Original Research

The Role of Computed Tomography in Evaluating Intra-Articular Distal Humerus Fractures

Am J Orthop. 2015 September;44(9):E326-E330

References

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There are limitations to our study. There is no gold standard for assessing the accuracy of classification decisions. Intraoperative classification could have served as a gold standard, but the fractures were not routinely assigned a classification during surgery. Brouwer and colleagues¹³ evaluated the diagnostic accuracy of CT (including 3-D CT) with intraoperative AO classification as a reference point and found improvement in intraobserver agreement but not interobserver agreement when describing fracture characteristics—and no significant effect on classification.

We used a single classification system, the one primarily used at our institution and by Dr. Itamura. There are many systems,^7,12,14 all with their strengths and weaknesses, and no one system is used universally. Adding a system would have allowed us to compare results of more than one system. Our aim, however, was to keep our form simple for the sake of participation and completion of the viewings by each volunteer.

Only 2-D CT was used for this study, as 3-D images were not available for all patients. Although this is a potential weakness, it appears that, based on the study by Doornberg and colleagues,² adding 3-D imaging resulted in only modest improvement in the reliability of classification and no significant improvement in agreement on treatment recommendation.

In addition, our results were likely biased by the fact that 8 of the 9 evaluators were trained by Dr. Itamura, who very often uses a posterior approach with an olecranon osteotomy for internal fixation of distal humerus intra-articular fractures, as previously described.^8,10 Therefore, selection of this treatment option may have been overestimated in this study. Nevertheless, after reviewing the literature, Ljungquist and colleagues¹⁵ wrote, “There do not seem to be superior functional results associated with any one surgical approach to the distal humerus.”

We did not give the evaluators an indication of patients’ activity demands (only age and sex), which may have been relevant when considering total elbow arthroplasty.

Last, performing another round of evaluations with only plain radiographs, before introducing CT, would have provided intraobserver reliability results on plain radiograph evaluation, which could have been compared with intraobserver reliability when CT was added. Again, this was excluded to encourage participation and create the least cumbersome evaluation experience possible, which was thought appropriate, as this information is already in the literature.

Conclusion

Adding CT changed classifications and treatment plans. Raters were more likely to change their classifications than their treatment plans. The addition of CT did not increase agreement between observers. Despite the added radiation and cost, we recommend performing CT for all intra-articular distal humerus fractures because it improves understanding of the fracture pattern and affects treatment planning, especially for fractures with a coronal shear component, which is often not appreciated on plain radiographs.