Objective assessment of plaster cast quality in pediatric distal forearm fractures: Is there an optimal index?

BACKGROUND: Several so-called casting indices are available for objective evaluation of plaster cast quality. The present study sought to investigate four of these indices (gap index, padding index, Canterbury index, and three-point index) as compared to a reference standard (cast index) for evaluation of plaster cast quality after closed reduction of pediatric displaced distal forearm fractures. METHODS: Forty-three radiographs from patients with displaced distal forearm fractures requiring manipulation were reviewed. Accuracy, sensitivity, specificity, false-positive probability, false-negative probability, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were calculated for each of the tested indices. RESULTS: Comparison among indices revealed diagnostic agreement in only 4.7% of cases. The strongest correlation with the cast index was found for the gap index, with a Spearman correlation coefficient of 0.94. The gap index also displayed the best agreement with the cast index, with both indices yielding the same result in 79.1% of assessments. CONCLUSION: When seeking to assess plaster cast quality, the cast index and gap index should be calculated; if both indices agree, a decision on quality can be made. If the cast and gap indices disagree, the padding index can be calculated as a tiebreaker, and the decision based on the most frequent of the three results. Calculation of the three-point index and Canterbury index appears unnecessary.

Where is the true location of the femoral piriform fossa?

OBJECTIVE: To analyze knowledge of the anatomic location of the piriform fossa using a questionnaire with anatomic figures. MATERIALS AND METHODS: Participants taking AO Trauma Brasil courses were requested to complete a questionnaire containing a photograph of the superior surface and a photograph of the lateral surface of the femur and answer a question asking which of four numbered points corresponded to the piriform fossa. RESULTS: Just 4.5% of respondents correctly chose point 2 (the piriform fossa) in both images, while 75.4% of respondents chose point 4 (the trochanteric fossa) as the correct anatomic structure. The subset of 4th-year residents' answers was significantly different from those of the other subsets, with 7.5% of correct answers. CONCLUSIONS: The low rate of correct answers indicates a tendency for the respondents to be influenced by illustrations in text books or examples in scientific publications that indicate the site of the piriform fossa incorrectly. Interest in the specialty of traumatology is possibly the reason why the subset of 4th-year residents had a better- than-average rate of correct answers.