.
Initially, a combination of plain radiographs and 2-dimensional computed tomography scans (2D) were evaluated, and then, 2 weeks later, a combination of radiographs, 2-dimensional computed tomography scans, and 3-dimensional reconstructions of computed tomography scans (3D) were assessed.

Results

Three-dimensional computed tomography improved both the intraobserver and the interobserver reliability of the AO classification system and the Mehne and Matta classification system.
Three-dimensional computed tomography reconstructions also improved the intraobserver agreement for all fracture characteristics, from moderate (average kappa [kappa2D] = 0.554) to substantial agreement (kappa3D = 0.793).
The addition of three-dimensional images had limited influence on the interobserver reliability and diagnostic characteristics (sensitivity, specificity, and accuracy) for the recognition of specific fracture characteristics.
Three-dimensional computed tomography images improved intraobserver agreement (kappa2D = 0.62 compared with kappa3D = 0.75) but not interobserver agreement (kappa2D = 0.24 compared with kappa3D = 0.28) for treatment decisions.

Conclusions

Three-dimensional reconstructions improve the reliability, but not the accuracy, of fracture classification and characterization. The influence of three-dimensional computed tomography was much more notable for intraobserver comparisons than for interobserver comparisons, suggesting that different observers see different things in the scans-most likely a reflection of the training, knowledge, and experience of the observer with regard to these relatively uncommon and complex injuries.

Reference

Two and Three-Dimensional Computed Tomography for the Classification and Management of Distal Humeral Fractures. Evaluation of Reliability and Diagnostic Accuracy.

Doornberg, Ring, et al.J Bone Joint Surg Am2006148 citationsDiagnostic study