ORIF using a posterior approach with an olecranon osteotomy was the most common choice of treatment method overall at both time points (58.1% and 63.7%) and was still the most common choice when each group of observers (residents, fellows, faculty) was considered separately (Figure 1).
When classifying the fractures, attending surgeons chose the multiplanar fracture pattern 25.6% of the time when viewing radiographs only, and remained consistent in choosing this pattern 23.3% of the time when CT was added to radiographs. Fellows and residents chose this fracture pattern much less often (8.9% and 7.8%, respectively) when viewing radiographs only. Both fellows and residents increased their choice of the multiplanar fracture pattern by 10% (18.9% for fellows, 17.8% for residents) when CT was added (Figure 2).
Overall, the recognition of a multiplanar fracture pattern increased when CT was added. On 30 occasions, an answer was changed from another classification pattern to the multiplanar pattern when CT was added. Only 6 times did an observer change a multiplanar pattern selection at round 1 to another choice at round 2.
Adding CT in round 2 changed the treatment plan for multiplanar fractures. At round 1, 73.7% chose ORIF using a lateral approach for treatment of the multiplanar fracture versus 10.5% who chose ORIF using a posterior approach with an olecranon osteotomy. The choice of the posterior approach with olecranon osteotomy increased to 51.9% at round 2, using the technique we have previously described.5,10
Overall intraobserver reliability for classification was fair (.393). It was moderate for the treatment plan (.426) between viewing rounds. Residents had the highest Cramer V value at .60 (moderate) for classification reliability, and faculty had the highest value at .52 (moderate) for treatment plan. All 3 groups (residents, fellows, attending surgeons) showed moderate intraobserver agreement for treatment plan (Table 1).
Interobserver reliability did not improve with the addition of CT in round 2. Reliability for classification was fair for round 1 and slight for round 2. Reliability was fair at both viewing rounds for treatment. For classification, the overall κ value was .21 for round 1 and .20 for round 2. For treatment plan, the overall κ value was .28 for round 1 and .27 for round 2. Attending surgeons decreased in agreement with regard to treatment plan with the addition of CT (.46, moderate, to .32, fair). Fellows had only slight agreement for both rounds with regard to classification as well as treatment (Table 2).
Discussion
In this study, CT changed both classification and treatment when added to plain radiographs. Interestingly, interobserver reliability did not improve for classification or treatment with the addition of CT. This finding suggests substantial disagreement among qualified observers that is not resolved with more sophisticated imaging. We propose this disagreement is caused by differences in training and experience with specific fracture patterns and surgical approaches.
Our fair to moderate interobserver reliability using radiographs only is consistent with a study by Wainwright and colleagues,11 who demonstrated fair to moderate interobserver reliability with radiographs only using 3 different classification systems. CT did not improve interobserver reliability in the present study.
To our knowledge, the effect of adding CT to plain radiographs on classification and treatment plan has not been evaluated. Doornberg and colleagues2 evaluated the effect of adding 3-dimensional (3-D) CT to a combination of radiographs and 2-D CT. Using the AO (Arbeitsgemeinschaft für Osteosynthesefragen) classification12 and the classification system of Mehne and Matta, they found that 3-D CT improved intraobserver and interobserver reliability for classification but improved only intraobserver agreement for treatment. Interobserver agreement for treatment plan remained fair. In parallel with their study, fracture classification in our study was more often changed with CT than the treatment plan was. Training level appeared not to affect this finding. We found fair interobserver agreement for treatment choice as well, which was not improved by adding CT. Doornberg and colleagues2 concluded that the “relatively small added expense of three-dimensional computed tomography scans seems worthwhile.”
When evaluating specific fracture patterns in the Mehne and Matta classification system, we observed that less experienced surgeons (residents, fellows) were much more likely to identify multiplanar fracture patterns with the aid of CT. Use of CT did not change attending surgeons’ recognition of these multiplanar fractures, suggesting that the faculty were more capable of appreciating these fracture patterns with radiographs only (Figure 3). We also observed that adding CT changed the predominant treatment plan for multiplanar fractures from a lateral approach to a posterior approach with an olecranon osteotomy. Failure to appreciate this component of the fracture before surgery could lead to an increased intraoperative difficulty level. Failure to appreciate it during surgery could lead to unexpected postoperative displacement and ultimately poorer outcome.
