The deformities of acute diaphyseal clavicular fractures: a three-dimensional analysis

Background Although minimally invasive surgeries have gained popularity in many orthopaedic fields, minimally invasive approaches for diaphyseal clavicular fracture have not been widely performed, which is attributed to difficulties in performing a closed reduction of fracture deformities of a curved bone in a three-dimensional space. The goal of this study was to investigate the radiographic parameters of fracture deformities in a three-dimensional space and to identify the risk factors for deformities. Methods The computed tomography images of 100 patients who sustained a clavicle fracture were included. Five parameters were used to analyze the deformities: change in clavicle length, fracture displacement, and fragment rotation around the X, Y, Z axes. The change in length was assessed using the length of the endpoint line. The displacement was assessed using the distance between the fracture midpoints. The rotation deformities were assessed using the Euler angles. The correlation between the parameters was evaluated with the Pearson correlation coefficient. The risk factors were evaluated using univariable analysis and multiple regression analysis. Results The average change in length was − 5.3 ± 8.3 mm. The displacement was 11.8 ± 7.1 mm. The Euler angles in the Z-Y-X sequences were -1 ± 8, 1 ± 8, and − 8 ± 13 degrees. The correlation coefficient between the change in length and the displacement was − 0.724 (p < 0.001). The variables found to increase the risk of shortening and displacement were right-sided fracture (p = 0.037), male sex (p = 0.015), and multifragmentary type (p = 0.020). The variables found to increase the risk of rotation deformity were the number of rib fractures (p = 0.001) and scapula fracture (p = 0.025). Conclusions There was a strong correlation between shortening and displacement. The magnitude of anterorotation around the X axis was greater than the magnitude of retraction around the Z axis and depression around the Y axis. The risk factors for shortening and displacement included right-sided fracture, male sex, and multifragmentary type. The risk factor for retraction around the Z axis was the number of rib fractures, and the risk factor for depression around the Y axis was scapula fracture. These results could be useful adjuncts in guiding minimally invasive surgical planning for diaphyseal clavicular fractures.