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Conclusion In the global analysis, the postoperative BAs were, on average, significantly higher than the preoperative measurements. When the preoperative angle was normal, the postoperative angle was, on average, 1. If the preoperative BA was abnormal, the postoperative angle was, on average, It was demonstrated that more severe fractures present better anatomic results when compared with moderate fractures. The present study also confirms a good interobserver correlation for the BA.
According to the literature, the BA assists the clinical outcome by correlating the variations between preoperative and postoperative measurements. The present study aims to compare the BA variation in pre- and postoperative radiographic measurements in fractures with severe and moderate deviation.
From April to June , 31 pre- and postoperative radiographs of calcaneal fractures were retrospectively analyzed. The present study was submitted to and authorized by the Ethics Committee of the Hospital and informed consent forms were not required since data were extracted from medical records and radiographs. The exclusion criteria were incomplete or poor quality radiographs, previous or pathological fractures, open fractures, medical contraindication for surgery, and calcaneal fractures with concomitant involvement of the ankle or foot bones.
All of the procedures were performed through the extended lateral approach. The BA was measured on pre- and postoperative radiographs of patients with calcaneal fractures. The study sample consisted of 31 patients, 4 females 6. Among the 31 patients, 1 had no recorded information on gender and age. The frequency distribution of the age of the patients by gender and the global distribution are shown in Table 1 , and the age distribution is shown in Table 2.
Patients were between 23 and 72 years old, with a mean age of The age group was of between 40 and 48 years old, concentrating Abbreviation: CV, coefficient of variation; SD, standard deviation. The variables of the present study are BA measurements made by two evaluators from radiographic examinations of severe and moderate deviated calcaneal fractures.
For the sample characterization and the descriptive analysis of the behavior of the variables, data were synthesized through descriptive statistics mean, median, minimum, maximum, SD, and coefficient of variation [CV] , descriptive graphs, and frequency distributions.
In the inferential analysis, the normality hypothesis of measurement distribution was verified by the Kolmogorov-Smirnov test and by the Shapiro-Wilk test. The test distribution was considered normal when both tests consistently concluded so. The preoperative BA measurements were compared with the postoperative values, and both were compared between the two evaluators. When the two measures had normal distributions, they were compared in pairs by a paired Student-t test.
When at least one of the measures did not have normal distribution, the two paired measures were compared using the Wilcoxon test. The agreement analysis was performed between the measurements of the two evaluators by quantifying the raw agreement percentage of cases in which the two measurements are equal, that is, in which D, the difference between the two measures, is equal to 0 and the intraclass correlation coefficient ICC. The ICC expresses the total variability proportion, which is due to the variability between units.
The ICC agreement was classified as follows:. In tests with asymptotic and exact p-value , the latter was considered. Table 3 shows the p-values of the normality tests for BA distributions measured by the two evaluators and for the overall distribution i.
Therefore, any inferential analysis comparing BAs used the parametric approach. The main statistics of the distributions of pre- and postoperative BA measurements for each evaluator and the global distribution regardless of the evaluator are shown in Table 4.
The BA distributions according to each evaluator and the global distribution are shown in the boxplot graphs in Fig. The graphs and statistics demonstrate that the angle increased after the surgery, and that the effect is significant.
According to both evaluators and at the overall analysis, the postoperative BA value is, on average, The statistics of the angle differences, both per evaluator and at the overall analysis, is shown in Table 5. For 2 observations from evaluator 1, the postoperative angle was smaller than the preoperative angle. It was concluded, therefore, that there was no significant difference between the variations of the angles from the two evaluators.
Table 6 shows the statistics of the difference between both angles, relative percentage to the preoperative value, per evaluator and globally. For the evaluators and at the overall analysis, the postoperative angle is, on average, The boxplots of the relative differences between the pre- and postoperative angles are shown in Fig. When comparing the relative differences between the pre and post-operative angles from both evaluators by the Wilcoxon test, the p-value was 0.
When the preoperative angles are outside the normal range, the relative BA difference ranges from That is, if the preoperative BA value is in the normal range, the postoperative angle will be, on average, 1. Table 7 shows the agreement analysis between the angle measurements performed by two evaluators. Regarding absolute agreement, both evaluators assigned the same measurement to the angle in only one case. Overall, the agreement between the evaluators is excellent, both regarding the estimated point value, equal to 0.
At the pre- and postoperative measurements, point and interval ICC estimates show excellent agreement between the two evaluators. The agreement analysis between the two evaluators showed that their angle assessments were different, but not significantly, presenting the same level of measurement expertise.
However, the lower the preoperative BA, which would mean a fracture with greater deviation, had a mean variation of It has been shown that the surgeon tends to anatomically reduce more severe fractures than those with minor deviations.
The present study has also confirmed a good interobserver correlation for BAs. Most of the literature analyzing the BA emphasizes angle restoration and prognosis significance. Although some authors suggest that BA restoration may have no effect on outcomes, most studies show that BA restoration guides anatomical reduction and improves outcomes.
Their observations suggest that BA accuracy can make it suitable as a screening tool in the diagnosis of calcaneal fracture. Consequently, it would not be necessary to measure the BA value on the contralateral side in patients with calcaneal fractures. Although the literature has demonstrated that the BA has good credibility, many classifications and measures are deemed unreliable. Another source of difficulty for angle measurement may be an overlap of the synthesis material to the reference points in the postoperative period.
Otero et al 32 demonstrated that even with trained observers and with an adequate configuration in BA radiographic measurement, interpretation differences are common. Two factors that increased error included a low level of observer training, such as increased obliquity on lateral radiographs.
In order to avoid discrepancies and to minimize potential risks of BA measurement failures, the measurements were previously defined, using properly trained observers and a measurement protocol; moreover, the performance of the evaluators was tested, and radiographs with low quality for measurements were excluded. As described by Bland and Altman, 34 repeated measurements on the same subject range around a true value, since the measurement error and the SD of repeated measurements allows the determination of the error size.
In our study, we have used the CV, that is, the measure used to estimate the experimental accuracy, and we have verified that BA measurements presented high variability among the 31 evaluated patients.
The results demonstrated, both for the evaluators and the overall sample, that the angle increased significantly after the surgery. The postoperative angle was, on average, It is noteworthy that the relative difference observed in the postoperative BA value was higher for lower preoperative angles, and that it decreases as the preoperative angle increases. When the preoperative angles are outside the normal range, the relative BA difference assumes values of That is, if the preoperative BA is in the normal range, the postoperative angle will be, on average, 1.
The ICC estimates the fraction of the total variability of measures due to variations between individuals. Otero et al 32 did not observe a significant difference in the ICC for the inter- or intraobserver BA measurement in both preoperative and postoperative radiographs.
Overall, the agreement among the evaluators was excellent equal to 0. In the pre- and postoperative measurements, estimates of point and interval ICC show excellent agreement between the two evaluators.
There are some limitations in the present study that may have influenced the results. It was a retrospective study with a small number of evaluators, with radiographs made for daily clinical care instead of research purposes, which could alter and affect angle measurements. Therefore, we have excluded some radiographs that could generate measurement doubts. An intraobserver analysis was not performed. In the present study, the BA was evaluated at two moments, pre- and postoperative, by two evaluators.
In the overall analysis, the postoperative BA measurements were, on average, significantly higher than the preoperative values. The relative difference observed in the angle after the surgery was higher for lower preoperative angle values and decreases as the preoperative values increases. Most severe fractures present better anatomical outcomes when compared with moderate fractures.
The present study has also confirmed a good interobserver correlation for BA. Publicado originalmente por Elsevier Ltda. Normalmente, o AB varia entre 20 a Todos os pacientes foram operados pelo acesso lateral estendido.
A Fig. Read article at publisher's site DOI : To arrive at the top five similar articles we use a word-weighted algorithm to compare words from the Title and Abstract of each citation. BMC Surg , , 24 Sep Cited by 1 article PMID: Int Orthop , 36 12 , 09 Nov Free to read.
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Fractura do calcâneo
Segundo Slatis et al. Lowery et al. Vinte pacientes eram do sexo masculino e dois do sexo feminino, sendo 11 casos com acometimento do lado direito e nove no lado esquerdo, e dois casos bilaterais. Tabela 5.